Displaying publications 201 - 220 of 426 in total

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  1. Nur Azam Badarulzaman, Ng, Jun Wei, Ahmad Azmin Mohamad, Purwadaria, Sunara, Zainal Arifin Ahmad
    MyJurnal
    A co-deposition of nickel-phosphorus-alumina (NiPA) composite coatings were obtained from an ordinary sulphate-based plating bath consisting of 5 g/l alumina (Al2O3) particles. The particles were dispersed by using mechanical agitation at 125 rpm. The presence of Ni3P and Al2O3 phases in the coatings was confirmed by XRD analysis. SEM/EDX results indicated that a smooth Ni3P coating was obtained and Al2O3 particles were embedded into the coating. Microscopic observation showed that the bonding between the Ni3P metal matrix and the Al2O3 ceramic particles was compact.
    Matched MeSH terms: Aluminum Oxide
  2. Ahmad Saat, Zaini Hamzah
    MyJurnal
    Clay has been regarded as very important natural industrial materials. All these industries exploit the properties that clay can be molded into any shape and fired to dry without losing its form. A study was carried out on clay samples from eight sites in the north-eastern part of Peninsular Malaysia. The study was accomplished by using X-ray diffraction (XRD) technique. The x-ray diffraction spectra obtained enable the determination of the lattice spacing associated with the types of clay and nonclay minerals present in the samples. Results of the study shows that the major components of clay minerals present in all samples studied are kaolinite and illite. The presence of kaolinite is confirmed by firing test in which the kaolinite diffraction peaks disappeared upon heating the samples at 600 o C. The presence of non-clay minerals such as quartz, mica, feldspar and chlorite are also observed.
    Matched MeSH terms: Aluminum Silicates
  3. Ramlan, O., Noraswana, N. F.
    MyJurnal
    A study on the distribution of Recent Ostracoda in offshore sediment was carried out around the South China Sea. A total of 30 sediment samples were taken from the sampling stations between latitude 1°48’ and 7°25’N and longitude 102°09’ and 105°16’E. From this study, 79 species of ostracods belonging to 16 families and 44 genera were identified. The dominant species was Foveoleberis cypraeoides with 937 individuals obtained. There were 13 to 43 species in total. Diversity Index, H(s), was in the range of 2.1 to 3.3, whereas the dominance values were between 4.4 and 14.7%. Several environmental parameters were measured including depth, temperature and salinity. The range values for each of these parameters are 13-72 m, 25.24-30.06o C and 27.74-34.91 ppt, respectively. The sediment texture in this study area can be categorized as sand, sandy mud, clayey mud, silty mud, silty clay, clayey sand, clayey silt and silty sand. The observations revealed that abundance and diversity of ostracod appeared to be principally controlled by depth. Two faunal assemblages were identified in terms of faunal composition, namely, shallow water (Hemikrithe orientalis, Neomonoceratina iniqua, Stigmatocythere indica, Cytherelloidea leroyi and Neocytheretta snellii) and deep water (Paracypris sp., Alataconcha pterogona, Bythocytheropteron alatum, Keijella paucipunctata and Actinocythereis scutigera). A comparative analysis showed a high degree resemblance between the study area and south-eastern Malay Peninsula (the South China Sea).
    Matched MeSH terms: Aluminum Silicates
  4. Tan YL, Abdullah AZ, Hameed BH
    Bioresour Technol, 2018 Sep;264:198-205.
    PMID: 29803811 DOI: 10.1016/j.biortech.2018.05.058
    Silica-alumina catalyst was prepared and used in the catalytic fast pyrolysis of durian rind in a drop-type two-stage reactor. The effects of catalytic temperature (400 °C-600 °C) and catalyst-to-durian rind ratio (1:30-3:30) were evaluated. Bio-oil yield was increased with increased catalytic temperature due to considerable dehydration process, but it was reduced with high catalyst loading due to the overcracking of organics into light gases. Silica-alumina catalyst possessed good selectivity and the products changed according to the temperature. The major components in bio-oil were hydrocarbons, furan derivatives, and aromatic compounds at 400 °C, 500 °C, and 600 °C, respectively. The hydrogen and carbon contents of bio-oil were reduced with high catalyst loading due to the overcracking of organics, and the deoxygenation process became unfavorable. The silica-alumina catalyst worked well in catalytic fast pyrolysis of durian rind, and the condition may be adjusted based on the desired products.
    Matched MeSH terms: Aluminum Oxide
  5. Syazwan Hafiz Mohd, Wan Elhami Wan Omar, Ai-Hong Chen
    MyJurnal
    This paper examines the chemical elements used as colour additives in cosmetic coloured contact lenses (Cos-CCL) using Field Emission Scanning Electron Microscope equipped with Energy Dispersive X-ray Spectroscopy (FESEM-EDX) analysis. The samples comprised two different Cos-CCL brands and colours (sample A1-black iris colour & B1-gray iris colour) with their respective clear contact lens counterparts as controls (sample A2 & B2). The parameters of Cos-CCL were observed carefully so that they resembled their respective controls. All the samples were analysed for chemical element characterisation by using EDX spectroscopy surface mapping analysis on both front and back surfaces. EDX spectroscopy point analysis was done on cross-section surface of Cos-CCL when colour additive pattern could not be detected by FESEM on either surface. FESEM-EDX spectroscopy analysis has revealed iron element in the colour additives of the A1 sample and aluminium elements in the B2 sample. These two elements were not present in the respective control samples. It can be concluded that iron and aluminium elements are exclusively attributed to the colour additive in Cos-CCL samples. It is important for manufacturers of Cos-CCL to disclose information of their products and create greater awareness on the risks facing users.
    Matched MeSH terms: Aluminum
  6. Edward Hingha Foday Jr, Nurul As'shikin Ramli, Hairu Nabilah Ismail, Nulhazwany Abdul Malik, Hazlami Fikri Basri, Fatihah Syahirah Abdul Aziz, et al.
    MyJurnal
    Malaysia is one of the developing countries that are facing an increase population
    with an increasing and significant generation of waste. Environmental problems may
    arise when the solid waste management is improper. The rate of generation is
    increasing and the composition is also changing as the nation becomes more
    urbanized and industrialized. The objective of this study is to present the data of
    municipal solid waste (MSW) generated in Taman Universiti, Skudai, Johor Bahru,
    Malaysia. The composition of MSW was studied by segregating it into different
    components such as food waste, paper, glass, plastics, metal and tin aluminums. It
    was observed that Taman Universiti area produced around 40% plastics waste which
    was the highest component compared to other waste, followed by food waste and
    papers with 38.2% and 21% respectively. Meanwhile, food waste was recorded the
    highest moisture content with 38.2% while glass had the lowest moisture content
    with 0.4%. The reliable estimate of MSW generated is important for proper waste
    management planning. These data could enhance in implementation of waste
    management system in that area.
    Matched MeSH terms: Aluminum
  7. Shahrol Mohamaddan, Chai Siew Fu, Ahmad Hata Rasit, Siti Zawiah Md Dawal, Keith Case
    MyJurnal
    Congenital talipes equinovarus (CTEV) or clubfoot is a complex deformity of the foot that is characterised by four main deformities; forefoot cavus and adductus, hindfoot varus and ankle equinus. Currently, the Ponseti method is the most general and recognized treatment with a high success rate of over 90%. The treatment involves gentle manipulation and serial casting. However, the casting method could create complications for the patients such as soft-tissue damage and inconvenience in following the treatment schedule especially for those living far away from hospital. The aim of this research is to develop an adjustable corrective device for clubfoot treatment based on the techniques in the Ponseti method and at the same time attempt to eliminate the side-effects. The prototype consists of six adjustable movements from six different mechanisms to correct the four deformities. The prototype was developed using 3D printing method and the main material used is polylactic acid (PLA), rubber, aluminium and cotton fabric with sponge. The total weight of the prototype is around 300 g.
    Matched MeSH terms: Aluminum
  8. Al-Makramani BMA, Razak AAA, Abu-Hassan MI, Al-Sanabani FA, Albakri FM
    Open Access Maced J Med Sci, 2018 Mar 15;6(3):548-553.
    PMID: 29610618 DOI: 10.3889/oamjms.2018.111
    BACKGROUND: The selection of the appropriate luting cement is a key factor for achieving a strong bond between prepared teeth and dental restorations.

    AIM: To evaluate the shear bond strength of Zinc phosphate cement Elite, glass ionomer cement Fuji I, resin-modified glass ionomer cement Fuji Plus and resin luting cement Panavia-F to Turkom-Cera all-ceramic material.

    MATERIALS AND METHODS: Turkom-Cera was used to form discs 10mm in diameter and 3 mm in thickness (n = 40). The ceramic discs were wet ground, air - particle abraded with 50 - μm aluminium oxide particles and randomly divided into four groups (n = 10). The luting cement was bonded to Turkom-Cera discs as per manufacturer instructions. The shear bond strengths were determined using the universal testing machine at a crosshead speed of 0.5 mm/min. The data were analysed using the tests One Way ANOVA, the nonparametric Kruskal - Wallis test and Mann - Whitney Post hoc test.

    RESULTS: The shear bond strength of the Elite, Fuji I, Fuji Plus and Panavia F groups were: 0.92 ± 0.42, 2.04 ± 0.78, 4.37 ± 1.18, and 16.42 ± 3.38 MPa, respectively. There was the statistically significant difference between the four luting cement tested (p < 0.05).

    CONCLUSION: the phosphate-containing resin cement Panavia-F exhibited shear bond strength value significantly higher than all materials tested.

    Matched MeSH terms: Aluminum Oxide
  9. Bradley DA, Zubair HT, Oresegun A, Louay GT, Ariffin A, Khandaker MU, et al.
    Appl Radiat Isot, 2018 Nov;141:176-181.
    PMID: 29673719 DOI: 10.1016/j.apradiso.2018.02.025
    In previous work we investigated the real-time radioluminescence (RL) yield of Ge-doped silica fibres and Al2O3 nanodot media, sensing electron- and x-ray energies and intensities at values familiarly obtained in external beam radiotherapy. The observation of an appreciable low-dose sensitivity has given rise to the realisation that there is strong potential for use of RL dosimetry in diagnostic radiology. Herein use has been made of P-doped silica optical fibre, 2 mm diameter, also including a 271 µm cylindrical doped core. With developing needs for versatile x-ray imaging dosimetry, preliminary investigations have been made covering the range of diagnostic x-ray tube potentials 30 kVp to 120 kVp, demonstrating linearity of RL with kVp as well as in terms of the current-time (mAs) product. RL yields also accord with the inverse-square law. Given typical radiographic-examination exposure durations from tens- to a few hundred milliseconds, particular value is found in the ability to record the influence of x-ray generator performance on the growth and decay of beam intensity, from initiation to termination.
    Matched MeSH terms: Aluminum Oxide
  10. Lee, K.Y., Ho, L.Y., Tan, K.H., Tham, Y.Y., Ling, S.P., Qureshi, A.M., et al.
    MyJurnal
    In the perspective of recent bauxite mining in Malaysia, this review aims to identify the potential
    environmental and health impacts on miners and surrounding communities. The environmental issues of
    bauxite mining include, air, water and soil pollution due to bauxite dust; leaching of bauxite into water
    sources resulting in reduced soil fertility as well as affecting agricultural food products and aquatic life.
    Bauxite occupational exposure affects the health of miners, and has negative consequences on the health of
    surrounding communities, such as increased respiratory symptoms, contamination of drinking water, other
    potential health risks from ingestion of bauxite and heavy metals, including noise-induced hearing loss and
    mental stress. This review discusses the processes of bauxite mining, its constituents and residual trace
    elements, and their impact on the environment and health of exposed workers and communities. It also
    explores the Malaysian legal requirements and standards of occupational exposure to bauxite.
    Matched MeSH terms: Aluminum Oxide
  11. Tijani MM, Aqsha A, Mahinpey N
    Data Brief, 2018 Apr;17:200-209.
    PMID: 29876387 DOI: 10.1016/j.dib.2017.12.044
    Synthesis and characterization of supported metal-based oxygen carriers were carried out to provide information related to the use of oxygen carriers for chemical looping combustion processes. The Cu, Co, Fe, Ni metals supported with Al2O3, CeO2, TiO2, ZrO2 were prepared using the wetness impregnation technique. Then, the X-ray Diffraction (XRD) characterization of oxidized and reduced samples was obtained and presented. The kinetic analysis using Thermogravimetric analyzer (TGA) of the synthesized samples was conducted. The kinetics of reduction reaction of all samples were estimated and explained.
    Matched MeSH terms: Aluminum Oxide
  12. Alsabery AI, Sheremet MA, Chamkha AJ, Hashim I
    Sci Rep, 2018 May 09;8(1):7410.
    PMID: 29743641 DOI: 10.1038/s41598-018-25749-2
    The problem of steady, laminar natural convection in a discretely heated and cooled square cavity filled by an alumina/water nanofluid with a centered heat-conducting solid block under the effects of inclined uniform magnetic field, Brownian diffusion and thermophoresis is studied numerically by using the finite difference method. Isothermal heaters and coolers are placed along the vertical walls and the bottom horizontal wall, while the upper horizontal wall is kept adiabatic. Water-based nanofluids with alumina nanoparticles are chosen for investigation. The governing parameters of this study are the Rayleigh number (103 ≤ Ra ≤ 106), the Hartmann number (0 ≤ Ha ≤ 50), thermal conductivity ratio (0.28 ≤ k w  ≤ 16), centered solid block size (0.1 ≤ D ≤ 0.7) and the nanoparticles volume fraction (0 ≤ ϕ ≤ 0.04). The developed computational code is validated comprehensively using the grid independency test and numerical and experimental data of other authors. The obtained results reveal that the effects of the thermal conductivity ratio, centered solid block size and the nanoparticles volume fraction are non-linear for the heat transfer rate. Therefore, it is possible to find optimal parameters for the heat transfer enhancement in dependence on the considered system. Moreover, high values of the Rayleigh number and nanoparticles volume fraction characterize homogeneous distributions of nanoparticles inside the cavity. High concentration of nanoparticles can be found near the centered solid block where thermal plumes from the local heaters interact.
    Matched MeSH terms: Aluminum Oxide
  13. Ismail Lias, Muhammad Hussain Ismail, Iskandar Dzulkernain Md Raffee, Mohd Aman Ihsan Mamat
    MyJurnal
    Aluminium foam tube is a metal that consists of porous medium with special characteristics such as good energy absorption, good heat transfer and high thermal conductivity. These make it suitable to be used in a wide range of applications such as in heat exchangers. The aim of this project is to identify and analyse mechanical behaviour and microstructure aluminium foam tube produced and fabricated with infiltration method with vacuum-gas. The density of aluminium foam tube was also determined and an average aluminium foam tube with porosity 50% - 80% with the average NaCl particle size 2mm, 3mm and 4mm was produced. Foams with porosity 60%-75% NaCl has higher energy absorption. These was based on foam structure, density and maximum compressive load test result.
    Matched MeSH terms: Aluminum
  14. Guan Ling Sim, Mohd Nizar Hamidon, Kamilu Iman Usman
    MyJurnal
    This study presents the sensitivity of graphene nanoribbon (GNR) when exposed to ammonia gas at room temperature. Alumina were used as a substrate and coated with GNR as sensing film for ammonia gas detection. Four different concentration of GNR in the category of maximum, high, low, and minimum were prepared. Each category of GNR will be dispersed on alumina substrate with area of 1cm2 and 4cm2. 30nm of gold contacts are sputtered on both ends of the sensing film. The ammonia gas can be detected by measuring the changes in resistance. The GNR as ammonia sensor shows good responses at room temperature. In repeatability test, maximum GNR shows least variation when exposed to ammonia with the value of 1.01% (4cm2) and 2.12% (1cm2). In a sensitivity test, 0.25% to 1.00% of ammonia gas was used and tested on maximum GNR. Maximum GNR on 4cm2 substrate shows higher sensitivity as compared to 1cm2. Reaction time of GNR on ammonia gas decreased as the concentration of ammonia increased. Larger surface area of sensing element required lesser reaction time.
    Matched MeSH terms: Aluminum Oxide
  15. Manan, N.M., Zainal Abidin, H.A., Mohd Zahari, N., Abdul Ghafar@Abdul Rapor, A.
    Ann Dent, 2015;22(2):9-14.
    MyJurnal
    Objective: This study examined the influence of visual art therapy techniques in reducing anxiety level
    among 4 to 6 years old paediatric dental patients.
    Methods: Eleven subjects were selected among 4 to 6 years old paediatric dental patients. The initial
    reaction towards dental procedure/treatment was evaluated using Frankl Behavior Rating Scale. The
    anxiety level was assessed by using Malay-Modified Child Dental Anxiety Scale (MCDASf
    ) to measure
    a child situational anxiety of pre- and post-treatment. Visual art making activities included free drawing,
    clay moulding and collage technique. The participant reaction to dental treatment was assessed by using
    Frankl Behavioural Rating Scale for two subsequent independent visits in two weeks interval. Median
    and Ordinal Test ranked the variables score of behavioural reaction towards dental treatment and anxiety
    level.
    Results: Play-doh (PD) subjects could accept dental procedures more if compared to free drawing (FD)
    and storytelling by collage (ST) subjects, which has lower post treatment-median scores in Visit 1 and
    Visit 2, FD and ST subjects need more time to show positive attitude towards dental treatment.
    Conclusion: These findings suggest dental anxiety level of children aged 4 to 6 years old reduced after
    the art therapy and play-doh(clay-moulding technique) is the art making activity of choice among 4 to 6
    years old paediatric dental patients.
    Matched MeSH terms: Aluminum Silicates
  16. Doris M, Aziz F, Alhummiany H, Bawazeer T, Alsenany N, Mahmoud A, et al.
    Nanoscale Res Lett, 2017 Dec;12(1):67.
    PMID: 28116608 DOI: 10.1186/s11671-017-1851-0
    In this study, low-bandgap polymer poly{[4,4-bis(2-ethylhexyl)-cyclopenta-(2,1-b;3,4-b')dithiophen]-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl} (PCPDTBT) nanostructures have been synthesized via a hard nanoporous alumina template of centrifugal process. Centrifuge has been used to infiltrate the PCPDTBT solution into the nanoporous alumina by varying the rotational speeds. The rotational speed of centrifuge is directly proportional to the infiltration force that penetrates into the nanochannels of the template. By varying the rotational speed of centrifuge, different types of PCPDTBT nanostructures are procured. Infiltration force created during the centrifugal process has been found a dominant factor in tuning the morphological, optical, and structural properties of PCPDTBT nanostructures. The field emission scanning electron microscopy (FESEM) images proved the formation of nanotubes and nanowires. The energy-dispersive X-ray spectroscope (EDX) analysis showed that the nanostructures were composed of PCPDTBT with complete dissolution of the template.
    Matched MeSH terms: Aluminum Oxide
  17. Rahman MA, Ahamed E, Faruque MRI, Islam MT
    Sci Rep, 2018 Oct 08;8(1):14948.
    PMID: 30297730 DOI: 10.1038/s41598-018-33295-0
    Various techniques are commonly used to produce nano-crystalline NiAl2O4 materials; however, their practical applications in the microwave region remain very limited. In this work, flexible substrates for metamaterials containing two different concentrations of NiAl2O4 (labelled Ni36 and Ni42) have been synthesised using a sol-gel method. The formation of spinel structures in the synthesised materials is confirmed, and their crystalline sizes are determined using scanning electron microscopy, X-ray diffraction, and energy dispersive X-ray techniques. The dielectric properties, conductivities, loss tangents, and other parameters of the NiAl2O4-based substrates are analysed to evaluate their applicability as dielectric materials for the microwave frequency range. The obtained results show that the fabricated Ni36 and Ni42 nickel aluminates possess dielectric constants of 4.94 and 4.97 and loss tangents of 0.01 and 0.007, respectively; in addition, they exhibit high flexibility and light weight, which make them suitable for applications as metamaterial substrates. The synthesised structures are also validated experimentally using a commercially available electromagnetic simulator; as a result, double negative behaviour of the flexible metamaterials has been observed. Furthermore, it is found that the prepared NiAl2O4 substrates can be used in the S-, C-, and X-bands of the microwave frequency region.
    Matched MeSH terms: Aluminum Oxide
  18. Ibrahim, R.E., Talari, M.K., Sabrina, M. Yahaya, Rosmamuhamadani, R., Sulaiman, S., Ismail, M.I.S.
    MyJurnal
    The aluminium-silicon (Al-Si) based on Metal Matrix Composites (MMCs) is widely used in lightweight
    constructions and transport applications requiring a combination of high strength and ductility. A grain
    refinement plays a crucial role in improving characteristics and properties of Al alloys. In this investigation,
    titanium diboride (TiB2) and scandium (Sc) inoculants were added to the Al-Si alloys for grain refinement of
    an alloy. In this investigation, the corrosion resistance rate of Al-Si cast alloy reinforced by TiB2 and Sc were
    measured by potentiostat (AUTOLAB) instrument. The aim of this research is to investigate the corrosion
    rate for Al-Si-TiB2-Sc composites that immersed in different concentration of acidic solutions. Besides, the
    immersion time of acidic solutions also was investigated. All the samples were prepared accordingly for
    ASTM standard by the composition of 6.0 wt% TiB2 and 0.6wt% Sc. All the samples undergo cold mounting
    technique for easy handling on corrosion tests. Then the samples were immersed in two different
    concentrations acidic medium solutions, which were 0.1.and 1.0 M hydrochloric acids (HCl). The corrosion
    rate also was investigated for immersion samples of 1.0 M HCl for 21 days. From the results obtained, added
    TiB2 and Sc onto Al-Si alloy gave the better properties in corrosion resistance. Corrosion rates to reduce when
    the samples were immersed in a lower concentration of acidic medium, 0.1 HCl. However, there are some
    significant on the result but it still following the corrosion rates trend. Thus, improvements to reinforcement
    content need to be done in further research to cover the lack of this corrosion rates trend.
    Matched MeSH terms: Aluminum
  19. Abdullah, M.A.A., Mamat, M., Rusli, S.A., Kassim, A.A.
    ASM Science Journal, 2018;11(101):96-104.
    MyJurnal
    Considering its excellent thermal stability, alkyl phosphonium surfactant: triisobutyl(methyl)phosphonium
    (TIBMP) was used in this research as an intercalant for surface
    modification of Na+-MMT via ion exchange process forming organomontmorillonite
    (OMMT). The OMMT was then used as filler in poly(methyl methacrylate) (PMMA) via
    melt intercalation technique. OMMT decomposed at a higher temperature than commercial
    alkyammonium modified MMT. Exfoliated and intercalated types of nanocomposites
    are obtained from PMMA/OMMTs at low and high content of OMMT loading, depending
    on the space of those clay platelets had to disperse in PMMA. The ability of OMMT to
    carry a certain load applied in PMMA matrix enhances the tensile strength in all composites.
    TIBMP are compatible with PMMA matrix, and significantly improves the tensile
    properties of PMMA composites.
    Matched MeSH terms: Aluminum Silicates
  20. Sharuddin Mohd Dahuri, Nor Hakimah Ahmad Subri, Norashady Mohd Noor
    MyJurnal
    his paper presents the structure and static model of engine camshaft analysis. For the purposes of this analysis, the finite element method is used. Camshaft is one of the critical components for effective and precise work of internal combustion engines. This camshaft rotates at high speed causing pressure and vibration in the system. Camshafts are also subject to varying fatigue burden due to cam plunger contact. These precise values are required to be determined to prevent failure in the camshaft. The objective of the project is to model and to perform pressure analysis on the camshaft machine. In this project the standard engine cam shafts are modeled and analyzed using the CATIA V5R21 software respectively. This model is created by the basic requirements of the engine. It is done with an existing background, such as the power of acting on cam by means of a valve while running at maxi mum speed. Here the approach becomes fully CAE based. CAE - based approaches enrich Research and limit the time span. A study was conducted to predict the behavior of the different camshafts structure of the material using the finite three - dimensional pressure of the element. Four types of materials such as Steel, Titanium, Aluminum and Magnesium are taken into account. FEA Stress and maximum displacement decisions are calculated and compared to all of the above materials. The conclusion is to focus on the material suitable for the camshaft to reduce the maximum displacement and weight. Titanium materials become the best material for camshaft manufacturing based on analysis.
    Matched MeSH terms: Aluminum
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