bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assembling Components with Probabilistic Lead Times
Authors: Yassine Noura , El-Rabih Silvana 
Published: May 2019

Abstract
This paper examines a production model in which N different types of components are used to assemble a finished product. The components are acquired from various suppliers in lots received at or before the beginning of the assembly process. The lead time between placing and receiving each of the N orders is assumed to be a random variable having a known probability density function. Based on recent results regarding the probability distribution and the expectation of the maximum of a set of independent random variables, the mathematical model describing this production/inventory situation is developed. The mathematical model is then used to derive a closed form formula for the optimal solution that minimizes the total production/inventory cost function. Moreover, the reorder point is shown to depend on the probability distribution and expected value of the random variable representing the maximum among the N lead times. The case in which each of the N lead times follows a Weibull distribution is investigated, and a numerical example is given to illustrate this case.
Improvement of the fretting wear resistance of Ti6Al4V by application of hydrostatic ball burnishing.
Authors: Swirad S 
Published: May 2019

Abstract
The objective of the research was to improve the fretting wear resistance of titanium alloy by hydrostatic ball burnishing. Ball burnishing is an economic surface finishing process for wide range of components. It is based on pressing and rolling a hydraulically floated ball along the surface of the component being treated, to plastically deform surface asperities. This process generates a deep field of compressive residual stresses (up to 1.0 mm) in the outer layers of the component. The compressive residual stresses and the high quality of the surface finish improve the wear resistance of the part. Experiments were made using ball-on-disc tribotester in oscillatory motion. 100Cr6 sphere co-acted with a disc made of titanium alloy Ti–6Al–4V. The friction force was monitored as a function of time during the test. Wear of disc was measured after the test using the non-contact 3D surface profiler. The optimal ball burnishing parameters have been determined after conducting the Taguchi L9 matrix experiment. During tests, normal load was kept constant at 50 N within the contact with frequency of 50 Hz and displacement amplitude of 0.02 mm. The results confirmed that hydrostatic ball burnishing had a significant influence on friction and wear.
Slope stability analysis using modified Fellenius’s and Bishop’s method
Authors: Zolkepli M F , Ishak M F , Zaini M S I 
Published: May 2019

Abstract
Analysis of slope stability is very important as many structures in hilly areas failed due to instability of slope. The aim of this study is to determine the factor of safety (FOS) of slopes located at Pahang Matriculation College by using limit equilibrium method. Two methods known as modified Fellenius’s method and modified Bishop’s method are used in this study. Laboratory testing involving index and engineering properties are conducted to determine the properties of soil within the study area. The soil at Pahang Matriculation College can be classified as sandy SILT with high plasticity. From the analysis, the FOS values for two slopes in saturated soil conditions (0 kPa suction) are between 1.262-2.885 when using Bishop’s method which are higher compare to 1.199-2.688 when using Fellenius’s method. The percentage differences of FOS between these two methods are between 5.25% to 7.33%. For slopes in unsaturated conditions (20 kPa suctions), the FOS are between 1.550-3.702 when using modified Bishop’s method which always higher compare to 1.492-3.507 when using modified Fellenius’s method. The percentage differences of FOS are between 3.89% to 5.56%. The relative accuracy of Bishop’s method is due to it consider only the vertical equilibrium of each slices and there is no need to consider the horizontal components of the interslice forces without introducing serious error in the FOS value.
Effect of marble dust and steel slag on consistency limits and compaction characteristics of lateritic soil
Authors: I. Adedokun Solomon , A. Ganiyu Abideen , A. Adedokun Mujeeb 
Published: May 2019

Abstract
Engineers are faced with the problems of providing very suitable materials for highway and other foundations construction. Lateritic soils are highly weathered indigenous soil available in large quantities but generally need improvements to adequately satisfy the required construction purposes. This research investigates the influence of steel slag and marble dust addition on some geotechnical properties of lateritic soil. The results revealed that the soil is well graded based on particle size distribution and is classified as A-2-5 under AASHTO system. With progressive increase in each stabiliser, both the liquid limit, plastic limit and plasticity index exhibit fluctuating patterns. In addition, both marble dust and steel slag increased the maximum dry density with increasing proportions in the soil sample but exhibit irregular patterns for optimum moisture content. This research provides an insight to the quality of lateritic soils obtainable in the study area, and the level of improvements required before they are suitable for road construction.
Load-deformation analysis on a slope at Gunung Pulai water treatment plant, Sultan Ibrahim Reservoir
Authors: Azman K , Mushairry M , Ahmad Safuan A R , Mohd Hanim O , Izni Syahrizal I , Mohammadreza V , Sophia C A , Mohd Azreen M A , Rini Asnida A , Radzuan S , Muhammad Azril H , Nur Asmawisham A Mohd , Mohd For M A , Sahrul Nizam T , Afif A R , Kamrul Zaman K , Hairul Hairi H , Zulkifly A W , Ismail D S A , Muhammad Fateh M A R 
Published: May 2019

Abstract
The Sultan Ibrahim Reservoir located at Gunung Pulai catchment area was previously managed by the Singapore’s Public Utilities Board before the Board handed over the reservoir to Johor State Government under current management of the Syarikat Air Johor. At the present time, the Syarikat Air Johor is operating a Gunung Pulai Water Treatment Plant consisted of two main plants, i.e. Water Sedimentation Plant and Water Filtration Plant for treating raw water from the reservoir before supplying to the consumers. However, the integrity of water treatment plant’s structure should be checked due to several cracks were observed, and moreover the structure was built over more than 90 years. The formation of the cracks in the Gunung Pulai Water Treatment Plant may be induced by movement of the sloping area to the south-east of Water Sedimentation Plant. The calculated Factor of Safety (FOS) via sensitivity analysis for cross sections of original slope indicates any decrease in friction angle and/or cohesion strength or increase in horizontal seismic load will further cause instability on slope. Also, the results of Load-Deformation analysis on cross sections of original slope show significant vertical displacement and horizontal displacement on the bottom and both sides of sedimentation tanks, respectively. The results indicate applied structural and water loads significantly affect deformation at both vertical and horizontal directions which could have contributed to FOS < 1 in slope stability analysis.
Numerical simulation of rock fragmentation by blasting using Discrete Element Method and Particle Blast Method
Authors: Shahrin Muhammad I. , Abdullah Rini A. , Jeon Seokwon , Jeon Byungkyu , Sa’ari Radzuan 
Published: May 2019

Abstract
Blasting is common activity used in quarry to fragment rock which the aim is to obtain maximum yield with desired fragmentation in a safer manner. This study has opened up new possibilities to optimize the blasting in order to achieve the desired fragmentation of rock. Discrete element method (DEM) and particle blast method (PBM) approach was used to investigate numerically the response of rock fragmentation induced by blasting. The numerical simulation performed in this study using the commercial software LS-DYNA. Calibration of the micro-parameters in bonded particle model (BPM) of rock has been conducted. In bench blasting simulation, DEM was used on the modelling of rock media, where PBM was used to simulate the blast loading which capable of modelling thermally non-equilibrium system. This numerical analysis is compared to rock fragment distribution fieldwork data. It shows that DEM-PBM simulation could reproduce the trends observed in fieldwork rock fragment distribution. Comparison between fieldwork data and numerical analyses is presented and discussed.
Compaction characteristics of Bangkok clay stabilized using rice husk ash, bottom ash, and lime
Authors: Eisazadeh A , Bhurtel A , Phai H 
Published: May 2019

Abstract
Amount of waste is becoming increasingly undesirable as human population increases day by day. For this reason, recycling wastes produced in different industries and thus lowering their quantities is one of the main focuses for researchers. Soil stabilization using waste by-products especially in road projects that require large amount of earth materials are currently popular and the successful utilization of these wastes can have positive impact on the environment. This can also reduce the construction costs significantly. Bangkok Clay is a well-known soil in Thailand that can possess poor engineering properties and hence there is a need for its improvement. Among all different kinds of waste, rice husk ash (RHA) and bottom ash (BA) are among the cheap materials that are produced in high volumes annually in Thailand and have the potential to be considered as replacement for earth materials. Lime has also been used in this study as common traditional binder in clayey soils that produces the cementitious materials via pozzolanic reaction with materials that are rich in silica and alumina. One of the main steps of construction in road projects is the compaction of stabilized materials which requires the preliminary collection of data from lab performed compaction tests. In this paper, the compaction characteristics of RHA- and BA-Bangkok clay mixtures with lime as a binder were studied. The results show that the MDD reduces and OMC rises with respect to increase in the ash content. Furthermore, the mix designs with RHA are more sensitive to the ash content. Bottom ash mix designs show higher MDD than rice husk ash-soil mixtures and have more potential to be used in road projects based on the compaction characteristics.
Identifying suitable sites for pump irrigation system from open source and shallow tube well in selected areas of Davao Del Sur through geographic information system-based water resources assessment
Authors: Trondillo M J F , Generallao I C , Valleser R A R , Lopez M T , Janson A Z , Bejarasco J A , Toriales I R 
Published: May 2019

Abstract
This paper features the Geographic Information System (GIS) in identifying suitable sites for small scale irrigation projects (SSIP) particularly pump irrigation system from open source (PISOs) and shallow tube well (STW) through water resource assessment. The development of GIS-based assessment model for SSIP and resource map in aid of SSIP planning and development is limited in some municipalities. To develop a reliable GIS-base framework, the ArcGIS tool and spatial method was used in compiling specific factors with field analysis and developing regional resource map for SSIP. The results showed that STW in Digos City and Municipality of Hagonoy is 117 units and 17 units respectively. The average water depth in existing STW is within the 6.5 meters with capacity to irrigate 3 to 5 hectares per unit, low investment with high water use efficiency and simple to operate. It was found out that most STW is provided by Department of Agriculture-Regional Field Office XI and Local Government Units. The STW is suitable for Digos City with an area of 379.32 hectares. While the PISOS were identified with different range of pump horsepower. There are 10 units of PISOS in Digos City and 15 units in Hagonoy mostly provided by National Irrigation Administration-XI. It was found out that in Digos City the 1,855.53 hectares are highly suitable and 14,377.55 hectares are not suitable for PISOS. The results of this study may assist the decision making processes for planning and development of SSIP using the developed protocol and tools for different purpose in agricultural production in Davao del Sur, Region XI and the whole country.
Physical properties of warm cup lump modified bitumen
Authors: Abdulrahman S , Hainin M R , Idham M K , Hassan N A , Warid M N M , Yaacob H , Azman M , Puan O C 
Published: May 2019

Abstract
Despite the several benefits of modifying bitumen with polymer; it is increasingly becoming difficult to ignore concerns about its high energy consumption and fume emissions during asphalt production. Previous studies found on natural rubber (NR) modified binders applied it as a hot mix asphalt (HMA), however in recent years there has been increasing interest in warm mix asphalt. This research explores the possibility of applying NR in warm mix asphalt (WMA) by comparing the physical properties of cup lump rubber modified bitumen with and without warm mix additive. Four percentages (2.5%, 5.0%, 7.5% and 10%) of Cup lump rubber (CLR) was used to modify 60/70 penetration grade bitumen, while three percentages (0.3%, 0.4%, and 0.5%) of Evotherm chemical was added to produce warm cup lump modified bitumen (WCMB). Storage stability, penetration, softening point, viscosity, ductility, and elastic recovery tests were conducted to determine the effect of CLR and Evotherm. The results show that storage stability and viscosity of the cup lump modified bitumen heavily depends on the CLR content. While a positive correlation exists between the increase in binder stiffness with increasing mixing and compaction temperatures. The addition of 0.5% Evotherm reduces the viscosity by 14%. Contrary to expectations, CLR was found to reduce the ductility of the bitumen while the presence of Evotherm in the blend increases the softening point. The use of warm NR modified bitumen in road construction is expected to lower the asphalt production temperature, carbon emission and cost without compromising the performance of the mix.
Dielectric measurement of bitumen: A review
Authors: Adamu I A , Aziz M M A , Yeow Y K , Mohd Jakarmi Fauzan , Arifuzzaman  
Published: May 2019

AbstractBitumen is a rheological, viscoelastic, thermoplastic and extremely complex material that has hydrocarbons as its predominant molecules with slight traces of others. Bitumen is semi-solid at room temperature, liquid at high temperature and solid at a very low temperature. Till date, a complete understanding of its properties have not been fully known. Various techniques/methods have been developed by many researchers to study the behavior of this complex material. Most of the techniques are proved to be effective in evaluating some of the properties but very costly. This paper presents a review on some of the work conducted on investigating the behaviors of bitumen using microwave technique. This technique has been shown to be simple, less time consuming and cost-effective in evaluating both physical and rheological properties of bitumen when compared with other techniques.
Performance of rutting, stripping and cracking of warm mix asphalt
Authors: Naqibah S. N. , Hainin M. R. , Idham M. K. , Warid M. N. M. , Hassan N. A. , Mohamed A. , Puan O. C. , Ismail C. R. 
Published: May 2019

Abstract
Hot Mix Asphalt (HMA) is a conventional mixtures and widely used in Malaysia. Emissions of Carbon Dioxide (CO2) during production of HMA due to high temperature give bad impact to the environment. During construction, cool weather is one of the factor that will easily influence the HMA mixtures where it will cause the reduction of temperature during compaction. This factor will affect the compaction process for the pavement which the most important part for road construction. It will reduce the density of the pavement and also the strength which cause shorter life span, rutting, cracking and stripping. Therefore, in this study, Warm Mix Asphalt (WMA) is one of the methods to overcome these issues. This study investigated the performance WMA in term of rutting, cracking and stripping incorporating different percentages of additives namely Evotherm (ET) and Evoflex (EF) with 0.3%, 0.4% and 0.5% by weight of bitumen. These additives were used to lower the mixing and compaction temperature of asphalt mixture. Asphalt mixture with nominal maximum aggregate size 14 mm (AC 14) with 5.3% optimum bitumen content were used in this study. The optimum additive content was evaluated based on the Marshall, Modified Lottman, Indirect Tensile Strength (ITS), and Asphalt Pavement Analyser (APA) tests. The results revealed that 0.4 % ET and 0.3 % EF additives were considered as optimum additive content. Both 0.4 % ET and 0.3 % EF gave better performance in stripping and rutting resistance. However, in cracking performance, 0.4 % ET was more susceptible in cracking compared with 0.3 % EF.
Implementation of chosen risk index during car-following behaviour under wet weather condition
Authors: Shariff M. , Puan O. C. , Mashros N. , Mohamed A. , Hassan N. A. , Ismail C. R. , Hainin M. R. 
Published: May 2019

Abstract
This study aims to examine the effects of wet weather on accident consequence during car-following behaviours. The study analysed drivers’ car-following headway on two-lane highways along passing and no passing zones associated with passenger cars and heavy goods vehicles (HGV). The speed and time gap of more than 200,000 vehicles were recorded during dry and wet weather at 4 specific sites in Peninsular Malaysia using Automatic Traffic Counter with pneumatic tubes. Rainfall data were acquired from the nearest rain gauge station. Chosen Risk Index (CRI) was used to characterize and evaluate the accident consequence caused by wet weather incidence. The results disclose that the drivers are more cautious to avoid accident severity during wet weather compared to dry weather irrespective of vehicle type and highway features. This result is evidenced by lower CRI values during wet weather compared to dry weather. The data shows that under wet weather condition the speed that gives lower risk of accident is in the range of 47.3 to 73.9 km/h and 56.5 to 74.0 km/h i.e. which associated with CRI values in the range of 0.60 to 0.75 and 0.53 to 0.79 at passing and no-passing zones, respectively. These findings are useful for the improvement of roadway design and the implementation of traffic safety interventions.
Phase field study of spacing evolution during wire and laser additive manufacturing under transient conditions
Authors: Wang Zheng , Jing Tao , Dong Hongbiao 
Published: May 2019

Abstract
Understanding the dynamic evolution of primary dendritic spacing in the laser melt pool is significant from a technological viewpoint because primary spacing is one of the foremost parameters that control the final mechanical properties of additive manufactured products. In this work, a multi-scale computational framework that couples FEM and a developed quantitative phase field method is employed to simulate the evolution of microstructure and primary spacing of a nickel-based superalloy during wire and laser additive manufacturing (WLAM) solidification. Transient conditions in the laser melt pool are considered in which both temperature gradient G and solidification speed VP
are made time-dependent. Through the use of this model, the dendritic morphology, tip velocity and spacing evolution during the solidification are investigated to provide the relationship between the laser processing parameters and the final spacing. Moreover, we attempted to clarify the intrinsic mechanism of spacing adjustment under different laser processing parameters from a novel perspective. This work provides meaningful understanding of spacing evolution in nickel-based superalloy and demonstrates the potential of controlling the complex microstructure morphologies and final primary spacing during wire and laser additive manufacturing process.
Prediction of Carbide Precipitation Using A Combined Partial Equilibrium - Para-Equilibrium - Lever Rule Approximation in Automobile Gear Materials
Authors: Zhang Hongwei , Nakajima Keiji , Su Mengmeng , Gao Shaoshao , Lei Hong , Wang Qiang , He Jicheng 
Published: May 2019

Abstract
The carbide precipitation nature of an automobile gear material, i.e. Fe-C-Mn-Si-Cr-Mo alloy, during carburization and element addition process are investigated through PE+PA+LR prediction. Results show that, carburization process greatly increases the amount of cementite as well as the hardness index at the surface part. Besides, the addition of Ti and V helps to formation of TiC and (V, Mo)C carbides but suppress the precipitation of cementite, which contributes equivalent hardness at surface and lighter weight to the alloy.
Kinetics of rapid crystal growth: phase field theory versus atomistic simulations
Authors: Galenko P K , Salhoumi A , Ankudinov V 
Published: May 2019

AbstractKinetics of crystal growth in undercooled melts is analyzed by methods of theoretical modeling. Special attention is paid to rapid growth regimes occurring at deep undercoolings at which non-linearity in crystal velocity appears. A traveling wave solution of the phase field model (PFM) derived from the fast transitions theory is used for a quantitative description of the crystal growth kinetics. The “velocity – undercooling” relationship predicted by the traveling wave solution is compared with the data of molecular dynamics simulation (MDS) which were obtained for the crystal-liquid interfaces growing in the 〈 100〉-direction in the Ni50Al50alloy melt.
Semi-grand canonical Monte Carlo simulation for derivation of thermodynamic properties of binary alloy
Authors: Ueno Kensho , Shibuta Yasushi 
Published: May 2019

Abstract
Semi-grand canonical Monte Carlo (SGCMC) simulations are performed to derive thermodynamic properties of binary alloy from atomistic-based simulations. Particularly, solidus and liquidus compositions are directly derived for Fe-Cr alloy described by two different EAM potentials. Although the SGCMC simulation can derive relationship between the free energy and composition at any temperature straightforwardly, partial phase diagram obtained from SGCMC simulations strongly depends on the choice of interatomic potential.
Analysis of columnar-to-equiaxed transition experiment in lab scale steel casting by a multiphase model
Authors: Sachi S. , Založnik M. , Combeau H. , Gandin Ch.-A. , Gennesson M. , Demurger J. , Stoltz M. , Poitrault I. 
Published: May 2019

Abstract
Correct prediction of composition heterogeneities and grain structure across a steel ingot is critical in optimizing the industrial processing parameters for enhanced performance. The columnar to equiaxed transtion (CET) is a microstructural transition which is strictly controlled as it affects the mechanical properties of the final product along with the macrosegregation patterns. Larger equiaxed regions are preferred for most industrial applications. CET is significantly affected by the number density of equiaxed grains and by the nucleation undercooling. 8 kg 42CrMo4 alloy steel ingots (240 mm x 60 mm x 60 mm) were cast. The cast structure was characterized by ASCOMETAL. The experiments were simulated with a process-scale model of solidification that incorporates a multiscale description of the microstructure formation. The goal of the present study is to show the capabilities of such a process-scale solidification model to explain the observed structure distributions (extent of the columnar and equiaxed zones, equiaxed-to-columnar transition).