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Hybrid Cascaded MLI topology using Ternary Voltage Progression Technique with Multicarrier Strategy
Jamuna Venugopal,Gayathri Monicka Subarnan 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.4
A major problem in conventional multilevel inverter is that an increase in power semiconductor switches causes an increase in cost and switching losses of the inverter. The multicarrier strategy adopted for the multilevel inverters has become more popular due to reduced cost, lower harmonic distortion, and higher voltage capability than the conventional switching strategy applied to inverters. Various topologies and modulation strategies have been reported for utility and drive applications. Level shifted based pulse width modulation techniques are proposed to investigate the performance of the multilevel inverter. The proposed work focuses on reducing the utilized switches so that the cost and the switching losses of the inverter do not go up and the consistent efficiency could be achieved. This paper presents the detailed analysis of these topologies. The analysis is based on the number of switches, DC sources, output level, maximum voltage, and the efficiency. As an illustration, single phase cascaded multilevel inverter topologies are simulated using MATLAB/SIMULINK and the experimental results demonstrate the viability of these inverters.
Jamuna Bai Aswathanarayan,Ravishankar Rai Vittal 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.6
The effects of different nutrient sources andtemperatures on attachment and biofilm formation ofPseudomonas fluorescens PSD4, a dairy isolate, werestudied. Initial adherence and attachment capabilitiesamong different strains were studied using microtitre plateassays. Biofilm development was observed using confocalmicroscopy. Strongly adherent cells were seen in proteinrich media. Citrate as a carbon source enhanced biofilmformation. Glucose did not favor biofilm development. Psychrotrophic P. fluorescens PSD4 formed stronglyadherent biofilms having high metabolic activities at lowtemperatures. P. fluorescens PSD4 with spoilage potentialwas capable of forming strong biofilms in dairy processingenvironments. Biofilm formation was influenced bynutrient availability and growth conditions. These factorsshould be considered for design of effective anti-biofilmstrategies.
Jamuna V.,Muniraj C.,Periasamy P. S. 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.4
Solar energy generation Photovoltaic modules that work reliably for 20–30 years in environmental conditions can only be cost-effective. The temperature inside the PV cell is not uniform due to an increase in defects in the cells. Monitoring the heat of the PV panel is essential. Therefore, research on photovoltaic modules is necessary. Infrared thermal imaging (IRT) has a significant role in determining the severity of problems in solar panels. Thus, in this work, a maximum power point tracking (MPPT) system based on a new image for thermal imaging is proposed to solve the photovoltaic (PV) defects using linear iterative fault diagnosis method. The thermal camera and new MPPT solution used for fault detection were developed to change the operating point to match the optimized MPP. The simulation work does go through the use of the proposed low-income food-deficient method in the MATLAB environment. The simulation results show the effectiveness of the proposed Linear Iterative Fault Diagnosis (LIFD) method and its ability to detect the fault and track the maximum power of the PV panel. The sensitivity, specificity and accuracy of the proposed work are 98%, 94% and 97%.
Hybrid Cascaded MLI topology using Ternary Voltage Progression Technique with Multicarrier Strategy
Venugopal, Jamuna,Subarnan, Gayathri Monicka The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.4
A major problem in conventional multilevel inverter is that an increase in power semiconductor switches causes an increase in cost and switching losses of the inverter. The multicarrier strategy adopted for the multilevel inverters has become more popular due to reduced cost, lower harmonic distortion, and higher voltage capability than the conventional switching strategy applied to inverters. Various topologies and modulation strategies have been reported for utility and drive applications. Level shifted based pulse width modulation techniques are proposed to investigate the performance of the multilevel inverter. The proposed work focuses on reducing the utilized switches so that the cost and the switching losses of the inverter do not go up and the consistent efficiency could be achieved. This paper presents the detailed analysis of these topologies. The analysis is based on the number of switches, DC sources, output level, maximum voltage, and the efficiency. As an illustration, single phase cascaded multilevel inverter topologies are simulated using MATLAB/SIMULINK and the experimental results demonstrate the viability of these inverters.
Dash, Soumya,Chakravarty, A.K.,Sah, V.,Jamuna, V.,Behera, R.,Kashyap, N.,Deshmukh, B. Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.7
Heat stress has adverse effects on fertility of dairy animals. Decline in fertility is linearly associated with an increase in combination of both temperature and humidity. The purpose of this study was to investigate the relationship between temperature humidity index (THI) and the pregnancy rate of Murrah buffaloes in a subtropical climate. The effects of genetic and non-genetic factors viz., sire, parity, period of calving and age group at first calving were found non-significant on pregnancy rate. The effect of THI was found significant (p<0.001) on pregnancy rate of Murrah buffaloes calved for first time and overall pregnancy rate. The threshold THI affecting the pregnancy rate was identified as THI 75. The months from October to March showed THI<75 and considered as non heat stress zone (NHSZ), while months from April to September were determined as heat stress zone (HSZ) with $THI{\geq}75$. The lowest overall pregnancy rate (0.25) was obtained in July with THI 80.9, while the highest overall pregnancy rate (0.59) was found in November with THI 66.1. May and June were identified as critical heat stress zone (CHSZ) within the HSZ with maximum decline (-7%) in pregnancy rate with per unit increase in THI. The highest overall pregnancy rate was estimated as 0.45 in NHSZ with THI value 56.7 to 73.2. The pregnancy rate was found to have declined to 0.28 in HSZ with THI 73.5 to 83.7. However, the lowest pregnancy rate was estimated as 0.27 in CHSZ with THI value 80.3 to 81.6.
Neuropharmacological screening of the methanolic extract of Hibiscus vitifolius flowers
Seethalakshmi, S,Chamundeeswari, D,Rani, S Jamuna,Parvathavardhini, S,Vasantha, J Kyung Hee Oriental Medicine Research Center 2005 Oriental pharmacy and experimental medicine Vol.5 No.4
The methanolic extract of Hibiscus vitifolius flowers (HVE), was evaluated for neurophamacological activities by carrying out rota rod, locomotor activity and traction performance in mice and swim endurance activity in rats in different dosages (10, 30 and 100mg/kg body weight). HVE showed a significant effect on central nervous system by increasing the time taken for rota rod, traction performance and locomotor activity while swimming time was found to be decreased when compared to normal control animals. These results suggest that HVE possess significant anxiolytic and anti depressant activity which may be attributed to the presence of flavonoid in HVE.
Wang Wei,Chan Yat Ho,Kwon SoYoung,Tandukar Jamuna,Gao Ruixuan 나노기술연구협의회 2022 Nano Convergence Vol.9 No.30
Nanoscale imaging of biological samples can provide rich morphological and mechanistic information about biological functions and dysfunctions at the subcellular and molecular level. Expansion microscopy (ExM) is a recently developed nanoscale fluorescence imaging method that takes advantage of physical enlargement of biological samples. In ExM, preserved cells and tissues are embedded in a swellable hydrogel, to which the molecules and fluorescent tags in the samples are anchored. When the hydrogel swells several-fold, the effective resolution of the sample images can be improved accordingly via physical separation of the retained molecules and fluorescent tags. In this review, we focus on the early conception and development of ExM from a biochemical and materials perspective. We first examine the general workflow as well as the numerous variations of ExM developed to retain and visualize a broad range of biomolecules, such as proteins, nucleic acids, and membranous structures. We then describe a number of inherent challenges facing ExM, including those associated with expansion isotropy and labeling density, as well as the ongoing effort to address these limitations. Finally, we discuss the prospect and possibility of pushing the resolution and accuracy of ExM to the single-molecule scale and beyond.