20,983 results on '"Santra, A."'
Search Results
2. Comparative Evaluation of Developmental Competence of Immature Cattle Oocytes in Three Different Culture Media
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Karmali, Pankaj, Bera, Sacchidananda, Menda, Rajendar, Shah, Vasim, Santra, A., and Das, S.K.
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- 2023
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3. Effect of feeding dried Moringa oleifera leaves on feed intake, milk production and biochemical parameters in Sahiwal cows
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Sonkar, Neetu, Singh, Nishma, Dubey, Meenu, Pathak, Rupal, Khune, V.N., Santra, A.K., Mishra, Sharad, and Dubey, Ashutosh
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- 2021
4. Enhancement of developmental competence of immature oocytes supplemented with growth factors in culture media
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Umdor, Sonia B., Karunakaran, M., Mandal, D.K., Santra, A., and Das, Subrata K.
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- 2021
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5. Tournament transitivity of graphs
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Santra, Kamal
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Mathematics - Combinatorics - Abstract
Let $G=(V, E)$ be a graph where $V$ and $E$ are the vertex and edge sets, respectively. For two disjoint subsets $A$ and $B$ of $V$, we say $A$ \textit{dominates} $B$ if every vertex of $B$ is adjacent to at least one vertex of $A$ in $G$. A vertex partition $\pi = \{V_1, V_2, \ldots, V_k\}$ of $G$ is called a \emph{transitive partition} of size $k$ if $V_i$ dominates $V_j$ for all $1\leq i
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- 2024
6. Dynamics of switching processes: general results and applications to intermittent active motion
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Santra, Ion, Olsen, Kristian Stølevik, and Gupta, Deepak
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Condensed Matter - Statistical Mechanics - Abstract
Systems switching between different dynamical phases is an ubiquitous phenomenon. The general understanding of such a process is limited. To this end, we present a general expression that captures fluctuations of a system exhibiting a switching mechanism. Specifically, we obtain an exact expression of the Laplace-transformed characteristic function of the particle's position. Then, the characteristic function is used to compute the effective diffusion coefficient of a system performing intermittent dynamics. Further, we employ two examples: 1) Generalized run-and-tumble active particle, and 2) an active particle switching its dynamics between generalized active run-and-tumble motion and passive Brownian motion. In each case, explicit computations of the spatial cumulants are presented. Our findings reveal that the particle's position probability density function exhibit rich behaviours due to intermittent activity. Numerical simulations confirm our findings.
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- 2024
7. Multipath entanglement purification strategies for quantum networks
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Mondal, Md Sohel and Santra, Siddhartha
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Quantum Physics - Abstract
In quantum networks multipath entanglement purification (MEP) between a pair of source-destination nodes can substantially strengthen their entanglement connection. An efficient MEP strategy can therefore increase the size of the network region where bipartite entanglement based quantum information processing tasks can be implemented. Here, we analyse MEP in a general model of a quantum network and obtain design criteria for efficient MEP strategies. Further, by simulating two different MEP strategies, based on these criteria, on different underlying network topologies we explore how the topology determines the effectiveness of a fixed MEP strategy. Finally, we show that a careful choice of MEP strategy can make the entanglement connection strength between source-destination network nodes effectively independent of its topology. Our results can therefore provide a useful guide for the design of quantum networks and entanglement distribution protocols.
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- 2024
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8. Modified Opposite-Spin-Scaled Double-Hybrid Functionals
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Santra, Golokesh, Bursch, Markus, and Wittmann, Lukas
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Physics - Chemical Physics - Abstract
We investigate the potential performance improvements of double-hybrid density functionals by replacing the standard opposite-spin-scaled MP2 (SOS-MP2) with the modified opposite-spin-scaled MP2 (MOS-MP2) in the nonlocal correlation component. Using the large and diverse GMTKN55 dataset, we find that MOS-double hybrids provide significantly better accuracy compared to SOS-MP2-based double hybrids when empirical dispersion correction is not employed. The non-covalent interaction subsets account for the majority of this improvement. Adding the DFT-D4 dispersion correction to MOS-type double hybrids does not provide any superior performance over conventional dispersion-corrected SOS-MP2-based double hybrids. Nevertheless, for nine tested transition metal sets, dispersion-corrected spin-component-scaled (SCS) double hybrids are still significantly better than any MOS-double hybrid functional.
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- 2024
9. Modeling of Terrain Deformation by a Grouser Wheel for Lunar Rover Simulation
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Kamohara, Junnosuke, Ares, Vinicius, Hurrell, James, Takehana, Keisuke, Richard, Antoine, Santra, Shreya, Uno, Kentaro, Rohmer, Eric, and Yoshida, Kazuya
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Computer Science - Robotics - Abstract
Simulation of vehicle motion in planetary environments is challenging. This is due to the modeling of complex terrain, optical conditions, and terrain-aware vehicle dynamics. One of the critical issues of typical simulators is that they assume terrain is a rigid body, which limits their ability to render wheel traces and compute the wheel-terrain interactions. This prevents, for example, the use of wheel traces as landmarks for localization, as well as the accurate simulation of motion. In the context of lunar regolith, the surface is not rigid but granular. As such, there are differences in the rover's motion, such as sinkage and slippage, and a clear wheel trace left behind the rover, compared to that on a rigid terrain. This study presents a novel approach to integrating a terramechanics-aware terrain deformation engine to simulate a realistic wheel trace in a digital lunar environment. By leveraging Discrete Element Method simulation results alongside experimental single-wheel test data, we construct a regression model to derive deformation height as a function of contact normal force. The region of interest in a height map is retrieved from the wheel poses. The elevation values of corresponding pixels are subsequently modified using contact normal forces and the regression model. Finally, we apply the determined elevation change to each mesh vertex to render wheel traces during runtime. The deformation engine is integrated into our ongoing development of a lunar simulator based on NVIDIA's Omniverse IsaacSim. We hypothesize that our work will be crucial to testing perception and downstream navigation systems under conditions similar to outdoor or terrestrial fields. A demonstration video is available here: https://www.youtube.com/watch?v=TpzD0h-5hv4, Comment: 7pages, 7 figures, to be published in proceedings of the 21st International and 12th Asia-Pacific Regional Conference of the ISTVS (ISTVS)
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- 2024
10. On the Necessity of World Knowledge for Mitigating Missing Labels in Extreme Classification
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Prakash, Jatin, Buvanesh, Anirudh, Santra, Bishal, Saini, Deepak, Yadav, Sachin, Jiao, Jian, Prabhu, Yashoteja, Sharma, Amit, and Varma, Manik
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Computer Science - Machine Learning ,Computer Science - Information Retrieval - Abstract
Extreme Classification (XC) aims to map a query to the most relevant documents from a very large document set. XC algorithms used in real-world applications learn this mapping from datasets curated from implicit feedback, such as user clicks. However, these datasets inevitably suffer from missing labels. In this work, we observe that systematic missing labels lead to missing knowledge, which is critical for accurately modelling relevance between queries and documents. We formally show that this absence of knowledge cannot be recovered using existing methods such as propensity weighting and data imputation strategies that solely rely on the training dataset. While LLMs provide an attractive solution to augment the missing knowledge, leveraging them in applications with low latency requirements and large document sets is challenging. To incorporate missing knowledge at scale, we propose SKIM (Scalable Knowledge Infusion for Missing Labels), an algorithm that leverages a combination of small LM and abundant unstructured meta-data to effectively mitigate the missing label problem. We show the efficacy of our method on large-scale public datasets through exhaustive unbiased evaluation ranging from human annotations to simulations inspired from industrial settings. SKIM outperforms existing methods on Recall@100 by more than 10 absolute points. Additionally, SKIM scales to proprietary query-ad retrieval datasets containing 10 million documents, outperforming contemporary methods by 12% in offline evaluation and increased ad click-yield by 1.23% in an online A/B test conducted on a popular search engine. We release our code, prompts, trained XC models and finetuned SLMs at: https://github.com/bicycleman15/skim, Comment: Preprint, 23 pages
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- 2024
11. Mechanistic Modeling of Lipid Nanoparticle Formation for the Delivery of Nucleic Acid Therapeutics
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Inguva, Pavan K., Mukherjee, Saikat, Walker, Pierre J., Kanso, Mona A., Wang, Jie, Wu, Yanchen, Tenberg, Vico, Santra, Srimanta, Singh, Shalini, Kim, Shin Hyuk, Trout, Bernhardt L., Bazant, Martin Z., Myerson, Allan S., and Braatz, Richard D.
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Condensed Matter - Soft Condensed Matter ,Computer Science - Computational Engineering, Finance, and Science ,Physics - Biological Physics ,Physics - Chemical Physics - Abstract
Nucleic acids such as mRNA have emerged as a promising therapeutic modality with the capability of addressing a wide range of diseases. Lipid nanoparticles (LNPs) as a delivery platform for nucleic acids were used in the COVID-19 vaccines and have received much attention. While modern manufacturing processes which involve rapidly mixing an organic stream containing the lipids with an aqueous stream containing the nucleic acids are conceptually straightforward, detailed understanding of LNP formation and structure is still limited and scale-up can be challenging. Mathematical and computational methods are a promising avenue for deepening scientific understanding of the LNP formation process and facilitating improved process development and control. This article describes strategies for the mechanistic modeling of LNP formation, starting with strategies to estimate and predict important physicochemical properties of the various species such as diffusivities and solubilities. Subsequently, a framework is outlined for constructing mechanistic models of reactor- and particle-scale processes. Insights gained from the various models are mapped back to product quality attributes and process insights. Lastly, the use of the models to guide development of advanced process control and optimization strategies is discussed., Comment: 67 pages, 10 figures
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- 2024
12. Commensurate supersolids and re-entrant transitions in an extended Bose-Hubbard ladder
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Madhusudan, Ashwath N, Santra, Gopal Chandra, Kaur, Inderpreet, Li, Weibin, and Nath, Rejish
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Condensed Matter - Quantum Gases ,Quantum Physics - Abstract
We investigate the ground state phases of an extended Bose-Hubbard ladder of unit filling via the density-matrix-renormalization-group method and, in particular, the effect of rung-hoppings. In contrast to a single-chain, a commensurate supersolid emerges, and based on the Luttinger parameter, we classify them into two types. The latter leads to a reentrant gapless behavior as the onsite interaction is increased while keeping all other parameters intact. A reentrant gapped transition is also found as a function of nearest-neighbor interactions. Further, we show that the string order characterizing the Haldane phase vanishes for a finite inter-chain hopping amplitude, however small it is. Finally, we propose two experimental platforms to observe our findings, using either dipolar atoms or polar molecules and Rydberg admixed atoms., Comment: 7 pages, 9 figures
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- 2024
13. Forces from coarse-graining nonequilibrium degrees of freedom: exact results
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Santra, Ion and Krüger, Matthias
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Condensed Matter - Statistical Mechanics ,Condensed Matter - Soft Condensed Matter - Abstract
We study paradigmatic examples of a tracer trapped in a harmonic potential and coupled to a bath particle of various types. Restricting to linear couplings between tracer and bath allows for analytical treatment. We discuss the resulting stochastic Langevin equation for the tracer and its relaxation function, for which this equation is averaged under an initial tracer position. For equilibrium, the tracer-bath force on average vanishes, a well known consequence of Boltzmann statistics. If tracer and bath are subject to different temperatures, the conditioned tracer-bath force is finite, and can be as large in magnitude as the force between tracer and trapping potential. For a bath particle with intrinsic memory, e.g., an active particle, even the noise felt by the bath particle takes a finite average under conditioning of the tracer. If the noise of the bath particle is non-Gaussian, the relaxation function of the tracer can be non-monotonic as a function of time. We display how these phenomena are reflected in the Langevin equation of the tracer., Comment: 22 pages, 7 figures
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- 2024
14. Coined Quantum Walk on a Quantum Network
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Bhavsar, Jigyen, Shekhar, Shashank, and Santra, Siddhartha
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Quantum Physics - Abstract
We explore a discrete-time, coined quantum walk on a quantum network where the coherent superposition of walker-moves originates from the unitary interaction of the walker-coin with the qubit degrees of freedom in the quantum network. The walk dynamics leads to a growth of entanglement between the walker and the network on one hand, and on the other, between the network-qubits among themselves. The initial entanglement among the network qubits plays a crucial role in determining the asymptotic values of these entanglement measures and the quantum walk statistics. Specifically, the entanglement entropy of the walker-network state and the negativity of the quantum network-qubit state saturate to values increasing with the initial network-entanglement. The asymptotic time-averaged walker-position probability distribution shows increasing localization around the initial walker-position with higher initial network entanglement. A potential application of these results as a characterisation tool for quantum network properties is suggested., Comment: Comments welcome
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- 2024
15. Risk-Aware Coverage Path Planning for Lunar Micro-Rovers Leveraging Global and Local Environmental Data
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Santra, Shreya, Uno, Kentaro, Kudo, Gen, and Yoshida, Kazuya
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Computer Science - Robotics - Abstract
This paper presents a novel 3D myopic coverage path planning algorithm for lunar micro-rovers that can explore unknown environments with limited sensing and computational capabilities. The algorithm expands upon traditional non-graph path planning methods to accommodate the complexities of lunar terrain, utilizing global data with local topographic features into motion cost calculations. The algorithm also integrates localization and mapping to update the rover's pose and map the environment. The resulting environment map's accuracy is evaluated and tested in a 3D simulator. Outdoor field tests were conducted to validate the algorithm's efficacy in sim-to-real scenarios. The results showed that the algorithm could achieve high coverage with low energy consumption and computational cost, while incrementally exploring the terrain and avoiding obstacles. This study contributes to the advancement of path planning methodologies for space exploration, paving the way for efficient, scalable and autonomous exploration of lunar environments by small rovers., Comment: 6 pages, 11 figures. Manuscript accepted at the IEEE International Conference on Space Robotics 2024
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- 2024
16. Development of Cattle Embryo Through In Vitro Technique Using Epidermal Growth Factor as A Media Supplement
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Prasad, Shiba, Prakash, C., Rohit, K., Karunakaran, M., Santra, A., and Das, Subrata K.
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- 2018
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17. Zirconium Oxynitride Thin Films for Photoelectrochemical Water Splitting.
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Streibel, Verena, Schönecker, Johanna, Wagner, Laura, Sirotti, Elise, Munnik, Frans, Kuhl, Matthias, Jiang, Chang-Ming, Eichhorn, Johanna, Santra, Saswati, and Sharp, Ian
- Abstract
Transition metal oxynitrides are a promising class of functional materials for photoelectrochemical (PEC) applications. Although these compounds are most commonly synthesized via ammonolysis of oxide precursors, such synthetic routes often lead to poorly controlled oxygen-to-nitrogen anion ratios, and the harsh nitridation conditions are incompatible with many substrates, including transparent conductive oxides. Here, we report direct reactive sputter deposition of a family of zirconium oxynitride thin films and the comprehensive characterization of their tunable structural, optical, and functional PEC properties. Systematic increases of the oxygen content in the reactive sputter gas mixture enable access to different crystalline structures within the zirconium oxynitride family. Increasing oxygen contents lead to a transition from metallic to semiconducting to insulating phases. In particular, crystalline Zr2ON2-like films have band gaps in the UV-visible range and are n-type semiconductors. These properties, together with a valence band maximum position located favorably relative to the water oxidation potential, make them viable photoanode candidates. Using chopped linear sweep voltammetry, we indeed confirm that our Zr2ON2 films are PEC-active for the oxygen evolution reaction in alkaline electrolytes. We further show that high-vacuum annealing boosts their PEC performance characteristics. Although the observed photocurrents are low compared to state-of-the-art photoanodes, these dense and planar thin films can offer a valuable platform for studying oxynitride photoelectrodes, as well as for future nanostructuring, band gap engineering, and defect engineering efforts.
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- 2024
18. Synaptic ribbon dynamics after noise exposure in the hearing cochlea.
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Ismail Mohamad, Noura, Santra, Peu, Park, Yesai, Matthews, Ian, Taketa, Emily, and Chan, Dylan
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Animals ,Mice ,Hearing Loss ,Noise-Induced ,Cochlea ,Hearing ,Noise ,Synapses - Abstract
Moderate noise exposure induces cochlear synaptopathy, the loss of afferent ribbon synapses between cochlear hair cells and spiral ganglion neurons, which is associated with functional hearing decline. Prior studies have demonstrated noise-induced changes in the distribution and number of synaptic components, but the dynamic changes that occur after noise exposure have not been directly visualized. Here, we describe a live imaging model using RIBEYE-tagRFP to enable direct observation of pre-synaptic ribbons in mature hearing mouse cochleae after synaptopathic noise exposure. Ribbon number does not change, but noise induces an increase in ribbon volume as well as movement suggesting unanchoring from synaptic tethers. A subgroup of basal ribbons displays concerted motion towards the cochlear nucleus with subsequent migration back to the cell membrane after noise cessation. Understanding the immediate dynamics of synaptic damage after noise exposure may facilitate identification of specific target pathways to treat cochlear synaptopathy.
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- 2024
19. Harmonic chain driven by active Rubin bath: transport properties and steady-state correlations
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Sarkar, Ritwick, Santra, Ion, and Basu, Urna
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Condensed Matter - Statistical Mechanics ,Condensed Matter - Soft Condensed Matter - Abstract
Characterizing the properties of an extended system driven by active reservoirs is a question of increasing importance. Here we address this question in two steps. We start by investigating the dynamics of a probe particle connected to an `active Rubin bath' -- a linear chain of overdamped run-and-tumble particles. We derive exact analytical expressions for the effective noise and dissipation kernels, acting on the probe, and show that the active nature of the bath leads to a modified fluctuation-dissipation relation. In the next step, we study the properties of an activity-driven system, modeled by a chain of harmonic oscillators connected to two such active reservoirs at the two ends. We show that the system reaches a nonequilibrium stationary state (NESS), remarkably different from that generated due to a thermal gradient. We characterize this NESS by computing the kinetic temperature profile, spatial and temporal velocity correlations of the oscillators, and the average energy current flowing through the system. It turns out that, the activity drive leads to the emergence of two characteristic length scales, proportional to the activities of the reservoirs. Strong signatures of activity are also manifest in the anomalous short-time decay of the velocity autocorrelations. Finally, we find that the energy current shows a non-monotonic dependence on the activity drive and reversal in direction, corroborating previous findings.
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- 2024
20. Weakly Supervised Detection of Pheochromocytomas and Paragangliomas in CT
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Oluigboa, David C., Santra, Bikash, Mathai, Tejas Sudharshan, Mukherjee, Pritam, Liu, Jianfei, Jha, Abhishek, Patel, Mayank, Pacak, Karel, and Summers, Ronald M.
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Electrical Engineering and Systems Science - Image and Video Processing ,Computer Science - Computer Vision and Pattern Recognition - Abstract
Pheochromocytomas and Paragangliomas (PPGLs) are rare adrenal and extra-adrenal tumors which have the potential to metastasize. For the management of patients with PPGLs, CT is the preferred modality of choice for precise localization and estimation of their progression. However, due to the myriad variations in size, morphology, and appearance of the tumors in different anatomical regions, radiologists are posed with the challenge of accurate detection of PPGLs. Since clinicians also need to routinely measure their size and track their changes over time across patient visits, manual demarcation of PPGLs is quite a time-consuming and cumbersome process. To ameliorate the manual effort spent for this task, we propose an automated method to detect PPGLs in CT studies via a proxy segmentation task. As only weak annotations for PPGLs in the form of prospectively marked 2D bounding boxes on an axial slice were available, we extended these 2D boxes into weak 3D annotations and trained a 3D full-resolution nnUNet model to directly segment PPGLs. We evaluated our approach on a dataset consisting of chest-abdomen-pelvis CTs of 255 patients with confirmed PPGLs. We obtained a precision of 70% and sensitivity of 64.1% with our proposed approach when tested on 53 CT studies. Our findings highlight the promising nature of detecting PPGLs via segmentation, and furthers the state-of-the-art in this exciting yet challenging area of rare cancer management., Comment: Accepted at SPIE 2024. arXiv admin note: text overlap with arXiv:2402.00175
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- 2024
21. Rigid clusters in shear-thickening suspensions: a nonequilibrium critical transition
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Santra, Aritra, Orsi, Michel, Chakraborty, Bulbul, and Morris, Jeffrey F.
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Condensed Matter - Soft Condensed Matter ,Condensed Matter - Statistical Mechanics - Abstract
The onset and growth of rigid clusters in a two-dimensional (2D) suspension in shear flow are studied by numerical simulation. The suspension exhibits the lubricated-to-frictional rheology transition but is studied at stresses above the levels that cause extreme shear thickening. At large solid area fraction, $\phi$, but below the jamming fraction, we find that there is critical $\phi_c$ beyond which the proportion of particles in rigid clusters grows sharply, as $f_{\rm rig} \sim (\phi-\phi_c)^{\beta}$ with $\beta=1/8$, and at which the fluctuations in the net rigidity grow sharply, with a susceptibility measure $\chi_{\rm rig} \sim |\phi-\phi_c|^{-\gamma}$ with $\gamma = 7/4$. By applying finite size scaling, the correlation length, arising from the correlation of rigid domains, is found to scale as $\xi \sim |\phi-\phi_c|^{-\nu}$ with $\nu = 1$. The system is thus found to exhibit criticality, with critical exponents consistent with the 2D Ising transition. This behavior occurs over a range of stresses, with $\phi_c$ increasing as the stress decreases, consistent with the known increase in jamming fraction with reduction of stress for shear-thickening suspensions.
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- 2024
22. Significance of Anatomical Constraints in Virtual Try-On
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Roy, Debapriya, Santra, Sanchayan, Mukherjee, Diganta, and Chanda, Bhabatosh
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Computer Science - Computer Vision and Pattern Recognition - Abstract
The system of Virtual Try-ON (VTON) allows a user to try a product virtually. In general, a VTON system takes a clothing source and a person's image to predict the try-on output of the person in the given clothing. Although existing methods perform well for simple poses, in case of bent or crossed arms posture or when there is a significant difference between the alignment of the source clothing and the pose of the target person, these methods fail by generating inaccurate clothing deformations. In the VTON methods that employ Thin Plate Spline (TPS) based clothing transformations, this mainly occurs for two reasons - (1)~the second-order smoothness constraint of TPS that restricts the bending of the object plane. (2)~Overlaps among different clothing parts (e.g., sleeves and torso) can not be modeled by a single TPS transformation, as it assumes the clothing as a single planar object; therefore, disregards the independence of movement of different clothing parts. To this end, we make two major contributions. Concerning the bending limitations of TPS, we propose a human AnaTomy-Aware Geometric (ATAG) transformation. Regarding the overlap issue, we propose a part-based warping approach that divides the clothing into independently warpable parts to warp them separately and later combine them. Extensive analysis shows the efficacy of this approach., Comment: arXiv admin note: substantial text overlap with arXiv:2208.08076
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- 2024
23. Quantifying shoreline dynamics in the Indian Sundarban delta with Google Earth Engine (GEE)-based automatic extraction approach
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Santra, Manali, Dwivedi, Chandra Shekhar, and Pandey, Arvind Chandra
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- 2024
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24. CdS/CuInS2 Quantum Dots Cosensitized Solar Cells Using Functionalized Polyurethane Gel Electrolytes
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Prakash, Ravi, Santra, Amita, Yaduka, Sparsh, and Maiti, Pralay
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- 2024
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25. An extensive review of preparation, stabilization, and application of single and hybrid nanofluids
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Das, Pritam Kumar, Santra, Apurba Kumar, Ganguly, Ranjan, Dash, Santosh Kumar, Muthusamy, Suresh, Sha, MizajShabil, and Sadasivuni, Kishor Kumar
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- 2024
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26. Heat and mass transfer in double-diffusive mixed convection of Casson fluid: biomedical applications
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Bathmanaban, P., Siva, E. P., Santra, S. S., Askar, S. S., Foul, A., and Nandi, S.
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- 2024
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27. Food waste generation and its industrial utilization: An overview
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Dey, Sukhendu, Santra, Megha, Choudhury, Moharana, Ghosh, Apurba Ratan, and Samanta, Palas
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- 2024
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28. Modeling predator–prey interaction: effects of perceived fear and toxicity on ecological communities
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Das, Bijoy Kumar, Sahoo, Debgopal, Santra, Nirapada, and Samanta, Guruprasad
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- 2024
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29. Molecular Insights into O‑Linked Sialoglycans Recognition by the Siglec-Like SLBR‑N (SLBRUB10712) of Streptococcus gordonii
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Di Carluccio, Cristina, Cerofolini, Linda, Moreira, Miguel, Rosu, Frédéric, Padilla-Cortés, Luis, Gheorghita, Giulia Roxana, Xu, Zhuojia, Santra, Abhishek, Yu, Hai, Yokoyama, Shinji, Gray, Taylor E, St. Laurent, Chris D, Manabe, Yoshiyuki, Chen, Xi, Fukase, Koichi, Macauley, Matthew S, Molinaro, Antonio, Li, Tiehai, Bensing, Barbara A, Marchetti, Roberta, Gabelica, Valérie, Fragai, Marco, and Silipo, Alba
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Chemical Sciences ,Clinical Research ,Infectious Diseases ,Dental/Oral and Craniofacial Disease ,Chemical sciences - Abstract
Streptococcus gordonii is a Gram-positive bacterial species that typically colonizes the human oral cavity, but can also cause local or systemic diseases. Serine-rich repeat (SRR) glycoproteins exposed on the S. gordonii bacterial surface bind to sialylated glycans on human salivary, plasma, and platelet glycoproteins, which may contribute to oral colonization as well as endocardial infections. Despite a conserved overall domain organization of SRR adhesins, the Siglec-like binding regions (SLBRs) are highly variable, affecting the recognition of a wide range of sialoglycans. SLBR-N from the SRR glycoprotein of S. gordonii UB10712 possesses the remarkable ability to recognize complex core 2 O-glycans. We here employed a multidisciplinary approach, including flow cytometry, native mass spectrometry, isothermal titration calorimetry, NMR spectroscopy from both protein and ligand perspectives, and computational methods, to investigate the ligand specificity and binding preferences of SLBR-N when interacting with mono- and disialylated core 2 O-glycans. We determined the means by which SLBR-N preferentially binds branched α2,3-disialylated core 2 O-glycans: a selected conformation of the 3'SLn branch is accommodated into the main binding site, driving the sTa branch to further interact with the protein. At the same time, SLBR-N assumes an open conformation of the CD loop of the glycan-binding pocket, allowing one to accommodate the entire complex core 2 O-glycan. These findings establish the basis for the generation of novel tools for the detection of specific complex O-glycan structures and pave the way for the design and development of potential therapeutics against streptococcal infections.
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- 2024
30. Entanglement topography of large-scale quantum networks
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Mondal, Md Sohel, Fields, Dov, Malinovsky, Vladimir S., and Santra, Siddhartha
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Quantum Physics - Abstract
Large-scale quantum networks, necessary for distributed quantum information processing, are posited to have quantum entangled systems between distant network nodes. The extent and quality of distributed entanglement in a quantum network, that is its functionality, depends on its topology, edge-parameter distributions and the distribution protocol. We uncover the parametric entanglement topography and introduce the notion of typical and maximal viable regions for entanglement-enabled tasks in a general model of large-scale quantum networks. We show that such a topographical analysis, in terms of viability regions, reveals important functional information about quantum networks, provides experimental targets for the edge parameters and can guide efficient quantum network design. Applied to a photonic quantum network, such a topographical analysis shows that in a network with radius $10^3$ kms and 1500 nodes, arbitrary pairs of nodes can establish quantum secure keys at a rate of $R_{sec}=1$ kHz using $1$ MHz entanglement generation sources on the edges and as few as 3 entanglement swappings at intermediate nodes along network paths., Comment: Comments welcome
- Published
- 2023
31. A Deep uGMRT view of the ultra steep spectrum radio halo in Abell 521
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Santra, Ramananda, Kale, Ruta, Giacintucci, Simona, Markevitch, Maxim, Luca, Federico De., Bourdin, Herve, Venturi, Tiziana, Dallacasa, Daniele, Cassano, Rossella, Brunetti, Gianfranco, and Buch, Kaushal
- Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present the first detailed analysis of the ultra-steep spectrum radio halo in the merging galaxy cluster Abell 521, based on upgraded Giant Metrewave Radio telescope (uGMRT) observations. The combination of radio observations (300-850 MHz) and archival X-ray data provide a new window into the complex physics occurring in this system. When compared to all previous analyses, our sensitive radio images detected the centrally located radio halo emission to a greater extent of $\sim$ 1.3 Mpc. A faint extension of the southeastern radio relic has been discovered. We detected another relic, recently discovered by MeerKAT, and coincident with a possible shock front in the X-rays, at the northwest position of the center. We find that the integrated spectrum of the radio halo is well-fitted with a spectral index of $-1.86 \pm 0.12$. A spatially resolved spectral index map revealed the spectral index fluctuations, as well as an outward radial steepening of the average spectral index. The radio and X-ray surface brightness are well correlated for the entire and different sub-parts of the halo, with sub-linear correlation slopes (0.50$-$0.65). We also found a mild anti-correlation between the spectral index and X-ray surface brightness. Newly detected extensions of the SE relic and the counter relic are consistent with the merger in the plane of the sky., Comment: 31 pages (total), 35 figures, 7 tables, 2 appendix (12 figures, 2 tables). Accepted for publication in Astrophysical Journal (APJ)
- Published
- 2023
32. New Measurement of the Hoyle State Radiative Transition Width
- Author
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Rana, T. K., Pandit, Deepak, Manna, S., Kundu, S., Banerjee, K., Sen, A., Pandey, R., Mukherjee, G., Ghosh, T. K., Nayak, S. S., Shil, R., Karmakar, P., Atreya, K., Rani, K., Paul, D., Santra, Rajkumar, Sultana, A., Basu, S., Pal, S., Sadhukhan, S., Mondal, Debasish, Mukhopadhyay, S., Bhattacharya, Srijit, Pal, Surajit, Pant, Pankaj, Roy, Pratap, Ali, Sk M., Mondal, S., De, A., Dey, Balaram, Datta, R., Bhattacharya, S., and Bhattacharya, C.
- Subjects
Nuclear Experiment - Abstract
The radiative decay of the Hoyle state is the doorway to the production of heavier elements in stellar environment. Here we report, an exclusive measurement of electric quadruple (E$_2$) transitions of the Hoyle state to the ground state of $^{12}$C through the $^{12}$C(p, p$^\prime$$\gamma$$\gamma$)$^{12}$C reaction. Triple coincidence measurement yields a value of radiative branching ratio $\Gamma_{rad}$/$\Gamma$ = 4.01 (30) $\times$ 10$^{-4}$. The result has been corroborated by an independent experiment based on the complete kinematical measurement $via.$ $^{12}$C(p, p$^\prime$)$^{12}$C reaction ($\Gamma_{rad}$/$\Gamma$ = 4.04 (30) $\times$ 10$^{-4}$). Using our results together with the currently adopted values of $\Gamma_{\pi}$(E$_0$)/$\Gamma$ and $\Gamma_{\pi}$($E_0$), the radiative width of the Hoyle state is found to be 3.75 (40) $\times$ 10$^{-3}$ eV. We emphasize here that our result is not in agreement with 34 $\%$ increase in the radiative decay width of the Hoyle state measured recently but consistent with the currently adopted value., Comment: 7 pages, 5 figures Submitted to Phys. Rev. Lett
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- 2023
33. Exact fluctuation and long-range correlations in a single-file model under resetting
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Santra, Saikat and Singh, Prashant
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Condensed Matter - Statistical Mechanics - Abstract
Resetting is a renewal mechanism in which a process is intermittently repeated after a random or fixed time. This simple act of stop and repeat profoundly influences the behaviour of a system as exemplified by the emergence of non-equilibrium properties and expedition of search processes. Herein, we explore the ramifications of stochastic resetting in the context of a single-file system called random average process (RAP) in one dimension. In particular, we focus on the dynamics of tracer particles and analytically compute the variance, equal time correlation, autocorrelation and unequal time correlation between the positions of different tracer particles. Our study unveils that resetting gives rise to rather different behaviours depending on whether the particles move symmetrically or asymmetrically. For the asymmetric case, the system for instance exhibits a long-range correlation which is not seen in absence of the resetting. Similarly, in contrast to the reset-free RAP, the variance shows distinct scalings for symmetric and asymmetric cases. While for the symmetric case, it decays (towards its steady value) as $\sim e^{-r t} / \sqrt{t}$, we find $\sim t e^{-r t}$ decay for the asymmetric case ($r$ being the resetting rate). Finally, we examine the autocorrelation and unequal time correlation in the steady state and demonstrate that they obey interesting scaling forms at late times. All our analytical results are substantiated by extensive numerical simulations., Comment: 16 pages, 7 figures
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- 2023
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34. Collective Enhancement of Nuclear Level Density and its fade-out in $^{161}$Dy
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Santhosh, T., Rout, P. C., Santra, S., Pal, A., Mohanto, G., Gandhi, Ramandeep, and Baishya, A.
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Nuclear Experiment - Abstract
The nuclear level density is a fundamental quantity in nuclear physics, governing various nuclear reactions and astrophysical processes. In this study, we report on the collective enhancement of nuclear level density and its fade-out with excitation energy in the deformed $^{161}$Dy, obtained through an exclusive measurement of neutron evaporation spectra. The $^{162}$Dy nucleus was populated via the transfer of a triton in a $^{7}$Li-induced reaction on $^{159}$Tb. Statistical model analysis of the neutron spectra revealed a large collective enhancement factor of 42$\pm$2, consistent with microscopic calculations. This enhancement factor is similar to the one obtained for mass A$\sim$170 in our previous measurement. The energy-dependent collective enhancement over a wide range of excitation energies was inferred by combining the present results with the available Oslo level density below the neutron binding energy., Comment: 6 pages, 5 figures, Accepted in Physical Review C
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- 2023
35. Experimental Evidence of Large Collective Enhancement of Nuclear Level Density and its Significance in Radiative Neutron Capture
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Santhosh, T., Rout, P. C., Santra, S., Shrivastava, A., Mohanto, G., Pandit, S. K., Pal, A., Gandhi, Ramandeep, Baishya, A., and Dhuri, Sangeeta
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Nuclear Experiment - Abstract
The collective enhancement of nuclear level density and its fade out with excitation energy in deformed $^{171}$Yb nucleus has been inferred through an exclusive measurement of neutron spectra.The statistical model analysis of neutron spectra demonstrated a large collective enhancement factor of 40$\pm$3 for the first time, which corroborates with the recent microscopic model predictions but is an anomalous result compared with the measurements in the nearby deformed nuclei. The complete picture of the energy dependent collective enhancement has been obtained by combining with Oslo data below neutron binding energy. The significance of large collective enhancement in radiative neutron capture cross section of astrophysical interest is highlighted., Comment: 12 pages, 5 figures
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- 2023
- Full Text
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36. On the Microscopic Level Density Models for Nuclei Near Z=28 Shell Closure
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E, Surayya H., Sunny, Jesmi, Musthafa, M. M, Midhun, C. V, Suryanarayana, S. V, Pandey, Jyoti, Pal, A, Rout, P. C, Santra, S, Joseph, Antony, and Ganesan, S.
- Subjects
Nuclear Experiment ,Nuclear Theory - Abstract
A comprehensive test of level density models for explaining the decay of excited compound nuclei, 54 Mn, 56 Fe, 58 Co, 60 Ni, 61 Ni and 63 Cu, in the energy range of 28 - 36 MeV has been performed. The compound nuclei of interest in the desired ranges are populated using 6 Li based transfer reactions. The proton decay spectrum for each excitation energy bins has been measured. The measured proton spectrum has been reproduced using statistical model calculations with different level density models. A variance minimised approach has been employed for analysing the prediction capability of different level density models. This approach has been converged to Gogny Hartree-Fock-Bogoliubov(HFB) microscopic level density model and which is attributed as the most accurate model for the desired nuclei.
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- 2023
37. Strong transitivity of a graph
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Paul, Subhabrata and Santra, Kamal
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Mathematics - Combinatorics - Abstract
A vertex partition $\pi = \{V_1, V_2, \ldots, V_k\}$ of $G$ is called a \emph{transitive partition} of size $k$ if $V_i$ dominates $V_j$ for all $1\leq i
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- 2023
38. Algorithmic study on $2$-transitivity of graphs
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Paul, Subhabrata and Santra, Kamal
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Mathematics - Combinatorics - Abstract
Let $G=(V, E)$ be a graph where $V$ and $E$ are the vertex and edge sets, respectively. For two disjoint subsets $A$ and $B$ of $V$, we say $A$ \emph{dominates} $B$ if every vertex of $B$ is adjacent to at least one vertex of $A$. A vertex partition $\pi = \{V_1, V_2, \ldots, V_k\}$ of $G$ is called a \emph{transitive partition} of size $k$ if $V_i$ dominates $V_j$ for all $1\leq i
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- 2023
39. Re-evaluation of the $^{22}$Ne($p$,$\gamma$)$^{23}$Na reaction rate: $R-$matrix analysis of the non-resonant capture and effect of the 8945 keV (${7/2}^{-}$) resonance strength
- Author
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Ali, Sk Mustak, Santra, Rajkumar, Sharma, Sathi, and Mondal, Ashok kumar
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Nuclear Theory ,Nuclear Experiment - Abstract
The $^{22}$Ne($p,\gamma$)$^{23}$Na capture reaction is a key member of the Ne-Na cycle of hydrogen burning. The rate of this reaction is critical in classical novae nucleosynthesis and hot bottom burning processes (HBB) in asymptotic giant branch (AGB) stars. Despite its astrophysical importance, significant uncertainty remains in the reaction rate due to several narrow low energy resonances lying near the Gamow window. The present work revisits this reaction by examining the contribution of the 8664 keV subthreshold state and the 151 keV doublet resonance state of 7/2$^-$ configuration in $^{23}$Na. Finite range distorted-wave Born approximation (FRDWBA) analyses of existing $^{22}$Ne($^3$He,$d$)$^{23}$Na transfer reaction data were carried out to extract the peripheral asymptotic normalization coefficients (ANC) of the 8664 keV state. The ANC value obtained in the present work is $\sim 25\%$ higher compared to the previous work by Santra et al.~\cite{SA20}. Systematic $R$-matrix calculations were performed to obtain the non-resonant astrophysical $S$-factor utilizing the enhanced ANC value. The resonance strengths of the 8945 keV doublets were deduced from shell model calculations. The total reaction rate is found to be $\sim 15\%$ higher at temperatures relevant for the HBB processes, compared to the recent rate measured by Williams et al.~\cite{WI20}, and matches the rate by Williams et al.~\cite{WI20} at temperatures of interest for classical novae nucleosynthesis.
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- 2023
40. Fuzzy gain scheduled adaptive sliding mode control of a vertical shaft hybrid magnetic bearing under variable rotor speeds
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Pusti, Subhankar, Santra, Tapan, Roy, Debabrata, and Yamada, Satoshi
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- 2024
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41. Impact of Thermal Radiation on Water-Based Hybrid Nanofluid (CuAl2O3H2O–CuAl2O3H2O–CuAl2O3H2O) Flow Over a Forward/Backward Moving Vertical Porous Plate
- Author
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Arulmozhi, S., Sukkiramathi, K., Santra, S. S., and Nandi, S.
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- 2024
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42. Heavy metal stress in the agro-environment: consequences, adaptations and remediation
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Moulick, D., Hossain, A., Barek, V., Chowardhara, B., Mukherjee, A., Pattnaik, B. K., Roy, P., Mahanta, S., Hazra, S., Sarkar, S., Garai, S., Ghosh, S., Bhutia, K. L., Choudhury, S., Ghosh, D., Santra, S. C., Pramanick, B., Karmakar, S., Atta, K., Dutta, D., Shankar, T., Sahoo, U., Sairam, M., Gangundi, S., Maitra, S., Brestic, M., and Skalicky, M.
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- 2024
- Full Text
- View/download PDF
43. Analytical and Numerical Solution for the Time Fractional Black-Scholes Model Under Jump-Diffusion
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Mohapatra, Jugal, Santra, Sudarshan, and Ramos, Higinio
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- 2024
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44. OmniLRS: A Photorealistic Simulator for Lunar Robotics
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Richard, Antoine, Kamohara, Junnosuke, Uno, Kentaro, Santra, Shreya, van der Meer, Dave, Olivares-Mendez, Miguel, and Yoshida, Kazuya
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Computer Science - Robotics ,Computer Science - Computer Vision and Pattern Recognition - Abstract
Developing algorithms for extra-terrestrial robotic exploration has always been challenging. Along with the complexity associated with these environments, one of the main issues remains the evaluation of said algorithms. With the regained interest in lunar exploration, there is also a demand for quality simulators that will enable the development of lunar robots. % In this paper, we explain how we built a Lunar simulator based on Isaac Sim, Nvidia's robotic simulator. In this paper, we propose Omniverse Lunar Robotic-Sim (OmniLRS) that is a photorealistic Lunar simulator based on Nvidia's robotic simulator. This simulation provides fast procedural environment generation, multi-robot capabilities, along with synthetic data pipeline for machine-learning applications. It comes with ROS1 and ROS2 bindings to control not only the robots, but also the environments. This work also performs sim-to-real rock instance segmentation to show the effectiveness of our simulator for image-based perception. Trained on our synthetic data, a yolov8 model achieves performance close to a model trained on real-world data, with 5% performance gap. When finetuned with real data, the model achieves 14% higher average precision than the model trained on real-world data, demonstrating our simulator's photorealism.% to realize sim-to-real. The code is fully open-source, accessible here: https://github.com/AntoineRichard/LunarSim, and comes with demonstrations., Comment: 7 pages, 4 figures
- Published
- 2023
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45. Integration of Vision-based Object Detection and Grasping for Articulated Manipulator in Lunar Conditions
- Author
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Boucher, Camille, Diaz, Gustavo H., Santra, Shreya, Uno, Kentaro, and Yoshida, Kazuya
- Subjects
Computer Science - Robotics ,Computer Science - Artificial Intelligence - Abstract
The integration of vision-based frameworks to achieve lunar robot applications faces numerous challenges such as terrain configuration or extreme lighting conditions. This paper presents a generic task pipeline using object detection, instance segmentation and grasp detection, that can be used for various applications by using the results of these vision-based systems in a different way. We achieve a rock stacking task on a non-flat surface in difficult lighting conditions with a very good success rate of 92%. Eventually, we present an experiment to assemble 3D printed robot components to initiate more complex tasks in the future.
- Published
- 2023
46. Crossover in densities of confined particles with finite range of interaction
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Santra, Saikat and Kundu, Anupam
- Subjects
Condensed Matter - Statistical Mechanics ,Mathematical Physics - Abstract
We study a one-dimensional classical system of $N$ particles confined within a harmonic trap. Interactions among these particles are dictated by a pairwise potential $V(x)$, where $x$ is the separation between two particles. Each particle can interact with a maximum of $d$ neighboring particles on either side (left or right), if available. By adjusting the parameter $d$, the system can be made nearest neighbour $(d=1)$ to all-to-all $(d=N-1)$ interacting. As suggested by prior studies, the equilibrium density profile of these particles is expected to undergo shape variations as $d$ is changed. In this paper, we investigate this crossover by tuning the parameter $f(=d/N)$ from $1$ to $0$ in the large $N$ limit for two distinct choices of interaction potentials, $V(x) = - |x|$ and $V(x) =- \log(|x|)$ which correspond to 1d one-component plasma and the log-gas model, respectively. For both models, the system size scaling of the density profile for fixed $f$ turns out to be the same as in their respective all-to-all cases. However, the scaling function exhibits diverse shapes as $f$ varies. We explicitly compute the average density profile for any $f \in (0,1]$ in the 1d plasma model, while for the log-gas model, we provide approximate calculations for large (close to $1$) and small (close to $0$) $f$. Additionally, we present simulation results to numerically demonstrate the crossover and compare these findings with our theoretical results., Comment: 38 pages, 6 figures
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- 2023
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47. Is valence CCSD(T) enough for the binding of water clusters? The isomers of (H$_2$O)$_6$ and (H$_2$O)$_{20}$ as a case study
- Author
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Santra, Golokesh, Shepelenko, Margarita, Semidalas, Emmanouil, and Martin, Jan M. L.
- Subjects
Physics - Chemical Physics - Abstract
Benchmark calculations on noncovalent interactions typically exclude correlation effects beyond valence CCSD(T) owing to their steep computational cost scaling. In this work, we consider their importance for water clusters, specifically, eight isomers of (H$_2$O)$_6$ and four Wales-Hodges isomers of (H$_2$O)$_{20}$. Higher order connected triples, $T_3$--(T), reduce dissociation energies of the latter by about 0.4 kcal/mol, but this is more than compensated by an increase of up to 0.85 kcal/mol due to connected quadruple excitations. In general, higher-order correlation effects favor more compact isomers over more `spread-out' ones. We also consider additional small effects for balance: scalar relativistics reduce binding in (H$_2$O)$_{20}$ by ca. --0.4 kcal/mol, which fortuitously is compensated by the ca. 0.55 kcal/mol diagonal Born-Oppenheimer correction. Core-valence correlation has the greatest impact, at ca. 1.3 kcal/mol for the icosamer., Comment: version updated from ResearchGate, now including 3-body contributions for water20
- Published
- 2023
48. Technical Design Report for the LUXE Experiment
- Author
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Abramowicz, H., Soto, M. Almanza, Altarelli, M., Aßmann, R., Athanassiadis, A., Avoni, G., Behnke, T., Benettoni, M., Benhammou, Y., Bhatt, J., Blackburn, T., Blanch, C., Bonaldo, S., Boogert, S., Borysov, O., Borysova, M., Boudry, V., Breton, D., Brinkmann, R., Bruschi, M., Burkart, F., Büßer, K., Cavanagh, N., Corso, F. Dal, Decking, W., Deniaud, M., Diner, O., Dosselli, U., Elad, M., Epshteyn, L., Esperante, D., Ferber, T., Firlej, M., Fiutowski, T., Fleck, K., Fuster-Martinez, N., Gadow, K., Gaede, F., Gallas, A., Cabrera, H. Garcia, Gerstmayr, E., Ghenescu, V., Giorato, M., Golubeva, N., Grojean, C., Grutta, P., Grzelak, G., Hallford, J., Hartman, L., Heinemann, B., Heinzl, T., Helary, L., Hendriks, L., Hoffmann, M., Horn, D., Huang, S., Huang, X., Idzik, M., Irles, A., Jacobs, R., King, B., Klute, M., Kropf, A., Kroupp, E., Lahno, H., Manghi, F. Lasagni, Lawhorn, J., Levanon, A., Levi, A., Levinson, L., Levy, A., Levy, I., Liberman, A., Liss, B., List, B., List, J., Lohmann, W., Maalmi, J., Madlener, T., Malka, V., Marsault, T., Mattiazzo, S., Meloni, F., Miron, D., Morandin, M., Moroń, J., Nanni, J., Neagu, A. T., Negodin, E., Paccagnella, A., Pantano, D., Pietruch, D., Pomerantz, I., Pöschl, R., Potlog, P. M., Prasad, R., Quishpe, R., Ranken, E., Ringwald, A., Roich, A., Salgado, F., Santra, A., Sarri, G., Sävert, A., Sbrizzi, A., Schmitt, S., Schulthess, I., Schuwalow, S., Seipt, D., Simi, G., Soreq, Y., Spataro, D., Streeter, M., Swientek, K., Hod, N. Tal, Teter, T., Thiebault, A., Thoden, D., Trevisani, N., Urmanov, R., Vasiukov, S., Walker, S., Warren, M., Wing, M., Yap, Y. C., Zadok, N., Zanetti, M., Żarnecki, A. F., Zbińkowski, P., Zembaczyński, K., Zepf, M., Zerwas, D., Ziegler, W., and Zuffa, M.
- Subjects
High Energy Physics - Experiment ,Physics - Instrumentation and Detectors - Abstract
This Technical Design Report presents a detailed description of all aspects of the LUXE (Laser Und XFEL Experiment), an experiment that will combine the high-quality and high-energy electron beam of the European XFEL with a high-intensity laser, to explore the uncharted terrain of strong-field quantum electrodynamics characterised by both high energy and high intensity, reaching the Schwinger field and beyond. The further implications for the search of physics beyond the Standard Model are also discussed.
- Published
- 2023
49. Tracer dynamics in the active random average process
- Author
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Santra, Saikat, Singh, Prashant, and Kundu, Anupam
- Subjects
Condensed Matter - Statistical Mechanics ,Mathematical Physics - Abstract
We investigate the dynamics of tracer particles in the random average process (RAP), a single-file system in one dimension. In addition to the position, every particle possesses an internal spin variable $\sigma (t)$ that can alternate between two values, $\pm 1$, at a constant rate $\gamma$. Physically, the value of $\sigma (t)$ dictates the direction of motion of the corresponding particle and for finite $\gamma$, every particle performs a non-Markovian active dynamics. Herein, we study the effect of this non-Markovianity in the fluctuations and correlations of the positions of tracer particles. We analytically show that the variance of the position of a tagged particle grows sub-diffusively as $\sim \zeta_{\text{q}} \sqrt{t}$ at large times for the quenched uniform initial condition. While this sub-diffusive growth is identical to that of the Markovian/non-persistent RAP, the coefficient $\zeta_{\text{q}} $ is rather different and bears the signature of the persistent motion of active particles through higher point correlations (unlike in the Markovian case). Similarly, for the annealed (steady state) initial condition, we find that the variance scales as $\sim \zeta_{\text{a}} \sqrt{t}$ at large times with coefficient $\zeta_{\text{a}} $ once again different from the non-persistent case. Although $\zeta_{\text{q}}$ and $\zeta_{\text{a}} $ both individually depart from their Markov counterparts, their ratio $\zeta_{\text{a}} / \zeta_{\text{q}}$ is still equal to $\sqrt{2}$, a condition observed for other diffusive single-file systems. This condition turns out to be true even in the strongly active regimes as corroborated by extensive simulations and calculations. Finally, we study the correlation between the positions of two tagged particles in both quenched uniform and annealed initial conditions. We verify all our analytic results by extensive numerical simulations., Comment: 38 pages, 13 figures
- Published
- 2023
- Full Text
- View/download PDF
50. Enabling Faster Locomotion of Planetary Rovers with a Mechanically-Hybrid Suspension
- Author
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Rodríguez-Martínez, David, Uno, Kentaro, Sawa, Kenta, Uda, Masahiro, Kudo, Gen, Diaz, Gustavo Hernan, Umemura, Ayumi, Santra, Shreya, and Yoshida, Kazuya
- Subjects
Computer Science - Robotics - Abstract
The exploration of the lunar poles and the collection of samples from the martian surface are characterized by shorter time windows demanding increased autonomy and speeds. Autonomous mobile robots must intrinsically cope with a wider range of disturbances. Faster off-road navigation has been explored for terrestrial applications but the combined effects of increased speeds and reduced gravity fields are yet to be fully studied. In this paper, we design and demonstrate a novel fully passive suspension design for wheeled planetary robots, which couples for the first time a high-range passive rocker with elastic in-wheel coil-over shock absorbers. The design was initially conceived and verified in a reduced-gravity (1.625 m/s${^2}$) simulated environment, where three different passive suspension configurations were evaluated against steep slopes and unexpected obstacles, and later prototyped and validated in a series of field tests. The proposed mechanically-hybrid suspension proves to mitigate more effectively the negative effects (high-frequency/high-amplitude vibrations and impact loads) of faster locomotion (~1\,m/s) over unstructured terrains under varied gravity fields., Comment: 8 pages, 12 figures
- Published
- 2023
- Full Text
- View/download PDF
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