http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Upender (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
Spectroscopic and Optical Properties of the VO2+ ion doped TeO2-TiO2-ZnO-Nb2O5 glass system
Swapna,G. Upender,V. Sreenivasulu,M. Prasad 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.8
Studies such as optical absorption, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Electron paramagnetic resonance (EPR) spectroscopy and Differential scanning calorimetry (DSC) were carried out on VO2+ ion doped TeO2-TiO2-ZnO-Nb2O5 glass system. Raman and FTIR spectra of the glasses revealed the presence of [TeO3], [TeO4] and [NbO6] structural units in the glass network. The Urbach energy (E), cut-off wavelength (c), optical band gap (Eopt), optical basicity () and electron polarizability () of the glasses were determined from optical absorption studies. The density (), molar volume (Vm), oxygen molar volume (Vo) and refractive index (n) were also measured. Spin-Hamiltonian parameters were calculated from the EPR studies. When Nb2O5 was increased at the expense of ZnO, the density, optical band gap and Urbach energy of the glasses increased, and the electronic polarizability and optical basicity decreased. The EPR spectra clearly showed that vanadium was in the glass as VO2+ and occupied octahedral sites with tetrahedral compression. Spin-Hamiltonian parameters gk and g? decreased as Nb2O5 content increased in the glass. The glass transition temperature (Tg) also increased with increasing Nb2O5 content in the glass.
-
M. VENKATESWARLU,G. UPENDER REDDY,D. VENKATA LAKSHMI 한국산업응용수학회 2018 Journal of the Korean Society for Industrial and A Vol.22 No.4
This paper examined the MHD and thermal behavior of unsteady mixed convection flow of a rotating fluid in a porous parallel plate channel in the presence of Hall current and heat source. The exact solutions of the concentration, energy and momentum equations are obtained. The influence of each governing parameter on non dimensional velocity, temperature, concentration, skin friction coefficient, rate of heat transfer and rate of mass transfer at the porous parallel plate channel surfaces is discussed. During the course of numerical computation, it is observed that as Hall current parameter and Soret number at the porous channel surfaces increases, the primary and secondary velocity profiles are increases while the primary andsecondaryskinfrictioncoefficientsareincreasesatthecoldwallanddecreasesattheheated wall. In particular, it is noticed that a reverse trend in case of heat source parameter
-
Suresh Sripada,D. Esther Kalpana Rani,G. Upender,P. Gayathri Pavani 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.5
Titanium boro tellurite glasses in the xB<sub>2</sub>O<sub>3</sub>−(90−x) TeO<sub>2</sub> + 10TiO<sub>2</sub> (where x = 0 to 50 mol%) system were prepared by using the conventional melt-quenching technique. Glass transition temperatures were measured with differential scanning calorimetry (DSC) and found to be in the range of 300 - 370 ℃. The Raman spectra showed a cleavage of the continuous TeO<sub>4</sub> (tbp) network by breaking of the Te-O-Te linkages. The relative transition of TeO<sub>4</sub> − groups to TeO<sub>3</sub> − groups is accompanied by a change in the oxygen coordination of the boron from 3 to 4 (BO<sub>3</sub> <sup>−</sup> to BO<sub>4</sub> <sup>−</sup>). The impedance plots Z▼(┺) versus Z▽(┺) for all the glass samples were recorded and found to exhibit a single circle. The AC conductivity of all glass samples was studied in the frequency range from 100 Hz to 1 MHz and in the temperature range from room temperature (RT) to 375 ℃. The AC conductivity decreased by about one order in magnitude with increasing B<sub>2</sub>O<sub>3</sub> content. The conductivity was found to be on the order of 10<sup>−4.5</sup> to 10<sup>−6</sup> (┯-cm)<sup>−1</sup> at 375 → and 1 MHz for 10 mol% and 50 mol% B<sup>2</sup>O<sup>3</sup> contents, respectively. The relaxation behavior in these glass samples is discussed based on the complex modulus and impedance data.
-
( Rupa Banerjee ),( Partha Pal ),( Zaheer Nabi ),( Upender Shava ),( Girish Ganesh ),( D. Nageshwar Reddy ) 대한장연구학회 2021 Intestinal Research Vol.19 No.4
Background/Aims: Information on pediatric inflammatory bowel disease (PIBD) and very early onset IBD (VEOIBD) are sparse in India, where IBD is emerging. We aimed to evaluate characteristics of VEOIBD and later onset PIBD (LO-PIBD) in India. Methods: We performed retrospective analysis of a large, prospectively maintained IBD registry. PIBD was divided in to VEOIBD (<6 years) and LO-PIBD (6-17 years). Demographic data, disease characteristics and treatment were compared between the PIBD groups and with other Asian/Western studies as well as the adult patients of the registry. Results: Of 3,752 IBD patients, 292 (7.8%) had PIBD (0-17 years) (175 Crohn’s disease [CD], 113 ulcerative colitis [UC], 4 IBD-undifferentiated; 22 VEOIBD [7.5%], and 270 LO-PIBD [92.5%]). VEOIBD patients had more severe disease compared to LO-PIBD in both UC (P= 0.003) and CD (P< 0.001). Familial IBD was more common in VEOIBD (13.6%) compared to LO-PIBD (9.2%). Ileal disease (L1) was an independent risk factor for diagnostic delay in pediatric CD. Diagnostic delay ( >6 months) was significantly lower in VEOIBD (40.9%) than in LO-PIBD (78.8%) (P< 0.001). Compared to other Asian and Western studies, extensive UC (72.5%) and complicated CD (stricturing/penetrating: 42.7%) were relatively more common. Perianal CD was relatively less frequent (7.4%). PIBD had a significantly higher number of complicated and ileal CD and extensive UC comparison to adult cohort of the registry. Conclusions: VEOIBD has more aggressive phenotype than LO-PIBD. Disease appears distinct from other Asian and Western studies and adult onset disease, with more complicated CD and extensive UC. (Intest Res 2021;19:398-407)
ScienceON
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
