http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Shah, Syed M.,Ravi Kumar, G.V.P.P.S.,Brah, G.S.,Santra, Lakshman,Pawar, Hitesh Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.7
Peripheral blood mononuclear cells (PBMCs) discriminate microbial pathogens and induce T-cell responses of appropriate effector phenotype accordingly. Toll-like receptors (TLRs), in part, mediate this microbial recognition and differentiation while the development of T-cell effector functions critically depends on the release of Th1- or Th2- type cytokines. In the present study, buffalo PBMCs were stimulated under in vitro culture conditions by Bacillus subtilis cell wall petidoglycan, a TLR2 ligand, in a dose- and time- dependent manner. The expression of TLR2 as well as the subsequent differential induction of the Th1 and Th2 type cytokines was measured. Stimulation was analyzed across five doses of peptidoglycan ($10{\mu}g/ml$, $20{\mu}g/ml$, $30{\mu}g/ml$, $40{\mu}g/ml$ and $50{\mu}g/ml$) for 3 h, 12 h, 24 h and 36 h incubation periods. We observed the induction of TLR2 expression in a dose- and time-dependent manner and the peptidoglycan induced tolerance beyond $30{\mu}g/ml$ dose at all incubation periods. The correlation between peptidoglycan stimulation and TLR2 induction was found positive at all doses and for all incubation periods. Increased production of all the cytokines was observed at low doses for 3 h incubation, but the expression of IL-4 was relatively higher than IL-12 at the higher antigen doses, indicating tailoring towards Th2 response. At 12 h incubation, there was a pronounced decrease in IL-4 and IL-10 expression relative to IL-12 in a dose- dependent manner, indicating skewing to Th1 polarization. The expression of IL-12 was highest for all doses across all the incubation intervals at 24 h incubation, indicating Th1 polarization. The relative expression of TNF-${\alpha}$ and IFN-${\gamma}$ was also higher while that of IL-4 and IL-10 showed a decrease. For 36 h incubation, at low doses, relative increase in the expression of IL-4 and IL-10 was observed which decreased at higher doses, as did the expression of all other cytokines. The exhaustion of cytokine production at 36 h indicated that PBMCs became refractory to further stimulation. It can be concluded from this study that the cytokine response to sPGN initially was of Th2 type which skews, more pronouncedly, to Th1 type with time till the cells become refractory to further stimulation.
Supercapacitor and OER activity of transition metal (Mo, Co, Cu) sulphides
Jansi Rani, B.,Pradeepa, S.S.,Hasan, Zinab M.,Ravi, G.,Yuvakkumar, R.,Hong, S.I. Elsevier 2020 The Journal of physics and chemistry of solids Vol.138 No.-
<P><B>Abstract</B></P> <P>Multifunctional transition metal (Mo, Co, Cu) sulphide electrocatalysts were synthesized employing hydrothermal method with stabilization at 180 °C for 24 h for both supercapacitors and water splitting applications. Rhombohedral (MoS<SUB>2</SUB>) and hexagonal (CoS and CuS) structures of the electrocatalysts were identified from the X-ray diffraction patterns. Raman-active modes confirmed the characteristic phonon vibrations. The prepared sulphides optical studies were examined employing photoluminescence spectroscopy and UV spectroscopy. Morphological variations observed for different sulphide nanostructures were confirmed by the scanning electron microscopy images. A comparative electrochemical study of MoS<SUB>2</SUB>, CoS and CuS was performed. Of the three candidates, MoS<SUB>2</SUB> has superior capacitive behaviour, exhibiting very high specific capacitance of 513F/g at 0.5 A/g, and moreover exhibited the highest oxygen evolution reaction current density of 442.7 mA/g at a scan rate of 10 mV/s. Furthermore, it maintained its performance for longer in 1000 cycles of galvanostatic charging and discharging and in 12 h of an oxygen evolution reaction stability test.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High specific capacitance of 513 F/g at 0.5 A/g was achieved for MoS<SUB>2</SUB>. </LI> <LI> Stability of 98% was achieved for MoS<SUB>2</SUB> after 1000 cycles of galvanostatic charging and discharging. </LI> <LI> A high current density of 442 mA/g was achieved at 10 mV/s. </LI> <LI> After a chronoamperometry test for 12 h, 100% oxygen evolution reaction activity was obtained for MoS<SUB>2</SUB>. </LI> <LI> The MoS<SUB>2</SUB> electrode is highly recommended as an efficient electrode for energy applications. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Extraction of Fundamental Component in Power Quality Application using Tunable-Q Wavelet Transform
G.Ravi Shankar Reddy,Rameshwar Rao 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.8
Application of a Tunable-Q Wavelet Transform based technique is proposed in this paper for the extraction of Fundamental frequency component in Power Quality Disturbances. The TQWT filters are designed to extract the fundamental frequency component from the complete voltage (or) current signal. This is achieved by tuning the Q-factor and redundancy of the wavelet by primarily investigating the presence of interharmonics near the fundamental frequency. To test the effectiveness of the proposed scheme, the system is verified with various Power Quality Disturbances as per IEEE standards encountered in power system are considered here.
Ravi Kumar M G,Mrinal Sarvagya 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.12
Underwater Acoustic (UWA) channels are known as some of the most challenging communication media. Since the Underwater acoustic channels are time varying multipath channel achieving the high data rate, a low latency and a high throughput which often is a very difficult objective. In this work, we designed an OFDM transceiver system which is suitable for underwater acoustic communication with limited bandwidth to enhance the data rate at the receiver. To enhance the data rate at the OFDM receiver we have used efficient adaptive modulation scheme, channel estimation and channel equalization schemes for UWA communication. We have focused on the efficient modulation schemes like QPSK, DPSK and 16-QAM which is best suited for adaptive techniques based on the SNR of the Rayleigh fading channel to enhance the data rate. The simulation results show that the performance of the OFDM system with the use of Adaptive modulation is better when compared to the OFDM system without Adaptive modulation schemes. Also we have used the Kalman filter for channel estimation which minimizes the mean squared error and gives us the best estimation even in the presence of noise. From the simulation results, we have found that these modulation techniques and channel estimation method are best suited to achieve high data rate for underwater acoustic communication.
Electrical Properties of Copper Substituted Nickel Ferrites
G. Ravi Kumar,Y. C. Venudhar,A. T. Raghavender,K. Vijaya Kumar 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.7
The Ni-Cu ferrites, Ni1−xCuxFe2O4 (0.0 ≤ x ≤ 1.0) were prepared by using the sol-gel method. The X-ray diffraction patterns of all the samples showed the formation of a single-phase spinel structure. The lattice parameter was found to increase with increasing copper concentration. The electrical properties, such as the d. c. conductivity as a function of the temperature, and the dielectric constant, the dielectric loss factor and the dielectric loss tangent as function of the frequency were investigated. The d. c. conductivity was found to increase with increasing temperature in accordance with the Verwey hopping mechanism. The dielectric constant, the dielectric loss factor and the dielectric loss tangent were found to decrease with increasing frequency. The dielectric constant followed the Maxwell-Wagner interfacial polarization. A suitable explanation was given for the frequency and the composition dependences of the dielectric properties.
G. Ravi Shankar Reddy,Dr.Rameshwar Rao 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.11
In this paper Application of an Empirical Wavelet Transform based technique is proposed to estimate time-varying PQ indices for accurate assessment of Power Quality Disturbances. The EWT approach mainly aims to extract the actual fundamental frequency component and disturbance components from any distorted signal. The empirical wavelet transform consists of two major steps: detect the Fourier supports, and build the corresponding wavelet accordingly to those supports; filter the input signal with the obtained filter bank to get the fundamental component and disturbance components. Since the extracted components contain only one frequency component, Hilbert transform is utilized to estimate the instantaneous frequency and amplitude information, from this information we can estimate time-varying PQ indices. The proposed method is employed to assess successfully all sorts of Power Quality Disturbances such as voltage sag, swell, interruption, transients, harmonics, spikes, notches etc. From the results we can say that the proposed method detects disturbance start time, end time, duration of existence and its content more accurately.