bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of Filler-Rubber Interaction by Grafting of Acrylamide onto Saponified Natural Rubber under Ultraviolet Radiation as a Continuous Process
Authors: Dechnarong Nattanee , Nimpaiboon Adun , Sakdapipanich Jitladda
Published: August 2015

Silica and carbon black have been widely used as the main reinforcing fillers for improving the properties of natural rubber (NR). In a silica-filled rubber compound, it is known that the low compatibility between NR and silica affects the mechanical properties of rubber products. In order to overcome this drawback, the functionalized saponified NR (FSPNR) was carried out by grafting acrylamide (AM) onto the saponified NR (SPNR) under UV radiation as a continuous process. An increasing in the bound rubber content and Mooney viscosity was found as an increasing AM content. Storage modulus at low strain amplitude of the silica-filled FSPNR was lower than that of the raw NR. In addition, SEM micrographs showed the good dispersion of silica in FSPNR. These confirmatory evidences indicate the improvement of rubber-filler interaction and the reduction of filler-filler interaction by functionalization under UV radiation.
Improvement of Structure and Properties of Nanocomposite Foams Based on Ethylene-Vinyl Acetate (EVA)/Natural Rubber (NR)/Nanoclay: Effect of NR Addition
Authors: Julyanon Juthapat , Kaesaman Azizon , Sakai Tadamoto , Lopattananon Natinee
Published: August 2015

Nanocomposite foams made of ethylene-vinyl acetate (EVA), natural rubber (NR) and nanoclay were fabricated by mean of melt mixing in an internal mixer, and later foaming using azodicarbonamide through compression molding. Effect of NR addition (10-40 phr) into the EVA nanocomposite foam was studied. Characterizations by using Oscillating disk rheometer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and mechanical tests were performed. The XRD analysis showed that the clay was mainly intercalated by the rubber. The SEM analysis revealed that the EVA/NR nanocomposite foams had closed-cell structures. Foaming EVA/NR/clay with composition of 100/0/5 (phr/phr/phr) led to low cell density and large cell size. The EVA nanocomposite foam also had low tensile strength, low compressive strength and low elastic recovery. However, the foam cell structure, i.e., greater cell density and smaller cell size, was obtained when combined with NR. Moreover, the strength and elastic recovery of the EVA nanocomposite foam were improved when the NR was added, and the improvement level was increased with increasing NR content.
Influence of Processing Oil Based on Modified Epoxidized Vegetable Oil with N-Phenyl-p-Phenylenediamine (PPD) on Extrusion Process Behaviors of Natural Rubber Compounds
Authors: Moojea-Te Chalida , Rungvichaniwat Adisai , Sahakaro Kannika
Published: August 2015

Rubber processing oil based on modified epoxidized vegetable oils (m-EVO) was prepared by a reaction of epoxidized palm oil EPO) or epoxidized soybean oil (ESBO) with N-Phenyl-ρ-phenylenediamine (PPD) at a mole ratio of 1:0.5. The comparison of m-EVO with aromatic oil (Treated distillate aromatic extract, TDAE) on extrusion process behaviors (output rate, extrusion rate, screw efficiency, heat generation, die swell, extrudate appearance) of carbon black (N330) filled natural rubber (NR) compound was made. It was found that the mooney viscosity of m-EVO based natural rubber compounds are slightly higher than that of the TDAE based natural rubber compound (ML(1+4)100°C: m-ESBO 65.5±0.7; m-EPO 59.7±0.2; TDAE 56.5±1.0), which probably due to the poorer filler dispersion in the compounds. The extrusion process behaviors for output rate (g/min: m-ESBO 191.0±0.6; m-EPO 191.2±0.4; TDAE 195.5±0.6), extrusion rate (cm3/min: m-ESBO 179.6±0.6; m-EPO 183.2±0.4; TDAE 186.4±0.6) and screw efficiency (%: m-ESBO 30.8±0.6; m-EPO 31.4±0.4; TDAE 32.0±0.6). All the three compounds show similar extrusion process behaviors in which the TDAE based compounds shows a marginal higher values than the m-EVO as its lower mooney viscosity lead to a better flow. The m-EPO and m-ESBO based natural rubber compounds show very similar extrusion process behaviors. The heat generation (°C: m-ESBO 61.0±0.8; m-EPO 62.1±0.4; TDAE 63.1±1.0) and die swell (%: m-ESBO 11.0±0.7; m-EPO 11.0±0.5; TDAE 12.7±0.3) of the m-EVO based natural rubber compounds are slightly lower than those of the TDAE based natural rubber compound. As there are no significant differences in the extrusion process behaviors, with respect to extrusion process, m-EVO can be used to replace TDAE oil.
In Situ Reinforcement of PLA Using Nylon 6 in PLA/Nylon 6 Extrudate Blend via Twin-Screw Extrusion
Authors: Thongpin Chanchai , Chaemprasith Kullanith , Teeralertpanich Jakapan , Saensuk Parisara , Kritape Nontawat
Published: August 2015

This research was aimed to study the possibility of in-situ reinforcement of PLA by elongated Nylon 6 in PLA/Nylon 6 blend during elongating of PLA/Nylon extrusion. PLA was melt blending with Nylon 6 in a twin screw extruder with various compositions i.e. 5, 10, 15 and 20 % of Nylon 6. The extrudate was drawn after leaving extrusion orifice die of 3 mm in diameter, with the pulling speed of 12 cycles per minute. The extrudate gauge length 15 cm were used to perform tension test in order to investigate tensile properties. The blending between PLA and Nylon 6 with 11 phr of benzene sulfonamide (BSA), based on Nylon 6, as a plasticizer was also investigated at the same PLA/Nylon 6 blend ratios. The extrusion used conditions were also the same. Tension was also performed onto the extrudates with the gauge length 15 cm. Thermal degradation was also investigated. The SEM micrographs of blends in the longitudinal direction of PLA/Nylon 6 extrudate showed elongated of Nylon 6 in PLA matrix phase. The elongated of Nylon 6 phase in PLA matrix phase was found very clear in the plasticized blends. This phenomenon clearly occurred for the blends composition of both 95/5 and 90/10, with and without plasticizer. The results also showed that Young’s modulus of the blends with 5 % Nylon 6 was increased about 10 % whereas at 10 % nylon 6, the modulus was not significantly different from neat PLA. With the addition of plasticizer, nylon 6 was elongated more than that in the blend with un-plasticized Nylon 6. Due to the lack in interfacial adhesion, shown by SEM micrograph, tensile strength was found to be decreased. As expected, the elongation at break under tension was increased with the content of nylon 6. This was due to the toughening effect of elongated Nylon 6. Thermal stability, notified by degradation temperature of PLA, Td, was found to be improved. This was due to the high thermal stability of nylon 6. The results from the research can inform that the elongated nylon 6 phase in PLA matrix can perform as fibrous reinforcement. At high content of nylon 6, i.e. 15 and 20 %, the elongation of nylon 6 was rather difficult due to the less matrix phase and low shearing between PLA and nylon 6. Phase compatibility improvement could be the factor to improve the in-situ reinforcement.
Investigation of Synthesis Parameters for Modification of Chitosan with Enrofloxacin
Authors: Srithongkham Saniwan , Sutcharee Piyawadee , Lertworasirikul Amornrat
Published: August 2015

This research aims to investigate synthesis parameters for modification of chitosan with enrofloxacin. Most modifications of chitosan are focused on amino group. There are many methods for modification of chitosan, for example, conjugation of amino group with carboxylic group by coupling agents. 1-Ethyl-3-(3-(dimethylamino) propyl) carbodiimide hydrochloride (WSC) andN-hydroxysuccinimide (NHS) are widely used coupling agents for amide formation under mild conditions. Those two coupling agents were applied in this study. Optimum amount and ratio of coupling agents, amount of enrofloxacin and reaction times were investigated. The chemical structures were characterized by Fourier transform infrared spectroscopy (FT-IR). The optimum synthesis conditions were determined from the absorbance ratios. Chitosan-enrofloxacin has antibacterial activity against bothS. aureusandE. coli.
Mechanical and Thermal Properties of Hemp Fiber Reinforced High Density Polyethylene Composites
Authors: Soitong Tawat
Published: August 2015

Hemp fiber reinforced composites was prepared using high density polyethylene (HDPE). Hemp fiber is a cellulosic fiber. It is used as reinforcement in thermoplastic matrix composite requires knowledge of their morphology and structure. In this paper, mechanical properties of chemically treated fiber reinforced HDPE composites were investigated over range of fiber content (0-50 wt%). The hemp fiber was alkali treated with 1-10 wt% to remove waxes and non-cellulosic surface components and triethoxyvinyl silane treated with 0.5-3 wt% to improve a better fiber-matrix interface. Fiber/matrix adhesion was assured by the use of use of polyethylene-graft-maleic anhydride (PE-g-MA) as a compatibilizer. Scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), X-Ray Diffraction (XRD) and tensile tests were carried out for hemp fibers high density polyethylene composite. Findings indicate that a 5 wt% NaOH treatment effectively improved the fiber-matrix interface resulting in improved mechanical properties. All 40 wt% alkali treated fiber reinforced HDPE composites displayed higher young’s modulus and lower elongation at break as compared to neat HDPE, compatibilization with PE-g-MA resulted in an increased young modulus of the composites as consequence of an improved fiber-matrix interfacial adhesion.
Mechanical and Thermal Properties of Silane Treated Pineapple Leaf Fiber Reinforced Polylactic Acid Composites
Authors: Pratumshat Supatra , Soison Phutthachat , Ross Sukunya
Published: August 2015

In this work, the mechanical and thermal properties of pineapple leaf fiber (PALF)/poly (lactic acid) (PLA) composites were studied. Pineapple leaf fibers were pretreated with 4 %wt sodium hydroxide solution followed by various silane solutions i.e. γ-(aminopropyl) trimethoxy silane (APS), γ-methacrylate propyl trimethoxy (A174) and bis [3-(triethoxysilyl) propyl] tetrasulfide (Si69). FTIR results show a significant functional groups of C=O and C=C of methacrylic group, NH2group and Si-O which are the characteristic of these silane coupling agents. SEM micrographs of pretreated PALF showed a rough surface while untreated and silane treated PALF revealed less roughness. It was found that the tensile strength at break of PLA is 56 MPa and tensile strength of composites decreased when fiber content increased. The tensile modulus of silane treated PALF composites were higher than PLA, whereas their impact strength were similar to PLA. Si69 treated PALF showed lower impact strength compared to the others silanes treated fiber which indicates more phase separation between fiber and matrix. This is related to high percentage of crystallinity of composite from Si69 treated fiber. It was also found that the addition of PALF did not change the glass transition temperature and melting temperature of PLA while the percentage of crystallinity increases as the fiber content increased. In addition WAXS study of composite from Si69 treated fiber reveals sharp crystalline peaks of PLA while the others silane treatments show amorphous characteristic of PLA.
Mechanical Properties of All-Cellulose Composites Made from Pineapple Leaf Microfibers
Authors: Tanpichai Supachok , Witayakran Suteera
Published: August 2015

Pineapple leaf microfibers were firstly prepared using steam explosion, and all-cellulose composites were subsequently prepared using a surface selective dissolution process with the solvent of lithium chloride and N,N-dimethylacetamide (LiCl/DMAc). Mechanical properties and surface morphology of all-cellulose composites with immersion times of pineapple leaf microfibers in the solvent of LiCl/DMAc were investigated using tensile testing and scanning electron microscopy, respectively. The tensile strength of the all-cellulose composites with 120 min-immersion time was approximately 28 times higher than that of the pineapple leaf microfiber mats. These biocomposites made from pineapple leaf microfibers could be one of the potential alternatives to replace glass fiber reinforced composites.
Morphology and Mechanical Properties of Polyoxymethylene and Acrylonitrile-Butadiene-Styrene Blends with Compatibilizer
Authors: Wacharawichanant Sirirat , Amorncharoen Parida , Wannasirichoke Ratiwan
Published: August 2015

The effects of polypropylene-graft-maleic anhydride (PP-g-MA) compatibilizers on the morphology and mechanical properties of polyoxymethylene (POM)/acrylonitrile-butadiene-styrene (ABS) blends were investigated. Two types of compatibilizers, PP-g-MA with maleic anhydride 0.50 wt% (PP-g-MA1) and PP-g-MA with maleic anhydride 1.31 wt% (PP-g-MA2) were used to study the interfacial adhesion of POM and ABS. POM/ABS blends with and without PP-g-MA compatibilizer were prepared by an internal mixer and molded by compression molding. Scanning electron microscope (SEM) was used to investigate the morphology of ABS phase in POM matrix. The results found that POM/ABS blends clearly demonstrated a two phase separation of dispersed ABS phase and the POM matrix phase, and ABS phase dispersed as spherical domains in POM matrix in a range of ABS 10-30 wt% and the blends containing ABS more than 30 wt% showed the elongated structure of ABS phase. The addition of PP-g-MA could improve the interfacial adhesion of POM/ABS blends due to the domain size of ABS phase decreased after adding PP-g-MA. The mechanical properties showed that the impact strength of POM/ABS blends decreased in a range of 10-20 wt% and did not change after 20 wt%. The addition of PP-g-MA did not change the impact strength of POM/ABS blends. The Young’s modulus of POM/ABS blends increased up to 30 wt% of ABS and then decreased. While the blends showed the decrease of tensile strength and percent strain at break with increasing ABS content. The addition of PP-g-MA increased the tensile strength of POM/ABS blends in a range of 30-40 wt% of ABS. The above results indicated that the morphology had an effect on the mechanical properties of polymer blends.
Surfactant Treatment and Leaching Combination Process for Preparation of Deproteinized Natural Rubber Latex
Authors: Suksaeree Jirapornchai , Taweepreda Wirach , Pichayakorn Wiwat
Published: August 2015

This study aimed to improve the efficacy of protein removal from fresh natural rubber latex (NRL) and to decrease the production cost by using surfactant treatment and leaching combination processes. The 0.5-3% anionic surfactants, i.e. sodium dodecyl sulfate or sodium lauryl ether sulfate, nonionic tween80 surfactant, or an amphoteric cocamidopropyl betaine surfactant was used in surfactant treatment process. Moreover, water, aqueous surfactant solutions, and/or 1-5% organic solvents (i.e. ethanol, isopropanol and/or acetone) was then used in leaching process. The fresh NRL was preserved by paraben compounds in the presence of surfactant at ambient temperature for 20-120 minutes, and then centrifuged. This might prevent the skin irritation of deproteinized NRL (DNRL) caused by ammonium stabilizer that normally uses in latex industry. The upper rubber mass was then leached for upto three cycles with leaching solvents, and then finally redispersed in distilled water. The milky-like DNRLs were obtained by these processes. Their dry rubber contents were 41-47% that could be adjusted. Their viscosities were 9-13 centipoises with the pH of 6.04-6.61. The protein residues in these DNRLs were 0.0000-0.3244% which were lower than that of fresh NRL (1.2428%). These indicated the efficacy of studied deproteinization process for 73.90-100.0%. Types and concentrations of surfactant, incubation times, leaching solvents, and cycles of leaching process affected the efficacy of deproteinization process. Moreover, the properties of these dried films were not different from that of fresh NR film. This DNRL could be further used for several applications including medical skin products.
Evaluation of Corrosion Performance of Zinc-Plated Underhood Automotive Fasteners Using Salt Spray Test
Authors: Astuty Amrin , Dalila Syairah Mohamad Zubir , Liza Mohd Anuar , Aezal Mohd Faim
Published: August 2015

Mechanical fasteners such as screws, nuts, bolts, and washers are integral components in a vehicle. Rust or corrosion mechanisms of fasteners in the automotive industry is complex and may probably due to many factors includes temperature, pH, ion concentrations, coatings compositions as well as fastener geometry. Most of underhood fasteners used by PROTON models are Zinc coated fasteners. PROTON requires interior fasteners are coated to a minimum of 5 μm, while exterior fasteners are of 8 μm minimum thickness. There is a need to understand the corrosion performance of such fasteners in order to improve cosmetic and functional performances of these fasteners. The main objective of this study is to evaluate corrosion performance of three different compositions of Zinc-coated underhood fasteners using laboratory test. Samples were subjected to salt spray test with 5% NaCl for specific periods of time, in accordance ASTM B117-90 and JIS Z 2371:2000 conforming to their corrosion resistance requirements based on coating type and thickness. Results of the study revealed that Zn-Ni and Zinc-flake platings exhibit superior corrosion resistance characteristics with rating number (RN) of 10 compared to conventional 8 μm hexavalent-chrome free plated fasteners.
Low Cost Synthesis of Hydrophobic Aluminum Alloy for Self-Cleaning Applications
Authors: Sooksaen Pat , Janmat Paradee , Thovasakul Wilaiwan , Chulasinont Onnuch
Published: August 2015

This research fabricated hydrophobic surfaces of aluminium alloy via electrochemical anodization and silane coating. The procedures consisted of electrochemical anodization in 1 and 1.5 M sulfuric acid using 12 volts dc. Anodization produced stable porous oxide layer on the surface. Aluminium alloy formed porous oxide structures with thickness in micrometer regime. The thickness of the porous layer was affected by the anodizing conditions such as electrolyte concentration and time. Dichloro methylsilane (5% in ethanol) was applied onto the porous surfaces by submerging the anodized surfaces into it for 10-60 min. After washing the treated surfaces with soap for many times, hydrophobic surfaces were obtained with some surfaces showed wetting angles greater than 100°. Water droplets of any sizes can roll off on these surfaces when tilted at angles above 10°. The treated aluminium surfaces can be applied for self-cleaning and anti-icing applications.
An XRD Phase Analysis of Al-F Re-Deposition Produced from Reactive Ion Etching
Authors: Pakpum Chu Pong
Published: August 2015

This paper reports the analysis of the composition, structure and phase of the re-deposition material that was generated from the reaction from CF4 plasma etching on the Al2O3-TiC substrate. The re-deposition was sputtered from the etching area and deposited on a silicon coupon for analysis. The morphology of the re-deposition was investigated by scanning electron microscope (SEM) and the composite element of the re-deposition was detected by using energy dispersive x-ray spectroscopy (SEM-EDX). X-ray diffraction (XRD) was used to analyse the structure and phase of the re-deposition. The results show that the prepared re-deposition was composed of F and Al atoms, with 51.24 At% and 27.67 At%, respectively. XRD revealed that this was owing to the chemical formula AlF3, which has a rhombohedral crystal structure in the most stable alpha phase (α-AlF3).
Analysis of Eddy-Current Measurement System for Residual Stress Assessment in Stainless Steel Grade 304
Authors: Jomdecha Cherdpong , Phung-On Isaratat
Published: August 2015

The objective of this paper is an analysis of statistical discreteness and measurement capability of an eddy-current measurement system for residual stress assessment in stainless steel Grade 304 (SS304). Cylindrical specimens with 50 mm in diameter and 12 mm thickness were prepared to generate residual stress by Resistance Spot Welding at which the welding currents were set at 12, 14, and 16 kA. The eddy-current measurement system was including a probe with frequency range of 0.1 to 3 MHz and an eddy current flaw detector. They were performed by contacting the probe on the specimen. The measurements were performed particularly in the vicinity of heat affected zone (HAZ). In order to determine the results of the residual stress measurement, the calibration curves between static tensile stress and eddy current impedance at various frequencies were accomplished. The Measurement System Analysis (MSA) was utilized to evaluate the changed eddy-current probe impedance from residual stress. The results showed that using eddy current technique at 1 MHz for residual stress measurement was the most efficient. It can be achieved the Gauge Repeatability & Reproducibility %GR&R at 16.61479 and Number of Distinct Categories (NDC) at 8. As applied on actual butt welded joint, it could yield the uncertainty of ± 58 MPa at 95 % (UISO).
The Comparison of Acoustic Emission Activities between Material Integrity and Leakage during CNG Cylinder Testing
Authors: Jirarungsatian Chalermkiat , Jomdecha Cherdpong , Pojnsirisilp Krisada
Published: August 2015

The objective of this paper is to study the different acoustic emission (AE) activities from material integrity and leakage which were obtained from CNG steel cylinder during pressurization. CNG type I cylinders were employed to test by hydrostatic stressing. The pressure was continuously increased to over 1.1 time of operating pressure or leakage occurrences. AE sensors, resonance frequency of 150 kHz, were mounted on the outside cylinder wall to detect the AE activities throughout the testing. AE activities were compared between AE of material expansion and leakage by amount of AE signals detected then analyzed by AE parameters. AE parameters including Amplitude, Count, Energy (MARSE), Duration and Rise time were analyzed to distinguish the AE data. The AE wave form in time and frequency domain were also considered in analysis process. The location of AE sources were located by the calculation the arriving differenced time of 2 or more sensors to indicate the position of cylinder faults. The results showed the AE signals of material expansion were randomly detected throughout the pressurization until the Enegy and Amplitude of detected signals were increased by high incresing rate where was leakage occurrences. AE parameters of Amplitude and Energy can be significantly represented the difference between material expansion and leakage. Addition, the Hit rate monitoring cloud be a notice activity before cylinder leaks. The benefits of this work are the AE characterization of the material expansion, leakage and noise for improvement of Type-1 CNG cylinder tests.
Wet Etching Technique to Reduce Pyramidal Hillocks for Anisotropic Silicon Etching in NaOH/IPA Solution
Authors: Pakpum Chu Pong
Published: August 2015

The various methods of silicon wet etching techniques, which utilize ultrasonic agitation to reduce pyramidal hillocks in etched patterns, were evaluated in NaOH+IPA solution. The comparison of the etching methods composed of; 1.) no agitation + sample horizontally orientated, 2.) ultrasonic agitation + sample horizontally orientated, 3.) ultrasonic agitation + sample vertically orientated, and 4.) ultrasonic with rotation agitation + sample vertically orientated. It was found that the percentages of the etched patterns presenting hillocks after etching were 100%, 79.77%, 32.67% and 2.62%, respectively. Ultrasonic coupled with rotation agitation along with the sample vertically orientated is the most powerful etching technique, offering a high yield of smooth etched surface. The difference in etch rate between without agitation and applying ultrasonic agitation was not observed in this experiment, as it was operated in a solution temperature 60-65°C and a 275nm/min etch rate was achieved. The theories that relate to each evaluated method are also discussed.
Remaining Creep Life Assessment of Service Superheat Tube Boiler
Authors: Thasanaraphan Pornsak , Thapnuy Pannawat , Ounpanich Duangporn , Vongbandit Pratip
Published: August 2015

The demand of remaining life assessment of the boilers arises from technical, economic, and legal reasons. Creep is major damage mechanism of primary superheat tube boiler during prolong operation at high temperature and pressure in a water tube boiler. This paper presents the calculation method for the remaining life assessment due to creep damage. The service-exposed primary superheat tube made of 2.25Cr-1Mo steels. During scheduled inspection, wall thickness measurement, metallographic investigation by replica technique, design data and operating condition were used to estimate the remaining life in the form of creep damage accumulation rate calculated from life fraction using Larson-Miller Parameter. The results indicate that the primary superheat tubes satisfy in extension service life. By attaining an accurate and timely discussion of the results, the engineer can manage the maintenance and inspection schedule for the critical part in the boiler.
Dispersion Stability of Drinking Water Treatment Sludge
Authors: Larpkiattaworn Siriporn , Khongwong Wasana , Tong-On Siriporn , Eamchotchawalit Chutima , Vorapeboonpong Chaiwat
Published: August 2015

The objective of this study is to improve the particle suspension stability of drinking water treatment sludge (DWTS) and comparable to other silicate powder which are bentonite, micro silica (micro-SiO2), and nano-silica (nano-SiO2). The main dispersion characteristic are related to particle size, and dispersion force. The representative samples of bentonite, micro-SiO2, nano-SiO2, and DWTS were dispersed at the same solid content in water. The particle size distribution and chemical composition of samples were analyzed. The suspended samples were measured for Zeta potential at the controlled pH value. Furthermore, turbidity of suspended samples were investigated at various sedimenting time. The results indicated that nano-SiO2 has the highest Zeta potential value at pH 8-12. The stability of particle dispersion could be implied from turbidity of suspension at various sedimenting time. Bentonite suspension performed more stability than other samples for longer time. However, stability of DWTS particles can be improved by particle size controlling and treatment with dispersion agent to create repulsive force from the charge on the particle surface.
Effect of Silica to Alumina Ratio on the Compressive Strength of Class C Fly Ash-Based Geopolymers
Authors: Timakul Patthamaporn , Thanaphatwetphisit Kanyarat , Aungkavattana Pavadee
Published: August 2015

This study investigated the effect of silica to alumina ratio on the compressive strength of geopolymer. The high calcium fly ash (Class C, ASTM 618) wastes from Mae Moh Thailand power plant, which is SiO2 (30.97%) and Al2O3 (17.16%)-rich materials was employed as the main solid part to prepare geopolymers, apart from kaolinite. The combination of sodium hydroxide (NaOH), sodium silicate (Na2SiO3) solution, and distilled water as 1:1:4 mass ratios were used as the liquid activator. The curing temperature in the oven was fixed at 75oC and varied curing time for 24, 48, 72 and 96 hours. Further curing was done at room temperature for 28 days before characterizations. XRD study of synthesized geopolymers showed a hump of not well-defined peaks and some major peaks of quartz, and unreacted kaolinite indicating the incomplete geopolymerization reaction. Infrared study showed the Al-O-Si and Si-O-Si bonds in all geopolymers samples. The compressive strength of geopolymer increased from 32 to 40 MPa when the ratio of SiO2 : Al2O3 was increased from 2.60 to 2.65. However, the compressive strength was decreased after increasing the SiO2 : Al2O3 ratio from 2.65 to 3.0. The highest compressive strength was found when the SiO2 : Al2O3 ratio was 2.65 with the curing condition at 75oC for 96 h which the samples also possessed high density.
Experimental Set-Up for Testing Cement Sheath Integrity in Arctic Wells
Authors: Albawi A. , De Andrade J. , Torsæter M. , Opedal N. , Stroisz A. , Vrålstad T.
Published: August 2015

Petroleum activities in the sensitive Arctic environment require increased focus on well integrity, since even small leaks can affect production and surrounding ecosystems. It is therefore of the utmost importance that the sealing ability of the annular well cement can be maintained here. This is challenging in normal locations, and difficulties are intensified when moving north. Due to the harsh topside conditions in the Arctic, the operational windows are short – and production will necessarily be turned on/off repeatedly. The temperature of any unheated injected fluid will also be lower here. As a result, Arctic wells will be subjected to strong downhole temperature variations over their life cycles. These cause the volume of well construction materials, like casing steel and annular well cement, to repeatedly expand and contract, which might lead to loss of well integrity through debonding or cracking of the annular cement sheath.

In the present paper we describe an experimental laboratory set-up that has been designed for studying the sealing ability of annular cement as a well is exposed to thermal cycling. The samples studied are small-scale well sections including casing, annular cement and rock formation. These are exposed to thermal cycles by using a computer controlled thermal platform, which heats up by means of electrical resistance and cools down through expansion of liquefied nitrogen. It has a temperature span from – 50°C to +200°C, and adjustable heating/cooling rates and holding times. During the thermal cycling experiments, any cracking and debonding occurring in the system is continuously monitored in-situ by Acoustic Emission (AE). To demonstrate the functioning of the set-up we present some initial results obtained using ordinary Portland G cement as annular sealant. In this work, the AE events collected during cycling are compared with data from post-experiment computed tomography (CT) scans.

The testing methodology presented in this paper is flexible, thus rock type, annular sealant type and casing type can be varied at will. Mud or filter cake effects can also be included. For all samples, the procedure will enable determination of when leakage paths appear (as a function of applied thermal cycles and time), where they appear (in the bulk cement or at its interfaces) and what their sizes, geometries and distributions are. This opens for improved material choices for Arctic well construction, and optimization of operational patterns and remediation strategies for the high north.
Technological Development in Oil Recovery in Ice Conditions
Authors: Wilkman Göran , Ritari Esa , Uuskallio Arto , Niini Mikko
Published: August 2015

Oil spills and oil recovery has become an issues as exploration and transportation is moving to more harsh offshore environment. In the early days of offshore development in the 1970ies and 1980ies most of the activity took place in open water where the existing systems; oil booms etc. where considered quite adequate. However, the recent incidents like Macondo in the Gulf of Mexico have shown that the traditional recovery methods are not sufficient, not even in open water conditions. What comes to conditions where the recovery has to be done among ice conditions and even more so in cold environment where it could be dark at very remote location? For the purpose to prevent incidents from happening and to be prepared to take proper actions in recovering spilled oil among ice we need a new approach to ensure safe operation without any harm to the environment. The accident of MT Antonio Gramsci in winter 1979 with an oil spill of 5.000 tons which mostly came to shore in the Western coasts of Finland created the impetus for changing the helpless status of the nation's winter response. The active development work in Finland thus started already in the early 1980ies by performing laboratory experiments as well as full-scale tests. Today we have a clear national target for 30.000 tons year-round response capability and are entering in the home waters to modern, tailored ice capable oil recovery vessels with dedicated tasks and integrated systems ready for oil recovery challenges in various conditions; open water and ice, warm and cold environment, good infrastructure and with no infrastructure at all. This paper describes the new possibilities in ship design relevant to oil recovery together with earlier studies in testing the possibility of oil collection from ice.
Operability of Lifeboats on Pack Ice: Coxswains’ Skill and Design Factors
Authors: Billard Randy , Rahman Md Samsur , Kennedy Allison , Ré António Simões , Veitch Brian
Published: August 2015

Increased resource exploration and transportation in the Arctic has catalyzed the evaluation of equipment and procedures to determine their suitability for ice covered waters. Remote operating locations and harsh physical environments present new operational challenges and increased complexity that must be addressed to ensure environmental and personnel safety is not compromised. Emergency response in sea ice is a specific area that must be assessed to ensure that personnel are able to escape, evacuate, and be rescued in conditions that will be experienced during operations in the north. Regulators will expect that operators will be able to demonstrate that lifeboats can be safely launched and that the craft can navigate to a safe zone for rescue of personnel.

The paper describes an investigation into the operability of conventional lifeboats in pack ice conditions. The investigation was based on field trials of a small Totally Enclosed Motor Propelled Survival Craft (TEMPSC) lifeboat that was operated in a range of controlled pack ice conditions. The study focused on observing how operators with different levels of experience and backgrounds operated in ice, how their behaviors impacted their ability to maneuver through the ice field and the impact on the vessel and crew. Participants in the trials had different levels of experience operating in ice and in small crafts. The coxswains who participated in the investigation had a range of operational experience with vessels in ice, including operators who have worked aboard icebreaking vessels, but with limited experience operating in small vessels, and operators with experience operating small vessels, but with limited experience operating in ice. During the field trials, coxswains employed different tactics for advancing through ice. The outcomes of the study were used to analyze the impact of different driving techniques on the ability of the coxswain to successfully maneuver through ice and the impact of driving style on vessel integrity and crew comfort. The results of the study assess the tactics which can be employed by coxswains in different ice concentrations and the outcomes can be used to define learning objectives for training programs designed to prepare coxswains for emergency operations in ice covered waters.
Stimulation of the RIG-I/MAVS Pathway by Polyinosinic:Polycytidylic Acid Upregulates IFN-β in Airway Epithelial Cells with Minimal Costimulation of IL-8
Authors: Dauletbaev Nurlan , Cammisano Maria , Herscovitch Kassey , Lands Larry C.
Published: August 2015

Pharmacological stimulation of the antiviral cytokine IFN-β in the airways may help to counter deleterious virus-induced exacerbations in chronic inflammatory lung diseases (asthma, chronic obstructive pulmonary disease, or cystic fibrosis). Polyinosinic-polycytidylic acid [poly(I:C)] is a known inducer of IFN-β but also costimulates an inflammatory response. The latter response is undesirable given the pre-existing airway inflammation in these diseases. The objective of our study was to identify conditions for poly(I:C) to selectively upregulate IFN-β in airway epithelial cells without a concomitant inflammatory response. The inflammatory response was gauged by production of the chemokine IL-8. Using cell lines and primary airway epithelial cells (both submerged and well-differentiated), we observed that pure poly(I:C) stimulated IFN-β mainly through the TLR3/TRIF pathway and IL-8 through an unidentified pathway. The magnitude of the IL-8 response stimulated by pure poly(I:C) matched or even exceeded that of IFN-β. Furthermore, this IL-8 response could not be pharmacologically downregulated without affecting IFN-β. In contrast, we show that stimulation of the RIG-I/MAVS pathway, such as when poly(I:C) is delivered intracellularly in a complex with liposomes or via nucleofection, selectively stimulates IFN-β with low IL-8 costimulation. The magnitude of IFN-β stimulation by liposome-encapsulated poly(I:C) is markedly diminished in well-differentiated cells. In conclusion, it is feasible to augment IFN-β production in airway epithelial cells without excessive costimulation of IL-8 if the RIG-I/MAVS pathway is stimulated, such as via liposomal delivery of poly(I:C). Better cytoplasmic delivery vehicles are needed to efficiently stimulate this pathway in well-differentiated cells.
The Novel Receptor C5aR2 Is Required for C5a-Mediated Human Mast Cell Adhesion, Migration, and Proinflammatory Mediator Production
Authors: Pundir Priyanka , MacDonald Clayton A. , Kulka Marianna
Published: August 2015

C5a generated during complement activation possesses proinflammatory and immunoregulatory properties critical for the development and modulation of allergic immune responses. In immune cells, C5a mediates its effects through binding to two G protein–coupled receptors, C5aR1 and C5aR2. Mast cells are key effectors in allergic reactions, and decades of research have suggested that the majority of C5a effects on mast cells are mediated through C5aR1, whereas the expression and function of C5aR2 have not been explored. We demonstrated that the human mast cell line Laboratory of Allergic Diseases 2 (LAD2) expresses surface C5aR2 but not C5aR1, whereas CD34+ cell–derived primary mast cells do not express surface C5aR1 or C5aR2. Stem cell factor and IL-4 upregulated C5aR2 expression on LAD2 cells. Furthermore, C5a caused internalization of LAD2 cell-surface C5aR2. We therefore used LAD2 cells as a model to study C5a/C5aR2-induced biological responses and signaling in human mast cells. We found that whereas C5a was unable to induce degranulation, it stimulated GM-CSF, TNF, CXCL10, and CCL2 production. C5a caused ERK phosphorylation, a signaling molecule important in cytokine and chemokine generation. In addition, C5a stimulated adhesion and chemotaxis of mast cells. Wortmannin, an inhibitor of PI3K, and small interfering RNA against β-arrestin-2 blocked C5a-induced adhesion. Silencing of C5aR2 using lentiviral short hairpin RNA rendered the cells unresponsive to C5a-induced adhesion, chemotaxis, and mediator release, as well as ERK phosphorylation. Overall, this study reveals a novel role for C5aR2 in C5a-mediated activation of mast cells and demonstrates that C5aR2 ligation initiates a β-arrestin-2–, PI3K-, and ERK-dependent signaling pathway in these cells.
Impact ofToxoplasma gondiion Dendritic Cell Subset Function in the Intestinal Mucosa
Authors: Cohen Sara B. , Denkers Eric Y.
Published: August 2015

The function of mucosal dendritic cell (DC) subsets in immunity and inflammation is not well understood. In this study, we define four DC subsets present within the lamina propria and mesenteric lymph node compartments based on expression of CD103 and CD11b. Using IL-12p40 YFP (Yet40) reporter mice, we show that CD103+CD11b− mucosal DCs are primary in vivo sources of IL-12p40; we also identified CD103−CD11b− mucosal DCs as a novel population producing this cytokine. Infection was preferentially found in CD11b+ DCs that were negative for CD103. Lamina propria DCs containing parasites were negative for IL-12p40. Instead, production of the cytokine was strictly a property of noninfected cells. We also show that vitamin A metabolism, as measured by ALDH activity, was preferentially found in CD103+CD11b+ DC and was strongly downregulated in all mucosal DC subsets during infection. Finally, overall apoptosis of lamina propria DC subsets was increased during infection. Combined, these results highlight the ability of intestinal Toxoplasma infection to alter mucosal DC activity at both the whole population level and at the level of individual subsets.
Arterial segments as microvascular interposition grafts in venous anastomosis in digital replantations
Authors: Saha Shiv Shankar , Pandey Anurag , Parwal Chirayu
Published: August 2015

Introduction: Microvascular anastomosis is a crucial procedure in replantation surgeries. Venous insufficiency is one of the most consistent cause of failure or re-exploration in these surgeries necessitating the use of venous grafts. Materials and Methods: We discuss our study of 9 such replantation surgeries executed in calendar year 2013-2014, including a double finger replantation done in the same patient having total amputation of 4 fingers of the same (right) hand, in which an arterial segment was used as a microvascular interposition graft for venous anastomosis. Out of these 9 surgeries, 3 were re-exploration procedures for venous compromise and 6 were successful primary replantations. Results: In all, 8 replants were successful and one failed due to arterial compromise. Discussion: In our experience and extensive review of the previously available literature, we would like to portray the advantages of arterial segments as microvascular grafts in replant surgeries. Specifically, in a crush amputation injury for which the use of a vascular interposition graft is being contemplated. If any other digit is also amputated and is unsuitable for replantation, it can act as a potential donor site to harvest the arterial segment. However, when dealing with single finger amputation, the surgeon must be confident about the single digital arterial anastomosis, before harvesting the second digital artery as a microvascular graft. Conclusion: In our study, we found the use of arterial grafts in microvascular anastomosis of veins advantageous, as arterial segments have better ability to resist spasm due to environmental changes, better pressure tolerance as compared to venous segments, and provide an appropriate calibre match and ease of harvest in the same operative field.
“Ride-on” technique and other simple and logical solutions to counter most common complications of silicone implants in augmentation rhinoplasty
Authors: Agrawal Kapil S. , Bachhav Manoj V. , Naik Charudatta S. , Gupta Shikha , Sarda Anup V. , Desai Vyoma
Published: August 2015

Augmentation rhinoplasty can be carried out using a wide range of materials including autologous bone and/or cartilage as well as alloplasts. Use of biologic bone and cartilage grafts results in lower infection rates, but they are associated with long-term resorption and donor-site morbidity. Alloplastic materials, in particular silicone, have been associated in literature with extrusion, necrosis of the tip, mobility and deviation or displacement of the implant, immobile nasal tip and infection. However, they have the advantages of being readily available and easy to reshape with no requirement for harvesting autografts. Aim: To overcome these problems associated with silicone implants for which the authors have devised a novel technique, the “rideon technique”. Materials and Methods: The present study was carried out on 11 patients over a period of 4 years. The authors have devised a simple technique to fix the silicone implant and retain it in place. Restricting the implant to only dorsum avoided common complications related to the silicone implant. Results: The authors have used this technique in 11 patients with encouraging results. Follow-up ranged from 12 months to 36 months during which patients were assessed for implant mobility, implant extrusion and tip necrosis. There was no incidence of above mentioned complications in these patients. Conclusion: The “rideon technique” provides excellent stability to silicone implants and restricting the implant only to dorsum not only eliminates chances of tip necrosis and thus implant extrusion but also maintains natural shape, feel and mobility of the tip.
Surgical revirgination: Four vaginal mucosal flaps for reconstruction of a hymen
Authors: Saraiya Hemant A.
Published: August 2015

Introduction: Over centuries, virginity has been given social, religious and moral importance. It is widely believed as a state of a female who has never engaged in sexual intercourse, and her hymen is intact. Hymenoplasty for torn hymen is carried out not only for the sake of cultural and religious traditions but also for the social status and interpersonal relationships. Materials and Methods: 2.5 cm long and 1 cm wide four vaginal mucosal flaps were raised from the anterior vaginal wall just behind labia minora. Two flaps were based proximally, and their two opposing flaps were based distally. These flaps were overlapped in a crisscross fashion and were sutured with 5/0 Polyglactin (Vicryl® ) sutures leaving no area raw. The donor area was closed primarily. When some remains of a torn hymen were found, one to three vaginal mucosal flaps were added to its remains as per the need for reconstruction. Results: We operated upon 11 patients. In nine cases, the hymen was reconstructed with four flaps. In remaining two, it was reconstructed from the remains using vaginal mucosal flaps. All flaps healed without any infection or disruption. Sutures got absorbed in 25-35 days. In all cases, this newly constructed barrier broke with only moderate pressure at the time of penetrative sex serving the purpose of the surgery completely. Conclusion: Erasing evidence of the sexual history simply by ‘Surgical Revirgination’ is extremely important to women contemplating marriage in cultures where a high value is placed on virginity.
Congenital urethrocutaneous fistula in an adolescent male
Authors: Kale Satish M. , Mody Nikunj B. , Patil Surendra B. , Sadawarte Pranam
Published: August 2015

A urethrocutaneous fistula is a common complication after hypospadias repair, but congenital fistula is a rare anomaly. We present a 16-year-old boy with this unusual anomaly. Its etiology, embryology, and management are discussed in brief.
Intraosseous keratin cyst of the distal phalanx
Authors: Prasad Rohini , Bhamidi Arivind , Rajeswaran Arun Kumar , Bhuvaneshwari Ramamurthy
Published: August 2015

Keratin or epidermoid cysts of the phalanges are rare lesions mimicking osteolytic lesions such as infection, malignancy and other tumours. Definitive diagnosis can be made by histopathology only and treatment is by simple excision and curettage. We present a case of intraosseous keratin cyst of the distal phalanx and review of literature.
Raman Spectroscopy Applied to the Noninvasive Detection of Monosodium Urate Crystal Deposits
Authors: Curran Declan J. , Rubin Laurence , Towler Mark R.
Published: August 2015

An off-the-shelf Raman Spectrometer (RS) was used to noninvasively determine the presence of monosodium urate (MSU) crystals on the metatarsophalangeal joint (MTPJ) of a single gout sufferer. The spectrum sourced from the clinically diagnosed gout sufferer was compared to that sourced from an age-matched healthy subject scanned using the same protocol. Minimal signal processing was conducted on both spectra. Peaks characteristic of MSU crystals were evident on the spectrum sourced from the gout sufferer and not on the spectrum from the healthy control.