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Fulltext Comparison of the effects of two laser photobiomodulation techniques on bio-physical properties of Zea mays L. seeds

Hasan M, Hanafiah MM, Alhilfy IHH, Aeyad Taha Z

PeerJ, 2021;9:e10614.
PMID: 33520446 DOI: 10.7717/peerj.10614

Background: Laser applications in agriculture have recently gained much interest due to improved plant characteristics following laser treatment before the sowing of seeds. In this study, maize seeds were exposed to different levels of laser treatment prior to sowing to improve their field performance. The aim of this study is to evaluate the impact of pre-sowing laser photobiomodulation on the field emergence and growth of treated maize seeds.
Methods: The maize seeds were first photobiomodulated with two lasers: 1) a helium-neon (He-Ne) red laser (632.8 nm), and 2) a neodymium-doped yttrium aluminum garnet (Nd:YAG) green laser (532 nm). Following three replications of randomized complete block design (RCBD), four irradiation treatments were applied (45 s, 65 s, 85 s, and 105 s) at two power intensities (2 mW/cm2 and 4 mW/cm2).
Results: Based on the results, maize seeds pretreated with a green laser and 2 mW/cm2 power intensity for 105 s exhibited the highest rate of seed emergence (96%) compared to the untreated control seeds with a lower seed emergence rate (62.5%). Furthermore, maize seeds treated with a red laser for 45 s showed an increased vigor index compared to the other treatment options and the control (P

Matched MeSH terms: Aluminum
Fulltext Impacts of gold nanoparticles on MHD mixed convection Poiseuille flow of nanofluid passing through a porous medium in the presence of thermal radiation, thermal diffusion and chemical reaction

Aman S, Khan I, Ismail Z, Salleh MZ

Neural Comput Appl, 2018;30(3):789-797.
PMID: 30100679 DOI: 10.1007/s00521-016-2688-7

Impacts of gold nanoparticles on MHD Poiseuille flow of nanofluid in a porous medium are studied. Mixed convection is induced due to external pressure gradient and buoyancy force. Additional effects of thermal radiation, chemical reaction and thermal diffusion are also considered. Gold nanoparticles of cylindrical shape are considered in kerosene oil taken as conventional base fluid. However, for comparison, four other types of nanoparticles (silver, copper, alumina and magnetite) are also considered. The problem is modeled in terms of partial differential equations with suitable boundary conditions and then computed by perturbation technique. Exact expressions for velocity and temperature are obtained. Graphical results are mapped in order to tackle the physics of the embedded parameters. This study mainly focuses on gold nanoparticles; however, for the sake of comparison, four other types of nanoparticles namely silver, copper, alumina and magnetite are analyzed for the heat transfer rate. The obtained results show that metals have higher rate of heat transfer than metal oxides. Gold nanoparticles have the highest rate of heat transfer followed by alumina and magnetite. Porosity and magnetic field have opposite effects on velocity.

Matched MeSH terms: Aluminum Oxide
Fulltext PREPARATION AND CHARACTERIZATION OF MAGNESIUM/ALUMINIUM LAYERED DOUBLE HYDROXIDE AS FILLER IN LOW-DENSITY POLYETHYLENE COMPOSITE

NUR ATHIRAH ZULKIFLI, MOHD AIDIL ADHHA ABDULLAH, MAZIDAH MAMAT

UMT Journal of Undergraduate Research, 2021;3(1):1-6.
MyJurnal

Polymer had been widely used in industries nowadays. However, the properties of the polymer itself are limited to a particular application. This study describes synthetic clay, layered double hydroxide (LDH), as a filler in low-density polyethylene (LDPE) composite. LDHs of magnesium/aluminium-dodecyl sulfate (Mg/Al-DS) and its grafted with triethoxymethylsilane (TEMS), (TEMS-g-Mg/Al-DS) were synthesized through co-precipitation and salinization reaction methods. The presence of alkyl group, v(C-H) in both LDH had confirmed through Fourier transform infrared (FTIR). The appearance of peaks in FTIR spectra within the absorbance range of 2800 – 2930 cm-1indicates a successful surface modification of LDH, supported by the changes of interlayer spacing and the presence of carbon from X-ray diffractogram and CHNS elemental analysis, respectively. The synthesized LDH was mixed with LDPE via melt intercalation method. The LDH modification resulted in higher interaction and compatibility between the LDPE matrix and LDH by the formation exfoliated type of nanocomposites, as suggested by XRD analysis.

Matched MeSH terms: Aluminum
Fulltext CHARACTERISTIC OF PRASEODYMIUM OXIDE DOPED MANGANESE/RUTHENIUM CATALYST IN METHANATION: EFFECT CALCINATION TEMPERATURE

Salmiah Jamal Mat Rosid, Susilawati Toemen, Wan Azelee Wan Abu Bakar, Sarina Mat Rosid, Wan Nazwanie Wan Abdullah, Siti Maisarah Aziz

Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2021;9(1):49-55.
MyJurnal

Lanthanide element in the methanation reaction gives an excellent catalytic performance at low reaction temperature. Praseodymium is one of lanthanide element and was chosen due to its properties which are thermally stable and provide excess of oxygen in the oxide lattice. Therefore, a catalyst of Ru/Mn/Pr (5:30:65)/Al2O3 (RMP, 5:30:65/Al2O3) was prepared via wetness impregnation method and the effect of calcination temperature on the catalyst performance was investigated using FTIR analysis. The RMP/Al2O3 catalyst calcined at 800 o C was chosen as an excel catalyst with CO2 conversion of 96.9% and CH4 formation of 45.1% at 350 o C reaction temperature. From the EDX mapping, it can be observed that the distribution of all element is homogeneous at 800 o C and 900 o C except Ru, O and Al at 1000 o C calcination temperature. The image from FESEM also shows the presence of some crystal shape on the catalyst surface. From the FTIR analysis, the peak stretching and bending mode of O-H bond decreased when the calcination temperature increased.

Matched MeSH terms: Aluminum Oxide
Fulltext The Effect of Tropical Environment on Fatigue Failure in Royal Malaysian Airforce (RMAF) Aircraft Structure and Operational Readiness

Venugopal A, Mohammad R, Koslan MFS, Sayd Bakar SR, Ali A

Materials (Basel), 2021 May 06;14(9).
PMID: 34066461 DOI: 10.3390/ma14092414

The environmental condition in which the Royal Malaysian Airforce is currently operating its aircraft is prone to corrosion. This is due to the high relative humidity and temperature. With most of its aircraft being in the legacy aircraft era, the aircraft's main construction consists of the aluminium 2024 material. However, this material is prone to corrosion, thus reducing fatigue life and leading to fatigue failure. Using the concept of either Safe Life or Damage Tolerance as its fatigue design philosophy, the RMAF adopts the Aircraft Structure Integrity Program (ASIP) to monitor its structural integrity. With the current problem of not having the structural limitation on corrosion-damaged structure, the RMAF has embarked on its fatigue testing method. Finite Element (FE) studies and flight tests were conducted, and the outcome is summarized. The conclusion is that the longeron tested on the aircraft can withstand the operational load, and its yield strength is below the ultimate yield strength of the material. These research outcomes will also enhance the ASIP for other aircraft platforms in the RMAF fleet for its structure life assessment or service life extension program.

Matched MeSH terms: Aluminum
Preparation, Stability and Thermal Characteristic of Al₂O₃/Bio-Oil Based Nanofluids for Heat Transfer Applications

Umar S, Sulaiman F, Abdullah N, Mohamad SN

J Nanosci Nanotechnol, 2020 12 01;20(12):7569-7576.
PMID: 32711628 DOI: 10.1166/jnn.2020.18616

Conventional thermal fluids with suspended nanoparticles, known as nanofluids, have been developed for heat transfer applications. Heat transfer loss could be reduced significantly if the thermophysical properties of the heat transfer fluid are improved, which to some extent, could reduce the present global environmental challenges associated with energy utilization, such as climate change and global warming. In this work, the role of the concentration of sodium dodecyl-benzene sulfonate (SDBS) in the stability of Al₂O₃/bio-oil nanofluid is investigated the zeta potential value, and its implications to the viscosity and thermal conductivity of the nanofluid are explored. The bio-oil based nanofluid is fixed using a two-step method in which the prepared base fluid is added with 13-nm alumina nanoparticles powder. Various weight fractions of SDBS (0.1, 0.2, 0.4, 0.6, and 1.0 wt%) are used for both 0.1 and 0.2 wt% Al₂O₃ to investigate the significance of the stability of a nanofluid on its thermal conductivity and viscosity. Results indicate that a stable nanofluid has reduced viscosity and increased thermal conductivity.

Matched MeSH terms: Aluminum Oxide
Carbon nanotubes fibres/aluminium-NiZnFe2O4 based electromagnetic transmitter for improved magnitude versus offset (MVO) in a scaled marine environment

Yahya N, Akhtar MN, Nasir N, Shafie A, Jabeli MS, Koziol K

J Nanosci Nanotechnol, 2012 Oct;12(10):8100-9.
PMID: 23421185

In seabed logging the magnitude of electromagnetic (EM) waves for the detection of a hydrocarbon reservoir in the marine environment is very important. Having a strong EM source for exploration target 4000 m below the sea floor is a very challenging task. A new carbon nanotubes (CNT) fibres/aluminium based EM transmitter is developed and NiZn ferrite as magnetic feeders was used in a scaled tank to evaluate the presence of oil. Resistive scaled tank experiments with a scale factor of 2000 were carried out. X-ray Diffraction (XRD), Raman Spectroscopy and Field Emission Scanning Electron Microscope (FESEM) were done to characterize the synthesized magnetic feeders. Single phase Ni0.76Mg0.04Zn0.2Fe2O4, obtained by the sol-gel method and sintered at 700 degrees C in air, has a [311] major peak. FESEM results show nanoparticles with average diameters of 17-45 nm. Samples which have a high Q-factor (approximately 50) was used as magnetic feeders for the EM transmitter. The magnitude of the EM waves of this new EM transmitter increases up to 400%. A curve fitting method using MATLAB software was done to evaluate the performance of the new EM transmitter. The correlation value with CNT fibres/aluminium-NiZnFe2O4 base transmitter shows a 152.5% increase of the magnetic field strength in the presence of oil. Modelling of the scale tank which replicates the marine environment was done using the Finite Element Method (FEM). In conclusion, FEM was able to delineate the presence of oil with greater magnitude of E-field (16.89%) and the B field (4.20%) due to the new EM transmitter.

Matched MeSH terms: Aluminum
Histological evaluation of a novel phosphorylated pullulan-based pulp capping material: An in vivo study on rat molars

Islam R, Toida Y, Chen F, Tanaka T, Inoue S, Kitamura T, et al.

Int Endod J, 2021 Oct;54(10):1902-1914.
PMID: 34096634 DOI: 10.1111/iej.13587

AIM: To evaluate the dental pulp response to a novel mineral trioxide aggregate containing phosphorylated pullulan (MTAPPL) in rats after direct pulp capping.
METHODS: Ninety-six cavities were prepared in the maxillary first molars of 56 male Wistar rats. The dental pulps were intentionally exposed and randomly divided into four groups according to the application of pulp capping materials: MTAPPL; phosphorylated pullulan (PPL); a conventional MTA (Nex-Cem MTA, NCMTA; positive control); and Super-Bond (SB; negative control). All cavities were restored with SB and observed for pulpal responses at 1-, 3-, 7- and 28-day intervals using a histological scoring system. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U-test with Bonferroni's correction, and the level of significance was set at 0.05. DMP1 and CD34 antigen were used to evaluate odontoblast differentiation and pulpal vascularization, respectively.
RESULTS: On day 1, mild inflammatory cells were present in MTAPPL and NCMTA groups; fewer inflammatory cells were present in the PPL, whereas SB was associated with a mild-to-moderate inflammatory response. A significant difference was observed between PPL and SB (p .05). SB exhibited incomplete mineralized tissue barriers, significantly different from NCMTA, MTAPPL and PPL (p

Matched MeSH terms: Aluminum Compounds
Fulltext Specific heats of neat and glycerol plasticized polyvinyl alcohol

Lee, Tin Sin, Wan Aizan Wan Abdul Rahman, Abdul Razak Rahman, Noor Azian Morad, Mohd Shahrul Nizam Salleh

Pertanika Journal of Science & Technology, 2010;18(2):-.
MyJurnal

The specific heats (Csp) of neat polyvinyl alcohol (NPVOH) and 40 phr glycerol plasticized polyvinyl alcohol (PPVOH) were measured using a method known as power compensate differential scanning calorimetry. A high purity sapphire (Al2O3) was used as a reference material. NPVOH has a melting temperature of approximately 480 K, while PPVOH has a value of 30 K lower than NPVOH. The amplitude increment of Csp for NPVOH was also higher than PPVOH at melting stage. Overall, Csp of NPVOH is lower than PPVOH because glycerol has reduced the rigidity of PVOH and subsequently induced the motion of molecular structure at an elevated temperature. Based on the specific heat outcomes, neat PVOH and glycerol plasticized PVOH required 1173.544 J/g and 1946.631 J/g, respectively, to heat from 330 to 550 K.

Matched MeSH terms: Aluminum Oxide
Fulltext Physical, chemical & mineralogical properties of fly ash

Khairul Nizar Ismail, Kamarudin Hussin, Mohd Sobri Idris

Journal of Nuclear and Related Technologies, 2007;2005(1):47-51.
MyJurnal

Fly ash is the finely divided mineral residue resulting from the combustion of coal in electric generating plants. Fly ash consists of inorganic, incombustible matter present in the coal that has been fused during combustion into a glassy, amorphous structure. Fly ash particles are generally spherical in shape and range in size from 2 μm to 10 μm. They consist mostly of silicon dioxide (SiO2), aluminium oxide (Al2O3) and iron oxide (Fe2O3). Fly ash like soil contains trace concentrations of the following heavy metals: nickel, vanadium, cadmium, barium, chromium, copper, molybdenum, zinc and lead. The chemical compositions of the sample have been examined and the fly ash are of ASTM C618 Class F.

Matched MeSH terms: Aluminum Oxide
Fulltext Comparison of antioxidant components and antioxidant capacity in different parts of nutmeg (Myristica fragrans)

Tan, K.P., Khoo, H.E., Azrina, A.

International Food Research Journal, 2013;20(3):1049-1052.
MyJurnal

This study aimed to determine and compare antioxidant components and antioxidant capacity in different parts (skin, pulp, mace and seed) of nutmeg. Freeze dried samples were extracted using 80% methanol, while Folin-Ciocalteu assay was employed to determine total phenolic content, aluminium chloride assay was applied to determine total flavonoid content and ascorbic acid was assessed by titrimetric method. Antioxidant activities were evaluated by ferric reducing antioxidant power and trolox equivalent antioxidant capacity (TEAC) assays. Results revealed that nutmeg seed contained the highest TPC followed by mace, skin and pulp. Similar observation was also found for TFC. The highest ascorbic acid content was found in nutmeg mace, while the lowest was in its pulp. For antioxidant activity, nutmeg seed possessed the highest FRAP and TEAC values, while nutmeg pulp had the lowest as compared to other parts. Phenolic compounds in nutmeg samples have exhibited strong correlation with antioxidant capacity. Therefore, nutmeg is a potential functional food with high antioxidants, especially nutmeg seed. Phenolic compounds in nutmeg samples have exhibited strong correlation with antioxidant capacity. Therefore, nutmeg is a potential functional food with high antioxidants, especially nutmeg seed.

Matched MeSH terms: Aluminum Compounds
Fulltext Comparative study of PGA and INAA for analyses of meteorite samples

Siong, Wee Boon, Ebihara, Mitsuru

Jurnal Sains Nuklear Malaysia, 2011;23(2):74-80.
MyJurnal

Prompt gamma-ray analysis (PGA) and instrumental neutron activation analysis (INAA) are essential for the study of rare samples such as meteorites because of non-destructivity and relatively being free from contaminations. The objective of this research is to utilize PGA and INAA techniques for comparative study and apply them to meteorite analyses. In this study, 11 meteorite samples received from the Meteorite Working Group of NASA were analyzed. The Allende meteorite powder was included as quality control material. Results from PGA and INAA for Allende showed in good agreement with literature values, signifying the reliabilities of these two methods. Elements Al, Ca, Mg, Mn, Na and Ti were determined by both methods and their results are compared. Comparison of PGA and INAA data using linear regression analysis showed correlations coefficients r2 > 0.90 for Al, Ca, Mn and Ti, 0.85 for Mg, and 0.38 for Na. The PGA results for Na using 472 keV were less accurate due to the interference from the broad B peak. Therefore, Na results from INAA method are preferred. For other elements (Al, Ca, Mg, Mn and Ti), PGA and INAA results can be used as cross-reference for consistency. The PGA and INAA techniques have been applied to meteorite samples and results are comparable to literature values compiled from previously analyzed meteorites. In summary, both PGA and INAA methods give reasonably good agreement and are indispensable in the study of meteorites.

Matched MeSH terms: Aluminum
Fulltext Corrosion protection of carbon steel using polyaniline composite with aluminium oxide

Ahmed A. Ahmed Al-Dulaimi, Shahrir Hashim, Mohammed Ilyas Khan

Pertanika Journal of Science & Technology, 2011;19(2):329-337.
MyJurnal

Polyaniline (PANI) and polyaniline composites with aluminium oxide (Al2O3) were prepared using the in situ polymerization method. The composites were then blended with acrylic paint and applied to carbon steel panels. The coated steel panels were evaluated for corrosion using the immersion test technique. The results revealed that the steel panels coated with polyaniline composites and with Al2O3 containing coatings had small corrosion as compared to the bare sample and the samples coated with polyaniline and paint alone. The samples were characterized by Fourier transform infrared (FTIR) and X-ray diffraction(XRD). In addition, the morphology of the finished samples was observed using the scanning electron microscopy (SEM). This novel composite was used as a paint pigment for enhancing the barrier properties and the paint protectable against aggressive ions. Meanwhile, corrosion was evaluated through visual monitoring using a digital camera after 60 days of fully immersion test in 5% NaCl. The weight loss method was also used to evaluate corrosion.

Matched MeSH terms: Aluminum Oxide
Fulltext Alkaline phosphatase activity assessment of two endodontic materials: a preliminary study

Rajan, S., Awang, H., Pooi, A.H., Hassan, H., Devi, S.

Ann Dent, 2008;15(1):5-10.
MyJurnal

Objective: An in vitro assessment of MG-63 human osteosarcoma cells' alkaline phosphatase (ALP) activity when in contact with calcium hydroxide powder (CH), paste (CHP) and grey mineral trioxide aggregate (MTA). Methods: MG-63 cells were seeded to the three selected materials for durations of 0.25, 0.5, 1, 24, 48 and 72 hours. BCIP-NBT assay was used and ALP activity quantified using ELISA reader at 410 nm. Results: The overall analysis for ALP activity indicated significant interaction between test materials and control (maintenance medium). Subsequently, the test materials were paired and analysed for initial (0.25, 0.5, 1 hour) and delayed response (24, 48 and 72 hours). During the initial response, CH exhibited an increased ALP activity compared to MTA. This interaction was not dependant on duration. The delayed response exhibited elevated ALP activity with CHP when compared to MTA and CH. The interaction of CHP was dependant on duration. Conclusion: All three materials exhibited increased ALP activity.

Matched MeSH terms: Aluminum Compounds
Fulltext Preliminary study on metallic coating of steel substrates through hot dip aluminizing by using energy dispersive X-ray spectroscopy (EDX) technique

Hishamuddin Husain, Anasyida Abu Seman, Abdul Razak Daud, Muhamad Daud

Journal of Nuclear and Related Technologies, 2009;2009(2):63-69.
MyJurnal

Even though a lot of new advanced materials have been developed nowadays, steel remains a major material in construction, automobiles, appliances, industrial machinery as well as in the nuclear industry. Due to steel easily corroded, a proper surface protection is required to avoid any failures and extended the life cycle of the components. Surface coating is an efficient and economical method to obtain desirable material surfaces properties. Hot dip aluminizing technique was utilized in this study. Experiments have been conducted on the mild steel substrates with 12mm diameter. Prior to hot dipping process, observation on grain growth at three different temperatures had also been conducted to understand the behaviour of steel under application of heat. The substrates were heated at 700ºC, 800ºC and 900ºC for 1 hour and the microstructure was analyzed. The temperature of 800C was chosen for hot dipping. The substrates were dipped into the molten aluminum maintained at temperature 800ºC for 2,4,6,8,10,15 and 20 minutes. Optical microscopy and energy dispersive X-ray spectroscopy were used in this investigation. From the microstructure observation, it showed the appearance of intermetallic layer covered by the top layer of Al on the mild steel substrate increased with the increase in dipping time ranging from 36 to 282μm. The result of EDX analysis revealed the existence of Fe and Al in form of Fe2Al5 phase for all the dipping time.

Matched MeSH terms: Aluminum
Fulltext The effect of pH on the survival of leptospires in water

Smith CE, Turner LH

Bull World Health Organ, 1961;24(1):35-43.
PMID: 20604084

One of the factors on which the incidence of leptospirosis is dependent is the survival time of shed leptospires in surface water or soil water, and this time is in turn affected by the acidity or alkalinity of the water. The authors have therefore studied the survival of four leptospiral serotypes in buffered distilled water at pH's ranging from 5.3 to 8.0. All survived longer in alkaline than in acid water, and significant differences between the serotypes were found in response to pH. Survival at pH's under 7.0 ranged from 10 to 117 days and at pH's over 7.0 from 21 to 152 days. Survival was also studied in aqueous extracts of soil samples from different areas in Malaya; no correlation was found between pH and survival time.It was also noted that in a group of Malayan ricefields a low incidence of leptospirosis in man was accompanied by a high infection rate among rodents, and when it was found that this phenomenon could not be explained by pH or salinity, attention was turned to the soil. Bentonite clay, similar to the montmorrillonite clay of the ricefields, was found to adsorb about half the leptospires in suspension. The authors recommend that field study of this laboratory observation be undertaken.

Matched MeSH terms: Aluminum Silicates
Fulltext Multivariate statistical analysis of antioxidants in dates (Phoenix dactylifera)

Abbas, F.M.A., Foroogh, B., Liong, M.T., Azhar, M.E.

International Food Research Journal, 2008;15(2):193-200.
MyJurnal

Four types of soft dates (SD), three types of semi-dried dates (SDD) and one type of dried dates (DD) were used in this study. The antioxidant activities were assessed using TEAC method (ABTS assay) and the ferric reducing/antioxidant power method (FRAP assay), while total phenolic content (TPC) and total flavonoid content (TFC) were measured using Folin-Ciocalteau and aluminum chloride colorimetric methods. Multivariate analysis of variance (MANOVA), discriminant analysis (DA) and principal component analysis (PCA) were used to analyze the data. MANOVA showed a strong significant difference between the eight types of dates. DA identified the relative contribution of each parameter in distinguishing the dates. DA also identified two functions responsible for discriminating the dates and showed the difference between different types of dates. The first function distinguished DD from other types of dates, whilst the second function discriminated SD and SDD, affording 100% correct assignation. PCA identified only one component responsible for explaining 98.85% of the total variance in antioxidant data. It is suggested that the TEAC method and the quantitative determination of TPC and TFC was suitable for differentiation of dates and quality control.

Matched MeSH terms: Aluminum Compounds
Fulltext Removal of methyl orange dye by manganese/aluminium-layered double hydroxide

Mamat, M., Abdullah, M.A.A., Jaafar, A.M., Soh, S.K.C., Lee, C.E.

ASM Science Journal, 2018;11(101):105-113.
MyJurnal

As textile production flourishes nowadays, the amount of dyed wastewater entering the
water body has also increased. Dyes could have serious negative impacts to the environment
and also the human health, hence, they need to be removed from the water body. In this
study, layered double hydroxide (LDH) of manganese/aluminium (MnAl) was synthesised
to be used as a potential adsorbent to remove methyl orange (MO) dye due to its unique
lamellar structure which provides LDH with high anion adsorption and exchange ability.
MnAl was synthesized by using co-precipitation method and characterized by powder X-ray
diffraction (PXRD), Fourier-Transform Infrared Spectroscopy (FTIR), Inductively coupled
plasma atomic emission spectroscopy (ICP-AES) and Carbon, Hydrogen, Nitrogen, Sulphur
(CHNS) elemental analysers, and Accelerated Surface Area and Porosity Analyzer (ASAP).
Adsorption studies were conducted at different contact times and dosages of MnAl to evaluate
the performance of MnAl in removing MO from water. Kinetic and isotherm models were
tested using pseudo-first order, pseudo-second order, Langmuir isotherm and Freundlich
isotherm. MnAl LDH was found to be perfectly fitted into pseudo-second order and Langmuir
isotherm.

Matched MeSH terms: Aluminum
Characterization of hydrocarbons in smoke aerosols from burning of three tropical wood species

Tan hs, Mohd Radzi Abas, Norhayati Mohd Tahir

Sains Malaysiana, 2016;45:365-371.

A study has been carried out to characterize hydrocarbons emitted from the burning of three tropical wood species. The woods were burned to ember and smoke aerosols emitted were sampled using high volume sampler fitted with a pre-cleaned glass fibre filters. Hydrocarbons were extracted using ultrasonic agitation with dichloromethane-methanol (3:1 v/v) as solvent and the extracts obtained were then fractionated on silica-alumina column. Detection and quantification of aliphatic and polycyclic aromatic hydrocarbons (PAHs) compounds were carried out using GC-MS. The results indicated that the major aliphatic hydrocarbons characterized were straight chain n-alkanes in the range of C12-C35 with Cmax in the range of C27-C33. Rhizophora apiculata and Hevea brasiliensis wood smoke exhibited a weak odd to even carbon number predominance with carbon preference index (CPI) values greater than one whereas Melaleuca cajuputi wood smoke aerosols did not exhibit similar pattern with CPI obtained close to one. The results obtained also indicated that burning of these wood resulted in formation of PAHs compounds in their smoke aerosols with predominance of three to four rings PAHs over the two, five and lesser of six rings PAHs. PAH diagnostic ratios calculated except for Flan/(Flan+Py) and Indeno/(Indeno+BgP) were consistent with the ratios suggested for wood combustion source as reported in literatures. In the case of the latter, two diagnostic ratios, the values were generally lower than the range normally reported for wood combustion.

Matched MeSH terms: Aluminum Oxide
Engineering geological properties of oil-contaminated granitic and metasedimentary soils

Zulfahmi Ali Rahman, Umar Hamzah, Noorulakma Ahmad

Sains Malaysiana, 2011;40.

Hydrocarbon is a light-non aqueous phase liquid or known as LNAPL. It poses environmental hazard if accidentally spilled out into the soil and water systems as a result of its insoluble nature in water. LNAPL component infiltrates into soil through pore spaces and afloat at the top of groundwater level. Some of this hydrocarbon would trap and clog within the voids, difficult to remove and costly to clean. The occurence of hydrocarbon in the soil definitely degraded the behaviour of soils in terms of engineering properties. This study aimed to investigate the engineering properties of oil-contaminated soil for two different residual soils originally developed from in-situ weathering of granitic and metasedimentary rocks. The physical characterisations of the soil were determined including particle size distribution, specific gravity test and x-ray diffraction (XRD). The engineering parameters for the contaminated and uncontaminated soils were Atterberg limits, compaction and soil shear strength (UU tests). The amounts of hydrocarbon added to soil were varied at 0%, 4%, 8%, 12% and 16% of dried weigth of soil samples. The results from the particle size distribution analysis showed that residual soil from granitic rock comprises of 38% sand, 33% silt and 4% clay while metasedimentary soil consists of 4% sand, 43% silt dan 29% clay. The mean values of specific gravity for the granitic and metasedimentary soils were 2.56 and 2.61, respectively. The types of minerals present in granitic soil sample were quartz, kaolinite and gibbsite while metasedimentary soil consists of quartz and kaolinite. The Atterberg limits value decreased as a result of increasing amount of added hydrocarbon into the soil. A similar behaviouir was observed with the values of maximum dry density and optimum water content with increasing hydrocarbon content. The overall unconsolidated undrained shear strength, Cu showed a decreasing trend with the increase in hydrocarbon content.

Matched MeSH terms: Aluminum Silicates

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