bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the influencing factors of space charge dynamic behavior in XLPE insulation under alternating current electric field
Authors: Xu Zhe , He Dongxin , Liu Hongshun , Li Qingquan , Zang Qingjing , Le Roy Séverine , Teyssèdre Gilbert
Published: March 2022

The dynamic behavior of space charges is one of the potential factors that cause electrical aging. In this paper, a bipolar space charge transport model was established under an AC electric field in cross-linked polyethylene. The effects of physical parameters on the dynamic behavior of space charges in an AC electric field were explored by changing the injection barrier heights, mobilities, trapping coefficients, and detrapping barrier heights of positive and negative charges. The effects of voltage conditions on space charge behavior were explored by changing the amplitude and frequency. The effects of temperature were studied by setting a temperature gradient similar to that of real cable operation. The asymmetry of the physical parameters could seriously aggravate the accumulation of space charges in the AC field. A set of physical parameters based on these results was identified. Both the increase in voltage amplitude and decrease in frequency enhanced the amount of and penetration into the insulation of the accumulated space charge. The dynamic behaviors of the space charges were more active with increased voltage amplitude and frequency. The temperature gradient in the cable insulation implies that the degree of accumulation, penetration into material, and activity of dynamic behaviors of the space charges at the warmest electrode are greater than those at the coldest. Compared with the DC field, the dynamic behavior of space charges in the AC electric field is more active and releases more energy. This research provides a theoretical basis for inhibiting the accumulation of space charges in an AC electric field.
Dual-peak electroluminescence spectra generated from Al
n

/12Ga1-n/12N (n = 2, 3, 4) for AlGaN-based LEDs with nonflat quantum wells
Authors: Nagasawa Yosuke , Kojima Kazunobu , Hirano Akira , Ippommatsu Masamichi , Honda Yoshio , Amano Hiroshi , Chichibu Shigefusa F
Published: March 2022

The metastability of Al
n

/12Ga1-n/12N (n = 2, 3, and 4) was investigated by the statistical analysis of electroluminescence (EL) spectra having dual peaks with a peak-to-peak distance (pp) of >10 nm generated from nonflat Al
x
Ga1-

x
N (x ∼ 0.2) quantum wells (QWs) fabricated on c(0001) sapphire substrates with a miscut of 1.0° towards the m[1

1
ˉ

00] axis. To explain the origins of the dual-peak EL (DPEL) spectra, which are often observed for AlGaN-QWs with Ga content of greater than 0.7, a nonflat QW model incorporating two metastable compositions, Al(n-1)/12Ga1-(n-1)/12N and Al
n

/12Ga1-n/12N (n: integer), is proposed. By the statistical analysis of peak wavelengths in DPEL spectra and the verification of EL spectral shapes, two series of featured EL peak wavelengths with intervals of 2–3 nm were obtained from five out of six LED wafers. The two series of featured EL peak wavelengths were assigned by comparison with the calculated EL wavelengths. Then, Al2/12Ga10/12N and Al3/12Ga9/12N were determined to be the origins of peaks with the longer and shorter wavelengths in the DPEL, respectively, in addition to the metastable Al
n

/12Ga1-n/12N (n= 4–9) compositions observed in our previous studies. When DPEL (pp> 10 nm) appeared, the difference in QW thickness between Al2/12Ga10/12N and Al3/12Ga9/12N tended to be larger than one monolayer (ML), indicating a significant amount of Ga or GaN mass transport. Furthermore, the Al2/12Ga10/12N and Al3/12Ga9/12N QWs are considered to have thicknesses of m ML (m: consecutive integers), suggesting the 1 ML configuration of Al and Ga atoms on the c(0001) plane. In addition, the DPEL obtained from nonflat Al
x
Ga1-

x
N (x ∼ 0.25) QWs by another research group was shown to be related to two metastable Al
n

/12Ga1-n/12N (n = 3, 4), similarly to our one exceptional LED wafer, which also agreed with the model proposed in this work.
Charge self-consistent electronic structure calculations with dynamical mean-field theory using Quantum ESPRESSO, Wannier 90 and TRIQS
Authors: Beck Sophie , Hampel Alexander , Parcollet Olivier , Ederer Claude , Georges Antoine
Published: March 2022

We present a fully charge self-consistent implementation of dynamical mean field theory (DMFT) combined with density functional theory (DFT) for electronic structure calculations of materials with strong electronic correlations. The implementation uses the Quantum ESPRESSO package for the DFT calculations, the Wannier90 code for the up-/down-folding and the TRIQS software package for setting up and solving the DMFT equations. All components are available under open source licenses, are MPI-parallelized, fully integrated in the respective packages, and use an hdf5 archive interface to eliminate file parsing. We show benchmarks for three different systems that demonstrate excellent agreement with existing DFT + DMFT implementations in other ab initio electronic structure codes.
Analysis of molecular ligand functionalization process in nano-molecular electronic devices containing densely packed nano-particle functionalization shells
Authors: Sher Omer , Han Yuanyuan , Xu Haoyuan , Li Hu , Daun Tianbo , Kumar Sharath , Grigoriev Anton , Panda Pritam Kumar , Orthaber Andreas , Serein-Spirau Francoise , Jarrosson Thibaut , Jafri S Hassan M , Leifer Klaus
Published: March 2022

Molecular electronic devices based on few and single-molecules have the advantage that the electronic signature of the device is directly dependent on the electronic structure of the molecules as well as of the electrode-molecule junction. In this work, we use a two-step approach to synthesise functionalized nanomolecular electronic devices (nanoMoED). In first step we apply an organic solvent-based gold nanoparticle (AuNP) synthesis method to form either a 1-dodecanethiol or a mixed 1-dodecanethiol/ω-tetraphenyl ether substituted 1-dodecanethiol ligand shell. The functionalization of these AuNPs is tuned in a second step by a ligand functionalization process where biphenyldithiol (BPDT) molecules are introduced as bridging ligands into the shell of the AuNPs. From subsequent structural analysis and electrical measurements, we could observe a successful molecular functionalization in nanoMoED devices as well as we could deduce that differences in electrical properties between two different device types are related to the differences in the molecular functionalization process for the two different AuNPs synthesized in first step. The same devices yielded successful NO2 gas sensing. This opens the pathway for a simplified synthesis/fabrication of molecular electronic devices with application potential.
Accessing negative Poisson’s ratio of graphene by machine learning interatomic potentials
Authors: Wu Jing , Zhou E , Qin Zhenzhen , Zhang Xiaoliang , Qin Guangzhao
Published: March 2022

The negative Poisson’s ratio (NPR) is a novel property of materials, which enhances the mechanical feature and creates a wide range of application prospects in lots of fields, such as aerospace, electronics, medicine, etc. Fundamental understanding on the mechanism underlying NPR plays an important role in designing advanced mechanical functional materials. However, with different methods used, the origin of NPR is found different and conflicting with each other, for instance, in the representative graphene. In this study, based on machine learning technique, we constructed a moment tensor potential for molecular dynamics (MD) simulations of graphene. By analyzing the evolution of key geometries, the increase of bond angle is found to be responsible for the NPR of graphene instead of bond length. The results on the origin of NPR are well consistent with the start-of-art first-principles, which amend the results from MD simulations using classic empirical potentials. Our study facilitates the understanding on the origin of NPR of graphene and paves the way to improve the accuracy of MD simulations being comparable to first-principle calculations. Our study would also promote the applications of machine learning interatomic potentials in multiscale simulations of functional materials.
Parylene-based memristive crossbar structures with multilevel resistive switching for neuromorphic computing
Authors: Shvetsov Boris S , Minnekhanov Anton A , Emelyanov Andrey V , Ilyasov Aleksandr I , Grishchenko Yulia V , Zanaveskin Maxim L , Nesmelov Aleksandr A , Streltsov Dmitry R , Patsaev Timofey D , Vasiliev Alexander L , Rylkov Vladimir V , Demin Vyacheslav A
Published: March 2022

Currently, there is growing interest in wearable and biocompatible smart computing and information processing systems that are safe for the human body. Memristive devices are promising for solving such problems due to a number of their attractive properties, such as low power consumption, scalability, and the multilevel nature of resistive switching (plasticity). The multilevel plasticity allows memristors to emulate synapses in hardware neuromorphic computing systems (NCSs). The aim of this work was to study Cu/poly-p-xylylene(PPX)/Au memristive elements fabricated in the crossbar geometry. In developing the technology for manufacturing such samples, we took into account their characteristics, in particular stable and multilevel resistive switching (at least 10 different states) and low operating voltage (<2 V), suitable for NCSs. Experiments on cycle to cycle (C2C) switching of a single memristor and device to device (D2D) switching of several memristors have shown high reproducibility of resistive switching (RS) voltages. Based on the obtained memristors, a formal hardware neuromorphic network was created that can be trained to classify simple patterns.
1T and 2H heterophase MoS2 for enhanced sensitivity of GaN transistor-based mercury ions sensor
Authors: Sharma Nipun , Nigam Adarsh , Bin Dolmanan Surani , Gupta Ankur , Tripathy Sudhiranjan , Kumar Mahesh
Published: March 2022

We report significantly enhanced sensitivity of AlGaN/GaN-based high electron mobility transistor (HEMT) sensor by the targeted synthesis of IT and 2H coexisting phase MoS2 and applying the gate bias voltage. The HEMT structures on Si (111) substrates were used for the detection of Hg2+ ions. The optimum sensitive regime in terms of V
GS and V
DS of the sensor was investigated by keeping the drain source voltage V
DS constant at 2 V and by only varying the gate bias voltage V
GS from 0 to 3 V. The strongest sensing response obtained from the device was around 0.547 mA ppb−1 at V
GS = 3 V, which is 63.7% higher in comparison to the response achieved at 0 V which shows a sensing response of around 0.334 mA ppb−1. The current response depicts that the fabricated device is very sensitive and selective towards Hg2+ ions. Moreover, the detection limit of our sensor at 3 V was calculated around 6.21 ppt, which attributes to the strong field created between the gate electrode and the HEMT channel due to the presence of 1T metallic phase in synthesized MoS2, indicating that the lower detection limits are achievable in adequate strong fields.
Plasma-assisted combustion with nanosecond discharges. I: Discharge effects characterization in the burnt gases of a lean flame
Authors: Minesi N Q , Blanchard V P , Pannier E , Stancu G D , Laux C O
Published: March 2022

The prediction of a flame response to plasma assistance requires extensive knowledge of discharge-induced plasma kinetics. Detailed studies of nanosecond discharges are common in N2/O2 and fresh combustible mixtures but are still lacking in burnt gases. To fill this gap, we define a reference test case and investigate the effects of nanosecond repetitively pulsed (NRP) discharges placed in the recirculation zone of a lean (Φ = 0.8) CH4-air bluff-body stabilized flame at atmospheric pressure. In this zone, the plasma discharge is created in a mixture of burnt gases. Quantitative optical emission spectroscopy, coupled with measurements of electrical energy deposition, is performed to provide temporally (2 ns) and spatially (0.5 mm) resolved evolutions of the temperatures and concentrations of N2(B), N2(C), N2
+(B), OH(A), NH(A), and CN(B) in the discharge. At steady state, the 10-ns pulses deposit 1.8 mJ at a repetition frequency of 20 kHz. Spatially resolved temperature profiles are measured during the discharge along the interelectrode gap. The temperature variations are more pronounced near the electrodes than in the middle of the gap. On average, the gas temperature increases by approximately 550 K. The heat release corresponds to about 20% of the total deposited electric energy. The electron number density, measured by Stark broadening of H

α
, increases up to about 1016cm−3. These characteristics allow to classify the discharge as a non-equilibrium NRP spark, as opposed to the thermal NRP spark where the temperature can reach 40 000 K and the degree of ionization is close to 100%. These measurements will serve (i) as a reference for future studies in the mini-PAC burner at the same conditions, (ii) to test discharge kinetic models, and (iii) to derive a simplified model of plasma-assisted combustion, which will be presented in companion paper.
High optical gain in InP-based quantum-dot material monolithically grown on silicon emitting at telecom wavelengths
Authors: Balasubramanian Ramasubramanian , Sichkovskyi Vitalii , Corley-Wiciak Cedric , Schnabel Florian , Popilevsky Larisa , Atiya Galit , Khanonkin Igor , Willinger Amnon J , Eyal Ori , Eisenstein Gadi , Reithmaier Johann Peter
Published: March 2022

We describe the fabrication process and properties of an InP based quantum dot (QD) laser structure grown on a 5° off-cut silicon substrate. Several layers of QD-based dislocation filters embedded in GaAs and InP were used to minimize the defect density in the QD active region which comprised eight emitting dot layers. The structure was analyzed using high resolution transmission electron microscopy, atomic force microscopy and photoluminescence. The epitaxial stack was used to fabricate optical amplifiers which exhibit electroluminescence spectra that are typical of conventional InAs QD amplifiers grown on InP substrates. The amplifiers avail up to 20 dB of optical gain, which is equivalent to a modal gain of 46 cm−1.
Ultraviolet (UV) irradiated induced changes in optical properties of PVA/Ag nanocomposite films
Authors: Nain Aditi , Dahiya Sanjay , Chahal Rishi Pal , Dhanda Ekta
Published: March 2022

PVA/Ag nanocomposite with different concentrations of silver nanoparticles (Ag NPs) was successfully synthesized by the solution casting method. The effect of concentration of Ag NPs and ultraviolet (UV) irradiation on optical and structural properties of PVA/Ag nanocomposites were investigated by UV-Vis spectrophotometer and Fourier transform infrared spectroscopy. The presence of an absorption peak at around 410 nm recorded by UV-Vis spectrophotometer shows silver nanoparticles are formed. The absorption spectra for prepared nanocomposites recorded over the wavelength range of 200–700 nm shows the intensity of absorption band increases with an increase in the concentration of Ag NPs and with the increase in time of ultraviolet (UV) irradiation. Decreases in the broadness of transmission band with an increment in enfeeblement transmission intensity by UV exposure make its use suitable as a bandpass filter. Decrease in the value of the optical band gap from 4.91 eV for pure PVA to 4.32 eV for PVA doped 0.04M Ag was observed which continuously reduces further with an increase in the concentration of Ag NPs (3.67 eV for PVA doped 0.08M Ag). Additionally, as the time for UV exposure increases the value of the optical band gap decreases from 4.32 eV without UV exposure to 3.81 eV and 3.43 eV for UV exposure of 120 min and 240 min respectively for PVA doped 0.04M Ag. This reduction in values of the optical band gap corresponds to the formation of charge formation complexes inside the PVA matrix. Various optical parameters such as refractive index, single oscillator energy, lattice dielectric constant, the strength of interband optical transition, average oscillator strength, etc are calculated for nanocomposite with different concentrations of Ag NPs before and after UV exposure for different times. The refractive index values were observed to increase from 1.69 for pure PVA to 1.85 without UV exposure, which further increases to 2.30 for UV exposure of 240 min for PVA doped 0.08M Ag. FTIR spectra show the interaction between PVA and Ag NPs and show changes caused in the structure of nanocomposite as the time of UV exposure increases.
Limiting energy density and gravity in Riemann-Cartan space-time
Authors: Minkevich A.V.
Published: March 2022

The gravitational interaction is discussed within the framework of gauge gravitational theory
in the Riemann-Cartan space-time. In the case of spatially homogeneous isotopic gravitating
systems the gravitational repulsion at extreme conditions near limiting energy density and the
transition from gravitational repulsion to attraction in dependence on energy density is
studied. The conversion to Friedman regime and the transition to gravitational repulsion at
very small energy densities is analyzed.
Multiple-pole solutions and degeneration of breather solutions to the focusing nonlinear Schrödinger equation
Authors: Zhang Zhao , Chen Junchao , Guo Qi
Published: March 2022

Based on the Hirota’s method, the multiple-pole solutions of the focusing Schrödinger equation are derived directly by introducing some new ingenious limit methods. We have carefully investigated these multi-pole solutions from three perspectives: rigorous mathematical expressions, vivid images, and asymptotic behavior. Moreover, there are two kinds of interactions between multiple-pole solutions: when two multiple-pole solutions have different velocities, they will collide for a short time; when two multiple-pole solutions have very close velocities, a long time coupling will occur. The last important point is that this method of obtaining multiple-pole solutions can also be used to derive the degeneration of N-breather solutions. The method mentioned in this paper can be extended to the derivative Schrödinger equation, Sine-Gorden equation, mKdV equation and so on.
Triggering spin reversal in nanomolecules and nanoclusters on demand
Authors: Yukalov V I , Yukalova E P
Published: March 2022

Spin reversal in magnetic nanomolecules and nanoclusters is considered. A method is suggested allowing us to maintain magnetic polarization in a metastable state for a long time and, also allows us to start the reversal process at any required time. This method can find applications for the operation of storage memory devices and for the regulation of processes in spintronics.
New γ-soft rotation in the interacting boson model with SU(3) higher-order interactions *
Authors: Wang Tao
Published: March 2022

The interacting boson model with

higher-order interactions offers a new route to enhance our understanding on γ-soft rotation. In this paper,

-like and

-like new γ-softness are observed, in which the corresponding energy levels in the ground and quasi-γ bands can be exactly degenerate and have a partial

dynamical symmetry. The spherical-like γ-softness is not related to the classical

dynamical symmetry. The transitional behaviors of

values of the low-lying levels and quadrupole moment of the

state are also discussed. Spherical-like γ-softness can be used to explain the low-lying spectra and

values in 110Cd normal states.
The research of combustion of solid fuel mixture based on low degree coals of metamorphism of the Kansko-Achinsky coal basin
Authors: Zhuikov A V , Zemlyanskiy N A , Chicherin S V , Junussova L R , Yelemanova A A , Grishina I I
Published: March 2022

The paper presents thermal analysis of combustion of Borodinsky brown coal with combustion heat of 16.34 MJ kg-1 and Balakhtinsky brown coal with combustion heat of 20.49 MJ kg-1 and their mixture in the mass proportion of 50/50%. Using the method of extrapolation of curves, the ignition and ignition temperatures of the coke residue were determined. The ignition temperature of Borodinsky coal was 332°C, the combustion temperature was 656°C. The ignition temperature of Balakhta coal was 358°C, the burnout temperature was 672°C. When adding 50% of Balakhta coal to 50% of Borodinsky coal the ignition temperature of the mixture decreased, the burnout temperature did not change, the fuel combustion index calculated in the work decreased and the heat of coal mixture combustion increased.
Numerical study of rotational dynamics of carbon nanotori during intermolecular interaction
Authors: Lun-Fu A V , Bubenchikov A M , Ovchinnikov V A
Published: March 2022

The group dynamics of the motion of a toroidal carbon molecules is investigated using the approaches of classical mechanics. The model of pair interaction of non-polar particles is used to describe the motion of molecules. The ability of group of nanotori to perform coordinated and directed movements caused by the van der Waals forces is analyzed. The influence of the speed of rotation of molecules on the emergence and suppression of group movement is studied.
Studying the possibility of using fullerenes inside carbon nanotubes as a molecular engine
Authors: Bubenchikov M , Bubenchikov A , Mamontov D , Ovchinnikov V
Published: March 2022

A simple model of a molecular engine is proposed, which consists of a fullerene dimer with a charge and a carbon nanotube. Calculations of molecular dynamics have been carried out, which help to estimate the efficiency of fullerene dimers as a molecular rotor. A dimer placed inside a carbon nanotube will move along the axis of the nanotube, but at the same time it needs to be given a lot of energy in order for it to leave it. The ability of molecules to move along a container is studied mechanically.
Study of the influence of the dzhanibekov effect on the dynamic state of fullerene C100
Authors: Bubenchikov M , Mamontov D , Azheev A , Azheev S
Published: March 2022

The most unsymmetrical fullerene from the class of C100 isomers was preselected. For such a fullerene, the moments of inertia with respect to the principal axes for its center of mass differ in the most significant way. This made it possible to highlight the intermediate axis of inertia. Molecular dynamics calculations of the fullerene isomer C100 (CS) have been performed under various initial conditions. By analyzing the angles and rates of rotation of the isomer, the contribution of the effect of the intermediate axis theorem to the dynamics of fullerene at room temperature is investigated.
Evaporation of a sessile droplet pinned by a groove on a heated substrate
Authors: Kunts K A , Kochkin D Y , Kabov O A
Published: March 2022

The process of evaporation of sessile water droplets on a heated substrate was experimentally studied. A droplet evaporation is a fundamental phase change process which requires thorough consideration in various conditions. In this work we investigated the evaporation of water droplets on the smooth copper substrate with a circle groove made on its surface, which helped to keep the sessile droplet stable. Thus, the contact area of the evaporating droplet with the substrate remained constant, while the contact angle varied over a wide range. The experiment was conducted with a help of Krüss DSA100.
Flow boiling of HFE-7100 in a minichannel with local heating
Authors: Belosludtsev V V , Zaitsev D V , Kabov O A
Published: March 2022

Flow boiling of dielectric fluids for cooling of modern electronics is appealing due to low saturation temperatures of such fluids. In the current paper the flow boiling experiments of HFE-7100 dielectric fluid were performed in a locally heated minichannel with height of 1.5 mm and were compared to flow boiling of pure water. A significant decrease in heat transfer performance and critical heat flux is observed for HFE-7100 compared to pure water.
Investigation of the gas-liquid flow hydrodynamics in minichannels of solar collectors under isothermal conditions
Authors: Chinnov E A , Ronshin F V
Published: March 2022

In the paper the new experimental data are presented to study the gas-liquid flow in minichannels with a thickness of 1 mm and 1.2 mm in isothermal conditions. The design (fluid input conditions) and the width of the channels were changed. The boundaries between the patterns of the gas-liquid flow were determined. Gas-liquid flow regimes maps were created. The patterns of a gas-liquid flow and transition between flow patterns were analyzed in detail. It made possible to find out the features of the gas-liquid flow in the solar collectors minichannels.
Modeling of heat transfer during the desublimation of substances into refrigerated containers
Authors: Gubanov S M , Moiseeva K M
Published: March 2022

This paper presents the results of the theoretical and computational analysis of the thermal processes during the desublimation of uranium hexafluoride and hydrogen fluoride in refrigerated containers. The technological scheme of the hydrogen fluoride desublimation in the containers refrigerated by the cold air is presented. We have substantiated the desublimation method of the uranium hexafluoride residues and hydrogen fluoride from the process stream into one container. The paper also provides the estimation of the maximum container loading, when the pressure of the saturated vapors above the surface of the desublimated mixture reaches the limiting value.
Studies of Dynamic Processes and Simulation Results in the Exchange of Energy in Energy Components
Authors: Kibartene Yulia , Kibartas Victor , Melnikov Viktor , Zigangirova Yelena
Published: March 2022

The paper presents some results of numerical simulation of processes for the problem of stabilization of thermal regimes at dynamic exchange of thermal energy in the energy components of generation, cogeneration, trigeneration (polygeneration with H2C), described by aperiodic links with delay and perturbations. The results of the research are presented in relative values for the comparison of the open-loop heat exchange system with perturbations and for the control options by deviation of the output coordinate, as well as by perturbation and by their combination. In particular, in the form of graphical dependences of the output temperature, dynamic perturbation and control action for five predetermined variants of parameters of dynamic links with the calculated duration of processes of 200 seconds. This makes it possible to study the stabilizing properties of heat exchange equipment when they are used in similar technologies for coal-fired, gas-fired or other thermal power plants, as well as for industrial process thermal equipment. The simulation tool MatlabSimulink was used.
Analysis of Possibilities for Involvement of H2C Technologies and RE-Components in Heat Generation Industrial Systems
Authors: Kibartene Yulia , Kibartas Victor , Melnikov Viktor , Zigangirova Yelena
Published: March 2022

The experience of technologically developed countries in solving the problems of improving the operational efficiency and environmental sustainability of coal-fired power generation of the Republic of Kazakhstan by involving H2C-technology and RE-components is summarized. It is shown that the successful example of technologically developed countries allows to use them as a transfer for energy systems of industrial heat generation in Kazakhstan.
Experimental determination of the air exchange system influence on the thermal conditions of a local working area heated by a gas infrared heater
Authors: Borisov B V , Maksimov V I , Nagornova T A , Vyatkin A V
Published: March 2022

The paper describes the results of experimental studies to determine thermal conditions of the local working area under natural and mixed convection states during the operation of a gas infrared heater (GIH). A horizontal panel and a mock-up with a uniform imitating a table and a worker were located in the area of GIH influence. The values of temperatures and heat flux density of the panel surfaces and air around the worker model were obtained during the GIH operation under natural and mixed convection states. It was established that the presence of the forced component of convection practically does not change the thermal conditions of the local working area.
Investigation of the Operating Parameters of Rectifier Devices Using Modern Software Tools
Authors: Zh Sarinova A , Drobinsky A V , Kirichenko L N
Published: March 2022

Rectifier devices that convert alternating voltage into constant voltage are widely used in the energy industry. Laboratory studies allow us to obtain results showing the nature of the time dependencies of the operating parameters of rectifier devices. In this regard, the use of software tools allows for a more accurate, less time-consuming construction of time diagrams of the operating parameters of rectifier devices.
Fragmented tipping in a spatially heterogeneous world
Authors: Bastiaansen Robbin , Dijkstra Henk A , von der Heydt Anna S
Published: March 2022

Many climate subsystems are thought to be susceptible to tipping—and some might be close to a tipping point. The general belief and intuition, based on simple conceptual models of tipping elements, is that tipping leads to reorganization of the full (sub)system. Here, we explore tipping in conceptual, but spatially extended and spatially heterogenous models. These are extensions of conceptual models taken from all sorts of climate system components on multiple spatial scales. By analysis of the bifurcation structure of such systems, special stable equilibrium states are revealed: coexistence states with part of the spatial domain in one state, and part in another, with a spatial interface between these regions. These coexistence states critically depend on the size and the spatial heterogeneity of the (sub)system. In particular, in these systems the crossing of a tipping point not necessarily leads to a full reorganization of the system. Instead, it might lead to a reorganization of only part of the spatial domain, limiting the impact of these events on the system’s functioning.
Long-term trends of direct nitrous oxide emission from fuel combustion in South Asia
Authors: Bansal Sangeeta , Raghuram Nandula , Adhya Tapan Kumar , Rahman Md Mizanur , Tshering Dendup , Dahal Khem Raj , Wakeel Abdul , Aminath Shazly , Safi Zikrullah , Nissanka Sarath , Pathak Himanshu , Aziz Tariq , Naher Umme Aminum , Dandeniya Warshi , Biswas Jatish Chandra , Taneja Jitender , Panda Ananta Narayan , Kaushik Himadri , Jain Niveta , Skiba Ute , Ramachandran Ramesh , Sutton Mark A
Published: March 2022

An increasing concentration of nitrous oxide (N2O) in the global atmosphere can perturb the ecological balance, affecting the climate and human life. South Asia, one of the world’s most populous regions, is a hotspot for N2O emission. Although agriculture traditionally dominated the region, economic activities are rapidly shifting towards industry and energy services. These activites may become the largest emitters of N2O in future. Yet, few attempts have been made to estimate long-term direct N2O emission from fuel combustion for the different energy-consuming sectors in the South Asian region. Therefore, the present study developed a comprehensive sectoral N2O emission inventory for South Asian countries for the time period of 1990–2017, with projections till 2041. It revealed that the average N2O emission from fuel combustion in the South Asia region is about 40.96 Gg yr−1 with a possible uncertainty of ±12 Gg yr−1, showing an increase of more than 100% from 1990 to 2017. Although India is the major contributor, with an average of 34 Gg yr−1 of N2O emissions, in terms of growth, small countries like Bhutan and Maldives are dominating other South Asian countries. Sector-wise, the residential sector contributed a maximum emission of 14.52 Gg yr−1 of N2O but this is projected to reduce by more than 50% by 2041. This is because of the successful promotion of cleaner fuels like liquefied petroleum gas over more polluting fuelwood. Power generation contributed 9.43 Gg yr−1of N2O emissions, exhibiting a maximum growth of 395%, followed by road transport (289%) and industry (231%). Future N2O emissions from transport, power and industry are projected to rise by 2.8, 3.3, and 23.9 times their 2017 estimates, respectively, due to the incapability of current policies to combat rising fossil fuel consumption. Mitigation options, such as replacing diesel and compressed natural gas vehicles with electricity-driven vehicles, can decelerate N2O emissions to 45% by 2041 for road transport. A 41% reduction is possible by displacing coal with renewables in the power and industry sectors. Overall, the South Asian contribution to global N2O emissions has enlarged from 2.7% in 1990 to 5.7% in 2007–2016, meaning there is an urgent need for N2O emission mitigation in the region.
A study of integrable form factors in massless relativistic AdS
3
Authors: Torrielli Alessandro
Published: March 2022

We show that the massless integrable sector of the AdS
3 × S
3 × T
4 superstring theory, which admits a non-trivial relativistic limit, provides a setting where it is possible to determine exact minimal solutions to the form factor axioms, in integral form, based on analyticity considerations, along the same lines of ordinary relativistic integrable models. We construct in full detail the formulas for the two- and three-particle case, and show the similarities as well as the differences with respect to the off-shell Bethe ansatz procedure of Babujian et al. We show that our expressions pass a series of non-trivial consistency checks which are substantially more involved than in the traditional case. We speculate on the problems concerned in a possible generalisation to an arbitrary number of particles, and on a possible connection with the hexagon programme.
Hypothetically Inspired Electro-Optic Chromophores for Laser Space Communication Applications
Authors: Dashaputre Tanmay , Sheeba Sherlin Y. , Vijayakumar T.
Published: March 2022

This paper describes the theoretically engineered electro optic chromophore (bromine based) and various characteristics of the chromophore. The simulation of halogen based (chlorine and bromine) electro optic chromophore is done. This chromophore can be especially used in the prospective applications due to its exceptional properties and conclusion drawn from the theoretically engineered electro optic chromophore. The halogens because of their electronic configuration tend to attain the stability with the other compound due to inductive effect. The halogen based chromophore enables the stable charge transfer due to change in the internal energy level The factors responsible for the enhancement of hyperpolarizability of the simulated chromophores which can lead to further advancement in the laser space communications applications are discussed.
Hydration of amino acids: An investigation using density functional theory
Authors: Sarath Kumar C. B. , Mayank  , Reji Rence P. , Gobinath M. , Sivalingam Y. , Surya V. J.
Published: March 2022

Herein, we have investigated the effect of hydration of seven amino acids (AAs) such as alanine, aspartic acid,cysteine, glutamine, lysine, methionine, and phenylalanine with different number of water molecules using density functional theory. Among the hydrophobic AAs, cysteine has the highest interaction with water whereas in hydrophilic AAs, aspartic acid has the highest interaction with water. With the increase in number of water molecules, it is noted that alanine forms the most stable complex with water and methionine+water complex has least stability.In addition, we have calculated the chemical descriptors like chemical potential, electronegativity, hardness, softness, electrophilicity index of AAs to validate their interaction with water molecules. Interestingly, the gas phase interaction energy results match with the trend of electrophilicity index valuesof AAs.
Magnetic Properties of Ultrathin As-deposited and Annealed Ta/CoFeB/TaOx Heterostructures
Authors: dey Jaydeb , Ranjan Das Soumya , Sinha Jaivardhan
Published: March 2022

In order to meet the ever-increasing demand of magnetic recording industry, it is important to developferromagnetic thin film heterostructure compatible for magnetic memory device. Here, we have developed ultrathin ferromagnetic film of transition metal borides(CoFeB) which has huge potential to be integrated in magnetic memory devices. In particular, we have studied the surface roughness and magnetic properties of sputter deposited Substrate/1 nm Ta/1.5 nm CoFeB/1nm TaOx heterostructures. Magnetic properties investigation of as-deposited and 300 ⁰C annealed Ta/CoFeB/TaOx heterostructure using vibrating sample magnetometer indicates the presence of in-plane anisotropy in both the film stacks and a reasonable increase in the saturation magnetization of annealed film stack. Importantly, possible boron diffusion as well as partial crystallization of CoFeB layer due to annealing play crucial roles in governing the magnetic properties in these film stacks. These results provide in-depth insight into the factors affecting saturation magnetization of such ultrathin film heterostructures.
Mechanical and Morphological study of Copper slag admixtured cement mortar under different curing media
Authors: Gopalakrishnan R. , Akash M. , Subashini S.
Published: March 2022

The hydration of ordinary Portland cement was measured on the respect of the setting time, compressive strength and morphology measurements in the presence of 0%, 10%, 20% and 30 wt% copper slag. These samples were cured in distilled water, seawater and groundwater. The results show that the replacement rates of copper slag (0%, 10%, 20% and 30 wt.%) raises the compressive strength and brings down the setting time. Both these findings suggest that at an early stage, seawater accelerates cement hydration but slows the later stage of hydration.
Solution based process of ZnO nanostructured thin films: A review
Authors: Sourav M , Leena B , Bakiyaraj G
Published: March 2022

The solution-based technique is recently gaining momentum for the fabrication of optoelectronic materials due to its cost-effectiveness, fabrication of large-scale thin films, processing at low temperature, low cost and simplicity of the process requirements. The properties of thin films depend on the diverse parameters like substrate, deposition time, source materials, doping agent, pH and temperature at which the process is done. ZnO nanostructured thin film has been widely used in organic and hybrid solar cells due to its precise characters such as reduced cost, simple processing, non-toxicity, better optoelectronic properties and good stability. In this review article, we have focused on different solution-based methods which are capable of yielding good quality thin films of ZnO with different morphology for various applications.
Synthesis and Structural studies of lightweight CNT/Cu composites: An overview
Authors: Dhall Shivani , Pushkarn Srijin , Kharangarh Poonam
Published: March 2022

An overview on structural and electrical properties of carbon nanotubes (CNTs) and Copper (Cu) based composite is presented keeping in mind their applications today and in the near future. CNTs are emerging as the most promising conducting wires in interconnection technology due to their higher electrical conductivity and extraordinary current-carrying capacity. In this work, we have found that, metal sputtering technique proved useful for the deposition of Cu nanoparticles on the surface of nanotubes. The structural and morphological studies of Cu deposited nanotubes were investigated by Raman spectroscopy and scanning electron microscopy (SEM). It was found that, the presence of prominent Raman bands in Cu deposited nanotubes is clear indication of the nanocompoites formation without destruction of carbon tubular structure. CNTs/Cu composites showed high conductivity and ampacity, making it uniquely suited for applications in microscale electronics and inverters.
An Improved double input dc converter for renewable energy application
Authors: Lavanya A. , Divya Navamani J. , Vijayakumar K.
Published: March 2022

A hybrid renewable energy system with more than one source like solar photovoltaic, wind energy, battery, and fuel cell increase the system’s reliability and flexibility. A suitable power electronic converter is required to integrate these sources and interface with the load simultaneously. Therefore, the paper’s main objective is to recommend a novel double input dc converter for a hybrid renewable energy system. This power electronic converter efficiently integrates the sources and supplies the load demand. The critical waveforms for various modes of operation of the proposed converter are discussed in detail and the output voltage equation is derived. The proposed double input converter has a simple structure and reduced components. The performance comparison with the currently reported converters in the literature is presented, and the double input converter is simulated and analysed using MATLAB/Simulink software. The theoretical analysis is validated through the simulation results of the designed double input dc converter for renewable energy application.
Growth and Gd doping of ZnO nanostructures with enhanced structural, optical properties and photocatalytic applications
Authors: Dash Debasrita , Sahu Dojalisa
Published: March 2022

In this study, pure and Gadolinium doped ZnO (Gd-ZnO) nanoparticles have been synthesized by wet chemical method and the effect of Gadolinium incorporation on the structure and optical activity of ZnO was examined. The average size of the undoped ZnO and Gd-ZnO (0.002 M and 0.003 M) nanoparticles was found to be 48 nm, 44 nm and 42 nm respectively which shows the lattice compression of ZnO after Gd doping. TEM study shows the hexagonal nanocrystallites of Gd-ZnO with size around 45 nm is formed. FTIR study shows the metal-oxygen band below 600 cm−1 and absorbance study gives the information about the narrowing of band gap of ZnO after Gd doping. The photocatalytic degradation efficiency of Gd-ZnO (92 %) has been found to be better as compared to undoped ZnO (89 %) in degrading methyl blue (MB). The photodegradation of MB is found to follow first order kinetics.
Synthesis and characterization studies of polypyrrole/iron tungstate nanocomposites for interfacial water evaporation
Authors: Robert Bellarmin V , Moorthy Arjun , Raja Saravanan M. E.
Published: March 2022

PPy-FeWO4 composites were synthesized by polymerization of pyrrole in presence of varying weight percentage of FeWO4 nanoparticles using FeCl3 as both catalyst and dopant. The synthesized polymer composites were characterized by FTIR, XRD, FESEM-EDAX, TEM and TGA analysis. The XRD and FTIR analysis confirmed showing near pure samples were achieved. The FESEM-EDAX and TEM studies showed the presence of FeWO4 nanoparticles which were well dispersed in the polymer matrix. The thermal degradation studies showed similar stability of polymer matrix in the presence of nanoparticles. Interfacial solar water evaporation devices were fabricated by depositing the polymer composite on floatable PU sponges. The studies revealed that 50-50 wt% PPy-FeWO4 showed maximum solar to vapour conversion up to 86% with an evaporation rate up to 1.2 kg m−2 hr−1.
DLC-1 facilitates germ granule assembly in Caenorhabditis elegans embryo
Authors: Day Nicholas J. , Ellenbecker Mary , Wang Xiaobo , Voronina Ekaterina
Published: March 2022

Interactions between DLC-1/LC8 family protein and several germ granule components suggest a role for DLC-1 in promoting phase separation of non-membrane bound cellular organelles. This function of DLC-1 was genetically validated and was independent of dynein motor or cell polarity.
End-of-life care for older people: the way forward
Authors: Van Den Noortgate Nele Julienne , Van den Block Lieve
Published: March 2022

Even though many older people will live longer in good health, many will also be confronted with frailty, multi-morbidity, cognitive decline, disability and serious illnesses in the last years of their life. The end-of-life trajectories of frail older people have a major impact on the care that needs to be provided. Older people develop different physical, psychological, and/or social needs in varying intensity during the last years of life. Moreover, determining a clear terminal phase of life is difficult in this population. In this commentary, we aim to highlight the importance of an integrated palliative, geriatric and rehabilitative care approach for older people, emphasizing the importance of setting-specific and cross-setting interventions. We stress the importance of person-centred care planning with the older patient and the role of their families, communities and society as a whole. We identify and formulate some of the research gaps that can be addressed in the near future.
The Role of Breastfeeding in Racial and Ethnic Disparities in Sudden Unexpected Infant Death: A Population-Based Study of 13 Million Infants in the United States
Authors: Bartick Melissa , Barr Alexis Woods , Feldman-Winter Lori , Guxens Mònica , Tiemeier Henning
Published: March 2022

Sudden unexpected infant death (SUID) disproportionately affects non-Hispanic Black (NHB) and American Indian/Alaskan Native infants, who have lower rates of breastfeeding than other groups. Using 13,077,880 live-birth certificates and 11,942 linked SUID death certificates from 2015 through 2018, we calculated odds ratios and adjusted risk differences of SUID in infants who were not breastfed across 5 racial/ethnic strata in the United States. We analyzed mediation by not breastfeeding in the race/ethnicity–SUID association. The overall SUID rate was 0.91 per 1,000 live births. NHB and American Indian/Alaskan Native infants had the highest disparity in SUID relative to non-Hispanic White infants. Overall, not breastfeeding was associated with SUID (adjusted odds ratio (aOR), 1.14; 95% confidence interval (CI): 1.10, 1.19), and the adjusted risk difference was 0.12 per 1,000 live births. The aOR of not breastfeeding for SUID was 1.07 (95% CI: 1.00, 1.14) in NHB infants and 1.29 (95% CI: 1.14, 1.46) in Hispanic infants. Breastfeeding minimally explained the higher SUID risk in NHB infants (2.3% mediated) and the lower risk in Hispanic infants (2.1% mediated) relative to non-Hispanic White infants. Competing risks likely explain the lower aOR seen in NHB infants of not breastfeeding on SUID, suggesting that social or structural determinants must be addressed to reduce racial disparities in SUID.