Papers by Esperanza Alvarez
La escuela tiene una responsabilidad muy grande respecto a la formación de ciudadanos de éxito qu... more La escuela tiene una responsabilidad muy grande respecto a la formación de ciudadanos de éxito que sean útiles a la sociedad. Es por eso que los educadores y padres de familia deben ser conscientes de la responsabilidad de formar de la mejor manera posible cada pequeño que llega a sus manos
Platinum monolithic catalyst for SO2 abatement in dust-free flue-gas from combustion units
Latin American Applied Research, 2002
A catalytic oxidation process of traces of SO2 to SO3 for the treatment of dust-free flue-gas fro... more A catalytic oxidation process of traces of SO2 to SO3 for the treatment of dust-free flue-gas from power stations and some special waste incinerators has been developed. The catalyst was prepared by impregnation of platinum precursors on alumina/silicates-based material. The behavior of this industrial sized honeycomb- type catalyst was studied at lab and pilot- plant scale. The evolution of SO2 conversion and some physico-chemical properties of the catalyst with time in operation were examined. The 7-8 wt.% of sulfate deposition on the fresh catalyst had no influence on the catalytic activity at steady state conditions. The catalyst showed SO2 to SO3 conversion value of 80-90 vol.% operating at a temperature of 450oC and space velocities of 3000-6150 h -1 (NTP).
Monolitos de carbón activado para la retención de compuestos organoclorados
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
Systems and Methods for Hydrothermal Conversion of Biomass
Revista Mexicana De Sociologia, 2005
Introducción a la musicoterapia
Terapia Ocupacional Revista Informativa De La Asociacion Profesional Espanola De Terapeutas Ocupacionales, 2004
Payment card system and method
La salud con alegría
ABSTRACT
Efecto del paclobutrazol en la proliferación de brotes y la resistencia al marchitamiento en vitroplantas de ñame cultivadas en medio líquido
Biotecnologia Vegetal, 2000
-1 , sobre la proliferacion de brotes y sobre la resistencia al marchitamiento despues del traspl... more -1 , sobre la proliferacion de brotes y sobre la resistencia al marchitamiento despues del trasplante. El retardante inhibio el crecimiento en longitud e indujo la formacion de brotes multifoliados en los puntos de ramificacion. El mayor efecto en la formacion de brotes y nudos se encontro con la concentracion de 1.0 mg.l -1 . Despues de 2 semanas de cultivo en el medio basal sin el retardante los brotes fueron transferidas al suelo. Las plantulas tratadas, en general, mostraron un menor indice de desecacion que el control. Palabras clave: cluster, Dioscorea, micropropagacion, retardantes del crecimiento
Adsorción y Desorción De Potasio en Suelos De Galicia (España) Desarrollados Sobre Distintos Materiales De Partida
The potassium sorption capacity of soils is a major factor determining the dynamics of this eleme... more The potassium sorption capacity of soils is a major factor determining the dynamics of this element in the soil-plant system and the requirements for potassium fertilisation. Low contents of available potassium are often a factor limiting crop yield in Galician soils. Potassium sorption depends on the nature of clay minerals; the hydroxy-aluminium vermiculites, common in surface horizons of Galician soils, bestow on them a capacity to fix potassium. The present paper studies potassium sorption and desorption by samples representative of A and B horizons of Galician (NW Spain) soils, developed from various parent materials. The mineralogical composition of the soil clay was studied by X-ray diffraction analysis; the presence of non-crystalline materials was tested using the pH in NaF and estimated by the aluminium and iron extracted by acid oxalate. Potassium sorption was determined by shaking the soil samples with 0.01 M CaCl2 containing various K concentrations, until equilibrium i...
Microbial biomass and activity in a forest soil under different tree species
Electronic Journal of Environmental, Agricultural and Food Chemistry
Microbial biomass, soil respiration and anaerobically mineralizable N were investigated in a fore... more Microbial biomass, soil respiration and anaerobically mineralizable N were investigated in a forest soil with three different stand types (Quercus robus, Pinus radiata and Eucalytus nitens) located in the temperate humid zone (Galicia, NW Spain). Microbial parameters and soil solution were analized in soil samples collected from the A horizon (0-10 cm) of the different stand types at winter and spring time. A similar significant influence of vegetation and sampling time was observed for microbial C and soil respiration values. When stand type was considered the values in soils followed the order Quercus > Pinus > Eucalytus, and higher values were shown by the winter samples. An opposite seasonal trend was observed for N mineralization since spring samples exhibited higher values than winter samples. A vegetation effect was also detected on N mineralization, Pinus soils showed lower values than those found in Eucalytus and Quercus soils. In contrast, for most soil solution para...
Metales pesados en el suelo
Lixiviación de metales pesados de columnas de suelo tratadas con purín de vacuno
Cancer research, 1990
The growth inhibitory activity of tiazofurin toward adenosine kinase deficient Chinese hamster ov... more The growth inhibitory activity of tiazofurin toward adenosine kinase deficient Chinese hamster ovary (CHO) cells was partially reversed by the presence of nicotinamide riboside. Similarly, the formation of tiazofurin 5'-monophosphate and the active metabolite, tiazofurin 5'-adenine dinucleotide could be partially inhibited by 100 microM nicotinamide riboside in CHO cells and substantially inhibited (80-90%) in adenosine kinase deficient cells. Tiazofurin phosphorylating activity from CHO cell extracts was resolved into two peaks by DEAE-cellulose chromatography. The first peak of activity was identified as adenosine kinase (ATP:adenosine 5'-phosphotransferase, EC 2.7.1.20). The second peak of activity correlated with a previously described 3-deazaguanosine phosphorylating activity that was identified as a nicotinamide ribonucleoside kinase. Contaminating purine nucleoside phosphorylase was removed by sedimentation through a sucrose density gradient which also resolved th...
Hafnium Reactivity Below 1500°C in Search of Better Processing of HfB2/SIC UHTC Composites
Ceramic Engineering and Science Proceedings
... Observed Crystalline Phases for Hf powder reactions (lh at 1500'C; found byXRD) HWZ (ver... more ... Observed Crystalline Phases for Hf powder reactions (lh at 1500'C; found byXRD) HWZ (very strong; sharp) No Hf pattern HfBz (very strong; sharp) HfC (weak; relativelv shard + Reactants "clean: a// picks are-shiffed to lower angle, suggesting a mixed phase) No Hf oattern ...
Determination of nicotinamide-adenine dinucleotide and thiazole-4-carboxamide-adenine dinucleotide in human leukocytes by reversed-phase high-performance liquid chromatography
Journal of Chromatography B: Biomedical Sciences and Applications, 1992
A high-performance liquid chromatographic assay for cellular nicotinamide-adenine dinucleotide an... more A high-performance liquid chromatographic assay for cellular nicotinamide-adenine dinucleotide and thiazole-4-carboxamide-adenine dinucleotide is presented that is appropriate for analysis of these dinucleotides in extracts of Ficoll-purified human leukemic cells. The separation, which is effected by reversed-phase chromatography, is highly reproducible and the limit of quantitation is as low as 10-15 pmol. The stability of these compounds in neutralized perchloric acid extracts is addressed and the applicability of the procedure to clinical specimens is demonstrated.
Environmental Earth Sciences, 2014
Aluminium smelters are major sources of F emission to the environment. We studied, in laboratory ... more Aluminium smelters are major sources of F emission to the environment. We studied, in laboratory experiments, the sorption and desorption of fluoride on organic and mineral horizons of soils located within 2 km from one of these factories, situated in the northern coast of Galicia (NW Spain). The soils, developed from granite, are acid (pH H 2 O 3.9-5.5), rich in organic matter (4-16 % C in the A horizon) and most A horizons have high Al saturation in the exchange complex. All samples showed a notable F sorption, between 1,066 and 1,589 mg kg-1 , after adding 200 mg F L-1 , which accounts for 53-80 % of F added. The sorption was slightly higher in the A horizons than in the respective organic horizons (differences of up to 194 mg kg-1). The fluoride sorption upon addition of 200 mg F L-1 correlated significantly (p \ 0.05) with soil pH in water (r =-0.77), iron extracted by acid ammonium oxalate (r = 0.68), aluminium plus iron extracted by acid ammonium oxalate (r = 0.63), exchange aluminium (r = 0.52) and clay percentage in soil (r = 0.76). The F sorption fitted to both Langmuir and Freundlich models. Desorbed F accounted for only 12-22 % of sorbed fluoride and correlated (p \ 0.05) negatively with non-crystalline (extracted by acid ammonium oxalate) Fe (r =-0.51) and clay content (r =-0.74) and positively with organic matter (r = 0.69) and with the effective cation exchange capacity of the soil (r = 0.50).
Scientia Agricola, 2011
Liming increases crop production through improved soil conditions in acidic soils. Among the effe... more Liming increases crop production through improved soil conditions in acidic soils. Among the effects of liming, increased availabilities of alkaline and alkaline-earth cations are worth mention. These availabilities may be affected by the particle size of applied limestone, which influences lime reactivity. The effects of particle size and application schedule of magnesium limestone were investigated on extractable Ca, Mg and K in soil, their concentrations in sward plants and dry-matter yield. Magnesium limestone of various particle sizes was applied to experimental plots at a rate of 3 t ha-1, a grass-clover sward was sown, and the plots were monitored during three years. The finest limestone (< 0.25 mm) in a single application yielded the highest soil Ca and Mg concentrations extracted by Mehlich-3 and NH4Cl. The same limestone split in three annual doses was less effective. Plots treated with the coarsest limestone (2-4 mm) did not differ from control plots. Liming had no eff...
Surface and Coatings Technology, 2008
Deposition of several coatings by Chemical Vapor Deposition in a Fluidized Bed was studied inside... more Deposition of several coatings by Chemical Vapor Deposition in a Fluidized Bed was studied inside porous coupons made of 409 steel. Four different coating systems were studied: TiAlSiN/TiAl/SS409, TiAlSiN/TiAlSi/SS409, TiAlN/Nb/TiAl/SS409 and TiSiN/Nb/TiSi/SS409. Though coating thickness decreased with depth inside the porous filter, the formation of Ti-based ceramic films with thicknesses around 1 micrometer was observed 0.5 mm inside the bulk of the samples. Coated substrates were exposed to a simulated coal gas at 643 K for 300 hours, in order to study their corrosion resistance under conditions that mimic a porous metal particulate filter of a coal gasification system. Some of the coatings did not provide enough protection against corrosion at the bulk of the porous coupons, and iron sulfide crystals were formed that plugged the pores. On the other hand, the TiSiN/Nb/TiSi/SS409 system showed no sign of corrosion.
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Papers by Esperanza Alvarez