bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Statistically Predicted Rate Constants for Pyrolysis of High-Density Plastic Using R Software
Authors: Nabi Rao Adeel Un , Naz Muhammad Yasin , Shukrullah Shazia , Ghamkhar Madiha , Rehman Najeeb Ur , Irfan Muhammad , Alqarni Ali O. , Legutko Stanisław , Kruszelnicka Izabela , Ginter-Kramarczyk Dobrochna , Ochowiak Marek , Włodarczak Sylwia , Krupińska Andżelika , Matuszak Magdalena
Published: August 2022

The surge in plastic waste production has forced researchers to work on practically feasible recovery processes. Pyrolysis is a promising and intriguing option for the recycling of plastic waste. Developing a model that simulates the pyrolysis of high-density polyethylene (HDPE) as the most common polymer is important in determining the impact of operational parameters on system behavior. The type and amount of primary products of pyrolysis, such as oil, gas, and waxes, can be predicted statistically using a multiple linear regression model (MLRM) in R software. To the best of our knowledge, the statistical estimation of kinetic rate constants for pyrolysis of high-density plastic through MLRM analysis using R software has never been reported in the literature. In this study, the temperature-dependent rate constants were fixed experimentally at 420 °C. The rate constants with differences of 0.02, 0.03, and 0.04 from empirically set values were analyzed for pyrolysis of HDPE using MLRM in R software. The added variable plots, scatter plots, and 3D plots demonstrated a good correlation between the dependent and predictor variables. The possible changes in the final products were also analyzed by applying a second-order differential equation solver (SODES) in MATLAB version R2020a. The outcomes of experimentally fixed-rate constants revealed an oil yield of 73% to 74%. The oil yield increased to 78% with a difference of 0.03 from the experimentally fixed rate constants, but light wax, heavy wax, and carbon black decreased. The increased oil and gas yield with reduced byproducts verifies the high significance of the conducted statistical analysis. The statistically predicted kinetic rate constants can be used to enhance the oil yield at an industrial scale.
Mechanical Behavior of Human Cancellous Bone in Alveolar Bone under Uniaxial Compression and Creep Tests
Authors: Wu Bin , Wu Yang , Liu Mao , Liu Jingjing , Jiang Di , Ma Songyun , Yan Bin , Lu Yi
Published: August 2022

In the process of orthodontic treatment, the remodeling of cancellous bone in alveolar bone (in this paper, cancellous bone in alveolar bone is abbreviated as CBAB) is key to promoting tooth movement. Studying the mechanical behavior of CBAB is helpful to predict the displacement of teeth and achieve the best effect of orthodontic treatment. Three CBAB samples were cut from alveolar bone around the root apex of human teeth. A uniaxial compression test was used to study the transient elastic properties of CBAB. A creep test was used to study the time-dependent viscoelastic properties of CBAB. Both tests were carried out at the loading rates of 0.02 mm/min, 0.1 mm/min and 0.5 mm/min. The results revealed that CBAB is a nonlinear viscoelastic and hyperelastic material. The stress–strain curve obtained from the uniaxial compression test could be divided into three stages: the collapse stage of the front section, the exponential stage of the middle section and the almost linear stage of the rear end. According to the strain–time curve obtained from the compression creep test, a trend of increasing strain over time was relatively obvious within the first 30 s. After 200 s, the curve gradually tended to plateau. Four hyperelastic models and three viscoelastic models were used to fit the test data. Finally, the fifth-order polynomial hyperelastic model (coefficient of determination “R2 > 0.999”) was used to describe the hyperelastic properties of CBAB, and the seven-parameter model of the generalized Kelvin modified model (“R2 > 0.98”) was used to describe the viscoelastic properties of CBAB.
Hilbert-Coding Metasurface for Diverse Electromagnetic Controls
Authors: Hao Jianjiao , Ye Fuju , Ruan Ying , Chen Lei , Cui Haoyang
Published: August 2022

Metamaterials, or metasurfaces, allow the flexible and efficient manipulation of electromagnetic (EM) wave. Although the passive coding metasurfaces have achieved a great deal of functionality, they also need a complex design process. In this paper, we propose Hilbert-coding metasurfaces for flexible and convenient EM regulation by arranging Hilbert-coding metamaterial units of different orders. To demonstrate this behavior, we designed 12 metasurfaces, then fabricated and measured 6 samples. Validation results on 6 Hilbert-coding metasurfaces show the deflection angles of the four single beam patterns obtained are about 21°, 13°, 12°, and 39°, with energy values of 7.75 dB, 7.3 dB, 7.2 dB, and 7.7 dB, respectively, and the deflection angles of the dual-beam patterns are 28.5° and 20° with energy values of 10.05 dB and 11.4 dB, respectively. The results are quite consistent with the simulation data, further confirming the feasibility of our idea. In addition, there are potential applications in Wireless Communications and Radar-imaging, like EM beam scanning and EM field energy distribution control in communication and imaging scenarios.
Probabilistic Aspects of Modeling and Analysis of Grinding Wheel Wear
Authors: Kacalak Wojciech , Lipiński Dariusz , Szafraniec Filip , Banaszek Kamil , Rypina Łukasz
Published: August 2022

In this article, the methodology of using probabilistic models of the grinding tool wear process is presented. Probabilistic modeling with empirical data allowed determining the values of other important process features. Among them, the distribution of active grains lifetime or distribution of cumulative attritious wear of the grinding grain apex could be distinguished. The results of modeling and wear analysis of grinding wheels as well as experimental results on peripheral grinding with zoned grinding wheels are presented. The analyzed grinding wheels consisted of three layers: two identical external layers with conventional structure and one internal layer containing the addition of abrasive aggregates. The external layers were profiled by chamfering the edges. As a result, their nominal surfaces were conical. The internal layer had a cylindrical shape and was designed for smoothing the surface after machining with external part. The tools were designed to increase the grinding efficiency and hence a good quality of machined surfaces could be acquired. For the experimental tests, the Ti6Al4V titanium alloy was used. It was found that the change in the shape and position of the grinding zone, as a result of volumetric wheel wear, caused a significant change in fracturing intensity. In the case of multilayer grinding tools, the wear process depends on the physical properties of each layer and their participation during machining of the workpiece. The presented methodology could be applied to a study on the machining process stages, which concerns temporary states and their variability according to the machining time.This makes it possible to reduce the cost of developing new tools dedicated to specific applications.
Excitation of Asymmetric Resonance with Symmetric Split-Ring Resonator
Authors: Al-Naib Ibraheem , Ateeq Ijlal Shahrukh
Published: August 2022

In this paper, a new approach to excite sharp asymmetric resonances using a single completely symmetric split-ring resonator (SRR) inside a rectangular waveguide is proposed. The method is based on an asymmetry in the excitation of a symmetric split-ring resonator by placing it away from the center of the waveguide along its horizontal axis. In turn, a prominent asymmetric resonance was observed in the transmission amplitude of both the simulated results and the measured data. Using a single symmetric SRR with an asymmetric distance of 6 mm from the center of a rectangular waveguide led to the excitation of a sharp resonance with a Q-factor of 314 at 6.9 GHz. More importantly, a parametric study simulating different overlayer analytes with various refractive indices revealed a wavelength sensitivity of 579,710 nm/RIU for 150 μm analyte thickness.
Role of Metallic Adlayer in Limiting Ge Incorporation into GaN
Authors: Turski Henryk , Wolny Pawel , Chlipala Mikolaj , Sawicka Marta , Reszka Anna , Kempisty Pawel , Konczewicz Leszek , Muziol Grzegorz , Siekacz Marcin , Skierbiszewski Czeslaw
Published: August 2022

Atomically thin metal adlayers are used as surfactants in semiconductor crystal growth. The role of the adlayer in the incorporation of dopants in GaN is completely unexplored, probably because n-type doping of GaN with Si is relatively straightforward and can be scaled up with available Si atomic flux in a wide range of dopant concentrations. However, a surprisingly different behavior of the Ge dopant is observed, and the presence of atomically thin gallium or an indium layer dramatically affects Ge incorporation, hindering the fabrication of GaN:Ge structures with abrupt doping profiles. Here, we show an experimental study presenting a striking improvement in sharpness of the Ge doping profile obtained for indium as compared to the gallium surfactant layer during GaN-plasma-assisted molecular beam epitaxy. We show that the atomically thin indium surfactant layer promotes the incorporation of Ge in contrast to the gallium surfactant layer, which promotes segregation of Ge to the surface and Ge crystallite formation. Understanding the role of the surfactant is essential to control GaN doping and to obtain extremely high n-type doped III-nitride layers using Ge, because doping levels >1020 cm−3 are not easily available with Si.
Investigation of Adhesion Performance of Wax Based Warm Mix Asphalt with Molecular Dynamics Simulation
Authors: Peng Chao , Yang Hanneng , You Zhanping , Ma Hongchao , Xu Fang , You Lingyun , Diab Aboelkasim , Lu Li , Hu Yudong , Liu Yafeng , Dai Jing , Li Zhibo
Published: August 2022

Compared with traditional hot mix asphalt (HMA), wax based warm mix asphalt (WWMA) can be mixed with the aggregate at a lower temperature and achieve the desired compaction. However, the adhesion performance of WWMA on aggregate is uncertain. To evaluate the adhesion performance of asphalt and aggregate, researchers used contact angle test, pull-off test, and ultrasonic washing experiments. However, these tests cannot adequately explain the microscopic mechanism of the interface between asphalt and aggregate. Molecular dynamics (MD) can better explain the adhesion mechanism of asphalt aggregates because they can be simulated at the molecular scale. So, the purpose of this research is to use the MD method to study the adhesion performance between WWMA and aggregate. Two aggregate oxides (CaCO3 and SiO2) models, the matrix asphalt model and WWMA models, were built in Materials Studio (MS) software. The adhesion work of asphalt and aggregate oxides was calculated. With the increase of wax modifier content, the adhesion work of asphalt and aggregate oxides (CaCO3 and SiO2) first increases and then decreases. When the wax modifier is increased to 3 wt%, the adhesion works of the WWMA-SiO2 and WWMA-CaCO3 increase by 31.2% and 14.0%, compared with that of matrix asphalt. In this study, the accuracy of the MD calculation result was verified by the pull-off experiments and the contact angle experiments. WWMA was prepared by a high-shear mixer emulsifier. In the pull-off experiments and the contact angle experiments, the tensile strength and the adhesion work between the aggregate and the asphalt containing 3% wax modifier reaches peak values. These values are 140.7% and 124.9%, compared with those between the aggregate and the matrix asphalt. In addition, the results of the pull-off experiments and the contact angle experiments are in good agreement with that of the MD simulation. Finally, Fourier transform infrared spectroscopy (FTIR) shows that the carbonyl content of WWMA is greater than that of matrix asphalt. It explains well that the wax modifier promotes the adhesion between asphalt and aggregate. This paper provides an important theoretical basis to understand the adhesion performance of WWMA and aggregate.
Inverse Estimation of Moisture Diffusion Model for Concrete Using Artificial Neural Network
Authors: Lee Jae Min , Lee Chang Joon
Published: August 2022

In this research, the moisture diffusion model for concrete was inversely estimated using artificial neural network (ANN) and the data collected from virtual experiments. In addition, the moisture distribution was predicted using the ANN model in numerical analysis. For inverse estimation, virtual experimental data were used. The virtual experimental data were generated by adding noise to the moisture distribution obtained by a numerical simulation using a known moisture diffusion model. ANNs of two architectures were used in the inverse estimation. For performance test, the inversely estimated ANN model and the known moisture diffusion model were compared. The predicted humidity distribution using the ANN and virtual experiment data were also compared. The inversely estimated ANN model was in a good agreement with the known moisture diffusion model used for the virtual experiment.
Evaluation of Incipient Enamel Caries at Smooth Tooth Surfaces Using SS-OCT
Authors: Shimada Yasushi , Sato Takaaki , Inoue Go , Nakagawa Hisaichi , Tabata Tomoko , Zhou Yuan , Hiraishi Noriko , Gondo Tadamu , Takano Syunsuke , Ushijima Kei , Iwabuchi Hirotoshi , Tsuji Yukiko , Alireza Sadr , Sumi Yasunori , Tagami Junji
Published: August 2022

(1) Background: Dental caries, if diagnosed at the initial stage, can be arrested and remineralized by a non-operative therapeutic approach preserving tooth structure. Accurate and reproducible diagnostic procedure is required for the successful management of incipient caries. The aim of this study was to evaluate the diagnostic accuracy of 3D swept-source optical coherence tomography (3D SS-OCT) for enamel caries at smooth tooth surface if the lesion was with remineralization. (2) Methods: Forty-seven tooth surfaces of 24 extracted human teeth visibly with/without enamel caries (ICDAS code 0–3) were selected and used in this study. The tooth surfaces of investigation site were cleaned and visually examined by four dentists. After the visual inspection, SS-OCT scanning was performed onto the enamel surfaces to construct a 3D image. The 2D tomographic images of the investigation site were chosen from the 3D dataset and dynamically displayed in video and evaluated by the examiners. A five-rank scale was used to score the level of enamel caries according to the following; 1: Intact enamel. 2: Noncavitated lesion with remineralization. 3: Superficial noncavitated lesion without remineralization. 4: Deep nonvacitated lesion without remineralization. 5: Enamel lesion with cavitation. Sensitivity and specificity for 3D OCT image and visual inspection were calculated. Diagnostic accuracy of each diagnostic method was calculated using weighted kappa. Statistical significance was defined at p = 0.05. (3) Results: 3D SS-OCT could clearly depict enamel caries at smooth tooth surface as a bright zone, based on the increased backscattering signal. It was noted that 3D SS-OCT showed higher sensitivity for the diagnosis of remineralized lesions and deep enamel lesions without cavitation, as well as cavitated enamel lesions (p < 0.05). No significant difference of specificity was observed between the two diagnostic methods (p > 0.05). Furthermore, 3D SS-OCT showed higher diagnostic accuracy than visual inspection (p < 0.05). (4) Conclusions: Within the limitations of this in vitro study, 3D SS-OCT showed higher diagnostic capacity for smooth surface enamel caries than visual inspection and could also discriminate lesion remineralization of enamel caries.
Effect of Marginal Bone Integrity and Aftermarket Abutment Screws on Dental Implant Systems—A Preliminary Study with Finite Element Method
Authors: Wu Yu-Ling , Tsai Ming-Hsu , Chen Hung-Shyong , Lin Ching-Ping , Wu Aaron Yu-Jen
Published: August 2022

Bone resorption around implants is quite common, and the maturity and popularization of computer-aided design and computer-aided manufacturing (CAD/CAM) technology have made the use of aftermarket abutment screws more widespread. This study aimed to explore the biomechanical influence of these two common factors on the internal stress of an implant system using three-dimensional finite element analysis (3D FEA). The FEA results indicated that under the same loading conditions, the use of an aftermarket screw had the greatest impact on the screw itself among the three components of the implant system, while the maximum stress increased by 6.3% and 10.5% in the bone integrity and bone loss models, respectively. Moreover, the marginal bone loss models had the greatest impact on the implant fixture, with a maximum stress increase of 51.8% on average. Evidently, the influence of bone loss might be far greater than that of the aftermarket screw; however, any factor could be enough to cause clinical failure. Therefore, we should pay more attention to the maintenance of the long-term peri-implant marginal bone integrity.
Long-Term Examination of Degradation and In Vivo Biocompatibility of Some Mg-0.5Ca-xY Alloys in Sprague Dawley Rats
Authors: Lupescu Ștefan , Munteanu Corneliu , Sindilar Eusebiu Viorel , Istrate Bogdan , Mihai Iuliana , Oprisan Bogdan , Pasca Aurelian-Sorin
Published: August 2022

The medical field has undergone constant development in recent years, and a segment of this development is occupied by biodegradable alloys. The most common alloys in this field are those based on Mg, their main advantage being the ability to degrade gradually, without affecting the patient, and also their ability to be fully absorbed by the human body. One of their most important conditions is the regeneration and replacement of human tissue. Tissue can be engineered in different ways, one being tissue regeneration in vivo, which can serve as a template. In vivo remodeling aims to restore tissue or organs. The key processes of tissue formation and maturation are: proliferation (sorting and differentiation of cells), proliferation and organization of the extracellular matrix, biodegradation of the scaffold-remodeling, and potential tissue growth. In the present paper, the design of the alloys in the Mg-Ca-Y system is formed from the beginning using high-purity components, Mg-98.5%, master-alloys: Mg-Y (70 wt.%–30 wt.%) and Mg-Ca (85 wt.%–15 wt.%). After 8 weeks of implantation, the degradation of the implanted material is observed, and only small remaining fragments are found. At the site of implantation, no inflammatory reaction is observed, but it is observed that the process of integration and reabsorption, over time, accentuates the prosaic surface of the material. The aim of the work is to test the biocompatibility of magnesium-based alloys on laboratory rats in order to use these alloys in medical applications. The innovative parts of these analyses are the chemical composition of the alloys used and the tests performed on laboratory animals.
Preparation of Porous Silicate Cement Membranes via a One-Step Water-Based Hot–Dry Casting Method
Authors: Sun Zhantong , Wang Xiaojuan , Yuan Haifeng , Sang Shizhong , Xu Huacheng , Huang Yijun , Gao Congjie , Gao Xueli
Published: August 2022

A commercial interest in the improvement in the separation performance and permeability of porous materials is driving efforts to deeply explore new preparation methods. In this study, the porous silicate cement membranes (PSCMs) were successfully prepared through an adjustable combination of hot–dry casting and a cement hydration process. The obtained membrane channel was unidirectional, and the surface layer was dense. The physical characteristics of the PSCMs including their pore morphology, porosity, and compressive strength, were diversified by adjusting the solid content and hot–dry temperature. The results indicated that with the solid content increasing from 40 wt. % to 60 wt. %, the porosity decreased by 8.07%, while the compressive strength improved by 12.46%. As the hot–dry temperature increased from 40 °C to 100 °C, the porosity improved by 23.04% and the BET specific surface area and total pore volume enlarged significantly, while the compressive strength decreased by 27.03%. The pore size distribution of the PSCMs exhibited a layered structure of macropores and mesopores, and the pore size increased with the hot–dry temperature. Overall, the PSCMs, which had typical structures and adjustable physical characteristics, exhibited excellent permeability and separation performance.
Low Leakage Current and High Breakdown Field AlGaN/GaN MIS-HEMTs Using PECVD-SiNx as a Gate Dielectric
Authors: Gao Xiaohui , Guo Hui , Wang Rui , Pan Danfeng , Chen Peng , Chen Dunjun , Lu Hai , Zhang Rong , Zheng Youdou
Published: August 2022

In this paper, SiNx film deposited by plasma-enhanced chemical vapor deposition was employed as a gate dielectric of AlGaN/GaN high electron mobility transistors (HEMTs). We found that the NH3 flow during the deposition of SiNx can significantly affect the performances of metal–insulator–semiconductor (MIS) HEMTs. Compared to that without using NH3 flow, the device with the optimized NH3 flow exhibited three orders of magnitude lower gate leakage current, two orders of magnitude higher ON/OF drain current ratio, and an increased breakdown field by 69%. In addition, an in situ N2 plasma surface treatment prepared prior to SiNx deposition can further improve DC performances of MIS-HEMTs to a very low gate leakage current of 10−9 mA/mm and a high ON/OFF drain current ratio up to 109 by reducing the interface state density. These results demonstrate the great potential for using PECVD-SiNx as a gate dielectric in GaN-based MIS-HEMTs.
Investigation of Nonlinear Piezoelectric Energy Harvester for Low-Frequency and Wideband Applications
Authors: Pertin Osor , Guha Koushik , Jakšić Olga , Jakšić Zoran , Iannacci Jacopo
Published: August 2022

This paper proposes a monostable nonlinear Piezoelectric Energy Harvester (PEH). The harvester is based on an unconventional exsect-tapered fixed-guided spring design, which introduces nonlinearity into the system due to the bending and stretching of the spring. The physical–mathematical model and finite element simulations were performed to analyze the effects of the stretching-induced nonlinearity on the performance of the energy harvester. The proposed exsect-tapered nonlinear PEH shows a bandwidth and power enhancement of 15.38 and 44.4%, respectively, compared to conventional rectangular nonlinear PEHs. It shows a bandwidth and power enhancement of 11.11 and 26.83%, respectively, compared to a simple, linearly tapered and nonlinear PEH. The exsect-tapered nonlinear PEH improves the power output and operational bandwidth for harvesting low-frequency ambient vibrations.
Advances in Cancer Diagnosis: Bio-Electrochemical and Biophysical Characterizations of Cancer Cells
Authors: Arafa Kholoud K. , Ibrahim Alaa , Mergawy Reem , El-Sherbiny Ibrahim M. , Febbraio Ferdinando , Hassan Rabeay Y. A.
Published: August 2022

Cancer is a worldwide leading cause of death, and it is projected that newly diagnosed cases globally will reach 27.5 million each year by 2040. Cancers (malignant tumors), unlike benign tumors are characterized by structural and functional dedifferentiation (anaplasia), breaching of the basement membrane, spreading to adjacent tissues (invasiveness), and the capability to spread to distant sites (metastasis). In the cancer biology research field, understanding and characterizing cancer metastasis as well as features of cell death (apoptosis) is considered a technically challenging subject of study and clinically is very critical and necessary. Therefore, in addition to the cytochemical methods traditionally used, novel biophysical and bioelectrochemical techniques (e.g., cyclic voltammetry and electrochemical impedance spectroscopy), atomic force microscopy, and electron microscopic methods are increasingly being deployed to better understand these processes. Implementing those methods at the preclinical level enables the rapid screening of new anticancer drugs with understanding of their central mechanism for cancer therapy. In this review, principles and basic concepts of new techniques suggested for metastasis, and apoptosis examinations for research purposes are introduced, along with examples of each technique. From our recommendations, the privilege of combining the bio-electrochemical and biosensing techniques with the conventional cytochemical methods either for research or for biomedical diagnosis should be emphasized.
Experimental Study on the Grinding of an Fe-Cr-Co Permanent Magnet Alloy under a Small Cutting Depth
Authors: Wang Ningchang , Jiang Feng , Zhu Jianhui , Xu Yuchun , Shi Chaoyu , Yan Heliang , Gu Chunqing
Published: August 2022

A small cutting depth is the key parameter to realize precision in the machining process. The stability of the machining process will directly affect the quality of machining. In this study, dry grinding experiments using an Fe-Cr-Co permanent magnet alloy with small cutting depths (5 μm) were carried out. The relationship between the number of peaks and valleys and the quality control of the grinding force, wheel speed and feed speed were analyzed. The relationship between the peak and valley values of the grinding force signals and the peak and valley values of the grinding surface obtained using a white light interferometer was revealed. The influence of the grinding parameters on the grinding forces was analyzed by processing the grinding force signals with a low-pass filter based on the rotational speed of the grinding wheel. The experimental results indicated that the difference in grinding force between the peak and valley could be reduced by increasing the grinding wheel speed, which was mainly due to a decrease in average grinding force when the maximum undeformed cutting thickness of the single abrasive decreased. The actual height difference between the grinding surface peak and valley could be realized by increasing the grinding wheel speed. The feed speed of the worktable had no effect on the grinding force signal and the peaks and valleys of the surface morphology. Lower surface roughness could be achieved by reducing the feed speed and increasing the grinding wheel speed.
Transient Heat Transfer Characteristics in a Flat Plate Heat Sink with Mini-Channels for Cooling High Heat Flux IGBT
Authors: Chen Changnian , Zhao Haoran , Liu Chaoyu , Chen Jian , Liu Chunyang , Zhang Tiezhu , Gong Weiping
Published: August 2022

Effective cooling of a high heat flux IGBT electronic system is highly related to system efficiency and safety. A flat plate heat sink was designed to experimentally investigate the transient heat transfer characteristics of IGBT cooling. It is made of aluminum with 20 mini-channels of 249 mm × 3 mm × 4 mm dimensions, which were manufactured by milling machines and melt inert gas (MIG) welding technology to ensure no deformation. Experiments were conducted using deionized water at atmospheric pressure with flow rates of 3.2–9.5 L/min and heat fluxes of 104–347 W/cm2. It was found that instantaneous start-stop and transient heating power variation might cause IGBT failure, especially under low Reynolds and Nusselt number conditions. The temperature rise rate and cooling rate vary with different system parameters. Heating rate can be reduced by high flow rate due to local subcooled boiling. The concept of respond time (RT) based on the piecewise function is suggested to evaluate the influence of transient condition on heating rate. Analysis of flow fluctuation indicated that it would not be a threat to the system except for in extreme cases. These findings provide a reference for the considerations of the design and manufacture of IGBT cooling flat plate heat sinks with mini-channels.
A Novel Manifold Dual-Microchannel Flow Field Structure with High-Performance Heat Dissipation
Authors: Yang Xing , Lin Kabin , Zhang Daxing , Liu Shaoyi , Han Baoqing , Wang Zhihai , Yu Kunpeng , Wu Wenzhi , Ge Dongming , Wang Congsi
Published: August 2022

With the development of miniaturization and integration of electronic devices, the conventional manifold microchannels (MMCs) structure has been unable to meet the heat dissipation requirements caused by the rapid growth of internal heat flux. There is an urgent need to design a new heat dissipation structure with higher heat dissipation capacity to ensure the working stability and life of electronic devices. In this paper, we designed a novel manifold dual-microchannel (MDMC) cooling system that embedded the microchannel structure into the manifold microchannel structure. The MDMC not only has good heat dissipation performance that can meet the development needs of electronic equipment to miniaturization and integration, but also has a compact structure that does not increase the overall thickness and volume compared with MMC. The high temperature uniformity and heat transfer performance of MDMC are significantly improved compared to MMC. The Tmax is reduced by 13.6% and 17.5% at the heat flux density of 300 W/cm2 and 700 W/cm2, respectively. In addition, the influence of the inlet−2 velocity and the total microchannels number on the heat transfer performance of the MDMC structure are numerically investigated. The results show that the decrease rate of Tmax and ΔT is about 6.69% and 16% with the increase of inlet−2 velocity from 1.2 m/s to 2.4 m/s and microchannels number from 10 to 48, respectively. At the same time, the best temperature uniformity is obtained when the number of microchannels is 16.
To the 140th anniversary of the birth of Professor Vasiliy Stepanovich Smirnov
Authors:   Plekhanov Russian University of Economics, Moscow, Agapkin A.M. , Rodina T.G. ,   Plekhanov Russian University of Economics, Moscow
Published: August 2022

This year marks the 140th anniversary of the birth of Vasiliy Stepanovich Smirnov (1882–1958), PhD in Engineering, professor, honored worker of science and technology of the RSFSR. V.S. Smirnov began his teaching career in 1907 at the Moscow Industrial School, which was then reorganized into the D.I. Mendeleev Institute of Chemical Technology. Since 1908, he taught chemistry and commodity science in trade schools, and since 1913 — at the Moscow Commercial Institute (later the Plekhanov Moscow Institute of National Economy), now the Plekhanov Russian University of Economics. For more than 45 years, he taught a course in commodity science of grain and flour products at the Plekhanov Moscow Institute of National Economy, where he organized a grain laboratory and for 10 years, from 1947 to 1957 he was the head of the Department of Commodity Science. For the first time in 1915, he wrote the section “Cereal Bread, Flour and Wheat Bread” in the textbook “Food Products”. In 1938, he wrote “Grain Products”, a four-volume textbook for higher educational institutions, and when it was reprinted in 1950, he was also the editor-in-chief of the entire textbook. In his research work, V.S. Smirnov pursued the goal of organizing technochemical control at processing enterprises to stabilize the quality of flour and cereals. He published more than 75 scientific articles, and 15 PhD theses were defended under his supervision. Vasiliy Stepanovich was a well-rounded specialist; his lectures were characterized by depth of content, practical orientation, and accessibility in acquisition. He was an excellent methodologist, and the textbooks prepared by him have not lost their significance up to date.
Study of the process of tea moisture sorption
Authors:   Research Institute for Storage Problems of the Federal Agency of State Reserves, Tarasova I.A. , Finogenova T.A. ,   Moscow State University of Food Production, Gurieva K.B. ,   Research Institute for Storage Problems of the Federal Agency of State Reserves
Published: August 2022

The article presents studies of the sorption characteristics of green and black tea. The obtained experimental data indicate that tea is a hygroscopic product, so with an increase in the relative humidity of the environment, the sorption rate and the amount of moisture absorbed by tea increase. It was found that small-leaf black tea is more susceptible to intense moisture than large-leaf tea. At high values of relative humidity of the environment, molds of the species Aspergillus and Penicillium most often develop. When the moisture content of tea does not exceed the norms of the standard, the microflora does not have a significant impact on the quality indicators of the product. To preserve the quality of the product, it is necessary to use packaging materials with high barrier properties and maintain a relative humidity of less than 65% in warehouses.
Quantitative detection of nitrates in green apples by ionometric method
Authors:   OGBPOU ", Aslamov A.P. ,   College of Food Industry, Trade and services", Trotsenko S.V. ,   OGBPOU "College of Food Industry, Trade and services", Elis T.V. ,   OGBPOU "College of Food Industry, Trade and services", Rybakova K.V. ,   OGBPOU "College of Food Industry, Trade and services", Denizhenko M.G. ,   OGBPOU "College of Food Industry, Trade and services"
Published: August 2022

The article discusses the importance of identifying nitric acid salts in fruits and vegetables, namely green apples, sold on the market. For determination, a potentiometric method with an ion-selective electrode ELIT-021 (nitrate) was used. As a result of the analysis, LOC was not exceeded in the samples, thus, they are fit for human consumption.
Zagadnienie ochrony interesów ubezpieczonego w umowie z ubezpieczeniowym funduszem kapitałowym
Authors: Chłopecki Aleksander
Published: August 2022

Przedmiotem artykułu jest zagadnienie ochrony interesów ubezpieczonego w umowie z ubezpieczeniowym funduszem kapitałowym. W artykule zostały zdefiniowane podstawowe metody i cele ochrony inwestora – a zarazem ubezpieczonego – jak również zakres przedmiotowy tej ochrony. Wskazuje się, że zakres ochrony dokonuje się poprzez prawo do informacji, ochronę przez nadmiernymi opłatami i misselingiem. Tezą artykułu jest również i to, że ochrona inwestora poprzez rozszerzanie obowiązków informacyjnych powinna być traktowana z ostrożnością – to znaczy przy uwzględnieniu racjonalnego poziomu percepcji inwestora.
Początek biegu terminu przedawnienia roszczeń poszkodowanego wobec ubezpieczyciela w ubezpieczeniu odpowiedzialności cywilnej
Authors: Zawadzka Julita
Published: August 2022

Opracowanie jest poświęcone ustaleniu zasad określania początku biegu przedawnienia bezpośredniego roszczenia poszkodowanego wobec ubezpieczyciela w ubezpieczeniu odpowiedzialności cywilnej w przypadku różnych podstaw prawnych roszczeń o naprawienie szkody. Przepisy Kodeksu cywilnego nie regulują tej kwestii wprost, stwierdzając tylko ogólnie, że roszczenia bezpośrednie poszkodowanego wobec ubezpieczyciela przedawniają się w terminie przewidzianym dla tych roszczeń w przepisach o odpowiedzialności za szkodę wyrządzoną czynem niedozwolonym lub wynikłą z niewykonania lub nienależytego wykonania zobowiązania, a więc w przepisach regulujących przedawnienie roszczenia poszkodowanego wobec ubezpieczonego. Nie sprecyzowano jednak, jak określić początek biegu tego terminu. W opracowaniu przyjęto, że również początek biegu przedawnienia roszczeń bezpośrednich poszkodowanego wobec ubezpieczyciela należy w każdym przypadku ustalić na podstawie tych przepisów, które określają początek biegu tego terminu dla roszczenia wobec ubezpieczonego, niezależnie od podstawy prawnej tego roszczenia.
O osobliwościach umowy ubezpieczenia na życie z ubezpieczeniowym funduszem kapitałowym. Rozważania na tle judykatury polskiej i niemieckiej
Authors: Zgonina Oskar
Published: August 2022

Celem niniejszej publikacji jest dokonanie oceny linii orzeczniczej w przedmiocie umowy ubezpieczenia na życie z ubezpieczeniowym funduszem kapitałowym. Rozważania podjęte zostały w oparciu o aktualne poglądy orzecznictwa zarówno sądów powszechnych, jak i Sądu Najwyższego oraz stanowiska wyrażone w piśmiennictwie. W judykaturze coraz częściej orzeka się o nieważności umów ubezpieczenia w postaci ubezpieczeń na życie z ubezpieczeniowym funduszem kapitałowym. Rodzi to potrzebę pogłębionych rozważań dotyczących m.in. kwestii wykazania przesłanek nieważności umów ubezpieczenia z UFK, sposobu uzyskania przez klienta rynku ubezpieczeniowego odpowiedniej ochrony sądowej, możliwości zwrotu składki uiszczonej na rzecz ubezpieczyciela w wykonaniu nieważnej czynności prawnej, jak również zagadnienia przedawnienia roszczeń z tytułu świadczenia nienależnego. Publikacja wzbogacona została o zagadnienia prawnoporównawcze, odwołujące się do orzecznictwa niemieckiego Bundesgerichtshof.
Habilidades del director (directora) de un festival de cine ambiental latinoamericano
Authors: Peña Zerpa Mixzaida Yelitza
Published: August 2022

Este artículo tiene como propósito comprender las habilidades que poseen los directores de los festivales de cine ambiental latinoamericanos. La investigación se enmarca dentro del Paradigma Cualitativo bajo el Enfoque Fenomenológico Interpretativo. Se aplicaron entrevistas en profundidad a los directores de tres países: México, Venezuela y Argentina. Se entiende que las habilidades le permiten tomar decisiones, resolver conflictos y manejar los recursos dentro de la gestión. Al igual que los conocimientos no son estáticos, están en constante evolución cuando la persona sigue aprendiendo y adquiriendo experiencias. Por ello, destacan las habilidades humanas, sin dejar por fuera las habilidades conceptuales.
Applying Partial Least Squares Approach to investigate the Moderating effect of Peer Support on Employee Commitment
Authors: Ahmad Ashfaq , Bibi Palwasha
Published: August 2022

In order to understand the challenges faced by higher education institute (HEI's) in Pakistan, the HEI's attempts to determine factors that impact on the commitment of employees. The objectives of this research, based on the Social Exchange Theory (SET), is to enrich this understanding by analyzing the buffering effect of peer support in the link between training and development (T&D), Working Climate (WC), and employee commitment (EC) in Pakistan's public sector higher education institutions. Using a proportionate-stratified random sampling process, a quantitative approach was advocated, with a survey as the strategy of inquiry from 385 respondents. The study shows that T&D and WC have a substantial association with EC in government sector universities, both theoretically and empirically. Furthermore, the findings support the hypothesis that peer support buffers the link between T&D, WC, and EC. The introduction of peer support as a moderator between the T&D, WC, and employee commitment relationships is the key contribution. The research also helps to better understand the dynamics of work engagement in higher education institutions, with a focus on the buffering function of peer support (PS) in the Pakistani setting.
Keywords: Training and Development, Working Climate, Peer support, employee Commitment, Social Exchange Theory.
Does Effectuation Theory Explain the Startup Behaviors of Entrepreneurs in Pakistan?
Authors: Chohan Afshan , Sandhu Muhammad Rizwan Saleem , Zaheer Muhammad
Published: August 2022

The very purpose of the study was to explore and confirm if the startups in Pakistan take the path of effectuation or causation according to the effectuation theory contributed by Sarasvathy. The qualitative survey design was used to interview fifteen (15) entrepreneurs from Lahore and Rahim Yar Khan. The interview guide was developed to interview the entrepreneurs. Interviews were then content analyzed to extract themes using the methods suggested in the literature. Findings of the study have supported that the startups in Pakistan take the path of effectuation rather than causation as almost all principles of effectuation were found implemented in all startups considered for the study. The study is the original contribution in terms of supplying empirical evidence for the principles of effectuation in the context of Pakistan. The study has been conducted only in the context of two cities with a limited number of entrepreneurs which limits its findings. Limitations of the study offer opportunity for future research with a broad-based sample. The study offers useful insights to both potential startups and policymakers.
Keywords: Effectuation theory, Causation, Entrepreneurship
Hedonic-Utilitarian Focused Mobile Application Engagement: A Moderated Moderation of Brand Image
Authors: Zaheer Nida , Rizwan Muhammad
Published: August 2022

This study aims to investigate the online customer experience and postpurchase behavior in the mobile application context. This study is experimental with a quantitative approach. Two hypothetical mobile apps were developed; hedonic motive and instrumental motive. Data was collected by surveying 420 online shoppers and, analyzed by employing SEM using Amos. Results suggest that a mobile app that is hedonic motive (Richer media experience) enhances the customer experience and customer engagement behavior respectively. Next, the need for touch provides a boundary condition between the influence of customer experience and customer engagement behavior. Lastly, brand image provided the moderated moderation between customer experience and repurchase intention. These findings have implications for the retailer that they can enhance the customer experience through creating an effective customer experience using hedonic elements of the app. Further, retailers using a strong brand image can mitigate the need for touch in the online shopping context.
Keywords: Mobile app, Hedonic motive, Instrumental motive, Engagement behavior
Test of Calendar Anomalies in Derivative Market of Pakistan in Context of Covid Environment
Authors: Naz Farah , Baig Barea , Zahra Kanwal
Published: August 2022

The aim of this study is to analyze impact and existence of three Calendar Anomalies i.e., day-of-the-week, month-of-the-year, and turn-of-the-month on the commodities i.e., gold, silver, natural gas, oil, and platinum that are traded on the Pakistan Mercantile Exchange (PMEX). The impact of calendar anomalies is investigated separately during and before COVID period. The simple OLS regression along with the three advanced models of Autoregressive Conditional Heteroskedasticity i.e., GARCH (1,1), TGARCH and EGARCH models are used in this research to study the calendar anomalies impact. The significant effect of day-of-the-week anomaly is observed in oil and silver commodity. Month-of-the-year anomaly exists in all commodities except oil. Whereas, significant turn-of-the-month effect is present in all the selected top traded commodities. This study is limited to different periods due to the newly launch commodities of PMEX. PMEX started daily data of silver, platinum, and natural gas from the year 2017, therefore only four commodities have been included in the current research.
Keywords: Calendar Anomalies, Day-of-the-Week Anomaly, Month-of-the-Year Anomaly, Turn-of-the-Year Anomaly, COVID.
Antecedents of Impulsive Buying Behavior through M-commerce in the Textile Sector of Pakistan
Authors: Basit Asma , Khalid Iqra , Maroof Lubna
Published: August 2022

This research aims to capture the essence of the customer urge of impulsivity in their buying behavior in mobile commerce (m-commerce) in the textile sector of Pakistan affected by the perceived utilitarian values (PUV) and perceived hedonic values (PHV). By taking the socio-cultural influence, in fostering excessive consumption habits, as a moderator the study tests its impact on the relationship between the consumers' perceived value and their IBB. Using the survey method, data is collected through a questionnaire in twin cities of Pakistan (n = 335). The results show that environmental stimuli significantly influence consumer perceived values (i.e., perceived utilitarian value and perceived hedonic value), and the consumers' perception of hedonic value significantly and directly impacts their IBB. In addition, the interaction effect of perceived hedonic value and socio-cultural influence significantly affects IBB. The findings provide valuable guidance for m-commerce retailers on enhancing their profits through consumer impulsive buying.
Keywords: Impulsive buying, hedonic value, utilitarian value, socio-cultural influences, M-Commerce, Smart PLS, Survey
CLASS DISCUSSIONS BASED ON CULTURAL ASPECTS TO FOSTER THE SPEAKING SKILL AMONG HIGH SCHOOL STUDENTS
Authors: Trinidad Trujillo Castro María , Rua Cortes Miyiret , Alberto Álvarez Guayara Henry , Aguilar-Cruz Paola Julie
Published: August 2022

This research study arose from the lack of opportunities students had to communicate and express their ideas regarding the content they had already learned using English as a Foreign Language (EFL). Speaking as a linguistic component in EFL is one of the most important skills in this context as it enables students to have better interaction and communication. This qualitative participatory action research study aimed at exploring the contributions that class discussions based on cultural aspects have on eleventh graders from Jorge Eliécer Gaitán High School in Florencia, Caquetá. Each intervention process in this research was developed using Argawati’s (2014) cycle; the cycle was composed of three guidelines: greeting, main activity, and closing. The class discussions were conducted following the ‘group investigation’ method to give students more opportunities for participating and exchanging ideas. The surveys, field notes, and audio-tape recordings were the instruments to gather the data during the intervention. The findings suggest that it is beneficial to use class discussions based on cultural aspects in EFL to promote students’ participation, and thus, evidence significant progress in the EFL speaking skill. Besides, class discussions based on cultural aspects make EFL learners be constantly practicing, requesting information, sharing ideas, and concluding regarding the cultural aspects, fostering a meaningful development of their speaking skill.
FORMS OF SPORTS TEACHERS TRAINING THE SYSTEM OF VOCATIONAL EDUCATION IN CHINA
Authors: Zhangliang Han , Terentieva Nataliia
Published: August 2022

At the present stage of the Chinese society development, the education and training system of teachers in the PRC faced the need of updating the forms and methods of training students, including future teachers of sports disciplines. This article analyzes modern forms of pedagogical work that are used in the system of higher sports and pedagogical education in the PRC, both traditional (lectures, practicals, consultations) and those that are unique (professional online projects and platforms) or innovative (volunteer movements, social practices, etc.). The purpose of this article is to present the results of the above analysis and to introduce this new data into the space of Ukrainian pedagogical science.
CONTINUITY OF THE EDUCATIONAL PROCESS IN SECONDARY AND HIGHER EDUCATION INSTITUTIONS IN CHINA: CITIZENSHIP EDUCATION
Authors: XIE Fei , KALASHNYK Nataliia
Published: August 2022

At the present stage of the society development, China plays a significant role in global and regional processes, turning up over the past few decades from a poor underdeveloped country to the world’s leaders in economic and science. In turn, this has led to significant political and socio-economic changes, which are associated with both government policies and subjective factors. The ideology in China is built in such a way that each individual considers it his/her duty to make a personal contribution to the development of the state. Civic (citizenship) education, which is aimed at forming love and respect for the Motherland, developing a sense of duty to the state and other citizens of the country, respect for other peoples, is given much attention at any level of education, from preschool to self-education. The article aims to make the analysis of the citizenship education process and its reflection over all stages of secondary and high education of China, reflecting the continuity principle.