Correlations equalities and some upper bounds for the critical temperature for spin one systems

Starting from correlation identities for the Blume-Capel spin 1 systems and using correlation inequalities, we obtain rigorous upper bounds for the critical temperature.The obtained results improve over effective field type results.Comment: 13 page

Biogas for partial substitution of diesel in power generators

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.In recent years, agricultural farms in Peru have started to implement equipment for anaerobic digestion of the organic residues of their production. At first, the main objective of the implementation was to obtain bio-fertilizers, but in this process, biogas was also obtained. Farms in Peru did not use this biofuel in any process, which is why they freed it or burnt it in torches, polluting the environment in both ways, due to the biogas content of methane. This last fuel has a high global warming potential (GWP) and carbon dioxide, result of the biogas burning is also a pollutant. In this context, an experimental device was designed and built to evaluate the performance of a Diesel cycle engine generator set of 40 kW using diesel and biogas as fuels. The generator set had a fixed speed of 1800 RPM. The tests were initially carried out using only diesel as fuel to obtain comparable parameters. The tests were made simulating an electric load of 62.5%. After this, a conversion kit was installed to allow the use of biogas in the engine. This equipment controls the Duty Cycle, which is a value between 0 and 1 that indicates the percentage of time the injectors are opened. The kit used as input signals the generated power, the electronic governor signal and the exhaust gases temperature. Then, tests were carried out partially substituting diesel for biogas. The biogas used for the test contained approximately 40% of methane. The results indicated that for higher Duty Cycles (higher quantities of biogas), the exhaust temperatures increased, due to the superior temperature of biogas combustion. With the percentage of methane available in the biogas, the substitution rates reached 17,9% and 36,7%, maintaining the generated power and reducing significantly the consumption of diesel. This technology makes possible the modular production of electric energy in agricultural farms, usually isolated, allowing the use of biogas commonly produced in the same place with the organic residues they manage, diminishing pollution, reducing costs and using the energy for useful purposes.dc201

Combined production of electricity and heat in a microcogeneration unit

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Diesel engines are widely used in industrial activities in Peru for electricity generation and heat production. The requirement of different types of energy and its separate generation represent a higher demand for fossil fuels, when the equipment used are internal combustion engines, and higher emission of high-temperature pollutant gases to the environment; all of this, with a deficient utilization of the energy supplied by the fuel. In this context, a Diesel cycle generator of 40 kW was evaluated for the production of electricity and heat. The engine was mapped with different electrical charges (5 kW, 10 kW, 15 kW, 20 kW, 25 kW and 30 kW) simulated by a copper resistance submerged in a tank with salty water. A regenerator was used for the recovery of the exhaust gases heat to allow cogeneration. The experimental device was monitored and instrumented with K type thermocouples, differential pressure sensors, power meters, flow meters, among others; all the signals were received and stored by a data acquisition system for its processing and interpretation. The electrical power, thermal power, specific fuel consumption, thermal efficiency and electric efficiency were evaluated for conventional electricity generation and for combined production of electricity and heatdc201

Design Specifications for an Auxiliary Incision Retractor in Dacryocystorhinostomy Surgeries

It is presented the design specifications for a Retractor Robotic System (RRS) based on the surgical necessities in the incisions procedure for a dacryocystorhinostomy. The specifications are conformed by a mathematical model, the experimental data measured, a modular flexible architecture, energy supplier system, the mechanical group, and the safety system. The specifications suggest that the use of flexible polymeric materials for the RRS provide a mayor adaptability of the system with the biological tissue; so a pneumatic actuator could be a suitable option.This research was funded by CONACYT (Consejo Nacional de Ciencia y Tecnología) Grant No. 86356

Antifungal activity of synthetic naphthoquinones against dermatophytes and opportunistic fungi: Preliminary mechanism-of-action tests

This study evaluated the antifungal activities of synthetic naphthoquinones against opportunistic and dermatophytic fungi and their preliminary mechanisms of action. The minimum inhibitory concentrations (MICs) of four synthetic naphthoquinones for 89 microorganisms, including opportunistic yeast agents, dermatophytes and opportunistic filamentous fungi, were determined. The compound that exhibited the best activity was assessed for its action against the cell wall (sorbitol test), for interference associated with ergosterol interaction, for osmotic balance (K+ efflux) and for membrane leakage of substances that absorb at the wavelength of 260 nm. All tested naphthoquinones exhibited antifungal activity, and compound IVS320 (3a,10b-dihydro-1H-cyclopenta [b] naphtho [2,3-d] furan-5,10-dione)-dione) demonstrated the lowest MICs across the tested species. The MIC of IVS320 was particularly low for dermatophytes (values ranging from 5-28 μg/mL) and Cryptococcus spp. (3-5 μg/mL). In preliminary mechanism-of-action tests, IVS320 did not alter the fungal cell wall but did cause problems in terms of cell membrane permeability (efflux of K+ and leakage of substances that absorb at 260 nm). This last effect was unrelated to ergosterol interactions with the membrane. © 2014 Ferreira et al

Antifungal activity of synthetic naphthoquinones against dermatophytes and opportunistic fungi: Preliminary mechanism-of-action tests

This study evaluated the antifungal activities of synthetic naphthoquinones against opportunistic and dermatophytic fungi and their preliminary mechanisms of action. The minimum inhibitory concentrations (MICs) of four synthetic naphthoquinones for 89 microorganisms, including opportunistic yeast agents, dermatophytes and opportunistic filamentous fungi, were determined. The compound that exhibited the best activity was assessed for its action against the cell wall (sorbitol test), for interference associated with ergosterol interaction, for osmotic balance (K+ efflux) and for membrane leakage of substances that absorb at the wavelength of 260 nm. All tested naphthoquinones exhibited antifungal activity, and compound IVS320 (3a,10b-dihydro-1H-cyclopenta [b] naphtho [2,3-d] furan-5,10-dione)-dione) demonstrated the lowest MICs across the tested species. The MIC of IVS320 was particularly low for dermatophytes (values ranging from 5-28 μg/mL) and Cryptococcus spp. (3-5 μg/mL). In preliminary mechanism-of-action tests, IVS320 did not alter the fungal cell wall but did cause problems in terms of cell membrane permeability (efflux of K+ and leakage of substances that absorb at 260 nm). This last effect was unrelated to ergosterol interactions with the membrane. © 2014 Ferreira et al

Reproductive biology of Cattleya eldorado, a species of Orchidaceae from the Amazonian white sand campinas

The orchid plants are highly prized for their lush exotic flowers. It is the largest plant family with more than 24000 species, which indicates a high diversity of forms and adaptations to different environments, including the capacity to attract, deceive and manipulate visitors involved in cross-pollination. Cattleya eldorado occurs in areas of white sand campinas, a typical vegetation type of the Amazon region, which is under strong anthropogenic pressure. This work's main objectives to know the biological processes of C. eldorado providing subsidies to maintain and manage it in its natural habitat. This study was conducted from 2000 to 2006 in the Campina Biological Reserve, during its flowering period. C. eldorado is an epiphytic orchid species that has the melittophyly syndrome and is adapted to its pollinator, the bee Eulaema mocsaryi recognizing their flowers by smell and by visual stimuli, through their color and reflection of ultraviolet light. C. eldorado is self-compatible, even if it requires a pollinating agent for the transfer of the pollinarium until its deposition in the stigmatic cavity of the flower.", 'enAs Orchidaceae são muito apreciadas por suas flores exóticas e exuberantes. É a maior família de plantas apresentando mais de 24000 espécies, o que denota uma alta diversidade de formas e adaptações a diferentes ambientes, como também para atração, engano e manipulação de visitantes na realização da polinização cruzada. Cattleya eldorado ocorre em áreas de campinas, que são formações vegetais típicas da região amazônica, que se encontram sob forte ação antrópica. Este trabalho tem como um de seus principais objetivos conhecer parte dos processos biológicos de C. eldorado fornecendo subsídios para conservá-la e manejá-la em seu habitat natural. Este estudo foi desenvolvido na Reserva Biológica de Campina, de 2000 a 2006, durante a sua floração. C. eldorado é uma espécie epifítica que apresenta a síndrome de melitofilia, estando adaptada ao seu polinizador, a abelha Eulaema mocsaryi, que reconhece suas flores pelo odor e pelo estímulo visual através de sua coloração e reflexão de luz ultravioleta. C. eldorado é uma espécie autocompatível, embora necessite de um agente polinizador para a transferência do polinário até sua deposição na cavidade estigmática da flor