Development and Testing of 2G High Temperature Superconducting (HTS) Field Coils for HTS Synchronous Machines

Muralidhar Bathula V. A. S.,Sharma D. K.,Choudhury U. K.,Rao V. V. 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3

High temperature superconducting (HTS) synchronous machines are compact and light weight machines with higher torque to weight ratio, lower noise and better dynamic response for strategic and critical industrial applications. The development of HTS fi eld coil is one of the main technological challenges in realizing the HTS synchronous machines, as it involves the selection of HTS tape, winding technology, handling of the HTS tape while winding on a winding machine and testing of the developed HTS coil at desired cryogenic temperatures. With advancements in HTS tape technology, recent 2G HTS tapes are off ered with higher engineering current densities with respect to 1G HTS tapes even at higher magnetic fi elds. Hence, the replacement of 1G HTS fi eld coils of previously designed 200 kVA HTS synchronous machine with 2G HTS fi eld coils at the same operating cryo-temperature shows a potential to enhance its capacity to 350 kVA (more than 75% increase in machine output). In the present work the details of design, development and testing of a double pancake type 2G HTS fi eld coil are presented for capacity enhancement of earlier 1G based 200kVA HTS synchronous machine.

Computational design of mould sprue for injection moulding thermoplastics

Lakkannan, Muralidhar,Mohan Kumar, G.C.,Kadoli, Ravikiran Society for Computational Design and Engineering 2016 Journal of computational design and engineering Vol.3 No.1

To injection mould polymers, designing mould is a key task involving several critical decisions with direct implications to yield quality, productivity and frugality. One prominent decision among them is specifying sprue-bush conduit expansion as it significantly influences overall injection moulding; abstruseness anguish in its design criteria deceives direct determination. Intuitively designers decide it wisely and then exasperate by optimising or manipulating processing parameters. To overwhelm that anomaly this research aims at proposing an ideal design criteria holistically for all polymeric materials also tend as a functional assessment metric towards perfection i.e., criteria to specify sprue conduit size before mould development. Accordingly, a priori analytical criterion was deduced quantitatively as expansion ratio from ubiquitous empirical relationships specifically a.k.a an exclusive expansion angle imperatively configured for injectant properties. Its computational intelligence advantage was leveraged to augment functionality of perfectly injecting into an impression gap, while synchronising both injector capacity and desired moulding features. For comprehensiveness, it was continuously sensitised over infinite scale as an explicit factor dependent on in-situ spatio-temporal injectant state perplexity with discrete slope and altitude for each polymeric character. In which congregant ranges of apparent viscosity and shear thinning index were conceived to characteristically assort most thermoplastics. Thereon results accorded aggressive conduit expansion widening for viscous incrust, while a very aggressive narrowing for shear thinning encrust; among them apparent viscosity had relative dominance. This important rationale would certainly form a priori design basis as well diagnose filling issues causing several defects. Like this the proposed generic design criteria, being simple would immensely benefit mould designers besides serve as an inexpensive preventive cliché to moulders. Its adaption ease to practice manifests a hope of injection moulding extremely alluring polymers. Therefore, we concluded that appreciating injectant's polymeric character to design exclusive sprue bush offers a definite a priori advantage.

Guillain-Barré syndrome associated with SARS-CoV-2 vaccination: how is it different? a systematic review and individual participant data meta-analysis

Yerasu Muralidhar Reddy 대한백신학회 2023 Clinical and Experimental Vaccine Research Vol.12 No.2

Purpose: An association between Guillain-Barré syndrome (GBS) and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccination has been reported. We aimed to summarize the clinical features of GBS associated with SARS-CoV-2 vaccination and determine the contrasting features from coronavirus disease-19 (COVID-19) associated GBS and GBS following other causes. Materials and Methods: We performed PubMed search for articles published between 1 December 2020 and 27 January 2022 using search terms related to “SARS-CoV-2 vaccination” and “GBS”. Reference searching of the eligible studies was performed. Sociodemographic and vaccination data, clinical and laboratory features, and outcomes were extracted. We compared these findings with post-COVID-19 GBS and International GBS Outcome Study (IGOS) (GBS from other causes) cohorts. Results: We included 100 patients in the analysis. Mean age was 56.88 years, and 53% were males. Six-eight received non-replicating virus vector and 30 took messenger RNA (mRNA) vaccines. The median interval between the vaccination and the GBS onset was 11 days. Limb weakness, facial palsy, sensory symptoms, dysautonomia, and respiratory insufficiency were seen in 78.65%, 53.3%, 77.4%, 23.5%, and 25%, respectively. The commonest clinical and electrodiagnostic subtype were sensory-motor variant (68%) and acute inflammatory demyelinating polyneuropathy (61.4%), respectively. And 43.9% had poor outcome (GBS outcome score ≥3). Pain was common with virus vector than mRNA vaccine, and the latter had severe disease at presentation (Hughes grade ≥3). Sensory phenomenon and facial weakness were common in vaccination cohort than post-COVID-19 and IGOS. Conclusion: There are distinct differences between GBS associated with SARS-CoV-2 vaccination and GBS due to other causes. Facial weakness and sensory symptoms were commonly seen in the former and outcomes poor.

Sphingolipids from Marine Organisms: A Review?

P.Muralidhar,P.Radhika,N.Krishna,D.VenkataRao,Ch.BheemasankaraRao 한국생약학회 2003 Natural Product Sciences Vol.9 No.3

Performance of concrete modified with SCBA and GGBFS subjected to elevated temperature

Palaskar, Satish Muralidhar,Vesmawala, Gaurang R. Techno-Press 2020 Advances in materials research Vol.9 No.3

This research paper presents the outcomes in terms of mechanical and microstructural characteristics of binary and ternary concrete when exposed to elevated temperature. Three parameter were taken into account, (a) elevated temperature (i.e., 200, 400, 600 and 800℃) (b) binary concrete with cementitious material sugarcane bagasse ash (SCBA) and ground granulated blast furnace slag (GGBFS) replacement percentage (i.e., 0, 15, 20, 25 and 30%) and (c) ternary concrete with cementitious material SCBA and GGBFS replacement percentage (i.e., 0, 15, 20, 25 and 30%). A total of 285 standard cube specimens (150 mm × 150 mm × 150 mm) containing Ordinary Portland Cement (OPC), SCBA, and GGBFS were made. These specimens then exposed to several elevated temperatures for 2 h, afterword is allowed to cool at room temperature. The following basic physical, mechanical, and microstructural characteristics were then determined and discussed. (a) mass loss ratio, (b) ultrasonic pulse velocity (UPV) (c) physical behavior, (d) compressive strength, and (e) field emission scanning electron microscope (FESEM). It was found that compressive strength increases up to 400℃; beyond this temperature, it decreases. UPV value and massloss decrease with increase in temperature as well as the change in color and crack were observed at a higher temperature.

Measurement of outgassing rates of Kevlar and S-Glass materials used in torque tubes of High Tc Superconducting (HTS) Motors

Thadela, S.,Muralidhar, BVAS,Kalyani, B,Choudhury, UK,Yadav, SN,Rao, V.V. The Korean Society of Superconductivity and Cryoge 2018 한국초전도저온공학회논문지 Vol.20 No.4

Torque tubes in High Temperature Superconducting (HTS) motor transfer torque from superconducting field winding rotor to the room temperature shaft. It should have minimum heat conduction property for minimizing the load on cryo-refrigerator. Generally, these torque tubes are made with stainless steel material because of high strength, very low outgassing and low thermal contraction properties at cryogenic temperatures and vacuum conditions. With recent developments in composite materials, these torque tubes could be made of composites such as Kevlar and S-Glass, which have the required properties like high strength and low thermal conductivity at cryogenic temperatures, but with a reduced weight. Development and testing of torque tubes made of these composites for HTS motor are taken up at Bharat Heavy Electricals Limited (BHEL), Hyderabad in collaboration with Central Institute of Plastics and Engineering Technology (CIPET), Chennai and Indian Institute of Technology (IIT), Kharagpur. As these materials are subjected to vacuum, it is important to measure their outgassing rates under vacuum conditions before manufacturing prototype torque tubes. The present study focusses on the outgassing characteristics of Kevlar and S-Glass, using an Outgassing Measurement System (OMS), developed at IIT Kharagpur. The OMS facility works under vacuum environment, in which the test samples are exposed to vacuum conditions over a sufficient period of time. The outgassing measurements for the composite samples were obtained using pressure-rise technique. These studies are useful to quantify the outgassing rate of composite materials under vacuum conditions and to suggest them for manufacturing composite torque tubes used in HTS motors.

Evaluation of sperm DNA fragmentation using multiple methods: a comparison of their predictive power for male infertility

Javed, Aamir,Talkad, Muralidhar Srinivasaih,Ramaiah, Manjula Kannasandra The Korean Society for Reproductive Medicine 2019 Clinical and Experimental Reproductive Medicine Vol.46 No.1

Objective: The usual seminal profile has been customarily used for diagnosing male infertility based on an examination of semen samples. However, sperm DNA fragmentation has also been causally linked to reproductive failure, suggesting that it should be evaluated as part of male infertility assessments. To compare the ability of the five most widely utilized methodologies of measuring DNA fragmentation to predict male infertility and reactive oxygen species by Oxisperm kit assay. Methods: In this case-control study, which received ethical committee approval, the participants were divided into fertile and infertile groups (50 patients in each group). Results: The alkaline comet test showed the best ability to predict male infertility, followed by the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay, the sperm chromatin dispersion (SCD) test, and the sperm chromatin structure assay (SCSA), while the neutral comet test had no predictive power. For our patient population, the projected cut-off point for the DNA fragmentation index was 22.08% using the TUNEL assay, 19.90% using SCSA, 24.74% using the SCD test, 48.47% using the alkaline comet test, and 36.37% using the neutral comet test. Significant correlations were found between the results of the SCD test and those obtained using SCSA and TUNEL (r = 0.70 and r = 0.68, respectively; p< 0.001), and a statistically significant correlation was also found between the results of SCSA and the TUNEL assay (r = 0.77, p< 0.001). Likewise, the results of the alkaline comet test showed significant correlations with those of the SCD, SCSA, and TUNEL tests (r = 0.59, r = 0.57, and r = 0.72, respectively; p< 0.001). Conclusion: The TUNEL assay, SCSA, SCD, and the alkaline comet test were effective for distinguishing between fertile and infertile patients, and the alkaline comet test was the best predictor of male infertility.

Corrigendum to "Evaluation of sperm DNA fragmentation using multiple methods: a comparison of their predictive power for male infertility"

Javed, Aamir,Talkad, Muralidhar Srinivasaih,Ramaiah, Manjula Kannasandra The Korean Society for Reproductive Medicine 2019 Clinical and Experimental Reproductive Medicine Vol.46 No.4

Synthesis of Mono, Bis-2-(2-Arylideneaminophenyl) Indole Azomethines as Potential Antimicrobial Agents

Rondla Rohini,P. Muralidhar Reddy,Kanne Shanker,Kodipelli Kanthaiah,Vadde Ravinder,Anren Hu 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.7

A series of mono and bis 2-2-(arylidineaminophenyl)indole azomethines have been synthesized by a condensation reaction of 2-(2-amino phenyl) indole with various mono and diketones RCO-R^l /R-CO-X-CO-R^l (1:1/2:1 ratio) in ethanol media. The synthesized azomethines were characterized via IR, ^1H-NMR, ^13C-NMR, MS and elemental analysis. The antimicrobial activity of these compounds against different bacteria and fungi was also evaluated.

Phase I and pharmacokinetic study of cisplatin and troxacitabine administered intravenously every 28 days in patients with advanced solid malignancies

Lin, Chia-Chi,Beeram, Muralidhar,Rowinsky, Eric K.,Takimoto, Chris H.,Ng, Chee M.,Geyer Jr, Charles E.,Denis, Louis J.,De Bono, Johann S.,Hao, Desiree,Tolcher, Anthony W.,Rha, Sun-Young,Jolivet, Jacqu Springer-Verlag 2009 Cancer chemotherapy and pharmacology Vol.65 No.1