Molecular mechanics and molecular dynamics analysis of Drexler-Merkle gears and neon pump

Over the past two years at the Materials and Process Simulation Center, we have been developing simulation approaches for studying the molecular nanomachine designs pioneered by Drexler and Merkle. These nanomachine designs, such as planetary gears and neon pump, are described with atomistic details and involve up to 10 000 atoms. With the Dreiding and universal force fields, we have optimized the structures of the two planetary gear designs and the neon pump. At the Fourth Foresight conference, we reported rotational impulse dynamics studies of the first and second generation designs of planetary gears undergoing very high-frequency rotational motions. We will explore stability of these designs in the lower frequency regimes which require long time simulations. We will report the molecular mechanics and molecular dynamics simulations performed on these model systems. We explore the following modes in these studies: (1) impulse mode; (2) constant angular velocity - perpetual rotation; (3) constant torque - acceleration from rest

El amor conyugal: integración de "Eros" e "Ágape" (“Deus caritas est”, nn. 2-11)

“El amor conyugal: Integración de ‘eros’ y ‘ágape’ (Deus Caritas est. nn. 1-11)” intenta ofrecer algunas reflexiones sobre el binomio ‘ágape-eros’ que la primera encíclica de Benedicto XVI plantea. Reaccionando contra una separación que se hizo en la historia precedente, el Papa propone una sabia integración de ambos como algo eminentemente humano y, por tanto, también cristiano. Dicha integración tiene consecuencias positivas en la vida de la pareja humana.“Conjugal Love: Integration of Eros and Agape (Deus Caritas est, nn. 1-11)” offers some reflections about this binomium which the first Encyclical of Benedict XVI suggests. Reacting against a historical separation between “eros” and “agape”, the Pope proposes the integration as something really human and christian also. This integration has positive effects in the human couple

Efecto del enriquecimiento con nutrientes en la degradación de clorpirifos, malatión y metil paratión

Con el fin de evaluar el efecto del enriquecimiento con nutrientes (una sal de fósforo o un fertilizante comercial con N, P y K) como alternativa para mejorar la capacidad de degradación de los microorganismos en una matriz sólida, contaminada con los pesticidas organofosforados: clorpirifos, malatión y metil paratión, se realizaron experimentos de cultivo bajo condiciones controladas de oscuridad, temperatura y humedad por 30 días. En todos los tratamientos hubo degradación de los pesticidas; sin embargo, en el tratamiento con fósforo los tiempos para degradar el clorpirifos y el metil paratión fueron mayores. La presencia de los pesticidas no generó efectos tóxicos detectables sobre la microflora en ninguno de los tratamientos evaluados. La actividad biológica de las matrices no presentó una relación directa con la capacidad de degradación. Abstract In order to evaluate the effect of inorganic nutrient addition (phosphorus or commercial fertilizer) over the microbial degradation capacity present in a solid matrix contaminated with chlorpyrifos, malathion and methyl parathion, microcosms assays were held under controlled conditions of light, moisture and temperature for 30 days. Results showed that even though three treatments microorganisms were able to degrade the three organophosphorus pesticides, microorganisms of phosphorus-enrichment treatment were less efficient to degrade Chlorpyrifos and Methyl Parathion than microorganisms of Fertilizer-enrichment treatment. It was not observed a direct relation between mineralization and microbial pesticides degradation capacity. The microbial activity was not affected by the presence of organophosphorus pesticides

Prostaglandin E 2 production and viability of cells cultured in contact with freshly mixed endodontic materials

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73861/1/j.1365-2591.2006.01070.x.pd

Liquid culture for isolating microorganisms with potential to degrade methyl parathion from agricultural soils and organic waste.

The search for microorganisms with high capacity for pesticide degradation is a very interesting attempt to approach bioremediation strategies in order to prevent contamination. This study evaluates the potential of agricultural soils and solid organic waste cultures microbial isolation as a strategy for screening microorganisms with potential for Methyl parathion (MP) degradation. For the study, microbial consortia were recovered from the liquid fraction of suspension cultures of agricultural soils and solid organic waste. Then, the MP degradation ability and its toxic effect on microbial activity were determined during microbial incubations under laboratory controlled conditions. The results showed that it is not possible to recover the active microorganisms that have potential to degrade the MP from the agricultural soils. However, an active consortium that would degrade both MP and its degradation products was isolated from the organic solid waste

Comentario Especial -- C. Wright Mills. "La elite del poder"

Uno de los problemas que a toda sociedad interesa definir exactamente, al menos del punto de vista de la Sociología, es de seguro el relativo a saber quién efectivamente ejerce el poder en un momento dado de su desarrollo histórico, particularmente en la hora presente

Liquid culture for isolating microorganisms with potential to degrade methyl parathion from agricultural soils and organic waste.

The search for microorganisms with high capacity for pesticide degradation is a very interesting attempt to approach bioremediation strategies in order to prevent contamination. This study evaluates the potential of agricultural soils and solid organic waste cultures microbial isolation as a strategy for screening microorganisms with potential for Methyl parathion (MP) degradation. For the study, microbial consortia were recovered from the liquid fraction of suspension cultures of agricultural soils and solid organic waste. Then, the MP degradation ability and its toxic effect on microbial activity were determined during microbial incubations under laboratory controlled conditions. The results showed that it is not possible to recover the active microorganisms that have potential to degrade the MP from the agricultural soils. However, an active consortium that would degrade both MP and its degradation products was isolated from the organic solid waste

Characterization of photodectors using a monochromator and a broadband light source in the xyz color space

ABSTRACT: Abstract- Photodetectors are sensors, which respond to the electromagnetic radiation of the spectrum. Their spectral response depends on many factors of the manufacturing process, e.g. the type of diode that is used or, in some cases, the optical elements that are added to limit the response band. In this paper, we propose an experimental methodology to obtain the spectral response of a photodetector by constructing the characteristic curve using the monochromatic response. For this purpose, we use a broadband source as input of the monochromator to vary the wavelength each five nm. The characteristic curves of one commercial color sensor were obtained (including the loss) using the output ratio of the monochromator. Via the numerical expression of the response curve, it is possible to model the actual response of the photodetectors to known or simulated spectra of electromagnetic radiation, and thus to generalize photometric measurements. Previously we have demonstrated the importance of obtaining such measurements to study light sources. Finally, this newly developed method helps studying the behavior of a photodetector in detail; hence, it enables the derivation of photometric measurements from known data or simulations

Gobernación de risaralda y universidad tecnológica de pereira unidas para fortalecer la metrología regional

En este documento se muestran algunos resultados del trabajo conjunto entre la Gobernación de Risaralda y la Universidad Tecnológica de Pereira para fortalecer la Red Regional de Normalización, Certificación y Metrología en el Eje Cafetero

Gobernación de risaralda y universidad tecnológica de pereira unidas para fortalecer la metrología regional

En este documento se muestran algunos resultados del trabajo conjunto entre la Gobernación de Risaralda y la Universidad Tecnológica de Pereira para fortalecer la Red Regional de Normalización, Certificación y Metrología en el Eje Cafetero