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41.
Pratap V Moumen N Subramanian RS 《Langmuir : the ACS journal of surfaces and colloids》2008,24(9):5185-5193
42.
N. Sankara Subramanian R. Vivek Sabaapathy P. Vickraman G. Vimal Kumar R. Sriram B. Santhi 《Ionics》2007,13(5):323-328
P-type porous silicon (PS) structure has been prepared by anodic electrochemical etching process under optimized conditions.
Photoluminescence studies of the PS structure show emission at longer wavelengths (red) for the excitation at 365 nm. Scanning
electron microscope investigations of the PS surface confirm the formation of uniform porous structure, and the pore diameter
have been estimated as 25 μm. Pd:SnO2/PS/p-Si heterojunction with top gold ohmic contact developed by conventional methods has been used as the sensor device.
Sensing properties of the device towards liquefied petroleum gas (LPG) and NO2 gas have been investigated in an indigenously developed sensor test rig. The response and recovery characteristics of the
sensor device at different operating temperatures show short response time for LPG. From the studies, maximum sensitivity
and optimum operating temperature of the device towards LPG and NO2 gas sensing has been estimated as 69% at 180 °C and 52% at 220 °C, respectively. The developed sensor device shows a short
response time of 25 and 57 s for sensing LPG and NO2 gases, respectively.
Paper presented at the Third International Conference on Ionic Devices (ICID 2006), Chennai, Tamilnadu, India, Dec. 7–9, 2006. 相似文献
43.
Complex impedance spectra were obtained on a crystal of CaCu3Ti4O12 (CCTO) from 289 to 456 K. As in the case of ceramic CCTO, these spectra can be interpreted as arising from a conducting material containing insulating barriers. This is then further evidence for the existence of planar defects within crystals of CCTO that act as insulating barriers and produce the large dielectric constant through a space charge mechanism. 相似文献
44.
Single-phase undoped LiNi0.8Co0.2O2 and Sr2+-doped LiNi0.8Co0.2O2 were synthesized by a low temperature tartaric acid assisted sol-gel method. Small quantities of Sr2+ were used as dopants in order to improve the electrochemical characteristics, especially the capacity and cycling performance
of LiNi0.8Co0.2O2. The electrochemical performance of the undoped material was promising with a first discharge capacity of 174 mAh/g and 165
mAh/g after 10 cycles with a 100% cycling efficiency in the tenth cycle. Addition of Sr2+ for Li in minimum quantities with the Sr2+/Li+ dopant mole ratio ranging from 10−4 to 10−8 resulted in improved electrochemical properties for dopant mole ratio of 10−6. The first discharge capacity was 182 mAh/g and the tenth was 174 mAh/g at the 10th discharge. The synthesis of Sr2+-doped LiNi0.8Co0.2O2 and its improved electrochemical properties have been discussed for the first time. The improved electrochemical properties
of Sr2+-doped LiNi0.8Co0.2O2 system are explained based on defect models. 相似文献
45.
S. Lal R. Raghavan T. N. Rangaswamy B. V. Sreekantan A. Subramanian S. D. Verma S. C. Tonwar R. H. Vatcha 《Proceedings Mathematical Sciences》1971,73(4):170-178
Detailed features of extremely collimated nuclear interactions induced by cosmic ray particles in carbon and brass (belonging to group I as classified in Part I of this series of papers) are presented. These extremely collimated nuclear interactions seem to be preferentially induced by pions rather than by nucleons; also the relative frequency of these seems to be less when brass is used as target compared to the case with carbon as target. The distribution of multiplicities of secondary particles emitted in the forward direction show certain regularities in the case of interactions induced by charged primaries. Observations on the γ-rays associated with these events give support to the interpretation that in these inelastic collisions pions are produced in pairs in the forward direction with low transverse momentum. It is suggested that such a low energy di-pion system could be the same as found in the so-called ABC effect. 相似文献
46.
Wei Wang Dr. Parthasarathi Subramanian Oscar Martinazzoli Jun Wu Prof. Dr. Lutz Ackermann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(45):10585-10589
Late-stage C−H glycosylations of structurally complex amino acids and peptides were accomplished by means of racemization-free manganese(I)-catalyzed C−H activation. Thus, glycosylative modifications proved to be viable by a linch-pin approach, featuring chemo- and site-selective C−H transformations. The peptide–saccharide conjugation provided modular access to structurally complex glycopeptides, likewise enabling the assembly of fluorescent-labelled glycopeptides. 相似文献
47.
Velusamy B. Subramanian Naresh Kumar Katari Thirupathi Dongala Sreekantha B. Jonnalagadda 《Biomedical chromatography : BMC》2020,34(1):e4719
A quality by design (QbD) based high-resolution HPLC method is described for determination of impurities in apixaban (APX) in the tablet dosage form. Employing a simple and stability-indicating HPLC method, nine known impurities were quantified with good peak resolution. Mobile phase A (MP-A) was prepared with buffer and acetonitrile 90:10 v/v, while mobile phase B (MP-B) contained water and acetonitrile 10:90 v/v. The gradient program was 0 min, MP-A 75%, B 25%; 20 min, MP-A 65%, B 35%; 30 min, MP-A 40%, B 60%; 40min, MP-A 40%, B 60%; 42 min, MP-A 75%, B 25%; and 50 min, MP-A 75%, B 25%. The chromatographic separation was achieved using a Zorbax RX C18 250 × 4.6 mm column, 5 μm (1.0 ml min−1, 280 nm, 50 μl) and a column temperature of 40°C. Several separation studies were carried out using design of experiments to optimize the method. Validation results confirm the applicability of the developed method for quality analysis and stability studies of the regular product on the manufacturing stream. 相似文献
48.
Two-unit warm standby redundant systems have been investigated extensively in the past. The most general model is the one
in which both the lifetime and repair time distributions of the units are arbitrary. However the study of standby systems
with more than two units, though very important, has received much less attention, possibly because of the built-in difficulties
in analyzing them. Such systems have been studied only when either the lifetime or the repair time is exponentially distributed.
When both these distributions are general, the problem appears to be intractable even in the case of cold standby systems.
The present contribution is an improvement in the state of art in the sense that a three unit warm standby system is shown
to be capable of comprehensive analysis. In particular we show that there are imbedded renewal points that render the analysis
possible. Using these imbedded renewal points we obtain the reliability and availability functions.
Emeritus
Deceased 23rd December 2003. 相似文献
49.
50.
M. Murugesan P. Selvam M. Sharon L. C. Gupta R. Pinto C. S. Gopinath S. Subramanian 《Applied Physics A: Materials Science & Processing》1997,64(2):177-179
Single phase Ba-free Sr-based YSr2Cu
3-x
M
x
O7+δ (M=Mo, W and Re) compounds have been stabilized by chemical doping. Superconductivity is observed for these phases in the
range 30–45 K. X-ray diffraction studies suggest a relatively small orthorhombicity compared to Ba-analogue. X-ray photoelectron
spectroscopic investigations reveal that the stabilizing cations are in the hexavalent state. The observation of the higher
oxidation state of M-ions accounts for the excess oxygen content in these phases which is in accordence with the diffraction
results.
Received: 10 June 1996 / Accepted: 20 September 1996 相似文献