Universitas Scientiarum

<font color="#000080">Universitas Scientiarum (Univ. Sci.) is registered at the ISSN National Centre (ISSN 0122-7483 printed version, ISSN 2027-1352 online version) and indexed in Scopus, Chemical Abstracts (CA), SciELO, Google scholar, ULRICHS-WEB, Latindex, Periódica, Redalyc, Indice Bibliográfico Nacional (Publindex), and Directory of Open Access Journals (DOAJ). Universitas Scientiarum is a refereed scientific journal and is edited at the Faculty of Sciences of the Pontificia Universidad Javeriana (Bogotá, Colombia) and has been published continuously since 1987. Universitas Scientiarum publishes original papers, reviews, brief communications, editorials, letters to the Editor, and reviews of books, handbooks and meetings. The journal receives manuscripts in Spanish, Portuguese or English. The journal will accept papers on any subject of natural, physical or exact sciences.<br></font><br>

List of Papers (Total 482)

Caracterización de la seguridad alimentaria y nutricional de la población del Verjón Bajo, localidad de Chapinero, Bogotá, D.C.

The purpose of this study was to characterize the alimentary and nutritional status of families at Vereda El Verjón Bajo, in the Chapinero district of Bogotá. The research conducted was an observational, transversal and descriptive study, which included 23 families. The data collection was performed using a food survey. The components analyzed were: socio-demographic...

Caracterización de los hábitos alimentarios y estilos de vida de los niños, de la institución obra misionera Jesús y María, Jardín Sol-Solecito, localidad de Suba, Bogotá D.C.

This study was aimed to characterize the food habits and lifestyles of the children of the Sol Solecito Kindergarden in Bogotá, D.C., using the Lund and Burk model as the conceptual framework for the analysis of conduct of children in relation to food. The study was descriptive and cross sectional. The sample consisted of 54 children, selected by a proportional random-stratified...

Influencia de la difusión en imágenes de resonancia magnética de gases

Resolution of nuclear magnetic resonance (NMR) experiments with gases employing magnetic field gradients is greatly reduced due to their rapid diffusion. In this paper, we present a solution to this problem based on a mixture of gases hyperpolarized with laser (LP) (3He or Xe) with other heavier and lighter buffer gases. In this way the diffusion coefficient can be modified up to...

Explicación, demostración y evaluación de un nuevo método para hallar el equilibrio térmico entre n cuerpos con cambios de fase

A special method is used to solve calorimetric problems where the final equilibrium state is sought and phase changes take place. This method makes use of the graph Temperature vs. Heat for the homogeneous heating of a given system of bodies.

Síntesis por radiación con microondas de nanotubos de carbono

Although at the present time a variety of methods and techniques is available for the synthesis and functionalization of carbon nanotubes, it is necessary to explore alternatives to improve the selective and homogeneous heating of the samples and to reduce the times to complete the processes. Microwave radiation offers an important opportunity to fulfil these requirements...

Sentido pedagógico de la evaluación. Estudio de caso en la Facultad de Ciencias de la Pontificia Universidad Javeriana

Educational assessment is an activity which is supported on a pedagogical foundation related to all human dimensions, in particular the cognitive, emotional and social spheres. Because of the above reasons, assessment is a complex task. As it is de-contextualized from its fundamentals and simplified, assessment loses its pedagogical sense; this is what happens when it is reduced...

Efecto del sustrato y la exposición a la luz en la producción de una cepa de Trichoderma sp.

In order to evaluate the effect of temperature and light conditions on biomass production of a Trichoderma sp. strain, three culture media were tested: rice 53% (w/w), rice 53% (w/w) -molasses 3% (w/w) and rice 53% (w/w)-molasses 10% (w/w) in distilled water. Incubation conditions were: 25°C, constant light and a photoperiod of 24 h light/24 h darkness during 8 days. The...

Análisis bibliométrico de los artículos originales publicados en la revista Universitas Scientiarum (1987-2007)

The bibliometric behavior of the journal was evaluated and several actions were defined to improve its quality, through the increase of the Price, the Burton-Kebler and the productivity indices. Volumes 1 to 12 comprising original articles (31.37%), thesis abstracts (46.88%), other documents (14.50%), reviews (1.85%), opinion articles (2.36%), brief communications (1.18%), and...

Programa innovador para evaluar uso y preferencia de hábitat

The species habitat preference is an important topic in biology, ecology, evolution, and management and conservation of biodiversity, since it allows us to determine the resources and conditions required by species for survival, reproduction and persistence through time. This topic is high priority due to the rapid climatic changes that, according to model predictions, will...

Electronic band structure of the ordered Zn0.5Cd0.5Se alloy calculated by the semi-empirical tight-binding method considering second-nearest neighbor

Usually, semiconductor ternary alloys are studied via a pseudo-binary approach in which the semiconductor is described like a crystalline array were the cation/anion sub-lattice consist of a random distribution of the cationic/anionic atoms. However, in the case of reported III-V and II-VI artificial structures, in which an ordering of either the cations or the anions of the...

Unidad para supervisión y control de medición de efecto hall con labview®

We assembled a Hall effect and electric conductivity measuring unit that allows the determination of transport properties in semiconductor and metal films, including the type and concentration of majority carriers and their mobility, from measurements of Hall voltage and current. It is clear that electrons are the charge carrier in metals, however some metals such as aluminum...

Caos cuántico en un billar rectangular

Numeric study of the rectangular billiards is approached from the context of the causal quantum theory. The conditions that make possible the existence of quantum chaos are verified, identifying irregular behavior through criteria such Lyapunov exponents and power spectra. Quantum potential is determined as well as Wigner and Ferry-Zhou potentials, analyzing the role they play in...

Efecto de la inoculación de Azospirillum brasilense y Glomus sp. en Gmelina arborea durante su germinación y manejo en vivero

Seeds of Gmelina arborea at three different maturity degrees were inoculated with Glomus manihotis, Glomus occultum and Azospirillum brasilense immobilized in alginate microbeads. Inoculated seeds were sown in two different growing systems: soil and compacted peat-Jiffy®. Forty-one days after sowing (das), the effects of growing system and microorganism application on seed...

Inmovilización de Bacillus licheniformis y Saccharomyces cerevisiae para la producción de etanol a partir de almidón de papa

We evaluated a sequential discontinuous system composed by Bacillus licheniformis and Saccharomyces cerevisiae for ethanol production. For the second phase of the process potato starch hydrolyzed were used, which was obtained from B. licheniformis cells. Both microorganisms were immobilized in a calcium alginate matrix of 3,2% and 2,5% (w/v), where was observed that these...

Evaluación de la capacidad probiótica "in vitro

The in vitro probiotic capacity of a native strain of Saccharomyces cerevisiae (A) was evaluated and compared with a commercial strain (B) used as a probiotic. The effect of the concentration of sugarcane molasses (10, 20 and 30% (w/v)) on the biomass production was investigated and kinetic parameters were determined. The best molasses concentration was 20% (w/v) and differences...

Evaluación del crecimiento y producción de Pleurotus ostreatus sobre diferentes residuos agroindustriales del departamento de Cundinamarca

The culture of Pleurotus ostreatus was evaluated to determine the best waste on which this mushroom can show the highest growth and production rates.. The substrates evaluated were agroindustrial wastes of the Department of Cundinamarca (dry skin of goldenberries (Physalis), skin of pea pods and maize cobs). The control substrate was sawdust of oak. The mixtures evaluated were...

In vitro regeneration of three chrysanthemum (Dendrathema grandiflora) varieties "via

Chrysanthemum (Dendrathema grandiflora) has a high demand in the Colombian and international cut flower markets. Since commercial production of this ornamental species is strongly affected by fungal diseases such as chrysanthemum white rust (Puccinia horiana), high doses of fungicides are being used posing increased environmental and commercial costs. Assessment of in vitro...

Comparación cinética y bioquímica de tres cepas de Clostridium tetani, para la producción de toxina tetánica

En este estudio se comparó el comportamiento bioquímico y cinético de tres cepas de Clostridium tetani, Harvard (Ha), Massachusetts (Ms) y Caracas (Ca); cepas utilizadas comúnmente en la producción del toxoide tetánico. Se realizaron pruebas bioquímicas para la identificación de los microorganismos anaerobios y se desarrollaron cultivos en reactor de 5L, bajo las siguientes...

Comportamiento de los indicadores de contaminación fecal en diferente tipo de aguas de la sabana de Bogotá (Colombia)

The world's population is growing at such rate that not only the demands for water supply have raised considerably but also its contamination levels. Residues from domestic and industrial origin have generated environmental problems and public health issues. Water contamination coming from domestic origin, shows a higher risk because of the quantity of organic matter and the...

Programa innovador para evaluar uso y preferencia de hábitat

The species habitat preference is an important topic in biology, ecology, evolution, and management and conservation of biodiversity, since it allows us to determine the resources and conditions required by species for survival, reproduction and persistence through time. This topic is high priority due to the rapid climatic changes that, according to model predictions, will...

Electronic band structure of the ordered Zn0.5Cd0.5Se alloy calculated by the semi-empirical tight-binding method considering second-nearest neighbor

Usually, semiconductor ternary alloys are studied via a pseudo-binary approach in which the semiconductor is described like a crystalline array were the cation/anion sub-lattice consist of a random distribution of the cationic/anionic atoms. However, in the case of reported III-V and II-VI artificial structures, in which an ordering of either the cations or the anions of the...

Unidad para supervisión y control de medición de efecto hall con labview®

We assembled a Hall effect and electric conductivity measuring unit that allows the determination of transport properties in semiconductor and metal films, including the type and concentration of majority carriers and their mobility, from measurements of Hall voltage and current. It is clear that electrons are the charge carrier in metals, however some metals such as aluminum...

Caos cuántico en un billar rectangular

Numeric study of the rectangular billiards is approached from the context of the causal quantum theory. The conditions that make possible the existence of quantum chaos are verified, identifying irregular behavior through criteria such Lyapunov exponents and power spectra. Quantum potential is determined as well as Wigner and Ferry-Zhou potentials, analyzing the role they play in...