bluuebunny/crossref_metadata_2025 huggingface dataset:
Directional Solidification Microstructure of a Ni-Based Superalloy: Influence of a Weak Transverse Magnetic Field
Authors: Li Xu , Wang Jun , Zhang Jiao , Han Yanfeng , Li Xi
Published: June 2015

A Ni-based superalloy CMSX-6 was directionally solidified at various drawing speeds (5–20 μm·s−1) and diameters (4 mm, 12 mm) under a 0.5 T weak transverse magnetic field. The results show that the application of a weak transverse magnetic field significantly modified the solidification microstructure. It was found that if the drawing speed was lower than 10 μm·s−1, the magnetic field caused extensive macro-segregation in the mushy zone, and a change in the mushy zone length. The magnetic field significantly decreases the size of γ’ and the content of γ-γ’ eutectic. The formation of macro-segregation under a weak magnetic field was attributed to the interdendritic solute transport driven by the thermoelectric magnetic convection (TEMC). The γ’ phase refinement could be attributed to a decrease in nucleation activation energy owing to the magnetic field during solid phase transformation. The change of element segregation is responsible for the content decrease of γ-γ’ eutectic.
The Concept about the Regeneration of Spent Borohydrides and Used Catalysts from Green Electricity
Authors: Liu Cheng-Hong , Chen Bing-Hung
Published: June 2015

Currently, the Brown-Schlesinger process is still regarded as the most common and mature method for the commercial production of sodium borohydride (NaBH4). However, the metallic sodium, currently produced from the electrolysis of molten NaCl that is mass-produced by evaporation of seawater or brine, is probably the most costly raw material. Recently, several reports have demonstrated the feasibility of utilizing green electricity such as offshore wind power to produce metallic sodium through electrolysis of seawater. Based on this concept, we have made improvements and modified our previously proposed life cycle of sodium borohydride (NaBH4) and ammonia borane (NH3BH3), in order to further reduce costs in the conventional Brown-Schlesinger process. In summary, the revision in the concept combining the regeneration of the spent borohydrides and the used catalysts with the green electricity is reflected in (1) that metallic sodium could be produced from NaCl of high purity obtained from the conversion of the byproduct in the synthesis of NH3BH3 to devoid the complicated purification procedures if produced from seawater; and (2) that the recycling and the regeneration processes of the spent NaBH4 and NH3BH3 as well as the used catalysts could be simultaneously carried out and combined with the proposed life cycle of borohydrides.
Rotational Efficiency of Photo-Driven Archimedes Screws for Micropumps
Authors: Lin Chih-Lang , Lin Yu-Sheng , Baldeck Patrice
Published: June 2015

In this study, we characterized the rotational efficiency of the photo-driven Archimedes screw. The micron-sized Archimedes screws were fabricated using the two-photon polymerization technique. Free-floating screws trapped by optical tweezers align in the laser irradiation direction and rotate spontaneously. The influences of the screw pitch and the number of screw blades have been investigated in our previous studies. In this paper, the blade thickness and the central rod of the screw were further investigated. The experimental results indicate that the blade thickness contributes to rotational stability, but not to rotational speed, and that the central rod stabilizes the rotating screw but is not conducive to rotational speed. Finally, the effect of the numerical aperture (NA) of the optical tweezers was investigated through a demonstration. The NA is inversely proportional to the rotational speed.
Plasmonics Meets Biology through Optics
Authors: De Sio Luciano , Caracciolo Giulio , Annesi Ferdinanda , Placido Tiziana , Pozzi Daniela , Comparelli Roberto , Pane Alfredo , Curri Maria , Agostiano Angela , Bartolino Roberto
Published: June 2015

Plasmonic metallic nanoparticles (NPs) represent a relevant class of nanomaterials, which is able to achieve light localization down to nanoscale by exploiting a phenomenon called Localized Plasmon Resonance. In the last few years, NPs have been proposed to trigger DNA release or enhance ablation of diseased tissues, while minimizing damage to healthy tissues. In view of the therapeutic relevance of such plasmonic NPs; a detailed characterization of the electrostatic interaction between positively charged gold nanorods (GNRs) and a negatively charged whole-genome DNA solution is reported. The preparation of the hybrid biosystem has been investigated as a function of DNA concentration by means of ζ-potential; hydrodynamic diameter and gel electrophoresis analysis. The results have pointed out the specific conditions to achieve the most promising GNRs/DNA complex and its photo-thermal properties have been investigated. The overall study allows to envisage the possibility to ingeniously combine plasmonic and biological materials and, thus, enable design and development of an original non invasive all-optical methodology for monitoring photo-induced temperature variation with high sensitivity.
Highly Sulfonated Diamine Synthesized Polyimides and Protic Ionic Liquid Composite Membranes Improve PEM Conductivity
Authors: Chen Bor-Kuan , Wu Tzi-Yi , Wong Jhong-Ming , Chang Yu-Ming , Lee Hsu-Feng , Huang Wen-Yao , Chen Antonia
Published: June 2015

A novel sulfonated diamine was synthesized from 1,4-bis(4-aminophenoxy) benzene [pBAB]. Sulfonated polyimides (SPIs) were synthesized from sulfonated pBAB, 1,4-bis(4-aminophenoxy-2-sulfonic acid) benzenesulfonic acid [pBABTS], various diamines and aromatic dianhydrides. Composite proton exchange membranes (PEMs) made of novel SPIs and a protic ionic liquid (PIL) 1-vinyl-3-H-imidazolium trifluoromethanesulfonate [VIm][OTf] showed substantially increased conductivity. We prepared an SPI/PIL composite PEM using pBABTS, 4,4′-(9-fluorenylidene) dianiline (9FDA) as diamine, 3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride (DSDA) as dianhydride and 40 wt % [VIm][OTf] with a high conductivity of 16 mS/cm at 120 °C and anhydrous condition. pBABTS offered better conductivity, since the chemical structure had more sulfonated groups that provide increased conductivity. The new composite membrane could be a promising anhydrous or low-humidity PEM for intermediate or high-temperature fuel cells.
Evaluation of Three MODIS-Derived Vegetation Index Time Series for Dryland Vegetation Dynamics Monitoring
Authors: Lu Linlin , Kuenzer Claudia , Wang Cuizhen , Guo Huadong , Li Qingting
Published: June 2015

Understanding the spatial and temporal dynamics of vegetation is essential in drylands. In this paper, we evaluated three vegetation indices, namely the Normalized Difference Vegetation Index (NDVI), the Soil-Adjusted Vegetation Index (SAVI) and the Enhanced Vegetation Index (EVI), derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) Surface-Reflectance Product in the Xinjiang Uygur Autonomous Region, China (XUAR), to assess index time series’ suitability for monitoring vegetation dynamics in a dryland environment. The mean annual VI and its variability were generated and analyzed from the three VI time series for the period 2001–2012 across XUAR. Two phenological metrics, start of the season (SOS) and end of the season (EOS), were detected and compared for each vegetation type. The mean annual VI images showed similar spatial patterns of vegetation conditions with varying magnitudes. The EVI exhibited high uncertainties in sparsely vegetated lands and forests. The phenological metrics derived from the three VIs are consistent for most vegetation types, with SOS and EOS generated from NDVI showing the largest deviation.
Trees in Canadian Cities: Indispensable Life Form for Urban Sustainability
Authors: Duinker Peter , Ordóñez Camilo , Steenberg James , Miller Kyle , Toni Sydney , Nitoslawski Sophie
Published: June 2015

We argue that a healthy urban forest contributes immensely to the sustainability of cities. The argument is based on a comprehensive array of values elicited from Canadians in several cities. To begin, we define the urban forest as inclusive of all the trees in the city and thus representing the predominant contributor to a city’s green infrastructure. Then we enumerate and explain the broad diversity of ways in which urban people value trees in the city. We, thus, show the myriad pathways by which trees contribute positively to any city’s social, economic, and ecological sustainability. Following a short summary of the ways in which trees may detract from people’s quality of life, we present promising management directions for urban-forest improvement, as we understand the situation in Canada. We conclude that all cities can enhance their sustainability by improving the urban forest.
Deoxynivalenol Impairs Weight Gain and Affects Markers of Gut Health after Low-Dose, Short-Term Exposure of Growing Pigs
Authors: Alizadeh Arash , Braber Saskia , Akbari Peyman , Garssen Johan , Fink-Gremmels Johanna
Published: June 2015

Deoxynivalenol (DON) is one of the major mycotoxins produced by Fusarium fungi, and exposure to this mycotoxin requires an assessment of the potential adverse effects, even at low toxin levels. The aim of this study was to investigate the effects of a short-term, low-dose DON exposure on various gut health parameters in pigs. Piglets received a commercial feed or the same feed contaminated with DON (0.9 mg/kg feed) for 10 days, and two hours after a DON bolus (0.28 mg/kg BW), weight gain was determined and samples of different segments of the intestine were collected. Even the selected low dose of DON in the diet negatively affected weight gain and induced histomorphological alterations in the duodenum and jejunum. The mRNA expression of different tight junction (TJ) proteins, especially occludin, of inflammatory markers, like interleukin-1 beta and interleukin-10 and the oxidative stress marker heme-oxigenase1, were affected along the intestine by low levels of DON in the diet. Taken together, our results indicate that even after low-level exposure to DON, which has been generally considered as acceptable in animal feeds, clinically-relevant changes are measurable in markers of gut health and integrity.
La gestion de l'écosystème urbain pour une ville durable (The management of urban ecosystem for a sustainable city)
Authors: Laganier Richard , Roussel Isabelle
Published: June 2015

Résumé. - Une analyse de la gestion de l'eau et de l'air dans les villes permet de retracer différentes étapes de la gestion de la nature en ville. La création d'un écosystème urbain ne peut se concevoir qu'en prenant en compte l'intégration de cet écosystème dans le cadre «naturel» sur lequel il s'appuie. L'objectif d'une ville durable consiste à minimiser les impacts négatifs que la ville peut apporter au milieu de manière à établir un véritable métabolisme. Cependant, cet objectif doit être porté par tous les habitants, il ne peut donc être atteint sans une modification profonde de la gouvernance urbaine.
Stifle arthrodesis using a locking plate system in six dogs
Authors: Nicetto T. , Petazzoni M.
Published: June 2015

Objectives: To describe the use of the Fixin locking plate system for stifle arthrodesis in dogs and to retrospectively report the clinical and radiographic outcomes in six cases.[uni2028]

Materials and methods: Medical records of dogs that had arthrodesis with the Fixin locking plate system were reviewed. For each patient, data pertaining to signalment and implant used were recorded. Plate series and thickness, number of screws placed, number of cortices engaged, and screw diameters were also recorded. The outcome was determined from clinical and radiographic followups. Radiographic outcomes assessed included the measurement of the postoperative femoral-tibial angle in the sagittal plane.

Results: Six dogs met the inclusion criteria for the study. Mean body weight was 13 kg (range: 3 - 34 kg). Radiographic follow-up (mean: 32 weeks, range: 3 - 52 weeks) was available for all dogs. In one case, an intra-operative complication occurred. In another case, a tibial fracture occurred 20 days after surgery. All arthrodeses healed and no implant complication was detected although all cases had mechanical lameness.

Clinical significance: Stifle arthrodesis can be performed successfully using a Fixin locking plate system.
The Effect of Chemical Solutions (Isopropyl Alcohol, Dichloromethane, Acetone and Triton X-100) on the Dispersion of Single-Walled Carbon Nanotubes
Authors: Wah Low Foo , Liu Wei Wen , Hashim U. , Lai Chin Wei
Published: June 2015

The effect of chemical solutions on the dispersion of single-walled carbon nantubes (SWCNTs) was studied. The SWCNTs were dispersed using several chemical solutions such as isopropyl alcohol (IPA), dichloromethane (DCM), acetone and triton X-100 (Triton-X) under ultrasonically process. The results show that the types of chemical solutions greatly affect the dispersion of SWCNTs. The IPA solution is found to be the best solution to disperse SWCNTs using ultrasonication process due to the difficultly of evaporation in room temperature to get a transparent solution.
Infuence of Nitrogen Gas Flow Rate on Nitrogenated Amorphous Carbon Film for Solar Cell Applications
Authors: Ishak A. , Malek Mohd Firdaus , Mamat Mohamad Hafiz , Rusop Mohamad
Published: June 2015

In this paper, the effect of nitrogen gas flow rate on electrical and electronic properties of nitrogen doped amorphous carbon film (a-C:N) by the use of constant +50 V is presented. The flow-rate of nitrogen gas into the furnace was influenced the resistivity as well as conductivity a-C:N film. The resistivity and conductivity of a-C:N films deposited at high nitrogen flow-rate (200 mL/min) produced low resistivity and high conductivity under deposition condition used. The highest resistivity (4.97x107 Ω.cm) and lowest resistivity (2.81x101 Ω.cm) is found at 0 mL/min (undoped) and 200 mL/min. The fabricated solar cell device with the configuration of Au/n-C:N/p-Si/Au for undoped (0 mL/min) and nitrogen doped (200 mL/min) achieved efficiency () 0.00111% and 0.00120 %, respectively.
Effect of Growth Time to the Structural and Field Emission Properties of ZnO Nanorods Prepared by Sol-Gel Method
Authors: Rafaie Hartini Ahmad , Md Nor Roslan , Mohd Amin Yusoff
Published: June 2015

The structural and field emission properties of ZnO nanorod at different growth time by sol-gel method have been successfully prepared. FESEM results illustrated that dense ZnO nanorods with hexagonal wurtzite structure were vertically well-aligned and uniformly distributed on the substrate. X-ray diffraction pattern analysis shows that all the obtained ZnO nanorods can be indexed to the hexagonal ZnO wurtzite structure. Field emission measurement was conducted for ZnO nanorod growth at different time to study emission properties. The turn-on field value decreases while field enhancement value increases as longer growth time was applied which related to the increasing of aspect ratio of ZnO nanorod respectively.
Investigated Effect of Points Charge of the Receptors on the Conduction of Semiconductor Nanowire
Authors: Al-Mufti M. Wesam , Hashim U. , Rahman Mijanur , Adam Tijjani , Azman A.H. , Muaz A.K.M. , Farehanim M.A.
Published: June 2015

The paper reported a study on an effect of the point charge of the bio-interface of a nanowire field biosensor on the conductance of the nanowire, through finite element calculations using COMSOL Multiphysics. A model with 5 layers starting with silicon nanowire of radius 10nm surrounded by a 2-nm oxide layer, and the oxide layer were surrounded by a 5 nm thick functional layer and 2 points charge were considered for this study and last layer is for electrolyte. The results shows that is different voltages with points change is that effected on the conductance of nanowire that is clear from different of potential distribution of point charge.
Thermal Annealing-Activated Crystallinity Metastasis of Al:ZnO Thin Films
Authors: Malek Mohd Firdaus , Mamat Mohamad Hafiz , Musa M.Z. , Rusop M.
Published: June 2015

Multilayered thin films of aluminum-doped ZnO (Al:ZnO) have been deposited by the sol-gel dip coating technique. Experimental results indicated that the thermal annealing temperature affected the crystallinity of the Al:ZnO films. X-ray diffraction (XRD) analysis showed that thin films were preferentially orientated along the c-axis plane. The preferred orientation along (0 0 2) plane becomes more pronounced as the thermal annealing being increased. The film thickness ranges between 180 and 690 nm. In our experiments, the most optimum condition of Al:ZnO annealing temperature was both 500 oC.
Mask Design Consideration for Low Aspect Ratio Wet Etch Micromachining on Silicon Substrate Planar Power Transformer
Authors: Abdul Razak Abdul Rahim , Hashim Uda , Zhafran Z.M. , Wesam A.
Published: June 2015

Commercial planar power transformer core majorly inserted manually as stand-alone components sandwiched on the stacked multilayer PCB of the power supply system. The indispensible gap within the layers still seems to produce significant losses due to leakage inductance meanwhile the low thermal conductivity of the PCB worsen the generated heat dispersion process. Thus this paper is to explore a new approach in order to attain a higher efficiency, high thermal conductivity dispersion and low cost mass production on this magnetic device using CMOS development procedure on a silicon wafer substrate. Considerations for the optimum mask design process for power transformer based pattern micromachining on the Silicon substrate process using low cost wet etching process are presented and discussed. The process are to manipule the anisotropy properties using concave and convex mask pattern to produce a correct final angle and pattern using recognized KOH solutions optimized ratio. The conventional wet etching concept has been explored with a several mask design template and comparison between several pattern size in order to attain the best fine structure and correct angle pattern up to 100 um depth. Several convex corner corners compensation methods has been reviewed which finally concluded to method proposed by Wei Fan and Dacheng Zhang has been verified within the 40% KOH:IPA in 50°C solutions experiment.
Hydrophilic Carbon Nano-Particles; Preparation and Applications
Authors: Ikeda Shoichiro , Nobumoto Akinari , Ono Hideo , Ono Shinji , Kawasaki Shinji , Rusop Mohamad
Published: June 2015

The hydrophilic carbon nanoparticles have been produced from synthetic graphite blocks by the electrochemical oxidation method in pure water. The resulting electrolyzed solution contains colloidal carbon nanoparticles (mean diameter is ca. 400 nm) and shows the pH value of around 2.5. The colloidal state of the solution is maintained more than a several years. After evaporation of water from the solution, carbon powders are obtained, which show a high solubility to water, namely the powder is hydrophilic. The electrolyzed solution containing carbon nanoparticles directly used as the electrical conductivity enhancer for the restoring the deteriorated lead-acid batteries by electrochemical method. The hydrophilic carbon nanoparticles were used as the environmental friendly solid-lubricant for the mechanical cutting coolants. In the case of aqueous coolants, the oily substances are used in the emulsion state in usual. By using the hydrophilic carbon nanoparticle suspension, no surfactants and no oily substances are required to maintain the suspension state. However, the cutting coolants are used in the pH values of alkaline state near 10, so the hydrophilic carbon nanoparticle solution has been neutralized by alkaline substances such as alkanolamines. In the case of oily cutting fluids for heavy duties, carbon mamo-particle powders are used after neutralized by basic barium dinonylnaphthalenesulfonate. The aqueous solutions of hydrophilic carbon nanoparticles exhibit the ability of sanitization effects to the cutting fluids and prolong the life times of them.
Catalytic Oxidation of Alkyl Benzene
Authors: Hossain M.A. Motalib , Ali Md Eaqub , Abd Hamid Sharifah Bee , Rahman Md. Motiar
Published: June 2015

Oxidation of benzylic C-H bonds of alkyl benzene for the synthesis of corresponding carbonyl compounds is a very important reaction for both commercial manufacturing and basic research. This paper reviews various kinds of catalysts involved in the oxidation of alkyl aromatic and their activity in various conditions and probable mechanism of action where applicable. The rate of conversion of alkyl aromatic and per cent of the yield of the corresponding products for each catalyst has been included.
Synthesis of Al-Doped ZnO Nanorod Arrays on Al-Doped ZnO Seed Layer and their Properties
Authors: Wahida M.N. , Mamat M.H. , Rusop Mohamad
Published: June 2015

Aluminium (Al)-doped zinc oxide (ZnO) nanorod arrays have been synthesized on a glass substrate, where the seed layer is Al-doped ZnO thin film as well, using the sonicated sol–gel immersion method. The nanorods structure was synthesized by preparing a solution 0.0026 M of zinc nitrate hexahydrate (Zn (NO3)2·6H2O, 98%, Systerm) as a precursor, 0.1 M hexamethylenetetramine (HMT, C6H12N4, 99%, Aldrich) as a stabilizer and 0.001M aluminum nitrate nonahydrate (Al (NO3)3∙9H2O, 98%, Analar) as a dopant, dissolved in deionized (DI) water. The resistivity is 7626.72 Ωcm and the conductivity is 1.31 x 10-4 Scm-1. The peak of UV emission of the sample is at 380 nm.
Influence of Hydrolysis Rate on Properties of Nanosized TiO2 Synthesized via Sol-Gel Hydrothermal
Authors: Bashiri Robabeh , Mohamed Norani Muti , Fai Kait Chong , Sufian Suriati
Published: June 2015

This paper presents the effect of different H2O: TTIP (Titanium tetraisopropoxide) molar ratios of 8 to 64 during the synthesis using sol-gel associated hydrothermal method on the physical properties. Characterization of all synthesized TiO2 were accomplished by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) and total surface area measurement, transmission electron microscopy analysis (TEM) and diffuse reflectance UV–Vis spectroscopy (DR-UV-Vis). The XRD analysis showed that anatase (101) was the major phase for all photocatalysts as verified by TEM results. The growth of crystallites with sizes ranging between 10 to 12 nm can be controlled by adjusting the H2O: TTIP molar ratios. Furthermore, no phase transformation from anatase to rutile observed by increasing the H2O: TTIP molar ratio. BET data displayed that all prepared photocatalysts are mesoporous materials with type IV adsorption behaviour. DR-UV-Vis spectroscopy revealed that the hydrolysis rate does not give any significant changes on the band gap energies. Among different photocatalysts, the prepared photocatalyst with the H2O: TTIP molar ratio 32 had the smallest crystal size, particle size, and the highest surface area which are suitable for better photocatalytic performance.
Design and Fabrication of Geometrically Enhanced Micromixer for Homogenous Mixing
Authors: Adam Tijjani , Hashim U. , Dhahi T.S.
Published: June 2015

At a macro scale level, mixing is generally achieved by a turbulent flow, which makes possible of segregating the fluid in small domains, thereby leading to an increase in the contact surface and decrease in the mixing path. At low Reynolds number, the viscous effects dominate inertial effects and a completely laminar flow occurs. In the laminar flow system, fluid streams flow parallel to each other and the velocity at any location within the fluid stream is variant with pressure when boundary conditions are constant and due to the change in surface area–to-volume tension and diffusion, do not simply scale linearly from large to small devices. This makes the use of microfluidic as a mixing device difficult. Thus, the study posed to bridge this gap by created geometrically enhanced Micromixer for homogenous mixing.
Green Synthesis of Silver Nanoparticles Using Momordica Charantia Fruit Extracts
Authors: Nahar M.K. , Zakaria Zarina , Hashim U. , Bari Md Fazlul
Published: June 2015

The synthesis of nanoparticles is in the spotlight in modern nanotechnology. In recent years, the development of competent green chemistry methods for synthesis of metal nanoparticles (NPs) has become a main limelight of researchers. Biological synthesis of nanoparticles using plant extract is currently under exploitation. The first time in this paper we have reported the green synthesis of silver nanoparticles (AgNPs) by reduction of silver nitrate, using fruit extracts of Momordica charantia (bitter melon); commonly found plant in south East Asia. The reaction process for the synthesis of silver nanoparticles is simple, cost-effective, novel, rapid and eco-friendly route using fruit extract of M. charantia plant, which acted as a reducing and stabilizing agent simultaneously at room temperature. Formation of the nanosilver was confirmed by surface Plasmon spectra using UV-Vis spectrophotometer and absorbance peak at 440 nm. Different silver ion concentration and contact times were experimenting in the synthesis of silver nanoparticles. The prepared nanoparticles properties were characterized by UV-Vis.
Synthesis and Characterized of Carbon Nanotubes from Fermented Tapioca
Authors: Nurulhuda Ismail , Poh R. , Mazatulikhma Mat Zain , Rusop Mohammad
Published: June 2015

Carbon nanotubes (CNT) has been synthesized by pyrolysing fermented tapioca liquid using an immersed heater. It was made single-walled carbon nanotubes (SWCNT) through heating at 700, 800 and 900 °C by the chemical vapour deposition (CVD) method and characterized by using Raman spectroscopy, thermogravimetric analysis and field emission scanning electron microscopy (FESEM). The synthesized SWCNT demonstrated larger diameters at 700 °C which decreased at 800 and 900 °C, respectively. The SWCNTs were indicated based on the radial breathing mode (RBM) peak present between 200 - 300 raman shift (cm-1). The diameters of synthesized CNTs ranged between 54 - 200 nm. Raman spectrum revealed that the G-bands were 1569, 1582 and 1576 cm-1, respectively, whereas the D-bands were 1346, 1350 and 1358 cm-1 for SWCNT synthesis at 700, 800 and 900 °C, respectively. The modified CVD method set up in the present study was successfully used for large scale synthesis of CNTs from an aqueous precursor such as fermented tapioca liquid.
Analysis of Photocurrent Responses of Anodized TiO2 Nanotubes Synthesized from Different Organic Electrolytes
Authors: Meriam Suhaimy Syazwan Hanani , Lai Chin Wei , Abd Hamid Sharifah Bee , Johan Mohd Rafie , Hasan M.R.
Published: June 2015

Self-organized titanium dioxide (TiO2) nanotubes (NTs) arrays were successfully fabricated via electrochemical anodization of titanium (Ti) foil in an organic electrolyte containing 5wt% of fluoride content. The present work compares two different organic electrolytes (glycerol and ethylene glycol) for the growth of self-organized TiO2 nanotubes by using anodic oxidation strategy. The resultant TiO2 NTs were then subjected to thermal annealing for manipulating the crystalline structure. The SEM images indicated changes in surface morphology of the TiO2 NTs in different electrolytes. It was found that the NT’s dimensional was 56.00nm based on the SEM analyses. Both samples exhibited good photocurrent response; however, TiO2 NTs synthesized in ethylene glycol electrolyte showed promising photocurrent response of 0.385 mA.
Post-Annealing Temperature Effect on ZnO Nanostructures Growth on Porous Silicon
Authors: Eswar Kevin Alvin , Fadzilah Suhaimi Mohd Husairi , Akhir Muzammil Mat , Abdullah Nurul Afaah , Abdullah Nurul Afaah , Asib N.A.M. , Mohamed Ruziana , Aziz Azlinda , Khusaimi Zuraida , Rusop Mohamad , Abdullah Saifollah
Published: June 2015

In this study, ZnO nanostructures were synthesized on porous silicon (PSi) substrate using hydrothermal immersion method. Different post-annealing temperatures were varied from 300°C to 600°C. Surface morphology was studied by field emission scanning electron microscopy. It shows that a better shape was produce at annealing temperatures of 500°C. Structural studies of ZnO nanostructure were implemented using X-ray diffraction grating. The result shows post-annealing can influence the crystallinty of ZnO. Photoluminescence spectra were used to study the optical properties of ZnO nanostructure. The result shows that peak corresponds to ZnO nanostructures are appeared in UV range. Besides, broad peaks are also appeared in visible range which is attributed to structural defects and PSi substrate.
Zinc Oxide/Carbon Nanotubes Nanocomposite: Synthesis Methods and Potential Applications
Authors: Noor Safitri Rika , Abu Bakar Suriani , Alfarisa Suhufa , Mohamed Azmi , Hashim Norhayati , Kamari Azlan , Md Isa Illyas , Rusop Mahmood Mohamad , Rahman Mohamed Abdul
Published: June 2015

Zinc oxide/carbon nanotubes (ZnO/CNTs) nanocomposite has been widely studied in the last few years due to their remarkable properties and versatile applications. Various methods have been presented in order to enhance the excellent properties of ZnO/CNTs nanocomposite. Here we reviewed several synthesis methods including single- and multiple steps to fabricate the ZnO/CNTs nanocomposite and the potential application of the nanocomposite in field emission and solar cell devices.
Surface Morphology of Acrylate/Carbon Nanotubes Nanocomposites on Mild Steel
Authors: Mahmud Muhammad Rashid , Shamsudin M.S. , Akhir Muzammil Mat , Harun Mohamad Kamal , Rusop Mohamad , Abdullah S.
Published: June 2015

Acrylate/carbon nanotubes nanocomposites were prepared using sol-gel method. Carbon nanotubes with different percentage (0.2%, 0.4%, 0.6%, 0.8% and 1.0%) incorporated into acrylate and deposited on mild steel. Surface of acrylate/carbon nanotubes composites were characterized using by field emission scanning electron microscope (FESEM). Carbon nanotubes uniformly distributed in acrylate observed by FESEM shows increase in percentage of carbon nanotubes blend with acrylate the peak distribution become decreases.
A Review on the Two-Dimensional Graphene Exploited in Organic Solar Cells Applications
Authors: Shamsudin M.S. , Sanip S.M.
Published: June 2015

Energy production and storage are both issues with increasing demands for improved performance and the requirement for greener energy resources constitute immense research interest. Graphene, (Gr) has incurred intense interest since its free standing form was isolated in 2004. Gr has immense potential to be used for low-cost, flexible, and highly efficient organic solar cells (OSC) due to its excellent electron-transport properties and extremely high carrier mobility. Numerous Gr-based OSC have been reported, in which Gr serves as different parts of the cell. One of the reasons for the current interest in Gr is the great potential for transparent conductive electrode (i.e. anode or cathode) in OSC. Gr is an ideal two-dimensional material which can be assembled into film electrodes with good transparency, high conductivity, and low roughness. Besides the potential to act as a transparent conductive electrode, Gr also has other attractive properties for solar devices. For example, Gr has been incorporated into photo-active conjugated polymers to improve the excitons (e-/h+ pairs) dissociation and the charge-transport properties of the materials. Additionally, Gr also has potential to be used as an interfacial photo-active layer, since its band gap and band-position can be induced and tuned via chemical functionalization or by controlling the size of the Gr sheets. Although Gr is still a relatively new material it has already made a wide and diverse impact and this review will enlighten us towards using Gr as a novel material for future energy storage/generation applications.
Single Phase CuO Thin Films Prepared by Thermal Oxidation in Air with Water Vapor
Authors: Liang Jian Bo , Li Xu Yang , Kishi Naoki , Soga Tetsuo
Published: June 2015

Single phase CuO films have been successfully synthesized by thermal oxidation of cupper foil in air with water vapor. The structural and optical properties of CuO films were investigated. It is observed that the grain size increases with increasing the oxidation temperature. The optical band gap of CuO film is determined by the transmittance and reflectance spectra.
The Synthesis of Graphene Oxide via Electrochemical Exfoliation Method
Authors: Md Disa Nurhafizah , Abu Bakar Suriani , Alfarisa S. , Mohamed Azmi , Md Isa Illyas , Kamari Azlan , Hashim Norhayati , Abd Aziz Azira , Rusop Mahmood Mohamad
Published: June 2015

In this study, electrochemical exfoliation method was adopted in the production of graphene oxide (GO). The electrolyte used was sodium dodecyl sulphate (SDS) aqueous solution at various concentrations from 0.001 to 1.0 M. The effect of SDS concentrations on the morphology of GO samples were characterized using field emission scanning electron microscopy (FESEM), energy dispersive X-ray, micro-Raman and UV-Vis spectroscopy. As evident by the FESEM analysis, the concentration of SDS does give effect to the GO obtained in this study. The lowest GO production is given by the lowest concentration of SDS used which is 0.001 M. However, in term of ID/IGratio, the sample prepared at 0.001 M has the lowest value (0.33) as compared to the sample prepared with highest SDS concentration of 1.0 M (ID/IG~1.12). Meanwhile, the presence of absorbance peaks in the range of 224-237 nm from UV-Vis spectra analysis were seen for the whole samples and this indicate the formation of GO.
Electrical and Structural Properties of Nanostructured Tin Doped Zinc Oxide Deposited by Sol-Gel Immersion Method
Authors: Karim Shafura , Mohd Saad Shafeena , Ishak Saurdi , Ahmed Azhar Najwa Ezira , Mohamed Ruziana , Mohd Noor Uzer , Mamat Mohamad Hafiz , Abu Bakar Ahmad Shuhaimi , Alrokayan Salman A.H. , A. Khan Haseeb , Rusop Mohammad
Published: June 2015

Tin-doped Zinc Oxide (Sn-doped ZnO) thin films were prepared using zinc nitrate hexahydrate as a starting material by sol-gel immersion method. The synthesized samples were characterized by current-voltage (I-V) measurement and Field Emission Scanning Electron Microscopy (FESEM). The Sn doping concentration were varied at 1.0 at.%, 2.0 at.%, 3.0 at.% and 4.0 at.%. FESEM images show that as the Sn concentration increased, the nanoparticles size of Sn-doped ZnO become denser and less grain boundary which might help in improvement of the electrical properties.
Electrical Properties of Undoped Zinc Oxide Nanostructures at Different Annealing Temperature
Authors: Nasir M.F. , Hannas Mohd , Mamat Mohamad Hafiz , Rusop Mohamad
Published: June 2015

This project has been focused on the electrical and optical properties respectively on the effect of Undoped zinc oxide (ZnO) thin films at different annealing temperature which is varied 400 oC, 450 oC, 500 oC, and 550 oC.Undoped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and UV-vis-NIR spectrophotometer for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 500 oC which its resistivity is 5.36 × 104 Ωcm-1. The absorption coefficient spectrum obtained from UV-Vis-NIR spectrophotometer measurement shows all films exhibit very low absorption in the visible (400-800nm) and near infrared (NIR) (>800nm) range but exhibit high absorption in the UV range.
Electrical Properties of Indium-Doped Zinc Oxide Nanostructures Doped at Different Dopant Concentrations
Authors: Nasir M.F. , Hannas Mohd , Mamat Mohamad Hafiz , Rusop Mohamad
Published: June 2015

This project has been focused on the electrical and optical properties on the effect of Indium doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different In dopant concentrations at 1 at%, 1.5 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 oC. In doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and UV-Vis-NIR spectrophotometer for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% In doping concentration which is 8.27× 103 Ωcm-1 The absorption coefficient spectrum obtained from UV-Vis-NIR spectrophotometer measurement shows all films exhibit very low absorption in the visible (400-800nm) and near infrared (NIR) (>800nm) range but exhibit high absorption in the UV range.
The Relation of Temperature Distribution on Silicon Wafer with Furnace Temperature and Gas Flow during Thermal Dry Oxidation Process
Authors: Azman A.H. , Norhafizah S. , Ramzan Mat Ayub , Md Arshad Mohd Khairuddin , Fathil M.F.M. , Kamarudin M.Z. , Nurfaiz M. , Farehanim M.A. , Hashim U. , Md Nuzaihan M.N. , Al-Mufti M. Wesam
Published: June 2015

Silicon dioxide film has been used as the gate dielectric material in MOS device technology for decades. The film is normally grown in a diffusion furnace using a dry thermal oxidation process. As the device is scaled down to nanometer dimensions, the SiO2 film uniformity requirement is more stringent than ever. In this paper, the effect of furnace temperature and the flow rate of oxygen gas on wafer temperature distribution was investigated. The result was recorded by using the Infrared Thermometer with Dual Laser Targeting device (IRT5000). We have found that the uniformity of temperature distribution on the wafer is almost directly proportional to the O2 flow rate for the entire furnace temperature range (900 - 1050°C). On the other hand, the effect of O2 flow rate on wafer temperature distributions clearly shows two distinct regions; for furnace temperatures of less than 1000 °C, the higher the O2 flow rate, the better the uniformity. For the furnace temperatures of more than 1000 °C, we did not observe any clear dependency of wafer temperature distribution on O2 flow rate.
Synthesis of Supported Gold Nanocatalysts for the Oxidation of Alkyl Benzenes
Authors: Rahman Md. Motiar , Ali Md Eaqub , Ara Mst. Gulshan , Abd Hamid Sharifah Bee , Hossain Md. Motalib
Published: June 2015

Selective oxidation of alkyl benzene, to its corresponding oxygen containing products, is a crucial reaction in organic researches and industrial manufacturing. In particular, the direct oxidation of lavish and cheapest aromatics, having carbon-hydrogen bonds, into corresponding ketones are the key transformations as the oxidation products are very important platform compounds for the production of useful prime, special chemicals and high economic valued fine chemicals, agrochemicals, pharmaceutical and perfumes in large scale. However, the oxidations of aromatic hydrocarbons have been remaining a challenging task due to the limitations of a suitable catalyst and requirement of chemical treatments (potassium permanganate/dichromate and ammonium cerium nitrate) which have been proven to be corrosive, not reusable, hazardous, and environmentally unfriendly and, also, have no selectivity at all. Instead of, scientists are paying more attention to use heterogeneous green catalysts along with support as well as novel oxidants e.g. hydrogen peroxide, tert-butyl peroxide and so on, due to its ecofriendly nature and availability. Silica/carbon/metal oxide supported nanoporous gold is a favorable catalyst due to its three dimensional open pore network structures, high surface to volume ratio, high reusability, distinct optolectronic and physio-chemical properties. Mesoporous carbon/silica/metal oxide supports provide well scattering of metal nanocatalysts and facilitate the transportation of molecules through the nanopores/nanochannels, thus increase the product with lowest cost and time. This paper has reviewed various gold-skeleton green catalysts and their synthetic method and mechanistic schemes for the selective oxidation of alkyl substituted aromatics.
ZnO Nanostructures Obtained by Mist-Atomization Method Growth on Different Au-Seeded Substrates Temperature
Authors: Abdullah Nurul Afaah , Asib N.A.M. , Aziz Aadila , Rusop M. , Mohamed Ruziana , Khusaimi Zuraida
Published: June 2015

Mist-atomization deposition method was applied in order to grow ZnO nanostructures with various surface morphologies. ZnO was deposited from the mixture of zinc nitrate hexahydrate (Zn (NO3)2.6H2O) and stabilizer, hexamethylenetetramine (HMTA, C6H12N4) aqueous solutions onto Au-seeded glass substrate. The mixture was sprayed onto the surface of Au-seeded glass substrate at various growth temperatures of room temperature (RT), 100, 200, and 300 °C. The obtained structures were characterised by room-temperature photoluminescence (PL), field emission scanning electron microscopy (FESEM), and UV-VIS-NIR spectrophotometer. It is found that ZnO growth on 300 °C substrate temperature shows the best absorbance properties and highest UV emission peak with denser distribution amongst all. The optical and morphological properties of sprayed ZnO nanostructures largely depend on the substrates temperature during spraying the zinc nitrate solution and on the Au-seeded glass substrates.
A Simplified Thermal Diffusion Process for Making the Silicon p-n Junction Using Sol-Gel Thin Films as the Educational Application
Authors: Takahashi Ryosuke , Nagaoka Shiro , Tsuji Takuto , Wakahara Akihiro
Published: June 2015

Learning by the actual experience of fabrication and evaluation of a p-n junction is a very effective way for students to obtain a deep meaningful understanding of the fundamentals of semiconductor physics. To achieve this requirement at a real-world classroom situation, a simplified fabrication process for making the silicon p-n junction as the educational application was studied. The process without using the lithography process, and in use of simple thermal diffusion furnace under the air environment for the impurity thermal diffusion process by using phosphorous silicate glass (PSG) thin film prepared by the Sol-Gel material as the phosphorus (P) diffusion source was proposed and tested. As the results, it was obtained that the impurity concentration and diffusion depth were controlled well by this method, and good rectification phenomenon of the p-n junction was successfully observed. The typical diode factor n of the p-n junction was approximately 2.3. The p-n junction also performed well as a solar cell. The FF is approximately 0.7. These results show that it is possible to use the p-n junction prepared by this simplified process as the educational device to help students’ understanding of the theory of the p-n junction.
Synthesis of Porous Anodic Alumina on Aluminium Manganese Alloys
Authors: Voon Chun Hong , Derman Mohd Nazree B. , Hashim U. , Foo Kai Loong , Ten Seng Teik
Published: June 2015

In this study, porous anodic alumina was formed on aluminium alloy substrate with increasing manganese content, from high purity aluminium with 0 wt% Mn to aluminium alloy with 2.0 wt% manganese by anodizing. Substrates were anodized at 50 V in 0.3 M oxalic acid of 15°C for 60 minutes. Images from the optical microscope revealed that no secondary phase existed in high purity aluminium and aluminium substrate with 0.5 wt% manganese while two phases were observed when the manganese contents were higher than 0.5 wt%. Element dispersive X ray spectroscopy spot analysis suggested that the secondary phase consists of both aluminium and manganese. Well ordered porous anodic alumina was obtained on high purity aluminium and aluminium substrate with 0.5 wt% manganese while pore arrangement of porous anodic alumina was significant disturbed when aluminium alloys with manganese contents higher than 0.5 wt% were anodized.
The Effect of Time Interval on Waste Cooking Palm Oil Injection for Carbon Nanotubes Production
Authors: Jusoh Norhafizah , Abu Bakar Suriani , Alfarisa Suhufa , Md Disa Nurhafizah , Jaafar Rosly , Mohamed Azmi , Md Isa Illyas , Hashim Norhayati , Kamari Azlan , Rusop Mahmood Mohamad
Published: June 2015

Carbon nanotubes (CNTs) were successfully synthesized using waste cooking palm oil (WCPO) as precursor by modified double-stages thermal chemical vapor deposition set-up. The total amount of 30 ml WCPO precursor was consumed during the experiment with 5.33 wt% ferrocene as catalyst. Precursor volume of 2 ml was injected continuously for different time intervals of 5, 8, 10 and 12 minutes respectively. The effect of time interval between injections on the production of CNTs were systematically studied using field emission scanning electron microscopy, micro-Raman spectroscopy and current-voltage (I-V) measurement system. It was detected that the differences in time interval of injections resulted in different quality and diameter of CNTs produced. Sample produced at 10 minutes of time interval of injection gave the smallest tubes diameter in the range of 39.45-49.01 nm and good crystallinity of 0.69 ID/IG ratio. This sample also gave the best I-V characteristic with conductivity of 6.06 x 10-1 S/cm.
Fabrication and Characterization of ZnO Thin Films by Sol-Gel Spin Coating Method for pH Measurement
Authors: Foo Kai Loong , Hashim U. , Voon Chun Hong , Kashif M.
Published: June 2015

Transparent semiconductor ZnO thin films deposited on interdigitated electrode (IDE) substrate substrates were obtained by low-cost sol-gel method. The coated ZnO films were annealed in furnace at 500°C for 2 hours. The influence of surface morphologies, crystallization and optical properties was investigated. The structural properties of the annealed ZnO thin films were examined with FESEM and AFM. XRD result shows that all polycrystalline ZnO thin film after annealing have the orientation along the (002) plane. Both FESEM and XRD results revealed that ZnO thin films were composed of hexagonal ZnO crystals in nanoscale dimensions. Moreover, UV-Vis was employed to study the optical properties of the ZnO films. Besides that, the deposited ZnO thin film will further use for pH by I-V curve tracer.
Assessing the relationship between environmental factors and malaria vector breeding sites in Swaziland using multi-scale remotely sensed data
Authors: Dlamini Sabelo Nick , Franke Jonas , Vounatsou Penelope
Published: June 2015

Many entomological studies have analyzed remotely sensed data to assess the relationship between malaria vector distribution and the associated environmental factors. However, the high cost of remotely sensed products with high spatial resolution has often resulted in analyses being conducted at coarse scales using open-source, archived remotely sensed data. In the present study, spatial prediction of potential breeding sites based on multi-scale remotely sensed information in conjunction with entomological data with special reference to presence or absence of larvae was realized. Selected water bodies were tested for mosquito larvae using the larva scooping method, and the results were compared with data on land cover, rainfall, land surface temperature (LST) and altitude presented with high spatial resolution. To assess which environmental factors best predict larval presence or absence, Decision Tree methodology and logistic regression techniques were applied. Both approaches showed that some environmental predictors can reliably distinguish between the two alternatives (existence and non-existence of larvae). For example, the results suggest that larvae are mainly present in very small water pools related to human activities, such as subsistence farming that were also found to be the major determinant for vector breeding. Rainfall, LST and altitude, on the other hand, were less useful as a basis for mapping the distribution of breeding sites. In conclusion, we found that models linking presence of larvae with high-resolution land use have good predictive ability of identifying potential breeding sites.