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Reservoir heterogeneity and fluid flow implication of the Late-Jurassic Arabian stromatoporoid-coral buildup facies during waterflood: An insight from 3D outcrop analog
No full textThis study constructs a 3D high-fidelity outcrop-based analog reservoir static model of the Late-Jurassic Arabian stromatoporoid-coral facies assemblages. The resulting model is used in reservoir simulation to investigate the collective influence of the facies heterogeneity on fluid flow and recovery during waterflood. Results show the permeability contrast and flow connectivity between the stromatoporoid/coral buildup facies with their contemporary interbuildup strata that can be mud-supported or grainstone facies. Thirty-five years of flow simulation during water flooding using a vertical 5-spot pattern with a 1 km spacing suggests different sweep efficiency at different stratigraphic levels. A substantial amount of oil remains in the analog reservoir, suggesting that the reservoir with these typical facies is still underutilized and has the potential to be developed further to improve ultimate recovery. � 2023 Elsevier B.V., All rights reserved
From Variations to Precision: Modeling and Optimization of Inner Spacer Etch in GAA FETs
No full textThis work introduces a robust machine learning framework for modeling and optimizing the inner spacer etch process in gate-all-around FET fabrication. Using an in-house Particle Monte-Carlo simulator, the etch process is modeled precisely across varied conditions. Gaussian Process Regression outperforms neural network models, achieving 98-99% accuracy in predicting etch front variations. Bayesian Optimization with adaptive sampling and successive domain reduction is utilized to fine-tune etch parameters, minimizing the error between predicted and target etch fronts. This integrated approach enables precise control over spacer-channel geometry, making this approach highly effective for advanced semiconductor manufacturing
Case study on process improvement in a 'transformer oil testing laboratory' using value stream mapping for improving service time
No full textThe purpose of this paper is to improve the report printing activity of the electrical testing laboratory after testing. At a transformer oil testing laboratory at Vadodara, Gujarat, India, customers were facing problem of delayed report delivery after testing of oil. A detailed study of the process was done to check if the value stream mapping and value stream analysis can be applied to improve the report delivery time. After study of ‘as is’ situation a new system was implemented for the transformer oil testing laboratory. Diagram of various activities were drawn for ‘as is’ condition and time taken for each activity was noted down. The non-value adding activity consuming unnecessary time ‘waiting’ was identified and removed. A new software was developed for reporting. It resulted into reduction of report issuance time by minimum 21 days for 2,698 samples out of 5,475 samples tested during FY 20–21
Joint Sparse Support Recovery for Direction of Arrival Estimation Using Rational Arrays
No full textIn array signal processing, integer linear arrays with sensors placed at multiples of the half-wavelength are standard. In this work, we overcome aperture constraints that often lead to under-utilized sensor resources by using rational arrays that position sensors at rational locations. By formulating direction-of-arrival (DOA) estimation as a joint sparse support recovery (JSSR) problem, we demonstrate that rational arrays can achieve superior performance compared to conventional integer arrays. Notably, rational non-uniform arrays can resolve O(M2) uncorrelated sources using only M sensors, even when the available aperture is limited, a feat that integer non-uniform arrays like nested and coprime configurations cannot attain without large apertures. We derive the performance of these arrays using a sufficient JSSR condition and validate our findings through extensive simulations covering both overdetermined and underdetermined DOA estimation scenarios
Periodic homogenization for switching diffusions
No full textIn the present work, we explore homogenization techniques for a class of switching diffusion processes whose drift and diffusion coefficients, and jump intensities are smooth, spatially periodic functions; we assume full coupling between the continuous and discrete components of the state. Under the assumptions of uniform ellipticity of the diffusion matrices and irreducibility of the matrix of switching intensities, we explore the large-scale long-time behavior of the process under a diffusive scaling. Our main result characterizes the limiting fluctuations of the rescaled continuous component about a constant velocity drift by an effective Brownian motion with explicitly computable covariance matrix. In the process of extending classical periodic homogenization techniques for diffusions to the case of switching diffusions, our main quantitative finding is the computation of an extra contribution to the limiting diffusivity stemming from the switching
Generation and annihilation of three dimensional magnetic nulls in extrapolated solar coronal magnetic field: data-based Implicit Large Eddy simulation
No full textThree-dimensional (3D) magnetic nulls are the points where magnetic field vanishes and are preferential sites for magnetic reconnection: a fundamental process which converts magnetic energy into kinetic energy, heat, and energy of non-thermal particles along with a rearrangement of magnetic field lines. Reconnection is ubiquitous in nature and plays a major role in various magnetically confined laboratory and space/astrophysical plasmas. In the solar corona, the reconnection manifests as coronal transients including solar flares, coronal mass ejections and coronal jets�often associated with 3D nulls. The nulls are generally found to be collocated with complex active regions on the solar photosphere and merits further attention, particularly in terms of their generation. A recent idealized magnetohydrodynamics simulation initiated with an analytically constructed preexisting proper radial null has identified magnetic reconnection to be responsible for spontaneous generation of these 3D nulls. It is then imperative to further explore the plausibility of spontaneous generation of nulls in naturally occurring plasmas, identify the mechanism and verify the outcome vis-�-vis observations. An apt test bed for such an initiative is the solar atmosphere, as abundant space and ground-based observations are available. In the above backdrop, the paper attempts to investigate 3D null generation by carrying out a data-based simulation of a C6.6 class flare associated with the photospheric active region NOAA 11 977. The simulation confirms spontaneous pairwise generation of 3D nulls with magnetic reconnections as the underlying cause. Importantly, magnetic field lines associated with the spontaneously generated nulls are found to trace observed chromospheric bright points�highlighting their observational relevance. Overall, such spontaneous generation and annihilation of nulls through magnetic reconnections opens up a new avenue for solar coronal and chromospheric heating. � 2024 Elsevier B.V., All rights reserved
Nucleobase self-assembly: aggregation, morphological characterization, and toxicity analysis
No full textThis study expands the platform for amyloidogenic building blocks, such as nucleobases, and their self-assembly. Here, we examine the self-assembly profile of nucleobases such as guanine, cytosine, and thymine and determine that these nucleobases, while aged, produce small globules which gradually transform into fibrillar assemblies. Notably, the amyloid-like fibrillation in adenine and uracil has already been reported; hence, it was imperative to understand the amyloidogenic propensity in these unexplored nucleobases. The aggregates formed by guanine, cytosine, and thymine interestingly reveal a distinctive spectrum characteristic of amyloidogenic proteins after binding to the amyloid-specific dye Thioflavin T (ThT). The MTT assay in human retinal pigment epithelial RPE-1 cell lines revealed the aggregates formed by these nucleobases are toxic with significantly more toxicity observed for aged samples as compared to the fresh ones. The in vivo assays in C. elegans nematodes further validated the toxicities induced by the aggregates and the heat shock survival assay suggests these metabolite assemblies affect the protein clearance machinery like other amyloids. Overall, the research offers additional support for the role of amyloidogenesis in IEMs and suggests a recognized toxicity mechanism for IEMs caused by the accumulation of nucleobases
