Displaying publications 1 - 20 of 423 in total

Abstract:
Sort:
  1. Mohamad Hidayad Ahmad Kamal, Anati Ali, Sharidan Shafie
    MATEMATIKA, 2019;35(2):260-270.
    MyJurnal
    The three dimensional free convection boundary layer flow near a stagnation point region is embedded in viscous nanofluid with the effect of g-jitter is studied in this paper. Copper (Cu) and aluminium oxide (Al2O3) types of water base nanofluid are cho- sen with the constant Prandtl number, Pr=6.2. Based on Tiwari-Das nanofluid model, the boundary layer equation used is converted into a non-dimensional form by adopting non- dimensional variables and is solved numerically by engaging an implicit finite-difference scheme known as Keller-box method. Behaviors of fluid flow such as skin friction and Nusset number are studied by the controlled parameters including oscillation frequency, amplitude of gravity modulation and nanoparticles volume fraction. The reduced skin friction and Nusset number are presented graphically and discussed for different values of principal curvatures ratio at the nodal point. The numerical results shows that, in- crement occurs in the values of Nusset number with the presence of solid nanoparticles together with the values of the skin friction. It is worth mentioning that for the plane stagnation point there is an absence of reduced skin friction along the y-direction where as for axisymmetric stagnation point, the reduced skin friction for both directions are the same. As nanoparticles volume fraction increased, the skin friction increased as well as the Nusset number. The results, indicated that skin frictions of copper are found higher than aluminium oxide.
    Matched MeSH terms: Aluminum Oxide
  2. Chiroma SM, Mohd Moklas MA, Mat Taib CN, Baharuldin MTH, Amon Z
    Biomed Pharmacother, 2018 Jul;103:1602-1608.
    PMID: 29864948 DOI: 10.1016/j.biopha.2018.04.152
    Cognitive impairments and cholinergic dysfunctions have been well reported in old age disorders including Alzheimer's disease (AD). d-galactose (D-gal) has been reported as a senescence agent while aluminium act as a neurotoxic metal, but little is known about their combined effects at different doses. The aim of this study was to establish an animal model with cognitive impairments by comparing the effects of different doses of co-administrated D-gal and aluminium chloride (AlCl3). In this study male albino wistar rats were administered with D-gal 60 mg/kg.bwt intra peritoneally (I.P) injected and AlCl3 (100, 200, or 300 mg/kg.bwt.) was orally administered once daily for 10 consecutive weeks. Performance of the rats were evaluated through behavioural assessments; Morris water maze (MWM) and open field tests (OFT); histopathological examination was performed on the hippocampus; moreover biochemical measurements of acetylcholinesterase (AChE) and hyperphosphorylated tau protein (p-tau) were examined. The results of this experiment on rats treated with D-gal 60 + AlCl3 200 mg/kg.bwt showed near ideal cognitive impairments. The rats exhibited an obvious memory and learning deficits, marked neuronal loss in hippocampus, showed increase in AChE activities and high expression of p-tau within the tissues of the brain. This study concludes that D-gal 60 + AlCl3 200 mg/kg.bwt as the ideal dose for mimicking AD like cognitive impairments in albino wistar rats. It is also crucial to understand the pathogenesis of this neurodegenerative disease and for drug discovery.
    Matched MeSH terms: Aluminum Compounds/administration & dosage; Aluminum Compounds/toxicity*
  3. Jawad AH, Abdulhameed AS, Reghioua A, Yaseen ZM
    Int J Biol Macromol, 2020 Nov 15;163:756-765.
    PMID: 32634511 DOI: 10.1016/j.ijbiomac.2020.07.014
    In this research, an attempt to develop zwitterion composite adsorbent is conducted by modifying chitosan (CHS) with a covalent cross-linker (epichlorohydrin, ECH) and an aluminosilicate mineral (zeolite, ZL). The zwitterion composite adsorbent of chitosan-epichlorohydrin/zeolite (CHS-ECH/ZL) is performed multifunctional tasks by removing two structurally different cationic (methylene blue dye, MB), and anionic (reactive red 120 dye, RR120) dyes from aqueous solutions. The surface property, crystallinity, morphology, functionality, and charge of the CHS-ECH/ZL are analyzed using BET, XRD, SEM, FTIR, and pHpzc, analyses, respectively. The influence of pertinent parameters namely CHS-ECH/ZL dosage (0.02-0.5 g), solution pH (4-10), temperature (303-323K), initial dye concentration (30-400 mg/L), and contact time (0-600 min) on the MB and RR120 removal are tested. The research findings revealed that the adsorption isotherm at equilibrium well explained in according to the Freundlich isotherm model, and the recorded adsorption capacities of CHS-ECH/ZL are 156.1 and 284.2 mg/g for MB and RR120 respectively at 30 °C. The mechanism of MB and RR120 adsorption onto the CHS-ECH/ZL indicates various types of interactions namely, electrostatic interaction, hydrogen bonding, and Yoshida H-bonding in addition to n-π interaction. Overall, this research introduces CHS-ECH/ZL composite as an eco-friendly zwitterion adsorbent with good applicability towards the two structurally different cationic and anionic dyes from aqueous environment.
    Matched MeSH terms: Aluminum Silicates
  4. Selvaraj M, Assiri MA, Singh H, Appaturi JN, Subrahmanyam C, Ha CS
    Dalton Trans, 2021 Jan 21.
    PMID: 33475664 DOI: 10.1039/d0dt04158k
    The Prins cyclization of styrene (SE) with paraformaldehyde (PFCHO) was conducted with mesoporous ZnAlMCM-41 catalysts for the synthesis of 4-phenyl-1,3-dioxane (4-PDO) using a liquid phase heterogeneous catalytic method. For a comparison study, the Prins cyclization reaction was also conducted over different nanoporous catalysts, e.g. mesoporous solid acid catalysts, AlMCM-41(21) and ZnMCM-41(21), and microporous catalysts, USY, Hβ, HZSM-5, and H-mordenite. The recyclable mesoporous ZnAlMCM-41 catalysts were reused in this reaction to evaluate their catalytic stabilities. Since ZnAlMCM-41(75) has higher catalytic activity than other solid acid catalysts, washed ZnAlMCM-41(75)/W-ZnAlMCM-41(75) was prepared using an efficient chemical treatment method and used with various reaction parameters to find an optimal parameter for the highly selective synthesis of 4-PDO. W-ZnAlMCM-41(75) was also used in the Prins cyclization of olefins with PFCHO and formalin (FN, 37% aqueous solution of formaldehyde (FCHO)) under different reaction conditions to obtain 1,3-dioxanes, which are widely used as solvents or intermediates in organic synthesis. Based on the nature of catalysts used under different reaction conditions, a reasonable plausible reaction mechanism for the Prins cyclization of SE with PFCHO is proposed. Notably, it can be seen from the catalytic results of all catalysts that the W-ZnAlMCM-41(75) catalyst has higher 4-PDO selectivity with exceptional catalytic activity than other microporous and mesoporous catalysts.
    Matched MeSH terms: Aluminum Silicates
  5. Zainul R, Abd Azis N, Md Isa I, Hashim N, Ahmad MS, Saidin MI, et al.
    Sensors (Basel), 2019 Feb 22;19(4).
    PMID: 30813385 DOI: 10.3390/s19040941
    This paper presents the application of zinc/aluminium-layered double hydroxide-quinclorac (Zn/Al-LDH-QC) as a modifier of multiwalled carbon nanotubes (MWCNT) paste electrode for the determination of bisphenol A (BPA). The Zn/Al-LDH-QC/MWCNT morphology was examined by a transmission electron microscope and a scanning electron microscope. Electrochemical impedance spectroscopy was utilized to investigate the electrode interfacial properties. The electrochemical responses of the modified electrode towards BPA were thoroughly evaluated by using square-wave voltammetry technique. The electrode demonstrated three linear plots of BPA concentrations from 3.0 × 10-8⁻7.0 × 10-7 M (R² = 0.9876), 1.0 × 10-6⁻1.0 × 10-5 M (R² = 0.9836) and 3.0 × 10-5⁻3.0 × 10-4 M (R² = 0.9827) with a limit of detection of 4.4 × 10-9 M. The electrode also demonstrated good reproducibility and stability up to one month. The presence of several metal ions and organic did not affect the electrochemical response of BPA. The electrode is also applicable for BPA determination in baby bottle and mineral water samples with a range of recovery between 98.22% and 101.02%.
    Matched MeSH terms: Aluminum
  6. Ahmad Saat, Zaini Hamzah, Zaharidah Abu Bakar
    MyJurnal
    Being an imperative material for man either used as building materials, pottery or as components in material industry and technology, knowledge of clays elemental contents is important. In the present study ten clay samples obtained from various locations in North-West Peninsular Malaysia were used. Majority of the clays were economically manufactured to be used as building materials or pottery. The objective of study was to determine the main elemental contents of the samples, and relate the results to the types of minerals, as well as to compare them with clays from other studies. In the study X-ray Fluorescence (XRF) coupled to samples dilution method and standard calibration samples was used. The elements detected in the study were Si, Al, Fe, Ti, K and Ca. Depending on locations, the percentage concentration ranged between 24.8 – 32.4 for Si, 10.8 – 19.0 for Al, 0.09 – 2.12 for Fe, 0.08 – 1.13 for Ti, 0.45 – 3.39 for K and trace amount of Ca and P. However, Mg that normally found in typical clay was not found in the studied samples. Comparing the oxide of the major elements with other studies, it was found that the clay samples contained mixtures of kaolinite (two-layered structure) and illite (three-layered structure).
    Matched MeSH terms: Aluminum Silicates
  7. 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
  8. 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
  9. Lisuzzo L, Cavallaro G, Pasbakhsh P, Milioto S, Lazzara G
    J Colloid Interface Sci, 2019 Jul 01;547:361-369.
    PMID: 30974251 DOI: 10.1016/j.jcis.2019.04.012
    The filling of halloysite nanotubes with active compounds solubilized in aqueous solvent was investigated theoretically and experimentally. Based on Knudsen thermogravimetric data, we demonstrated the water confinement within the cavity of halloysite. This process is crucial to properly describe the driving mechanism of halloysite loading. In addition, Knudsen thermogravimetric experiments were conducted on kaolinite nanoplates as well as on halloysite nanotubes modified with an anionic surfactant (sodium dodecanoate) in order to explore the influence of both the nanoparticle morphology and the hydrophobic/hydrophilic character of the lumen on the confinement phenomenon. The analysis of the desorption isotherms allowed us to determine the water adsorption properties of the investigated nanoclays. The pore sizes of the nanotubes' lumen was determined by combining the vapor pressure of the confined water with the nanoparticles wettability, which was studied through contact angle measurements. The thermodynamic description of the water confinement inside the lumen was correlated to the influence of the vacuum pumping in the experimental loading of halloysite. Metoprolol tartrate, salicylic acid and malonic acid were selected as anionic guest molecules for the experimental filling of the positively charged halloysite lumen. According to the filling mechanism induced by the water confinement, the vacuum operation and the reduced pressure enhanced the loading of halloysite nanotubes for all the investigated bioactive compounds. This work represents a further and crucial step for the development of halloysite based nanocarriers being that the filling mechanism of the nanotube's cavity from aqueous dispersions was described according to the water confinement process.
    Matched MeSH terms: Aluminum Silicates
  10. Cristancho RJ, Hanafi MM, Omar SR, Rafii MY
    Plant Biol (Stuttg), 2011 Mar;13(2):333-42.
    PMID: 21309980 DOI: 10.1111/j.1438-8677.2010.00378.x
    Aluminium (Al) phytotoxicity is an important soil constraint that limits crop yield. The objectives of this study were to investigate how growth, physiology, nutrient content and organic acid concentration is affected by Al, and to assess the degree of Al tolerance in different oil palm progeny (OPP). Four OPPs ['A' (Angola dura × Angola dura), 'B' (Nigerian dura × Nigerian dura), 'C' (Deli dura × AVROS pisifera) and 'D' (Deli dura × Dumpy AVROS pisifera)] were grown in different Al concentrations (0, 100 and 200 μm) in aerated Hoagland solution, pH 4.4, for 80 days. We observed a severe reduction (57.5%) in shoot dry weight, and root tips were reduced by 46.5% in 200 μm Al. In 'B' and 'C', the majority of macro- and micronutrients in plants were reduced significantly by 200 μm Al, with Mg being lowered by more than 50% in roots and shoots. The 200 μm Al treatment resulted in a 56.50% reduction in total leaf area, a 20% reduction in net photosynthesis and a 17% reduction in SPAD chlorophyll value in the third leaf. Root tips (0-5 mm) showed a significant increase in oxalic acid content with increasing Al concentration (∼ 5.86-fold); progeny 'A' had the highest concentration of oxalic acid. There was a significant interaction between Al concentration × OPP on total leaf number, root volume, lateral root length, Mg and K in root and shoot tissues, and Ca and N in shoots. The OPPs could be ranked in their tolerance to Al as: 'A' > 'D' > 'B' > 'C'.
    Matched MeSH terms: Aluminum/toxicity*
  11. Tehubijuluw H, Subagyo R, Yulita MF, Nugraha RE, Kusumawati Y, Bahruji H, et al.
    PMID: 33712959 DOI: 10.1007/s11356-021-13285-y
    Red mud as industrial waste from bauxite was utilized as a precursor for the synthesis of mesoporous ZSM-5. A high concentration of iron oxide in red mud was successfully removed using alkali fusion treatment. Mesoporous ZSM-5 was synthesized using cetyltrimethylammonium bromide (CTABr) as a template via dual-hydrothermal method, and the effect of crystallization time was investigated towards the formation of mesopores. Characterization using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption-desorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) indicated the formation of cubic crystallite ZSM-5 with high surface area and mesopore volume within 6 h of crystallization. Increasing the crystallization time revealed the evolution of highly crystalline ZSM-5; however, the surface area and mesoporosity were significantly reduced. The effect of mesoporosity was investigated on the adsorption of methylene blue (MB). Kinetic and thermodynamic analysis of MB adsorption on mesoporous ZSM-5 was carried out at a variation of adsorption parameters such as the concentration of MB solution, the temperatures of solution, and the amount of adsorbent. Finally, methanol, 1-butanol, acetone, hydrochloric acid (HCl), and acetonitrile were used as desorbing agents to investigate the reusability and stability of mesoporous ZSM-5 as an adsorbent for MB removal.
    Matched MeSH terms: Aluminum Oxide
  12. Van Rostenberghe H, Ho JJ, Lim CH, Abd Hamid IJ
    Cochrane Database Syst Rev, 2020 07 01;7:CD012011.
    PMID: 32609375 DOI: 10.1002/14651858.CD012011.pub2
    BACKGROUND: Phototherapy is a well-established effective therapy for treating babies with significant neonatal jaundice. Studies have shown that increasing light intensity will increase its efficiency. A potentially inexpensive and easy way of increasing the intensity of light on the body of the infant may be to hang reflective materials from the sides of phototherapy units.

    OBJECTIVES: To assess the effects of reflective materials in combination with phototherapy compared with phototherapy alone for unconjugated hyperbilirubinaemia in neonates.

    SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 11), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and the Cumulative Index of Nursing and Allied Health Literature (CINAHL), on 1 November 2019. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

    SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials if the participants, who were term or preterm infants, received phototherapy with curtains made of reflective materials of any type in the treatment arm, and if those in the comparison arm received similar phototherapy without curtains or other intensified phototherapy, such as a double bank of lights.

    DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. We used the GRADE approach to assess the certainty of evidence.

    MAIN RESULTS: Of 15 studies identified, we included 12 (1288 babies) in the review - 11 comparing phototherapy with reflective materials and phototherapy alone, and one comparing a single phototherapy light bank with reflective materials with double phototherapy. All reflective materials consisted of curtains on three or four sides of the cot and were made of white plastic (five studies), white linen (two studies), or aluminium (three studies); materials were not specified in two studies. Only 11 studies (10 comparing reflective materials versus none and one comparing reflective curtains and a single bank of lights with a double (above and below) phototherapy unit) provided sufficient data to be included in the meta-analysis. Two excluded studies used the reflective materials in a way that did not meet our inclusion criteria, and we excluded one study because it compared four different phototherapy interventions not including reflective materials. The risk of bias of included studies was generally low, but all studies had high risk of performance bias due to lack of blinding of the intervention. Three studies (281 participants) reported a decline in serum bilirubin (SB) (μmol/L) at four to eight hours (mean difference (MD) -14.61, 95% confidence interval (CI) -19.80 to -9.42; I² = 57%; moderate-certainty evidence). Nine studies (893 participants) reported a decline in SB over 24 hours and showed a faster decline in SB in the intervention group, but heterogeneity (I² = 97%) was too substantial to permit a meaningful estimate of the actual effect size (very low-certainty evidence). Subgroup analysis by type of reflective material used did not explain the heterogeneity. Exchange transfusion was reported by two studies; both reported none in either group. Four studies (466 participants) reported the mean duration of phototherapy, and in each of these studies, it was reduced in the intervention group but there was substantial heterogeneity (I² = 88%), precluding meaningful meta-analysis of data. The only two studies that reported the mean duration of hospital stay in hours showed a meaningful reduction (MD -41.08, 95% CI -45.92 to -36.25; I² = 0; moderate-certainty evidence). No studies reported costs of the intervention, parental or medical staff satisfaction, breastfeeding outcomes, or neurodevelopmental follow-up. The only study that compared use of curtains with double phototherapy reported similar results for both groups. Studies that monitored adverse events did not report increased adverse events related to the use of curtains, including acute life-threatening events, but other rarer side effects could not be excluded.

    AUTHORS' CONCLUSIONS: Moderate-certainty evidence shows that the use of reflective curtains during phototherapy may result in greater decline in SB. Very low-certainty evidence suggests that the duration of phototherapy is reduced, and moderate-certainty evidence shows that the duration of hospital stay is also reduced. Available evidence does not show any increase in adverse events, but further studies are needed.

    Matched MeSH terms: Aluminum*
  13. Abd Wahil MS, Ja'afar MH, Md Isa Z
    PeerJ, 2023;11:e15132.
    PMID: 37197586 DOI: 10.7717/peerj.15132
    BACKGROUND: The presence of aluminium (Al) in the human body may impact brain neurodevelopment and function, and it is thought to contribute to autism spectrum disease (ASD). The main objective of this study was to assess the association between urinary Al and the development of ASD among Malaysian preschool children in the urban city of Kuala Lumpur.

    METHOD: This was an unmatched case-control study in which children with ASD were recruited from an autism early intervention center and typically developed (TD) children were recruited from government-run nurseries and preschools. Urine samples were collected at home, assembled temporarily at study locations, and transported to the laboratory within 24 h. The Al concentration in the children's urine samples was determined using inductively coupled plasma mass spectrometry (ICP-MS).

    RESULT: A total of 155 preschool children; 81 ASD children and 74 TD children, aged 3 to 6 years, were enlisted in the study. This study demonstrated that ASD children had significantly higher urinary Al levels than TD children (median (interquartile range (IQR): 2.89 (6.77) µg/dL versus 0.96 (2.95) µg/dL) (p 1, p 

    Matched MeSH terms: Aluminum
  14. Kato M, Azimi MD, Fayaz SH, Shah MD, Hoque MZ, Hamajima N, et al.
    Chemosphere, 2016 Dec;165:27-32.
    PMID: 27619645 DOI: 10.1016/j.chemosphere.2016.08.124
    Toxic elements in drinking water have great effects on human health. However, there is very limited information about toxic elements in drinking water in Afghanistan. In this study, levels of 10 elements (chromium, nickel, copper, arsenic, cadmium, antimony, barium, mercury, lead and uranium) in 227 well drinking water samples in Kabul, Afghanistan were examined for the first time. Chromium (in 0.9% of the 227 samples), arsenic (7.0%) and uranium (19.4%) exceeded the values in WHO health-based guidelines for drinking-water quality. Maximum chromium, arsenic and uranium levels in the water samples were 1.3-, 10.4- and 17.2-fold higher than the values in the guidelines, respectively. We next focused on uranium, which is the most seriously polluted element among the 10 elements. Mean ± SD (138.0 ± 1.4) of the (238)U/(235)U isotopic ratio in the water samples was in the range of previously reported ratios for natural source uranium. We then examined the effect of our originally developed magnesium (Mg)-iron (Fe)-based hydrotalcite-like compounds (MF-HT) on adsorption for uranium. All of the uranium-polluted well water samples from Kabul (mean ± SD = 190.4 ± 113.9 μg/L; n = 11) could be remediated up to 1.2 ± 1.7 μg/L by 1% weight of our MF-HT within 60 s at very low cost (<0.001 cents/day/family) in theory. Thus, we demonstrated not only elevated levels of some toxic elements including natural source uranium but also an effective depurative for uranium in well drinking water from Kabul. Since our depurative is effective for remediation of arsenic as shown in our previous studies, its practical use in Kabul may be encouraged.
    Matched MeSH terms: Aluminum Hydroxide/pharmacology; Aluminum Hydroxide/chemistry*
  15. Sheikholeslami M, Shah Z, Shafee A, Khan I, Tlili I
    Sci Rep, 2019 02 04;9(1):1196.
    PMID: 30718893 DOI: 10.1038/s41598-018-37964-y
    In the present research, aluminum oxide- water (Al2O3-H2O) nanofluid free convection due to magnetic forces through a permeable cubic domain with ellipse shaped obstacle has been reported. Lattice Boltzmann approach is involved to depict the impacts of magnetic, buoyancy forces and permeability on nanoparticles migration. To predict properties of Al2O3- water nanofluid, Brownian motion impact has been involved. Outcomes revels that considering higher magnetic forces results in greater conduction mechanism. Permeability can enhance the temperature gradient.
    Matched MeSH terms: Aluminum Oxide
  16. Maidur SR, Patil PS, Katturi NK, Soma VR, Ai Wong Q, Quah CK
    J Phys Chem B, 2021 Apr 22;125(15):3883-3898.
    PMID: 33830758 DOI: 10.1021/acs.jpcb.1c01243
    The structural, thermal, linear, and femtosecond third-order nonlinear optical (NLO) properties of two pyridine-based anthracene chalcones, (2E)-1-(anthracen-9-yl)-3-(pyridin-2-yl)prop-2-en-1-one (2PANC) and (2E)-1-(anthracen-9-yl)-3-(pyridin-3-yl)prop-2-en-1-one (3PANC), were investigated. These two chalcones were synthesized following the Claisen-Schmidt condensation method. Optically transparent single crystals were achieved using a slow evaporation solution growth technique. The presence of functional groups in these molecules was established by Fourier transform infrared and NMR spectroscopic data. The detailed solid-state structure of both chalcones was determined from the single-crystal X-ray diffraction data. Both crystals crystallized in the centrosymmetric triclinic space group P1̅ with the nuance of unit cell parameters. The crystals (labeled as 2PANC and 3PANC) have been found to be transparent optically [in the entire visible spectral region] and were found to be thermally stable up to 169 and 194 °C, respectively. The intermolecular interactions were investigated using the Hirshfeld surface analysis, and the band structures (highest occupied molecular orbital-lowest unoccupied molecular orbital, excited-state energies, global chemical reactivity descriptors, and molecular electrostatic potentials) were studied using density functional theory (DFT) techniques. The ultrafast third-order NLO properties were investigated using (a) Z-scan and (b) degenerate four-wave mixing (DFWM) techniques using ∼50 fs pulses at 800 nm (1 kHz, ∼4 mJ) from a Ti:sapphire laser amplifier. Two-photon-assisted reverse saturable absorption, self-focusing nonlinear refraction, optical limiting, and optical switching behaviors were witnessed from the Z-scan data. 3PANC demonstrated a stronger two-photon absorption coefficient, while 2PANC depicted a stronger nonlinear refractive index among the two. The time-resolved DFWM data demonstrated that the decay times of 2PANC and 3PANC were ∼162 and ∼180 fs, respectively. The second hyperpolarizability (γ) values determined by DFT, Z-scan, and DFWM were found to be in good correlation (with a magnitude of ∼10-34 esu). The ultrafast third-order NLO response, significant NLO properties, and thermal stability of these chalcones brands them as potential candidates for optical power limiting and switching applications.
    Matched MeSH terms: Aluminum Oxide
  17. Salih, A.M., Wan Md. Zin Wan Yunus, Khairul Zaman Mohd Dahlan, Mohd Hilmi Mahmood, Mansor Ahmad
    MyJurnal
    Synthesis of palm oil based-urethane acrylate (POBUA) resins was carried out by acrylation of epoxidizedpalm oil (EPOP) using acrylic acid in the presence of a catalyst and followed by isocyanation to obtainthe POBUA. Using the monomer as a diluent in the formulation, 4% of photoinitiator and incorporationof organoclay (1-5% wt), nanocomposites were obtained upon UV irradiation. The X-ray DiffractoryXRD study revealed that the nanocomposites obtained were of the exfoliation type. The presence ofthe clay improved the hardness and did not affect the thermal stability. Similarly, it increased the glasstransition temperature Tg but reduced the modulus as the clay content was increased. The improvementof the tensile strength was only obtained when the clay concentration was 5 phr.
    Matched MeSH terms: Aluminum Silicates
  18. Fahmi Fariq Muhammad, Khaulah Sulaiman
    Dihexyl-sexithiophene (DH6T) was doped with tris (8-hydroxyquinolinate) aluminum (Alq3) to prepare blends of DH6T/ Alq3 by dissolving the mixture in the chloroform/hexane co-solvent. Solid films with different thickness deposited on quartz substrates were obtained from the blends via casting process. Optical absorption spectroscopy has been performed to measure the optical band gap of pure and doped DH6T as well as variations in the band gap with dopant concentration (weight %). This variation in optical band gap with dopant concentration was determined quantitatively with fitted and extrapolated techniques and observed qualitatively from the red shift appeared along the optical absorption spectra. The results showed that within a specific dopant content, the optical energy gap, Eg of DH6T decreases from 2.69 eV to 1.8 eV with increasing dopant concentration to 23.1%.
    Matched MeSH terms: Aluminum
  19. Zaleha K, Nasiratul_shahida MN, Siang HY, Kamaruzzaman BY
    Sains Malaysiana, 2016;45:1019-1024.
    Meiobenthos in Bidong Archipelago in coastal water of the South China Sea is hypothesised to have a certain trend of
    distribution particularly in the island ecosystem where it is usually having different type of sea bottom. Nonetheless, since
    it is located in a tropical area, the trend at the sub-tidal could be less obvious due to absent of clear season. Meiobenthic
    sampling was carried out in Karah Island, an island in Bidong Archipelago, from the intertidal, towards the sub-tidal
    zone covering the coral and non-coral area to see the trend in the density and composition. A transparent hand core
    was used to collect benthos samples. Nematoda and harpacticoid copepods dominated the intertidal and sub-tidal zone
    respectively. Harpacticoid copepods were higher in density in the non-coral sediment than the coral area. This could be
    due to the high content of silt and clay in the coral area (2.98% of silt and clay). The 2-dimension MDS analysis on the
    density data indicated the highest degree of scattering and an over-lapping condition for those intertidal and sub-tidal
    samples respectively. ANOSIM result showed that the degree of similarity was lower at the intertidal (70%) than the subtidal
    (reaching 90%) in the first sampling before both became no significant different in the second sampling. It could
    indicate the stable condition in the subtidal than the intertidal ecosystem. The comparatively low density of meiobenthos
    could indicate their response towards the environmental condition in the area which will only be confirmed by long term
    ecological study.
    Matched MeSH terms: Aluminum Silicates
  20. Shuhaimi-Othman M, Mushrifah I, Lim EC, Ahmad A
    Environ Monit Assess, 2008 Aug;143(1-3):345-54.
    PMID: 17987397
    Water from 15 sampling stations in Tasik Chini (Chini Lake), Peninsular Malaysia were sampled for 12 months from September 2004 until August 2005 and analyzed for 11 metals including iron (Fe), aluminum (Al), manganese (Mn), barium (Ba), zinc (Zn), lead (Pb), copper (Cu), cadmium (Cd), nickel (Ni), chromium (Cr) and cobalt (Co). Results showed that the mean (min-max) metal concentrations (in micrograms per liter) in Tasik Chini waters for the 12 months sampling based on 15 sampling stations (in descending order) for Fe, Al, Mn, Ba, Zn, Pb, Cu and Cd were 794.84 (309.33-1609.07), 194.53 (62.37-665.93), 29.16 (16.68-79.85), 22.07 (15.64-29.71), 5.12 (2.224-6.553), 2.36 (1.165-4.240), 0.832 (0.362-1.443) and 0.421 (0.254-0.696) respectively. Concentration for three metals i.e. Ni, Cr and Co were too low and not detected by the graphite furnace Atomic Absorption Spectrophotometry (AAS). Comparison with various water quality standards showed that the mean metals concentration in surface water of Tasik Chini were low and within the range of natural background except for Fe and Al. In general, metal concentrations in Tasik Chini water varied temporally and spatially. The main factors influencing these metal concentrations in the water were the raining season and mining activities. Stations located at Tanjung Jerangking and Melai areas were the most effected due to those factors.
    Matched MeSH terms: Aluminum/analysis
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links