bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Al2O3 nanoparticle additives on the performance characteristics of rough journal bearings
Authors: Gunnuang Waleephan , Aiumbhornsin Chatchai , Wongsa-Ngam Jittraporn , Mongkolwongrojn Mongkol 
Published: May 2021

Abstract
This paper investigates the influence of Al2O3 nanoparticle additives on static and dynamic characteristics of water-lubricated rough journal bearings under thermo-hydrodynamic lubrication (THL). The time-dependent modified Reynolds equation and the approximated adiabatic energy equation have been formulated and solved numerically with boundary conditions and initial conditions. The results are presented for dimensionless maximum film pressure, dimensionless maximum film temperature, dimensionless minimum film thickness, eccentricity ratio, attitude angle, dimensionless friction force, spring constants, damping coefficients and mass parameters for both journal bearings with transverse roughness patterns and with longitudinal roughness patterns under a dimensionless load of 7. The results show that journal bearings with Al2O3 nanoparticle additives tend to significantly increase load carrying capacity and minimum film thickness by decreasing both the eccentricity ratio and temperature rise for longitudinal roughness patterns. For journal bearings with longitudinal roughness patterns and lubricated with Al2O3 nanoparticle additives, the stability region tends to increase.
Comparison of two different surface for rolling airless tire by finite element method
Authors: Suvanjumrat Chakrit , Rugsaj Ravivat , Phromjan Juthanee 
Published: May 2021

Abstract
Drum testing was carried out to determine rolling tire performance. The finite element method was used to model the drum testing instead. In order to yield accurate results, the generalized Maxwell’s viscoelastic material model with hyperelastic material model was employed to simulate the drum testing on the airless tire. However, it consumed a lot of simulation time because of the contact surface between tire and drum was difficult to compute by using a finite element method. The finite element model of rolling an airless tire on a flat surface was developed. The contact patch and spoke deformation were carried out to investigate the surface effects. The spoke deformation of rolling an airless tire on a flat surface was found to be in accord with the curvature surface of the drum. The flat surface showed little difference in the contact area against the drum. Particularly, it was found that the analysis time of rolling an airless tire on a flat surface was less than the drum 10.13 times.
Development of a herbal cream mixer with a homogenizer-stirrer and circulating water cooling system
Authors: Suttibak Suntorn , Deesapa Kamonrat , Saengmanee Chayarnon , Chuntanapum Athika 
Published: May 2021

Abstract
This paper presents a study on the development of a herbal cream mixer with a homogenizer-stirrer and circulating water cooling system. The machine is designed to address problems in the production of herbal creams and lotions by the entrepreneurs of the Thangrak Company Limited, Chiang Yuen Sub district, Muang District, Udon Thani, Thailand. It has a capacity of around 100 liters and employs a circulating water-cooling system. The homogenizer uses a 3-horsepower electric motor to control the rotation speed of the stirring head, which in turn controls the mixer speed. The level of the machine is adjusted using an electric hoist. Cream was produced in 80 liter batches. Mixer speed was tested at four levels: 30 Hz (1,800 rpm), 35 Hz (2,100 rpm), 40 Hz (2,400 rpm) and 45 Hz (2,700 rpm). The total time of each run was approximately 30 minutes. The results showed that a temperature reduction of the ingredients from an initial temperature of around 70°C down to approximately 33°C. The process took around 1 hour and 30 minutes. From the experimental results, it was found that the product made at 1,800 rpm had a lower viscosity of around 78.4 Pa.s. The cream of this batch was not as homogenized as it should have been. However, tests at 2,100, 2,400, and 2,700 rpm produced a creamy material with increased viscosities of 94.3, 94.8 and 96.7 Pa.s, respectively. The herbal cream products made in the developed mixer with homogenizer-stirrer and a circulating water-cooling system were homogenous. They compared favorably with herbal cream products sold in the market. The designed mixer produced a cream product that is more homogenous, while the products now available on the market have separated cream and are not as well homogenized.
Numerical study on bending response of auxetic 2D-lattice plates
Authors: Suttakul Pana , Fongsamootr Thongchai 
Published: May 2021

Abstract
In this study, the bending response of 2D-lattice plates having auxetic unit cells is determined by using the homogenization method based on equivalent strain energy. The auxetic unit cells in this study are different topologies of re-entrant hexagonal unit cells. In the homogenization method, the effective out-of-plane elastic properties of an auxetic 2D-lattice plate are obtained from the strain energy values of its unit cell under different curvature modes, determined by the finite element method. In the analysis, the auxetic unit cells are considered as frames whose struts are modeled as Euler beams. The effective elastic properties, i.e., the effective bending moduli, Poisson’s ratios, and shear modulus, are described as the bending response of a 2D-lattice plate subjected to out-of-plane bending. In the validation, the effective elastic properties of some auxetic 2D-lattice plates obtained from their unit cells by the homogenization method are numerically compared with those obtained from direct structural analysis of the plates. Besides, the obtained results show how the bending response of the auxetic 2D-lattice plates can be adjusted by varying their unit-cell geometries, especially the internal cell angle.
Effect of carbon content on microstructure and mechanical properties of sintered Fe-Mo-Mn-C alloys
Authors: Wanalerkngam A. , Boonmee S. , Krataitong R. , Morakotjinda M. , Pongsak W. , Tosangthum N. , Tongsri R. 
Published: May 2021

Abstract
Sintered Fe-Mo-Mn-C alloys were produced by sintering of mixtures of pre-alloyed Fe-0.5Mo-0.15Mn powder and varied carbon amounts (0.30-1.20 wt.% with 0.15% increments) followed by slow cooling in furnace. Microstructures and mechanical properties of the sintered alloys varied with added carbon content. With up to 0.75 wt.% carbon additions, the sintered alloys exhibited polygonal ferrite plus non-cooperative eutectoid decomposition products. With 0.90 wt.% carbon addition, the whole microstructure of the sintered alloy mainly consisted of non-cooperative eutectoid decomposition products. With 1.05 and 1.20 wt.% carbon additions, the microstructures of the sintered alloys consisted of large grain boundary carbides and mixed non-cooperative and cooperative eutectoid decomposition products within grains. Tensile strength showed the maximum value in the sintered alloy with 1.05 wt.% carbon addition. Elongation values decreased sharply with increasing carbon contents of up to 0.60 wt.%, beyond which the values were constant.
FEM model of protection bullet helmet made from composite material.
Authors: Promma R. , Phongphinittana E. , Nimdum P. 
Published: May 2021

Abstract
Damage evolution, mechanical behaviour, energy absorbtion, back-face deformation (BFD) and the perforation performance of Kevlar epoxy woven composite with and without foam (PU foam) were examined for various impact energies based on the drop weight test. The Kevlar woven composite induces different damage and deformation depending on its hybrid patterns. The Kevlar composite with PU foam decreases significantly, and the BFD of shell composite and transform locally deformation become a global nature. In addition, damage type - as fibres break - is primary dominant for Kevlar composite without PU foam. However, the role major damage as delamination, significantly appear for Kevlar composite with PU foam. In order to investigate the damage mechanism, energy absorbtion and BFD, FEM simulation were also performed. The FEM simulation is in very good agreement with the drop weight test. Finally, the FEM study showed that PU foam is able to decrease significantly, the BFD of composite shell, and the contact force on the skull, during ballistic impact.
The study on the characterization of sintered hot forging and austenite stainless steels
Authors: Eiumtadanai Sittipong , Mahathanabodee Sithipong , Tongsri Ruangdaj , Vetayanugul Bhanu , Sumate  , Poomiapiradee  
Published: May 2021

Abstract
The powder metallurgical (PM) process, consisting of compaction and sintering, is commonly used to produce sintered structural parts applied in various industrial fields. Sintered parts always have porosity due to limited materials transport by solid-state diffusion from powder particles to voids between them. Sintered specimens with low porosity show superior mechanical properties. Hot forging is one of processes for enhancing density of sintered parts. This process was applied to sintered austenitic stainless steels ( 303L, 304L, 310L and 316L). The hot-forged specimens showed increased density. This led to remarkable increase of hardness (up to 5 times). Due to the hot working nature of the process, microscopic changes in the hot-forged specimens during the process were examined. It was found that grain size and volume fraction of twins were significantly deceased.
Sintered Fe-Mo-Mn-Si-C alloys
Authors: Nakornkaew P. , Patcharawit T. , Wila P. , Morakotjinda M. , Yotkaew T. , Tosangthum N. , Tongsri R. 
Published: May 2021

Abstract
Sintered Fe-Mo-Mn-Si-C alloys were produced by alloying silicon and carbon elements to pre-alloyed Fe-0.5Mo-0.15Mn powder via sintering of mixtures of pre-alloyed powder and varied silicon carbide amounts (0.5-4.0 wt.% with 0.5 increment). The sintered alloys were cooled in a sintering furnace. Microstructures and mechanical properties of the sintered alloys were altered depending on added silicon carbide content. With up to 2.0 wt.% silicon carbide additions, the sintered alloys exhibited polygonal ferrite plus eutectoid decomposition products, showing non-cooperative ferrite and carbide growth mode. With silicon carbide contents of ≥ 2.5 wt.%, the sintered alloys exhibited microstructural feature similar to that of a ductile iron, i.e., a common feature consisted of a black particle enveloped with ferrite and pearlite. Tensile strengths of the sintered alloys increased but elongation values decreased with increasing added silicon carbide content. The sintered alloys produced by 3.5 and 4.0 wt.% silicon carbide showed high strengths and considerably good elongation values.
Sintered Fe-Ni-Si-C alloys
Authors: Kaewkam Tiwat , Kansuwan Panya , Ohtake Naoto , Wila Pongsak , Krataithong Rungtip , Tosangthum Nattaya , Yotkaew Thanyaporn , Tongsri Ruangdaj 
Published: May 2021

Abstract
The aim of this research is to explore the effect of nickel content on microstructural development and mechanical properties of sintered Fe-Ni-Si-C alloys. The sintered alloys were prepared from powder mixtures of pre-alloyed Fe-Ni-based powders (nickel contents varied as 0.45, 0.90, 1.80, and 4.00 wt.%) and fixed 4 wt.% silicon carbide powder by using a powder metallurgical process. Sintering was performed in a vacuum furnace at 1250°C for 45 minutes and slow cooling in the furnace. Microstructures of sintered alloys varied with nickel contents. Nickel showed a strong influence on promoting bainitic ferrite/martensite-austenite (BF/M-A) structure formation. Retained austenite in BF/M-A structure was found to increase with increasing nickel content. Tensile properties (strength and elongation value) of sintered alloys increased with increasing nickel content.
Phase transformation and mechanical properties of sintered Fe-Mo-Si-C-(Cu) alloys
Authors: Morakotjinda Monnapas , Ruangchai Kittikhun , Vetayanugul Bhanu , Krataitong Rungtip , Tosangthum Nattaya , Wiengmoon Amporn , Tongsri Ruangdaj 
Published: May 2021

Abstract
Sintered Fe-Mo-Si-C alloys, prepared from pre-alloyed Fe-0.85Mo powder, fixed 4wt. % silicon carbide powder and varied graphite powder contents, showed microstructures similar to those of ductile cast irons, i.e., the microstructural feature consisted of a black particle enveloped with matrix consisting of ferrite halo and pearlite. The varied added-graphite content caused morphological change from black nodular to black vermicular particles. With increasing added-graphite content resulted in the decrease of black nodular/vermicular particle fraction, the increase of pearlite fraction and the slight change of ferrite fraction. The black nodular particles were either graphite or Fe-Mo-Si-C/graphite core-shell particles whereas black vermicular particles were totally composed of carbon. With 2 wt.% copper addition, the morphologies of black nodular and vermicular particles in sintered Fe-Mo-Si-C-Cu alloys were not affected, but one component of the matrix changed from pearlite to duplex structure consisting of bainitic ferrite (BF) and martensite-austenite (M-A) constituent. The change of matrix component from pearlite to duplex BF/M-A structure led to drops of ultimate tensile strengths and elongation values but small effects on yield strengths and hardness values. No benefits of tensile properties were gained from the duplex structure due to coarse BF/M-A size.
Evaluation of conventional invasive measurements and examination of non-invasive measurement technique on human body core temperature
Authors: Yoshida Atsumasa , Kamon Rinzo , Naka Takuma , Chigusa Narihisa , Kinoshita Shinichi , Kawabata Takashi 
Published: May 2021

Abstract
It is important in many cases to measure and monitor, human body core temperatures, to prevent the likes of heat stroke and hypothermia. Measuring core body temperatures is also important for example, in relation to the basal body temperatures of women, and for improving the quality of life for vulnerable people such as infants, and those with cervical spine injuries. In doing so, thermal environmental changes can be monitored. However, todays conventional measuring method is apparently invasive because a temperature sensor has to be inserted into the body, from the outside. Characteristics of the body parts measured were considered by the subject experiments. There was a difference in core temperatures, depending on the measurement body parts, and it was found that the temperature decreased in the order of rectum, sublingual, and tympanic during normal times. It was confirmed that the tympanic temperature showed the most significant increase in core temperature, with running and the sublingual temperature the best in responsiveness. As a non-invasive core temperature measurement method, the basic characteristics were examined by the heat transfer experiment for the dual-heat-flux method. Thus, it was clarified that adequate temperature accuracy can be guaranteed if appropriate materials, thicknesses, and sizes are selected and the adiabatic condition for the peripheral part is fulfilled.
Numerical simulation of tooth extraction socket: alveolar bone regeneration
Authors: Furukawa Rintaro , Nagayama Katsuya , Matsuo Masato 
Published: May 2021

Abstract
Recently, regenerative medicine has received attention owing to the progress of an aging society. Regenerative dentistry, such as bone regenerative therapy and implant treatment to regain bone loss as a result of active periodontal disease, is actively performed. The alveolar bone is a functional bone that supports teeth and buffers occlusal pressure. In the implant treatment, the implant is inserted into the tooth after it has been extracted. After the implant is inserted, the alveolar bone will regenerate over about three months and the implant will be fixed in place. During this process of alveolar bone regeneration, there have been problems with the implant and alveolar bone not bonding. This work was contributed to dental regenerative medicine by building a simulation model of alveolar bone regeneration. After tooth extraction is performed, the alveolar bone regenerates by chemically converting calcium (Ca) secreted from the newly formed blood vessels into hydroxyapatite, which is the main component of bone. Thus, its internal structure and external shape are mechanically affected around the bone. The main purpose of this study is to establish a mathematical model, introduced as the Ca transport model that is secreted from the newly formed blood vessels, and mechanical factor model expressed as bone remodeling for analyzing and predicting the interaction of angiogenesis and bone regeneration. As a result, we were able to obtain a good agreement between the qualitative features of the experimental images and the simulation results.
Numerical simulation of skin formation: epidermal stem cells and undulation of the basal layer
Authors: Oba Shu , Nagayama Katsuya 
Published: May 2021

Abstract
The basal layer at the base of the epidermis produces new epidermal cells once a week and plays an important role in skin formation. Interestingly, the basal layer undulates, and the amplitude of this undulation is dependent on age or disease. However, the mechanisms driving this phenomenon have not been well studied. This work simulated the skin formation process using an original method to understand the mechanism of the undulation formation in the basal layer. The basal layer has cells with both short and long cell cycles, but only the former has been examined in previous studies. Accordingly, we more accurately simulated the skin formation process by including cells with a long cell cycle and observed undulation of the basal layer. Based on our findings, we propose that the basal layer undulates due to the interaction between two types of basal layer cells.
Experimental investigation on durian thorns
Authors: Phungsara Bundit , Phongphinittana Ekkarin , Jearanaisilawong Petch 
Published: May 2021

Abstract
Durian is a fruit that has a round shape with thorny shell. When a durian is ripe and falling down from a tall branch to the ground, its thorn help absorb shock from an impact with the ground and lessen the damage to its soft internal flesh. This research aims to investigate the structure of durian thorn and its mechanical properties. Among varieties of durian cultivars, Monthong durian is selected as a representative variety because of its popularity and availability. Thorns and components of durian peels are harvested from a ripened durian and stored in vacuum refrigerated bags. Modulus of Elasticity of each component is measured by performing uniaxial tensile tests on coupon samples. The results show the gradients of modulus of elasticity at various points on the durian peels. The experimental results can be used as inputs for finite element simulations of durian thorns for further analysis.
Design of opener shape for improving gimbal tongue shift on y-axis
Authors: Klayaubol Warut , Pimsarn Monsak 
Published: May 2021

Abstract
There are four necessary components for testing read-write efficiency of Slider, which are [1] Slider electrical testing machine [2] Fixture, a tool for holding Slider while testing [3] Slider to read and write data in hard disk drive and [4] Opener, a mechanism to open a fixture for loading and unloading Slider. The opener should open a fixture only in x direction but it appears that the opener drives a fixture in both x and y directions which results in misalignment of Slider in a fixture. A poor Slider alignment definitely affects a read-write efficiency of Slider. Therefore, this article will show a study of opener shape that relates to fixture behaviour and also a comparison of four designs of opener-arm angle (15 degrees, -15 degrees, -30 degrees and -40 degrees) by using Finite Element Analysis (FEA). Result shows -40 degrees opener is the best one that can open the fixture only in y direction and meets the design requirement.
Computational study of the flow field characteristics of the radial-swirl burners for a small gas turbine
Authors: Soontornpasatch Tosaporn 
Published: May 2021

Abstract
The aim of this study is to investigate the flow field characteristics of the radial-swirl burner which is developed for a small gas turbine. To create a stable flame during the combustion process, the burner has to create a reversal flow area or a recirculation flow. Without this zone, the combustion process cannot be created. Therefore, the characteristics of the flow field in the burner is very critical. The current study applied two types of the radial-swirl burner. One has a straight-type vane and the other has a nozzle-type vane. The flow angle of both types are varied from 40°, 50° and 60°. The mass flow rate of air is varied from 1.0 to 1.8 kg/min. The commercial computational fluid dynamic program, ANSYS FLUENT is also used. The results of the simulation are discussed in this paper.
Effect of audio pre-processing technique for neural network on lung sound classification
Authors: Chaiyot Krittaya , Plermkamon Supattra , Radpukdee Thana 
Published: May 2021

Abstract
In this paper, we intended to study the effect of two audio pre-processing methods to multilayer feedforward network performance on lung sound classification problem. The first one is Mel Frequency Cepstral Coefficients (MFCC) and the second is the MFCC supplement with Linear Discriminant Analysis (LDA). Datasets applied in this study came from Kaggle Respiratory Sound Database, which is the largest resource for machine learning. As a result, MFCC supplement with LDA has both good performance and significant improvement than conventional MFCC.
Structural analysis of three-dimensional finite element model to design multifunction wheelchair for patients
Authors: Keangin P. , Chawengwanicha P. , Wimala N. , Nakbanpotkul T. 
Published: May 2021

Abstract
The disabled and patients, especially hemiplegia and paraplegia cases and elder need to use a wheelchair for movement and admitted to the hospital or stay at home. The problem of using wheelchairs for patients and the elder is due to their different shapes. There is only a standard type of wheelchair in a hospital, therefore could not respond to differences in shape and usability. The ability of a wheelchair that does not provide enough facilities will result in the service as being ineffective in achieving and will make patients feel uncomfortable. The basis of the strength analysis, as well as stress distribution of the device structure design, is still minimal due to computer program limitations. A comprehensive understanding of the fundamentals of strength analysis will support the recommendation to design of wheelchair to handle patient for appropriate use in each situation. This research aim provides strength analysis to design the multifunction wheelchair. The multifunction wheelchair is designed to be turned into a bed, height-adjustable to use in a situation where a standard wheelchair could not be achieved due to the height is not enough and arm rest’s width adjustable for the convenience of patients with different body shapes. The detail regarding concept design and strength analysis of main components are solved by the finite element method (FEM) with a three-dimensional model. The results obtained from the simulation solution are examined and compared with the analytical solution. It is found that the highest maximum stress value does not exceed the yield strength of the material. The obtained results can be helpful in determining the basis for the guideline of wheelchair design and develop medical instruments situation by using principles of engineering.