bluuebunny/crossref_metadata_2025 huggingface dataset:
A simulation on desired neutron flux for the boron neutron capture therapy (BNCT) purpose by using Monte Carlo N-Particle (MCNPX)
Authors: Shalbi S , Sazali N , Wan Salleh W N
Published: March 2020

Boron Neutron Capture Therapy (BNCT) is a nuclear application to cure cancer by using the interaction between the boron compound and the slow (thermal and epithermal) neutron beam obtained from the neutron source. The previous feasibility study shows that the thermal column can generate higher thermal neutrons for BNCT application at the TRIGA MARK II reactor. Currently, the BNCT facility is planned to be developed at the thermal column. Thus, to fabricate the nuclear application such as BNCT required several required such as the study of design, material, neutron desired and safety for the application. Therefore, the use of simulation software such as Monte Carlo N-Particle (MCNP) was extensively essential to identify and determine the most convenient design of the BNCT facility with proper safety requirement standard. Besides that, the simulation also useful in terms of identifying good material and best geometry and the uses of simulation can guide to make sure this research achieves the best results. Generally, MCNP function to track the particle over its energy range using the irradiation transport and the neutron flux and the gamma flux produced from the simulation using MCNPX code was consider right if the relative errors contributed was lower than 5%. This research simulates that the uncovered collimator provides high neutron flux and high collimator performance compared to the fully covered collimator. This research is useful in the simulate on the desired neutron from the BNCT facility design at the TRIGA MARK II reactor.
Relative assessment of anti-quorum sensing in Piper betle leaves extract via pyoverdin assay
Authors: Mohamed Sedek S A , Abd Latif M N , Arifin M A , Abdul Munaim M S
Published: March 2020

Anti-quorum sensing property has been a popular alternative approach over bactericidal/bacteriostatic property in combating bacterial infection while simultaneously tackling the dilemma of antibiotic resistance. We presented pyoverdin assay as an initial screening to qualitatively determine the anti-quorum sensing activity in Piper betle by measuring the loss of absorbance at wavelength 630 nm. Growth of Pseudomonas aeruginosa was proven to be unaffected by the presence of the P. betle leaves extract. The regression value (R2) of the quorum sensing (QS) activity in untreated supernatant of P. aeruginosa was 0.9636 and we presented the QS activity in fold-change, normalized to untreated sample for a fair comparison between batch of assays. We further assessed the QS activity in the extracts of P. betle leaves and found the QS activity of P. aeruginosa grown in the presence of ethyl acetate extract at 200 μg/ml was reduced to 0.6-fold. As the concentrations went lower, higher fold of QS activity was observed, suggesting that P. betle leaves extract is demonstrating anti-QS activity at a higher concentration. Further fractionate of ethyl acetate crude extracts resulted in three fractionates with high anti-QS activity with >50% reduction in QS activity and five fractionates with intermediate anti-QS activity. The use of pyoverdin assay to qualitatively portray the anti-QS activity could shorten the lengthiness of extracting and measuring the signaling molecule yet, produces reliable information to screen for anti-QS activity and guide for further fractionation and purification of bioactive compound.
Sustainability analysis on landfilling and evaluation of characteristics in landfill leachate: a case study
Authors: Mohd-Salleh S N A , Shaylinda M Z N , Othman N , Azizan M O , Yashni G , Afnizan W M W
Published: March 2020

Issues on solid waste management in the most Asian developing countries is not recent. Unfortunately, Malaysia is still practicing landfilling method to dispose the solid wastes. The apparent consequence of this method is the production of highly polluted wastewater called leachate, which can cause several inconveniences and issues. The characterization of landfill leachate is merely important because it can guide towards the possible appropriate treatment. The main focus of this study was to analyse the leachate characteristics at Simpang Renggam Landfill Site, Johor, Malaysia for five consecutive months from January to May of 2018. There were 16 analyzed parameters; namely temperature, pH, total dissolved solids (TDS), conductivity, suspended solids (SS), colour, turbidity, ammonia (NH3-N), dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD5), BOD5/COD ratio, as well as heavy metals (iron (Fe), chromium (Cr), arsenic (As), lead (Pb)). All parameters were analyzed according to the Standard Methods for the Examination of Water and Wastewater, and have followed the procedures of respective instruments. Leachate in SRLS could be classified as stabilized ones, by considering the characteristics and the age of landfill. SRLS is recommended to upgrade its management system for better waste disposal and leachate treatment.
Ozonolysis of wastewater from rubber industry
Authors: Rosmod K , Boonkitkoson A , Kokoo R , Srisurat T
Published: March 2020

The chemical industries currently release pollutants into air, soil, and water. For rubber industry, large amount of wastewater is produced resulting in huge energy demand for water treatment. However, there are several restriction factors for wastewater treatment i. e., contaminated oil from machinery and foul odour from organic matter caused by microbial enzymes. To overcome these problems, this research focused on wastewater treatment from rubber industry via ozonolysis. Two cases of experiments were carried out in a bubble column with capacity of 500 ml including with and without ozonolysis. Ozone concentration were maintained at 64 mg/L. Samples of 10 ml were collected every 4 h and then analyzed by GC- MS. The BOD, COD, and operating cost were investigated. The results showed that the BOD and COD decrease by 40% when ozonolysis was applied. The colour of wastewater become clear after ozonolysis. In addition, the operating cost of ozonolysis process is lower than that of without ozonolysis.
A Novel Microbial Biofilm Carrier for Wastewater Remediation
Authors: Al-Amshawee S K , Yunus M Y , Azoddein A A
Published: March 2020

Biological wastewater treatment via biofilm colonies are still in their early stages of evolution. Solid carriers made of wide range of materials in different designs have been introduced to increase biofilm growth by delivering high surface area which expands microbes’ attachment. It reduces 70-90% of total wastewater contamination (Based on the treatment circumstances and influent properties). In addition, it is considered a low-cost biological process and highly preferred by wastewater industries. Despite that, biofilm carriers failed to deliver a stable biotreatment. Unsteady bioremediation could occur because of using ineffective designed carrier which disturbs the microbial growth. Numerous biofilm carriers had been reviewed and mentioned in this paper like K1, AMT, BioBall, …etc. Then, two carrier designs named as Ultra and Micro media were introduced to carry and protect biofilm and microbial colonies from being removed during the process. Its expected that the new biofilm carriers can improve moving bed biofilm reactor (MBBR) performance in terms of stability, biomass accumulation, clogging, and biofilm growth. At the end, unharmful wastewater can be discharged to the waterways or recycled back into the industry. Finally, this study suggests designing carriers having crimped surfaces to enhance the extracellular polymeric substance attachment.
Evaluation of current situation of melaleuca forest in the U Minh Ha national park, Vietnam under the situation of climate change and proposed solutions for conservation and sustainable development
Authors: Thi Thanh V H , Vu Hoang P P , Trong K H , Ho Thanh P P
Published: March 2020

U Minh Ha National Park (UMHNP) is one of the important biosphere reserves in Viet Nam, this park still has a pristine ecosystem like natural melaleuca forest on peatland in the core zone of UMHNP. Melaleuca forest is not only economic revenue for native people but also the habitat for all the species in UMHNP. However, facing to current climate change and fire prevention of UMHNP has made the growth of melaleuca forest get some negative effects. Melaleuca cajuput can grow in a wetland if the depth of water is not high and waterlogged duration is not last long. If the water depth is over 50 cm and waterlogged duration is more than 5-6 months the roots of this land will be damaged. Currently under the condition of climate change, in the dry season, the high temperature and prolonged heat make the herbaceous and liana vegetation die and form burning materials. Unevenly distributed rainfall combined with prolonged heat increases the risk of forest fire, especially in the last months of the dry season. To prevent forest fires, the U Minh Ha national management board always maintains high water levels in canals, maintaining high water levels for a long time reducing the risk of forest fire but also makes peat land dilated leads to the fallen of Melaleuca trees. At the same time, at the beginning of the rainy season, heavy local rainfall led to the phenomenon of alum in this area. This research has shown the current state of U Minh Ha National Park under climate change status and proposed some measures to help Melaleuca forest grows sustainably.
Quality Evaluation of Tourmaline Green Appearance Based on CIECAM16 Color Appearance Model
Authors: Yuan Bin , Guo Ying , Li Yinuo , Jia Haoyuan
Published: March 2020

Tourmaline minerals are mainly produced in pegmatite, which is mainly produced in pegmatite.At present, the color evaluation of green tourmaline in China needs to be supplemented. In this paper, the CIECAM16 color appearance model is used to calculate the color appearance attribute parameters of green tourmaline samples, and the tristimulus XYZ of green tourmaline color measured by Colori5 colorimeter is used as the input data of CIECAM16 color appearance model to predict the color appearance attribute of green tourmaline under different conditions. The CIECAM16 color appearance model written by computer C++ language is used to calculate the color appearance attribute parameters under different illuminance levels under D65 light source, different environment (Average, Dim, Dark) conditions and different illumination light source color temperatures (D65, D50, A). Through analysis and calculation of the color appearance attribute parameters, it is found that that the increase of illuminance has a more intuitive effect on the visual brightness Q, while the change of ambient light and shade has a greater effect on the brightness than the change of light source. The A light source has a more obvious effect on the tourmaline of color than D65 and D50 light sources.
Analysis of Stress Distribution of Double-layer Shoulder Beam of Concrete-filled Steel Tubular
Authors: Wang Yang , Qi Baofeng , Peng Yao
Published: March 2020

At present, single-layer shoulder beam can not meet the operation of large-tonnage bridge cranes with different elevations. However, due to the complexity of the bearing forms of double-layer shoulder beam, there is no corresponding design formula in the code. In order to study the one-way pushing force performance of concrete filled steel tubular (CFST) double-layer shoulder beam with mid-column, combined with the prototype of the shoulder beams in a shipbuilding building, the scale of the beam was analyzed by ABAQUS software, and the P-Δ curve was calculated, the failure process and the stress mechanism were described, and the stress distribution law of lower shoulder beams in elastic stage was emphatically analyzed.
A Concrete Pouring Temperature Forecast Method for Hydraulic Structures
Authors: Zhu Zhenyang , Liu Yi , Tan Yaosheng , Zhou Mengxia
Published: March 2020

To address problems with the existing concrete pouring temperature forecast methods, an improved forecast method is presented in this paper. A concrete temperature variation calculation method during pouring is proposed. In this method, the effect of the external environmental temperature on the concrete pouring temperature for various measures is calculated using a finite element model. The relationships between heat conductivity, thermal diffusivity, surface heat transfer coefficient and the concrete temperature rise coefficient are obtained via fitting, and the reliability of these relationship equations are verified.
Numerical Simulation of Thermal Performance in Hollow-structure Aluminum of Bullet Train
Authors: Shi Weibing , Li Li , Li Mengmeng , Zeng Xiao
Published: March 2020

In order to know the characteristic of heat transfer performance in hollow-structure aluminium, the flow and heat transfer in it of bullet train “Fuxing” was numerical simulated. Changes for the equivalent thermal conductivity under the influence of four factors—the temperature difference, wall thickness, rid thickness and number of cavities, were studied and analysed separately adopting control variate numerical method. Numerical simulation results showed that the influence of temperature difference and wall thickness on the equivalent thermal conductivity of profiles were limited; the number of cavities and rib thickness were the main factors affecting the equivalent thermal conductivity of profiles, with the number of cavities and rib thickness increasing, the equivalent thermal conductivity of hollow aluminum increased, and viced versa. In the practical application, proper parameters of hollow-structure were selected to reduce heat transfer and energy consumption of train.
Effect of Scratches on Passive Anti-corrosion in Cr-Mn Ferroalloy
Authors: Li Junlong , Feng Jianrui , Li Dingbo , Wu Xiuwen , Ling Yunhang
Published: March 2020

To study the scratch effect on the metal corrosion, some special scratches on the Cr-Mn ferroalloy were formed by rubbing a sandpaper on the sample surface. Two environmental cases are considered, that is, a humidity air, and a humidity air bottomed with alkaline–organic solution successively. The micro-surfaces of the samples are observed by Energy dispersive spectrometer, and the elementary contents are analyzed on an area and a line. Special scratches on the surface of Cr-Mn ferroalloy do not accelerate the metal corrosion in a humid organic alkaline environment. On the contrary, it would play a positive role in the sample passive anti-corrosion process. Chromium oxide and manganese oxide particles are produced by the oxidation of metals in a humidity air would gather in the grooves caused by the scratches. The relative study is less reported till now.
Accelerating Materials Discovery Based on Generalized Low-dimensional Conformation Performance Relationships
Authors: Qu Yuanyuan , Meng Xiangying , Jia Zixi , Liu Xiaofeng , Liu Dongyan , Li Shanshan , Bian Fang
Published: March 2020

The construction of conformation-performance relationships (CPRs) is the core issue of efficient material design. Different from traditional CPRs originating from experience summarizations or rational model cognitions, a strategy of generalized low-dimensional conformation-performance relationships (GLD-CPRs) for rapid material discovery has been established in this work by the aid of material information technology, providing us with a new perspective to material gene (MG) and its function on performance. From a pure computing perspective, the strategy has been concreted by a case study of semiconductor bandgap engineering. Based on more than 20,000 items of self-produced semiconductor bandgap and attributes data, a set of CPRs for bandgap regulation towards arbitrary semiconductor of the same kind has be generated using GLD-CPRs strategy. By comparing with the reported studies, the reliability of the strategy is confirmed. Finally, future improvements needed by GLD-CPRs are addressed.
Preparation of Latent Curing Agent for Epoxy Resin by Encapsulation Technology
Authors: Yang Xiaojun , Zhao Liyang , Li Qingyang , Ma Limin
Published: March 2020

The microcapsule-type curing agents DDM-PMMA and IZ-PU were prepared by solvent evaporation method and interfacial polymerization method, respectively. The surface morphology of the two microcapsules was characterized by SEM. The coating efficiency and latency were analyzed by DSC analysis of the one-component adhesive composed of the microcapsule-type curing agent and epoxy resin. Two encapsulation methods were compared in terms of hydrophilicity or lipophilicity of the core material, formation time of the microcapsules, coating efficiency and latency of the microcapsules.
Study on Fatigue Limit Test of TCS Stainless Steel
Authors: Ren Junlin , Li Qiang , Wang Binjie , Yin Yi
Published: March 2020

Material fatigue limit plays a vital role in the fatigue life of railway vehicle parts. According to the fatigue test method, the fatigue performance of TCS stainless steel used in railway rolling stock was studied in this paper. The corresponding fatigue limit calculation methods of lifting method and group method were given, and the P-S-N curve of TCS stainless steel under test conditions and fatigue limit under different survival rates were obtained. The results showed that the fatigue limit of TCS stainless steel was 176.43 MPa under 50% survival rate, 163.21 MPa under 90% survival rate, and 152.44 MPa under 99% survival rate. The results of this paper provide basic data for the application of TCS stainless steel in railway rolling stock.
Study on the Performance of Vertical Axis Wind Turbine with Two Sets of Blades
Authors: Peng Yixiang , Guo Yonghui , Wan Kui , Gao Ye
Published: March 2020

This paper investigated the impact of added auxiliary blades on the performance of vertical axis wind turbine through adjusting blade spacing and blade pitch angle by means of experimentation. The results show that a critical value of blade spacing affects the performance of turbine, and with the decrease of blade spacing, the output power coefficient of the turbine decreases but the automatic startup performance increases when under low tip speed ratio. In addition, the output power of pitch angle β was the largest when it was 3°, which increased by 3.9% compared with that of 0°. The power of pitch angle β was relatively close in the range of -3°∼5°.
Relation between Dynamic Characteristics and Parameters of a Two-degree-of-freedom Vibro-impact System with Multi-elastic Constraints
Authors: Yin Fengwei , Luo Guanwei
Published: March 2020

A mechanical model of mechanical vibration system with multi-elastic constraints was founded. Based on the multiple parameter and multiple objective cooperative simulation calculation, the three-dimensional parameter space was constructed by the key parameters such as constrained stiffness, excitating frequency and clearance threshold. The large data onto two-dimensional parameter bifurcation diagrams reflecting the correlation between dynamic properties and parameters of the model are obtained. The mode types, existing regions and bifurcation characteristics of periodic impact vibration of the system on the parameter plane of frequency and clearance are described with the change of constrained stiffness. Similarly, the three-dimensional parameter spaced consisting of mass ratio, or damping ratio and excitating frequency and clearance threshold are analyzed. The results show that the high mass ratio excites rich and wonderful periodic vibration, and different damping ratio determines, the bifurcation characteristics and the number of chattering impacts groups in the small frequency domain. The mode types and transition rules of the fundamental periodic impact vibration in small frequency domain and subharmonic impact vibration in high frequency domain induced by different parameters of the system are revealed.
Numerical Simulation on Cooling Process of Phase Change Cool Storage Device for Rail Vehicle Air Conditioning System
Authors: Wang Hongyu , Han Bing , Li Mengmeng , Zeng Xiao , Wang Suna
Published: March 2020

In order to face emergency situation of the rail vehicle air conditioning system, a cool storage device was designed. The device was made up of phase change paraffin and heat exchanger. For the purpose of optimum system design, the mathematic model of phase change and heat transfer in process of cool discharging was established, numerical simulation was finished. Discharging rate of cool and cooling capacity of the device was analyzed. According to the calculation results, the wind speed and air temperature had the greatest influence on the cooling effect, while the thermal conductivity had little effect on it.
Based on the Shipping Prosperity and Ship Renewal Decision
Authors: Xiang Jiale , Gan Xuezeng , Zhang Honggang
Published: March 2020

As the carrier of the shipping industry, the carrying capacity of the ship is determined by the state of the ship in a large extent, and affects the amount of related costs incurred in the operation of the ship. The timely renewal of the ship can not only keep the ship in good operating condition, but also guarantee the minimum transportation capacity of the shipping enterprise. This paper will study and analyze the relationship between shipping prosperity and ship renewal, to find the best ship renewal opportunity, provide the best ship renewal scheme for ship operation enterprises, to ensure that ships operate in the optimal state, and at the same time, ensure the continuous renewal of shipping capacity and create the greatest economic benefits for shipping enterprises.
Thermal-structural Coupling Researches on Transmission Shafting of the Intermediate Gearbox of a Certain Helicopter
Authors: Wang Ao , Hu Xiaozhou , Wu Minggui , Luo Cheng
Published: March 2020

To study the lubrication performance and structural strength of transmission shafting of the intermediate gearbox of a certain helicopter, applying theories of tribology and heat transfer, thermal-structural coupling simulations of the entire transmission shafting, which mainly consists of a spiral bevel gear pair, two bearings, are performed based on the software platform of ANSYS Workbench. Both steady-state temperature field and stress field are obtained, and influences of rotational speed, torque on the thermal-structural coupling effect are discussed.
Research on Automatic Spray Equipment of Thin Spray Support Technology for New Material in Coal Mine Roadway
Authors: Dong Huihui , Lou Andong , Zhu Jianguo , Min Fusong
Published: March 2020

Based on a new type of non-reactive polymer powder material for thin spray-on support technology in coal mine roadway, an automatic spray equipment for coal mine roadway thin spray-on support is designed and developed. It has Kinds of movements and motion trajectories. This paper introduce The technological basis and working principle of the equipment, design basis, and overall system composition of the equipment, which including: mechanical system, hydraulic system, and control system. Compared with the concrete spraying technology, the thin spray-on technology can reduce the material transportation volume by more than 90%, significantly reduce the labor intensity of workers, improve the construction efficiency and the construction environment. It is an ideal choice for closure and supporting for the future underground roadways.
Three Dimensional Carbon Supported Ultrasmall Fe2O3 Nanoparticles as Anode Material for Lithium Ion Batteries
Authors: Jieru Wang , Xu Junming , Zhang Linjuan
Published: March 2020

In this article, carbon nanotubes were grown on free standing multi-layer graphene sheet to form three dimensional carbon (3D-carbon) materials, and then used as support of Fe2O3 nanoparticles. Ultrasmall Fe2O3 nanoparticles were uniformly deposited on the surface of the 3D-carbon. Due to the synergistic effect of Fe2O3 nanoparticles and 3D-carbon, the electrochemical properties are higher than that of bare Fe2O3 material and multi-layer graphene sheet supported Fe2O3. Reversible capacity 528 mAh g-1 is maintained at a high current density of 500 mA g−1 after 50 cycles. This composite shows a stable cycling and high rate performance.
Study on the Preparation of Lifepo4 by Hydrothermal Method
Authors: Liu Y , Luo G Y , Gu Y J , Wu F Z , Mai Y , Dai X Y
Published: March 2020

A simple hydrothermal process combined with carbon coating is attempted to prepare nano particle LiFePO4 cathode materials for Li-ion batteries. A carbon coating process with glucose is used to make LiFePO4/C composites. The structure, morphology and electrochemical properties of the materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and constant current charge/discharge. The X-ray diffraction pattern indicates that the pure phase LiFePO4 material could be prepared at different reaction temperatures, and the pure phase LiFePO4 material could not be prepared with the reaction time of 6 h. SEM test shows that the dispersion of LiFePO4 particles become better with the increase of reaction temperatures and the morphology is more regular with the increase of reaction temperature. But when the reaction temperature increases to 200 °C, LiFePO4 particles reaggregate severely. As the reaction time increases, the particles of the sample gradually grow. The electrochemical performance indicates that the sample synthesized at 180 °C for 10 h has the highest specific capacity of 139.5 mAh·g−1 at 0.1 C. This study shows that proposed process can be a potential promising way to prepare high performance LiFePO4 cathode materials.
Assessment of Antifungal Activity of Aloe Vera Toothpaste against Candida Albicans
Authors: Thaweboon S , Thaweboon B
Published: March 2020

Herbal products have been the basis for medical therapy and are noted as a form of alternative medicine. Modern medicine also employs the use of many herbal products for therapeutic purposes. Aloe vera is a medicinal herb whose mucilaginous gel is traditionally used to treat different diseases. It consists of the active compounds which include methylchromones, flavonoids, aloesin, aloe-emodin, sterols, amino acids, aloemannan, aloin, acemannan, aloeride, naftoquinones, saponin and vitamins. Aloe vera toothpaste, consequently, has been developed by the Thailand Institute of Scientific and Technological Research (TISTR) to fulfill a strategy of good oral hygiene. The aim of this study was to investigate the antifungal activity of aloe vera toothpaste againstCandida albicansin vitro. Toothpaste containing 10% aqueous extract of the aloe vera leaf was prepared by TISTR. The toothpaste solution was prepared by mixing 0.66 g of toothpaste in 1 mL of sterile deionizing water. The suspensions of 107cfu/mL (equivalent to 0.5 McFarland Standard) ofCandida albicansATCC 10231 and 2 clinical isolates were prepared and added to toothpaste solution. After 50 sec, the final solution was transferred to D/E neutralizing broth and cultured at 37 °C for 24-48 h on Sabouraud dextrose agar. Sterile distilled water was used as a control. Colony forming unit (CFU) was counted after incubation. The result showed that aloe vera toothpaste had a significant inhibitory effect against tested candida species compared with a control. In conclusion, result from the present study is scientific information to prove that aloe vera toothpaste could be assigned as natural toothpaste against candida infection. With proper tooth brushing, it is a simple manner, leading to good oral care.
Preparation of Nano-Graphite Oxide
Authors: Luo Xue-ping , Lai Qi
Published: March 2020

In order to get high yield of nano-Graphite oxide through raw materials of nature graphite, the preparation process of oxidation, expansion, and ultrasound smash were studied. It is found that the more intense of oxidation reaction is, the more crack the expanded graphite is, and more completely the expansion of the nano-Graphite oxide will be. The Large expansion volume of the nano-Graphite oxide can be more easily crushed into nano-Graphite oxide at the same ultrasonic time. And the longer the ultrasonic time is, the more the yield of nano particle size of expanded nano-Graphite oxide is. And the less ultrasonic time can get the smaller nano particle size. The result shows that the best process conditions of nano-Graphite oxide are as follows: Vsulfate acid: VNitrate acid = 5:1, m (fine graphite): m (Potassium permanganate) = 1:0.18. The expansion temperature is 950-1000°C, and ultrasonic time is 10h.
Surface plasmon resonance sensor based on core-shell metal nanorods
Authors: C Chau Y-F
Published: March 2020

A surface plasmon resonance (SPR) sensor based on core-shell metal nanorod arrays for ultra-sensitive refractive index sensing applications is proposed using three-dimensional finite element method. Simulation results show that the absorptance (A) of the proposed structure can be reached A=90.0% which is about 3.5 times enhancement compared to its solid counterpart (A=25.57%). Result shows that the sensitivity can be obtained as high as 700.00 nm/RIU (RIU is the refractive index unit). The proposed SPR sensor could be a desirable candidate for applications in nanophotonic devices.
Growth of graphene on stainless steel by chemical vapor deposition using soybean oil as a carbon source
Authors: Ruammaitree A
Published: March 2020

Graphene is a 2-dimension material which consists of carbon atoms arranged in a flat honeycomb lattice. Graphene has many outstanding properties such as high electron mobility, superb strength, and great flexibility. Although graphene film can be fabricated by economical method such as chemical vapor deposition, the utilization of flammable gas (such as methane, acetylene) in the graphene growth process is still dangerous therefore the safe flammable gas storage and gas line installation are needed. Soybean oil is available vegetable oil which contains carbon, hydrogen and oxygen. Utilization of soybean oil as a carbon source instead of hydrocarbon gas for graphene growth by chemical vapor deposition can avoid an explosion of flammable gas and save the installation cost of gas system. However, the presence of oxygen in soybean oil may obstruct the growth of graphene by chemical vapor deposition. Fortunately, annealing stainless steel with carbon at high temperature can eliminate oxygen from the surface. In this study, the growth of graphene on stainless steel by chemical vapor deposition using soybean oil as a carbon source has been study. The presence and quality of graphene are investigated by Raman spectroscopy. The morphology and element analysis are measured using scanning electron microscope and energy-dispersive X-ray spectroscopy, respectively.
Rubberwood sawdust filled natural rubber composites: effects of filler loading and zinc oxide content
Authors: Homkhiew C , Pianhanuruk E , Rawangwong S , Boonchouytan W , Numrat R
Published: March 2020

The aim of this work is to investigate the effects of rubberwood sawdust (RWS) and zinc oxide contents on mechanical properties of natural rubber (NR)/RWS composites. The curing characteristics of the composites were determined and the composites were vulcanized at 150°C for 10 min and a pressure of 1000 psi using a hot press machine. The properties of the composites such as tension, hardness and morphology were characterized. The increasing additions of RWS in range of 20-100 phr increased the minimum torque (ML), maximum torque (MH) and hardness of NR/RWS composites, but tensile strength and elongation at break of the composites decreased. Further, an increment of zinc oxide contents in range of 3-5 phr into the composites slightly affected the ML, MH, hardness and tensile properties. Therefore, the addition of zinc oxide 3 phr is recommended to achieve the properties of NR/RWS composites as well as saving cost.
Removal of fluoride ions from groundwater using surface-modified ultrafiltration membrane
Authors: Yanwachiragul W , Lohwacharin J , Sajomsang W , Singto S
Published: March 2020

Zeolitic imidazolate framework no.8 (ZIF8), a kind of metal organic frameworks (MOFs), has potential use in water treatment due to water stability. However, there are few studies of ZIF8/polyamide as a thin-film nanocomposite (TFN) membrane. Herein, a film on the surface of ultrafiltration membrane was generated with ZIF8 nanoparticles to fabricate the TFN membrane. Thus, the objective was to investigate feasibility of the ZIF8 membrane for fluoride removal from water. A scanning electron microscopy analysis demonstrates that the ZIF8 layer was successfully made on the UF surface. The ZIF8 layer rendered an increase in the fluoride rejection, probably through size sieving by small windows of the MOFs, compared to the virgin UF membrane, while sacrificed the water permeability. It is anticipated that reducing large voids between ZIF8 particles and thickness of the ZIF8 layer improve the fluoride rejection and water permeability.
Facile preparation of monolithic magnetic porous carbon acid catalysts via surface self-assembly method and their applications in conversion of xylose into furfural
Authors: Toumsri P , Auppahad W , Panpranot J , Chuenchom L
Published: March 2020

Furfural is a versatile chemical derived from pentosane-rich agricultural and forestry residues. Considered as an important platform chemical, furfural can be converted into valuable chemicals and biofuels. The furfural production from xylose was produced through the hydrolysis and subsequent cyclodehydration reaction of xylose sugar catalyzed generally by various catalysts containing SO3H. Nevertheless, their tedious multi-step preparation and the final catalysts usually in the form of fine powder make them difficult to be separated from the liquid systems after use, leading to time consumption for the industrial scale production. In the this work, novel magnetic porous carbonaceous acid catalyst (SO3H-MPBG) in the form of monoliths have successfully been prepared using sugarcane bagasse as scaffold via a self-assembly surface coating method from phloroglucinol/glyoxylic acid precursors with soft-template F127 and Fe3+ as a source for magnetic iron particles. Then facile subsequent hydrothermal sulfonation with concentrated H2SO4 at 180°C resulted in magnetic mesoporous carbon bearing SO3H group (SO3H-MPBG). The SO3H-MPBG was characterized by various techniques including XRD, FT-IR, N2 sorption analysis, elemental analysis, and VSM. A SO3HMPBG showed strong magnetism due to the presence of iron magnetic particles and possessed a BET specific surface area of 252.96 m2/g. The sample showed acceptable xylose conversion (86.13%) and furfural selectivity (55.70%) when performed at 170°C for 3 h using γ-valerolactone (GVL) as a solvent. Besides, the catalyst was easily separated after the catalytic tests using a magnet, confirming its magnetic stability.
Determination of radioactivities in gamma vulcanized natural rubber latex (GVNRL) for the assessment of radiological safety
Authors: Toyen D , Saenboonruang K
Published: March 2020

Due to great potentials of utilizing products made from gamma vulcanized natural rubber latex (GVNRL) in applications that require less use or less release of hazardous chemicals during rubber vulcanization, the radiological health risks in rubber producers/users caused by radioactivities from natural radioisotopes containing in GVNRL must be thoroughly determined and evaluated. As a result, this work determined the activity concentrations of 226Ra, 232Th, and 40K in GVNRL samples that were pre-vulcanized with 12-kGy and 24-kGy gamma irradiation using gamma spectroscopy. The results showed that the average radioactivity concentrations (± standard deviation) of 226Ra, 232Th, and 40K in 12-kGy (24-kGy) GVNRL were 30.8±1.5 (31.2±2.7) Bq kg-1, 89.1±0.6 (89.7±0.4) Bq kg-1, and 95.4±1.6 (93.2±2.2) Bq kg-1, respectively. These results implied that GVNRL vulcanized with 12-kGy and 24-kGy gamma irradiation had statistically similar radioactivity concentrations and higher gamma doses did not result in increasing radioactivies. Furthermore, when compared these results with the values from nonvulcanized natural rubber latex (NRL), of which the activity concentrations of 226Ra, 232Th, and 40K were 29.9±1.2 Bq kg-1, 95.2±1.1 Bq kg-1, and 96.2±1.0 Bq kg-1, respectively, it could be concluded that the use of gamma irradiation for rubber vulcanization did not statistically increase or change activity concentrations of the mentioned radioisotopes, thus, it is radiologically safe for related personnel to work or use GVNRL products.
Comparative X-ray shielding properties of bismuth oxide/natural rubber composites using a Monte Carlo code of PHITS
Authors: Toyen D , Saenboonruang K
Published: March 2020

Natural rubber (NR) is a material for potential development as a flexible X-ray shielding material, subject to improvement in its attenuation ability as one of the necessary measures to ensure safety for radiation-related workers and the general public. Consequently, this work used Monte Carlo coding and the Particle and Heavy Ion Transport System (PHITS) to simulate the X-ray shielding properties of NR composites that were added with Bi2O3 particles at different Bi2O3 contents (0–50 wt% in 10-wt% increments) and different material thicknesses (2, 4, and 6 cm). The X-ray source used for the simulation was a point source with energy ranges of 0.05, 0.1, 0.5, 5.0, and 15.0 MeV, respectively, and the detector was assumed to have 100% detection efficiency. The simulated results showed that at lower energies of X-rays (0.05 and 0.1 MeV), the values of X-ray transmission substantially decreased with increasing filler contents and material thicknesses. However, at higher energies of X-rays (0.5, 5.0, and 15.0 MeV), changes in the X-ray transmission ratios for different filler contents and material thicknesses were not as pronounced as for the lower-energy X-rays due to the high penetration ability of the high-energy X-rays. In particular, the highest attenuation ability of the materials obtained in this work was in the NR composites with 50 wt% Bi2O3, which had the values of half value layer (HVL; the thickness required to attenuate the incoming X-ray intensity by 50%) of 0.002, 0.004, 0.324, 0.990 and 1.540 m for X-ray energies of 0.05, 0.1, 0.5, 5.0, and 15.0 MeV, respectively. Other parameters including the linear attenuation coefficients (μ) and HVL of all filler contents were also reported and thoroughly discussed in this work.
Effect of zeolite types on properties of polybutylene succinate/polylactic acid films
Authors: Preedanorawut R , Threepopnatkul P , Sittatrakul A
Published: March 2020

In the current study, the effect of modified zeolite using (3-aminopropyl) triethoxysilane in polybutylene succinate (PBS) and polylactic acid (PLA) blend was investigated. Two types of modified zeolite i.e., zeolite 5A and 13X at 3wt% of polymer blend between PBS and PLA were mixed together in twin-screw extruder and thin-films were produced by cast-film extruder. The thickness of each film is between 50 – 70 micron. Mechanical properties, thermal properties, morphological properties and permeability of oxygen, carbon dioxide as well as water vapour were investigated. Adding of zeolite 5A into PBS/PLA blend was found to increase more tensile strength and Young’s moduluswith the comparison to zeolite 13X whereas the zeolite 13X and 5A had increased the percentage of elongation at break more than PBS/PLA blend. The zeolite 5A and 13X tended to increase the thermal stability of the composite films. Gas permeation results showed that PBS/PLA with zeolite 5A allowed the permeation of carbon dioxide and oxygen more than 13X in composite films. Moreover, water vapour transmissionrate of PBS/PLA with zeolite 5A was higher than the one with zeolite 13X.
UV-protection property of Eri silk fabric dyed with natural dyes for eco-friendly textiles
Authors: Rungruangkitkrai N , Mongkholrattanasit R , Phoophat P , Chartvivatpornchai N , Sirimungkararat S , Wongkasem K , Tuntariyanond P , Nithithongsakol N , Chollakup R
Published: March 2020

Eri silk (Samia ricini) is a wild silkmoth which has been promoted and supported to culture for textile industry in Thailand. Especially for the recent decade, textile industry was interested to develop eri silk for casual eco-friendly textile style with functional properties. This research aims to study on UV protection property of eri silk fabric dyed with natural dyes from plant extracts and their washing fastness property. The processes included extracting the colorants from Thai plants i.e. natural indigo, Burma padauk bark, Neem bark, etc., mordanting the eri silk yarn with potassium aluminum sulphate, iron (II) sulfate and dyeing with their natural dyes to increase the washing fastness property. Eri silk fabrics were woven by the dyed eri yarn providing an excellent protection (UPF 50+) with a proper shade for making 3 prototype clothing products. The result shows that UPF property of eri silk fabric dyed with Burma padauk bark, Gloden shower seed, Neem bark, Andaman satinwood leave and mordanted with iron (II) sulfate presented highest UPF (>100) with good washing fastness. Three prototype products were designed with color matching with natural dyes and fabricated which were hat, scarf and dress. The first product, hat, made from the hand-weave fabric comprised of Ne 20/2 eri spun silk yarn as a warp yarn and Ne 20/2 eri spun silk yarn that dyed from Burma padauk bark as weft yarns. Second product was scarf which made from Ne 20/2 eri spun silk yarn as a warp yarn and Ne1.2 eri hand-reel silk yarn dyed from natural indigo and Burma padauk bark as weft yarns. The last product was dress which made from Ne 30/2 eri spun silk yarn that dyed from sappen as a warp yarn and Ne 30/2 eri spun silk yarn that dyed from indigo as weft yarns. These eco-friendly eri silk products exhibited excellent functional UV-protection property.
Apatite inducing ability on silk fabric and its ammonium gas adsorptivity
Authors: Thongbai C , Buntham S , Ngamcharussrivichai C , Kashima D P
Published: March 2020

Silk fabric contains silk fibroin protein which consists of an amino group. This amino group can act as a nucleation site of hydroxyapatite by inducing the Ca2+ ions from surrounding solution at an appropriate pH. To increase the initial Ca2+ ions on the surface of silk fabric, the commercial grade silk fabric was drenched in CaCl2 solution for 12 h, Na2HPO4 solution for 20 min, and CaCl2 for 20 min, respectively. Finally, the fabric was rinsed by deionized water and the drenching processes were repeated for 7 times in order to increase the inducing ability of hydroxyapatite. XRD patterns showed the phases of hydroxyapatite coexisted with monetite. The sample drenched in CaCl2 over 12 h gave more apatite peak intensity which was a result of increased Ca2+ ions over the surface and dot mapping technique with SEM showed the well distribution of both calcium (Ca) and phosphorus (P) on silk fabric. It is worth noting that hydroxyapatite induced on the surface of silk fabric can enhance the selectivity in ammonia gas adsorption. An ammonia gas adsorption resulted in better performance of silk with hydroxyapatite over raw silk fabric were displayed. These results are promising for development of Thai silk in term of superior ammonia gas adsorption characteristic.
Electromagnetic interaction between talcum particle and topological insulator
Authors: Summueang C , Boonchui S
Published: March 2020

We identify the electromagnetic interaction between talcum particle and surface of topological insulator which unsatisfied ordinary Maxwell’s equations. For theoretical approach, we use the dyadic green’s function including with the method of an image charge and the topological magneto-electric (TMEP). We describe the electromagnetic response taking into account the property of material in case of the dielectric constant. Our numerical approach demonstrates and discuss the interaction and characteristic of electromagnetic responses between talcum and topological insulator.
Application of polymer blend based on natural rubber latex and acrylic resin as a binder for wall paints
Authors: Worlee A , Homdong N , Hayeemasae N
Published: March 2020

In this study, the polymer blends based on natural rubber latex and acrylic resin was prepared. It was then utilized as a binder for paint. The blending ratios between natural rubber latex and acrylic resin were varied from 30/70, 40/60, 50/50, 60/40, and 70/30 (w/w) where the natural rubber latex was pre-vulcanized prior to be blended with acrylic resin. The investigation was monitored through the physical and mechanical properties of the blends. Highest tensile strength and elongation at break were found at the blending ratio at 30/70 (w/w) of natural rubber latex and acrylic resin. This may be attributed to the compatibility between elastic phase of the natural rubber and hard phase of acrylic resin. When adding higher ratio of natural rubber latex, the tensile strength and elongation at break dropped continuously, indicating inhomogeneity of these two phases. To confirm the compatibility of the blend at 30/70 (w/w), the gel content was also observed. It is clear that such blend completely dissolved in non-polar solvent unlike other blending ratios. Therefore, this blending ratio is highly suggested and appropriate for applying as binder for paint.
A wide energy range neutron shielding material based on natural rubber and boron
Authors: Jumpee Chayanit , Rattanaplome Tithinun , Kumwang Natthaporn
Published: March 2020

Neutron have been used in many applications. Neutrons have no electric charge and have high penetrating power. Therefore, the use of neutron shielding material is one of the methods to effectively prevent neutron radiation hazard. In this work, neutron shielding materials were designed using the Monte Carlo N-Particle (MCNP) transport code in order to select proper materials for a wide energy range neutron shielding. Thicknesses of 1 cm and 4 cm were chosen for shielding neutron in the wide energy spectrum (10E-8 - 100 MeV). MCNP simulation results indicated that the best shielding material was 2 layers of 2 cm natural rubber (NR) and 2 cm NR with 20 part per hundred rubber (phr) boron powder. This shielding material can reduce the neutron dose by 17.91 ± 0.09 % with the total macroscopic cross section of 0.042 cm−1. The optimal neutron shielding materials were fabricated. The mechanical properties and aging properties of shielding materials was found to meet the requirement of Thai Industrial Standard (TIS 2377-2551 Rubber flooring). Therefore, the designed shielding material can be utilized to shield against wide energy range neutrons.