bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of local magnetic fields in actinide tetrafluorides
Authors: Walter Eric D. , Capan Cigdem , Casella Amanda J. , Carter Jennifer C. , McNamara Bruce K. , Soderquist Chuck Z. , Sinkov Sergey I. , Clark Richard A. , Heller Forrest D. , Sweet Lucas E. , Corbey Jordan F. , Cho Herman
Published: June 2021

Fluorine-19 magnetic shielding tensors have been measured in a series of actinide tetrafluorides (AnF4) by solid state nuclear magnetic resonance spectroscopy. Tetravalent actinide centers with 0–8 valence electrons can form tetrafluorides with the same monoclinic structure type, making these compounds an attractive choice for a systematic study of the variation in the electronic structure across the 5f row of the Periodic Table. Pronounced deviations from predictions based on localized valence electron models have been detected by these experiments, which suggests that this approach may be used as a quantitative probe of electronic correlations.
Droplet evaporation and phase transition modes in supercritical environment by molecular dynamic simulation
Authors: Wang Zhanyuan , Zhou Lei , Shu Gequn , Wei Haiqiao
Published: June 2021

The phase change process of a single hydrocarbon droplet in a supercritical environment has different features compared with subcritical evaporation. In this study, droplets surrounded by supercritical nitrogen are investigated by molecular dynamic simulation. Dodecane droplets are considered in order to reproduce the phase change process of actual fuel, and the radius ranges from 10 nm to 25 nm under various subcritical, transcritical, and supercritical conditions. The emphasis is to describe the entire phase change process and distinguish its different stages. Under supercritical conditions, traditional D2-law theory is invalid and the radius of droplets increases dramatically accompanied by huge fluctuation after a special time. Based on analysis toward fluid properties crossing this time point, the phases classification for supercritical mixture is provided and three phase change stages are distinguished in order, which can be divided by the onset time of supercritical transition, the disappearance of surface tension, and one-phase diffusion, respectively. Additionally, gas/liquid-like features have been observed in the supercritical binary dodecane–nitrogen coexisting system and the defined pseudo-boiling mole fraction (Xpb) is introduced to clarify such deviation in properties of supercritical mixture. At last, by judging whether supercritical transition and undroplet phenomenon will happen, three phase transition modes are summarized for droplets under supercritical conditions.
Demand-driven spreading patterns of African swine fever in China
Authors: Yang Jiannan , Tang Kaichen , Cao Zhidong , Pfeiffer Dirk U. , Zhao Kang , Zhang Qingpeng , Zeng Daniel Dajun
Published: June 2021

African swine fever (ASF) is a highly contagious hemorrhagic viral disease of domestic and wild pigs. ASF has led to major economic losses and adverse impacts on livelihoods of stakeholders involved in the pork food system in many European and Asian countries. While the epidemiology of ASF virus (ASFV) is fairly well understood, there is neither any effective treatment nor vaccine. In this paper, we propose a novel method to model the spread of ASFV in China by integrating the data of pork import/export, transportation networks, and pork distribution centers. We first empirically analyze the overall spatiotemporal patterns of ASFV spread and conduct extensive experiments to evaluate the efficacy of a number of geographic distance measures. These empirical analyses of ASFV spread within China indicate that the first occurrence of ASFV has not been purely dependent on the geographical distance from existing infected regions. Instead, the pork supply–demand patterns have played an important role. Predictions based on a new distance measure achieve better performance in predicting ASFV spread among Chinese provinces and thus have the potential to enable the design of more effective control interventions.
Magnetism in curved geometries
Authors: Streubel Robert , Tsymbal Evgeny Y. , Fischer Peter
Published: June 2021

Curvature impacts physical properties across multiple length scales, ranging from the macroscopic scale, where the shape and size vary drastically with the curvature, to the nanoscale at interfaces and inhomogeneities in materials with structural, chemical, electronic, and magnetic short-range order. In quantum materials, where correlations, entanglement, and topology dominate, the curvature opens the path to novel characteristics and phenomena that have recently emerged and could have a dramatic impact on future fundamental and applied studies of materials. Particularly, magnetic systems hosting non-collinear and topological states and 3D magnetic nanostructures strongly benefit from treating curvature as a new design parameter to explore prospective applications in the magnetic field and stress sensing, microrobotics, and information processing and storage. This Perspective gives an overview of recent progress in synthesis, theory, and characterization studies and discusses future directions, challenges, and application potential of the harnessing curvature for 3D nanomagnetism.
Hysteresis curves reveal the microscopic origin of cooperative CO2 adsorption in diamine-appended metal–organic frameworks
Authors: Edison John R. , Siegelman Rebecca L. , Preisler Zdeněk , Kundu Joyjit , Long Jeffrey R. , Whitelam Stephen
Published: June 2021

Diamine-appended metal–organic frameworks (MOFs) of the form Mg2(dobpdc)(diamine)2 adsorb CO2 in a cooperative fashion, exhibiting an abrupt change in CO2 occupancy with pressure or temperature. This change is accompanied by hysteresis. While hysteresis is suggestive of a first-order phase transition, we show that hysteretic temperature-occupancy curves associated with this material are qualitatively unlike the curves seen in the presence of a phase transition; they are instead consistent with CO2 chain polymerization, within one-dimensional channels in the MOF, in the absence of a phase transition. Our simulations of a microscopic model reproduce this dynamics, providing a physical understanding of cooperative adsorption in this industrially important class of materials.
Intrinsic piezoelectric ferromagnetism with large out-of-plane piezoelectric response in Janus monolayer CrBr1.5I1.5
Authors: Guo San-Dong , Guo Xiao-Shu , Cai Xiu-Xia , Mu Wen-Qi , Ren Wen-Cai
Published: June 2021

A two-dimensional (2D) material system with both piezoelectric and ferromagnetic (FM) orders, referred to as a 2D piezoelectric ferromagnetism (PFM), may open up unprecedented opportunities for intriguing physics. Inspired by experimentally synthesized Janus monolayer MoSSe from MoS2, in this work, the Janus monolayer CrBr1.5I1.5 with dynamic, mechanical, and thermal stabilities is predicted, which is constructed from synthesized ferromagnetic CrI3 monolayer by replacing the top I atomic layer with Br atoms. Calculated results show that monolayer CrBr1.5I1.5 is an intrinsic FM half semiconductor with valence and conduction bands being fully spin-polarized in the same spin direction. Furthermore, monolayer CrBr1.5I1.5 possesses a sizable magnetic anisotropy energy. By symmetry analysis, it is found that both in-plane and out-of-plane piezoelectric polarizations can be induced by a uniaxial strain in the basal plane. The calculated in-plane d22 value of 0.557 pm/V is small. However, more excitingly, the out-of-plane d31 is as high as 1.138 pm/V, which is obviously higher compared with that of other 2D known materials. The strong out-of-plane piezoelectricity is highly desirable for ultrathin piezoelectric devices. Moreover, strain engineering is used to tune piezoelectricity of monolayer CrBr1.5I1.5. It is found that compressive strain can improve d22 and tensile strain can enhance d31. A FM order to antiferromagnetic order phase transition can be induced by compressive strain, and the critical point is about 0.95 strain. That is to say that 2D piezoelectric antiferromagnetism can be achieved by compressive strain, and the corresponding d22 and d31 are 0.677 and 0.999 pm/V at 0.94 strain, respectively. It is also found that magnetic order has important effects on piezoelectricity of monolayer CrBr1.5I1.5. Finally, similar to CrBr1.5I1.5, the PFM can also be realized in the monolayers CrF1.5I1.5 and CrCl1.5I1.5. Amazingly, their d31 can reach up to 2.578 and 1.804 pm/V for monolayers CrF1.5I1.5 and CrCl1.5I1.5. Our paper proposes a realistic way to achieve PFM with large d31, making these systems very promising for multifunctional semiconductor spintronic applications.
Formation of extraordinary density alkanethiol self-assembled monolayers on surfaces of digitally photocorroded (001) GaAs/AlGaAs nanoheterostructures
Authors: St-Onge René , Vermette Jonathan , Hassen Walid M. , Dubowski Jan J.
Published: June 2021

We report the formation of extraordinary density 16-mercaptohexadecanoic acid (MHDA) self-assembled monolayer (SAMs) on surfaces of freshly etched and re-etched bulk (001) GaAs and on GaAs surfaces of a (001) GaAs/Al0.35Ga0.65 As nanoheterostructure exposed by digital photocorrosion (DIP). Our results demonstrate the advantage of a 2-step thiolation process in achieving high-quality MHDA SAMs on (001) GaAs surfaces. However, the development of the systematically increasing quality SAMs, as suggested by the Fourier-transform infrared absorption (FTIR) data, has been observed on the surfaces of GaAs subsequently revealed by DIP of the GaAs/Al0.35Ga0.65 As nanoheterostructure. An MHDA SAM with the maximum absorbance intensity of the asymmetric -CH2 vibrations, νasym = 2919.6 cm−1, equal to 1.08 × 102 and characterized by the full-width-at-half-maximum of 20.3 cm−1, represents the best quality SAM ever obtained on the surface of (001) GaAs. The underlying mechanism has been explained in terms of the formation of nanostructured surfaces with the increasing concentration of low-coordination number surface atoms available for the interaction with MHDA thiolates. The increased surface density of highly-organized SAMs remains in a qualitative agreement with the proposed cone model of DIP nanostructured surfaces.
A symmetric hyperbolic formulation of the vacuum Einstein equations in affine-null coordinates
Authors: Ripley Justin L.
Published: June 2021

We present a symmetric hyperbolic formulation of the Einstein equations in affine-null coordinates. Giannakopoulos et al. [Phys. Rev. D 102, 064035 (2020)] recently showed that the most commonly numerically implemented formulations of the Einstein equations in affine-null coordinates (and other single-null coordinate systems) are only weakly—not strongly—hyperbolic. By making use of the tetrad-based Newman–Penrose formalism, our formulation avoids the hyperbolicity problems of the formulations investigated by Giannakopoulos et al. [Phys. Rev. D 102, 064035 (2020)]. We discuss a potential application of our formulation for studying gravitational wave scattering.
SETD2-mediated H3K14 trimethylation promotes ATR activation and stalled replication fork restart in response to DNA replication stress
Authors: Zhu Qian , Yang Qiaoyan , Lu Xiaopeng , Wang Hui , Tong Lili , Li Zheng , Liu Ge , Bao Yantao , Xu Xingzhi , Gu Luo , Yuan Jian , Liu Xiangyu , Zhu Wei-Guo
Published: June 2021

Significance

ATR is a central molecule involved in the DNA replication stress response and repair that ensures genome stability. Whether chromatin modifiers or chromatin modifications also regulate ATR activation, however, is unclear. We conclude that SETD2-mediated H3K14me3 recruits the RPA complex to chromatin and thus promotes ATR activation during conditions of replication stress. Using a series of biological and molecular approaches, we carefully delineated this new SETD2-H3K14me3-RPA-ATR axis that promotes ATR activation and improves cancer cell survival in response to DNA replication stress. Our data open up future opportunities to generate cancer therapeutics strategies based on this pathway.
“Soft” oxidative coupling of methane to ethylene: Mechanistic insights from combined experiment and theory
Authors: Liu Shanfu , Udyavara Sagar , Zhang Chi , Peter Matthias , Lohr Tracy L. , Dravid Vinayak P. , Neurock Matthew , Marks Tobin J.
Published: June 2021

Significance

Highly abundant methane is vastly underutilized as a feedstock for chemicals and fuels reflecting its inertness. One seemingly attractive approach to methane utilization would be direct catalytic oxidative coupling of methane (OCM) with O
2
to produce ethylene, a valuable chemical feedstock. However, the exothermicity leads largely to nonselective oxidation to CO
2
, a challenge that remains despite decades of research. These results raise the intriguing question of whether the “softer” isoelectronic oxidant, S
2
, might achieve analogous SOCM with acceptable selectivity. Here, we report a combined experimental and computational investigation of the SOCM reaction mechanism, comparing and contrasting with that of conventional OCM. We find that SOCM shows promising selectivity to ethylene and proceeds via a very different pathway than does OCM.
NAD(H)-mediated tetramerization controls the activity of
Legionella pneumophila
phospholipase PlaB
Authors: Diwo Maurice , Michel Wiebke , Aurass Philipp , Kuhle-Keindorf Katja , Pippel Jan , Krausze Joern , Wamp Sabrina , Lang Christina , Blankenfeldt Wulf , Flieger Antje
Published: June 2021

Significance

Secreted bacterial phospholipases, which hydrolyze host membranes, may also harm the pathogen itself. Sophisticated activation mechanisms are therefore required to prevent self-damage before protein export but warrant activity at the pathogen–host interface. Here we structurally analyzed PlaB, a surface-exposed highly active phospholipase and virulence factor of the lung pathogen
Legionella pneumophila
. Unexpectedly, we found that NAD(H), a central cofactor of energy metabolism, stabilizes an inactive tetrameric form of PlaB. Since NAD(H) is confined to the intracellular milieu of the bacterium, we propose that this sophisticated NAD(H)-dependent oligomerization mechanism protects
L. pneumophila
from damage and simultaneously enables the function of PlaB as a virulence factor after export and association to the bacterial surface.
Neurophysiological coordination of duet singing
Authors: Coleman Melissa J. , Day Nancy F. , Rivera-Parra Pamela , Fortune Eric S.
Published: June 2021

Significance

Cooperation, turn taking, and other social behaviors often depend on temporal coordination between individuals. How brains use sensory cues from participants to synchronize performances is not known. We examined the interactions between sensory cues and motor activity in the brains of female and male plain-tailed wrens that rapidly take turns to produce a duet that sounds as if a single bird is singing. We made simultaneous neurophysiological recordings from the brains of pairs of awake, duetting wrens. We discovered that inhibition driven by auditory feedback from the partner alternated with the premotor activity used by each individual to produce its own vocalizations. These data show how sensory feedback links the brains of cooperating animals through the modulation of motor circuits.
Mitochondrial apoptotic priming is a key determinant of cell fate upon p53 restoration
Authors: Sánchez-Rivera Francisco J. , Ryan Jeremy , Soto-Feliciano Yadira M. , Clare Beytagh Mary , Xuan Lucius , Feldser David M. , Hemann Michael T. , Zamudio Jesse , Dimitrova Nadya , Letai Anthony , Jacks Tyler
Published: June 2021

Significance

It has long been observed that activation of p53 can yield two main cell fates: either apoptotic cell death or cell cycle arrest. However, what determines this cell fate remains to be fully elucidated. Here we show that the state of mitochondrial priming prior to activation of p53 can determine cell fate. Highly primed cells commit to apoptosis, while less-primed cells commit to cell cycle arrest. We show that modulation of priming in either direction can alter cell fate; increasing priming in poorly primed cells yields apoptosis, while decreasing priming in highly primed cells yields arrest. Drugs that increase priming enforce an apoptotic fate, suggesting a p53-independent strategy for augmenting efficacy of cancer chemotherapy drugs that kill via p53.
Neural basis of opioid-induced respiratory depression and its rescue
Authors: Liu Shijia , Kim Dong-Il , Oh Tae Gyu , Pao Gerald M. , Kim Jong-Hyun , Palmiter Richard D. , Banghart Matthew R. , Lee Kuo-Fen , Evans Ronald M. , Han Sung
Published: June 2021

Significance

Opioid-induced respiratory depression (OIRD) is the direct cause of death from opioid overdose, which accounts for the current global opioid crisis. Here, we report that neurons expressing the μ-opioid receptors in the lateral parabrachial nucleus of the pontine respiratory group are necessary and sufficient for the pathogenesis of OIRD. Activating these neurons through endogenous or artificial G protein–coupled receptor signaling pathways rescues OIRD in intact mice, suggesting its therapeutic utility in OIRD patients.
Segregation, integration, and balance of large-scale resting brain networks configure different cognitive abilities
Authors: Wang Rong , Liu Mianxin , Cheng Xinhong , Wu Ying , Hildebrandt Andrea , Zhou Changsong
Published: June 2021

Significance

Mastering diverse cognitive tasks is crucial for humans. We study how the brain’s functional organization at rest is configured to support diverse cognitive phenotypes. Emphasizing the multilevel, hierarchical modular structure of brain’s functional connectivity to derive eigenmode-based measures, we demonstrate that the resting brain’s functional organization in healthy young adults is configured to maintain a balance between network segregation and integration. This functional balance is associated with better memory. Furthermore, brains tending toward stronger segregation versus integration foster different cognitive abilities. Thus, the segregation–integration balance empowers the brain to support diverse cognitive abilities. These findings yield high potential to understand the role of whole-brain resting state dynamics in human cognition and to develop neural biomarkers of atypical cognition.
Tryptophanemia is controlled by a tryptophan-sensing mechanism ubiquitinating tryptophan 2,3-dioxygenase
Authors: Klaessens Simon , Stroobant Vincent , Hoffmann Delia , Gyrd-Hansen Mads , Pilotte Luc , Vigneron Nathalie , De Plaen Etienne , Van den Eynde Benoit J.
Published: June 2021

Significance

Besides being a protein building block, the essential amino acid tryptophan is a neurotransmitter precursor and a potent immunomodulator. Therefore, its systemic concentration needs to be constant in spite of irregular dietary supply. How this is achieved is unclear. Dietary tryptophan is degraded in the liver by tryptophan 2,3-dioxygenase (TDO). We report that tryptophan itself regulates TDO stability: Abundant tryptophan binds to noncatalytic exosites and stabilizes active tetrameric TDO. Hence, tryptophan is rapidly degraded and tryptophanemia contained. When tryptophan is scarce, it detaches from exosites, inducing tetramer dissociation and unmasking a degron triggering TDO polyubiquitination and proteasome-mediated degradation. Tryptophan catabolism is interrupted and blood level maintained. Matching catabolism to dietary supply, this mechanism ensures rapid and tight control of tryptophanemia.
A CO
2
greenhouse efficiently warmed the early Earth and decreased seawater
18
O/
16
O before the onset of plate tectonics
Authors: Herwartz Daniel , Pack Andreas , Nagel Thorsten J.
Published: June 2021

Significance

Due to the lower luminosity of the young Sun, climate modelers struggle to explain why the climate on early Earth was not freezing cold. This “faint young Sun paradox” is in conflict with apparently hot Archean ocean temperatures (∼70 °C) that can be estimated from the
18
O/
16
O stable isotope ratio of chemical sediments. We show that the later temperatures had been overestimated because the
18
O/
16
O of seawater also changed over time due to intense carbonatization and silicification of the oceanic crust, which consumes heavy
18
O. Because these processes require high fluxes of CO
2
, greenhouse warming by a CO
2
-rich atmosphere appears most feasible to explain all observations.
Exploring the perceptual inabilities of Eurasian jays (
Garrulus glandarius
) using magic effects
Authors: Garcia-Pelegrin Elias , Schnell Alexandra K. , Wilkins Clive , Clayton Nicola S.
Published: June 2021

Significance

While we know that humans are often deceived by magic effects, little is known concerning how nonhuman animals perceive these intricate techniques of deception. Here, we tested the susceptibility to be misled by three different magic effects on a sample of six Eurasian jays (
Garrulus glandarius
). We demonstrate that, similar to humans, Eurasian jays are susceptible to magic effects that utilize fast movements. However, unlike humans, Eurasian jays do not appear to be misled by magic effects that rely on the observer’s intrinsic expectations in human object manipulation. Magic effects can provide an insightful methodology to investigate perception and attentional shortcomings in human and nonhuman animals and offer unique opportunities to highlight cognitive constraints in diverse animal minds.
Iron robbery by intracellular pathogen via bacterial effector–induced ferritinophagy
Authors: Yan Qi , Zhang Wenqing , Lin Mingqun , Teymournejad Omid , Budachetri Khemraj , Lakritz Jeffrey , Rikihisa Yasuko
Published: June 2021

Significance

Ehrlichia chaffeensis
infects and proliferates inside monocytes and macrophages by acquiring iron from the cellular labile iron pool and causes a potentially fatal disease called human monocytic ehrlichiosis. This report reveals a unique bacterial iron hijacking mechanism.
Ehrlichia
deploys a protein Etf-3 via the bacteria type IV secretion system. Etf-3 binds ferritin and induces ferritinophagy, thereby increasing the cellular labile iron pool for
Ehrlichia
to acquire iron for intracellular proliferation. This, in concert with coregulation of bacterial and host cell superoxide dismutases with type IV secretion system, enables
Ehrlichia
to prevent reactive oxygen species–induced host cell damage mediated by labile iron. This finding unifies current concepts of intracellular bacterial infection, ferritinophagy, and ROS, which may be exploited to inhibit
Ehrlichia
infection.
Structures suggest an approach for converting weak self-peptide tumor antigens into superagonists for CD8 T cells in cancer
Authors: Wei Pengcheng , Jordan Kimberly R. , Buhrman Jonathan D. , Lei Jun , Deng Hexiang , Marrack Philippa , Dai Shaodong , Kappler John W. , Slansky Jill E. , Yin Lei
Published: June 2021

Significance

Tumor vaccines using modified self-antigens that structurally enhance T cell receptor–peptide–major histocompatibility complex interactions greatly improve a T cell protective response against the tumor’s unmodified self-antigen. X-ray crystal structures of these interactions explain how the native and modified peptides can interact with the same T cell receptor, but with different affinities and abilities to drive T cell proliferation and differentiation.
Exchange-mediated mutual correlations and dephasing in free-electrons and light interactions
Authors: Talebi Nahid , Březinová Iva
Published: June 2021

The quantum world distinguishes itself from the classical world by being governed by probability amplitudes rather than probabilities. On a single-particle level, quantum phases can be manipulated leading to observable interference patterns that can be used as a probe e.g. in matter wave microscopy. But the quantum world bears even more fascinating effects when it comes to the interplay between more than one particle. Correlations between quantum particles such as entanglement can be exploited to speed up computational algorithms or enable secure cryptography. Here, we propose and numerically explore a thought experiment to address the question whether quantum correlations between particles can be used in matter wave microscopy. Specifically, we address the following questions: can information be transferred between two mutually spin-correlated free-electron wavepackets? Can Coulomb and exchange correlations be linked to the decoherence and dephasing mechanisms of matter waves? Using a time-dependent Hartree–Fock algorithm, we will show that the exchange term has a substantial role in transferring the information between two mutually spin-correlated electrons, whereas the Hartree potential (or mean-field Coulomb potential) dominates the dephasing on a single-particle level. Our findings might facilitate fermionic matter wave interferometry experiments designed to retrieve information about non-classical correlations and the mechanism of decoherence in open quantum systems.
Reduction of Vortex Formation in Mechanical Heart Valve During LV Filling
Authors: Badiger V , Nageswaran S
Published: June 2021

Mechanical valve implanted in mitral position has a tremendous effect on the flow dynamics in Left Ventricle (LV). The purpose of this study is to develop a new valve configuration to reduce the vortex ring formation caused by an artificial heart valve in an isovolumetric environment to generate a smoother flow field. Flow Inhibitors (FI) were built on the proximal end of the leaflet of various shapes and sizes to understand their effect on flow dynamics. The test geometries were designed based on the principles of Bernoulli’s law of fluid dynamics, pressure staging, and counter disturbance. In this research, equally spaced FI with centralized flow showed a lower and gradual pressure gradient as opposed to the control valve that was used earlier in the study done with a 27mm St. Jude mechanical valve. The pressure gradient dropped gradually from 1.4 Pa to 0.3 Pa as compared to a sudden drop in pressure in the control valve from 1.3 Pa to 0.2 Pa. The velocity value set was 0.8 m/s for simulation which dropped to 0.4 m/s in equally spaced FI centralized flow valve as compared to 0.3 m/s in the control valve. When compared on the basis of smoothness of flow field and gradual drop in the pressure, the former is weighted to be a better design. Flow inhibitor coupled with pressure staging method proved to be effective in enhancing the performance of bileaflet valve.
Implementation of different techniques for removing artifacts in diaphragmatic SEMG, and evaluation of these in automatic and online applications
Authors: Valle D A , Hernández A M
Published: June 2021

Respiratory muscles superficial electromyography (SEMG) is an important source of information in the monitoring of ventilated patients. One of the main problems in the acquisition of SEMG signals is the different sources of interference. The most common artifacts are the baseline wander (BW) normally generated by motion, and power line interference (PLI). In this paper, different methods were selected and evaluated for the removal of these artifacts in a simulated SEMG signal of the right diaphragm muscle. The best performance technique for the removal of each artifact was determined using frequency analysis and estimation of criteria such as the signal to noise ratio, relative error, cross-correlation, and coherence of the power spectrum density. The computational cost of each of the techniques was estimated to also assess how appropriate it is to implement in online applications and limited hardware. The study demonstrates that the spectral interpolation technique has a good performance in removing PLI from the SEMG signal but has a high computational cost, unlike the adaptive LMS filter. On the other hand, the SSA-based technique proved to be the best performing for BW removal and its computational cost is adequate in a more limited hardware system.
Removal of Artifacts from Electroenchaphalography Signal using Multiwavelet Transform
Authors: Paulchamy B. , Chidambaram S. , Basheer Jamshid M.
Published: June 2021

The signal from the brain can be recorded using Electroenchaphalography (EEG). The proposed work summarizes a unique method which is used for the removal of mixed artifacts presented in the electroencephalography signal during the acquisition process. Artifacts comprises of various bio-potential unit such as electrooculogram, electrocardiogram, and electromyogram. These artifacts are referred as a noise sources which is responsible for the complexity of the EEG signal. The artifacts obtained from the EEG signal leads towards improper diagnosis of pathological conditions. The EEG signal which is obtained from the brain is the multi-dimensional signal with the various statistical properties. Time consumption of the EEG signal is not reproducible due to the biological properties of the signal. The information of the EEG signal consists of the data of the neuron levels which is collected for every millisecond with the temporal resolution scale. In account of special cases, EEG signal contains noise and artifacts where information is collected using the extraction of signals. To obtain the information of the artifacts the proposed technique is used to maintain higher accuracy in the extraction process. The proposed technique consists of multiwavelet transform to remove the artifacts from the input EEG signal. In the proposed multiwavelet transform, the signal which consists of noisy features can be decomposed using GHM and thresholding technique. This experimental analysis shows the removal of artifacts from the EEG signals. The pathological conditions are removed which leads to the increase in the accuracy of the system. Also, this research findings shows that the proposed multiwavelet transform based approach outperforms significantly with respect to conventional approaches. The reconstructed EEG signal has the lesser reliability range which is measured in-terms of signal to noise ratio and power spectral density.
Development of an Automated Nebulizer Spray Pyrolysis System and Its Application in the P-N junction Diode Fabrication
Authors: Jagadeesan V , Subramaniam Venkat
Published: June 2021

An automated nebulizer spray pyrolysis (ANSP) system is developed for fabricating p-Zn:CuO/n-Si junction diode. The mechanical carriage for the X-Y movement and the proposed ANSP system is designed using the Solid Works design software tool. ATmega-328 microcontroller-based control system was developed to control and move the spray nozzle in the X and Y-axis direction. Zn:CuO (p-type) precursor solution is sprayed on the silicon wafer (n-type) using this ANSP system to form p-Zn:CuO/n-Si junction diode. The process parameters and operating conditions were optimized. The fabricated p-Zn:CuO/n-Si junction diode parameters such as ideality factor (η) and barrier height (φb) were studied under dark and light conditions using Keithley electrometer. The investigation results revealed that the junction diode has the lowest ideality factor and barrier height.
Reliability Evaluation of Underwater Sensor Network in Shallow Water Based on Propagation Model
Authors: Padmavathy N , Rao Ch Venkateswara
Published: June 2021

Underwater wireless sensor networks are composed of numerous vehicles/sensors that are deployed in précised acoustic vicinity to execute collaborative monitoring and data assembling tasks. These sensor nodes establish an acoustic communication link among them and the surface station. The unpredictable variations in the underwater parameters (depth; temperature; salinity; pH) introduce changes in signal speed randomly, which affect the link formation. Hence, designing a feasible channel model is essential to estimate the effect of underwater parameters and their losses (absorption loss, spreading loss) on the connectivity of underwater networks. In this work, an acoustic channel model has been considered which distinguishes the effect of frequency and the aforementioned parameters on link formation. A methodology for evaluating the reliability of the underwater sensor network deployed in shallow water scenarios based on the acoustic propagation model has been proposed. The network is deployed as 3D reference architecture, where the nodes are randomly deployed in a fixed scenario depth and the source node is deployed with an adjustable buoy length. The influence of underwater parameters, network parameters, and simulation time on the two-terminal reliability of underwater sensor networks has been analyzed. The simulation results indicated that the maximum reliability is achieved at lower frequencies when compared to higher frequencies.
Design of microstrip patch antenna at 2.4 GHz for Wi-Fi and Bluetooth applications
Authors: Arora Ayush , Rana Arpit , Yadav Abhimanyu , Yadava R.L.
Published: June 2021

In this paper, the Rectangular Patch Antennas are designed and their performance parameters such as return loss, voltage standing wave ratio, gain, and radiation pattern have been calculated and compared. Design frequency is 2.4 GHz, the copper-coated substrate material is FR-4 Epoxy having dielectric constant ε = 4.4 and thickness is 1.5 mm. The feeding technique, used in MSA is Microstrip 50 Ω feed line. Using a parametric study found that the proposed antenna design will be useful for ISM band applications like Wi-Fi, Bluetooth.
Leaky wave antenna for millimeter wave utilization
Authors: Agarwal Ruchi , Agarwal Ayushi , Dwivedi Aman , Sharma Ashutosh
Published: June 2021

The simulation of planar periodic leaky-wave antenna for ultra-wideband application is introduced here. The antenna proposed here comprises 15 matched unit cells with high directivity which provides a backward to forward beam scanning range of 80° with frequency from 24.4GHz to 27.5GHz and has filtering capability making the design simpler. The calculated efficiency is 90% which is the gain to the directivity ratio of the designed antenna. The bandwidth range is between 24.4 GHz to 27.5GHz. The work is outlined and assembled on Roger’s substrate (particularly good for 5G applications) and has a gain of 13.92dB which represents an excellent choice for communication systems.
Lie Detection using Speech Processing Techniques
Authors: Fathima Bareeda E P , Shajee Mohan B S , Ahammed Muneer K V
Published: June 2021

The objective of this paper is to design and set up an efficient lie detector that can detect lies in spoken sentences in an object language. Usually lie detection make use of invasive methods that extract different physiological signals such as EEG etc., from the subject’s body and analyze them to decide on the presence of lie in the utterances. This work proposes an efficient lie detection technique based on the non-invasive method that involves only recording the subject’s speech utterances. Discriminative and meaningful features are extracted from the speech and classifiers are built based on SVM to discriminate between truth and lie. The classifier will be trained efficiently so that a better performance can be obtained compared with existing lie detectors. This paper aims to exploit the psycho-neural aspects and dependence of speech signals to predict and detect the presence of lies in isolated speech utterances.
Semi-supervised Learning Techniques for Speech Emotion Recognition
Authors: Remya K , Shajee Mohan B S , Ahammed Muneer K V
Published: June 2021

The core objective of this paper is to explore semi-supervised learning methods for recognizing emotions contained in speech. Semi-supervised learning techniques are used when the availability of labeled examples are sparse. There are different methods that are used in the semi-supervised settings. These techniques include generative model, graph based methods, metric based methods etc., The speech emotion data is considered for this experiment. Speech signal contains emotion specific data also. Emotion dependent features are extracted from the speech. This paper aim to enhance some existing techniques for semi-supervised learning that are used for speech emotion recognition.
Design and Comparison of the effect of SRR Metamaterial on the performance of Microstrip Patch Antenna of various shapes at millimetre-wave band Useful for 5G enabled Internet of Things Applications
Authors: Colaco John , Lohani R.B.
Published: June 2021

5G is the creation of apprehending the total potential IoT. Since the request for 5G and Web of things, applications such as e-health, keen homes, e-learning, work from domestic, virtual conferences, and another gushing of online high-quality video substance is exponentially expanding day by day. The authors in this research have designed, compared and examined the execution of different Microstrip Antenna geometrical patches with and without metamaterial such as Circular Shape, Rhombus Shape, Square shape, Elliptical shape, and Triangular shape for 5G enabled IoT systems at 27 GHz, millimeter-Wave Band. In this research, authors have utilized Rogers RT/Duroid 5880 substrate with 50-ohm Microstrip Transmission line nourish. After Comparing and Examining the performance, authors have found square Patch Microstrip Antenna appears way better execution and exceedingly proficient than other shapes.
Read Textual features in Images and convert to Editable form by extended use of Artificial Neural Networks, Deep learning and Maximally Stable Extremal Region techniques
Authors: Joseph Gladwin S. , Vinoth Kumar C.
Published: June 2021

Nowadays most of the information is stored in images and there is a need to convert this information into an editable format. The objective of this paper includes the development of a user-friendly tool to extract text from the video or to recognize well-written handwriting in a scanned document to an editable form. The proposed methodology is robust and can provide high-grade performance with layout distortion. The explication utilizes modalities like Optical Character Recognition (OCR), Artificial Neural Networks (ANN), Deep Learning and Maximally Stable Extremal Regions (MSER) techniques for text detection. The video extraction can be attained by using video to frame conversion and then to use the Structural Similarity Index Measure (SSIM). The prototype is developed using MATLAB and provided with a GUI, which is deployable on a workstation. The generated GUI is employed to define Region of Interest (ROI), specify the required text layout, highlighting the specific portions of the image, select the appropriate language and also export the text to a word document or notepad applications where it can be edited.
Comparative Analysis of OFDM MIMO and IDMA OFDM MIMO using Aqua Sim Simulator for Underwater Communication
Authors: Shahapur Salma S , Khanai Dr Rajshri , Torse Dr D A
Published: June 2021

Underwater wireless acoustic communication is a central aiding skill used in underwater monitoring with the help of sensor nodes. Designing Underwater wireless networking is challenging as the water environment is dynamic as well as hard. In this paper we combine OFDM MIMO with IDMA to improve the network performance. The experimentation was simulated using Aqua Sim simulator an underwater imitation software that is based on NS2. The key objective of our paper is twofold. First is connection of communication functionalities such as BPSK modulation, Turbo code, Random Interleaver, UWMAC and three routing protocols. This implementation has modulation scheme, MAC and routing protocol from Aqua Sim simulator. Where the novel contribution to the work is implementation of Turbo code in NS2 for the appealing results. Secondly the OFDM MIMO and IDMA OFDM MIMO implementation is tested with 50 nodes and the various parameters such as BER, Throughput, delay, packet delivery ratio, energy consumption has been investigated. IDMA OFDM MIMO gives good results in terms of BER, packet delivery ratio, Throughput but consumes more energy.
Investigation of Graphene as a Sensing Layer for Future Prostate Cancer Biosensing Applications
Authors: Sarkar A , Sreenath M , Srinivas K , Teja N V
Published: June 2021

The work proposes simulation, characterization and synthesis of sensing layer for bio sensor application. So far no curable treatment is there for prostate cancer if it is not treated at earlier phase i.e. in right time. So biosensor is having major impact on detection at initial phase. Next generation sensor (NGS) includes graphene. This paper proposes biosensor and in the regard of graphene, and same will be analyzed for sensing layer. Chirality (associated with chiral indices and chiral angle) and electrical properties of grapheme along with some key properties are also simulated in ninithi software and comparison of mathematical model is also reported. So we have followed a substrate free easy way to produce graphene at atmospheric pressure. This process could be an easy and comparatively inexpensive method for preparing graphene. Finally the synthesized graphene is characterized by Scanning Electron Microscope (SEM) and the crystal growth is visualized through X ray diffraction (XRD) which are thriving implementation for a biosensing platform.
A simple semi-circular arc shaped frequency and polarization reconfigurable antenna
Authors: Kumari Ranjana , Suri Pranav , Kaudinya Prabhakar , Katheria Piyush Singh
Published: June 2021

A simple semi-circular shaped antenna having frequency as well as polarization reconfigurability is presented in this work. The proposed antenna has a size of 70.4 × 67.5 × 1.52 mm3. This antenna consists of three switches (S1, S2 and S3) which have been used to attain frequency reconfigurability and polarization reconfigurability in both LP (linear polarization) and CP (circular polarization). When switch S1 is OFF and any of switch S2/S3 is ON then we are obtaining frequency at Single Band (2.4 GHz). When Switch S1 is ON and any of the Switch S2/S3 is OFF then we are obtaining frequency at dual Band (2.4 GHz and 5.52 GHz). When all the switches S1, S2 and S3 are ON at the same time then we are obtaining frequency at Single Band (5.52 GHz). The simulated fractional bandwidth of the lower band centred at 2.4 GHz is observed to be 17.4% and for the upper band centred at 5.52 GHz is observed to be 5%. Proposed antenna gain greater than 2dBi is obtained for all five cases along with less than 2 VSWR with excellent radiation efficiency. The proposed reconfigurable antenna is suitable for Bluetooth and WLAN application.
A Reconfigurable Wearable Antenna for Mid Band 5G Applications
Authors: Muduli Arjuna , Kanneboina Murali Krishna , Mudumunthala Krishna Vamsi , Valluri Sriram
Published: June 2021

Soon, everything should be connected by 5G wireless, including wearable devices that are booming fast recently. Wearable antennas are becoming increasingly common in consumer electronics. To achieve 5G, wearable devices should support much wide band width and high rate of data with better consistency. In this paper a reconfigurable wearable antenna is implemented on a fabric substrate. The proposed antenna may fit for reconfiguration of the frequency to work on MID band (3 – 5.5GHz) of 5G. The proposed antenna can be a part of military uniform or any other garment and can be employed in Wi-Fi, WLAN, Satellite,5G mobile and cognitive radio communication. The shape of the antenna has been accomplished by placing each feature of reconfiguration mentioned above in the same antenna and performing the parametric analysis to obtain an optimal prototype that could allow the achievement of good results with fabric such as polyester as substrate.
UVM based verification of iAPX 186 processor modules
Authors: Rajthilak S. , Mohankumar N.
Published: June 2021

UVM is used to enable faster development and reuse of System Verilog based Verification Environment. The use of UVM is to develop reusable test bench. The UVM class library contains configuration database, TLM and component hierarchy. Each and every component in the verification environment has a specific functionality. The UVM has a list of base class which are pre-stored and System Verilog environment can be built by deriving the base classes. Two parameters have been used namely Coverage and Assertions. Coverage is used to measure whether all features of the design specification is tested. Assertions are used for checking the behavior of the design. In this work, we design the individual blocks like Interrupt Controller, Timer module, DMA Controller, Execution Unit and Bus Interface Unit of 80186 processor using Verilog and Verify its functionality behavior using the two parameters using UVM.
Gaussian vortex beam modeling for multiplexing in data communication using OAM
Authors: Abhyankar Girish G. , Gad R.S. , Panem Charanarur , Chodankar Deepak , Naik G.M.
Published: June 2021

Optical vortices carrying orbital angular momentum (OAM) are being explored for improving the overall aggregate capacity along with the spectrum efficacy of data communications systems. The OAM carrying vortex beams provide an additional degree in space division multiplexing consistent with other physical dimensions like amplitude, frequency/wavelength, polarization & phase, leading towards continual increase of the overall transmission capacity along with the spectral efficacy through N-dimensional multiplexing. OAM has unlimited modes which are intrinsically orthogonal thus rendering OAM carrying beams to be efficiently multiplexed and subsequently demultiplexed. In this paper we simulate and study the intensity profiles and phase structures of Gaussian vortex beams. The clockwise and anti-clockwise spiraling of the phase structures for mutually opposite values of the topological charge of OAM and also diverging pattern of the phase structure along the direction of propagation are simulated.
A review of free fatty acid determination methods for palm cooking oil
Authors: Nurulain S , Aziz NA , Najib MS , Salim MR , Manap H
Published: June 2021

Free fatty acids (FFA) is one of the main content of palm cooking oil. High percentage of FFA in palm oil can affect human health and the quality of palm oil. Based on quality standards specification set by Malaysia Palm Oil Board (MPOB), the allowable content of free fatty acid (FFA) for crude palm oil (CPO) must not exceed 5%, meanwhile less than 0.1% of FFA in Refined Bleached Deodorized Oil (RBDO). There are many researches have been carried out to determine the level of FFA. However, they are using different type of cooking oil. A few researches are also reported regarding the palm cooking oil but they are using different method such as titration, spectroscopic, gas chromatography, reflection method and other type of detectors. All methods to determine the amount of free fatty acids (FFA) in palm cooking oil are reviewed in this paper.
A mobile air particle system using an optical sensor for haze measurement
Authors: Nurulain S , Hafiza Z , Siera R , Musfirah M , Salim MR , Manap H
Published: June 2021

This paper presents a development of a mobile haze measurement system which can measure the amount of particulate matter and display in real time. The current haze measurement system called high volume sampler is difficult to move around due to its big size and the reading is not available in real time. Therefore, an alternative for the haze measurement system need to be developed. It uses an optical sensor as a working principle and Arduino board as a microcontroller. The measurement system is able to measure particulate matter from the smoke generated using a mosquito coil. The reading from the developed haze measurement system is verified using a commercial sensor called Dust Mate.