Harmonic Minimization in Multilevel Converter Using an Adaptive Learning Algorithm

There is a wide use of multilevel converters as they can be used with high power and high voltage applications. A multilevel converter consists of large number of voltage levels in load  voltage and load current. A multilevel converter has number of various advantages like good quality of output voltage waveform, smaller values of  inductor and capacitor in passive filters. The output consists of less harmonics. Reduction in total harmonic distortion can be obtained  with the help of multilevel converter. Using learning algorithm like neural network, output voltage is controlled. Error in the reference voltage and output voltage is reduced. Neural network replaces the PI controller completely. A reduction in THD in output voltage and output current can be obtained by neural network by large margin as compared to PI controller. This increases the wide application of AC motor as load as it reduces torque pulsation and RF/EMI effect. It increases the efficiency by reducing power losses.    &nbsp

Harmonic Minimization in Multilevel Converter Using an Adaptive Learning Algorithm

There is a wide use of multilevel converters as they can be used with high power and high voltage applications. A multilevel converter consists of large number of voltage levels in load  voltage and load current. A multilevel converter has number of various advantages like good quality of output voltage waveform, smaller values of  inductor and capacitor in passive filters. The output consists of less harmonics. Reduction in total harmonic distortion can be obtained  with the help of multilevel converter. Using learning algorithm like neural network, output voltage is controlled. Error in the reference voltage and output voltage is reduced. Neural network replaces the PI controller completely. A reduction in THD in output voltage and output current can be obtained by neural network by large margin as compared to PI controller. This increases the wide application of AC motor as load as it reduces torque pulsation and RF/EMI effect. It increases the efficiency by reducing power losses.    &nbsp

Facile Green Synthesis of Novel Nanocarbon Materials from Agricultural Waste

A novel synthesis method for the elucidation of porous graphene nanosheets (PGN) from agricultural product like wood and coconut shell charcoal is reported herein. Precursors for the present study is obtained by the thermal decomposition of agricultural waste namely wood (WS) and coconut shell (CSS). The chemical modification of the carbon structures present in the samples are achieved by using a modified Hummers’ method followed by extensive sonication. Analysis of chemically treated samples with various spectroscopic and microscopic techniques revealed the presence of few layer large area graphene (PGN) with oxygen functionalities added to it. Agricultural waste material are potential precursors for the large scale synthesis of low cost graphene sheet and graphene quantum dots

Risk factors associated with in-hospital mortality in critically ill elderly patients with venous thromboembolism

Background: Venous thromboembolism (VTE) is a major cause of morbidity and mortality for patients admitted to the intensive care unit (ICU). The present study aims to investigate the risk factors for in-hospital mortality among critically ill elderly patients with VTE. Methods: This was a retrospective cohort study utilizing data from the large medical information mart for intensive care IV (MIMIC-IV) database. All elderly patients diagnosed with VTE were included in the analysis. The analyses were conducted using SPSS version 26.0 software and MedCalc version 19.6. Univariable and multivariable logistic regression models were conducted to explore potential risk factors associated with in-hospital mortality. Results: The study population had a median age of 75 years, with a range from 69.0 to 82.0 years, and males represented 50.4% of the cohort. Among critically ill VTE patients, the in-hospital mortality rate was 18.5% (237 out of 1282). Multivariable regression analysis revealed that longer ICU stays [OR: 1.034; 95% CI: 1.010-1.059, p=0.005], higher Charlson comorbidity index (CCI) scores [OR: 1.090; 95% CI: 1.001-1.187, p=0.046], elevated simplified acute physiology score II (SAPS II scores) [OR: 1.039; 95% CI: 1.023-1.056, p<0.001], increased red blood cell distribution width (RDW) levels [OR: 1.088; 95% CI: 1.006-1.178, p=0.035], lower mean arterial pressure (MAP) [OR: 0.975; 95% CI: 0.957-0.994, p=0.011], presence of severe liver disease [OR: 2.036; 95% CI: 1.051-3.941, p=0.035], and the necessity for renal replacement therapy (RRT) [OR: 2.478; 95% CI: 1.315-4.671, p=0.005] were significantly associated with an increased risk of in-hospital mortality among elderly ICU patients with VTE. Conclusions: The study identifies numerous independent risk factors associated with in-hospital mortality among critically ill elderly patients with VT. These factors include prolonged length of ICU stay, elevated scores on the CCI and SAPS II, increased RDW, reduced MAP, the presence of severe liver disease, and the necessity for RRT

Particle Swarm Optimization Approach for Maximizing the Yield of a Coal Preparation Plant

This paper presents the use of particle swarm optimization to maximize the clean coal yield of a coal preparation plant that typically has multiple cleaning circuits that produce the same product quality so that the blend of clean coal meets the targeted product quality contraints. Particle swarm is used for the yield optimization while satisfying multiple product quality restraints. The results show a 2.73% increase in the yield can be achieved leading to additional revenue of $5,460,000 per annum for a plant producing 10 million tons of clean coal per year without significantly adding to the implementation/operation cost

Reaction of sulphate radical anion (SO<SUB>4</SUB><SUP>&#8226;-</SUP>) with hydroxy- and methyl-substituted pyrimidines: a pulse radiolysis study

Reactions of sulphate radical anion (SO4&#8226;-) with 4,6-dihydroxy-2-methyl pyrimidine (DHMP), 2,4-dimethyl-6-hydroxy pyrimidine (DMHP), 6-methyl uracil (MU) and 5,6-dimethyl uracil (DMU) have been studied by pulse radiolysis at pH 3 and at pH 10. The transient intermediate spectra were compared with those from the reaction of hydroxyl radical (&#8226;OH). It is proposed that SOSO4&#8226;- produces radical cations of these pyrimidines in the initial stage. These radical cations are short-lived except in the case of DMHP where a relatively longer lived radical cation is proposed to be formed. When there is a hydrogen atom attached to the N(1) or N(3) position, a deprotonation from these sites is highly favored. When there is no hydrogen attached to these sites, deprotonation from a substituted methyl group is favored. At acidic pH, deprotonation from nitrogen is observed for DHMP, MU and DMU. At basic pH, the radical cation reacts with OH- leading to the formation of OH adducts

Reaction of oxide radical ion (O<SUP>&#8226;-</SUP>) with substituted pyrimidines

Pulse radiolysis technique has been used to investigate the reaction of oxide radical ion (O&#8226;-) with 4,6-dihydroxy-2-methyl pyrimidine (DHMP), 2,4-dimethyl-6-hydroxy pyrimidine (DMHP), 5,6-dimethyl uracil (DMU) and 6-methyl uracil (MU) in strongly alkaline medium. The second-order rate constants for the reaction of O&#8226;- with these compounds are in the range 2-5 &#215; 108 dm3 mol-1 s-1. The transient absorption spectra obtained with DHMP have two maxima at 290 and 370 nm and with DMHP have maxima at 310 and 470 nm. The transient spectrum from DMU is characterized by its absorption maxima at 310 and 520 nm and that of MU by its single maximum at 425 nm. The intermediate species were found to react with N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) with high G(TMPD&#8226;+) values ranged between 3.9 &#215; 10-7 molJ-1 and 4.8 &#215; 10-7 molJ-1. These radicals undergo decay by second-order kinetics (2k/&#949; = 1.0-1.7 &#215; 106 s-1). The reaction of O&#8226;- with the selected pyrimidines is proposed to proceed through a hydrogen abstraction from the methyl group forming allyl type radicals. These are mainly oxidizing radicals and hence readily undergo electron transfer reactions with TMPD

Clinico-pathological profile of abdominal tuberculosis and their treatment response in a tertiary care centre

Background: Abdominal tuberculosis is an important clinical entity having varied mode of clinical presentation. So the diagnosis of abdominal TB is difficult and careful approach to the patients and supportive investigation data are necessary to make the final diagnosis. Objectives of the study were to evaluate the clinic-pathological profile of patients with abdominal TB in a tertiary care centre in northern Kerala and to assess their response to anti-tubercular therapy under DOTS.Methods: This was a retrospective follow up study conducted in the department of Pulmonary Medicine in association with the department of Gastro-medicine and Surgery, and medical college DOTS centre Pariyaram Medical College, Pariyaram Kannur district–Kerala, India. Total 55 patients with abdominal TB diagnosed on the basis of clinical profile and supported investigation data like gross morphological findings at endoscopy, colonoscopy, diagnostic laparoscopy, laparotomy or histologically proven caseating granulomas were selected for this study.Results: Out of the 55 patients, 31 were males and 24 females with age ranging 16-80 (Mean 30.01±11.7) years. Abdominal pain was the most common presenting symptom in 45 (81.81%). The diagnosis of abdominal TB was confirmed histopathologically in 42 (76.36%). Remaining 13 (23.64%) cases were diagnosed microscopically and with supportive clinical and imaging background. All the patients were treated under DOTS.Conclusions: Neither clinical features, laboratory, radiological and Endoscopic methods nor bacteriological and histopathological findings by themselves provide a gold standard in the diagnosis of abdominal TB. If diagnosed early, it can be treated successfully with anti-TB drugs

Analysis of Behavioral Characteristics of Jammers to Detect Malicious Nodes in Mobile ADHOC Networks

Wireless ADHOC Networks are used to establish a wireless connection between two computing devices without the need for a Wi-Fi access point or router. This network is decentralized and uses omnidirectional communication media, which makes it more vulnerable to certain types of attacks compared to wired networks. Jamming attacks, a subset of denial-of-service (DoS) attacks, involve malicious nodes that intentionally interfere with the network, blocking legitimate communication. To address this issue, the proposed method analyzes various characteristics of nodes, such as packets sent, received, and dropped, at each node. Using the packet delivery ratio and packet drop ratio, the method detects jamming nodes from normal nodes, improving network performance. The network is simulated in NS2 environment