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Zn7/3Sb2/3O4 is a secondary phase in ZnO-based varistors. Acceptor impurities, such as Li+, increase the resistivity. This effect is produced by a modification of the grain boundary barriers. The role of the cationic distribution in the mentioned events is worth clarifying. The Li0.5Zn5/3Sb2.5/3O4 room-temperature structure was determined by means of a neutron diffraction and synchrotron X-ray diffraction investigation. The title compound was prepared by conventional ceramic process. The elemental composition of the investigated sample was verified by means of electron microscopy—energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The neutron experiment was performed at the high-intensity neutron diffractometer with position-sensitive detector at the D1B beamline of the Laue-Langevin Institute, Grenoble. The high resolution synchrotron measurement was carried out at MCX beamline of Elettra Sincrotrone Trieste. Rietveld analysis was performed with the FullProf program. Li0.5Zn5/3Sb2.5/3O4 belongs to the spinel family, space group F d 3 ¯ m (227). The measured lattice parameter is a = 8.5567(1) Å. The Li+1 and Zn+2 ions are randomly distributed among the tetrahedral and octahedral sites as opposed to Sb+5 ions which have preference for octahedral sites. Fractional coordinate of oxygen, u = 0.2596(1), indicates a slight deformation of the tetrahedral and octahedral sites. The data given in this paper provide structural support for further studies on measurements and microscopic explanations of the interesting properties of this family of compounds.

In this work CdS/CdTe solar cell that uses a Mo thin film as a back contact on last layer was protected against MoO x formation and scratching by using an ITO thin film. The back contact was fabricated by using Cu/Mo and Cu/Mo/ITO. The Cu layer was used to form Cu x Te onto CdTe film. The films Cu, Mo and ITO were deposited by rf-sputtering. The cell efficiency is degraded when it is annealed at 400 °C in air. We show evidences that the p-n junction remains good and the oxidation of Mo is the main cause of the cell efficiency degradation. Also we show that the ITO thin film deposited onto Mo avoid the MoO x formation when the solar cell is annealed at same conditions. All solar cell characteristics are preserved. The solar cells were fabricated in the superstrate configuration by using Glass/ITO/ZnO/CdS/CdTe/back contact layers. The CdTe film was grown by conventional CSS technique. The cells were activated by using CHClF 2 -argon-oxygen gases. DRX spectra and HR-SEM were made for Mo/Glass and ITO/Mo/CdTe before and after annealing at 400 °C in air.

Rust scales of commercially available low carbon steels from Venezuela (AlSI 1010), Mexico and Cuba (AISI 1019) were characterised after exposure at two typical atmospheres in the Caribbean region: Merida (rural-urban; RU) and Progreso (marine-coastal; MC). Low carbon steel surfaces rusting in those atmospheres formed mainly the oxyhydroxides lepidocrocite (y-FeOOH), goethite (a-FeOOH) and akaganeite (β-FeOOH). Different amounts of lepidocrocite, goethite and akaganeite and the oxide phases hematite (α-Fe 2 O 3 ), magnetite (Fe 3 O 4 ) and maghemite (γ-Fe 2 O 4 ) were found, depending on the deposition rates value of air-borne salinity, time-of-wetness (TOW) and temperature present in every particular test site. The rust scale composition and air pollution are used to explain the corrosion rates and corrosion behaviour of the exposed low carbon steels in the tests sites.

We studied the formation of the band gap on CdS thin films deposited on glass substrates by chemical bath deposition (CBD) and close spaced sublimation (CSS) techniques. In order to obtain the first stages of films growth, we used small deposition times for both methods. Films growth by CBD were prepared by two modalities on the bath agitation: magnetic agitation with a magnetic stirrer, and a new proposal based on ultrasonic vibration. Morphological, structural, and optical results were obtained on films. Values of the band gap energy obtained by the absorption method, are agree with the values reported in the literature, but squared absorption coefficient vs. energy curves, showed differences between them. An explanation on this behavior with the optical window effects, the surface roughness, the structural results, the films thickness, and the growth technique is given. CBD technique with ultrasonic vibration produces films with more cleaner surfaces and better optical properties.

The influence of a chromate film on the corrosion behaviour of Zn, Zn–Co and ZnFe coatings was investigated. XPS, AES techniques were applied for characterisation of the iridescent chromate films, while the XRD method was used for the corrosion product analysis. Atmospheric field (4 years data), accelerated (neutral salt spray and SO2 cabinet) tests and electrochemical measurements were applied for the corrosion resistance studies. The beneficial influence of alloying for chromated Zn electrodeposits was observed under the conditions, where Cl− ions were the dominant pollutant (marine test site, Cl− cabinet, Cl− aqueous solution). The degree of protection from the chromate film, in spite of their lower thickness, was detected to be higher for the alloyed samples. A higher concentration of Cr(VI) compounds in the passive chromate layers of alloyed samples may be the reason of their superior corrosion resistance.

ZrO2–SiO2 sol–gel powders were produced using tetraethoxysilane (TEOS) and zirconium propoxide. After gellation, the ZrO2 crystallization process was investigated using X-ray diffraction (XRD), thermal analysis (DTA/TGA), and scanning electron microscopy (SEM). Fresh gels were amorphous. Thermal treatments were carried out from 100 to 1400°C for a total annealing time of 182 h. Tetragonal zirconia, (Z(t)) was the first phase to crystallize, between 300 and 500°C. Crystallization temperature was lower for zirconia-rich compositions, increasing as silica content was raised. DTA analysis showed that Z(t) crystallization occurred in two stages. Complete tetragonal–monoclinic zirconia transformation occurred near 1000°C, and was clearly observed only in ZrO2-rich compositions (>80%). Silica remains amorphous until 1200°C, when ZrSiO4 formation took place. A metastable sol-gel phase diagram was proposed to show the crystallization process between 100 and 1400°C.

The role of the corrosion products in the inhibition of Zn alloy coating corrosion has not been considered fully to date. Atmospheric corrosion data on Zn, Zn-Fe, Zn-Co, and Zn-Ni electrodeposits exposure to marine and urban test sites of a humid, tropical climate during a 3-year period revealed that Zn-Ni and Zn-Co coatings are more resistant than Zn and Zn-Fe. Corrosion products formed on these samples have been characterized by x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). Sodium chlorhydroxysulfate (NaZn4Cl[OH]6SO4·6H2O) and zinc hydroxychloride (Zn5[OH]8Cl2·H2O) were determined to be the main constituent compounds of corrosion films formed in both test sites. It is assumed that the amorphous structure and properties of the oxide phase may play an important role in determining coating corrosion resistance.

A new ceramic pigment with the cordierite high temperature structure was synthesised by sol-gel processing. A small region of a solid solution phase was detected containing

Aluminum thin films grown on silicon by free evaporation were studied by grazing incidence X-ray diffraction and atomic force microscopy techniques. The behavior of the films during current flowing, the induced changes by large periods of current applied, as well as the temporal evolution of the deformation due to thermal expansion because of the Joule effect, were studied. We explain the degradation of the films by a combined action of thermal effects and mechanical stress between film and substrate. The results could conduce to a new method to measure some thermal properties on metallic thin films.

Cobalt oxide thin films were prepared by the dipping sol-gel process, using two different inorganic precursors: cobalt chloride and cobalt nitrate salts. Also, samples with a different number of dipping-annealing cycles (3, 5, and 7) where prepared. Composition, structure, surface morphology and optical properties of such films have been characterised by means of X-ray diffraction, differential thermogravimetric analysis (DTA), transmittance spectra and atomic force microscopy (AFM). The results show that starting from distinct precursors leads to different properties: film water contents, surface roughness, crystallite size, total film transmittance, absorption coefficient and refractive index. Absorption coefficients higher than 104 cm−1 where found for all the samples. Refractive indices vary from n ~ 1.9–2.8 in the near infrared region. Our study shows that using a relatively simple preparation method like the sol-gel process, cobalt oxide films with specific properties, can be made.

The subsolidus phase diagram CaO-Al{sub 2}O{sub 3}-Ta{sub 2}O{sub 5} has been determined at 1300--1350 C. Two ternary phases are present, Ca{sub 2}AlTaO{sub 6} and the new phase, CaAlTaO{sub 5}. From Rietveld refinement of powder X-ray diffraction data, CaAlTaO{sub 5} has the sphene structure, monoclinic 6.6760(3), 8.9546(3), 7.3494(3) {angstrom}, {beta} = 114.098 (3){degree}, space group C2/c, and Ca{sub 2}AlTaO{sub 6} has a partially ordered double perovskite structure, monoclinic 5.3915(3), 5.4321(4), 7.6508(4) {angstrom}, {beta} = 90.076(5){degree}, space group P2{sub 1}/c. The Al and Ta cations form a rock-salt-type arrangement with 3% cross substitution of Al on Ta sites and vice versa.

The photoactivation time of sol–gel nanostructured titania, in an ethanol suspension, was studied by optical methods in the UV–Vis region. Titania activation was induced using a Hg lamp and the process was analyzed using light transmittance. The Hg lamp light beam was transmitted through the sample and collected with a spectrophotometer as a function of time. The titania powder was thermally treated to observe the effect in the photoactivation. When the photoactivation of the titania suspension occurs, the transmittance falls and afterwards, a constant value is reached. It was found that the activation time depends on the crystalline structure and the crystallite size.

Sol–gel silica reservoirs were synthesized using tetraethoxysilane and functionalized with OH groups to stabilize dopamine into a ceramic matrix. The synthesis was made in air and N2 atmosphere. The dopamine–silica reservoirs were analyzed by FTIR spectroscopy, DTA–TGA and BET techniques. Nanostructured materials with a high specific surface area (500 m 2 /g) and a mean pore size between

We studied changes induced by electrical current (DC) on gold thin films by using a combination of scanning tunnelling microscopy and grazing incidence X-ray diffraction. The results show that the process inducing device failure is based on surface diffusion that produces the growth of microcrystals at the expense of mechanically strained microcrystals. The de-percolation and loss of adherence to the substrate reduce the heat transfer which in turn produce an increase of film temperature. This temperature increase induces a large mechanical stress due to the differential dilatation of substrate and film. The result of these processes is the final failure of current conduction by the film.

The temporal evolution of the surface topography and x-ray diffractogram of gold thin films was obtained. We found by STM that the surface roughness decreased exponentially with time. X-ray analysis indicates that the microcrystals are strained i.e., the x-ray peaks shift with elapsed time towards the gold standard reflections. The rearrangement of the gold film is induced by surface strains that appear during film growth rather than by the thermal motion of atoms. A DC current was applied to the films to induce surface changes and to study electromigration phenomena. Results show that current effects accelerate film failure by surface diffusion produced by the growth of microcrystals at the expense of mechanically strained microcrystals.

We study the modification of gold thin film surface by Scanning Tunnelling Microscopy (STM) and grazing incidence X-ray to understand the process of electromigration. As a result of the applied current we have observed by STM a large movement of matter in the film surface that results in a strong rearrangement and modification of all the surface structures in a matter of minutes. We obtained that the 〈111〉 peak position shift towards the gold standards with elapsed time indicating that the surface strains formed during film growth disappears. The conclusion of the study is that the electrical current induces a rearrangement of the gold film surface.

The temporal evolution of the surface topography and X-ray spectrum of gold thin films is obtained. We found by scanning tunneling microscopy that the surface roughness decreases exponentially with time. As the X-ray incidence angle decreases the peak positions shift and the peak half-widths increase. These results indicate that microcrystals in the surface are under strain and are smaller than in the bulk. The X-ray peak positions shift with elapsed time towards the gold standards. The conclusion of the study is that rearrangement of the gold film surface is induced by surface strains that appear during film growth. Thus, the surface smoothing is due to relaxation of the stress in the material rather than to the thermal motion of atoms.

The dehydration process at ambient conditions (25°C and 70% relative humidity) of titania aqueous emulsions, was monitored using the photoacoustic technique. Titania was obtained by the sol-gel method, the powders were thermally treated from ambient temperature up to 700°C and dispersed in water to form an emulsion. The photoacoustic signal as a function of time, shows two dehydration stages which were parametrized as a sigmoidal curve. The mechanisms inducing the increase in the dehydration rate with the temperature pretreatment are discussed.

En el presente trabajo, investigamos la correlación entre algunos parámetros magnéticos y el nivel de contaminación por metales pesados en suelos urbanos de la ciudad de Morelia, en el occidente de México. El estudio magnético fue llevado a cabo en 98 muestras urbanas provenientes de diferentes tipos de uso de suelo. La mayoría de las muestras contienen minerales ferrimagnéticos como responsables de la magnetización, pertenecientes probablemente a las soluciones sólidas de las titanomagnetitas/ titanomaghemitas. Esto es inferido a partir de las mediciones de susceptibilidad en función de la temperatura y de los experimentos de magnetización remanente isotérmica (MRI). Estas mediciones indican además, que la mayoría de las muestras se saturan casi completamente antes de los 300 mT. Adicionalmente, los valores S-200 (S-200 = IRM-200/SIRM, donde IRM-200= magnetización a campo inverso de 200 mT después de la saturación magnética) se encuentran entre 0.7 y 1.0, característicos de minerales de baja coercitividad magnética. Las curvas promedio de magnetización remanente isotérmica de saturación (SIRM) pueden ser usadas como un indicador del nivel de contaminación, ya que estas curvas muestran diferentes valores de saturación de acuerdo al nivel de contaminación por metales pesados: Cu, Ni, Cr y Sr. Estas asociaciones de (titano)magnetitas con metales pesados fueron observadas bajo el Microscopio Electrónico de Barrido, revelando algunos agregados complejos en lugar de las esférulas detectadas comúnmente., In this work, we investigate the correlation between some magnetic parameters and the level of contamination by heavy metals in urban soils from Morelia city, western Mexico. The magnetic study was carried out on 98 urban soils samples belonging to distinct land uses. Most of analyzed samples contain ferrimagnetic minerals as the responsible for magnetization, most probably corresponding to the titanomagnetites/titanomaghemites solid solutions. This is inferred from the susceptibility vs. temperature measurements and the isothermal remanent magnetization (IRM) experiments. These measurements also indicate that most of samples are almost completely saturated before 300 mT. Additionally, the S-200 values (S-200 = IRM-200/ SIRM, where IRM-200= Back-field of 200 mT after magnetic saturation) are between 0.7 and 1.0, characteristic of low coercivity magnetic minerals. The averaged saturation isothermal remanent magnetization (SIRM) curves can be used as an indicator of pollution level, as these curves show different saturation values according to the level of contamination by heavy metals: Cu, Ni, Cr and Sr. These associations of (titano)magnetite with heavy metals were observed by Scanning Electron Microscope revealing some complex aggregates rather than commonly detected spherules., Universidad Nacional Autónoma de México through the projects CONACYT 118971 and PAPIIT IN 223110

A year-long study of the composition and morphology of the corrosion products formed on zinc plates, using XRD (with Bragg-Brentano and grazing incidence geometry) and SEM techniques, was carried out in marine and rural atmospheres with a humid tropical climate in southeast of Mexico. These samples were analyzed after 1, 3, 6, 9, and 12 month exposures, for two different angles to the horizontal, 22° and 45°. The main phases determined were: zincite, ZnO; simonkolleite, Zn 5 (OH) 8 Cl 2 H 2 O; zinc hydroxychlorosulfate, Zn 12 (OH) 15 Cl 3 (SO 4 ) 3 H 2 O and zinc sulfate hydroxide hydrate, Zn 4 SO 4 (OH) 6 5H 2 O. The differences in the development and morphology of the phases formed, on the skyward and groundward faces, are analyzed. The film of the corrosion products is very sensitive to the environmental conditions, as rainy and dry seasons and the level of contaminants.

Data analysis of the initial superficial layers of copper patina formed in several marine environments, using X-ray diffraction and cathodic reduction techniques, are presented. It was observed that cuprite phase decreases and the paratacamite phase increases, as corrosion develops on the surface of copper. The data presented show good agreement with previously published eletrochemical reactions of copper corrosion in marine environments.

Polycrystalline solid solutions with formula Li4 − 3xInxSiO4: 0 ≤ x ≤ 0.15 were prepared by solid state synthesis. These materials were found to exhibit lithium ion vacancies. From ac impedance measurements conductivities with values around 1 × 10 −5 Ω −1 cm −1 at 250 °C, are found.

RESUMEN El centro historico de la ciudad de San Francisco de Campeche, Mexico, cuenta con edificios civiles y militares de la epoca colonial, los cuales se encuentran sometidos a la accion de agentes ambientales como humedad, radiacion solar, temperatura, erosion eolica, accion biologica y productos de origen antropogenico que inducen su deterioro. El objetivo del presente estudio fue diagnosticar el dano y posible origen de costras negras en el Baluarte de San Pedro, edificio representativo del sistema defensivo de la ciudad. Las patologias de deterioro y el analisis mediante difraccion de Rayos X realizado en muestras representativas del edificio indican la presencia de yeso en los muros sur y suroeste del Baluarte. Lo anterior es indicio de la accion de emisiones de vehiculos automotores que circulan diariamente sobre las avenidas circundantes. Por otra parte, existe abundante colonizacion microbiana cuya actividad se relaciona con la presencia de oxalatos de calcio, compuestos caracteristicos de procesos de biodeterioro. Palabras Clave: Deterioro; edificios historicos; San Francisco de Campeche; Baluarte de San Pedro; biodeterioro. ABSTRACT The downtown of San Francisco de Campeche, Mexico, has several civilian and militarian ancient buildings dating from the Hispanic colonization. These buildings are exposed to environmental agents such as high relative humidity and temperature, sun radiation, wind erosion, biologic action and anthropogenic products, which produce their deterioration. The objective of this paper is to present and discuss the diagnosis of deterioration of the San Pedro bastion as well as the possible origin of black crusts observed over the walls. Visual inspection and X Ray Diffraction analysis detected gypsum at south and southwest walls, which is indicative of the action of combustion products of vehicles circulation over neighboring avenues. Moreover, it was observed abundant microbial colonization, which activity is related to the presence of calcium oxalates that are evidence of a bio-deterioration process. Keywords: Deterioration; historic buildings; San Francisco de Campeche; Bastion of San Pedro; biodeterioration.

IFC-305 was encapsulated into nanostructured titania and functionalized with OH groups by the sol-gel process using titanium n-butoxide, to be used in a drug delivery system for the treatment of liver cancer. Synthesis was carried out at different molar hydrolysis ratios: 4, 8, 16 and 24 mol of water; and drug concentration of 10, 20 and 30%. Characterization of IFC-titania reservoirs was carried out by Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal analysis (DTA-TGA), scanning electron microscopy (SEM), and N2 adsorption-desorption isotherms (BET), confirms that IFC-305 is entrapped and stabilized in the TiO2-OH matrix. Drug liberation in vitro was determined by UV spectrometry over a period of 1000 h. This study demonstrated that the higher water content and the higher amount of loaded IFC, favored hydrogen bonding between titania-OH surface and IFC-NH groups, increasing the rate of drug release.

Knowledge of the mechanical and petrographic properties of limestone rocks is an important issue to different areas of science and engineering. Sedimentary limestone rock is one of the most abundant materials in the Peninsula of Yucatán used for decorative and building construction. This work studies the petrographic, mineralogical, and physical properties of three different types of limestone slabs of the state of Yucatán.

ac impedance spectroscopy studies were carried out in polycrystalline samples of Li 2 Zr 1− x Ti x O 3 :0 x α =1×10 −6 (ω cm) −1 at 400°C rising to α =1×10 −3 (ω cm) −1 at 750°C. It was found that the conductivity and the E a values decrease with increasing Ti 4+ content. The dielectric constant decreases sharply with increasing Ti content. Using the same ac data the hopping rate characteristics and dc component were investigated.

Co-based soft ferromagnetic amorphous ribbons (Vitrovac R 6025) were crystallized by annealing at various temperatures (100–250 K below the crystallization temperature, 831 K) for times ranging from 1 to 18 h. The initial permeability was determined from complex permeability plots in the frequency range 5 Hz–13 MHz. A decrease in initial permeability μ i as a function of annealing time was observed for all annealing temperatures. This decrease was sharper at higher temperatures. The domain wall relaxation frequency ƒ 0 exhibited inverse behaviour; the product μ i ƒ 0 was practically constant for all the experiments. It is shown that these results can be interpreted on the basis of a reversible magnetization mechanism of domain wall bowing, and that the decrease in permeability results from increased wall pinning due to crystallization.

The role of atmospheric pollution in degradation of historic building has been studied for long time along the world because it increases stone decay and the lost of historic materials (Massey, 1999; Graedel, 2000; Monna, 2008). The preservation of Cultural Heritage is considered a strategic factor in countries integration because of their economical, social and cultural implications (Cassar et al., 2004; Sessa 2004, Moropoulou and Konstanti, 2004). Latin-american countries have an important building legacy from prehispanic, colonial and modern periods. This is the case of Mexico which currently count with 15 sites included in UNESCO s cultural heritage list. Most of them are located in urban areas like Mexico City, Morelia, Guanajuato, San Miguel de Allende and San Francisco de Campeche, between others. San Francisco de Campeche is a small City located at the south east of Mexican Republic, just in the occidental coast the Peninsula of Yucatan, inside the Gulf of Mexico Basin (Fig. 1). The City was founded in 1527, by Spanish colonizers leaded by Francisco de Montejo, “el Mozo”. During the XVII century, it was the only point for exportation of goodness from Yucatan to Europe. Because of these conditions, French, Netherlanders and British pirates considered the city a legitimate target. At that time, authorities designed an impressive military defensive system to protect the City and their inhabitants. Forts, batteries and a rampart surrounding San Francisco de Campeche urban core were built by using calcareous materials based on masonry structures made with limestone quarry blocks joined and covered with mortars made with slike lime and sahacab, a typical calcareous clay material used since prehispanic period for building construction. Nowadays, about 1500 buildings are located into the historic and architectonic complex included in 1999 in the UNESCO`s Cultural Heritage List.

Diffusion of substances in tissue is an extremely complex process. Various phantoms have been proposed as a model to simulate biological organs and to study physicochemical effects on the human body. Low concentration aqueous agar phantoms systems are specially suited for this purpose (Madsen et al., 2005), because they resemble the desired tissue, and are inexpensive to prepare (Bauman et al., 2004). Recently, they have been suggested for the study of the treatment of neurodegenerative diseases of the central nervous system (CNS) by implantation of nanoreservoirs, for controlled drug release into the brain (Staples et al., 2006). A variety of experimental methods have been developed for the study of drug diffusion phenomena in such a complex system. Methylene blue can be used to monitor the diffusion processes inside a gel-like material to simulate the actual process that takes place in the living tissue, since the size of this molecule is similar to that of some chemotherapeutic drugs (Buchholz et al., 2008). Methylene blue is a heterocyclic aromatic chemical compound with the molecular formula C16H18N3SCl, a scheme of the molecule is shown in Figure 1. Additionally, methylene blue is a molecule that has played important roles in microbiology and pharmacology. It has been widely used to stain living organisms, to treat methemoglobinemia, and recently it has been considered as a drug for photodynamic therapy (Tardivo et al., 2005). This compound shows in-vivo activity against several types of tumors, when locally injected and illuminated with read laser light (Tardivo et al., 2005). Orth and coauthors have demonstrated that intratumoral injection of 1% methylene blue followed by illumination by an argon-pumped dye laser, was able to kill xenotransplanted tumors in animals and recurrent esophageal tumors in patients (Orth et al., 1998).

One of the most important subjects of interest in dentistry and teeth preservation is related to the effects of bleaching agents on the integrity of the dental pieces. This is especially crucial when teeth surface has received some damage, generated by chemical, biological and mechanical agents or weathering in the case of dental pieces recovered from burial sites. In this work the time evolution of the effects of bleaching agents on the surface of dental pieces is monitored using diffuse reflectance in the visible spectrum is reported. The effects were monitored in teeth previously subject to chemical agents. Bleaching was induced using commercial whitening products. It is shown that the time evolution of the reflectance depends strongly on the condition of the surface as well as on the thickness of enamel. Additionally the colorimetric analysis of the samples during the bleaching is presented. This is especially useful in for comparing with previous studies. In order to complement our studies, the effects of the bleaching on the surface of the teeth were monitored by scanning electron microscopy.

Background Explicit criteria for judging medication safety and use issues in patients with chronic kidney disease (CKD) are lacking. Study Design Quality improvement report. Setting & Participants Nephrologists (n = 4), primary care physicians (n = 2), hospital pharmacists with expertise in nephrology (n = 4), and community pharmacists (n = 2). The PAIR (Pharmacotherapy Assessment in Chronic Renal Disease) criteria were applied retrospectively to 90 patients with CKD in a randomized study. Quality Improvement Plan Development of an explicit set of criteria to enable rapid and systematic detection of drug-related problems (DRPs). Using a RAND method, experts judged the clinical significance of DRPs and the appropriateness of a community pharmacist intervention. The PAIR criteria include 50 DRPs grouped into 6 categories. Outcomes DRPs detected using the PAIR criteria compared with implicit clinical judgment by nephrology pharmacists. Measurements Prevalence of DRPs and reliability, validity, and responsiveness of the PAIR criteria. Results A mean of 2.5 DRPs/patient (95% CI, 2.0-3.1) was identified based on the PAIR criteria compared with 3.9 DRPs/patient (95% CI, 3.4-4.5) based on clinical judgment of nephrology pharmacists. Inter-rater reliability coefficients (κ) by PAIR category varied from 0.80-1.00, with an intraclass correlation coefficient (ICC) of 0.93 (95% CI, 0.89-0.95) for total DRPs per patient. Test-retest reliability coefficients by category varied from 0.74-1.00, with an ICC of 0.91 (95% CI, 0.82-0.96) for total DRPs per patient. During the study, the mean number of DRPs per patient did not change significantly when assessed using the PAIR criteria and clinical judgment. Limitation The prevalence of PAIR DRPs may be underestimated due to the retrospective nature of the validation. Conclusion The prevalence of DRPs requiring the intervention of community pharmacists is high in patients with CKD. The PAIR criteria are reliable, but their responsiveness remains to be shown.

Controlled drug delivery systems are investigated to increase the chemical stability of the drug and to eliminate the side effects caused by the systemic administration via the circulatory system. Functionalized silica and titania xerogels are emerging as a new category of drug host systems. In the treatment of neurological disorders, which occur primarily in the central nervous system, a ceramic device can be implanted directly near a damaged tissue, thus avoiding passage through the blood brain barrier and reducing the necessary drug doses. Valproic acid (VPA), an often used anticonvulsant drug, encapsulated within a titania device has been successfully tested on mice as a therapy for epileptic disorders and is necessary to understand how to control the kinetics of drug release by changing the synthesis parameters.

The analysis of the surface of teeth is an important field of research and technological development due to the importance of dental pieces in health and aesthetics. The presence of cracks as well as the etching effects on teeth surface, due to different chemical agents, affects not only the appearance of teeth but its integrity. In this work, laser thermography analysis of dental pieces with damage in the form of cracks is presented. The technique consists in the illumination of the surface at the center of the sample, using a 300 mW pulsed solid state laser beam focused with a gradium lens, and monitoring the spatial and temporal distribution of the temperature field. The heating of the sample is monitored using a focal plane array infrared camera, sensitive in the spectral range 7.5-13 μm with a noise equivalent temperature difference of 0.12°C. The data acquisition was performed by the PC firewire port using a PCI-8254R card and a home-made program in Labview 8.0 was used for data acquisition. The images were processed in a home-made linux program to obtain the experimental table values. Our results are compared with position and frequency scans obtained by infrared photothermal radiometry. It is shown that the crack in the tooth appears as an increase in the photothermal signal. In contrast, the thermographic image shows a more detailed structure in which close to the crack the temperature increases, but at the crack the signal falls.

In this work the possibilities of infrared thermography for the study of burned human bones of outstanding interest in archaeology and anthropology are explored. The technique used consisted in the illumination of the sample using an infrared solid state laser beam and the observation and the monitoring of the surface temperature with an infrared camera. The bones analyzed were previously thermally treated in a furnace and boiled in water. It is shown that the effect of the thermal treatments can be observed in the infrared images, from which the dynamics of the cooling process of the sample is obtained. It is shown that the cooling process of the samples could be used to identify the possible burning treatment at which a given material could have undergone previously. As an auxiliary technique X-ray diffraction was used to analyze the crystallization of the material and to look for a correlation with different thermal treatments.

Studies on photocatalytic degradation of lignin are scarce, even though it is an effective method for treatment of industrial effluents. In the present work, an advanced oxidation process (AOPs), leading to the photodegradation of lignin aqueous solutions, is proposed by using microstructured (T-MT) and nanostructured (T-NT) titanium dioxide compounds. Hydrothermal synthesis, in accordance with an experimental factorial design considering time of synthesis, NaOH concentration and synthesis temperature, was used to produce tunable TiO 2 photocatalysts for further study of its effects on the degradation of lignin. Photocatalytic reactions were conducted in a micro reactor batch system under UV irradiation. The catalysts were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), surface area and porosity analyzer (BET), energy-dispersive X-ray spectroscopy (EDS) and UV-Vis diffuse reflectance spectroscopy. In order to optimize the yield reaction, an experimental factorial design was performed. According to our results, nanostructured TiO 2 consisting in different structural features and light absorption properties were produced using this method. It is shown that T-MT and T-NT compounds exhibit a wide range of values, for the kinetic parameters, in photoinduced degradation of methylene blue (MB) and lignin.

Se observaron y describieron los cambios anatómicos en estructuras reproductivas, botón a fruto maduro, se establecieron los estados fenológicos y el desarrollo estructural del fruto a través del tiempo en frutos de uchuva ecotipo Colombia. Esta investigación se realizó en un huerto comercial de uchuva (Physalis peruviana) localizado en el municipio de Granada, Cundinamarca, Colombia. El estudio confirmó que anatómicamente los frutos de uchuva ecotipo Colombia y de tipo ruderal son similares, lo que demuestra la ausencia de cambios anatómicos apreciables que expliquen el mayor tamaño de los frutos del ecotipo Colombia. The anatomical changes in reproductive structures were observed and described frrom button to mature fruit and the phenological states and the structural development of the Cape gooseberry fruit, ecotype Colombia, were established settled down. This investigation was made in a commercial Cape gooseberry (Physalis peruviana) orchard located in the municipality of Granada, Cundinamarca, Colombia. The study confirmed that anatomically the Cape gooseberry fruits, ecotype Colombia, and ruderal type are similar, which demonstrates the absence of appreciable anatomical changes that explain the greater size of the fruits of ecotype Colombia.

The analysis of teeth is an interesting field, given the importance of these pieces for the individual or for humanity in the case of remains recovered from an archeologically site; therefore, the development of non-destructive techniques is important to study these materials. Photothermal techniques are ones of the most interesting possibilities; they are based in the generation of a train of thermal waves inside of a material due to the illumination with modulated light. Among these techniques photothermal radiometry has an outstanding role, since it is a non-contact technique, based in the detection of infrared emission of the samples heated with the laser. The experimental configuration consists of an Ar laser beam that impinges on the surface of the teeth and the infrared radiation generated is measured using a HgCdTe IR detector. Results for the analysis of cracks on teeth and the low frequency profiles are presented. A strong influence of the signal due to the microstructure of teeth is observed. Furthermore, surface effects are analyzed changing the color of teeth when whitening products are applied. The process of whitening is monitored in real time by optical spectroscopy in the visible and by photothermal radiometry.

In the present work is encapsulated in sol-gel silica, Exoli which has been genetically modified. This bacterium without modification has been extensively studied into sol-gel silica. Nevertheless, this work shows the results of the synthesis parameters research to maintain the modified microorganism alive.

In this work we present the phase structure evolution, with long annealing times, of mixed oxides powders in the TiO2-ZrO2 system, obtained by the sol-gel method. Several compositions were synthesized via the catalytic hydrolysis of titanium and zirconium butoxides, HNO3 was added to adjust the pH=3. Pure zirconia and titania were also prepared. Long thermal treatments were applied from 100–1000°C, increasing the temperature every 100°C. These samples were heated during 20 h at each temperature.

Amorphous samples of Vitrovac(R) 6025 metallic alloys were nanocrystallized by thermal annealing at temperatures in the range 576–716 K, well below the crystallization temperature (831 K, as obtained by differential scanning calorimetry at 20 K/min) and times in the range 10–90 min. Initial magnetic permeability exhibited a maximum of ∼109 000 (from ∼20 000 for the as‐quenched state) for annealing times of ∼15 min, and then a decrease toward a plateau value (30 000–40 000) for longer times. Domain wall relaxation frequency showed the opposite behavior, a minimum of ∼9 kHz (from 40 kHz for the as‐quenched value) for the permeability maximum, and then a stabilization at ∼15 kHz. Transmission electron microscopy observations confirmed that for annealing times up to 60 min., crystallite size is smaller than 30 nm. Permeability and relaxation frequency results are interpreted in terms of the dependence of wall bulging on anisotropy and free‐wall surface area between pinning sites.

The equation of motion for ferromagnetic domain walls is compared with initial permeability measurements of Co‐based soft ferromagnetic amorphous ribbons at frequencies in the range 100 Hz–13 MHz. The analysis of these results by complex permeability methods leads to an equivalent circuit formed by a parallel RL arrangement in series with a small resistance RW due to resistance of the measurement coil. This equivalent circuit, however, cannot model the irreversible magnetization behavior for fields higher than the pinning (or propagation) field. It is shown that the equation of motion is also consistent only with the reversible magnetization mechanism, if the displacement term, x, represents instead the bulging of the pinned wall. The correlations between the terms in the equation of motion and the elements of the equivalent circuit are established.

The influence of thermal treatments on the magnetostriction constant of Vitrovac/sup R/ 6025 amorphous alloys is reported. Annealing conditions (673 and 523 K at several annealing times) were chosen to result in nanocrystallization. The presence of nanocrystals led to a significant magnetic softening. No changes were observed on the saturation magnetization value at room temperature on the treated samples, as compared with the as-quenched sample. The magnetostriction constant, /spl lambda//sub s/, shifts from --0.14/spl times/10/sup -6/ for the as-quenched sample to positive values for the treated alloys. Samples annealed at 673 K exhibited two components of /spl lambda//sub s/ which depended on the tensile stress, /spl sigma/; one for low stress, and the other for high stress values, with the change at /spl sigma/=400 MPa. This behavior is interpreted in terms of a two-phase model, where one phase is the Fe-enriched residual amorphous fraction, and the other one is formed by Co-rich nanocrystals. For annealing at 723 K, a well-known relationship, /spl lambda//sub s/(/spl sigma/)=/spl lambda//sub s/(0)-A/spl sigma/, was observed, with no resolution of components. This difference is interpreted on the basis of the nanocrystals size: for 673 K, the nanocrystals are smaller than the exchange length, while they are larger for 723 K. >

Fourier Transform infrared spectroscopy has been employed to study the shells of two kind of mollusks, American oysters (Crassostrea virginica) and mussels (Ischadium recurvum). It is shown that it is possible to distinguish the different calcium carbonate lattice vibrations in each case, mussel shells present aragonite vibration frequencies, and the oyster shells present those corresponding to calcite. The superposition, shift and broadening of the infrared bands are discussed. Changes in the vibration modes due to successive thermal treatments are also reported.

Most of the inorgaiiic hiomineralized matcrials are deposited on an orpanic matrix that controls thc orientation and structure of the crystals. It is thought that chcmical groups at tlic suriace oi thc matrix may act as a tcmplaie for the nucleation and growth of the mineral. A x-ray diiiraction study of the texturization development of the bivalve mollusk sh~lls is preseiiteu: spccifically. !he mussel Ischurlirrnr r-rcrrnwu (Rafinesque. 1870). in different growing stagcs. Tlic x-ray reflections show a preferred orieiitation thnt changes as thc mollusk gows, and at tlic final stages oiily two crystallographic plancs prcvail. In the last deciides a great effort has heen dedicated to study and to understaiid naturiil hiomineralized niaterials. in order to desigii nnd develop new advanced materials with spccific properties to use thcm on different tcchnology applications [1.2]. For iiistaiice, the production oF cenients with a hiph hardness and free oi mncro-defects. can be improved by imitating the high resistance and hardncss of the nacre produccd by a species of marinc hivalve (mother of pciirl) 131. There has heen a great interest to study thc growth mechanisms of the crystals developcd hy liviiig organisms. as well as the variatioii oF their propenies with the agiiig of the orgaiiism. iiiiu to undcrstand their difierences with the geologic;il world. In Geology. the stable crystal phiiscs are iormed under cenain conditions oF ieiiiperature. pressure. etc. Meanwhile in the hiology world the organisins maintaiii a strong coiitrol durine growth which also is influenccd by ihc environmental coiiditions that could rcsult in the dcvelopmcnt of prefcrrcd orieiitation of tlic crystals. Crystals in living systems grow up iii a controlled shape under the dircctioii of thc orgmic molecules and tissues. ln the niiiierals the crystals generally are precipitated Froni solution or from solidification oF a meltcd material: in contrast. thc inorganic materials in liviiig orgaiiisms grow froin the organic matrix u.hich has a strong influeiicc to define the crystal .;li;ipc aiid the crystalline ph;ise io be developcd. For exiimple the shells of ihe mollusks start to grow From their edges where two polyniorphs oF calcium carbonate. calcite and ar;igonite. are foniieu within a protein niatrix. In this work ihe study of the teXturimtioii of the crystallinc phascs during succcssivc stagcs of growth iii tlie iiiussel Is

The present work was addressed to study the visible light induced performance as photocatalysts of mesoporous N y Ti 1–x Ce x O 2–y structures obtained under microwave irradiation. The titanium dioxide ( TiO 2) was doped with cerium and nitrogen in order to improve the quantum efficiency of the TiO 2 and to shift its adsorption spectra to the visible region. The prepared meso-powders were analyzed by means of X-ray diffraction (XRD), scanning Electron microscopy (SEM), infrared (IR) spectroscopy, transmission electronic microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The surface area was evaluated by means of the Brunauer-Emmett-Teller (BET) method and ultraviolet (UV)-visible diffuse reflectance measurements were performed in order to determine the band gap energy. In addition, the photocatalytic activity of the samples was evaluated by monitoring the photodegradation of methylene blue (MB) under UV and visible light energy irradiation. The results show that our methodology is an effective way for incorporating cerium and nitrogen into TiO 2 compound, which in turn, increases its photocatalytic activity. The diffuse reflectance analysis confirms that the absorption edge was shifted towards the visible region of the optical spectrum. The XRD diffraction patterns indicate homogeneous solid solutions in which prevails the anatase phase. It was observed a reduction in crystal size from 13.1 nm to 7.7 nm for N y Ti 0.98 Ce 0.02 O 2–y in comparison to TiO 2. The textural properties of the synthesized compounds were determined, by means of adsorption isotherms indicating the formation of mesoporous structures. IR spectra show characteristic vibration signals attributed to Ti–O–Ti bonds, as well as vibrations assigned to cerium and nitrogen bonds. The XPS analyses evidence the presence of Ce 3+/ Ce 4+ redox couple and Ti–N bonds. The photocatalityc efficiency was evaluated in the degradation of MB monitoring the absorbance change at 664 nm. The degradation of this compound was 91.4% using N y Ti 0.98 Ce 0.02 O 2–y as photocatalyst under UV energy in 90 min. Also 38.7% of MB degradation was achieved in 150 min under visible light radiation.