bluuebunny/crossref_metadata_2025_split huggingface dataset:
A method to improve accuracy of definition and promptness of forecasting of spacecraft motion parameters
Authors: Пічугін М. Ф. , Кожушко Я. М. , Борцова М. В. , Клімішен О. О. 
Published: September 2022

The subject of the presented paper is the methods used to define spacecraft motion parameters. The goal of the paper is to develop approaches to improve accuracy of definition and promptness of forecasting of motion parameters. The tasks are 1) to determine the aspects influencing the result accuracy at defining initial conditions of the spacecraft motion, 2) to reveal the drawbacks of traditional methods and 3) to suggest some possible ways that can be used to improve accuracy and promptness at defining the spacecraft motion parameters. During the research it is revealed that the result accuracy at defining the initial conditions of the spacecraft motion is influenced by three aspects – a random component caused by presence of random errors in trajectory measurements, a dynamic component due to dynamic errors of the used model of the spacecraft motion and the error defined by the size of convergence region of the minimization method that is used to solve the multi-point boundary problem. To receive the least inaccuracy at defining the spacecraft motion parameters it is necessary to process some optimal quantity of measuring information which should ensure sufficient compensation of random errors and at the same time prevent the dynamic error from influencing considerably. At it it should be taken into account that the amount of the measured information should not be less than it is necessary to ensure convergence of the algorithm used to define those motion parameters. The main results are as follows. For solving the task of increasing accuracy of spacecraft motion parameters definition the paper suggests a new method based on minimization with definition of initial approximation region. The suggested method implements a non-local approach to minimization of the goal function, which ensures better as compared to traditional methods convergence. To increase the promptness of spacecraft motion forecasting it is suggested to use the mathematical apparatus of differential transformations. It allows decreasing the computational expenditures 3 to 4 times as compared to the regular ballistic and navigational algorithms while the given accuracy is preserved. On the basis of the performed research the following conclusions can be made. To increase the accuracy of the spacecraft motion parameters definition it is necessary to optimize the required number of measurement orbit passes, for that it is appropriate to use the Nelder-Mead search method. At implementing the advanced coordinate methods of the spacecraft control, to increase the promptness of the spacecraft motion forecasting, it is necessary to considerably decrease the computational expenditures for the motion parameters definition. To achieve that it is reasonable to use the mathematical apparatus of the differential transformations.
Hubungan Antar Kebiasaan Membaca dengan Penguasaan Kosa Kata Bahasa Inggris Siswa
Authors: Lasut Elizabeth Meiske Maythy 
Published: September 2022

Mastery of English vocabulary is one of the academic goals teachers expected students achieve. It becomes a problem if the goal is not attained. From various previous research results, it was found out that there were predictors of this failure, and one of which was students reading habit. This quantitative, descriptive-correlative research tried to analyze and answer the research questions whether students’ English vocabulary has a correlation with their reading habit. The instrument was distributed to 70 sixth grade students who were the respondents of this study. The data were analyzed using the Mean Score and Pearson Correlation. The results obtained showed that the frequency of reading was only occasionally, with sufficient time, and moderate attitude towars reading. In addition, it was found that the level of English vocabulary achievement was only moderate level. Finally, this study also proved that students reading frequency, time spent, and attitude towards reading have significant relationships with the level of students’ English vocabulary achievement. All of these relationships showed a positive direction. Therefore, it is suggested that English teachers should encourage their students to do lot of reading activities, and to give them reading tasks that should be done in the school library.
Hubungan Antara Pengintegrasian Teknologi Informasi dan Komunikasi Dalam Pembelajaran Dengan Hasil Belajar Matematika Peserta Didik
Authors: Likuayang Otniel , Rindengan Mersty Elisabeth , Mangangantung Jeanne Miera 
Published: September 2022

The purpose of this quantitative study is to obtain information about the level of ICT integration in learning and student’s mathematics achievement, and at the same time to prove whether there is a significant relationship between the two variables. The respondents of the study were 90 grade five students who enrolled in second semester academic year 2021-2022, in one private school in North Minahasa. To collect the data needed for ICT integration in learning, the researcher distributed a self-construct questionnaire based on the theory of TAM, which was arranged according to Likert’s Scale with 5 alternative answers, from never to always. Meanwhile, the data of students’ mathematics achievement were based on the result of their mathematics exam. The result of the study showed that both ICT integration in learning and students’ Mathematics achievement were in moderate or sufficient categories. Moreover, the result proved that there is a significant relationship between ICT integration in learning and students’ Mathematics achievement. Therefore, it is recommended that Mathematics teachers implement ICT integration in learning because of the contribution it might give to maximize students’ Mathematics achievement.
Cephalometric characteristics of the upper respiratory tract in Ukrainian young men and young women with an orthognathic bite without and with the type of face taken into account
Authors: Kostiuchenko-Faifor O. S. , Gunas I. V. , Belik N. V. , Shapoval О. М. , Veretelnyk S. P. 
Published: September 2022

The upper respiratory tract is a component of the respiratory system, which ensures the performance of several key human functions at once. The variability of cephalometric indicators of this structure of the human body, depending on the peculiarities of body structure, nationality, sex, and other factors, is one of the current topics of discussion among modern scientists. The purpose of the study is to establish the peculiarities of the cephalometric characteristics of the upper respiratory tract in young people without pathology of the upper respiratory tract with an orthognathic bite without and taking into account the type of face. For 72 Ukrainian young women and 46 young men with an orthognathic bite and the absence of pathology of the upper respiratory tract, taken from the database of the research center and the pediatric dentistry department of National Pirogov Memorial Medical University, Vinnytsya, determination of cephalometric parameters of the upper respiratory tract itself was carried out. The face type of young women and young men was determined using Garson's morphological index. The statistical analysis of the obtained results was carried out in the licensed statistical package “Statistica 6.0” using non-parametric estimation methods. In Ukrainian young women and young men without and taking into account the type of face, the percentile range of cephalometric parameters of the upper respiratory tract proper was established (distance PASmin – the size of the retroglossal oropharyngeal airway space, distance PM-UPW – the size of the nasopharyngeal airway space, distance U-MPW – the size of the retropalatal oropharyngeal airway space, distance V-LPW – the size of the hypopharyngeal airway space, area UAA – the size of the upper airway area). Sex differences (significantly greater, or a tendency towards greater values in young men) of distance V-LPW values were found in representatives without taking into account the face type by 13.8 %, with a wide face type – by 11.6 % and with a narrow face type – by 15.9 %; as well as the size of the UAA area in representatives without taking into account the face type by 20.6%, with a very wide face type – by 21.2 %, with a wide face type – by 21.6 % and with an average face type – by 23.1 %. Both in young women and in young men, no reliable differences or trends in the magnitude of the cephalometric parameters of the upper respiratory tract between representatives with different types of faces were established.
Advanced Statistical Optimization of Parameters at Plasma Spraying of Hydroxyapatite Coatings
Authors: Dyshlovenko S. , Pierlot C. , Tomaszek R. , Pawlowski L. , Roussel P. 
Published: September 2022

Abstract
Spray process of hydroxyapatite was optimized by an advanced statistical planning of experiments. Full factorial design of 24 experiments was used to find effects of four principal plasma spray parameters, i.e. electric power, plasma forming gas composition, carrier gas flow rate and distance of spraying onto microstructure of hydroxyapatite (HA) coatings and powders. The Nemrod software has been applied to obtain the mathematical model of influence of these parameters onto experimental response. The chosen response was the volume fraction of HA crystal phase with regard to its decomposition phases. Two most important factors influencing this response are electric power supplied to torch and art of powder injection. The crystal phase content of powders and coatings was determined using X–ray diffraction (XRD) quantitative analysis. The morphologies of coatings surfaces, cross sections were characterized using scanning electron microscope (SEM).
Effect of Steam Treatment during Plasma Spraying on the Microstructure of Hydroxyapatite (HA) Splats and Coatings
Authors: Li H. , Khor K.A. , Cheang P. 
Published: September 2022

Abstract
The major problems with plasma sprayed hydroxyapatite (HA) coatings for hard tissue replacement are severe HA decomposition and insufficient mechanical properties of the coatings. The loss of crystalline HA after high temperature spraying is due mainly to the loss of OH- in terms of water. The present study employed steam to treat HA droplets and coatings during both in-flight and flattening stages. The microstructure of the HA coatings and splats was characterized using scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffractometry (XRD). Results showed that a significant increase in crystallinity of the HA coating was achieved through the steam treatment (e.g., from 58% to 79%). The Raman spectroscopy analyses on the individual splats and coatings indicate that the mechanism involves entrapping of water molecules by the individual HA droplets upon their impingement. It further suggests that the HA decomposition has already taken place before the impingement of the droplets on pre-deposited materials or the substrate. The improvement in crystallinity and phases, e.g., from tricalcium phosphate and amorphous calcium phosphate to HA, was achieved by reversing the HA decomposition through providing extra OH-ions. Furthermore, the steam treatment during the spraying also accounts for remarkably increased adhesion strength from 9.09 MPa to 23.13 MPa.
The Influence of Thermal Treatment on Hydroxyapatite Coatings Obtained by HVOF
Authors: Fernández J. , Gaona M. , Guilemany J.M. 
Published: September 2022

Abstract
Hydroxyapatite (HAp) is known to be bioactive, i.e. able to bond to bone. This makes HAp very suitable to be applied as coatings on bone-metallic implants. In this work high velocity oxy-fuel spraying (HVOF) was used successfully for obtaining hydroxyapatite coatings on Ti-6Al-4V substrates. With optimized HVOF process parameters, coatings with similar bond strength to plasma sprayed HAp coatings, good microstructure and higher crystallinity degree than atmospheric plasma sprayed ones were obtained. As-deposited HAp coatings contains amorphous calcium phosphate (ACP) that can be crystallized by a heat-treatment of 60 minutes at 700 °C, resulting in a more stable coating when they are immersed in simulated body fluid (SBF).Coating structural characteristics of as-sprayed and post heat treated coatings were analysed with X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy analyser (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Furthermore, in vitro tests were done in order to evaluate the coating response. Surface changes were observed for as-sprayed coating but not after a post heat treatment. Moreover, the strength of the coatings were evaluated after in vitro leaching. The high degree crystallinity of the post heat treated coating improves the adhesion between the coating and the substrate after an in vitro test in a free-protein simulated body fluids (SBF). Consequently a relation between the amorphicity, the in vitro response and mechanical degradation of the coating was found.
Plasma Spraying of Hydroxyapatite Coatings Obtained from Two different Precursors
Authors: Garcia E. , Zhang Z.B. , Coyle T.W. , Gan L. , Pilliar R. 
Published: September 2022

Abstract
In this work the suitability of two different liquid precursors of hydroxyapatite (HA) as feedstock for the air plasma spray (APS) coating technique was studied and compared. The precursors were organic (calcium nitrate tetrahydrate and triethyl phosphate) and inorganic (calcium nitrate tetrahydrate and ammonium dihydrogen phosphate) sol-gel solution precursors employed in a previous work to produce thin films by a dipping technique. We report on the formation of porous hydroxyapatite coatings on Ti6Al4V substrates. The microstructures found in of both types of coatings are characterized by features typically found in solution precursor plasma spray processes; a combination of melted and unmelted deposits and small hollow spheres. Transmission electron microscopy revealed submicron/nanocrystalline features forming those deposits. Hydroxyapatite was the main crystalline phase present in the coatings. Small amount of other crystalline phases were also found due to the high temperature of the substrates during the spraying.
Gas Tunnel Type Plasma Spraying of Hydroxyapatite Coatings
Authors: Marks M.F. , Kobayashi A. 
Published: September 2022

Abstract
A crystalline hydroxyapatite (HA) coating was deposited using gas tunnel type plasma spraying at different spraying distances. In this study, the microstructure, adhesion and microhardness of the resulting coatings were investigated to clarify the effect of the spraying distance on the features of sprayed coatings. The results showed that the spraying distance greatly affects the microhardness, adhesion, and crystallinity of the sprayed HA coatings. Microhardness value was increased as the spraying distance was decreased, mainly due to the formation of dense coating with lower porosity. Adhesion was increased, as the spraying distance was decreased due to a good mechanical bonding between the first apatite layer and the substrate. X-ray diffraction patterns of HA coatings showed the formation of high crystalline apatite coating at short spraying distance.
The Role of Hydroxylapatite Coating Characteristics in Bone Integration after Two Decades of Follow-up in Human Beings
Authors: Frayssinet Patrick , Hardy Dominique , Rouquet Nicole 
Published: September 2022

Abstract
HA-coatings have been widely used in human surgery to increase the biocompatibility of metal alloys used as arthroplasty material. Their characteristics are of fundamental importance for their behaviour in the organism and in particular their degradation rate. We had the opportunity to perform histological analysis of human femurs containing well functioning HA-coated hip prostheses implanted for various periods from a few days up to several years. It was showed that the coatings exhibit degradation signs very early after the implantation and the released debris have different fates depending their size and shape. These results can be compared with those obtained in animals or in vitro. It was shown that the bone tolerate the contaminant phases which can be formed during the plasma spraying.
Investigation of Plasma Sprayed Hydroxyapatite Coatings
Authors: Levingstone T.J. , Stokes J. , Looney L. 
Published: September 2022

Abstract
The crystallinity of hydroxyapatite (HA) coatings used in femoral implant applications is a crucial factor. A coating containing a large percentage of amorphous phases will dissolve quickly. This leaves the coating mechanical weak and thus reduces its functional life. The crystallinity of the final coating largely depends on the parameters selected during the spraying process. In this study the design of experiment technique was used to investigate the parameters that have the greatest effect on the crystallinity of the coating. The effect of furnace heat treatment in air at 600°C, 700°C and 800°C on the crystallinity of the coating was also investigated. The coatings were analysed using scanning electron microscopy (SEM) and X-ray diffraction (XRD).
New Developments in Cold Spray Based on Higher Gas- and Particle Temperatures
Authors: Schmidt T. , Gaertner F. , Kreye H. 
Published: September 2022

Abstract
In cold spraying, bonding is associated with shear instabilities caused by high strain rate deformation during the impact. It is well known, that bonding occurs, when the impact velocity of an impacting particle exceeds a critical value. This critical velocity depends not only on the type of spray material, but also on the powder quality, the particle size and the particle impact temperature. Up to now, optimization of cold spraying mainly focused on increasing the particle velocity. The new approach presented in this contribution demonstrates capabilities to reduce critical velocities by well-tuned powder sizes and particle impact temperatures. A newly designed temperature control unit was implemented to a conventional cold spray system and various spray experiments with different powder size cuts were performed to verify results from calculations. Microstructures and mechanical strength of coatings demonstrate that the coating quality can be significantly improved by using well-tuned powder sizes and higher process gas temperatures. The presented optimization strategy, using copper as an example, can be transferred to a variety of spray materials and thus, should boost the development of the cold spray technology with respect to the coating quality.
Structure Formation of Ni-based Composite Coatings during Low Pressure Gas Dynamic Spraying
Authors: Maev R.Gr. , Leshchynsky V. , Papyrin A. 
Published: September 2022

Abstract
The response of Ni-SiC powders deposited by Gas Dynamic Spraying (GDS) with various particle velocities, and their compaction behavior to the different packing densities were studied in parallel. Bulk compacts (90–99% dense), made in the form of 6 mm diameter by 3 mm thick disks, were analyzed to determine the structural changes occurring within the particles and at the particle boundaries, and to examine their mechanical properties. Optical microscopy and SEM observations revealed the presence of a lamellar morphology and a strong interparticle bonding in the composite coating. An analysis of the experimental data revealed the retention of the nanoscale structure and a localized grain refinement. Adiabatic shear band areas were observed and thought to be responsible for the grain refinement. Powder layers, which were shear compacted to the packing density (up to 90% dense), showed the best densification characteristics. Correspondingly, coatings with enhanced mechanical properties and a strong exchange coupling between hard and soft phases are obtained.
Gas Dynamic Spray Composite Coatings for Iron and Steel Castings
Authors: Beneteau M. , Birtch W. , Villafuerte J. , Paille J. , Petrocik M. , Maev R.Gr. , Strumban E. , Leshchynsky V. 
Published: September 2022

Abstract
The present study was carried out to evaluate the applicability of the Gas Dynamic Spraying (GDS) of different powder compositions for depositing wear-resistant composite coatings on iron and steel castings. This process, simply known as “cold spray,” utilizes the kinetic energy of particles sprayed at supersonic velocities to produce a bonding of the particles to the substrate. Ni and Cu based coatings containing W, Zn and TiC as reinforcement were made by the low pressure GDS technique and investigated. The coatings microstructures were studied by both optical and scanning electron microscopy. Phase composition, hardness and wear resistance of the GDS coatings were analyzed. The ball-on-disc sliding wear test was used for assessing the wear resistance characteristics of the coatings using a ceramic (Si3N4) ball. W and TiC reinforced coatings showed the best wear performance. These were further evaluated in greater detail. In addition to the obtained test results, the application prospects for such GDS coatings were discussed.
Low Pressure Gas Dynamic Spray Forming Near-net Shape Parts
Authors: Weinert H. , Maeva E. , Leshchynsky V. 
Published: September 2022

Abstract
Thermal spraying processes are well known in industry for providing relatively dense components. The Gas Dynamic Spray (GDS) technologies are a growing alternative, especially after the great success of certain applications such as plasma and thermal spray formed components. One of the advantages of GDS is the possibility to obtain complex thin-walled shapes of various powder materials and composites. The optional post-spraying processes such as sintering, sizing and little machining may be applied. Using the low pressure radial injection GDS method, some new thin wall components have been formed. The process involves the automatic mechanical removal of sprayed ring components from a mould. Both the structure and properties of powdered material along with the GDS technology itself were studied. The main spraying and mould parameters were found to achieve high durability of moulds, which allowed the realization of a large scale GDS forming technology.
Kinetic Sprayed Rare Earth Iron Alloy Composite Coatings
Authors: Van Steenkiste T. 
Published: September 2022

Abstract
One of the unique advantages of the kinetic spray process is its ability to mix constituents that would normally react with each other to form coatings. We have used this attribute to produce composite coatings with different rare earth iron alloys (REFe2) and several ductile matrices. Composite coatings of Terfenol-D ((Tb0.3Dy0.7)Fe1.9) and SmFe2 were combined with ductile matrices of aluminum, copper, iron, molybdenum, tantalum, and nickel. Evidence of an induced magnetic coercivity was measured for the REFe2- Mo and Fe composite coatings. Coatings were produced on flat substrates and shafts. Coating morphology as well as the physical, magnetostrictive and magnetic properties of these coatings will be discussed.
Effect of Spraying Parameters on the Microstructure and Bond Strength of Cold Spray Aluminum Alloy Coatings
Authors: Sansoucy E. , Jodoin B. , Richer P. , Ajdelsztajn L. 
Published: September 2022

Abstract
Aluminum alloy powders of different compositions and phases, Al/B4C, Al-Co-Ce, and Al 5083, were sprayed using the Cold Spray deposition process. The resulting coatings and the effects of several process parameters were evaluated using scanning electron microscopy and bond strength tests. The results show that the bond strengths depend on the powder composition but do not vary significantly with the powder feed rate. Adhesion strength values were obtained for Al/B4C and Al 5083 coatings. The Al-Co-Ce coatings failed at the coating-adhesive interface, indicating a superior adhesion strength than what was achieved in the bond strength tests.