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49 results on '"Sahu, Vivek"'

3. Fractional Hardy inequality with singularity on submanifold

Author

Adimurthi, Roy, Prosenjit, and Sahu, Vivek

Subjects
Mathematics - Analysis of PDEs, 46E35 (Primary), 26D15 (Secondary)
Abstract

We establish fractional Hardy inequality on bounded domains in $\mathbb{R}^{d}$ with inverse of distance function from smooth boundary of codimension $k$, where $k=2, \dots,d$, as weight function. The case $sp=k$ is the critical case, where optimal logarithmic corrections are required. All the other cases of $spk$ are also addressed., Comment: 34 pages. arXiv admin note: text overlap with arXiv:2308.11956

Published
2024

4. Boundary Hardy inequality on functions of bounded variation

Author

Adimurthi, Roy, Prosenjit, and Sahu, Vivek

Subjects
Mathematics - Analysis of PDEs, 46E35, 26D15, 39B62
Abstract

Classical boundary Hardy inequality, that goes back to 1988, states that if $1 < p < \infty, \ ~\Omega$ is bounded Lipschitz domain, then for all $u \in C^{\infty}_{c}(\Omega)$, $$\int_{\Omega} \frac{|u(x)|^{p}}{\delta^{p}_{\Omega}(x)} dx \leq C\int_{\Omega} |\nabla u(x) |^{p}dx,$$ where $\delta_\Omega(x)$ is the distance function from $\Omega^c$. In this article, we address the long standing open question on the case $p=1$ by establishing appropriate boundary Hardy inequalities in the space of functions of bounded variation. We first establish appropriate inequalities on fractional Sobolev spaces $W^{s,1}(\Omega)$ and then Brezis, Bourgain and Mironescu's result on limiting behavior of fractional Sobolev spaces as $s\rightarrow 1^{-}$ plays an important role in the proof. Moreover, we also derive an infinite series Hardy inequality for the case $p=1$., Comment: 25 pages

Published
2024

5. Fractional boundary Hardy inequality for the critical cases

Author

Adimurthi, Roy, Prosenjit, and Sahu, Vivek

Subjects
Mathematics - Analysis of PDEs, 46E35 (Primary), 26D15 (Secondary)
Abstract

We establish generalised fractional boundary Hardy-type inequality, in the spirit of Caffarelli-Kohn-Nirenberg inequality for different values of $s$ and $p$ on various domains in $\mathbb{R}^d, d \geq 1$. In particular, for Lipschitz bounded domains any values of $s$ and $p$ are admissible, settling all the cases in sub critical, super critical and critical regime. In this paper we have solved the open problems posed by Dyda for the critical case $sp =1$. Moreover we have proved the embeddings of $W^{s,p}_{0}(\Omega)$ in subcritical, critical and supercritical uniformly without using Dyda's decomposition. Additionally, we extend our results to include a weighted fractional boundary Hardy-type inequality for the critical case., Comment: 50 pages

Published
2023

6. Effect of Secondary Swirl Strength on the External Aerodynamics of a Gas Turbine Fuel Injector

Author

Sahu, Vivek, Chugh, Devin, Mittal, Deepanshu, Shanmugadas, K. P., Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Ivanov, Vitalii, Series Editor, Haddar, Mohamed, Series Editor, Cavas-Martínez, Francisco, Editorial Board Member, di Mare, Francesca, Editorial Board Member, Kwon, Young W., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, Xu, Jinyang, Editorial Board Member, Singh, Krishna Mohan, editor, Dutta, Sushanta, editor, Subudhi, Sudhakar, editor, and Singh, Nikhil Kumar, editor

Published
2024
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7. Characterization of Primary Atomization Processes of Like-on-Unlike Impinging Injectors

Author

Mahato, Bikash, Sahu, Vivek, Vikram, R., Ganesh, P., Shanmugadas, K. P., Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Ivanov, Vitalii, Series Editor, Haddar, Mohamed, Series Editor, Cavas-Martínez, Francisco, Editorial Board Member, di Mare, Francesca, Editorial Board Member, Kwon, Young W., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, Xu, Jinyang, Editorial Board Member, Das, Sudev, editor, Mangadoddy, Narasimha, editor, and Hoffmann, Jaap, editor

Published
2024
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12. Investigation of Strain Localization in Additively Manufactured AlSi10Mg Using CPFEM

Author

Chakrabarty, Aniket, Chakraborty, Pritam, Sahu, Vivek Kumar, Gurao, Nilesh P., Khutia, Niloy, Cavas-Martínez, Francisco, Series Editor, Chaari, Fakher, Series Editor, di Mare, Francesca, Series Editor, Gherardini, Francesco, Series Editor, Haddar, Mohamed, Series Editor, Ivanov, Vitalii, Series Editor, Kwon, Young W., Series Editor, Trojanowska, Justyna, Series Editor, Krishnapillai, Shankar, editor, R., Velmurugan, editor, and Ha, Sung Kyu, editor

Published
2022
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23. COMPARISON OF HYPERBARIC BUPIVACAINE IN CONVENTIONAL DOSE TO ISOBARIC LEVOBUPIVACAINE USED FOR INFRA UMBILICAL SURGERIES.

Author

Anand, Manish, Sahu, Vivek, Kumar, Nethala Ravi, and Burlikodandaramu

Subjects
*BUPIVACAINE, *CARDIOTOXICITY, *ANESTHETICS, *HEART beat, *ABDOMINAL surgery
Abstract

Background: For spinal anaesthesia, levobupivacaine is considered an effective alternative anesthetic agent to conventional bupivacaine owing to the faster recovery profile and lower probability of cardiovascular toxicity. Aim: To comparatively assess the analgesic and hemodynamic features of conventional dose of hyperbaric bupivacaine to isobaric levobupivacaine used for infra umbilical surgeries. Methods: Thepresent clinical study included 120 subjects from ASA I and ASA II categories presented for elective infra umbilical surgeries and were randomly divided into 2 groups of 60 subjects each. Group, I subjects was given 0.5% hyperbaric bupivacaine at the dose of 3ml, and Group II was given 0.5% isobaric levobupivacaine at the dose of 3ml. Hemodynamic parameters including SpO2, NIBP, and heart rates were assessed every 15 minutes till 2 hours postoperative. Side effects including nausea and vomiting, bradycardia, and hypotension were also evaluated. Results: Sensory block onset was slower in the levobupivacaine group and sensory block levels were comparable. For levobupivacaine, analgesia duration was significantly lower. With levobupivacaine, shorter motor blockade duration and slower motor blockade onset were seen. Complete motor blockade was seen in all subjects. Concerning hemodynamic parameters, lesser incidence of bradycardia and hypotension and high cardiovascular stability was observed. No incidence of PDPH, shivering, nausea, or vomiting was seen in any subject. Conclusion: The present study concludes that significantly similar effects concerning analgesia duration are seen with Bupivacaine as with levobupivacaine. However, Bupivacaine showed better cardiovascular stability making Levobupivacaine use successful for lower abdominal surgeries. [ABSTRACT FROM AUTHOR]

Published
2023

24. Normal and dwell fatigue behavior of a near-alpha titanium alloy - IMI 834

Author

Yazar K.U., Karmakar Anish, Sahu Vivek, Bhattacharjee Amit, and Suwas Satyam

Subjects
titanium alloy, imi 834, dwell fatigue, Engineering (General). Civil engineering (General), TA1-2040
Abstract

Dwell sensitivity of titanium alloys at ambient temperature (~250 C) is a well-known phenomenon, although the question about the exact micromechanical reasons responsible for this still remains open. In this work, the normal and dwell fatigue response of a near-alpha titanium alloy, IMI 834, is studied. Samples with three different microstructures, namely, fully lamellar, fully equiaxed and bimodal, are evaluated for their dwell fatigue behaviors. A reduction in fatigue life by at least an order of magnitude is seen in all the three microstructures. Large plastic strain accumulation (almost equal to the monotonic ductility) was observed during the dwell fatigue loading condition and this is held responsible for this large debit in fatigue life. The normal fatigue lives decreased in the order, bimodal > fully equiaxed > fully lamellar, while the dwell fatigue lives decreased in the order, fully equiaxed > fully lamellar > bimodal. Bimodal microstructure showed a dwell fatigue debit of 17, while fully lamellar and fully equiaxed showed a debit of 9 and 10, respectively.

Published
2020
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32. PLANT DISEASE DETECTION USING CONVOLUTIONAL NEURAL NETWORK

Author

Prakanshu Srivastava, Kritika Mishra and Sahu, Vivek Kumar

Subjects
Plant Disease Detection Machine Learning Image Processing Deep Learning Convolutional Neural Network
Abstract

When plants and crops are suffering from pests it affects the agricultural production of the country. Usually, farmers or experts observe the plants with eye for detection and identification of disease. But this method is often time processing, expensive and inaccurate. Automatic detection using image processing techniques provide fast and accurate results. This paper cares with a replacement approach to the development of disease recognition model, supported leaf image classification, by the utilization of deep convolutional networks. Advances in computer vision present a chance to expand and enhance the practice of precise plant protection and extend the market of computer vision applications within the field of precision agriculture. a completely unique way of training and therefore the methodology used facilitate a fast and straightforward system implementation in practice. All essential steps required for implementing this disease recognition model are fully described throughout the paper, starting from gathering images to make a database, assessed by agricultural experts, a deep learning framework to perform the deep CNN training. This method paper may be a new approach in detecting plant diseases using the deep convolutional neural network trained and finetuned to suit accurately to the database of a plants leaves that was gathered independently for diverse plant diseases. The advance and novelty of the developed model dwell its simplicity healthy leaves and background images are in line with other classes, enabling the model to distinguish between diseased leaves and healthy ones or from the environment by using CNN. Plants are the source of food on earth. Infections and diseases in plants are therefore a big threat, while the foremost common diagnosis is primarily performed by examining the plant body for the presence of visual symptoms [1]. As an alternative to the traditionally time-consuming process, different research works plan to find feasible approaches towards protecting plants. In recent years, growth in technology has engendered several alternatives to traditional arduous methods [2]. Deep learning techniques are very successful in image classification problems. &nbsp

Published
2021
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38. Comparative evaluation of dexmedetomidine and pregabalin as premedication agent to attenuate adverse hemodynamic and stress response in patients undergoing laparoscopic cholecystectomy.

Author

Jain, Anshul, Sinha, Rajeev, Pandey, Shivali, and Sahu, Vivek

Subjects
PREMEDICATION, HEART beat, DRUG side effects, BLOOD pressure, DEXMEDETOMIDINE, BLIND experiment
Abstract

Background: Laparoscopic cholecystectomy is the most commonly performed laparoscopic procedure. The goal of anesthetic management is to minimize stress response and early discharge. Dexmedetomidine, and pregabalin have been used successfully to attenuate laryngoscopy and intubation response in various surgical procedures. Aim: To compare efficacy of pregablin and dexmedetomidine in attenuating hemodynamic and stress response. Setting and Design: A prospective, double blind randomized trial comprising 130 ASA physical status class I and II patients posted for laparsoscopic cholecystectomy. Materials and Methods: Patients were randomized in to Group A and Group B. Group A received intravenous dexmedetomidine in a dose of 1ug.kg-1, through an infusion pump 20 min prior to induction of anaesthesia. Group B subjects received oral pregabalin 150 mg. Parameters observed were vitals, discharge time, cortisol level, side effects if any. Results: Post intervention heart rate got reduced significantly in Group A and it remained low in comparison to baseline during whole peri-operative period. In Group B, immediate post-pneumoperitoneum heart rate, and post exubation heart rate was higher than baseline. Blood pressure (BP) decreased significantly post intervention in Group A which persisted till pneumoperitoneum. In Group B there was statistically significant rise in systolic, diastolic and mean blood pressure postpneumoperitoneum as compared to baseline blood pressure. Post-operative cortisol level was significantly higher than baseline values and the level is more in Group B. Conclusion: Intravenous dexmedetomidine is more effective than oral pregabalin in attenuating perioperative stress response. [ABSTRACT FROM AUTHOR]

Published
2019
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48. Experimental Characterization of Hybrid Solid-State and Fluidic Cooling for Thermal Management of Localized Hotspots.

Author

Sahu, Vivek, Joshi, Yogendra K., Fedorov, Andrei G., Bahk, Je-Hyeong, Wang, Xi, and Shakouri, Ali

Subjects
*SUPERLATTICES, *SOLID state electronics, *FLUIDICS, *HEAT sinks (Electronics), *THERMAL management (Electronic packaging), *COOLING
Abstract

A hybrid cooling scheme utilizing superlattice coolers (SLCs) along with microchannel heat sink for thermal management of hotspots is presented. In this paper, we have studied the effect of operating and design parameters on the performance of the SLC. We have also experimentally investigated the effect of interface thermal resistance as well as thermal resistance between the ground electrode and superlattice using two test configurations: one with on-chip microchannels and another with off-chip microchannels. We demonstrated heat removal capability at the localized hotspots of more than over 300 W/cm2. [ABSTRACT FROM AUTHOR]

Published
2015
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49. Cooling power optimization for hybrid solid-state and liquid cooling in integrated circuit chips with hotspots.

Author

Yazawa, Kazuaki, Ziabari, Amirkoushyar, Yee Rui Koh, Shakouri, Ali, Sahu, Vivek, Fedorov, Andrei G, and Joshi, Yogendra

Abstract

We report theoretical investigation and optimization of a hot-spot cooling method. This hybrid scheme contains a liquid cooling microchannel and superlattice hotspot cooler(s). This analysis of the hybrid method aims to solve the potential thermal management challenges for hotspots especially in 3D stacked multichip packaging. The goal is to reduce the overall cooling power and optimize the energy efficiency. Starting with a generic modeling of the superlattice cooler system, the cooling temperature as a function of the superlattice thickness and the driving current is found. The analytic results are then compared with full 3D numerical simulation. The role of spreading thermal resistance in the chip substrate was found to be important. The later part of this report is the integration of the microchannel with the hotspot cooler. The pumping power is modeled based on the microchannel design and fluid properties. The total cooling power, the sum of the electrical power to pump the liquid and the electrical power to drive the superlattice cooler, is found as a function of overall heat dissipation of the chip including hotspot(s). As the goal is to keep the hottest point on the chip below certain threshold (e.g. 85°C), the result shows a dramatic reduction of the required total cooling power, when hybrid cooling scheme - superlattice hotspot cooler in conjunction with microchannel cooler - is used. Above particular analysis is based on the specific microchannel, but this proposed scheme allows us a systematic study to reduce the pump power further. [ABSTRACT FROM PUBLISHER]

Published
2012
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