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981.
982.
Fifteen new ternary RZn2?xGa2+x, R3Zn11?xGax and RZn11?xGax (R = Y, Lu, Gd–Tm) compounds have been synthesized by reacting the elements at 960 °C, followed by annealing at 400 °C. The crystal structure of all the compounds was solved from powder X-ray counter data and their compositions were confirmed by EDS analysis. Additionally, single crystal X-ray diffraction studies were also performed for the DyZn8.6Ga2.4 phase. It was found that the new compounds crystallize with BaAl4, La3Al11 and BaHg11 structure types, respectively. 相似文献
983.
Photosynthesis,photoprotection and antioxidant activity of purging nut under drought deficit and recovery 总被引:1,自引:0,他引:1
Marcelo F. Pompelli Ricardo Barata-Luís Hermerson S. Vitorino Eduardo R. Gonçalves Eduardo V. Rolim Mauro G. Santos Jarcilene S. Almeida-Cortez Vilma M. Ferreira Eurico E. Lemos Laurício Endres 《Biomass & bioenergy》2010,34(8):1207-1215
Biodiesel is an alternative to petroleum diesel fuel. It is a renewable, a biodegradable, and also a non-toxic fuel. The general interest to produce biodiesel from Jatropha (Jatropha curcas L.) seeds oil has increased but its ability to grow on drought-prone areas has barely been investigated. The objective of this work was to identify some physiological processes that allow the Jatropha to produce in severe arid conditions by studying its leaf gas exchange and antioxidant systems under drought stress and recovering. It measured the activity of antioxidant enzymes involved in the scavenge of reactive oxygen species (ROS), as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutamine synthetase (GS), as well as malondialdehyde (MDA) content. It was also analyzed the chlorophyll (CHL), carotenoids, amino acids and soluble proteins contents. Net photosynthesis (A) and stomata conductance (gs) decreased associate with drought stress and dropped to zero in soil water beneath 5%. Drought induced decrease in stomatal and non-stomatal photosynthetic activity. The activities of SOD, CAT, APX and GS and MDA content in leaves were significantly higher in the water-stressed plants compared to well-watered plants and decreased when the plants were rewatered. These observations suggest that oxidative stress resulting from drought deficit in Jatropha could result in the production of antioxidative enzymes to counteract the oxidative damage, and the enzymes may contribute to its ability to survive in the adverse arid environment. 相似文献
984.
Mário David Gonçalo Borges Jorge Gomes João Pina Isabel Campos Plasencia Enol Fernández-del-Castillo Iván Díaz Carlos Fernandez Esteban Freire Álvaro Simón Kostas Koumantaros Michel Dreschner Tiziana Ferrari Peter Solagna 《Journal of Grid Computing》2014,12(3):543-558
The European Grid Infrastructure (EGI) is providing a sustainable pan–European Computing Grid to support e–Science, integrating more than 350 computing resource centers worldwide. One of its main challenges is that the middleware driving this production infrastructure is constantly evolving, as it adapts to the changing needs of the EGI Community. Since the software is provided by external technology providers, it needs to pass through a quality verification process before it is included in the EGI official release called Unified Middleware Distribution (UMD). Therefore, all software components undergo a release process covering the definition of the functionality and quality criteria, the verification of those criteria, and the testing under production environments. This paper details the design, development and implementation of this software validation process. An analysis is performed on several metrics to evaluate the process impact on the stability of the production infrastructure, by capturing malfunctions and other issues at the initial testing phases. 相似文献
985.
Ki Tae ParkSang Gon Kim Jeong Hwan ChunDong Hyun Jo Byung-Hee ChunWoo In Jang Gyung Bo KangSung Hyun Kim Ki Bong Lee 《International Journal of Hydrogen Energy》2011,36(17):10891-10900
The organic-inorganic composite membranes are prepared by inserting poly(styrene sulfonate)-grafted silica particles into a polymer matrix of sulfonated poly(arylene ether sulfone) copolymer. The first step consisted in using atom transfer radical polymerization method to prepare surface-modified silica particles grafted with sodium 4-styrenesulfonate, referred to as PSS-g-SiO2. Ion exchange capacities up to 2.4 meq/g are obtained for these modified silica particles. In a second step, a sulfonated poly(arylene ether sulfone) copolymer is synthesized via nucleophilic step polymerization of sulfonated 4,4′-dichlorodiphenyl sulfone, 4,4′-dichlorodiphenyl sulfone and phenolphthalin monomers in the presence of potassium carbonate. The copolymer is blended with various amounts of silica particles to form organic-inorganic composite membranes. Esterification reaction is carried out between silica particles and the sulfonated polymer chains by thermal treatment in the presence of sodium hypophosphite, which catalyzed the esterification reaction. The water uptake, proton conductivity, and thermal decomposition temperature of the membranes are measured. All composite membranes show better water uptake and proton conductivity than the unmodified membrane. Moreover, the membranes are tested in a commercial single cell at 80 °C and 120 °C in humidified H2/air under different relative humidity conditions. The composite membrane containing 10%(w/w) of PSS-g-SiO2 particles, which have ester bonds between polymer chains and silica particles, showed the best performance of 690 mA cm−2 at 0.6 V, 120 °C and 30 %RH, even higher than the commercial Nafion® 112 membrane. 相似文献
986.
Gonçalves Taisa Guidini de Oliveira Káthia Marçal Kolski Christophe 《Cognition, Technology & Work》2017,19(2-3):493-515
Cognition, Technology & Work - Task modeling is undoubtedly a key step for task analysis during the development of iterative systems since it helps not only in the understanding of what users... 相似文献
987.
Leonardo M. Da Silva Débora V. Franco Lindomar G. Sousa Ismael C. Gonçalves 《Journal of Applied Electrochemistry》2010,40(4):855-864
The filter-press electrochemical ozonizer is characterized as a function of the applied electric current, temperature, and
linear velocity of the electrolyte-free water. Lead dioxide electroformed on surface of a non-platinized fine mesh stainless
steel support was used as anode. Electrolysis of the electrolyte-free water was carried out using the membrane electrode assembly
(MEA) adequately compressed by means of a specially designed clamping system. Electrochemical characterization studies were
carried out galvanostatically as a function of temperature and linear velocity of the circulating water. It was verified that
the electrochemical ozone production (EOP) taking place at the reacting zones formed at the solid polymer electrolyte (SPE)/mesh
electrode interface is not considerably affected by circulating water when the linear velocity inside the distribution channels
is higher than 1.20 cm s−1. A current efficiency for the EOP of 13% and a specific electric energy consumption of 70 Wh g−1 were obtained when an electric current of 130 A was applied at 30 °C. The reactor service life test revealed that the MEA
using the lead dioxide fine mesh electrode as anode and a fine mesh stainless steel electrode as cathode, pressed against
the SPE, is stable for the ozone production. 相似文献
988.
Luiz Fernando Gonçalves Jefferson Luiz Bosa Tiago Roberto Balen Marcelo Soares Lubaszewski Eduardo Luis Schneider Renato Ventura Henriques 《Journal of Electronic Testing》2011,27(4):551-564
This paper presents a proactive maintenance scheme for fault detection, diagnosis and prediction in electrical valves. The
proposed scheme is validated with a case study, considering a specific valve used for controlling the oil flow in a distribution
network. The scheme is based in self-organizing maps, which perform fault detection and diagnosis, and temporal self-organizing
maps for fault prediction. The adopted fault model considers deviations either in torque, in the valve’s gate position or
in the opening or closing time. The map which performs the fault detection, diagnosis and prediction, is trained with the
energy spectral density information, obtained from the torque and position signals by applying the wavelet packet transform.
These signals are provided by a mathematical model devised for the electrical valve. The training is performed by fault injection
based on parameter deviations over this same mathematical model. The proposed system is embedded into an FPGA-based platform.
Experimental results demonstrate the effectiveness of the proposed approaches. 相似文献
989.
Alessandro Ribeiro Gonçalves Carlos Eduardo Vergani Eunice Teresinha Giampaolo Ana Cláudia Pavarina 《The Journal of Adhesion》2013,89(2):139-150
Cylinders (3.5 × 5.0 mm) of the reline resins Kooliner (K), New Truliner (N), Tokuso Rebase Fast (T), and Ufi Gel Hard (U) were bonded to cylinders (20 × 20 mm) of the denture base resin Lucitone 550 (L), and samples were divided into two controls and four test groups (n = 8). Shear tests (0.5 mm/min) were performed after polymerization or immersion in water (37°C) for 7 days (controls); two or seven cycles of disinfection by immersion in sodium perborate (50°C/10 min) or microwave irradiation (650 W/6 min). Statistical analyses (α = 0.05) revealed that two cycles of microwave and chemical disinfection increased the mean bond strengths of materials T (9.08 to 12.93 MPa) and L (18.89 to 23.02 MPa). For resin L, seven cycles of chemical (15.72 MPa) and microwave (17.82 MPa) disinfection decreased the shear bond strength compared with the respective control (21.74 MPa). Resins U (13.12 MPa), K (8.44 MPa), and N (7.98 MPa) remained unaffected. 相似文献
990.
Schrepp Martin Pérez Cota Manuel Gonçalves Ramiro Hinderks Andreas Thomaschewski Jörg 《Universal Access in the Information Society》2017,16(3):629-640
Universal Access in the Information Society - Products should guarantee a sufficiently high user experience for all intended user groups. A good user experience means not only that it is sufficient... 相似文献