bluuebunny/crossref_metadata_2025 huggingface dataset:
Reasons for Vaccine Rejection in 0 to 2 Years Old Children Registered to Family Health Centers in Konya
Authors: Kucukkendirci Hasan , Kara Fatih , Turgut Gulsum Gulperi
Published: February 2021

Objective According to the 2017 report of the World Health Organization (WHO), ∼1.5 million people die from vaccine preventable diseases. The WHO is working to generate and popularize effective vaccination programs. However, the concept of “vaccine rejection,” which first started in Europe and United States, has started to make an impact in Turkey during the past 10 years. It is therefore seen as a growing danger in future. This study was conducted to determine, detect, and prevent the reasons of vaccine rejection that have increased in recent years.

Methods A cross-sectional study was conducted between June and December at 2015. In all districts of Konya (n = 31), it was aimed to reach all 242 families who rejected vaccination to their 0 to 2 years old babies. Families having more than one child refused to vaccinate all of their children. A questionnaire consisting of 47 questions was prepared by the researchers, using the standard trainings of the Ministry of Health and the literature. A total of 172 families agreed to participate in this study. The questionnaire was applied to the parents using the telephone interview technique. Data were presented as mean ± standard deviation and percentage.

Results About 41.3% (n = 71) of the mothers were high school graduates, 50.6% (n = 87) of their fathers were university graduates. About 82.6% (n = 142) of the participants received examination, treatment and follow-up services from family physicians and family health personnel. About 20.9% (n = 36) of the children were the only children of the family. About 55.8% (n = 96) of the families also refused the vaccination for other children. About 83.7% (n = 144) of the unvaccinated children had infants/children follow-up care. While all participants stated that vaccines had side effects, 31.4% (n = 54) of these believed that vaccines cause autism or paralysis in infants. About 62.2% (n = 107) of their mothers did not receive tetanus vaccine during pregnancy. The highest rate of nonvaccination was with the second dose of hepatitis A vaccine, which 96.5% (n = 166) refused. The most accepted vaccine was the first dose of hepatitis B vaccine, which was refused by 18.0% (n = 31). About 79.7% (n = 137) of the participants did not know the reason for the vaccination and 95.9% (n = 165) thought that the vaccines were not required. All participants received information from the health personnel about the vaccines. While 9.9% (n = 17) of the families thought that vaccines cause infertility, 44.8% (n = 77) did not receive vaccination because the vaccines were produced abroad.

Conclusion A growing number of families refuse to have their babies vaccinated. The production of vaccines abroad is a major cause of insecurity. There are also beliefs that vaccines cause infertility. Vaccine production in Turkey should be accelerated and public education about vaccines should be reviewed. Training provided to families about vaccines should also be reviewed.
Determining the water content of nominally anhydrous minerals at the nanometre scale
Authors: Patabendigedara Sarath , Nowak Derek , Nancarrow Mitchell J. B. , Clark Simon Martin
Published: February 2021

The amount and distribution of water in nominally anhydrous minerals (NAMs) are usually determined by Fourier-transform infrared spectroscopy. This method is limited by the spot size of the beam to the study of samples with dimensions greater than a few micrometers. Here, we demonstrate the potential of using photoinduced force microscopy for the measurement of water in NAMs with samples sizes down to the nanometer scale with a study of water concentration across grain boundaries in forsterite. This development will enable the study of water speciation and diffusion in small-grained rock matrixes and allow a determination of the influence of nanoscale heterogeneity on the incorporation of water to NAMs.
A compact low impedance angular distribution Blumlein-type pulse forming network
Authors: Liu Xiao , Li Song , Peng Wei , Gao Jingming , Yang Hanwu
Published: February 2021

A pulse forming network (PFN) has the advantages of compactness and long pulse achievability, which could meet the requirements of military and industrial applications of pulsed power technology well. In this paper, a compact low impedance Blumlein-type PFN based on ceramic capacitors is investigated numerically and experimentally. Generally, in order to increase the compactness of the PFN, an angular distribution and an axially parallel connected structure with a theoretical peak energy density of up to 5.8 J/L are employed. The dimensions of the PFN are Φ 560 × 345 mm2. A sharpening switch, which can efficiently reduce rise-time of the output pulses, is utilized to improve the performance of the PFN. The compact low impedance Blumlein-type PFN was assembled in our laboratory. The results of low voltage experiments show that the PFN could generate quasi-square pulses with an output power of 50 MW and a peak voltage of approximately 13.2 kV on a matched dummy load. Impedance and output pulse duration of the PFN are 3 Ω and 135 ns, respectively. The results of high voltage experiments show that pulses with a power of about 1 GW and an energy density of about 2.5 J/L were obtained. Experiments show reasonable agreement with numerical analysis.
Application of machine learning in understanding atherosclerosis: Emerging insights
Authors: Munger Eric , Hickey John W. , Dey Amit K. , Jafri Mohsin Saleet , Kinser Jason M. , Mehta Nehal N.
Published: February 2021

Biological processes are incredibly complex—integrating molecular signaling networks involved in multicellular communication and function, thus maintaining homeostasis. Dysfunction of these processes can result in the disruption of homeostasis, leading to the development of several disease processes including atherosclerosis. We have significantly advanced our understanding of bioprocesses in atherosclerosis, and in doing so, we are beginning to appreciate the complexities, intricacies, and heterogeneity atherosclerosi. We are also now better equipped to acquire, store, and process the vast amount of biological data needed to shed light on the biological circuitry involved. Such data can be analyzed within machine learning frameworks to better tease out such complex relationships. Indeed, there has been an increasing number of studies applying machine learning methods for patient risk stratification based on comorbidities, multi-modality image processing, and biomarker discovery pertaining to atherosclerotic plaque formation. Here, we focus on current applications of machine learning to provide insight into atherosclerotic plaque formation and better understand atherosclerotic plaque progression in patients with cardiovascular disease.
Numerical study of the phase behavior of rod-like colloidal particles with attractive tips
Authors: Jack Justin T. , Millett Paul C.
Published: February 2021

Suspensions of anisometric particles are known to self-assemble into various liquid crystal (LC) phases, namely, the nematic, smectic (A or B or both), and in some cases, columnar phases, due to the effects of excluded volume. For some applications, LC phases with higher degrees of order are desired, but due to the fact that these phases generally exist at larger volume fractions, they can be difficult to handle experimentally. Here, we explore the effect of a weak attractive interaction localized at the tips of rod-like particles on the phase behavior of these suspensions. We perform large-scale molecular dynamics simulations of rigid rod-like particles with both monodispersed and polydispersed lengths and a variety of aspect ratios. The rods are composed of rigidly connected beads, and the inter-rod bead interactions are modeled with a combination of Weeks–Chandler–Anderson and Lennard-Jones potentials. By increasing rod-tip attraction, we observe a favoring of the higher order smectic phase over the lower order nematic phase at lower volume fractions. With sufficiently strong rod-tip attraction, the nematic phase is removed from the phase diagram. Furthermore, we show how polydispersity influences this competition between LC phases.
Topological slow light via coupling chiral edge modes with flatbands
Authors: Yu Letian , Xue Haoran , Zhang Baile
Published: February 2021

Chiral edge modes in photonic topological insulators host great potential to realize slow-light waveguides with topological protection. Increasing the winding of the chiral edge mode around the Brillouin zone can lead to broadband topological slow light with ultra-low group velocity. However, this effect usually requires careful modifications on a relatively large area around the lattice edge. Here, we present a simple and general scheme to achieve broadband topological slow light through coupling the chiral edge modes with flatbands. In this approach, modifications inside the topological lattice are not required. Instead, only several additional resonators that support the flatbands need to be attached at the lattice edge. We demonstrate our idea numerically using a gyromagnetic photonic crystal, which is ready to be tested at microwave frequencies.
Full-dimensional quantum dynamics study of isotope effects for the H2 + NH2/ND2/NHD and H2/D2/HD + NH2 reactions
Authors: Zhang Xiaoren , Zhang Zhaojun , Gatti Fabien , Zhang Dong H.
Published: February 2021

A full-dimensional quantum dynamical study for the bimolecular reactions of hydrogen molecules with amino radicals for different isotopologues is reported. The nonreactive amino radical is described by two Radau vectors that are very close to the valence bond coordinates. Potential-optimized discrete variable representation basis is used for the vibrational coordinates of the amino radical. Starting from the reaction H2 + NH2, we study the isotope effects for the two reagents separately, i.e., H2 + NH2/ND2/NHD and H2/D2/HD + NH2. The effects of different vibrational mode excitations of the reagents on the reactivities are studied. Physical explanations about the isotope effects are also provided thoroughly including the influence of vibrational energy differences between the different isotopologues and the impact of the tunneling effect.
Effect of heat treatment on internal stress in barium titanate nanocube assemblies and their dielectric property
Authors: Itasaka Hiroki , Mimura Ken-ichi , Yasui Kyuichi , Hamamoto Koichi , Kato Kazumi
Published: February 2021

Heat treatment is a key process to determine the dielectric properties of nanocrystalline barium titanate (BaTiO3) ceramics, which are a prospective candidate to realize further miniaturization of dielectric components in electric devices. Here, we use Raman spectroscopy and scanning microwave impedance microscopy to investigate the dependence of the internal stress and the relative permittivity of BaTiO3 nanocube three-dimensional assemblies on heat treatment temperature. We show that heat treatment in the temperature range from 700 °C to 1000 °C causes internal compressive stress in the nanocube assemblies without grain growth. The internal compressive stress is caused by formation of tight attachments between neighboring BaTiO3 nanocubes and of Ti-rich phases in the nanocube assemblies in the lower and higher temperature ranges, respectively. We also show that the relative permittivity of the nanocube assemblies at 3 GHz shows a positive correlation with the internal compressive stress. The result indicates that the internal compressive stress enhances the relative permittivity of BaTiO3 nanocubes.
Microfluidic sample preparation for respiratory virus detection: A review
Authors: Zenhausern Ryan , Chen Chia-Hung , Yoon Jeong-Yeol
Published: February 2021

Techniques used to prepare clinical samples have been perfected for use in diagnostic testing in a variety of clinical situations, e.g., to extract, concentrate, and purify respiratory virus particles. These techniques offer a high level of purity and concentration of target samples but require significant equipment and highly trained personnel to conduct, which is difficult to achieve in resource-limited environments where rapid testing and diagnostics are crucial for proper handling of respiratory viruses. Microfluidics has popularly been utilized toward rapid virus detection in resource-limited environments, where most devices focused on detection rather than sample preparation. Initial microfluidic prototypes have been hindered by their reliance on several off-chip preprocessing steps and external laboratory equipment. Recently, sample preparation methods have also been incorporated into microfluidics to conduct the virus detection in an all-in-one, automated manner. Extraction, concentration, and purification of viruses have been demonstrated in smaller volumes of samples and reagents, with no need for specialized training or complex machinery. Recent devices show the ability to function independently and efficiently to provide rapid, automated sample preparation as well as the detection of viral samples with high efficiency. In this review, methods of microfluidic sample preparation for the isolation and purification of viral samples are discussed, limitations of current systems are summarized, and potential advances are identified.
Acoustic orbital angular momentum prism for efficient vortex perception
Authors: Jiang Xue , Wang Nengyin , Zhang Chuanxin , Fang Xinsheng , Li Shengquan , Sun Xiaoyu , Li Yong , Ta Dean , Wang Weiqi
Published: February 2021

Acoustic orbital angular momentum (OAM) has emerged as a new multiplexing degree of freedom in acoustic communication and shows application prospect in particle manipulation. The separation and detection of acoustic vortices carrying different OAM are significant in OAM-based signal de-multiplexing. In this work, we theoretically proposed and experimentally demonstrated an OAM prism for efficient and quantitative vortex perception, which converts the spiral vortices into the transmitted plane waves of different refraction angles. The refraction angle is linearly dependent on the topological charge of the vortices, enabling the expedient readout of the information coded in each vortex. The designed OAM prism provides a simple and effective method for vortex perception and on-chip detection in the transmission field.
Electrical and optical characterizations of spin-orbit torque
Authors: Huang Hanshen , Wu Hao , Yu Tian , Pan Quanjun , Dai Bingqian , Razavi Armin , Wong Kin , Cui Baoshan , Chong Su Kong , Wu Di , Wang Kang L.
Published: February 2021

To further reduce the energy consumption in spin–orbit torque devices, it is crucial to precisely quantify the spin–orbit torque (SOT) in different materials and structures. In this work, heavy metal/ferromagnet and heavy metal/ferrimagnet heterostructures are employed as the model systems to compare the electrical and optical methods for the SOT characterization, which are based on the anomalous Hall effect and the magneto-optical Kerr effect, respectively. It is found that both methods yield the consistent SOT strength for the current-driven magnetization switching measurements and the harmonic measurements. Our results suggest that the optical method is a feasible and reliable tool to investigate SOT, which is a powerful way to develop insulator-based magnetic systems in the future.
Structured sequences emerge from random pool when replicated by templated ligation
Authors: Kudella Patrick W. , Tkachenko Alexei V. , Salditt Annalena , Maslov Sergei , Braun Dieter
Published: February 2021

Significance

The structure of life emerged from randomness. This is attributed to selection by molecular Darwinian evolution. This study found that random templated ligation led to the simultaneous elongation and sequence selection of oligomers. Product strands showed highly structured sequence motifs which inhibited self-folding and built self-templating reaction networks. By the reduction of the sequence space, the kinetics of duplex formation increased and led to a faster replication through the ligation process. These findings imply that elementary binding properties of nucleotides can lead to an early selection of sequences even before the onset of Darwinian evolution. This suggests that such a simplification of sequence space could result in faster downstream selection for sequence-based function for the origin of life.
ZMYND8 preferentially binds phosphorylated EZH2 to promote a PRC2-dependent to -independent function switch in hypoxia-inducible factor–activated cancer
Authors: Tang Bo , Sun Rui , Wang Dejie , Sheng Haoyue , Wei Ting , Wang Liguo , Zhang Jun , Ho Thai H. , Yang Lu , Wei Qiang , Huang Haojie
Published: February 2021

Significance

The multiple-domain protein ZMYND8 is well known as a chromatin reader that recognizes methylated, acetylated, and/or mutated histones. Here we report that ZMYND8 is overexpressed in human ccRCC, and that it preferentially binds T487-phosphorylated EZH2. We show that in hypoxia-stimulated or von Hippel–Lindau–deficient cells, ZMYND8 binding of EZH2 is important for maintenance of EZH2 phosphorylation level, inhibition of PRC2 complex formation, and enhanced interaction between EZH2 and FOXM1. Our results reveal a reader function of ZMYND8 in recognizing a phosphorylation “code” on a nonhistone protein. Our findings also identify ZMYND8 binding as a facet of regulation and function of EZH2 phosphorylation in the Polycomb-dependent to -independent switch of EZH2/PRC2 activities.
Northward dispersal of dinosaurs from Gondwana to Greenland at the mid-Norian (215–212 Ma, Late Triassic) dip in atmospheric
p
CO
2
Authors: Kent Dennis V. , Clemmensen Lars B.
Published: February 2021

Significance

Sharply contrasting climate zonations under high atmospheric
p
CO
2
conditions can exert significant obstacles to the dispersal of land vertebrates across a supercontinent. This is argued to be the case in the Triassic for herbivorous sauropodomorph dinosaurs, which were confined to their initial venue in the Southern Hemisphere temperate belt of Pangea for about their first 15 million years. Sauropodomorphs only appear in the fossil record of the Northern Hemisphere temperate belt about 214 million years ago based on a composite magnetostratigraphy of the Fleming Fjord Group in East Greenland. The coincidence in timing within a major dip in atmospheric
p
CO
2
from published paleosol records suggests the dispersal was related to a concomitant attenuation of climate barriers in a greenhouse world.
GFRAL-expressing neurons suppress food intake via aversive pathways
Authors: Sabatini Paul V. , Frikke-Schmidt Henriette , Arthurs Joe , Gordian Desiree , Patel Anita , Rupp Alan C. , Adams Jessica M. , Wang Jine , Beck Jørgensen Sebastian , Olson David P. , Palmiter Richard D. , Myers Martin G. , Seeley Randy J.
Published: February 2021

Significance

Growth and differentiation factor-15 (GDF-15) acts through its receptor, GFRAL, expressed within the area postrema to reduce food intake and body weight. However, we do not yet understand GFRAL neuron transcriptional profile, regulation, the direct downstream target sites of GFRAL neurons, or the necessary cell types required for GDF-15 activity. Herein, we identify the genetic signature of GFRAL neurons and show that these cells are positively regulated by a number of aversive stimuli, project to both the nucleus of the solitary tract and more densely to the parabrachial nucleus, and that CGRP
PBN
neurons are required for the aversive and anorectic effects of GDF-15.
Transiently structured head domains control intermediate filament assembly
Authors: Zhou Xiaoming , Lin Yi , Kato Masato , Mori Eiichiro , Liszczak Glen , Sutherland Lillian , Sysoev Vasiliy O. , Murray Dylan T. , Tycko Robert , McKnight Steven L.
Published: February 2021

Significance

Assembly of intermediate filaments (IFs) is reliant upon amino-terminal head domains. These head domains are of low sequence complexity and are assumed to function in the absence of structural order. Herein, we provide evidence that the head domains of the desmin and neurofilament light (NFL) IF proteins self-associate via the formation of labile but structurally specific cross-β interaction. Disease-causing mutations in the head domains of both proteins cause enhanced cross-β interactions. By assembling desmin and NFL IFs bearing isotopically labeled head domains, we provide evidence of structural order in properly assembled biological filaments. We propose that these observations on IF head domains may be instructive to the function of low complexity domains operative in other aspects of cell biology.
A surprising formula for Sobolev norms
Authors: Brezis Haïm , Van Schaftingen Jean , Yung Po-Lam
Published: February 2021

Significance

The Sobolev spaces, introduced in the 1930s, have become ubiquitous in analysis and applied mathematics. They involveLpnorms of the gradient of a functionu. We present an alternative point of view where derivatives are replaced by appropriate finite differences and the Lebesgue spaceLpis replaced by the slightly larger Marcinkiewicz spaceMp(aka weakLpspace)—a popular tool in harmonic analysis. Surprisingly, these spaces coincide with the standard Sobolev spaces, a fact which sheds additional light onto these classical objects and should have numerous applications. In particular, it rectifies some well-known irregularities occurring in the theory of fractional Sobolev spaces. The proof relies on original calculus inequalities which might be useful in other situations.
Fabrication of a poly(N-vinyl carbazole)/ϵ-Ga2O3 organic–inorganic heterojunction diode for solar-blind sensing applications
Authors: Dai Jie , Li Shan , Liu Zeng , Yan Zuyong , Zhi Yusong , Wu Zhenping , Li Peigang , Tang Weihua
Published: February 2021

Herein, a poly(N-vinyl carbazole) (PVK)/ϵ-gallium oxide (ϵ-Ga2O3) heterojunction device was fabricated by spin coating prepared PVK solution onto a ϵ-Ga2O3 thin film produced by metal-organic chemical vapor deposition. Under 254 nm ultraviolet light, the device shows obvious rectification characteristics of 37 at ±2 V and has a response speed of 0.52 s rise time and 0.11 s decay time at 5 V. Current–voltage measurement confirmed that the prepared device has the potential to become a self-powered photodetector and displays good stability and a fast response speed under various light intensities and different voltages.
Optical properties of lattice-matched GaAsPBi multiple quantum wells grown on GaAs (001)
Authors: Himwas C , Kijamnajsuk S , Yordsri V , Thanachayanont C , Wongpinij T , Euaruksakul C , Panyakeow S , Kanjanachuchai S
Published: February 2021

Quaternary alloy GaAsPBi is a novel III–V compound with attractive optical properties and can in principle be grown lattice-matched to GaAs. However, the practical realization of the alloy by metal-organic vapor phase epitaxy and molecular beam epitaxy (MBE)—the two main growth technologies—is fraught with difficulties. Here, using standard solid-source MBE, GaAsPBi films, and GaAsPBi/GaAs multiple quantum wells (MQW) have been grown lattice-matched to (001) GaAs. The structural integrity of the films/MQW is investigated and confirmed by various in- and ex-situ diffraction and spectroscopic techniques. All GaAsPBi structures—films and MQWs—are luminescent at room temperature. Photoluminescence shows that all the samples exhibit an S-shape temperature dependency, indicating strong localizations. Of most significance to practical applications is the observation that the emission from GaAsPBi MQWs is more efficient than their non-quantum well (QW) counterparts (up to 30× at room temperature). These results confirm the long-known benefits of carrier confinements by QWs, demonstrated here for the first time in the GaAsPBi-based system despite the challenge of the crystal growths.
Non-Hermitian topological phases and exceptional lines in topolectrical circuits
Authors: Rafi-Ul-Islam S M , Siu Zhuo Bin , Jalil Mansoor B A
Published: February 2021

We propose a scheme to realize various non-Hermitian topological phases in a topolectrical (TE) circuit network consisting of resistors, inductors, and capacitors. These phases are characterized by topologically protected exceptional points and lines. The positive and negative resistive couplings R
g in the circuit provide loss and gain factors which break the Hermiticity of the circuit Laplacian. By controlling R
g, the exceptional lines of the circuit can be modulated, e.g. from open curves to closed ellipses in the Brillouin zone. In practice, the topology of the exceptional lines can be detected by the impedance spectra of the circuit. We also considered finite TE systems with open boundary conditions, the admittance spectra of which exhibit highly tunable zero-admittance states demarcated by boundary points (BPs). The phase diagram of the system shows topological phases that are characterized by the number of their BPs. The transition between different phases can be controlled by varying the circuit parameters and tracked via the impedance readout between the terminal nodes. Our TE model offers an accessible and tunable means of realizing different topological phases in a non-Hermitian framework and characterizing them based on their boundary point and exceptional line configurations.
A spectral model for interchange transport in tokamak scrape-off layers
Authors: Peret M. , Fedorczak N. , Tamain P. , Ghendrih Ph. , Vermare L. , Supra Tore , Teams WEST
Published: February 2021

The intermittent convection of plasma filaments, or blobs, is commonly considered to be responsible of the transport across flux surfaces in scrape-off layer (SOL) of fusion devices. Isolated filament models are generally derived from vorticity conservation in order to deduce the speed of these filaments, showing good predictions against experimental measurements on individual filaments, but yet unable to predict the total flux associated to these events. In this work, the isolated filament approach is extended to a model of poloidal spectra for both potential and density fluctuations. An heuristic closure is used to derive analytical descriptions of these spectra are obtained, resulting in predictions for a wide variety of observables from fluctuation levels, correlation lengths and associated fluxes. Results are verified against flux-driven simulations and then validated against a broad set of experimental measurements from circular plasma. Predictions for the SOL width take the form of the engineering scaling law that finds sound agreement with experimental scaling built from multi-machine databases.
Gyrokinetic modelling of light to heavy impurity transport in tokamaks
Authors: Lim K. , Garbet X. , Sarazin Y. , Grandgirard V. , Obrejan K. , Lesur M. , Gravier E.
Published: February 2021

Impurity transport is numerically investigated for different types of impurity, such as helium (He), argon (Ar), and tungsten (W). Both turbulent and neoclassical transports are treated self-consistently using the full-f gyrokinetic software GYSELA. For a light impurity (He), the transport is mainly controlled by turbulence, while neoclassical transport is found to be dominant in the case of a heavy impurity (W). The impact of a poloidal asymmetry of the impurity density is also studied in detail and it is found to be strong in case of a high charge impurity, due to its Boltzmann-type response. Such strong asymmetry might lead to a core accumulation of heavy impurities by reducing the thermal screening factor of neoclassical transport. The two main contributions to neoclassical transport—Pfirsch–Schlüter (PS) flux and banana–plateau (BP) flux—are also studied. Depending on their mass (A) and charge (Z), the magnitudes of each flux are determined accordingly. Tungsten shows a strong PS flux compared to the other impurities, while BP flux is dominant in the case of argon. An analytical model including the effect of poloidal asymmetry is compared with the numerical simulation and a good agreement is found between them.
The Effect of Cooperative Learning Model Type Team Games Tournament (TGT) with Play Wheel Media on Students’ Interest in Biology Education STKIP Pembangunan Indonesia
Authors: Azis P A , Pertiwi N D
Published: February 2021

In the learning process required a learning model that can improve learning outcomes and increase student interest in learning. One of them is the Cooperative Teams Games Tournament (TGT) learning model with a rotating wheel media. This model provides learning assistance and games for the discussion team with the help of students and self-study assistance without the help of the instructor from this process which then arises student interest in learning. The purpose of this study was to study the great learning of the Teams Games Tournament (TGT) Cooperative Learning model with the turning wheel media on the Student Interest in Biology Education in STKIP-PI Makassar. This study uses quantitative data analysis techniques by conducting analysis tests with hypothesis testing using trials. Based on the results of calculating student value data using the t-test and then proceed with the calculation of the percentage of influence with the coefficient of determination then it can be refuted as referred to the Cooperative Teams Games Tournament (TGT) learning model with the rotary wheel media for the benefit of student learning in Biology Education STKIP-PI Makassar is tall. Percentage of magnitude of influence shown by the results of the coefficient of determination is 51.05%. Means the Teams Games Tournament (TGT) Cooperative Learning Model with the rotary wheel media has a positive influence to increase student interest in learning.
Mass sensitivity of Langmuir-Blodgett monolayer film coated surface acoustic wave resonators to volatile organic solvents
Authors: Ivanov G R , Avramov I D , Strijkova V J , Marinov Y G , Vlakhov T E , Bogdanova E , Hadjichristov G B
Published: February 2021

Langmuir-Blodgett (LB) monolayer films deposited from a Dipalmytoyl Phosphatidyl Ethanolamine head labelled with Nitrbenzoxadiazole (DPPE-NBD), have been studied for their ability to be used as sensing layer for chemical gas sensors. DPPE-NBD molecules are known for their similarity to bio membrane molecules. Therefore, it is expected that they can serve as a matrix for immobilization of proteins, enzymes, aptamers, while preserving their function for selective reaction with organic analytes. In this study, LB monolayers of DPPE-NBD were deposited on Rayleigh Surface Acoustic Wave (RSAW) resonant devices working at 411 MHz and simultaneously on ultra-flat Si wafer substrates for Atomic Force Microscopy (AFM) inspection. Depositions were carried out both at a low surface pressure where the liquid-expanded phase dominates, and at a high surface pressure, where the liquid-condensed (solid) phase dominates. AFM topography reveals the liquid and solid phase coexistence as well as the formation of 3D pyramids of 3 to 30 nm height and 50 to 1000 nm in diameter. In a vapour sensing experiment, the RSAW devices were exposed subsequently to vapours of 6 volatile organic compounds (VOCs) and water. The most significant resonant frequency shift of 225 kHz which corresponds to 11.42 ng mass change was observed with chloroform vapours when the substrate with the solid phase LB monolayer was used as a sensing layer. Adsorption and desorption of the vapours was very fast (a few seconds) and completely reversible. The higher-pressure deposited LB film demonstrates higher sensitivity to all gases. Mechanisms of this behaviour are discussed.
Scientific instrument for creation of effective Cooper pair mass spectroscopy
Authors: Mishonov T M , Varonov A M
Published: February 2021

We describe electronic instruments for creation of effective Cooper pair spectroscopy. The suggested spectroscopy requires study of electric field effects on the surface of cleaved superconductors. The electronic instrument reacquires low noise amplifier with 106 amplitude amplification which we have formerly used for study of Johnson-Nyquist and Schottky noises. The nonspecific amplifier is followed by high-Q tunable resonance filter based on schematics of general impedance converter topology which is also and innovative device. The work of the device is based on the Manhattan equation of operational amplifier. After a final nonspecific amplification the total amplification can exceed 109 and in such a way sub-nano-volt signals can be reliably detected. In short the observation of new effects in condensed matter physics leads to creation of new generation of electronic equipment.
Interaction of solitons with a qubit in an anisotropic Heisenberg spin chain with first and second-neighbor interactions
Authors: Varbev S , Boradjiev I , Kamburova R , Chamati H
Published: February 2021

Solitons provide a promising means to control the state of a spin-qubit in quantum information technology. In this paper, we consider the anisotropic interaction between a soliton, propagating in a ferromagnetic Heisenberg spin chain and a spin-

1
2

particle (qubit). The spin chain exhibits an on-site anisotropy and spin-spin nearest-neighbor and next-nearest-neighbor interactions. The Bloch sphere picture is employed to investigate the spin-

1
2

dynamics. We found that increasing the anisotropic and the second neighbor interactions leads to an increase of the deviation of the spin-

1
2

particle from its initial state.
Origin of the magnetic exchange in insulators: Localized vs. delocalized electrons
Authors: Georgiev M , Chamati H
Published: February 2021

The present study focuses on the fundamental physical principles underlying the exchange interactions between two metallic centers in magnetic insulators. Using the variational method in conjunction with the Heisenberg model, we demonstrate that the exchange symmetry is tightly related to the magnetism of the considered system and that the electrons’ distributions affect the corresponding exchange interactions.
Bound Soliton–Defect Spin States in Anisotropic Ferromagnetic Chains
Authors: Kamburova R S , Primatarowa M T
Published: February 2021

The interaction of soliton with an impurity spin in a discrete anisotropic ferromagnetic chain is studied. The defect spin in our model is characterized by modification of the exchange interaction with its neighbors. A perturbed nonlinear Schrödinger (NLS) equation for the spin amplitude is derived on the basis of a semiclassical and a continuum approximation. A specific feature of this type of defect is that it leads to perturbations to all terms of the NLS equation. Localized soliton-defect spin solutions are obtained for the case of dark and bright solitons and their stability is analyzed.
Dilute nitrides heterostructures grown by liquid phase epitaxy for solar cells applications
Authors: Donchev V , Milanova M
Published: February 2021

In this paper, we present a study on liquid phase epitaxy (LPE) grown dilute nitride GaAsSbN layers and p-i-n heterostructures for use in multijunction solar cells. The composition of the layers and chemical bonding of Sb and N in the compounds were determined by energy- dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The electrical properties of the grown samples were characterized by Hall effect measurements. Nominally undoped layers are n-type with Hall carrier concentration of 5 × 1016cm-3. Mg was successfully used as acceptor dopant for obtaining closely compensated layers with electron concentration of 1015 cm-3 as well as p-type layers with high free hole concentrations in the range (5-7) × 1018cm-3. Temperature-dependent photoluminescence spectra at low and high excitation were measured to evaluate the optical quality and identify localized states in the grown layers. Non-contact surface photovoltage method provided information about the absorption characteristics of the GaAsSbN layers. A series of GaAs/GaAsSbN/GaAs heterostructures based on closely compensated i-GaAsSbN have been also grown by LPE. The red limit of the structures determined from surface photovoltage measurements was extended down to 1.2 eV. Single junction p-i-n solar cells with area 0.16 cm2 were performed based on the grown structures. A power conversion efficiency of 4.1 % was measured for the fabricated cells under AM1.5 air global conditions.
Solution deposition of ZnO thin films
Authors: Stankova S , Volobujeva O , Dikov Hr , Ganchev M
Published: February 2021

A solution deposition technique is investigated as an approach for formation of nanostructured ZnO films with tailored geometric shape and aspect ratio, electrical conductivity, and high optical transmittance. Having in mind thermodynamic particulars of ZnO precipitation from aqueous solutions, we show deposition of thin films of intrinsic ZnO with well-defined hexagonal wurtzite structure and with high optical transmittion in the visible region. Deposition of doped layers of Al:ZnO with aluminium concentration up to 3 wt% does not cause degradation of the wurtzite structure and sheet resistance of the films is near 8.0*102 Ω / □. After applying thermal annealing, the absorption edge gets sharper and optical band gap is found to be near 3.26 eV for direct transitions. Addition of the ethanol in the aqueous deposition solution leads to formation of ZnO nanostructured films with trigonal configuration.
Renewable energy resources in the system of sustainable development of Carpathian region of Ukraine
Authors: Arkhypova L M , Mandryk O M , Moskalchuk N M , Prykhodko M M , Radlovska K O
Published: February 2021

The scientific novelty presented in this paper is to substantiate the extension of the resource potential of renewable energy sources in the Carpathian region with the creation of a set of maps in the geographic information system “Map Info”. For each type of renewable energy (solar, wind, small hydropower) a number of technical issues and advantages, technological ecologically safe priorities are defined. The detailed regional calculation of wind, solar, hydropower potential for the Carpathian region of Ukraine has been performed. The spatial limitations and possibilities of introducing renewable energy sources in the sustainable development of the region are scientifically substantiated. Renewable energy scenarios are proposed.
Investigation of the separation of combed heap of winter wheat
Authors: Lezhenkin O M , Halko S V , Miroshnyk O O , Vershkov O O , Lezhenkin I O , Suprun O M , Shchur T G , Kruszelnicka W , Kasner R
Published: February 2021

The article deals with the problem of separation of combed heap of winter wheat with an experimental working unit consisting of a segregator and a sieve. In order to expand the range of information on the qualitative side of the functioning of the working unit, it is suggested to introduce an additional assessment parameter – the impurity separation efficiency coefficient. Experimental studies of the technological process of the working unit were carried out using the mathematical theory of experimental design, where the response function was represented by the functional dependence of the change in the impurity separation efficiency coefficient on the specific feed of the combed heap, the oscillation frequency of the working unit and the diameter of the sieve openings. To conduct the experimental studies, the Box-Behnken design was selected. Verification of the significance of the obtained coefficients according to Student’s t-test showed that all the coefficients were significant. The adequacy of the model was assessed according to Fisher’s test. As a result of the calculations, it was established that the model was adequate and could be used for further research.
The separation assessment of small-seeded mixtures of agricultural crops
Authors: Kovalyshyn S , Ptashnyk V , Shvets O , Ivashchyshyn F , Nester B , Kasner R , Urbańska P
Published: February 2021

The paper confirms that the effective separation of small-seeded mixtures of crops can be achieved if we use electrical separation methods that take into account the difference in electrical conductivity and dielectric constant of the components, their ability to receive and give a charge etc. Having examined electrical conductivity and polarization properties of winter oilseed rape and Galium aparine seeds by the method of impedance spectroscopy, it was found out that the frequency dependence of the real part of their complex resistance is of the same type and has a decreasing character. The maximum capacity of winter oilseed rape is 50 % higher than the corresponding capacity of Galium aparine, and the maximum accumulation of charge by seeds is observed in the frequency band for which the real part of the complex resistance takes close values for both Galium aparine and winter oilseed rape. The revealed difference in electrical conductivity and dielectric constant of the studied seeds of winter oilseed rape and Galium aparine causes different charges, which is one of the main conditions for their effective separation in electric separators, which use an electric field of corona discharge as an additional working body.
A bar model of a temporary wooden support used to remove deflections of buildings
Authors: Gromysz K
Published: February 2021

The deflection of buildings located in mining areas is removed by uneven raising of the overground part of the structure by means of supports consisting of a hydraulic piston jack and a stack of underpinning elements. Temporary supports may also consist of stacks of wooden elements only. The article presents a bar model of a temporary support consisting of a stack of elements. The model, which is described by a differential, second-order equation, allows to determine horizontal displacements. It was demonstrated that the unintended eccentricity and the initial curvature of the element have influence on such displacements. In addition, the effect of the load transmitted by the deformed adjacent supports is important. The model presented can be used to determine the limit load capacity of temporary supports due to unintended horizontal displacements of the structure. The model therefore allows to design safely the removal of building structures’ deflections.
Experimental stand and researches on pantograph-catenary contact force control using chaos theory
Authors: Rusu-Anghel S , Mezinescu S S , Lihaciu I C
Published: February 2021

Due to the oscillating behaviour of the pantograph and the catenary during the movement of the locomotive, the contact force changes to wide limits, resulting in electrical sparks with consequences: premature wear of the contact wire, electromagnetic disturbances, energy loss. Suitable control of the contact force at speeds exceeding 160 km/h may diminish these effects. Due to the particularities of the pantograph-catenary system and many random external factors, existing control methods do not always give the best results. The authors’ research has shown that the contact force signal contains a chaotic component that can be offset by chaos theory methods. Their own studies have demonstrated theoretically and by simulation that this approach can largely eliminate the separating the pantograph from the catenary and will lessen excessive forces. Experimental research, conducted by the authors and presented in this article, has been done in laboratory conditions on a specially built test stand and confirms that this new approach to active pantograph control produces superior results to existing methods.
Comparative study between the melting process of an aluminum batch and a steel batch in a high frequency induction furnace
Authors: Iagăr A , Popa G N , Diniş C M
Published: February 2021

In this work we analyzed a laboratory induction furnace, having a small capacity, fed by a high-frequency static converter. The measurements were carried out in the case of an aluminum batch, and a steel batch, using the power quality analyzer CA8334B. We studied the influence of the type, temperature and amount of processed material, on the electrical parameters of induction furnace during the melting process. Large electromagnetic disturbances (harmonic currents, current unbalances, reactive power consumption) were recorded, especially during the preheating period of crucible and the first stage of heating, when the furnace worked at low power, for the both batches. The experiments allowed the elaboration of some measures for optimization of melting process in the analyzed induction furnace, in terms of efficiency and mitigation of electromagnetic disturbances.
Ozone and anions generator for disinfection of enclosed spaces
Authors: Popa G N , Popa L , Diniş C M
Published: February 2021

After the pandemic of SARS-CoV-2, people’s lives will be different. It seems that in the next period, due to the spread of SARS-CoV-2 virus worldwide, all objects, surfaces and spaces that people come in contact with must be disinfected frequently. At the same time, the atmosphere in closed spaces must be disinfected because the transmission of the virus through the air is made easier. It seems that an effective method of disinfection (viruses, bacteria, etc.) is the use of ozone generators. Ozone in the air over a certain dose affects the human respiratory system.

It is known the role of anions on human health, especially given that the vast majority will spend time indoors. Staying in homes for long periods of time has negative effects on the humans body.

The paper presents and analyze ozone, anions, and the their generators. It is presented a generator that can produce both ozone (measured with an electrochemical sensor) at a certain concentration for limited periods of time, as well as anions in high concentrations that have a beneficial effect on humans health. Air quality is measured (with an electrochemical sensor), and in conditions of low quality, the generator can provide higher concentrations of anions. The ozone and anions generator is controlled with microcontroller development board. The flowchart of the program used in the microcontroller is presented.
Experimental analysis of the influence of clogging on the filtration process for internal combustion engines
Authors: Bucevschi R , Socalici V , Budiul Berghian A , Birtok Băneasă C
Published: February 2021

This article presents the analysis of the laboratory tests results carried out to investigate the effects of the clogging phenomenon developed at internal combustion engine filters. A classical filter module from an aspirated engine was used to carry out the tests, composed of air ducts, filter housing and a standard panel filter element made of paper, mounted on the test stand designed by the authors, for analysis of flow state parameters in dynamic mode.
Modular load-bearing structures for the study of interactions between the soil and working parts of agricultural machines
Authors: Cardei P , Constantin N , Sfîru R , Muraru V , Condruz P
Published: February 2021

The authors outline in this article the principles underlying the conception and design of modular load-bearing structures (MLBS) for the study of the interaction between soil and the agricultural machinery working bodies for the inter-study study of 3D CAD design. It presents the main scientific problems faced by agricultural machines for soil works, main reasons for the conception and realization of this machine or category of machines. It also presents the scientific but also economic reasons for the modulation or modular design of this machine, an operation that has led to several possible working variants, which require power sources for traction of different values. It also presents the multifunctionality acquired through the possibility of using work parts and their supports of different types and mountable on the structure in different formations.