492 results on '"A. Kieger"'
Search Results
2. Effect of yttrium on the performances of zirconia based catalysts for the decomposition of N2O at high temperature
- Author
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Granger, P., Esteves, P., Kieger, S., Navascues, L., and Leclercq, G.
- Published
- 2006
- Full Text
- View/download PDF
3. Catalytic reduction of N2O by NH3 in presence of oxygen using Fe‐exchanged zeolites
- Author
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Mauvezin, M., Delahay, G., Kißlich, F., Coq, B., and Kieger, S.
- Published
- 1999
- Full Text
- View/download PDF
4. Adrenal Gland Hemangioma
- Author
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Kieger, Alexander J., Nikolaidis, Paul, and Casalino, David D.
- Published
- 2011
- Full Text
- View/download PDF
5. Kinetics of the selective catalytic reduction of NO by NH3 on a Cu-faujasite catalyst
- Author
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Delahay, Gérard, Kieger, Stéphane, Tanchoux, Nathalie, Trens, Philippe, and Coq, Bernard
- Published
- 2004
- Full Text
- View/download PDF
6. Selective Catalytic Reduction of Nitrous Oxide by Ammonia on Iron Zeolite Beta Catalysts in an Oxygen Rich Atmosphere: Effect of Iron Contents
- Author
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Delahay, G, Mauvezin, M, Coq, B, and Kieger, S
- Published
- 2001
- Full Text
- View/download PDF
7. Kinetics and Mechanism of the N2O Reduction by NH3 on a Fe-Zeolite-Beta Catalyst
- Author
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Coq, Bernard, Mauvezin, Mathias, Delahay, Gérard, and Kieger, Stephane
- Published
- 2000
- Full Text
- View/download PDF
8. The simultaneous catalytic reduction of NO and N2O by NH3 using an Fe-zeolite-beta catalyst
- Author
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Coq, Bernard, Mauvezin, Mathias, Delahay, Gérard, Butet, Jean-Baptiste, and Kieger, Stephane
- Published
- 2000
- Full Text
- View/download PDF
9. Influence of co-cations in the selective catalytic reduction of NO by NH3 over copper exchanged faujasite zeolites
- Author
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Kieger, Stéphane, Delahay, Gérard, and Coq, Bernard
- Published
- 2000
- Full Text
- View/download PDF
10. A new mechanism for the selective catalytic reduction of NOx by NH3 on Cu-zeolite catalysts
- Author
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Coq, B., Kieger, S., Delahay, G., Berthomieu, D., and Goursot, A.
- Published
- 2000
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- View/download PDF
11. The selective catalytic reduction of N2O by NH3 on a Fe-BEA Catalyst
- Author
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Mauvezin, Mathias, Delahay, Gérard, Coq, Bernard, and Kieger, Stephane
- Published
- 2000
- Full Text
- View/download PDF
12. Selective Catalytic Reduction of Nitric Oxide by Ammonia over Cu-FAU Catalysts in Oxygen-Rich Atmosphere
- Author
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Kieger, Stéphane, Delahay, Gérard, Coq, Bernard, and Neveu, Bernard
- Published
- 1999
- Full Text
- View/download PDF
13. 3:36 PM Abstract No. 312 Primary versus secondary retrograde pedal access for lower extremity peripheral vascular disease
- Author
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Bagla, S., Shah, S., Sajan, A., Kieger, A., and Piechowiak, R.
- Published
- 2020
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14. Completely Unacceptable Levels in Conjoint Analysis: A Cautionary Note.
- Author
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Green, Paul E., Kieger, Abba M., and Bansal, Pradeep
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CONJOINT analysis ,MARKETING research ,PREDICTION models ,MARKETING models ,MATHEMATICAL models ,DECISION making ,INDUSTRIAL design ,UTILITY functions ,DISTRIBUTION (Probability theory) ,QUESTIONNAIRES - Abstract
An experiment is reported on the extent to which respondents adhere to the implications of choosing the "completely unacceptable" level in hybrid conjoint (and related) applications. The findings indicate that the form of the instructions matters, but that respondents often ignore the implications of previous responses when responding to full-profile options containing unacceptable attribute levels. The authors discuss the impact of this inconsistency on internal predictive validity in both empirical and theoretical terms. [ABSTRACT FROM AUTHOR]
- Published
- 1988
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15. Abstract No. 443 Pedal access for retrograde lower extremity peripheral arterial disease in an outpatient based lab (OBL) setting
- Author
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Smirniotopoulos, J., Piechowiak, R., Kieger, A., Shah, S., and Bagla, S.
- Published
- 2019
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16. Abstract No. 651 Identifying
- Author
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Dunlap, R., Demmert, A., Kieger, A., Bishop, C., and Holly, B.
- Published
- 2018
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17. Abstract No. 655 - CT-guided intramuscular Botox injection in the treatment of chronic pelvic pain: patient outcomes and safety profile
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Minwell, G., Kieger, A., Marker, D., and Hong, K.
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- 2016
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18. Abstract No. 596 - CT-guided intramuscular Botox injection and the evolving chronic pelvic pain practice paradigm
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Kieger, A., Marker, D., and Hong, K.
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- 2016
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19. Hybridization-Induced 'Off-On' 19F-NMR Signal Probe Release from DNA-Functionalized Gold Nanoparticles.
- Author
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Kieger, Alexander, Wiester, Michael J., Procissi, Daniel, Parrish, Todd B., Mirkin, Chad A., and Thaxton, C. Shad
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- 2011
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20. Antibiotic Management of Staphylococcal Osteomyelitis: WITH PARTICULAR REFERENCE TO ANTIBIOTIC-RESISTANT INFECTIONS
- Author
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MEYER, THOMAS L., KIEGER, A. BILL, and SMITH, WILLIAM S.
- Published
- 1965
21. Catalytic reduction of N2O by NH3 in presence of oxygen using Fe exchanged zeolites.
- Author
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Mauvezin, M., Delahay, G., Kißlich, F., Coq, B., and Kieger, S.
- Abstract
The influence of ammonia on the reduction of N
2 O in presence of oxygen over Fe zeolite has been studied. It is found that BEA zeolite is the most efficient host structure for iron ions to catalyse the reduction of N2 O with NH3 . [ABSTRACT FROM AUTHOR]- Published
- 1999
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22. Aluminum toxicity in tomato. Part 2. leaf gas exchange, chlorophyll content, and invertase activity.
- Author
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Simon, L., Kieger, M., Sung, S. S., and Smalley, T. J.
- Published
- 1994
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23. A Tautomeric Pair of 2,2-Dimethyl-6-carbamoyl-9-phenyldihydropurines.
- Author
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Beagley, B., Booth, B. L., Eastwood, P. R., Kieger, S., Pritchard, R. G., Alves, M. J., Carvalho, A., and Proença, M. F. J. R. P.
- Published
- 1995
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24. Kinetics of the selective catalytic reduction of NO by NH3 on a Cu-faujasite catalyst
- Author
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Delahay, Gérard, Kieger, Stéphane, Tanchoux, Nathalie, Trens, Philippe, and Coq, Bernard
- Subjects
- *
NITRIC oxide , *AMMONIA , *COPPER , *ZEOLITES - Abstract
The kinetics of the selective catalytic reduction (SCR) of NO by NH3 in the presence of O2 has been studied on a 5.5% Cu-faujasite (Cu-FAU) catalyst. Cu-FAU was composed of cationic and oxocationic Cu species. The SCR was studied in a gas phase-flowing reactor operating at atmospheric pressure. The reaction conditions explored were:
458 K, 250 (ppm) < 3000, 1000 (ppm) < 4000, 1 (%) < 4. The kinetic orders were 0.8–1 with respect to NO, 0.5–1 with respect to O2, and essentially 0 with respect to NH3. Based on these kinetic partial orders of reactions and elementary chemistry, a wide variety of mechanisms were explored, and different rate laws were derived. The best fit between the measured and calculated rates for the SCR of NO by NH3 was obtained with a rate law derived from a redox Mars and van Krevelen mechanism. The catalytic cycle is described by a sequence of three reactions: (i) CuI is oxidized by O2 to “CuII-oxo”, (ii) “CuII-oxo” reacts with NO to yield “CuII-NxOy”, and (iii) finally “CuII-NxOy” is reduced by NH3 to give N2, H2O, and the regeneration of CuI (closing of the catalytic cycle). The rate constants of the three steps have been determined at 458, 483, and 513 K. It is shown that CuI or “CuII-oxo” species constitute the rate-determining active center. [Copyright &y& Elsevier] - Published
- 2004
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25. Wasserstoff-Plasma-Schmelzreduktion: Ein alternativer Weg zur Stahlerzeugung?
- Author
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Plaul, J. F. and Kieger, W.
- Abstract
Copyright of BHM Berg- und Hüttenmännische Monatshefte is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2004
26. A case of adrenal cavernous hemangioma resected due to tumor growth accompanied by intratumoral hemorrhage.
- Author
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Ueda, Takayuki, Yanagi, Masato, Kusakabe, Takashi, Shigihara, Takeshi, Shibasaki, Mikio, Nagasawa, Masato, Hamasaki, Tsutomu, and Kondo, Yukihiro
- Published
- 2024
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27. Progress and challenges in nitrous oxide decomposition and valorization.
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Wu, Xuanhao, Du, Jiaxin, Gao, Yanxia, Wang, Haiqiang, Zhang, Changbin, Zhang, Runduo, He, Hong, Lu, Gaoqing (Max), and Wu, Zhongbiao
- Subjects
GREENHOUSE gases ,OZONE layer depletion ,CARBON offsetting ,CLEAN energy ,EMISSION control - Abstract
Nitrous oxide (N
2 O) decomposition is increasingly acknowledged as a viable strategy for mitigating greenhouse gas emissions and addressing ozone depletion, aligning significantly with the UN's sustainable development goals (SDGs) and carbon neutrality objectives. To enhance efficiency in treatment and explore potential valorization, recent developments have introduced novel N2 O reduction catalysts and pathways. Despite these advancements, a comprehensive and comparative review is absent. In this review, we undertake a thorough evaluation of N2 O treatment technologies from a holistic perspective. First, we summarize and update the recent progress in thermal decomposition, direct catalytic decomposition (deN2 O), and selective catalytic reduction of N2 O. The scope extends to the catalytic activity of emerging catalysts, including nanostructured materials and single-atom catalysts. Furthermore, we present a detailed account of the mechanisms and applications of room-temperature techniques characterized by low energy consumption and sustainable merits, including photocatalytic and electrocatalytic N2 O reduction. This article also underscores the extensive and effective utilization of N2 O resources in chemical synthesis scenarios, providing potential avenues for future resource reuse. This review provides an accessible theoretical foundation and a panoramic vision for practical N2 O emission controls. [ABSTRACT FROM AUTHOR]- Published
- 2024
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28. Direkte Demokratie - Möglichkeiten und Grenzen.
- Author
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Kieger, Heinz
- Published
- 1996
29. N 2O decomposition in the presence of ammonia on faujasite-supported metal catalysts
- Author
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Mauvezin, Mathias, Delahay, Gérard, Coq, Bernard, and Kieger, Stéphane
- Published
- 1999
- Full Text
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30. Rare Case of Adrenal Hemangioma Discovered Incidentally during Renal Colic Investigation.
- Author
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Almajed, Ebtesam H., Alshamrani, Abdullah M., Alqahtani, Adel S., Alzahrani, Abdulrahman J., Alahmadi, Thamer, and Asiri, Shuaa M.
- Subjects
ADRENAL tumors ,MAGNETIC resonance imaging ,HEMANGIOMAS ,SYMPTOMS ,RENAL colic ,VASCULAR endothelium ,ADRENAL glands - Abstract
Objective: Rare disease Background: Hemangiomas of the adrenal gland are rare benign non-functional tumors arising from the gland's vascular endothelium. Adrenal hemangiomas are rare in clinical settings, often discovered incidentally during an unrelated diagnostic investigation. Case Report: A 39-year-old man presented with a heterogeneous, enhancing 4.56×4.24×3.9-cm mass originating from the right adrenal gland's lateral limb, discovered incidentally on computed tomography (CT) to investigate renal colic. He was routinely followed up for 2 years with serial CT scans; the mass exhibited considerable growth compared with baseline, with a relatively stable appearance with hyperdense soft tissue component, fat, and foci of calcification. Dexamethasone suppression test demonstrated suppressed cortisol response, indicating a non-functional mass. Therefore, laparoscopic right adrenalectomy was performed, owing to the benign nature of the preoperative diagnosis of myelolipoma and mass size. The patient experienced an uneventful recovery, with no perioperative complications. The resected mass was 5×4×4 cm in size and weighed 30 g. Histopathology confirmed adrenal hemangioma. Serial sectioning revealed an encapsulated lesion with heterogeneous solid and cystic surfaces. Light microscopy examination showed dilated and congested vascular channels lined by flattened endothelium. Focal mature adipose tissue was seen. Conclusions: The infrequent occurrence of adrenal hemangiomas and their nonspecific clinical and radiological presentation results in a considerable diagnostic challenge and, often, misdiagnosis. Surgical resection is usually necessary to exclude malignant disease, alleviate pressure-related symptoms, and decrease risk of retroperitoneum hemorrhage. These lesions are associated with a good prognosis. One limitation of this report is the lack of preoperative adrenal magnetic resonance imaging of the incidental adrenal mass. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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31. Den Ruhestand absichern neben Versorgungswerk.
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- 2024
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32. Anticipatory duties under the human right to science and international biomedical law.
- Author
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Yotova, Rumiana
- Subjects
INTERNATIONAL law ,INTERNATIONAL environmental law ,ANTHROPOSOPHY ,HUMAN rights ,MEDICAL sciences ,MEDICAL technology - Abstract
This paper assesses the interplay between international human rights law and international biomedical law as two specialised regimes within international law. The focus lies specifically on the anticipatory duties arising under the human right to benefit from science and its applications on the one side and under international biomedical law on the other. International biomedical law instruments adopt a human rights-based approach to the regulation of biology and medicine, so one of the questions is whether the anticipatory duties in biomedical law are indeed a specific application of the corresponding duties in international human rights law, modified, expanded and elaborated further to better address the distinctive subject matter, namely, the interface between the individual and science and technology in a medical context? Or whether the anticipatory duties in international biomedical law draw from international environmental law and/or general international law? The main question that this paper aims to address concerns the precise scope and content of the anticipatory duties under international biomedical law and their relationship to human rights. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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33. 30-P-06-Effect of the reductant nature on the catalytic removal of N2O on a Fe-zeolite-beta catalyst
- Author
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Delahay, G., Mauvezin, M., Coq, B., and Kieger, S.
- Published
- 2001
- Full Text
- View/download PDF
34. New Insights into the Effect of Ce Doping on the Catalytic Performance and Hydrothermal Stability of Cu-USY Zeolite Catalysts for the Selective Catalytic Reduction of NO with NH 3.
- Author
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Sun, Qi, Yang, Haipeng, Wan, Jie, Hua, Wanru, Liu, Yanjun, Wang, Xiaoli, Shi, Chunxiao, Shi, Qingai, Wu, Gongde, and Zhou, Renxian
- Subjects
ZEOLITE catalysts ,CATALYTIC doping ,CATALYTIC reduction ,NEAR infrared reflectance spectroscopy ,X-ray photoelectron spectroscopy ,ZEOLITES ,CATALYSIS ,NITRITES - Abstract
5Cu-USY and Ce-doped 5Cu8Ce-USY zeolite catalysts were prepared by the conventional impregnation method. The obtained catalysts were subjected to the hydrothermal ageing process. The catalytic performance of the selective catalytic reduction of NO
x with NH3 (NH3 -SCR) was evaluated on both fresh and aged catalysts. Physical/chemical characterizations such as X-ray diffraction (XRD), H2 temperature-programmed reduction (H2 -TPR), and X-ray photoelectron spectroscopy (XPS) were performed, along with detailed in situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) experiments including CO adsorption, NH3 adsorption, and NO + O2 reactions. Results showed that, for the 5Cu-USY catalyst, hydrothermal ageing treatment could somehow improve the low-temperature SCR activity, but it also led to significant formation of unfavorable byproducts NO2 and N2 O. Such an activity change can be attributed to hydrothermal ageing inducing the migration of isolated Cu+ species in the sodalite cavities towards the super cages of the USY zeolites. The increased content of Cu+ species in the super cages was beneficial for the low-temperature activity improvement, but, at the same time, it also facilitated ammonia oxidation at high temperatures. Ce doping after hydrothermal ageing has a "double-edged sword" effect on the catalytic performance. First of all, Ce doping can inhibit Cu species migration by self-occupying the internal cage sites; thus, the catalytic performance of 5Cu8Ce-USY-700H remains stable after ageing. Secondly, Ce doping introduces a CuOx –CeO2 strong interaction, which facilitates lattice oxygen mobility by forming more oxygen vacancies so as to increase the concentration of surface active oxygen. These changes, on the one hand, could help to promote further oxidative decomposition of nitrate/nitrite intermediates and improve the catalytic performance. But, on the other hand, it also causes the byproduct generation to become more severe. [ABSTRACT FROM AUTHOR]- Published
- 2023
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35. Fabrication of Cu–Ce/FDU-12 Catalyst with Outstanding NH3–SCR Performance.
- Author
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Liu, Hanyu, Yang, Jian, Li, Zhifang, Cui, Jinxing, Yang, Changlong, and Ma, Yuanyuan
- Abstract
Al modified FDU-12 molecular sieve (Al–FDU-12) was successfully prepared by hydrothermal method and then Cu/Al–FDU-12 and Cu–Ce/Al–FDU-12 denitrification catalysts were synthesized using the impregnation process. Through experiment investigated was the impact on the NH
3 –SCR (selective catalytic reduction of NO with NH3 as the reductant) activity of different loadings of active component. The sulfur tolerance of the catalyst was also investigated. The results exhibited that the optimal loadings of Cu and Ce were 20 and 10%, respectively. The NOx conversion of Cu20Ce10/Al–FDU-12 reached 80%, while its N2 selectivity was over 99% at 250°C. The addition of Ce can improve the redox characteristics as well as the amount of surface chemisorbed oxygen, which facilitated the "FAST SCR" reaction. In addition, Cu+ is preferentially oxidized to form Cu2+ , NOx is combined with Cu2+ to form the active intermediate Cu2+ –Nx Oy and further reacts with NH3 to generate N2 and H2 O, yet Cu+ , thus promoting the catalytic cycle. What's more, the catalyst had good catalytic activity when SO2 was introduced. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
36. Entropic influence on the generation of Fe(IV)O species at mononuclear Fe(II) sites in metal-organic frameworks.
- Author
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Saiz, Fernan and Bernasconi, Leonardo
- Published
- 2023
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37. Looking for future biological control agents: the comparative function of the deutosternal groove in mesostigmatid mites.
- Author
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Bowman, Clive E.
- Subjects
BIOLOGICAL pest control agents ,WAVES (Fluid mechanics) ,VISCOUS flow ,LAMINAR flow ,PIPE flow ,MICROCHANNEL flow ,QUARRIES & quarrying - Abstract
The physics of fluid laminar flow through an idealised deutosternum assembly is used for the first time to review predatory feeding designs over 72 different-sized example species from 16 mesostigmatid families in order to inform the finding of new biological control agents. Gnathosomal data are digitised from published sources. Relevant gnathosomal macro- and micro-features are compared and contrasted in detail which may subtly impact the control of channel- or 'pipe'-based transport of prey liquids around various gnathosomal locations. Relative deutosternal groove width on the mesostigmatid subcapitulum is important but appears unrelated to the closing velocity ratio of the moveable digit. Big mites are adapted for handling large and watery prey. The repeated regular distance between deutosternal transverse ridges ('Querleisten') supports the idea of them enabling a regular fluctuating bulging or pulsing droplet-based fluid wave 'sticking' and 'slipping' along the groove. Phytoseiids are an outlier functional group with a low deutosternal pipe flow per body size designed for slot-like microchannel transport in low volume fluid threads arising from daintily nibbling nearby prey klinorhynchidly. Deutosternal groove denticles are orientated topographically in order to synergise flow and possible mixing of coxal gland-derived droplets and circumcapitular reservoir fluids across the venter of the gnathosomal base back via the hypostome to the prey being masticated by the chelicerae. As well as working with the tritosternum to mechanically clean the deutosternum, denticles may suppress fluid drag. Shallow grooves may support edge-crawling viscous flow. Lateral features may facilitate handling unusual amounts of fluid arising from opportunistic feeding on atypical prey. Various conjectures for confirmatory follow-up are highlighted. Suggestions as to how to triage non-uropodoid species as candidate plant pest control agents are included. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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38. A systematic DFT screening of cationic faujasitetype zeolites for the adsorption of NO, NO2 and H2O.
- Author
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Karamanis, Ioannis, Daouli, Ayoub, Monnier, Hubert, Dziurla, Marie-Antoinette, Maurin, Guillaume, and Badawi, Michael
- Published
- 2023
- Full Text
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39. Advancements in low-temperature NH3-SCR of NOx using Ba-based catalysts: a critical review of preparation, mechanisms, and challenges.
- Author
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Ogugua, Paul Chinonso, Wang, Enlu, Jinyang, Zhou, Wang, Qi, and Su, Huihui
- Subjects
DIESEL motor exhaust gas ,CATALYSTS ,ATMOSPHERIC ammonia ,ACTIVATION energy ,CARBON monoxide ,SURFACE reactions ,ELECTROCATALYSIS - Abstract
Presently, selective catalytic reduction (SCR), with either carbon monoxide, urea, hydrocarbons, hydrogen, or ammonia as a reductant, has become a nitrogen oxide (NO
x ) removal technology (NOx conversion) of many catalytic companies and diesel engine exhaust gas. Although, there exists a serious threat of low-temperature limitations. So far, certain scientists have shown that barium-based (Ba-based) catalysts have the potential to be highly effective at SCR of NOx at low temperatures when ammonia is used as the reducing agent. The process of NOx storage and reduction which alternate SCR is known as the Lean NOx trap. Herein, we give the condensed advancements and production of the catalysts that involve BaO in low-temperature NH3 -SCR of NOx , the advantages of BaO catalysts compared to the recently hot electrocatalysis, the stability of BaO catalyst materials, and the condensed advancements and production of the catalysts that involve BaO in low-temperature NH3 -SCR of NOx . These catalysts are viewed in the light of their preparation method, particulate, and posture in mixed oxides. Also, the characteristic features of Ba-based catalysts are carefully considered and briefed under the following areas: preparation method and precursor, crystallinity, calcination temperature, morphology, acid sites, the specific surface area for reaction, redox property, and activation energy of catalysts. More to these are the discussions on Eley–Rideal [E-R] and Langmuir–Hinshelwood [L–H] mechanisms, the H2 O/SO2 and O2 permissiveness, and the NH3 -SCR reaction mechanism over Ba-based catalysts highlighting their possible effects. Finally, we proposed the prospect and the likely future research plan for the low-temperature NH3 -SCR of NOx . [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
40. Mechanistic Insight into the Propane Oxidation Dehydrogenation by N 2 O over Cu-BEA Zeolite with Diverse Active Site Structures.
- Author
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Wu, Ruiqi, Liu, Ning, Dai, Chengna, Xu, Ruinian, Yu, Gangqiang, Wang, Ning, and Chen, Biaohua
- Subjects
COPPER ,DEHYDROGENATION ,ZEOLITE catalysts ,ZEOLITES ,ACTIVATION energy - Abstract
The present work theoretically investigated propane oxidation dehydrogenation by utilizing N
2 O as an oxidant (N2 O-ODHP) over Cu-BEA with three different types of active site, including monomeric Cu ([Cu]+ ), dimeric Cu ([Cu−Cu]2+ ), and distant monomeric Cu sites ([Cu]+ —[Cu]+ ). Energetically, we calculated that the monomeric [Cu]+ is favorable for the αH dehydrogenation step (∆E = 0.05 eV), which, however, suffers from high barriers of N2 O dissociation and βH dehydrogenation steps of 1.40 and 1.94 eV, respectively. Although the dimeric [Cu−Cu]2+ site with a Cu—Cu distance of 4.91 Å is much more favorable for N2 O dissociation (0.95 eV), it still needs to overcome an extremely high barrier (∆E = 2.15 eV) for βH dehydrogenation. Interestingly, the distant [Cu]+ —[Cu]+ site with the Cu—Cu distance of 5.82 Å exhibits low energy barriers for N2 O dissociation (0.89 eV) and ODHP steps (0.01 and 0.33 eV) due to the synergistic effect of distant [Cu]+ . The microkinetic analyses quantitatively verified the superior activity of the distant [Cu]+ —[Cu]+ site with a reaction rate being eight to nine orders of magnitude higher than those of the monomeric and the dimeric Cu sites, and this is related to its ready charge-transfer ability, as shown by the partial Density of State (PDOS) analysis and the static charge differential density analysis in this study. Generally, the present work proposes that the distance between the [Cu]+ sites plays a significant and important role in N2 O-ODHP over the Cu-based zeolite catalyst and modulates Cu—Cu distance, and this constitutes a promising strategy for highly-efficient Cu-zeolite catalyst design for N2 O-ODHP. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
41. Effect of the preparation method on the catalytic properties of copper-containing zeolite Y applied for NH3-SCR-DeNOx.
- Author
-
Suharbiansah, Rujito S. R., Lukman, Muhammad Fernadi, Nannuzzi, Chiara, Wach, Anna, Góra-Marek, Kinga, Liebau, Michael, Palčić, Ana, Pöppl, Andreas, Berlier, Gloria, Bordiga, Silvia, Gläser, Roger, and Jabłońska, Magdalena
- Published
- 2023
- Full Text
- View/download PDF
42. Synthesis, Characterization, and NH 3 -SCR Catalytic Performance of Fe-Modified MCM-36 Intercalated with Various Pillars.
- Author
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Szymaszek-Wawryca, Agnieszka, Díaz, Urbano, Samojeden, Bogdan, and Motak, Monika
- Subjects
METALLIC oxides ,IRON ,FERRIC oxide ,CATALYST structure ,CATALYST testing ,IRON oxides ,ZEOLITES - Abstract
Two series of MCM-36 zeolites intercalated with various pillars and modified with iron were synthesized, analyzed with respect to their physicochemical properties, and tested as catalysts for the NH
3 -SCR process. It was found that the characteristic MWW morphology of MCM-36 can be obtained successfully using silica, alumina, and iron oxide as pillars. Additionally, one-pot synthesis of the material with iron resulted in the incorporation of monomeric Fe3+ species into the framework positions. The results of catalytic tests revealed that the one-pot synthesized sample intercalated with silica and alumina was the most efficient catalyst of NO reduction, exhibiting ca. 100% activity at 250 °C. The outstanding performance of the material was attributed to the abundance of Lewis acid sites and the beneficial influence of alumina on the distribution of iron species in the zeolite. In contrast, the active centers originating from the Fe2 O3 pillars improved the NO conversion in the high-temperature range. Nevertheless, the aggregated particles of the metal oxide limited the access of the reacting molecules to the inner structure of the catalyst, which affected the overall activity and promoted the formation of N2 O above 300 °C. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
43. Zeolite-encaged mononuclear copper centers catalyze CO2 selective hydrogenation to methanol.
- Author
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Chai, Yuchao, Qin, Bin, Li, Bonan, Dai, Weili, Wu, Guangjun, Guan, Naijia, and Li, Landong
- Subjects
COPPER ,HYDROGENATION ,CHEMICAL amplification ,CARBON offsetting ,CARBON dioxide - Abstract
The selective hydrogenation of CO
2 to methanol by renewable hydrogen source represents an attractive route for CO2 recycling and is carbon neutral. Stable catalysts with high activity and methanol selectivity are being vigorously pursued, and current debates on the active site and reaction pathway need to be clarified. Here, we report a design of faujasite-encaged mononuclear Cu centers, namely Cu@FAU, for this challenging reaction. Stable methanol space-time-yield (STY) of 12.8 mmol gcat -1 h-1 and methanol selectivity of 89.5% are simultaneously achieved at a relatively low reaction temperature of 513 K, making Cu@FAU a potential methanol synthesis catalyst from CO2 hydrogenation. With zeolite-encaged mononuclear Cu centers as the destined active sites, the unique reaction pathway of stepwise CO2 hydrogenation over Cu@FAU is illustrated. This work provides a clear example of catalytic reaction with explicit structure-activity relationship and highlights the power of zeolite catalysis in complex chemical transformations. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
44. Mothers with justice‐involved sons: Socioeconomic impacts of COVID‐19 by neighborhood disorder in the United States.
- Author
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LaBerge, Alyssa, Osuna, Amanda Isabel, Cavanagh, Caitlin, and Cauffman, Elizabeth
- Subjects
MOTHERS of criminals ,SOCIOECONOMIC factors ,COVID-19 pandemic ,NEIGHBORHOODS ,JUVENILE offenders ,UNEMPLOYMENT statistics ,CHILD care ,MOTHER-child relationship - Abstract
Women, particularly mothers, have faced disparate socioeconomic consequences throughout the COVID‐19 pandemic. Research has yet to examine whether the consequences of the pandemic vary based on the level of neighborhood disorder, which is associated with various health conditions, including COVID‐19 complications. The present study utilizes data from a diverse sample of 221 women with justice‐involved sons interviewed during the early months of the COVID‐19 pandemic. Negative binominal and logistic regression analyses were conducted to examine whether perceived neighborhood social disorder is related to socioeconomic impacts of the COVID‐19 pandemic, and whether the relation varies for mothers with and without children in their home during the pandemic. The results suggest that greater perceived neighborhood social disorder was associated with increased in COVID‐19‐related socioeconomic consequences. Neighborhood social disorder affected socioeconomic impacts above and beyond the effects of having a child living in the home. Additionally, Latinas experienced greater socioeconomic impacts than women of other races and ethnicities. The results indicate a key relationship between the neighborhood conditions a woman lives in and the extent of the socioeconomic consequences they faced during the early months of the COVID‐19 pandemic. Future directions and direct implications of the study findings are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
45. Navigating Turbulent Environments: Exploring Resilience in SMEs through Complex Adaptive Systems Perspective.
- Author
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Yapicioglu, Balkiz
- Abstract
This study seeks to explore how owner–managers of small and medium-sized enterprises navigate a constantly changing and turbulent environment following a traumatic experience and how they build resilience in their organizations by drawing upon memories through a complex adaptive system lens. Specifically, this study investigates the major factors shaping the management strategies of SMEs operating in the infrastructure construction sector in North Cyprus, where foreign aid/the patron country is the primary source of financing and therefore the major driver of strategies. To gather primary data, semistructured interviews were conducted with owner–managers of grade 1 construction SMEs, who can participate in internationally financed public projects. A qualitative approach using thematic analysis was adopted, and findings indicate that the most influential factor shaping the management strategies of SMEs in North Cyprus is the macro characteristics of the sociopolitical environment. These characteristics evoke memories for owner–managers and lead to a dissipative approach towards managing their SMEs, creating resilience in the face of North Cyprus' ever-changing political environment. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
46. Coordinated Regulation of Central Carbon Metabolism in Pyroligneous Acid-Treated Tomato Plants under Aluminum Stress.
- Author
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Ofoe, Raphael, Thomas, Raymond H., and Abbey, Lord
- Subjects
CARBON metabolism ,KREBS cycle ,PENTOSE phosphate pathway ,PEARSON correlation (Statistics) ,CALVIN cycle - Abstract
Aluminum (Al) toxicity is a major threat to global crop production in acidic soils, which can be mitigated by natural substances such as pyroligneous acid (PA). However, the effect of PA in regulating plant central carbon metabolism (CCM) under Al stress is unknown. In this study, we investigated the effects of varying PA concentrations (0, 0.25 and 1% PA/ddH
2 O (v/v)) on intermediate metabolites involved in CCM in tomato (Solanum lycopersicum L., 'Scotia') seedlings under varying Al concentrations (0, 1 and 4 mM AlCl3 ). A total of 48 differentially expressed metabolites of CCM were identified in the leaves of both control and PA-treated plants under Al stress. Calvin–Benson cycle (CBC) and pentose phosphate pathway (PPP) metabolites were considerably reduced under 4 mM Al stress, irrespective of the PA treatment. Conversely, the PA treatment markedly increased glycolysis and tricarboxylic acid cycle (TCA) metabolites compared to the control. Although glycolysis metabolites in the 0.25% PA-treated plants under Al stress were comparable to the control, the 1% PA-treated plants exhibited the highest accumulation of glycolysis metabolites. Furthermore, all PA treatments increased TCA metabolites under Al stress. Electron transport chain (ETC) metabolites were higher in PA-treated plants alone and under 1 mM, Al but were reduced under a higher Al treatment of 4 mM. Pearson correlation analysis revealed that CBC metabolites had a significantly strong positive (r = 0.99; p < 0.001) association with PPP metabolites. Additionally, glycolysis metabolites showed a significantly moderate positive association (r = 0.76; p < 0.05) with TCA metabolites, while ETC metabolites exhibited no association with any of the determined pathways. The coordinated association between CCM pathway metabolites suggests that PA can stimulate changes in plant metabolism to modulate energy production and biosynthesis of organic acids under Al stress conditions. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
47. Phaeogromids of the mesopelagic marine plankton: Temporal variability of concentrations and observations of feeding structures of four species from the mesopelagic in the Mediterranean Sea.
- Author
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Dolan, John R. and Coppola, Laurent
- Subjects
MARINE plankton ,SPECIES ,PROTISTA ,SEAWATER - Abstract
Challengerids, phaeogromids rhizarian protists, are emblematic protists of the deep sea but are also enigmatic as they occur in very low concentrations. In previous studies, we reported on temporal changes in abundance at a near‐shore mesopelagic site, but only as part of sampling of the entire microplankton assemblage, not well‐suited for examining phaeogromids. Consequently, we turned to using a closing plankton net to provide material from large volumes of seawater, thus allowing for more robust estimates of concentrations and material for observations of living cells, to our knowledge the first made. Here, we report our results on the four most commonly occurring species: Challengeranium diadon, Challengereron willemoesii, Challengeria xiphodon, and Euphysetta lucani. In contrast to our previous report, we found that changes in concentrations were not related to water column stratification, and the four species roughly co‐varied with time. Observations of live cells revealed that all four species deploy tentacle‐like pseudopods and also very large unstructured webs of fine pseudopods. The similarities in feeding webs suggest similar prey are exploited, and the similar temporal changes in abundances suggest a common factor or factors (unknown at this time) govern their concentrations. Films of live cells are provided in Supplementary Files. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
48. Non-Nutritive Sweeteners Acesulfame Potassium and Sucralose Are Competitive Inhibitors of the Human P-glycoprotein/Multidrug Resistance Protein 1 (PGP/MDR1).
- Author
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Danner, Laura, Malard, Florian, Valdes, Raquel, and Olivier-Van Stichelen, Stephanie
- Abstract
Non-nutritive sweeteners (NNS) are popular sugar replacements used in foods, beverages, and medications. Although NNS are considered safe by regulatory organizations, their effects on physiological processes such as detoxification are incompletely understood. Previous studies revealed that the NNS sucralose (Sucr) altered P-glycoprotein (PGP) expression in rat colon. We also demonstrated that early-life exposure to NNS Sucr and acesulfame potassium (AceK) compromises mouse liver detoxification. Building upon these initial discoveries, we investigated the impact of AceK and Sucr on the PGP transporter in human cells to assess whether NNS influence its key role in cellular detoxification and drug metabolism. We showed that AceK and Sucr acted as PGP inhibitors, competing for the natural substrate-binding pocket of PGP. Most importantly, this was observed after exposure to concentrations of NNS within expected levels from common foods and beverage consumption. This may suggest risks for NNS consumers, either when taking medications that require PGP as the primary detoxification transporter or during exposure to toxic compounds. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
49. High abscisic acid and low root hydraulic conductivity may explain low leaf hydration in 'Mandarin' lime exposed to aluminum.
- Author
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Silva, Giselle Schwab, Gavassi, Marina Alves, Carvalho, Brenda Mistral de Oliveira, and Habermann, Gustavo
- Subjects
PLANT transpiration ,HYDRAULIC conductivity ,ROOT growth ,ABSCISIC acid ,HYDRATION ,ALUMINUM ,PLANT biomass - Abstract
The first symptom of aluminum (Al) toxicity is the inhibition of root growth, which has been associated with low leaf hydration, with negative consequences for leaf gas exchange including stomatal conductance (g
s ) observed in many plant species. Here we asked whether low leaf hydration occurs before or after the inhibition of root growth of Citrus × limonia Osbeck ('Mandarin' lime) cultivated for 60 days in nutrient solution with 0 and 1480 μM Al. The length, diameter, surface area and biomass of roots of plants exposed to Al were lower than control plants only at 30 days after treatments (DAT). Until the end of the study, estimated gs (measured by sap flow techniques) was lower than in control plants from 3 DAT, total plant transpiration (Eplant ) and root hydraulic conductivity (Lpr ) at 7 DAT, and midday leaf water potential (Ψmd) and relative leaf water content at 15 DAT. Abscisic acid (ABA) in leaves was twofold higher in Al-exposed plants 1 DAT, and in roots a twofold higher peak was observed at 15 DAT. As ABA in leaves approached values of control plants after 15 DAT, we propose that low gs of plants exposed to Al is primarily caused by ABA, and the maintenance of low gs could be ascribed to the low Lpr from 7 DAT until the end of the study. Therefore, the low leaf hydration in 'Mandarin' lime exposed to Al does not seem to be caused by root growth inhibition or by a simple consequence of low water uptake due to a stunted root system. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
50. DFT Investigations of the Reaction Mechanism of Dimethyl Carbonate Synthesis from Methanol and CO on Various Cu Species in Y Zeolites.
- Author
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Zhou, Yuan, Zhang, Guoqiang, Song, Ya, Yu, Shirui, Zhao, Jingjing, and Zheng, Huayan
- Subjects
COPPER ,ZEOLITES ,DENSITY functionals ,ETHANES ,DENSITY functional theory - Abstract
In this study, a density functional theory method is employed to investigate the reaction mechanisms of dimethyl carbonate (DMC) formation, through oxidative carbonylation of methanol, on four types of Y zeolites doped with Cu
+ , Cu2+ , Cu2 O and CuO, respectively. A common chemical route is found for these zeolites and identified as, first, the adsorbed CH3 OH is oxidized to CH3 O species; subsequently, CO inserts into CH3 O to CH3 OCO, which reacts with CH3 O to form DMC rapidly; and finally, the adsorbed DMC is released into the gas phase. The rate-limiting step on Cu2+ Y zeolite is identified as oxidation of CH3 OH to CH3 O with activation barrier of 66.73 kJ·mol−1 . While for Cu+ Y, Cu2 O-Y and CuO-Y zeolites, the rate-limiting step is insertion of CO into CH3 O, and the corresponding activation barriers are 63.73, 60.01 and 104.64 kJ·mol−1 , respectively. For Cu+ Y, Cu2+ Y and Cu2 O-Y zeolites, adsorbed CH3 OH is oxidized to CH3 O with the presence of oxygen, whereas oxidation of CH3 OH on CuO-Y is caused by the lattice oxygen of CuO. The order of catalytic activities of these four types of zeolites with different Cu states follows Cu+ Y ≈ Cu2 O-Y > Cu2+ Y > CuO-Y zeolite. Therefore, CuY catalysts with Cu+ and Cu2 O as dominated Cu species are beneficial to the formation of DMC. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
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