bluuebunny/crossref_metadata_2025 huggingface dataset:
Delamination of Kaolinite by Intercalation of Urea Using Milling
Authors: Jikan Suzi Salwah , Badarulzaman Nur Azam , Yahaya Shehu , Adamu Ajiya Dahiru
Published: March 2017

The effect of milling on structure of kaolinite-urea intercalates were studied. Untreated and treated kaolinite samples were examined by Field scanning electron microscopy (FESEM), X-ray powder diffraction (XRPD) and Fourier transform infrared (FT-IR) spectroscopy. The basal spacing of kaolinite measured by X-ray powder diffraction (XRPD) increased from 1.02 to 3.62 nm after intercalation by urea. Significantly, nature of intercalation was reached through formation of hydrogen bonds between urea and both Si-O and AlOH groups of the interlayer surface of kaolinite.
Effect of Na2O and K2O on the Solubility and Chemical Properties of P2O5-CaO-Na2O-K2O-Al2O3 Glass
Authors: Mohamad Siti Hafizah , Muhamad Nor Mohd Al Amin
Published: March 2017

The effect addition of Na2O on the solubility properties of phosphate glass of the composition, 45P2O5-18CaO-xNa2O-(34-x)K2O-6Al2O3, where x = 0,5,10,15 and 20 wt. %. has been studied. Glass transition temperature (Tg) of glass samples, weight loss and pH of the immersion solution were measured. The Tg value of the phosphate glass also decreased with the incorporation of Na2O up to 10 wt. % and increased with the incorporation of 15 and 20 wt. %. These results indicates that the solubility and Tg value of phosphate glass were highly influence by the glass composition. The substitution of Na2O to the phosphate glass system with the present of K2O has decrease the solubility of phosphate glass. The released of phosphate and calcium ion seem to decrease with the increasing of Na2O content in the glass composition.
The Effect of Flux to Physical and Chemical Properties of Ceramic Body Using Ball Clay from Kampung Dengir, Besut, Terengganu
Authors: Ahmad Zaid Siti Nadhirah , ABDUL HALIM Muhammad Syukri , Abdullah Mohd Aidil Adhha , Muhamad Nor Mohd Al Amin
Published: March 2017

The fluxing agent usually used to reduce the sintering temperature of ceramic production. In order to achieve this study, the potassium feldspar had used as a fluxing agent in range between 15.2 - 42.5 %. The mixture of slurry was formulated by using ball clay, silica, polyethylene glycol and potassium feldspar to produce the ceramic pieces. The sample was prepared by aging the mixed clay with additives and aging for 24 hours before casting on the flat mould to form rectangular ceramic pieces. The body pieces then undergo thermal treatment at temperature of 800C, 900°C, 1000°C, 1100°C and 1200°C for 2 hours with heating rate 5°C/min as to study the effect of flux towards sintering behavior of the samples. The characterization of the samples was conduct in order to study the chemical composition of sample. The effect of the fluxing agent towards sintering temperature was evaluated in order to investigate the firing shrinkage, density, porosity and water absorption. The result shows at temperature of 1100°C with increasing the amount of flux, the firing shrinkage decreasing from 18 to 13 %. Increasing the amount of flux had decrease the porosity and water absorption of ceramic pieces and the density of the ceramic pieces almost uniform. The optimum amount of flux was 42.5% and sintering temperature was 1100°C.
Effect of Curing Time and Sintering to the Properties of Geopolymer Mortars
Authors: ISMAIL Salwa , MOHD RAZALI Mohammad Faizal , Johari Izwan B. , Ahmad Zainal Arifin , Kasim Shah Rizal
Published: March 2017

In this study, the geopolymer mortars were synthesized with fly ash (FA) and silica powder as aluminosilicate sources and a combination of sodium hydroxide (NaOH) solution, sodium silicate (Na2SiO3) solution and distilled water as alkaline activator. Commercial sago was used as a pore former in the mortars. The percentage of sago used were 10, 20 and 30 wt% of FA. The amount of added water used in each mixture was 5% by weight of FA, NaOH solution and Na2SiO3 solution. The formed geopolymer mortars were cured for 1, 3 and 7 days and sintered at 1000 °C. X-ray fluoresence (XRF) shown that FA contains higher amount of silica (SiO2) and alumina (Al2O3) which is important as aluminosilicate sources. The properties of the geopolymer mortars before and after sintered at 1000 °C have been investigated. The results show that geopolymer mortars with 10% of sago content with curing time of 7 days and sintered at 1000 °C give the highest compressive strength of 13.5 MPa.
Mechanical Properties of Copper Ferrite CuFe2O4-Polymer Composite Fabricated Using 3D Printer
Authors: Lee Chye Heng , Yeoh Cheow Keat , Hamzah Khairul Amali , Teh Pei Leng
Published: March 2017

The effect of speed of powder dispenser on the mechanical properties of ABS-CuFe2O4 composites was studied. The samples in the experiment were printed by a 3D printer which produces three-dimensional objects from the digital file which are built up layer by layer. The amount of filler content added into each sample was controlled by the speed of powder dispenser which is off, low, medium, and high. The properties of pure ABS and composite ABS CuFe2O4 samples were investigated based on the distribution of fillers. Weight percentage (wt. %) of filler added into each sample was determined by using thermogravimetric analysis (TGA). Tensile test and Vickers microhardness were carried out to determine the effect of filler content on mechanical properties. Addition of filler content in ABS matrix slightly decreases the strength of composite from 17.1 MPa to 14.64 MPa.
Effect of Glycerol on the Properties of Tapioca Starch Film
Authors: Adamu Ajiya Dahiru , Jikan Suzi Salwah , Talip Balkis Haji A. , Badarulzaman Nur Azam , Yahaya Shehu
Published: March 2017

Biodegradable films from tapioca starch (TPS) were formed by tape casting. The impact of glycerol (0, 5, 10, 15 and 20%) on the mechanical properties was investigated. The increase in glycerol content reduces the tensile strength while increasing the elongation at break. The varying concentrations of glycerol led to changes in tapioca starch edible film properties, potentially affecting film performances. The merging and increase in the intensity of absorption between 3700-3300 cm-1 as a result of increase in glycerol proportion is due to possible interaction of the OH groups in TPS and glycerol thereby increasing intermolecular H-bond.
Extraction of Rice Straw Alpha Cellulose Micro/Nano Fibres
Authors: Mamat Razali Nur Amira , Wan Ya'acob Wan Mohd Hanif , Ahmad Rusdi Rusaini Athirah , Abdul Aziz Fauziah
Published: March 2017

Rice straw cellulose a biomass materials, naturally found in abundance. It is low cost, eco-friendly and biodegradable. Alpha cellulose is prepared from rice straw using chemical method namely acid hydrolysis and alkaline treatment. Both of the samples treatments were bleached using sodium chlorite (NaClO2). Alkaline treatment shows higher in producing alpha cellulose, 20.68% rather than 12.20% by acid hydrolysis.
Effect of Temperature towards the Corrosion Behavior of Titania Nanotube Anodized in H2O2-Based Organic Electrolyte
Authors: Lee Kar Chun , Sreekantan Srimala
Published: March 2017

Hydrogen peroxide (H2O2) is a stronger oxidizing agent relative to the commonly used H2O in anodization of Titania Nanotube (TNT). Despite having higher oxide growth rate and more superior photocatalytic property, the substitution of H2O2 as oxygen source is sometimes accompanied with foil corrosion. In this work, it is shown that foil corrosion is originated from temperature elevation during anodization process. Conversely, foil corrosion can be prevented by monitoring the anodization temperature. Essentially, the corrosion of foil is not directly influenced by the type of oxidation source used. Foil corrosion occurs due to temperature elevation when using H2O2 as oxidation source.
Properties of Aminosilane Modified Nanocrytalline Cellulose (NCC) from Oil Palm Empty Fruit Bunch (OPEFB) Fibers
Authors: Mohd Nurul Hanisah , Arman Alim Aina Aqila , Zahari Johan Iskandar , Yarmo Mohd Ambar , Ahmad Ishak , Abu Tahari Maratun Najiha , Kargarzadeh Hanieh , Othaman Rizafizah
Published: March 2017

Oil palm empty fruit bunch (OPEFB) is one of the lignocellulosic materials which very well known as an abundant waste at oil mills and need to be utilized. The nanocrystalline cellulose (NCC) was extracted from OPEFB fiber through several of chemical treatment and hydrolyzed with sulphuric acid (H2SO4). NCC acts as support to modify with aminosilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxy silane (AEAPDMS) which has possibility for carbon dioxide (CO2) capture. The objective of this study was to evaluate the effect of NCC properties after modified with AEAPDMS. The raw OPEFB fiber, cellulose, NCC and modified NCC were characterized by attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), x-ray diffraction (XRD) but the morphology and the size of NCC was studied by transmission electron microscopy (TEM). The NCC treated with AEAPDMS was proved by FTIR with the emerging of several new peaks especially for NH2 bending and wagging around 1600 cm-1 and 798 cm-1, respectively. While, the XRD result showed the CrI of modified NCC decreased to 64 % from 76 % after the treatment due to the interaction of silanization occurred during the treatment since AEAPDMS has amorphous region. The NCC used in this study was classed as nanomaterial within nanosize and rod-like morphology observed by TEM analysis. Thus, these results give a good possibility for the AEAPDMS modified NCC to capture CO2 via covalent bonding.
Structural and Optical Characterization of TiO2/ZnO Thin Films Prepared by Sol-Gel Method
Authors: Zulkiflee Nur Syahraain , Hussin Rosniza , YAHYA Hasrul
Published: March 2017

Thin film has been extensively study due to better structural, surface morphology, and optical properties. The combination of two materials will enhance the properties of thin film. In this study, TiO2/ZnO thin films were deposited on glass substrates via sol-gel method. TiO2 acts as pre-deposited thin film with calcination temperatures at 400 °C, 500 °C, and 600 °C. The post-deposition of TiO2/ZnO thin films were calcined at 500 °C and 600 °C. TiO2 sol-gel was synthesis from titanium (IV) butoxide and butanol as the precursor, while ZnO sol-gel was synthesis from zinc acetate dehydrate and isopropanol as the precursor. The TiO2/ZnO thin films were characterized by X-ray diffraction (XRD), atomic force microscope (AFM), and ultraviolet visible spectroscopy (UV-Vis). The effect of calcination temperature and pre-deposited TiO2 thin films show difference results of bilayer thin films. The XRD analysis shows all TiO2/ZnO thin films growth with TiO2 anatase crystalline phase at orientation (1 0 1) and ZnO zincite phase at orientation (1 0 1). The structural properties of TiO2/ZnO thin films were improved by controlling the calcination temperature. Based on AFM analysis, the RMS value for TiO2/ZnO decreases as the calcination temperature increased. The compacted and dense surface roughness were controlled by the temperature. Meanwhile, the percentage of thin film ultraviolet transmittance can be enhanced with combination of two materials, TiO2 and ZnO. Therefore, the pre-deposited layer of thin film with influenced by calcination temperature will improve the crystallinity, surface morphology, and optical properties of TiO2/ZnO thin films.
Characterization of 3 mol% Fe from Different Source Doped 8YSZ Ceramics
Authors: Johar Banjuraizah , Shing Phan Khor , Zaili Nur Azmera
Published: March 2017

Pure 8 mol% yttria stabilized zirconia (YSZ) and 3mol % of Fe-doped YSZ electrolyte from different source of Fe (p)in oxide form (pure iron oxide powders, Fe2O3) and Fe(s) source from salt (iron nitrate, Fe(NO3)3) were prepared and sintered at 1550°C for 2 hours. The effect of Fe dopant from different source of Fe to the crystal structure and ionic conductivity of 8YSZ samples were investigated. The addition of 3 mol % Fe from iron nitrate source (sample 3Fe(s)YSZ) greatly enhanced the growth of monoclinic phase as compared to 8YSZ sintered samples while the addition of 3 mol % Fe from pure iron oxide powder source (sample 3Fe(s)YSZ) enhanced the crystallization of cubic phase and decrease the monoclinic phase. The addition of Fe significantly enhanced the ionic conductivity of 8YSZ sample for both source of Fe. However, 3Fe(p)8YSZ has smaller grain resistivity and thus has higher conductivity compared to 3Fe(s)YSZ.
Radiation Damage Study of Electrical Properties in GaN LEDs Diode after Electron Irradiation
Authors: Abdullah Yusof , Hedzir Anati Syahirah , Hasbullah Nurul Fadzlin , Muridan Norasmahan , CHE HAK Cik Rohaida , Mahat Sarimah
Published: March 2017

Nitride-based light emitting diodes (LEDs) is an attractive material due to its high temperature tolerance and suitable to be used in extreme environment. The irradiation process of Gallium Nitride (GaN) diode was carried out by electron irradiation with 1000 kGy and 1500 kGy doses with a conveyor speed of 50 kGy per pass. Capacitance-voltage (C-V) and current-voltage (I-V) characterization for both pre and post irradiation samples was done. Both current and capacitance show decreasing while reverse leakage current increased after irradiation. The reverse leakage current revealed that the current were start leakage at 1.0 x10 -7 A and 1.0 x10-9 A for 1000 kGy and 1500 kGy irradiations respectively. The current-voltage graph indicated that the effect of electron irradiation on diode produced weak spots as defect cause leakage current. The traps and bulk defect is believed to contributed to the leakage current increased.
Corrosion Properties of Sn-9Zn Solder in Acidic Solution
Authors: Jumali Nordarina , Mohamad Ahmad Azmin , Mohd Nazeri Muhammad Firdaus
Published: March 2017

The corrosion properties of Sn-9Zn lead-free solder was studied through potentiodynamic polarization in different concentration of hydrochloric acid (0.5, 1.0, 1.5, 2.0 M). Two types of polarization profile were observed for Sn-9Zn solder at lower concentration acid (0.5 to 1.0 M) and one at higher concentration acids (1.5 to 2.0 M). The morphological analysis showed that two distinctive structures of lamellar-like groove and irregular shaped of the corrosion product compounds formed on the solder surface after being polarized at different concentrations. Phase and elemental analyses revealed the formation of mixed corrosion product such as SnO, SnO2, ZnO, ZnO2, and Zn(OH)2 on the surface after polarization.
Effect of Firing Temperature on Mechanical and Physical Properties of Porcelain Balls as Grinding Media
Authors: YAHYA Hasrul , Othman Mohd Roslee , Ahmad Zainal Arifin
Published: March 2017

Porcelain balls as grinding media are produced by firing process of clay, quartz and feldspar mixtures. This application need high technological properties such as high compressive strength and hardness, wear resistance, low water absorption and excellent chemical resistance. These properties are associated with higher firing temperatures. The porcelain balls were prepared by mixing 30 wt.% clay, 40 wt.% feldspar and 30 wt.% quartz. The samples were sintered at 1200°C, 1230°C, 1250°C, 1270°C and 1300°C for 2 hours with heating rate of 3°C/min. Both green powder and fired samples were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy (SEM).The properties of the fired samples were evaluated by compressive strength, hardness, shrinkage, water absorption, bulk density, and porosity measurement. Increasing of compressive strength, hardness and density are associated with increasing of firing temperatures. Porcelain balls PB1 and PB2 can be produced as grinding media with optimum mechanical and physical properties at firing temperature 1270°C and 1250°C, respectively.
Influence of Cerium Additive on the Reduction Behaviour of Tungsten Oxide under Carbon Monoxide Atmosphere
Authors: Salleh Fairous , Tengku Saharuddin Tengku Shafazila , Samsuri Alinda , Othaman Rizafizah , Mohammad Hisham Mohammad Wahab , Yarmo Mohd Ambar
Published: March 2017

The reduction of pure WO3 and Ce/WO3 has been studied by using temperature programmed reduction (TPR), X-ray diffraction (XRD), and FESEM analysis. The reduction behavior were examined by non-isothermal reduction up to 900 oC then continued with isothermal reduction at 900 oC for 45 min under (40% v/v) carbon monoxide in nitrogen (CO in N2) atmosphere. The TPR results shows that reduction peak of Ce/WO3 were shifts to lower temperature as compared with to the pure WO3. In addition, TPR results indicate that addition with ceria give better reducibility compared to pure WO3. Based on the characterization of the reduction products after hold 45 min using XRD, pure WO3 were completely converted to WO2 and W metal phases. While, after addition of Ce to the WO3, the reduction was enhanced to W phases and some suboxide W5O14 and W3O5 with no WO2 phase remained and carbide observed. This is associated to the formation of alloy complex Ce2WO6 which gave remarkable effect to the reduction.
Reduction of Molybdenum Trioxide by Using Hydrogen
Authors: Latif Mohd Nor , Samsuri Alinda , Mohamed Hisham Mohamed Wahab , Yarmo Mohd Ambar
Published: March 2017

Metallic molybdenum was synthesized through reduction of molybdenum trioxide (MoO3) by using hydrogen as a reducing agent. The reduction behavior of MoO3 were investigated by using temperature programmed reduction (TPR). The reduced phases were characterized by X-ray diffraction spectroscopy (XRD). The XRD results indicate that the reduction of MoO3 proceed in two steps reduction (MoO3 → MoO2 → Mo) with formation of intermediate phases of Mo4O11 during first step of reduction. However, the TPR results showed only one broad peak that correspond to all reduction step that was merge into one peak. It seem that, increasing the temperature cause the rapid reduction that correlated with thermodynamic consideration data that show the formation of metallic molybdenum is become feasible by increasing the temperature.
The Relationship between XRD Peak Intensity and Mechanical Properties of Irradiated Lead-Free Solder
Authors: Paulus Wilfred @ Sylvester , Rahman Irman Abdul , Jalar Azman , Othman Norinsan Kamil , Ismail Roslina , Wan Yusoff Wan Yusmawati , Abu Bakar Maria
Published: March 2017

The variation on mechanical properties and crystalline structure of gamma-irradiated Sn-rich lead-free solder (SAC) were intensively investigated using nanoindentation and X-ray diffraction (XRD) techniques. Samples of solder on a printed circuit board (PCB) with copper substrate were irradiated at low dose (5 Gray) of gamma from Co-60 source. The nanoindentation hardness for β-Sn phase of the solder was found to increase from 0.1935 GPa to 0.2210 GPa after the irradiation. Furthermore XRD peak intensity was also observed to increase as well indicating the occurrence of defect in β-Sn crystal structure due to gamma radiation. The defect contributes to the increment of the hardness by indicating the change in crystallite size of the grains. Microstructure analysis by FESEM-EDAX has also confirmed the indentation was performed with no cracks in subsurface on β-Sn area.
The Effect of Annealing to the Hardness of Oxide Dispersion Strengthened (ODS) Fe-15Cr-0.3Y2O3 Alloy
Authors: Shamsudin Farha Mizana , Abdullah Yusof , RADIMAN Shahidan , Hamid Nasri A.
Published: March 2017

The objective of this study is to investigate the microstructure and effect of annealing to the hardness properties of oxide dispersion strengthened (ODS) Fe-15Cr-0.3Y2O3 alloy. This type of alloy was prepared by mechanical alloying (MA) method followed by compacting and sintering. The microstructure of milled Fe-15Cr-0.3Y2O3 alloy powders and pellet was examined by using field emission scanning electron microscope (FESEM). The milled alloy powders consist of nearly spherical shape of powder particles with average size of 10 µm. For the alloy pellet microstructure, the formations of Y2O3 nanoparticles with average size of 5 nm were observed indicating the dispersion and incorporation of this nano-scale dispersoids into the alloy matrix. Fe-15Cr-0.3Y2O3 alloy pellet was annealed at temperature of 600°C, 800°C and 1000°C, respectively for the Vickers hardness test. The Vickers hardness test was performed by using a micro-Vickers hardness tester with a load of 200 gf. The hardness value (HV) of this alloy pellet started to decrease at temperature of 600°C indicating the grain growth of this material at high temperature
Determination of Indoor 222Rn Concentrations Level on Different Room Sizes in Academic Building at Universiti Malaysia Kelantan Jeli Campus
Authors: Razab Mohammad Khairul Azhar Abdul , Abdul Razab Mohammad Khairul Azhar , Abd Karim Siti Fatimah , AZHAR Nur Ezati , Abdullah Nor Hakimin , Mohamed Noor An'amt , Mohamed Mazlan , ABDULLAH @ ABDUL KARI Zulhisyam , ADAM Noraina
Published: March 2017

The objectives of this study are to briefly monitor the 222Rn concentration in selected study area and to investigate its correlation with the environmental factors (pressure, humidity and temperature). 222Rn concentrations were monitored in three different sizes of lecture rooms known as BK 6, BK 7 and BK 8 at academic building, Universiti Malaysia Kelantan (UMK) Jeli Campus. Radon monitor known as Sentinel 1030 has been used to collect 210 readings of 222Rn concentration data. Environmental factors for each study areas was analyzed by using Pearson correlation. The average 222Rn concentrations for BK 6, BK 7 and BK 8 were found at 0.29 pCi/L, 0.31 pCi/L and 0.72 pCi/L, respectively. BK 8 with 277.97 m³ obtained higher 222Rn concentrations than BK 6 with 440.98 m³, followed by BK 7 with 292.67 m³. From the results, 222Rn concentration in BK 6 and BK 7 are influenced by temperature and pressure, correspondingly. However, no correlation of environmental factors found in BK 8.
The Effects of Altitude Levels on 222Rn Concentration in Academic Building at Universiti Malaysia Kelantan Jeli Campus
Authors: Razab Mohammad Khairul Azhar Abdul , Abd Karim Siti Fatimah , AZHAR Nur Ezati , Abdul Razab Mohammad Khairul Azhar , Abdullah Nor Hakimin , Mohamed Noor An'amt , Mohamed Mazlan , ABDULLAH @ ABDUL KARI Zulhisyam , ADAM Noraina
Published: March 2017

Highly continuous exposure to Radon (222Rn) concentrations can affects human health and cause lung cancer. This study aims to briefly monitor 222Rn concentration at different level altitude and to investigate correlation between their environmental parameters sort of temperature, humidity and pressure in indoor space. Lecture rooms known as BK 4 in the first floor and BK 8 in the third floor at academic building Universiti Malaysia Kelantan (UMK) Jeli Campus were selected as the study areas. The total of 210 readings indoor 222Rn concentrations data have been collected for the whole study using Radon Sentinel Model 1030. Average 222Rn concentration in BK 4 and BK 8 were found to have range from 0.36 pCi/L to 0.73 pCi/L and 0.40 pCi/L to 0.93 pCi/L, respectively. 222Rn concentration is higher at BK 8 with height 14.4 meter than BK 4 with height 4.8 meter from the ground. Negative correlations were obtained between 222Rn concentrations over pressure, temperature and humidity at BK 4. Meanwhile, 222Rn concentrations over pressure and humidity at BK 8 have shown positive correlation and negative correlation with temperature.
Characterizations and Application of Supported Ionic Liquid [bmim][CF3SO3]/SiO2 in CO2 Capture
Authors: Marliza Tengku Sharifah , Yarmo Mohd Ambar , Hakim Azizul , Abu Tahari Maratun Najiha , Taufiq-Yap Yun Hin
Published: March 2017

Supported ionic liquid (IL) [bmim][CF3SO3] on SiO2 was prepared, characterized and its potential evaluated for CO2 capture via adsorption and desorption studies using gas adsorption analyzer. The physical and chemical properties were determined using N2 adsorption/desorption and CO2-TPD analysis. The increasing IL loading caused a drastic decrease in the surface area as well as pore volume due to the confinement of IL within the micropore and mesopore area. However, the increasing IL loading increased the basicity of the sorbent which significantly enhanced CO2 chemisorption. Supported [bmim][CF3SO3] on SiO2 revealed the physical and chemical adsorption of CO2 and resulted in a remarkable CO2 adsorption capacity at atmospheric pressure and room temperature (66.7 mg CO2/gadsorbent) which has great potential in industrial applications.
Influence of the Calcination Temperature on the Catalytic Properties of Os/Bentonite for Glycerol Hydrogenolysis
Authors: Hamzah Noraini , Samad Wan Zurina , Yarmo Mohd Ambar
Published: March 2017

Selective catalytic hydrogenolysis of glycerol on Os/bentonite catalyst represents a low cost and green route for 1,2-propanediol which is major commonity chemical used in the production of antifreeze functional fluids, paints and humectants. The experimental results combined with the characterization studies using TPR, FESEM-EDX and XPS techiniques revealed that the optimum calcination temperature was 300 °C with glycerol conversion obtained was 80.7%. This might be due to the presense of Os metal species as a active site with binding energy (BE) of Os 4f at 51.2 eV in XPS analysis. TPR profile also shows two obvious peak at reduction temperature of 95 °C and 140 °C represent for Os3+ and Os4+ species respectively. The presence of Os3+ and Os4+ species were also confirmed by XPS analysis.
Effects of TiN Single Layer Coating on the Wear of ZTA Cutting Inserts and Surface Roughness of Workpiece
Authors: Azhar Ahmad Zahirani Ahmad , Mokhtar Mokhzani , Ratnam Mani Maran , Ahmad Zainal Arifin
Published: March 2017

Single layer TiN coated and uncoated zirconia toughened alumina (ZTA) cutting inserts were fabricated and used to machine stainless steel 316 in a turning process. The powders of alumina, yttria partially stabilized zirconia and magnesia were mixed and uniaxially pressed into rhombic cutting tool inserts and subsequently sintered at 1600°C for four hours in air. The inserts were coated with TiN layer using the PVD process. Results of wear area illustrate that the coated ZTA inserts show 66.7% increase in wear resistance compared to uncoated ZTA inserts. Commercially available Si3N4 inserts were used to compare the wear performance. Results of Si3N4 flank wear show a 64% more wear resistance compared to coated ZTA inserts. This may be attributed to the lower strength of coated ZTA cutting insert flank. Therefore, it is shown that single coating of TiN provides a significant advantage in the ZTA cutting performance and better quality surface finish.
Impact of Sintering Temperatures on Microstructure, Porosity and Mechanical Strength of Refractory Brick
Authors: Job Ajala Amkpa , Badarulzaman Nur Azam , Aramjat Abu Bakar
Published: March 2017

Riyom clay sample was investigated and have porosity of 18.6 %, firing shrinkage of 7.8 %, bulk density 2.2 g/cm3 and cold crushing strength. Chemical composition was analyzed using the XRF. The refractoriness of the fireclay was 1621 °C. The thermal shock resistance was up to 25 cycles. The apparent porosity fell within the standard value of 10-30 % for refractory fireclay bricks. The investigation proved that the Riyom clay deposit belong to the alumino-silicate group of bricks. The clay is therefore, suitable for production of refractory bricks for furnace lining.
Effects of Soda Lime Silicate Content on Industrial Stoneware Bodies Prepared by Pressing Method
Authors: Bakil Siti Natrah Abdul , Hussin Rosniza , Aramjat Abu Bakar
Published: March 2017

Stoneware clay includes ball clay in every respect except that do not sintering to a white product. Indeed, stoneware containing soda lime silicate could improve physical and mechanical properties. Thus, the aim of this study was to investigate influence of soda lime silicate content on industrial stoneware bodies with different weight percent (wt%) at sintering temperature 950 °C and 1100 °C. Rectangular sample were produced by uniaxial pressing at 40 MPa. Chemical composition was determined by using XRF. The thermal behavior was determined by thermogravimetric and different thermal analysis (TGA-DTA). The scanning electron microscopy (SEM) was used for microstructure analysis. The water absorption of the sample was determined using Archimedes’ method. The mechanical strength of stoneware bodies is important for many type applications and can be determined by measuring flexural strength (MOR). The water absorption decreased with optimum weight percent (wt%) of soda lime silicate into industrial stoneware bodies. The experimental result showed that desirable properties of stoneware bodies can be achieved with 5 wt% of soda lime silicate. As conclusion, optimum 5 wt% of soda lime silicate will influence physical and mechanical properties of industrial stoneware bodies.
Self-Propelled Sweepers-Air Flow Performance Part 1: Suction Air Volume Performance
Authors:   MTC2, Sweeper, Cleaner, and Machinery
Published: March 2017

This SAE Standard establishes a test method and a definition for
disclosing the suction air volume performance of self-propelled
sweepers that solely use a pneumatic conveyance means for the
collection and transfer of "sweepings" into a collection
hopper.

The purpose of the document describes a test practice for
measuring the suction air movement occurring in vacuum and
regenerative air street sweepers described in SAE J2130. The
document also proposes a format for the presentation of the
results. The document can be used to disclose or compare particular
operating performance criteria under similar conditions.
FLUID POWER PIPING CLEANING PROCESS
Authors:   Industrial Fluid Power Components
Published: March 2017

The procedures and guidelines detailed in this SAE Information Report provide various techniques and processes to properly clean fluid power piping prior to assembly and operation.
SHIP SYSTEMS AND EQUIPMENT—FASTENERS—SELECTION AND IDENTIFICATION REQUIREMENTS
Authors:   Ship Systems - Fasteners Committee
Published: March 2017

This SAE Standard provides a comprehensive list of requirements for the selection, identification, and control of metric and inch sized fasteners for use in shipboard applications for both shipbuilder installed joints and for use in shipboard components. The fastener selection requirements include the following:

a

Materials

b

Thread selection

c

Plating, coatings, and surface treatments

d

Locking devices and elements

e

Screw thread fastener inserts

f

Fastener part or identifying numbers

g

Identification markings
Seasonal and Spatial Changes in Trace Gases over Megacities from
AURA TES Observations
Authors: Cady-Pereira Karen E. , Payne Vivienne H. , Neu Jessica L. , Bowman Kevin W. , Miyazaki Kazuyuki , Marais Eloise A. , Kulawik Susan , Tzompa-Sosa Zitely A. , Hegarty Jennifer D.
Published: March 2017

Abstract. The AURA TES instrument is collecting closely spaced observations over 19 megacities. The objective is to obtain measurements that will lead to better understanding of the processes affecting air quality in and around these cities, and better estimates of the seasonal and interannual variability. We explore the TES measurements of ozone, ammonia, methanol and formic acid collected around the Mexico City Metropolitan Area and in the vicinity of Lagos (Nigeria). The TES data exhibit seasonal signals that are correlated with AIRS CO and MODIS AOD, with in situ measurements in the MCMA and with GEOS-Chem model output in the Lagos area. TES was able to detect an extreme pollution event in the MCMA on April 9, 2013, which is also evident in the in situ data. TES also shows that biomass burning has a greater impact south of the city than in the caldera where Mexico City is located. TES measured enhanced values of the four species over the Gulf of Guinea south of Lagos. Since it observes many cities from the same platform, with the same instrument and applyies the same retrieval algorithms, TES data provide a very useful tool for quickly comparing air quality measures of two or more cities. We compare the data from the MCMA and Lagos, and show that while the MCMA has occasional extreme pollution events, Lagos consistently has far higher levels of these trace gases.
An assessment of geographical distribution of different plant functional types over North America simulated using the CLASS-CTEM modelling framework
Authors: Shrestha Rudra K. , Arora Vivek K. , Melton Joe R. , Sushama Laxmi
Published: March 2017

Abstract. The performance of the competition module of the CLASS-CTEM (Canadian Land Surface Scheme and Canadian Terrestrial Ecosystem Model) modelling framework is assessed at 1° spatial resolution over North America by comparing the simulated geographical distribution of plant functional types (PFTs) with two observation-based estimates. The model successfully reproduces the broad geographical distribution of trees, grasses and bare ground although limitations remain. In particular, compared to the two observation-based estimates, the simulated fractional vegetation coverage is lower in the arid south-west North American region and higher in the Arctic region. The lower than observed simulated vegetation coverage in the south-west region is attributed to lack of representation of shrubs in the model and plausible errors in the observation-based data sets. The observation-based data indicates vegetation fractional coverage of more than 60 % in this arid region, despite only 200–300 mm of precipitation that the region receives annually and observation-based leaf area index (LAI) in the region are lower than one. The higher than observed vegetation fractional coverage in the Arctic is due to the lack of representation of moss and lichen PFTs and also likely because of inadequate representation of permafrost in the model as a result of which the C3 grass PFT performs overly well in the region. The model generally reproduces the broad spatial distribution and the total area covered by the two primary tree PFTs (needleleaf evergreen and broadleaf cold deciduous trees) reasonably well. The simulated fractional coverage of tree PFTs increases after 1960s in response to the CO2 fertilization effect and climate warming. Differences between observed and simulated PFT coverages highlight limitations in the model and provide insight into physical and structural processes that need improvement.
Calibration of a simple and a complex model of global marine
biogeochemistry
Authors: Kriest Iris
Published: March 2017

Abstract. The assessment of the ocean biota's role in climate climate change is often carried out with global biogeochemical ocean models that contain many components, and involve a high level of parametric uncertainty. Examination the models' fit to climatologies of inorganic tracers, after the models have been spun up to steady state, is a common, but computationally expensive procedure to assess model performance and reliability. Using new tools that have become available for global model assessment and calibration in steady state, this paper examines two different model types – a complex seven-component model (MOPS), and a very simple two-component model (RetroMOPS) – for their fit to dissolved quantities. Before comparing the models, a subset of their biogeochemical parameters has been optimised against annual mean nutrients and oxygen. Both model types fit the observations almost equally well. The simple model, which contains only nutrients and dissolved organic phosphorus (DOP), is sensitive to the parameterisation of DOP production and decay. The spatio-temporal decoupling of nitrogen and oxygen, and processes involved in their uptake and release, renders oxygen and nitrate valuable tracers for model calibration. In addition, the non-conservative nature of these tracers (with respect to their upper boundary condition) introduces the global bias as a useful additional constraint on model parameters. Dissolved organic phosphorous at the surface behaves antagonistically to phosphate, and suggests that observations of this tracer – although difficult to measure – may be an important asset for model calibration.
Large-scale coastal and fluvial models constrain the late Holocene evolution of the Ebro delta, Spain
Authors: Nienhuis Jaap H. , Ashton Andrew D. , Kettner Albert J. , Giosan Liviu
Published: March 2017

Abstract. The distinctive plan-view shape of the Ebro Delta, Spain, reveals a rich morphologic history. The degree to which the form and depositional history of the Ebro and many other deltas represent autogenic (internal) dynamics or allogenic (external) forcing remains a prominent challenge for paleo-environmental reconstructions. Here we use simple coastal and fluvial morphodynamic models to quantify paleo-environmental changes that affected the Ebro delta over the late Holocene. Based on numerical model experiments and the preserved and modern Ebro delta shape, we estimate that a phase of rapid shoreline progradation began approximately 2100 years BP, requiring a large increase (doubling) in coarse-grained fluvial sediment supply to the delta. We do not find evidence that changes in wave climate aided this delta expansion. River profile models suggest that such an instantaneous and sustained increase in coarse-grained, beach-compatible sediment to the delta would require a combination of flood discharge increase and increased sediment input into the river channel from upstream drainage basin erosion. The persistence of rapid delta progradation throughout the last 2100 years suggests an anthropogenic signal of sediment supply and flooding intensity. Our findings highlight how scenario-based investigations of deltaic systems using simple models can assist first-order quantitative paleo-environmental reconstructions, elucidating the effects of past human influence and climate change and allowing a better understanding of the future of deltaic landforms.
Multiple domain evaluation of watershed hydrology models
Authors: Kumarasamy Karthik , Belmont Patrick
Published: March 2017

Abstract. Watershed scale models simulating hydrology and water quality have advanced rapidly in sophistication, process representation, flexibility in model structure, and input data. Given the importance of these models to support decision-making for a wide range of environmental issues, the hydrology community is compelled to improve the metrics used to evaluate model performance. More targeted and comprehensive metrics will facilitate better and more efficient calibration and will help demonstrate that the model is useful for the intended purpose. Here we introduce a suite of new tools for model evaluation, packaged as an open-source Hydrologic Model Evaluation (HydroME) Toolbox. Specifically, we demonstrate the use of box plots to illustrate the full distribution of common model performance metrics, such as R2, use of Euclidian distance, empirical Quantile-Quantile (Q-Q) plots and flow duration curves as simple metrics to identify and localize errors in model simulations. Further, we demonstrate the use of magnitude squared coherence to compare the frequency content between observed and modeled streamflow and wavelet coherence to localize frequency mismatches in time. We provide a rationale for a hierarchical selection of parameters to adjust during calibration and recommend that modelers progress from parameters with the most uncertainty to the least uncertainty, namely starting with pure calibration parameters, followed by derived parameters, and finally measured parameters. We apply these techniques in the calibration and evaluation of models of two watersheds, the Le Sueur River Basin (2880 km2) and Root River Basin (4300 km2) in southern Minnesota, USA.
Moment-based Metrics for Global Sensitivity Analysis of Hydrological Systems
Authors: Dell'Oca Aronne , Riva Monica , Guadagnini Alberto
Published: March 2017

Abstract. We propose new metrics to assist global sensitivity analysis, GSA, of hydrological and Earth systems. Our approach allows assessing the impact of uncertain parameters on main features of the probability density function, pdf, of a target model output, y. These include the expected value of y, the spread around the mean and the degree of symmetry and tailedness of the pdf of y. Since reliable assessment of higher order statistical moments can be computationally demanding, we couple our GSA approach with a surrogate model, approximating the full model response at a reduced computational cost. Here, we consider the generalized Polynomial Chaos Expansion (gPCE), other model reduction techniques being fully compatible with our theoretical framework. We demonstrate our approach through three test cases, including an analytical benchmark, a simplified scenario mimicking pumping in a coastal aquifer, and a laboratory-scale conservative transport experiment. Our results allow ascertaining which parameters can impact some moments of the model output pdf while being uninfluential to others. We also investigate the error associated with the evaluation of our sensitivity metrics by replacing the original system model through a gPCE. Our results indicate that the construction of a surrogate model with increasing level of accuracy might be required depending on the statistical moment considered in the GSA. Our approach is fully compatible with (and can assist the development of) analysis techniques employed in the context of reduction of model complexity, model calibration, design of experiment, uncertainty quantification and risk assessment.
A Validation and Code-to-Code Verification of FAST for a
Megawatt-ScaleWind Turbine with Aeroelastically Tailored Blades
Authors: Guntur Srinivas , Jonkman Jason , Sievers Ryan , Sprague Michael A. , Schreck Scott , Wang Qi
Published: March 2017

Abstract. This paper presents validation and code-to-code verification of the latest version of the U.S. Department of Energy, National Renewable Energy Laboratory wind turbine aeroelastic engineering simulation tool, FAST v8. A set of 1,141 test cases, for which experimental data from a Siemens 2.3 MW machine have been made available and were in accordance with the International Electrotechnical Commission 61400-13 guidelines, were identified. These conditions were simulated using FAST as well as the Siemens in-house aeroelastic code, BHawC. This paper presents a detailed analysis comparing results from FAST with those from BHawC as well as experimental measurements, using statistics including the means and the standard deviations along with the power spectral densities of select turbine parameters and loads. Results indicate a good agreement among the predictions using FAST, BHawC, and experimental measurements. These agreements are discussed in detail in this paper, along with some comments regarding the differences seen in these comparisons relative to the inherent uncertainties in such a model-based analysis.
A model for quick load analysis for monopile-type offshore wind
turbine substructures
Authors: Schløer Signe , Garcia Castillo Laura , Fejerskov Morten , Stroescu Emanuel , Bredmose Henrik
Published: March 2017

Abstract. A model for Quick Load Analysis, QuLA, of an offshore wind turbine substructure is presented. The aerodynamic rotor loads and damping are precomputed for a load-based configuration. The dynamic structural response is represented by the first global fore-aft mode only and is computed in the frequency domain using the equation of motion. The model is compared to the state of the art aeroelastic code, Flex5. Both both life time fatigue and extreme loads are considered in the comparison. In general there is good similarity between the two models. Some deviation for the sectional forces are explained in terms of the model simplifications. The difference in the sectional moments are found to be within 14 % for the fatigue load case and 10 % for the extreme load condition.
RELAÇÕES ENTRE PERFORMANCE E FLUXOS MIGRATÓRIOS NA OBRA DE LIDA ABDUL
Authors: Duarte Camila Silveira
Published: March 2017

Este artigo visa compreender como se dão as relações entre os processos de migração e criação artística nos trabalhos desenvolvidos pela artista afegã Lida Abdul. Esta tessitura constrói-se a partir de uma breve apresentação de sua trajetória artístico biográfica, além de uma análise na qual especula-se e argumenta-se sobre a influência de sua experiência como refugiada, na criação e produção de suas performances e vídeo-arte, tomando como exemplo a obra intitulada “Dome”, na qual torna-se evidente a perspicácia da artista ao capturar instantes, elaborar emoções, promover debates e olhar cuidadosamente para a realidade ao fazer dela um espaço para a produção e compartilhamento de sensibilidades e percepções.
EXERCÍCIO DE DESCONSTRUÇÃO APONTAMENTOS SOBRE GESTÃO AUTÔNOMA E O CAMPO ARTÍSTICO CONTEMPORÂNEO
Authors: Petroni Ilze
Published: March 2017

Com base na experiência empírica, este artigo destina-se como um ensaio crítico, como uma especulação dialética entre praxis e teoria, acerca dos limites ou incapacidade de a autonomia das gestões autônomas de arte contemporânea em relação ao microcosmo social específico em que participam, além de sua colocação nas periferias ou limites do mesmo. Pretende questionar as premissas de tais gestões de arte à luz da instituição que as regula e modeliza.
UNA PREETENSIÓN LIBERTADORA Y UNA PREDISPOSICIÓN DE ORDEN: GESTIONES AUTÓNOMAS DE ARTE CONTEMPORÁNEO EN AMÉRICA LATINA
Authors: Sepúlveda Jorge , Bustos Guillermina
Published: March 2017

Breve resenha sobre a estrutura e metodologia de trabalho dos grupos de gestão autônoma na América Latina. De que maneira se organizam coletiva e colaborativamente, como estabelecem seus próprios parâmetros institucionais, ensaiam novas possibilidades locais de produzir e entender as artes no contemporâneo. Suas ações se radicam em um constante exercício de perseguição da incerteza, em um recorrente e sempre provisória ação de por a prova o sabido e o pensado.
Chaucer's Return from Lombardy, the Shrine of St. Leonard at Hythe, and the “corseynt Leonard” in the House of Fame, Lines 112–18
Authors: Lightsey Scott
Published: March 2017

Chaucer's reference to Saint Leonard in the House of Fame, lines 112–18, has been glossed as a humorous jest on the difficulty of marriage since the time of Skeat. This article reinterprets these lines in light of comparative textual analysis, the historical context of the cult of Saint Leonard, and the geographical context of Chaucer's travel from Lombardy in 1378. It finds that Chaucer likely passed through the port of Hythe, Kent, there visiting the Church of St. Leonard, where he would have encountered its marvelous “Eolus scepter” as part of the local maritime cult of Saint Leonard.
Speaking “Amys” in the Franklin's Tale: Rhetoric, Truth, and the Poetria nova
Authors: Turner Joseph
Published: March 2017

The Franklin's Prologue and Tale offer a model of poetic image-making derived from Geoffrey of Vinsauf's Poetria nova. The Franklin's exploration of the colors of rhetoric in his prologue anticipates the illusionist's ability to manipulate the black rocks in the tale. In manipulating language and the natural world, this system of poetry threatens to obscure truth. As a result, the Franklin's Tale is as much about poetic illusion as magical illusion, and as much about factual truth (or reality) as ethical truth.