bluuebunny/crossref_metadata_2025 huggingface dataset:
Persepsi Harga dan Promosi Terhadap Keputusan Pembelian online pada Marketplace Shopee Paska Pandemic Covid-19
Authors: Rajagukguk Peter , Hardani Hardani , Kartawijaya Ferry
Published: May 2023

Penelitian ini bertujuan untuk menganalisis faktor-faktor yang mempengaruhi keputusan pembelian oline pada marketplace shopee paska pandemic covid-19. Faktor yang digunakan sebagai variabel independen adalah Harga (X1), dan promosi penjualan (X2). terhadap Keputusan Pembelian (Y) sebagai variabel dependen. Penelitian dilakukan terhadap masyarakat di kabupaten Tangerang dengan responden 105 dengan accidental sampling methode. Jenis penelitian explanatory research dengan metode deskriptif kuantitatif,  Metode pengumpulan data menggunakan, observasi, kuesioner dan dokumentasi, dengan  pengolahan data menggunaan  SPSS versi 25. Penelitian ini menunjukkan  bahwa ada pengaruh  yang kuat antara promosi penjualan, persepsi harga terhadap keputusan pembelian dengan nilai korelasi 0,732 yang berarti korelasi antar variabel kuat. Ini menunjukkan bahwa promosi penjualan dan persepsi harga memiliki pengaruh yang kuat dan signifikan terhadap keputusan pembelian. Berdasarkan hasil uji regresi, Y= 1,723+0.395X1+0.354X2 promosi penjualan dan persepsi harga berpengaruh positif terhadap keputusan pembelian. Hasil uji koefisien determinasi menunjukkan bahwa R square sebesar 0,536. Menggambarkan bahwa secara simultan faktor promosi dan persepsi harga mempengaruhi keputusan pembelian online sebesar 53,6%.

Kata Kunci: Harga, Keputusan Pembelian, Promosi
Influence of Surface Geometry and Microstructural Features on the Delamination and Crack Propagation of Brittle Convex Thermal Barrier Films during Thermal Cyclic Loading
Authors: Nastic Aleksandra , Pershin Larry , Mostaghimi Javad
Published: May 2023

The influence of air plasma sprayed alumina coating geometry, microstructure, interface roughness on its delamination and crack propagation resistance during low temperature thermal cycling, i.e. thermal mismatch stress, is investigated both numerically and experimentally. Previous studies on thermal cycling loading concentrate on flat, numerically designed locally curved specimens and/or mathematically modeled roughness without extension towards real coating morphology, which renders the conclusions less practically driven. Results show that arbitrarily oriented cracks originate predominantly near the coating/substrate interface and propagate along zones of high tensile and shear residual stress. The crack path deflection was attributed to the complex stress concentration structure resultant from the intricate microstructural porosity and coating general convex geometry. Microstructural features such as porosity increase the interfacial and coating tensile stress, which may lead to important delamination processes even during low temperature thermal cycling.
Thermo-Physical Properties of Plasma-Sprayed K2Ti6O13 Coatings for Diesel Engine Piston
Authors: Sun Yin-Qiu , Zhu Yong-Sheng , Luo Xiao-Tao , Gao Jiu-Tao , Li Chang-Jiu
Published: May 2023

A new challenge in the transport systems concerns with improving efficiency. Thermal swing coatings are interesting candidates for internal combustion engines due to their potential to reduce cooling requirements and increase efficiency. K2Ti6O13 (KTO) thermal barrier coatings (TBCs) were prepared by atmospheric plasma spraying through powder structure design and optimization of deposition conditions. The thermophysical properties of plasma-sprayed KTO deposits and their effect on the thermal swing have been investigated. Their thermal conductivities were tested by a laser flash method and the thermal performance of the coatings was further examined by thermal swing test. The phases, nominal chemical compositions and microstructure of KTO deposits were characterized by X-ray diffraction (XRD) and scanning electron microscopy combined with energy dispersive spectrometry (SEM-EDS). The results indicated that the chemical composition change occurs to the coatings resulting in a deviation from nominal stoichiometry due to chemical reactions between the plasma gas and particles. The thermal conductivity of the coating is very sensitive to the coating compositions, and the coating prepared using porous powder under pure argon presents a single K2Ti6O13 phase and high porosity, and the lowest thermal conductivity of 0.85 W/m·K.
Enhancing Production Control for PTWA Engine Bore Coating
Authors: Kowalsky K. , Barton D. , Cook D. , Berghorn C.
Published: May 2023

Plasma Transferred Wire Arc (PTWA) is a well-established thermal spray process that is used in high-volume production by multiple automotive OEMs. Benefits of these PTWA thermal spray coatings include closer bore spacing, improved thermal transfer, lower bore distortion, increased resistance to corrosion and abrasion, reductions in weight and friction, enhanced durability, and product cost savings. For automobiles, this leads to increased fuel economy and lower emissions. Millions of engine cylinder bores per year are coated using the PTWA thermal spray process. To ensure optimal surface coatings, it is vital to monitor the process variables. Although some process monitoring already exists in current production, new technological advancements allow for additional variables to be monitored. Arc voltage is of particular importance as it can be viewed real-time in situ to the PTWA process to determine the curvature of the feedstock wire. Straight wire is ideal for achieving peak system performance. If the wire has excessive curvature, it can lead to out-of-tolerance conditions that detrimentally affect the quality of the surface coating. Therefore, in-situ monitoring of wire curvature is both desirable and necessary for producing the highest quality PTWA thermal spray coatings possible.
Oxide Characterization of Copper Cold Spray Feedstock Powders with X-Ray Photoelectron Spectroscopy
Authors: Katsari Christina Maria , Kotsakis Yannis , Yue Stephen , Guerreiro Bruno , Poirier Dominique , Giallonardo Jason D.
Published: May 2023

In conventional powder processing, there has been considerable work on classifying feedstock powders based on particle size distribution, morphology, microstructure and composition, since these influence processability and final properties. Cold spray is a new application for powders and conventional characterization may be insufficient to assess powder cold sprayability. In particular, metallic powders have an oxide layer, which breaks during impact with the substrate or with another coating layer during cold spray; this fragmentation facilitates bonding. It has been suggested that the thickness of the oxide layer can influence the mechanism of fragmentation; thicker oxides are easier to remove, revealing clean metal surfaces that can metallurgically bond. Consequently, not all high-purity powders or powders that are stored in ambient conditions have the potential to give good coating properties after cold-spray. This work focuses on surface oxidation of the powders, characterizing the variation of oxide film aspects with size and composition of nominally pure copper powders using X-ray Photoelectron Spectroscopy (XPS). The results indicate the presence of Cu (I) and Cu (II) oxide species on the surface of as-received, naturally aged and heat-treated powders; their thickness is determined using the depth profiling feature.
Comparative Study of Ni-, Co- and Fe-Based Laser Cladding Coatings for Wear and Corrosion Resistance
Authors: Larouche Bernard , Hepp Rolf , Reisel Guido , Fiala Petr
Published: May 2023

Among hardfacing processes using welding, laser cladding is nowadays one of the most efficient surface coating techniques. It is widely used to increase wear and corrosion resistance of machine parts as a result of the unique process characteristics such as low heat input (smaller heat affected zone), distortion free clad layers, lower dilution rate, finer coating microstructure as well as good metallurgical bonding at the coating/substrate interface. A wide range of new hardfacing materials and corrosion-resistant alloys are available on the market and in this study, different coatings of Ni-, Co- and Fe-based alloys as well as carbide-based metal matrix composites have been deposited by laser cladding for benchmarking purposes. Coatings were deposited onto mild steel substrates using a high-power diode laser. Coating microstructure and hardness were investigated as well as their tribological properties such as 2-body and 3-body abrasion, slurry abrasion and cavitation erosion resistance. Corrosion performance of coatings was also investigated with the salt spray test. Coatings are ranked according to their performance in the different tests and relationships between microstructure and coating properties are discussed.
Influence of Nozzle Diameter on Electric Arc Dynamics in a Cascaded-Anode Plasma Torch
Authors: Ruelle Céline , Goutier Simon , Rat Vincent , Kéromnés Alan , Rivaud Geoffroy , Chazelas Christophe , Meillot Érick
Published: May 2023

Electric arc dynamics in plasma torch affects plasma jet stability and consequently, coating properties. Depending on plasma torch design, voltage fluctuations can vary from 100 % to only a few percent of the mean voltage. Particularly, cascaded-anode plasma torch leads to very low voltage fluctuation owing to the presence of neutrodes that limit the amplitude of arc fluctuations. However, electric arc dynamics and electrode erosion process in this type of plasma torch are still poorly understood. The aim of this work is to deepen the knowledge on the influence of nozzle diameter on electric arc dynamics for two plasma forming gas compositions by means of several diagnostics devices (end-on imaging, current and voltage time monitoring, plasma jet brightness fluctuations and thermal balance determination). Reducing nozzle diameter from 9 mm to 6.5 mm results in higher voltage fluctuations, lower mean voltage and lower plasma torch thermal efficiency, probably due to a more evenly distributed warm plasma gas in the anode nozzle volume, as suggested by the higher plasma brightness. Nozzle observations after testing show significant wear in a 6.5 mm diameter nozzle, which may be evidence of a longitudinal movement of the electric arc on the anode surface, leading to high voltage fluctuations.
A Novel Approach to In Situ Coating Thickness Measurements in Thermal Spraying
Authors: Hudomalj Uroš , Sichani Ehsan Fallahi , Weiss Lukas , Nabavi Majid , Wegener Konrad
Published: May 2023

Coating thickness is considered to be one of the most important characteristics of thermally sprayed coatings. Despite this, there is a lack of a measurement method that could evaluate in situ the coating thickness with a sufficient accuracy that could be used as a feedback signal for online, closed-loop control. Offline methods that produce spatially resolved coating thickness measurements by capturing the surface topography have already been demonstrated to provide results with a high accuracy, comparable to the standard reference microscopical measurement method. However, up to now, the approach has not been applied in situ. This paper presents a novel approach to in situ measure spatially resolved coating thickness. It is based on a differential distance measurement of sample thickness before and after applying the coating. A high-resolution 3D camera is used to capture the surface topography and include it in the thickness measurement. The technique provides a 3D view of the deposited coating thickness measured in situ and gives results with excellent accuracy when compared to the reference microscopical method.
Towards a General Cold Spray Additive Manufacturing Framework for Fabricating Complex Structural Components
Authors: Li Wenbo , Wu Hongjian , Shi Zhoukun , Liao Hanlin , Costil Sophie , Deng Sihao
Published: May 2023

As an emerging additive manufacturing method, cold spray additive manufacturing (CSAM) has attracted more and more researchers’ attention due to its unique advantages. However, only a few researchers have studied the fabrication of complex structural components. Therefore, it is important to develop a general CSAM framework that is suitable for the fabrication of different shapes of workpieces. In particular, the choice for the optimal kinematic spraying parameters, the prediction of deposit evolution and the planning of spraying trajectory are the most basic and crucial. Different sub-modules are integrated in the proposed framework to solve these problems. In detail, the modeling methodology is used to obtain the optimal kinematic spraying parameters and to predict the deposit evolution in the simulation. Based on the feasible parameters, the trajectory planification methodology is used to generate the spraying trajectory for the workpiece being manufactured, especially the workpiece with complex structure. Finally, the simulation and experimental results of a fabrication for a workpiece with complex structure provide the developed system is reliable and effective. The framework developed in this paper can considered as a general tool for additive manufacturing of with complex structural workpieces in the CSAM.
Property Characterization of Al1050 Bulk Cold Spray Deposits and Numerical Study of Thermomechanical Effects during the Additive Growth
Authors: Sokore Mohamed , Deng Sihao , Liao Hanlin , Raoelison Rija Nrina , Gao Shuohong
Published: May 2023

Cold Spraying is an emerging additive manufacturing method that uses a high-speed collision of micrometre sized powders capable of producing a solid-state bonding. Such a principle has led to the recent development of a coating for various surface functionalization and additive manufacturing applications. This paper is the result of an experimental study on the evolution of the deposit properties (ultimate strength, and porosity) generated by the additive growth during cold spraying. The deposit characterization shows the existence of ultimate strength gradient. For samples taken from the bottom to the top of the deposit, the ultimate strength decreases but there is no significant change in porosity value. The porosity evolutions do not allow to establish a generalized law of variation. The numerical analysis of the additive growth shows that the thermomechanical response of the stacking powder during the additive growth can decrease the bonding capacity, the thermomechanical heating (due to the plastic work) and the gradient of thermal kinetics.
Mixed-Material Feedstocks for Cold Spray Additive Manufacturing of Metal-Polymer Composites
Authors: Schwenger Matthew S. , Kaminskyj Madison S. , Haas Francis M. , Stanzione Joseph F.
Published: May 2023

High-performance polymers such as poly(ether ether ketone) (PEEK) are appealing for a wide variety of industrial and medical applications due to their excellent mechanical properties. However, these applications are often limited by relatively low thermal stability and conductivity compared to metals. Many methods developed to metallize polymers, including vapor deposition and thermal spray processes, can lead to poor quality control, low deposition rate, and high cost. Thus, cold spray is a promising potential alternative to rapidly and inexpensively produce polymer-metal composites. In this study, we investigated the deposition characteristics of metalpolymer composite feedstock, composed of PEEK powder with varying volume fractions of copper (Cu) flake added, onto a PEEK substrate. We prepared the Cu-PEEK composite powder in varying compositions by two methods: hand-mixing the powders and cryogenically milling the powders. Scanning electron microscopy (SEM) of the feed mixtures shows that cryogenically milling the polymer and metal powders together created uniformly distributed micron-scale domains of Cu on PEEK particle surfaces, and vice versa, as well as consolidating much of the porous Cu flake. In lowpressure cold spray, the relatively large volume fractions of PEEK in the composite mixtures allowed for lower operating temperatures than those commonly used in PEEK metallization (300-500 °C). While the deposition efficiencies of each mixture were relatively similar in single-layer experiments, deposits formed after multiple passes showed significant changes in deposition efficiency and composition in PEEK-rich feedstock mixtures. SEM of deposit surfaces and cross-sections revealed multiple co-dominant mechanisms of deposition, which affect both the porosity and final composition of the deposit. Though present in all samples analyzed, the effects of cryogenic milling were more prevalent at lower Cu concentrations.
Methods for 3D Volume Building in Cold Spray Additive Manufacturing
Authors: Wu Hongjian , List Alexander , Gärtner Frank , Klassen Thomas , Deng Sihao
Published: May 2023

Cold spraying (CS) has proved as an attractive and rapidly developing solid-state material deposition process that allows for fast formation of high quality, large 3D volume objects. Low risks of undesirable heat effects lead to increased interest in CS-based rapidly additive manufacturing (AM). However, by continuous powder spraying and high-pressure gas operation, cold spray additive manufacturing (CSAM) in terms of shape building is rather sensitive to operating parameters and imposes high requirements on the control of process conditions and locally needed kinematics. Every step of the manufacturing process therefore needs to be well conceived and planned, especially with regard to the toolpath planning and implementation. This is not only essential to meet basic performance requirements, but also needed to realize the desired accuracy. In order to tackle above needs, the present study presents a new toolpath planning method for 3D volume build-up to improve manufacturing accuracy and flexibility by cold spray additive manufacturing. Applied benchmarking tests prove acceptable shape accuracy and demonstrate that the current method can enhance the capabilities of CSAM for nearnet shape construction. This implies that careful planning and manufacturing strategies should enable to overcome the challenges associated with CSAM.
Analyzing Cold Spray of Polymer-Coated Metal Particles on Polymeric and Composite Substrates
Authors: Singh Nand Kishore , Mennie Nicholas Beau , Nault Isaac , Koohbor Behrad , Haas Francis M. , Jha Ratneshwar
Published: May 2023

Metallization of polymers and fiber-reinforced polymer composites is gaining attention due to the widespread application of these components in various industries, such as wind energy, aerospace, and automotive industries. Cold spray is a promising new technique to achieve the metallization of polymer and fiber-reinforced polymer composites. This work investigates the deposition mechanisms of polymer-coated metallic particles on polymer-based substrates by finite element analyses. Impact mechanics of PEEK-coated nickel particles impacting PEEK and carbon fiber-reinforced PEEK substrates are modeled. Results show the prominence of mechanical interlocking of metallic particles in the substrate, which occurs due to their entrapment inside the substrate, caused by the high energy impact-induced welding of scraped PEEK coating. The PEEK coating acts as a cushioning component, effectively mitigating the impact energy of the metallic component. The scraped PEEK coating also accumulates on the upper half of the particle, forming a cap welded to the substrate and sealing the metallic particle inside. It is observed that the depth of the carbon fiber mat in the substrate affects the mechanism and the success of deposition.
Cold Spraying of Inconel 625 Thick Deposits
Authors: Taherkhani Farrokh , List A. , Keller S. , Kashaev N. , Gärtner F. , Klassen T.
Published: May 2023

Cold spraying (CS) of high strength materials, e.g., Inconel 625 is still challenging due to the limited material deformability and thus high critical velocities. Further fine tuning and optimization of cold spray process parameters is required, to reach higher particle impact velocities as well as temperatures, while avoiding nozzle clogging. Only then, sufficiently high amounts of well-bonded particle-substrate and particle-particle interfaces can be achieved, assuring high cohesive strength and minimum amounts of porosities. In this study, Inconel 625 powder was cold sprayed on carbon steel substrates using N2 as propellant gas under different refined spray parameter sets and powder sizes for a systematic evaluation. Coating microstructure, porosity, electrical conductivity, hardness, cohesive strength and residual stress were characterized in as-sprayed condition. Increasing the process gas temperature or pressure leads to low coating porosity of less than 1 % and higher electrical conductivity. The as-sprayed coatings show microstructures with highly deformed particles and well bonded internal boundaries. X-ray diffraction reveals that powder and deposits are present as γ- solid-solution phase without any precipitations. By work hardening and peening effects, the deposits show high microhardness and compressive residual stresses. With close to bulk material properties, the optimized deposits should fulfill criteria for industrial applications.
Design of Powder Feedstocks for Net Shape Coatings
Authors: Lanz Oliver , Schubert Manuel , Goes Wellington , Ruggiero Giuseppe , Björklund Stefan , Joshi Shrikant
Published: May 2023

For the last few years, the HVAF process has been established as a commercially used process and has gained an increasing share in the market of thermal spraying. The main thermal spray materials being used for HVAF spraying have been those based on the tungsten carbide family. Economical aspects and European regulations on chemicals management REACH (Registration, Evaluation and Authorisation of Chemicals) have motivated the demand for thinner WC based coatings, which are still dense and wear resistant. This demand has progressively increased, and the trend shows a further growth in the need for thermal spray feedstock for HVAF sprayed net shape coatings. The challenge for powder producers lies in providing suitable spray powders, with high and consistent quality as well as in considerable volume, to be able to make reliable recommendations to the users of HVAF technology. A deeper understanding of powder requirements for net shape coatings, matching the needs with new powder solutions, and appreciation of the differences in behavior or performance depending on powder type are essential to address the above challenges and constitutes the theme of this paper.
Alloy Design of Feedstock Material for Additive Manufacturing—Exploring the Al-Co-Cr-Fe-Ni-Ti Compositionally Complex Alloys
Authors: Gerdt L. , Müller M. , Heidowitzsch M. , Kaspar J. , Lopez E. , Zimmermann M. , Leyens C. , Hilhorst A. , Jacques P.J.
Published: May 2023

The need for sustainable use of resources requires continuous improvement in the energy efficiency and development of new approaches to the design and processing of suitable materials. The concept of high entropy alloys (HEAs) has recently been extended to more general compositional complex alloys (CCAs) and multi-principal element alloys (MPEAs). One of the major challenges on the way to application of these alloys is the extensive design and selection efforts due to the great variety of possible compositions and its consequences for workability and resulting material properties. The favorable high-temperature strength of Ni-based and Co-based superalloys is ascribed to a defined γ/γ’ structure consisting of a disordered FCC A1 matrix and ordered L12 γ’ precipitates. In the current work we extended this design concept to CCAs, allowing disordered BCC A2 and ordered B2 phases in additions or in substitution of the original γ/γ’ structure. We used a high-throughput screening approach combining CALPHAD-based computational tools with in situ alloying by means of laser cladding. Wall-type specimens with gradient composition in the system Al-Co-Cr-Fe-Ni-Ti with varying Al, Ti and Cr content were analyzed. The combined modelling and experimental screening approach was demonstrated to be a powerful tool for designing new high performance AM-ready feedstock.
Effects of Thermal Exposure on Microstructure of Thermal Barriers Deposited by Hybrid Plasma Spraying
Authors: Musalek Radek , Tesar Tomas , Medricky Jan , Lukac Frantisek , Dudik Jonas
Published: May 2023

Hybrid plasma spraying combines plasma spraying of dry powders and liquids (suspensions and solutions). Combination of these two approaches allows deposition of microstructures consisting of both conventional coarse and ultrafine splats. Moreover, splats with dissimilar size may have also different chemistry. Such combination is potentially interesting for many fields of thermal spraying, including thermal barrier coatings (TBCs), as novel microstructures may be economically and relatively easily obtained. The technology has recently reached a level, where coatings with interesting hybrid microstructures may be reliably deposited, so that their potential for practical applications may be evaluated. In this study, first experimental TBCs with YSZ-based hybrid topcoat were deposited by hybrid water/argon stabilized plasma (WSP-H) technology. Al2O3 and YAG were selected as secondary phase deposited from suspension as both provide strong materials contrast in scanning electron microscope (SEM) so they can be used as “markers” in the coating microstructure. Samples were exposed to thermal cycling simulating in-service TBC conditions in order to test their thermal shock resistance. Changes of the coating microstructure were studied by SEM analysis and X-ray diffraction.
Influence of Size and Mixing Ratio of Micro-Forging Particle on Al Alloy Coating Structure via an In-Situ MF Cold Spray with Simultaneous Injection of Powder form Axial/Radial Directions of Nozzle
Authors: Sakaki Kazuhiko , Saito Chilhaya , Kawakami Ryo
Published: May 2023

In our laboratory, we have developed a method to simultaneously inject different powders from the central axis direction and radial direction of the cold spray nozzle and are producing a composite coating by this method. In the previous research of our laboratory, an Al-12Si alloy coating with excellent wear resistance was produced by micro-forging assisted cold spray using the simultaneous nozzle injection method of powder in the axial and radial directions. Here, Al- 12Si alloy, which has excellent wear resistance, was used for the coating-formed particles, and stainless steel was used for the micro-forging particles. However, because the micro-forging particles were hollow, they remained in the coating. In this paper, we evaluated the influence of increasing the mixing ratio of micro-forging particles instead of solid (no holes) micro-forging particles on the coating structure. At the same time, the behaviors of particles by computational fluid dynamics are also investigated.
A Study on the Powder Manufacturing Effect on Flowability and Deformability of Pure Cu Powders in Cold Spray Application
Authors: Eftekhari Niloofar , Saha Dulal , Jahed Hamid
Published: May 2023

The quality of feedstock powder is a critical factor in determining the properties of coatings deposited using cold spray (CS). However, most commercially available powders are not designed or optimized for CS applications, making it challenging to tailor powders to desired quality. In this research, we investigated and compared the cold-sprayability of four different Cu powders produced by electrolysis and gasatomization methods. We assessed the powders' microstructure, particle morphology and size distribution to understand the effect of manufacturing methods on Cu powder characteristics. We also studied the flowability of the powders using the shear cell method and evaluated their mechanical properties and deformability for CS using nano-indentation. Our results showed that gas-atomized powders with equiaxed grains exhibited promising flowability and deformability for CS applications, outperforming the other powders tested. Specifically, the spherical morphology of gas-atomized powders provided less surface area than the irregular-shaped electrolytic powder, reducing the interaction of surface forces and contributing to smooth powder flow. Additionally, the gasatomized powder with small dendrites in the microstructure exhibited the highest nano-hardness value (HIT= 1.6±0.1 GPa), while the porous electrolytic Cu powder had the lowest value (HIT= 0.7±0.2 GPa). In conclusion, we found that gas-atomized Cu powders with equiaxed grains may hold promise as the optimised feedstock for CS application, considering both effective metrics of flowability and deformability.
Suspension Sprayed YSZ Thermal Barrier Coatings on Inconel 718 Aerospike Manufactured by Laser Powder Bed Fusion
Authors: Toma Filofteia-Laura , Gruber Samira , Selbmann Alex , Leyens Christoph , Propst Martin , Dorau Tim , Bach Christian
Published: May 2023

Additive Manufacturing (AM) processes offer geometrical freedom to design complex shaped parts that cannot be manufactured with conventional processes. This leads to new applications including aerospace propulsion systems where the Ni-superalloy based material has to withstand high operating temperatures. In this contribution suspension plasma sprayed YSZ TBC coating was applied on the spike contour of an additively manufactured aerospike engine demonstrator. The engine was designed for a hydrogen peroxide / kerosene 6 kN thrust at 2.0 MPa chamber pressure and was manufactured from nickel-based superalloy Inconel 718 powder using the laser powder bed fusion process (LPBF). Due to the novelty of the application of suspension sprayed YSZ thermal protection coatings on additively manufactured Inconel 718 components, extensive tests were necessary to characterize the interaction between the coating and the component.
Optimization of Parameters for HVOF Spraying of Fine WC-NiCr Powders
Authors: Singh Surinder , Osi Alexander , Wade Scott , Berndt Christopher C. , Ming Ang Andrew Siao , Howse Hugo , Schlӓfer Thomas
Published: May 2023

Thermal spray WC-NiCr coatings generally requires grinding processing to meet the surface finish requirements. The cost associated with grinding can potentially be reduced through the deposition of finer (– 30 + 5 μm) feedstock rather than the more conventional commercial (– 45 + 15 or – 53 + 20 μm) feedstock. Additionally, such a fine powder is likely to require lower energy spray parameters, resulting in less heat input to the substrate, which could be beneficial in application on heat sensitive substrates. However, the spray parameters need to be optimised to mitigate increased degradation of coatings due to unacceptable brittleness caused by decarburisation and oxidation, and to produce defect-free dense coatings. In the present work, a theoretical model to optimise spray parameters was developed, which suggested an oxygen-to-fuel ratio slightly more than 3.3 and a shorter barrel to avoid decarburisation in coatings. In total four parameter sets suggested by the theoretical model were selected to spray the fine-cut powder using a 100 mm long barrel. Scanning electron microscopy, X-ray diffraction, microhardness, and 3Dprofilometer were used to analyse the produced coatings. The coatings deposited using optimised parameters exhibited the best performance in terms of low porosity, inter-splat cracks, brittleness, and roughness. Coating deposited at lower kerosine and oxygen flow rates, with reduced stand-off distance, was denser, crack-free, and ductile. Hence, the fine-cut powder can be used to produce a finer as-sprayed finish, thereby demonstrating the potential in reducing grinding efforts. Additionally, successful deposition of coatings using low energy parameters, making this an attractive option for thermally sensitive substrates.
Antipathogenic Coatings for Antibiotics Reduction in Broiler Farming
Authors: Breitrück Anne , Kreikemeyer Bernd , Henkel K.-M.
Published: May 2023

In the current work, typical thermal-sprayed copper-based alloys are investigated to reduce the spread of pathogenic germs in broiler farming. Compressed air and nitrogen are used as process gas, while the coating torches and the alloys were varied. The results demonstrate a significant reduction in pathogenic load due to the coatings. This accounts especially for the bacterial strain E.ceocurm, which is the predominant bacteria in broiler farming. Further investigations regarded the microstructure and the electrical conductivity of the coatings.
Repair of Damaged Fiber Reinforced Polymer Composites with Cold Spray
Authors: Anni Ibnaj Anamika , Kaminskyj Madison S. , Uddin Kazi Zahir , Haas Francis M. , Koohbor Behrad , Kaminskyj Madison S. , Stanzione III Joseph F. , Haas Francis M. , Koohbor Behrad , Stanzione III Joseph F.
Published: May 2023

The promising structural properties of fiber-reinforced polymer composites make them widely popular in the energy, automotive, defense, and aerospace industries. One of the most challenging limitations associated with the use of composites in the above applications is the maintenance and repair protocols. In this study, a novel cold spray approach is introduced as an efficient alternative for the structural repair of fiber composites. Damages in the form of circular tapered holes are created in glass fiber-reinforced polymer (GFRP) composite substrates using a conventional drilling process. The in-lab created damages are repaired by cold spray with thermoplastic (nylon 6) and thermoset (polyester epoxy resin, PER) materials. The fundamental adhesion mechanisms are investigated through microstructural observations, which point to adiabatic shear instability due to the occurrence of severe plastic deformation as a governing factor. Microstructural examinations also suggest that no significant fiber damage or surface degradation occurs after the repair by cold spray. Mechanical tests performed on neat, damaged, and repaired composites reveal the partial recovery of structural performance and load-bearing capacity after cold spray repair. Results obtained in this work highlight cold spray as a promising alternative technique for onsite structural repair of composite structures with minimal pre/post-processing requirements.
EXAMINATION OF YOUNG PEOPLE'S FAMILY BELONGING ACCORDING TO PARENTAL ATTITUDE PERCEPTION AND SOME VARIABLES
Authors: ALTUN Atilla , DEMİREL Barış
Published: May 2023

This study aims to investigate whether there is a relationship between the perception of family authority and the level of family sense of belonging among young people. Data were collected from 217 students who continue their education in the department of child development at the associate and undergraduate levels at Kırıkkale University.  “Family Sense of Belonging Scale" was used to measure the sense of belonging, and "Parental Attitude Scale" was used to measure the perception of family authority. According to the results obtained from the research, a significant difference was found between the oppressive-extremely controlling parental attitudes and the democratic and liberating parental attitudes in the sub-dimension of self-belonging. In addition, a significant difference was found between the oppressive-extremely controlling parental attitude and the democratic and liberating groups in general family sense of belonging. Over-controlling parental attitudes decrease self-relatedness and general family belonging relatively compared to other dimensions. It was determined that the protective-demanding parental attitude was the most common perception among the participants, followed by the democratic parental attitudes. It was concluded that the general family belonging of the participants was high, and especially the self-affirmation was higher than the sub-dimension of family sense of belonging. It was concluded that the perception of family sense of belonging was highest in family structures where the best understood member of the family was the mother, and the perception of family belonging was the lowest in the participants who got along best with their grandparents.
Pemetaan Perubahan Tutupan Lahan Hutan Mangrove di Kawasan Balikpapan Barat
Authors: Sihaloho Yossy , Abdunnur Abdunnur , Bulan Dewi Embong
Published: May 2023

Ekosistem mangrove yang ada terus mengalami perubahan selama 20 tahun terakhir. Perubahan ini perlu dipetakan untuk mengetahui letak dan luasan perubahan mangrove di Balikpapan Barat dari tahun 2009 hingga 2015. Penelitian ini bertujuan untuk menganalisis perubahan tutupan lahan pada hutan mangrove di kawasan Balikpapan Barat periode 1995-2015. Penelitian ini menggunakan data Penginderaan Jauh yaitu Citra Satelit Landsat 5, Landsat 7 Enhanced Thematic Mapper (ETM+) dan Landsat 8 Operational Land Imager (OLI). Sebaran tutupan lahan mangrove dipetakan secara digital melalui interpretasi citra satelit Landsat 5, Landsat 7 Enhanced Thematic Mapper (ETM+) dan Landsat 8 Operational Land Imager (OLI) menggunakan metode Supervised Classification. Hasil interpretasi tersebut kemudian dipetakan (layout) untuk memberikan informasi agar lebih mudah dibaca dan dipahami. Hasil klasifikasi ini kemudian diuji akurasi lapangan untuk mengetahui dimana terjadi perubahan, pola perubahan dan faktor-faktor penyebab perubahan tersebut. Hasil penelitian menunjukkan bahwa perubahan tutupan lahan hutan mangrove/konversi hutan mangrove dari tahun 1995 ke tahun 2015 menjadi vegetasi non-mangrove sebesar 6,97 ha, konversi lahan hutan mangrove menjadi lahan terbuka sebesar 3,44 ha, konversi lahan Lahan hutan mangrove menjadi pemukiman seluas 16,72 ha dan konversi lahan hutan mangrove menjadi badan air seluas 11,40 ha. Perubahan mangrove yang terjadi memiliki pola acak (penyebaran tidak merata) akibat meningkatnya faktor pertumbuhan manusia dan alih fungsi lahan menjadi tambak.
FEATURES OF GRAVIMETERS IN MODERN GRAVIMETRIC SYSTEMS
Authors:   NTUU В«Kyiv Polytechnic Institute named after Igor SikorskyВ», BEZVESILNA Olena , GRYNEVYCH Mariia ,   State University В«Zhytomyr PolytechnicВ»
Published: May 2023

The paper reviews modern gravimeters of aviation gravimetric systems, their design and principle of operation. Their advantages and disadvantages, features of their functioning and processing of the received data are analyzed. It is shown that high-precision measurements of gravitational acceleration (g) are extremely relevant and necessary for many fields of science and technology. The main characteristics of known aviation gravimeters are given. It has been established that known aviation gravimeters have insufficient accuracy (2-10 mGal). Under the action of the g, the armature moves down inside the magnetic circuit and causes a change in the electromagnetic flux. Under the action of an external electromagnetic flow of an obstacle, this flow will induce two EMF obstacles in two sections, which are included in series-opposite. The total effect of these errors on the output signal of the gravimeter-invention will be zero. The mutual connection of the sections provides cancellation of errors due to the influence of external electromagnetic flows, which can be significant when installing the gravimeter on such a moving object as an airplane. In the same way, the device works under the action of the main obstacle for aviation gravimeters of the vertical acceleration of the aircraft, the errors due to the influence of which are cancelled in the TG. In TG, the residual instrumental errors are cancelled, since they will have opposite signs in the two measuring channels of the two sections of the secondary winding, which are connected oppositely. It is shown that the new TG has significantly greater accuracy than known aviation gravimeters due to the cancellation of errors due to the effects of vertical acceleration of the aircraft, external electromagnetic fields, and residual instrumental errors. It is substantiated that the new TG has significantly greater accuracy than known aviation gravimeters due to the cancellation of errors due to the influence of the vertical acceleration of the aircraft, the influence of external electromagnetic fields, and the influence of residual instrumental errors.
ANALYSIS OF THE PROSPECTS OF THE IMPLEMENTATION OF HYDROGEN ENERGY IN THE ENERGY BALANCE OF COMPANIES IN THE AVIATION INDUSTRY
Authors: BOYKO Serhiy , KOTOV Oleksiy ,   Zaporizhia Polytechnic National University, VYSHNEVSKY Svyatoslav ,   Vinnytsia National Technical University, MELNYK Olga ,   Donetsk National University of Economics and Trade named after Mykhailo Tugan-Baranovskyi, PODHORNYH Nadia ,   Kremenchug Flight College of Kharkiv University of Internal Affairs
Published: May 2023

Hydrogen energy technologies, such as hydrogen storage of energy from renewable sources of electricity, by storing hydrogen as a battery for autonomous and distributed generation and refueling for hydrogen transport, are actively being introduced into the transport industry of developed countries. The transport industry of Ukraine is inextricably linked with the energy industry and has its own characteristics. World experience shows that the introduction of the latest technologies in the transport sector definitely gives a number of unambiguous bonuses for further stable development. Meanwhile, the objects of the transport industry of Ukraine have significant territories that are technologically not involved in the agricultural industry and cannot be used for the development of the cultural and social sphere. In turn, the objects of the transport industry of Ukraine make up its transport infrastructure and are located throughout the territory of Ukraine. Today, hydrogen energy includes a set of technologies for production, transportation, accumulation and use of the universal secondary energy carrier – hydrogen. Thus, in the concept of hydrogen energy, hydrogen complements the most important secondary energy carrier – electricity, the energy use of hydrogen is determined by the possibility of environmentally clean production of electricity and long-term storage with the minimization of losses, including in large volumes. The development of renewable energy, which receives energy from variable natural resources of solar and wind energy, as well as the active implementation of technologies of distributed generation and “smart” networks stimulate the urgency of solving the problem of long-term energy storage. The approach is also designed to settle the issue of the use of wind turbines and SPPs in power supply systems by stabilizing the return of the electric energy generated by them to the network. Undoubtedly, WPPs and SPPs can be connected to the network if necessary, meanwhile, using the proposed approach there is an opportunity to reduce the loss of energy obtained from natural sources and to use it rationally and efficiently. In the conditions of aviation industry enterprises, it is relevant and possible to introduce into the general structure of power supply systems based on renewable energy sources. The proposed approach to the introduction of hydrogen energy in the conditions of aviation industry enterprises allows to effectively use sources of electrical energy based on renewable energy sources both in autonomous power supply systems and to integrate them into existing power supply systems
DETERMINATION OF THE EFFICIENCY OF APPLICATION OF PACKAGES OF TEXTILE MATERIALS FOR THE PRODUCTION OF A SPECIAL PURPOSE JACKET
Authors: HARANINA Olha , REDвЂ™KO Yana , KAMENETS Serhiy , VATAN Raisa ,   Kyiv National University of Technologies and Design
Published: May 2023

The results of research into the properties of modern textile materials, in particular, insulating materials, are presented for choosing a package of textile materials that will be the most effective in terms of quality for the production of a special-purpose jacket that will be used in low-temperature conditions. As insulating materials for the study of consumer properties of textile material packages, the material вЂњTinsuletвЂќ, batting and sintepon, upper fabric вЂњOxfordвЂќ, lining fabric вЂњNylonвЂќ were used. Both the materials themselves and the packages of textile materials from the top fabric вЂњOxfordвЂќ, insulation material and lining fabric вЂњNylonвЂќ were studied. It is assumed that the choice of insulating material is among the presented assortment on the market of Ukraine. It was established that the most effective package is the package using the insulating material вЂњTinsuletвЂќ. This package is characterized by the highest indicators of breaking load and air permeability, as well as the lowest surface density. All tested materials meet the requirements specified in DSTU EN 14058:2008. Today it is becoming relevant to study and compare the properties of the insulation material вЂњTinsuleitвЂќ with the materials of batting and sintepon, which are actively used by manufacturers in Ukraine. Therefore, it became necessary to compare the performance of one of the most modern insulating materials, вЂњTinsuleitвЂќ, with batting, which has been used for about a hundred years, but which is almost gone in Europe and the USA. Rational results, which testify to the absolute superiority of the insulation material вЂњTinsuleitвЂќ, were provided when evaluating the indicators of breaking load, air permeability, surface density of the insulation materials вЂњTinsuleitвЂќ, sintepon, batting, top fabric вЂњOxfordвЂќ and lining fabric вЂњNylonвЂќ separately and in composition of packages of textile materials. Therefore, in the case of replacement in the production of special clothing, insulation materials of batting and sintepon with вЂњTinsuleitвЂќ during the production in Ukraine, the term of use of special clothing will be significantly increased due to the improvement of strength properties, and the economic efficiency of its use will significantly improve. Increasing breathability and reducing the weight of clothing will provide opportunities for longer stay in low temperature conditions and have greater mobility and mobility of the consumer, thanks to which the demand for this special clothing will only grow.
TECHNICAL AND ECONOMIC SUBSTANTIATION FOR SELECTION OF THE METHOD OF ELECTRO-THERMAL PROTECTION OF SOLAR PANELS IN THE SPACECRAFT POWER PLANTS
Authors: HILORME Tetiana , Nakashydze Liliya ,   Oles Honchar Dnipro National University
Published: May 2023

An actual scientific and practical problem of the energy sustainable development of space activities is the choice of solar cells for the uninterrupted supply of energy in the power plants of space vehicles. The operational risks of solar cells in the conditions of space activity are analyzed. It is proposed to use the method of evaluating the analytical hierarchical process of providing electrothermal protection of solar cells in power plants of space vehicles, which allows obtaining a set of optimal options. The selection of criteria for the parameters selection of electrothermal protection of solar cells, which take into account the specific operational risks of power plants in outer space, is substantiated: ensuring uninterrupted operation of solar cells; availability of service in extraordinary situations; lifetime of solar cells; the cost of solar panels; technical security; weight and size indicators. Five alternative options for electro-thermal protection of solar cells were chosen, which, unlike the existing ones, take into account all phases of the life cycle during the implementation of space activities and significantly increase operational characteristics. It is argued that the chosen optimal alternative вЂњSolar cells with protection based on resettable fusesвЂќ will allow increasing the active service life and, as a result, reducing the number of repairs (current and capital) of solar cells in the conditions of space activities. It is argued that the introduction of this option can achieve an increase in operational criteria: service availability in non-staff situations by 26%, the term of active operation by 20% and technical safety by 24%. The article defines the directions for the further development of this technique as the possibility of developing scenarios for the operation of solar cells in power plants of space vehicles based on the change and interaction of parameters (concepts).