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Your search keyword '"Sen, P. K."' showing total 13 results
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13 results on '"Sen, P. K."'

1. Transformation equation for frames undergoing non-uniform acceleration such as SHM and rotational motion

Author

Brahma, Ranchhaigiri and Sen, A. K.

Subjects
General Relativity and Quantum Cosmology
Abstract

Lorentz transformation equations provide us a set of relations between the spacetime co-ordinates as observed from two different inertial frames. In case, one of the frames is moving with a uniform rectilinear we have Rindlers transformation equations under such a situation. In the present work we extend the Rindlers equations to a situation where we have in general non-uniform acceleration. First we consider the non-inertial frame to undergo simple harmonic motion (SHM) and as a second case we consider the non-inertial frame to move uniformly along a circle. This set of transformation equations will have applications in various branches of Physics and in general in Astrophysics.

Published
2024

2. Seismic Image Denoising With A Physics-Constrained Deep Image Prior

Author

Voytan, Dimitri P., Ravula, Sriram, Ardel, Alexandru, Liebman, Elad, Dhara, Arnab, Sen, Mrinal K., and Dimakis, Alexandros

Subjects
Physics - Geophysics
Abstract

Seismic images often contain both coherent and random artifacts which complicate their interpretation. To mitigate these artifacts, we introduce a novel unsupervised deep-learning method based on Deep Image Prior (DIP) which uses convolutional neural networks. Our approach optimizes the network weights to refine the migration velocity model, rather than the seismic image, effectively isolating meaningful image features from noise and artifacts. We apply this method to synthetic and real seismic data, demonstrating significant improvements over standard DIP techniques with minimal computational overhead.

Published
2024

3. Gravitational field due a moving Schwarzschild object

Author

Brahma, Ranchhaigiri and Sen, A. K.

Subjects
General Relativity and Quantum Cosmology
Abstract

In this paper we analyze the spacetime geometry due to a Schwarzschild object having accelerated motion. In the beginning we investigated the gravitational field due to a uniformly moving Schwarzschild object and obtained the spacetime line element for such an object. After analyzing the necessary boundary conditions the obtained line element is found to be consistent. Next we extended our work to a uniformly accelerated Schwarzschild object. In that case we obtained the spacetime line element for both when the acceleration is along the $X-$direction and when the acceleration is in an arbitrary direction on the $XY$ plane. The boundary conditions of those line elements have been examined. Such work will have immense applications in astrophysics when we calculate the geodesic equations of test particles in the gravitational field of objects having uniform accelerated motion.

Published
2024

5. Social support and help-seeking worldwide

Author

Szkody, Erica, Spence, Anjolee, Özdoğru, Asil, Tushir, Bhawna, Chang, Fennie, AKKAŞ, Handan, Sotomayor, Ian, Pavlova, Iuliia, Petrovic, Ivana, Norvilitis, Jill, Pena-Shaff, Judith, Maney, Julia, Arrow, Kaitlyn, Rodriguez, Laura, Moussa-Rogers, Mary, McTighe, Michael, Ogba, Kalu T. U., Yeung, Stephanie Ka Wai Au, Stoppa, Tara, Yang, Yuanyuan, Gosnell, Courtney L., Jérémie-Brink, Gihane, Van Nostrand, Joshua J., Arriaga, Patrícia, Martin, Amy, Maksimovic, Ana, Ursu, Andreea, Karakulak, Arzu, Fitapelli, Brianna, Ashdown, Brien K., Sen, Celia K. Naivar, Chartier, Chris, Shane-Simpson, Christina, Redker, Christopher M., McKinney, Cliff, Baro, Danisha, Manrique-Millones, Denisse, Reis, Eduardo Silva, Adamopoulou, Eirini, Volkan, Eliz, Tair, Ergyul, Trujillo, Ethan, Kocalar, Halil Emre, Blocker, Heidi, Malik, Hinza, Orta, İrem Metin, Santos, Jay Claus, Grahe, Jon, Cuccolo, Kelly, Wignall, Liam, McLain, Malorie, Kosic, Marianna, Aita, Moet, Nash, Monique, Miracle, Ogba Oluchi, Christiano, Olivia, Dimitrova, Radosveta, Varma, Rahul, Mann, Rebecca, Dhakal, Sandesh, Estrada-Villalta, Sara, Haden, Sara, Hamilton, Sarah, Camgöz, Selin Metin, Aljuberi, Shams, Chin, Stephanie, Kohn, Steven, Verma, Sunil K., Fletcher, Tifani, Singh, Tushar, Sanders, Abigail, Collado, Adryana, Adusei, Akua, Itani, Alaa, Kaser, Amanda, Wolfe, Amber, Stout, Amy, Akhavan, Anahita, Kirton, Angelique, Çeçen-Eroğul, Ayşe Rezan, Bilir, Bilge, Dupiton, Camille, Lovett, Caroline, Orsini, Chloe, Kpodo, Christney, Aceto, Christopher, Redden, Clare, NyKanen, Danielle, Yildiz, Deniz, Lutringer, Emily, Sevinç, Ender, Baranski, Erica, Khan, Fahd, Jia, Fanli, Cramariuc, Gabriel, Zhang, Guolin, Resulbegoviq, Hakile, Maree, Haneen, Kaur, Harleen, Nelson, Jessie, Espinoza, Jimena Santa Cruz, Hubbard, JoAnna, Edlund, John, Protzko, John, Hoang, Jolie, Stork, Jordan, Vasu, Jordan, Salazar, Jose Verdis, Myhers, Karyssa, Hayward, Kaylynn, Lu, Kevin, Beardmore, Leisha, Levkiv, Liliia, Godoy, Linda Katheryn Hernandez, Paulett, Liseth, Gonzalez, María Fernanda Bonilla, Kalantzis, Maria, Rodrigues, Mariana, Álvarez, Marinés Mejía, Ott, Marissa, Zlokovich, Martha, Brosnan, Mary Kate, Mazzaferro, Mateus, Yetkin, Melis, Johnson, Mikayla, Vukelic, Milica, Clark, Mitchell, AlMalik, Mohammad, Fedavi, Neda, Means-Simonsen, Noah, Cabrera, Onassis, Kovacevic, Panta, Zhang, Qingyi, Rushing, Rachel, Varakis, Rafail, Richardson, Randall, Koch, Sara, Lewis, Savannah, Barrera, Scott, Zheng, Sifan, Liu, Siyu, Papka, Sophia, Das, Sreeja, Ghimire, Srijana, Verma, Tanya, Hillman, Taylor, Ozkusen, Ugur C., Zhang, Xinyi (Spencer), Gu, Yiwen, Redd, Bryce, and Cascalheira, Cory J.

Published
2024
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9. Quantification of Lymphangiogenesis in the Murine Lymphedema Tail Model Using Intravital Microscopy.

Author

Mohan, Ganesh, Khan, Imran, Diaz, Stephanie M., Kamocka, Malgorzata M., Hulsman, Luci A., Ahmed, Shahnur, Neumann, Colby R., Jorge, Miguel D., Gordillo, Gayle M., Sen, Chandan K., Sinha, Mithun, and Hassanein, Aladdin H.

Abstract

Background: Lymphedema is chronic limb swelling resulting from lymphatic dysfunction. It affects an estimated five million Americans. There is no cure for this disease. Assessing lymphatic growth is essential in developing novel therapeutics. Intravital microscopy (IVM) is a powerful imaging tool for investigating various biological processes in live animals. Tissue nanotransfection technology (TNT) facilitates a direct, transcutaneous nonviral vector gene delivery using a chip with nanochannel poration in a rapid (<100 ms) focused electric field. TNT was used in this study to deliver the genetic cargo in the murine tail lymphedema to assess the lymphangiogenesis. The purpose of this study is to experimentally evaluate the applicability of IVM to visualize and quantify lymphatics in the live mice model. Methods and Results: The murine tail model of lymphedema was utilized. TNT was applied to the murine tail (day 0) directly at the surgical site with genetic cargo loaded into the TNT reservoir: TNTpCMV6 group receives pCMV6 (expression vector backbone alone) (n = 6); TNTProx1 group receives pCMV6-Prox1 (n = 6). Lymphatic vessels (fluorescein isothiocyanate [FITC]-dextran stained) and lymphatic branch points (indicating lymphangiogenesis) were analyzed with the confocal/multiphoton microscope. The experimental group TNTProx1 exhibited reduced postsurgical tail lymphedema and increased lymphatic distribution compared to TNTpCMV6 group. More lymphatic branching points (>3-fold) were observed at the TNT site in TNTProx1 group. Conclusions: This study demonstrates a novel, powerful imaging tool for investigating lymphatic vessels in live murine tail model of lymphedema. IVM can be utilized for functional assessment of lymphatics and visualization of lymphangiogenesis following gene-based therapy. [ABSTRACT FROM AUTHOR]

Published
2024
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10. Exacerbated ischemia-reperfusion injury in fatty livers is mediated by lipid peroxidation stress and ferroptosis.

Author

Rokop, Zachary P., Zhang, Wenjun, Ghosh, Nandini, Biswas, Nirupam, Das, Amitava, Lin, Jingmei, Sen, Chandan K., and Kubal, Chandrashekhar

Abstract

Ischemia-reperfusion injury is a common problem in liver surgery and transplantation. Although ischemia-reperfusion injury is known to be more pronounced in fatty livers, the underlying mechanisms for this difference remain poorly understood. We hypothesized that ferroptosis plays a significant role in fatty liver ischemia-reperfusion injury due to increased lipid peroxidation in the presence of stored iron in the fatty liver. To test this hypothesis, the ferroptosis pathway was evaluated in a murine fatty liver ischemia-reperfusion injury model. C57BL6 mice were fed with a normal diet or a high fat, high sucrose diet for 12 weeks. At 22 weeks of age, liver ischemia-reperfusion injury was induced through partial (70%) hepatic pedicle clamping for 60 minutes, followed by 24 hours of reperfusion before tissue harvest. Acyl–coenzyme A synthetase long-chain family member 4 and 4-hydroxynonenal were quantified in the liver tissues. In separate experiments, liproxstatin-1 or vehicle control was administered for 7 consecutive days before liver ischemia-reperfusion injury. Exacerbated ischemia-reperfusion injury was observed in the livers of high fat, high sucrose diet fed mice. High fat, high sucrose diet + ischemia-reperfusion injury (HDF+IRI) livers had a significantly greater abundance of acyl–coenzyme A synthetase long-chain family member 4 and 4-hydroxynonenal compared with normal diet + ischemia-reperfusion injury (ND+IRI) livers or sham fatty livers, which indicated an increase of ferroptosis. HFD fed animals receiving liproxstatin-1 injections had a significant reduction in serum aspartate transaminase and alanine transaminase after ischemia-reperfusion injury, consistent with attenuation of ischemia-reperfusion injury in the liver. Ferroptosis plays a significant role in ischemia-reperfusion injury in fatty livers. Inhibiting ferroptotic pathways in the liver may serve as a novel therapeutic strategy to protect the fatty liver in the setting of ischemia-reperfusion injury. [ABSTRACT FROM AUTHOR]

Published
2024
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12. Non-Intrusive Online Time Domain Reflectometry Technique for Power Cables

Author

Subudhi, Ch Santosh and Sen, S K

Abstract

Commercially available Time Domain Reflectometry technique relies on direct injection of the probe signal into the power cable conductors. This requires disconnecting the cable conductors from the bus resulting in undesirable downtime of the load centres. Couplers have been proposed for galvanic isolation between the power and instrumentation circuits in online reflectometry systems for live cables. However, couplers weaken and distort the injected signal reducing the sensitivity of the system, besides being bulky and intrusive. Another problem in online reflectometry is the unwanted travel of the probe signal upstream of the cable and its reflections. These are the reasons for the limited commercial availability of online reflectometry products. This article presents a novel Online Time Domain reflectometry scheme for detecting local partial damages in live electric cables. The scheme proposes the use of a clamp-on type inductive coupler along with a specially designed narrow-band pulse to reduce signal distortion. An innovative application of the quarter wave transformer principle is proposed to maximize signal travel downstream of the cable and thereby eliminate the echoes generated by the undesired reflections from upstream. The proposed scheme is non-intrusive and easy to install on in-service cables. The scheme is experimentally validated on energized cables in a real distribution panel.

Published
2024
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13. Reconstruction of Multiple Target Bodies Using Trans-Dimensional Bayesian Inversion With Different Constraints

Author

Wei, Xiaolong, Sun, Jiajia, and Sen, Mrinal K.

Abstract

Geophysical geometry inversion aims to reconstruct the geometrical characteristics of subsurface target bodies, which is different from conventional inversion techniques that focus on subsurface physical properties (e.g., density and velocity). The published works on geometry inversion either focus on recovering one “optimal” model without considering uncertainty or are limited to situations where only a single anomalous body is sought when uncertainty is quantified. We aim to recover the geometries of multiple anomalous bodies and quantify their uncertainty in the trans-dimensional Bayesian framework. We adopt a sparse geometry parameterization strategy which allows approximating the shapes of anomalous bodies via a set of simple geometries (e.g., ellipses). To address the problem of multiple bodies in an area of study, we propose two strategies. The first strategy randomly samples a tuning parameter (i.e., $\alpha $ ) associated with the computation of the alpha shapes. In the second strategy, we devise two categories of geometries for sampling: parent and child geometries. Each child geometry is assigned to one parent geometry, and various geometrical families represent the multiple target bodies. To understand the effects of multiple data constraints and structural constraints, we design several scenarios, where the borehole gravity and gravity gradient data serve as additional data constraints and seismic imaging provides the structural constraint on the top of target bodies. We apply our method to the modified Pluto salt model consisting of three salt bodies with drastically different shapes and volumes. The results demonstrate that our framework is capable of recovering the disconnected anomalous bodies while taking into account multiple data constraints as well as structural constraints.

Published
2024
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