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Fulltext Distribution of Recent Ostracoda in offshore sediment of the South China Sea

Ramlan, O., Noraswana, N. F.

Pertanika Journal of Science & Technology, 2014;22(2):433-444.
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
Catalytic fast pyrolysis of durian rind using silica-alumina catalyst: Effects of pyrolysis parameters

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
Fulltext Preliminary study of cosmetic coloured contact lenses chemical elements analysis using energy dispersive X-ray spectroscopy

Syazwan Hafiz Mohd, Wan Elhami Wan Omar, Ai-Hong Chen

Pertanika Journal of Science & Technology, 2017;25(103):73-82.
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
Fulltext Municipal solid waste characteristics in Taman Universiti, Skudai, Johore, Malaysia

Edward Hingha Foday Jr, Nurul As'shikin Ramli, Hairu Nabilah Ismail, Nulhazwany Abdul Malik, Hazlami Fikri Basri, Fatihah Syahirah Abdul Aziz, et al.

Journal of Advanced Research Design, 2017;38(1):13-20.
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
Fulltext Development of adjustable foot corrective device for clubfoot treatment

Shahrol Mohamaddan, Chai Siew Fu, Ahmad Hata Rasit, Siti Zawiah Md Dawal, Keith Case

Pertanika Journal of Science & Technology, 2017;25(105):251-258.
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
Fulltext Effect of Luting Cements On the Bond Strength to Turkom-Cera All-Ceramic Material

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
Radioluminescence sensing of radiology exposures using P-doped silica optical fibres

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
Fulltext Environmental and occupational health impact of bauxite mining in Malaysia: a review

Lee, K.Y., Ho, L.Y., Tan, K.H., Tham, Y.Y., Ling, S.P., Qureshi, A.M., et al.

International Medical Journal Malaysia, 2017;16(2):137-150.
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
Fulltext X-ray diffraction and TGA kinetic analyses for chemical looping combustion applications

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
Fulltext MHD convective heat transfer in a discretely heated square cavity with conductive inner block using two-phase nanofluid model

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
Fulltext Mechanical behaviour and microstructure Aluminium Foam Tube Produce (AFTP) using infiltration method with vacuum-gas

Ismail Lias, Muhammad Hussain Ismail, Iskandar Dzulkernain Md Raffee, Mohd Aman Ihsan Mamat

Pertanika Journal of Science & Technology, 2017;25(103):223-232.
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
Fulltext Sensitivity study of Graphene Nanoribbon with NH3 at room temperature

Guan Ling Sim, Mohd Nizar Hamidon, Kamilu Iman Usman

Pertanika Journal of Science & Technology, 2017;25(102):259-266.
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
Fulltext The influence of visual art therapy on paediatric dental patient: a pilot study

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
Fulltext Determining the Effect of Centrifugal Force on the Desired Growth and Properties of PCPDTBT as p-Type Nanowires

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
Fulltext Preparation of NiAl2O4-Based Flexible Substrates for Metamaterials with Negative Dielectric Properties

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
Fulltext Corrosion behaviour of Al-Si cast alloy reinforced with titanium diboride (TiB2) and scandium (Sc)

Ibrahim, R.E., Talari, M.K., Sabrina, M. Yahaya, Rosmamuhamadani, R., Sulaiman, S., Ismail, M.I.S.

Journal of Engineering and Science Research, 2018;2(2):1-8.
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
Fulltext Influence of alkylphosphonium modified montmorillonite to the tensile properties of PMMA composites

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
Fulltext Stress analysis of engine camshaft from light metal

Sharuddin Mohd Dahuri, Nor Hakimah Ahmad Subri, Norashady Mohd Noor

Journal of Engineering and Science Research, 2018;2(1):37-44.
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
Deoxygenation of pyrolysis vapour derived from durian shell using catalysts prepared from industrial wastes rich in Ca, Fe, Si and Al

Tan YL, Hameed BH, Abdullah AZ

Sci Total Environ, 2020 Feb 10;703:134902.
PMID: 31753498 DOI: 10.1016/j.scitotenv.2019.134902

Catalysts prepared from industrial wastes rich in Fe, Ca, Si, and Al were used in catalytic upgrading of pyrolysis vapour derived from durian shell and their effect on product yield and properties were compared. With same silica-to-alumina ratio, catalyst prepared from oil palm ash (AS-OPA) with lower Fe and Ca contents gave higher liquid yield (8.32 wt%) with alcohols (28.90%), hydrocarbons (46.00%), and nitrogen-containing compounds (21.46%) while catalyst prepared from electric arc furnace slag (AS-EAF) with higher Fe and Ca contents produced lower liquid yield (50.21 wt%) with high amount of esters (25.80%) and hydrocarbons (72.82%). The presence of AS-OPA and AS-EAF catalysts enhanced deoxygenation degree of bio-oil to 81.13% and 85.49%, respectively. The catalytic performance of AS-EAF at different temperatures (400-600 °C) and AS-EAF/durian shell ratios (1:30, 2:30, 3:30) was investigated. Increasing catalytic temperature enhanced production of bio-oil, reduced oxygenates and enhanced formation of esters. The liquid yield and yield of esters decreased with increasing catalyst loading. Hydrocarbons (mainly neopentane) were the major chemical compounds found in bio-oil produced over AS-EAF. Besides that, AS-EAF showed good deoxygenation performance with highest selectivity of hydrocarbons at 500 °C and AS-EAF/durian shell ratio of 2:30. Catalytic fast pyrolysis of durian shell using waste-derived catalysts is an effective waste management strategy as the bio-oil produced can be a potential alternative source of energy or chemical feedstocks.

Matched MeSH terms: Aluminum Oxide
Fulltext Effect of Tilt Angle and Pin Depth on Dissimilar Friction Stir Lap Welded Joints of Aluminum and Steel Alloys

Chitturi V, Pedapati SR, Awang M

Materials (Basel), 2019 Nov 26;12(23).
PMID: 31779107 DOI: 10.3390/ma12233901

Automobile, aerospace, and shipbuilding industries are looking for lightweight materials for cost effective manufacturing which demands the welding of dissimilar alloy materials. In this study, the effect of tool rotational speed, welding speed, tilt angle, and pin depth on the weld joint were investigated. Aluminum 5052 and 304 stainless-steel alloys were joined by friction stir welding in a lap configuration. The design of the experiments was based on Taguchi's orthogonal array for conducting the experiments with four factors and three levels for each factor. The microstructural analysis showed tunnel defects, micro voids, and cracks which formed with 0° and 1.5° tilt angles. The defects were eliminated when the tilt angle increased to 2.5° and a mixed stir zone was formed with intermetallic compounds. The presence of the intermetallic compounds increased with the increase in tilt angle and pin depth which further resulted in obtaining a defect-free weld. Hooks were formed on either side of the weld zone creating a mechanical link for the joint. A Vickers hardness value of HV 635.46 was achieved in the mixed stir zone with 1000 rpm, 20 mm/min, and 4.2 mm pin depth with a tilt angle of 2.5°, which increased by three times compared to the hardness of SS 304 steel. The maximum shear strength achieved with 800 rpm, 40 mm/min, and a 4.3 mm pin depth with a tilt angle of 2.5° was 3.18 kN.

Matched MeSH terms: Aluminum

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