bluuebunny/crossref_metadata_2025 huggingface dataset:
Design Procedure and Fabrication of Reproducible Silicon Vernier Devices for High-Performance Refractive Index Sensing
Authors: Troia Benedetto , Khokhar Ali , Nedeljkovic Milos , Reynolds Scott , Hu Youfang , Mashanovich Goran , Passaro Vittorio
Published: June 2015

In this paper, we propose a generalized procedure for the design of integrated Vernier devices for high performance chemical and biochemical sensing. In particular, we demonstrate the accurate control of the most critical design and fabrication parameters of silicon-on-insulator cascade-coupled racetrack resonators operating in the second regime of the Vernier effect, around 1.55 μm. The experimental implementation of our design strategies has allowed a rigorous and reliable investigation of the influence of racetrack resonator and directional coupler dimensions as well as of waveguide process variability on the operation of Vernier devices. Figures of merit of our Vernier architectures have been measured experimentally, evidencing a high reproducibility and a very good agreement with the theoretical predictions, as also confirmed by relative errors even lower than 1%. Finally, a Vernier gain as high as 30.3, average insertion loss of 2.1 dB and extinction ratio up to 30 dB have been achieved.
Social Sustainability Issues and Older Adults’ Dependence on Automobiles in Low-Density Environments
Authors: Nakanishi Hitomi , Black John
Published: June 2015

An implicit assumption underlying government strategies to achieve a more sustainable urban transportation system is that all automobile users will be encouraged or persuaded to use more “green” transportation: public transportation, walking and cycling. Little consideration has been given as to how sustainable transportation policies and programmess might impact on different age groups in society, including those retired or semi-retired, despite the fact that an unprecedented number of older drivers will be on the highways in the next few decades. There is limited literature on the contextual factors behind their continued reliance on automobiles, their actual driving behavior (e.g., route choice and time of day to drive) framed within the context of social sustainability. This paper introduces the elements of transportation and social sustainability then conducts a comprehensive international literature review focusing on older drivers, their travel choices and associated social sustainability issues. It describes a case study, low-density city and presents empirical evidence, from two surveys conducted in Canberra, Australia. The paper concludes with future research directions that address these issues associated with sustainable transportation.
The Justice Dimension of Sustainability: A Systematic and General Conceptual Framework
Authors: Stumpf Klara , Baumgärtner Stefan , Becker Christian , Sievers-Glotzbach Stefanie
Published: June 2015

We discuss how the normative dimension of sustainability can be captured in terms of justice. We (i) identify the core characteristics of the concept of sustainability and discuss underlying ethical, ontological and epistemological assumptions; (ii) introduce a general conceptual structure of justice for the analysis and comparison of different conceptions of justice; and (iii) employ this conceptual structure to determine the specific characteristics and challenges of justice in the context of sustainability. We demonstrate that sustainability raises specific and partly new challenges of justice regarding the community of justice, the judicandum, the informational base, the principles, and the instruments of justice.
The Costs of Benefit Sharing: Historical and Institutional Analysis of Shared Water Development in the Ferghana Valley, the Syr Darya Basin
Authors: Soliev Ilkhom , Wegerich Kai , Kazbekov Jusipbek
Published: June 2015

Ongoing discussions on water-energy-food nexus generally lack a historical perspective and more rigorous institutional analysis. Scrutinizing a relatively mature benefit sharing approach in the context of transboundary water management, the study shows how such analysis can be implemented to facilitate understanding in an environment of high institutional and resource complexity. Similar to system perspective within nexus, benefit sharing is viewed as a positive sum approach capable of facilitating cooperation among riparian parties by shifting the focus from the quantities of water to benefits derivable from its use and allocation. While shared benefits from use and allocation are logical corollary of the most fundamental principles of international water law, there are still many controversies as to the conditions under which benefit sharing could serve best as an approach. Recently, the approach has been receiving wider attention in the literature and is increasingly applied in various basins to enhance negotiations. However, relatively little attention has been paid to the costs associated with benefit sharing, particularly in the long run. The study provides a number of concerns that have been likely overlooked in the literature and examines the approach in the case of the Ferghana Valley shared by Kyrgyzstan, Tajikistan and Uzbekistan utilizing data for the period from 1917 to 2013. Institutional analysis traces back the origins of property rights of the transboundary infrastructure, shows cooperative activities and fierce negotiations on various governance levels. The research discusses implications of the findings for the nexus debate and unveils at least four types of costs associated with benefit sharing: (1) Costs related to equity of sharing (horizontal and vertical); (2) Costs to the environment; (3) Transaction costs and risks of losing water control; and (4) Costs as a result of likely misuse of issue linkages.
Discharge Alterations of the Mures River, Romania under Ensembles of Future Climate Projections and Sequential Threats to Aquatic Ecosystem by the End of the Century
Authors: Lobanova Anastasia , Stagl Judith , Vetter Tobias , Hattermann Fred
Published: June 2015

This study aims to assess the potential alterations in the hydrological regime attributed to projected climate change in one of the largest rivers in the Carpathian Area, the Mures River, and to estimate associated threats to riverine ecosystem. The eco-hydrological model, Soil and Water Integrated Model (SWIM), was applied on the Mures River basin, calibrated and validated against records at a gauging station in Alba-Julia town. A set of nine future projections for climatic parameters under one emissions scenario A1B over the period 1971–2100 were fed into the SWIM model. To provide functional link between hydrological regimes and riverine ecosystems, each of the nine simulated discharge time series were introduced into the IHA (Indicators of Hydrological Alterations) tool. Triggered changes in hydrological patterns of the Mures River were assessed at the basin and sub-basin scales. The obtained results present a strong agreement through all nine climate projections; suggesting an increase in the discharge of Mures River for the winter season; a decrease in summer and prolongation of the low flow periods by the end of the century. Anticipated changes would pose threats to aquatic ecosystems; altering normal life-cycles; and depleting natural habitats of species.
Les lacs d'origine volcanique (Volcanic origin lakes)
Authors: Mottet Gérard
Published: June 2015

Résumé. - De nombreux lacs agrémentent les régions volcaniques : lacs de barrage, lacs de maars, lacs sous-glaciaires, de cratères, de caldeiras, de grands complexes volcano-tectoniques. Les explosions de 1984 et 1986 au Cameroun Occidental montrent qu'ils doivent être surveillés aussi bien dans les régions de forte activité volcanique que dans les autres.
Dérive des continents : paléoclimats et distribution des couvertures pédologiques tropicales (Continental drift : paleoclimates and distribution of the pedological tropical covers)
Authors: Tardy Yves , Roquin Claude
Published: June 2015

Résumé. - Les couvertures pédologiques tropicales, rangées sous la dénomination de latérites sont des témoins vivants de zonalité climatique, dont l'évolution accompagne la lente migration des continents par rapport à l'équateur et aux tropiques. Cependant les héritages des successions paléoclimatiques anciennes sont partout présents dans les sols, de sorte que les latérites sont aussi d'excellentes archives de l'oscillation du climat global ainsi que, sous l'effet de la dérive des continents, du glissement des climats régionaux, tantôt vers l'humide ou l'aride, tantôt vers le chaud ou le frais.
Influence of two types of self-retaining retractors on multifidus muscle blood flow during dorso lateral thoracolumbar hemilaminectomy in dogs
Authors: Rohner D. , Forterre S. , Rohrbach H. , Bürki A. , Gorgas D. , Howard J. , Forterre F.
Published: June 2015

Objectives: To assess the influence of the use of Gelpi and Grevel retractors on multifidus muscle blood flow during hemilaminectomy, using a dorsolateral approach, for acute disc extrusion in dogs as measured by laser speckle contrast imaging (LSCI).

Methods: Blood flow in the multifidus muscles was measured intra-operatively using LSCI prior to insertion of the retractors, immediately after hemilaminectomy and removal of the retractors, and after 10 minutes of lavage of the surgical site. Plasma creatine kinase levels were measured preoperatively and 12–24 hours postoperatively.

Results: Muscular blood flow was significantly decreased following retraction and remained lower than initial values 10 minutes after lavage in all dogs. The decrease in blood flow was significantly greater with Gelpi re-tractors (n = 8) than with Grevel retractors (n = 10). No significant relation was found between the duration of retraction and postoperative changes in creatine kinase levels or blood flow.

Clinical significance: Findings in this study demonstrate a drop in blood flow within the multifidus muscles using the dorsolateral approach regardless of retractor type used. Gelpi retractors seem to have greater influence on muscular blood flow than Grevel retractors. Further studies are warranted to confirm this second finding.
Floral cost vs. floral display: Insights from the megadiverse Myrtales suggest that energetically expensive floral parts are less phylogenetically constrained
Authors: Vasconcelos Thaís N. C. , Proença Carolyn E. B.
Published: June 2015

• Premise of the study: Floral display describes the effect of flower size combined with the number of flowers per inflorescence. There is strong evidence that a floral‐display trade‐off operates under energetic constraint, with few‐flowered inflorescences likely to have larger flowers than many‐flowered inflorescences. Flower size can be estimated by different variables; thus, we propose that the variable for flower size that is most highly (negatively) correlated with the number of flowers per inflorescence will also be the best estimate of floral cost. Ranking the correlation with the phylogenetic signal of the variable can provide additional insight into the evolution of floral display.

• Methods: The Myrtales were chosen as a model order based on age, worldwide distribution, and diversity of reproductive strategies. Ninety‐nine species representing all families and one quarter of generic diversity across its geographic and ecological range were sampled to reconstruct a phylogeny based on rbcL and ndhF sequences. Correlation coefficients were calculated for flower size variables vs. the number of flowers per inflorescence. Phylogenetic signal was measured for all variables and for floral display.

• Key results: Flowers per inflorescence showed significant negative correlation with the following flower size variables (weakest to strongest): filament length < anther size < flower depth < flower diameter. As the correlation of each character with number of flowers per inflorescence rose (suggesting increased cost), the values for phylogenetic signal diminished (suggesting less constraint).

• Conclusions: We conclude that energetically costly floral characters appear to be less phylogenetically constrained, while low‐cost floral characters maintain higher levels of phylogenetic inertia.
Do Residents Perform TKAs Using Computer Navigation as Accurately as Consultants?
Authors: Schnurr Christoph , Eysel Peer , König Dietmar Pierre
Published: June 2015

The implantation of a total knee arthroplasty (TKA) is a milestone in a resident’s surgical training. Studies demonstrate higher loosening rates after TKA by inexperienced surgeons. Alignment outliers should be avoided to achieve a long implant survival. Therefore, our study questioned whether residents implant knee prostheses using computer navigation as accurately as experienced consultants.

The data for 662 consecutive TKAs were analyzed retrospectively. The operations were performed by 4 consultants (n=555) and 5 residents under supervision by a consultant (n=107). Cutting errors were recorded from the navigation data. The postoperative mechanical axis and operation time were recorded. Operation time was significantly prolonged if residents performed the operation vs consultants (139 vs 122 minutes, respectively). The analysis of cutting errors within each surgeon’s first 20 navigated operations resulted in no significant difference between residents and consultants. During the subsequent operations, a trend toward a more accurate placement of the prosthesis was detected for consultants. The rate of outliers with a mechanical axis deviation >2° was low and did not significantly differ between residents and consultants (3.7% vs 2.3%, respectively).

Our study shows that residents implant their first TKA using computer navigation as accurately as experienced consultants. However, the residents’ operations take longer and therefore incur additional costs for the teaching clinic.
Heterotopic Ossification Revisited
Authors: Mavrogenis Andreas F. , Soucacos Panayotis N. , Papagelopoulos Panayiotis J.
Published: June 2015

Heterotopic ossification is the abnormal formation of mature lamellar bone within extraskeletal soft tissues where bone does not exist. Heterotopic ossification has been classified into posttraumatic, nontraumatic or neurogenic, and myositis ossificans progressiva or fibrodysplasia ossificans progressive. The pathophysiology is unknown. Anatomically, heterotopic ossification occurs outside the joint capsule without disrupting it. The new bone can be contiguous with the skeleton but generally does not involve the periosteum. Three-phase technetium-99m (99mTc) methylene diphosphonate bone scan is the most sensitive imaging modality for early detection and assessing the maturity of heterotopic ossification. Nonsurgical treatment with indomethacin and radiation therapy is appropriate for prophylaxis or early treatment of heterotopic ossification. Although bisphosphonates are effective prophylaxis if initiated shortly after the trauma, mineralization of the bone matrix resumes after drug discontinuation. During the acute inflammatory stage, the patient should rest the involved joint in a functional position; once acute inflammatory signs subside, passive range of motion exercises and continued mobilization are indicated.

Surgical indications for excision of heterotopic ossification include improvement of function, standing posture, sitting or ambulation, independent dressing, feeding and hygiene, and repeated pressure sores from underlying bone mass. The optimal timing of surgery has been suggested to be a delay of 12 to 18 months until radiographic evidence of heterotopic ossification maturation and maximal recovery after neurological injury. The ideal candidate for surgical treatment before 18 months should have no joint pain or swelling, a normal alkaline phosphatase level, and 3-phase bone scan indicating mature heterotopic ossification.
Surgical Treatment of Adult Idiopathic Scoliosis: Long-Term Clinical Radiographic Outcomes
Authors: Li Ming , Shen Yu , Gao Zhong-li , Fang Xiu-tong , Xie Yang , Wang Chuan-feng , Zhao Ying-chuan , Zhu Xiao-dong
Published: June 2015

More adults are suffering from adult idiopathic scoliosis and seeking treatment for their spinal deformities. Adult idiopathic scoliosis can lead to painful spinal osteoarthritis, progressive deformity, spinal stenosis with radiculopathy, muscle fatigue from coronal and sagittal plane imbalance, and psychological effects with a visible deformity. Primary treatment of such conditions is conservative; however, some patients are resistant to conservative treatment or are not candidates for it, and they require surgery. Back pain is likely the most common indication for surgical treatment of scoliosis in adult patients. Pedicle screws offer 3-column purchase and a longer arm compared with hook placement on the lamina. This study is a retrospective analysis of a consecutive series of patients with adult idiopathic scoliosis who were treated with pedicle screw placement. Significant back pain relief and satisfaction can be achieved and maintained over the long term. Restoration of coronal and sagittal balance, or improvement thereof, was achieved in all patients with balance problems. This study clarified several important characteristics of adult scoliosis, and we believe that useful conclusions can be drawn regarding its surgical indications and strategies: (1) pedicle screw construct can gain effective results for treatment of adult idiopathic scoliosis due to its perceived superior power of correction; (2) younger patients present for surgery for different reasons than older patients (progressive deformity or pain); and (3) pain improvement is a more reliable outcome in older patients than younger patients, although younger patients rarely have severe pain symptoms.
Outcomes for Myopic LASIK With the MEL 90 Excimer Laser
Authors: Reinstein Dan Z. , Carp Glenn I. , Lewis Tariq A. , Archer Timothy J. , Gobbe Marine
Published: June 2015

PURPOSE:

To evaluate the visual outcomes of myopic LASIK performed with the MEL 90 excimer laser (Carl Zeiss Meditec AG, Jena, Germany) using the Triple-A profile with a 500-Hz pulse rate.

METHODS:

Retrospective analysis of the first 286 myopic LASIK procedures (147 patients) by two experienced surgeons in which the VisuMax femtosecond laser and MEL 90 excimer laser (Carl Zeiss Meditec) were used following a standardized surgical technique. Inclusion criteria were preoperative spherical equivalent refraction (SEQ) up to −10.38 diopters (D), cylinder up to 5.00 D, and corrected distance visual acuity (CDVA) of 20/25 or better. No nomogram adjustments were made. Patients were observed for 3 months. Flap thickness was between 80 and 110
µ
m and optical zone was between 6 and 7 mm. Standard outcomes analysis was performed.

RESULTS:

Preoperatively, mean SEQ was −3.83 ± 1.83 D (range: −0.13 to −10.38 D) and mean cylinder was −0.94 ± 0.86 D (range: 0.00 to −5.00 D). Mean age was 36.4 years (range: 18.2 to 74.1 years) with 50% female patients. Of this population, 138 eyes were treated by one surgeon and 148 eyes by another. The mean predictability of SEQ was −0.13 ± 0.34 D (range: −1.00 to +1.00 D). Postoperative SEQ was ±0.50 D in 88% and ±1.00 D in 100% of eyes. Preoperative CDVA was 20/20 or better in 97% of eyes. Postoperative uncorrected distance visual acuity was 20/20 or better in 92% and 20/25 or better in 99% of eyes. One line of CDVA was lost in 6% of eyes and no eyes lost two or more lines. There was statistically significant improvement in mesopic contrast sensitivity (CSV-1000) at 3 (
P
= .021), 6, 12, and 18 (all
P
≤.001) cycles per degree.

CONCLUSIONS:

The MEL 90 excimer laser using the Triple-A ablation profile with a 500-Hz pulse rate was found to achieve a small but real increase in contrast sensitivity and high efficacy for myopia up to −10.00 D and cylinder up to 5.00 D without the need for a nomogram adjustment.

[
J Refract Surg.
2015;31(5):316–321.]
Synthesis of Co/CNTs Catalyst via Strong Electrostatic Adsorption: Effect of Calcination Condition
Authors: Akbarzadeh Omid , Mohd Zabidi Noor Asmawati , Abdullah Bawadi , Subbarao Duvvuri
Published: June 2015

In this study, CNTs samples were prepared by refluxing CNTs in nitric acid for 16 h at 110 °C and then followed by thermal treatment. The Co catalyst was synthesized by the strong electrostatic adsorption (SEA) method on the treated CNTs support. The Co/CNTs samples were then calcined at temperatures of 300, 350, 400, 450 °C. Samples were characterized by TEM and N2 adsorption. The size of cobalt nanoparticles and the textural properties were influenced by the calcination temperature. The TEM results showed that cobalt nanoparticles were well dispersed on the treated CNTs support.
A Review of High-κ Material for Biosensor Application
Authors: Norhafiezah S. , Ramzan Mat Ayub , Md Arshad Mohd Khairuddin , Azman A.H. , Farehanim M.A. , Hashim U.
Published: June 2015

The aim of this paper is to review several high-κ materials pertaining to their suitability as biocompatible layer in biosensor applications. The recent challenges and issues related to the process development of the stated applications were discussed. The materials were chosen based on the ideal biosensor characteristics such as biocompatibility of the material, the limit of detection, the sensitivity of the biosensor, etc. Based on our studies, TiO2 thin-film has emerged as the most promising high-κ material for biosensor applications because of its excellent biocompatibility. The additional merits were its chemical stability and non-toxicity that makes the TiO2 film the most sought after high-κ materials in biosensor application recently.
Effect of Mesoporous Silica Support on the Performance of Copper/Zinc Oxide Catalyst in Hydrogenation of CO2 to Methanol
Authors: Tasfy Sara Faiz Hanna , Shima Shaharun Maizatul , Mohd Zabidi Noor Asmawati , Subbarao Duvvuri
Published: June 2015

Cupper/zinc oxide catalyst supported on mesoporous silica (SBA-15) prepared at different sol acidity have been synthesized. The influence of preparation conditions on the textural properties and morphology of the mesoporous silica were investgated. The morphology and textural properties of the SBA-15 synthesized through the acidic route was found to be strongly influence by the pH of the synthesis sol. The effects of supported Cu/ZnO catalyst in CO2 hydrogenation was investigated in a three-phase reactor system at 483K, 22.5bar, and H2/CO2 of 3. The catalytic preformance was found to be strongly affected by the morphology of SBA-15. The maximum in the methanol synthesis activity (57.8 %) and methanol selectivity (66.4) was attained for the catalyst supported by SBA-15 synthesized at lower acidity (pH of 2).
Influence of Deposition Substrate Temperature on Optical and Electrical Properties of In Situ Boron Doped Amorphous Carbon Film for Solar Cell Applications
Authors: Ishak A. , Nazaruddin M.M. , Rani Hazimin M.M. , Saurdi I. , Rusop Mohammad
Published: June 2015

The effect of deposition subtrate temperatures by the applied of constant -20 V on electrical and optical properties of in-situ boron-doped amorphous carbon films were determined. From Tauc’s plot, optical band gap () was determined, and decreased as deposition temperature increased (1.99 eV to 1.90 eV) while the resistivity values were slowly deteriorates from 1.84x106 Ωcm to 4.31x105 Ωcm. The highest and lowest efficiecny of Au/a-C:B/n-Si/Au devices were achieved at 350°C (0.063641 %) and 200°C (0.042691 %), respectively. It can be concluded that by comparing with deposition temperature ranging from 200°C to 350°C under deposition condition used, at 350°C showed the optimum value for solar cell applications.
Characterization of Cu2Zn1-xCdxSnS4 Nanostructures
Authors: Ibraheam A.S. , Al-Douri Y. , Hashim U. , Al-Mufti M. Wesam
Published: June 2015

Pentrary alloys of Cu2Zn1-xCdxSnS4 nanostructures have been grown on glass substrate using sol-gel technique. The concentration of Cd has showed obvious effect for characterization study. Field emission-scanning electron microscope (FE-SEM) and atomic force microscope (AFM) have provide nanostructures of the utilized alloys. Those alloys give good impression about increasing the grain size with Cd concentration increasing, that lead to increasing the surface coarse.
Temperature Induced Formation of Goethite from Magnetite
Authors: Karim Mohammad Ziaul , Ali Md. Eaqub , Abd Hamid Sharifah Bee
Published: June 2015

Over the past few decades, magnetite nanoparticle has been profusely because of their wide range of applications. The co-precipitation method is the simplest and suitable method for the preparation of this nanoparticle. It goes through several reaction steps for the formation of various phases of magnetic nanoparticles. Goethite (FeO(OH)), is one of the intermediates, and it drastically suppressed with the magnetic properties of the Fe oxide phase. In our study, it was shown that at 30°C temperature pure magnetic nanoparticles is formed. But when precipitation temperature is increase to 80°C, goethite is also present with the magnetite nanoparticle. Hence, it is deduced that precipitation temperature plays a significant role in accelerating goethite phase formation when synthesising magnetite nanoparticle by this precipitation method. Data obtained from Raman spectroscopy and XRD supported the above observation.
Morphological, Structural and UV Sensing Properties of Fe-Doped ZnO Nanorods
Authors: Humayun Q. , Hashim U.
Published: June 2015

Iron (Fe) doped ZnO nanorods were synthesized on glass substrate using a sol-gel hydrothermal growth method by adopting various concentration ratios of 0.8 at% Fe, 1 at% Fe and 3 at% Fe respectively. The X-ray diffraction (XRD) analysis show that all the grown ZnO nanorods have a hexagonal wurtzite structure and are preferentially oriented along the c-axis perpendicular to the substrate surface. At 3 at% Fe-doping, the crystalline quality and the preferential orientation of ZnO nanorods are improved and below 3 at% Fe-doping concentration crystalline quality and the preferential orientation of ZnO nanorods is weakened in turn. The surface morphology analysis of the samples show that the ZnO nanorods are grown vertically to the substrate surface and highly interconnected. Such interconnected network will facilitates the electron transport along the nanorods axis. Current-voltage and current-time characterization under the exposure of UV light ON/OFF sates with exhibited excellent current gain of 1.12 and good response/recovery time of 30 and 10 s showed that the fabricated device can be used for UV sensing applications.
Epoxidised Natural Rubber/Silica Organic-Inorganic Composite for Tyre Masterbatch
Authors: Azira Abd Aziz , Verasamy D. , Abdullah N.S. , Kamal M.M.
Published: June 2015

Epoxidized natural rubber (ENR) / silica (Si) organic-inorganic composites were prepared by using a sol-gel technique. The choice of ENR (50 mol % epoxidation level), as a matrix was made because of its polar nature which can interact with the silica. The processing of the masterbatch was carried out by sol-gel method at room temperature by dispersing the silica in the rubber and coagulated with steam bath. The performance of the composites was evaluated in this work for the viability of ENR/Si in tyre compounding. Compounding was carried out on a two roll mill, where the additives and curing agents was later mixed. Characterization of these composites was performed by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) for dispersion as well as mechanical testing. Silica was also efficient as primary reinforcing filler in ENR with regard to modulus and tensile strength, resulting on an increase in the stiffness of the rubbers. Improvement in tensile strength over the control crosslinked rubber sample was probably due to synergisms of silica reinforcement and crosslinking of the rubber phase.
An In-House Approach for Fabrication of Poly-Silicon Nanobiosensor Using Conventional Photolithography and Etching Method
Authors: Md Nuzaihan M.N. , Hashim U. , Voon Chun Hong , Rahim Ruslinda A.
Published: June 2015

In this work, we demonstrated a method to fabricate and characterize poly-silicon nanowires for biosensing application using conventional photolithography and etching process. Nanowires Mask must be first designed using AutoCAD, before patterning onto chrome mask. Chrome mask was used for better photo masking and to transfer structure onto poly-silicon layer. The poly-silicon nanowires process flow were developed which includes all the fabrication process such as growth, deposition, lithography and etching process. In order to prove the effectiveness of the fabricated devices as a biologically sensor (Biosensor), the poly-silicon nanowires is modified chemically to allow the integration with biological element. The drain (Id) was found to increase after the DNA immobilization and hybridization. These results demonstrate that the in-house fabricated poly-silison nanobiosensor is capable as a platform for label-free biosensing. The morphological characterizations were carried out using a Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM). Besides that, the electrical measurement of the poly-silicon biosensor were carried out using a KEITHLEY 6487 picoampmeter/voltage source.
Critical Surface Tension of HSF54 Carbon Composite Electrodes on Paper Substrate
Authors: Mohamad Zin R. , Che Seman Fauziahanim , Soon Chin Fhong
Published: June 2015

The wettability of the carbon composite electrode on paper substrate was studied using contact angle measurement. Y-Shield HSF54 carbon composite material were coated on paper substrates with a mask using squeegee coating technique. Contact angles of the ten polar probe liquids with the HSF54 electrodes were measured using a customed-built image acquisition system. With the contact angles obtained for each probe liquid placed on the electrodes, the surface tension of the electrodes was determined using Fox-Zisman theory. The result showed that the critical surface tension of HSF54 carbon composite electrodes was 37.2 mN/m which is considered to be moderately hydrophobic.
Current-Voltage Characterization of Gallium Arsenide Nanowires Using a Conductive Atomic Force Microscopy
Authors: Muhammad R. , Wahab Yussof , Othaman Zulkafli , Sakrani Samsudi
Published: June 2015

Utilizing semiconductor nanowires for optoelectronics device requires exact knowledge of their current-voltage properties. In this report, we examine accurate on-top imaging and I-V characterization of individual vertical Gallium Arsenide Nanowires (GaAs NWs) using conductive atomic force microscopy without additional microscopy tools, thus allowing versatile application. The measured current-voltage characteristic of a single NW shows the typical performance of a Schottky contact, which caused by the contact between the metallic AFM tip and the top of NWs. The height of the Schottky barrier is dependent on the diameter of the nanowires. The linear part of the curve was used to calculate the differential resistance, which was found to be about 25 to 100 MΩ. Energy band gap for GaAs NW was found to be 1.5 eV by differential conductivity measurement.
Controlled Growth of WO3-Loaded TiO2 Nanotubes for Tandem Solar-Driven Water Splitting Cell
Authors: Lai Chin Wei , Lau Kung Shiuh , Abd Hamid Sharifah Bee
Published: June 2015

Nowadays, hydrogen production using solar-driven photoelectrochemical (PEC) water splitting has attracted considerable attention since the introduction of TiO2 photoelectrodes. However, TiO2 is not able to split water on its own because the cleavage requires more than 1.4 V or even up to 1.9 V, including the redox potential of water (1.23 V) and unavoidable over-potentials. Many semiconductors have been studied, but only a very few large band gap materials can generate enough photo-voltage to cleave water for a single photoelectrode PEC water splitting cell especially processing under solar illumination. In the present study, development of WO3-loaded TiO2 nanotubes (WTNT) is a possible solution to generate a voltage that is high enough to split the water while absorbing more light (photons) from a greater part of solar spectrum. Furthermore, WTNT offered several advantages over the pure TiO2 photoelectrode, such as excellent chemical and thermal stability, active at room temperature as well as responsive to UV and visible illumination. The paper concludes by presenting the comparison results between unmodified TiO2 and WTNT photoelectrode in term of morphology, phase, elemental analysis, electrical properties, and electrochemical properties for the tandem solar-driven water splitting cell.
Biological Synthesis of Nanosilver by Using Plants
Authors: Nahar M.K. , Zakaria Zarina , Hashim U. , Bari Md Fazlul
Published: June 2015

Nanotechnology is a most promising area that is increasing day by day and play a vital role in environments, biotechnological and biomedical fields. In recent years, the development of effective green chemistry methods for synthesis of various metal nanoparticles has become a main focus of researchers. They have investigated to find out a sustainable technique for production of well-characterized nanoparticles. A variety of chemical and physical methods have been exploited in the synthesis of silver nanoparticles (AgNPs) and these procedures remain expensive, high energy consumption and involve the use of hazardous chemicals. Therefore, there is an essential need to develop environmentally benign and sustainable procedures for synthesis of metallic nanoparticles. Increasing awareness of green chemistry and biological processes has need to develop a rapid, simple, cost-effective and eco-friendly methods. One of the most considered methods is production of nanosilver using plants and plant-derived materials which is the best candidates and suitable for large-scale biosynthesis of silver nanoparticles. Eco-friendly bio-organisms in plant extracts contain proteins, which act as both capping and reducing agents forming of stable and shape-controlled AgNPs. This review describes the recent advancements in the green synthesis of silver nanoparticles by using plants.
Structural, Morphological and Optical Properties of Sol-Gel Derived ZnO Thin Film for UV Sensing Application
Authors: Humayun Q. , Hashim U.
Published: June 2015

In the current research we have studied the structural, morphological, optical and ultraviolet (UV) light sensing properties of ZnO thin film. The film was prepared by sol-gel technique and deposited on glass substrate by spin coating method. The structural analysis was performed by X-ray diffractometer (XRD) while the surface morphology and optical properties of the deposited thin film were monitored using field emission scanning electron microscope and UV-VIS spectrophotometer. The FESEM image displayed the homogenous coverage of ZnO nanoparticles over the surface of glass substrate. The deposited thin film shows an average transmittance value of more than 90%, in the visible light spectrum. The calculated value for optical band-gap was 3.26 eV. Refractive indices and dielectric constants were calculated by utilizing the bandgap value by considering different relations. Current to voltage characterization was conducted by using Kiethley sourcemeter connected with ultraviolet (UV) light illuminated LED’s. The excellent photo to dark current (Iph/Id) ratio (5.49) and rapid rise and decay time (15 s and 6 s) and the measured responsivity (1 A/W) suggest that the deposited ZnO thin film can be used for ultraviolet (UV) light sensing application.
Phase and Particle Size Analysis of SnO2 Nanomaterials
Authors: Abdul Aziz Nor Diyana , Elong Kelimah , Kamarulzaman Norlida
Published: June 2015

Tin Oxide (SnO2) is a metal oxide which has many applications in industry. In this study, SnO2 powders were synthesized by a self-propagating combustion (SPC) method. The product was annealed at 800 °C for 12 and 24 h before characterizing with X-Ray Diffraction (XRD) for phase studies. X-Ray Diffraction results showed that both samples are pure of tetragonal structure with space group P42/mnm. The sample annealed at a longer period, that is, 24 h, shows a higher degree of crystallinity compared to the 12 h annealed sample. It also shows a smaller full width at half maximum (FWHM), indicating larger crystallite size for the 24 h annealed sample. The particle size analysis reveals that there are two groups of particle size distributions for both samples. SEM results give values that are different from the particle sizer results due to the different nature of the measurement methods.
Nanofluid as Cooling Medium in Polymer Electrolyte Membrane (PEM) Fuel Cell: A Study on Potentials and Possibilities
Authors: Zakaria Irnie Azlin , Michael Zeno , Wan Mohamed Wan Ahmad Najmi
Published: June 2015

Keywords: Thermal management; PEM fuel cell;Nanofluid Abstract. Tremendous need for an optimum conversion efficiency of a Polymer Exchange Membrane Fuel Cell (PEMFC) operation has triggered varieties of advancements namely on the thermal management engineering scope. Excellent heat dissipation is correlated to higher performance of a fuel cell thus increasing its conversion efficiency. This study reveals the potential advancement in thermal engineering of a fuel cell stack related to nanofluid technology. Nanofluids are seen as a potential evolution of nanotechnology hybridisation with fuel cell serving as a cooling medium. The thermophysical characteristics have been reviewed and challenges with regards to fuel cell application is discussed. Nanofluid has been successfully tested on many thermal management systems isolated from thermoelectrical environments such as fuel cell. The main challenge is formulating a nanofluid coolant with high thermal conductivity but with strict limit on electrical conductivity of less than 5 μS/cm. Lack of electrical conductivity data for various nanofluids in open literature is another challenge in nanofluid application in fuel cell.
Fabrication of PDMS Microfluidic via Room Temperature Rapid Prototyping Process
Authors: Adam Tijjani , Hashim U. , Dhahi T.S.
Published: June 2015

An in-expensive way of fabricating PDMS microfluidic using room temperature curing process is presented which can be used for both laboratory and commercial scale. The microfluidic was designed using AutoCAD for master mold preparation and subsequently created with SU8 for rapid prototyping process; the micro mixer and the whole mixer were fabricated in less than without using costly fabrication steps. The device profiles were observed for structural integrity and evaluation by dropping two food coloring dyes through the two inlets and collecting the sample at outlet. Flow rate and mixing efficiency were quantitatively measured by analyzing the recorded flow profiles and values of the image collected from the high powered microscope at inlet and outlet locations is fully obtained and will be presented in our next publication
Silicon Nanowire Surface Preparation Using Chitosan
Authors: Adam Tijjani , Hashim U. , Dhahi T.S.
Published: June 2015

Chitosan (CS) is an interesting polysaccharide biopolymer that widely used in the fields of agriculture, horticulture, industry, biomedicine and chemical sensor due to its numerous advantage like non-toxic nature, excellent film forming ability, good mechanical strength, high permeability and cost effectiveness. The chitosan solution (0.05 %) was prepared by dissolving 0.05g chitosan (Sigma corp) in 10 ml of acetic acid (2mol/L). after the is the preparation of preparation of chitosan: A very small amount of chitosan were taken and dissolved in distilled water. The solution was then ultrasonicated for 90 minutes to obtain a homogenized solution. The spectra shows featureless absorption in the 400-800 nm and a sharp absorption peak at 250 nm regions which are similar to the spectra of chitosan in the previous research. The UV-vis spectra of chitosan in at different concentration. The spectra show featureless absorption in the 400-800 nm. A sharp absorption peak at approximately 300 nm. The observed absorption peak in chitosan solution depends on the solution concentration. When the chitosan concentration was less, the peak was not that clearly seen compared to the concentration of 0.05.
Toxicity of SWCNT Synthesized from Fermented Tapioca on SH-SY5Y Cells
Authors: Nurulhuda Ismail , Poh R. , Mazatulikhma Mat Zain , Rusop Mohammad
Published: June 2015

The unique physical properties and strength of carbon nanotube (CNT) lend to its wide application in many fields as diverse engineering, physics and biomedicine. Biomedicine, the toxicity of CNTs was cause for concern on the application as a delivery tool for therapeutic proteins, peptides and genes in the treatment of cancer and neurodegeneration. CNTs were reported to exert adverse effects on normal neuronal function, probably due accumulation in the brain, leading to brain damage. Thus, toxicity tests of CNTs on cells would be relevant in determining potential side effects and dosage. This study was set out to evaluate the toxicity of SWCNTs derived from fermented tapioca on SH-SY5Y cells. Fermented tapioca, was a well known Malaysian local food, and was an excellent precursor for SWCNT synthesis. The raw synthesized SWCNTs were directly used to study the effect on SH-SY5Y cells. Cytotoxicity and neurotoxicity test were performed. The neurotoxicity test results showed higher cell viability compared to the cytotoxicity test. Cell viability for neurotoxicity test was above 50 % for CNT concentration ranges of 250 μg/ml and below. However cell viability decreased markedly at 500 μg/ml. The percentage of cell viability was high at 50 μg/ml and below for the first 24 h of treatment but longer treatment duration resulted in significant decrease in cell viability for all concentrations above 10 μg/ml. These findings demonstrated that CNTs were safe when used at concentration less than 10 μg/ml.
Progress in ZnO Nanostructure for Sensing Based Using Low Temperature Method
Authors: Mohamed Ruziana , Khusaimi Zuraida , Abdullah Nurul Afaah , Aziz Aadila , Shafura A.K. , Eswar Kevin Alvin , Mamat Mohamad Hafiz , Rusop M.
Published: June 2015

Semiconductor ZnO nanostructure with low dimension for gas sensing has been studied due to its features such as good sensitivity, selectivity and show fast response in gas sensing detection. This attractive material could be growth in a variety nanostructure such as one-dimensional nanostructure eg; the nanorods, nanowire, nanobelts and nanotubes and two-dimensional (2D) eg; nanosheet, nanodisk and nanoflakes. ZnO can also be tuned to perform a mixture of nanostructure to improve the performance of its detection. This paper provides the report in synthesis of ZnO nanostructure with a simple method at low temperature for sensor application.
Photodegradation of Methylene Blue over Cr Doped TiO2 and Cr Doped TiO2 Supported TUD-1 Photocatalysts
Authors: Ooi Yee Khai , Yuliati Leny , Lee Siew Ling
Published: June 2015

A series of visible light driven photocatalysts of Cr-doped TiO2 and Cr-doped TiO2 supported on TUD-1 have been successfully synthesized via surfactant-free sol-gel method followed by wet impregnation procedure. XRD analysis revealed that both anatase and rutile phases existed in Cr-doped TiO2 samples. After loading onto TUD-1, both Ti and Cr were incorporated in the highly porous siliceous matrix. As observed, more tetrahedrally coordinated Ti species was formed in Cr-doped TiO2 after supporting onto TUD-1. The photocatalytic performance of the synthesized materials was tested in the photodegradation of Methylene Blue under visible light irradiation. Results showed that 2.5 mol% Cr dopant gave the highest photocatytic activity to TiO2 in dye photodegradation. Besides, all the 2.5Cr-TiO2 supported on TUD-1 materials had higher photocatalytic activity than that of 2.5Cr-TiO2. Among the materials prepared, 2.5Cr-TiO2/30TUD-1 appeared as the most superior photocatalyst which gave the highest dye photodegradation of 75%.
Design and Synthesis of Silica Supported Nanoporous Gold-Palladium Bimetallic Catalyst for Alkyl Benzene Oxidation
Authors: Saha Subrata , Ali Md Eaqub , Maamor Azman , Basirun Wan Jeffery
Published: June 2015

Gold palladium (Au-Pd) bimetallic catalysts are very promising for various reactions including oxidative catalysis. Mesoporous silica supported Au-Pd catalysts have large surface area, controlled hydrophobi and file-cities and are thus highly efficient for the oxidation of alkyl benzene to selective products. Alkyl Benzene oxidation is important for the productions of drugs, perfumes, polymers, insecticides and pesticides. Unfortunately, the efficient oxidation of alkyl benzene has been remaining a challenging task due to lack of suitable catalysts. Functionalized mesoporous silica with ordered surface and uniform porosity is an exciting template for the synthesis of supported catalysts. Metal precursors could be co-impregnated on the highly ordered surface of ammine functionalized silica. This method facilitates great dispersion of the Au-Pd clusters with tiny and controlled particle size. Here, we described a two-step adsorption –reduction method along with various ratios of metal loadings for the synthesis of silica supported nanoporous Au-Pd catalyst for alkyl benzene oxidation.
Dielectric and I-V Characteristic of Lead Titanate Thin Films Prepared on ITO Glass Substrate
Authors: Zainal Nurbaya , Wahid Mohd Hafiz , Rusop Mohammad
Published: June 2015

Performance of lead titanate, (PbTiO3) thin films have been successfully investigated on microstructural properties, I-V characteristic, dielectric properties, and ferroelectric properties. PbTiO3 offers variety of application as transducer, ferroelectric random access memory, transistor, high performance capacitor, sensor, and many more due to its ferroelectric behavior. Preparation of the films are often discussed in order to improve the structural properties, like existence of grain boundaries, particle uniformity, presents of microcrack films, porosities, and many more. Yet, researchers still prepare PbTiO3 thin films at high crystallization temperature, certainly above than 600 ̊C to obtain single crystal perovskite structure that would be the reason to gain high spontaneous polarization behavior. Although this will results to high dielectric constant value, the chances that leads to high leakage current is a major failure in device performance. Thus, preparation the thin films at low annealing temperature quite an essential study which is more preferable deposited on low-cost soda lime glass. The study focuses on low annealing temperature of PbTiO3 thin films through sol-gel spin coating method and undergo for dielectric and I-V measurements.
Structural Properties of Stannic Oxide Coated Aluminium-Doped Zinc Oxide Nanorods
Authors: Ismail Ahmad Syakirin , Malek Mohd Firdaus , Abdullah Muhammad Amir Ridhwan , Mamat Mohamad Hafiz , Rusop M.
Published: June 2015

Aluminium (Al) - doped zinc oxide (ZnO) nanorods was deposited using sol-gel immersion method. To study the effect of stannic oxide coating (SnO2) on the structural properties of the ZnO nanorods, SnO2 with different layers were deposited on the top of ZnO nanorods, from 1 to 5 layers. The structural properties of the samples have been characterized using field emission scanning electron microscopy (FESEM), atomic force microscopy and x-ray diffraction (XRD). The analyses showed that by increasing the deposited layer, the surface roughness of the samples reduced and also reduced the porosity of the surface.