bluuebunny/crossref_metadata_2025 huggingface dataset:
r-GO/MWCNTs Nanocomposite Film as Electrode Material for Supercapacitor
Authors: Noothongkaew Suttinart , Thumthan Orathai , Chamninok Pattanasuk , An Ki Seok
Published: August 2017

We synthesized a reduced graphene oxide (r-GO) multi-walled carbon nanotube (MWCNTs) nanocomposite film via layer by layer (LBL) assembly. This structure was prepared by vacuum filtration and heat-treated at a low temperature of 500°C. The morphology of the sample was determined by field emission electron spectroscopy (FE-SEM). The structural detail and the chemical analysis were characterized by using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The cyclic voltammetry (CV) curve of r-GO/MWCNTs nanocomposite appeared nearly rectangular in shape. The current density (A/g) was gradually increased by increasing the scan rate of the voltage, as high as a scan rate of 500 mVs-1. At a current density of 10 mAg-1, the specific capacitance of the nanocomposite, estimated by galvanostatic (GA) charge/discharge measurement, is 150 Fg-1. These nanocomposites can be developed for supercapacitor electrodes.
Pre-Immobilization of Anaerobic Mixed Culture on Electrode of the Upflow Bio-Filter Circuit Microbial Fuel Cell
Authors: Sinprasertchok Chinnatad , Chollacoop Nuwong , Charojrochkul Sumittra , Sombatmankhong Korakot
Published: August 2017

Microbial extracellular electron transfer is a significant process in a microbial fuel cell (MFC). Owing to many potential losses in the electron transfer from microorganism to an electrode, a promotion of microbial attachment to electrode should be a productive solution to this difficulty of MFC. We also introduced here a prior colonization of microbes on electrode instead of a conventional immobilization which entirely occurred in a MFC reactor to expedite an attachment of microorganisms on the electrode surface. Coconut shell-based granular activated carbons (CGACs) used as one of the electrodes in the upflow bio-filter circuit microbial fuel cell were immersed in Lysogeny broth (LB) at pH 7 before an inoculation of anaerobic consortium from a wastewater treatment plant was performed. The immobilization was proceeded in an Erlenmeyer flask at 30°C with a shaking speed of 100 rpm throughout an experiment. CGACs taken from a collection of flasks were examined a surface with scanning electron microscopy (SEM). On the 3rd day of immobilization, SEM images showed that a colonization was seen obviously in large pores on CGAC surface. There were quite plentiful possessions on a rough surface while smooth surface not supporting well at the beginning got worse in attraction of bacteria on day 9 of immobilization. An addition of fresh LB into immobilization solution was conducted to improve the microbial attachment to smooth surface of CGAC. At 9 days after inoculation, the consequence of fresh medium filling did obviously raise the number of bacteria on the plain surface as opposed to earlier experiment.
Pelletization of Iron Oxide Based Sorbents for Hydrogen Sulfide Removal
Authors: Janetaisong Pathompong , Lailuck Viset , Supasitmongkol Somsak
Published: August 2017

Biogas derived from anaerobic digestion of biological wastes has been extensively used for heating purposes and/or electricity generation. Presence of hydrogen sulfide (H2S) in biogas affects engine performance adversely, thus reducing H2S content is a valuable part in practical application before utilizing biogas. Adsorptive separation is very appealing due to being an economical and effective method including the use of iron oxide based adsorbents. Pelletization of iron oxide adsorbents has never been reported among the adsorbents described to date. Therefore, H2S capture in two iron oxides (ferric oxide (Fe2O3) and magnetite (Fe3O4)) was experimentally investigated to determine technical feasibility of shaping pellets based on active iron oxide sorbent in removing H2S from a simulated gas stream (0.35 vol.% H2S balanced in N2). Many factors affecting the behavior of gas adsorption such as gas in-flow rate, adsorption temperature, binder loadings and textural characteristics were considered. The pellet strengths were also undertaken using a bulk crushing strength analyzer. The results indicated that higher temperature favors the diffusion of H2S molecules from the surface into the bulk of iron oxides. The H2S-sorption capacity of Fe3O4 sorbent was higher than that of Fe2O3 sorbent corresponding with the different pore volume and surface area in each adsorbent. With the same active Fe3O4, the extruded pellet produced with starch binder showed the excellent H2S uptake and crushing resistance. The higher gas in-flow rate had positive impact to contacting efficiency and mass transfer of solid and gas phase. The adsorbed H2S gas can be readily desorbed from the pellets with the desorption temperature below 60°C and the H2S-sorption capacity was consistent over repeated cycles. The pellets can be reused several times for consecutive adsorption/desorption cycles, without loss of performance in a large-scale reactor and therefore represent serious candidates for use in commercial absorbers.
BaO-Al2O3-SiO2-B2O3 Glass-Ceramic SOFCs Sealant: Effect of ZnO Additive
Authors: Laorodphan Nattapol , Ayawanna Jiratchaya
Published: August 2017

The crystallization of planar solid oxide fuel cells (SOFCs) sealant glasses in the systems BaO-Al2O3-SiO2-B2O3 (BaBS) and BaO-Al2O3-SiO2-B2O3-ZnO (BaBS-Zn) was investigated via both X-ray diffractometer and scanning electron microscopy with energy dispersive spectroscopy. The effect of nucleation heat-treatment of the BaBS glass at different temperature for 5 hours, i.e. 550 and 590 °C, on the crystallization behavior was also studied. Thermal expansion profiles of the glasses indicate that both glasses have a low sealing temperature. XRD patterns of all BaBS glass-ceramics, devitrified at 800 °C for 30 hours, show that Ba2Si3O8, BaAl2Si2O8, Ba3B2O6 and some unknown crystalline phases were found. It was also found that crystalline size of unknown barium aluminosilicate with low silicon content depends on the nucleation heat-treatment temperature. For the ZnO-containing glass, ZnO reduces the coefficient of thermal expansion value of glass and causes the devitrification of large needle-like barium zinc silicate phases. The crack at the YSZ/BaBS-Zn glass-ceramic interface was also observed. Two barium silicate phases, which are BaZnSiO4 and BaZn2Si2O7 were devitrified in ZnO-containing glass-ceramic.
Microwave-Assisted Preparation of Sodium Silicate as Biodiesel Catalyst from Rice Husk Ash
Authors: Kumchompoo Jaturon , Wongwai Wasinee , Puntharod Ratchadaporn
Published: August 2017

In this research, sodium silicate (Na2SiO3) was prepared by rice husk ash reacted with 10 M sodium hydroxide. The mixtures were heated by microwave at 400, 600, and 800 watt for 5 and 10 minutes. The formation of sodium silicate was characterized by Fourier transform infrared spectrophotometer. The vibrations of (Na)O–Si–O(Na) and O–Si–O were observed at 595 and 1023-986 cm-1, respectively, except at 800 watt disappeared those vibrations. The results of flame atomic absorption spectrophotometer provided the mole ratio of sodium and silicon was 2:1 as heating the product at 600 watt for 5 and 10 minutes. The phase of sodium silicate was characterized by X-ray diffraction. Sodium silicate could be used as catalyst as in biodiesel production from palm oil. The percentage of yield was 81 by volume.
Characterisation of NiO-YSZ Porous Anode-Support for Solid Oxide Fuel Cells Fabricated by Ceramic Injection Moulding
Authors: Chuankrerkkul Nutthita , Chauoon Sirima , Meepho Malinee , Pornprasertsuk Rojana
Published: August 2017

Ceramic injection moulding (CIM) has advantages for a cost effective fabrication of large-scale, near-net-shape products. In this work, CIM is carried out to prepare porous anode-support for solid oxide fuel cells (SOFC) applications. The CIM process started with a preparation of feedstocks by mixing powder with binder. The feedstock is then injected into the mould of desired shapes. The mouldings were subsequently undergo the removal of the binder (debinding) and, finally, sintering. It is shown that porous nickel oxide-yttria stabilized zirconia (NiO-YSZ) anode-support for SOFC were successfully prepared by CIM technique. In addition, a water-soluble based binder system, consisted mainly of polyethylene glycol (PEG), has been used in this work. This is to avoid the use of organic solvents when wax-based binder was used. Therefore, it can promote more environmentally friendly process. The removal of binder was carried out using water debinding technique. The porous anode for SOFC was subjected to systematic characterisation. The effect of processing parameters, such as powder characteristics and powder/binder ratio has been investigated. Rate of binder removal was also studied. The porous anode specimens were characterised for their properties and microstructure. It was also found that the porosity of the specimens can be controlled by adjusting the sintering temperatures and holding times.
Microstructure, Hardness and Wear Properties of Sintered Fe-Mo-Si-C Steels with Spheroidal Graphite Iron/Compacted Graphite Iron-Like
Authors: Ruangchai Kittikhun , Wiengmoon Amporn , Morakotjinda Monnapas , Krataitong Rungtip , Tanprayoon Dhritti , Yotkaew Thanyaporn , Tosangthum Nattaya , Patakham Ussadawut , Tongsri Ruangdaj
Published: August 2017

Sintered Fe-Mo-Si-C steels were prepared from pre-alloyed Fe-0.85Mo powder added with fixed 4wt.% silicon carbide powder and varied graphite powder contents. It was found that the graphite powder addition caused morphological change from black nodular to black vermicular particles and resulted in decrease of black nodular/vermicular particle fraction, increase of pearlite fraction and slight change of ferrite fraction. The black nodular particles were either graphite or Fe-Mo-Si-C/graphite core-shell particles whereas vermicular particles were totally composed of carbon. The microstructural features showed influence on mechanical property of the sintered Fe-Mo-Si-C alloys. Wear properties of the sintered steels were strongly affected by their microstructural components. The sintered Fe-0.85Mo+4wt.%SiC steels showed highest friction coefficient and volume loss. Addition of graphite to the sintered Fe-0.85Mo+4wt.%SiC steels, not only changed morphology and chemistry of black particles but also reduced friction coefficient and volume loss. The reduction of both determined wear properties were attributed to the presence of vermicular graphite particles.
Influence of Bi2O3 on Crystalline Phase Content and Thermal Properties of Åkermanite and Diopside Based Glass-Ceramic Sealant for SOFCs
Authors: Lawita Pornchanok , Theerapapvisetpong Apirat , Jiemsirilers Sirithan
Published: August 2017

Solid oxide fuel cell (SOFC) is an electrochemical energy conversion device which is considered as clean energy source generator with reliability and relatively inexpensive production cost. One of the most important components for planar design SOFC is the hermetic seal that prevents fuel from leaking out of between the stack of fuel cells. Glass-ceramics are attractive materials as sealing materials for this device. The expected coefficient of thermal expansion (CTE) of the glass-ceramic sealants should be between 9 and 12 x 10−6 K−1. Glass – ceramics based on åkermanite (Ca2MgSi2O7) crystalline phase were reported their high CTE value from about 10 to 11.3 x 10−6 K−1. In this study, glass compositions in the CaO-MgO-B2O3-Al2O3-SiO2 system with varying amounts of Bi2O3 from 0 to 10 wt. % were prepared by conventional melting and investigated their properties. The selected compositions were derived from ternary åkermanite–forsterite–anorthite phase diagram. Phase composition and quantitative phase analysis of glass–ceramics were examined by X-ray diffractometer. The onset of crystallization (Tx) and crystallization temperature (Tc) were measured by DTA. The thermal properties of bulk glass samples and heat treated samples at 900 oC for 2 h which were glass transition temperature (Tg), dilatometric softening temperature (Ts), and coefficient of thermal expansion (CTE) were determined by dilatometer. Furthermore, the long-term stability of their CTE was investigated. The samples were continued to soak at 800 °C for 100 h and observed their change in CTE value. The results found that the åkermanite phase tended to increase with increasing amount of Bi2O3 content.
Synthesis of Ternary Semiconductor Silver Bismuth Telluride by Chemical Bath Deposition
Authors: Termsaithong Patamaporn , Rodchanarowan Aphichart
Published: August 2017

In this study, the synthesis of the ternary semiconductor sensitized silver bismuth telluride (AgBiTe2: SBT) particles was produced in the solution of AgNO3, Bi (NO3)3×5H2O and Na2O3Te by using a chemical bath deposition (CBD) method and annealing at 200°C for 1 h. According to scanning electron microscopy (SEM), the particle size of SBT after annealing was bigger than before annealing. Based on X-ray diffraction, the SBT after annealing for 1h became more crystalline. In addition, the XRF data also demonstrated that the SBT powder consists of Ag, Bi, and Te as dominant elements. The XRD result confirms a successful growth of the SBT particles with rhombohedral crystal structure. Based on the obtaining results, the SBT particles were successfully synthesized and potentially applied for solar cell application.
Zeolite Supported Bimetallic Catalyst System: The Effect of Metal Loading for Catalytic Pyrolysis of Jatropha Residue
Authors: Goodwin Vituruch , Amnaphiang Phanwatsa , Thungngern Pimpreeya , Shin Kong Kah , Udomsap Parncheewa , Chollacoop Nuwong
Published: August 2017

Two transition metals were loaded on H-ZSM-5 zeolite to produce bimetallic zeolite supported catalysts for catalytic pyrolysis reaction. Ni and Co metal were loaded on H-ZSM-5 via wet impregnation method. The loading sequence was applied using one-step and two-step loading method. The different loading sequence affect surface properties of catalyst and catalytic activity in pyrolysis reaction. The bimetallic catalysts were prepared at Ni+Co metal loading content of 10+10 wt% (Ni:Co=1:1) to 10+20 wt% (Ni:Co=1:2 or 2:1). All bimetallic catalysts supported on H-ZSM-5 were calcined and characterized by X-ray Diffraction (XRD), Surface area analysis (BET) and Temperature Programmed Desorption of ammonia (NH3-TPD). The XRD patterns of bimetallic zeolite supported catalysts revealed that loading of two metals at high content affect crystalline structural of ZSM-5 support. All XRD patterns illustrated peaks characteristic of ZSM-5, cobalt oxide and nickel oxide. The NH3-TPD results showed number of acid sites of the catalyst which revealed that the acid sites of ZSM-5 support was weakened with transition metal added. The two-step loading of 10+20 wt% metals on ZSM-5 reduced the peak intensities of NH3 desorption due to the metal particles aggregate on acid sites of ZSM-5. The two-step 10+20 wt% bimetallic catalysts has the lowest surface acidity, followed by the one-step 10+20 wt%, the two-step 10+10 wt% and the one-step 10+10 wt% bimetallic catalysts, respectively. Jatropha residue was used for catalytic pyrolysis study. Jatropha residue and bimetallic catalyst was pyrolyzed at 500 °C in a pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The product vapor was analyzed by GC/MS for the different groups of organic products such as fatty acid, aldehydes, ketones, aliphatic hydrocarbons, aromatic hydrocarbons and nitrogen compounds. The product from catalytic pyrolysis of jatropha residue with bimetallic zeolite supported catalysts enhance deoxygenation reaction that resulted in high aliphatic and aromatic hydrocarbons product. The one-step loading at ratio Ni:Co = 1:1 (10+10 wt%) gave the highest hydrocarbons product yield at 57.81%.
Effect of Silica Base Catalyst on Transformation of Methanol to Hydrocarbon
Authors: Lao-Ubol Supranee , Somwongsa Phunthinee , Laoauyporn Pracha , Panith Pasinee , Larpkiattaworn Siriporn , Chen Shih Yuan
Published: August 2017

Five different types of silica catalyst (SBA-15, SBA-15-PO3H2, and three different Si/Al ratio of commercial zeolites (30, 80 and 280) were used to study the transformation of methanol to hydrocarbon (MTH). The aim of this study was to investigate the effect of pore diameter and acidity in the structure of silica catalysts on the process performances in terms of methanol conversion and hydrocarbon selectivity. The mesoporous silica catalysts were prepared by co-condensation method. The catalysts samples were characterized by GC-MS, XRD, BET, and NH3-TPD techniques. The catalytic performance of synthesized and commercial catalysts for MTH process was evaluated using a homemade fixed bed reactor at temperature (300°C). It was found that the liquid hydrocarbon product provided by zeolite catalysts is aromatic hydrocarbons-rich. High Si/Al zeolites with larger pore size lead to higher selectivity and yield to paraffins (C1-C7). In contrast to commercial zeolite catalyst, SBA-15 and its modification with phosphorus species showed no conversion under studied condition. These results indicate that both pore diameter and acidity influence the product distribution in methanol to hydrocarbon process.
The Mechanical Properties Study of Waste Bakelite Aggregate Concrete
Authors: Usahanunth Nopagon , Kongsong Waranon , Tuprakay Seree , Ruangchuay Tuprakay Sirawan , Sinthaworn Suppachai , Charoenrien Sathian
Published: August 2017

This paper focuses on industrial thermosetting plastic waste reduction by recycling as the material for natural coarse aggregate replacement in concrete. This substitution of aggregate is an integration approach to preserve the natural resources and environment as well as develop the alternative recycled aggregate material to meet 3R principle and sustainable development. Bakelite waste is prohibited from disposing of sanitary landfill and direct burning because of hazardous disposal and emission reasons .There are many studies of plastic aggregate to substitute natural coarse aggregate especially PET and PE aggregate. However, there is no study of Waste Bakelite Aggregate (WBA) mixed in concrete in Thailand. This study aim is investigating the mechanical properties of Waste Bakelite Aggregate Concrete (WBAC) compare to conventional concrete (CC).The methodology is based on an experimental program by testing of concrete specimens. The data obtained from sample test according to BS standard. These test results present compressive strength of all samples both CC and WBAC. The relationship charts between mechanical properties and the waste Bakelite aggregate replacement percentage will be illustrated including the compressive strength predictable equation model. Furthermore, the chemical extraction test of waste Bakelite aggregate concrete and the durability of WBAC are notified for the utilization. WBAC is an alternative material that can be applied to the non-structural concrete product to replace the natural aggregate and helpful in waste plastic pollution mitigation.
In Vivo Testing of Sericin-Polyurethane Nanofiber Mats for Wound Healing in Rats
Authors: Kampeerapappun Piyaporn , Siridamrong Pornpen
Published: August 2017

The objective of this study was to investigate sericin-polyurethane nanofiber cover (SUC) for wound dressing materials in a rat skin. Sericin-polyurethane blended nanofibers were fabricated by using electrospinning. The composition of 3%w/v polyurethane in ethanol and 19% w/v sericin were blended and electrospun at 15 kV, 20 cm from tip to collector with a feed rate of 6.2 ml/hr. The mats, approximately 1.5 mm thick, were sterile by gamma irradiation with a radiation dose of 15 kGy. The samples of in vitro and in vivo testing were separated into three groups; gauze, polyurethane nanofiber cover (UC), and SUC. In vitro cultured L929 cell lines were investigated with inverted microscope. It was found that cells migrated to SCU. For in vivo tests, the remaining wound in rats was measured on day 2-14 after excision. Compared to original size of wound samples, the size of the wound remained 24% for SUC, 33% for gauze, and 34% for UC at day 8. The sericin, an active agent, contained in SUC mats was about 5 µl at 1.5 ×1.5 cm. It can be concluded that sericin is non-toxic to cells and can promote wound healing process in rats.
Fluoride Recharge Ability of Resin-Based Pit and Fissure Sealant with Synthesized Mesoporous Silica Filler
Authors: Surintanasarn Atikom , Siralertmukul Krisana , Thamrongananskul Niyom
Published: August 2017

The aim of this study was to examine the effects of active filler in resin-based pit and fissure sealant on fluoride release and recharge abilities. Mesoporous silica was synthesized from tetraethyl orthosilicate (TEOS) using sol-gel method. Resin-based sealant was incorporated with 5% w/w of filler (<45 μm): synthesized mesoporous silica (S), calcium carbonate (C), and fluoro-alumino silicate glass (F). Resin-based sealant without filler added was the control. Ten specimens of each group were separately stored in 3 mL of deionized water and the fluoride concentration, before and after fluoride recharge, were measured every 3 days (from day 3 to day 27). Fluoride release before recharge was only found in F (0.1024±0.0077 ppm) and then gradually decreased to baseline. After two recharges, the highest fluoride release was found in S (0.0804±0.0095 ppm after first recharge and 0.0601±0.0092 after second recharge), followed by F (0.0386±0.0024 ppm after first recharge and 0.0313±0.0027 ppm after second recharge), and then decreased to baseline. Fluoride recharge was not found in C and control. This result suggested that resin-based pit and fissure sealant containing synthesized mesoporous silica filler has fluoride recharge ability which might prevent secondary caries at material-enamel interface.
Effect of Process Parameters on Biomimetic Deposition of Calcium Phosphate on 3D Printed Hydroxyapatite
Authors: Thammarakcharoen Faungchat , Suwanprateeb Jintamai
Published: August 2017

Factors influencing calcium phosphate deposition on three dimensional printed hydroxyapatite (3D printed HA) by biomimetic process including soaking times (2, 4 and 6 hrs), solution temperatures (23, 37 and 50 °C) and solution refreshment (refreshed and non-refreshed) were studied. It was found that the weight change of the samples increased with increasing soaking times at all temperatures regardless of solution refreshment. Using refreshed solution resulted in greater increase in weight change than using non-refreshed solution. In the case of solution temperature, two opposite trends were observed depending on the solution refreshment. Increasing solution temperatures in non-refreshed solution exhibited a decrease in the weight change whereas the increase in the weight change was observed when using refreshed solution. This could be related to the competition between the dissolution of 3D printed HA and the deposition of new calcium phosphate crystals during biomimetic process. Octacalcium phosphate and HA were found to be the main phases of biomimetically deposited 3D printed HA.
Mechanical Properties of As-Exposed Al-SiCp Composite Fabricated by Powder Injection Moulding
Authors: Patcharawit Tapany , Ngeekoa Arada , Tongkerd Wanphen , Takhampom Sutam , Lapkeaw Supitcha , Chuankrerkkul Nutthita
Published: August 2017

This research investigated mechanical degradation of powder injection moulded SiCp-reinforced aluminium composite subjected to moderate temperature exposures. Aluminium composite of 20 vol.% SiCp reinforcement was produced by powder injection moulding and sintering at 680°C, followed by 500°C solution treatment plus 150°C for 6 hours artificial aging, and subsequent exposures at 100, 200 and 300°C for 10 and 100 hours. It was found that short-term exposure for 10 hours provided increasing hardness with increasing exposure temperature, while long-term exposure for 100 hours led to an opposite result. The maximum micro Vickers hardness was obtained at 182.2 Hv for Al-SiCp composite exposed at 300°C for 10 hours. Tensile strength was however found deleterious with increasing both exposure temperature and time. The maximum tensile strength was achieved at 191.2 MPa for Al-SiCp composite exposed at 100°C for 100 hours. The formations of AlN, Mg2Si and Al2Cu were observed in both age-hardened and as-exposed conditions. Furthermore, the highest temperature exposure at 300°C and extended exposure time at 100 hours resulted in the lowest hardness and tensile properties due possibly to the loss of coherency of precipitates. SiCp clusters were the main cause of the tensile failure.
Effect of M-Type Hexaferrites on Mechanical and Magnetic Properties of Hydroxyapatite Ceramics
Authors: Wongmaneerung Rewadee
Published: August 2017

The overall aim of this study is to establish the inter-relationships between phase formations, mechanical properties and magnetic properties of the novel ceramic in hydroxyapatite system for biomaterial applications. First, barium hexaferrite and strontium hexaferrite powders were prepared as M-type hexaferrite phases. Hydroxyapatite was prepared from cockle shells via co-precipitation method. After that, a combination between hydroxyapatite+barium hexaferrite and hydroxyapatite+strontium hexaferrite was mixed together then shaping and sintering at 1200 °C for 2 h. The sintered samples were characterized phase formation, mechanical and magnetic properties by using X-ray diffraction (XRD), Universal testing and VSM measurements, respectively. XRD patterns for all samples showed a combination between hydroxyapatite and hexaferrite phases. Compressive strength of all samples tends to increase with increasing of the amount of hexaferrite phases due to densification mechanism. However, the increasing of these values, it appears that there is no difference in the statistical significant. For magnetic properties, the coexistence of barium hexaferrite and strontium hexaferrite phases reveals magnetic hysteresis loops, showing the change from diamagnetic to ferromagnetic behavior.
Effect of Solids Loadings, Sintering Temperatures and Sintering Periods on Microstructure of Hydroxyapatite
Authors: Jongprateep Oratai , Nueangjumnong Chonthicha , Palomas Jednupong
Published: August 2017

Attributed to its biocompatibility and osteoconductivity, hydroxyapatite (HAp, Ca10(PO4)6(OH)2) has been extensively utilized as a bioactive material. As the implant material, HAp is required to be fabricated into a porous form. The present study was therefore aimed at synthesizing HAp powder by solution combustion technique and at fabricating porous HAp specimens. Calcium nitrate and ammonium dihydrogenphosphate (NH4H2PO4), with Ca/P ratio equal to 2.3, were used as initial reagents in the HAp synthesis process. X-ray diffraction analysis confirmed that HAp was present as the primary phase, while minor secondary phases, Tri-calcium phosphaste (TCP) and CaO, were also observed. To prepare porous specimens, HAp slip with solids loadings ranging from 15 to 25 vol% was cast into acrylic molds and sintered. The sintering temperatures were 1350°C and 1450°C, and sintering periods ranged from 2 to 4 hours. Results from microstructural analysis revealed that high solids loadings, sintering temperatures and sintering periods resulted in decreasing of porosity. Porosity in the range between 30 and 90%, which was in an acceptable range for orthopedic applications, was observed.
Effect of Bleaching on Color Change of Stained Resin Composites
Authors: Raksakmanut Ratcha , Nithipratheep Ampaporn , Weeriyanan Ornjira , Pittayaporn Panida , Komonpale Waivich , Techakunakorn Trong , Luanprueg Nuttaporn , Promserane Jakgree
Published: August 2017

The aim of this study was to evaluate the effects of bleaching on color change of stained resin composites. Ninety disk-shaped specimens were prepared with 3 different composite materials (Estelite ∑ Quick, Premise, and Filtek Z350 XT). After stored in artificial saliva at 37°C for 24 hours in an incubator, the 30 specimens of each material were divided into 3 subgroups and immersed in either coffee, red wine, or artificial saliva (control) at 37°C. After 24 days, spectrophotometric measurement was performed. After the staining process, the bleaching agent (Opalescence, 10% carbamide peroxide) was applied to the surface of the specimens, 8 hours per day for 14 days. After the bleaching process, spectrophotometric measurement was performed. The color differences between specimens before and after bleaching were statistically significant (ΔE*ab>3.3) for all composites in the red wine staining. The highest-level color change after bleaching was observed for Filtek Z350 XT in red wine staining, while the least value was found in Estelite ∑ Quick in coffee staining. In summary, color changes of all red wine-stained composites after bleaching were noticeable and have higher level of color change than coffee-stained composites.
Flexural Strength and Cytotoxicity of ZCC, a Resin Modified Zinc-Calcium Liner Prototype
Authors: Thunyakitpisal Pasutha , Thunyakitpisal Nonglax , Jiemsirilers Sirithan , Pongkao Kashima Dujreutai
Published: August 2017

Objective: To investigate the flexural strength and cytotoxicity of ZCC, a resin modified zinc oxide-calcium carbonate liner prototype, compared with commercial dental liners.
Materials and Methods: ZCC, Dycal, Ultra-Blend® plus (UB), and TheraCal LC® (TC) were evaluated for flexural strength. Six samples of each material were incubated in growth medium (10% fetal bovine serum supplemented DMEM) for 24 h. Primary human dental pulp cells were cultured in the conditioned medium from each sample, with growth media used as a control. Cytotoxicity was determined using an MTT assay. Data were analyzed by one-way ANOVA. The value of p<0.05 was considered significant.
Results: UB had the highest flexural strength with Dycal presenting the lowest values (p<0.05). ZCC demonstrated significantly higher flexural strength values compared with those of TC and Dycal (p<0.05). The MTT assay indicated that Dycal conditioned media significantly reduced cell viability at 24 and 48 hours (p<0.05). There was no significant difference in viability between the control, ZCC, UB, and TC groups at 24 and 48 hours (p>0.05).
Conclusion: ZCC met the requirements for flexural strength per ISO 9917-2:2010(E). There was no significant difference in viability between the control and ZCC group at 24 and 48 hours.
Preparation of Activated Carbon from Sugarcane Bagasse Waste for the Adsorption Equilibrium and Kinetics of Basic Dye
Authors: Chaiwon Tawan , Jannoey Panatda , Channei Du Ang Dao
Published: August 2017

This research aimed to study the preparation of activated carbon from sugarcane bagasse waste. The sugarcane bagasse adsorbent was prepared by calcination at 600°C for 2 hours with the use of sulfuric acid (H2SO4) as a chemical activation. The adsorption surface possessed high specific surface area (838 m2/g) with mesoporous diameter. Factors explaining adsorption including adsorption isotherm, adsorption kinetic and adsorption mechanism were constructed from methylene blue adsorption experiments. It was found that the equilibrium data was best represented by Freundlich isotherm, showing multilayer coverage of dye molecules at the outer surface of adsorbent with a cooperative adsorption (physisorption and chemisorption). The kinetic of methylene blue adsorption was found to follow pseudo-second-order rate kinetic model, with a good correlation coefficient. This indicated that the overall rate of the dye adsorption process was controlled by the chemisorption process.
Exploitation of Ag3PO4 Impregnated Alginate Beads for the Photocatalytic Degradation of Dye Solution under Sunlight Irradiation
Authors: Wanchai Katnanipa
Published: August 2017

Ag3PO4-alginate beads (AAB) were synthesized by simple precipitation method and their structure was characterized by XRD, FT-IR and SEM/EDS, respectively. The AAB was evaluated as the photocatalyst for degradation of methylene blue (MB) under sunlight irradiation. The results showed that AAB exhibited the high performance for degradation of MB (97.6%) in 60 min. The kinetic studied demonstrated that the photocatalytic reactions followed the pseudo first-order model. Moreover, AAB can maintain full photodegradation activity for at least five cycles. Consequently, the AAB are promising materials for the photocatalytic of dyes or similar organic contaminant in environmental pollution cleanup.
Hardfacing of 3.5% Chromium Cast Steel by Flux Cored Wire Arc Welding Process
Authors: Treeparee Teerachod , Muangjunburee Prapas
Published: August 2017

Hardfacing weld is a technique which mainly improves and extends the useful life of engineering components. The purpose of this research is to improve welding procedure for one layer and three layers hardfacing of 3.5% Chromium cast steel and to study wear behavior of hardfacing layers. Flux Cored Wire Arc Welding (FCAW) process has been used as a welding process of this research by choosing austenitic stainless steel and martensitic hardfacing wire to weld the buffer and hardfacing layer respectively. Preheating was also used in this study. Abrasive wear test of hardfacing deposit were conducted in accordance with procedure “A” standard of ASTM G65. In addition, microstructures and macrostructure of worn surface deposits were analyzed by using optical microscope. These results showed that there is no crack and defect in the Heat Affected Zone (HAZ) and other regions. The hardness of preheating sample in HAZ regions was lower than the ones without preheating. Therefore, preheating samples should be done before welding. The abrasive wear resistance of three layers hardfacing deposit was better than one layer hardfacing deposit because one layer hardfacing deposit was more diluted from buffer layer than three layers hardfacing deposit. Moreover, weight loss of one hardfacing layer was also higher than three layers.
Fabrication Study of Hydrophobic Polyurethane Sponge for Oil Absorption Application
Authors: Prakulpawong Peeranut , Wiriyanantawong Jinjutha , Pornpoonsawat Janista , Yodyingyong Supan , Triampo Darapond
Published: August 2017

In this research, the researchers study the fabrication of oil absorption, hydrophobic polyurethane (PU) sponge for application in an oil-spill cleanup model. Virgin PU is initially hydrophilic. PU is made hydrophobic by incorporating hydrophobic silica aerogel (SA) into PU 3D porous structure by stirring method and UV-treatment method. UV-irradiation promotes the attachment of SA onto the PU surface. Varying UV irradiation time and concentration of SA is done to attain an optimal attachment of SA on PU. Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), contact angle measurements (CA) are used to determine the adhesion of SA on PU. The loadings of SA with and without UV-treatment are compared. Results show that SA-PU with UV-treatment has more loading of SA than SA-PU without treatment. FT-IR spectra and SEM micrographs verify the results. Moreover, the SA-PU is tested for oil absorption to simulate oil-spill cleanup. The findings show fast (less than 3 seconds), recoverable oil-spills cleanup with simple method of preparation. In addition, SA-PU with UV treatment has higher absorption rate and %absorption efficiency when compared to original PU and SA-PU without UV treatment.
The Effect of Carboxymethyl Cellulose from Various Agriculture Wastes on the Viscosity and Physical Properties of Low Concentration Solution of Surfactant
Authors: Sritapunya Thritima , Sommanas Gulisara , Surachaijarin Hathairat
Published: August 2017

The goal of this work was the synthesis and the improvement of viscosity of surfactant with carboxymethyl cellulose (CMC) from different types of agriculture wastes to reduce a quantity of wastes. Cavendish banana peels, corn silk and bagasse as agricultural wastes were selected to synthesis CMC by extraction with NaOH to cellulose. Then cellulose was modified by reacting with monochloroacetic acid to obtain CMC which was investigated the functional group by Fourier Transform Infrared Spectrometer (FTIR). Moreover, a 0.5 wt% of synthesized CMC was prepared in 14 wt% of sodium lauryl sulfate (SLS) solution to estimate viscosity by rotational viscometer, transparency by visible spectrophotometer and stability by observation, comparing with commercial thickener (PEG400). The results showed that CMCs of all three agriculture wastes can increase the viscosity of the surfactant solution and more increase than solution with PEG400. The SLS solution containing the CMC of corn silk provided the highest viscosity of 22.4 Cp by rotation speed of 250 rpm. However, the values of transparency and stability of surfactant solution with CMCs are slightly lower than that of solution with PEG400, except for the addition of CMC from bagasse, it was precipitated in yellow color in a short time.
Adsorptive Properties of Fly Ash Zeolite Synthesized via Microwave and Ultrasonic Pretreatments
Authors: Setiabudi Agus , Nashrah Nisa , Putri Hanifah Permana , Yuliani Galuh
Published: August 2017

Being abundant and hazardous solid waste, the utilization of fly ash was sought. This study aimed to convert coal fly ash into zeolite using reflux method combined with microwave and ultrasonic pretreatments. Fly ash was reacted with NaOH 2 M, ultrasonicated for 30 minutes and irradiated using microwave for 45 minutes. The resulting solution was then refluxed for 24 hours. The zeolite formation was confirmed by FTIR and XRD analysis. The zeolite was then activated by 20% HCl for 2 hours. Fly ash, zeolites and activated zeolite were characterized for their adsorptive properties using a cationic dye via batch experiment. The maximum adsorption capacity (Qm) of fly ash, zeolite, and acid activated zeolite were 0.0003 mg g, 51 mg/g, and 101 mg/g, respectively. BET analyses indicated that the surface area of fly ash was 7 m2/g, while that for zeolite and acid activated zeolite were 82.4 m2g and 82.6 m2/g, respectively. The FTIR showed the Si-OH groups were significantly enhanced upon acid activation indicated by absorption peak at 960-1100 cm-1. It can be concluded that the chemisorption via cation-exchange or monolayer interaction played a major role in the adsorption mechanism of zeolite, supported by the allignment of the adsorption data plots to Langmuir isoterm adsorption model.
Photo-Oxidative Degradation Polyethylene Containing Titanium Dioxide and Poly(Ethylene Oxide)
Authors: Soitong Tawat , Wongsaenmai Supattra
Published: August 2017

Biodegradable Polyethylene (PE) may be used in the fabrication of plastic films which can replace common films prepared from nondegradable polymers. A photodegradable polyethylene composite film was prepared by mixing titanium dioxide/poly(ethylene oxide) into the PE matrix (PE/TiO2/PEO). The composites films were prepared using 0-3 wt.% of TiO2 and 0-10 wt.% of PEO by melt mixing. It was then compression molded in to films at 180 ◦C. The photo-degradation test was performed under 400 W UV lamp in the ambient air. The resulting composite materials were investigated by the Fourier transform infrared spectra (FTIR), Scanning electron microscope (SEM), weight loss monitoring, and Differential scanning calorimeter (DSC). The PE/TiO2/PEO composites film showed a high photocatalytic activity, the weight loss rate of it is about two times higher than that of PE/TiO2 film and ten times higher than that of neat PE film. The FTIR spectra films after UV irradiation showed that the carbonyl peak intensity for composite films the intensity is greater than that of neat PE film. The degraded PEO produced an acid and an aldehyde, which were able to facilitate PE degradation and the addition of PEO/TiO2 brought about the facilitative effect of the PE degradation.
Photocatalytic Activity of Cu-Doped Cerium Dioxide Nanoparticles
Authors: Channei Du Ang Dao , Jannoey Panatda , Nakaruk Auppatham , Phanichphant Sukon
Published: August 2017

Pure CeO2 and Cu-doped CeO2 nanoparticles with different doping amounts of Cu in the range of 0.5-2.0 wt.% were synthesized by the combination of homogeneous precipitation and impregnation methods. The effect of Cu on the correlation of structural, optical and photocatalytic properties of CeO2 were studied. The XRD results indicated that phase structures of pure CeO2 and Cu-doped CeO2 nanoparticles were cubic fluorite phase and no other characteristic peaks related to Cu were detected. TEM images revealed that all samples were spherical in shape with the size less than 10 nm. The shift of absorption edge of Cu-doped CeO2 catalysts, corresponding to a decrease of band gap energies from 3.2 to 2.8 eV, was also observed as the amount of Cu dopant increased. The photocatalytic performances of the Cu-doped CeO2 exhibited higher activity than pure CeO2 for photocatalytic degradation of methylene blue under visible light irradiation, and the CeO2 doped with 1.0 wt.% Cu exhibited the highest photocatalytic activity.
Comparison Study of Photocatalytic Activity of Titanium-Rich Materials Derived from Natural Minerals Ores Using Acidic Leaching
Authors: Kansaard Thanaphon , Phoohinkong Weerachon , Mekprasart Wanichaya , Sanguanpak Samanya , Wannagon Anucha , Pecharapa Wisanu
Published: August 2017

Over past decades, titanium dioxide-based materials have been recognized as effectively practical photocatalysts for purification of toxicity waste. However, pure TiO2 photocatalyst is highly active under ultraviolet illumination. In this work, the effort has been focused on the synthesis of titanium-rich materials starting from minerals ores ilmenite ores and leucoxene ores by ball-milling process in combined with hydrochloric acid leaching method with optimized conditions. Crystallinity and morphologies of as-prepared samples were characterized by X-rays diffraction technique and scanning electron microscope. The photocatalytic activities of both derived-materials were studied and compared by degradation of Rhodamine B organic dye as organic toxicity compound under ultraviolet light and visible light. The results illustrate that the leucoxene-derived sample exhibits superior catalytic performance to the sample derived from ilmenite ores due to the greater Ti-content of the starting leucoxene ores.
Synthesis and Impedance Spectroscope of B-Doped La9.33+x/3(SiO4)6-x(BO4)xO2 Apatite Oxide Ion Conductor
Authors: Huang Zhao Xiang , Yu Kan , Liang Jun , Sheng Xiao Li
Published: August 2017

B2O3 was doped into the oxide ion conductor La9.33(SiO4)6O2 according to the formula La9.33+x/3(SiO4)6-x(BO4)xO2 where 0 ≤ x ≤ 2. Samples were prepared by solid state reaction; difficulty was experienced in obtaining fully homogenised products at intermediate x, although they were nominally single-phase by X-ray powder diffraction. A small conductivity enhancement was observed at intermediate B content which further illustrates the important role of La vacancies in optimising the conductivity of La silicates with the apatite structure.
Characterization Analysis According to Growth Temperature of Carbon Nanowall on Metal Coated Substrate for Electrode Application of Energy Storage
Authors: Park Jong Kug , Choi Won Seok , Hwang Hyun Suk , Lee Kyoung Hak , Kim Jung Hyun , Joung Yeun Ho
Published: August 2017

Secondary cells, which are the core storage media of energy storage systems (ESS), and carbon nanowalls (CNWs), which are expected to improve the performance of supercapacitors while being used as their electrodes, were investigated in this study. CNWs were directly grown on the substrate, and the substrate was a Si wafer with a nickel layer deposited on top of it. The nickel layer was deposited with the RF-magnetron sputtering method using a 4-inch Ni target. The CNWs were grown on the prepared substrate using microwave plasma-enhanced chemical vapor deposition (PECVD). The substrate temperature was changed from 550 to 800°C by 50°C increments to identify the growth characteristics according to the growth temperature. The surficial and cross-sectional images according to the temperature were analyzed using a field emission scanning electron microscope (FE-SEM). It was confirmed that the density of the CNWs increased along with the temperature. Especially, it was confirmed that the density increased dramatically at 750°C or higher.
A Study on Chicken Feather Filled Hybrid Glass Fiber - Polymer Composite
Authors: Kowshik C.S. Suhas , Hiremath Pavan , Shettar Manjunath , Naik Nithesh
Published: August 2017

In this study, hybrid composites were prepared using chicken feather as filler material. Hybrid composites were tested for tensile and flexural strength. Composites were prepared by hand-layup technique by varying the weight percentage of chicken feather (0, 4, 8 wt.%). Samples were tested according to ASTM standard. SEM images were studied to find the fracture and interfacial characteristics of the composites. Results indicated that, these composites can be used in domestic, automobile and structural applications, where minimal load is applied.
An Investigation of Dissimilar Welding Aluminum Alloys to Stainless Steel by the Tungsten Inert Gas (TIG) Welding Process
Authors: Nguyen Van Nhat , Nguyen Quoc Manh , Huong Thao Dang Thi , Huang Shyh Chour
Published: August 2017

Welding dissimilar materials has been widely applied in industries. Some of them are considered this as a strategy to develop their future technology products. Aluminum alloy and stainless steel have differences in physical, thermal, mechanical and metallurgic properties. However, selecting a suitable welding process and welding rods can solve this problem. This research aimed to investigate the T-joint welding between A6061 aluminum alloy and SUS304 stainless steel using new welding rods, Aluma-Steel by the Tungsten Inert Gas (TIG) welding process. The mechanical properties, the characteristics of microstructure, and component analysis of the welds have been investigated by the mechanical testing, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). As a result, the fracture occurred at the adjacent area between welding seam and A6061 alloys plate. The thermal cracking appeared at central welding-seam along the base metals if high welding current. A large amount of copper elements found in the welds due to using the new welding rod, Aluma-Steel rod.
Effects of Y on the Microstructure and Mechanical Properties of Mg-Zn-Y-Zr Magnesium Alloys
Authors: Wang Da Yu , Du Zhi Ming , Zhang Hong Juan , Chen Li Hua , Wang Chang Shun
Published: August 2017

Mg-Zn-Zr-Y billets with different mass fraction of Y (wt%(Y)=0.2%、0.5%、1.0%、1.5%、2.0%) was prepared by permanent mold casting. The increase in Y content has shown grain refinement effects on the microstructure morphologies of Mg–Zn–Y–Zr alloys. When the content of Y achieves 1.0 wt%, the grain refinement effect of the Y is most obvious than any more contents of the Y content. In the test result of XRD, the type of precipitated phase in Mg-Zn-Zr-Y alloys is related to atomic ratio of Y/Zn. With content of Y increases, atomic ratio of Y/Zn increases,the precipitated phase in alloy is changed from Phase I to Phase W. Tensile strength and extension rate of alloy increase with the increasing of Y content; When Y content reaches 1.0%, mechanical property reaches maximum value.When content of Y exceeds 1.0%, with the increasing of Y content, mechanical property of alloy declines gradually.
Observation of Furnace-Induction Quenched Microstructure in High Carbon High Chromium Steel
Authors: Mizobe Koshiro , Egawa Kohei , Kida Katsuyuki
Published: August 2017

There are two major heating methods used in industrial situations. One is furnace heating which is popular for mass production as it hardens the steel uniformly. The other is induction heating which is energy saving but hardens the steel unevenly. We developed a combined heat treatment method, furnace-induction heating (FIH), and observed the material structure using picral and nital etching.