170 results on '"R. Escudero"'
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2. Deinking paper in a neutral medium, through a treatment with amino acids, in flotation columns
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J. Gonzalez Pineda and R. Escudero García
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Mixed waste from office paper (MOW) is an excellent source of low-cost, high-quality fiber for the papermaking industry. The limitations in the application of conventional deinking to such paper are related to the negative environmental impacts that chemical substances can cause, which is why deinking in a neutral medium is receiving increasing attention. This study focuses on investigating the effect of the application of the amino acids Aspartate Glutamate and Asparagine, in the deinking of office paper, using a flotation column on a laboratory scale.The methodology involves the sample preparation, a pretreatment, flotation, the manufacture of paper, microscopy analysis, and finally the evaluation of optical properties. Different doses for each of the amino acids and of the mixture of the three were tested, at different conditions of temperature and pH in the pretreatment.The best optical characteristics were obtained when using the mixture of the three amino acids at 0.6% on a dry weight basis of the paper to be deinked, proposed in this study, with 90.8% whiteness. From scanning electron microscopy analysis, no superficial damage to fiber morphology is observed in any of the fiber samples after deinking.
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- 2022
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3. Multicriteria seismic hazard and social vulnerability assessment in the Puerto Vallarta metropolitan area, Mexico: toward a comprehensive seismic risk analysis
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Diana L. Jaimes, Christian R. Escudero, Karen L. Flores, and Araceli Zamora-Camacho
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Atmospheric Science ,Earth and Planetary Sciences (miscellaneous) ,Water Science and Technology - Published
- 2022
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4. Geotechnical zonation and soil–structure interaction at Puerto Vallarta, México
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Adan Gomez Hernandez, Araceli Zamora Camacho, Karen L. Flores, Christian R. Escudero, Adolfo Preciado, and Alejandro Ramirez Gaytan
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Atmospheric Science ,Hydrogeology ,Vulnerability assessment ,Natural hazard ,Soil structure interaction ,Earth and Planetary Sciences (miscellaneous) ,Geotechnical engineering ,Soil classification ,Standard penetration test ,Seismic risk ,Geology ,Penetration test ,Water Science and Technology - Abstract
We performed a seismic vulnerability assessment that involves geotechnical and building structure analysis for Puerto Vallarta, Mexico, a city located along the pacific coast. Puerto Vallarta, like many other Latin American cities, has significant seismic risk. We implemented the multichannel analysis of surface waves and the horizontal-to-vertical spectral ratio methods to estimate shear wave velocity and soil resonance frequency. We considered a standard penetration test to determine the penetration resistance and soil classification. We divided the Puerto Vallarta into four zones according to a building taxonomy based on construction materials and structural systems and story number and height. The VS30 parameter shows that Puerto Vallarta has soil types C, D, and E according to the National Earthquake Hazard Reduction Program (NEHRP). We classified the soil into three types based on the estimated fundamental period, TS. Both VS30 and TS parameters showed an overall transition of soil properties from the mountain toward the valley area. The standard penetration tests corroborate the results of the implemented geophysical methods. The correlation between the fundamental period of the soil and the fundamental period of the most common building types at each zone of Puerto Vallarta indicates high seismic vulnerability. We identify building vulnerability to resonance effects principally at the south and along the coast of the Puerto Vallarta. This work combines academic and governmental efforts to solve a real and transcendental problem since it might directly affect the regulation and evaluations of structures in the area.
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- 2021
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5. Multicriteria seismic risk assessment in Puerto Vallarta metropolitan area, Mexico
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Diana L. Jaimes, Christian R Escudero, Karen L. Flores, and Araceli Zamora-Camacho
- Abstract
The destructive effects of an earthquake are enhanced when the population is not prepared. The experiences from the past highlighted the importance of proper planning based on adequate scientific data. The Puerto Vallarta metropolitan area (PVMA) comprises medium-sized, rapid-growing urban areas of independent administrative and political entities that maintain a constant, direct socioeconomic interrelation. The PVMA is located in a region with a complex tectonic setting that produces important seismic activity and is affected by beaches, rivers, and estuary systems that produce complex soils and subsoil conditions. Moreover, the PVMA constantly undergoes anthropogenic processes that modify the local geomorphology and produce improper urbanization. Therefore, the PVMA constitutes an ideal natural laboratory to implement and test techniques to estimate seismic hazard, social vulnerability, and seismic risk. These techniques can be later implemented in other similar cities around the world. To determine the seismic hazard, social vulnerability, and seismic risk of the PVMA, we implemented the Multicriteria Evaluation Method within a Graphical Information System considering geomorphological (i.e., bedrock, soil, slope, curvature, flow accumulation), geophysical (peak ground acceleration, shear velocity, vibration frequency), and social information (population density, age, disabilities, health access, housing, and economic activity). We estimate the seismic hazard, social vulnerability, and seismic risk by considering three possible earthquakes. The results indicate a heterogeneous distribution of seismic risk with levels between moderate to high. Finally, a seismic risk microzonation in terms of the percentages of the seismic risk levels is proposed for the Puerto Vallarta metropolitan area.
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- 2022
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6. Multicriteria seismic hazard assessment in Puerto Vallarta metropolitan area, Mexico
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Karen L. Flores, Christian R. Escudero, and Araceli Zamora-Camacho
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021110 strategic, defence & security studies ,Atmospheric Science ,geography ,Peak ground acceleration ,geography.geographical_feature_category ,Seismic microzonation ,010504 meteorology & atmospheric sciences ,Bedrock ,0211 other engineering and technologies ,02 engineering and technology ,01 natural sciences ,Hazard ,Tectonics ,Seismic hazard ,Thematic map ,Natural hazard ,Earth and Planetary Sciences (miscellaneous) ,Physical geography ,Geology ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
Puerto Vallarta, a medium-size tourist city, located in the Pacific Coast of Mexico, in a similar way as many other coastal cities, combines human activity with the potential occurrence of natural hazard events. In this way, the use of new tools to evaluate the impact of such events seems imperative. Puerto Vallarta is located within a tectonic setting where the Rivera microplate subducts beneath the North American plate and is affected by seismic activity. We performed a seismic hazard assessment by implementing a GIS-based multicriteria evaluation model. The seismic microzonation map of Puerto Vallarta was performed using a criteria set of six thematic layers, i.e., peak ground acceleration values, soil, bedrock, slope gradient, curvature, and flow accumulation. We performed the integration of the criteria set by implementing the Analytical Hierarchy Process to assign a weight to each criterion according to its contribution to the seismic hazard, i.e., PGA (0.38), soil (0.25), rock (0.14), curvature (0.10), slope (0.08), and flow accumulation (0.07). The thematic maps were integrated using GIS according to the normalized weights. We classified the seismic hazard microzonation of Puerto Vallarta into five hazard levels, i.e., low (18%), low-medium (28%), medium (22%), medium–high (20%), and high (12%). The map shows heterogeneous distribution over the territory. However, the study area can be divided into three zones, i.e., the northern mountainous area, the Ameca River Valley, and the southern mountainous area. There is an overall increment of seismic hazard from south to north. However, the highest seismic hazard levels dominate the Rio Ameca Valley showing that it is more susceptible to deposits of soft sediment and thus can be affected in the occurrence of a major earthquake. The main objective of this paper was to implement a technique to quickly estimating seismic hazards levels using available data when there is no sophisticated geophysical and engineering analysis. Using the GIS-based multicriteria techniques in seismic hazard assessment allows to elucidated areas where factors influencing surface response to earthquakes interact and raise the soil amplification susceptibility.
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- 2020
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7. Polybenzimidazole-crosslinked-poly(vinyl benzyl chloride) as anion exchange membrane for alkaline electrolyzers
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Roxana E. Coppola, D. Herranz, R. Escudero-Cid, N. Ming, Pilar Ocón, Norma B. D'Accorso, and Graciela C. Abuin
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060102 archaeology ,Ion exchange ,Renewable Energy, Sustainability and the Environment ,020209 energy ,06 humanities and the arts ,02 engineering and technology ,DABCO ,Chloride ,chemistry.chemical_compound ,Benzyl chloride ,Membrane ,chemistry ,Chemical engineering ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Ionic conductivity ,Hydroxide ,0601 history and archaeology ,Thermal stability ,medicine.drug - Abstract
Zero-gap liquid alkaline water electrolyzers have great potential for hydrogen production. In order to enhance their actual performance, one of the key components to investigate is the anionic exchange membrane that allows the conduction of anions between the electrodes. This paper reports the preparation and characterization of membranes composed of a polybenzimidazole, either poly(2,5-benzimidazole) (ABPBI) or poly[2-2′-(m-phenylene)-5-5′-bibenzimidazole] (PBI), crosslinked with different ratios of poly(vinylbenzyl chloride) (PVBC), forming thermally stable and homogeneous films. Quaternization of these films with 1,4-diazabicyclo (2.2.2) octane (DABCO) followed by immersion in an alkaline solution lead to the introduction of quaternary ammonium groups and hydroxide anions respectively. Adequate thermal stability is observed in the temperature range of application (below 100 °C). Measurements of KOH and water and related swelling reflect the higher absorption capacity of ABPBI based membranes relative to PBI based ones. ABPBI-c-PVBC/OH 1:2 membranes at 50 °C are characterized by high ionic conductivity values (48 mS cm−1), reaching 380 mA cm−2 at cell voltage 1.98 V. In conclusion, we consider that these membranes are competitive candidates as anion exchange membranes for zero-gap alkaline water electrolyzers, and can be further enhanced to reach the performance of state of the art AEM’s.
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- 2020
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8. P-, S-wave velocity and VP/VS of the Colima Volcanic Complex from local earthquake tomography
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Christian R. Escudero
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Geochemistry and Petrology - Published
- 2022
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9. O156 Iberian piglet’s post-weaning body size is highly correlated with oxidative status of their mothers supplemented with vitamin E and/or hydroxytyrosol during late gestation and lactation
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G. Gómez, H. Laviano, R. Escudero, A. Heras, M. Muñoz, J. García-Casco, Y. Núñez, R. Benítez, F. Sánchez-Esquiliche, A. González-Bulnes, C. Óvilo, C. López-Bote, and A.I. Rey
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- 2022
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10. Appropriateness of surgery performed for abdominal aortic aneurysm at tertiary hospitals in Spain
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Xavier, Bonfill, M Jesús, Quintana, José R, Escudero, Manuel, Miralles, Joan, Fité, Ederi, Mikelarena, Borja, Castejón, Marta, Garnica, Inés, Fernández DE Valderrama, Ana, Rodriguez-Montalban, José I, Pijoan, Sergi, Bellmunt-Montoya, and Stefanie, Suclupe
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operative ,medicine.medical_specialty ,Concordance ,medicine.medical_treatment ,Patient characteristics ,Endovascular aneurysm repair ,Tertiary Care Centers ,Blood Vessel Prosthesis Implantation ,Surgical procedures ,Abdomen ,Humans ,Medicine ,Aged ,Retrospective Studies ,Surgical repair ,Aortic aneurysm ,business.industry ,Endovascular Procedures ,medicine.disease ,University hospital ,Aneurysm ,Patient preference ,Abdominal aortic aneurysm ,Surgery ,Cross-Sectional Studies ,Treatment Outcome ,Elective Surgical Procedures ,Spain ,Charlson comorbidity index ,abdominal ,Cardiology and Cardiovascular Medicine ,business ,Aortic Aneurysm, Abdominal - Abstract
Background: The aim of this study was to analyze the appropriateness of the type of repair (open or endovascular) performed for abdominal aortic aneurysm (AAA) in five university hospitals in Spain, according to evidence-based recommendations. Methods: A multicenter, retrospective cross-sectional study of patients with AAA who underwent elective open surgical repair (OSR) or endovascular aneurysm repair (EVAR). Data were collected on demographic and clinical variables and type of surgical repair. A pair of vascular surgeons from each participating hospital performed a blinded assessment based on GRADE recommendations. The concordance between the two evaluators and the agreement between their evidence-based recommendation and the procedure performed were assessed. Results: A total of 186 patients were selected; 179 were included. Mean age was 72.5 years (standard deviation [SD], 8.4), mean Charlson Comorbidity Index (CCI) was 2.04 (SD, 1.9). OSR was performed in 53.2% (N.=99) and EVAR in 46.8% (N.=87) of cases. Overall, 65.9% (118/179) of interventions performed were considered appropriate: 50% (47/94) of OSRs and 83.5% (71/85) of EVARs. The patient characteristics were similar for all the hospitals, but the chosen surgical technique did show significant differences among these centers. There were no significant differences among the hospitals in the proportion of cases judged as appropriate, either overall (P=0.346) or for each type of procedure (P=0.531 and P=0.538 for OSR and EVAR, respectively). Conclusions: In this study, most of the AAA repairs performed were appropriate according to GRADE recommendations. A higher proportion of EVARs were considered appropriate than OSRs. Choice of AAA repair should be standardized using evidence-based clinical practice guidelines, while incorporating patient preferences, to reduce the existing variability and ensure appropriate selection of AAA repair technique.
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- 2021
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11. The Tesistan, Mexico Earthquake (Mw 4.9) of 11 May 2016: Tectonic, Seismic Environment and Ground Motion Analysis
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William Bandy, Alejandro Ramirez Gaytan, Christian R. Escudero, Adolfo Preciado, and Edilson F. Salazar-Monroy
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Ground motion ,Rift ,Subduction ,Metals and Alloys ,02 engineering and technology ,Induced seismicity ,010502 geochemistry & geophysics ,Geotechnical Engineering and Engineering Geology ,01 natural sciences ,Graben ,Tectonics ,020303 mechanical engineering & transports ,Geophysics ,Seismic hazard ,0203 mechanical engineering ,Seismology ,Geology ,0105 earth and related environmental sciences - Abstract
To highlight the importance of small earthquakes in seismic hazard, we present a study of the 11 May 2016, Mw 4.9, Tesistan earthquake. According to historical data from instrumental seismicity, this earthquake represents the largest event recorded near Guadalajara. Due to the close proximity of the event to the city, accelerations were considerable higher than those caused by historical severe earthquakes. From the analysis of regional seismicity, its occurrence: (i) shows a clear correlation with seismicity in the subduction zone and (ii) appears to be related to tectonic activity along a previously unmapped SE extension of the faults which form the northern wall of the Plan de Barrancas/Santa Rosa Graben, located to the northwest within the more regional Tepic-Zacoalco Rift. The analysis of the two strong ground motions recorded within the city reveals considerable site effects.
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- 2019
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12. Aerosolized Lipid Amphotericin B for Complementary Therapy and/or Secondary Prophylaxis in Patients with Invasive Pulmonary Aspergillosis: A Single-Center Experience
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Pilar Martín-Dávila, Luis Máiz, E. Gómez-García de la Pedrosa, E Filigheddu, Santiago Moreno, E. Venanzi, J López, R Escudero, Francesca Gioia, and J. Fortún
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Adult ,Complementary Therapies ,Male ,0301 basic medicine ,medicine.medical_specialty ,Antifungal Agents ,Drug-Related Side Effects and Adverse Reactions ,Aerosolized amphotericin B ,Antifungal therapy ,Invasive aspergillosis ,Veterinary (miscellaneous) ,030106 microbiology ,Single Center ,Chemoprevention ,Applied Microbiology and Biotechnology ,Microbiology ,Group A ,Group B ,030207 dermatology & venereal diseases ,03 medical and health sciences ,0302 clinical medicine ,Amphotericin B ,Internal medicine ,Secondary Prevention ,medicine ,Humans ,Respiratory system ,Aged ,Retrospective Studies ,Aerosols ,Invasive Pulmonary Aspergillosis ,Univariate analysis ,Proportional hazards model ,business.industry ,Retrospective cohort study ,Middle Aged ,Survival Analysis ,Treatment Outcome ,Female ,business ,Agronomy and Crop Science ,medicine.drug - Abstract
Experience with aerosolized lipid amphotericin B (aeLAB) as therapy or secondary prophylaxis in patients with invasive pulmonary aspergillosis (IPA) is anecdotal. We performed a single-center retrospective cohort study to evaluate the efficacy of systemic antifungal therapy with and without aeLAB in patients with proven or probable IPA. Complete or partial response at 3 months was the primary end-point. Clinical response and mortality at 12 months, occurrence of adverse drug reactions and respiratory fungal colonization were secondary end-point. Eleven patients (39%) received aeLAB in addition to systemic antifungal therapy (group A), and 22 (61%) received systemic antifungal therapy only (group B). The use of aeLAB was not standardized. Amphotericin B lipid complex was used in all patients but one, who received liposomal amphotericin B. Five patients received aeLAB as antifungal complementary therapy and 6 received it as secondary prophylaxis. Except for the requirement of inhaled corticosteroids and home oxygen therapy, more frequent in group A, both groups were similar in baseline conditions. A better (nonsignificant) clinical outcome was observed at 3 months in patients receiving aeLAB. Only uncontrolled baseline condition was associated with one-year mortality in univariate analysis (p = 0.002). A multivariate Cox regression analysis suggests that aeLAB, corrected for uncontrolled underlying disease, reduces mortality at 12 months (HR 0.258; 95% CI 0.072–0.922; p = 0.037). Although no significant difference was observed in the main variable (3-month clinical response) and in spite of methodological limitations of the study, the possible survival benefit of aeLAB, adjusted for the control of the underlying disease, could justify the performance of well-controlled studies with a greater number of patients.
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- 2019
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13. Geotechnical Seismic Vulnerability Assessment of Puerto Vallarta, México
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Christian R. Escudero, Alejandro Ramirez Gaytan, Karen L. Flores, Adan Gomez Hernandez, Adolfo Preciado, and Araceli Zamora Camacho
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Vulnerability assessment ,Forensic engineering ,Geology - Abstract
We performed a seismic vulnerability assessment that involves geotechnical and building structure analysis for Puerto Vallarta, Mexico, a city located along the pacific coast. Like many other Latin American cities, has significant seismic risk. We implemented the multi-channel analysis of surface waves and the horizontal-to-vertical spectral ratio methods to estimate shear wave velocity and soil resonance frequency. We considered standard penetration test to determine the penetration resistance and soil classification. We also defined building typologies based on construction materials and structural systems. The VS30 parameter shows that Puerto Vallarta has the three poorest soil classifications. The resonance frequency parameter shows four zones with different fundamental soil periods. We inferred the building's vulnerability from the coupling between the structural and soil fundamental period and the soil characteristics. The analysis shows several vulnerable buildings scatters within the city, e.g., within the tourist area, confined masonry buildings from one to five stories and moment resistance frame buildings up to 12 in the tourist area, poorly confined masonry houses of one to two stories, and confined masonry buildings of one to five stories in the residential/commercial. We present an approach that combines the academic and government to solve a real and transcendental problem since it might directly affect the regulation and structure evaluations in the area. We are sure that these exercises are of great interest in urban growth areas in other parts of the world, especially in Latin America, to achieve seismic risk mitigation.
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- 2021
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14. Application of Crosslinked Polybenzimidazole-Poly(Vinyl Benzyl Chloride) Anion Exchange Membranes in Direct Ethanol Fuel Cells
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Juan Carlos Pérez-Flores, Jesús Canales-Vázquez, Kerly Ochoa-Romero, Roxana E. Coppola, Norma B. D'Accorso, R. Escudero-Cid, Pilar Ocón, Graciela C. Abuin, Daniel Herranz, and Carlos Palacio
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Filtration and Separation ,02 engineering and technology ,Electrolyte ,DABCO ,lcsh:Chemical technology ,010402 general chemistry ,01 natural sciences ,Article ,fuel cell ,chemistry.chemical_compound ,anion exchange membrane ,crosslinked ,Chemical Engineering (miscellaneous) ,lcsh:TP1-1185 ,lcsh:Chemical engineering ,quaternized ,Octane ,Aqueous solution ,Ion exchange ,Chemistry ,Process Chemistry and Technology ,lcsh:TP155-156 ,021001 nanoscience & nanotechnology ,Direct-ethanol fuel cell ,0104 chemical sciences ,polybenzimidazole ,Membrane ,Benzyl chloride ,direct ethanol ,0210 nano-technology ,Nuclear chemistry - Abstract
Crosslinked membranes have been synthesized by a casting process using polybenzimidazole (PBI) and poly(vinyl benzyl chloride) (PVBC). The membranes were quaternized with 1,4-diazabicyclo[2.2.2]octane (DABCO) to obtain fixed positive quaternary ammonium groups. XPS analysis has showed insights into the changes from crosslinked to quaternized membranes, demonstrating that the crosslinking reaction and the incorporation of DABCO have occurred, while the 13C-NMR corroborates the reaction of DABCO with PVBC only by one nitrogen atom. Mechanical properties were evaluated, obtaining maximum stress values around 72 MPa and 40 MPa for crosslinked and quaternized membranes, respectively. Resistance to oxidative media was also satisfactory and the membranes were evaluated in single direct ethanol fuel cell. PBI-c-PVBC/OH 1:2 membrane obtained 66 mW cm&minus, 2 peak power density, 25% higher than commercial PBI membranes, using 0.5 bar backpressure of pure O2 in the cathode and 1 mL min&minus, 1 KOH 2M EtOH 2 M aqueous solution in the anode. When the pressure was increased, the best performance was obtained by the same membrane, reaching 70 mW cm&minus, 2 peak power density at 2 bar O2 backpressure. Based on the characterization and single cell performance, PBI-c-PVBC/OH membranes are considered promising candidates as anion exchange electrolytes for direct ethanol fuel cells.
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- 2020
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15. Elective, Non-urgent Procedures and Aesthetic Surgery in the Wake of SARS-COVID-19: Considerations Regarding Safety, Feasibility and Impact on Clinical Management
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Dirk F. Richter, J. Benito-Ruiz, R. Escudero, Kai O Kaye, Gabriela Casabona, J. Montes, Felix J. Paprottka, T. Stasch, L. Moke, R. Fakin, University of Zurich, and Kaye, K
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Male ,COVID-19 PCR test ,COVID-19 prophylaxis ,030230 surgery ,Clinical care protocol ,030207 dermatology & venereal diseases ,COVID-19 Testing ,0302 clinical medicine ,Patient selection ,Informed consent ,Health care ,Medicine ,Longitudinal Studies ,Disease management (health) ,10266 Clinic for Reconstructive Surgery ,Risk management ,Aged, 80 and over ,Procedure flow ,Age Factors ,Disease Management ,Middle Aged ,2746 Surgery ,Patient safety ,Elective Surgical Procedures ,Original Article ,Female ,Coronavirus Infections ,Adult ,medicine.medical_specialty ,Contamination management ,SARS-Cov-2 ,Pneumonia, Viral ,Context (language use) ,610 Medicine & health ,03 medical and health sciences ,Sex Factors ,Preoperative Care ,Humans ,Surgery, Plastic ,Elective surgery ,Pandemics ,Personal Protective Equipment ,Occupational Health ,Aged ,Postoperative Care ,Infection Control ,Clinical Laboratory Techniques ,business.industry ,COVID-19 ,Evidence-based medicine ,IGM/IGG antibody rapid testing ,Surgery ,Communicable Disease Control ,Feasibility Studies ,business ,Aesthetic surgery - Abstract
Background The worldwide spread of a novel coronavirus disease (COVID-19) has led to a near total stop of non-urgent, elective surgeries across all specialties in most affected countries. In the field of aesthetic surgery, the self-imposed moratorium for all aesthetic surgery procedures recommended by most international scientific societies has been adopted by many surgeons worldwide and resulted in a huge socioeconomic impact for most private practices and clinics. An important question still unanswered in most countries is when and how should elective/aesthetic procedures be scheduled again and what kind of organizational changes are necessary to protect patients and healthcare workers when clinics and practices reopen. Defining manageable, evidence-based protocols for testing, surgical/procedural risk mitigation and clinical flow management/contamination management will be paramount for the safety of non-urgent surgical procedures. Methods We conducted a MEDLINE/PubMed research for all available publications on COVID-19 and surgery and COVID-19 and anesthesia. Articles and referenced literature describing possible procedural impact factors leading to exacerbation of the clinical evolution of COVID-19-positive patients were identified to perform risk stratification for elective surgery. Based on these impact factors, considerations for patient selection, choice of procedural complexity, duration of procedure, type of anesthesia, etc., are discussed in this article and translated into algorithms for surgical/anesthesia risk management and clinical management. Current recommendations and published protocols on contamination control, avoidance of cross-contamination and procedural patient flow are reviewed. A COVID-19 testing guideline protocol for patients planning to undergo elective aesthetic surgery is presented and recommendations are made regarding adaptation of current patient information/informed consent forms and patient health questionnaires. Conclusion The COVID-19 crisis has led to unprecedented challenges in the acute management of the crisis, and the wave only recently seems to flatten out in some countries. The adaptation of surgical and procedural steps for a risk-minimizing management of potential COVID-19-positive patients seeking to undergo elective aesthetic procedures in the wake of that wave will present the next big challenge for the aesthetic surgery community. We propose a clinical algorithm to enhance patient safety in elective surgery in the context of COVID-19 and to minimize cross-contamination between healthcare workers and patients. New evidence-based guidelines regarding surgical risk stratification, testing, and clinical flow management/contamination management are proposed. We believe that only the continuous development and broad implementation of guidelines like the ones proposed in this paper will allow an early reintegration of all aesthetic procedures into the scope of surgical care currently performed and to prepare the elective surgical specialties better for a possible second wave of the pandemic. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.
- Published
- 2020
16. Synthesis of luminescent terbium-thenoyltriflouroacetone MOF nanorods for green laser application
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Joan Reyes-Miranda, U. Caldiño, Ángel de Jesús Morales-Ramírez, D.Y. Medina-Velazquez, R. Escudero, Randi Lopez, Rosario Ruiz-Guerrero, and M.F. Morales Perez
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Lanthanide ,Materials science ,Photoluminescence ,Analytical chemistry ,FOS: Physical sciences ,chemistry.chemical_element ,Terbium ,Phosphor ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Inorganic Chemistry ,Crystallinity ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Chromaticity ,Spectroscopy ,Condensed Matter - Materials Science ,Organic Chemistry ,Materials Science (cond-mat.mtrl-sci) ,021001 nanoscience & nanotechnology ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,chemistry ,Nanorod ,0210 nano-technology ,Luminescence - Abstract
In this study, a thenoyltriflouroacetone ligand (TTA) with a Tb3+ MOF was synthesized (Tb=10 and 50% mol) and its structural and luminescent properties were analyzed. The metalorganic compound was generated in a simple one-pot reaction from terbium nitrate and 2-thenoyltrifluoroacetone precursors at room temperature. By means of FTIR, it was confirmed the presence of carbon groups, which made possible the terbium ion chelation, and also the Tb-O bonds vibration modes. HNMR results confirm that the complex with 10% mol of Tb3+ contains three coordinates molecules of TTA and two waters molecules. The powders exhibit rod-like morphology with size about 170 nm of diameter and a length about 2 {\mu}m, the rod-like nature of powders was confirmed by SEM and TEM analyses. By XRD it was concluded that at higher terbium concentration (TTA-50Tb sample) higher the crystallite size and crystallinity, in fact the TTA-10Tb sample shows a partial-amorphous nature. By photoluminescence analyses, the 5D4-7FJ (J=3, 4, 5 and 6) emissions were recorded for both synthesized samples ({\lambda}exc=376 nm). Furthermore, it was observed that the emission intensity was enhanced in a factor of 3.5 for the TTA-50Tb. The energy transfer efficiency from TTA to Tb3+ (antenna effect) was 0.984 for TTA-10Tb and 0.993 for TTA-50Tb. Decay time analyses indicate effective lifetime of 1.45 and 1.60ms for the samples doped at 10 and 50%, respectively, indicating that the forbidden transition rules are stronger at higher crystallinity. The integrated intensities of the 5D4 - 7F5 (green at 541 nm) and 5D4 - 7F6 (blue at 486 nm) emissions and their intensity ratios IG/IB upon 376 nm excitation have been evaluated for TTA-10Tb andTTA-50Tb samples., Comment: Optical Materials (2018)
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- 2019
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17. Active surveillance as a successful management strategy for patients with clinical stage I germ cell testicular cancer
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R Escudero-Ávila, I Osman, M Japón-Rodríguez, P Sancho, Juan Manuel Praena-Fernández, B Vargas, Rafael Medina, B Perez-Valderrama, F Fernandez, J D Rodríguez-Castaño, and Ignacio Duran
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Adult ,Male ,0301 basic medicine ,Oncology ,Cancer Research ,medicine.medical_specialty ,Adolescent ,medicine.medical_treatment ,Population ,Testicular Neoplasm ,Disease ,Multimodal Imaging ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Testicular Neoplasms ,Internal medicine ,Humans ,Medicine ,Longitudinal Studies ,Stage (cooking) ,Watchful Waiting ,education ,Testicular cancer ,Aged ,Retrospective Studies ,education.field_of_study ,Chemotherapy ,business.industry ,Disease Management ,General Medicine ,Seminoma ,Middle Aged ,Neoplasms, Germ Cell and Embryonal ,Prognosis ,medicine.disease ,Survival Rate ,Radiation therapy ,030104 developmental biology ,Population Surveillance ,030220 oncology & carcinogenesis ,business ,Orchiectomy ,Follow-Up Studies - Abstract
Cancer-specific survival for patients with clinical stage I (CSI) germ cell testicular cancer (GCTC) is outstanding after inguinal orchidectomy regardless the treatment utilized. This study evaluated whether active surveillance (AS) of such patients yielded similar health outcomes to other therapeutic strategies such as adjuvant chemotherapy, radiotherapy or primary retroperitoneal lymphadenectomy as described in the literature. Patients with CSI GCTC were screened between January 2012 and December 2016. Patients had previously undergone inguinal orchidectomy as the primary treatment and chosen AS as their preferred management strategy after receiving information about all available strategies. Out of 91 patients screened, 82 patients selected AS as their preferred management strategy. Relapse rate in the overall population was 20% (95% CI 12–30) and median time to relapse was 11.5 months (range 1.0–35.0). In patients with seminomatous tumors, relapse rate decreased to 13% and median time to relapse was 13 months; whereas in patients with non-seminomatous tumors, relapse rate was 33% (IA) or 29% (IB) and median time to relapse was 12 months in stage IA and 4.5 months in stage IB patients. All relapses were rescued with three or four cycles of chemotherapy and two also required a retroperitoneal lymphadenectomy. All patients are currently alive and free of disease. The clinical outcomes of patients with CSI GCTC managed by AS in this series were excellent. This strategy limited the administration of active treatments specifically to the minority of patients who relapsed without compromising performance.
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- 2018
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18. Oxigenoterapia transcorneal como tratamiento de hifema persistente en un paciente con anemia de células falciformes
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L. Manfreda-Domínguez, R. Escudero-Igualada, Antonio Duch-Samper, R. Clemente-Tomás, P. Neira-Ibáñez, and Á. Olate-Pérez
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Ophthalmology - Abstract
Resumen Caso clinico Paciente varon de 10 anos, de raza negra, con antecedente de traumatismo leve en ojo izquierdo; presenta agudeza visual corregida de 0,2 en escala de Snellen, hifema con altura de 1 mm, presion intraocular (PIO) de 12 mmHg en ese ojo, con incremento de PIO a 20 mmHg a las 72 h. Con el resultado positivo del estudio de drepanocitos, se decide tratamiento medico con oxigenoterapia transcorneal. Se logra el aclaramiento de la camara anterior, con agudeza visual corregida de 0,8 y la reduccion de la PIO a 8 mmHg. Discusion En los pacientes con hifema persitente en el contexto de una drepanocitosis, la oxigenoterapia transcorneal es una buena alternativa terapeutica. Se obtienen resultados satisfactorios inmediatos con la disminucion de la PIO y el aclaramiento de la camara anterior.
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- 2018
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19. Manejo de la perforación conjuntival y Seidel tardío poscirugía XEN ®
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Antonio Duch-Samper, A. Barreiro-Rego, Á. Olate-Pérez, A. Gargallo-Benedicto, V.T. Pérez-Torregrosa, R. Escudero-Igualada, and M. Cerdà-Ibáñez
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03 medical and health sciences ,Ophthalmology ,0302 clinical medicine ,030221 ophthalmology & optometry ,030217 neurology & neurosurgery - Abstract
Resumen Caso clinico Mujer de 78 anos con antecedentes de cirugia XEN®. A los 18 meses de seguimiento se observa perforacion conjuntival a nivel del implante, decidiendose intervencion quirurgica. En esta se constato un trayecto subconjuntival corto (0,5 mm). Se intenta, sin exito, extraerlo mediante traccion, sin embargo, el XEN® se rompe con facilidad. Finalmente se decide seccionarlo hasta nivel escleral, y suturar la conjuntiva. Durante la primera semana poscirugia existe disminucion de la presion intraocular (6 mmHg), para posteriormente aumentar progresivamente hasta 25, optandose por iniciar tratamiento medico. Discusion La exposicion conjuntival del XEN® es una complicacion rara, pero potencialmente grave. Para evitarla es importante una tecnica quirurgica meticulosa durante su implantacion. En caso de suceder es importante identificar la causa. Si es debida al trayecto subconjuntival corto, una alternativa terapeutica es la seccion del implante a este nivel para evitar nuevas complicaciones.
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- 2018
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20. Alkali-doped polyvinyl alcohol – Polybenzimidazole membranes for alkaline water electrolysis
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Pilar Ocón, Graciela C. Abuin, Liliana A. Diaz, R. Escudero-Cid, Roxana E. Coppola, and D. Herranz
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Electrolysis ,Materials science ,Electrolysis of water ,Alkaline water electrolysis ,Filtration and Separation ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,Polyvinyl alcohol ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,law ,Polymer chemistry ,General Materials Science ,Glutaraldehyde ,Polymer blend ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
We developed an innovative polymer blend system composed of polyvinyl alcohol (PVA) and polybenzimidazole as an anionic membrane for application to zero gap alkaline electrolysers. The challenge was to combine PVA with either poly[2-2′-(m-phenylene)-5-5′-bibenzimidazole] (PBI) or poly (2,5-benzimidazole) (ABPBI) to complement these neutral polymers, which must be doped to conduct, with hydroxyl groups that benefit the OH− transport mechanism. We studied PVA-PBI and PVA-ABPBI membranes with compositions varying between 2:1 and 8:1, with 4:1 being best ratio. PVA is crosslinked inside PVA-PBI 4:1 and PVA-ABPBI 4:1 membranes with glutaraldehyde (GA) by immersion in a reaction solution with different GA contents ranging from 0.5 vol% to 50 vol% to enhance the stability of the membranes. The chemical stability in a KOH environment, thermal and mechanical properties, surface morphology, swelling, water/KOH sorption, and conductivity of the linear alkali-doped (L-PVA-PBI, L-PVA-ABPBI) and crosslinked (C-PVA-PBI, C-PVA-ABPBI) membranes were analysed. The best results were observed for the C-PVA-ABPBI 4:1 membrane crosslinked in 0.5 vol% GA, which exhibited specific conductivities at 90 °C of 50 mS cm−1 and 90 mS cm−1 when doped using 15 wt% and 30 wt% KOH, respectively. In short-term electrolysis tests performed with circulated 15 wt% KOH at 50 °C, this membrane exhibited a current density that was twice that of the commercial porous Zirfon® diaphragm (i.e., 300 mA cm−2 and 140 mA cm−2, respectively) at a cell voltage of 2.0 V. The performance achieved with the C-PVA-ABPBI membrane in a 15 wt% KOH electrolyte at 70 °C was good (i.e., 360 mA cm−2 at a cell voltage of 1.9 V).
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- 2017
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21. Cord blood-derived platelet concentrates as starting material for new therapeutic blood components prepared in a public cord blood bank: from product development to clinical application
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Dinara, Samarkanova, Luciano, Rodríguez, Joaquim, Vives, Ruth, Coll, Elisabet, Tahull, Carmen, Azqueta, Elena, Valdivia, Margarita, Codinach, Elisenda, Farssac, Jesus, Gaitan, Jose R, Escudero, and Sergio, Querol
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Blood Platelets ,Platelet-Derived Growth Factor ,Transforming Growth Factor beta1 ,Platelet-Rich Plasma ,Blood Banks ,Humans ,Cord Blood Banking and Bone Marrow Transplant ,Fetal Blood ,Diabetic Foot - Abstract
BACKGROUND: There are many advantages to using cord blood (CB) as a source of therapeutic platelet and plasma derivatives for regenerative medicine. These include availability, universal use, young donor source, and virally safe biological material, rich in tissue regenerative factors. MATERIALS AND METHODS: We aimed to validate a bioprocess design for the production of cord blood-derived platelet concentrates (CBPC) in a public Cord Blood Bank (CBB). CBPC was defined as a product of 10±5 mL, 1,000±200×10(9)/L total platelets, free of erythrocytes and leukocytes. A total of 300 CB units were centrifuged in two steps to enrich for platelets, in compliance with Good Manufacturing Practice. The samples were tested for the degree of platelet activation present, and the levels of growth factor were analysed to evaluate their potential function. CBPC were then activated after thawing with 10% calcium gluconate to generate platelet gels (CBPG) to treat patients with diabetic foot ulcers. RESULTS: After processing, 84% of the products fulfilled the acceptance criteria. Final products contained 1,017±149×10(6) platelets/mL in 10±3mL of plasma. Platelet recovery was 50±9%. The methods described here ensure depletion of white and red blood cells down to a residual concentration of 0.2±0.1×10(6)/mL and 0.03±0.02×10(6)/mL, respectively. Platelets showed low levels of activation during processing, but were significantly activated after thawing, as indicated by an increase in CD62p expression. The growth factors EGF, VEGF, bFGF, PDGF AB/BB and TGF-β1 were at concentrations of 1,706±123 pg/mL; 1,602±227 pg/mL; 314±26 pg/mL; 30±1.5 ng/mL; 24±2 ng/mL (mean±standard error of mean), respectively. For clinical evaluation, a total of 21 CBPG were applied in 3 patients, with no reported adverse events and improvement of ulcers in all of them. DISCUSSION: We designed and validated a highly reproducible, closed system method to manufacture high quality CBPC suitable for clinical applications using CB units not suitable for transplantation in a public CBB.
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- 2019
22. Variation in the choice of elective surgical procedure for abdominal aortic aneurysm in Spain
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M Jesús, Quintana, Ignasi, Gich, Julián, Librero, Sergi, Bellmunt-Montoya, José R, Escudero, and Xavier, Bonfill
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Adult ,Male ,Hospitals, Low-Volume ,Time Factors ,Databases, Factual ,open surgical repair ,endovascular aneurysm repair ,Blood Vessel Prosthesis Implantation ,Postoperative Complications ,abdominal aortic aneurysm ,Risk Factors ,Humans ,Hospital Mortality ,Longitudinal Studies ,Practice Patterns, Physicians' ,Aged ,Retrospective Studies ,Original Research ,Aged, 80 and over ,variability ,Endovascular Procedures ,Middle Aged ,Treatment Outcome ,Elective Surgical Procedures ,Spain ,Female ,Hospitals, High-Volume ,Aortic Aneurysm, Abdominal - Abstract
Objective The two main surgical treatments for abdominal aortic aneurysm (AAA) are open surgical repair (OSR) and endovascular aneurysm repair (EVAR). The aim of this study was to analyze variation among Spanish hospitals in the use of OSR or EVAR for AAA. A secondary aim was to assess changes in preferences for these two procedures over time. Methods This was a retrospective longitudinal study based on discharge data from public hospitals in Spain during 2002–2012. Patient inclusion criteria were: age >18 years, elective admission, primary diagnosis of unruptured AAA, and surgical treatment with OSR or EVAR. The characteristics of the treating center, patients, and in-hospital mortality were recorded. Results We included 16,737 patients from 114 hospitals; 6,809 (40.7%) underwent EVAR and 9,928 (59.3%) underwent OSR. The total volume of surgeries increased throughout the period, and the probability that any given procedure was EVAR increased by 20% per year (OR 1.20, P
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- 2019
23. Performance of a Fe-N-C catalyst for the oxygen reduction reaction in direct methanol fuel cell: Cathode formulation optimization and short-term durability
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Alessandro Hugo Monteverde Videla, R. Escudero-Cid, Luigi Osmieri, Pilar Ocón, and Stefania Specchia
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Inorganic chemistry ,Proton exchange membrane fuel cell ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Catalysis ,Oxygen reduction reaction ,law.invention ,Non-noble metal catalyst ,Iron-phthalocyanine ,Rotating ring-disk electrode ,Direct methanol fuel cell ,chemistry.chemical_compound ,law ,Nafion ,Rotating disk electrode ,General Environmental Science ,Process Chemistry and Technology ,021001 nanoscience & nanotechnology ,Cathode ,0104 chemical sciences ,chemistry ,Methanol ,0210 nano-technology - Abstract
A non-noble metal (NNM) catalyst for oxygen reduction reaction (ORR) was synthesized using Fe(II)-phthalocyanine as unique source of Fe, N, and C, and SBA-15 ordered mesoporous silica as templating agent, resulting in a material with an extremely high specific surface area and a high microporosity (around 50%). FESEM, FTIR and Raman analyses were performed to investigate the morphology and the physicochemical properties of the catalyst. The ORR activity and the methanol tolerance were tested in rotating disk electrode (RDE), and the selectivity towards a complete 4-electrons reduction was investigated by rotating ring disk electrode (RRDE) test and hydrogen peroxide reduction test in RDE, showing very promising results. Thus, the Fe-N-C catalyst was tested at the cathode of a DMFC after determination of the optimal electrode formulation regarding catalyst loading and Nafion ® content, showing a maximum power density of 20 mW cm −2 at 90 °C. A short term durability test to assess the behavior of both the Fe-N-C and the Pt/C catalysts was conducted on the DMFC, showing a better performance of the non-noble catalyst. Thus, the Fe-N-C catalyst is a potential good candidate to be used as catalytic material for DMFC cathode, in alternative to Pt. The performance in a H 2 /O 2 PEMFC was tested as well, showing a power density of 105 mW cm −2 at 60 °C.
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- 2017
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24. An optimised synthesis of high performance radiation-grafted anion-exchange membranes
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Mohamed Mahmoud Nasef, Julia Ponce-González, Rachida Bance-Souahli, Emma L. Cunningham, Simon D. Poynton, R. Escudero-Cid, Emanuele Magliocca, William E. Mustain, Lianqin Wang, John R. Varcoe, Robert C. T. Slade, and Daniel K. Whelligan
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Aqueous solution ,Chromatography ,Ion exchange ,Trimethylamine ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Grafting ,01 natural sciences ,Pollution ,Diluent ,Chloride ,0104 chemical sciences ,chemistry.chemical_compound ,Membrane ,ETFE ,chemistry ,medicine ,Environmental Chemistry ,0210 nano-technology ,Nuclear chemistry ,medicine.drug - Abstract
High performance benzyltrimethylammonium-type alkaline anion-exchange membranes (AEM), for application in electrochemical devices such as anion-exchange membrane fuel cells (AEMFC), were prepared by the radiation grafting (RG) of vinylbenzyl chloride (VBC) onto 25 μm thick poly(ethylene-co-tetrafluoroethylene) (ETFE) films followed by amination with trimethylamine. Reductions in the electron-beam absorbed dose and amount of expensive, potentially hazardous VBC were achieved by using water as a diluent (reduced to 30–40 kGy absorbed dose and 5 vol% VBC) instead of the prior state-of-the-art method that used organic propan-2-ol diluent (required 70 kGy dose and 20 vol% VBC monomer). Furthermore, the water from the aqueous grafting mixture was easily separated from the residual monomer (after cooling) and was reused for a further grafting reaction: the resulting AEM exhibited an ion-exchange capacity of 2.1 mmol g−1 (cf. 2.1 mmol g−1 for the AEM made using a fresh grafting mixture). The lower irradiation doses resulted in mechanically stronger RG-AEMs compared to the reference RG-AEM synthesised using the prior state-of-the-art method. A further positive off-shoot of the optimisation process was the discovery that using water as a diluent resulted in an enhanced (i.e. more uniform) distribution of VBC grafts as proven by Raman microscopy and corroborated using EDX analysis: this led to enhancement in the Cl− anion-conductivities (up to 68 mS cm−1 at 80 °C for the optimised fully hydrated RG-AEMs vs. 48 mS cm−1 for the prior state-of-the-art RG-AEM reference). A down-selected RG-AEM with an ion-exchange capacity = 2.0 mmol g−1, that was synthesised using the new greener protocol with a 30 kGy electron-beam absorbed dose, led to an exceptional beginning-of-life H2/O2 AEMFC peak power density of 1.16 W cm−2 at 60 °C in a benchmark test using industrial standard Pt-based electrocatalysts and unpressurised gas supplies: this was higher than the 0.91 W cm−1 obtained with the reference RG-AEM (IEC = 1.8 mmol g−1) synthesised using the prior state-of-the-art protocol.
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- 2017
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25. Attenuation of Coda Waves in Western Mexico Using Local Seismicity
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Christian R. Escudero, Nathalie García‐Millán, and Felipe de Jesús Escalona-Alcázar
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Anelastic attenuation factor ,010504 meteorology & atmospheric sciences ,Subduction ,Scattering ,Attenuation ,Geophysics ,Induced seismicity ,010502 geochemistry & geophysics ,01 natural sciences ,Coda ,Geochemistry and Petrology ,Lithosphere ,Seismogram ,Geology ,Seismology ,0105 earth and related environmental sciences - Abstract
Coda waves are an important instrument to study the elastic properties of the lithosphere. The attenuation of coda waves in western Mexico is analyzed using seismograms recorded during the mapping of the Rivera subduction zone experiment. The coda‐wave attenuation is measured by means of Q within the single‐backscattering model and the single‐isotropic scattering model schemes. The frequency dependence of Q is analyzed using the power fit formulation Q ( f )= Q f α . The resulting Q , Q , and α are then used to study the seismic attenuation properties in western Mexico. We compare our results with the crustal structure by means of the surface geology, seismic activity, crustal thickness, and P ‐wave velocity patterns in the study area. There is a poor correlation of the attenuation parameters with such crustal features. However, an analysis of the variations of the P ‐wave velocity shows that the seismic attenuation parameters correlate to some extent with seismic velocity variations previously noted in the study area, where low attenuation and weak frequency dependence correlate with low‐velocity variation.
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- 2016
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26. Performance of carbon-supported palladium and palladium ruthenium catalysts for alkaline membrane direct ethanol fuel cells
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Manuel Montiel, Pilar Ocón, Enrique Fatás, S. Carrión-Satorre, José Luis García Fierro, and R. Escudero-Cid
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Renewable Energy, Sustainability and the Environment ,Chemistry ,Inorganic chemistry ,Energy Engineering and Power Technology ,Nanoparticle ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrocatalyst ,Direct-ethanol fuel cell ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Fuel Technology ,Membrane ,Ethanol fuel ,0210 nano-technology ,Bimetallic strip ,Palladium - Abstract
The activity of carbon supported palladium-based catalysts towards ethanol oxidation reaction in alkaline medium is investigated. To this end, Pd and Pd x Ru (x = 1, 6, 12) materials are synthesized supported on Vulcan XC72R by a modified impregnation method. These materials are characterized physicochemically and their composition varies between 40 and 50 wt. % of metal content. The mean size of nanoparticles is below 4 nm, and the size of the majority of particles ranges from 2 to 6 nm. The catalytic activity of these samples is also tested in half-cell and alkaline membrane direct ethanol fuel cell (AMDEFC). Lower onset potential and higher oxidation current densities is observed in palladium-rich bimetallic catalysts. By using the prepared samples as anode of AMDEFC and a commercial membrane of polybenzimidazole as solid electrolyte, the maximum power density is observed for Pd 12 Ru/C, 97 mW cm −2 , almost doubling the value achieved by the catalyst Pd/C (50 mW cm −2 ), and above the obtained by commercial PtRu/C catalyst (89 mW cm −2 ).
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- 2016
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27. Probe effects on the local gas holdup conditions in a fluidized bed
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David R. Escudero, Emily A. Whitemarsh, and Theodore J. Heindel
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Work (thermodynamics) ,Petroleum engineering ,Chemistry ,General Chemical Engineering ,Gas holdup ,Horizontal orientation ,02 engineering and technology ,Mechanics ,021001 nanoscience & nanotechnology ,Vertical orientation ,Volumetric flow rate ,020401 chemical engineering ,Fluidized bed ,Fluidization ,0204 chemical engineering ,Aeration ,0210 nano-technology - Abstract
Fluidized beds are found in the energy production industry, and knowing their hydrodynamic conditions, such as local gas holdup or volumetric gas fraction, is important for effective operation. Local measurement probes are commonly used to measure local gas holdup. Although the probes are typically as small as possible to mitigate their influence on the local conditions, the invasive nature of this measurement technique has the potential to alter the fluidized bed behavior. This study used a noninvasive measurement technique, X-ray computed tomography (CT) imaging, to determine the local time-average gas holdup everywhere within a 10.2 cm diameter fluidized bed filled with 500–600 μm glass beads in which simulated probes were inserted. Three different simulated probe tips (pointed, rounded, and flat) and two different orientations (horizontal and vertical) were investigated at four different bed heights and two different fluidization velocities. The results show increases in local time-average gas holdup when the probes were present, but the scale of the effects was dependent upon the height at which the probes were placed; the lower the probe within the fluidized bed, the larger the local effects. The shape of the probe tip did not show any differences in the local gas holdup. On the other hand, probe orientation was an important factor, with the horizontal orientation showing a sustained increase in gas holdup values farther from the probe. The two different flow rates used in this study (1.5 U mf and 3 U mf , where U mf is the minimum fluidization velocity) also showed differences in the amount of variation in gas holdup, but the trends were inconsistent. Overall, the local hydrodynamic effects of the simulated invasive probes of this work were minimized when: (i) the probes were placed in the central part of the bed, outside the aeration region and top of the bed, (ii) the fluidized bed was operated at higher superficial gas velocities, and (iii) the probes were mounted in a vertical orientation.
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- 2016
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28. Ensayo de preservación de madera tratada con Zn y Mn efectividad de tratamiento antilixiviante con bórax luego de cinco años de contacto con el suelo
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C. Mantero, M. Rabinovich, R. Escudero, Claudia Marcela Ibanez, and Jorge Franco
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040101 forestry ,0106 biological sciences ,Cementerio de estacas ,cementerio de estacas ,Materials Science (miscellaneous) ,Manufactures ,Pinus taeda ,Forestry ,04 agricultural and veterinary sciences ,SD1-669.5 ,01 natural sciences ,Industrial and Manufacturing Engineering ,reciclaje ,TS1-2301 ,pinus taeda ,tratamiento en etapas ,lcsh:Manufactures ,010608 biotechnology ,lcsh:SD1-669.5 ,0401 agriculture, forestry, and fisheries ,Chemical Engineering (miscellaneous) ,protección de maderas ,lcsh:Forestry ,lcsh:TS1-2301 - Abstract
A través de un ensayo de campo implementado de acuerdo a la norma EN 252, se evaluó la efectividad de tratamientos en etapas, tendientes a disminuir la lixiviación de una solución rica en Zn y Mn obtenida a partir de un proceso de reciclado aplicada en la madera por el método Bethell. La segunda etapa antilixiviante agregó bórax por pincelado o por el método Bethell. Se utilizó madera de Pinus taeda. Este trabajo presenta el análisis de la evolución del proceso de deterioro a lo largo de 5 años de ensayo de campo y su evaluación. Se utilizó el índice climático de Scheffer como método de evaluación del riesgo microbiológico en el sitio del ensayo y se realizó un análisis microscópico de la madera, para verificar el tipo de deterioro presente. Los tratamientos al 3% y al 6% en Zn con agregado de bórax por el método Bethell fueron los de mejor desempeño entre los evaluados a pesar de no haber superado el desempeño del preservante de referencia. Se observó la presencia de los tres tipos de pudrición, blanca, marrón y blanda tanto en controles sin tratamiento como en maderas tratadas, en un sitio con condiciones intermedias para el deterioro.
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- 2016
29. Selective sentinel lymph node biopsy after neoadyuvant chemoterapy
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H.A. Reyes Iborra, Patricia Lopez Arribas, A. Cano Cuetos, A. Fuencisla, R. Escudero Viñolo, P. Lopez Arribas, and E. Martínez Gómez
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Sentinel lymph node ,Biopsy ,Medicine ,Surgery ,General Medicine ,Radiology ,business - Published
- 2019
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30. Seismic Anisotropy and Mantle Flow Driven by the Cocos Slab Under Southern Mexico
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Berenice R. Garibaldi, Leslie A. Bernal-López, Christian R. Escudero, Gerardo León Soto, and Raul Valenzuela
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geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Mantle wedge ,Volcanic arc ,Subduction ,Volcanic belt ,Flat slab subduction ,010502 geochemistry & geophysics ,01 natural sciences ,Geophysics ,Geochemistry and Petrology ,Slab window ,Transition zone ,Oceanic trench ,Seismology ,Geology ,0105 earth and related environmental sciences - Abstract
Shear wave splitting measurements were made using SKS and SKKS waves recorded by the Meso-American Subduction Experiment, which was deployed in southern Mexico starting at the coast of the Pacific Ocean and running north toward the Gulf of Mexico. In this segment of the Middle America Trench the oceanic Cocos plate subducts under the continental North American plate. The active volcanic arc is located at the southern end of the Trans-Mexican Volcanic Belt. Unlike most subduction zones, however, the volcanic arc is not subparallel to the trench. In the fore-arc, between the trench and the Trans-Mexican Volcanic Belt, the Cocos slab subducts subhorizontally. Beneath the volcanic belt, however, the slab dives steeply into the mantle. A marked difference in the orientation of the fast polarization directions is observed between the fore-arc and the back-arc. In the fore-arc the fast axes determined using SKS phases are oriented NE–SW, in the same direction as the relative motion between the Cocos and North American plates, and are approximately perpendicular to the trench. Physical conditions in the subslab mantle are consistent with the existence of A-type olivine and consequently entrained mantle flow is inferred. Strong coupling between the slab and the surrounding mantle is observed. In the back-arc SKS fast polarization directions are oriented N–S and are perpendicular to the strike of the slab. Given the high temperatures in the mantle wedge tip, the development of A-type, or similar, olivine fabric throughout the mantle wedge is expected. The orientation of the fast axes is consistent with corner flow in the mantle wedge.
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- 2015
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31. Geophysical Studies across Rivera Plate and Jalisco Block, Mexico: TsuJal Project
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Juan José Dañobeitia, R. Bartolome, Felipe de Jesús Escalona-Alcázar, Elizabeth Trejo-Gómez, Carlos Suárez Plascencia, Modesto Ortiz Figueroa, Arturo Castellón, William L. Bandy, F. Alejandro Nava, Araceli Zamora-Camacho, Diego Córdoba, Christian R. Escudero, Juan Manuel Espíndola, Diana Nuñez, Francisco Nuñez-Cornu, and Carlos Mortera
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Canyon ,geography ,geography.geographical_feature_category ,Accretionary wedge ,010504 meteorology & atmospheric sciences ,Subduction ,North American Plate ,Geophysics ,Induced seismicity ,010502 geochemistry & geophysics ,01 natural sciences ,Graben ,Passive margin ,Structural geology ,Seismology ,Geology ,0105 earth and related environmental sciences - Abstract
Nuñez-Cornu, Francisco ... et al.-- 14 pages, 9 figures, 1 table, In the spring of 2014, an onshore–offshore geophysical experiment (“Crustal Characterization of the Rivera plate–Jalisco Block Boundary and Its Implications for Seismic and Tsunami Hazard Assessment”) was carried out in the frame of the TsuJal project to define the crustal architecture of the western Mexican active margin and identify potential structural sources that can trigger earthquakes and tsunamis at the convergence between the Rivera plate (RP) and the Jalisco Block (JB) within the North American plate. In this work, we present the preliminary results about bathymetric, structural geology, and wide‐angle seismic data of the southern coast of Bahía de Banderas. These data indicate the slab thickness in this area is about 10 km and presents a dip angle of about 8°. Continental crustal thickness below Puerto Vallarta is about 20 km, but no evidences of continental Moho and clear subduction features (trench, accretionary prism) are observed. Nevertheless, this model supports the hypothesis that the region of Bahía de Banderas is under strong crustal stresses generating structural lineaments with the same trends offshore and inland due to the convergence of the RP against the JB. Most of the seismicity reported can be associated with the main structural lineaments. Moreover, the Banderas Canyon (BC) is apparently in an eastward opening process, which seems to continue through the Rio Pitillal river valley; no seismic or morphological evidences were found to suggest the BC is a continuation of the Vallarta graben. Offshore, the Sierra de Cleofas, located south of María Cleofas Island, marks the limit between the RP and the JB along 100 km. It may be the result of the RP pushing against the JB establishing the beginning of the current subduction process, with associated seismic activity. If a subduction type earthquake occurs in this area, the associated magnitude will be about 7.5 and could have a tsunamigenic effect, This Research is funded by Consejo Nacional de Ciencia y Tecnología (CONACYT) – Fondo Mixto CONACYT – Gobierno de Jalisco (FOMIXJAL) 2008-96567 (2009); CONACYT–FOMIXJAL 2008-96539 (2009); CONA-CYT–FOMIXJAL 2010-149245 (2011); CONACYT–FOMIXJAL (2012-08-189963) (MEXICO); Ciencias de la Tierra y Cambio Global (CGL; 2011-29474-C02-01) Dirección General de Investigación (DGI) Plan Nacional I+D+i (España). National Oceanography Centre (NOC) Cruise JC098, RRS James Cook (United Kingdom); Funding for the EL PUMA campaign was provided by Universidad Nacional Autónoma de México (UNAM) (Comisión Académica de los Buques Oceanográficos de la UNAM [CABO]) and Dirección General de Asuntos del Personal Académico de la UNAM (DGAPA) Grant Number IN115513-3; Secretaría de Marina (Mexico) ARM Holzinger; Secretaría de Defensa Nacional (Mexico); Unidad Municipal de Proteccion Civil y Bomberos (Puerto Vallarta, Mexico); Unidad Estatal de Proteccion Civil y Bomberos (Nayarit State, Mexico); Unidad Municipal de Proteccion Civil y Bomberos (Jalisco State, Mexico); Reserva de la Biosfera (Islas Marías) Comisión Nacional de Áreas Naturales y Protegidas (CONANP)-Secretaría de Medio Ambiente y Recursos Naturales (SEMARNAT); Órgano Desconcentrado de Prevención y Readaptacion Social de la Secretaría de Gobernación (SEGOB); Secretaría de Relaciones Exteriores (Mexico)
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- 2015
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32. P-Wave Velocity Tomography from Local Earthquakes in Western Mexico
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William Bandy, Christian R. Escudero, Juan A. Ochoa-Chávez, and Francisco Nuñez-Cornu
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geography ,geography.geographical_feature_category ,Rift ,010504 meteorology & atmospheric sciences ,Volcanic arc ,Subduction ,Lineament ,Continental crust ,Crust ,010502 geochemistry & geophysics ,01 natural sciences ,Mantle (geology) ,Geophysics ,Volcano ,Geochemistry and Petrology ,Geology ,Seismology ,0105 earth and related environmental sciences - Abstract
In western Mexico, the subduction of the Rivera and Cocos plates beneath the North America plate has deformed and fragmented the overriding plate, forming several structural rifts and crustal blocks. To obtain a reliable subsurface image of the continental crust and uppermost mantle in this complex area, we used P-wave arrivals of local earthquakes along with the Fast Marching Method tomography technique. We followed an inversion scheme consisting of (1) the use of a high-quality earthquake catalog and corrected phase picks, (2) the selection of earthquakes using a maximum location error threshold, (3) the estimation of an improved 1-D reference velocity model, and (4) the use of checkerboard testing to determine the optimum configuration of the velocity nodes and inversion parameters. Surprisingly, the tomography results show a very simple δVp distribution that can be described as being controlled by geologic structures formed during two stages of the separation of the Rivera and Cocos plates. The earlier period represents the initial stages of the separation of the Rivera and Cocos plates beneath western Mexico; the later period represents the more advanced stage of rifting where the Rivera and Cocos plates had separated sufficiently to allow melt to accumulate below the Colima Volcanic complex. During the earlier period (14 or 10–1.6 Ma), NE–SW-oriented structures/lineaments (such as the Southern Colima Rift) were formed as the two plates separated. During the second period (1.6 Ma to the present), the deformation is attributed to magma, generated within and above the tear zone between the Rivera and Cocos plates, rising beneath the region of the Colima Volcanic Complex. The rising magma fractured the overlying crust, forming a classic triple-rift junction geometry. This triple-rift system is confined to the mid- to lower crust perhaps indicating that this rifting process is still in an early stage. This fracturing, along with fluid circulation and associated heat advection within the fractures, can easily explain the observed distribution of δVp, as well as many of the results of previous seismological studies. Also surprisingly, we find no evidence at deep crustal depths to support either a trenchward migration of the volcanic arc or toroidal asthenospheric flow through the slab tears bounding the Jalisco Block to the NW and SE.
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- 2015
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33. Geometry of the Rivera–Cocos Subduction Zone Inferred from Local Seismicity
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Francisco Nuñez-Cornu, Christian R. Escudero, and Quiriat J. Gutierrez
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Geophysics ,Rift ,Subduction ,Geochemistry and Petrology ,Trench ,Slab window ,Slab ,North American Plate ,Geometry ,Induced seismicity ,Seismology ,Geology ,Earthquake location - Abstract
The Rivera microplate and the Cocos plate are subducting beneath the North American plate. To obtain new insights into the subduction geometry, we located earthquakes recorded by seismic stations deployed during the Mapping the Rivera Subduction Zone experiment from January 2006 to June 2007. We implemented standard procedures for earthquake location, and we also manually corrected phase detections and picks to increase accuracy of the earthquake catalog. We located about 2100 earthquakes within the 2.0–5.3 M L magnitude range. The average location error is 0.8 km horizontally and 1.0 km vertically, and the origin time has a mean error of 0.2 s. We observed crustal seismicity over the subducted Rivera microplate at no depth greater than 25 km; on the other hand, seismicity over the subducted Cocos plate is present to depths of 40 km. The Rivera plate shows a gently subduction angle near the trench, then dives more steeply into the mantle at an angle of 34° in the north and 37° in the south near the Colima graben. The distance between the inflection and the trench gradually increases from 40 km in the north of the study area to 60 km in the south near the Colima rift (CR). The Cocos plate has a slightly curved subducted slab with oblique geometry dipping toward the CR, ranging in dip from 18° in the south to 30° in the north.
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- 2015
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34. Evaluation of polyaniline-Nafion ® composite membranes for direct methanol fuel cells durability tests
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Enrique Fatás, L. Sotomayor, R. Escudero-Cid, Manuel Montiel, Pilar Ocón, and B. Loureiro
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Materials science ,Renewable Energy, Sustainability and the Environment ,Analytical chemistry ,Energy Engineering and Power Technology ,Condensed Matter Physics ,Durability ,Dielectric spectroscopy ,chemistry.chemical_compound ,Direct methanol fuel cell ,Fuel Technology ,Membrane ,chemistry ,Chemical engineering ,Nafion ,Polyaniline ,Methanol ,Methanol fuel - Abstract
A Nafion ® membrane has been both electrochemically and chemically modified in-situ to incorporate polyaniline (PANi) into its structure. The proposed objective was to decrease the methanol (MeOH) permeability and thus improve the durability of a direct methanol fuel cell device. Permeability and conductivity of the modified membranes were measured using the unmodified Nafion ® 117 as a reference. The permeability was determined from the electrochemical oxidation of permeated methanol, and the conductivity was determined via electrochemical impedance spectroscopy. To evaluate the effect of these modifications, the performance of a MeOH/O 2 single-cell was measured using different MeOH flows and concentrations. The device durability was evaluated under a constant potential and at different operating times. The power density, p , at high MeOH flows and concentrations was 7 times higher for the PANi-modified membrane than the unmodified Nafion ® 117. The durability of the modified membranes containing small amounts of PANi was 2 times higher using low MeOH flows and concentrations, while the power densities were similar. Impedance measurements were performed before and after the long-term durability tests in order to identify the improvements at the different parts of the fuel cell.
- Published
- 2015
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35. Modelo de gestión avanzada de regadíos. Uso de teledetección y sistemas de información geográfica para la optimización de recursos hídricos y mejorar la productividad de una comunidad de regantes. Proyecto I+D OPTIREG: Gestión eficiente en Regadíos
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R. Escudero Barbero, B. Sánchez Hernández, P. Fernández Pesado, and S. Iglesias Gómez
- Published
- 2018
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36. Transcorneal oxygen therapy for persistent hyphema in a patient with sickle cell disease
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R. Escudero-Igualada, L. Manfreda-Domínguez, R. Clemente-Tomás, P. Neira-Ibáñez, Antonio Duch-Samper, and Á. Olate-Pérez
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Male ,Intraocular pressure ,medicine.medical_specialty ,Visual acuity ,genetic structures ,Anterior Chamber ,medicine.medical_treatment ,Context (language use) ,Disease ,Anemia, Sickle Cell ,03 medical and health sciences ,0302 clinical medicine ,Eye Injuries ,Ophthalmology ,Oxygen therapy ,medicine ,Humans ,Child ,Hyphema ,Intraocular Pressure ,Sickle cell trait ,business.industry ,Corneal Edema ,General Medicine ,medicine.disease ,eye diseases ,Oxygen ,Left eye ,030221 ophthalmology & optometry ,sense organs ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Clinical case The case concerns a 10-year-old boy of African origin, who suffered a mild ocular trauma to the left eye. Upon examination, the best visual acuity was 0.2 using the Snellen scale, with a 1 mm height hyphema, intraocular pressure (IOP) of 12 mmHg on left eye, with an increase up to 20 mmHg within 72 h. With a positive test for sickle cell disease, it was decided to treat medically with transcorneal oxygen therapy. Clearing of the anterior chamber was achieved, with an improvement in the best visual acuity to 0.8, and lowering of IOP to 8 mmHg. Discussion In the context of patients with persistent hyphema with sickle cell trait, transcorneal oxygen therapy is an effective alternative therapy. Achieving immediate and favorable results by lowering the IOP and improving the clearing of the anterior chamber.
- Published
- 2018
37. CFD simulation of a sparger type venturi to generate bubbles in a two-phase flotation system
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J E Gembe Huaroco, R Escudero García, and H Arcos Gutiérrez
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- 2018
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38. Management of conjunctival perforation and late Seidel after XEN surgery
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A. Barreiro-Rego, Antonio Duch-Samper, V.T. Pérez-Torregrosa, A. Gargallo-Benedicto, Á. Olate-Pérez, R. Escudero-Igualada, and M. Cerdà-Ibáñez
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Intraocular pressure ,medicine.medical_specialty ,Conjunctiva ,Medical treatment ,business.industry ,medicine.medical_treatment ,Glaucoma ,Stent ,General Medicine ,Microsurgery ,medicine.disease ,Surgery ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,030221 ophthalmology & optometry ,medicine ,Implant ,business ,Complication ,030217 neurology & neurosurgery - Abstract
Clinical case The case concerns a 78 year-old woman with a history of XEN® surgery, in whom a conjunctival perforation was observed at the implant level at 18-months of follow-up, for which surgical intervention was decided. During surgery a short subconjunctival portion was found (0.5 mm). An unsuccessful attempt was made to extract it by traction, but the XEN® broke easily. Finally, it was decided to cut it to scleral level, and suture the conjunctiva. During the first week there was a decrease in intraocular pressure (6 mmHg), to subsequently increase to 25, and deciding to start medical treatment. Discussion Conjunctival exposure of the XEN® stent is a rare but potentially serious complication. To avoid it, a meticulous surgical technique is important when implanting it. If this occurs, it is important to identify the cause. If it is due to a short subconjunctival portion, a therapeutic alternative is to cut the implant at this level to avoid further complications.
- Published
- 2018
39. Poly (vinyl alcohol) and poly (benzimidazole) blend membranes for high performance alkaline direct ethanol fuel cells
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D. Herranz, Enrique Fatás, Carlos Palacio, R. Escudero-Cid, Manuel Montiel, Pilar Ocón, UAM. Departamento de Física Aplicada, and UAM. Departamento de Química Física Aplicada
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Alkaline ,Vinyl alcohol ,Materials science ,Blend membrane ,02 engineering and technology ,Electrolyte ,PBI ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Ethanol fuel ,Thermal stability ,Fuel cells ,chemistry.chemical_classification ,Potassium hydroxide ,Ion exchange ,Ethanol ,Renewable Energy, Sustainability and the Environment ,Física ,Polymer ,Química ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Membrane ,chemistry ,Chemical engineering ,PVA ,0210 nano-technology - Abstract
A series of poly(vinyl alcohol)-blend-poly(benzimidazole) (PVA:PBI) membranes are synthesized with different ratios of PVA and PBI (2:1, 4:1, 6:1 and 8:1) using the casting method. These materials are doped in KOH 6 M solution in order to study their suitability for fuel cell applications. The Infra-red (IR) and Raman spectra confirm the successful doping of the membranes and the dimensional changes due to water and KOH uptakes during the doping are similar to other PBI-based membranes. XPS measurements are performed to evaluate the characteristics of these materials after the doping process. The thermal stability of the membranes is excellent in the range of desired temperatures (below 100 °C) and the conductivity values found are between 10−2and 10−1S cm−1. These results are optimal to consider these membranes as candidates for anion exchange membranes (AEMs) and they are tested in a single cell with ethanol as fuel. The PVA:PBI 4:1 membrane have the best behaviour in fuel cell, reaching a power density of 76 mW cm−2, approximately 50% better than the doped PBI in the same conditions. These important results can be considered highly promising for the future application of these membranes in alkaline polymer electrolyte membrane fuel cells (APEMFC)., This work has been partially supported by the Spanish Ministry of Economy, Industry and Competitiveness (MINECO) under projects ENE2016-77055-C3-1-R and CTQ2015-68844-REDT, and by the Madrid Regional Research Council (CAM) under project S2013/MAE-2882 727 (RESTOENE-2).
- Published
- 2018
40. Effect of Solids on Gas Dispersion Characteristics: Addition of Hydrophobic and Hydrophilic Solids
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Francisco J. Tavera and R. Escudero
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Coalescence (physics) ,Materials science ,Chromatography ,Bubble ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,020401 chemical engineering ,Chemical engineering ,Slurry ,Bubble coalescence ,0204 chemical engineering ,0210 nano-technology ,Gas dispersion - Abstract
There is a controversy on the role of solids in flotation systems in terms of the characteristics of the solid-liquid-gas dispersions. The effect of slurries containing carbon or silica on the characteristics of gas-slurry dispersions generated in a flotation column was studied. Experimental results suggest that hydrophilic solids prevent bubbles coalescence, and produces large bubble surface areas, available to collide and collect particles during flotation. On the other hand slurries with hydrophobic particles produce larger bubbles, affecting both the performance and the hydrodynamics of the process.
- Published
- 2017
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41. Application of a non-noble Fe-N-C catalyst for oxygen reduction reaction in an alkaline direct ethanol fuel cell
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Luigi Osmieri, Stefania Specchia, R. Escudero-Cid, Pilar Ocón, Alessandro Hugo Monteverde Videla, and UAM. Departamento de Química Física Aplicada
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Cyclic voltammetry ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,Redox ,Oxygen ,Catalysis ,Rotating disk electrode ,chemistry.chemical_compound ,Anion exchange membrane fuel cell ,Hydrogen peroxide reduction ,Hydrogen peroxide ,Fe(II)phthalocyanine ,rotating disk electrode ,anion exchange membrane fuel cell ,stability ,hydrogen peroxide reduction ,cyclic voltammetry ,Fe(II)-phthalocyanine ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Física ,021001 nanoscience & nanotechnology ,Direct-ethanol fuel cell ,0104 chemical sciences ,0210 nano-technology ,Stability - Abstract
A Fe-N-C non-noble metal (NNM) catalyst for oxygen reduction reaction (ORR) was prepared via hard templating method using Fe(II)-phthalocyanine. Its electrochemical behavior towards the ORR was tested in alkaline conditions using cyclic voltammetry (CV) and rotating disk electrode (RDE) techniques. The kinetics of the reduction of the adsorbed oxygen, the selectivity, and the activity towards hydrogen peroxide reduction reaction (HPRR) were investigated. The ethanol tolerance and the stability in alkaline conditions were also assessed with the purpose to verify the good potentiality of this catalyst to be used in an alkaline direct ethanol fuel cell (DEFC). The results evidence that the ORR occurs mainly following the direct 4 e–reduction to OH−, and that the Fe-N-C catalyst is highly ethanol tolerant and shows a promising stability. The alkaline DEFC tests, performed after the optimization of the ionomer amount used for the preparation of the catalyst ink, show good results at low-intermediate currents, with a maximum power density of 62 mW cm−2. The initial DEFC performance can be partially recovered after a purge-drying procedure, This work was supported by the Madrid Regional Research Council (CAM) [RESTOENE-2 grant n. S2013/MAE2882], the Spanish Economy and Competitiveness Ministry [ENE2016 grant n. 77055-C3-1-R], and the Italian Ministry of Education, University and Research [PRIN NAMEDPEM grant n. 2010CYTWAW].
- Published
- 2017
- Full Text
- View/download PDF
42. Management of conjunctival perforation and late Seidel after XEN
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Á, Olate-Pérez, V T, Pérez-Torregrosa, A, Gargallo-Benedicto, R, Escudero-Igualada, M, Cerdà-Ibáñez, A, Barreiro-Rego, and A, Duch-Samper
- Subjects
Postoperative Complications ,Humans ,Female ,Stents ,Glaucoma Drainage Implants ,Conjunctiva ,Glaucoma, Open-Angle ,Aged ,Prosthesis Failure - Abstract
The case concerns a 78 year-old woman with a history of XENConjunctival exposure of the XEN
- Published
- 2017
43. Degradation of DMFC using a New Long-Term Stability Cycle
- Author
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Enrique Fatás, R. Escudero-Cid, Juan Carlos Pérez-Flores, and Pilar Ocón
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Materials science ,Renewable Energy, Sustainability and the Environment ,Electronic engineering ,Analytical chemistry ,Degradation (geology) ,Context (language use) ,Polarization (electrochemistry) ,Methanol fuel ,Power (physics) ,Voltage ,Dielectric spectroscopy ,Anode - Abstract
The understanding of the degradation mechanisms involved in the performance of direct methanol fuel cells (DMFCs), constitute important matter for the future implementation of this technology. In this context, it is necessary to develop new and reliable analysis tools to simulate realistic operating conditions. To reflect these, the present study used a “start-run-stop-run’” (SRSR’) test in three different characteristic voltages (at open-circuit potential (OCP), 0.3, and 0.1 V). The electrical loss performance at different operating times (0, 22, 40, and 60 h) working under SRSR’ test was followed by analysis of polarization curves and electrochemical impedance spectroscopy (EIS). The results reveal a decrease of 65% in the maximum density power, 30 mW/cm2, with a degradation rate of 1.2 mV/h at 50 mA/cm2. In addition, the contribution to the overall loss of fuel-cell performance was observed to follow the order: anode reaction > cathode reaction > IR resistance. Ex situ characterizations confirm this re...
- Published
- 2014
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44. Acoustic fluidized bed hydrodynamics characterization using X-ray computed tomography
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Theodore J. Heindel and David R. Escudero
- Subjects
Materials science ,General Chemical Engineering ,Multiphase flow ,Mineralogy ,General Chemistry ,Electrical capacitance tomography ,Mechanics ,Industrial and Manufacturing Engineering ,Local Void ,Fluidized bed ,Environmental Chemistry ,Particle size ,Fluidization ,Tomography ,Sound pressure - Abstract
Acoustic vibration in a fluidized bed can be used to enhance the fluidization quality of particulate matter; this particular noninvasive method provides no internal changes to the bed material structure. However, due to the complexity of this multiphase flow system, characterizing the hydrodynamics of a fluidized bed has become critical in understanding this system behavior. The local void fraction behavior in a cold flow 3D fluidized bed with and without acoustic intervention is investigated in this research. Several noninvasive techniques like gamma-ray computed tomography (GRT), X-ray computed tomography (XCT), or electrical capacitance tomography (ECT), can be used to study the void fraction distribution in multiphase flow systems. In this study, XCT imaging is used to determine the time-average local void fraction or gas holdup. Experiments are implemented in a 10.2 cm ID fluidized bed filled with glass beads or ground walnut shell, having a material density of 2500 kg/m 3 and 1440 kg/m 3 , respectively, and particle size ranges between 212 and 600 μm. In this study, three different bed height-to-diameter ratios are examined: H/D = 0.5, 1 and 1.5. The loudspeaker’s frequency, used as the acoustic source, is fixed at 150 Hz with a sound pressure level of 120 dB for glass beads, and 200 Hz and 110 dB for ground walnut shell. Local time-average gas holdup results show that the fluidized bed under the presence of an acoustic field provides a more uniform fluidization, the bed exhibits less channeling, and the jetting phenomena produced by the distributor plate is less prominent when compared to no acoustic field. Thus, acoustic intervention affects the local hydrodynamic behavior of the fluidized bed.
- Published
- 2014
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45. The effect of functionalised multi-walled carbon nanotubes in the hydrogen electrooxidation reaction in reactive currents impurified with CO
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Ana Sofia Varela, P. Hernández-Fernández, Pilar Ocón, Enrique Fatás, and R. Escudero-Cid
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,Proton exchange membrane fuel cell ,Nanotechnology ,Carbon nanotube ,Condensed Matter Physics ,Cathode ,law.invention ,Dielectric spectroscopy ,Catalysis ,Anode ,Fuel Technology ,Chemical engineering ,law ,Electrode ,Rotating disk electrode - Abstract
The present article investigates the tolerant effect exerted by a functionalised multi-walled carbon nanotube (MWCNT) support compared with the Vulcan XC-72 support for a nanoparticulate Pt catalyst. The negative effect produced in the hydrogen oxidation reaction (HOR) by the presence of a Pt contaminated with high CO coverage was analysed. This investigation was conducted using a rotating disk electrode (RDE) and a single cell with membrane electrode assemblies (MEAs) with loads of 0.3 mg Pt/cm 2 for the anode and 0.6 mg Pt/cm 2 for the cathode at various poisoning times. To this end, polarisation curves were performed, and electrochemical impedance spectroscopy (EIS) measurements were analysed. In addition, the recovery of the poisoning/de-poisoning process was studied. The –OH groups anchored to the MWCNT support exert a protective effect on the Pt nanoparticles, making the catalyst more efficient in a PEMFC fed with H 2 + CO.
- Published
- 2014
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46. Nefropatía aguda por oxalato y pancreatitis crónica
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R. Escudero-Sánchez, J. Villacorta-Pérez, M. Fernández Gil, M.C. Guerrero-Márquez, and G.M. Fernández-Juarez
- Subjects
medicine.medical_specialty ,business.industry ,Internal medicine ,MEDLINE ,Medicine ,Pancreatitis ,General Medicine ,business ,medicine.disease ,Gastroenterology - Published
- 2015
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47. Tumor de células granulares de mama. Un diagnóstico que se debe considerar
- Author
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R. Escudero Esteban, G. del Estad Cabello, P. Yáñez Fernández, and S. Gomez Benitez
- Subjects
medicine.medical_specialty ,Pathology ,medicine.diagnostic_test ,business.industry ,Wide local excision ,medicine.medical_treatment ,Ultrasound ,medicine.disease ,Breast cancer screening ,Granular cell ,Breast cancer ,medicine ,Mammography ,Radiology, Nuclear Medicine and imaging ,Histopathology ,skin and connective tissue diseases ,Breast carcinoma ,business - Abstract
The granular cell tumour is a very rare tumour which originates in the Schwann cells, and is generally benign. It is usually located in the head and neck, and its appearance in the breast is uncommon. Although it is rare tumour, granular cell tumours of the breast have a higher prevalence than previously recognised. This tumour usually imitates breast cancer due to its clinical and imaging data, with its diagnosis being by histopathology. The treatment is a wide local excision, and its prognosis is good with a low recurrence rate. We present two cases of granular tumours of the breast in post-menopausal women that simulated a breast carcinoma in the ultrasound and mammography. The first was detected in the breast cancer screening program, and the second during follow up of an invasive ductal carcinoma.
- Published
- 2014
- Full Text
- View/download PDF
48. Nephrogenic Systemic Fibrosis Risk and Liver Disease
- Author
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Martin R. Prince, Stephen M. Lagana, Daniel S. Chow, Lee A. Finkelstone, Robert F. Hanna, Mark R. Escudero, and Vesselin Z. Miloushev
- Subjects
medicine.medical_specialty ,Pathology ,Cirrhosis ,Article Subject ,business.industry ,Incidence (epidemiology) ,Gadodiamide ,lcsh:Diseases of the genitourinary system. Urology ,lcsh:RC870-923 ,medicine.disease ,Gastroenterology ,Transplantation ,Liver disease ,Nephrology ,Nephrogenic systemic fibrosis ,Hepatocellular carcinoma ,Internal medicine ,Clinical Study ,medicine ,Risk factor ,business ,medicine.drug - Abstract
Objective. Evaluate the incidence of nephrogenic systemic fibrosis (NSF) in patients with liver disease in the peritransplant period.Materials and Methods. This IRB approved study retrospectively reviewed patients requiring transplantation for cirrhosis, hepatocellular carcinoma (HCC), or both from 2003 to 2013. Records were reviewed identifying those having gadolinium enhanced MRI within 1 year of posttransplantation to document degree of liver disease, renal disease, and evidence for NSF.Results. Gadolinium-enhanced MRI was performed on 312 of 837 patients, including 23 with severe renal failure (GFR < 30 mL/min/1.73 cm2) and 289 with GFR > 30. Two of 23 patients with renal failure developed NSF compared to zero NSF cases in 289 patients with GFR > 30 (0/289;P<0.003). High dose gadodiamide was used in the two NSF cases. There was no increased incidence of NSF with severe liver disease (1/71) compared to nonsevere liver disease (1/241;P=0.412).Conclusion. Renal disease is a risk factor for NSF, but in our small sample our evidence suggests liver disease is not an additional risk factor, especially if a low-risk gadolinium agent is used. Noting that not all patients received high-risk gadolinium, a larger study focusing on patients receiving high-risk gadolinium is needed to further evaluate NSF risk in liver disease in the peritransplant period.
- Published
- 2014
- Full Text
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49. Relative Source Time Function Studies of Earthquakes along the Denali-Totschunda Fault System
- Author
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Christian R. Escudero and Diane I. Doser
- Subjects
Seismic gap ,geography ,Focal mechanism ,geography.geographical_feature_category ,Source time function ,Bedrock ,Magnitude (mathematics) ,Fault (geology) ,Geophysics ,Geochemistry and Petrology ,Seismic moment ,Geology ,Seismology ,Aftershock - Abstract
We use the relative source time function method to estimate the source properties of aftershocks of the November 2002 Denali earthquake sequence to determine if there are systematic variations in scaling relationships of these events that can be related to seismic moment, focal mechanism, event date/time and location along the fault, and bedrock type. Our results show self‐similarity over earthquakes of magnitude less than five and stress‐drop dependence on focal mechanism. Strike‐slip events appear to have larger stress drops. We observed a clear stress‐drop decrease from west to east that correlates with changes in earthquake focal mechanisms along the Denali fault.
- Published
- 2013
- Full Text
- View/download PDF
50. Minimum fluidization velocity in a 3D fluidized bed modified with an acoustic field
- Author
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Theodore J. Heindel and David R. Escudero
- Subjects
Materials science ,General Chemical Engineering ,General Chemistry ,Mechanics ,Industrial and Manufacturing Engineering ,Vibration ,Creep ,Fluidized bed ,Mass transfer ,Environmental Chemistry ,Particle ,Geotechnical engineering ,Fluidization ,Sound pressure ,Audio frequency - Abstract
Fluidized beds are used in a variety of process industries because they provide uniform temperature distributions, low pressure drops, and high heat/mass transfer rates. Minimum fluidization velocity is an important factor in understanding the hydrodynamic behavior of fluidized beds, and this characteristic may be modified through high frequency (sound) vibrations. The effects caused by sound wave frequency and sound pressure level on the minimum fluidization velocity in a 3D fluidized bed are investigated in this study. Experiments are carried out in a 10.2 cm ID cold flow fluidized bed filled with either glass beads or ground walnut shell, and particle sizes ranged between 212 and 600 μm. In this study, four different bed height-to-diameter ratios are examined: H/D = 0.5, 1, 1.5, and 2. Moreover, the sound frequency of the loudspeaker used as the acoustic source ranged between 50 and 200 Hz, and the sound pressure level ranged 90–120 dB. Results show that the minimum fluidization velocity is influenced by the frequency change. As the frequency increases, the minimum fluidization velocity decreases until a specific frequency is reached, beyond which the minimum fluidization velocity increases. With increasing sound pressure level, the minimum fluidization velocity decreases because the additional vibration forces imparted to the bed particles helps to loosen the bed, reducing the interparticle forces, which reduces the required energy for particle fluidization. Thus, acoustic fields provide an improvement in the ease of fluidization of these particles.
- Published
- 2013
- Full Text
- View/download PDF
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