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1 – 10 of 172Suvranshu Pattanayak, Susanta Kumar Sahoo, Ananda Kumar Sahoo, Raviteja Vinjamuri and Pushpendra Kumar Dwivedi
This study aims to demonstrate a modified wire arc additive manufacturing (AM) named non-transferring arc and wire AM (NTA-WAM). Here, the build plate has no electrical arc…
Abstract
Purpose
This study aims to demonstrate a modified wire arc additive manufacturing (AM) named non-transferring arc and wire AM (NTA-WAM). Here, the build plate has no electrical arc attachment, and the system’s arc is ignited between tungsten electrode and filler wire.
Design/methodology/approach
The effect of various deposition conditions (welding voltage, travel speed and wire feed speed [WFS]) on bead characteristics is studied through response surface methodology (RSM). Under optimum deposition condition, a single-bead and thin-layered part is fabricated and subjected to microstructural, tensile testing and X-ray diffraction study. Moreover, bulk texture analysis has been carried out to illustrate the effect of thermal cycles and tensile-induced deformations on fibre texture evolutions.
Findings
RSM illustrates WFS as a crucial deposition parameter that suitably monitors bead width, height, penetration depth, dilution, contact angle and microhardness. The ferritic (acicular and polygonal) and lath bainitic microstructure is transformed into ferrite and pearlitic micrographs with increasing deposition layers. It is attributed to a reduced cooling rate with increased depositions. Mechanical testing exhibits high tensile strength and ductility, which is primarily due to compressive residual stress and lattice strain development. In deposits, ϒ-fibre evolution is more resilient due to the continuous recrystallisation process after each successive deposition. Tensile-induced deformation mostly favours ζ and ε-fibre development due to high strain accumulations.
Originality/value
This modified electrode arrangement in NTA-WAM suitably reduces spatter and bead height deviation. Low penetration depth and dilution denote a reduction in heat input that enhances the cooling rate.
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In this paper, it can be seen from AFM images of the as-deposited ZnO and CZO films, and the particle size and shape are not clear, while by increasing annealing temperature, they…
Abstract
Purpose
In this paper, it can be seen from AFM images of the as-deposited ZnO and CZO films, and the particle size and shape are not clear, while by increasing annealing temperature, they become distinguishable. By increasing temperature to 600°C, ZnO and CZO, CAZO and aluminum-doped zinc oxide (AZO) films particles became almost spherical. Due to high content of Cu in CZO target, and of Al in AZO target which was 5% weight ratio, doping plays a great role in the subject. Therefore, the annealing processing strongly affect the size and the shape of nanoparticles.
Design/methodology/approach
In this paper, the authors tried to study, in detail, nobel optical characterizations of ZnO films doped by transition metals in different annealing temperature. The authors found that the values of skin depth, optical density, electron–phonon interaction, steepness parameter, band tail width, direct and indirect carriers transitions and the dissipation factor, free carriers density and roughness of films affect the optical properties, especially the optical absorptions of ZnO films doped by transition metals. Also these properties were affected by annealing temperatures. The authors also found that topography characterizations strongly were affected by these parameters.
Findings
The CZO films have maximum value of coordination number ß, with considering NC = 4, Za = 2, Ne = 8. The CZO films annealed at 500 °C have maximum value of optical density. The as-deposited CAZO films have maximum value of steepness parameters in about of 0.13 eV. The as-deposited AZO films have maximum value of dispersion energy Ed in about of 5.75 eV. Optical gap and disordering energy plots of films can be fitted by linear relationships Eg = 0.49 + 0.2 EU and Eg = 0.52 + 0.5 EU, respectively.
Originality/value
With considering Nc = 4, Za = 2, Ne = 8 for ZnO films, coordination number ß has maximum value of 0.198. CZO nanocomposites films annealed at 500°C have maximum value of optical density. Different linear fitting of ln (α) for films were obtained as y = Ax + B where 5<A < 17 and 5<B < 12. As-deposited CAZO nanocomposites films have minimum value of electron phonon interaction in about of 4.91 eV. Optical gap and disordering energy plots can be fitted by linear relationships Eg = 0.49 + 0.2 EU and Eg = 0.52 + 0.5 EU for as-deposited films and films annealed at 500°C, respectively. Steepness parameters of as-deposited CAZO nanocomposites films have maximum value of 0.13 eV. Dispersion energy Ed for as-deposited AZO nanocomposites films has maximum value of 5.75 eV.
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Aizhan Doshibekova, Indira Jurinskaya, Salikh Tashpulatov, Raushan Zhilisbayeva, Lazzat Sarttarova, Rustam Akbarov and Marzhan Kalmakhanova
This paper aims to study the possibility of electroplating copper coatings on chemically and chemical-galvanically nickel-plated acrylic fibers, to be further processed into yarn…
Abstract
Purpose
This paper aims to study the possibility of electroplating copper coatings on chemically and chemical-galvanically nickel-plated acrylic fibers, to be further processed into yarn, fabrics, knitwear and nonwoven materials.
Design/methodology/approach
Electrically conductive fibers with different copper contents have been obtained, and the effect of electrolyte pH, its composition, current strength at the first and second cathodes, as well as the metallization time on the electrophysical, physical and mechanical properties of copper-containing fibers, has been studied.
Findings
The studies have shown that with an increase in the copper content, the electrical conductivity, the uniformity of the coating and the uniformity of the electrophysical properties (for chemical-galvanically nickel-plated fiber) increase. In the case of copper plating of chemically nickel-plated fiber, the coefficient of variation in electrical resistance increases with increasing plating time, even though the copper content increases, and the coefficient of variation in copper content and electrical resistance decreases. The physical and mechanical properties of copper-containing fibers differ slightly from the original (subjected to copper plating) and industrial Nitron fibers. With copper plating, the strength of the fiber practically does not decrease, and the elongation decreases somewhat, compared with the mass-produced Nitron fiber.
Originality/value
The physical and mechanical properties of copper-containing fibers are quite high, which makes it possible to be successfully further processed into yarn, fabrics, knitwear and nonwoven materials.
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Małgorzata Iwanicz-Drozdowska, Łukasz Kurowski and Bartosz Witkowski
This paper aims to evaluate the role of depositor-specific features in a bank resolution. As the resolution framework in the EU is rather new, there are no empirical studies…
Abstract
Purpose
This paper aims to evaluate the role of depositor-specific features in a bank resolution. As the resolution framework in the EU is rather new, there are no empirical studies referring to the efficiency of this mechanism in protecting financial stability. Thus, the authors have checked the role of societal awareness of deposit guarantee schemes and the resolution, as well as the trust in public institutions, in avoiding bank runs in the case of resolution scenarios.
Design/methodology/approach
The study is based on telephone interviews conducted with 1,000 Poles, including bank customers whose banks have undergone resolution in recent years, and basic statistics of the resolved banks. The authors then apply two classes of models: binary probit regression and ordered probit regression.
Findings
The findings have indicated that the trust in public institutions and the experience gained with age play a key role in overall depositor behaviour. However, for resolutions, declared trust is replaced by case-specific trust based on the obtained information.
Research limitations/implications
The survey is based on a sample of Polish citizens. In the future, international surveys may help diagnose cross-country differences among depositors. Moreover, studies on communication approaches may also support finding highly effective ways to reach various cohorts of depositors.
Originality/value
The existing literature on depositor behaviour in bank failure scenarios has relied on an experimental approach to test various research hypotheses. The research sample is not based on an experiment but on the responses of customers whose banks have actually undergone resolution.
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Vimal Kumar Deshmukh, Mridul Singh Rajput and H.K. Narang
The purpose of this paper is to present current state of understanding on jet electrodeposition manufacturing; to compare various experimental parameters and their implication on…
Abstract
Purpose
The purpose of this paper is to present current state of understanding on jet electrodeposition manufacturing; to compare various experimental parameters and their implication on as deposited features; and to understand the characteristics of jet electrodeposition deposition defects and its preventive procedures through available research articles.
Design/methodology/approach
A systematic review has been done based on available research articles focused on jet electrodeposition and its characteristics. The review begins with a brief introduction to micro-electrodeposition and high-speed selective jet electrodeposition (HSSJED). The research and developments on how jet electrochemical manufacturing are clustered with conventional micro-electrodeposition and their developments. Furthermore, this study converges on comparative analysis on HSSJED and recent research trends in high-speed jet electrodeposition of metals, their alloys and composites and presents potential perspectives for the future research direction in the final section.
Findings
Edge defect, optimum nozzle height and controlled deposition remain major challenges in electrochemical manufacturing. On-situ deposition can be used as initial structural material for micro and nanoelectronic devices. Integration of ultrasonic, laser and acoustic source to jet electrochemical manufacturing are current trends that are promising enhanced homogeneity, controlled density and porosity with high precision manufacturing.
Originality/value
This paper discusses the key issue associated to high-speed jet electrodeposition process. Emphasis has been given to various electrochemical parameters and their effect on deposition. Pros and cons of variations in electrochemical parameters have been studied by comparing the available reports on experimental investigations. Defects and their preventive measures have also been discussed. This review presented a summary of past achievements and recent advancements in the field of jet electrochemical manufacturing.
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Bassam Abdallah, Mahmoud Kakhia, Karam Masloub and Walaa Zetoune
Niobium Nitride (NbN) was interesting material for its applications in the medicinal tools or tools field (corresponding to saline serum media) as well as in mechanical…
Abstract
Purpose
Niobium Nitride (NbN) was interesting material for its applications in the medicinal tools or tools field (corresponding to saline serum media) as well as in mechanical properties. The aim of this work was depositing NbN thin films on two types of substrates (stainless steel (SS304) and silicon (100)) using plasma technique at varied powers (100–150 W).
Design/methodology/approach
DC magnetron sputtering technique at different powers were used to synthesis NbN films. Film structure was studied using X-ray diffraction (XRD) pattern. Rutherford elastic backscattering and energy dispersive X-ray were used to examine the deposited film composition. The films morphology was studied via atomic force microscopy and scanning electron microscopy images. Corrosion resistance of the three NbN/SS304 films was studied in 0.9% NaCl environment (physiological standard saline).
Findings
All properties could be controlled by the modification of DC power, where the crystallinity of samples was changed and consequently the corrosion and microhardness were modified, which correlated with the power. NbN film deposited at higher power (150 W) has shown better corrosion resistance (0.9% NaCl), which had smaller grain size (smoother) and was thicker.
Originality/value
The NbN films have a preferred orientation (111) matching to cubic structure phase. Corrosion resistance was enhanced for the NbN films compared to SS304 substrates (noncoating). Therefore, NbN films deposited on SS304 substrate could be applied as medicinal tools as well as in mechanical fields.
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Nehem Tudu, Mayuri Baruah and Shashi Bhushan Prasad
Prior to manufacturing, designing plays a vital role in the selection of materials and other design parameters. Therefore, during the deposition of materials, substrate materials…
Abstract
Purpose
Prior to manufacturing, designing plays a vital role in the selection of materials and other design parameters. Therefore, during the deposition of materials, substrate materials provide support and affect the microstructure of the deposits, which may not be desirable in the manufactured product. Hence, the main purpose of the study is to analyse the behaviour of the microstructure at the interface of deposited material and substrate.
Design/methodology/approach
In this study, two blocks of Inconel 625 (IN625) and Stainless steel 304L (SS304L) metal powders were deposited on an SS304L substrate using laser directed energy deposition (DED) technique. Deposited blocks comprised 50% IN625 + 50% SS304L or 100% IN625. After deposition, microstructural behaviour at the interface of the deposits and substrates was analysed using different tests such as optical microscopy (OM), microhardness testing, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). An improvement in microstructure was proposed by performing heat treatment of the deposited sample.
Findings
Formation of martensite and precipitates at the interface of the deposit and substrate was observed. Formation of martensite and precipitates such as α, carbide and δ phases were observed in OM and SEM images. Due to the formation of these phases, interface regions showed a peak in the hardness graphs. Post-heat treatment of the samples was one of the solutions to resolve these issues.
Originality/value
This paper suggests the formation of a heat-affected zone (HAZ) at the interface of the deposit and substrate, which may negatively affect the overall utility of the deposited part. The properties of the HAZ were investigated. To suppress these detrimental effects, post-heat treatment of the deposited sample was performed, and the samples were further analysed. The post-heat-treated samples exhibited as reduction in HAZ thickness and had more uniform hardness throughout the cross-section compared with the untreated samples.
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Chandan Kumawat, Bhupendra Kumar Sharma, Taseer Muhammad and Liaqat Ali
The purpose of this study is to determine the impact of two-phase power law nanofluid on a curved arterial blood flow under the presence of ovelapped stenosis. Over the past…
Abstract
Purpose
The purpose of this study is to determine the impact of two-phase power law nanofluid on a curved arterial blood flow under the presence of ovelapped stenosis. Over the past couple of decades, the percentage of deaths associated with blood vessel diseases has risen sharply to nearly one third of all fatalities. For vascular disease to be stopped in its tracks, it is essential to understand the vascular geometry and blood flow within the artery. In recent scenarios, because of higher thermal properties and the ability to move across stenosis and tumor cells, nanoparticles are becoming a more common and effective approach in treating cardiovascular diseases and cancer cells.
Design/methodology/approach
The present mathematical study investigates the blood flow behavior in the overlapped stenosed curved artery with cylinder shape catheter. The induced magnetic field and entropy generation for blood flow in the presence of a heat source, magnetic field and nanoparticle (Fe3O4) have been analyzed numerically. Blood is considered in artery as two-phases: core and plasma region. Power-law fluid has been considered for core region fluid, whereas Newtonian fluid is considered in the plasma region. Strongly implicit Stone’s method has been considered to solve the system of nonlinear partial differential equations (PDE’s) with 10–6 tolerance error.
Findings
The influence of various parameters has been discussed graphically. This study concludes that arterial curvature increases the probability of atherosclerosis deposition, while using an external heating source flow temperature and entropy production. In addition, if the thermal treatment procedure is carried out inside a magnetic field, it will aid in controlling blood flow velocity.
Originality/value
The findings of this computational analysis hold great significance for clinical researchers and biologists, as they offer the ability to anticipate the occurrence of endothelial cell injury and plaque accumulation in curved arteries with specific wall shear stress patterns. Consequently, these insights may contribute to the potential alleviation of the severity of these illnesses. Furthermore, the application of nanoparticles and external heat sources in the discipline of blood circulation has potential in the medically healing of illness conditions such as stenosis, cancer cells and muscular discomfort through the usage of beneficial effects.
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Haijing Sun, Jianing Cui, He Wang, Shuai Yang, Souavang Xaikoua, Yong Tan, Xin Zhou, Baojie Wang and Jie Sun
The purpose of this paper is to study the effect of temperature on Zn–Ni alloys in ChCl–Urea.
Abstract
Purpose
The purpose of this paper is to study the effect of temperature on Zn–Ni alloys in ChCl–Urea.
Design/methodology/approach
Based on cyclic voltammetry experiments, the deposition behavior and kinetics of the Zn–Ni alloy are studied. The nucleation process of the Zn–Ni alloy is studied in detail via chronoamperometry experiments. The effects of the deposition temperature on the microstructure, Ni content and phase composition of Zn–Ni alloy coatings are investigated via scanning electron microscopy and X-ray diffraction (XRD) combined with classical thermodynamics.
Findings
The results show that with increasing temperature, the reduction peak shifts toward a more positive electric potential, which is beneficial for the co-electric deposition process, and the diffusion coefficient is estimated. With increasing temperature, the nucleation process of the Zn–Ni alloy becomes a three-dimensional instantaneous nucleation, the typical kinetic parameters are determined using the standard 3D growth proliferation control model and the Gibbs free energy is estimated. The Zn–Ni alloy coatings are prepared via normal co-deposition. With increasing temperature, the degree of crystallinity increases, the coating gradually becomes uniform and compact and the XRD peak intensity increases.
Originality/value
The nucleation process of the Zn–Ni alloy at different temperatures is analyzed. The diffusion coefficient D and Gibbs free energy are calculated. The contribution of the three processes at different temperatures is analyzed. The effect of temperature on the morphology of the Zn–Ni alloy coatings is studied.
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While poverty alleviation is the first core goal of Sustainable Development Goals (SDGs), and microfinance institutions (MFIs) are considered important instruments for poverty…
Abstract
Purpose
While poverty alleviation is the first core goal of Sustainable Development Goals (SDGs), and microfinance institutions (MFIs) are considered important instruments for poverty alleviation in developing countries as they provide credit access to the poor, there is surprisingly little evidence of the drivers of the lending behavior of microfinance institutions. Hence, the purpose of this study is to identify the factors that influence the credit growth of MFIs in Sub-Saharan Africa (SSA).
Design/methodology/approach
The study relies on unbalanced panel dataset of 130 MFIs operating across 31 countries in SSA during the period 2004–2014 constituting 546 useable observations. The study uses the Arellano-Bover/Blundell-Bond two-step generalized method of moments (GMM) Windmeijer bias-corrected standard errors to estimate the models.
Findings
The results confirm that while capitalization, liquidity and size are positively associated with credit growth, profitability negatively impacts credit growth; whereas, other MFI specific factors namely portfolio quality, deposit growth and nondeposit borrowing growth have little direct effects on MFI credit growth. The results also show that MFI credit growth is pro-cyclical but negatively related to GDP per capita consistent with the theory of convergence. On the other hand, inflation and employment are not important covariates in the credit growth of MFIs.
Practical implications
The findings suggest that if MFIs improve their liquidity and size by attracting more deposits and nondeposit borrowings, among others, they can increase credit access to the poor. Moreover, since the lending behavior of MFIs is not resilient to GDP shocks, different measures are needed to increase the financial stability of the microfinance industry. In this respect, since MFI capitalization is positively associated with credit growth and MFI credit growth is pro-cyclical, the findings provide useful insights to central banks/regulatory authorities and the Basel Committee as to the need for a counter-cyclical capital buffer requirement in the microfinance industry.
Originality/value
The study is the first comprehensive study to examine the drivers of MFI lending behavior as an extension to lending behavior models from the banking industry.
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