Intensive Experimental Work Research Articles

Complex multiphase predicting of additive manufactured high entropy alloys based on data augmentation deep learning

Additive Manufacturing (AM) can rapidly fabricate and produce customized, large-scale components, thereby fully exploiting High-Entropy Alloys (HEAs)' performance and industrial value—their broad potential for application in extreme service environments such as nuclear energy and aerospace. Because HEAs have a vast composition space, researchers can accurately map their mechanical properties by HEAs phases to reduce time-consuming and intensive experimental work. However, it is still a considerable challenge to predict HEAs phases accurately. And machine learning (ML) can predict the phases to accelerate the study of HEAs.To accurately predict the HEAs phases, the study propose deep learning (DL) algorithms that rely on AM process parameters and data augmentation and do the following: (i) This study developed a more detailed phase classification strategy for HEAs to enable the model to predict the complex multiphase of HEAs; (ii) The process parameters of AM affect the formation of the HEAs phase. In this study, the process parameters of AM are added to the model features to improve the model's accuracy in predicting the HEAs phase; (iii) To alleviate the data scarcity dilemma of HEAs, this study use data augmentation to improve DL's performance further. The results show that after adding AM process parameters to the model and performing data augmentation, the DL model's accuracy to 91.23%. In addition, this study manufactured four new HEAs through AM experiments to verify the robustness and practicality of their algorithms.

Porous Material (Titanium Gas Diffusion Layer) in Proton Exchange Membrane Fuel Cell/Electrolyzer: Fabrication Methods & GeoDict: A Critical Review

Proton exchange membrane fuel cell (PEMFC) is a renewable energy source rapidly approaching commercial viability. The performance is significantly affected by the transfer of fluid, charges, and heat; gas diffusion layer (GDL) is primarily concerned with the consistent transfer of these components, which are heavily influenced by the material and design. High-efficiency GDL must have excellent thermal conductivity, electrical conductivity, permeability, corrosion resistance, and high mechanical characteristics. The first step in creating a high-performance GDL is selecting the appropriate material. Therefore, titanium is a suitable substitute for steel or carbon due to its high strength-to-weight and superior corrosion resistance. The second crucial parameter is the fabrication method that governs all the properties. This review seeks to comprehend numerous fabrication methods such as tape casting, 3D printing, freeze casting, phase separation technique, and lithography, along with the porosity controller in each process such as partial sintering, input design, ice structure, pore agent, etching time, and mask width. Moreover, other GDL properties are being studied, including microstructure and morphology. In the future, GeoDict simulation is highly recommended for optimizing various GDL properties, as it is frequently used for other porous materials. The approach can save time and energy compared to intensive experimental work.

Atomic Pd dispersion in triangular Cu nanosheets with dominant (111) plane as a tandem catalyst for highly efficient and selective electrodehalogenation

Single-atom alloys (SAA) in which active metal atoms are atomically dispersed in an inert host possess unique geometric and electronic structures, and generally own higher catalytic performance than their monometallic counterparts. Whereas it is still challenging to facilely synthesize well-defined single atoms embedded in single crystals dominated with a specific active plane. Herein, we synthesized Pd single atoms anchored in triangular Cu nanosheets (Pd1Cu SAA) with dominant active (111) plane via wet chemical synthesis and galvanic replacement as a high-performance catalyst for the electrocatalytic hydrodehalogenation (ECHD) of the refractory tribromophenol. Based on intensive theoretical calculations and experimental work, a hydrogen spillover mechanism was firstly proposed and verified for the highly efficient and selective ECHD. Hydrogen spillover occurs from the hydrogen-rich Pd to the hydrogen-deficient Cu host with a marginal kinetic energy barrier due to the short reaction distance and the negligible interfacial resistance. Meanwhile, the strong metal-support interaction between Pd and peripheral Cu optimizes the adsorption of hydrogenated products to allow for the further catalytic reaction. Consequently, by decoupling the ECHD process into hydrogen adsorption, hydrogen spillover and hydrodebromination, Pd1Cu SAA as a tandem catalyst completely reduced tribromophenol with high phenol selectivity. The intrinsic catalytic activity of Pd and Cu in Pd1Cu SAA substantially outperforms their monometallic counterparts by 14.4 and 3.2 times, respectively. This work showcases that the atomic dispersion of noble metals in SAA offers a promising catalyst design strategy to attain unprecedented catalytic properties via isolating activation and desorption steps.

Development of Ultra Low-Cost Data Acquisition System (DAS) for Developing Countries

The Data Acquisition System (DAS) is an important equipment in measurement systems especially in weather monitoring and also very crucial in many areas such as agricultural, communication, transportation, sport and industrial processes. This work proposes a weather monitoring system based on an Arduino Mega 2560 microcontroller board. The microcontroller has the ability to monitor, record and display the information of atmospheric sensor parameters connected to its analogue and digital pins. The outputs of analogue sensors are connected to the microcontroller through separate ADC for sampling. An LCD attached to the microcontroller displays the measured parameters. For analysis, the data is stored in excel format and can be copied directly from microSD card. The DAS was tested and examined through intensive experimental work. The tables and plots obtained from the experiment for standardizing the sensors, it is clear that there is a close conformity between the data collected by the developed system and the existing standard systems. The need for extra cost baud rate and expensive third-party computer software for interfacing to download data from the logger have been eliminated. There is no need of internet for any linking or configuration. It is evident that the DAS is of better choice in terms of cost and maintenance. The system will be helpful in monitoring and recording of atmospheric parameters.
 HIGHLIGHTS
 
 Only a few weather monitoring stations in Nigeria are functioning as a result of the high cost, maintenance and repair services of imported DAS systems. Also, imported DAS devices are often not suitable for the tropical environment
 Other problems include: proprietary software that lacks flexibility, the necessity for third-party software to extract data and difficulties in getting usable parts and unexpected changes in production designs
 Developed DAS device offers a higher resolution compared to existing devices
 Low-cost and flexible meteorological DAS system with ease of installation
 Convenience in deployment for weather data acquisition and research purposes in relevant fields
 
 GRAPHICAL ABSTRACT

Prediction of Mechanical Properties of Wrought Aluminium Alloys Using Feature Engineering Assisted Machine Learning Approach

Data-mining based machine learning (ML) method is emerging as a strategy to predict aluminium (Al) alloy properties with the promise of less intensive experimental work. However, ML models for wrought Al alloys are limited due to the difficulty in feature digitalization of the variety of manufacturing processes. Hence, most previous studies were constrained to specific alloy designations, which impeded the applicability of those ML models to broader wrought Al alloys. In the present work, we propose a novel feature engineering, called procedure-oriented decomposition (POD), assisting prediction framework to address the complexity introduced by manufacturing processes for wrought Al alloys. In this model, both chemical compositions and manufacturing processes are integrated as features. Correlation mapping of these features to the wrought Al alloys mechanical properties is established using the support vector regressor (SVR) model. The prediction framework demonstrates a high prediction accuracy and potential to design new alloys.

Cost-effective synthesis method of facile environment friendly SnO2 nanoparticle for efficient photocatalytic degradation of water contaminating compound.

The present study demonstrates an intensive experimental work based on the tin oxide (SnO2) nanoparticle synthesis which was successfully carried out by a simple conventional precipitation method followed by calcination at 700 °C. The synthesized nanoparticles were characterized by X-ray powder diffraction (XRD), UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDAX). The XRD pattern proves that tetragonal rutile structure SnO2 nanoparticles were formed. The crystallite particle size calculation from Scherer's equation revealed the average size of 28.5 nm. The absorption spectrum of SnO2 nanoparticles showed absorption band at about 290 nm and the band gap energy (Eg) from Tauc plot was obtained at 3.8 eV. The photocatalytic degradation of pharmaceutical compound, 4-aminopyridine (5 ppm) using synthesized SnO2 nanoparticle, was assessed. The effect of variable catalyst dosage, pH and irradiation sources, were studied. The optimum catalyst dosage and pH were found to be 1.5 gm/L and 6.5, respectively. The degradation efficiency of water contaminant 4-aminopyridine under UV light and solar light irradiation for 120 min were found to be 97% and 11%, respectively. The reusability of the catalyst was checked and has been found stable after three photocatalytic runs.

ВИКОРИСТАННЯ МЕТОДУ СИТУАТИВНОГО МОДЕЛЮВАННЯ НА ЗАНЯТТЯХ З ІНОЗЕМНОЇ МОВИ ПРОФЕСІЙНОГО СПІЛКУВАННЯ

The purpose of the article is to study the peculiarities of using the situation modeling methodology at the lessons of foreign language for professional communication at higher military educational institutions. The problems of providing the national security, defense of our state, creating the revolutionary new and progressive form of the National Guard and Ukrainian Armed Forces demands the future officers, seasoned professionals. It should also be remembered that in the conditions of rapid integration of our country into the EU, we need specialists who will who will worthily represent our state on the international scene. Today, one of the most important aspects is upbringing servicemen who successfully fulfill their functional duties, but also those who have a good command of a foreign language. This problem can be successfully solved subject to the condition that much practice for performing professional tasks is available. The use of alternative teaching methods, including the method of modeling the professional situations of a military nature, contributes to the improvement of learning material acquiring, the motivation of applicants for higher education and the practical development of real situations of military life. The concepts «interactive learning», «situation modeling», «simulation», «imitation» and «mimic warfare» are considered in the context of studying English for professional communication (EPC). Attention is focused on the types of interactive technologies that can be used in foreign language classes, on the advantages of imitation games for mastering a foreign language by cadets. Based on consideration of interactive games, it was found that the subject of simulations, imitations and role-playing games may be topographic maps, the content of combat documents, briefings, units organizations and armament, interrogations of prisoners of war It is proved that now there is an intensive experimental work aimed at improving and introducing the newest methods of teaching a foreign language in the education system. Key words: situation modeling, game, imitation, simulation, EPC, cadets.

A High-Efficient Low-Cost Converter for Capacitive Wireless Power Transfer Systems

Growth of the Internet of Things (IoT) spurs need for new ways of delivering power. Wireless power transfer (WPT) has come into the spotlight from both academia and industry as a promising way to power the IoT devices. As one of the well-known WPT techniques, the capacitive power transfer (CPT) has the merit of low electromagnetic radiation and amenability of combined power and data transfer over a capacitive interface. However, applying the CPT to the IoT devices is still challenging in reality. One of the major issues is due to the small capacitance of the capacitive interface, which results in low efficiency of the power transfer. To tackle this problem, we present a new step-up single-switch quasi-resonant (SSQR) converter for the CPT system. To enhance the CPT efficiency, the proposed converter is designed to operate at low frequency and drive small current into the capacitive interfaces. In addition, by eliminating resistor-capacitor-diode (RCD) snubber in the converter, we reduce the implementation cost of the CPT system. Based on intensive experimental work with a CPT system prototype that supports maximum 50 W (100 V/0.5 A) power transfer, we demonstrate the functional correctness of the converter that achieves up to 93% efficiency.

Моделирование теплопроводности порошковой среды применительно к задаче селективного лазерного плавления

The speed and the cost of implementation of new techniques are directly dependent on the efficiency of each of the technological chain at all stages, from design and product design to create of its original mockup in full value. Dramatically accelerate the passage of these steps help to high-tech methods of 3-D computer modeling and the creation of hard copies of machine parts. Currently all over the world carry out intensive scientific research and experimental structure work not only on the creation of new, but also on the improvement technology previously deve­loped of methods and layered systems of laser synthesis of volume products (LSOI) machine parts. Methods of selective laser sintering(SLS), melting (SLM) and a three-dimensional laser melting (the DMD) is one of the most promising ways to implement rapid prototyping techno­logy[1]. There fore, the study of this topic at this point is urgent. Currently in many industries, are large heat flows from one surface to another, whereby even slight contact resistance causes local overheating, which is often highly undesirable. In this work was to study the effectiveness the thermal conductivity of granular systems, which was seen as a function of porosity, thermal conductivity, filling the pores of the material, the thermal conductivity of the gas microgap, the thermal conductivity of the particles themselves and contact the thermal conductivity at the junction of the particles. For theoretical studies of selective laser sintering it is necessary to develop methods to describe the effective thermal conductivity (EKT) powder medium, which take into account, that heating the partial or complete melting of the material areas may occur, resulting in a change in the structure of the medium. This implies an important requirement for EKT model: structural model in the limit of the total melting particulate material should give a value of the effective thermal conductivity, which is cross-linked with an effective thermal conductivity given by non-structured model. For the case of complete melting particles melt method is proposed for calculating the effective thermal conductivity gas as described in work.

Electrochemical Degradation of Nafion Ionomer to Functionalize Graphene as a Support for Core-Shell Palladium-Ruthenium Alloy @ Platinum Electrocatalysts

A simple but effective electrochemical route to functionalize graphene is demonstrated. Cyclic voltammetric sweeps are performed in 0.5 M H2SO4 aqueous solution on electrodes containing carbon cloth, graphene, and Nafion ionomer. With supply of ambient oxygen, the formation of hydroxyl radicals from the oxygen reduction reaction during CV cycles initiates the decomposition of Nafion ionomer that engenders oxygenated functional groups on the graphene surface. Raman analysis suggests a minor change for the graphene structure. Exploring various amounts of Nafion ionomer, we determine the optimized conditions for graphene functionalization. Contact angle is used to evaluate the effect of Nafion ionomer decomposition. X-ray photoelectron spectroscopy is employed to study relevant functional groups. Afterwards, nanoparticles of Pd9Ru are synthesized and impregnated on those functionalized graphene (FGN) via a wet chemical reflux process. X-ray diffraction patterns of the as-synthesized samples suggest successful formation of alloy without presence of individual Pd and Ru nanoparticles. Images from transmission electron microscope confirm the average size of 3-4 nm. Subsequently, the Pd9Ru/FGN undergoes Cu under potential deposition, followed by a galvanic displacement reaction to deposit a Pt monolayer on the Pd9Ru surface (Pd9Ru@Pt). Intensive experimental work is ongoing to investigate the electrochemical active surface area (ECSA) and electrocatalytic activities of Pd9Ru@Pt/FGN.

Striped quantum Hall state in a half-filled Landau level

Nature of the fractional quantum Hall state at Landau level filling factor 5/2 remains elusive despite intensive experimental and theoretical work. While the leading theoretical candidates are Moore-Read Pfaffian (Pf) and its particle-hole conjugate anti-Pfaffian (APf), neither received unambiguous experimental support. We show that a state that is intermediate between them, made of alternating stripes of Pf and APf in the bulk, is a viable candidate. Such a state is shown to be incompressible and thus a charge insulator in the bulk, but a heat conductor due to the presence of gapless neutral bulk modes. We argue that properties of such a state is consistent with existing numerical and experimental work, and discuss possible experimental probes of its presence.

Improving Energy Efficiency in Iron Ore Sintering through Segregation: a Theoretical Investigation

In iron ore sintering, effective segregation of the particulate bed on the strand can result in productivity increases and decreased fuel rate. To find the optimum level of segregation for a given blend, intensive experimental work will be necessary to assess the impact of different segregation levels. The impact of segregation on sintering performance can also be quantified using mathematical modelling. In this work, a well-validated sintering mathematical model has been developed and the effects of mean granule size, bed voidage, bed bulk density, coke mass segregation as well as increased bed permeability on the sintering performance have been investigated. It was concluded that the variation in coke mass down the bed and increased bed permeability are the major factors giving increased sinter yield and productivity in segregated beds. Coke mass segregation has a large impact on maximum bed temperature, residence time above the critical temperature and, consequently, the total heat available to the bed at the critical melt formation period. The effect of variations in granule size and bulk density, caused by segregation, on coke combustion efficiency and bed temperature is small. Bed permeability has the largest impact on flame front speed and, therefore, sinter productivity. Based on differences in bottom and top bed temperatures, the optimal coke mass segregation level was identified. Results from this study provide useful guidelines on optimal segregation level to maintain sintering performance and reduce energy consumption and therefore ironmaking costs.

Extrapolation of Al2O3–water nanofluid viscosity for temperatures and volume concentrations beyond the range of validity of existing correlations

The emergence of nanofluids as an attractive new class of thermal fluids, with enhanced heat transfer characteristics, rapidly stimulated their use in engineering applications. It also led to the need of an intensive experimental work to determine the thermophysical properties of nanofluids affecting heat transfer such as density, viscosity, thermal conductivity and specific heat capacity. Contradictory results were obtained by several researchers for the dependence of the nanofluid viscosity on temperature, nanoparticle diameter and nanoparticle volume concentration. In regard to these variables, a summarizing work was presented by Khanafer and Vafai (2011) who successfully presented a quite general correlation for the effective viscosity of Al2O3-water nanofluid with temperature ranging from 20 to 70 °C, nanoparticle volume concentration between 1 and 9 vol%, and nanoparticle diameter between 13 and 131 nm. The present work presents a methodology for extrapolating this correlation beyond its range of validity, as a first attempt to obtain an approximate expression to systematically evaluate the viscosity of Al2O3–water in simulation of heat transfer applications for the range of temperatures from 5 to 20 °C and nanoparticle volume fractions below 1 vol%. New experimental data was obtained for the viscosity of Al2O3–water nanofluid within this range of low temperature and volume fraction, showing good agreement with most of the corresponding extrapolation values.

Prospects for the use of genetically modified crops with improved nutritional properties as feed materials in poultry nutrition

Genetically modified (GM) plants constitute an increasingly significant part of the crops available on the feed market. To date, the most common GM plants have been those with enhanced agronomic traits. Known as ‘first-generation transgenic plants’, they are substantially equivalent to materials from conventional, parental plant lines. Recently, intensive experimental work using genetic engineering methods, have resulted in the production of transgenic plants with substantial changes in chemical composition, these are referred to as second-generation GM plants. The main objective of such transgenesis is to improve the nutritional properties of crops by increasing the level of desirable substances or decreasing the quantity of harmful compounds in the seeds. This review discusses the use of GM crops with enhanced nutritional properties as feed materials for poultry. On the basis of the information presented, it can be concluded that GM crops with improved nutritional value, enhanced available phosphorus content, an increased concentration of limiting amino acids, or containing genes expressing transgenic enzymes or antimicrobial substances could offer poultry producers considerable benefits.

Wetted wall cyclone — A novel concept

Wetted wall cyclone is based on a novel concept of having a gravity fed water film flowing down along the inner walls of a cyclone. This equipment can be used for simultaneous cooling and cleaning – both particulate and gaseous impurities – of a gas. This work encompassed planning and designing of infrastructural equipment, like orifice meter, venturi feeder, rotary air lock and wetted wall cyclone carrying out intensive experimental work and detailed analysis of data thereof. The particulate matter removal under both dry and wet conditions is studied at different air velocities. Experiments were performed by introducing fly ash and talc as pollutants. The overall and grade efficiencies have been obtained under both dry and wet conditions at varying inlet velocity at constant solid loading. Wetting the cyclone walls increased the overall collection efficiency marginally by about 2% when talc was used as the contaminant. However, analysing the grade efficiency data showed a marked improvement of up to 33% in the collection efficiency for fine particles in the range of 1 to 3 μm.

Diesel engines with low-pressure exhaust-gas recirculation

Excellent driving performance and low fuel consumption make the diesel engine an attractive power unit for road traffic. It is an essential component for achieving fuel consumption targets demanded in future. The disadvantages of the compression ignition engine are the high, function-related nitrogen oxide and particulate emissions, in addition to costs. Compliance with future emission standards poses a technological challenge for it. Intensive experimental and numerical work allowed BorgWarner Turbo & Emissions Systems to determine the relevant influencing parameters of low-pressure- circuit exhaust-gas recirculation for the turbocharger and develop measures to protect the aerodynamic components in targeted manner. These measures would lead to anticipate that series use of low-pressure-circuit exhaust-gas recirculation would appear realistic as a contribution to further reducing pollutant emissions of the diesel engine.

Attacking a Small Beast: Ar–CO, a Prototype for Intermolecular Forces

Abstract The study of intermolecular forces has been of increasing interest in the past. New theoretical and experimental techniques have been developed which allow an improved understanding of these important interactions. We will give an introduction to the theoretical concepts of the description of intermolecular forces. We will tackle Ar–CO as prototype system of intermolecular forces which has been subject of intensive experimental and theoretical work in the past and has evolved to one of the most investigated intermolecular complexes. We will give here an overview over the numerous theoretical and experimental studies which have been published in the literature. A comparison between the most recent ab initio studies and the experimental work demonstrates a lack of sufficient agreement. We have carried out a semi-empirical fit of the potential energy surface to five of the seven known intermolecular modes. All modes could be reproduced within 0.4 cm using our new potential energy surface. The most significant deviation which was found in comparison to previous ab initio potentials was the appearance of a second local minimum in the potential energy surface. These results indicate a lack of a sufficient accurate theoretical description of intermolecular forces for this “little beast” which remains still a challenge for the future.

HIV-1 infection kinetics in tissue cultures.

Despite intensive experimental work on HIV-1, very little theoretical work has focused on HIV-1 spread in tissue culture. This article uses two systems of ordinary differential equations to model two modes of viral spread, cell-free virus and cell-to-cell contact. The two models produce remarkably similar qualitative results. Simulations using realistic parameter regimes showed that starting with a small fraction of cells infected, both cell-free viral spread and direct cell-to-cell transmission give an initial exponential phase of viral growth, followed by either a crash or a gradual decline, extinguishing the culture. Under some conditions, an oscillatory phase may precede the extinction. Some previous models of in vivo HIV-1 infection oscillate, but only in unrealistic parameter regimes. Experimental tissue infections sometimes display several sequential cycles of oscillation, however, so our models can at least mimic them qualitatively. Significantly, the models show that infective oscillations can be explained by infection dynamics; biological heterogeneity is not required. The models also display proportionality between infected cells and cell-free virus, which is reassuringly consistent with assumptions about the equivalence of several measures of viral load, except that the proportionality requires a relatively constant total cell concentration. Tissue culture parameter values can be determined from accurate, controlled experiments. Therefore, if verified, our models should make interpreting experimental data and extrapolating it to in vivo conditions sharper and more reliable.

Combined Air-Oil Cooling on a Supercharged TC & IC TAM Diesel Engine

In order to reduce the maximum cylinder wall temperatures of an air-cooled TC&IC diesel engine with large longitudinal and circumferential temperature gradients, a curved, squared cross-sectional channel supplied with engine lubrication oil was introduced into the upper part of the cylinder wall. Numerical analyses of the heat transfer within the baseline air-cooled cylinder and intensive experimental work helped to understand the temperature situation in the cylinder at diverse engine running conditions. The results of the combined cooling were greatly affected by the design, dimensions, position of the channel, and the distribution of the cooling oil flow, and are presented in the paper.

Concrete Human Psychology

For L. S. Vygotsky the end of the '20s was a time of intensive theoretical and experimental work in developing the basic postulates of his cultural-historical theory of the human mind. The relatively calm and, in spite of everything, happy first five years of his life in Moscow, after moving there in 1924 from Gomel', lay behind him. This was a period of his development as a psychologist when his star was in the ascendancy; when within a few years, this still quite young man was transformed from a provincial teacher, known to no one, into one of the leading and most outstanding figures in young Soviet psychology, a scholar with an inviolable scientific authority, surrounded by a group of young, also talented, and solemnly dedicated disciples; a man with a deep awareness of his mission in the development of science, full of ideas, intentions, and plans, most of which, unfortunately, were destined to remain unrealized because of Vygotsky's premature death. Vygotsky worked all these years rapidly and intensively, as if he had a presentiment of his death. One after the other, great works, which today constitute the body of the cultural-historical concept, and have long since become part of the treasures of Soviet and world psychological literature, flowed from his pen. Almost every one of them was prepared by degrees, in preliminary sketches and notes Vygotsky had made mostly for himself, not intending them for print. But even this special "inner speech" of Vygotsky's is usually in the form of independent, coherent, and sometimes fully finished texts, thanks to his generally striking capacity to live and do everything in his life immediately "from scratch," without any "rough drafts." Such is the manuscript published below, which Vygotsky wrote in 1929; it is from his family archives, kindly provided by his daughter, G. L. Vygotskaya. This work gives us a glimpse into the creative laboratory of this extraordinary thinker, enabling us, with almost visual clarity, to view the process of crystallization of some of the basic postulates of his cultural-historical theory, which we know well from Vygotsky's classical works of the early '30s. Moreover, it also contains a number of original ideas and reflections that were not dealt with further in his later works. In this sense, Vygotsky's notes published here should shed new light on some of the fundamental postulates of his concept, sometimes within a context that makes them extremely timely for contemporary psychology as well.