Efeito da temperatura no desempenho catalítico de óxidos de ferro contendo cobre e alumínio

Aluminum and copper doped hematite was evaluated in the high temperature shift (HTS) reaction at several temperatures in order to find catalysts that can work in different operational conditions. It was found that the catalysts work in kinetic regime in the range of 300-400 ºC. Both copper and aluminum increases the activity and selectivity. Aluminum acts as textural promoter whereas copper acts as structural one. The most promising catalyst is that with both copper and aluminum which showed higher activity and selectivity than a commercial sample. This catalyst has the advantages of being non toxic and can work at low temperatures.

La imagen corporal en danza/movimiento terapia

El cáncer de mama es el tumor más frecuente en la población femenina. El impacto tanto físico como psicológico y social del diagnóstico y los tratamientos quirúrgicos y farmacológicos significan un antes y después en la vida de estas mujeres. Este estudio de tipo descriptivo-exploratorio investiga lo que significa para esta población el haber pasado por esta enfermedad en relación con su imagen corporal y qué es lo que puede aportar la Danza Movimiento Terapia (DMT) para aliviar los síntomas psicológicos y sociales que sienten como consecuencia del impacto de la enfermedad. A través de un cuestionario extenso y un taller de DMT con un grupo de mujeres operadas de cáncer de mama exploramos los diferentes aspectos implicados en la imagen corporal. Los resultados de este estudio exploratorio nos muestran la importancia que tiene para esta población el aspecto relacional que engloba la imagen corporal.

Um banho termostático de baixo custo (temperatura ambiente até 0ºC)

Thermal baths to decrease ambient temperature are an indispensable tool for most research and teaching laboratories, especially those in tropical or equatorial regions. A simple and inexpensive thermal bath has been developed based on a scratched compressor. It has three possible setups for cooling: sample immersed into the bath, sample flowing through the bath, and cooling liquid flowing in a jacket around the sample. It has been tested for 40 months. The temperature ranges from room temperature to 0 °C, when using water. The repeatability is better than 3% and the precision varies from 0.5% to 2%.

Extração de matéria orgânica aquática por abaixamento de temperatura: uma metodologia alternativa para manter a identidade da amostra

In this work was developed an alternative methodology to separation of aquatic organic matter (AOM) present in natural river waters. The process is based in temperature decreasing of the aqueous sample under controlled conditions that provoke the freezing of the sample and separation of the dark extract, not frozen and rich in organic matter. The results showed that speed of temperature decreasing exerts strongly influence in relative recovery of organic carbon, enrichment and time separation of the organic matter present in water samples. Elemental composition, infrared spectra and thermal analysis results showed that the alternative methodology is less aggressive possible in the attempt of maintaining the integrity of the sample.

Remoção de metais pesados de efluentes aquosos pela zeólita natural escolecita - influência da temperatura e do pH na adsorção em sistemas monoelementares

Cation exchange capabilities of a Brazilian natural zeolite, identified as scolecite, were evaluated for application in wastewater control. We investigated the process of sorption of chromium(III), nickel(II), cadmium(II) and manganese(II) in synthetic aqueous effluents, including adsorption isotherms of single-metal solutions. The natural zeolite showed the ability to take up the tested heavy metals in the order Cr(III) > Cd(II) > Ni(II) > Mn(II), and this could be related to the valence and the hydration radius of the metal cations. The influence of temperature (25, 40 and 60 ºC) and initial pH value (from 4 to 6) was also evaluated. It was found that the adsorption increased substantially when the temperature was raised to 60 ºC and that maximum adsorption capacity was observed at pH 6. These results demonstrate that scolecite can be used for removal of heavy metals from aqueous effluents, under optimized conditions.

Otros factores físicos de importancia para los seres vivos : luz, temperatura, corriente

Capítol 9 del llibre 'Conceptos y técnicas en ecología fluvial' que es refereix a la influència de factors com la temperatura de l'aigua, la disponibilitat de llum i la velocitat de la corrent en els organismes que viuen en els sistemes fluvials

La Metodologia cooperativa per potenciar una educació per la ciutadania a través de l'expressió corporal

L'experiència que es presenta aquí s'ha portat a terme en un centre escolar de Girona. És un centre obert a la realitat social, que assumeix com a funció principal la formació de persones íntegres, amb l'objectiu de desenvolupar uns bons ciutadans i ciutadanes. És una escola sensibilitzada en l'educació en valors. La nostra intenció és la de donar a conèixer una pràctica realitzada per uns nois i unes noies de quart curs d'educació secundària, amb la intenció de potenciar actituds de cooperació, per estimular el compromís efectiu en la construcció d'una societat més justa

Influência da temperatura do ar de secagem sobre o teor e a composição química do óleo essencial de Lippia alba (Mill) N. E. Brown

Leaves of Lippia alba were submitted to six different drying treatments, using air at ambient temperature and heated up to 80 °C. The essential oil was extracted by steam distillation and analyzed by GC-MS. For the dried leaves, the oil content was reduced by 12 to 17% when compared with the fresh plant (0.66%). The major oil component was citral, representing 76% for the fresh plant, and varying from 82 to 84% for the dried material. These results showed that L. alba can be submitted to a drying process of up to 80 ºC without degradation and/or loss of the major, [LC1] active component.

Estudo termogravimétrico do efeito da temperatura e da atmosfera na absorção de dióxido de enxofre por calcário

Thermogravimetry was applied to investigate the effects of temperature and atmosphere on conversion of sulfur dioxide (SO2) absorbed by limestone. Ranges of temperature and particle size were studied, typical of fluidized-bed coal combustion. Isothermal experiments were performed at different temperatures (between 750 and 950 ºC) under local atmospheric pressure (~ 697 mmHg) in dynamic atmospheres of air and nitrogen. The maximum conversion was 29% higher in nitrogen atmosphere than in air atmosphere. The optimum conversion temperature was found at 831 ºC in air atmosphere and at 894 ºC in nitrogen atmosphere.

Desenvolupar competències ètiques a l'educació musical i corporal. Un estudi empíric als estudis de mestre en educació infantil a la Universitat de Barcelona

This paper presents an ongoing investigation regarding ethical competence, protective factors, strengths of character and coping strategies analyzed in a sample of students in Early Childhood Education Degree from the University of Barcelona. Along with a theoretical study will be an observational study using standardized instruments and standardized, which include the VIA-IS questionnaire Seligman. With all that is expected to draw conclusions to improve the training of teachers in kindergarten, especially since the subjects of musical expression and body where they develop these skills ethics.

Otimização e validação da técnica de extração líquido-líquido com partição em baixa temperatura (ELL-PBT) para piretróides em água e análise por CG

The liquid-liquid extraction with the low temperature partition technique was developed for the analysis of four pyrethroids in water by CG. Using a factorial design the extraction technique was optimised evaluating the effect of the variables ionic strength, contact time and proportion between sample and solvent volumes. The validation parameters sensitivity, precision, accuracy and detection and quantification limits were evaluated. The LOD and LOQ of the method varied from 1.1 to 3.2 µg L-1 and 2.7 to 9.5 µg L-1, respectively.

Nióbia magnética como adsorvente de contaminantes orgânicos em meio aquoso: efeito da temperatura e do pH

This work describes novel materials based on pure iron oxide and iron oxide/niobia composite to produce a magnetic adsorbent. These materials were prepared with synthetic iron oxide and characterized by powder XRD, SEM, FTIR, TPR and Mössbauer spectroscopy. Results showed that the main iron oxides formed were goethite (aFeOOH) and maghemite (gFe2O3) with small particle size. The iron oxide and iron oxide/niobia composite showed high adsorption ability for organic compounds. The positive enthalpy indicated an endothermic adsorption process suggesting physical adsorption.

Influência da temperatura de secagem sobre o rendimento e a composição química do óleo essencial de Tanaecium nocturnum (barb. Rodr.) bur. & K. Shum

The yields and chemical compositions of the essential oils obtained by steam distillation of the fresh and dried (30 and 40 ºC) leaves, stems and roots of Tanaecium nocturnum are reported. The identification and quantification of the volatile constituents were accomplished by GC/MS and GC/FID, respectively. The essential oils obtained from the various parts of the plant were constituted mainly of benzaldehyde. Large losses and variations in the quantities of the components during the drying process were observed. The presence of mandelonitrile in higher concentration in the stem and roots indicates that this species produces cyanogenic glycosides.

Espai corporal i praxi constructiva grafomotora a l'edat pre-escolar

En totes les investigacions sobre I'evolució ontogeneticadel nen es parteix d'una serie de pressuposits que,plantejats d'una manera explícita o no, determinen el seuenfoc i les seves conclusions teoriques. La relació existententre desenvolupament i aprenentatge n'es un dels mesimportants. Aquesta relació pot considerar-se com a unidireccional(a/ el desenvolupament es una condició previaa I'aprenentatge o b/ I'aprenentatge és desenvolupament)o be com a mútua i interdependent

Influência da luz e da temperatura sobre a oxidação do óleo essencial de capim-limão (Cymbopogon citratus (D.C.) Stapf)

The identification of the chemical compounds of the essential oil was performed with a gas chromatograph coupled to a mass spectrometer. The oil was left in the presence and absence of light and submitted to different temperatures to evaluate its stability. The yields of the major compounds were evaluated every fifteen days. Citral and myrcene, the major compounds of the essential oil, were degraded over time in both the presence and absence of light, but temperature only influenced the degradation of myrcene.