bluuebunny/crossref_metadata_2025 huggingface dataset:
KAJIAN DAERAH IMBUHAN AIR TANAH (GROUNDWATER RECHARGE AREA) DALAM RENCANA TATA RUANG WILAYAH (RTRW) KOTA BENGKULU DAN KABUPATEN BENGKULU TENGAH
Authors: Prabowo Benny Bayu , Suhartoyo Hery , Barchia M. Faiz , Utama Satria Putra , Hermawan Bandi
Published: October 2022

Penelitian ini bertujuan untuk (1) Mengetahui porsi daerah Imbuhan air tanah (Groundwater Recharge Area) di Kota Bengkulu dan Kabupaten Bengkulu Tengah  dalam RTRW Kota Bengkulu dan Kabupaten Bengkulu Tengah. (2) Mengetahui kesesuaian penggunaan lahan Kota Bengkulu dan Kabupaten Bengkulu Tengah terhadap daerah Imbuhan air tanah (Groundwater Recharge Area). (3) Mengetahui kesesuaian daerah Imbuhan air tanah (Groundwater Recharge Area) dengan RTRW Kota Bengkulu dan Kabupaten Bengkulu Tengah. Penelitian ini dilaksanakan pada bulan Maret – April 2020 di Kota Bengkulu dan Kabupaten Bengkulu Tengah. Data yang digunakan dalam penelitian ini antara lain adalah data Demnas, Peta Geologi dan Citra Satelite Spot Perekaman Tahun 2016. Data Demnas di ektraksi melalui analisis spasial sehingga menghasilkan data, Linement Density, Drainage Density dan Slope Gradient, kemudian data Geologi diturunkan menjadi data Lithologi serta data Citra Satelite di ekstraksi menjadi data tutupan lahan. 5 parameter tersebut dilakukan pemberian bobot dan Factor Rate kemudian dilakukan Overlay dan didapatkan hasil dengan kelas Rendah, Sedang, Baik dan Sangat Baik. Kota Bengkulu di dominasi kelas Sedang 30,052% dan Baik 39,031% dengan sebaran sebagian besar di wilayah Kecamatan Muara Bangkahulu, Sungai Serut, sebagian singaran pati selebar serta kampung melayu sedangkan kelas Baik dan Sangat Baik berada di Wilayah Kecamatan yang berbatasan langsung antara 2 Kabupaten. Hasil Overlay Daerah Imbuhan Air Tanah terhadap Pola Ruang dalama RTRW Kota Bengkulu menunjukkan bahwa Kawasan resapan air masuk ke dalam kelas Baik Daerah Imbuhan Air Tanah. Daerah ini juga masuk ke dalam Cagar Alam yang masuk dalam Kawasan Lindung dalam Pola Ruang. Kabupaten Bengkulu tengah di dominasi oleh kelas rendah dikarenakan daerah ini sebagian besar lithologinya merupakan andesit.
Temporary abstinence challenges: what do we need to know?
Authors: Butters Anna , Kersbergen Inge , Holmes John , Field Matt
Published: October 2022

Participation in temporary abstinence challenges (TACs) continues to increase with campaigns established in several countries. Temporarily abstaining from alcohol as part of such challenges is associated with ongoing benefits including reductions to alcohol consumption after the TAC. We identified three research priorities regarding TACs which are outlined in this paper. First, the role of temporary abstinence itself is unclear with post-TAC reductions in alcohol consumption still apparent among participants who do not remain fully abstinent throughout the challenge. It is necessary to establish to what degree temporary abstinence itself, rather than the combination of abstinence and the additional supports provided by TAC organisers (e.g. mobile applications, online support groups), contributes to changes in consumption after the TAC.Second, little is known about the psychological changes underlying these changes in alcohol consumption, with conflicting evidence as to whether increases in someone’s belief in their ability to avoid drinking mediates the association between participation in a TAC and reductions in consumption afterwards. Other potential psychological and social mechanisms of change have been subjected to little, if any, scrutiny.Third, evidence of increased consumption post-TAC among a minority of participants indicates a need to establish for whom or in what circumstances participation in a TAC may result in unintended negative consequences.Focussing research in these areas would increase the confidence with which participation could be encouraged. It would also enable campaign messaging and additional supports to be prioritised and tailored to be as effective as possible in facilitating long-term change.
The impact of Holocene deglaciation and glacial dynamics on the landscapes and geomorphology of Potter Peninsula, King George Island (Isla 25 Mayo), NW Antarctic Peninsula
Authors: Heredia Barión Pablo , Strelin Jorge , Roberts Stephen , Spiegel Cornelia , Wacker Lukas , Niedermann Samuel , Bentley Michael , Pearson Emma , Manograsso Czalbowski Tamara , Davies Sarah , Schnetger Bernhard , Grosjean Martin , Arcusa Stephanie , Perren Bianca , Hocking Emma , Kuhn Gerhard
Published: October 2022

The timing and impact of deglaciation and Holocene readvances on the terrestrial continental margins of the Antarctic Peninsula have been well-studied but are still debated. Potter Peninsula on King George Island (Isla 25 de Mayo), South Shetland Islands (SSI), NW Antarctic Peninsula has a detailed assemblage of glacial landforms and stratigraphic exposures for constraining deglacial landscape development and glacier readvances. We undertook new morphostratigraphic mapping of the deglaciated foreland of the Warszawa Icefield, an outlet of the Bellingshausen (Collins) Ice Cap on Potter Peninsula, using satellite imagery and new lithofacies recognition and interpretations, combined with new chronostratigraphic analysis of stratigraphic sections, lake sediments, and moraine deposits. Results show that deglaciation on Potter Peninsula began before c. 8.2 ka. Around c. 7.0 ka, the Warszawa Icefield and the marine-facing Fourcade Glacier readvanced across Potter Peninsula and to the outer part of Potter Cove. Evidence of further readvances on Potter Peninsula is then absent until the Warszawa Icefield margin was landward of its present position on three occasions, c. 1.7–1.4 ka, after c. 0.7 ka (most likely c. 0.5–0.1 ka), and by 1956 CE. The timing of Holocene deglaciation and glacier fluctuations on Potter Peninsula are broadly coeval with other glacier- and ice-free areas on the South Shetland Islands and the northern Antarctic Peninsula, and likely driven by interactions between millennial-to-centennial-scale changes in solar insolation and irradiance, the southern westerlies, and the Southern Annular Mode.
Retrieval Practice Is Costly: It Is Beneficial Only When Working Memory Capacity Is Abundant
Authors: Zheng Yicong , Sun Pengyuan , Liu Xiaonan L.
Published: October 2022

Numerous studies have shown that learned information practiced by testing is better retained than that practiced by restudying (the testing effect). However, results are inconsistent regarding the effect of working memory (WM) capacity on the testing effect. Here, we hypothesized that the effect of WM only emerges when task demands challenge WM capacity. We manipulated WM demands by pretraining 30 undergraduate participants in a multisession visual search task before an associative learning task involving a test/restudy manipulation. The results showed that, while participants with higher WM capacity showed a consistent testing effect, the benefit of testing only emerged in participants with lower WM capacity when learning familiar stimuli (low WM demands). We simulated the results using a modified source of activation confusion (SAC) model, which implemented a dual-process account of the testing effect. The results suggested that the testing effect only emerges when WM capacity is adequate for both processes.
Decade on restoration needs behavioural science
Authors: Cerullo Gianluca , Nielsen Kristian Steensen
Published: October 2022

Global agendas under the UN Decade on Ecosystem Restoration are highlighting the critical importance of large-scale ecosystem restoration for the benefits of people, climate, and biodiversity. Current focus in restoration science has prioritised a mechanistic understanding of the ecological drivers of restoration successes and failures. However, large-scale implementation of lasting and successful restoration outcomes fundamentally hinges on understanding and changing key social and behavioural dynamics across the spectrum of restoration actors and stakeholders. This dimension of restoration has overwhelmingly been side-lined in restoration research and practice, limiting the realisation of ambitious restoration commitments. Behavioural science can inform and help shape successful outcomes across at least three stages of restoration, by (i) helping understand and combat degradation prior to project implementation (ii) by determining which, where and why restoration actions are deployed and (iii) by ensuring the lasting legacy of restoration projects across decadal timescales.
Returning a smile: Initiating a social interaction with a facial emotional expression influences the evaluation of the expression received in return
Authors: Kroczek Leon O. H. , Mühlberger Andreas
Published: October 2022

Face-to-face social interactions are characterized by the reciprocal exchange of facial emotions between interaction partners. Typically, facial emotional expressions have been studied in passive observation paradigms, while interactive mechanisms remain unknown. In the current study we investigate how sending a facial emotional expression influenced the evaluation of an emotional expression received in return. Sixty-eight participants were cued to direct a facial emotional expression (happy, angry, neutral) towards a virtual agent in front of them. The virtual agent then responded with either the same or another emotional expression (happy, angry). Evaluation of the response expressions was measured via ratings of valence and arousal as well as EMG recordings of the M. corrugator supercilii and the M. zygomaticus major. Results revealed a significant interaction between the emotion of the initial facial expression and the response expression. Valence of happy response expressions were increased when participants had initially displayed a smile compared to a neutral expression or a frown. This was also reflected in the EMG responses. Initiating an interaction with a smile increased Zygomaticus activation for happy relative to angry response expressions compared to when the interaction was initiated with a frown. In contrast, no interplay of the initial and the response expression was observed in the Corrugator. These findings demonstrate that smiling or frowning at another person can modulate socio-emotional processing of subsequent social cues. Therefore, the present study highlights the interactive nature of facial emotional expressions.
Meditation and Sleep Health Kernels for Teens in Communities with High Violence Exposure
Authors: Moses Jacqueline
Published: October 2022

Background: After-school settings hold significant potential for high reach and high impact interventions for Black and Latinx teens in urban communities characterized by poverty and violence. Evidence-based kernels are brief, low-cost interventions that can be implemented within existing community programs to promote poly-strengths skill-building. Objective: The present study examined feasibility of and enthusiasm for meditation and sleep health kernels implemented within the Park Internship Program in Miami-Dade County, FL for teens living in urban communities with high violence exposure. Method: Teens provided quantitative and qualitative feedback for meditation and sleep health activities via anonymous surveys and permanent product data. Audio recordings of meditations were coded to assess quality of adherence to brief scripts. Results: Strong evidence was revealed for feasibility (staff adherence, teen participation) and enthusiasm (acceptability, utility, and generalizability). Conclusion: Findings indicate that evidence-based meditation and sleep health kernels can be meaningfully integrated into community programs accessible to teens living in urban communities with high violence exposure.
Interoceptive Technologies for Psychiatric Interventions: From Diagnosis to Clinical Applications
Authors: Schoeller Felix , Horowitz Adam Haar , Maes Pattie , Jain Abhinandan , Reggente Nicco , Christov-Moore Leonardo , TROUSSELARD Marion , Klein Arno , Barca Laura , Pezzulo Giovanni , Allen Micah , Garcia Teresa , Zhang Ben , Pollack Ursula , Miller Mark , Salomon Roy , Riva Giuseppe , DiLernia Daniele , Tsakiris Manos , VERDONK Charles , CHALAH Moussa A. , Dumas Guillaume , Adrien Vladimir , Friston Karl
Published: October 2022

The perception of body signals play a crucial role in cognition and emotion, which may lead to catastrophic outcomes when it becomes dysfunctional. To characterize these mechanisms and intervene on interoception for either diagnostic or treatment purposes, a mounting body of research is concerned with interventions on interoceptive channels such as respiration, cardioception, or thermoception. However, we are still lacking a mechanistic understanding of the underlying psychophysiology. For example, interoceptive signals are often both the cause and consequences of some distress in various mental disorders, and it is still unclear how interoceptive signals bind with exteroceptive cues. In this article, we present existing technologies for manipulating interoception and review their clinical potential in light of the predictive processing framework describing interoception as a process of minimization of prediction errors. We distinguish between three kinds of stimuli: artificial sensations that concern the direct manipulation of interoceptive signals, interoceptive illusions that manipulate contextual cues to induce a predictable drift in body perception, and emotional augmentation technologies that blend artificial sensations with contextual cues of personal significance to generate specific moods or emotions. We discuss how each technology can assess and intervene on the precision-weighting of prediction errors along the cognitive and emotional processing hierarchy and conclude by discussing the clinical relevance of interoceptive technologies in terms of diagnostic stress tests for evaluating interoceptive abilities across clinical conditions and as intervention protocols for conditions such as generalized anxiety disorders, post-traumatic stress disorders, and autism spectrum disorders.
Studying trait-characteristics and neural correlates of the emotional ego- and altercentric bias using an audiovisual paradigm
Authors: Goregliad Fjaellingsdal Tatiana , Makowka Nikolas , Krämer Ulrike M.
Published: October 2022

In social interactions, emotional biases can arise when the emotional state of oneself and another person are incongruent. A person’s ability to judge the other’s emotional state can then be biased by their own emotional state, leading to an emotional egocentric bias (EEB). Alternatively, a person’s perception of their own emotional state can be biased by the other’s emotional state leading to an emotional altercentric bias (EAB). Using a modified audiovisual paradigm, we examined in three studies (n=171; two online & one lab-based study) whether emotional biases can be considered traits by measuring two timepoints within participant and relating empathy trait scores to emotional biases, as well as the electrophysiological correlates of emotional biases. In all studies, we found a congruency effect, reflecting an EEB and EAB of small size. Both biases failed to correlate significantly within participants across timepoints and did not display significant relationships with empathy trait scores. On the electrophysiological level, we did not find any neural emotional bias effects in the time-frequency domain. Our results suggest that EEB and EAB effects are strongly task sensitive. Caution is warranted when studying interindividual differences in emotional biases using this paradigm, as they did not show significant test-retest reliabilities.
“Don’t fake the big O”: Portrayals of faking orgasm among women inCosmoandGlamour
Authors: Stelzl Monika , Malloy Briea
Published: October 2022

Many women report faking orgasm, at least on occasion, during heterosex (i.e., heterosexual sexual activities). The reasons for the practice include validating the skill of a male lover, a way of ending sexual encounters, and to avoid pathologization that is often associated with orgasmic absence. Constructions of heterosex, female sexuality, and sexual pleasure are influenced by multiple sources including the media. However, there is a lack of systematic research on how faking orgasm is presented in the media. This gap in research provided an opportunity to investigate women’s magazines’ portrayals of the practice. Using constructionist thematic analysis, 69 online articles, published by two popular women’s magazines, Cosmopolitan and Glamour, were analyzed. From the examined articles, two major themes emerged: faking as a common practice (especially via women’s first-hand accounts) and instructing the reader not to fake. It is our contention that together the two themes create a distinctly postfeminist portrayal of faking orgasm. On the one hand, the magazines included and highlighted women’s own experiences and reasons for faking orgasm. On the other hand, female readers were instructed to avoid faking in the name of personal responsibility and empowerment. Notably, the magazines omitted any discussion of gender power relations in their appeals for choice and sexual agency. Overall, this study expands our understanding of women magazines’ contradictory portrayals of women’s sexuality, sexual pleasure, and navigation of its absence.
Dialectical behaviour therapy skills training: A feasibility study with active duty military
Authors: Jewer Chimène , Forsyth Ashleigh
Published: October 2022

LAY SUMMARY

This study looked at the use of dialectical behaviour therapy (DBT) skills group training with military personnel. DBT skills group training teaches coping skills to manage emotions; it has been well researched and used effectively with civilians and Veterans, but less is known about its use with military personnel. The General Mental Health (GMH) clinic receives a large volume of referrals for military personnel who have difficulty with coping skills and managing emotions. On the basis of previous research, a modified DBT skills group therapy program was developed for the clinic to offer an efficient, effective treatment program for these clients in this busy clinic. Military personnel may be a particularly good fit for this type of group-based treatment because they are familiar with working in small group settings. This treatment can also allow for a timelier return to work, minimizing interruptions to military deployments and operations. Study results showed that program participants had lower levels of depression and a greater ability to manage emotions and cope more effectively after the program. Treatment gains were largely maintained at six-month follow-up. This research suggests that DBT skills group training may be an effective treatment for military personnel.
Nanostructured CVD Tungsten Carbide Coating on Aircraft Actuators and Gearbox Shafts Reduces Oil Leakage and Improves Durability
Authors: Zhuk Yuri
Published: October 2022

Wear and corrosion of aircraft actuator parts and helicopter gearbox rotating shafts and also wear of seals working against these parts can lead to oil leaks, which require expensive maintenance and increase the risk of failure. The Hardide nanostructured Chemical Vapor Deposition (CVD) Tungsten Carbide coating can help reduce oil leakage from gearboxes and actuators and increase maintenance intervals. The coating protects metal pistons and shafts from abrasion and corrosion, keeping their surface roughness parameters within optimum ranges for longer; this reduces seal wear and makes the whole unit more durable and reliable. The 50-100 microns thick CVD Hardide coating can be applied uniformly on internal and external surfaces and has enhanced fatigue and anti-galling properties. The coating has enhanced wear resistance outperforming Hard Chrome by 14 times and Thermal Spray WC-Co (12%) by 3 times. The fine-grain coating nanostructure wears uniformly so even worn Hardide coating shows no hard micro-grain asperities which are abrasive for seals. The coating is free from porosity and from Cobalt binder and is an excellent barrier against corrosion. As a result the coating keeps the optimal seal-friendly surface finish for longer even in abrasive and corrosive environments. The coating was qualified by Airbus as an environmentally-friendly replacement for Hard Chrome plating.
Hybrid Suspension/Solution Precursor Plasma Spraying of a Complex Ban (Mg1/3Ta2/3)O3 Perovskite: Effects of Processing Parameters and Precursor Chemistry on Phase Formation and Decomposition
Authors: Hou Huidong , Veilleux Jocelyn , Gitzhofera François , Wang Quansheng , Liu Ying
Published: October 2022

Ba(Mg1/3Ta2/3)O3 (BMT), a high melting point refractory oxide, is envisioned as a thermal barrier coating material. In this study, six chemical reagents combinations are investigated as BMT coating precursors: one BMT powder suspension and five Ta2O5 suspensions in nitrate solutions or acetate solutions. A hybrid suspension / sol plasma spray process is designed to axially inject these precursors into a RF thermal plasma torch to synthesize BMT and to deposit nanostructured coatings. X-ray photoelectron spectroscopy (XPS) was used to evaluate the element evaporation during plasma spraying. Thermogravimetric analysis and differential thermal analysis (TG/DTA) are applied to investigate the BMT formation. Parameters such as precursor chemistry and proportion, plasma power, spray distance and substrate preheating are studied with regards to the coating phase structure. The results indicate that the combination of twice the Mg stoichiometric amount with a power of 50 kW shows the best results when using nanocrystalline Ta2O5 as Ta precursor. When choosing nitrates as Ba and Mg precursors, predominant crystalized BMT can be obtained at lower plasma power (45 kW) when compared to acetates (50 kW). BaTa2O6, Ba3Ta5O15, Ba4Ta2O9, Mg4Ta2O9 are the main secondary phases during BMT preparation process. Because of the complicated acetate decomposition, the coating deposition rate from nitrate precursors is higher than that from acetate ones.
An Investigation into the Mechanism for Enhanced Mechanical Properties in Friction Stir Welded AA2024-T3 Joints Coated with Cold Spraying
Authors: Li Na , Li Wenya , Yang Xiawei , Xu Yaxin , Feng Yan , Vairis Achilles
Published: October 2022

Using cold spraying (CS), a surface layer with a modified microstructure and enhanced mechanical properties was formed on a 3.2 mm thick friction stir welded (FSW) AA2024-T3 joint. The combined effect of “shot peening effect (SPE)” and “heat flow effect (HFE)” during CS were used to enhance joint mechanical properties. The microstructure evolution of the FSW AA2024-T3 joints in the surface layer following CS coatings and their effect on mechanical properties were systematically characterized with electron back-scattered diffraction, transmission electron microscopy, differential scanning calorimetry and mechanical tests. Based on these experiments, a grain refinement, finer and more S phases, and improved amount of Guinier-Preston-Bagaryatsky (GPB) zones produced by CS treatments are proposed. The deposition of aluminium coating on the joint, lead to hardness recovery in the stir zone and the development of two low hardness zones as the density of GPB increased. The tensile properties of FSW AA2024-T3 joints improved with the application of the aluminium coatings. Experiments and analysis of the enhanced mechanical properties mechanism indicate that SPE with a high plastic deformation and HFE with an intensive heat flow are necessary for the production of refined grains and increased numbers of GPB zones.
Cold Spraying of Metallic Powders Onto Polymeric Substrates: Influence of Gas Preheating Temperature on the Coating Deposition
Authors: Sabard A. , Albassam A. , Chadha S. , Hussain T.
Published: October 2022

Common issues such as ice formation on wind turbine blades and lightning strikes on airplanes can be mitigated by metallizing polymers and composites used on the outer surface of the component. Cold gas dynamic spray is a novel process that has the potential to be used for metallization of polymer and composite surfaces to produce electrically and/or thermally conductive components. In this study, mixed Cu-Zn and Al-Zn feedstock powders were deposited onto polypropylene and nylon-6 substrates to investigate the viability of metallizing nonmetallic surfaces using a commercially available low-pressure cold spray process. The behavior of the individual metallic particles upon impact on the polymers and the deformation of the substrate were characterized by coating the two feedstock powders onto a nylon-6 substrate over a wide temperature range. The Cu-Zn coating was deposited in thicknesses up to 1 mm onto the nylon-6 substrate using optimized parameters. To understand the deposition of the metallic powder onto the polymers, the process was modeled using computational fluid dynamics methods. The correlation of the gas and particle modeling with examination of the coating microstructure highlighted the major importance of the particle velocity during cold spray deposition.
Investigation of Cold Spray Bonding Mechanism Focusing on the Thin Oxide Film Present in the Deposition Interface
Authors: Ichikawa Yuji , Tokoro Ryotaro
Published: October 2022

To understand the adhesion mechanism of cold spraying, the characteristics of a newly formed cold spray surface are essential. This surface is formed by the dynamic plastic deformation of the substrate and particles during cold spray impact. Over the surface, the amount of newly generated surface, bonding state, and strength can differ. Even within an individual attached particle, the amount of plastic deformation also differs. To determine the relationship between the coating deposition mechanism, microstructure, and adhesion strength, tensile adhesion strength tests of cold sprayed copper coatings on an aluminum substrate were carried out. Then, using an Auger electron spectroscopic analyzer, the remained oxide film at the fracture surface, which is the bonding interface, was analyzed. The natural oxide film that covers the surface of the substrate before the impact, which is broken by plastic deformation during the spray process. However, the results show that it is not broken at the center of the collision crater, where the amount of plastic deformation of the substrate material is small. Hence, at the center of the collision crater, the oxide film still covers the substrate. Moreover, the results reveal that the adhesion strength is not uniform but is strong at the edge of the crater, where the oxide film has been removed by the colliding particle. These results reveal insights that will be valuable for future improvements in the adhesion strength of cold spray coatings.
Organic Composite Metallization Using Low Pressure Cold Spraying
Authors: Costil S. , Aubignat E. , Langlade C. , Gillet V. , Courant B. , Casari P. , Knapp W.
Published: October 2022

Polymer metallization using cold spray method, due to low process temperature, is a potential candidate to form electrically conducting polymers as well as composites and improve the mechanical properties of their surface (abrasion, corrosion, etc.). Low Pressure Cold Sprayed copper coatings on PEEK (Poly-Ether-Ether-Ketone) based composites reinforced by carbon fibers have been investigated. Cold Spraying involves high erosion on composite materials due to solid state and high velocity particles thus a new way has been developed. Based on the elastic behaviors of organic materials, pure PEEK matrix has been added on the composite surface to behave as an interfacial layer between the composite and the coating. Optimization of the LPCS parameters has then been carried out using a careful choice of powder size distribution in order to avoid substrate destruction, erosion and delamination of the coating. Consequently, dense thick copper coatings have been obtained and analyzed in terms of microstructure implementing SEM observations. Finally, electric measurements have been performed in order to check the efficient metallization of the composites. A new way for metallic coating on organic composites using Low Pressure Cold Spraying is then demonstrated.
Effects of Feedstock Mixing Composition on the Cold Sprayability of Bimodal Size 316L/Fe Powder Mixtures
Authors: Chu Xin , Che Hanqing , Yue Stephen , Vo Phuong
Published: October 2022

In this study, 43 μm 316L stainless steel and 23 μm commercial purity Fe feedstocks were used. The following coatings were made by cold spray: single component 316L, Fe, and their binary composites with nominal compositions of 20 wt.% Fe (20Fe), 50 wt.% Fe (50Fe) and 80 wt.% Fe (80Fe). The coatings were characterized (microstructure, flattening ratio, composition) and the cold sprayability metrics (DE, porosity, coating cohesion strength) were analyzed. Results show that the single component 316L coating has a much better DE and coating cohesion strength, and a slightly lower porosity as compared with the Fe coating, whereas all the composite coatings have the similar cohesion strength. Moreover, the 20Fe coating features the highest porosity and the lowest DE; 50Fe coating features the lowest porosity; and the 80Fe coating features the highest DE. To characterize the feedstock mixture composition, in addition to the usual approach of weight or volume fraction, the ratio of the 316L and Fe particle numbers in a mixture (i.e. particle number fraction), was calculated. Using this metric, the effects of the feedstock mixing composition on the cold sprayability of bimodal size 316L/Fe powder mixtures can be better explained.
Analysis and Optimization of the HVOF Process by Artificial Neural Networks Model
Authors: Meimei Liu , Zexin Yu , Chaoyue Chen , Hanlin Liao , Sihao Deng
Published: October 2022

In the High Velocity Oxygen Fuel (HVOF) technology, the coating properties are sensitive to the behaviors of in-flight particles, which are mainly influenced by the processing parameters. However, due to the complex chemical and thermodynamic reactions, the real-time optimization of the coating properties during the HVOF process is still a challenging issue. This study focused on establishing an Artificial Neural Networks (ANN) model to analyze the influence of the processing parameters on the characteristics of in-flight particles. Hydroxyapatite (HA) powders were selected to deposit onto the stainless steel substrates via an improved HVOF spraying system. Combined with an Accuraspray-g3 system applied to acquire the temperature and velocity of inflight HA particles, the artificial neural network algorithm was well trained to predict the velocity and temperature of in-flight particles. The relationship between the variations of the operating parameters (gas flow rates and fuel-to-oxygen ratio) and the behaviors of in-flight HA particles was investigated, which therefor contributes to analyzing and optimizing the mechanical performance and crystallinity of the HA coatings.
Deposition of Lamellae Well Bonded Dense Ceramic Coatings by Plasma Spraying Through Materials Design
Authors: Li Chang-Jiu , Zhang Qi-Lan , Yao Shu-Wei , Yang Guan-Jun , Li Cheng-Xin
Published: October 2022

It is usually difficult to deposit dense ceramic coatings with splats well bonded by plasma spraying at room temperature. Following the recent research progress on the splat interface bonding formation, it was found that there is a well defined relationship between the critical bonding temperature and materials melting point. Thus, it was proposed to control the lamellae bonding through the deposition temperature. In this study, to examine the feasibility of the bonding theory, a novel approach for the development of coating microstructure through materials design is proposed. Accordingly typical ceramic materials were selected of relative low melting point for plasma spraying of dense coating with well bonded splats. The experiment was conducted by using K2Ti6O13 for splat deposition at ~110°C cooling down from a higher temperature to avoid substrate adsorbates and coating was deposited at room temperature in ambient temperature without substrate preheating. Results show that the splat is fully bonded with a ceramic substrate, while the coatings present a dense microstructure with a similar fracture morphology to sintered bulk ceramics. Moreover, the erosion test at 90° further confirmed the formation of a ceramic coating with lamellae fully bonded.
Investigation of High Temperature Compressor Abradable Coatings for Gas Turbine Applications
Authors: Tan Winnie , Zois Dimitrios , Wilson Scott , Dorfman Mitchell R.
Published: October 2022

Abradable coatings are typically applied on the compressor section of gas turbines to reduce air leakage and increase compressor performance. In pursuit of engine efficiency, the service temperatures of the components are higher than before. The use of nickel-graphite coating in compressor applications in higher temperature environments diminishes the abradable property of the coating. In the current study, a series of abradable coatings were prepared with combustion and plasma spray methods and tested at gas turbine conditions. Coating microstructure, hardness, abradability, and erosion resistance was investigated and compared against conventional nickel-graphite coating. In addition, coatings were aged to mimic the aging cycle in industrial gas turbines and compared to as-sprayed coating properties.
TEM Studies of a Nano-Crystalline Cold Sprayed Ni-20Cr Coating
Authors: Kumar M. , Singh H. , Singh N.
Published: October 2022

In the current work a nano-crystalline Ni-20Cr coating was developed on a boiler tube material by cold-spray process. The coating powder was synthesized in-house by mechanical milling using a planetary ball mill. The average crystallite size of the developed powder was calculated to be 10 nm. The crystallite size of the coating was found to be 18 nm, and hence the retention of nano-crystallinity in the coating was established. However the grain growth occurred to some extent, which may be due to temperature rise involved in the cold spray process. A detailed TEM analysis of coated samples before and after exposure to high temperature oxidation was carried out.
Thermally Sprayed Slippery and Icephobic Surfaces
Authors: Niemelä-Anttonen H. , Koivuluoto H. , Kylmälahti M. , Laakso J. , Vuoristo P.
Published: October 2022

Minimizing ice adhesion and preventing ice accumulation on different surfaces has remained in scientific focus from the mid 1900’s. Decades after, scientists are combatting the same challenges, which only outlines the complex nature of ice and ice adhesion related research. One approach to exploit passive coating technology for low ice adhesion utilizes slippery surfaces that combine porous solid material with lubricating liquid. This study presents a novel method in creating functional slippery liquid infused porous surfaces, SLIPS, by exploiting flame spray technique. We demonstrate the functionality of these thermally sprayed SLIPS in ice adhesion and wettability. The ice adhesion results confirmed the potentiality of thermally sprayed SLIPS as ice repellent surfaces with an order of magnitude lower ice adhesion strength compared to polished stainless steel.
Effect of Molten Particle Temperature on the Bonding Formation During Plasma Spraying of Metal Alloy Coatings
Authors: Wang Jun , Tian Jia-jia , Li Chang-Jiu
Published: October 2022

Molten droplet temperature is a dominant factor influencing the bonding formation at the interface between splats during plasma spraying. In this study, the effect of molten droplet temperature on the interface bonding formation between nickel-base alloy splats was investigated. One novel shellcore- structured Mo-clad NiCr powder and conventional NiCr powder were used as the feedstock. Stainless steel with surface polishing was used as the substrate. The NiCrMo particle with a temperature over 2647 °C was generated by plasma spraying in comparison with that about 2167 °C for NiCr droplet. The molten droplet temperature when it impacted on the substrate surface was changed continuously by changing spray distance. The particle temperature was measured by DPV2000 and the interface bonding state was characterized by the cross-section samples of splat-substrate interface prepared by FIB. Results show that the interface bonding ratio can be increased from ~40% to 80% when the average molten droplet temperature is increased from ~2167 to 2647 °C.
Numerical Study on Particle Trajectories Close to the Substrates in Thermal Spray Processes with High-Kinetic and Low-Pressure Conditions
Authors: Mauer Georg , Vaßen Robert
Published: October 2022

In thermal spray processes, the interaction between the gas jet and the particulate feedstock can affect the coating build-up mechanisms considerably. Especially under high-kinetic and low-pressure conditions, small particles are subjected to rapid deflection and velocity changes close to the substrate. In this work, numerical studies were performed to investigate the particle trajectories in the substrate boundary layers (BL). Typical conditions for suspension plasma spraying (SPS) and plasma spray-physical vapor deposition (PS-PVD) were taken as a basis. Particular importance was attached to the consideration of rarefaction and compressibility effects on the drag force. The particle impact conditions in the different thermal spray processes are compared. Possible effects on the resulting coating build-up mechanisms and microstructure formation are discussed.
Utilizing Big Data Informatics for Thermal Spray Materials Design
Authors: Cheney Justin
Published: October 2022

Utilizing big data to govern decisions is becoming increasingly valuable and the thermal spray process is no exception. The thermal spray process is unique as a material process in its capability to employ a wide range of advanced materials technologies: metals, ceramics, cermets, and oxides among others. Like any process, the thermal spray technology is most effective when utilizing material feedstock which is specifically designed for thermal spray. This paper will discuss how big data techniques can be employed to design disruptive materials technology. The thermal spray process presents unique challenges to modelling and simulation work due to the inherent complexity of the process. However, these challenges offer the opportunity to develop materials tailored for specific thermal spray processes to yield improved coating performance. Furthermore, big data material informatics can significantly accelerate the discovery of new alloy solutions. More than 100 years of experimental research underpins the science employed, but modern computational tools and materials informatics principles enable new decision strategies to be utilized. The big data approach relies on calculations which predict the microstructure of millions of alloy compositions and utilizing proprietary data mining algorithms to identify unique materials spaces which would never be discovered experimentally.
Internal Diameter Coating Processes for Bond Coat (HVOF) and Thermal Barrier Coating (APS) Systems
Authors: Tillmann W. , Schaak C. , Hagen L. , Mauer G. , Matthäus Thermico G.
Published: October 2022

Current developments in different industrial sectors show an increasing demand on thermally sprayed internal diameter (ID) coatings. But up to now, the research focus is mainly on conventional processes such as arc spraying and plasma transferred wire arc spraying (PTWA), especially for cylinder liner surfaces. However, efficient HVOF and APS torches are meanwhile available for ID applications. Thus, in the present work, the focus of research is on the ID spraying of bond coats (BC) and thermal barrier coatings (TBC) for high temperature applications. An HVOF-ID gun IDCoolFlow mono with a N2 injection was used to spray dense BCs (MCrAlY). The TBCs (YSZ) were sprayed by applying an SM-F100 Connex APS torch. Initially, flat steel samples were used as substrates. The morphology and properties of the sprayed ID coating systems were investigated with respect to the combination of different HVOF and APS spray parameter sets.
Ballistic Testing of a Double-Layer Shaped Charge Liner Fabricated by Kinetic Spraying
Authors: Lee Seungtae , Kim Jaeick , Lee Changhee , Lee Seong , Kim Sijo
Published: October 2022

Shaped charge is a weapon that is devised to penetrate armor. The explosion performance of it was relatively low. The liner, which is the core component of shaped charge, is generally formed as Cu material because of good penetration ability. The double-layer liner was designed to increase the explosive power of the shaped charge and to enhance the performance of the weapon through the explosion after penetration. Reactive Al and Al-Ni coating layers were successfully deposited on the cone-shaped Cu liner via kinetic spray to fabricate a double-layer liner. A ballistic test was conducted to compare the explosive power between single Cu liner and double layer liners. Alumina and intermetallic compound of Al-Ni, which are evidence of the exothermic reaction, were investigated by EDAX, XRD techniques. Al2O3 and AlNi were detected on 4th target plate, which means that an explosion occurred after penetration. The explosive power of the liners was compared by measuring the penetration area of target plate and the number of broken support bolts. The explosive power of double layer liner was larger than that of the single Cu liner.
Multivariate Analysis of the Influence of Process Parameters on Suspension Plasma-Sprayed Coatings
Authors: Zhao Yongli , Peyraut François , Planche Marie-Pierre , Liao Hanlin , Montavon Ghislain , Ilavsky Jan , Lasalle Audrey , Allimant Alain
Published: October 2022

Suspension plasma spray (SPS) is far more complicated than conventional plasma spray and requires a deep knowledge about the influence of process parameters and their correlations. In this study, YSZ coatings were manufactured by SPS with six different process parameters such as plasma power, suspension mass load, original powder size, substrate surface topology, spray distance, and spray step. Afterwards, the porosity of as-prepared coatings was investigated by image method and X-ray transmission technique. A multivariate analysis on the collected experimental data was carried out by employing mathematical statistics methods. The results showed that: 1) Coating porosity has a negative correlation with plasma power and suspension mass load and a positive correlation with the original powder size, spray distance, spray step, and substrate roughness; 2) Spraying distance is the main factor affecting to coating porosity, followed by suspension mass load and substrate surface roughness, respectively. A linear model for porosity prediction was developed and was verified by experiments. The mechanism by which process parameters influence coating porosity is also discussed.
Suspension High Velocity Oxy Fuel (SHVOF) Thermal Spraying of Cr2O3 and Cr2O3 with Graphene Platelets for Dry Sliding Wear Protection
Authors: Pulsford J. , Bai M. , Hussain T.
Published: October 2022

Thermally sprayed Cr2O3 coatings have been shown to provide excellent protection against wear in many engineering applications. These coatings are traditionally applied using air plasma spray technology; however, suspension high velocity oxy fuel thermal spraying (SHVOF) is a promising method to improve coating properties as this technique enables powder feedstocks too small to be processed by mechanical feeders to be sprayed, allowing the production of coatings with improved density and mechanical properties. Furthermore, the addition of graphene nanoplatelets (GNPs) to the liquid feedstock has been shown to improve the mechanical properties of SHVOF sprayed ceramic coatings. In this study, an aqueous based nanometric Cr2O3 suspension and a Cr2O3 suspension with 1 wt.% GNP, prepared via a proprietary process, were sprayed by a SHVOF thermal spray onto 304 stainless steel substrates. The microstructure of Cr2O3 and Cr2O3 + GNP coatings was analyzed using SEM and XRD alongside microhardness, fracture toughness and porosity investigations. Dry sliding wear performance was investigated using a ball on flat tribometer against an alpha alumina ball at loads of 16, 30 and 47 N. The GNP containing coating exhibited improved mechanical properties, however its response to sliding wear was very similar to the non-GNP coating.
Direct Spraying of Fine Ceramic Particles in Thermal Spray
Authors: Shahien Mohammed , Suzuki Masato , Akedo Kentaro Shinoda Jun
Published: October 2022

Deposition of ceramic coatings by spraying of fine powder particles is a promising solution to obtain uniform microstructure and improved properties, because it is expected to form small splats with reduced residual stress and pore size. Although direct injection of fine particles has many challenges such as poor rheological properties (e.g., low flow ability and agglomeration), and small momentum to inject and impact, it is still attractive and worth to try. From this point of view, we have improved feeding and injection technique of fine powder particles, which enables us to directly spray fine ceramic particles with a newly developed low power dc plasma torch. Preliminary results obtained with this system will be compared with those by other fine powder spray technology such as suspension plasma spray and hybrid aerosol deposition to show similarity and difference when the injection methods of the fine powder particles are different in this paper.
Mechanisms of Structure Formation and Thermo-Physical Properties of Gas Detonation Sprayed Fe-Al Type Coatings
Authors: Senderowski Cezary , Panas Andrzej J. , Fikus Bartosz , Wołczyński Waldemar
Published: October 2022

The paper reports the results of structure examination of intermetallic Fe-Al type coatings obtained by the detonation gun spraying on a C45 plain carbon steel substrate. The structure was analysed with scanning (SEM), transmission (TEM) electron microscopy techniques and electron (SAE) and X-ray diffraction methods as well as quantitative inspection of composition in microareas (EDX). Special attention was paid to the interface between the coating and the substrate analyzing particularly the substructure of the individual grains contained up to 15μm away from the substrate surface layer. The results allowed explaining the formation mechanism of the coating morphology with a contribution of intermetallic phases Fe3Al, FeAl, FeAl2 and Fe2Al5 as well as the ε phase taking into consideration the influence of velocity, temperature and pressure on the powder particles during the D-gun spraying. It was established that the coating produced with the DGS method had sublayer morphology of alternate flattened and partially melted grains with wide range of Al content from 39 up to 63 at.%. Partial melting of the individual powder particles brought about the appearance of the amorphous grains and subsequently columnar crystals of the Fe-Al type phases formed sequentially at the interface area coating and cold substrate surface layer material, which was essential in the mechanism of the Fe- Al coating formation. It was established, that in the area of the polycrystalline dispersive structure formed from the highly plasticized FeAl grains during D-gun spraying, complex oxide films identified as Al2O3-γ formed, serving as specific composite reinforcement in the intermetallic Fe-Al coating. A mechanism of crystallization of partially melted Fe-Al particle containing nominally 63 at.% Al was carried out in the work in an attempt to explain the formation of different sub-layers within the Fe-Al intermetallic coating at the interface 045 steel surface layer.