bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistics anxiety, predictions of exam performance and actual exam performance in UK Psychology students.
Authors: Jones Andrew , Knibb Graeme , Christiansen Paul
Published: October 2022

Statistics anxiety is common among social science students, with over 70% experiencing some form of anxiety when undertaking statistics modules at degree level. Statistics anxiety has been assumed to impact negatively on students’ academic performance, however, evidence is equivocal. Despite much evidence examining statistics anxiety and test performance, little research has explored student self-prediction on test performance. Two-hundred and two undergraduate students completed Statistics Anxiety Rating Scales and provided self-predicted test performance scores. Test performance data was obtained from a formal statistics assessment. Results found statistics test anxiety to be negatively associated with self-predicted performance, but positively associated with test performance. The findings highlight the complex relationship between statistics anxiety and test performance and are supportive of research that suggests there may be an optimal level of anxiety for performance in statistics assessments. Our results have implications for informing statistics curricula and reducing statistics anxiety in educational settings.
The Impact of Elizabeth Bishop’s Tragic Experiences on her Poetry
Authors: Mohammed Mamdouh Ali Ahmed
Published: October 2022

Elizabeth Bishop is one of the most renowned modern American female poets. Her early life was characterized by some tragic events. However, she overcame all such saddening happenings and established herself as a major twentieth-century American writer. The paper investigates how some of the important topics handled in the author’s poetry can be traced back to her biographical background. The significance of the study is that it brings to light the role played by the tragic incidents in the poet’s life in the formation of her poetic production; which could enable her readers to understand some of her most famous poems better and enjoy them more. The method applied is the Biographical Critical Approach. By applying this approach, the researcher aims to indicate how the poet depended on her memories of actual events which took place in her life to author a number of her well-known poems. The study reaches some significant findings through the analysis of the selected literary texts. The researcher, for instance, draws attention to the way Bishop tackled the idea of death when she encountered it for the first time in her life. Moreover, the effect of the loss of the literary figure’s parents, especially the mother, on the under-discussion literary works is illustrated. Further, the study demonstrates how the writer expressed a lot of wisdom and stoicism in the face of destiny after reaching maturity. The analyzed literary texts evidently immortalize certain tragic events in Bishop’s life.
Google Translate in Massive Open Online Courses: Evaluation of Accuracy and Comprehensibility among Female Users
Authors: Alshammari Dalal K. , Altuwairesh Nasrin
Published: October 2022

The increasing production of audiovisual texts online has led to the growing use of Machine Translation (MT) in its raw form to facilitate multilingual access. In this study, we examine the accuracy of Google Translate’s English–Arabic subtitles and their comprehensibility among female users through a case analysis of Massive Open Online Courses (MOOCs). We also seek to contribute to the research on MT by providing empirical evidence on the use of MT in audiovisual contexts, which is a relatively new and under-researched study area. The research questions considered in this study are: (i) What types of accuracy errors can be identified in Google Translate’s English–Arabic translation of MOOC subtitles? (ii) What effects do machine-translated MOOC subtitles have on female users’ comprehension? The study used a mixed-methods approach. First, 147 machine-translated subtitles of five MOOC videos were annotated by six evaluators based on five accuracy error types: mistranslation, terminology, omission, addition, and untranslated-segment errors. Second, the comprehensibility of the machine-translated subtitles was examined through a quasi-experiment. Sixty-two female participants were divided into two groups. Each group was presented with MOOC videos with either machine- or human-translated subtitles. Then, the participants completed a comprehension test. The qualitative analysis of the accuracy errors showed the occurrence of all five accuracy error types. The quantitative analysis of users’ comprehension revealed a lack of statistically significant differences between the examined groups. The study’s results suggested that MT can be useful in facilitating users’ access to MOOC video content.
Uncertainty about maternal mortality in India: New, higher estimates from the National Family Health Survey-4
Authors: Franz Nathan , Gupta Aashish , Spears Dean , Coffey Diane
Published: October 2022

Background: Mortality rates in India shape global statistics, including about the United Nations’ (UN) Sustainable Development Goals (SDGs). SDG 3 sets a target global maternal mortality ratio (MMRatio) of fewer than 70 maternal deaths per 100,000 live births by 2030. However, because vital registration is incomplete, maternal mortality rates in many countries including India are based on indirect estimates, data from mortality surveillance sites, or household surveys.Objective: This paper presents empirical national and regional maternal mortality estimates for India using National Family Health Survey-4 (NFHS-4) data. We compare the findings to existing estimates of maternal mortality made using the Sample Registration System (SRS), a nationally representative network of demographic surveillance sites, and the UN.Results: Building on a recent literature measuring maternal mortality based on household reports of deaths of recent members, we calculate a MMRatio from the NFHS. We estimate 228 maternal deaths per 100,000 live births for 2012-16 (95% CI: [204, 266]). In contrast, the SRS reports an MMRatio of 130 for 2014-16. The difference in the total number of maternal deaths in India implied by the NFHS rather than the SRS is greater than the total number of maternal deaths in any country except Nigeria. We find that differences between the NFHS and the SRS are largest in the Empowered Action Group states of north India. We use demographic decomposition to show that the difference between the NFHS and the SRS is mostly accounted for by not classifying adult female deaths as maternal, rather than by not detecting deaths at all. However, the NFHS also finds higher all-cause mortality among women of childbearing age than does the SRS. As we detail, some aspects of the NFHS results raise issues of data quality for its maternal mortality information, which must be weighed against questions of data quality for the SRS and other sources.Contribution: If the NFHS-4 maternal mortality figures are correct, it would imply that, rather than being on track to meet SDG 3, India needs urgent additional investment in maternal health, particularly in the poorer Empowered Action Group states.
“[S]ome vicious mole of nature”: Hamlet’s Erratic Behaviour and Brain Neurotransmitter Imbalance
Authors: Alyo Mohammad Wajih J.
Published: October 2022

The aim of this paper is to investigate, from a neuroscientific perspective, the complex but still unravelled mystery of Hamlet’s inconsistent conduct in Shakespeare’s classic tragedy. Adopting the ‘medical diagnosis’ method, the paper contends that such manifestations of Hamlet’s eccentric comportment as depression, social isolation, impulsiveness, sleep disorder, aversion to women, and procrastination, are all salient symptoms of low levels of dopamine, a vital brain neurotransmitter responsible for reward and motivation. The paper concludes that ‘dopamine deficiency’ in Hamlet’s brain has a devastating impact on his mood and outlook on life. It aggravates his depression, adversely affects his disposition, focus, cognition, and motivation and subsequently deprives him of the incentive to act. The significance of this study is that it identifies the reason for Hamlet’s hesitation, enhances understanding of the play and enriches representations of the leading role in the play on stage. Shakespeare portrays Hamlet as severely afflicted with such an intricate neural illness (not identified in Elizabethan England then), expertly dramatizing the devastating impact on his protagonist of the acute clash between will and inability. Hamlet’s hamartia is, consequently, not a fault of his making, not a commonplace Aristotelian tragic error of judgment, or a psychological personality flaw, but – as Hamlet intuitively prophesies – a birth defect, the result of ‘some vicious mole of nature.’
There’s More in the Data! Using Month-Specific Information to Estimate Changes Before and After Major Life Events
Authors: Hudde Ansgar , Jacob Marita
Published: October 2022

Sociological research is increasingly using panel data to examine changes in diverse outcomes over life course events. Most of these studies have one striking similarity: they analyse changes between yearly time intervals. In this paper, we present a simple but effective method to model such trajectories more precisely using available data. The approach exploits month-specific information regarding interview and life-event dates. Using fixed effects regression models, we calculate monthly dummy estimates around life events and then run nonparametric smoothing to create smoothed monthly estimates. We test the approach using Monte Carlo simulations and GSOEP data. Monte Carlo simulations show that the newly proposed smoothed monthly estimates outperform yearly dummy estimates, especially when there is rapid change or discontinuities in trends at the event. In the real data analyses, the novel approach reports an amplitude of change that is roughly twice as large amplitude of change and greater gender differences than yearly estimates. It also reveals a discontinuity in trajectories at bereavement, but not at childbirth. Our proposed method can be applied to several available data sets and a variety of outcomes and life events. Thus, for research on changes around life events, it serves as a powerful new tool in the researcher’s toolbox.
Species composition of cave-dwelling reptiles and their micro- habitats in Agusan del Sur, Philippines
Authors: Kamir Rhim Ayyah C. , Nuñeza Olga M.
Published: October 2022

Rhim Ayyah C. Kamir* & Olga M. Nuñeza
Ecological relationship between Lepidosaphes beckii (Newman, 1869) (Homoptera Diaspididae) and its two parasitoids Aphytis melinus DeBach, 1959 and A. lepidosaphes Compere, 1955 (Hymenoptera Aphelinidae) on lemons orchads in two localities of Mitidja Algeria
Authors: Agagna Yasmina , Boudjemaa Khadidja , Oussalah Narimene , Beloued Ibtissem , Aroua Khaoula , Biche Mohamed
Published: October 2022

Yasmina Agagna1, Khadidja Boudjemaa1, Narimene Oussalah1, Ibtissem Beloued1, Khaoula Aroua2 & Mohamed Biche
Thermal Cyclic Life of Functionally-Graded Gadolinium Zirconate/Yttria Stabilized Zirconia Thermal Barrier Coating
Authors: Johari Azril Dahari , Manap Abreeza , Yunus Salmi Mohd
Published: October 2022

In this study, two types of thermal barrier coatings (TBC); duplex and functionally graded coatings were deposited on superalloy Nimonic 263 substrates using air plasma spray process. The duplex coating consists of YSZ top coat and NiCrAlY bond coat. The functionally graded coating consists of five layers with GZ as top layer, GZ+YSZ and YSZ+NiCrAlY as intermediate layers. The TBC samples were subjected to isothermal heat treatment at 1100 °C for 100 hours before undergoing thermal cyclic tests at 1200 °C up to 20% spallation to evaluate the oxidation and thermal fatigue resistance of the coatings. Results indicate that the functionally graded GZ TBC has a better cyclic life than the duplex YSZ TBC after isothermal heat treatment. The isothermal heat treatment also improved the thermal cyclic lifetime of the functionally graded GZ TBC by more than threefold in comparison to the as-sprayed GZ TBC.
Fabrication of Ceramic Coatings by Cold-Spray in Agglomerated Y2O3 Particles
Authors: Yang Yang , Han Rifei , Kong Lingyan , Xiong Tianying , Li Tiefan
Published: October 2022

As a candidate material against plasma etching, yttrium oxide has been coated onto etching chamber by plasma spray technique. However, the plasma spray technique introduces undesirable coating properties such as porous structure and deleterious thermal effects. To reduce the disadvantage of thermal impact, cold spray was used as an alternative technology to deposit thick and dense yttrium oxide coatings. Primary nanoscale Y2O3 were used as the original powder, for the ceramic materials are intrinsic brittle and are difficult to be deposited by cold spray. The nano-powder were first agglomerated by hydrothermal treatment with addition of inorganic salt to acquire suitable powder for cold spray, and then deposited on aluminum alloy 6061 substrates by cold spray process with compressed air as propellant gas. About 200μm yttrium oxide coatings were formed on the substrate alloy. Different processing parameters were employed to optimize microstructure and properties of the coating.
Study of Mechanical Performance and Residual Stress in Kinetic Metallization WC-Co Coatings
Authors: Ang Andrew S.M. , Berndt Christopher C. , Luzin Vladimir , Crowe Travis , Gabel Howard
Published: October 2022

The metal finishing process of electrolytic hard chrome (EHC) plating has been identified as a source of environmental pollution in most industrialized countries like Australia, Europe and USA. The key driver for the technology replacement is that the EHC plating process uses hexavalent chromium, which is a known carcinogen. Our previous research has identified that cold spray nanostructured tungsten carbide cobalt (WC-Co) coatings can be a suitable alternative to provide a functional coating in wear applications. This work explores at another similar technology- Kinetic Metallization for deposition of WC-Co coatings. In this work, the objective is to characterize the residual stress profile of these WC-Co coatings that are deposited by the latest KM systems. These coating systems are used in critical applications such as landing gear pistons and axle journals, hydraulic rods, engine shaft journals, and numerous other external surfaces that operate under high cyclic loading conditions. As such, the residual stress developed during the KM coating process has a significant influence on the fatigue properties of the components. Thus, knowledge of stresses and their linkage with other properties and production parameters is essential for the quality control of these critical structures.
Microstructural Characterization and Room Temperature Erosion Behaviour of As-Deposited SPS, EB-PVD and APS YSZ-based TBCs
Authors: Lima Rogerio S. , Guerreiro Bruno M. H. , Aghasibeig Maniya
Published: October 2022

The erosion behaviour at room temperature (RT) of as-deposited SPS, EB-PVD and APS YSZ-based TBCs was investigated. All coatings were deposited on Inconel 625 alloy coupons. The same APS CoNiCrAlY bond coat was employed for all SPS and APS TBCs. The erodent material was 50 μm alumina and the impact angles were 15° and 90°. A total of 4 different types of SPS YSZ-based TBCs were tested, which consisted of two distinct columnar-segmented and two distinct columnar-grown microstructures. The EB-PVD and APS YSZ TBCs were employed as benchmarks. The erosion performance of the different TBCs in this study was ranked based on the coating volume loss after wear testing. The TBC microstructures and phase compositions were evaluated via SEM and XRD. The erosion mechanisms of the different TBCs were compared by analyzing the cross-sectional and top surface microstructures of the as-sprayed and eroded TBCs. These are released results from the Surftec Industrial R&D Group of the National Research Council of Canada (NRC).
Phase Stability, Fracture Toughness and Thermal Cycling Behavior of Supersonic Suspension Plasma Sprayed Scandia-Yttria Co-doped Zirconia Thermal Barrier Coatings
Authors: Fan Wei , Bai Yu , Kang Yongxia , Zhang Lei , Li Benqiang
Published: October 2022

In this work, one new technique named as supersonic suspension plasma spraying (SSPS) is applied to deposit quasi-columnar scandia-yttria co-doped zirconia (ScYSZ) and yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBCs). The phase composition, microstructural evolution, fracture toughness and failure behavior of both TBCs before and after thermal cycling tests at 1300 °C were systematically studied. It was found that both as-sprayed TBCs were fully non-transformable tetragonal (t’) phase. After the thermal cycling test, tetragonal (t) phase and cubic (c) phase formed for the SSPS-YSZ TBC, while single t’ phase retained for the SSPS-ScYSZ coating. The fracture toughness of the ScYSZ coating was comparable or superior to that of the YSZ coating. As for the thermal cycling behavior, the lifetime of the ScYSZ coating was better than that of the YSZ coating, which confirmed that ScYSZ was a promising alternative material for YSZ.
Suspension Sprayed YSZ Thermal Barrier Coatings: Road to Industrial Application
Authors: Barbosa Maria , Toma Filofteia-Laura , Fraunhofer Denise Beitelschmidt , Ligabue Omar , Bursich Simone , Tagliaferri Luca
Published: October 2022

Thermal barrier coatings (TBCs) are one of the most promising applications for suspension thermal spraying. By using a liquid feedstock, coating morphologies close to the columnar-like structure of electron-beam physical vapor deposition (EB-PVD) are possible. Additionally, vertically cracked TBC coatings (VC-TBC) have shown a great potential for industrial applications. In this work, we will analyze the process window for TBCs produced by using suspension spraying. Commercially available alcohol- and water-based YSZ suspensions have been processed using suspension atmospheric plasma spraying (S-APS) and suspension high-velocity oxy-fuel (S-HVOF) to achieve both columnar-like and VC morphologies. The coatings have been analyzed and compared in terms of microstructure, phase composition, bond strength and thermal cycling performance. Additionally, the suitability of S-APS and S-HVOF TBCs for industrial applications will be discussed, as well as which actions are needed to increase its competitiveness.
Investigation of Cold Spray on Polymers by Single Particle Impact Experiments
Authors: Che Hanqing , Yue Stephen , Vo Phuong
Published: October 2022

Cold spray has been proved to be a viable method for metallization of polymers and polymer composites. It has been reported that the mechanism of cold spray on polymeric substrates is different from the conventional mechanism on metallic substrates (i.e. adiabatic shear instability). In this work, single particle impact experiments were performed on polymeric substrates as well as mild steel. The particle-substrate interactions on different substrates were analyzed. Based on the results, the mechanism of cold spray on polymeric substrates is discussed and compared to that on metallic substrates.
Modeling the Continuous Heat Generation in the Cold Spray Coating Process
Authors: Ozdemir Ozan C. , Chen Qiyong , Muftu Sinan , Champagne Victor K.
Published: October 2022

In cold spray, 5-150 μm particles (of metal, ceramic, composite, and other materials) are accelerated to supersonic velocities through a deLaval nozzle with an inert gas (generally He or N2) that can reach 1000 °C. In the process, the gas jet impingement on the target and the extreme plastic deformation of impacting particles cause heat generation in the coating layers and the substrate. The heat generation has been argued to cause residual stress, which may cause coating-substrate delamination. In this study, heat generation due to gas impingement and particle plastic deformation has been predicted from CFD and FEA simulations, respectively. Furthermore, a finite volume method has been presented for transiently simulating the coating buildup and bulk heat generation in the coating and the substrate. The model is intended to assist researchers understand thermal affects in the coating process and help design more informed coating patterns to reduce negative thermal effects.
Influence of Grain Size on the Corrosion and Wear Behaviour of HVAF-Sprayed Fe-Based Coatings
Authors: Bobzin K. , Öte M. , Knoch M.A. , Sommer J.
Published: October 2022

The current study investigates the influence of the grain size fraction D of a FeCrB/WC-Co feedstock material on the coating properties. In previous studies, novel FeCrB/WC-Co wear and corrosion protection coatings applied by means of high velocity air-fuel (HVAF) spraying were developed by the authors. It was observed that coatings, which were produced with a slightly decreased powder grain size fraction and identical chemical composition showed improved coating properties, i.e. reduced crack formation in the coating at high powder feed rates . and lower current densities at high overpotentials. The goal of this study is to investigate the influence of the powder grain size fraction on the coating properties in more detail. Furthermore, the underlying mechanism for the improved coating properties, with regard to their corrosion behaviour, is investigated. Therefore, the FeCrB/WC-Co feedstock material with the grain size fractions of -20 +3 μm and -32 +11 μm and identical chemical composition was applied by means of HVAF-spraying and the coatings were subsequently analysed. Light microscopy was used to investigate the microstructure of the coatings. The wear and corrosion properties were analysed using pin-on-disc (POD) and electrochemical polarization tests respectively. XRD-measurements were used to investigate the phase composition and to develop a hypothesis for the different corrosion behaviours of the investigated coatings. The results show that HVAF-sprayed FeCrB/WC-Co coatings produced with a powder grain size fraction of -20 +3 μm exhibit lower current densities at high overpotentials, compared to the coatings produced with a powder grain size fraction of -32 +11 μm.
Cost Effective Iron Based Alloys for Abrasive Wear
Authors: Maroli Barbara , Frykholm Robert , Bengtsson Sven , Höganäs Sweden
Published: October 2022

A common method to combat abrasive wear and prolong the life of a component is to hardface the exposed region by overlay welding. State of the art coatings for these applications consist of a nickel-based ductile matrix with hard tungsten carbide particles embedded in it. An alternative with low environmental impact in combination with high performance to cost ratio is to use iron-based alloys. Critical in affecting the abrasive and impact wear resistance of these alloys is the coating quality e.g. porosity, cracks, dilution from the substrate combined with chemistry, size and volume fraction of the hard phase particles formed during solidification. Selection of the process parameters is critical for producing sound clads with expected properties. This paper focuses on the properties of PTA welded and laser cladded M2, M4 and A11 high speed steel coatings. Clad quality, hardness, abrasive wear resistance and microstructure are presented and interpreted with support of thermodynamic simulations.
Determination of the Temperature Distribution of a Substrate Exposed to a Moving Cold or Thermal Spray Heat Source
Authors: Mahdavi Amirhossein , McDonald André
Published: October 2022

A three-dimensional transient heat conduction model was developed to evaluate analytically the surface temperature profile of substrates that were exposed to the impingement of a moving time-dependent heat source such as a cold spray nozzle or thermal spray torch. The estimated surface temperature profile was compared to the experimental results of the surface temperature of an aluminium substrate under impingement of a moving air jet generated by a low-pressure cold spray system. Close agreement between the analytical model and the experimental data was found. It was also found that the velocity of the moving heat source significantly affected both the profile and maximum temperature of the substrate. A non-dimensional characteristic velocity was defined and considered to take into account the effect of the velocity of the moving heat source, to broaden the application of the model to a wide range of materials and conditions. It was found that as the non-dimensional characteristic velocity increased, the thermal energy that was conducted into the substrate decreased. It was concluded that, with knowledge of the characteristic velocity, the analytical model was capable of predicting the spatial and temporal surface temperature of the substrate exposed to a moving heat source produced by spray nozzles and torches.
Preparation of Functional, Compositionally Graded Metal Oxide Films via the Solution Precursor Plasma Spray Process
Authors: Yu Zexin , Liu Meimei , Moliere Michel , Liao Hanlin , Moussa Hatem , Schneider Raphaël , Wang Weize
Published: October 2022

The results accumulated up to now by a number of research works tend to show that a single metal oxide semiconductor (MOS) cannot achieve the multiple objective required to make an efficient photocatalytic system, which includes not only the light response, but also the photochemical stability and the avoidance of the recombination of photogenerated electron/hole pairs. Mixing different MOS is considered a promising strategy as it induces beneficial synergistic effects. In this work, we have developed an original method to prepare compositionally graded films that are active in photodegradation applications. The selected compositionally graded films are the CuO-ZnO and CeO2-ZnO pairs that were deposited via the Solution Precursor Plasma Spray (SPPS) process. Various composition gradients were achieved using different modes of injection of the precursor solutions, generating distinct “film configurations”. We characterized the resultant films by SEM and XRD. We determined the corresponding optical bandgap energies through UV-Vis adsorption spectrometry. Then we evaluated the photocatalytic performances of these CuO-ZnO and CeO2-ZnO films through the photodegradation of aqueous solutions of the Orange II dye. The CeO2-ZnO-M films proved capable of degrading almost entirely the Orange II dye within 2 hours, under UV light. Finally, we discuss the correlation between the various film configurations and their photodegradation efficiency. This exploratory work tackles the relatively novel field represented by the use of compositionally graded oxide films for enhanced photochemical reactivity and stresses the effectiveness and versatility of the SPPS technique for the preparation of a large variety of photocatalytic films.
Influence of Aluminum Oxide Grit Reuse on Surface Preparation and Bond Strength of Thermally Sprayed Coatings
Authors: Odake Samantha Mayumi Zanella , Sucharski Gustavo Bavaresco , Paredes Ramón Sigifredo Cortés , Fernandes Irene Bida de Araujo Siqueira , Vaz Rodolpho Fernando
Published: October 2022

Thermally sprayed coatings rely on mechanical anchoring as the main bond mechanism, which depends on previous surface preparation, i.e. cleaning, roughening and preheating. In this work, aluminum oxide (Al2O3) grit was used to blast surfaces in order to show the influence of the abrasive reuse on the decrease in granulometry, surface roughness, cleanliness and consequently on the coating adhesion strength. SEM images illustrate the difference in grain sizes and EDS was used to study the contamination of the abrasive with the substrate elements. To understand the granulometry reduction, the samples were blasted and after each cycle the abrasive was classified with different sieves, and then the mass was measured. The abrasive was mixed and the process was repeated for five cycles. Sa, Sz, Ssk and Sku were the parameters chosen for the roughness characterization and were compared to the grain size decrease, showing a significant correlation between them. Lastly, the adhesion strength of the coatings was measured according to ASTM-C633 and compared to both the roughness and blast cycle. The results show that a small fraction of abrasive with finer grit reduces the roughness significantly. However, the adhesion strength was not affected.
The Effects of Impurities on The Properties of YSZ Thermal Barrier Coatings
Authors: Xiaojuan Ji , Yueguang Yu , Deming Zhang , Yujie Li , Haoran Peng , Wei’ao Hou
Published: October 2022

Lowering the impurity content in the thermal barrier coating has the effect of improving the high temperature stability and service life. SiO2, Al2O3, TiO2 and Fe2O3 are several common low melting point oxide impurities in the YSZ (Yttria- Stabilized Zirconia) top coatings, and they all have some influence on the performance of the coatings. But there is no quantitative research on the relationship between impurity content and the properties of the coatings. In this paper, YSZ spraying materials with SiO2, Al2O3 and Fe2O3 with the content changing from less than 0.01wt% to 1wt% were designed. The bond coatings were all NiCoCrAlY and were prepared by HVOF (High-Velocity Oxygen-Fuel). The top coatings were prepared by APS (Atmospheric Plasma Spraying). The microstructure, phase structure and thermal shock resistance of the above coatings were investigated. The results showed that the increase of oxide impurity content was more prone to thermal shock failure. It shows that the oxide impurity has a significant influence on the properties of YSZ coating.
Synthesis of Carbon Nanotube Reinforced Al Matrix Composites via Cold Spray Deposition
Authors: Xie Xinliang , Chen Chaoyue , Xie Yingchun , Liao Hanlin , Tan Zhanqiu , Li Zhiqiang , Ji Gang
Published: October 2022

For fabrication of high strength carbon nanotube (CNT) reinforced Al matrix composites, the uniform dispersion, strong interface bonding and high structural integrity of CNTs have been regard as the three most important issues. In this work, two distinct approaches, namely high shear dispersion (HSD) and shift-speed ball milling (SSBM), were applied to disperse CNTs (1.5 wt.%) into pure Al powders. These two kinds of CNTs/Al composite powders as well as pure Al powders (as comparison) were deposited onto stainless steel plates under the same processing parameters. The deposition efficiency, microstructure, as well as the structural integrity of CNTs in the coatings produced from different starting powders were comparatively investigated. According to the XRD and Raman analysis, the brittle Al4C3 phase was not formed in both CNTs/Al composite coatings. Some structural damages of CNTs were found in both composite coatings, especially the one fabricated from HSD composite powder. The dispersion of CNTs onto Al particle surfaces by HSD approach did not achieve significant strengthening effect on the composite coatings, but adversely affect the metallic bonding of the particles. The microhardness of CNTs/Al composite coating produced from SSBM powders reached to ~115 HV0.1, showing a significant improvement compared to the pure Al coating. The strengthening mechanisms of the cold sprayed CNTs/Al composite coatings were also investigated.
Potential New Application for VLPPS Process as an Additive Manufacturing Device
Authors: Darut Geoffrey , Niederhauser Aymeric , Jaccoud Bertrand , Sigrist Martin , Mock Elmar , Planche Marie Pierre , Liao Hanlin , Montavon Ghislain
Published: October 2022

Additive manufacturing offers the ability to produce complex parts or shapes by layer based printing method using 3D modeling software equipment. Among the different technologies, 3D Printing and Rapid Prototyping are well established. However, thermal spraying makes a contribution towards this field as Cold Spray for repairing metal components. VLPPS and PS-PVD are both thermal spray processes using plasma technology in a very low-pressure controlled atmosphere. These conditions allow to obtain different precursor states: molten and/or vapor. As a result, the microstructure of the coating is unique in the community (lower scale elements, pore architecture) and the properties are improved. Furthermore, vapor phase of metal can react with some gases to generate oxides or nitrides. Another opportunity presented in this study is the ability of this vapor phase to fill mold. The objective is to demonstrate that VLPPS process can be employed as an additive manufacturing device to create well-defined objects.
The Design of Readable Arc Spray Alloys For Boilers Using Big Data Techniques
Authors: Cheney Justin
Published: October 2022

Thermal spray materials used in power generation applications are required to function within a challenging array of requirements. The coatings must be applied over typically large surface areas cost effectively, the coating must be resistant to extreme erosion and/or corrosion, the coatings must function at high temperatures and, if possible, the thickness of the coatings should be readable with standard equipment such as an Elcometer gauge. Simultaneously meeting all these requirements and advancing the alloy technology is a daunting if not impossible task if done via experiments alone or through scientific intuition. However, the design of new alloys which must possess a variety of attributes simultaneously is well suited for big data techniques. The calculation of millions of alloys and advanced data mining techniques help to quickly identify the best alloy for the application. This paper details how this process was used to design Metco 8294, a proprietary alloy. Metco 8294 is unique in that it is a Fe-based alloy of high hardness, coating adhesion, and erosion resistance, and is readable in the as-sprayed condition and after high temperature exposure.
Development and Investigations of Special DC-Plasma Generator “Penta”
Authors: Zimmermann Stephan , Szulc Michal , Schein Jochen , Müller-Roden Karin , Schmengler Christian , Wank Andreas , Zierhut Jochen
Published: October 2022

Due to the growing application fields, the development of plasma generators has become increasingly important in recent years. Nowadays, DC-plasmas used for a plethora of coatings on metallic surfaces, metallization of plastic materials, surface cleaning and activation, plasma welding and spacecraft propulsion systems. The use of plasma generators for surface coating has grown enormously in the field of thermal insulation and wear-resistant coatings, especially with regard to deposition of refractory oxide ceramic layers using powders such as aluminum oxide, alumina / titania, zirconia and chromium oxide. In addition, for the plasma-assisted surface treatment, generators for both wide extended planar surfaces, as well as structures that are more complex have designed and industrially established. Nonetheless, new plasma sources still developed to provide more-efficient, tailor-made solutions due to their specific characteristics. Within this paper, a brief overview of the new innovative development of DC-plasma generator “Penta” shown. Thereby the special setup, first diagnostic results, including coatings, presented and discussed. The paper concludes with an outlook for future diagnostic measurements and possible future applications for this DC-plasma torch.
Bacillus sp.–Triggered Biocorrosion of Arc Sprayed Aluminum Coatings in Artificial Seawater
Authors: Abdoli Leila , Liu Yi , He Xiaoyan , Li Hua
Published: October 2022

Thermal sprayed marine coatings in the marine environment usually encounter chloride-induced corrosion and microbiologically induced corrosion. Formation of microbial biofilm is crucial for subsequent attachment of large fouler and understanding the initiation and growth of the biofilm is essential for possibly controlling the occurring of biofouling. This paper reports the formation of Bacillus sp. bacterial biofilm on arc sprayed aluminum coatings and its effect on the corrosion behaviors of the coatings. Results show fast and pronounced attachment and colonization of the bacteria on aluminum coatings. The bacterial biofilm was systematically examined by CLSM, FESEM, and Raman spectroscopy. Electrochemical assessment revealed that the aluminum coating immersed in the bacteria-containing media showed higher corrosion resistance than the sterile samples. A model was proposed to explain how the microorganisms and their metabolic by-products protect the coatings against penetration of corrosive media. The results would give insight into design and fabrication of thermal sprayed coatings for enhanced anti-biocorrosion performances in the marine environment.
Influence of Spray Pattern on Residual Stresses and Coating Properties of Arc-Sprayed Aluminum Bronzes Sprayed with Different Gas Mixtures
Authors: Hauer M. , Banaschik R. , Krömmer W. , Henkel K.-M.
Published: October 2022

The alloys CuAl9Ni5Fe4Mn and CuMn13Al8Fe3Ni2 were arc-sprayed with a spiral-shaped pattern in this work, using both pressurized air and a mixture of nitrogen and hydrogen. Process temperatures were recorded by thermographic imaging and residual stresses were measured by modified hole-drilling method. Moreover, analyses of the cavitation erosion behavior and other properties were carried out. It was found that a change in the spray pattern can strongly reduce residual stresses and material loss by cavitation erosion.
Evaluation of High Velocity Oxy-Fuel (HVOF) Deposition Process on Erosion and Abrasion Resistance of Tungsten Carbide Coatings
Authors: Lamana Murilo Sérgio , Pukasiewicz Anderson Geraldo Marenda
Published: October 2022

Erosion and abrasion are both wear processes in which a particle that strikes the surface removes material, either by impact (erosion) or contact (abrasion). These wear processes can cause damages to components, which can be protected by coatings to reduce the damage occurrence. Thermally sprayed coatings are considered candidates for a protective system against abrasion and erosion. The HVOF spray process is one of the most used thermal spray processes due to the ability of producing dense coatings, with good values of hardness and toughness. Among the materials used in thermally sprayed coatings, WC-Co based coatings are often used, as it offers a combination of high hardness, toughness and adherence, which can provide a good wear resistance. In this work, the influence of different HVOF process parameters, specifically the type of fuel used, on the residual stresses and properties of these coatings was studied. It was noted that coatings deposited by HVOF with kerosene liquid fuel, presented lower porosity, compared with coatings deposited by gas fuel. It was also observed that the coatings with lower porosity provide a better abrasion resistance, meanwhile the erosion was controlled by toughness for 30° and higher hardness for 60° of impact angle.
Taxonomic and ecological analysis of vascular plants of the pine forest of the Irtysh Region
Authors: Yelkenova B.Z. , Beisenova R.R. Beisenova , Karipbayeva N.V. , Polevik V.V.
Published: October 2022

The article presents a taxonomic, biomorphological, geographical analysis of the biodiversity of the flora of herbaceous species of pine forests of the Irtysh region, which is represented by 168 plant species belonging to 116 genera and 42 families. Analysis of the largest flora families of herbaceous species shows that the dominant communities are Artemisia L. — Festucaria Heist. ex Fabr. and Artemisia L. — Poaceae Barnhart (Artemisia L., Festuca Heist. ex Fabr., Stipa capillata L.) phytocenoses. In all the studied sites, the following plant species are dominates or codominants of Festuca rupicola Heuff., Agropyron cristatum (L.) Gaertn., Stipa capillata L., Artemisia vulgaris L., Carex supina Willd. ex Wahlenb., Spiraea hypericifolia L. The flora is based on angiosperms, including dicotyledons — 137 species (81 %); monocotyledons — 28 species (16.6 %). Gymnosperms are represented by two species of Pinus sylvestris L., Juniperus sabina L., and there is also one species of Eguisetum arvense L. horsetail. The richness of the flora is also emphasized by some quantitative indicators of its taxonomic composition: the average species saturation of one family is 4, the maximum is 36. There are 9 rich families with the number of species above the average (21.4 % of the total number of families), and 22 the poorest, single — species families (52.3 %). The top ten leading families contain 71 % of the total floral diversity. The high level of floristic diversity of the studied territory is due to the variety of ecological conditions of plant habitats (the valley of the Irtysh River with a high variation in moisture and salinity, a variety of rocks of the adjacent riverside uplands) and anthropogenic activities leading to an increase in weed and adventitious plant species.
Термофильное сбраживание бытовых пищевых отходов
Authors: Жапарова С.Б. , Баязитова З.Е. , Курманбаева А.С. , Какабаев А.А. , Бекпергенова Ж.Б.
Published: October 2022

В мезофильных условиях анаэробное сбраживание является наиболее распространенным в мире, но термофильное сбраживание имеет несколько важных преимуществ из-за скорости роста микроорганизмов и реакций, которые они производят, а также деградации глубокого органического вещества из-за увеличения растворимости органических соединений. Сброженную массу, подготовленную в мезофильных условиях, нельзя использовать в качестве биоудобрения, так как могут остаться остатки патогенных организмов (вирусов, бактерий, яиц гельминтов), а повышение температуры позволяет их нейтрализовать. Эффективный инокулянт был выбран для бескислородной ферментации пищевых отходов и избыточного активного ила. Установлено оптимальное соотношение инокулята и субстрата для начала процесса бескислородной ферментации. Эксперименты с колбами и лабораторными биогазовыми реакторами показали, что ферментация пищевых отходов ОКВ значительно увеличивает скорость и расход биогаза. Оптимальное соотношение ОКВ и пищевых отходов в смеси коферментов составляет 50/50 в зависимости от общего содержания органических веществ в смеси. Максимальная скорость метаногенеза наблюдалась в смесях И/С 70/30 и И/С 55/45 (после 18 сут.) и 156 мл CH4 и 178 мл CH4 соответственно. Это показывает стабильность анаэробного процесса. Показано, что после предварительной обработки и активации полигона ТБО органическая часть твердых бытовых отходов, пищевых отходов и сточных вод может быть использована для запуска процесса анаэробного сбраживания в анаэробных реакторах.
Оптимизация питательной среды для продукции протеазы фитопатогенным грибом Fusarium graminearum и характеристика фермента
Authors: Абайлдаев Ә.О. , Кузовлев В.А. , Хакимжанов А.А.
Published: October 2022

Одним из современных направлений повышения устойчивости злаковых культур к грибковым болезням является изучение гидролитических пищеварительных ферментов патогенов и их белковых ингибиторов в зерне. В данном исследовании определена оптимальная питательная среда для получения протеазы фитопатогенного гриба Fusarium graminearum, содержащая 1 % глюкозу и 1 % дрожжевой экстракт в качестве индуктора синтеза фермента. Период культивирования гриба при внесении 3,8×106 конидий/100 мл составляет 12–14 дней, при котором синтез протеазы максимальный. Методом аффинной (биоспецифической) хроматографии из наработанного в препаративном количестве КФ очищена экстрацеллюлярная сериновая трипсиноподобная протеаза, представленная по данным ДДС-электрофореза двумя белками с М.в. 24 и 27 кДа. Установлены основные физико-химические свойства фермента, важные для проявления активности и взаимодействия с белковыми ингибиторами — рН и температурный оптимумы, термостабильность, чувствительность к ионам металлов. Эти характеристики для трипсиновой протеазы F. graminearum приводятся впервые. Результаты исследования могут быть использованы в поиске специфических ингибиторов протеаз в зерне, как защитных белков, для их применения в оценке устойчивости сортов пшеницы к грибному поражению.
FACTORS OF INFLUENCE ON FOOD SECURITY OF THE STATE
Authors: Pavlovska Iryna G.
Published: October 2022

The article is devoted to determining the factors that affect the food security of any country. The work defines the concept of "food security". It has been proven that food security is affected by a large number of factors. The classical distribution of influence factors is given. An improved classification of factors affecting the food security of the state is proposed, which, unlike the existing ones, proposes to consider all factors (by the criterion of subjectivity, by the position regarding the object of influence, by the nature of the consequences, by types and by the duration of the impact on the object) in depending on the level of the system - mega-level, macro-level, meso-level and micro-level, which will allow building a stable system of food security of the state. The main subjects of guaranteeing (ensuring) food safety are presented, depending on the hierarchical levels of the system. Stabilizing and destructive factors affecting the food security of the state in the context of internal influencing factors are carefully considered. It is suggested that within the framework of the classification of factors affecting food security by species, consider institutional factors, to which boycotts, sanctions and anti-sanctions should be classified. The global factors affecting food security affecting all levels of the system are given separately. The need for state support was noted as one of the most important factors influencing food security. It was concluded that the development of food security is influenced by numerous factors that can be grouped and classified according to the main characteristics, to assess their impact on the overall level of food security in order to make the necessary effective management decisions, develop measures to reduce the level of internal and external threats and increase economic security of the country, the region, every person and the world community in general.
FEATURES AND SIGNIFICANCE OF MANAGEMENT OF MARKETING ACTIVITIES OF A TOURIST ENTERPRISE
Authors: Barvinok Nataliia V.
Published: October 2022

The article reveals the essence of the concepts "marketing in tourism", "marketing activity of a tourist enterprise", considers the management of the marketing activity of a tourist enterprise as a managerial activity related to planning, organization, coordination, control, audit and stimulation of actions to intensify the process of demand formation on the tourist product and increasing the profits of the tourist enterprise. The main attention is focused on the performance of marketing functions in tourism based on the specifics of the tourist product, which distinguish the sale of the tourist product from the sale of other goods and services. The main aspects of the tourist product are considered, through which the essence and peculiarities of the marketing activity of the tourist enterprise are revealed in order to expand the sales market. It has been established that effective management of marketing activities of a tourist enterprise, performance of all marketing functions is a tool for solving the problem of matching demand and supply for a tourist product. Due to the peculiarities of tourism activity, the study of consumers is the most important direction of marketing activity. Studying the nature and mechanism of the influence of various factors on the behavior of consumers of tourist services, their motivation, makes it possible to determine the likely reaction of customers to certain offers of a tourist enterprise and allows you to turn a potential buyer into your client.