bluuebunny/crossref_metadata_2025 huggingface dataset:
Wear Resistant Coatings for Radial Shaft Sealing Systems
Authors: Haas W. , Haiser H. , Putzier U. , Putzier J.
Published: May 2021

Due to advanced technical, economic and environmental reasons, radial shaft and hydraulic rod seals demand new wear resistant counterface materials. Thermal spraying offers one alternative to common hardening and hard plating technologies. Applying corrosion resistant ceramic coatings by Thermal Spraying leads to new applications in sealing systems. The combination with PTFE-compound sealing materials can be used with aqueous, non-lubricating and corrosive fluids. The authors have carried out extensive research on how the coating material and the surface structure of the coating effect hydraulic rod and radial shaft sealing systems. The presented results show that the influence of the coating on the sealing is critical for the performance of both standard and new custom sealing systems.
Applications of PTA Powder Welding in Petroleum Chemical Industry
Authors: Huang X. , Wang R. , Xu L. , Luo H. , Yin X.
Published: May 2021

Plasma transferred arc (PTA) welding is widely used in the petroleum and chemical industry to deposit nickel and cobalt-based materials on key parts for the purpose of surface modification. As test results show, the process improves corrosion, wear, and high-temperature resistance, prolonging the service life of components and equipment and reducing production costs.
The Experimental Study on Arc Sprayed Mouldmaking for Plastic Products
Authors: Xu B. , Ma S. , Liu X. , Chen Z.
Published: May 2021

This paper describes some of the problems solved in the development of a mold-making process in which the molds are coated using a 2mm wire arc-spraying system. A water solution release agent has been chosen to meet industry standards and requirements. The composition of backup materials was chosen based on compression strength testing. The material selected has high ultimate compression strength and high thermal conductivity and can be readily incorporated in the mold-making process.
Ca/P Ratio and Biocompatibility of Hydroxyapatite Coatings
Authors: Frayssinet P. , Tourenne F. , Rouquet N. , Primout I. , Mathon D.
Published: May 2021

The decomposition of HA during plasma-spraying can lead to the appearance of calcium oxide (CaO) in the calcium phosphate coatings and an increase of the Ca/P ratio (> 1.67). Rehydration can cause an increase in the pH of the extracellular fluids in close vicinity to the coating and rapid degradation of its thickness. Metal cylinders coated with HA were implanted in rabbit condyles for two months and analyzed by histology to evaluate the effect of the presence of CaO in the coatings during early implantation. Three groups of coatings containing different amounts of CaO: 0.2, 0.5, and 0.9% were implanted. The mean coating thickness was measured on five different sites randomly chosen on each section. The percentage of the coating perimeter in contact with newly farmed bone tissue was also measured. A very small difference in coating thickness was observed between the 0.5% group and the two others. The percentage of coating perimeter in contact with the bone increased with the CaO content. These results show that CaO contamination of the calcium phosphate coating does not impair integration and does not increase degradation during the early stages of implantation.
Development of Fabrication Processes for Tubular Solid Oxide Fuel Cell (SOFC) by Plasma Spraying
Authors: Ju W.T. , Hong S.H.
Published: May 2021

The atmospheric pressure plasma spray processes for functional layers of the tubular solid oxide fuel cell are developed to build a fuel cell structure consisting of air electrode, ceramic electrolyte, and fuel electrode. Further more the characteristics of each film are also investigated. The layers of LSM (La0.65Sr0.35MnO3) air electrode and Ni/8YSZ fuel electrode have porosities of 23 ~32 % sufficient for supplying fuel and oxidant gases efficiently to electrochemical reaction interfaces. The measured electrical conductivities of the electrodes are higher than 90 S/cm at 1000 °C, which satisfy the requirement as the current collecting electrodes. The YSZ electrolyte film has a high ionic conductivity of 0.07 S/cm at 1000 °C, but shows a bit too porous to block the oxygen molecule penetration through it. A unit tubular SOFC is fabricated by the optimized plasma spray processes for depositing each functional film and forming a porous cylindrical supporting tube of the cell, and turns out to have a promising capability of electricity generation.
Combined Metallurgical and Ceramic Coating in the Development of Tubular Ozone Generators
Authors: Gadow R. , Killinger A. , Voss A. , Friedrich C.
Published: May 2021

This paper discusses the development of a metal-coated glass tube that produces ozone more economically than traditional methods. It describes the principle of ozone generation, provides information on ozonizer tubes, and presents the criteria for selecting thermal spray powders. It examines the properties of several multilayer coatings consisting of an oxide ceramic top layer, an Al/Si interlayer, and a borosilicate glass substrate. It was found that the porosity and surface roughness of the oxide layer have a significant impact on the dielectric strength of the composite and the efficiency of the ozone-producing tube.
Ceramic-Clad Ceramic System for Ultrasonic Wave Guidance
Authors: Marple B.R. , Jen C.-K. , Voyer J.
Published: May 2021

Ceramic-clad ceramic components were developed to address the need for buffer rods capable of operating under severe conditions. The buffer rods were produced using plasma spraying to build up a 500-nm thick layer of alumina on a solid alumina rod. Both conventional plasma spraying and high power plasma spraying techniques were employed to deposit the alumina coating directly onto a pre-roughened surface. Characterization of the resulting coatings indicated a level of porosity of several percent, substantially higher than that of the dense core. The room temperature wave propagation characteristics exhibited by these clad buffer rods were significantly improved over that of the unclad components.
Fatigue Behavior of Type 316L Stainless Steel Coated with Plasma-Sprayed Alumina in Corrosive Environment
Authors: Kisuki H. , Sugano M. , Oshima T. , Nasu Y. , Okazaki K. , Nakata K.
Published: May 2021

Fatigue properties of the Al2O3 plasma-sprayed SUS316L stainless steel rod specimens coated on different spraying conditions have been studied in a physiological saline solution (0.9 % NaCl solution) to evaluate the potential of surgical implant application. Fatigue tests were conducted in push-pull loading at the stress ratio of R = -1, and frequency of 2 Hz. Microstructure related with fatigue damage was examined by SEM and TEM. The fatigue strength of Al2O3 plasma-sprayed metals significantly depended on spraying conditions: the effects of spraying on fatigue strength decreased with increasing the applied stress amplitude. As-blasted specimens were higher in fatigue strength than Al2O3 plasma-sprayed specimens. It was found that the plasma spraying had significant effects on fatigue crack growth behavior in the early stage of crack propagation. Fatigue cracks preferentially originated from dents that had been caused on the substrata metal surface subjected to grit-blasting. These results are discussed with both the compressive residual stresses due to the grit blasting which was carried out prior to plasma spraying and the corrosion-resistance of the alumina deposit.
Interface Characterization of Different Apatite Coatings
Authors: Antolotti N. , Bertini S. , Scrivani A. , Fanara C. , Rustichelli F. , Ranz X. , Rey C.
Published: May 2021

The decomposition of bioactive plasma sprayed apatite layers and the weakness of their interface with the metallic substrate limit the longevity of orthopaedic prostheses. Analysis of the coating and of the metal-apatite interface using EDS, XPS, and IR techniques indicates alterations of the apatite composition which can be related to several chemical reactions occurring either in the plasma or on the surface of the implant. EDS shows a calcium-rich layer on the apatite side of the interface whereas after dissolution of the apatite, XPS indicates that phosphorus atoms are incorporated in the metal surface. Depending on the rate of decomposition, calcium oxide may possibly form and weaken the apatite-metal interface. Fluorohydroxyapatite coating have proven to decompose less and differently and to be more effective than hydroxyapatite coatings.
Thermal Spraying Applied onto High Energy Railway Braking: Characterization of Friction Performances
Authors: Bartys H. , Guerin J.D. , Bricout J.P. , Oudin J.
Published: May 2021

Friction materials for braking devices on high-speed trains must be able to dissipate large amounts of energy levels and do so with a minimum amount of mass. Low thermal diffusivity materials such as coated steel discs are of particular interest to researchers in this field. This paper investigates the wear behavior of stellite coatings, based on cobalt or nickel alloys, applied to aluminum titanate pads. The coatings are assessed in terms of friction coefficient, contact temperature, and wear as compared to cermet coated steel discs.
A New Aluminum-Silicon/Boron Nitride Powder for Clearance Control Applications
Authors: Morrell P. , Bettridge D.F. , Greaves M.D. , Dorfman M.R. , Russo L.D. , Britton C. , Harrison K.
Published: May 2021

Abradable coatings are used in gas-turbine engines to optimize compressor performance by maintaining tight blade tip clearances. The most common such coatings are thermally sprayed Al-Si/polyester, Al-Si/graphite, and Ni/graphite. Al-Si/graphite coatings have performed well in terms of wear but are prone to corrosion, which can lead to spalling and a reduction in engine efficiency. In this paper, we chart the development of a powder-based Al-Si/BN abradable material designed to overcome in-service corrosion and analyze laboratory and engine testing results.
Optimisation of Concurrent Fibre Winding and Low Pressure Plasma Spraying for the Manufacture of Titanium Matrix Composite Rings
Authors: Baik K.H. , Grant P.S.
Published: May 2021

A concurrent fibre winding and low pressure plasma spraying (LPPS) process has been developed to manufacture multiple fibre reinforced titanium matrix composite (TMC) rings in a single spraying operation. Optimisation of the LPPS parameters has been successively performed for two different sizes of Ti-6Al-4V powders by experimental design and statistical analysis, which provided minimum porosity and surface roughness for both powders. The most important LPPS parameters affecting porosity and surface roughness of deposits were Ar gas flow rate and chamber pressure. During TMC manufacture, the coarse Ti-6Al-4V powder spraying provided enhanced infiltration between fibres but caused degradation of fibre tensile strength, as well as a rough ring surface. The fine Ti-6Al-4V powder gave no significant degradation of fibre strength and a relatively smooth ring surface. Four-ply SiC fibre reinforced TMCs manufactured by the spray-wind process have also been evaluated in terms of porosity, fibre distribution and fibre damage.
Mechanical and Microstructural Characterisation of a Free Standing Plasma Sprayed Alumina
Authors: Damani R.J.
Published: May 2021

Plasma spraying, commonly used for wear and heat resistant barriers, can be used to produce free-standing bulk ceramic parts as well. In this work the microstructure and phase development of a bulk plasma-sprayed alumina material with about 14 % porosity and splat like grains is investigated in the as-sprayed and various annealed material conditions, using electron microscopic and x-ray diffraction techniques. The fracture characteristics are investigated using standard CT specimens in in-situ SEM experiments. The mechanical response of the material is clearly a result of two features: the pronounced alignment of microstructure itself, and the occurrence of a splat-internal microcrack sub-structure in the as-sprayed condition. This microcrack substructure is a consequence of a splat internal columnar subgrain structure which occurs as a result of the rapid cooling conditions on deposition. The morphology of this subgrain structure and its phase composition is seen to change extensively on annealing. It is found that the mechanical behaviour of the as sprayed material is dominated by this internal subgrain structure, but the behaviour of sufficiently annealed material is dominated by the morphology and mechanical stability of the splat like grains themselves. The biggest change on annealing is not an overall sintering effect, but rather the recrystallisation of the splat internal substructure
Novel ZrO2-Mullite Composites Produced by Plasma Spraying
Authors: Khor K.A. , Li Y.
Published: May 2021

Zirconia can induce enhanced fracture toughness to a number of ceramics when introduced as a reinforcement either in the form of particulates, dispersed phase or whiskers because of its unique tetragonal-monoclinic transformation. This paper presents the preparation of ZrO2 reinforced mullite by plasma spraying a mixture of zircon and alumina. The dissociation of zircon into zirconia and silica in a plasma flame is well-known. Pre-mixed powders of zircon and alumina are injected into a dc plasma jet. The plasma sprayed particles are collected in distilled water and analyzed. The results indicate that the plasma sprayed powders consist of zirconia, zircon and alumina. It was found that fine, mostly amorphous and chemically homogeneous composite powders can be obtained by ball milling and plasma spraying. Recrystallization of amorphous phases and formation of mullite occurred at about 1000 °C in plasma sprayed powders. This value is more than 500 °C lower than the formation of mullite in as-milled powders. Uniform coatings with good structural integrity were obtained by plasma spraying. The amount of amorphous phases was much higher in plasma sprayed coatings than in spheroidized powders, and the relative quantity of mullite in coatings after heat treatment is about 4 times as much as that obtained in the spheroidized powders.
Fabrication of Simulated Nuclear Fuel Pellets by Induction Plasma Deposition
Authors: Gitzhofer F. , Mailhot K. , Boulos M.I. , Jung I.H. , Lee J.S. , Park H.S.
Published: May 2021

A study on induction plasma shape forming with yttria stabilized zirconia (YSZ) was conducted as part of an effort to develop a new method for producing nuclear fuel. YSZ was selected because its melting point is similar to that of UO2. Nuclear fuel pellets were made using a large (70 mm) induction plasma flame that sprays more than 100 pellets simultaneously and a small (10 mm) supersonic plasma flame that produces one pellet at a time. Process optimization for the large induction plasma flame was done based on chamber pressure, plasma plate power, powder spraying distance, sheath gas composition, probe position, and particle size. The best results were 97.11% theoretical density (TD) for 5-mm thick pellets. For the single pellet approach, densities as high as 99% TD have been obtained in 12-mm thick free-standing pellets.
Physico-Chemical Treatment of Zirconia Coatings for Thermal Barriers
Authors: Troczynski T. , Third N. , Pawlowski L. , Covelli L. , Smurov I.
Published: May 2021

This paper explains how laser-beam remelting influences the quality of ceramic coatings on superalloy substrates. The coatings studied consist of Al2O3-Ni ceramic layers. Test results showed that a laser power density of 0.103 x 109 W/m2 is ideal for a beam rate of 1 to 2 m/min. It was also found that coating quality could be further improved by adding a diffusive Cr-Al layer prior to laser remelting. This added step reduces pore volume and layer thickness and increases adhesion without cracks, chips, or spalls. The examination also showed that, depending on cooling rate, it is possible to obtain layers that are similar in composition but different in structure or even amorphic.
Free Form Fabrication of Metallic Components Using the Directed Light Fabrication Process
Authors: Lewis G.K. , Milewski J.O. , Nemec R.B. , Thoma D.B.
Published: May 2021

The Directed Light Fabrication (DLF) process uses a laser beam and metal powder, fed into the laser focal zone, to produce free-standing metal components that are fully dense and have structural properties equivalent to conventional metal forming processes. The motion of the laser focal zone is precisely controlled by a motion path produced from a 3-dimensional solid model of a desired component. The motion path commands move the focal zone of the laser such that all solid areas of the part are deposited and the part can be built (deposited) in its entirety to near net shape, typically within +/-0.13mm. The process is applicable to any metal or intermetallic. Full density and mechanical properties equivalent to conventionally processed material are achieved.
Preparation of Perovskite Powders and Coatings by RF-Suspension Plasma Spraying
Authors: Schiller G. , Muller M. , Gitzhofer F.
Published: May 2021

Perovskite-type LaMnO3 powders and coatings have been prepared by a novel technique, the reactive suspension plasma spraying (SPS) using an inductively coupled plasma of about 40 kW plate power and an oxygen plasma sheath gas. Suitable precursor mixtures were found on the basis of solid state reactions, solubility and the phases obtained during the spray process. Best results were achieved by spraying a suspension of fine MnO2 powder in a saturated ethanol solution of LaCl3 with a 1:1 molar ratio of La and Mn. Low reactor pressure was helpful in order to diminish the amount of corrosive chlorine compounds in the reactor. As-sprayed coatings and collected powders showed perovskite contents of 70-90%. After a post-treatment with an 80% oxygen plasma an almost pure LaMnO3 deposit was achieved in the center of the incident plasma jet.
Reactive Plasma Spray Forming for Ferromagnetic Materials Synthesis on AI Substrate
Authors: Folio F. , Lacour A.
Published: May 2021

A composite was obtained by spraying ferromagnetic powder with a plasma arc torch onto an aluminum substrate. The influences of spraying conditions (substrate temperature, plasma gas composition, powder granulometry) on the efficiency of the induction heating by the composite are investigated.
Latest Gas Turbine Repair Techniques Using Laser Technology
Authors: Williams A.D. , Humphries J.L.
Published: May 2021

Over recent years, with the drive for new higher power, higher efficiency Gas Turbine engines, manufacturers have had to look at new alloys and new coating techniques to achieve and support the industry requirements. Repair technology has therefore had to keep pace with the OEM advances and much research and development has been undertaken in developing new repair processes. Many of the alloys now used are directionally solidified or single crystal, which until now have been deemed irreparable by traditional welding techniques. Recent developments in the use of lasers have not only rendered these alloys salvageable but have also reduced the overall repair time and therefore the cost. This paper looks at the use of laser technology as a repair process for gas turbine components, touching briefly on laser cutting and drilling but concentrating mainly on laser powder feed welding and its applications.
Microplasma Spraying
Authors: Yushchenko K. , Borisov Y. , Pereverzev Y. , Vojnarovitch S. , Darmochval V. , Bobric V. , Ramaekers P. , Raa G.
Published: May 2021

Microplasma spraying unit is characterised by small dimensions, low level of noise and emissions, low power consumption (kW*h/kg). The process provides deposition of coatings on small sized parts and components, including those with fine sections, this being unachievable with any other methods. This makes it possible to widen the scales of the application of plasma spraying and to produce different functional coatings. Microplasma jet has diameter 2-4 mm and length 30-50 mm. Velocities of different powder particles in conditions of microplasma spraying were measured. They amount 15- 60 m/s. Coating from iron-, nickel- and copper alloys were produced. Microstructure and properties of this coatings were studied. A real capability was demonstrated of microplasma spraying of narrow strips of 1-3 mm width with 0.2-0.5 mm thickness on the surface of stainless steel sheets of 0.5 mm thickness and of aluminum alloy of 1 mm thickness, as well as on the surface of 2-6 mm diameter cylindrical samples. The spraying spot has the form of an ellipse elongated along the vertical with 1.1-1.5 axes ratio, depending on the spraying conditions.
Computational Code for Detonation Spraying Process
Authors: Gavrilenko T.P. , Nikolaev Y.A. , Ulianitsky V.Y. , Kim M.C. , Hong J.W.
Published: May 2021

Interactive Computational Code is presented that provides a high-productivity analysis of the complex detonation spraying technology. It is based on exact gas dynamics theory taking into account chemical reactions for description of the gaseous detonation phenomena. It deals with specific features of the process like non-homogeneity of gaseous mixture compositions due to gas filling operation and powder injection into the barrel. Acceleration and heating of powder particles by the detonation product flow were simulated including particle melting, fragmentation and vaporization. Calculations for different fuels and powder materials were accomplished. Optimum conditions (gas mixture, barrel length, powder injection point, etc.) to provide highest velocity and appropriate temperature for typical metal and cermet powders are discussed. The conditions for coating formation by the detonation gun «Ob» were established and samples were produced. Experimental data on detonation coating properties are presented to prove the theoretical results.
Application of Overdriven Gaseous Detonation for Spraying
Authors: Gavrilenko T.P. , Nikolaev Y.A. , Ulianitsky V.Y.
Published: May 2021

The use of overdriven detonation waves can promote coating fabrication from powder materials with high melting temperature and improve the quality coating for all materials. The detonation products flow behind overdriven detonation has kinetic and thermal energy values significantly exceeding those for self-sustaining Chapman-Jouguet's detonation, conventionally used for detonation spraying. This makes it possible to design a micro-gun and, as a consequence, the equipment for internal surface coating.
Thermal Barrier Coatings – Why, How, Where and Where To
Authors: Wigren J. , Pejryd L.
Published: May 2021

Thermal barrier coatings are used in several industries to improve thermal efficiency. Examples are gas turbine engines and marine diesels. The performance and life of thermal barrier coated components depend on a variety of factors all related to the specific application. This paper gives an overview of some of the aspects to consider and put special attention to. The different features, in the microstructure, will be discussed with respect to their appearance and influence on the performance of the TBC. Thermal conductivity, microstructure, failure mechanisms and different applications are highlighted.
Enhanced Atmospheric Plasma Spraying of Thick TBCS by Improved Process Control and Deposition Efficiency
Authors: Lugscheider E. , Ladru F. , Gourlaouen N. , Gualco C.
Published: May 2021

The gasturbine industry is performing utmost efforts to allow increased operation temperatures to improve engine efficiency by a reduced cooling air/fuel-ratio. The reason is to save fuel and at the same time lower emission rates. A possible solution to improve the insulation of the Thermal Barrier Coating (TBC) is followed by the strategy of developing reliable thick TBCs. To be successful concerning the coating quality and to apply thick TBCs at reasonable costs and spray time it is necessary to apply the coating consistently by high deposition rates. The plasma spraying of thicker coatings leads to long spray periods which demands for a process control to keep the process parameters within the tolerances during the entire spray procedure. A major property is the control of substrate temperature with pyrometer systems and to define the process tolerances. Furthermore, a high deposition efficiency is of prime importance to shorten spray times. The optimisation of the gas composition in terms of viscosity and thermal conductivity (SPRAL 22) enables to increase dramatically this efficiency by 30% to 70%. Moreover, in order to reduce thermal expansion mismatch between substrate and ceramic top coat, a high amount of porosity is beneficial to lower young's modulus of the ceramic top. This can be achieved by adding a polymer powder to the yttria partly stabilised zirconia powder. It also leads to an increase in deposition efficiency.
Oxygen Transport Through the Zirconia Top Coat in Thermal Barrier Coating Systems
Authors: Fox A.C. , Clyne T.W.
Published: May 2021

The gas permeability of plasma sprayed yttria-stabilised zirconia coatings has been measured over a range of temperature, using hydrogen and oxygen gas. The permeability was found to be greater for coatings produced with longer stand-off distances, higher chamber pressures and lower torch powers. Porosity levels have been measured using densitometry and microstructural features have been examined using SEM. A model has been developed for prediction of the permeability from such microstructural features, based on percolation theory. Agreement between predicted and measured permeabilities is good. Ionic conduction through the coatings has also been briefly explored. It is concluded that transport of oxygen through the top coat in thermal barrier coating (TBC) systems, causing oxidation of the bond coat, occurs primarily by gas permeation rather than ionic conduction, at least up to temperatures of about 1000°C and probably up to higher temperatures. Top coat permeabilities appreciably below those measured will be required if the rate of bond coat oxidation is to be reduced by cutting the supply of oxygen to the interface.
Thermal Expansion of Thermally Sprayed Coatings
Authors: Beghini M. , Bertini L. , Frendo F.
Published: May 2021

The coefficient of thermal expansion (CTE) of a NiCoCrAlY coating was investigated in this work. The CTE was inferred from the measured length variations of coated prismatic symmetric specimens (i.e. having the coating on two opposite surfaces) at various temperature increments. The elongation of the specimen was evaluated from the relative positions of two markers, which was recorded during the test by a CCD video camera; analysis with subpixeling technique allowed high resolution in the dilatation measurements. Analytical relationships used to determine the coating's CTE were based on the simple multilayer beam model; the temperature dependent elastic moduli of the layers had been determined by four point bend test in a previous work. Coated specimens were employed having different substrate thicknesses in order to check the accuracy of measurements.
Microstructures and Characterization of Zirconia Coatings Formed by Laser Combined Plasma Spraying
Authors: Zhou Z. , Eguchi N. , Shirasawa H. , Ohmori A.
Published: May 2021

Hybrid plasma spraying combined with YAG laser irradiation was studied in order to obtain the optimum zirconia coatings for thermal barrier use. Zirconia coatings of approximately 150 ;Um in thickness were formed on the NiCrAlY under coated steel substrates both by means of conventional plasma spraying and hybrid plasma spraying under a variety of conditions. Post-laser irradiation was also conducted on the plasma as-sprayed coating for comparison. The microstructure of each coating was studied in detail and, for some representative coatings, thermal barrier properties were evaluated by hot erosion and a hot oxidation test. With hybrid spraying, performed under optimum conditions, it was found that a microstructure with appropriate partial densification and without connected porosities was formed and that cracks, which are generally produced in the post-laser irradiation treatment, were completely inhibited. In addition, hybrid spraying formed a smooth coating surface. These microstructural changes resulted in improved coating properties with regard to hardness, high temperature erosion resistance and oxidation resistance. Keywords: Hybrid spraying, YAG laser, Plasma-spraying, Thermal barrier coating, Zirconia, NiCrAlY, Densification, Hot-erosion resistance. Oxidation resistance, Roughness.
Thermal Spray Application for the Next Millennium A Business Development Perspective
Authors: Kassabji F. , Jacq G. , Durand J.P.
Published: May 2021

For over 60 years, thermal spraying technology has advanced steadily in aerospace, power generation, and biomedical applications. Worldwide R&D efforts have produced new coating materials, new functionalities, and new processes with significant application potential in the near term. Likewise, more project teamwork, more market driven R&D, and end used education will carry thermal spraying into the next millennium.
Rekordoldali médiamegjelenítés a DSpace 7-ben
Authors: Kiss Tamás , Kanász-Nagy Zoltán
Published: May 2021

Közgyűjtemények és kutatói közösségek részéről az elmúlt évek során növekvő igény mutatkozott nyílt forráskódú, könnyen telepíthető, testre szabható és üzemeltethető repozitóriumi megoldásokra. A digitális objektumok tárolására, valamint repozitálására vonatkozó elvárások kielégítésére megfelelő megoldásokat nyújt a DuraSpace nevű, not-for-profit közösség által 2002 óta fejlesztett repozitóriumi szoftver, a DSpace jelenlegi, hetes számú verziója. A DSpace 7 azonban egyelőre csak béta verzióban érhető el és olyan hiányosságokkal rendelkezik, amelyek megoldása az általunk kiszolgálni kívánt intézményi igények sürgőssége miatt nem várhatott a DuraSpace fejlesztői által meghatározott ütemterv szerinti implementációkra. Ezek közé tartozott a médiamegjelenítés és -lejátszás hiánya, melyek pótlására a cikk szerzői, valamint kollégáik (Tápai-Kovács Annamária webdizájner és Sipos Dániel szoftverfejlesztő) vállalkoztak, felajánlva a létrejött kódot a DuraSpace közösség, és így a DSpace 7 kódbázisa számára. A cikk a DuraSpace-szel megvalósult együttműködés rövid történetét tárgyalja és a vonatkozó fejlesztés médiatípusonkénti kódrészleteit adja közre.
PEDOPHILIA AS A FORM OF SEXUAL DEVIANCE FROM A SOCIAL BONDS THEORETICAL PERSPECTIVE
Authors: Ermania Widjajantin  , Rusmilawati Windari
Published: May 2021

Sexual crimes have seen a considerably increase in Indonesia. It not only affects women but also children. Sexual crime against children is also known as “pedophilia” and has now become a terrifying phenomenon. The escalation of sexual crime against children in Indonesia shows that there is a dire need to look into possible prevention strategies to sexual crime prevention. Considering the rapid increase of case of pedophilia in Indonesia, the government has enacted more severe punisment to the offender, that is, by imposing chemical castration under the Law No. 17 Year 2016 on the second amendment of the Law No. 23 Year 2002 on child protection. This article examines the causal factors of pedophilia by employing the social bonds theory introduced by Travis Hirschi. The primary premise of this theory states that deliquency comes up when social bonds tend to be fragile or not unavailable, or in other words, the stronger there bonds, the less likelihood of delinquency. Hirschi also mentioned four social bonds that push up socialization and conformity in society, those are: attachment, commitment, involvement, dan belief. Finally, the problems raised in this article is how does pedophilia in perspective of social bonds theory?. This article is a legal research with normative approach. It is geared to look phaedophilia as a sexual deviance in perspective of social bonds theory.
New record of Caenis nigropuctatula Malzacher, 2015 (Ephemeroptera: Caenidae) from Southern India
Authors: Srinivasan Pandiarajan , Sivaruban Thambiratnam , Barathy Sivaruban , Isack Rajasekaran
Published: May 2021

Caenis nigropuctatula Malzacher, 2015, a new mayfly record of the fauna of Indian Ephemeroptera, is recorded from the Vaigai River, Tamil Nadu, India. It is known before from Thailand, Java, and Sumatra. The distribution map of C. nigropuctatula is given.
Iatrogenic neurological injury after radiofrequency ablation and epidural steroid injections: illustrative cases
Authors: Shields Lisa B. E. , Iyer Vasudeva G. , Zhang Yi Ping , Shields Christopher B.
Published: May 2021

BACKGROUND

Neck pain is often chronic and disabling. Cervical facet joint injections and epidural steroid injections are frequently used to manage chronic neck pain and cervicogenic headaches. While minimal side effects are commonly associated with these treatments, severe complications are exceedingly rare.

OBSERVATIONS

The authors report 4 cases of iatrogenic neurological injury after radiofrequency ablation (RFA) and epidural steroid injections. One patient experienced left shoulder, scapular, and arm pain with left arm and hand weakness that developed immediately after RFA for chronic neck pain. Electromyography/nerve conduction velocity (EMG/NCV) studies confirmed denervation changes in the left C8–T1 distribution. Three patients complained of numbness and weakness of the hands immediately after an interlaminar cervical epidural block. One of these patients underwent EMG/NCV that confirmed denervation changes occurring in the left C8–T1 distribution.

LESSONS

Spine surgeons and pain management specialists should be aware of neurological injuries that may occur after cervical RFA and epidural steroid injections, especially after a multilevel cervical procedure and with severe cervical spinal stenosis. EMG/NCV studies plays an important role in detecting and localizing neurological injury and in differentiating from conditions that mimic cervical root injuries, including brachial plexus trauma due to positioning and Parsonage-Turner syndrome.
Investigating teachers and students’ perceptions of written corrective feedback in the context of tertiary education in Oman
Authors: Bahrouni Farah , Tuzlukova Victoria
Published: May 2021

This paper focuses on written corrective feedback in the testing context of the English language foundation program at Sultan Qaboos University in Oman. In more detail, in response to the encountered testing problem that involves variability in written corrective feedback and, as a consequence, inconsistent evidence of student position in relation to their improvement in writing and ways to achieve it, the authors discuss the ways teachers respond to students’ writing, the type of feedback they deliver, and the strategies they adopt to provide their feedback. The reported study uses mixed methods research methodology, and is grounded on the understanding of giving feedback to students as a social action that is implemented in specific cultural, institutional, and interpersonal contexts with a purpose to accomplish educational and social goals. The participants of the study are foundation program students and English language teachers representing the multicultural teaching community of the Centre for Preparatory Studies at Sultan Qaboos University. The results of the study reveal that written corrective feedback is by no means unanimous among all students and teachers. Diversity in the teachers’ background yields a corresponding diversity in the way it is perceived, provided, and interpreted. Undoubtedly, teachers’ ultimate goal, in any context, is to help students improve their writing skills in all respects, be it in form, content, or organization. Yet, its effectiveness in improving students’ writing remains inconclusive.
The Effect of Collaborative Prewriting Discussions on L2 Writing: Complexity, Accuracy, and Fluency (CAF)
Authors: Naghavi Mohammad , Nakhleh Mahboubeh
Published: May 2021

The present study essayed to investigate the impact of collaborative pre-writing discussions on three aspects of writing skill namely, complexity, accuracy and fluency (CAF). To reach this goal, 60 intermediate male EFL learners ranging from 22 to 28 years at Shahid Beheshti Language Center in Tehran, Iran participated in the study. For the purpose of homogeneity, the standardized English Proficiency Test (Preliminary English Test) was administered to 88 students and they were divided into two intact experimental and control groups. The experimental group, which was divided into six groups of five was exposed to and performed on a-40- minute essay writing tasks held two sessions per week lasting ninety-minutes for ten weeks with collaborative pre-writing discussions. Moreover, the students in experimental group were required to complete a questionnaire at the end of the study to find out about their feelings regarding prewriting discussions prior to writing in L2. The control group received the same materials and teacher as experimental group, except for, there was no collaborative pre-writing discussions to write the essays. After the raters were trained and familiarized with the rating process, the essays by both groups were collected and scored holistically based on the assessment measure provided to the two raters. In order to provide plausible answers to the research questions posed above, a series of one way ANOVA was employed to evaluate the participants' overall performance in the two conditions. The results indicated that collaborative pre-writing discussions were superior to mainstream methods. Thus, the findings can have an immediate implication for EFL teachers and practitioners who are searching for cutting edge ways of developing EFL learners' writing performance.
Effectivity of Indonesian Rice Husk as an Adsorbent for Removing Congo Red from Aqueous Solutions
Authors:   Graduate School of Mathematics and Natural Sciences, Univesitas Sriwijaya, Palembang, South Sumatera 30139, Indonesia, Paapla Neza Rahayu , Normah Normah ,   Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Sriwijaya, Ogan Ilir,  South Sumatera 30662, Indonesia, Taher Tarmizi ,   Department of Environmental Engineering, Institut Teknologi Sumatera, Kecamatan Jati Agung, Lampung Selatan 35365, Indonesian, Mohadi Risfidian ,   Graduate School of Mathematics and Natural Sciences, Univesitas Sriwijaya, Palembang, South Sumatera 30139, Indonesia, Rachmat Addy ,   Graduate School of Mathematics and Natural Sciences, Univesitas Sriwijaya, Palembang, South Sumatera 30139, Indonesia, Lesbani Aldes ,   Graduate School of Mathematics and Natural Sciences, Univesitas Sriwijaya, Palembang, South Sumatera 30139, Indonesia
Published: May 2021

Indonesian rice husk biochar (RH-BC) was prepared by pyrolysis method at 500°C and characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, surface-area-specific analysis by Brunauer-Emmett-Teller, and scanning electron microscopy. The RH-BC were used as adsorbents for enhancing the adsorption of Congo red compared to pristine rice husk (RH) in aqueous solutions. The results of characterization through surface-area-specific analysis showed the surface area of RH-BC (72.25 m2/g) was ten times higher than RH (7.08 m2/g) owing to high-temperature treatment. The results of the adsorption study showed that the RH and RH-BC followed the pseudo-second-order kinetic model and the Freundlich isotherm equation with maximum adsorption capacities of 85.470 mg/g and 72.993 mg/g for the RH-BC and RH, respectively. The thermodynamic parameters of adsorption indicated spontaneous and endothermic processes. The reusability of the adsorbents (RH and RH-BC) showed that they are potentially suitable for extracting Congo red from aqueous solution up to three adsorption-desorption cycles. Their performance sharply decreases after the fourth and fifth cycles.
Severe Infantilehepatic Hemangioma or Hepatoblastoma: About a Rare Case and Literature Review
Authors: J Toughza
Published: May 2021

Childhood liver tumors are rare, but two-thirds are of malignant origin. Basically, before the age of 3, the main diagnoses are Hepatoblastoma (HB) and hemangioma. Infantile Hepatic Hemangioma (HHI) is a subclass of infantile hemangiomas that are the most common self-limiting benign tumors of early childhood. Only the diffuse forms or associated with congestive heart failure can be fatal. Careful clinical examination associated with biological and radiological elements does not always allow a diagnosis to be made. The biopsy is still performed frequently for diagnostic or prognostic purposes. Because of the diagnostic difficulties with HB, and the severity of some forms of HHI, we report the case of a newborn with diffuse HHI, observed at the Cheikh Khalifa International University Hospital in Casablanca. This was a newborn male in whom symptomatology of the disease consisted of increased abdominal volume, hepatomegaly and signs of respiratory struggle. The ultrasound described the existence of a multi-hetero-nodular hepatomegaly, and the CT scan a liver increased in size, seat of a large mass, poorly limited with bumpy contours of predominant tissue density with individualization of a central area of fluid density necrosis, containing calcifications. The AFP rate was high. An ultrasound-guided percutaneous biopsy confirmed the diagnosis of HHI. The course was very rapid and fatal in this patient with diffuse HHI with congestive heart failure.
COVID-19 Australia: Epidemiology Report 41: Reporting period ending 9 May 2021
Authors:   COVID-19 National Incident Room Surveillance Team
Published: May 2021

This is the forty-first epidemiological report for coronavirus disease 2019 (COVID-19), reported in Australia as at 23:59 Australian Eastern Standard Time [AEST] 9 May 2021. It includes data on COVID-19 cases diagnosed in Australia.
KARAKTERISTIK TANAH TERDAMPAK DAN TIDAK TERDAMPAK LIKUIFAKSI BERDASARKAN UJI SWEDISH WEIGHT SOUNDING PADA KELURAHAN PETOBO
Authors: Setiawan Hendra , Kurniawan Sigit
Published: May 2021

Gempa bumi 28 September 2018 yang mengguncang Kota Palu dan sekitarnya dengan kekuatan 7,4 MW memicu terjadinya likuifaksi di beberapa lokasi, salah satunya adalah di sebagian wilayah Petobo. Likuifaksi yang terjadi di daaerah ini mengakibatkan pergeseran tanah yang masif sehingga menimbulkan kerugian material dan korban jiwa.Penelitian ini bertujuan untuk mengetahui karakteristik tanah terdampak dan tidak terdampak likuifaksi berdasarkan uji Swedish Weight Sounding pada Kelurahan Petobo. Pengujian lapangan yang dilakukan yaitu dengan alat uji Swedish Weight Sounding. Adapun pengujian laboratorium yang dilakukan meliputi pengujian Analisa saringan dan batas-batas Atterberg. Hasil yang diperoleh dari penelitian ini meliputi hasil pengujian laboratorium dan pengujian di lapangan. Untuk hasil pengujian di laboratorium, jenis tanah yang didapat pada lokasi tersebut yaitu CL dan CL-ML. Sedangkan untuk hasil pengujian lapangan, nilai Nsw di daerah tidak terdampak berkisar antara 0-250 n/m, nilai Nsw untuk daerah terdampak berkisar antara 8-72 n/m, nilai qa di daerah tidak terdampak berkisar antara 0-230 kN/m2, nilai qa untuk daerah terdampak berkisar antara 0-167,6 kN/m2,  nilai qu untuk daerah tidak terdampak berkisar antara 30-180 kN/m2, dan nilai qu untuk daerah terdampak berkisar antara 30-133,2 kN/m2.Kata Kunci : Tidak terdampak likuifaksi, terdampak likuifaksi, Swedish Weight Sounding, Likuifaksi
Upaya Meningkatkan Indeks Pembangunan Manusia dengan Pemenuhan Kebutuhan Pokok Mahasiswa UNESA Terdampak Covid-19
Authors: Rachmawati Lucky , Fikriyah Khusnul , Indrarini Rachma , Perdini Ladi Watjuba , Hanifa Nurul
Published: May 2021

The aim of implementing this community service is expected to support government programs in an effort to increase the Human Development Index by Fulfilling the Basic Needs of UNESA Students Affected by Covid-19. The method of implementing activities starts from tracking information affected by Covid-19, identifying partner problems, determining solutions to be offered, implementing PKM activities, monitoring and evaluation, and the final stage is compiling reports. Participants in PKM activities are students receiving basic needs packages of 50 students. The result of this activity is the Fulfillment of the Basic Needs of UNESA Students Affected by Covid-19, of course this activity can support government programs in an effort to increase the Human Development Index.
Training Bahasa Inggris Dasar Peramu Wisata Untuk Forum Muda Berkarya (FMB) Desa Wisata Hijau Bilebante Kabupaten Lombok Tengah
Authors: Kamarudin Kamarudin , Tawali Tawali , Imran Fathurrahman
Published: May 2021

This community service aims to improve knowledge, basic English skill for teenagers especially English for tour guide both theoretically and practically. This program involved the teenagers of Working Youth Forum (FMB) Bilebante Green Tourism Village, Central Lombok Regency. The presenters of this program were the English lecturers of UNDIKMA who are still active. The program took place in Bilebante Green Tourism Village, Central Lombok Regency. The method implemented planning, acting, and observing in which through giving the material presentation focusing on some materials such as; English for tourism, modal auxiliaries, eight parts of speech, and mini conversation practice realizing the materials given. The result of this community service revealed that the respondents were very enthusiastic and interest to participate actively within the process of the program given start from the first till the end. The capability of the respondents was also increase regarding on how to use English language expression for tour guide, vocabulary items, and become more confident. They expected the same program may be re-conducted or proceeded in another time since it has positive effect toward presentation, and their communicative English language skill.
Penguatan Keluarga dalam Pendidikan Anak di Masa Pandemi Covid-19
Authors: Nuraeni Nuraeni , Gunawan I Made Sonny , Suharyani Suharyani
Published: May 2021

The purpose of this community service activity is to increase the knowledge and understanding of parents on the importance of understanding emotions in order to care for and teach children to learn at home to be more fun. This community service activity is carried out by providing counseling in the form of socialization and technical guidance for school principals and elementary school teachers throughout Mataram. There were 60 participants in this community service activity. The results of this community service show the active participation of school principals and elementary school teachers, which can be seen from the many questions asked by community service activity participants. In addition, from what has been said, many teachers are interested in wanting to learn again about ways to manage emotions, so the community service team plans to provide training for teachers as a form of follow-up activities.
Implementasi Program Parenting bagi Orang Tua Siswa di PAUD Al-Akram Desa Sepapan Kabupaten Lombok Timur
Authors: Suharyani Suharyani , Alit Suarti Ni Ketut , Tamba I Wayan , Gunawan I Made , Astuti Farida Herna
Published: May 2021

The purpose of this community service program is to assist the managers and teachers of PAUD Al Akram in maximizing 6 aspects of child development, namely aspects of religious and moral values, physical and motoric aspects, cognitive aspects, social emotional aspects, language aspects and art aspects found in students. through the implementation of parenting programs for parents. This service method uses mentoring and counseling with the target being the managers and teachers of PAUD Al-Akram. The result of this service program is that after 6 months of mentoring to managers and teachers, Al Akram PAUD already has a routine schedule of once every 2 weeks for parenting activities for parents of students with parenting material plans that are quite systematic and structured using a learning approach. adults and according to the character of the local community.