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531.
We present here the effect of degradation on electronic properties of polymer solar cells. Investigations were performed on two types of solar cells based on the bulk‐heterojunction network of poly(3‐hexylthiophene) and phenyl [6,6] C61 butyric acid methyl ester, one with slow degradation whereas other with faster degradation. Samples were prepared in identical conditions with controlled atmosphere, but for faster degradation, one of the samples was exposed to ambient air (rich in O2 and H2O molecules) before deposition of top metal electrode. The sample with slow degradation showed linear degradation in short circuit current density (Jsc), whereas the sample with faster degradation exhibited exponential degradation in Jsc. Linear degradation happens due to degradation in the active layer only whereas the exponential degradation is because of through degradation of the solar cell. The effect of degradation is investigated on different diode parameters. Because of different degradation processes in the two samples, the variations in diode parameters with time are different. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
532.
The characteristic of the radiation emitted from relativistic positrons channelled between the major planes in single crystal have been calculated. The sharp peaks of the emission spectrum in the keV region is predicted correctly and is compared with previous calculations. 相似文献
533.
A. Khalife U. Pathak R. Richert 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,83(4):429-435
Steady state and time-resolved dielectric relaxation experiments are performed at high
fields on viscous glycerol and the effects of energy absorption from the electric field
are studied. Time resolution is obtained by a sinusoidal field whose amplitude is switched
from a low to a high level and by recording voltage and current traces with an
oscilloscope during this transition. Based on their distinct time and frequency
dependences, three sources of modifying the dynamics and dielectric loss via an increase
in the effective temperature can be distinguished: electrode temperature, real sample
temperature, and configurational temperatures of the modes that absorbed the energy.
Isothermal conditions that are desired for focusing on the configurational temperature
changes (as in dielectric hole burning and related techniques) are maintained only for
very thin samples and for moderate power levels. For high frequencies, say
ν > 1 MHz, changes of the real temperature will
exceed the effects of configurational temperatures in the case of macroscopic samples.
Regarding microwave chemistry, heating via cell phone use, and related situations in which
materials are subject to fields involving frequencies beyond the MHz regime, we conclude
that changes in the configurational (or fictive) temperatures remain negligible compared
with the increase of the real temperature. This simplifies the assessment of how time
dependent electric fields modify the properties of materials. 相似文献
534.
535.
Vijai N. Pathak Rahul Joshi Neetu Gupta 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2365-2378
A series of [N-(un)alkylated-2-arylindol-3-yl]thiocarboxamides(6) have been synthesized by the condensation of alkyl [N-(un)alkylated-2-arylindol-3-yl]dithiocarboxylates (5) with appropriate secondary amines in absolute alcohol. Compound 5 was prepared by the reaction of N-(un)alkylated-2-arylindoles with carbon disulphide in the presence of potassium-t-butoxide followed by alkyl iodide under nitrogen atmosphere. All of the compounds have been characterized on the basis of their elemental and spectral data and have been screened for their antibacterial and antifungal activities. Some of the synthesized compounds have shown promising activity. 相似文献
536.
A. S. Kanekar P. N. Pathak P. K. Mohapatra V. K. Manchanda 《Journal of Radioanalytical and Nuclear Chemistry》2010,283(3):789-796
Extraction of uranium from tissue paper, synthetic soil, and from its oxides (UO2, UO3 and U3O8) was carried out using supercritical carbon dioxide modified with methanol solutions of extractants such as tri-n-butyl phosphate (TBP) or N,N-dihexyl octanamide (DHOA). The effects of temperature, pressure, extractant/nitric acid (nitrate) concentration, and of hydrogen
peroxide on uranium extraction were investigated. The dissolution and extraction of uranium in supercritical CO2 modified with TBP, from oxide samples followed the order: UO3 ≫ UO2 > U3O8. Addition of hydrogen peroxide in the modifier solution enhanced the dissolution/extraction of uranium in dynamic mode. DHOA
appeared better than TBP for recovery of uranium from different oxide samples. Similar enhancement in uranium extraction was
observed in static mode experiments in the presence of hydrogen peroxide. Uranium estimation in the extracted fraction was
carried out by spectrophotometry employing 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Br-PADAP) as the chromophore. 相似文献
537.
D. K. Pant G. A. Chaugule K. K. Gupta P. G. Kulkarni P. B. Gurba P. Janardan R. D. Changrani P. K. Dey P. N. Pathak D. R. Prabhu A. S. Kanekar V. K. Manchanda 《Journal of Radioanalytical and Nuclear Chemistry》2010,283(2):513-518
This paper deals with the optimization of experimental conditions for the estimation of Np in spent fuel dissolver solution using 2-thenoyltrifluoroacetone (HTTA) as extractant. The quantitative extraction of Np from the dissolver solution employing 0.5 M HTTA/xylene was followed by its estimation by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) after stripping it from the organic phase with 8 M HNO3. The reliability of the method was checked by standard addition technique. The method is precise and accurate yielding Np analytical recovery of 99 ± 1%. 相似文献
538.
Dhurba Rai Anant D. Kulkarni Shridhar P. Gejji Rajeev K. Pathak 《Theoretical chemistry accounts》2009,123(5-6):501-511
It is demonstrated through the present ab initio theoretical investigation that an external electric field can bring about a phenomenal enhancement in the strength of the bond between water and carbon-dioxide molecules from a van der Waals type (binding energy ~0.085 eV), to strong covalent type (binding energy ~7.45 eV), resulting in an exotic molecular complex. The onset of this effect is characterized by an abrupt change in the dipole moment of the composite system at a particular field-value, concomitant with the O–C=O ? O=C–O resonance in the CO2 moiety of the complex. This field-induced bond formation is further confirmed by the emergence of a characteristic intermolecular stretching mode (~317 cm?1) in the vibrational response of the system. This exotic bond that exhibits a covalent-like character, which accompanied by a charge-transfer, renders the carbon atom a substantial negative charge. 相似文献
539.
Some new 2-[5-(aryl)-[1,3,4]oxadiazole-2-ylsulfanyl]alkanoic acids were synthesized and studied for their antibacterial activity. These compounds were prepared from aromatic carboxylic acid hydrazides. Aromatic carboxylic acid hydrazides 1 on refluxing with carbon disulfide and methanolic potassium hydroxide and then on subsequent acidification with hydrochloric acid furnish 5-aryl-1,3,4-oxadiazole-2-thiones 2. 2-Chloro alkanoic acids react with 2 in alkaline media and on acidification yield the title compounds 3. These compounds were characterised by CHN analyses, IR, mass and 1H NMR spectral data. All the compounds were evaluated for their in vitro antibacterial activity against two Gram negative strains (Escherichia coli and Pseudomonas aeruginosa) and two Gram positive strains (Bacillus subtilis and Staphylococcus aureus) and their minimum inhibitory concentration (MIC) were determined. 相似文献
540.
H.K. Pathak 《Nonlinear Analysis: Theory, Methods & Applications》2009,71(12):6068-6076
In this paper, we introduce the concept of generalized quasicontraction mappings in an abstract metric space. By using this concept, we construct an iterative process which converges to a unique fixed point of these mappings. The result presented in this paper generalizes the Banach contraction principle in the setting of metric space and a recent result of Huang-Zhang for contractions. We also validate our main result by an example. 相似文献