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11.
Allakhverdiev K Ismailov N Salaeva Z Mikailov F Gulubayov A Mamedov T Babaev S 《Applied optics》2002,41(1):148-153
We report the results of investigating a low-voltage, polarization-insensitive, reflective-type modulator based on an epsilon-GaSe crystal and operated at the 1.960-eV line of a He-Ne laser. We demonstrate that the modulation in an Al-epsilon-GaSe-Cu device results mainly from the Franz-Keldysh effect. Relatively high speed and low operating voltage could make these modulators with Schottky-barrier contacts attractive devices in the red range of the spectrum. 相似文献
12.
Sardar Muhammad Bilal Atta ur Rehman Khan Samee Ullah Khan Sajjad A. Madani Babar Nazir Mazliza Othman 《Wireless Personal Communications》2014,77(4):2497-2515
Over the last few years, vehicular ad hoc networks (VANETs) have gained popularity for their interesting applications. To make efficient routing decisions, VANET routing protocols require road traffic density information for which they use density estimation schemes. This paper presents a distributed mechanism for road vehicular density estimation that considers multiple road factors, such as road length and junctions. Extensive simulations are carried out to analyze the effectiveness of the proposed technique. Simulation results suggested that, the proposed technique is more accurate compared to the existing technique. Moreover, it facilitate VANET routing protocols to increase packet delivery ratio and reduce end-to-end delay. 相似文献
13.
M. Hariharan C.Y. Fook R. Sindhu Abdul Hamid Adom Sazali Yaacob 《Digital Signal Processing》2013,23(3):952-959
Dysfluency and stuttering are a break or interruption of normal speech such as repetition, prolongation, interjection of syllables, sounds, words or phrases and involuntary silent pauses or blocks in communication. Stuttering assessment through manual classification of speech dysfluencies is subjective, inconsistent, time consuming and prone to error. This paper proposes an objective evaluation of speech dysfluencies based on the wavelet packet transform with sample entropy features. Dysfluent speech signals are decomposed into six levels by using wavelet packet transform. Sample entropy (SampEn) features are extracted at every level of decomposition and they are used as features to characterize the speech dysfluencies (stuttered events). Three different classifiers such as k-nearest neighbor (kNN), linear discriminant analysis (LDA) based classifier and support vector machine (SVM) are used to investigate the performance of the sample entropy features for the classification of speech dysfluencies. 10-fold cross validation method is used for testing the reliability of the classifier results. The effect of different wavelet families on the classification performance is also performed. Experimental results demonstrate that the proposed features and classification algorithms give very promising classification accuracy of 96.67% with the standard deviation of 0.37 and also that the proposed method can be used to help speech language pathologist in classifying speech dysfluencies. 相似文献
14.
Tailoring magnetic and dielectric properties of rubber ferrite composites containing mixed ferrites 总被引:1,自引:0,他引:1
M. R. Anantharaman K. A. Malini S. Sindhu E. M. Mohammed S. K. Date S. D. Kulkarni P. A. Joy Philip Kurian 《Bulletin of Materials Science》2001,24(6):623-631
Rubber ferrite composites containing various mixed ferrites were prepared for different compositions and various loadings.
The magnetic and dielectric properties of the fillers as well as the ferrite filled matrixes were evaluated separately. The
results are correlated. Simple equations are proposed to predetermine the magnetic and dielectric properties. The validity
of these equations is verified and they are found to be in good agreement. These equations are useful in tailoring the magnetic
and dielectric properties of these composites with predetermined properties. 相似文献
15.
K. Mohanan C.J. Athira Y. Sindhu M.S. Sujamol 《中国稀土学报(英文版)》2009,27(5):705-710
A heterocyclic ligand synthesized by the coupling of diazotized 4-aminoantipyrine with acetylacetone reacted with lanthanide(III) nitrate to form complexes of the type [Ln(HAAP)2(NO3)3] where, Ln=La(III), Ce(III), Pr(III), Nd(III), Sm(III), or Gd(III) and HAAP= 3-{[2-(N-1-phenyl-2,3-dimethylpyrazol-3-in-5-on-4-yl)]hydrazone}pent-2,3,4-trione. The ligand and metal complexes were characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements, UV-Visible, infrared, far infrared and proton NMR spectral data. The spectral data revealed that the ligand existed in the hydrazo form and coordinated to the metal ion without deprotonation in a neutral tridentate manner, through carbonyl oxygen of pyrazolone ring, hydrazo nitrogen and carbonyl oxygen of the acetylacetone moiety. The molar conductance values adequately supported their non-electrolytic nature. The ligand and the praseodymium(III) complex were subjected to X-ray diffraction studies. Thermal decomposition behavior of the lanthanum(III) complex was also examined. 相似文献
16.
Grapefruit juice is consumed widely in today's health conscious world as a protector against cardiovascular diseases and cancers.
It has however, been found to be an inhibitor of the intestinal cytochrome P – 450 3A4 system, which is responsible for the
first pass metabolism of many drugs. The P – glycoprotein pump, found in the brush border of the intestinal wall which transports
many of these cytochrome P – 450 3A4 substrates, has also been implicated to be inhibited by grapefruit juice. By inhibiting
these enzyme systems, grapefruit juice alters the pharmacokinetics of a variety of medications, leading to elevation of their
serum concentrations. Most notable are its effects on the calcium channel antagonist and the statin group of drugs. In the
case of many drugs, the increased serum concentration has been found to be associated with increased frequency of dose dependent
adverse effects. In this review, we have discussed the phytochemistry of grapefruit juice, the various drugs involved in the
drug – grapefruit juice eraction with their mechanisms of action and have presented the clinical implications of these interactions. 相似文献
17.
K. Mohanan B. Sindhu Kumari G. Rijulal 《中国稀土学报(英文版)》2008,26(1):16-21
A bishydrazone formed by the condensation of isatinmonohydrazone and salicylaldehyde reacted with lanthanide(Ⅲ) chloride to form complexes of the type [Ln(HISA)2Cl3], where, Ln=La(Ⅲ), Ce(Ⅲ), Pr(Ⅲ), Nd(Ⅲ), Sm(Ⅲ), Eu(Ⅲ), or Gd(Ⅲ) and HISA= [(2-hydroxybenzaldehyde)-3-isatin]bishydrazone. Both reactions were carried out under microwave conditions. The ligand and the metal complexes were characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements, UV visible, infrared, far infrared, and proton NMR spectral data. The ligand acted as neutral tridentate, coordinating through the carbonyl oxygen, azomethine nitrogen, and phenolic oxygen without deprotonation. The ligand and lanthanum(Ⅲ) complex were subjected to X-ray diffraction studies. The X-ray diffraction pattern of ligand exhibited its crystalline nature and that of the lanthanum(Ⅲ) complex indicated its amorphous character. The thermal decomposition behaviour of the complex, [La(HISA)2Cl3], was examined in the temperature range of 40-800 ℃ using TG, DTG, and DTA. The ligand and the metal complexes were screened for their antifungal activities. 相似文献
18.
Archana Pandey Abhishek Prasad Sindhu Singh Om Parkash Devendra Kumar 《Journal of Materials Science: Materials in Electronics》2008,19(11):1122-1127
Effect of manganese and cobalt doping (0.50 mole%) on electrical properties of ZnO based varistors has been studied using
complex plane modulus analysis. It is found that total resistivity of Mn doped sample is more as compared to that of Co doped
sample. This has been ascribed to existence of Mn in variable valence states viz. Mn2+, Mn3+ and Mn4+ which promotes hopping conduction leading to increase in the conductivity as compared to Co doped sample, in which Co exists
predominantly in +3 state with traces of Co2+ or Co+4 states. This accounts for its less conductivity. Mechanism of conduction is the same for grains and grainboundaries. 相似文献
19.
This study addresses the fully developed magnetohydrodynamic flow of non-Newtonian fluid in a microchannel using tangent hyperbolic fluid model. The physical situation has been modeled by accessing boundary layer theory along with the physical aspects of thermophoresis and Brownian motion. The heat and mass transport phenomena are depicted through graphical interpretations. The modeled equations are nondimensionalized using dimensionless variables. The obtained corresponding equations are solved by employing Runge–Kutta–Fehlberg scheme accompanied with shooting technique. The fluctuations in distinct entities of physical connotations, like, the Nusselt number, friction factor and Sherwood number are explored in this examination. A notable reduction in the concentration field of the tangent hyperbolic fluid has been obtained for a larger chemical reaction parameter. The result shows that non-Newtonian fluids exhibit higher Nusselt number than Newtonian fluids. Furthermore, a significant enhancement in Nusselt number has been attained through a rise in the power-law index and thermophoresis aspect. 相似文献
20.
The present investigation throws light on the heat transfer behavior of hybridized (ferro-aluminum alloy [AA7075]) nanofluid. In addition to that, influences of thermal radiation, magnetic effect, and chemical reaction are also considered for the exploration. Here, the flow is deliberated due to a porous stretching cylinder. The equations that portray the fluid flow are transfused to simple ordinary differential equations by applying similarity elements. Then, the procured equations have been solved by adopting the Runge–Kutta–Fehlberg 4th–5th order tool. The extracted solution are exported to plot graphs for velocity, thermal, and solutal profiles with the concerned parameters, and using these plots, the discussion has been produced for the behavior of all flow fields. The behavior of the thermal profile shows substantial enhancement with an increase in the solid volume fraction of hybrid nanofluid. The velocity and concentration panel de-escalates for larger values of Reynolds number. A significant discussion on the skin friction drag, Nusselt number, and Sherwood number has been produced. 相似文献