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排序方式: 共有362条查询结果,搜索用时 15 毫秒
51.
Vinamrita Singh Swati Arora P. K. Bhatnagar Manoj Arora R. P. Tandon 《Journal of Polymer Research》2012,19(6):1-6
We have investigated the degradation of P3HT:PCBM (poly(3-hexylthiophene):6,6-phenylC61 butyric acid methyl ester) solar cell beyond 150?h of fabrication in continuation to our earlier reported work up to 150?h of fabrication. The current- voltage characteristics of degraded Indium tin oxide/poly(3,4-ethylenedioxythiopene):poly(styrenesulfonate)/poly(3-hexylthiophene):6,6-phenylC61 butyric acid methyl ester/Aluminum (ITO/PEDOT:PSS/P3HT:PCBM/Al) solar cell can be explained by considering the tunneling current through electrode interfaces, increase in both the interface states density and the thickness of interface with time for150-200?h. Beyond 200?h of fabrication, a significant reduction in the occupation probability at the electrode interfaces explains the experimental results up to 300?h fairly well. Calculations based on realistic parameters and activity at both the electrode interfaces (ITO/PEDOT:PSS and P3HT:PCBM/Al) confirm that degradation at P3HT:PCBM/Al interface is more prominent than that at ITO/PEDOT:PSS interface. 相似文献
52.
V. Bhatnagar P. Manolatos K. Ptackova G. Van Goethem S. Webster 《Nuclear Engineering and Design》2011,241(9):3376-3388
This paper is an introduction to the research and training activities carried out under the Euratom 7th Framework Programme (FP7, 2007-2011) in the field of nuclear fission science and technology, covering in particular nuclear systems and safety, and including innovative reactor systems and partitioning and transmutation. It is based on the more than 40 invited lectures that were delivered by Euratom project coordinators and keynote speakers at the FISA-2009 Conference (FISA, 2009), organised by the European Commission DG Research, 22-24 June 2009, Prague, Czech Republic.The Euratom programme must be considered in the context of current and future nuclear technology and the respective research effort:
- •
- Generation-II (i.e. yesterday, NPP construction 1970-2000): safety and reliability of nuclear facilities and energy independence in order to ensure security of supply worldwide;
- •
- Generation-III (i.e. today, construction 2000-2040+): continuous improvement of safety and reliability, and increased industrial competitiveness in a growing energy market;
- •
- Generation-IV (i.e. tomorrow, construction from 2040) for increased sustainability though optimal utilisation of natural resources and waste minimisation, and increased proliferation resistance.
53.
M. Hossein Alaei Puneet Mahajan Mathias Brieu Djimedo Kondo S. Javed Ahmed Rizvi Sandeep Kumar Naresh Bhatnagar 《Iranian Polymer Journal》2013,22(11):853-863
Particulate composite materials (PCM) consisting of a matrix reinforced by micro to nano-sized dispersed phase are receiving the attention of designers as a promising futuristic materials. This study unearths the thermal and mechanical behavior of maleic anhydride grafted polypropylene/silica (MA-g-PP/silica) composites for reinforcement ranging from micro- to nano-size. The monodisperse silica spherical particles were used in all the formulations of composites. Further the volume fraction was kept the same in all the compounded thermoplastic composites ranging from 100 nm to 130 μm in a co-rotating conical twin-screw micro-compounder. The micrographs were obtained from transmission electron microscopy (TEM) and the scanning electron microscopy (SEM). The SEM and TEM results revealed a good dispersion of the silica spheres within the MA-g-PP matrix. The compounded composite materials were injection molded to fabricate tensile test specimens (ASTM D638 type V) and tested for tensile properties. In order to investigate the effect of particle size on crystallite structure of the matrix, the composites were tested on differential scanning calorimeter and X-ray diffraction (WAXD). The thermal stability and degradation kinetics were studied via thermogravimetric analysis. The results show increase in crystallization rate, crystallinity percentage, Young’s modulus, strength and thermal stability of MA-g-PP by addition of the silica particles. Further it was observed that the small-sized dispersed phase had better overall thermal and mechanical behavior than its larger sized counterpart. 相似文献
54.
Anthony J. De Lucca Carol H. Carter‐Wientjes Stephen M. Boué Mary P. Lovisa Deepak Bhatnagar 《Journal of food science》2013,78(7):M1029-M1035
Trans‐2‐hexenal (T2H), a plant‐produced aldehyde, was intermittently pumped over a 7 d period into a small, bench top model of stored corn (nonsterile, moisture content about 23%). Naturally occurring bacteria and fungi, including added Aspergillus flavus, grew rapidly on corn not treated with T2H vapor. However, intermittently pumped T2H (30 min per 2 h or 30 min per 12 h) significantly reduced bacterial and fungal viable populations, with nearly 100% fungal viability loss observed after either (1) one day of pumping at the 30 min per 2 h rate or (2) pumping cycles of 30 min per 12 h period over the initial 48 to 72 h of incubation. Data suggest that short‐term intermittent fumigation of stored corn with T2H could prevent growth of bacteria and mycotoxigenic fungi such as A. flavus. 相似文献
55.
56.
Ajay Bhatnagar Michael J. Hoffman Reinhold H. Dauskardt 《Journal of the American Ceramic Society》2000,83(3):585-596
Fracture and environmentally assisted subcritical crack-growth processes are examined in bulk Y-Si-Al-O-N oxynitride glasses with compositions typical of the grain boundary phase of silicon nitride ceramics. Both long-crack (in compact tension specimens) as well as short-crack behavior (using indentation techniques) were investigated to establish a reliable fracture toughness and to elucidate the anomalous densification behavior of the oxynitride glass. Environmentally assisted subcritical crack-growth processes were studied in inert, moist, and wet environments under both cyclic and static loading conditions. Behavior is discussed in terms of the interaction of the environment with the crack tip. Likely mechanisms for environmentally assisted crack growth are discussed and related to the subcritical crack-growth behavior of silicon nitride ceramics. 相似文献
57.
B. J. Skromme E. Luckowski K. Moore M. Bhatnagar C. E. Weitzel T. Gehoski D. Ganser 《Journal of Electronic Materials》2000,29(3):376-383
Electrical properties, including current-voltage (I-V) and capacitance-voltage (C-V) characteristics, have been measured on
a large number of Ti, Ni, and Pt-based Schottky barrier diodes on 4H-SiC epilayers. Various nonideal behaviors are frequently
observed, including ideality factors greater than one, anomalously low I-V barrier heights, and excess leakage currents at
low forward bias and in reverse bias. The nonidealities are highly nonuniform across individual wafers and from wafer to wafer.
We find a pronounced linear correlation between I-V barrier height and ideality factor for each metal, while C-V barrier heights
remain constant. Electron beam induced current (EBIC) imaging strongly suggests that the nonidealities result from localized
low barrier height patches. These patches are related to discrete crystal defects, which become visible as recombination centers
in the EBIC images. Alternative explanations involving generation-recombination current, uniform interfacial layers, and effects
related to the periphery are ruled out. 相似文献
58.
59.
Compressive behaviour of open and closed cell polyurethane foam samples under large deformation is studied using micro-Computed Tomography (micro-CT), Digital Volume Correlation (DVC) technique and micro-Finite Element (micro-FE) modelling. The micro-CT images of the foam samples at different compression strains are used to determine anisotropy in the foams, to obtain qualitative information on deformation mechanisms, to quantify the deformation and strains using a local DVC approach and to generate images for micro-FE modelling of the foam samples. Micro-FE modelling predicts the deformation using an elastoplastic material model coupled with continuum damage mechanics. Two different types of boundary conditions, experimentally derived (ExBC) and interpolated from DVC (IPBC), were implemented to evaluate the displacements in the micro-FE models. A reduced integration scheme in micro-FE analysis resulted in high artificial energy and was discarded in favour of full integration. The displacement predicted by IPBC matched with DVC displacement contours for closed cell foam. The ExBC-predicted axial displacement (W) showed a better agreement with DVC than transverse displacements (U, V) contours. However, a significant statistical comparison (R2 > 0.70) of all displacements was obtained for both IPBC and ExBC. For open cell foam, both boundary conditions predicted a significant difference in the displacement contours with respect to DVC measurements. Still, the axial displacements of ExBC and IPBC showed a better statistical significance (R2 > 0.70). 相似文献
60.
The systems Y3–x
GdxFe5O12 withx=0, 0.5 and 3 have been synthesized by the amorphous citrate process. Their structural and magnetic properties have been studied for various heat-treatment schedules. The systems withx=0, 0.5 and 3 are amorphous when heat treated up to 650, 600 and 500° C, respectively, and the results of amorphous, as well as crystallized, samples are discussed. The volume fraction of the garnet phase is found to increase with higher heat-treatment temperature. Besides the garnet phase, two other phases appear to grow, the volume fraction of the spinel phase increasing with increase in gadolinium concentration. Microstructral properties have been further correlated with the magnetic properties. 相似文献