bluuebunny/crossref_metadata_2025 huggingface dataset:
Machine learning prediction of interaction energies in rigid water clusters
Authors: Bose Samik , Dhawan Diksha , Nandi Sutanu , Sarkar Ram Rup , Ghosh Debashree
Published: August 2018

A new machine learning based approach combining support vector regression (SVR) and many body expansion (MBE) that can predict the interaction energies of water clusters with high accuracy (for decamers: 2.78% of QM estimates).
Ultrafast charge transfer excited state dynamics in trifluoromethyl-substituted iridium(iii) complexes
Authors: Bevernaegie Robin , Marcélis Lionel , Moreno-Betancourt Angélica , Laramée-Milette Baptiste , Hanan Garry S. , Loiseau Frédérique , Sliwa Michel , Elias Benjamin
Published: August 2018

Ultrafast spectroscopic studies on the excited state interplay in trifluoromethyl-substituted iridium(iii) complexes.
A microfluidic cardiac flow profile generator for studying the effect of shear stress on valvular endothelial cells
Authors: Lee Joohyung , Estlack Zachary , Somaweera Himali , Wang Xinmei , Lacerda Carla M. R. , Kim Jungkyu
Published: August 2018

A microfluidic flow profile generator is introduced to recapitulate the shear profiles of mitral and aortic inflows for valvular mechanobiology studies.
Slow magnetic relaxation in mononuclear complexes of Tb, Dy, Ho and Er with the pentadentate (N3O2) Schiff-base dapsc ligand
Authors: Sasnovskaya Valentina D. , Kopotkov Vyacheslav A. , Kazakova Anna V. , Talantsev Artem D. , Morgunov Roman B. , Simonov Sergey V. , Zorina Leokadiya V. , Mironov Vladimir S. , Yagubskii Eduard B.
Published: August 2018

AC measurements revealed field-induced single-ion magnet behavior of Dy and Er Kramers ion complexes. The properties of complexes were rationalized by superposition CF model.
A nitrogen-doped graphene cathode for high-capacitance aluminum-ion hybrid supercapacitors
Authors: Lei Haiping , Tu Jiguo , Tian Donghua , Jiao Shuqiang
Published: August 2018

A long-life and high-capacitance (254 F g−1) pseudocapacitive nitrogen-doped graphene cathode was employed in aluminum-ion hybrid supercapacitors.
Ultra-compact branchless plasmonic interferometers
Authors: Thomaschewski Martin , Yang Yuanqing , Bozhevolnyi Sergey I.
Published: August 2018

A novel ultra-compact Mach–Zehnder interferometer without the requirement of on-chip waveguide branching and splitting.
Simple method to construct three-dimensional porous carbon for electrochemical energy storage
Authors: Wei Huanhuan , Liao Kexuan , Shi Penghui , Fan Jinchen , Xu Qunjie , Min Yulin
Published: August 2018

A material derived from a nitrogen-enriched superabsorbent polymer in waste diapers provides a new basis for obtaining low-cost carbon materials.
Borophene layers on an Al(111) surface – the finding of a borophene layer with hexagonal double chains and B9 nonagons using ab initio calculations
Authors: Karthikeyan J. , Ranawat Yashasvi S. , Murugan P. , Kumar Vijay
Published: August 2018

A modulated borophene layer made of boron (wine-red and pink balls) nonagons (one shown by black lines) and hexagonal double chains on the (111) surface of Al (grey balls).
An ionic liquid crystal-based solid polymer electrolyte with desirable ion-conducting channels for superior performance ambient-temperature lithium batteries
Authors: Wang Shi , Liu Xu , Wang Ailian , Wang Zhinan , Chen Jie , Zeng Qinghui , Wang Xuefei , Zhang Liaoyun
Published: August 2018

Almost all the traditional ionic liquids lack liquid crystal properties.
A user's guide to the thiol-thioester exchange in organic media: scope, limitations, and applications in material science
Authors: Worrell Brady T. , Mavila Sudheendran , Wang Chen , Kontour Taylor M. , Lim Chern-Hooi , McBride Matthew K. , Musgrave Charles B. , Shoemaker Richard , Bowman Christopher N.
Published: August 2018

The dynamic exchange of thiols and thioesters in organic media was explored, leading to room temperature plasticity in crosslinked polymers.
Effects of a Complexity-Based Approach on Generalization of Past Tense –
ed
and Related Morphemes
Authors: Owen Van Horne Amanda J. , Curran Maura , Larson Caroline , Fey Marc E.
Published: August 2018

Purpose

In a previous article, we reported that beginning treatment for regular past tense –
ed
with certain types of verbs led to greater generalization in children with developmental language disorder than beginning treatment with other types of verbs. This article provides updated data from that study, including the addition of data from 3 children, results from naturalistic language samples, and data from a third time point.

Method

Twenty 4- to 9-year-old children with developmental language disorder (10 per condition) were randomly assigned to receive language intervention in which the verbs used to teach regular past tense –
ed
were manipulated. Half received easy first intervention, beginning with highly frequent, telic, phonologically simple verbs, and half received hard first intervention, beginning with less frequent, atelic, and phonologically complex verbs. The design used a train-to-criterion approach, with children receiving up to 36 visits. Performance was assessed using elicited production probes and language samples before intervention, immediately following intervention and 6–8 weeks later.

Results

Children in the hard first group showed greater gains on the use of regular past tense –
ed
in both structured probes (at immediate post only) and in language samples (at both immediate and delayed post). Gains attributable to therapy were not observed in untreated morphemes.

Conclusions

This study suggests that the choice of therapy materials, with an eye on the role that treatment stimuli play in generalization, is important for treatment efficacy. Clinicians should consider early selection of atelic, lower-frequency, phonologically complex verbs when teaching children to use regular past tense –
ed
. Further work expanding this to other morphemes and a larger population is needed to confirm this finding.
Load cycling of underground distribution cables including thermal soil resistivity variation with soil temperature and moisture content
Authors: Gouda Ossama E. , Osman Gomaa F.A. , Salem Waleed A.A. , Arafa Shawky H.
Published: August 2018

As it is known the load of distribution cables is not constant with respect to the daytime, increasing the current in some hours may lead to an increase of soil surrounding the cable resistivity due to the migration of soil moisture content. Formation of dry zones may cause failure of cable insulation. Also because the soil thermal properties change with time according to the weather conditions of different seasons, the current capacity changes significantly from time to time. This paper studies the effect of dry zone formation during load cycling of underground cables on their temperature rise and the temperature distribution in the surrounding which is not considered by IEC 60853‐2. The thermal model of the cables using the thermoelectric equivalent method is modified by including the thermal soil resistivity variation with soil temperature and moisture content. The finite element method is used also in this study to obtain heat map of the cable and surrounding soil. Additionally, experimental work of three soil types was investigated to study the effect of temperature and moisture content variation on the soil thermal resistivity and the dry zone formation of each soil type. Field measurements of temperature distribution surrounding the cables are done.
Reducing the scenarios of network topology changes for adaptive coordination of overcurrent relays using hybrid GA–LP
Authors: Chabanloo Reza Mohammadi , Safari Mohsen , Roshanagh Reza Gholizadeh
Published: August 2018

In this study, using the concept of setting groups (SGs), an adaptive protection scheme is proposed to increase the reliability of the system. Connection and disconnection of switches and distributed generators result in various scenarios for network topology changes. A hybrid genetic algorithm (GA) and linear programming (LP) method is utilised to solve the problem, where the GA, in a near‐optimal manner, classifies the scenarios of the network topology changes into a limited number of SGs and the LP algorithm optimally coordinates the overcurrent relays within the SGs. Simulations are performed on a radial distribution network and a meshed distribution network. Although by increasing the number of SGs the average operating time of the relays is decreased, the number of changes in the relay settings is increased. Therefore, the multi‐objective optimisation algorithm is used to determine, the desired number of SGs. The results show the efficiency of the proposed adaptive protection scheme.
Double‐deck optimal schedule of micro‐grid based on demand‐side response
Authors: Dou ChunXia , Meng ChiHua , Yue Wenbin , Zhang Bo
Published: August 2018

In order to fully consume renewable energies and schedule demand‐side resources more hierarchically, a double‐deck optimal schedule model of micro‐grid, which connects to power grids and concludes battery energy storage system (BESS), is proposed. Unlike the original peak‐valley time‐of‐use (TOU) price, in the upper layer optimal schedule, the improved TOU price which takes account into the user's satisfaction can express the adjusted loads accurately and the resulting net loads can be treated as a link between upper and lower layer scheduling. For the reason of having no precise model of BESS, the lower model for the goal of minimising the operation cost is solved by action dependent heuristic dynamic programming algorithm that is not relying on the accurate controlled object model. This algorithm is used to obtain the most optimal performance index function and control strategy by the optimal iterative process, which is based on the back propagation neural network used for evaluating the optimal performance index. Analysis of examples and results has been presented to show the effectiveness of the proposed strategies.
Photonic approach for on‐board and ground radars in automotive applications
Authors: Serafino Giovanni , Amato Francesco , Maresca Salvatore , Lembo Leonardo , Ghelfi Paolo , Bogoni Antonella
Published: August 2018

While automotive radars are driving the development of high‐performance technologies for remote sensing, pushing radiofrequency systems to higher frequencies, photonics is gradually changing the approach to micro‐ and millimetre wave RF generation and distribution. With its unique features, photonics can extend the potential of radars, in particular for ground‐based traffic surveillance and on‐board automotive applications, enhancing traffic safety and enabling the deployment of smart driver‐less vehicles. In fact, microwave photonics offers unprecedented flexibility and stability, such as −113 dBc/Hz (at 100 kHz offset frequency) at 80 GHz, with the capability of generating an extremely broad range of carrier frequencies. Moreover, it can employ signals which span up to several GHz of bandwidth, thus allowing higher precision in target detection and discrimination. This study compares photonic and electronic technologies, and it demonstrates, through simulation results, the benefits of a multiple input, multiple output photonic radar when applied to automotive case‐study scenarios.
MIMO array for short‐range, high‐resolution automotive sensing
Authors: Sayin Alp , Pooni Sukhjit , Hoare Edward , Antoniou Michael
Published: August 2018

The study introduces the concept of multiple input–multiple output (MIMO) radar or sonar arrays for short‐range, high‐resolution sensing in vehicular applications. The use of a MIMO architecture, which is becoming increasingly popular in this field, is selected to reduce the amount of physical elements in the array needed for beamforming, but also to allow signal processing approaches for forming narrow beams in the near‐field of the array. The study analytically derives the proposed signal processing approach, and then verifies it via simulated and experimental data in a laboratory environment with scientific equipment assembled for this purpose.
Reduced‐dimension STAP using a modified generalised sidelobe canceller for collocated MIMO radars
Authors: Zhao Xiang , He Zishu , Wang Yikai , Sun Guohao
Published: August 2018

This study addresses the problem of beam‐space post‐Doppler reduced‐dimension (RD) space–time adaptive processing (STAP) using a modified generalised sidelobe canceller (GSC) in an airborne collocated multiple‐input multiple‐output (MIMO) radar. Steering vectors corresponding to the nulls of beamforming are used to construct the blocking matrix (BM) of the GSC processor with optimal signal to clutter plus noise ratio. However, it is difficult to determine the beampattern nulls for a collocated MIMO radar which is equivalent to a virtual array with coherent amplitude weights. To build a valid BM of the GSC‐based STAP processor, the authors propose a BM modification method based on the modified Gram–Schmidt orthogonalisation algorithm. The authors prove that the modified RD‐GSC processor can achieve the performance equal to that of the fully optimal processor conditionally. The authors also show that the proposed method has reduced computational complexity and fast convergence rate. Numerical simulations are presented to demonstrate the effectiveness of the proposed methods.
Temperature‐dependent surface charge and discharge behaviour of converter transformer oil–paper insulation under DC voltage
Authors: Du Boxue , Chang Rui , Zhu Wenbo , Li Jin , Jiang Jinpeng
Published: August 2018

Ambient temperature has significant influence on properties of oil–paper insulation, which makes surface discharge process complex. This paper aims at revealing the influence mechanism of ambient temperature on surface charge and discharge behaviours under DC voltage. The oil–paper with thickness of 0.08 mm was used and the ambient temperature varies from 20 to 80°C in this paper. The results of surface potential decay (SPD) experiments show that the initial surface potential declines and the process of SPD is accelerated with increasing temperature because of higher carrier mobility. Additionally, both shallow and deep trap energy level become deeper, the shallow trap density is enlarged while the deep trap density is shrunken at higher temperature. The surface discharge tests were performed and Weibull results indicate that it is prone to occurring surface discharge at higher ambient temperature. The possibility of surface discharge under negative voltage is larger than that under positive voltage because of polarity effect. It is concluded that more carriers escape from deep traps to participate in the procedure of surface discharge at higher temperature, which declines the surface discharge voltage.
Impact of the Hall effect in star formation and the issue of angular momentum conservation
Authors: Marchand P. , Commerçon B. , Chabrier G.
Published: August 2018

We present an implementation of the Hall term in the non-ideal magnetohydrodynamics equations into the adaptive-mesh-refinement codeRAMSESto study its impact on star formation. Recent works show that the Hall effect heavily influences the regulation of the angular momentum in collapsing dense cores, strengthening or weakening the magnetic braking. Our method consists of a modification of the two-dimensional constrained transport scheme. Our scheme shows convergence of second order in space and the frequency of the propagation of whistler waves is accurate. We confirm previous results, namely that during the collapse, the Hall effect generates a rotation of the fluid with a direction in the mid-plane that depends on the sign of the Hall resistivity, while counter-rotating envelopes develop on each side of the mid-plane. However, we find that the predictability of our numerical results is severely limited. The angular momentum is not conserved in any of our dense core-collapse simulations with the Hall effect: a large amount of angular momentum is generated within the first Larson core, a few hundred years after its formation, without compensation by the surrounding gas. This issue is not mentioned in previous studies and may be correlated to the formation of the accretion shock on the Larson core. We expect that this numerical effect could be a serious issue in star formation simulations.
Effects of electron distribution anisotropy in spectroscopic diagnostics of solar flares
Authors: Dzifčáková E. , Karlický M.
Published: August 2018

Aims. We analyzed effects of the bi-Maxwellian electron distribution representing electron temperature anisotropy along and across the magnetic field on the ionization and excitation equilibrium with consequences on the temperature diagnostics of the flare plasma.

Methods. The bi-Maxwellian energy distributions were calculated numerically. Synthetic X-ray line spectra of the bi-Maxwellian distributions were calculated using non-Maxwellian ionization, recombination, excitation and de-excitation rates.

Results. We found that the anisotropic bi-Maxwellian velocity distributions transform to the nonthermal energy distributions with a high-energy tail. Their maximum is shifted to lower energies and contains a higher number of the low-energy particles in comparison with the Maxwellian one. Increasing the deviation of the parameter p = T∥/T⊥ from 1, changes the shape of bi-Maxwellian distributions and ionization equilibrium, and relative line intensities also increase. The effects are more significant for the bi-Maxwellian distribution with T∥ > T⊥. Moreover, considering different acceleration mechanisms and collisional isotropization it is possible that the bi-Maxwellian distributions with high deviations from the Maxwellian distribution are more probable for those with p >  1 than for those with p <  1. Therefore, distributions with p >  1 can be much more easily diagnosed than those with p <  1. Furthermore, we compared the effects of the bi-Maxwellian distributions on the ionization equilibrium and temperature diagnostics with those for the κ-distributions obtained previously. We found that they are similar and at the present state it is difficult to distinguish between the bi-Maxwellian and κ-distributions from the line ratios.
Selection of electrode tips for the resistance spot welding of dissimilar stainless steels
Authors: Khuenkaew Teerawut , Kanlayasiri Kannachai
Published: August 2018

This research sought to resolve the issue of electrode tip selection used in the resistance spot welding for two different stainless steel grades under otherwise identical welding parameters: SUS316 and SUS425. The study used a full fractional design in order to perform the analysis of the variables involved, while the quality of the weld was assessed by considering the indentation depth, penetration, and nugget diameter. The results of the study described the nugget diameter and penetration for all welds with the various different electrode tips which met the specified requirements of the customers. A single type of upper R30 and lower R30 electrodes achieved acceptable indentation depth. Ideally, good weld quality would demand a large nugget diameter, shallow indentation, and good penetration, all contribution to an acceptable overall appearance. Both R30 electrode tips are able to achieve the desired quality requirements in the spot welding process.
The research of hidden Markov models for overall equipment effectiveness analysis in smart manufacturing system
Authors: Yu Hung Chia- , Yang Cheng Chen-
Published: August 2018

In the manufacturing industry, excellent product quality and increased production flexibility can be achieved by eliminating waste and improving production efficiency. In the past, the manufacturing industry used manual records of production information, but this method is characterized by low efficiency and high error rates. Even if a programmable logic controller and radio-frequency identification are employed, problems still occur because of constraints such as different machine types and high costs. The use of a cyber–physical system and information visualization requires the collection of manufacturing information in order to facilitate the analysis of manufacturing data. Monitoring the machining status. This study proposes an approach for segmenting machine-processed signals. With plug-and-play noninvasive current-sensing equipment to collect machine production information, this approach can immediately determine the state of the manufacturing process and calculate the machine utilization, machine production cycle, and production quantity. The goal is to enable the use of this method with this equipment, improve machine utilization, instantly identify the production quantity, and reduce equipment idle time to reduce manufacturing waste, thus rendering production management more convenient and faster.
Bendability and failure mechanisms of dual phase steel under air-bending at elevated temperatures
Authors: Pornputsiri Natthasak , Kanlayasiri Kannachai
Published: August 2018

In this study, process parameters such as the bending angle and bending temperature of the metal sheets for pure bending of advanced high strength steel sheet DP980 were investigated using the air-bending method. This investigation focused on bendability and failure mechanisms. Experimental studies were carried out with various bending temperatures and the bending angle parameters to identify effect on springback angle, initial crack, and the evolution of the microstructure. Prior to testing, the DP steel sheets were heattreated at different temperatures (room temperature, 200 °C, 400 °C, and 600 °C) with a heating rate of 2 °C/S and 5 minutes of holding time in an electric furnace. As a result of the experiments performed at different temperature values and bending angle values, it was determined that an increase in the bending angle reduces the size of the springback angle. It was also determined that an increase in air-bending-temperature reduces the amount of springback. Air-bending-temperature also affected the microstructure evolution and slowed the cracking of the bent surface.
Critical path analysis programming method without network diagram
Authors: Hein Soe Paing , Min Htike Thein
Published: August 2018

Project scheduling is an important task in project management which monitors the project duration, resource utilization and affects the benefit of project for all kinds of project such as construction, IT, renewable energy, product design and manufacturing etc. Among many methods for project management, critical path method (CPM) is one of the better-known planning and control techniques in project scheduling. In this study, CPM-based computerized program was developed together with modeling of step by step calculations of parameters of interest such as earliest starts and finishes, slack and float times of project activities resulting in determination of critical path for the project. One advantage of computer implementation of CPM using MATLAB in this study is that unlike conventional method, it eliminates necessity to conventionally draw network diagram to perform critical path analysis.
Dielectric elastomer generator with diaphragm configuration
Authors: Song Zhen-Qiang , Sathin Sriyuttakrai , Li Wei , Ohyama Kazuhiro , Zhu ShiJie
Published: August 2018

The dielectric elastomer generator (VHB 4905, 3M) with diaphragm configuration was investigated with the constant-voltage harvesting scheme in order to investigate its energy harvesting ability. The maximum energy density and energy conversion efficiency is measured to be 65 J/kg and 5.7%, respectively. The relatively low efficiency indicates that higher energy conversion efficiency is impeded by the viscosity of the acrylic elastomer, suggesting that higher conversion efficiency with new low-viscosity elastomer should be available.
Patient waiting time and satisfaction in GP clinic at a tertiary hospital in Thailand
Authors: Boonma Apichart , Sethanan Kanchana , Talangkun Sukangkana , Laonapakul Teerawat
Published: August 2018

This study aims to investigate patient waiting time in General Practice Clinic and identify the main cause of the problem through patient satisfaction survey. 9,232 Patients were randomly observed and quantitative data such as arrival time and waiting time were recorded. Other 1,200 patients were randomly selected for satisfaction survey which is considered as qualitative data. The result indicated that average waiting time of patients was 175.87 minutes with standard deviation of 68.66 minutes. Waiting time at GP clinic appeared to be the longest with an average of 92.9 minutes and standard deviation of 43.4 minutes. Also, based on the obtained data, patients remained positive until their waiting time exceeded 2 hours.
Bio-degradable material realization for antenna fabrication in wireless communications
Authors: Homsai Thanakorn , Phongcharoenpanich Chuwong , Sriseubsai Wipoo
Published: August 2018

The biodegradable PBS material is presented to be applied for microwave device design (antenna). The PBS is forming by using compression molding. The PBS thickness is 1 mm with the flexible characteristic. In this paper, the antenna design for the operating frequency band of 2400-2500 MHz is design using the bio-degradable material with the dielectric constant of 3.2. The prototype was fabricated. The characteristics of the proposed device were presented. The effected of the curved antenna and substrate are described in this work.
Machine components clustering with DSM and repeating method : case study of a soil mixing machine
Authors: Kongsin Tanongsak , Klongboonjit Sakon
Published: August 2018

In this study, components of the machine are analyzed to group all components into modular groups with a case study of a soil mixing machine. The study begins by creating a design structure matrix of all components. Next, the design structure matrix is transferred into a distance matrix of all components with Jaccard method. After that, the equation of complete linkage must be applied to change the distance matrix to a tree dendrogram for showing the relationship of machine components and dependent coefficient. With this tree dendrogram, six clusters are arranged:- the 1st cluster has 8 modules at the lowest dependent coefficient, the 2nd cluster has 7 modules, the 3rd cluster has 6 modules, the 4th cluster has 5 modules, the 5th cluster has 4 modules, and the 6th cluster has 2 modules at the highest dependent coefficient. Finally, the 1st cluster with 8 modules is considered to be the most proper cluster for this soil mixing machine by applying the repeating method to analyze all six clusters.
Effect of tempered bead techniques on maximum HAZ hardness for in service pipeline welding
Authors: Srisutraporn Sermsak , Paoniam Rittichai , Poopat Bovornchok , Kwankaew Supolchai
Published: August 2018

This research intends to investigate the main factors of tempered bead techniques affecting on maximum HAZ hardness for in-service pipeline welding. Tempering parameters to be considered are the overlap ratio, weld bead sequences, and subsequent welding processes. This research consists of two parts of experimental procedure. Firstly, critical HAZ hardness (< 350 HV) in the first weld bead was estimated using computational simulation. Secondly, welding experiments were conducted with tempered techniques. Experimental setup included the used material of API 5L Gr. B pipe steel with nominal size of DN 200, wall thickness of 8.18 mm, and water piping How of 18.77 m3/hr. As a results, it suggested that the overlap weld ratio of 50h and 75%, weld bead sequences, as well as subsequent SMAW processes, were proficient of reducing significantly maximum HAZ hardness at the weld root. Nevertheless, in the case that the weld root was built up, maximum HAZ hardness was slightly changed with different weld bead sequences.
Broadband dielectric characterization of novel organic substrates for microwave applications
Authors: Yusof Ismail Muhammad , Ijaz Malik Hasan , Adnan Sharmiza , Rizal Masrol Shaiful
Published: August 2018

This paper presents three novel substrate materials with efficient dielectric characteristics. Different types of innovative substrate materials used for microwave electronics have been discussed. It has been demonstrated that the repeatability of results for paper substrate based electronics can be maintained using the proposed substrate materials. Three different substrate materials derived from recycled sources such as newspaper, copier paper and carton paper and banana pulp have been presented. The paper substrates were manufactured and processed to reduce the moisture content that might degrade the performance. A broadband dielectric material characterization of the proposed substrate shows a stable electromagnetic behaviour over the X – band operation with relative permittivities of 1.81, 1.63 and 1.84 along with loss tangents of 0.053, 0.046 and 0.057 respectively.
Impact of climate change on the groundwater sustainability in the lower Chao Phraya basin, Thailand
Authors: Tanachaichoksirikun Pinit , Seeboonruang Uma , Saraphirom Phayom
Published: August 2018

This research investigates the impact of climate change on the hydraulic heads of Thailand's Lower Chao Phraya basin. The research also determines the sustainability of groundwater as the result from climate change. In the study, the climatic scenario (IPSL-CM5A-MR) of the Representative Concentration Pathways (RCP) between 2.6, 4.5 and 8.5 were considered, and the simulations were carried out using the three-dimensional groundwater flow model (i.e. MODFLOW-2000) predicting the groundwater behavior between 2017 and 2036. The findings revealed that the impact of climate change on the hydraulic head fluctuation was positively correlated. Specifically, under the IPSL-CM5A-MR RCP 4.5 that has the highest average precipitation, the average hydraulic head increased. In conclusion, the sustainability of groundwater in the Lower Chao Phraya basin was sufficient during the simulated time. However, the groundwater budget was lower than the average groundwater budget during 2009 – 2014 indicating, the groundwater storage was continuously decreased. Specifically, the 2nd, and 3rd (Phra Pradeang and Nakorn Luang) aquifers may be facing the groundwater shortage in the future.
Study of fatigue crack initiation location of wheel and rail under rolling contact using finite element method
Authors: Jaifu Apichai , Raeon Suthep , Pimsarn Monsak
Published: August 2018

The rail transit system is widely used for freight and passenger transportation. Due to the fact that its economic worthiness and high safety mode. Maintenance and damage prevention of wheel and rail are important factors affecting the safety of the system. The previous studies show that the most damage of wheel and rail is fatigue cracking, which is caused by the contact stress resulting from wheel and rail interaction. This article presents the study of the fatigue crack initiation location of wheel and rail under rolling contact at the wheel speed of 80 km/h using Finite Element Method (FEM). The three dimensional finite element models were created using the UIC60E1 wheel profile and BS100 rail profile. The Dang Van criteria was applied to analyse the fatigue crack initiation location in case of the wheel's position was changed along the rail lateral direction while the rail inclination angle was also varied at 0, 1/40, 1/30 and 1/20, respectively. The analysing results show that the fatigue crack initiation, determined by the Dang Van stress ratio, tends to increase when the wheel is moved from gauge side to field side. Additionally, the fatigue crack damage is likely to decrease when the rail inclination increases up to the inclination of 1/30 and the fatigue crack initiation locations were found underneath the wheel and rail surfaces. The obtained result can be a primary guideline for maintenance planning.
Assessment of land cover on soil erosion in Lam Phra Phloeng watershed by USLE model
Authors: Wattanasetpong Jatuwat , Seeboonruang Uma , Sirikaew Uba , Chen Walter
Published: August 2018

Soil loss due to surface erosion has been a global problem not just for developing countries but also for developed countries. One of the factors that have greatest impact on soil erosion is land cover. The purpose of this study is to estimate the long-term average annual soil erosion in the Lam Phra Phloeng watershed, Nakhon Ratchasima, Thailand with different source of land cover by using the Universal Soil Loss Equation (USLE) and GIS (30 m grid cells) to calculate the six erosion factors (R, K, L, S, C, and P) of USLE. Land use data are from Land Development Department (LDD) and ESA Climate Change Initiative (ESA/CCI) in 2015. The result of this study show that mean soil erosion by using land cover from ESA/CCI is less than LDD (29.16 and 64.29 ton/ha/year respectively) because soil erosion mostly occurred in the agricultural field and LDD is a local department that survey land use in Thailand thus land cover data from this department have more details than ESA/CCI.
Track-quality index and degradation of railway track structure:
The construction track doubling project of northeast line from
thanon chira junction to khon kaen station, Thailand
Authors: Phanyakit Thawatchai , Satiennam Thaned
Published: August 2018

In the past, the railway network has not been developed, and new construction added has been
mostly degraded caused by long useful life, and lack of maintenance due to a budget constraint. Currently,
93% of railway in Thailand is single track which results in delays due to low capacity and low average speeds,
delayed train on a single track will also delay the train passing it. In some areas of the network, the amount
of travel and transportation exceeds the capacity received, so delays in travel and transportation is quite high.
Due to this above reason, the service of railway is not effective in terms of convenience and speed of service.
Punctuality and cost is high compared with road transport. The biggest challenge that railways faces is the
insufficient number of tracks and outdated or old trains. Most the trains cannot travel at their optimum speed
because they do not get clearances on time. Thai government has a policy to develop railway track network
and services to improve transportation efficiency and save fuel energy used in the transportation sector of the
country. Thus, it is necessary to develop the rail transportation system from the existing network as a single
track to the current double track network. This study focuses on investigating the degradation of the existing
railway structure during the construction track doubling Project. Data were inspected by Track Inspection Car
EM120N before the commencement of construction for analysing the condition with the Track Quality Index
/ TQI) in order to predict the degradation of the railway to plan maintenance and further renewal of the
railway. The study found that the TQI value of the existing track structure during the two years of the doubling
track construction (2017-2018) has changed significantly.
Detonation effects of shallow buried explosive in sandy soil on target plate acceleration in a small-scale blast test
Authors: Zulkifli Abu Hassan , Aniza Ibrahim , Norazman Mohamad Nor
Published: August 2018

Small-scale blast tests were carried out to observe and measure the influence of sandy soil towards explosive blast intensity. The tests were to simulate blast impact imparted by anti-vehicular landmine to a lightweight armoured vehicle (LAV). Time of occurrence of the three phases of detonation phase in soil with respect to upward translation time of the test apparatus were recorded using high-speed video camera. At the same time the target plate acceleration was measured using shock accelerometer. It was observed that target plate deformation took place at early stage of the detonation phase before the apparatus moved vertically upwards. Previous data of acceleration-time history and velocity-time history from air blast detonation were compared. It was observed that effects of soil funnelling on blast wave together with the impact from soil ejecta may have contributed to higher blast intensity that characterized detonation in soil, where detonation in soil demonstrated higher plate velocity compared to what occurred in air blast detonation.
Numerical simulation of two-dimensional laminar unsteady flow past a right trapezoidal cylinder at low Reynolds number: study of sharpening angle, time step, grid independence and domain size
Authors: Lamtharn Sodsai , Pimsarn Monsak
Published: August 2018

Numerical simulation of two-dimensional laminar unsteady flow past a right trapezoidal cylinder at low Reynolds number (Re = 100), zero of the flow approaching angle and sharpening angle of the right trapezoidal of 22.5° with a side ratio B/A = 1 are carried out to provide moreapplicable data for engineering design of barred tee in aspect of structural integrity. A finite volume method, non-uniform meshing with second-order implicit time discretization into eight-node quadratic quadrilateral finite elements is employed. An incompressible flow SIMPLEC code with constant fluid properties is used. The convective terms using a third-order QUICK scheme. The numerical simulation result is compared against the published results of flow past a square cylinder. The effect of sharpening angle on the response of the right trapezoidal cylinder is investigated. A special study of the effects of flow on significant factor for time step, grid independence, blockage ratio, domain size, upstream and downstream extents, size domain next to cylinder and size domain extent are performed systematically. The Strouhal number and RMS lift coefficients of fully saturated flow are calculated. The result shown that increasing of sharpening angle, the Strouhal number is negligible changed whilst the RMS lift coefficients significantly increased.
Real time monitoring of soil moisture content for landslide early warning: wn experimental study
Authors: Thumtuan Panupong , Chub-Uppakarn Tanan , Chalermyanont Tanit
Published: August 2018

Landslides occur commonly after heavy rainfall. More accurate and immediate prediction of landslides for early warning purpose can be achieved when real time water content of the soil slope is known. In this experimental study, the water content was measured using time domain reflectometers (TDR). Five TDRs were installed with equal vertical spacing in a test pit. The measured results were sent to and stored on a web server and real time monitoring was made online. All TDRs results showed a good and accurate water content response of the soil to the rainfall from top to the bottom of the test pit.
Prequalification criteria, according to the government procurement and supplies management Act, B.E. 2560 (2017): branch/type, class, right to bid, ability to carry out
Authors: Vanborsel Boonruk , Subsomboon Kumpon
Published: August 2018

The objective of this article is to study new bidding prequalification criteria of the Royal Thai government sectors according to the Government Procurement and Supplies Management Act, B.E. 2560 (2017) and compare with the seven government agencies according to Regulations on Procurement, 1992 by emphasizing branch/type of construction, class of the construction entrepreneur/contractor, right to bid per one contract, and number of project to carry out on concurrent time. Content analysis was used in this research, by studying and analysing the prequalification criteria of the Government Procurement and Supplies Management Act, B.E. 2560 (2017) comparing to Regulations on Procurement, 1992 The findings of prequalification criteria concluded that Act, 2017 defined 7 branches/types of construction for construction entrepreneur whereas building construction, road maintenance, and traffic safety were repealed. The right to bid per one contract volume lower than 5 million baht are allowed. There is no limit for the number of project and total project value on concurrent period comparing with Regulations, 1992.
Comparing watershed soil erosion of Taiwan and Thailand
Authors: Liu Yi-Hsin , Anh Nguyen Kieu , Chen Walter , Wattanasetpong Jatuwat , Seeboonruang Uma
Published: August 2018

Tropical watersheds in Taiwan and Thailand face the same severe soil erosion problem that is increasing at an alarming rate. In order to evaluate the severity of soil erosion, we quantitatively investigate the issue using a common soil erosion model (Universal Soil Loss Equation, USLE) on the Shihmen reservoir watershed of Taiwan and the Lam Phra Ploeng basin of Thailand, and compare their respective erosion factors. The results show an interesting contrast between the two watersheds. Some of the factors (rainfall factor, slope-steepness factor) are higher in the Shihmen reservoir watershed, while others (soil erodibility factor, cover and management factor) are higher in the Lam Phra Ploeng basin. The net result is that these factors cancel each other out, and the amount of soil erosion of the two watersheds are very similar at 68.03 t/ha/yr and 67.57 t/ha/yr, respectively.
Development of ammonia gas sensor based on Ni-doped reduce graphene oxide
Authors: Tubthong Thanva , Wisitsoraat Anurat , Tansarawiput Chookiat , Opaprakasit Pakorn , Sreearunothai Paiboon
Published: August 2018

The work aims to develop a simple and low cost ammonia gas sensor based on reduced graphene oxide (rGO). Reduced graphene oxide doped with nickel sulfate (NiSO4/rGO) was used as a sensing material. The sensor was fabricated by a simple drop-cast and spin-coat technique. The performance of the nickel-doped reduce graphene oxide were studied in terms of electrical changes as well as chemical interactions. It was found that after the fabricated sensor was exposed to ammonia vapour for 10 min, the average resistivity was increased to 43% from initial resistance and retained about 8% resistance change upon ammonia removal. The mechanism of the sensor reaction with the ammonia gas is also studied using Fourier Transform Infrared Spectroscopy (FTIR) and is discussed. This preliminary work may help develop the highly sensitive ammonia gas sensor.
Design of natural-rubber panel railroad crossing using finite element method
Authors: Sukhom Aunna , Jangchud Ittipol , Pimsarn Monsak , Charoensuk Jarruwat , Treeporncharoen Veerachai
Published: August 2018

Thailand has a railway system that is available throughout the country, so there are several railroad crossings. These crossings are generally made of concrete or logs with multiple constraints. There are some disadvantages of concrete railroad crossing, such as, crack, noise during car passing over. To overcome these disadvantages, the softer materials should be used instead. Therefore, this research proposes the natural rubber, widely grown throughout Thailand, panel railroad crossing. However, the natural rubber alone is not enough to withstand the harsh condition. Thus, it is necessary to have some addition ingredients that will enhance the natural rubber properties. The material used in this research is a rubber compound between Chloroprene Rubber (CR) 75% and Natural rubber (NR) 25% blend with additives such as carbon black (CB), magnesium oxide (MgO) and sulfur (S8). The objectives of this article were to analyze the deformation of the natural rubber panel railroad crossing and to evaluate its safety factor, defined as the ratio of strain at break and the maximum equivalent strain, using finite element method. In the analysis, the applied loading of the model was obtained from the State Railway of Thailand. The analyzed results reveal that the deflection of rubber panels passes the standard from State Railway of Thailand. Safety factor of external rubber panel is 27.03 and for internal rubber panels are 9.12 and 15.29. The metal pads had elastically deformed and concrete railroad sleeper deformation was very small.
The Karen villagers’ knowledge development in road construction: a case study of Panoki –Kopadoh (PNK) route
Authors: Sirikaew Uba , Sae-Ueng Songklod , Khwanpruk Somkiat , Sriworasa Thanom
Published: August 2018

The Karen, of Panoki village agreed to upgrade the unpaved PNK route to a bamboo reinforced concrete road which used money from the donation. At the beginning of the road construction project, 2010, there were many problems concerned with construction technique and accidents. Civil Engineering Department, Engineering Faculty, King Mongkut’s Institute of Technology Ladkrabang (KMITL) was invited to be a road construction consultant of Panoki-Kopadoh (PNK) route during 2012 to 2017. As the villages of Panoki in Tak province and Kopadoh in Chiang Mai province are in Thailand’s northern remote mountainous areas connected by a 16.5 km unpaved narrow track of Panoki-Kopadoh (PNK) route. In fact, the majority of volunteer villagers understand only the Karen language, lack the basic construction skills, and show no regard for personal safety and hygiene. The consulting team thus provided a training program prior to construction and assisted with technical advice since the onset of the project. As an achievement of the project depends on people participation, this research is to examine the pre-and post-training local workers’ knowledge development and attitudes toward the academic services provided by KMITL through direct observations, a Likert-scale-based questionnaire, and in-depth interviews. The findings reveal that the participating villagers have learned to construct a bamboo reinforced concrete road and are intent on applying the knowledge to similar projects in the future. They exhibit the higher level of knowledge development following the training and also hold a positive attitude toward KMITL’s academic services.
An evaluation of public truck terminal implementation and truck ban policy in a medium-size city of Thailand: a case study of Khon Kaen city
Authors: Chhorn Vuchlung , Prabnasak Jaruwit , Chompoo-Inwai Chow
Published: August 2018

This study aims at investigation the potential impacts of a public truck terminal implementation along with truck ban policy adaptation in Khon Kaen City, Thailand. A four-step model is developed and used for examining traffic condition changes due to the terminal relocation. Three different terminal locations are set. Truck traffic of each scenario are estimated and converted to total network cost, and then compared with the base-case scenario. The most suitable truck terminal location is suggested. Also, several concerns regarding the public truck terminal and truck ban policy in the study area are given.
Zigbee wireless sensor network localization evaluation schemewith weighted centroid method
Authors: Thammavong Lonesy , Khongsomboon Khamphong , Tiengthong Thanadol , Promwong Sathaporn
Published: August 2018

Using wireless communication system, appropriate and correct indoor localization with Zigbee sensor network and could provide interesting services and applications. In this study the Zigbee transmission model with positioning method by using the relative-span exponentially weighted centroid method for the indoor localization. The experimental results and analyze results are evaluated a distance error. The ZigBee transmission model in measurement consists of 121 positions with distance between positions to positions is 0.3 meter. The experimental setup at every position operated at frequency band from 2.3 GHz to 2.5 GHz. The accuracy of estimated position is considered in the term of distance error with the cumulative distribution function (CDF) of distance error is shown. The result presents optimal value for REWL is 0.2 and mean of distance error is 0.65 m.