RF Performance Enhancement of Gallium Oxide MOSFET using p-type NiO Pocket near Source and Drain Regions

The paper puts forward an impact of using p-type NiO pocket near the channel/drain and channel/source interface regions on the RF performance of the gallium oxide MOSFET. This arrangement results in smaller electric field near the respective junctions and helps to compensate for the leakages that arises from the increased value of parasitic components. The key figures of merits used in the analysis are transconductance (gm), intrinsic capacitances (gate to drain capacitance Cgd and gate to source capacitance Cgs), output conductance (gd), cut-off frequency (fT), transconductance frequency product (TFP), gain frequency product (GFP) and the gain transconductance frequency product (GTFP). The analysis was carried out by using Atlas 2D device simulator

Boosting Principal Component Analysis by Genetic Algorithm

This paper presents a new method of feature extraction by combining principal component analysis and genetic algorithm. Use of multiple pre-processors in combination with principal component analysis generates alternate feature spaces for data representation. The present method works out the fusion of these multiple spaces to create higher dimensionality feature vectors. The fused feature vectors are given chromosome representation by taking feature components to be genes. Then these feature vectors are allowed to undergo genetic evolution individually. For genetic algorithm, initial population is created by calculating probability distance matrix, and by applying a probability distance metric such that all the genes which lie farther than a defined threshold are tripped to zero. The genetic evolution of fused feature vector brings out most significant feature components (genes) as survivours. A measure of significance is adapted on the basis of frequency of occurrence of the surviving genes in the current population. Finally, the feature vector is obtained by weighting the original feature components in proportion to their significance. The present algorithm is validated in combination with a neural network classifier based on error backpropagation algorithm, and by analysing a number of benchmark datasets available in the open sources.Defence Science Journal, 2010, 60(4), pp.392-398, DOI:http://dx.doi.org/10.14429/dsj.60.49

Effect of Shifting Cultivation on Soil Microbial Biomass C, N and P under the Shifting Cultivations Systems of Kangchup Hills, Manipur, North- East India

ABSTRACT: The seasonal changes in the soil microbial biomass C, N and P have been carried out in four different shifting cultivation sites i.e., recently slashed and burnt site, 3-year old fallow site, 7-year old fallow site and a protected forest site. The soil microbial biomass C, N and P was found to be maximum in protected forest site followed by 7-year old fallow site, 3-year old fallow site and minimum in recently slash and burnt site. Seasonally microbial biomass C, N and P were highest during rainy season and lowest during winter in all the four study sites. A significant positive correlation was observed between the microbial biomass C, N and P with abiotic factors, such as, soil moisture, soil temperature and soil organic carbon in all the four study sites. Thereby it shows that soil temperature, soil moisture and organic carbon influences the microbial biomass C, N and P

A positive 'amount effect' in the Sahayadri (Western Ghats) rainfall

We present stable oxygen isotopic ratios (δ18O) of rainfall collected over three years (July to October 2000- 02) at Mangalore. We observe an apparent positive correlation between the monthly, amount-weighted mean oxygen isotopic ratio of the rainwater and monthly total rainfall, contrary to the generally expected negative trend in many island and continental stations. We offer an explanation for this observation and propose that the 'amount effect' in the annual rainfall still remains with a negative slope, and thus can be useful in palaeomonsoon reconstruction using oxygen isotopic variations of annually laminated speleothems

Placenta previa: risk factors, feto-maternal outcome and complications

Background: Placenta previa is defined as placenta that is implanted somewhere in the lower uterine segment either over or very near the internal cervical os. Placenta previa and coexistent accrete syndromes contribute substantively to maternal and perinatal morbidity and mortality.Methods: All This is a retrospective study of 88 cases of placenta previa, which were admitted under department of obstetrics and gynecology in our institute during July 2017 to June 2019. All patients of placenta previa with gestational age > 28 weeks up to full term were included in the study. All cases were confirmed by ultrasound examination. Outcome measures prevalence of placenta previa, maternal and neonatal outcomes, and case fatality rate.Results: The total number of deliveries performed during the study period was 16330, of them, 88 cases were placenta previa. Thus, the prevalence of PP was 0.53%. Multiparity was one of the etiological factors in 84.09%, whereas previous LSCS was 47.73%, previous H/O D and E was 14.73%, previous H/O placenta previa was 7.95%. Obstetric hysterectomy was done in 7 (7.95%) patients out of 88 patients. 92.04% of patients delivered with cesarean section and 7.95% patients delivered with normal vaginal delivery. 22 (26.50%) babies out of 83 live born were admitted in NICU.Conclusions: Advancing maternal age, multiparity, prior cesarean section, and prior abortions are independent risk factors for placenta previa. Placenta previa remains a risk factor for adverse maternal and perinatal outcome. The detection of placenta previa should encourage a careful evaluation with timely delivery to reduce the associated maternal and perinatal complications. Measures to reduce the primary caesarean section rate should be adopted

Ionophoretic Technique for the Determination of Stability Constants of Mixed Complexes (M-Nitrilotriacetate-5-Amino Pentanoate Systems)

A new method, involving the use of paper electrophoresis is described for the study of the equilibria in mixed ligand complex systems in solution. This technique is based on the movement of a spot of metal ion under an electric field with the complexants added in the background electrolyte at p\u27H = 8.5. Concentration of the primary ligand (NTA) was kept constant while that of the secondary ligand (5-amino pentanoic acid) was varied. The plots of-log [5-amino pentanoic acid] against mobility were used to obtain information on the forma tion of mixed complex and to calculate its stability constants. The binary equilibria M(II)-(5- amino pentanoic acid) and M(II)-NTA have also been studied since this is a prerequisite for the investigation of mixed complexes. The stability constants of the cornplexes, metal-nitrilotriacetate- 5-amino pentanoate have been found to be 5.85, 5.50, 5.22, 3.96 and 3.90 (log K values) for Cu(II), UOz(II), Ni(II), Co(II) and Zn(II) complexes, respectively, at fL = 0.1 mol/L and a temperature of 35 -c

Fetomaternal outcome in COVID-19 infected pregnant women: a preliminary clinical study

Background: WHO has declared COVID-19 infection a health emergency of international concern on 11th March, 2020. It is not clear whether clinical characteristics of pregnant women with COVID-19 differ from those of nonpregnant women and whether it aggravates COVID-19 symptoms and whether antiviral therapy is necessary for COVID-19 infected pregnant women.Methods: This is prospective study of 125 cases based on the compiled clinical data for pregnant women with COVID-19 between 15th April 2020 and 10th June 2020. A laboratory confirmed positive case of COVID-19 infection in pregnant women were included.Results: The most common symptoms at presentation were cough in 61.6% (77/125) and fever in 46.4% (58/125). Other reported symptoms were sore throat in 13.6% (17/125), myalgia in 10.4% (13/125) while 38.4% (48/125) were asymptomatic. There were total 97 deliveries (including 2 twins’ deliveries) among which 3 cases had IUD. Present study reported 96 live births. The incidence of missed abortion was 2.4% (3/125). The incidence of preterm birth before 37 weeks was 8.2% (8/97). Ninety-six (96.9%) of neonates were tested for SARS-CoV-2 viral nucleic acid on nasopharyngeal and pharyngeal samples and 16.67% (16/96) were resulted positive.Conclusions: At present, there is no evidence regarding the greater risk of pregnant women to succumb to COVID-19 infection and experience severe pneumonia. The risks of spontaneous abortion and preterm birth are not increased as reported in this study but shows possibility of vertical transmission when it manifests during the third trimester of pregnancy

RECTENNAS DESIGN, DEVELOPMENT AND APPLICATIONS

ABSTRACT The present paper describes the development of rectenna in terms of its applications in Microwave Power Transmission, Harmonic Rejection, CP radiation and ISM band. These rectennas consist of several antennas such as dipole, antenna arrays, slot meander line and rhombic loop antennas along with the rectifying diodes. In some cases more than one rectifying devices have also been used and antenna is found to be act at dual bands. It has also found that rectenna reject the harmonics upto 3 rd order and enhanced the performance characteristics. The maximum efficiency about 91% with 1.2 W of input power has been observed if the rectenna is used for microwave transmission