bluuebunny/crossref_metadata_2025_split huggingface dataset:
SHE-MTJ based ReLU-max pooling functions for on-chip training of neural networks
Authors: Vadde Venkatesh , Muralidharan Bhaskaran , Sharma Abhishek 
Published: February 2024

We present a detailed investigation of various routes to optimize the power consumption of the spintronic-based devices for implementing rectified linear activation (ReLU) and max-pooling functions. We examine the influence of various spin Hall effect layers, and their input resistances on the power consumption of the ReLU-max pooling functions, we also access the impact of the thermal stability factor of the free-ferromagnet layer on the power consumption and accuracy of the device. The design for ReLU-max pooling relies on the continuous rotation of magnetization, which is accomplished by applying orthogonal spin current to the free-FM layer. We also demonstrate the non-trivial power-resistance relation, where the power consumption decreases with an increase in SHE resistance. We utilize the hybrid spintronic-CMOS simulation platform that combines Keldysh non-equilibrium Green’s function (NEGF) with Landau-Lifshitz-Gilbert-Slonzewski (LLGS) equations and the HSPICE circuit simulator to evaluate our network. Our design takes 0.343 μW of power for ReLU emulation and 17.86 μW of power for ReLU-max pooling network implementation at a thermal stability factor of 4.58, all while maintaining reliable results. We validate the efficiency of our design by implementing a convolutional neural network that classifies the handwritten-MNIST and fashion-MNIST datasets. This implementation illustrates that the classification accuracies achieved are on par with those attained using the ideal software ReLU-max pooling functions, with an energy consumption of 167.31 pJ per sample.
Towards fully electrically controlled domain-wall logic
Authors: Vermeulen B. B. , Raymenants E. , Pham V. T. , Pizzini S. , Sorée B. , Wostyn K. , Couet S. , Nguyen V. D. , Temst K. 
Published: February 2024

Utilizing magnetic tunnel junctions (MTJs) for write/read and fast spin-orbit-torque (SOT)-driven domain-wall (DW) motion for propagation, enables non-volatile logic and majority operations, representing a breakthrough in the implementation of nanoscale DW logic devices. Recently, current-driven DW logic gates have been demonstrated via magnetic imaging, where the Dzyaloshinskii-Moriya interaction (DMI) induces chiral coupling between perpendicular magnetic anisotropy (PMA) regions via an in-plane (IP) oriented region. However, full electrical operation of nanoscale DW logic requires electrical write/read operations and a method to pattern PMA and IP regions compatible with the fabrication of PMA MTJs. Here, we study the use of a Hybrid Free Layer (HFL) concept to combine an MTJ stack with DW motion materials, and He+ ion irradiation to convert the stack from PMA to IP. First, we investigate the free layer thickness dependence of 100-nm diameter HFL-MTJ devices and find an optimal CoFeB thickness, from 7 to 10 Å, providing high tunneling magnetoresistance (TMR) readout and efficient spin-transfer torque (STT) writing. We then show that high DMI materials, like Pt/Co, can be integrated into an MTJ stack via interlayer exchange coupling with the CoFeB free layer. In this design, DMI values suitable for SOT-driven DW motion are measured by asymmetric bubble expansion. Finally, we demonstrate that He+ irradiation reliably converts the coupled free layers from PMA to IP. These findings offer a path toward the integration of fully electrically controlled DW logic circuits.
Ab initio study of p- and n-type doping of two-dimensional MoO2: investigation of a pn-homojunction
Authors: Ndang Amassa Kevin , Etindele Anne Justine , Douma Dick Hartmann , Kenmoe Stephane , Nithaya Chetty 
Published: February 2024

Abstract
Based on density functional theory, we studied the effect of p- and n-type doping on the structural and electronic properties of MoO2 monolayers and bilayers. We used niobium (Nb) and nitrogen (N) as p-type dopants, and technetium (Tc) and fluorine (F) as n-type dopants through atomic substitutions. Our study shows that the presence of a substituent in the 4 × 4 supercell of MoO2 leads to a slight distortion and negligible modification of the lattice parameter. Both p- and n-type doped monolayers exhibit a metallic character. The bilayers obtained by vertically stacking n-p doped monolayers all exhibit a metallic character, as their band diagrams do not show a band gap. The study of their charge difference highlights a physisorption phenomenon. This type of material, which features a nucleophilic site in the p-doped region and an electrophilic site in the n-doped region, is a promising candidate for catalysis. When n-type and p-type doped monolayers are horizontally joined, the resulting stack exhibits a semi-conductor behavior.The special feature of this stacking is that we obtain a true pn junction, that is a space charge zone associated with a potential jump. For its application in infrared junction diodes, we have demonstrated both quantitatively and qualitatively the existence of a potential jump at the junction.
Bifacial flexible CIGS thin-film solar cells with nonlinearly graded-bandgap photon-absorbing layers
Authors: Ahmad Faiz , Monk Peter B , Lakhtakia Akhlesh 
Published: February 2024

Abstract
The building sector accounts for 36% of energy consumption and 39% of energy-related greenhouse-gas emissions. Integrating bifacial photovoltaic solar cells in buildings could significantly reduce energy consumption and related greenhouse gas emissions. Bifacial solar cells should be flexible, bifacially balanced for electricity production, and perform reasonably well under weak-light conditions. Using rigorous optoelectronic simulation software and the differential evolution algorithm, we optimized symmetric/asymmetric bifacial CIGS solar cells with either (i) homogeneous or (ii) graded-bandgap photon-absorbing layers and a flexible central contact layer of aluminum-doped zinc oxide to harvest light outdoors as well as indoors. Indoor light was modeled as a fraction of the standard sunlight. Also, we computed the weak-light responses of the CIGS solar cells using LED illumination of different light intensities. The optimal bifacial CIGS solar cell with graded-bandgap photon-absorbing layers is predicted to perform with 18%–29% efficiency under 0.01–1.0-Sun illumination; furthermore, efficiencies of 26.08% and 28.30% under weak LED light illumination of 0.0964 mW cm−2 and 0.22 mW cm−2 intensities, respectively, are predicted.
Sustainable energy harvesting and breath sensing with electrospun triboelectric nylon-6
Authors: Jelmy E J , Sunil Mathew , Kandappanthodi Chitra , Rincy P , Saji K J , Pillai Suresh C , John Honey 
Published: February 2024

Abstract
A high-performance triboelectric nanogenerator (TENG) has been developed for breath sensing applications, utilizing tribopositive electrospun nylon-6 nanofibers and tribonegative fluorinated ethylene propylene (FEP). The optimization toward the development of electrospun nylon-6-based TENG includes a range of factors such as the applied force and frequency on tribo responses, the thickness of the fiber mat, the concentration of nylon-6 in the fiber mats, and the selection of the tribonegative material for pairing with nylon-6 nanofiber. Among these parameters, the nanofiber prepared with 18 wt% nylon-6, characterized by a uniform fiber distribution, the highest surface area of 55.69 m2 g−1, and an optimal thickness of 0.169 mm, demonstrated excellent TENG performance, among others. The TENG module constructed using nanofiber in a 4 cm2 area showed the TENG responses of more than 30 μA short-circuit current, 200 V open-circuit voltage, and 90 nC charge when hand-pressed. It achieved a substantial power density of 890 mW m−2 at 20 MΩ by applying a constant force of 10 N at a 10 Hz frequency. Charging a 1 μF capacitor to approximately 30.1 V in just 30 s highlights the potential of electrospun nylon-6 as a promising material for nanogenerator energy harvesting and sensing applications. The TENG device was found to be sufficient to power small, portable electronics such as LEDs and digital watch displays. A wearable belt was fabricated to showcase its breath-sensing capabilities by pairing it with FEP. The microcontroller connected to the TENG in the wearable belt is used to analyze the output produced through breathing patterns, subsequently activating a buzzer and LED by the nature of the breathing.
Effect of notch angle on creep deformation and rupture behavior of 304HCu SS
Authors: Sahoo Kanhu Charan , Sreevidya N , Sakthivel T , Reddy G V Prasad 
Published: February 2024

Abstract
Multiaxial creep deformation behaviour of U-notched 304HCu austenitic stainless steel (304HCu SS) has been studied by altering the angle of the U-notch, by 30°, 60°, 90°, and 120°, for a fixed root radius of 1.25 mm. The associated stress concentration factor for the U-notch geometry is about 1.8–1.86 with decrease in notch angle. Creep rupture lives of all notched specimens are above the un-notched specimen. However, decrease in rupture life and increase in creep rupture ductility has been observed with an increase in notch angle. At all notch angles, nearly intergranular creep cavitation failure with isolated cavities was observed at the notch center. In contrast, at the notch root, with decrease in notch angle the fracture mode changed from mixed mode to intergranular fracture. Finite element analysis (FEA) of stationary state of stress distribution indicated that von-Mises stress throughout the notch throat plane and maximum principal stress near the notch root region were found to increase with increase in notch angle. However, away from the notch root the maximum principal stress was found to decrease with increase in notch angle. Hydrostatic stress distribution remained same near the notch root at all the notch angles, but tends to increase towards the specimen center with decrease in notch angle. Similarly, at the notch throat plane, triaxiality factor (TF) was found to increase with decrease in notch angle. The creep damage evaluated through FEA coupled with continuum damage mechanics (CDM) proposed by Kachanov-Rabotov (K-R) model was found to increase with an increase in notch angle, resulting in decrease in creep rupture life. Creep damage evaluated as a function of notch depth, during initial creep exposure, revealed significant damage for 1.675 mm notch depth in comparison to 2 and 2.5 mm notch depths which resulted in lower rupture life for 1.675 mm notch depth.
A one-way street for phonon transport: past, present and future of solid-state thermal rectification
Authors: Rurali Riccardo 
Published: February 2024

Abstract
Thermal rectification is the dependence of the thermal conductivity on the direction of heat propagation. This fascinating effect could be exploited for the design of thermal devices, such as the thermal diode, and could find application in energy harvesting and thermal management. Where did we start from, what has been achieved and what does the future hold?
ReARTSim: an ReRAM ARray Transient Simulator with GPU optimized runtime acceleration
Authors: Sui Yu , Yu Tianhe , Song Shiming 
Published: February 2024

Abstract
The demand for computation driven by machine learning and deep learning applications has experienced exponential growth over the past five years (Sevilla et al 2022 2022 International Joint Conference on Neural Networks (IJCNN) (IEEE) pp 1-8), leading to a significant surge in computing hardware products. Meanwhile, this rapid increase has exacerbated the memory wall bottleneck within mainstream Von Neumann architectures (Hennessy and Patterson et al 2011 Computer architecture: a quantitative approach (Elsevier)). For instance, NVIDIA graphical processing units (GPUs) have gained nearly a 200x increase in fp32 computing power, transitioning from P100 to H100 in the last five years (NVIDIA Tesla P100 2023 (www.nvidia.com/en-us/data-center/tesla-p100/); NVIDIA H100 Tensor Core GPU 2023 (www.nvidia.com/en-us/data-center/h100/)), accompanied by a mere 8x scaling in memory bandwidth. Addressing the need to mitigate data movement challenges, process-in-memory designs, especially resistive random-access memory (ReRAM)-based solutions, have emerged as compelling candidates (Verma et al 2019 IEEE Solid-State Circuits Mag.
11 43–55; Sze et al 2017 Proc. IEEE
105 2295–329). However, this shift in hardware design poses distinct challenges at the design phase, given the limitations of existing hardware design tools. Popular design tools today can be used to characterize analog behavior via SPICE tools (PrimeSim HSPICE 2023 (www.synopsys.com/implementation-and-signoff/ams-simulation/primesim-hspice.html)), system and logical behavior using Verilog tools (VCS 2023 (www.synopsys.com/verification/simulation/vcs.html)), and mixed signal behavior through toolbox like CPPSIM (Meninger 2023 (www.cppsim.org/Tutorials/wideband_fracn_tutorial.pdf)). Nonetheless, the design of in-memory computing systems, especially those involving non-CMOS devices, presents a unique need for characterizing mixed-signal computing behavior across a large number of cells within a memory bank. This requirement falls beyond the scope of conventional design tools. In this paper, we bridge this gap by introducing the ReARTSim framework—a GPU-accelerated mixed-signal transient simulator for analyzing ReRAM crossbar array. This tool facilitates the characterization of analog circuit and device behavior on a large scale, while also providing enhanced simulation performance for complex algorithm analysis, sign-off, and verification.
Phylogenomics and plastomics offer new evolutionary perspectives on Kalanchoideae (Crassulaceae)
Authors: Han Shiyun , Zhang Sijia , Yi Ran , Bi De , Ding Hengwu , Yang Jianke , Ye Yuanxin , Xu Wenzhong , Wu Longhua , Zhuo Renying , Kan Xianzhao 
Published: February 2024

Abstract

Background and Aims
Kalanchoideae is one of three subfamilies within Crassulaceae and contains four genera. Despite previous efforts, the phylogeny of Kalanchoideae remains inadequately resolved with persistent issues including low support, unstructured topologies and polytomies. This study aimed to address two central objectives: (1) resolving the pending phylogenetic questions within Kalanchoideae by using organelle-scale ‘barcodes’ (plastomes) and nuclear data; and (2) investigating interspecific diversity patterns among Kalanchoideae plastomes.

Methods
To explore the plastome evolution in Kalanchoideae, we newly sequenced 38 plastomes representing all four constituent genera (Adromischus, Cotyledon, Kalanchoe and Tylecodon). We performed comparative analyses of plastomic features, including GC and gene contents, gene distributions at the IR (inverted repeat) boundaries, nucleotide divergence, plastomic tRNA (pttRNA) structures and codon aversions. Additionally, phylogenetic inferences were inferred using both the plastomic dataset (79 genes) and nuclear dataset (1054 genes).

Key Results
Significant heterogeneities were observed in plastome lengths among Kalanchoideae, strongly correlated with LSC (large single copy) lengths. Informative diversities existed in the gene content at SSC/IRa (small single copy/inverted repeat a), with unique patterns individually identified in Adromischus leucophyllus and one major Kalanchoe clade. The ycf1 gene was assessed as a shared hypervariable region among all four genera, containing nine lineage-specific indels. Three pttRNAs exhibited unique structures specific to Kalanchoideae and the genera Adromischus and Kalanchoe. Moreover, 24 coding sequences revealed a total of 41 lineage-specific unused codons across all four constituent genera. The phyloplastomic inferences clearly depicted internal branching patterns in Kalanchoideae. Most notably, by both plastid- and nuclear-based phylogenies, our research offers the first evidence that Kalanchoe section Eukalanchoe is not monophyletic.

Conclusions
This study conducted comprehensive analyses on 38 newly reported Kalanchoideae plastomes. Importantly, our results not only reconstructed well-resolved phylogenies within Kalanchoideae, but also identified highly informative unique markers at the subfamily, genus and species levels. These findings significantly enhance our understanding of the evolutionary history of Kalanchoideae.
Health-Related Quality of Life Among Patients With Stroke: A Cross-Sectional Study
Authors: Ayasrah Shahnaz M , Ahmad Muayyad M , Abuadas Fuad H , Abu-Snieneh Hana M , Basheti Iman A 
Published: February 2024

Abstract

Purpose
To assess levels and predictive factors of health-related quality of life (HRQOL) among stroke patients.

Methods
The study employed a cross-sectional predictive correlational design. Levels of HRQOL were assessed using the Stroke-Specific Quality of Life (SS-QOL) scale, and the Hospital Anxiety and Depression Scale was employed to assess psychological aspects among 209 Saudi stroke patients. The analysis included demographic and medical variables to comprehensively explore influencing factors.

Results
A two-step hierarchical multiple regression analysis was performed. The overall SS-QOL summary score (49 items) showed a mean score of 94.4 (SD = 8.1), indicating poor functioning. Nine predictor variables were found to significantly predict HRQOL levels, including age (β = −0.212, p ≤ .001), female (β = −5.33, p ≤ .001), unmarried (β = 2.48, p ≤ .001), low gross monthly income (GMI) (β = −9.02, p ≤ .001), medium GMI (β = −8.36, p ≤ .001), having a medical history of hypertension (β = 2.7, p ≤ .01), time since stroke (β = 3.26 p ≤ .001), and being a probable case of anxiety (β = −4.29, p ≤ .001) and/or depression (β = −2.75, p ≤ .001). These variables collectively explained ~76% of the variance in HRQOL scores (adjusted R2 = .762, F (16,192) = 42.6, p ≤ .001).

Conclusions
Stroke patients exhibited poor HRQOL levels influenced by various factors. Clinicians should consider these predictors and intervene early to enhance HRQOL among patients at risk, emphasizing the importance of optimizing patient outcomes.
Estimation of inbreeding and kinship coefficients via latent identity-by-descent states
Authors: Guan Yongtao , Levy Daniel 
Published: February 2024

Abstract

Motivation
Estimating the individual inbreeding coefficient and pairwise kinship is an important problem in human genetics (e.g. in disease mapping) and in animal and plant genetics (e.g. inbreeding design). Existing methods, such as sample correlation-based genetic relationship matrix, KING, and UKin, are either biased, or not able to estimate inbreeding coefficients, or produce a large proportion of negative estimates that are difficult to interpret. This limitation of existing methods is partly due to failure to explicitly model inbreeding. Since all humans are inbred to various degrees by virtue of shared ancestries, it is prudent to account for inbreeding when inferring kinship between individuals.

Results
We present “Kindred,” an approach that estimates inbreeding and kinship by modeling latent identity-by-descent states that accounts for all possible allele sharing—including inbreeding—between two individuals. Kindred used non-negative least squares method to fit the model, which not only increases computation efficiency compared to the maximum likelihood method, but also guarantees non-negativity of the kinship estimates. Through simulation, we demonstrate the high accuracy and non-negativity of kinship estimates by Kindred. By selecting a subset of SNPs that are similar in allele frequencies across different continental populations, Kindred can accurately estimate kinship between admixed samples. In addition, we demonstrate that the realized kinship matrix estimated by Kindred is effective in reducing genomic control values via linear mixed model in genome-wide association studies. Finally, we demonstrate that Kindred produces sensible heritability estimates on an Australian height dataset.

Availability and implementation
Kindred is implemented in C with multi-threading. It takes vcf file or stream as input and works seamlessly with bcftools. Kindred is freely available at https://github.com/haplotype/kindred.
A methodological primer of extracellular vesicles isolation and characterization via different techniques
Authors: Aliakbari Farhang , Stocek Noah B , Cole-André Maxximuss , Gomes Janice , Fanchini Giovanni , Pasternak Stephen H , Christiansen Gunna , Morshedi Dina , Volkening Kathryn , Strong Michael J 
Published: February 2024

Abstract
We present four different protocols of varying complexity for the isolation of cell culture-derived extracellular vesicles (EVs)/exosome-enriched fractions with the objective of providing researchers with easily conducted methods that can be adapted for many different uses in various laboratory settings and locations. These protocols are primarily based on polymer precipitation, filtration and/or ultracentrifugation, as well as size-exclusion chromatography (SEC) and include: (i) polyethylene glycol and sodium chloride supplementation of the conditioned medium followed by low-speed centrifugation; (ii) ultracentrifugation of conditioned medium; (iii) filtration of conditioned media through a 100-kDa exclusion filter; and (iv) isolation using a standard commercial kit. These techniques can be followed by further purification by ultracentrifugation, sucrose density gradient centrifugation, or SEC if needed and the equipment is available. HEK293 and SH-SY5Y cell cultures were used to generate conditioned medium containing exosomes. This medium was then depleted of cells and debris, filtered through a 0.2-µM filter, and supplemented with protease and RNAse inhibitors prior to exosomal isolation. The purified EVs can be used immediately or stably stored at 4°C (up to a week for imaging or using intact EVS downstream) or at −80°C for extended periods and then used for biochemical study. Our aim is not to compare these methodologies but to present them with descriptors so that researchers can choose the “best method” for their work under their individual conditions.