bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication and Photocatalytic Degradation of TiO2/Porous Activated Carbon-Zeolite Composite Cylinder
Authors: Nawaukkaratharnant Nithiwach , Wasanapiarnpong Thanakorn , Sujaridworakul Pornapa , Mongkolkachit Charusporn
Published: August 2015

Activated carbon, zeolite and titanium dioxide are wildly used for removing the organic compounds in waste water. Although, these materials exhibit high performance (in powder form), reclaiming of these materials from the waste water treatment system is still hard. The objective of this study is to fabricate hollow cylinder activated carbon-zeolite samples which were used as a porous substrate. Various ratios of activated carbon, zeolite NaA and clay were mixed with special binder to form dough before extruded to be hollow cylinder shape. The hollow cylinder samples were cut into 2.5 cm long and then were fired at 600 °C for 2 hours under 5%CO2+N2 atmosphere. The fired samples were dip-coated with TiO2-P25 and fired at 600 °C for 1 hour under 5%CO2+N2 atmosphere for testing the photocatalytic degradation of lignin solutions under UV light. The results showed that the strength of fired samples increasing with the ratio of clay increased. The XRD patterns of samples having clay addition showed peaks of zeolite and quartz. The physical properties, microstructure and photodegradation will be discussed.
Influence of Carbon Nanotubes on Photocatalytic Activities of Titanium Dioxide Nanocomposite Powders
Authors: Daram Phuangphaga , Thongsuwan Wiradej , Jiansirisomboon Sukanda
Published: August 2015

This research aims to produce TiO2-based composite powder by growing of carbon nanotubes (CNTs) on the surface of micron-sized TiO2 particles using a chemical vapor deposition (CVD) technique. This nanocomposite powder will be further used as feedstock powder to build up as a coating using a thermal spray technique. This coating is expected to have better photocatalytic efficiency over that of pure TiO2 coating. For composite powder preparation, rutile-phase of TiO2 powder with particle size in a range of 25 – 45 µm was used as a starting powder. The powder was placed in a CVD apparatus under ethanol atmosphere as a carbon source. The best CNTs growing condition was found to be 650°C for 60 min. The starting powder and as-synthesized composite powders were characterized by scanning electron microscopy, energy dispersive spectrum, Raman spectroscopy and UV-vis spectroscopy. The results showed that CNTs were successfully grown in-situ on the surface of TiO2 particles. The photocatalytic activities under visible-light were examined based on a degradation of methylene blue. The degradation efficiency of the TiO2/CNTs composite powder was found to be higher than that of pure TiO2. It is expected that the TiO2/CNTs nanocomposite powder could be further used to fabricate various of nanocomposite products.
Fe-Sn Intermetallics Synthesized via Mechanical Alloying-Sintering and Mechanical Alloying-Thermal Spraying
Authors: Meesa-Ard Pinya , Uthaisangsuk Vitoon , Tosangthum Nattaya , Sheppard Panadda , Wila Pongsak , Tongsri Ruangdaj
Published: August 2015

Iron (Fe)-tin (Sn) intermetallics were synthesized by using two different routes. These two routes had a common synthesis step, in which Fe powder (19 wt. %) was mechanically alloyed with Sn powder (81 wt. %) for 25 h under argon atmosphere. The mechanically alloyed powders were then treated with different heating routes. In the first route, the compacts of the mechanically alloyed powders were sintered at different temperatures for different times. It was found that the FeSn2 content increased with increasing temperature and time. There were small traces of Fe, Sn and FeSn found in the sintered materials. In the second route, the mechanically alloyed powders were plasma-sprayed using different currents of 300, 400 and 500 A. It was found that the porous coatings produced by plasma sprayng consisted of mixed Fe, Sn, FeSn2, SnO, FeO and Fe3O4 for all employed currents.
Sintered Frictional SiC-Reinforced Cu-Base Composites
Authors: Damnernsawat Jiraporn , Kaewtatip Pongpan , Tosangthum Nattaya , Vetayanugul Bhanu , Wila Pongsak , Tongsri Ruangdaj
Published: August 2015

Lead-free frictional materials are important components in safety and power transmission parts of automobiles. In order to avoid using lead-containing friction modifiers, non-toxic ceramic particles are considered to be used as reinforcements. In this research work, copper-based friction materials have been developed by using press and sinter method. Pre-alloyed bronze (Cu-10Sn) powder was admixed with iron (Fe), graphite (C) and varied amounts of silicon carbide (SiC) powders. The admixed powders were compacted into disc-shape samples, which were then sintered at different temperatures in the range of 800-950 °C. It was found that sintered density and hardness of the sintered copper-based friction materials reduced with increasing SiC content. Microstructures of the sintered materials showed inhomogeneity due to uneven distribution of coarse Fe and SiC particles. The coarse SiC particles also prohibited bonding between metal powder particles. However, the sintered materials showed high room-temperature friction coefficients, which were in the range of 0.50-0.90, particularly the materials containing 4 wt. % of SiC particles.
Organomodified Clay and its Influence on Thermal and Fire Behaviors of Clay/Fire Retardant/Poly Vinyl Ester Composites
Authors: Mahesh K. R. Vishnu , Murthy H.N. Narasimha , Swamy B.E. Kumara , Raghavendra N. , Krishna M.
Published: August 2015

The objective of this research was to examine the synergistic effect of organomodified nanoclay and fire retardants on the thermal decomposition, glass transition temperature and fire retardation behaviour of nanoclay/Poly vinyl ester composites. The two nanoclays such as Cloisite-15A and Cloisite-Na are used along with two fire retardants as Aluminium Tri Hydroxide (ATH) and Magnesium Hydroxide (MH) in the present study. The nanoclay/fire retardants were dispersed in poly vinyl ester using twin screw extrusion. TEM and AFM of nanoclay/Poly vinyl ester specimens revealed that 4 wt% Cloisite-15A/Poly vinyl ester exhibited exfoliation and distribution of nanoclay which were superior to that of Cloisite-Na/Poly vinyl ester. The synergistic effect of Cloisite-15A and 30 % ATH increased glass transition temperature by 18 % and reduced thermal degradation by 47 % and Limiting Oxygen Index (LOI) by 52 % when compared with that of Poly vinyl ester after the curing process in all the cases.
Spectroscopic and Thermo–Mechanical Studies of Liquid Crystal Elastomer
Authors: Gharde Rita A. , Mani Santosh A. , Jessy P.J. , Amare Jyoti R. , Keller Patrick
Published: August 2015

The structure and influence of temperature on mechanical deformation of Liquid Crystal Elastomers (LCEs) were studied using various techniques like Raman Spectroscopy (RS), Fourier Transform Infrared (FTIR) Spectroscopy and Polarizing Microscopy Studies (PMS) etc. The spectroscopic studies confirmed the presence of functional group attached to the sample. The shrinkage in length was observed while heating whereas material returns to its original length on cooling which revealed the correlation of mechanical behavior of Liquid Crystal Elastomers with temperature. This spontaneous shape changing property indicates that LCE material plays an important role in biological applications.
Thermal and Mechanical Properties of Acrylonitrile-Butadiene Rubber Modified Polybenzoxazine as Frictional Materials
Authors: Jantaramaha Jakkrit , Jubsilp Chanchira , Rimdusit Sarawut
Published: August 2015

Frictional composites based on polybenzoxazine (PBA-a) and acrylonitrile-butadiene rubber (NBR) are developed in this study. Mechanical, thermal and tribological properties of the PBA-a/NBR composites at 0, 2, 5, 10 and 15wt% of NBR particle contents are evaluated. Curing behaviors of the NBR-benzoxazine molding compounds are examined by differential scanning calorimetry to show an exothermic peak of about 222°C compared with that of the benzoxazine resin, i.e. 232°C suggesting curing acceleration of the benzoxazine resin due to the presence of the NBR particles. The storage modulus of the NBR-filled PBA-a is observed to systematically decrease from 5.2 GPa of the neat PBA-a to 2.8 GPa with an addition of 15wt% of the rubber particles. Glass transition temperature (Tg) of the composites evaluated by dynamic mechanical analysis increases with increasing of NBR particle contents, i.e. from 172°C for PBA-a to 186°C for PBA-a/15wt% NBR. Furthermore, the friction coefficients of the composites with 2wt% NBR are determined to be 0.603 for static type and 0.528 for kinetic type. Those values are improved from the value of 0.597 and 0.475 for unmodified polybenzoxazine, respectively. Therefore, the obtained outstanding properties, i.e. storage modulus, glass transition temperature and friction coefficient make the polybenzoxazine composites highly attractive to be utilized as friction materials.
Use of Coir-Filled LLDPE as a Reinforcement for Natural Rubber Composite
Authors: Kaewduang Manit , Chaichana Ekrachan , Jongsomjit Bunjerd , Jaturapiree Adisak
Published: August 2015

Cellulose based fibers such as sisal, jute and coir are ones of the most frequently used reinforcing fillers for composite materials including natural rubber composites because they can improve mechanical properties of their composites. However, the main disadvantages of these composites are the poor compatibility between the fiber surface and the host matrices, mainly due to the highly hydrophilic character of the fibers and the hydrophobic character of the host materials. Therefore, in this research, coir had been modified with linear low-density polyethylene (LLDPE) prior to introducing into the natural rubber composites. The coir-filled LLDPE was synthesized by in situ polymerization with MAO/metallocene catalyst, named as modified coir. The unmodified coir and modified coir were then blended with natural rubber latex to obtain natural rubber composites. The morphology and thermal dynamic mechanical properties of the composites were investigated by scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA). The composites blended with the modified coir showed the better compatibility between the coir and the natural rubber than those with the unmodified coir. In addition, they also showed the greater storage modulus and lower tan delta than the unmodified counterpart and the pure natural rubber without the reinforcement.
Effect of Saccharin Sodium on the Microstructure and Hardness of Electrodeposited Ni-W Coatings
Authors: Kumar Das Malay , Hao Ruru , Srikaen Ekachai , Thueploy Adisak , Limpanart Sarintorn , Boonyongmaneerat Yuttanat , Qin Jia Qian
Published: August 2015

Nickel-tungsten alloy were fabricated by electrodeposition on carbon steel. The influences of saccharin sodium on the coatings were analyzed using XRD, SEM, and hardness tester. This study reveals that the presence of saccharine sodium has a profound impact on the morphology of the coatings. Moreover, the addition of saccharine sodium tends to enhance the tungsten content in the coatings along with hardness and the grain size of the deposits.
The Effects of O2:N2 Gas Ratios on Structural, Optical, Electrical Properties of TiOxNy Thin Film Deposited by Reactive DC Magnetron Sputtering
Authors: Khumtong Tanakorn , Sakdanuphab Rachsak
Published: August 2015

In this work, titaniumoxynitride (TiOxNy) thin films were deposited on glass slide substrates by using reactive dc magnetron sputtering technique. The reactive gas ratios between O2and N2were studied in the range of 15-30% with a constant of Ar gas at 110 sccm and a time of 120 minutes. Microstructure, optical, and electrical properties of TiOxNythin films were analysis by using SEM, AFM, GIXRD, UV-VIS spectrophotometer, and 4-point probe measurements. We found that the thickness of the films decreases from 1.0 to 0.8 μm by increasing of O2gas ratios. The TiOxNythin films have smooth surface related to small nanograin size. The roughness of the films slightly decreases when O2gas ratios increase. From optical transmission spectra, we observed that the transparent of the films increases with different O2gas ratio and shifts the band gap from 2.67 to 3.32 eV. The resistivity of the films obviously increases from 3.04 x 10-3Ω-cm to 5.45 Ω-cm depending on O2gas ratio. These results indicate the phase changes of the TiOxNyfilms from metallic to oxide phases. The XRD spectra show poor crystalline TiN (220) and TiO2(021) at 15% of O2ratio and then the films become amorphous structure by increasing the O2gases. The O2:N2gas ratios also affects to the different concentration of oxygen and nitrogen into the TiOxNythin films that lead to the various structural, optical and electrical properties.
The Influence of N2 Partial Pressure on Color, Mechanical, and Corrosion Properties of TiN Thin Films Deposited by DC Reactive Magnetron Sputtering
Authors: Nimnual Pisitpat , Sakulkalavek Aparporn , Sakdanuphab Rachsak
Published: August 2015

Multi-functional thin films have gained increasing importance in a decorative application. Among the available material, titanium nitride (TiN) thin film is interesting due to its golden color and mechanical resistance. Beside their properties, the corrosion property of TiN films is mainly considered in order to extend the life time. In this work, the TiN thin films were deposited on 3x3 cm2 Si(100) substrates by dc reactive magnetron sputtering technique. The effects of N2 partial pressure (PN2) on deposited film properties such as microstructure, surface morphology, color, mechanical and corrosion properties were investigated. We found that the crystal structure of the TiN films exhibit the (200) preferred orientation. The color of TiN films change from gold-yellow to gold-red colors by increasing of N2 partial pressure that could be explained by Drude model. The TiN films have smoother surface when the N2 partial pressure increases. Standard corrosion tests in artificial sweat solution show the corrosion current density (icorr) in the range between 0.25 to 4.25 mA/cm2 and the polarization resistance increases with increasing of N2 partial pressure. The highest hardness of the film is approximately 40 GPa with elastic modulus of 340 GPa. We conclude that N2 partial pressure corelates with color, mechanical property and corrosion resistance of TiN films, which were optimized to use in decorative application.
Changes in Structural, Morphological, and Corrosion Properties of CrN Thin Film Effected by Varying N2 Pressure in the Sputtering Process
Authors: Wongtanasarasin Wichuda , Sakdanuphab Rachsak , Suwansukho Kajpanya , Sakulkalavek Aparporn
Published: August 2015

In this study, we investigate a facet of the fabrication process of chromium nitride (CrN) film intended as a protective coating for pineapple blades. CrN thin films were deposited on unpolished stainless steel substrates (AISI304) by DC reactive magnetron sputtering in Ar+N2 gases. In principle, the proportion of nitrogen partial pressure to the total pressure in the sputtering process should have considerable effects on the CrN film’s chemical composition, its crystal structure, its hardness, and its corrosion resistance. We tested this supposition out by using several different nitrogen partial pressures in the sputtering process and observed the films deposited. The coatings were deposited at five different nitrogen partial pressures of 4.0x10-4 mbar, 8.0x10-4 mbar, 1.2x10-3 mbar, 1.6x10-3 mbar, and 2.0x10-3. The deposition times were controlled to achieve 5-µm thick films in each deposition. The films were analyzed by several analytical methods, such as X-ray diffraction (XRD), scanning electron microscope, micro-hardness and potentiostat in pineapple juice. The XRD spectra of the films showed face-centered cubic structure with (200) preferred orientation, positively identifying them as Cr2N and CrN thin films. The calculated d-spacing and lattice parameter of the CrN films increased with increasing nitrogen partial pressure; the ranges were 0.283–0.287 nm and 0.491-0.497 nm, respectively. The cross-section morphology of the CrN films reveals the columnar grain growth with a high density. The crystal structure and the grain texture correspond with the hardness property. The films corrosion potential, an indicator of their corrosion property, was varied from -0.14 to -0.05 volts with varying nitrogen pressure. The most corrosion resistant and the good hardness were the film fabricated at the nitrogen partial pressure of 1.2x10-3 mbar.
Resistive Switching Behavior of Ti/ZnO/Mo Thin Film Structure for Nonvolatile Memory Applications
Authors: Sakdanuphab Rachasak , Sakulkalavek Aparporn
Published: August 2015

In this work, we study the resistive switching behavior of a new model metal/insulator/metal (MIM) junction. The MIM junction consists of titanium front electrode, zinc oxide insulation layer and molybdenum back electrode. The Ti/ZnO/Mo structure was prepared on 3x3 cm2 soda lime glass substrates using dc magnetron sputtering for metal electrodes and rf magnetron sputtering for ZnO layer. The thicknesses of Ti, ZnO and Mo films were controlled at 200nm, 50nm and 500nm, respectively. The crystalline structure and microstructure of the films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). The current-voltage (I-V) characteristics of the device cells were obtained by using dc voltage sweep mode. The XRD spectra of the devices show Mo(100) and ZnO(002) preferred orientations. The Mo and ZnO film surfaces exhibit dense crystallized grains with the root mean square roughness (RMS) of 1.0 and 1.4 nm, respectively. The device cells behave unipolar resistive switching characteristics with reversible, controllable and reliability within 150 cycles. The difference between high resistive state (HRS) and low resistive state (LRS) is about 103 times. A low operating voltage range of 0.50-0.60V is obtained for switching from HRS to LRS at a current compliance of 10mA. The new MIM structure was demonstrated and suggested a potential to use as nonvolatile memory application.
Effect of Sputtering Power on Morphological, Structural and Optical Properties of Al-Doped Zinc Oxide Film
Authors: Boonprakom Patthamapun , Rattanasakulthong Watcharee
Published: August 2015

Transparent conductive Al-doped zinc oxide (ZnO:Al) films with different sputtering power were prepared on glass substrate using an RF sputtering technique. Two main peaks of the hexagonal wurtzite structure in the (002) and (004) direction were observed in every deposited ZnO:Al film. Intensities of these peaks were increased with the increasing sputtering power. Moreover, the surface roughness tended to increase with increasing sputtering power whereas the electrical resistance decreased with increasing sputtering power. The ZnO:Al film deposited at 150 and 200 W showed maximum optical transmittance of over 80% in the visible wavelength range. All results confirmed that the sputtering power directly affected film thickness because the higher sputtering power gave rise to a higher deposition rate; the surface morphology of the deposited films was dependent on the sputtering power and the optical properties were indirectly affected by the power of the deposition process.
Morphological and Magnetic Properties of Co100-xCux Film Prepared by RF-Sputtering
Authors: Chaloeipote Gun , Rattanasakulthong Watcharee
Published: August 2015

Granular Co100-xCux films with different compositions of x = 19, 40, 54, 65 and 76 were deposited on glass substrates using sputter deposition. Co (HCP) and Cu (FCC) phases were observed in all deposited Co-Cu films. Film thickness was increased with increasing Cu-composition. The minimum and maximum values of electrical resistance measured using a four-point probe were observed on the Co24Cu76 and Co46Cu54 films, respectively, which confirmed that the electrical property of the films is a function of the film thickness and composition. The morphological and magnetic properties of all deposited films were clearly dependent on film composition. The AFM result confirmed the dependence of surface morphology and magnetic properties on the film composition because of the difference in the deposition rate between Co and Cu atoms during the sputtering process. The VSM results showed that all films had a ferromagnetic phase when the magnetic field was applied perpendicular to the film plane. All results confirmed that the desired morphological, electrical and magnetic properties of Co-Cu granular film can be achieved by manipulating its chemical composition.
Correlation of Acoustic Emission and Corrosion Resistance of Lacquer Coatings on Tin-Free Steel
Authors: Srisungsitthisunti Pornsak , Daopiset Siriporn , Kanjanaprayut Noparat
Published: August 2015

Acoustic emission (AE) is a non-destructive technique which is well known for crack monitoring. Moreover, it has been widely used for corrosion and erosion damage on metallic structures. In this study, AE technique was applied for quick monitoring of corrosion resistance of lacquer coatings on tin free steel and laminated steel for food can-packaging. There were three types of coatings: (A) BPA-NI lacquer, (B) BPA-complied lacquer, and (C) PET lamination. These coatings were investigated in flat-sheet and in deformed sheet. Cathodic disbonding (CD) technique was carried out to cause separation between the coating and the metal substrate and initialize corrosion damage. AE signals was detected immediately with potential excitation, and showed good correlation with coating corrosion resistance during corrosion development. AE count signal matched with resulting current during CD, and proportional to corroded areas. In addition, coatings properties were measured before and after the CD process by electrochemical impedance spectroscopy (EIS). A combination of AE and CD techniques offers an in-situ non-destructive corrosion monitoring of coating quality before and during delamination development, and useful for can-packaging testing.
Effect of Weld Line Formation on Morphology and Mechanical Properties for 3D-MID Technology
Authors: Chuaping Supakit , Mann Thomas , Dangtungee Rapeephun , Siengchin Suchart
Published: August 2015

The topic of this research work was to demonstrate the feasibility of a 3D-MID concept using injection molding technique and investigate the effects of two weld line types on the structure and mechanical properties such as tensile, flexural strength and morphology. In order to obtain more understanding of the bonds between polymer and metals, two different polymer bases of polyphthalamide (PPA) with the same type and amount of filler content were produced by injection molding at the different processing conditions. A mold was designed in such a way that weld and meld line can be produced with different angles by changing as insert inside of the mold. The mechanical properties such as stiffness, tensile strength and flexural strength were determined in tensile and flexural tests, respectively. The results showed in line with the expectation of high reduction on mechanical properties in area where weld/meld lines occurred. The result of tensile test was clearly seen that weld and meld line showed a considerable influence on mechanical properties. The reduction in tensile strength was approximately 58% according to weld line types, whereas in flexural strength was approximately 62%. On the other hand, the effect of the injection times and mold temperatures on the tensile strength were marginal.
Influence of Process Parameters on Spinning Force Using Finite Element Analysis and the Taguchi Method
Authors: Sangkharat Thanapat , Dechjarern Surangsee
Published: August 2015

Metal spinning process is widely used for producing complex symmetry components. Main advantage of spinning process is a lower power requirement for large deformation with good surface finish. The aim of this paper is to investigate the influences of spinning process parameters, on spinning force. A three dimensional finite element model of the spinning process of SPCC sheet was successfully developed using elastic-plastic material property. The spinning experiments were carried out on a turning lathe and spinning forces were measure forces using a piezoelectric force transducer. The finite element prediction was compared with the experimental measurements and the results agreed well. Applying the Taguchi method, the effect of four process parameters, i.e. roller diameter, spindle speed, feed rate and feed depth, on spinning force were studied. The Taguchi main effect analysis and ANOVA results show that roller diameter and feed depth are the most important factor influencing the spinning force.
Effect of Rice Husk and Rice Husk Ash on Properties of Lightweight Clay Bricks
Authors: Janbuala Sutas , Wasanapiarnpong Thanakorn
Published: August 2015

The objective of this study is to investigate the effect of rice husk and rice husk ash which have the difference chemical composition and organic matter on porosity and properties of lightweight clay brick . Comparative adding between rice husk and rice husk ash were varied by 10, 20, 30, 40 % by weight. The results showed that more adding of rice husk and rice husk ash increase pore in microstructure and water absorption, while decrease bulk density. Porosity and water absorption are maximized when the rice husk are added at 40 %. The clay brick with 10, 20 and 30 % of rice husk or rice husk ash addition showed the required density and compressive strength followed the industrial standard of lightweight brick. The addition with 10 % of rice husk showed the best properties as 1.20 g/cm3 of bulk density and 4.6 MPa of compressive strength with 36.57 % of porosity. Whereas, the 10 % addition of rice husk ash showed 1.18 g/cm3 of bulk density and 5.97 MPa with 37.27 % of porosity.
Bleached Shellac as an Alternative Polymeric Matrix for In Situ Microparticle
Authors: Praphanwittaya Pitsiree , Phaechamud Thawatchai
Published: August 2015

Bleached shellac (BS), a biodegradable natural resin purified from insect lac, has been used in a varity of controlled drug delivery systems. Nevertheless, there were negligible researches explored the potential of it as in injectable in situ microparticles (ISM) applications. The goal of this study was to utilize BS to form ISM (shellac-solution dispersed into an external olive oil phase, as o/o emulsion) prepared by two-syringe technique. Addition of glyceryl monostearate (GMS) as stabilizer obviously decreased the emulsion droplet size. ISM emulsion comprising 5% w/w GMS in external phase could form into droplets and precipitate in form of microparticles after exposure to phosphate buffer. 2-Pyrrolidone was the most appropriate solvent to form massive microparticles with regular shape especially at ratio of 7:3 external:internal phases. ISM transformation was occurred after exposure to phosphate buffer and tended to reduce the droplet size when ratio of external phase was higher than 50%. Incorporation of doxycycline hyclate did not influence the amount and size of ISM. Therefore shellac exhibited as an alternative polymer matrix for ISM which higher amount of GMS could reduce the size of emulsion droplet and volume phase ratio seriously influenced on emulsion size and ISM formation.
Effects of Water Temperatures on Water-Soluble Binder Removal in Ceramic Materials Fabricated by Powder Injection Moulding
Authors: Buggakupta Wantanee , Chuankrerkkul Nutthita , Surawattana Juthathep
Published: August 2015

This work focuses on the debinding conditions of the ceramic materials fabricated by powder injection moulding. Ceramic powder materials, including alumina and alumina-based composites were prepared as feedstocks and mixed with water-soluble polyethylene glycol (PEG) and polyvinyl butyral (PVB). The PEG/PVB binder mixture, with PEG to PVB ratio of 85:15 by weight and powder loading of 44 vol%, were thoroughly mixed and injected into the mould at the temperature of 190 °C to obtain rod-like specimens. Prior to sintering, the as-injected specimen was then leached in water, the temperature of which was varying from 30 (ambient temperature), 45 to 60 °C, in order to get rid of PEG and leave the specimens in shape by PVB. The rate of PEG removal according to different water temperatures was investigated. The experimental results suggested that PEG could completely be eliminated by 45 and 60 °C water without any dimensional disintegration in 5 hours whereas those leached in 30 °C water showed only 70% PEG removal. Higher water temperatures led to fast PEG removal rate at the beginning and then gradually decreased with elapsed times.
Electromechanical Displacement of Soft/Hard PZT Bi-Layer Composite Actuator
Authors: Ngernchuklin Piyalak , Boonruang Arjin , Jeerapan Chalearmchai , Laoauyporn Pracha , Kanchanasutha Sittichai , Ryu Jung Ho
Published: August 2015

PZTs can be classified into two types, i.e., soft and hard PZTs, which are categorized by the piezoelectric and ferroelectric properties such as coercive field, piezoelectric strain, mechanical quality factor etc. It is known that the combination effect of the soft/hard PZT composites can generate large strain/actuation compared to monolithic PZT ceramics. In this study, soft and hard PZT powders were co-pressed into bi-layer disks with various ratios between soft and hard PZT powders, ranging from 0:100~100:0 vol. % (with 10 % increments) and then they were co-sintered. Due to the difference in the planar shrinkage of the two layers and thermal expansion coefficient mismatch, dome-shaped bi-layer composites with various dome heights were obtained. It was shown that the constrained layer either soft PZT or hard PZT affected various properties including the dome geometry, the strain-E-field response, and the displacement hysteresis loop. The electromechanical properties and actuation performance of such bi-layer composite actuators have been investigated and compared to the soft and hard PZT single layer counterparts.
Concrete GBS LNG Solution for Shallow Arctic Regions
Authors: Raven John , Maughan John , Pinnerød Erik , Egge Magnus
Published: August 2015

The Arctic is becoming increasingly important in securing energy supplies for the future, notwithstanding the economic, environmental and social challenge. Also, finding and extracting oil and gas in the Arctic and Subarctic regions is itself challenging due to extreme temperatures, ice conditions, remoteness and a sensitive natural environment.

Liquefied Natural Gas (LNG) can be produced Onshore, Offshore (FLNG) and near shore. Onshore is the most common LNG solution, however in hostile Arctic environments and remote areas onshore construction becomes expensive and challenging. Likewise Offshore LNG (FLNG), considered for export of offshore gas reserves and normally produced from deep water subsea wells, is not yet considered feasible for hostile Arctic environments where pack ice is prevalent.
Ice Breaking and Accumulation Around a Moored Structure: Ice Basin Tests and Numerical Simulations
Authors: Bonnemaire B. , Serré N. , Lundamo T. , Fredriksen A. , Jensen A. , Gürtner A. , Teigen S.
Published: August 2015

Today's best engineering practice for the design of a stationary floating structure in ice infested water is articulated around physical testing in an ice basin and numerical modelling of the structure response to the relevant ice interactions.

Ice basin testing is the best way to simulate the complex scenario of a moored floating structure interacting with drifting intact level ice and ridges. It is also per today the main source of experience for the design of such structures as full scale experience is sparse. However, ice basin testing suffers from deviations due to scaling effects or mismatch between one or several of the achieved and targeted properties (of the modelled ice and structure).

As a consequence, the outcome of ice basin tests needs to be assessed and correction of measurements are required. An efficient way is to use an engineering numerical model to simulate the achieved ice-structure interaction in the ice basin, qualify the numerical model by comparing simulation results and measurements, and then simulate the targeted interactions with the numerical model. Such a numerical model may further be used to simulate the full range target design conditions for the ice structure interaction.

The RITAS ice basin campaign tested a structure element designed to gain insight in the level ice bending and accumulation process around a traditional moored floating arctic structure design. These measurements are well suited to assess the validity of a numerical model designed to replicate this type of interaction.

The SimShipIce numerical model is an engineering tool which focuses on replicating the steering processes during the interaction between a moored structure and drifting intact level ice and ridges. Such a model needs to be calibrated against ice basin test outcome.
Exploration Drilling with Riserless Dual Gradient Technology in Arctic Waters
Authors: Stave Roger , Fossli Børre , Endresen Cato , Rezk Ramzy Hussein , Tingvoll Geir Inge , Thorkildsen Martin
Published: August 2015

Riserless dual gradient technology enables drilling tophole with weighted and engineered mud without discharge to sea. A Suction Module is run and installed subsea. This has a collection chamber where well returns are collected and diverted to a subsea mud pump. A Mud Return Line allows pumping or lifting the mud and cuttings back to surface. In this way a "closed loop system" is established; mud and cuttings are collected at seafloor and returned to the shakers as with post-BOP drilling techniques. The technique eliminates discharges of mud and cuttings at seafloor and thereby a weighted and engineered mud system may be used to solve difficult drilling challenges, improve drilling efficiency and safety.

Selection of the technology is typically driven by its ability to impact drilling efficiency and safety, but in arctic and other environmental sensitive areas also by the fact that discharges to sea can be reduced of totally eliminated. Riserless dual gradient technology has been used to drill wells in artic locations. If a 0-discharge requirement also apply for the surface conductor, a purpose designed SpudBase may be used. This will allow spudding the well / setting and cementing of conductor pipe without discharges at seafloor. Thereafter the 26" hole can be drilled with weighted mud, the surface casing run and cemented. The entire tophole drilling may hence be drilled riserless with return to surface. Cuttings may be collected at the shakers and shipped to shore for disposal. The mud is recirculated and reused throughout the entire drilling operation.
Peak Ice Loads on a Lifeboat in Pack Ice Conditions
Authors: Kennedy Allison , Ré António Simões , Veitch Brian
Published: August 2015

Field testing of a modified Totally Enclosed Motor Propelled Survival Craft (TEMPSC) was conducted in March 2013 in managed level ice conditions. This testing was part of a multi-year trials program, conducted by the National Research Council (NRC), which aims to investigate design considerations for a conventional TEMPSC operating in ice. During the March 2013 testing campaign, the TEMPSC was equipped with a side impact panel and bow visor, both instrumented with load cells to measure local ice impact forces. The resulting local ice load measurements taken during this field trials campaign are presented and the operational performance is discussed. This was the first year during the trials campaign in which local loads on the stem were measured and recorded.

The results of this set of field trials could be useful to support the implementation of new TEMPSC design considerations to allow for better performance in harsh, northern conditions. It could also provide operational insight to promote more effective and low stress navigation through ice conditions.
A New Ice Simulation Tool Using a Multi-Model Program
Authors: Septseault Cyril , Béal Pierre-Antoine , Le Yaouanq Sébastien , Dudal Alexey , Roberts Brian
Published: August 2015

In June 2012, Technip signed an agreement with Cervval (a specialist software company in Brittany) and Bureau Veritas (BV) to develop an ice-modelling simulation program. The long term aim is for the simulator to predict the flow of ice around both fixed and floating structures and calculate the ice-loadings on the platforms. The program will ultimately allow platform structures to be optimised, to minimise ice loadings and ice rubble build-up, prior to final design verification in an ice test basin.

Initially the program has been developed to predict ice behaviour in shallow waters since there are several projects imminent in the North Caspian but will be equally applicable in Arctic regions. Cervval has been developing the software with ice expertise input and verification from BV. The program is unique in the Arctic industry in that it uses a multi-model simulator which is able to cope with the complexity of calculating the kinematic and failure behaviour for the ice sheet and for each ice fragment that results from contact with the structure or from collision with other ice rubble particles for ice mechanical properties.

Currently the program is able to simulate the flow of an ice sheet as it encroaches on a conical structure, which is a type of platform design that Technip has developed specifically for projects offshore Kazakhstan. The design tool is able to predict vertical and horizontal loads on the structure with good accuracy. It also predicts the geometry of the ice accumulation in front of the structure above and below the ice sheet.

The next stage in the software development is to consider ice interaction with a straight sloping wall structure, then vertical walled structures (such as artificial islands) and finally a range of floating structures.

The paper presents details of the simulator, the status of the development & verification program and plans for the future. A typical set of ice simulations are shown and a comparison with ice basin test results is presented as a measure of the program's accuracy.
DYPIC Project: Technological and Scientific Progress Opening New Perspectives
Authors: Kerkeni Sofien , Dal Santo Xavier , Doucy Olivier , Jochmann Peter , Haase Andrea , Metrikin Ivan , Løset Sveinung , Jenssen Nils Albert , Hals Torbjorn , Gürtner Arne , Moslet Per Olav , Støle-Hentschel Susanne
Published: August 2015

DYPIC – Dynamic Positioning in ICE - is an international research and development project partially financed by the national research agencies of Germany, Norway and France. This 3-years initiative (2010–2012) focused on the development of Dynamic Positioning (DP) technology for the Arctic environment. The projects' backbone was formed by two extensive experimental campaigns performed in 2011 and 2012. This paper summarizes the work performed within the project and spotlights the technical and scientific findings emerged from it. Special attention is payed to two facets of the project: the design of experimental devices, systems and setups for ice tank testing including the development of a dynamic positioning system for model basin facility, and the development of an ice basin numerical simulator. Finally, the opened perspectives are discussed with a special focus on the operational matters.
Dynamic Routing through Waters Partially Covered with Sea Ice
Authors: Schütz Peter
Published: August 2015

We present a methodology for tactical route optimization in waters covered by sea ice. The ice conditions are time-dependent and uncertain. This paper proposes a methodology for determining the fastest route through ice covered waters based on a stochastic dynamic programming model. As such, the focus is on the routing element of the methodology rather than on how to predict ice conditions or model ship performance. Preliminary results for a small, but artificial test case from the Bay of Bothnia are presented as well.

Introduction

The reduced sea ice coverage in the Arctic Ocean has attracted a lot of attention to shipping in Arctic waters. However, sea areas covered with ice can be found all over the world: For example, the Bay of Bothnia and the Gulf of Finland in the Baltic Sea freeze every year. In fact, the Baltic Sea might be covered completely by sea ice during an extreme winter. The northern part of the Caspian Sea is prone to sea ice during winter and also Bohai Bay in the Yellow Sea is known for forming sea ice.
The Human NK Cell Response to Yellow Fever Virus 17D Is Primarily Governed by NK Cell Differentiation Independently of NK Cell Education
Authors: Marquardt Nicole , Ivarsson Martin A. , Blom Kim , Gonzalez Veronica D. , Braun Monika , Falconer Karolin , Gustafsson Rasmus , Fogdell-Hahn Anna , Sandberg Johan K. , Michaëlsson Jakob
Published: August 2015

NK cells play an important role in the defense against viral infections. However, little is known about the regulation of NK cell responses during the first days of acute viral infections in humans. In this study, we used the live attenuated yellow fever virus (YFV) vaccine 17D as a human in vivo model to study the temporal dynamics and regulation of NK cell responses in an acute viral infection. YFV induced a robust NK cell response in vivo, with an early activation and peak in NK cell function at day 6, followed by a delayed peak in Ki67 expression, which was indicative of proliferation, at day 10. The in vivo NK cell response correlated positively with plasma type I/III IFN levels at day 6, as well as with the viral load. YFV induced an increased functional responsiveness to IL-12 and IL-18, as well as to K562 cells, indicating that the NK cells were primed in vivo. The NK cell responses were associated primarily with the stage of differentiation, because the magnitude of induced Ki67 and CD69 expression was distinctly higher in CD57− NK cells. In contrast, NK cells expressing self- and nonself-HLA class I–binding inhibitory killer cell Ig-like receptors contributed, to a similar degree, to the response. Taken together, our results indicate that NK cells are primed by type I/III IFN in vivo early after YFV infection and that their response is governed primarily by the differentiation stage, independently of killer cell Ig-like receptor/HLA class I–mediated inhibition or education.
The Presence and Preferential Activation of Regulatory T Cells Diminish Adoptive Transfer of Autoimmune Diabetes by Polyclonal Nonobese Diabetic (NOD) T Cell Effectors into NSG versus NOD-scid Mice
Authors: Presa Maximiliano , Chen Yi-Guang , Grier Alexandra E. , Leiter Edward H. , Brehm Michael A. , Greiner Dale L. , Shultz Leonard D. , Serreze David V.
Published: August 2015

NOD-scid.Il2rgnull (NSG) mice are currently being used as recipients to screen for pathogenic autoreactive T cells in type 1 diabetes (T1D) patients. We questioned whether the restriction of IL-2R γ-chain (Il-2rγ)–dependent cytokine signaling only to donor cells in NSG recipients differently influenced the activities of transferred diabetogenic T cells when they were introduced as a monoclonal/oligoclonal population versus being part of a polyclonal repertoire. Unexpectedly, a significantly decreased T1D transfer by splenocytes from prediabetic NOD donors was observed in Il-2rγnull-NSG versus Il-2rγ–intact standard NOD-scid recipients. In contrast, NOD-derived monoclonal/oligoclonal TCR transgenic β cell–autoreactive T cells in either the CD8 (AI4, NY8.3) or CD4 (BDC2.5) compartments transferred disease significantly more rapidly to NSG than to NOD-scid recipients. The reduced diabetes transfer efficiency by polyclonal T cells in NSG recipients was associated with enhanced activation of regulatory T cells (Tregs) mediated by NSG myeloid APC. This enhanced suppressor activity was associated with higher levels of Treg GITR expression in the presence of NSG than NOD-scid APC. These collective results indicate NSG recipients might be efficiently employed to test the activity of T1D patient–derived β cell–autoreactive T cell clones and lines, but, when screening for pathogenic effectors within polyclonal populations, Tregs should be removed from the transfer inoculum to avoid false-negative results.
Antimony-ResistantLeishmania donovaniExploits miR-466i To Deactivate Host MyD88 for Regulating IL-10/IL-12 Levels during Early Hours of Infection
Authors: Mukherjee Budhaditya , Paul Joydeep , Mukherjee Sandip , Mukhopadhyay Rupkatha , Das Shantanabha , Naskar Kshudiram , Sundar Shyam , Dujardin Jean-Claude , Saha Bhaskar , Roy Syamal
Published: August 2015

Infection with antimony-resistant Leishmania donovani (SbRLD) induces aggressive pathology in the mammalian hosts as compared with ones with antimony-sensitive L. donovani (SbSLD) infection. SbRLD, but not SbSLD, interacts with TLR2/TLR6 to induce IL-10 by exploiting p50/c-Rel subunits of NF-κB in infected macrophages (Mϕs). Most of the TLRs exploit the universal adaptor protein MyD88 to activate NF-κB. We now show that infection of Mϕs from MyD88−/− mice with SbRLD gave rise to significantly higher intracellular parasite number coupled with elevated IL-10/IL-12 ratio in the culture supernatant as compared with infection in wild type (WT) Mϕs. Τhese attributes were not seen with SbSLD in similar experiments. Further, SbRLD infection upregulated miR-466i, which binds with 3′-untranslated region, leading to the downregulation of MyD88. Infection of MyD88−/− Mϕ or IL-12−/− Mϕ with SbRLD induced IL-10 surge at 4 h, whereas the same in WT Mϕ started from 12 h. Thus, absence of IL-12 in MyD88−/− mice favored early binding of NF-κB subunits to the IL-10 promoter, resulting in IL-10 surge. Infection of MyD88−/− mice with SbRLD showed significantly higher organ parasites coupled with ill-defined and immature hepatic granulomas, whereas in WT mice there were less organ parasites and the granulomas were well defined. From the survival kinetics it was observed that SbRLD-infected MyD88−/− mice died by 60 d postinfection, whereas the WT mice continued to survive. Our results demonstrate that SbRLD has evolved a unique strategy to evade host antileishmanial immune repertoire by manipulating host MyD88 to its advantage.
An investigation into e-learning acceptance and gender amongst final year students
Authors: Chinyamurindi Willie , Shava Herring
Published: August 2015

Background: The use of electronic learning (e-learning) systems is gaining popularity especially within a Higher Education (HE) context. However, scholars have identified some factors that affect the utilisation and the acceptance of such systems, one of which is the gender divide, which favours mostly males ahead of females.Objectives: The objective of this study was to investigate the acceptance of the e-learning system within a South African HE setting, including the influential role of gender in the acceptance of such a system. Method: Quantitative data was collected through a cross-sectional survey using 113 registered final year students at a South African university who were making use of an e-learning system as part of their teaching delivery. The measuring instrument used was the technology acceptance instrument (TAI) and included measures of computer self-efficacy (CSE), perceived ease of use (PEU), perceived usefulness (PU), and behavioural intention to use (BIU). Results: The presence of a gender divide was found to exist in this study. Women’s ratings of the acceptance of e-learning systems were found to be slightly higher than those of the male respondents. In addition to this, elements of the TAI were found to be related to one another. Conclusion: The study concludes by arguing that lecturers and facilitators need to pay attention to usage patterns of e-learning systems as they affect how such systems are adopted by their students. Therefore, preceding student acceptance of electronic learning systems should be efforts to address any issues that affect the acceptance and effective utilisation of such systems.