1,885 research outputs found
Sustainable machining and optimization of machining parameters utilizing different dielectrics in EDM machining of Waspaloy
No full textThis study investigates the influence of various dielectric fluids on the performance of Electric Discharge Machining (EDM) in machining Waspaloy, a corrosion-resistant superalloy known for its high hardness and enhanced corrosion resistance. The purpose of this work is to fill the knowledge gap about the machining of Waspaloy using different dielectric fluids by using a Copper-5Graphite (CuGr5) composite tools. Experiments were conducted using a EDM machine with copper graphite composite electrodes and five distinct dielectric fluids, including hydrocarbon oil, kerosene, sunflower oil, used motor oil, and groundnut oil. The effects of key process parameters such as current, voltage, pulse on time, pulse off time, and gap distance on Material Removal Rate (MRR) and Surface Roughness (Ra) were evaluated. Dielectric fluid properties, including viscosity, density, thermal conductivity, and dielectric strength, were comprehensively characterized. Results revealed that MRR increased with current and pulse-on time up to a threshold, beyond which thermal damage reduced efficiency. Sunflower oil demonstrated the most favorable performance, achieving an MRR of up to 0.570 mm(3)/min and Ra as low as 1.012 mu m, attributed to its high dielectric strength (40 kVA), moderate viscosity, and superior thermal conductivity. In contrast, kerosene and hydrocarbon oil, while effective in debris flushing, resulted in inconsistent spark stability and increased surface roughness at higher energy settings due to lower dielectric strength and flash points. Used motor oil and groundnut oil, though sustainable, exhibited higher surface roughness and limited MRR under elevated parameter settings owing to their higher viscosity and lower heat dissipation capabilities. A novel predictive equation for MRR and Ra, integrating dielectric fluid properties and machining parameters, was developed to enhance process optimization. Surface morphology analysis using SEM revealed characteristic features such as craters, recast layers, microcracks, and resolidified debris, highlighting the interplay between thermal, electrical, and mechanical effects during EDM. This research promotes sustainable manufacturing by assessing bio-based and waste-derived dielectric fluids as environmentally responsible alternatives to conventional EDM oil.
Development of Hankel-SVD hybrid technique for multiple noise removal from PD signature
No full textDetection and measurement of partial discharge (PD) phenomena combined with the separation and identification of PD sources is the way to achieve effective insulation integrity assessment. However, during measurement, PD signals are coupled with interferences (discrete spectral, pulsive, and white noises). Recovering PD signals from such interferences would improve PD source separation (thus identification), but still remains a challenging task. Several denoising methods have been proposed to suppress interferences. However, using a universal method to achieve interference removal is probably impossible, as the characteristics of the interferences are distinct. This study proposes a novel low-rank H-Matrix-based singular value decomposition (SVD) filter (H-SVD) that removes different types of interferences. Denoising is done by projecting the measured pulse in a lower dimensional signal space. To assess the effectiveness of the proposed method, H-SVD filter is first applied to simulated PD data and later on real-time PD data with the introduction of three different types of synthetic noises. The results of the evaluation metrics confirm that H-SVD has significant performance improvements compared to existing state-of-the-art PD denoising methods
On generalized semi-Pareto and semi-Burr distributions and random coefficinet minification process
No full textNo abstract availabl
Technical effectiveness of artificial recharge structures in hard rock area - A case study in Coimbatore District, India
No full textK. Palanisami, A. Raviraj, B. Jayakumar, S. Gurunathan, T. Arivalagan and S. Thirumurth
Vitamin K status in diabetic patients with chronic kidney disease stage 3-5 and its effects on chronic kidney disease - mineral bone disorder
No full textDiabetic kidney disease (DKD) is common in Malaysia. Vitamin K deficiency among DKD patients may be associated with higher incidence of chronic kidney disease-mineral bone disorder (CKD-MBD). This study was conducted to determine the prevalence of vitamin K deficiency in diabetic patients with CKD stage 3-5. We also correlated vitamin K deficiency with baseline demographic, biochemical results and analysed the effects of vitamin K levels on CKD-MBD. This was a single centre cross-sectional study on diabetic patients with CKD stage 3-5. Demographic profiles were recorded, blood samples were measured for vitamin K level (phylloquinone, proteins induced by vitamin K absence II (PIVKA-II), prothrombin time) and bone markers (parathyroid hormone (PTH), alkaline phosphatase, corrected calcium and phosphate). This study was approved by UKM ethic and research committee (FF-2018-375). Forty-five patients with a median age of 70 (IQR:13) years were recruited. Majority were females (53.3%) and Malays (64.4%). Prevalence of patients with insufficient vitamin K was 28.9 % based on the low level of phylloquinone (0.66 ng/mL) and 2.2% based on prolonged prothrombin time (>14.5 s). PIVKA-II was found to be positively correlated with serum creatinine and PTH levels. There were positive correlations between phylloquinone with serum triglyceride and total cholesterol. Prothrombin time was found to be negatively correlated with corrected calcium and total cholesterol. Malay race (p = 0.039) and high serum PTH (p = 0.016) were significantly associated with higher PIVKA-II concentrations. Multivariable analysis showed serum triglyceride (OR 0.112CI 95 % (0.02-0.66)p = 0.017) and serum PTH (OR 1.997CI 95 % (1.01-3.95)p = 0.047) were independent predictors for abnormal phylloquinone and PIVKA-II levels, respectively. In conclusion, the prevalence of Vitamin K deficiency was high in diabetic patients with CKD stage 3-5. Serum triglyceride and serum PTH were independent predictor of Vitamin K deficiency
Difference in root K(+) retention ability and reduced sensitivity of K(+)-permeable channels to reactive oxygen species confer differential salt tolerance in three Brassica species
No full textAdvance Access publication 23 June 2016Brassica species are known to possess significant inter and intraspecies variability in salinity stress tolerance, but the cell-specific mechanisms conferring this difference remain elusive. In this work, the role and relative contribution of several key plasma membrane transporters to salinity stress tolerance were evaluated in three Brassica species (B. napus, B. juncea, and B. oleracea) using a range of electrophysiological assays. Initial root growth assay and viability staining revealed that B. napus was most tolerant amongst the three species, followed by B. juncea and B. oleracea At the mechanistic level, this difference was conferred by at least three complementary physiological mechanisms: (i) higher Na⁺ extrusion ability from roots resulting from increased expression and activity of plasma membrane SOS1-like Na⁺/H⁺exchangers; (ii) better root K⁺ retention ability resulting from stress-inducible activation of H⁺-ATPase and ability to maintain more negative membrane potential under saline conditions; and (iii) reduced sensitivity of B. napus root K⁺-permeable channels to reactive oxygen species (ROS). The last two mechanisms played the dominant role and conferred most of the differential salt sensitivity between species. Brassica napus plants were also more efficient in preventing the stress-induced increase in GORK transcript levels and up-regulation of expression of AKT1, HAK5, and HKT1 transporter genes. Taken together, our data provide the mechanistic explanation for differential salt stress sensitivity amongst these species and shed light on transcriptional and post-translational regulation of key ion transport systems involved in the maintenance of the root plasma membrane potential and cytosolic K/Na ratio as a key attribute for salt tolerance in Brassica species.Koushik Chakraborty, Jayakumar Bose, Lana Shabala and Sergey Shabal
sj-docx-1-pie-10.1177_09544089221115481 - Supplemental material for Development of protective coating for X8CrNiMoVNb16-13 alloy in high-temperature molten salt environment through high-velocity oxy-fuel sprayed NiCrMoNb and Cr<sub>3</sub>C<sub>2</sub>-25NiCr powder coating
No full textSupplemental material, sj-docx-1-pie-10.1177_09544089221115481 for Development of protective coating for X8CrNiMoVNb16-13 alloy in high-temperature molten salt environment through high-velocity oxy-fuel sprayed NiCrMoNb and Cr3C2-25NiCr powder coating by V Sreenivasulu, P Subramani, V Jayakumar, K Mageshkumar, N Arivazhagan, M Manikandan, Szymon Tofil and M Sathishkumar in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
sj-docx-2-pie-10.1177_09544089221115481 - Supplemental material for Development of protective coating for X8CrNiMoVNb16-13 alloy in high-temperature molten salt environment through high-velocity oxy-fuel sprayed NiCrMoNb and Cr<sub>3</sub>C<sub>2</sub>-25NiCr powder coating
No full textSupplemental material, sj-docx-2-pie-10.1177_09544089221115481 for Development of protective coating for X8CrNiMoVNb16-13 alloy in high-temperature molten salt environment through high-velocity oxy-fuel sprayed NiCrMoNb and Cr3C2-25NiCr powder coating by V Sreenivasulu, P Subramani, V Jayakumar, K Mageshkumar, N Arivazhagan, M Manikandan, Szymon Tofil and M Sathishkumar in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
Pompano farming at Vethalai using low-cost cages: Technology demonstration initiative by Mandapam RC
No full textAn artisanal type of cage was fabricated at Mandapam Regional
Centre with 6×6 m outer and 5×5 m inner square frame,
which is made of 50mm GI pipe for farming demonstrations involving
local fishermen at Vethalai village, Ramnad District, Tamil Nadu.The ongoing pompano farming
demonstration in an artisanal type of sea cages is a way forward for
the spread of mariculture in India.
(Reported by G. Gopakumar,
A. K. Abdul Nazar, R. Jayakumar, G. Tamilmani,
M. Sakthivel, C. Kalidas, P. Ramesh Kumar &
Johnson B., Mandapam Regional Centre
Artisanal innovation in cage farming of pompano at Vethalai, Ramanathapuram
No full textOn 25th July 2012, pompano from an artisanal cage was
harvested. The total harvest was 92 kg, the length and weight
ranges observed were 16 to 32 cm and 62 to 433 grams.The harvest was handed over to the farmer Shri.Nagadoss
by Dr. G. Gopakumar, Scientist-in-Charge. The farm gate price
for the harvested pompano was `120/kg- and it was sold by
the merchant in the retail market at `180/kg-.
Reported by G.Gopakumar, A. K. Abdul Nazar,
R. Jayakumar, G. Tamilmani, M. Sakthivel, C. Kalidas,
P. Ramesh Kumar & Johnson B., Mandapam Regional Centr
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