bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Playometric and Circuit Training on Motor Educability’s Back Roll Component
Authors: Vala Sangitaben , Kasundra Prabhulal M
Published: January 2023

The purpose of this research study was to study the effect of dynamic learning through plyometric and circuit training on the hip component. For this research study, 25 students from plyometric group, 25 from circuit group and 25 from controlled group of Sri Sathyasai Vidyalaya, Jamnagar have been selected as subjects. To measure gait, Johnson's forward gait test has been selected as the standard of measurement. (ANCOVA) test was applied to find out the differences between the means and LSD test was applied to test the significance at 0.05 level, the plyometric and circuit groups were found to be significantly more active than the control group.

Abstract in Gujarati Language:

આ સંશોધન અભ્યાસનો હેતુ પ્લાયોમેટ્રિક અને સર્કીટ તાલીમ દ્વારા ગત્યાત્મક શિક્ષણના પીછે ગબડ ઘટક પર થતી અસરનો અભ્યાસ કરવાનો હતો. આ સંશોધન અભ્યાસ માટે શ્રી સત્યસાંઈ વિદ્યાલય, જામનગરના પ્લાયોમેટ્રિક જૂથના 25, સર્કિટ જૂથના 25 અને નિયંત્રિત જૂથના 25 એમ કુલ 75 વિદ્યાર્થીઓને વિષયપાત્રો તરીકે પસંદ કરી પીછે ગબડ માપન માટે જોનસનની આગે ગબડ કસોટીની માપનના ધોરણ તરીકે પસંદ કરી આંકડાઓનું એકત્રિકરણ કરી ત્રણેય જૂથના પ્રાપ્તાંકો પર સહવિચરણ પૃથક્કરણ (ANCOVA) ટેસ્ટ લાગુ પાડી મધ્યકો વચ્ચેના તફાવતો જાણવા માટે LSD ટેસ્ટ લાગુ પાડી 0.05 કક્ષાએ સાર્થકતા ચકાસતાં પ્લાયોમેટ્રિક અને સર્કિટ જૂથોની પીછે ગબડ પ્રવૃત્તિ નિયંત્રિત જૂથ કરતાં વધુ સાર્થક જોવા મળી હતી.

Keywords: પ્લાયોમેટ્રિક, રમતગમત, સર્કિટ તાલીમ
PENGARUH PENCAMPURAN LIMBAH KARBIT TERHADAP STABILISASI SWELLING VOLUMETRIK (3D) TANAH LEMPUNG EKSPANSIF
Authors: Diki Oematan Antonius , Tugas Sudjianto Agus , Riman
Published: January 2023

Tanah lempung ekspansif adalah jenis tanah yang memiliki sifat kembang susut yang sangat tinggi. Volume pori tanah lempung ekspansif akan mengalami pembesaran ketika terjadi musim kemarau sehingga akan terjadi proses penyusutan, sedangkan volume tanah akan mengalami pengembangan ketika terjadi musim hujan. Bila suatu konstruksi dibangun di atas tanah lempung ekspansif maka akan terjadi kerusakan-kerusakan yang berakibat buruk bagi konstruksi tersebut. Untuk memperbaiki tanah lempung ekspansif bisa dilakukan dengan metode stabilisasi tanah secara kimiawi dengan memanfaatkan limbah dari bengkel las karbit yang tidak digunakan. Pada penelitian ini akan menggunakan limbah karbit sebagai bahan stabilisasi swelling volumetrik (3D) tanah lempung ekspansif di daerah Kecamatan Tirtoyudo.  Komposisi campuran limbah karbit dan tanah lempung ekspansif yang akan digunakan adalah Tanah 100% + limbah karbit 0%, tanah 95% + limbah karbit 5%, tanah 90% + limbah karbit 10%, tanah 85% + limbah karbit 15% dan tanah 80% + limbah karbit 20%. Pengujian yang dilakukan pada tanah lempung ekspansif Tirtoyudo meliputi uji sifat fisis, sifat mekanis dan uji swelling volumetrik (3D). Dari penelitian yang telah dilaksanakan didapat nilai swelling volumetrik tanah lempung ekspansif dengan penambahan limbah karbit 0%, 5%, 10%, 15% dan 20%, nilai swelling volumetrik yang dihasilkan adalah 20,93%, 16,68%, 10,37%, 13,68%, dan 6,18%.
Numerical characterization of shock separation in a laboratory-scale nozzle
Authors: Nedjari Mohammed , Benarous A. , Benazza A.
Published: January 2023

The purpose of this work is to perform a CFD study of the free shock separation (FSS) in an overexpanded nozzle. The original contraction profile of the nozzle was numerically replaced by a set of curves, where the overall length was identical with the test-rig. For the baseline case, the static pressure and the separation location exhibited a good agreement with the experimental measurements, provided by the DLR. The Error-function contraction profile has revealed a relative displacement of 1.38% on the separation location in the core flow direction. In this case, there was an increase in the thrust coefficient, that has been improved up to 1.7% in comparison with the baseline nozzle design.
Step potential and Ramsauer-Townsend effect in Wigner-Dunkl quantum mechanics
Authors: Askari Ali , Hassanabadi Hassan , Won Sang Chung
Published: January 2023

In this paper the continuity equation for Wigner-Dunkl-Schrodinger equation is studied. Some properties of ¨ ν-deformed functions related to Dunkl derivative are also studied. Based on these, the step potential and Ramsauer-Townsend effect are discussed in Wigner-Dunkl quantum mechanics
Molecular dynamics simulations of CBD and THC with a DPPC / DPPG monolayer membrane: Comparative study with morphine and lidocaine
Authors: Vargas Castañeda Gonzalo Rafael , González J. A. , Espinosa G.
Published: January 2023

In recent years, the discussion about using marijuana to treat some specific diseases has been the reason for several studies to determine how Cannabis could affect or benefit the human body, such as chronic pain. However, the legal status of marijuana in different parts of the world remains a problem when conducting experiments for academic purposes. In this way, algorithms based on molecular dynamics are of great help to study the change in the physical properties of membranes, which is our first defense barrier, in the presence of external agents. Here we used equilibrium molecular dynamics to study the interactions of a DPPC/DPPG monolayer membrane with CBD and THC, these two molecules being one of the main components of Cannabis, and compare the interactions with morphine and lidocaine which are drugs with well-known anesthetic properties. We also used the umbrella sampling method to determine the variations of the potential of mean forces as every single drug crosses the membrane obtaining an approximation of the hydration free energy, we obtained a value of 57 kJ mol-1 for CBD and 5 kJ mol-1 for THC; values reported for the first time using molecular dynamics.
Single Pedicle Advancement Flap Models for Teaching Veterinary Reconstructive Surgical Techniques
Authors: McGowan Rachel Z. , Brookes Victoria J. , Jermyn Kieri , Stanley Felicity , Rotne Randi
Published: January 2023

Reconstructive surgical techniques are used in both general and referral veterinary practice to facilitate closure of challenging wound defects. During veterinary studies, there are often limited opportunities for students to practice these techniques on live patients or cadavers. Surgical models, including suture pads and ovariohysterectomy models, have been successfully incorporated into veterinary teaching, providing students with additional practice. Models to simulate veterinary reconstructive surgical techniques are lacking. In the current study, a single pedicle advancement flap model was designed. The design consisted of a silicone model secured by a plate, providing tension. Fifth-year veterinary science students ( n = 34) were surveyed to assess the model’s impact on surgical technique and confidence. Students were also assessed to determine surgical technique using the models. It was hypothesized that students who had two additional practice sessions using the models (Trial group, n = 17) would show greater improvement in technique than students who had no practice sessions between assessments (Control group, n = 17). Students strongly agreed (median score 5/5) that using the model helped to reinforce the subdermal plexus flap technique and improved their confidence in performing a subdermal plexus flap. Students from both groups performed significantly better in the follow-up assessment compared with the initial assessment. No significantly greater improvement was observed in technique between the control and the trial groups. Results suggest that the students’ reconstructive surgical technique improved after a single practice session and that the single pedicle advancement flap model can be used synergistically with other teaching methods.
Estética de la corrida de toros y las peleas de gallos según Palma
Authors: Pantigoso Pecero Manuel
Published: January 2023

Este artículo se inicia señalando a Palma como precursor de la tauromaquia y la gallística; luego analiza las corridas de toros a partir de su analogía con el proceso de la escritura, tomando en cuenta el ritmo, la lucha de contrarios, el silencio y el misterio. En esa misma línea, se ofrecen ejemplos relativos a las peleas de gallos. Se destacan algunos libros referidos a esta afición y la presencia de Palma como antecedente del conocido relato de Valdelomar.
Ricardo Palma, el crítico Federico Larrañaga y un reportaje íntimo (1908)
Authors: Holguín Callo Oswaldo
Published: January 2023

En 1908, el periodista, crítico de arte y empresario de cine Federico Larrañaga entrevistó a Ricardo Palma, quien a sus setenta y cinco añosseguía al frente de la Biblioteca Nacional, aunque cada vez más alejado de la actividad literaria por los achaques propios de la ancianidad. El original reportaje incidió en algunos aspectos de la vida íntima o doméstica de don Ricardo, entonces y hoy poco conocidos, y salió publicado con fotografías en la fugaz revista Siluetas.
Reedición del drama Rodil
Authors: Díaz Ortiz Pedro
Published: January 2023

El drama Rodil fue la primera obra impresa de Ricardo Palma. Se publicó en 1851 y fue estrenado en 1852. Gracias al Club Nacional ha sidoreeditado por primera vez y presentado el 19 de abril del 2022. Durante mucho tiempo Rodil fue considerado una obra perdida hasta que en 1952 se halló un ejemplar en la Biblioteca del Club Nacional. Acerca de esta historia y del interés de Rodil tratamos en este artículo.
antiguos pregones de Arequipa comparados con los de Lima mencionados por Don Ricardo Palma
Authors: Coloma Pocari César
Published: January 2023

En el presente trabajo de investigación se estudia, por primera vez, los “pregones” con los que los antiguos vendedores ambulantes de Arequipa ofrecían su mercancía. Eran totalmente distintos a los de la vieja Lima, a los que se refiere don Ricardo Palma y otros autores de la época. La fuente principal de este trabajo está compuesta por tres notas publicadas en el antiguo diario El Deber de Arequipa, los años 1925, 1926 y 1935, que se reproducen ad pedem litteræ.
cartas de Riva Agüero debido al anteproyecto del monumento a Ricardo Palma de 1932 y la respuesta del municipio limeño
Authors: Mera Ávalos Arnaldo
Published: January 2023

El 28 de julio de 1932, denominado Año de la Barbarie, se publicó en el diario El Comercio un anteproyecto del monumento que la ciudad de Lima erigiría conmemorando el centenario del nacimiento de Ricardo Palma. Ese hecho motivó que José de la Riva Agüero y Osma - amigo y discípulo de Palma a quien homenajeó tanto en vida en un discurso de 1912, como producido su deceso en 1919- publicara el 14 de agosto de 1932 en dicho diario una carta abierta sobre el tradicionista que, a su vez, originaría una respuesta inmediata de la autoridad edil, el día 15, y una réplica del intelectual el 16 de agosto de ese año. Del contenido de las tres misivas trata el presente artículo. A través de las dos de Riva Agüero veremos el profundo respeto que sintió hacia el tradicionista buscando, por ello, la mejor ubicación a un proyecto que, si bien colocaría su primera piedra en enero de 1935, en los festejos del cuatricentenario de la fundación de la ciudad que los vio nacer, no llegaría a concretarse en vida del intelectualfallecido en 1944.
Ricardo Palma y la poesía amorosa en “Juvenilia”(1850-1860)
Authors: Arroyo Laguna Eduardo
Published: January 2023

Sin desdecir el valor literario de las Tradiciones peruanas, la obra poética de Ricardo Palma permite tener una dimensión completa de este escritor. En su obra de juventud, Juvenilia, su poesía es alta lírica, así como tiene en casos, un carácter satírico, político y filosófico.
Subjetivación de las “marcas de historicidad” en la tradición “Un litigio original” de Ricardo Palma
Authors: Valenzuela Garcés Jorge
Published: January 2023

El propósito de este artículo es analizar el modo en que son subjetivadas las llamadas marcas de historicidad propias del discurso histórico en la tradición “Un litigio original” de Ricardo Palma. Defendemos la idea de que Palma, al subjetivar estas marcas, a través del humor, la ironía y el empleo de un registro lingüístico coloquial, logra desmontar la oficialidad del patrón discursivo histórico y su pretendida hegemonía durante el siglo XIX. Se emplea como marco teórico las propuestas de Pomian sobre el discurso histórico y las llamadas marcas de historicidad trabajadas en su libro Sobre la historia.
¿Cabe hablar de un «tradicionismo» español?
Authors: Vega Miguel Ángel
Published: January 2023

Tras delimitar conceptualmente los términos costumbrismo y «tradicionismo», intentamos localizar y determinar los posibles rasgos y caracteres de un género, la «tradición», en algunos testimonios de la literatura española que cabría interpretar como paralelos o  consecuencia del tipo de relato que Ricardo Palma naturalizó en la literatura hispanoamericana. Bécquer, Gabriel Miró o Concha Espina son posibles casos de un «tradicionismo» español.
Wellington Castillo y César Ángeles Caballero. La partida de dos palmistas
Authors: Sarmiento Antonio
Published: January 2023

Sentido y merecido homenaje a Wellington Castillo y César Ángeles Caballero, miembros correspondiente y de número, respectivamente, del Instituto Ricardo Palma. Los dos grandes intelectuales partieron este año a la eternidad, dejando hondo pesar no solo entre sus familiares y amigos, sino, además, en el ámbito de la cultura y las letras peruanas. A manera de homenaje póstumo, se reseña la participación que ambos tuvieron en la revista Aula Palma.
Cold-Sprayed FeCoNiCrMn High-Entropy Alloy (HEA) Coating: Microstructure and Tribological Properties
Authors: Yin Shuo , Lupoi Rocco , Li Wenya , Xu Yaxin , Song Bo , Yan Xingchen , Kuang Min
Published: January 2023

High-entropy alloys are of great interest due to their unique phase structure. They are constructed with five or more principal alloying elements in equimolar or near-equimolar ratios and thus derive their performance from multiple elements rather than one. In this work, solid-state cold spraying is used for the first time to produce a FeCoNiCrMn high-entropy alloy coating. As a low-temperature process, cold spraying completely retained the high-entropy phase structure in the coating without any phase transformation. Examination shows that the grains underwent significant refinement due to dynamic recrystallization and that the coatings are much harder than the feedstock powder because of increased dislocation density and grain boundaries.
Comparative Analysis of the Effect of CO2 Laser Radiation on Light Propulsion Acceleration of Powder Particles During Laser Cladding
Authors: Sergachev D.V. , Kovalev O.B. , Grachev G.N. , Smirnov A.L. , Pinaev P.A.
Published: January 2023

The purpose of this work is to study the effect of laser radiation on powder particles transported by gas during laser cladding. The temperature and velocity of particles entering the light field of a CO2 laser were determined by measuring particle radiation as well as the scattered radiation of the diode laser, two independent methods. It is shown that under the action of laser radiation, the particles acquire additional acceleration due to the vapor pressure from the irradiated part of the particle surface. This sonic recoil vapor pressure can significantly affect the in-flight characteristics of powder particles in a gas jet. Particle velocities due to laser acceleration exceeded 100 m/s in a carrier gas with a flow rate less than 30 m/s. Particle temperature depends on several factors and was found to vary from ambient temperature to the boiling point of the powder.
Investigation of CMAS Resistance of Sacrificial Suspension Sprayed Alumina Topcoats on EB-PVD 7YSZ Layers
Authors: Mikulla Christoph , Naraparaju Ravisankar , Schulz Uwe , Toma Filofteia-Laura , Barbosa Maria , Leyens Christoph
Published: January 2023

Molten calcium-magnesium-aluminum-silicate (CMAS) particles cause significant degradation of thermal barrier coatings (TBCs) in aero-engines. One way to protect TBCs against CMAS attack is through the application of a sacrificial topcoat. In this work, Al2O3 coatings were deposited on top of EB-PVD 7wt% YSZ layers via suspension thermal spraying using an aqueous Al2O3 suspension. Spray parameters were varied in order to obtain Al2O3 layers with two different microstructures and porosity levels. The coating systems were evaluated by means of CMAS infiltration testing at 1250 °C. It was found that the porosity and morphology of Al2O3 strongly influence CMAS infiltration and the formation of reaction products and that CMAS mitigation is a function of coating morphology and the speed at which Al2O3 reacts with CMAS deposits.
Effect of Laser Remelting on the Microstructure and Erosion-Corrosion Resistance of NbC Thermal Spray Coatings
Authors: Fals Hipólito Carvajal , Roca Angel Sanchez , Fogagnolo João Batista , Fanton Leonardo , Belém Maria Júlia Xavier , Lima Carlos Roberto Camello
Published: January 2023

In this study, NbC coatings, 250 µm thick, were deposited by low-velocity flame spraying on stainless steel substrates and were laser remelted in a controlled argon atmosphere. Isolated passes transverse of the coatings were performed at different focal lengths at speeds of 10, 15, and 20 mm/min. Using the selected laser parameters, layers were recast with eight passes at 10% superposition. Erosion-corrosion tests were performed and coating surfaces and cross-sections were characterized via SEM, EDS, and XRD analysis. Modified surfaces of dense, 800-µm thick coatings with no defects and excellent metallurgical bonding with the substrate were obtained. It was found that dilution of the coating with the substrate formed a gradient of chemical composition and mechanical properties and that erosive-corrosive wear resistance was highest for an erodent impact angle of 90°.
Equipment and Technologies of Atmospheric Air Plasma Spraying of Functional Coatings
Authors: Sergachev D.V. , Kuzmin V.I. , Gulyaev I.P. , Bochegov A.A. , Vandysheva I.V.
Published: January 2023

The present work demonstrates the possibilities of atmospheric air plasma spraying. It presents various approaches to the development and optimization of spraying modes using diagnostic equipment and provides examples of industrial approbation of the technology.
A New Approach to Simulate Coating Thickness in Cold Spray
Authors: Wu Hongjian , Xie Xinliang , Liu Memei , Deng Sihao , Liao Hanlin
Published: January 2023

This paper presents a novel approach for predicting cold spray coating thickness. The coating thickness distribution is a collection of single coating profiles associated with different spray angles and spraying distances. 3D geometric models of these profiles are developed and coupled with robotic trajectories and spraying parameters to simulate coating deposition. Based on the results of the simulation, the robot trajectory, operating parameters, and spray strategy can be adjusted by a feedback loop until the desired coating thickness distribution is achieved. Experimental verification shows that the method has good prediction accuracy and wide application potential.
Dense to Columnar Microstructure Evolution of Ba(Mg1/3Ta2/3)O3 TBCs Through Tailoring of Suspension Plasma Spray Conditions
Authors: Hou Huidong , Veilleux Jocelyn , Gitzhofer François , Wang Quansheng
Published: January 2023

Solution precursor plasma spraying (SPPS) was used to deposit barium magnesium tantalate thermal barrier coatings on titanium alloy substrates. The suspension was axially fed into an inductively-coupled RF plasma torch with a 25-mm converging nozzle. By selecting an atomization probe with a bimodal distribution of droplet size and adjusting the precursor feed rate and spraying distance, it was possible to tune the coating microstructure from dense splat-like layers to columns with intracolumnar porosity of 4.3% and intercolumnar porosity of 10%. The deposition rate achieved is suitable for commercial use.
Deposition of Silicon Carbide-Based Coatings Using High-Velocity Oxyfuel Spraying
Authors: Riley M.A. , Tabecki A.K. , Zhang F.
Published: January 2023

This study assesses the microstructure and properties of SiC-based coatings deposited using liquid and gas-fueled HVOF spraying techniques and a recently developed SiC-YAG ceramic powder. The coatings are shown to be superior to plasma and high-frequency pulse deposition sprayed SiC in terms of density and microstructure and comparable in terms of adhesion values. SEM and EDX analysis of the coatings shows that hard SiC particles are retained in a YAG binder, forming a composite that exhibits good sliding wear and erosion behaviors. Due to its low density (< 4 g/cm3), the SiC composite may be an alternative to coating materials such as WC-CoCr and Cr3C2-NiCr in weight-sensitive applications.
Research on High-Temperature Performance of CoCrAlSiY Coatings
Authors: Shuting Zhang , Lina Si , Hongyan Xu , Hongjuan Yan
Published: January 2023

This work investigates the high-temperature oxidation kinetics of CoCrAlSiY coatings with different Si concentrations. Hot-corrosion resistance is determined at 800 and 900 °C via hot salt coating, thermal shock resistance is measured at 1050 °C, and the oxidation and corrosion products are analyzed through mineralogical and micro analysis. The results show that Si promotes the formation of an Al2O3 film that improves oxidation and corrosion resistance, but excessive amounts reduce thermal shock resistance.
Influence of Nozzle Expansion Ratio of Circular and Rectangular Cross-Section Nozzle on Velocity and Temperature of Copper Particle with HP Cold Spraying by Computational Fluid Dynamics and Experimental Analysis
Authors: Sakaki Kazuhiko , Iljima Kiyotaka , Tsubata Tomoki
Published: January 2023

This study compares the performance of circular and rectangular cold spray nozzles based on numerical simulations and experimental results. It shows how nozzle geometry and gas pressure affect the velocity and temperature of copper particles at various points in their travel. The goal of the investigation is to establish a nozzle design that achieves a uniform spray pattern with suitable particle impact velocity for the materials and temperatures involved. It was found that a rectangular nozzle with an expansion ratio in the range of 11-12 can provide a more uniform particle velocity with high deposition efficiency at a reasonable gas pressure.
Metal Matrix Composites Using Surface Modified Particles Fabricated by Cold Spray Technique
Authors: Okimura Nana , Ata Nobuhisa , Hirata Yuki , Ohtake Naoto , Akasaka Hiroki
Published: January 2023

This paper describes a process that has been developed for producing thick composite coatings with friction and wear properties that were once only achievable in diamond-like carbon (DLC) films. The process is based on cold spraying and the use of surface modified metallic powders. In this investigation, two such powders were prepared by placing either copper or titanium particles on a negatively biased stainless steel tray and then coating them with a DLC film by pulse plasma chemical vapor deposition. The powders are then cold sprayed onto aluminum plates, creating metal-matrix composite coatings. The thickness of the Cu-DLC composite coating is 250 µm and that of the Ti-DLC coating is 435 µm. In each case, the presence of dispersed DLC in the metal matrix was verified by Raman spectroscopy. Sliding wear tests were also conducted, revealing that the Cu-DLC composite has a lower coefficient of friction than copper film, while the Ti-DLC composite has lower specific wear rate than titanium film.
Microstructural Characteristics of Arc Sprayed CoCr-Based Coatings
Authors: Tillmann W. , Hagen L.
Published: January 2023

Due to their superior wear resistance and oxidation behavior, Stellite coatings are widely used in industrial applications where they are exposed to high temperature. Common processes for applying Stellite coatings include high-velocity oxyfuel spraying, laser cladding, and plasma transferred arc welding. Although Stellite welding consumables are available, there are few studies on arc-sprayed Stellite coatings in the literature. This work investigates the microstructural characteristics of an arc-sprayed deposit produced using a CoCr-based cored wire with 4.5 wt% W. The deposit is examined both in its as-sprayed state and after high-temperature exposure. Microstructure formation is assessed via SEM and EDX analysis, phase transformation processes are determined by XRD analysis, and friction and wear properties are measured. The findings are presented and discussed and compared with those obtained from conventional CoCr-based coatings.
Design the Compositions of Low Friction Coefficient Bimodal Coatings for Heavy Load Component
Authors: Ye Fuxing , Mi Pengbo , Li Changjiu
Published: January 2023

In this study, copper-doped bimodal WC-Co powders are applied to steel substrates by high-velocity oxyfuel spraying and the coatings are evaluated based on their microstructure and high-temperature wear performance. It is shown that the addition of copper reduces coating porosity without affecting the structure of the WC. It also inhibits the decomposition of WC and has a solid diffusion function. The friction coefficients and wear rates determined at different temperatures were found to be consistently low with minimum values being obtained at 450 °C. At high temperatures, the soft copper flows to the surface, forming a self-lubricating film that reduces friction and wear.
Effects of Composition on Mechanical Properties of Suspension Plasma-Sprayed Hydroxyapatite/Titania Coating
Authors: Abir Mirazul Mahmud , Morakul Sarita , Otsuka Yuichi , Miyashita Yukio , Mutoh Yoshiharu
Published: January 2023

In this study, hydroxyapatite, titania, and HA-TiO2 composite layers are deposited by suspension plasma spraying on titanium substrates and assessed by means of SEM and XRD analysis, Raman spectroscopy, and acoustic emission testing. The coatings exhibited dense microstructures with low porosity and good interfacial bond strength. The main phase in the HA and composite coatings was found to be similar to the peak of the feedstock powder. In the composite and titania coatings, besides rutile and anatase, a significant percentage of thermally stable Ti3O5 was observed, which is favorable for photocatalytic performance.
Engineered Thermal Sprayed Oxygen Evolution Electrode for Hydrogen Production by Alkaline Water Electrolysis
Authors: Jiang Tao , Wang Yan , Montavon Ghislain , Liao Hanlin , Liu Taikai , Reissner Regine , Ansar Syed Asif
Published: January 2023

This study shows how HVOF-sprayed NiAl coatings produced using chemical and electrochemical activation processes can serve as oxygen evolution electrodes in alkaline water electrolysis systems. Freestanding hierarchical NiAl structures produced without chemical binders exhibit electrocatalytic performance comparable to state-of-the-art noble catalysts characterized by very low overpotential and high current density without degradation.
CFD Enhanced Thermal Spray Process for Coating of Cylinder Bores of Car Engines
Authors: Schilder Bernd , Garling Andre , Reimer Fabian , Hamann Matthias , Joos Rainer , Hϋger Jens , Pöhlmann Mathias , Lampke Thomas
Published: January 2023

In this paper, the principles of computational fluid dynamics are used to simulate the complex gas flows in the cylinder bore of an automotive engine during internal-diameter twin-wire arc spraying. A number of experiments are conducted as well and the results are presented and analyzed in order to optimize the properties of the coating. The combination of simulation and experiments led to the development of a process that achieves uniform layer adhesion strength over the length of the cylinder bore.
The Mechanisms of Enhancement of Inter-Particle Bonding in In-Situ Micro-Forging Assisted Cold Spray
Authors: Wei Ying-Kang , Luo Xiao-Tao , Li Chang-Jiu
Published: January 2023

In this study, high-strength aluminum alloy AA7055 deposits are prepared using a recently developed cold spray process that employs in-situ microforging. The in-situ hammering effect is achieved by mixing large shot-peening particles into the spray powder and is shown to enhance interparticle bonding along with the plastic deformation of deposited particles. The underlying mechanisms are discussed based on the characterization of interface microstructure and the distribution of oxide film at the interparticle interface.
Feasibility Study of GaN Coatings by Cold Spray Technique
Authors: Zhou Shaoyun , Bernard Chrystelle A. , Ravi Kesavan , Ichikawa Yuji , Ogawa Kazuhiro
Published: January 2023

This study investigates the feasibility of producing GaN coatings on stainless steel, aluminum, and indium tin oxide glass substrates by downstream injection low-pressure cold spraying. The formation of GaN layers on all three materials appears to be due to pseudo deformation of super agglomerated GaN particles. The deposition results showed a saturation limit to coating thickness with the number of passes. Based on XRD spectra of the coating and powder, no phase transformations took place during the spraying process.
Influence of Particle Size and Spray Parameters on Structural, Mechanical, and Electrical Insulation Properties of Alumina Coatings by Atmospheric Plasma Spraying
Authors: Yamane Toshiyuki , Fujimori Kazuya , Kitamura Junya , Wada Tetsuyoshi
Published: January 2023

This study assesses the influence of particle size and spray parameters on the structural, mechanical, and electrical insulation properties of alumina coatings deposited by atmospheric plasma spraying. It has been found that the combination of a relatively fine feedstock powder and high velocity plasma spraying promotes the formation of denser coatings with high dielectric strength. Correlations between dielectric strength and deposition efficiency, coating hardness, crystal structure, and surface roughness are also assessed.
Techno-Economic Assessment of Coating-Based Resistive Heating Systems versus Conventional Heat Tracers
Authors: Rad Milad Rezvani , Ngaokere Kingsley , Kumar Amit , McDonald André , Hayden Daniel
Published: January 2023

The economic feasibility of using thermal-sprayed heat generating coatings for temperature control in steel pipes was investigated. A data-intensive model was developed to compare fabrication, installation, operation, and maintenance expenditures with those of conventional heating cables. The multi-layered coating consists of flame-sprayed Al2O3 and NiCr layers and cold-sprayed copper. Scalability factors were incorporated in the model to estimate the total projected costs for fabricating the coatings as opposed to installing heat tracing. Although material costs for the coating and heat tracing were approximately the same, the cost of fabrication for the coating was higher due mainly to labor expenses. However, the coating-based system was found to be more energy efficient than heat tracing due to the good adhesion and reduced thermal contact resistance between the heating elements and pipe.
Microstructure and Phase Compositions of Silicon Carbide Coatings Prepared by Plasma Spray-Vapor Deposition
Authors: Wang Di , Zhang Shan-Lin , Li Chang-Jiu
Published: January 2023

In this work, silicon carbide coatings were fabricated by plasma spray-vapor deposition in order to study the effect of plasma gas mixtures on coating microstructure and phase composition. Coatings deposited by Ar-H2 plasma gas were found to contain a composite phase of SiC and Si. Moreover, the content of Si increased with increasing H2 content in the gas. The deposition of Si is possibly due to the reaction of C and hydrogen species in the plasma jet, which would explain why pure SiC coatings were obtained when Ar-N2 gas was used.
The Microstructure and Deposition Behavior of NiCr Alloy Coatings Using Laminar Plasma Spraying
Authors: Zhang Hui-Yu , Liu Sen-Hui , Li Cheng-Xin , Yang Guan-Jun , Li Chang-Jiu , Zhang Shan-Lin , Li Lu
Published: January 2023

This study demonstrates a method of plasma spraying in which the plasma is maintained in a laminar (rather than turbulent) state, achieving a much greater jet length with less ambient air engulfment. In the experiments, NiCr coatings were produced at spraying distances between 250 mm and 500 mm, showing that specific structures can be realized by changing stand-off distance. Structures with high porosity, for example, are generated at relatively short distances; dense structures, on the other hand, are obtained at longer stand-off distances that allow feedstock powder to reach a fully melted state. XRD analysis shows that the spraying process does not change the chemical composition of the material, and EDS results indicate that chemical and metallurgical bonding are achieved.
A Novel Numerical and Experimental Investigation Into Radial Injection for Suspension High Velocity Oxy Fuel (SHVOF) Thermal Spray
Authors: Chadha S. , Jefferson-Loveday R. , Hussain T.
Published: January 2023

In suspension high-velocity oxyfuel (SHVOF) thermal spraying, the suspension is usually injected axially into the combustion chamber. Deposition of oxygen sensitive materials such as graphene can be difficult using this approach as the particles degrade with extended exposure to oxygen at high temperatures. Radial injection outside of the nozzle, however, reduces in-flight particle time thereby accommodating oxygen sensitive nanomaterials. The aim of this study is to investigate how radial injection parameters affect in-flight particle conditions during SHVOF spraying. The models used in this work are shown to accurately predict flame temperature in the combustion chamber for an Al3O2 suspension. Experimental observations of the liquid jet obtained using high-speed imaging are compared to numerically predicted values. The results indicate that in-flight particle characteristics can be improved by more than 30% in SHVOF spraying by optimizing the suspension flow rate and radial injection angle.
Deposition of Co3O4 Films as High-Performance Supercapacitor Electrodes Via the Solution Precusor Plasma Spray Route Place
Authors: Yu Zexin , Liu Meimei , Song Chen , Moliere Michel , Liao Hanlin , Ma Yangzhou , Huang Xuanning , Song Guangsheng , Song Chen
Published: January 2023

In this work, binder-free Co3O4 films with in-situ oxygen vacancies are deposited in a one-step process by solution precursor plasma spraying (SPPS). It is believed to the first time Co3O4 layers composed of hexagonal flakes were synthesized through the SPPS route. Specific capacitances up to 1700 F/g were obtained at a scan rate of 5 mV/sec, almost 97% of which was retained after 13,000 cycles at 20 mV/sec. This supercapacitor-like performance is attributed to the synergistic effects of a binder-free composition with in-situ oxygen vacancies and porous nanostructures.
Effect of Hydrogen Admixture on Plasma Jet Characteristics in Low Pressure Spray Processes
Authors: Mauer Georg
Published: January 2023

In plasma spraying, hydrogen is widely used as a secondary working gas. Under low-pressure conditions, even small amounts of hydrogen can have a significant effect on the plasma jet as mechanisms such as diffusion and recombination come into play. This study investigates the influence of Ar-H2 mixtures on electron densities, temperature distributions, and local composition in the plasma jet using optical emission spectroscopy. Several mechanisms reported in the literature are consulted to explain the observed phenomena.
A Novel Strategy for Applying Oxide-Free Self-Fluxing Alloy Coatings by Self-Fusing Atmospheric Plasma Spraying
Authors: Dong Xin-Yuan , Luo Xiao-Tao , Zhang Shan-Lin , Li Chang-Jiu
Published: January 2023

In this study, NiCrBSi powders with a size range of 30-50 μm were deposited on mild steel substrates by self-fusing atmospheric plasma spraying. Particle temperatures exceeded 2400 °C and the deposits were remarkably dense with low oxygen content. Based on the results, a novel strategy is proposed to directly deposit dense, oxide-free coatings by plasma spraying without the need of post-spray fusing processes.
Effect of High-Temperature (550°C) on Tribological Properties of Eco-Friendly Carbon-Based Composite Coating for Piston Ring Application
Authors: Tyagi Ankit , Walia R.S. , Murtaza Qasim
Published: January 2023

The aim of this work is to develop and assess an eco-friendly carbon-based composite coating for piston ring applications. The coatings were produced from sugarcane waste and Mo, NiCr, and CrC powders using high-velocity oxyfuel spraying and thermal chemical vapor deposition. SEM-EDS and XRD analysis confirms the presence of carbides and oxides that cause coating hardness to increase with increasing temperature. At 550 °C, under a 20 N load with a sliding velocity 0.3 m/sec, the friction coefficient of the coating was found to be 0.2, the wear value was 130 μm, and friction force was 4N. The results indicate that the friction and wear properties of the coatings improve with increasing temperature due to the formation of tribo-oxidative films and the effects of graphitization associated with the presence of carbon.
Tailoring Thermal Properties of Plasma Spray Ceramic Coatings for Aluminum Molding
Authors: Levasseur David , Simard Jimmy , Chiesa Franco
Published: January 2023

Coatings applied on steel molds used for casting aluminum parts have two main purposes: avoid mold metal reaction and control thermal transfer to obtain directional solidification. The coatings widely known to foundry operators are water-based sodium-silicate bonded ceramic suspensions; they are air sprayed and cured on mold surfaces and typically last for 100 casting cycles. Although thermal sprayed coatings have been shown to last more than 5000 casting cycles, they are not yet the preferred mold protection method. This study addresses the issue by developing a knowledge base of thermal transfer properties that can be achieved with air plasma sprayed magnesium zirconate powders. The properties are assessed on an instrumented mold using the inverse technique for different coating compositions.
Improvement of Wear Resistance by Thermal Spraying on Surface Layers Prepared by Plasma Transferred Arc Welding on Gray Cast Iron Components
Authors: Oechsner M. , Engler T. , Ellermeier J. , Heider B. , Reisgen U. , Sharma R. , Zokoll E. , González Olivares E.
Published: January 2023

This study evaluates the erosion-corrosion performance of thermal spray hardcoats on bronze-coated gray cast iron. In the experiments, gray cast iron plates are coated with a bronze powder by PTA welding and the coatings are characterized based on microstructure and corrosion and wear testing. The bronze coatings provide good corrosion protection, but are shown to be susceptible to cavitation and erosion wear. To compensate, thermal spray hardcoats, including atmospheric plasma sprayed Al2O3 and Cr2O3 and HVOF sprayed WC-Co, were applied over bronze-coated cast iron and corrosion and wear tests were performed. It is shown that the thermal spray hardcoats greatly improve wear resistance, but despite their interconnected porosities, do not affect the corrosion performance of the underlying bronze.
Cr-Doped Al2O3 Deposited by Solution Precursor Plasma Spraying by Hybrid Water-Stabilized Plasma Torch
Authors: Tesar Tomas , Musalek Radek , Medricky Jan , Cizek Jan , Lukac Frantisek , Csaki Stefan , Chraska Tomas
Published: January 2023

This study investigates the co-deposition of aluminum and chromium oxides from solution precursor feedstocks with the aim of maximizing the α-alumina content. A hybrid water-stabilized plasma torch was used to spray the feedstock materials and the deposition principles were studied. The chemical composition of the deposits corresponded to the formulation of the feedstocks, indicating a uniform deposition of both materials. It was found that α-phase content can be increased in the coatings by increasing the Cr-forming precursor in the solution.
Modeling of Suspension Plasma Spraying Process
Authors: Dalir E. , Mostaghimi J. , Dolatabadi A
Published: January 2023

In this work, numerical models are developed and used to simulate magneto-hydrodynamic fields inside a dc plasma torch during suspension plasma spraying and their influence on arc attachment. A Reynolds stress model is used to simulate turbulent plasma flow and a discrete phase model simulates the effects of arc fluctuation on suspension droplets in the plasma jet. Submicron yttria-stabilized zirconia particles, suspended in ethanol, are modeled as multicomponent droplets and the KHRT model is used to simulate their breakup. The results show that particles are significantly affected by plasma arc fluctuations and that fine particles near the centerline of the torch are hotter and experience better penetration into the plasma jet.
HVOF Spraying MCrAlY Coatings on Single Crystals with Various Sand Blasting Forces
Authors: Lu Xiaoliang , Yuan Kang , Yu Yueguang , Zhang Deming , Liu Jianming
Published: January 2023

Sand blasting and high-velocity thermal spray processes can produce residual stresses in superalloy substrates that can significantly influence microstructure development. To investigate this effect, single-crystal superalloy substrates were sand blasted using different levels of force (zero, light, and heavy) and then coated with a MCrAlY layer by HVOF spraying. Cross-sectional analysis of an as-sprayed sample revealed a subsurface depletion zone with a composition rich in Mo nano precipitates. Cross-sectional examinations after vacuum heat treating and at various points during oxidation testing showed that elemental interdiffusion occurred between the coating and substrate and that sand blasting intensity has a major influence on the depth of the interdiffusion zones.
Anti-Corrosion Performance of the NiCrAlY Coatings Deposited by Two Different Spraying Technologies
Authors: Li Shuqing , Yang Weihua , Ma Guojia , Li Qilian
Published: January 2023

In this study, nickel-base superalloy coatings are deposited on CrMoAl substrates by different spraying methods and the coatings are evaluated based on their microstructure, phase composition, surface and splat morphology, bond strength, and corrosion properties. In the experiments, NiCrAlY powders with a particle size range of 30-45 μm were sprayed by conventional air plasma and a new laser hybrid plasma spraying technique. The spraying parameters are presented along with test results, observations, and conclusions. The coatings produced by laser hybrid plasma spraying had an average porosity of 0.9%, a bonding strength of 117 MPa, and significantly better corrosion properties than the APS layers.
Gas Gun Flyer Plate Impact Testing of Stainless Steel Deposited by Low Pressure Plasma Spraying and Cold Gas Dynamic Spraying
Authors: Jones David R. , Morrow Benjamin M. , Hollis Kendall J.
Published: January 2023

In this study, 316 stainless was deposited by low-pressure plasma spraying under various conditions to obtain different coating structures and by cold gas dynamic spraying for comparison. The coatings were characterized by cross-sectional metallography to assess porosity, oxidation, particle flattening, and elemental composition. The samples were also subjected to flyer plate impact testing in a gas gun to determine their shock propagation and porosity compaction properties. Comparing the results with that of the reference sample shows the effect of deposition conditions on the dynamic behavior of the coatings.
Three-Dimensional Modelling of Cold Spray for Additive Manufacturing
Authors: Garmeh Saeed , Dolatabadi Ali
Published: January 2023

This study employs a three-dimensional simulation to investigate the cold gas dynamic manufacturing process. During the buildup of the desired object, sharp edges, stagnation points, and corners are likely to form that can influence the trajectories of the particles. This leads to dispersion and lack of particle deposition in these areas, which can eventually reduce the precision and efficiency of the build process. A cylindrical and frustum-shaped object are numerically simulated on a substrate to represent typical additively manufactured parts. Particle trajectories and impact conditions with and without these objects are compared. The results provide useful information for understanding the limitations and challenges associated with cold gas dynamic manufacturing, which can help improve the quality and precision of the process.
Effect of Laser Texturing of Substrate Surface on Coating Properties of Cold-Sprayed and Laser-Assisted Cold-Sprayed Aluminum Coatings
Authors: Koivuluoto Heli , Kiilakoski Jarkko , Costil Sophie
Published: January 2023

In this study, aluminum coatings were cold sprayed, with and without laser assistance, on laser-textured aluminum 6060 and Fe52 steel substrates. The results indicate that laser texturing makes for a cleaner coating interface than grit blasting and that the benefits are greatest when spraying on harder substrate materials. For the steel substrate, the optimized topography achieved through laser texturing assisted in particle deformation, leading to the formation of a much tighter coating structure. Laser-assisted cold spraying, in turn, improved deposition efficiency as well as coating density and adhesion. Separately or together, the two processes have proven to be beneficial for cold spraying.
On Parametric Analysis of Cold Spray of Metallic Coating Onto Ceramic Substrates Using Ceramic Damage Evolution Approach
Authors: EcheverrÍa Marco José , Quintero Pedro O. , Ozdemir Ozan , Ibitayo Dimeji , Champagne Victor K.
Published: January 2023

In this work, a fine copper layer was deposited on an aluminum nitride substrate via cold spraying. Parametric modeling was used to develop a parameter selection map that helped guide preliminary experiments to validate the model for different substrate surfaces, nozzle geometries, gas dynamics, standoff distances, and deposition angles. Further modifications were then made to include failure prediction based on particle impact, leading to the deposition of well-adhered cold-sprayed copper on a ceramic surface.
Cold Spray Metal Coating of Wood for Cabinet Making Applications
Authors: Lomonaco Patrizio , Debray Antoine , Delloro Francesco , Jeandin Michel , Favini Bernardo , Bousquet Arnaud , Leprize’ Seven
Published: January 2023

This study assesses the feasibility of cold spraying metal onto wood for commercial applications. It was found that particle adhesion and coating build-up differ significantly from the standard case of spraying metal on metal. Phenomena such as fiber rupture and buckling, pore filling, and particle anchoring required a new approach for process development and verification. First, a microscale analysis of the unique features of wood was necessary to define the deposition surface. Next, a wide range of cold spray tests were conducted to obtain metal coatings on four species of wood. To better understand the dependency of deposition efficiency on particle state conditions, a CFD models and FEA simulations were used to investigate single and multi-particle impacts on local wood structures as observed in SEM and microtomography images. A conventional pull-off test was used to collect adhesion strength data and a numerical counterpart of the test has been developed, making it possible to compare macroscopic adhesion behavior of real and virtual interfaces.
Analysis of Interface Delamination of Cold Sprayed Coatings Due to Thermal Cycling
Authors: Lin Enqiang , Nault Isaac , Champagne Victor K. , Nardi Aaron , Müftü Sinan
Published: January 2023

This study investigates the effect of thermal cycling on cold-spray chromium coatings deposited on steel substrates. First, equilibrium stress states are determined for different coating thicknesses. Next, the potential for crack initiation and growth is simulated based on periodic heating and cooling cycles. The corresponding crack driving forces are characterized using interface stresses and energy release rate as a function of the thermal cycles. The effects of coating thickness, embedded microcracks, and initial residual stress on the driving forces are investigated systematically to demonstrate the risk of coating fracture and delamination.