La utilización de la biomasa como combustible renovable

The evolution of different ecosystems of the tropical region of Colombia has been the result of the geographical position, of the action of the pedological and pedological factors and processes, of the climatic, tectonic and geological action of the action of the micro and macro fauna and especially of the anthropic intervention on the renewable natural resources. Some of the causes that have led, in the form of a chain reaction, to the deterioration of the environment are: the action of natural phenomena, non-technical mining, migration of the rural population to urban centers, road infrastructure, industrialization, colonization, the use of wood for energy, overgrazing, legal and illicit crops, water and soil contamination due to the use of pesticides and agrochemicals and the expansion of the agricultural frontier, among others. Agriculture is the human activity that depends more on the natural environment and has a closer relationship with it. Naturally, agriculture has become one of the main causes of changes in the environment.La evolución de los diferentes ecosistemas de la región tropical de Colombia ha sido el resultado de la posición geografica, de la acción de los factores y procesos pedologicos y edafológicos, de la acción climática, tectónica y geológica, de la acciónde la micro y macro fauna y en especial de la intervención antròpica sobre los recursos naturales renovables. Algunas de las causas que han llevado, en forma de reacción en cadena, al deterioro del medio ambiente, son: la acción de los fenómenos naturales, la minería no tecnificada, la migración de la población rural a los centros urbanos, la infraestructura vial, la industrialización, la colonización, la utilización de la madera para energía, el sobre pastoreo, los cultivos lícitos e “ilícitos” , contaminación de aguas y suelos por el uso de pesticidas y agroquímicos y la ampliación de la frontera agrícola entre otros. La agricultura es la actividad humana que más depende del medio ambiente natural y tiene una relación más estrecha con él. Inevitablemente la agricultura se ha convertido en una de las causas principales de modificación en el medio ambiente

Giant gartersnake spatial ecology in agricultural and constructed wetlands

The spatial ecology of a species is a vital component of informed management and restoration plans, yet little is known about how animals use restored or constructed habitat. We assessed home ranges, core areas, and habitat selection of the federally threatened Giant Gartersnake (Thamnophis gigas) using rice agricultural habitat and recently constructed wetlands used as conservation banks. Space use patterns were estimated from radio tracking 19 unique adult female snakes over 2 years at a site that is the center of conservation efforts for the species. Home ranges (95% kernel density contour) and core areas (50% kernel density contour) were estimated for size, configuration, and overlap of the home range utilization distributions. Generalized linear mixed-effects models were used to assess habitat influences on microhabitat use. Contrary to expectations, but consistent across years, we found home ranges in the agricultural habitat were on average 80% smaller and had less variation among individuals than those in the constructed wetlands. Snakes in agricultural habitat also had greater and more uniform home range overlap as indicated by the utilization distribution overlap index. We combined all of the snakes to analyze microhabitat selection and used a matched location-random point design. Vegetation patch edges were used more often than interior locations in patches greater than six meters in diameter. This indicates that habitat complexity is an important consideration for habitat conservation plans. We were unable to detect differences in habitat use based upon vegetation composition at a small spatial scale. Temperature also influences reptile habitat selection, and a thermal description of the three macrohabitats (terrestrial vegetation, emergent vegetation, and open water) at our site showed extreme afternoon temperatures limit the use of terrestrial surface habitat by the Giant Gartersnake. The restricted home ranges observed in the snakes in agriculture suggest we need further investigation into dispersal movements and habitat connectivity to better inform regional conservation planning. Recovery efforts for the Giant Gartersnake, including construction and management of new wetlands, will benefit from greater knowledge of their space use patterns described by our research.Keywords: garter snake, habitat selection, Thamnophis gigas, spatial ecology, home range, thermal ecolog

Real-time control of divertor detachment in H-mode with impurity seeding using Langmuir probe feedback in JET-ITER-like wall

Burning plasmas with 500 MW of fusion power on ITER will rely on partially detached divertor operation to keep target heat loads at manageable levels. Such divertor regimes will be maintained by a real-time control system using the seeding of radiative impurities like nitrogen (N), neon or argon as actuator and one or more diagnostic signals as sensors. Recently, real-time control of divertor detachment has been successfully achieved in Type I ELMy H-mode JETITER-like wall discharges by using saturation current (Isat) measurements from divertor Langmuir probes as feedback signals to control the level of N seeding. The degree of divertor detachment is calculated in real-time by comparing the outer target peak Isat measurements to the peak Isat value at the roll-over in order to control the opening of the N injection valve. Real-time control of detachment has been achieved in both fixed and swept strike point experiments. The system has been progressively improved and can now automatically drive the divertor conditions from attached through high recycling and roll-over down to a user-defined level of detachment. Such a demonstration is a successful proof of principle in the context of future operation on ITER which will be extensively equipped with divertor target probes

Neoker Single Crystal Alumina Fibers as reinforcement in Al-based MMC: first steps

α-Al2O3 whiskers are good candidates for use as strengtheners in advanced composites, specifically, single crystal -Al2O3 whiskers grown with c-axis orientation, because of their favorable fracture strength, stiffness, and creep resistance, even at high temperatures are optimum reinforces. Very few methods are currently available to obtain single-crystal α-Al2O3 whiskers, and these methods were too complex and expensive for use on an industrial scale. A novel method for obtaining c-axis alumina single-crystal whiskers (developed at the Institute of Ceramic Materials of Galicia) has been scaled-up to industrial production by Neoker, a Spin-Off of the of the University of Santiago de Compostela, Spain. The technology for the production of the whiskers involves the reaction between aluminum and powdered silica in Ar atmospheres containing metal vapors. Aluminum is the most popular matrix for the metal matrix composites (MMCs). The Al alloys are quite attractive due to their low density, their capability to be strengthened by precipitation, their good corrosion resistance, high thermal and electrical conductivity, and their high damping capacity. The reinforcement in AMCs could be in the form of continuous/discontinuous whiskers, whisker or particulates, in volume fractions ranging from a few percent to 70%. Properties of AMCs can be tailored to the demands of different industrial applications by suitable combinations of matrix, reinforcement and processing route. The composites studied in the present work were prepared by infiltration processes where the reinforcements were pressed into a preform that was then infiltrated by the molten Al allo

Valorisation of pork by-products to obtain antioxidant and antihypertensive peptides

The porcine liver could be used for the extraction of zinc-protoporphyrin (ZnPP) as a natural red meat pigment. During the autolysis process, porcine liver homogenates was incubated at pH 4.8 and 45 °C under anaerobic conditions to obtain insoluble ZnPP. After incubation, the homogenates were readjusted at pH 4.8, and at pH 7.5 before being centrifuged at 5500 × g for 20 min at 4 °C and the resulting supernatant were compared with the obtained at pH 4.8 at the beginning of the incubation. The molecular weight distributions of the porcine liver fractions at both pHs were very similar, however, eight essential amino acids were more abundant in fractions obtained at pH 4.8. Regarding the ORAC assay, porcine liver protein fraction at pH 4.8 showed the highest antioxidant capacity but antihypertensive inhibition was similar for both pHs. Peptides with strong bioactivity potential from aldehyde dehydrogenase, lactoylglutathione lyase, SEC14-like protein 3 and others were identified. The findings have demonstrated the potential of the porcine liver to extract natural pigments and bioactive peptides.info:eu-repo/semantics/publishedVersio