bluuebunny/crossref_metadata_2025_split huggingface dataset:
PENGARUH SUPERVISI KEPALA SEKOLAH DAN KOMPETENSI PEDAGOGIK GURU TERHADAP KINERJA GURU SD SE-KECAMATAN PANGKALAN KERINCI KABUPATEN PELALAWAN
Authors: Romawi Tri , Isjoni Isjoni , Daud Afrianto 
Published: September 2022

This study aims to determine the effect of principal supervision and pedagogical competence of teachers on the performance of elementary school teachers in Pangkalan kerinci sub-district of pelalawan district. The population in this study was all teachers of SD Se, Pangkalan Kerinci District, Pelalawan Regency, totaling 180 respondents, and the research sample was 30 respondents. The data analysis used is correlation analysis, correlation coefficient, and coefficient of determination. The results of this study show that there is a positive influence between the principal's supervision (X1) on Teacher Performance (Y) and the Determinant Coefficient = (0.774)2 x100 = 60%. There is also a positive influence between Paedagogic Competence (X2) and Teacher Performance (Y) with Determinant Coefficient = (0.742 )2 x100 = 5.50%. While the Influence of Principal Supervision (X1) and Paedagogic Competence (X2) on Teacher Performance (Y) has a determination coefficient of r2y1.2 = (0.839)2 x100 = 70.4 %. Conclusions from the variables of Principal Supervision and Paedagogic Competence with variables of elementary teacher performance in Pangkalan Kerinci District, Pelalawan Regency has a positive direction.
Characterization of Nanocrystalline Thermally Sprayed Coatings by Means of 4-Point-Bending Fatigue Tests
Authors: Hahn M. , Fischer A. 
Published: September 2022

Abstract
The future demands of diesel engines require new options for low-friction and wear-resistant materials in order to increase efficiency and achieve environmentally sound solutions. Efforts are made to improve the performance and reduce the weight of engine blocks by coating the Aluminium cylinder bores with thermal-spray processes. Thus beside other means today nanocrystalline coatings are currently discussed, which should allow for the desired combination of structural, productional, and topographical properties. Beside sufficient tribological properties it is important that the composite (base material and coating) allows for an elongated endurance under cyclic mechanical and thermal stresses. In this work a four-point-bending test was used to examine deleterious failure mechanisms during fatigue such as spalling of the coating or delamination from the substrate. Therefore various thermally sprayed coatings were bent in tension and compression. The results were analysed in relation to the coating microstructure.
Cavitation Erosion for WC Cermet Coating Prepared by HVOF
Authors: Mizuno H. , Aoki I. , Tawada S. , Ibe H. , Sato K. , Kitamura J. 
Published: September 2022

Abstract
Cavitation erosion is one of the serious problems that affect lifetime and performance on hydraulic machineries and its components. Surface modification techniques is required to apply to hydraulic components, such as water turbine and radial flow pump, in general. Here, the techniques, which can easily be applied to large area, is must be required for actual applications in the fields. Thus, thermal sprayed WC cermet coatings with high abrasion resistance under wet conditions are one of the promising solutions as the protective coatings against cavitation erosion. In this study, WC/Cr3C2/Ni and WC/Co/Cr coatings prepared using a high-velocity oxygen fuel (HVOF) spraying have been evaluated by a magneto-striction vibratory apparatus to investigate the cavitation erosion resistance. The microstructures of the sprayed coatings after the cavitation erosion test have been analyzed by SEM to clarify the erosion mechanism. It has been found that the cavitation erosion resistance of the WC cermet coatings is significantly affected by primary particle size of WC, powder compositions and spray conditions. In the WC/10wt%Co/4wt%Cr, the coating with WC average particle size of 6.3 µm sprayed by optimized spray conditions achieved the highest cavitation erosion resistance than the other WC coatings as well as base materials of stainless steel used in the actual components.
Development of a Sealing Technical Layer for SOFCs Applications
Authors: Caron N. , Bianchi L. , Méthout S. 
Published: September 2022

Abstract
Solid oxide fuel cell are being widely considered as the promising answer to the fossil energy decrease. To achieve high efficiency and longevity for SOFC stack it is essential to maintain stable hermetic sealing. In order to obtain an efficient airtightness between two SOFC layers, the authors had developed a solid seal composed with a ceramic matrix charged with glass particles. The seal is plasma-sprayed using low-cost manufacturing methods such as atmospheric plasma spraying. This technical deposit can be plasma-sprayed on a wide range of substrates: whatever its nature and shape. It is solid, distortable and adhesive to its support at ambient temperature. The sealing properties are acquired when the SOFC is put into service: the glassy phase migrates into the peculiar plasma-sprayed microstructure of the ceramic matrix towards the interface involving the airtightness. The performance of this seal are pretty good: the leak rate observed at 70 mbar is 0.0042 mbar.l/s whereas the preconisation of the US Department of Energy is 0.005 mbar.l/s.
Effect of the Structural Scale of Plasma-Sprayed Alumina Coatings on their Friction Coefficients
Authors: Darut G. , Ageorges H. , Denoirjean A. , Montavon G. , Fauchais P. 
Published: September 2022

Abstract
The objective of this study is to compare the tribological properties of alumina coatings structured at two different scales, a micrometric one manufactured by atmospheric plasma spraying (APS) and a nanometric one manufactured by suspension plasma spraying (SPS). Coatings architectures were analyzed and their friction coefficient in dry sliding mode measured. Sub-micrometric-sized coatings present a lower friction coefficient compared to micrometric- sized one, thanks to their higher cohesion and smaller structural feature characteristic sizes.
CFD Optimised Nozzles for Increased Particle Velocities and Lowered Gas Consumption in the HVOF Spraying Process
Authors: Wielage B. , Paczkowski G. , Rupprecht C. , Landes K. , Schein J. , Zimmermann S. , Weissenfels G. , Menzen R. 
Published: September 2022

Abstract
Well-adjusted processing conditions are the basics for a high quality of thermal sprayed coatings. For HVOF spraying that means super sonic particle velocities and moderate particle temperatures. To fulfil these requirements, a certain speed of the gas jet is necessary. If low fuel and gas consumption is aspired, this can only be realised with adapted nozzle designs. Some efficient ways of nozzle design optimisation are shown in this paper. Novel methods and strategies in computed fluid dynamics are explained and correlated to experimental results. For this purpose, gas jet and particle velocities are investigated by means of laser optical measurements.
Plasma Sprayed Oxygen Electrode for Solid Oxide Fuel Cells and High Temperature Water Electrolyzers
Authors: Syed A.A. , Ilhan Z. , Schiller G. 
Published: September 2022

Abstract
Perovskite-type LSM and LSCF deposits were developed for oxygen electrode for solid oxide fuel cell and high temperature water electrolyzer by atmospheric plasma spraying (APS) using different feedstock powders. The deposits were tailored to exhibit high oxygen catalytic activity, oxygen surface exchange and diffusion rates, gas permeability and electronic-ionic conductivity. Deposits did not exhibit undesired secondary phases that may form in plasma. Promoting partial melting of the surface of the particles ensured interlayer cohesion and very porous deposit. In SOFC mode cells with LSCF cathodes operating at 800 °C had more than 700 mW/cm² power densities at 0.7 V, which was 35% better than that of cells with LSM cathode. When operating in electrolyzer mode at 800 °C the cells with LSCF oxygen electrode also proved significantly enhanced electrochemical performance compared to cells with LSM oxygen electrode. At a current density of 1 A/cm2 the voltage for water splitting was reduced to around 1.4 V at an operating temperature of 800 °C and to 1.28 V at 850 °C.
Thermal Spray Coatings in Printing and Papermaking
Authors: Jungklaus H. 
Published: September 2022

Abstract
The effects of globalization, technology improvement, capacity consolidation, and rising customer demands drive the printing and papermaking business worldwide. Consumption of paper, paperboard, and tissue exceeded 500 million tons in 2007, and it is estimated that one-third to one-half of this production is printed. Paper production in total is not experiencing drastic growth rates due to the increasing market share of digital media; however, market segments such as paperboard and packaging are showing growing demand. In printing, new technologies focus on production speed and quality improvement. For both printing and papermaking, the cost of energy and raw materials requires ongoing improvements in production efficiency. For equipment and machinery manufacturers serving these industries, high-end technology that lowers cost and improves quality drives the market leaders. In both industries, functional roll surfaces generated by thermal spraying help to achieve design and development objectives. The paper gives examples for the role of thermal spray coatings in both industrial areas.
Review of Applications of Thermal Spraying in the Printing Industry in Respect to OEMs
Authors: Döring J.-E. , Hoebener F. , Langer G. 
Published: September 2022

Abstract
Printing machines mirror the art of precise manufacturing and adjusting of fast moving and heavy components with an accuracy of few micrometers. In order to meet the challenge of fast and high quality printing combined with a long lifetime of the machines, the core components transporting the print substrate and the different kinds of ink and other liquids needs to be coated, what is done more and more by applying thermal spray processes. The main requirements cover wear and corrosion resistance as well as suitable wetting and special needs like the ability of laser engraving. Moreover, the coatings are post processed to achieve a sufficiently low surface roughness combined with an appropriate microstructure resulting in a fine structure if laser engraving is considered. This paper will give a review of applications, techniques and materials, which are well-established in printing industry in respect to the specific demands of the case of operation. This covers the surfaces in the printing unit namely the printing and blanket cylinders but also the inking and dampening systems.
Hollow Droplets Micro Explosive Thermal Spraying: Fundamentals
Authors: Solonenko O.P. , Gulyaev I.P. , Smirnov A.V. 
Published: September 2022

Abstract
The peculiarities of plasma treatment of agglomerated YSZ powders as well as mechanically pretreated metal and metal alloy powder with the aim of their spheroidization and subsequent thermal spraying of produced HOSP powders are analyzed. Formation of splats from hollow droplets deserves a special attention for thermal spraying. In this case, immediately prior to particle – substrate collision, we have a droplet that consists of a liquid shell enclosing a gas cavity heated to a temperature close to the particle surface temperature. The paper presented includes the results of computer simulation and model experiments carried out under full control of pre-impact key physical parameters (KPPs): temperature Tp0, velocity up0, external diameter of droplet Dp0, thickness of its shell Δp0 , temperature of substrate Tb0, and its surface state. It was shown that formation of splats from hollow droplets proceeds in a manner more stable compared to the case of “dense” molten particles obtained from fused and crushed compacts, and this provides for a more perfect splat-substrate, splat-splat and coating-substrate interface. Advantages of hollow metal, metal alloy and metal oxide powders over corresponding dense powders for thermal spraying by the example of thermal barrier coatings are discussed. Since the splat formation process involving hollow droplets proceeds, following their high-velocity impact deformation on the base/substrate, in an explosive manner, this type of spraying can be referred as HOSP micro explosive thermal spraying.
Plasma Spraying of Metal Coatings using CO2 Based Gas Mixtures
Authors: Pershin L. , Chen L. , Mostaghimi J. 
Published: September 2022

Abstract
The use of gas mixtures containing hydrocarbons for plasma generation results in higher plasma enthalpy because, molecular gases must dissociate before ionization which requires larger energy input. The torch developed at CACT which operates with CO2+CH4 gas mixtures was used for coating deposition with input power in a range of 30 to 45 kW. This study was focused on the effect of CO2+CH4 mixtures on the particle parameters during spraying of Ni alloy powder. Results of gas composition analysis at various distances from the nozzle exit are presented. The particle in-flight conditions, coating microstructure, and deposition efficiency also were analyzed.
Analysis of the Deposition Mechanism in the Solution Precursor Plasma Spraying using Numerically Predicted Particle Conditions
Authors: Shan Y. , Wang Y. , Coyle T. 
Published: September 2022

Abstract
Solution precursor plasma spraying has been used to deposit ceramic coatings with submicron/nanocrystalline structures. Previous studies revealed that the deposition mechanism in the solution precursor plasma spraying differs from that in the conventional plasma spraying. To increase the understanding of the deposition mechanism in the solution precursor plasma spraying, a numerical model is used to predict the particle conditions on the substrate. Five types of particle conditions, melted particles; small sintered particles; dry agglomerates; wet agglomerates; and wet droplet are assumed based on the computed temperature distribution of the particles. An analysis of the deposition mechanism in the solution precursor plasma spraying is performed. Experiment results s are also collected to verify the numerical prediction and the analysis of the deposition mechanisms.
Deposition Mechanism of Cold Sprayed MCrAlY Coatings Focused on Nanostructure
Authors: Ichikawa Y. , Miyazaki T. , Ogawa K. , Shoji T. , Jeandin M. 
Published: September 2022

Abstract
Thermal-sprayed MCrAlY coatings are widely used for land-based gas turbine applications. The cold spray may increase the coating density owing to the high-velocity particle impacts during spraying. Many researchers have considered critical velocity to be the most important factor of the deposition mechanism of cold-sprayed coatings. However, this dominant parameter of critical deposition condition has not been completely understood. In order to understand the mechanism, two approaches were used in this study. One is the transmission electron microscope (TEM) observation of the interface between the coating and the substrate, and the other is the cross-sectional observation of the deposited particle by using the focused ion beam (FIB) cutting technique. From the TEM observations, there are no evidences of melting at the interface, and it is found that the actual bonding occurred at the nascent surfaces. Generally, there is a native oxide on the surface of the particles and substrate. After the plastic deformation of the particles and substrate, the native oxide breaks down; subsequently, a nascent surface can be created and direct contact initiates deposition. From the results of these investigations, it is thought that the dominant factor for deposition is the plastic deformation of the particles and substrates.
Predicting Quenching and Cooling Stresses within HVOF Deposits
Authors: Stokes J. 
Published: September 2022

Abstract
Due to the nature of the HVOF and other thermal spray processes, residual stress build up in thick deposits is a significant and limiting problem. The residual stress-state that evolves in a deposit is largely dependent on the thermal conditions to which the system has been subjected, and is a combination of quenching stresses, which arise during deposition, and cooling stresses, post-deposition. It follows that precise control of these phenomena is essential, if a thick deposit or one with low levels of residual stress are to be thermally sprayed. This paper applies looks at analytical and finite element techniques used to predict quenching and cooling stresses within tungsten carbide-cobalt thermally sprayed deposits. The analysis investigates and predicts the quenching and cooling stresses using improved analytical and FEA techniques by validating the models with experimental results such as X-Ray Diffraction and the Hole Drilling Method. The result of this paper is a thermo-mechanical equation for quenching stress which includes the effects of misfit strain, the Poisson’s effect, variation of coating and substrate thicknesses, thermal expansion and process temperature effects.
Mechanical Properties of W-Re and W-Re-HfC Alloys Made by Vacuum Plasma Spray
Authors: O'Dell J.S. , McKechnie T.N. 
Published: September 2022

Abstract
The mechanical properties of tungsten-rhenium and tungsten-rhenium-hafnium carbide alloys produced by vacuum plasma spray forming have been evaluated. The results of both tensile and three-point bend tests at room temperature and elevated temperatures will be discussed. In addition, the results of a microstructural analysis will be presented.
Microstructure and Wear Behavior of Arc Sprayed WC-12Co/FeB and WC-12Ni/FeB Composite Coatings
Authors: He D. , Fu B. , Jiang J. , Li X. 
Published: September 2022

Abstract
A ceramic composite coating of a FeB alloy reinforced with cobalt-coated tungsten carbide (WC-12Co) particles and nickel-coated tungsten carbide (WC-12Ni) particles was deposited on a mild steel substrate by arc spraying cored wire, respectively. The microstructure and the worn surfaces of the coatings were analyzed by X-ray diffraction (XRD), Scanning electron microscope (SEM). And wear mechanisms of the coatings have been discussed on the basis of the observation. The results showed that adding WC powders can obviously increase the hardness and abrasive wear resistance property of the coating. The average microhardness of the coatings is about 900~1000 HV0.1. In the experimental conditions, the coatings have the excellent abrasive wear resistance which is 7~10 times higher than that of the Q235 mild steel. Plastic microcutting and brittle peeling play the predominant role in abrasion wear of the coating.
Modeling of Oxygen Input Into Particles at Arc Spraying
Authors: Korobov Y. , Boronenkov V. 
Published: September 2022

Abstract
A scheme of an oxygen input by particles at Arc Spraying is offered. Both external and internal diffusion processes are taken into account. The oxygen input was separately examined at arc-burning zone and spraying distance. At first the oxygen is dissolved in liquid metal drop up to a limit of saturation. Then slag formation begins accompanied by metal – slag interaction. Modeling of these processes was performed on a base of oxygen input/output mass balance. It was completed by computation of oxygen diffusion flows into gas and metal through interface surface. Mutual influence of alloying elements was also taken into account at slag formation on particle surface. The modeling results are represented in case of arc sprayed steel (1.1 C, 1.9 Mn, 0.8 Si). Propane - air mixture was used as a transporting gas. Good similarity with experiment data was achieved. As shown by calculations, basic share of oxygen input occurs in the arc-burning zone. The investigation results were used in core wire developing and gun designing as well.
Suspension Plasma-Sprayed Alumina Coating Structures: Operating Parameters vs. coating Architecture
Authors: Tingaud O. , Grimaud A. , Denoirjean A. , Montavon G. , Rat V. , Coudert J.-F. , Fauchais P. , Chartier T. 
Published: September 2022

Abstract
Suspension plasma spraying (SPS) is a fairly recent technology that is able to process sub-micrometric-sized feedstock particles and permits the deposition of layers thinner (from 5 to 50 µm) than those resulting from conventional atmospheric plasma spraying (APS). SPS consists in mechanically injecting within the plasma flow a liquid suspension of particles of average diameter varying between 0.02 and 1 µm. Upon penetration within the DC plasma jet, two phenomena occur sequentially: droplet fragmentation and evaporation. Particles are then processed by the plasma flow prior their impact, spreading and solidification upon the surface to be covered. Depending upon the selection of operating parameters, among which plasma power parameters (operating mode, enthalpy, spray distance, etc.), suspension properties (particle size distribution, powder mass percentage, viscosity, etc.), and substrate characteristics (topology, temperature, etc.), different coating architectures can be manufactured, from dense to porous layers. Nevertheless, the coupling between the parameters controlling the coating microstructure and properties are not yet fully identified. The aim of this study is to further understand the influence of parameters controlling the manufacturing mechanisms of SPS alumina coatings, in particular the spray patterns influence.
Arc Sprayed Coatings Obtained from Iron Based Cored Wires Under High Temperature Abrasive Wear Conditions
Authors: Pokhmurska H. , Wielage B. , Grund T. , Student M. , Sirak Y. 
Published: September 2022

Abstract
Development of new arc sprayed iron based coatings for protection against gas abrasive wear at room and elevated temperatures are of the great interest because of permanently increasing pressure to reduce production and repair costs of power production facilities. Two cored wires in steel cover with Fe-Cr-B-Al and Fe-Cr-N-Al filling are proposed as an alternative choice for self fluxing and cermet coatings that are considered nowadays for protection of screen tubes of boilers of power stations that are operated under the temperatures 500-600 °C. Oxidation behaviour of arc sprayed coatings is estimated by gravimetric measurements. Abrasive wear resistance at elevated temperatures after 1 hour is investigated by means of laboratory unit that alloys a rotation of coated specimens in heated quartz sand. It is shown that abrasion wear lost of carbon steel increases 1.5 times when test temperature increases from 20 °C to 550 °C. For all investigated coatings the 20-25% decrease of wear lost is observed at higher temperature. Arc sprayed coatings of both investigated systems improve significally the abrasive wear resistance of carbon steel. At room temperature the improvement by factor 1.3-2.2 times and at the temperature 550 °C by factor 2.7-4.6 is observed depending on chemical composition of coatings.