bluuebunny/crossref_metadata_2025 huggingface dataset:
Overlap in Meaning Is a Stronger Predictor of Semantic Activation in GPT-3 Than in Humans
Authors: Digutsch Jan , Kosinski Michal
Published: December 2022

Modern large language models generate texts that are virtually indistinguishable from those written by humans and achieve near-human performance in comprehension and reasoning tests. Yet, their complexity makes it difficult to explain and predict their functioning. We examined a state-of-the-art language model (GPT-3) using lexical decision tasks widely used to study the structure of semantic memory in humans. The results of four analyses showed that GPT-3’s patterns of semantic activation are broadly similar to those observed in humans, showing significantly higher semantic activation in related (e.g., “lime–lemon”) word pairs than in other-related (e.g., “sour–lemon”) or unrelated (e.g., “tourist–lemon”) word pairs. Yet, GPT-3’s semantic activation is better predicted by similarity in words’ meaning (i.e., semantic similarity) rather than their co-occurrence in the language (i.e., associative similarity). This suggests that GPT-3’s semantic network is organized around word meaning rather than their co-occurrence in text.
Can models of learning in non-mathematical domains explain knowledge transfer in arithmetic?
Authors: Murphy April , Young Andrew G. , Boncoddo Rebecca , Alibali Martha W. , Rogers Timothy Thomas , Kalish Charles
Published: December 2022

This paper considers whether approaches to learning and memory developed in non-mathematical cognitive domains can explain when and how mathematical learning will transfer from practice problems to novel problems. Studies in non-mathematical cognition suggest that different practice experiences lead learners to acquire different memory models of the practiced facts, which in turn produce different patterns of transfer to novel queries. In experiments with adults and children, we show that the same factors strongly influence learning and transfer in arithmetic, with different practice experiences producing equally good learning of studied problems but remarkably different patterns of transfer to novel problems. The results suggest that the struggles faced by children learning math may partly arise from the kinds of practice to which they are exposed, and also that it may be useful to view mathematical knowledge as being supported by the same learning and memory processes that underpin non-mathematical knowledge.
Mothers’ and fathers’ infant-directed speech have similar acoustic properties, but these are not associated with direct or indirect measures of word comprehension in 8–month-old infants
Authors: Rosslund Audun , Hagelund Silje , Mayor Julien , Kartushina Natalia
Published: December 2022

Previous research on infant-directed speech (IDS) and its role in infants’ language development has largely focused on mothers, with fathers being investigated scarcely, if at all. Here we examine the acoustics of IDS as compared to adult-directed speech (ADS) in Norwegian mothers and fathers to 8–month-old infants, and whether these relate to direct (eye-tracking) and indirect (parental report) measures of infants’ word comprehension. Forty- five parent-infant dyads participated in the study. Parents (24 mothers, 21 fathers) were recorded reading a picture book to their infant (IDS), and to an experimenter (ADS), ensuring identical linguistic context across speakers and registers. Results showed that both mothers’ and fathers’ IDS had exaggerated prosody, expanded vowel spaces, and more variable and less distinct vowels. We found no evidence that acoustic features of parents’ speech were associated with infants’ word comprehension, suggesting that a facilitating role of IDS may appear later in development.
Citizen science matters: theorizing citizen science and exploring its promises for addressing Mekong environmental problems
Authors:   Can Tho University, Vietnam, Nguyen Minh Quang
Published: December 2022

Starting with the view that the emergence of citizen science initiatives proves the fullest potential to address environmental problems and promote sustainability from the ground up, this conceptual paper aims to explore why citizen science matters for a low-carbon future in the Mekong region. Based on a literature review and semi-structured expert interviews, this paper highlights the im-portance and unique impacts of citizen science in science, policy, and sustainability education spheres. These impacts are reflected in case studies of United States and Belgium. Results from empirical data also reveal that citizen science is transforming research, educating and informing the public, and decentralizing and informing policy. The results further provide promises for ad-dressing environmental problems in Mekong countries where environmental degradation seems to be getting murkier. The paper concludes with a discussion as to how citizen science should be embedded in local environmental governance as it revolutionizes our understanding of the envi-ronmental challenges and promotes evidence-informed policy making.
Stakeholders’ perceptions and responses to climate change impacts on agricultural sector in mountainous areas of Thua Thien Hue province
Authors:   University of Agriculture and Forestry, Hue University, Le Thi Hoa Sen , Nguyen Tien Dung ,   University of Agriculture and Forestry, Hue University
Published: December 2022

This study aims to analyse stakeholder perceptions and responses on climate change (CC) impacts on agricultural sector in the mountainous areas of Thua Thien Hue province. Data was collected by surveying 462 farmers in Nam Dong and A Luoi districts with a structure questionnaire; in-depth interviews of 29 agricultural officials; 12 agricultural input suppliers, and representatives of 18 community organizations. The research results show that stakeholders have very different perceptions regarding the causes, impacts, and responses to CC (P value <.00). Most stakeholders believe that CC has many causes of which deforestation and too much waste were the two main factors. However, more than 45% of farmers believe that CC is due to God. Regarding CC impacts, a large percentage (81.4%) of interviewed farmers were most concerned about drought due to its increased intensity and widespread effects. Meanwhile, agricultural officials were focused on foreseen and shocked extreme events such as landslides and flash floods, which occur only at par-ticular sites along the streams. Agricultural enterprises are often proactive and aware of people’s concerns to provide related services such as resistant seeds, irrigation facilities, and fertilizers. However, very few (8.44%) farm households in the region have access to these services because of limited financial capacity.
Bayesvl: an R package for user-friendly Bayesian regression modelling
Authors:   Centre for Interdisciplinary Social Research, Phenikaa University, Hanoi, Vietnam, Vuong Quan-Hoang ,   Vietnam Institute for Advanced Study in Mathematics, Ministry of Education and Training, Nguyen Minh-Hoang ,   Centre for Interdisciplinary Social Research, Phenikaa University, Hanoi, Vietnam, Ho Manh-Toan ,   Centre for Interdisciplinary Social Research, Phenikaa University, Hanoi, Vietnam
Published: December 2022

Compared with traditional statistics, only a few social scientists employ Bayesian analyses. The existing software programs for implementing Bayesian analyses such as OpenBUGS, WinBUGS, JAGS, and rstanarm can be daunting given that their complex computer codes involve a steep learning curve. In contrast, this paper introduces a new open software for implementing Bayesian network modelling and analysis: the bayesvl R package. The package aims at providing an intuitive gateway for beginners of Bayesian statistics to construct and analyse mathematical models in social sciences. To achieve this aim, the bayesvl package integrates three core functions seamlessly: (i) designing Bayesian network models using directed acyclic graphs (DAGs) of bnlearn, (ii) generating attractive visualization of ggplot2, and (iii) simulating data and computing posterior distribution using the Markov chain Monte Carlo (MCMC) algorithms of rstan and rethinking. A case example illustrates how the bayesvl package helps leverage users’ intuition in creating and evaluating mathematical models of their social scientific problems while minimizing the daunting aspect of writing complex computer codes.
Scientists’ motivation to patent and commercialize their inventions at universities and research institutes
Authors:   Vietnam Intellectual Property Research Institute, Nguyen Huu Can
Published: December 2022

Self-determination theory (SDT) and a literature review suggests that scientists’ motivation to patent and commercialize their inventions is effort expended by a variety of intrinsic and extrinsic reasons. Based on qualitative analysis results, we found explorative evidence that both intrinsic reasons belonging to the scientists themselves and extrinsic ones arising from the environment of the scientists’ inventive activities are positively associated with the scientists’ motivation. Therefore, to implement the Intellectual Property Strategy to 2030, policymakers need to consider a variety of factors including not only extrinsic rewards, but also personal and social aspects related to intrinsic desires.
Public interest in social research ethics: An analysis of the top 50 articles in Altmetric database
Authors:   National Ageing Research Institute, Melbourne, Australia, Tran Van Kham ,   University of South Australia, Adelaide, Australia, Pham Huy Cuong ,   University of Social Sciences and Humanities, Vietnam National University, Hanoi, Vietnam, Tran Thanh Nam ,   University of Education, Vietnam National University, Hanoi, Vietnam, Nguyen Thi Thai Lan ,   University of Social Sciences and Humanities, Vietnam National University, Hanoi, Vietnam, Nguyen Thi Kim Nhung ,   University of Social Sciences and Humanities, Vietnam National University, Hanoi, Vietnam
Published: December 2022

Social media influences public awareness, politics, and the economy. A new web-based metric called Altmetric has recently been developed for use in scientific fields, which provides a complementary measure of the impact of scientific articles. This study aims to identify and characterise the top 50 articles with high Altmetric attention scores (AASs) in social research ethics, which have received the most significant amount of attention from the general public and scholars.Using the Altmetric database, we searched for 438 AAS articles with content in social research ethics, which were published in 172 journals in social sciences using the Web of Science and Scopus databases. We determined the top 50 articles with the highest AASs using the Altmetric.com databases and then analysed them with some criteria of the journal, year, type of article, a field of research, main topic, and ethical research consideration.Among the 50 chosen articles, the journal that published the most articles on social research ethics that received the most attention on social media was the International Journal of Social Research Methodology (n=7). The most frequent keywords appearing in these articles are ethics (n=20), research ethics (n=14), social media (n=13), and privacy (n=7). Articles in the journal with higher impact factors (IFs) and Scimagor’s ranks were expected to have higher AASs. The research areas with articles with high AASs are philosophy and religious study (27), medical, pharmacology and health sciences, and studies in human society. Our study presents a detailed list and analysis of the top 50 articles with the highest AASs in social research ethics, which paint a significant picture of public attention in social research ethics. Indeed, this picture shows that despite having public interests in this topic, the level is less considerable compared to its vital position in social research in contemporary life
The development and evaluation of a provider-focused educational intervention about alcohol use disorder in patients with cirrhosis
Authors: Johnson Emily , Ghosh Monty , Daniels Vijay John , Wild T Cameron , Campbell-Scherer Denise , Mellinger Jessica , Winder Gerald S , Fernandez Anne C , Kirkwood Jessica , Tandon Puneeta
Published: December 2022

Background:

Alcohol use disorder (AUD) is a leading cause of cirrhosis. Insufficient clinician knowledge and comfort managing AUD impacts access to treatment. Using Kern’s Framework for Curriculum Development, we aimed to (i) develop and evaluate the effect of an “AUD in cirrhosis” educational intervention on clinicians’ knowledge, attitudes, comfort, preparedness, and intention (practice habits) to integrate AUD management into their practice, and (ii) assess clinicians’ motivation using Self Determination Theory.

Methods:

Kern’s approach was used for curriculum development. Pilot session feedback informed a three-part flipped-classroom series conducted by interdisciplinary clinicians in hepatology, psychiatry, primary care, and addiction psychology. Participants watched a video followed by a live session focused on (a) withdrawal, (b) screening and brief intervention, and (c) prescribing pharmacotherapy. Questionnaires assessing knowledge and practice habits were adapted from the literature. Attitudes were evaluated using the Short Alcohol and Alcohol Problems Perception Questionnaire (SAAPPQ). Self Determination Theory informed motivation questions.

Results:

Paired sample t-tests on pre-post questionnaires ( n = 229 clinicians; 95 completed questionnaires) revealed significant improvements in preparedness and comfort screening, providing a brief intervention, prescribing pharmacotherapy, and SAAPPQ domains. No significant changes were observed in the intention to prescribe pharmacotherapy. Effect size analysis showed medium to large effects across most topic areas.

Conclusions:

The developed sessions improved knowledge, attitudes, and practice habits of clinicians caring for this patient population. Given the rise in AUD and significant consequences in cirrhosis, this data offers promise that interactive education may improve practice habits of clinicians interfacing with this patient population.
René Girard and the Coherence of the Redemptive Work: Example, Instruction, and the Sacrifice of the Cross
Authors: Roumas Nicholas G.
Published: December 2022

René Girard’s mimetic theory opens up a possibility of unifying the ethical and objective dimensions of Christ’s redemptive work, harmonizing a problematic tension that arises from the redemptive act. To demonstrate this, I draw on Girard’s writings on the Gospels to show how a Girardian reading of the cross leads to an understanding of the redemptive work of Christ as simultaneously exemplary, didactic, and sacrificial, with no real distance between any of these terms.
The Climate Crisis and the Church: A Landscape for Theological Education
Authors: Keesmaat Sylvia C.
Published: December 2022

Acknowledging that the climate crisis is the defining issue of our time, this paper argues that theological education needs to be attentive to the following in order to provide resources for the anxiety and grief that the community is coping with: 1) the biblical tradition of lament; 2) biblical texts that grapple with climate catastrophe; 3) the legacy of colonialism; 4) the possibility of resurrection hope. In addition, this paper suggests that traditional theological education is deeply implicated in our current climate crisis and briefly outlines how the curriculum would need to be refocused in order to realistically equip clergy to vigorously engage the challenges their communities are struggling with.
God Keep Our Land? Unsettling Christian Theology
Authors: Barter Jane
Published: December 2022

Jamaican novelist and critic Sylvia Wynter famously wrote that “the central mechanism at work” in processes of colonization “was and is that of representation.” Canadian theology is becoming ever more responsive to Wynter’s call as it thinks through the manner in which the mechanism of theological representation supported and continues to support colonization. This is the challenge that I, too, wish to take up, and I will do so through thinking about how we represent time within settler colonialism, and how our understanding of time and its redemption is, in fact, deeply invested with theological suppositions that afflict both Canadian and Canadian theological understandings of the time of reconciliation.
Influence of Plasma-Sprayed Processes on La10(SiO4)6O3 Electrolyte Coatings
Authors: Gao W. , Lapostolle F. , Liao H.-L. , Coddet C.
Published: December 2022

La10(SiO4)6O3 electrolyte ceramic coatings based on solid oxide fuel cell (SOFC) operated at intermediate temperature were deposited onto an aluminum substrate by atmospheric plasma spraying (APS). By proper selection of the spraying parameters, particularly, adjusting the hydrogen gas flow rate, the sprayed La10(SiO4)6O3 electrolyte ceramic coatings show a good densification. The results suggested that the use of APS technique allowed providing new opportunity in novel electrolyte ceramic coating preparation with low production costs.
Mullite and Mullite/ZrO2-7wt%Y2O3 Powders for Thermal Spraying of Environmental Barrier Coatings
Authors: Garcia E. , Guimarães J. , Miranzo P. , Osendi M.I. , Wang Y. , Lima R.S. , Moreau C.
Published: December 2022

In this study, two processing routes are used to produce mullite powders for thermal spraying and the influence of each method on particle morphology and microstructure is investigated. Different thermal treatments are performed to improve grain cohesion and powder flow and their effect on the crystal structure of the powder is assessed as well. The powders are plasma sprayed, in-flight characteristics are measured, and splats are collected and analyzed. A correlation among powder morphology, in-flight particle properties, and splat morphology is established to better understand the influence of powder processing route on coating formation.
Latest Developments in Suspension and Liquid Precursor Thermal Spraying
Authors: Fauchais P. , Montavon G.
Published: December 2022

This review presents recent developments in suspension and solution precursor thermal spraying and demonstrates some of the tools available to characterize plasma-liquid interactions and the coatings produced. It compares and contrasts the two methods with conventional thermal spraying routes and identifies areas needing improvement.
Microstructures and Functional Properties of Al2O3 and TiO2 Suspension Sprayed Coatings: An Overview
Authors: Toma F.-L. , Berger L.-M. , Stahr C.C. , Naumann T. , Langner S.
Published: December 2022

This paper describes the properties and behaviors of alumina and titania coatings that have recently been produced using suspension spraying techniques. It examines coating microstructures and phase compositions are shows how they are influenced by different operating parameters and interactions. A selection of new experimental results obtained by the authors is also presented. In the case of Al2O3, the goal was to retain a high ratio of the thermodynamically stable α-phase. In the case of TiO2, the spraying process was optimized to preserve the anatase phase in order to obtain photocatalytically active layers.
Basic Principles to Obtain Oxide Ceramic Coating Systems with Reduced Sliding Wear by Suspension Plasma Spraying
Authors: Erne M. , Bach Fr.-W. , Möhwald K. , Kolar D.
Published: December 2022

In this study, suspension plasma spraying is used to produce self-lubricating titanium oxide coatings. Certain nonstoichiometric titanium oxide phases, called Magneli phases, exhibit a reduction in friction under dry sliding conditions at elevated temperatures. These phases, however, tend to undergo crystal changes during thermal spraying, resulting in the loss of their good friction behavior. In this work, the goal is to stabilize these phases with suitable lattice substitutions for Ti4+. The resulting phases are shown to be homologous to TinO2n-1, but have the advantages of a three-component system, making them more thermally stable with a broader area of formation.
Improved Deposition Characteristics of Diamond Enhanced by Plastically Deformed Nickel Layer in Kinetic Sprayed Bronze-Diamond Composite Coating
Authors: Na H. , Bae G. , Yoon S. , Lee C. , Kim H.J.
Published: December 2022

This study compares the deposition behavior of kinetic sprayed bronze-diamond composite coatings produced using different mixtures of helium and nitrogen gas. To determine impact properties of the diamond particles, bare and nickel-coated diamonds are deposited on bronze layers and the effects of plastic deformation are examined using SEM and finite-element analysis. The results indicate that the deposition efficiency of diamond is determined by several factors and depends more on the angle and shape of the diamond particles than on the deformation properties of the bronze matrix.
Structure and Corrosion Behavior of Cold-Sprayed Tantalum Coatings
Authors: Koivuluoto H. , Vuoristo P. , Näkki J.
Published: December 2022

Cold spraying enables the production of pure and dense metallic coatings with very little porosity and oxygen content, all of which play an important role in corrosion resistance. This study investigates the microstructure, denseness (impermeability), and corrosion properties of tantalum coatings produced by high-pressure cold spraying. Various tests were conducted to assess corrosion behaviors in different aqueous solutions. Microstructural studies showed that interfaces in the coatings were practically free of voids and confirmed that high levels of localized plastic deformation occurred as expected during spraying. The study also confirmed that the polarization behavior of the cold-sprayed tantalum is similar to that of the corresponding tantalum bulk in saline as well as sulfuric and hydrochloric acid solutions.
Fabrication of Cu-MoS2 Composite Coating by Cold Spraying and Evaluation of Its Property
Authors: Yamada M. , Wakabayashi J. , Fukumoto M. , Kitamura J.
Published: December 2022

Molybdenum disulfide (MoS2) films are widely used to improve friction performance, but they are difficult to fabricate using conventional thermal spray processes due to thermal decomposition of the feedstock powder. In this study, Cu-MoS2 composite coatings are fabricated by cold spraying using mechanically milled powders containing different concentrations of MoS2. Investigators found that increasing the concentration of MoS2 in the powder improved some coating properties while degrading others. Through testing it was determined that the ideal concentration of MoS2 is 5wt%. Increasing the milling time of the powder mixture also provided benefits in terms of hardness and wear resistance.
A Study on the Influence of Plasma Deposited HA and TiO2 Coatings on Fatigue Lives of Low-Carbon Steel Specimens with Respect to Various Powder In-Flight Properties
Authors: Cizek J. , Khor K.A. , Siegl J. , Bensch J.
Published: December 2022

This work investigates the influence of plasma-sprayed deposits on the fatigue life of coated specimens. Hydroxyapatite (HA) and TiO2 were deposited on dog-bone shaped substrates under different spraying conditions while measuring in-flight particle temperature and velocity. The coated specimens were then subjected to cyclic bending with constant deflection and the number of cycles to failure was recorded. It was found that the higher the temperature and velocity of particles during spraying, the greater the improvement in fatigue life up to a maximum of 46% compared to uncoated samples.
Antibacterial Property and Biocompatibility of Plasma Sprayed Hydroxyapatite-Silver Composite Coatings
Authors: Zheng Xuebin , Chen Yikai , Xie Youtao , Ji Heng , Huang Liping , Ding Chuanxian
Published: December 2022

In this study, vacuum plasma spraying was used to apply hydroxyapatite-silver composite coatings on titanium substrates, which were then exposed to E. coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The coatings exhibited excellent antibacterial performance (K > 95%) against all three strains, attributed to the release of silver ions. Cytotoxicity, hemolysis, and simulated body fluid immersion tests showed that added silver affects neither the biocompatibility nor bioactivity of the hydroxyapatite, one of the most widely used medical implant materials due to its close chemical structure with natural bone.
Bio-Ceramic Composite Coatings by Cold Spray Technology
Authors: Choudhuri A. , Mohanty P.S. , Karthikeyan J.
Published: December 2022

This work shows that hydroxyapatite (HA) can be cold sprayed simultaneously with titanium to form thick biocompatible coatings without compromising the phase constituents of the bioceramic material. XRD analysis indicates that the phase composition of the HA in the deposit is identical to that of the powder. The work also shows that very dense Ti and Ti-HA composite coatings can be produced using sponge Ti powders and nitrogen process gas. The adhesion strength of the cold-sprayed Ti-HA exceeded the reported values of comparable plasma-sprayed coatings.
Behavior of HVOF WC-10Co4Cr Coatings with Different Carbide Size in Fine and Coarse Particle Abrasion
Authors: Ghabchi Arash , Varis Tommi , Turunen Erja , Suhonen Tomi , Liu Xuwen , Hannula S.-P. , Ghabchi Arash
Published: December 2022

This study assesses the effect of carbide grain size on the wear performance of HVOF-sprayed WC-CoCr coatings. The coatings were produced from two powders, one of conventional grain size and one with submicron carbide. Both coatings were subjected to abrasive rubber wheel wear tests in wet and dry conditions with 220 nm titania particles and 368 μm sand particles, respectively. Detailed examination before and after wear tests shows that the wear mechanism depends on the relative size of the carbide and abrasive particles.
Nano Particle Embedded High Temperature FGM Coatings by Hybrid Spray Process
Authors: Guduru R.K. , Varadaraajan V. , Roche A.D. , Mohanty P.S.
Published: December 2022

This study evaluates the potential of functionally graded composite coatings fabricated with a novel spraying process. The hybrid process embeds varying amounts of ceramic particles in a metal matrix by combining HVOF and wire arc spray streams. In this case, ceramic nanoparticles (SiO2, Cr2O3, Al2O3) from liquid precursors are embedded in a matrix synthesized from NiCr wire feedstock. The resulting coatings are evaluated based on high-temperature performance and the composition and dispersion of particles in the NiCr matrix. Uniform size distribution and dispersion of nanoparticles is shown to correlate not only with denser coatings, but also improved corrosion, wear, and oxidation resistance.
Numerical Model for Liquid Precursor Break-Up under Plasma Spray Conditions
Authors: Marchand C. , Mariaux G. , Vardelle M. , Vardelle A. , Lefort P.
Published: December 2022

Plasma spraying using liquid precursors makes it possible to produce finely-structured coatings with a broad range of microstructures and properties. Nonetheless, issues with coating reproducibility and control of deposition efficiency continue to be a concern. With conventional dc plasma torches that inject liquid feedstock transversely into the plasma stream, coating quality depends on transient interactions between the liquid and plasma jet. Numerical models may assist in understanding these interactions provided they are able to predict droplet fragmentation, which determines the trajectories of droplets and their behavior in the plasma flow. Although various models for droplet fragmentation have been proposed in the literature, they include parameters and constants that need to be validated for plasma spraying conditions. This study simulates liquid material injection and break-up in the plasma jet using an enhanced Taylor analogy break-up (TAB) model. Model constants are adapted to plasma spray conditions by observation of liquid behavior in the plasma flow, which is accomplished by means of a shadowgraph system using pulsed backlight illumination.
Thermal and Kinetic Energy Influence on Diamonds during the Spraying of Diamond-Bronze Abrasive Coatings
Authors: Nebel J. , Vogli E. , Tillmann W.
Published: December 2022

Detonation spraying provides the opportunity to produce superabrasive diamond grinding tools under atmospheric conditions. In this study, several methods are used to assess the effects of the spraying process on diamond particles, including SEM analysis, energy dispersive X-ray spectroscopy, differential thermal analysis, thermogravimetric analysis, X-ray diffraction, Raman spectroscopy, and friability and fracture force testing. It was found that under optimized conditions, the thermal and mechanical impact of the detonation can remain low enough to ensure the reliability of the diamonds with no adverse effects.
Preparation and Ion Diffusion Performance of the Nanoporous TiO2 Coating through Vacuum Cold Spray
Authors: Yang G.-J. , Li C.-J. , Li C.-X. , Gao J.-C. , Fan S.-Q.
Published: December 2022

This study investigates the effect of powder size on the porosity and diffusion properties of vacuum cold sprayed TiO2 coatings. In the experiments, coating samples are produced using powders with different primary particle sizes. Porosity and pore size in the TiO2 coatings are assessed via nitrogen adsorption and desorption and correlated with the diffusion coefficient of I3ֿin acetonitrile. The results show that pore size is significantly influenced by primary particle size, but porosity is the same regardless of the particle size of the powder. The I3ֿion diffusion coefficient is shown to increase with increasing pore size and can thus be adjusted through proper selection of the powder feedstock.
Structural, Mechanical and Erosion Properties of Plasma Sprayed Yttrium Oxide Coatings by Axial Injection of Fine Powder Slurries for Semiconductor and Flat-Panel-Display Applications
Authors: Kitamura J. , Ibe H. , Yuasa F. , Tang Z. , Burgess A.
Published: December 2022

In this study, high-power axial-injection suspension plasma spraying is used to synthesize yttrium oxide coatings from fine powder slurries. The coatings are assessed based on microstructure, hardness, and porosity and compared with coatings produced by other spraying methods. Resistance to erosion from CF4 containing plasma is also investigated. Test results show that the suspension plasma sprayed Y2O3 coatings are superior in terms of density, hardness, uniformity, and plasma erosion resistance. They also retain a smoother surface when exposed to plasma that contains CF4.
Production of Particle Reinforced Graded Coatings by Wire Arc Spraying
Authors: van Rodijnen F. , Knapp S. , Wilden J. , Jahn S. , Drescher V.E.
Published: December 2022

The aim of this investigation is to show that it is possible to inject powder into a wire arc spray process as an alternative to using cored wire to produce particle-reinforced coatings. The equipment, materials, and procedures used are described in the paper along with the microstructure and properties of the coatings obtained. By changing the feedrate of CrC particles injected into a stream of chromium steel droplets, particle-reinforced graded layers were produced by wire arc spraying on the fly without having to stop the process.
Influence of Spray Gun Moving Direction on Properties of Twin Wire Arc Sprayed Hard Material Based Layers
Authors: Tillmann W. , Vogli E. , Abdulgader M. , Carpenter K.R. , Monaghan B.J. , Norrish J.
Published: December 2022

The intent of this study is to gain a better understanding of the twin wire arc spray process, particularly the correlation between spray path or gun movement and coating quality. Coatings were deposited on steel substrates using solid nickel and cored WC-Cr wire while moving the gun in various directions relative to the orientation of the electrodes. The coatings obtained are evaluated based on porosity, hardness, thickness, adhesion strength, and microstructure. It is observed that gun movements cause inhomogeneities in the spray cone that affect different coating properties in different ways depending on the direction of the movement and gas pressure.
Low Cost HVAF for Thermal Spraying of WC-Co
Authors: Gorlach I.A.
Published: December 2022

In this research, a low cost high-velocity air-fuel (HVAF) system was developed and applied for thermal spraying of WC-Co coatings. The resulting coatings were evaluated using optical and scanning electron microscopy (SEM), X-ray diffraction (XRD) and Vickers microhardness measurements. The quality of sprayed WC-Co coatings shows that the developed HVAF system can be an alternative to the existing HVOF with substantial savings on operating costs.
Use of Low-Pressure Plasma Spraying Equipment to Produce Thin Films and Thick Coatings Using Liquid and Gaseous Precursors
Authors: Guittienne Ph. , Hollenstein Ch. , Dorier J.-L. , Gindrat M. , Refke A.
Published: December 2022

This work shows that low-pressure plasma spraying equipment can be used to deposit layers of varying thickness from liquid or gaseous precursors. In particular, HMDSO and oxygen are used to deposit SiOx thin films over large areas at deposition rates exceeding 35 nm/s and conversion efficiency better than 50%. The coatings are analyzed ex-situ by FTIR absorption spectroscopy and the microstructure and morphology of layer cross-sections are examined by SEM. The effects of various process parameters are investigated as well.
The Development and Characterization of Novel Yttria-Stabilized Zirconia Coatings Deposited by Very Low Pressure Plasma Spray
Authors: Spinhirne N. , Hirschfeld D. , Hall A. , McCloskey J.
Published: December 2022

In this investigation, very low pressure plasma spraying (VLPPS) was used to produce yttria-stabilized zirconia (YSZ) coatings through both liquid and vapor deposition. Coatings created by liquid deposition were found to have a microstructure consisting of dense splats, while vapor-deposited layers exhibited a columnar structure similar to coatings produced by e-beam PVD. Columnar microstructure formation was dependent on substrate temperature and vapor flux continuity. Clear evidence of competitive crystal growth was observed in well-defined columnar coatings. Microstructures consisting of layers of splats and columns were also observed.
Novel NiZn-Ferrite Powders and Coatings for Electromagnetic Applications
Authors: McCartney D.G. , Zhang D. , Yellup J.Y. , Brühl M. , Bobzin K. , Richardt K. , Talako T. , Ilyushchanka A.
Published: December 2022

This paper reports on the development of NiZn-ferrite powders and their deposition by air plasma and high-velocity oxyfuel spraying. The microstructure and phase composition of the powders and coatings are analyzed and the influence of process parameters on coating development is assessed for sprayed layers up to 500 μm thick. Particular attention is paid to the degradation of the spinel crystal structure, the formation of iron oxide phases, and elemental loss during spraying. The results show that a degree of ferrite decomposition occurs with the loss of zinc and formation of wüstite and that zinc loss is very dependent on the surface-to-volume ratio of the powder.
Preparation of High-Purity Yttria Powders and Coatings
Authors: Ji X.-J. , Ren X.-J. , Li Zh.-D. , Huang X.-Ch. , Hou W.-Ao
Published: December 2022

High-purity globular yttria powders prepared by spray drying and sintering were deposited by air plasma spraying. The effect of powder properties and spraying parameters on coating structure and porosity was investigated. Yttria powders with grain size in the 20 to 50 μm range and loose density greater than 1.2 g/cm3 seemed to be the optimum selection for producing dense, high-quality coatings.
Estimation of Molten Content of the Spray Stream from Analysis of Experimental Particle Diagnostics
Authors: Srinivasan V. , Sampath S.
Published: December 2022

Particle melting is one of the key issues in air plasma spraying of high-temperature ceramics such as YSZ. This study aims to estimate the molten content of the spray stream from in-flight particle temperature measurements. Particle temperature distribution is delineated into particle states (unmolten, partially molten, completely molten) as a first approximation, which is then used to estimate the molten content in the spray stream. The estimated percentage of molten content is shown to correlate well with deposition efficiency measurements for a wide range of process conditions and feedstock characteristics. The use of this estimation technique for other materials and processes is also discussed.
Microstructure, Mechanical and Shielding Properties of Fe67.5Ni23.5B9 Coating / 321 Stainless Steel Laminated Composite by the Air-Plasma Spraying Procedure
Authors: Yang W. , Zhou C.
Published: December 2022

In this study, boron-rich iron-nickel coatings were deposited on stainless steel by air-plasma spraying. Coating microstructure was characterized by SEM, EDS, and XRD analysis and adhesion strength, tensile properties, and residual stress were measured. The shielding effectiveness of the coating samples, including their ability to absorb thermal neutrons and attenuate γ rays, was investigated as well. The results show that the coating samples possess the microstructure and properties necessary for possible use in radiation shielding systems.
Characterization of Atomized Metallic Powders Using De Laval Nozzle
Authors: Khatim O. , Planche M.P. , Dembinski L. , Coddet C.
Published: December 2022

The aim of this work is to analyze the morphology and composition of iron-aluminide (FeAl) powders produced by liquid metal atomization using a de Laval nozzle. The variables studied are atomization gas pressure and melt nozzle diameter. Different sized powders were characterized via SEM, XRD, and EDS analysis and were found to be similar in composition and shape (spherical) regardless of their size. The paper provides a detailed description of how the powders were produced, classified, and tested, and presents and interprets the results.
Improvement of Impact Resistance of WC-Cr3C2-Ni Based Coatings by Means of Hardness Control of Undercoat
Authors: Kitamura J. , Osawa S. , Ibe H. , Mizuno H. , Tawada S.
Published: December 2022

This study shows how the impact resistance of WC-Cr3C2-Ni coatings can be improved by as much as an order of magnitude through the addition of an undercoat with suitable hardness. It also investigates the effect of powder modifications and substrate hardness. Undercoats with Vickers hardness ranging from400-600 HV provided the biggest increases in impact resistance, but at around 700 HV and above, they are shown to have the opposite effect. The influence of the process used to apply the undercoat and the magnitude of the impact load used for testing are also considered in the study.
The Electrical and Mechanical Properties of Kinetic Sprayed Carbon Nanotube Aluminum Composite Coating
Authors: Kang K. , Xiong Y. , Lee C.
Published: December 2022

In this investigation, carbon nanotube (CNT) aluminum composite coatings are produced by kinetic spraying. Electrical and mechanical properties are evaluated and compared with those of cold-sprayed pure aluminum coatings. The CNT aluminum composite coatings exhibited higher conductivity and hardness than the pure aluminum, which is attributed to the high electrical conductivity and dispersion hardening effects of embedded CNTs in the aluminum matrix.
Phase Composition Changes of Plasma Sprayed TiO2 Coatings Deposited under Different In-Flight Temperatures and Velocities
Authors: Cizek J. , Khor K.A.
Published: December 2022

Changes in phase composition of titania (TiO2) coatings were studied with respect to in-flight particle characteristics during atmospheric plasma spraying. A CCD camera was used to record the average temperature and velocity of TiO2 particles within the plasma jet for six combinations of spraying parameters selected according to Taguchi design of experiments. Phase composition of the coatings was assessed by means of X-ray diffractometry and numerically specified using Rietveld analysis. Changes in composition between the powders and coatings were observed with respect to the in-flight properties of the titania particles during spraying. In general, it was shown that the amount of impurity phases (hematite, quartz) present in the powder decreased after deposition and that in-flight temperature has only a moderate effect on the phase composition of TiO2 coatings. For comparison purposes, additional coatings were deposited by cold spraying and phase composition changes were assessed.
Characterization of Residual Stresses in Al and Al-Al2O3 Cold Sprayed Coatings
Authors: Rech S. , Trentin A. , Vezzù S. , Legoux J.-G. , Irissou E. , Arsenault B. , Lamontagne M. , Moreau C. , Guagliano M.
Published: December 2022

In the present work, pure Al and Al-Al2O3 composite coatings are deposited by cold spraying while measuring in-flight particle velocities. Residual stresses, evaluated using the Almen curvature method, X-day diffraction, and modified layer removal, are correlated with particle velocity, coating thickness, and alumina content. Peening stresses due to plastic deformation were estimated to be less than 100 MPa and are shown to be nearly constant through the thickness of the coatings.
High Temperature Behavior of Newly Developed Oxide Dispersion Strengthened NiCoCrAlY Coatings
Authors: Bobzin K. , Schläfer T. , Richardt K. , Brühl M.
Published: December 2022

This work demonstrates the capabilities of oxide dispersion strengthened MCrAlY coatings and the process used to produce the feedstock powders. Mechanically alloyed powder mixtures were prepared in a high-energy ball mill using commercial NiCoCrAlY and YPSZ powders combined in different amounts. A high-velocity oxyfuel torch was used to deposit the powders on Inconel substrates that were then heat treated for 6 h at 1050 °C. Samples were also produced from unaltered NiCoCrAlY powder to serve as a reference. In high-temperature erosion tests, the strengthened coatings had a mass loss of 47 mg/cm2 after 30 sec compared to 38 mg/cm2 for the unstrengthened sample. High-temperature corrosion tests showed that the strengthened coatings were not dense enough to protect the substrate from oxidation. The hard phases inhibited sintering and diffusion effects during heat treatment. As a result, dislocations, defects, and voids could not move and were used by oxygen for diffusion. In further investigations, the strengthened coatings will be treated at a higher temperature to achieve a better sintering effect.
Influence of the Substrate Hardness on the Rolling Contact Fatigue of WC-17%Co Hardmetal Coatings
Authors: Berger L.-M. , Lipp K. , May U.
Published: December 2022

In this paper, as part of a systematic study on the rolling contact fatigue of HVOF-sprayed hardmetal coatings, the behavior of WC-17%Co coatings on hardened and nonhardened substrates is compared. To obtain a meaningful assessment, the coatings were applied to roller specimens made from soft as well as case-hardened MnCr steel. Two coating thicknesses were used with the expectation that maximum stress will occur in the substrate, in one case, and in the other case, in the coating. Test results show that the durability of HVOF-sprayed WC-Co is significantly better on nonhardened (soft) substrates and that the limiting factor for endurable Hertz pressure is the fatigue strength of the coating.
Tribological Properties of HVOF Sprayed Tungsten Carbide Coatings after EDM Process
Authors: Żórawski W. , Radek N.
Published: December 2022

This study investigates the tribological properties of two HVOF-sprayed tungsten carbide coatings, each with a different content of cobalt, which were subjected to electrical discharge machining (EDM). It was found that the electrospark deposition of WC8Co over the HVOF-sprayed WC12Co and WC17Co coatingsresults in the formation of a homogeneous layer of tungsten carbide with a low cobalt content. The EDM layer is well bonded with the HVOF-sprayed coating as confirmed by the gradual change in the content of the elements in the coating and layer. The friction coefficients obtained for the two coatings with the EDM layer are very similar as their composition, microstructure, hardness, and surface roughness are approximately the same.
Effects of Heat Treatment on the Mechanical Properties of Plasma-Sprayed 316L Coatings
Authors: Tian B.-H. , Chang L. , Qu W.-L. , Gao Y.
Published: December 2022

To improve the mechanical properties of 316L stainless steel coatings prepared by plasma spraying, post-spray heat treatments were conducted at 600-800 °C for 1-2 hours. The effect on microstructure and hardness was assessed via XRD and SEM analysis and microhardness measurements. The results show that heat treatment at various temperatures improved coating hardness as well as fracture behavior.
Ecodesign of Surface Coatings: How to Conciliate Environmental and Technical Performances?
Authors: Serres N. , Hlawka F. , Cornet A. , Costil S. , Langlade C. , Machi F.
Published: December 2022

The aim of this study is to propose coatings that could potentially replace hard chromium as a means of corrosion and wear protection. Two NiCrBSi coatings are evaluated, one produced by laser cladding, the other by atmospheric plasma spraying with a post-laser treatment. Although laser-clad NiCrBSi exhibits the best technical properties, the APS coatings were found to be more environmentally justifiable based on the use of life cycle assessment (LCA) software.
Recent Application of Thermal Spray to Thermal Power Plants
Authors: Notomi A. , Sakakibara N. , Torigoe T.
Published: December 2022

This paper presents recent developments in thermal spray coating technology for thermal power plants. As for thermal barrier coatings for gas turbines, to accommodate the high gas temperatures required to improve thermal efficiency, a new ceramic topcoat material with low conductivity was developed. As for wear-resistant coatings for boiler parts, a C-Cr-Fe alloy coating was developed that is lower in cost than conventional chromium carbide cermet. Field tests of boiler parts show that the erosion wear rates of these coatings are as good or better than that of conventional cermet.
Drag Reduction and Self-Cleaning of Thermal Sprayed Surfaces by the Combination of Materials with Positive and Negative Thermal Expansion Coefficients
Authors: Wilden J. , Jahn S. , Drescher V.E. , Schaaf P.
Published: December 2022

This work investigates some of the unique properties that can be achieved by combining materials with positive and negative thermal expansion coefficients. In the experiments, different mixtures of MCrAlY, WO3, and Y2O3 powders are deposited on stainless steel substrates by laser cladding and HVOF spraying. To facilitate the formation of negative expansion coefficient particles in a positive expansion coefficient matrix, nucleation centers are created by ion implantation followed by heat treating. SEM examination and XRD analysis of the coatings obtained confirm the viability of the processing approach.
External Ballistics of Powder under Detonation Spraying
Authors: Ulianitsky V. , Shtertser A. , Pervushin D. , Smurov I.
Published: December 2022

This study investigates the influence of spraying distance and substrate orientation on the formation of metallic coatings by detonation spraying. Deposition efficiency was determined for aluminum, copper, titanium, and steel powders sprayed at different distances on substrates oriented at different angles. The results show that detonation products maintain their influence on sprayed particles even outside the barrel despite the pulsed nature of the detonation spraying process. Numerical calculations of particle acceleration and heating inside the barrel are performed for several materials and a theory of the processes outside the barrel is proposed. Optimal spraying parameters allowing 60-80% deposition efficiency are defined and experimentally validated for the materials studied.