bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of eco-friendly composites: palm kernel shell treated with sodium bicarbonate filled recycled high-density polyethylene
Authors: Husna Nadiatul , Lim Bee Ying , Voon Chun Hong , Teh Pei Ling 
Published: December 2019

Abstract
Palm kernel shells (PKS) treated by commercial sodium bicarbonate (SB) filled recycled high-density polyethylene (rHDPE) were produced using melt compounding. These environmentally friendly composites were prepared using twin-screw extruder by varying untreated and treated filler loading (0, 10 and 30 php). In this study, the tensile properties of untreated rHDPE/PKS and treated rHDPE/PKS-SB were investigated. The composites were subjected to tensile test and the fracture surfaces were observed under scanning electron microscope (SEM). The results showed that SB treatment improved the filler-matrix adhesion and interaction of composites. Meanwhile, the SEM micrographs on the fracture surfaces confirmed that SB treatment which may influence the tensile properties of these composites.
Synthesis of SiC nanowhiskers by microwave heating: effect of size of graphite
Authors: Kahar Suhaimi Mat , Voon Chun Hong , Lim Bee Ying , Arshad Mohd Khairuddin Md , Foo Kai Loong , Parmin Nor Azizah , Gopinath Subash C. B. , Ruslinda A. Rahim 
Published: December 2019

Abstract
Silicon carbide is a promising material for various applications, especially for applications in high frequency, high power and high temperature and harsh conditions such as highly oxidative and corrosive environment. Currently, silicon carbide is produced by conventional heating process. For silicon carbide nanomaterials, various methods have been attempted. In this study, SiC nanowhiskers were synthesized by microwave heating of blends of graphite and silica in the ratio of 3: 1. Graphite of two different size, namely micro graphite and nano graphite were used. The blends firstly prepared by ultrasonic mixing graphite and silica in ethanol followed by drying. The blends were then heated by using laboratory microwaves furnace to 1450 °C at heating rate of 20 °C/min for 20 minutes. Finally, the SiC nanowhiskers was characterized by using scanning electron microscope.
Injection Moulding Recommended Parameters Simulation Analysis of Rice Husk Composite
Authors: Jaya Haliza , Zulkepli Nik Noriman , Omar Mohd Firdaus , Rahman Shayfull Zamri Abd , Halim Khairul Anwar Abdul 
Published: December 2019

Abstract
Study of recommendation parameters for injection moulding process was carried out with aid of Autodesk Moldflow Insight. Rice husk filled low-density polyethylene was used as the raw material. Standard dog- bone shape mould with ASTM were used throughout the simulation analysis. The investigations were carried out on fill analysis, fill + pack analysis and cool analysis on injection moulded dog-bone shape. From the simulation analysis, the recommended parameters of the injection moulding process for rice husk composites were determined.
Mechanical properties of Sn based lead free solder under different temperature
Authors: Ismail Norliza , Bakar Maria Abu , Jalar Azman , Jasmin Muhammad Amer Hariths 
Published: December 2019

Abstract
In this study, effect of different temperature condition was investigated towards Sn-3.0Ag-0.5Cu (SAC305) solder wire. Tensile test with 0.1 mms−1 strain rate was performed at room temperature (25°C), 60°C, 120°C and 150°C chamber condition. Mechanical properties of SAC305 solder wire were evaluated from stress-strain curves which focused on yield stress, ultimate tensile stress (UTS) and elongation. From the stress-strain curves, there are exhibit the dynamic softening behavior for investigated solder wire. The higher temperature applied during the tensile test, induced the reduction of yield stress and UTS properties. However, elongation properties varied with the temperature condition. Highest percentage of elongation have been indicated at temperature 120°C. Therefore, different temperature conditions applied during tensile test have significant effect to the evaluated mechanical properties of SAC305 solder wire.
Morphology and biodegradability of microcrystalline cellulose / chitosan films
Authors: Chie Song Cheah , Wahab Mohamad Kahar Ab 
Published: December 2019

Abstract
The microcrystalline cellulose (MCC) chitosan film was produced through solution casting with different composition of chitosan and different plasticizers. Glycerol and polyethylene glycol (PEG) was used as a plasticizer in the MCC/chitosan film. Several testing on the biodegradability were conducted such as scanning electron microscope (SEM), moisture absorption and soil burial test. Results show that addition of plasticizer able to improve the miscibility of chitosan on the MCC film. According to moisture absorbtion and soil burial test, the addition of plasticizer showed the MCC/chitosan films were better in water resistance due to the plasticizer was able to facilitate the dispersion of chitosan in MCC films. The morphological analysis also found out that better interaction between MCC and chitosan when polyethylene glycol and glycerol was used as plasticizers in the films.
Thermoplastic Polyurethane (TPU) / Organo- fluoromica Nanocomposites for Biomedical Applications: In Vitro Fatigue Properties
Authors: Osman Azlin Fazlina , Martin Darren James 
Published: December 2019

Abstract
Poly(dimethylsiloxane) (PDMS) / poly(hexamethylene oxide) (PHMO)-based thermoplastic polyurethane (TPU) nanocomposite was investigated for potential use in biomedical application. Studies on the in vitro fatigue behaviour of the TPU and TPU nanocomposite (under physiological saline solution, 37°C conditions) were highlighted in this article. The data were compared with those of commercially available silicone elastomer (Nusil MED 4860). Results indicated that the TPU nanocomposite (2MED-C (2HM)) had greater fatigue properties than the virgin TPU, which provide strong evidence of its greater capacity to withstand cyclic forces than the host TPU when exposed to physiological fluid. This was caused by the presence of well dispersed and impermeable organofluoromica platelets in the TPU matrix resulted in more tortuous path for the physiological fluid diffusion, thereby decreasing the fluid permeability of the polymer. Eventhough the silicone elastomer has lesser hysteresis than the virgin TPU and TPU nanocomposite, its fatigue strength is much lower than those of the TPU nanocomposite. The findings revealed the potential of PDMS/PHMO based TPU nanocomposite to replace silicone elastomer as biomaterial, particularly for implantable biomedical device application.
Corrosion Assessment of Sn-0.7Cu Lead-Free Solder in 1 M Hydrochloric Acid
Authors: Cong Tan Xing , Mohamad Ahmad Azmin , Nazeri Muhammad Firdaus Mohd 
Published: December 2019

Abstract
The corrosion performance of Sn-0.7Cu solder alloy is investigated in 1 M Hydrochloride acid by means of potentiodynamic polarization technique at the scan range of -2VSCE to 1 VSCE was applied to the sample at the scan rate of 1mV/s. Supporting morphological analysis was done by using Scanning Electron Microscope while phase analysis was confirmed by using X-ray Diffraction analysis. Morphological analysis showed two type of oxide layer has formed as corrosion product, which are compact oxide layer and loose rod-like oxide layer after corrosion analysis which confirmed to be SnO and SnO2. This indicate that complete protection from further corrosion was impossible due to the incomplete passivation layer formation.
Determination of the strength of the flat wagon fitting stops by elastic viscous interaction with fittings of the tank container
Authors: Fomin O , Lovska A , Bazyl L , Radkevych O , Skliarenko I 
Published: December 2019

Abstract
The article highlights the peculiarities of determining the strength of the flat wagon fitting stops, taking into account the viscous and elastic-viscous interaction with the fittings of the tank container. Mathematical modelling was performed to determine the dynamic load of the flat wagon with tank containers in the case of shunting collision taking into account elastic, viscous and elastic-viscous interaction between fittings and fitting stops. It is established that the elastic interaction does not compensate for the dynamic loads acting on the flat wagon in the case of shunting collision. Accelerations acting on the flat wagon with the tank containers do not exceed the normative values taking into account movement of the fittings relative to the fitting stops by viscous and elastic-viscous interaction. It was established that the strength of the bearing structure of the flat wagon and fitting stops is provided by viscous or elastic-viscous connections between fittings and fitting stops, taking into account the possible movements of tank containers in relation to the frame. The conducted researches will provide efficiency increase of combined transportations and develop recommendations for designing modern constructions of railway rolling stock.
Modeling the Dynamic Response of Railway Track
Authors: Kurhan D , Kurhan M 
Published: December 2019

AbstractThe authors developed a model based on the dynamical theory of elasticity, which allows us to describe the dynamic equilibrium of strains of the railway track layers. The model of the stress-strain state for the railway track consists in a combination of the geometry equations of the outline of a part in the system’s space, involved into interaction at a given time and the equations of the dynamic equilibrium of its deformation. Considering the obligation to register the course of the process in time, for each time step of integration the outline of the strains propagations front is determined. The strains propagations front is described by the equations of propagation in the material of the elastic spatial wave of oscillations. It allows determining complete spatial-temporal account of the deflection dynamics of the rail support, which enables the execution of calculations, including for conditions of fast-speed and high-speed trains. With the application of the developed model, a number of scientific and practical problems were solved.
Synthesis of quasioptimal control of the technical systems with the direct current drive
Authors: Loveikin V S , Romasevych Yu O , Korobko M M 
Published: December 2019

Abstract
The paper presents an approximate solution of the optimal control problem of the technical system driven by the direct current motor. The braking mode of the system is under consideration. The optimization criterion was a nonlinear integral functional, which reflects the root-mean-square value of the electric drive power during the system’s braking mode. It was found, that the necessary condition of the criterion minimum – Euler-Poisson equation – is a sixth-order nonlinear differential equation. It is impossible to find its analytical solution. In order to find the approximate solution a direct variational method was applied. Proper selection of the class of the basis functions allowed to reach the absolute minima of the terminal criteria and meeting the boundary conditions of the system’s movement. The first provides decreasing of the dynamical forces in the system transmission; the latter is connected with the statement of the problem. Among the class of functions, the one was found, which minimizes the integral criterion. In order to illustrate the approximate solution of the optimal control problem, the plots have been built. They show the smoothness of the system movement and practicability of the obtained result. All calculations have carried out in an analytical form.
Predictive assessment of change of basic geometric characteristics of rail track during the operation
Authors: Potapov D O , Vitolberg V G , Malishevskaya A S , Plis P V , Trishchun R M 
Published: December 2019

Abstract
The frequency and scope of scheduled preventive work depends on multiple factors: type and design of the upper track structure, plan and profile of the track, quality of the track maintenance, as well as operational, climatic and topographical conditions. Also, each type of work is affected by these factors in different ways. In addition, the factors themselves are unstable along the length of the track. Therefore, under different operating conditions, the frequency and scope of routine track maintenance are different. Since currently regulatory technical documents and domestic scientific sources contain no requirements for high-speed sections of the Ukrainian railways and, thus, a problem of organization of control of the track state in these operating conditions appears. The methodology for determining the scope and frequency of the scheduled preventive routine track maintenance work is proposed. The method is based on the use of the normal law of distribution of frequency and depth of the respective geometrical irregularities of the railway track. The maximum effect of the proposed method can be achieved through the use of modern track geometry cars with an automated data collection and interpretation system that are predominantly used in the high-speed traffic areas.
Determination method of dynamic characteristics of mobile terrestrial robotic complex manipulator
Authors: Strutynskyi S V 
Published: December 2019

Abstract
A method for determining the dynamic characteristics of the mobile terrestrial robotic complex manipulator is developed. A new concept for finding dynamic characteristics is proposed. It involves determining the manipulator displacement during its “quasi-rigid” movement along with the chassis along the road surface with isolated inequality through a rectangular projection. The manipulator is considered to be undeformed and its position relative to the chassis unchanged. Having considered “quasi-rigid” displacement of the manipulator, the dynamic loads acting on it are defined. At the same time, dynamic deformations of the manipulator corresponding to the “deformation” movement of the manipulator elastic system relative to its position corresponding to the “quasi-rigid” displacement are considered. Based on the proposed concept, a method for determining the dynamic characteristics of the manipulator was developed. It involves the development of a mathematical model of the manipulator when presenting it through a multi-mass dynamic system. The system of dynamics equations is presented as a structural mathematical model by means of which the dynamic characteristics of the manipulator corresponding to the robotic complex displacement along the road with a single irregularity are found. The coefficients of dynamic loads in the elastic system of the manipulator are determined by simulation.
Research into the track/vehicle interaction processes for underground railways
Authors: Vitolberg V G , Bugaets N V , Malishevskaya A S , Shumyk D V , Yakovenko Y S 
Published: December 2019

Abstract
The article deals with determination of dynamic forces in interaction between a rail vehicle and underground track for working out recommendations in terms of a longer service life of the permanent track without extra charges. The issue is of importance for enterprises under limited resources. The research was conducted with mathematical model methods for the vehicle/track dynamic system (the principles were developed earlier), as the experimental work in the underground tunnels was complicated by intensive train traffic during a day. A special feature of the research was consideration of a rail as a bar rested on discrete elastic-dissipative supports in a design diagram of the vehicle/track dynamic system. Thus, the authors established the effects of unequal elasticity of the track rail support on the value of vertical dynamic forces when a metro coach moves on the track. In particular, the dependencies of dynamic factors and amplitude ratios of vertical forces on speeds of metro coaches along the discrete elastic- dissipative track were obtained. An exceptional value of the research is consideration of both vertical and horizontal lateral forces on the vehicle/track interaction. It allowed the authors to define the value of vertical and horizontal lateral forces which occurred when metro coaches moved along straight and curved sections of the track according to the speed and curve radius.
Theoretical analysis of RC beams reinforced with high strength rebar’s and steel plate
Authors: Bobalo Taras , Blikharskyy Yaroslav , Kopiika Nadiia , Volynets Mykhailo 
Published: December 2019

Abstract
The article introduces the comparative results of the deformability and fracture resistance of steel reinforced concrete beams with combined reinforcement obtained on the basis of laboratory tests with the results of computer-aided mathematical modelling of such structures. The results were compared for the purpose of mathematical model testing and its further usage in the study of the optimal reinforcement percentage in steel reinforced concrete beams with combined reinforcement. Results obtained on the basis of the proposed mathematical model show sufficient correlation with the experimental data up to the stage of structure strength exhaustion. As the result it enables to evaluate the features of destruction of the tested samples with the sufficient accuracy, namely, their load-carrying capacity, cracks formation, to analyze stresses in both steel bars and tapes, monitor deflections and deformations during the loading of the tested beams. Deviation of the experimental values for steel reinforced concrete beam with the combined reinforcement from the data obtained according to mathematical model: up to 5.0% for fracture resistance; up to 14.3% for deformability.
Influence of load level during strengthening of reinforced concrete beams on their reliability
Authors: Khmil Roman , Tytarenko Roman , Blikharskyy Yaroslav , Vashkevych Rostyslav 
Published: December 2019

Abstract
The main purpose of article is to study the influence of load level on the reliability of non-damaged reinforced concrete beams with rectangular cross-section during strengthening by adding stretched steel reinforcement. On the basis of real samples testing of the existing and advanced methods of reliability estimation (depending on the variant of random parameter of the load level at the strengthening moment), adapted to the national norms of reinforced concrete structure design, the recommended value of failure-free probability P(β) – within ranges 0.999624-0.999758 and 0.999606-0.999775 (for two of considered variants, respectively). The comparative analysis of obtained results is conducted depending on the additional steel bar diameter (Ø10 mm, Ø12 mm, Ø14 mm) and load level at the strengthening moment (0.0×Mult, 0; 0.3×Mult, 0; 0.5×Mult, 0; 0.75×Mult, 0, where Mult, 0 is bearing capacity of non-strengthened beam). Practical utility of the study results could be associated with the possibility of usage both existing as well as developed methodology to evaluate reliability for design of bended reinforced concrete elements, strengthened with additional stretched steel rebar subjected to load (simulation of the actual element performance during strengthening), especially in the case of proving reliability levels of its design.
Theoretical calculation method for crack resistance of jacketed RC columns
Authors: Krainskyi Pavlo , Vegera Pavlo , Khmil Roman , Blikharskyy Zinoviy 
Published: December 2019

Abstract
Theoretical method of crack width calculation in jacketed reinforced concrete columns is described and validated in this paper. The total number of tested columns was 12. The initial load applied to the column before strengthening was the main variable parameter in this test. Columns were strengthened by reinforced concrete jacketing after loading. Two RC columns were tested without strengthening to serve as reference samples. Two RC columns were strengthened with RC jacketing without any initial loading to determine maximum strengthening effect. Loading was applied in steps. This study is the calculation of the crack resistance parameters RC columns, strengthened by RC jacketing under the influence of various initial loads. Crack width and pattern were checked after each step. The maximum allowed crack width for test samples was adopted as wmax
= 0.3 mm. The rest eight samples were preliminarily loaded to 0.3; 0.5; 0.7 and 0.9 of reference columns bearing capacity, strengthened and tested to failure. The results of theoretical calculation deviate from test results by 13.6…27.9%.
Exact solution of buckling problem of the column loaded by self-weight
Authors: Krutii Yu , Vandynskyi V 
Published: December 2019

Abstract
This work proposes the new method of investigation the buckling problem of the uniform column under the axial distribution load, which presented by self-weight. The new method is based on the exact solution of the appropriate differential equation for the buckling of a column. The solution is expressed with dimensionless fundamental functions and initial parameters. Due to the exact solution, the formulas in an explicit form for variables of the state of a column – deflections, angular displacement, bending moment and transverse force – were defined. They generally define the stress-strain state of the column Due to the dimensionless nature of the fundamental functions the analytical form of load is defined. That has limited the problem of determination of critical load to determination the unknown non-dimensional buckling coefficient through characteristic equation. An example of determining the buckling coefficient for a hinged column was considered. The values of buckling coefficient for most popular design schemes are given. The proposed method does not require discretization od scheme and is a real alternative to applying approximate methods when solving stability problems of this class.
Stability of light steel thin-walled structures filled with lightweight concrete
Authors: Semko V O , Mahas N M , Fenko O G , Sirobaba V O , Hasenko A V 
Published: December 2019

Abstract
The article presents the results of stability calculation of reinforced concrete columns using light steel thin-walled structures investigation. Two steel thin-walled profiles of type “C” or “∑” were used as the steel shell of such columns. The profiles were combined in the form of a box section with bolts. To increase the stability of the shell, the inner cavity was filled with concrete with lightweight aggregates. Technique of steel thin-walled elements stability calculation with consideration of concreting and joint work of the whole structure involves two types of calculation: for central compression and for joint action of compression and uniaxial bending. To verify the analytical calculations, a computer simulation was performed, which proved the correctness of the theoretical calculations and made it possible to clearly observe the different forms of column stability loss at different coefficients of overload. It was found that the increase of bearing capacity due to the thickness of the profile varies within 2-10%. For smaller profiles this difference is significant (10-23%), and for larger profiles - smaller (5-8%). This is due to the complexity of the manufacturing technology and the cost of materials.