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991.
Pilar Castro Garrido Irene Luque Ruiz Miguel Ángel Gómez-Nieto 《Journal of Intelligent Information Systems》2014,43(1):33-57
Society is changing and technological advances provide mechanisms to facilitate the development of a large number of tasks in technical, humanities, health and social areas. Nowadays, application of the improvement of people’s quality of life is generating significant interest, giving birth to systems oriented to the supervision, care and help for people in the development of their daily affairs. Thus, we may assume that its application to the supervision of a specific group of people can improve the quality of life for many people. OBCAS implements a monitoring service through mobile devices capable of providing enough information for an intelligent system. The multi-agent component provides the intelligence for the system, allowing it to run the appropriate services by adjusting them to the user’s profile and preferences. AGATHA is an application based on OBCAS that provides an alarm service during a supervision process. AGATHA has been tested on the supervision of elderly and victims of gender violence, and the result shown in this paper has been satisfactory. 相似文献
992.
993.
994.
Leonardo S.G. Teixeira Marcelo B. Couto Giancarlos S. Souza Miguel Andrade Filho Júlio C.R. Assis Paulo R.B. Guimarães Luiz A.M. Pontes Selmo Q. Almeida Josanaide S.R. Teixeira 《Biomass & bioenergy》2010,34(4):438-441
Tallow is a raw material for biodiesel production that, due to their highly centralized generation in slaughter/processing facilities and historically low prices, may have energy, environmental, and economic advantages that could be exploited. However beef tallow biodiesel have unfavorable properties due the presence of high concentration of saturated fatty esters. One way to overcome these inconveniences is using blending procedures. In this way, blends of beef tallow biodiesel with soybean biodiesel and with conventional mineral diesel fuel were prepared and the quality of the mixtures was monitored with the purpose to study ideal proportions of the fuels. By measurement of the viscosity, density, cold filter plugging point, and flash point, it was demonstrated that tallow biodiesel can be blended with both mineral diesel and soybean biodiesel to improve the characteristics of the blend fuels, over that of the tallow. 相似文献
995.
Adriana Romero Matías Jobbágy Miguel Laborde Graciela Baronetti Norma Amadeo 《Catalysis Today》2010,149(3-4):407-412
The effect of the Ni(II)–Mg(II)–Al(III) layered double hydroxide (LDH) activation conditions over the surface and bulk composition and the catalytic performance in ethanol steam reforming (ESR) is studied. Ternary oxides were prepared by thermal decomposition of LDHs synthesized using the homogeneous precipitation method with urea. Catalyst precursor is submitted to two different activation treatments: calcinations at 400, 500, 600 and 700 °C with subsequent reduction at 720 °C, or direct reduction at 720 °C. The samples were characterized by sorptometry, H2 chemisorption, ICP chemical analysis, thermogravimetric analysis, X-ray diffraction, X-ray photoelectronic spectroscopy and temperature programming reduction. The catalysts obtained by calcination at 600 °C and then reduction at 720 °C and those directly reduced at 720 °C showed the better performance in ESR. The precursor submitted to a proper thermal treatment develops, through a decoration-demixing process, a Ni(II)-poor spinel-type shell onto NiO domains. 相似文献
996.
AbstractThis work deals with modeling, simulating and construction of a lower-limb exoskeleton with motion in the three anatomical planes, as well as to evaluate its performance to resolve trajectory tracking by means of feedback control schemes. The purpose is to create a scale-lab platform of a full-actuated exoskeleton to test tracking control of the main lower-limb joints to reproduce anatomical movements of a human being with no neuromuscular diseases. This functional scale-lab platform is the first step towards the design of neuromuscular rehabilitation tests based in full-automated assistive devices such as a lower-limb exoskeleton. 相似文献
997.
Miguel A. Altieri Peter Rosset 《The International journal of environmental studies》2013,70(3-4):165-185
This paper describes the agroecological principles necessary to guide the conversion of high‐input conventional systems to a low‐input management based on crop diversification and livestook integration schemes which break the monoculture nature of conventional systems. The new crop‐crop and crop‐animal combinations result in a series of synergisms and complementarities among farming system components which lead to optimal recycling of organic matter and nutrients, and to balanced pest‐natural enemy populations. Thus, agroecological design goes beyond “input‐substitution” by establishing systems capable of sponsoring their own soil fertility, crop protection and yield constancy. These new agroecosystems provide a sustainable level of productivity with minimal need for external (conventional or organic) resources. Biological structuring sponsors the functioning of the system. 相似文献
998.
Miguel Fernando Delgado-Pamanes Simitrio Ignacio Maldonado-Ruiz Martha Patricia Guerrero-Mata Zeydy Lizbeth Olvera-Vázquez 《Welding International》2013,27(9):629-639
ABSTRACTResistance spot welding is the most important method in the industry of self-supporting or monocoque body joinery because of its automation, its speed, the flexibility of welding parts with a complicated shape, and it is economical because it does not require a filler metal, and it is also possible to apply pre-heating and post-heating pulses to improve the weldability of the spot weld, which is defined as the ability of the structure to adequately protect passengers against injuries in the event of a collision, and this mainly depends on the integrity and mechanical performance of the weld button. In order to extend the lifetime of vehicles, galvanized steels are produced. However, zinc coatings have increased the difficulty of weldability, with higher currents being required in the process, since there is less resistance at the weld interface due to improved electrical conductivity. This work investigates the effect of galvanizing on the reduction of the lifetime of the electrodes, for this reason, it follows that there is a loss in the mechanical properties in the weld buttons as the number of spot welds increases. The main aim of this study is to correlate the electrode wear with the mechanical properties of the weld buttons. The experiment procedure consists of making 1,000 spot welds; and every twenty-fifth spot weld after the first was examined by means of stereoscopy, hardness tests, unbuttoning tests and shear stress tests. In terms of electrode wear, the face was evaluated using impressions on carbon paper, optical microscopy and X-ray spectroscopy. 相似文献
999.
The catalytic performance of Pt, PtSn and PtGe supported on γ-Al2O3 (γ-A) deposited by dipcoating of spheres of α-Al2O3 (α-A) was studied in the n-decane dehydrogenation. The effect of Sn and Ge addition to Pt on the activity and selectivity was analyzed. The catalytic characterization was carried out using cyclohexane dehydrogenation (CHD), cyclopentane hydrogenolysis (CPH), temperature-programmed reduction (TPR), hydrogen chemisorption, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and scanning electronic microscopy (SEM). Pt(0.5)Sn/γ-A/α-A catalyst had the best catalytic performance and showed a low electronic interaction between the metals, with a surface segregation of Sn and the presence of oxidized Sn stabilized on the support. PtGe catalysts presented strong interactions with probable alloy formation. The catalytic performance of these catalysts is comparable to that reported in the patents. 相似文献
1000.
In this study, a novel colloidal shell formation phenomenon was observed when sulfuric acid droplets underwent neutralization in marine cylinder lubricant at 115 ± 5 °C using heating microcapillary videomicroscopy. Immediately upon injection, shells formed, wrapping the acidic droplets and detached slowly afterward. Shells were optically transparent, about 2 μm thick, and strongly cohesive and rigid since they could deform the contained acid droplet into a non-spherical shape. Shell surface is most likely hydrophobic since the acid droplets did not wet it. It is thought that these shells were made of hydrated calcium sulfate nanoparticles embedded within an organic matrix. This material was presumably formed when oil additives reacted with sulfuric acid right upon exposure. The discovery of this shell formation, which has not been previously reported in the literature, could be important since these shells could be precursors in the formation of well-known deposits found in diesel engine cylinder liners such as “liner lacquer” or “bore glaze,” which impact negatively the performance of marine diesel engines. 相似文献