bluuebunny/crossref_metadata_2025 huggingface dataset:
Humidity Sensors on Thermally Oxidized Silicon Substrates
Authors: Low Cheng Yang , Chan Kah Yoong , Ng Zi Neng , Hoon Jian Wei , Pang Wai Leong
Published: June 2014

In recent years, as a ceramic semiconducting material, zinc oxide (ZnO) has received great attention in sensing applications, including ultra-violet (UV), gas, and humidity sensors. In this work, ZnO based humidity sensors were fabricated on thermally oxidized silicon substrates. The contact electrodes for the sensors were realized using patterned aluminium (Al) films. ZnO films were deposited on the substrates as the active layer for the sensors using radio frequency (RF) magnetron sputtering technique. The electrical properties of the sensors were tested in various relative humidity (RH) levels. The ZnO humidity sensors have showed a decrease in resistance with increasing humidity level. The fabrication process and the characteristics of the ZnO humidity sensors will be revealed in this work.
Development of Water Adsorbents Synthesized from Spent Bleaching Earth to Dehydrate Ethanol Water Mixture
Authors: Abd Aziz Zharin Shah , Nour Abdurahman Hamid , Rosli Mohd Yunos
Published: June 2014

Water adsorbent to dehydrate water ethanol mixture was synthesized from spent bleaching earth (SBE) using modified fusion method. The SBE was regenerated using heat at 750°C. Predetermined alumina, Al2O3and a stochiometric amount of KOH was added to the regenerated SBE, mixed and fused at several temperatures for 12 hours in a furnace. The fused mixture was grounded and mixed with water to get 40-55% KOH solution in water. This mixture was aged for several pre determined temperature for several pre determined days in a closed container before crystallization took place in 5 part by weight 5% KOH for 48 hours. The product obtained was washed 3 times with distilled water using filtration set and dried in oven at 220°C for 20 hours. Results from Karl Fischer Titration showed that the product was able to absorb water up above 0.0200 g/g adsorbent which was approximately 50% performance of commercial zeolite A. The best conditions for synthesizing the water adsorbent from SBE were : 80 g alumina added per 100 gram kaolin, fused temperature of 650°C, aging temperature of 80°C for 5 days. However, XRD results showed that the synthesized product was not the type of zeolite A.
Effects of Heat Generation or Absorption on Free Convection Flow of a Nanofluid Past an Isothermal Inclined Plate
Authors: Akilu S. , Narahari M.
Published: June 2014

In this paper, the effects of internal heat generation or absorption on free convection flow of a nanofluid past an isothermal inclined plate have been investigated numerically. The governing boundary-layer equations are first transformed into a system of coupled nonlinear ordinary differential equations using similarity variables. An efficient implicit finite-difference scheme known as the Keller-box method is employed to solve the resulting nonlinear equations. The effects of internal heat generation or absorption parameter on the flow fields have been presented graphically and discussed. It is found that the rate of heat transfer decreases with increasing heat generation, Brownian motion and thermophoresis parameters whereas it increases with increasing heat absorption parameter and Prandtl number.
Simple and Low-Cost Preparation of Carbon-Coated Titanium Dioxide via Hydrothermal Method
Authors: Mohd Hatta Mohd Hayrie , Lintang Hendrik O. , Buang Nor Aziah , Yuliati Leny
Published: June 2014

In the present study, carbon-coated titanium oxide (C-TiO2) was synthesized by hydrothermal method using dichloromethane as the novel low-cost carbon source. XRD patterns revealed that after purification method, only diffraction peaks of anatase TiO2 can be observed. On the other hand, the formation of carbon can be suggested from DR UV-visible spectrum and SEM image, which showed the additional of absorption band in the visible region and the successful formation of carbon that grew both on the surface with a unique noodle-like structure and surroundings of the TiO2 with non-uniform bulk structure, respectively.
Synthesis of Silica-Coated Copper Nanoparticles and its Application to Red Color Glaze
Authors: Shiomi Shohei , Matsubara Eiichiro , Taguchi Hajime , Hashida Shozo , Yokoyama Tadanori
Published: June 2014

A core-shell structure of Cu@SiO2, namely, silica-coated Cu nanoparticles, was synthesized by a simple liquid phase reaction. The reaction bath was optimized by evaluating the balance between the dissolution behavior of Cu nanoparticles and the deposition rate of SiO2shells for coating. The Cu nanoparticles were fabricated by an electroless deposition method. The deposition and dissolution behaviors of Cu were quantitatively evaluated by quartz crystal microbalance (QCM) measurements, combined with the reducing ability evaluated by the mixed potential measurements. SiO2shells were synthesized by a sol-gel process of tetraethyl orthosilicate (TEOS). The optimal responsiveness bath condition was also elucidated by the QCM measurement to evaluate the deposition rate of SiO2shells, which was much faster than the dissolution rate of Cu nanoparticles, indicating that the SiO2shells sufficiently coated the Cu nanoparticles. The stability of annealed Cu@SiO2nanoparticles was considerably increased and by using them, the red color glaze is achieved in easy and safe way.
Alumina Reinforced Epoxidized Natural Rubber in Latex Phase Mixing: Effect of Alumina Content
Authors: Khaokong Chuanpit , Phinyocheep Pranee
Published: June 2014

This work is preliminary studied of alumina-reinforced epoxidized natural rubber prepared via latex-mixing method without coupling agent. The effect of alumina content on distribution of filler and mechanical properties was investigated. Epoxidized natural rubber latex (ENR) was synthesized by in situ epoxidation of natural rubber using formic acid and hydrogen peroxide. The vulcanizing chemicals and alumina were then added in to ENR latex. The alumina content was varied from 10 to 75 phr. Prevulcanization at 70oC for 24 h and post-vulcanization at 110oC for 15 minutes was performed. The mixing time for a hour at mixing speed 600 rpm was chosen due to it shows the regular dispersion of filler in the matrix. The alumina content which can be added in epoxidized natural rubber decreased as epoxidation increased. The amount of alumina added was limited by the rigidity of high epoxidation content rubber. Modulus was increased with the increased of alumina content, whereas at alumina content 10 phr give the highest tensile strength corresponding to well dispersion of filler in matrix. Alumina addition in epoxidized natural also increases the hardness of rubber, which results to decreasing of rebound resilience property. This may caused by molecular stiffness of epoxide ring in ENR and excellent hardness of alumina particle. Furthermore, alumina addition also enhances a thermal stability of composite.
Biomimetic Porosity of Gelatin-Hydroxyapatite Scaffold for Bone Tissue
Authors: Normahira Mamat , Raimi Razali Khairul , Nasir Fazli Mohd Nashrul , Norazian Abd Razak , Adilah Hashim
Published: June 2014

Biomimetic Porosity of Gelatin/hydroxyapatite (HA) scaffold was fabricated by using solvent casting method and particulate leaching technique. The composite solution were prepared by adding fixed weight percentages of HA (30wt%) with different concentration a gelatin solution (0.25wt%, 0.30wt%, 0.35wt%, 0.40wt% and 0.50wt%) . Five different composites polymers were poured into a mold with size of 15mm x 15mm x 10mm cube and dried in the oven dryer under 60°C to 90°C. After that, the dry composite scaffolds were immersed in the 8% of glutaraldehyde (GA) solution in a few minute for crosslinking process. Porosity of the scaffold is obtained by doing liquid displacement method. Meanwhile, the mechanical properties (Youngs Modulus) of the scaffolds are obtained by doing compressive test on the scaffold. Lastly, the microstructure and morphology of the composite scaffolds were observed under Scanning Electron Microscope (SEM). It was found that, when gelatin concentration were increased in the composite scaffold, percentages of liquid adsorption will increase, thus indicate that, the scaffold which has high percentage of liquid adsorption has poor mechanical properties and excellent permeability. Besides, SEM result shows that, the scaffolds have pore size in the range of 3 μm - 22μm. and do not exhibit uniform pores distribution. Pore size of the scaffold depends upon the sizes of the NaCl particles.
Changes in Characteristics and Physicochemical through Vermicomposting of Pome Sludge by Epigeic Earthworm E. eugeniae
Authors: Bidattul Syirat Zainal , Ibrahim Mahamad Hakimi , Astimar Abdul Aziz , Nahrul Hayawin Zainal
Published: June 2014

The aims of this study was to investigate the characteristics and physicochemical changes of vermicompost during composting of palm oil mill effluent (POME) sludge processed by epigeic earthworm (E. eugeniae) within 60 days. The value of macronutrients, micronutrients and heavy metals and pH in vermicompost comes out to be (pH8.3), carbon (C) (45.2%), CN ratio (18.1%), phosphorus (P) (5.02%), ferum (Fe) (0.6%), copper (Cu) (16.8 ppm), zink (Zn) (119.54 ppm), mangan (Mn) (1049.86 ppm), potassium (K) (0.81%), nitrogen (N) (2.5%), calcium (Ca) (11.42%) and magnesium (Mg) (2.99%), and was compared with compost from EFB-POME sludge and compost from mesocarp fiber-POME sludge. In addition, the amino acid content in vermicompost detected was very low as compared to raw POME. Meanwhile, three types of fungus were detected in vermicompost which are fromPaecilomycessp.,Fusariumsp. andPenicilliumsp. The results suggested that POME sludge could be recycled to form compost by using vermicomposting technology, as well as act as a good organic fertilizer.
Mechanical, Thermal, and Morphological Properties of Thermoplastic Starch/Poly(lactic acid/Poly(butylene adipate-co-terephthalate) Blends
Authors: Tachaphiboonsap Sujaree , Jarukumjorn Kasama
Published: June 2014

Thermoplastic starch (TPS)/poly (lactic acid) (PLA) blend and thermoplastic starch (TPS)/poly (lactic acid) (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend were prepared by melt blending method. PLA grafted with maleic anhydride (PLA-g-MA) was used as a compatibilizer to improve the compatibility of the blends. As TPS was incorporated into PLA, elongation at break was increased while tensile strength, tensile modulus, and impact strength were decreased. Tensile properties and impact properties of TPS/PLA blend were improved with adding PLA-g-MA indicating the enhancement of interfacial adhesion between PLA and TPS. With increasing PBAT content, elongation at break and impact strength of TPS/PLA blends were improved. The addition of TPS decreased glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm) of PLA. Tgand Tcof TPS/PLA blend were decreased by incorporating PLA-g-MA. However, the presence of PBAT reduced Tcof TPS/PLA blend. Thermal properties of TPS/PLA/PBAT blends did not change with increasing PBAT content. SEM micrographs revealed that the compatibilized TPS/PLA blends exhibited finer morphology when compared to the uncompatibilized TPS/PLA blend.
Rheological Behavior Characterization of Natural Rubber Containing Different Gel
Authors: Thongseenuch Saengchao , Taweepreda Wirach , Suchiva Krisda
Published: June 2014

This research, natural rubber containing different gel contents were prepared by deproteinization and saponification treatment from high ammonium natural rubber latex. Deproteinization natural rubber was further treated as acetone extraction and then transesterification. It was founded that gel content and molecular weights of treated natural rubber were decreased and almost absented for transesterification treatment. Rheological respond on small amplitude oscillating shear (SAOS) and large amplitude oscillating shear (LAOS) deformation of treated natural rubber were captured by using rubber process analyzer (RPA 2000). Firs harmonic rheological properties, storage modulus, G and loss modulus, G decreased as gel content and molecular weight decreased. It was believed that gels, explicitly branching points, were destroyed after the natural rubber was deproteinized, transesterification, or saponification according to the molecular structure of natural rubber presumed by Tanaka et al, which functional groups contain protein and fatty acid are participated in branching to forming gel structure. It was concluded that gel content as the same as molecular structure of natural rubber could be characterized as rheological behavior.
Surface Modification of Poly(lactic acid) (PLA) via Alkaline Hydrolysis Degradation
Authors: Tham Cho Yin , Abdul Hamid Zuratul Ain , Ahmad Zulkifli , Ismail Hanafi
Published: June 2014

Surface hydrophobicity of poly (lactic acid) have raise the concerns of surface incompatibility of PLA to function as biomaterial. Thus, various approaches have been made to improve the surface hydrophilicity of PLA. In the present paper, PLA materials were surface modified by alkaline hydrolysis. The indication of the reduction in water contact angle value, from 65 ̊ to 50 ̊ and 15 ̊, in 0.01M and 1M alkaline concentration respectively, proven surface hydrophilicity of PLA film was improved. Further alkaline treatment after 24 hours shows not significant reduction in contact angle. Whereas, the erosion of film surfaces treated under 1M alkaline solution have been observed under polarized optical microscopy. Intrinsic viscosity measurement was also conducted to monitor the surface treatment process. As a whole, surface treatment was successful and sufficient when no further decreased in contact angle value, thus prevent extensive surface erosion.
Vapochromic Copper (I) Pyrazolate Complex Materials for Phosphorescent Chemosensors of Ethanol
Authors: Ghazalli Nur Fatiha , Yuliati Leny , Endud Salasiah , Shamsuddin Mustaffa , Lintang Hendrik O.
Published: June 2014

Here chemosensor materials of trinuclear copper (I) pyrazolate complexes have been successfully synthesized and isolated using two types of 3,5-dimethyl and 4-(3,5-dimethoxybenzyl)-3,5-dimethyl pyrazole ligands. Upon excitation at 280 nm, the resulting trinuclear 3,5-dimethyl copper (I) pyrazolate complex (complex A) and trinuclear 4-(3,5-dimethoxybenzyl) copper (I) pyrazolate complex (complex B) showed emission bands centered at 590 and 604 nm, respectively. These results were in good agreement with their greenish-white powders and it is characteristic of phosphorescent metal complexes from the weak Cu (I)-Cu (I) metallophilic interaction. Upon direct or stepwise exposure to ethanol vapor with series of concentrations (12.5, 25, 50, 100, 150 and 200μL in 22 mg of chemosensor), the emission of chemosensor complex A was not shifted even after 1 d. Interestingly, chemosensor complex B showed gradually changes in both emission band with shifting from 602 to 552 nm and color with changing from orange to green under Ultra-violet (UV) hand lamp (254 nm) at the dark room due to the attachment of benzyl ring to the pyrazole ligand. This positive response for chemosensor complex B was reversible; hence, this optical phosphorescent material can be used for developing vapochromic sensors of ethanol.
A Study on Biocompatibility of Gadolinium Based Anodizing Coating AZ91D Magnesium Alloy in Simulated Body Fluid (SBF) Solution
Authors: Alina Ab. Aziz Farah , Norbahiyah Siti , Zamzuri Mohd Zain Mohamad
Published: June 2014

Pure Mg and AZ91D alloy was anodized with and without the gadolinium nitrate Gd (NO3)3 in different concentrations (0.001g/l, 0.025g/l, 0.05g/l, 0.075g/l and 0.09g/l) at a constant current density and treatment time of 10mA/cm2 and 5 minutes. The results showed that the optimum gadolinium concentration is 0.075g/l due to obtaining the anodic film with high corrosion resistance. The surface morphology and microstructure of anodic coating were investigated by scanning electron microscopy (SEM) , optical microscope (OM), and potentiodynamic polarization, respectively.
Synthesis and Characterization of Hafnium Carbide Based Ceramics
Authors: Matović Branko , Bučevac Dušan , Maksimović Vesna , Nenadović Snežana , Pantić Jelena , Gautam Devendraprakash , Yano Toyohiko
Published: June 2014

Hafnium carbide powder was synthesized by sol-gel polycondensation of hafnium chloride with citric acid. The starting materials were dissolved in water and mixed homogeneously on a hot plate until a precomposite gel was formed. Pyrolysis of the obtained gel resulted in formation of monoclinic hafnia and amorphous carbon, which after subsequent heat treatment transformed into hafnium carbide. Materials were analyzed by means of X-ray diffraction and electron microscopy investigations. The results showed that the obtained carbide powder was composed of nearly equiaxed particles of narrow size distribution. The obtained hafnium carbide powder was densified via spark plasma sintering (SPS) at 1950 oC using molybdenun silicide as sintering additive. Microstructure and mechanical properties of the obtained hafnium carbide ceramics were investigated.
Dielectric Properties and Optical Absorption of Single-Crystalline BaTi2O5 Synthesized Using High-Purity BaCO3 as Source Material
Authors: Shiga Keiji , Katsui Hirokazu , Goto Takashi
Published: June 2014

Highly pure transparent single-crystalline BaTi2O5, 6 mm in diameter and 15 mm in length, was prepared by a floating zone (FZ) method using high purity BaCO3as a source material. The as-prepared crystal was partially dark blue and became transparent by annealing at 773 K in air. The maximum value of permittivity (εmax) was 36000 at the frequency of 100 kHz and the Curie temperature (TC) was 757 K.
Enhanced Thermoelectric Properties of Mg2Si0.3Sn0.7 Compounds by Bi Doping
Authors: Yang Mei Jun , Shen Qiang , Zhang Lian Meng
Published: June 2014

The single phase of Bi-doped Mg2Si0.3Sn0.7compounds have been successfully fabricated by solid state reaction and spark plasma sintering (SPS). The effect of Bi doping concentration on the thermoelectric properties of Mg2Si0.3Sn0.7is investigated. The doping of Bi atom results in the increase of carrier concentrations and ensures the increase of electrical conductivity. Although the thermal conductivity and Seebeck coefficient shows a slight increase, the figure of merit of Mg2Si0.3Sn0.7compounds still increases with the increasing contents of Bi-doping. When Bi-doping content is 1.5at%, the Mg2Si0.3Sn0.7compound obtained the maximum value,ZT, is 1.03 at 640 K.
In Situ Observation of Diamagnetic Fluid Flow in High Magnetic Fields
Authors: Wang Yan , Hirota Noriyuki , Okada Hidehiko , Liu Tie , Wang Qiang , Sakka Yoshio
Published: June 2014

The effect of high magnetic field on diamagnetic fluid flow has been studied by in-situ optical observation. The Schlieren optics utilizable under high magnetic fields was developed to carry out in-situ observation of the behavior of feeble magnetic fluids. Using a crystal of the diamagnetic aluminum potassium sulfate dodecahydrate, the behavior of the downward flow of high concentration solution in the sample dissolution process was observed. It was found that the direction of diamagnetic fluid flow was changed under spatially varied magnetic field. This phenomenon was understood qualitatively by considering the magnetic force acting on the high concentration solution and the surrounding solution.
Fabrication of Porous Al with Controlled Pore Size by Spark Plasma Sintering
Authors: Li Qi Zhong , Zhang Dong Ming , Zhang Lian Meng
Published: June 2014

Porous Al with controlled pore size was prepared by the spacer method including spark plasma sintering and the dissolution of space-holding NaCl particles. The NaCl of the controlled pore size (particle diameter control range of 5˰ڌm~20˰ڌm) were prepared by precipitation method. The effects of sintering condition such as the sintering electric current intensity, voltage and the size, morphology and content of NaCl powder on the porosity and size of porous Al are investigated. The porous Al with higher porosity of 69.41% and smaller pore size of 5 ڌm was obtained.
Perpendicular Magnetic Anisotropy in Pt/Co/AlO Trilayer Structures Depending on AlO Thickness and Fabrication Method
Authors: Yang Tim , Wang Z.Q. , Kohda Makoto , Seki Takeshi , Takanashi Koki , Nitta Junsaku
Published: June 2014

We investigate the perpendicular magnetic anisotropy dependence on the AlO capping layer in Pt/Co/AlO films. AlO was deposited on Pt/Co films by RF magnetron sputtering and atomic layer deposition (ALD) with varying thickness. It is found that the prolonged deposition of thick AlO layers by RF magnetron sputtering causes significant damage to the Pt/Co underneath while AlO layers formed by ALD can be of arbitrary thickness with no damage to the magnetic properties of the films. The decline of the magnetic properties can be attributed to the method of AlO deposition for each process. In the RF magnetron sputtering, AlO atoms with high kinetic energy are ejected from a sputter target resulting in the degradation of Pt/Co films, while the process of deposition of AlO by ALD is governed by a series of chemically reactive condensations allowing for arbitrary deposition thickness of AlO.
Effect of Subsurface Deformation on Sliding Wear Behavior of Ti-29Nb-13Ta-4.6Zr Alloys for Biomedical Applications
Authors: Lee Yoon Seok , Niinomi Mitsuo , Nakai Masaaki , Narita Kengo , Hieda Junko , Cho Ken
Published: June 2014

The wear mechanisms of conventional Ti–6Al–4V extra-low interstitial (Ti64) and the new Ti–29Nb–13Ta–4.6Zr (TNTZ) were studied to investigate the wear properties of Ti64/TNTZ for application in spinal fixation devices. Ti64 and TNTZ balls and discs were first prepared as wear-test specimens. A ball-on-disc frictional wear-testing machine was used in air to perform the frictional wear tests of the Ti64 and TNTZ discs mated against Ti64 and TNTZ balls. The wear mechanisms were investigated using a scanning electron microscopy to analyze the worn surfaces and wear debris. The volume losses for the TNTZ discs were larger than those for the Ti64 ones, regardless of the mating ball material. Furthermore, the morphologies of the wear tracks and the debris of the Ti64 and TNTZ discs were different, suggesting that the wear mechanisms for the Ti64 and TNTZ discs were abrasive and delamination wear caused by mild and severe subsurface deformations of the Ti64 and TNTZ, respectively, regardless of the mating ball material.
Dynamical Structure Factor of Magnetic Excitation in Underdoped La1.90Sr0.10CuO4 Measured by Chopper Neutron Spectrometer
Authors: Sato Kentaro , Matsuura Masato , Enoki Masanori , Yamada Kazuyoshi , Fujita Masaki
Published: June 2014

We have performed inelastic neutron scattering measurement on high-transition temperature superconductor La1.90Sr0.10CuO4 with utilizing a Fermi chopper spectrometer. We succeeded in converting the observed neutron scattering intensity into a dynamical structure factor in the absolute unit by attempting two methods with analyzing (i) incoherent scattering intensity from the sample itself and (ii) that from vanadium standard. The total squared moment  was evaluated to be 0.176 μB2/Cu, which is much smaller than the value for the parent compound, indicating a markedly change of electronic state by hole-doping.
Pyrolysis Behavior of Boron-Containing Phenol-Formaldehyde Resin (BPFR) Modified by B2O3
Authors: Lu Qin , Chen Fei , Shen Qiang , Qin Yan , Huang Zhi Xiong , Zhang Lian Meng
Published: June 2014

In this study, pure boron-containing phenol-formaldehyde resin (BPFR) and boron oxide (B2O3) modified BPFR have been pyrolyzed at elevated temperatures in air and their thermal decomposition behavior is mainly explored. The structural evolution and chemical composition change during pyrolysis are characterized by thermal gravity (TG), Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). It is shown that the mass residues of pure BPFR are 27.1 and 8.7 wt.% after being pyrolyzed at 600 and 1000 °C for 2 h, respectively. In comparison with the pure BPFR, the mass residue of B2O3 modified BPFR is obviously higher, with the values of 72.9 and 39.7 wt.% at 600 °C and 1000 °C, respectively. The results of FT-IR prove the degradation and failure of the resin matrix are mainly resulted from the fracture of methylene and the release of small molecules. The XRD characterization shows the residues are amorphous carbon and B2O3. FE-SEM exhibits the melting B2O3 layer formed on the surface of the samples which could prevent oxygen from diffusing into composites during oxidation to some extent.
Lamellar and Rod-Like Eutectic Growth of TiB2-TiC-TiN Composites by Arc-Melting
Authors: Cheng Eric Jian Feng , Katsui Hirokazu , Goto Takashi
Published: June 2014

TiB2-TiC, TiB2-TiN and TiB2-TiCxN1-x composites were prepared by arc-melting mixtures of TiB2, TiC and TiN powders. 28TiB2-72TiC (mol%) composite showed a lamellar eutectic structure, while 55TiB2-45TiN (mol%) composite with a lamellar structure consisted of TiB2, TiN and TiB. 36TiB2-44TiC-20TiN (mol%) was a quasi-binary eutectic composite having a rod-like structure.
Grain Boundary Segregation-Induced Phase Transformation and Grain Growth in Y2O3-Stabilized ZrO2 Polycrystals
Authors: Matsui Koji , Yoshida Hidehiro , Ikuhara Yuichi
Published: June 2014

We systematically investigated the phase transformation and grain-growth behaviors during sintering in 2 and 3 mol% Y2O3-stabilized tetragonal ZrO2 (2Y and 3Y) and 8 mol% Y2O3-stabilized cubic ZrO2 polycrystals (8Y). In particular, grain-boundary segregation and grain-interior distribution of Y3+ ions were examined by high-resolution transmission electron microscopy (HRTEM)- and scanning transmission electron microscopy (STEM)-nanoprobe X-ray energy dispersive spectroscopy (EDS) techniques. Above 1200°C, grain growth during sintering in 8Y was much faster than that in 2Y and 3Y. In the grain boundaries in these specimens, amorphous layers did not present; however, Y3+ ions segregated at the grain boundaries over a width of about 10 nm. The amount of segregated Y3+ ions in 8Y was significantly less than in 2Y and 3Y. This indicates that the amount of segregated Y3+ ions is related to grain growth behavior; i.e., an increase in segregated Y3+ ions retards grain growth. Therefore, grain-growth behavior during sintering can be reasonably explained by the solute-drag mechanism of Y3+ ions segregating along the grain boundary. In 2Y and 3Y, the cubic-phase regions were formed in grain interiors adjacent to the grain boundaries and/or the multiple junctions in which Y3+ ions segregated, which can be explained by a grain boundary segregation-induced phase transformation (GBSIPT) mechanism.
Appraisal of the practice of ocular self-medication in Cape Coast Metropolis, Ghana
Authors: Kyei Samuel , Ocansey Stephen , Abu Emmanuel Kwasi , Gyedu Bismark Nyarko
Published: June 2014

The purpose of the present study was to assess the practice of ocular self-medication among people of the Cape Coast Metropolis, Central Region of Ghana. A population-based survey involving 421 respondents ≥18 years old was conducted. A pre-tested interview-based questionnaire was used to collect data on demographics, ocular symptoms for which selfmedication was practiced, medical knowledge and self-care orientation. Households were systematically and randomly selected as study units. Analysis was done using SPSS version 16. Descriptive results were expressed as frequency, percentage, and mean±standard deviation, X2 test was used for associations, and logistic regression was used to test for predictors of the practice of ocular self-medication. Prevalence of ocular self-medication was 23.3% with itchy eye being the main ocular symptom for which self-medication was practiced. Local pharmacies were the main source of drug for ocular self-medication. There was no association between medical knowledge and the practice of ocular self-medication (X2=0.126; P=0.722). Some 25.5% experienced adverse effects. In conclusion, the practice of ocular self-medication was without recourse to adequate concept of the practice of self-care but its negative effect was mitigated by the low self-care orientation of the people.
Stability of WISC-R scores in students with borderline intellectual functioning
Authors: Jankowska Anna Maria , Bogdanowicz Marta , Takagi Anna
Published: June 2014

BACKGROUND
 Previous studies on the measurement of intelligence in students with learning difficulties indicate low stability of results observed over time. Therefore, careful analysis of changes in intelligence quotient, as well as in results within Verbal and Performance scale subtests, is necessary.
 PARTICIPANTS AND PROCEDURE
 The aim of the research was to analyze changes in WISC-R scores over time in students with borderline intellectual functioning. Test-retest stability of WISC-R was evaluated for Full, Verbal (VIQ), and Performance (PIQ) scales. The study involved 30 students, who were tested three times, when their mean age was 8, 10.8, and 13.6 years old.
 RESULTS
 The results showed that Full Scale IQ was fairly stable over time and remained below the average level, between –1.01 and –2.00 standard deviations. Significant changes were observed in the Verbal and Performance scale; VIQ decreased and PIQ increased over time. An initially insignificant statistical difference between the scales grew as time progressed. Furthermore, considerable subtest score fluctuation was observed; over time scores in the Vocabulary subtest significantly decreased whereas in Block Design and Picture Arrangement they increased.
 CONCLUSIONS
 The authors argue that delayed acquisition of verbal skills may result from chronic school failure and deficiency of educational support experienced by this group of students. Meanwhile, non-verbal skills, that are less dependent on educational influences and academic knowledge, improve with students’ development through their engagement in everyday life activities.
Association between p53 codon 72 polymorphism and systemic lupus erythematosus
Authors: Nabavi Mohammad , Ghaderi Abbas , Fattahi Mohammad Javad , Danaie N. , Zangooie R. , Faranoush Mohammad
Published: June 2014

Cel pracy: Toczeń rumieniowaty układowy (TRU) jest schorzeniem tkanki łącznej o przebiegu układowym. W patogenezie choroby uczestniczy kilka genów, spośród których gen p53 odgrywa istotną rolę w kontroli cyklu komórkowego. Celem badania była analiza częstości występowania polimorfizmu genu p53 u pacjentów z TRU oraz zależności między polimorfizmem genu p53 a cechami klinicznymi i laboratoryjnymi choroby.

Materiał i metody: Badanie kliniczno-kontrolne przeprowadzono u pacjentów z rozpoznanym TRU w Szpitalu im. Namaziego w Sziraz (Iran). Do badania zakwalifikowano 77 pacjentów z rozpoznanym TRU – 9 mężczyzn (11,8%) oraz 68 kobiet (88,2%) o średniej wieku 25,61 ±10,69 roku, a także 80 osób zdrowych o średniej wieku 51,82 ±14,25 roku, tworzących grupę kontrolną. Z kartoteki szpitalnej pozyskano dane uczestników badania, uwzględniając profil epidemiologiczny, wywiad chorobowy, objawy schorzenia oraz wyniki badań laboratoryjnych. Ekspresję genu p53 oznaczano w lizowanych limfocytach. Uzyskane dane analizowano przy wykorzystaniu oprogramowania SPSS w wersji 14.00 dla systemu Windows, przyjmując poziom istotności statystycznej jako p < 0,05.

Wyniki: Częstość występowania genotypów Arg/Arg, Pro/Pro i Arg/Pro wśród osób zdrowych z grupy kontrolnej wyniosły odpowiednio 38,8%; 28,8% i 37,5%, natomiast w grupie pacjentów z TRU – odpowiednio 29,2%; 12,3% i 58,5%. Wykazano tym samym większą zależność między chorobą a postacią heterozygotyczną badanego polimorfizmu niż występowaniem alleli homozygotycznych. Stwierdzono istotną zależność między różnymi typami alleli genu p53 a niektórymi cechami klinicznymi TRU. Nie potwierdzono natomiast związku między różnymi typami alleli a początkowymi objawami choroby ani wynikami badań laboratoryjnych.

Wniosek: W populacji irańskiej funkcjonalna onkoproteina p53 z polimorfizmem kodonu 72 może odgrywać ważną rolę w patogenezie i obrazie klinicznym TRU.
Lipid profiles in rheumatoid arthritis patients treated with disease-modifying antirheumatic drugs
Authors: Filipowicz-Sosnowska Anna , Głuszko Piotr , Rupiński Robert
Published: June 2014

Choroby układu sercowo-naczyniowego są główną przyczyną wzrostu śmiertelności u chorych na reumatoidalne zapalenie stawów (RZS). Ryzyko zgonów spowodowane chorobami sercowo-naczyniowymi jest o 50% większe u chorych na RZS w porównaniu z ogólną populacją. W ciągu ostatniej dekady do leczenia RZS wprowadzono wiele nowych technologii i strategii, jednak ryzyko rozwoju chorób sercowo-naczyniowych nie uległo istotnej zmianie.

Problem zmian w profilu lipidów, jednego z czynników ryzyka wystąpienia zdarzeń sercowo-naczyniowych u chorych na RZS w wyniku leczenia lekami modyfikującymi przebieg choroby (LMPCh), jest przedmiotem licznych kontrowersyjnych doniesień. W pracy przedstawiono aktualne dane na temat profilu lipidów u chorych na RZS, leczonych syntetycznymi i biologicznymi LMPCh i ich znaczenia w indukcji miażdżycy.
Carbohydrate metabolism disorders in patients with rheumatoid arthritis
and ankylosing spondylitis – impact of treatment
Authors: Dąbrowski Piotr , Majdan Maria
Published: June 2014

Przewlekły stan zapalny w reumatoidalnym zapaleniu stawów i zesztywniającym zapaleniu stawów kręgosłupa leży u podstaw przyspieszonej miażdżycy naczyń, insulinooporności i jej następstw. Na zaburzenia metabolizmu glukozy w obu tych chorobach istotny wpływ może mieć stosowana farmakoterapia. W artykule przedstawiono doniesienia kliniczne dotyczące badań nad wpływem leków modyfikujących przebieg choroby, w tym leków biologicznych, glikokortykosteroidów (GKS) oraz powszechnie stosowanych niesteroidowych leków przeciwzapalnych (NLPZ), na insulinooporność oraz zaburzenia gospodarki węglowodanowej. Większość z nich dowodzi korzystnego w tym zakresie działania hydroksychlorochiny, metotreksatu oraz inhibitorów czynnika martwicy nowotworów (tumor necrosis factor – TNF), ze szczególnym uwzględnieniem infliksymabu. Protekcyjne działanie w postaci zmniejszenia ryzyka rozwoju cukrzycy mogą wykazywać także NLPZ. Ostatnie badania dowodzą, że wbrew powszechnej ocenie korzyści z zastosowania GKS, zwłaszcza w początkowym, aktywnym stadium choroby, mogą przeważać nad ich negatywnymi skutkami w zakresie gospodarki węglowodanowej.
The effects of clinical, epidemiological and economic aspects of changes in classification criteria of selected rheumatic diseases
Authors: Owczarek Aleksander J. , Michalik Rafał , Kotyla Przemysław , J. Kucharz Eugeniusz
Published: June 2014

W pracy przedstawiono epidemiologię i aspekty socjoekonomiczne trzech najczęstszych chorób reumatycznych: reumatoidalnego zapalenia stawów (RZS), tocznia rumieniowatego układowego (TRU) oraz twardziny układowej (TU). Częstość występowania chorób reumatycznych w populacji szacuje się na 4–5%. Współczynnik chorobowości dla RZS w Polsce wynosi 0,45% populacji dorosłej i jest zbliżony do współczynnika w Unii Europejskiej, który wynosi 0,49%. Szacuje się, że średnia częstość występowania tocznia rumieniowatego układowego wynosi 40–55/100 tys. osób. Roczna zapadalność na TU wynosi 19–35 przypadków na milion mieszkańców (w zależności od kraju, w którym przeprowadzono badania). W Polsce blisko 18% wszystkich hospitalizacji jest związanych ze schorzeniami reumatycznymi. Wprowadzenie nowych kryteriów klasyfikacyjnych dla RZS, umożliwiających klasyfikowanie wczesnych postaci choroby i szersze ich zastosowanie w praktyce klinicznej, wpłynie zapewne na zmianę oceny częstości występowania tej choroby w populacji.
Solar irradiance in the heterogeneous albedo environment of the Arctic coast: measurements and a 3-D model study
Authors: Kreuter A. , Buras R. , Mayer B. , Webb A. , Kift R. , Bais A. , Kouremeti N. , Blumthaler M.
Published: June 2014

Abstract. We present a unique case study of the solar global irradiance in a highly heterogeneous albedo environment at the Arctic coast. Diodearray spectroradiometers were deployed at three sites around Ny Ålesund, Svalbard, and spectral irradiances were simultaneously measured under clear-sky conditions during a 24 h period. The 3-D radiative transfer model MYSTIC is applied to simulate the measurements in various model scenarios. First, we model the effective albedos of ocean and snow and consequently around each measurement site. The effective albedos at 340 nm increase from 0.57 to 0.75, from the coastal site in the west towards the site 20 km east, away from the coast. The observed ratios of the global irradiance indicate a 15% higher average irradiance, at 340 nm east relative to west, due to the higher albedo. The comparison of our model scenarios suggest a snow albedo of > 0.9 and confirm the observation that drift ice has moved into the Fjord during the day. The local time shift between the locations causes a hysteresis-like behavior of these east–west ratios with solar zenith angle (SZA). The observed hysteresis, however, is larger and, at 340 nm, can be explained by the drift ice. At 500 nm, a plausible explanation is a detector tilt of about 1°. The ratios between afternoon and morning irradiances at the same SZA are investigated, which confirm the above conclusions. At the coastal site, the measured irradiance is significantly higher in the afternoon than in the morning. Besides the effect of changing drift ice and detector tilt, the small variations of the aerosol optical depth have to be considered also at the other stations to reduce the discrepancies between model and observations. Remaining discrepancies are possibly due to distant high clouds.
Heterogeneous reaction of N2O5 with airborne TiO2 particles and its implication for stratospheric particle injection
Authors: Tang M. J. , Telford P. J. , Pope F. D. , Rkiouak L. , Abraham N. L. , Archibald A. T. , Braesicke P. , Pyle J. A. , McGregor J. , Watson I. M. , Cox R. A. , Kalberer M.
Published: June 2014

Abstract. Injection of aerosol particles (or their precursors) into the stratosphere to scatter solar radiation back into space has been suggested as a solar-radiation management scheme for the mitigation of global warming. TiO2 has recently been highlighted as a possible candidate particle because of its high refractive index, but its impact on stratospheric chemistry via heterogeneous reactions is as yet unknown. In this work the heterogeneous reaction of airborne sub-micrometre TiO2 particles with N2O5 has been investigated for the first time, at room temperature and different relative humidities (RH), using an atmospheric pressure aerosol flow tube. The uptake coefficient of N2O5 onto TiO2, γ(N2O5), was determined to be ~1.0 × 10−3 at low RH, increasing to ~3 × 10−3 at 60% RH. The uptake of N2O5 onto TiO2 is then included in the UKCA chemistry–climate model to assess the impact of this reaction on stratospheric chemistry. While the impact of TiO2 on the scattering of solar radiation is chosen to be similar to the aerosol from the Mt Pinatubo eruption, the impact of TiO2 injection on stratospheric N2O5 is much smaller.
Joint analysis of continental and regional background environments in the Western Mediterranean: PM1 and PM10 concentrations and composition
Authors: Ripoll A. , Minguillón M. C. , Pey J. , Pérez N. , Querol X. , Alastuey A.
Published: June 2014

Abstract. The complete chemical composition of atmospheric particulate matter (PM1 and PM10) from a continental (Montsec, MSC, 1570 m a.s.l.) and a regional (Montseny, MSY, 720 m a.s.l.) background site in the Western Mediterranean Basin (WMB) were jointly studied for the first time for a relatively long-term series (January 2010–March 2013). Differences on average PM concentration and composition and on seasonal variation between both sites were attributed to: distance to anthropogenic sources, altitude, height evolution of the planetary boundary layer (PBL) throughout the year, variations in the air mass origin, and changes in meteorology. The diverse meteorological episodes showed different influence at regional and continental scale. When long-range transport from Central and Eastern Europe and from North Africa occurs, the continental background site is frequently more influenced, thus indicating a preferential transport at high altitude layers. Conversely, the regional background was more influenced by regional processes. In winter, anticyclonic conditions enhance the stagnation of air masses with the consequent accumulation of pollutants at regional scale in the WMB, whereas the continental background site remains in the free troposphere. Totally different conditions drive the aerosol phenomenology in summer. Weak pressure gradients and elevated insolation generate recirculation of air masses and enhances the development of the PBL, causing the aging of aerosols and incrementing pollutant concentrations over a larger area, including the continental background. This is reflected in a more similar relative composition and absolute concentrations of PM components at both regional and continental background environments in the warmer season Peculiarities of the WMB are: (a) high relevance of African dust transport and regional dust resuspension; (b) low biomass burning contribution; (c) low summer nitrate concentrations; and (d) high aerosol homogenization in summer.
A permanent Raman lidar station in the Amazon: description, characterization, and first results
Authors: Barbosa H. M. J. , Barja B. , Pauliquevis T. , Gouveia D. A. , Artaxo P. , Cirino G. G. , Santos R. M. N. , Oliveira A. B.
Published: June 2014

Abstract. A permanent UV Raman lidar station, designed to perform continuous measurements of aerosols and water vapor and aiming to study and monitor the atmosphere from weather to climatic time scales, became operational in the central Amazon in July 2011. The automated data acquisition and internet monitoring enabled extended hours of daily measurements when compared to a manually operated instrument. This paper gives a technical description of the system, presents its experimental characterization and the algorithms used for obtaining the aerosol optical properties and identifying the cloud layers. Data from one week of measurements during the dry season of 2011 were analyzed as a mean to assess the overall system capability and performance. Both Klett and Raman inversions were successfully applied. A comparison of the aerosol optical depth from the lidar and from a co-located Aerosol Robotic Network (AERONET) sun photometer showed a correlation coefficient of 0.86. By combining nighttime measurements of the aerosol lidar ratio (50–65 sr), back-trajectory calculations and fire spots observed from satellites, we showed that observed particles originated from biomass burning. Cirrus clouds were observed in 60% of our measurements. Most of the time they were distributed into three layers between 11.5 and 13.4 km a.g.l. The systematic and long-term measurements being made by this new scientific facility have the potential to significantly improve our understanding of the climatic implications of the anthropogenic changes in aerosol concentrations over the pristine Amazonia.
Continuous measurements of atmospheric water vapour isotopes in western Siberia (Kourovka)
Authors: Bastrikov V. , Steen-Larsen H. C. , Masson-Delmotte V. , Gribanov K. , Cattani O. , Jouzel J. , Zakharov V.
Published: June 2014

Abstract. The isotopic composition of atmospheric water vapour at the land surface has been continuously monitored at the Kourovka astronomical observatory in western Siberia (57.037° N, 59.547° E; 300 m a.s.l.) since April 2012. These measurements provide the first record of δD, δ18O and d-excess in this region. Air was sampled at 8 m height within a forest clearing. Measurements were made with a wavelength-scanned cavity ring-down spectroscopy analyzer (Picarro L2130-i). Specific improvements of the measurement system and calibration protocol have been made to ensure reliable measurements at low humidity during winter. The isotopic measurements conducted till August 2013 exhibit a clear seasonal cycle with maximum δD and δ18O values in summer and minimum values in winter. In addition, considerable synoptic timescale variability of isotopic composition was observed with typical variations of 50–100‰ for δD, 10–15‰ for δ18O and 2–8‰ for d-excess. The strong correlations between δD and local meteorological parameters (logarithm of humidity and temperature) are explored, with a lack of dependency in summer that points to the importance of continental recycling and local evapotranspiration. The overall correlation between δD and temperature is associated with a slope of 3‰ °C−1. Large d-excess diurnal variability was observed during summer with up to 30‰ decrease during the night and the minima manifested shortly after sunrise. Two dominant diurnal cycle patterns for d-excess differing by the magnitude of the d-excess decrease (21‰ and 7‰) and associated patterns for meteorological observations have been determined. The total uncertainty of the isotopic measurements was quantified as 1.4–11.2‰ for δD, 0.23–1.84‰ for δ18O and 2.3–18.5‰ for d-excess depending on the humidity.
The MOPITT Version 6 product: algorithm enhancements and validation
Authors: Deeter M. N. , Martínez-Alonso S. , Edwards D. P. , Emmons L. K. , Gille J. C. , Worden H. M. , Sweeney C. , Pittman J. V. , Daube B. C. , Wofsy S. C.
Published: June 2014

Abstract. The MOPITT Version 6 (V6) product for carbon monoxide (CO) incorporates several enhancements which will benefit many users of MOPITT data. V6 algorithm improvements are described in detail, and V6 validation results are presented. First, a geolocation bias related to the orientation of the MOPITT instrument relative to the TERRA platform was characterized and eliminated. Second, the variable a priori for CO concentrations for V6 is based on simulations performed with the CAM-Chem chemical transport model for the years 2000–2009 instead of the model-derived climatology for 1997–2004 used for V5. Third, meteorological fields required for V6 retrieval processing are extracted from the MERRA ("Modern-Era Retrospective Analysis For Research And Applications") reanalysis. Finally, a significant latitude-dependent retrieval bias in the upper troposphere in Version 5 products has been substantially reduced.
An abrupt slowdown of Atlantic Meridional Overturning Circulation during 1915–1935 induced by solar forcing in a coupled GCM
Authors: Lin P. , Song Y. , Yu Y. , Liu H.
Published: June 2014

Abstract. In this study, we explore an abrupt change of Atlantic Meridional Overturning Circulation (AMOC) apparent in the historical run simulated by the second version of the Flexible Global Ocean–Atmosphere–Land System model – Spectral Version 2 (FGOALS-s2). The abrupt change is noted during the period from 1915 to 1935, in which the maximal AMOC value is weakened beyond 6 Sv (1 Sv = 106 m3 s−1). The abrupt signal first occurs at high latitudes (north of 46° N), then shifts gradually to middle latitudes (∼35° N) three to seven years later. The weakened AMOC can be explained in the following. The weak total solar irradiance (TIS) during early twentieth century decreases pole-to-equator temperature gradient in the upper stratosphere. The North polar vortex is weakened, which forces a negative North Atlantic Oscillation (NAO) phase during 1905–1914. The negative phase of NAO induces anomalous easterly winds in 50–70° N belts, which decrease the release of heat fluxes from ocean to atmosphere and induce surface warming over these regions. Through the surface ice–albedo feedback, the warming may lead to continuously melting sea ice in Baffin Bay and Davis Strait, which results in freshwater accumulation. This can lead to salinity and density reductions and then an abrupt slowdown of AMOC. Moreover, due to increased TIS after 1914, the enhanced Atlantic northward ocean heat transport from low to high latitudes induces an abrupt warming of sea surface temperature or upper ocean temperature in mid–high latitudes, which can also weaken the AMOC. The abrupt change of AMOC also appears in the PiControl run, which is associated with the lasting negative NAO phases due to natural variability.