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  1. Fulltext ‘Batu reput’ used as raw material in fertilizer production
    Mohd Nazry Salleh, Farizul Hafiz Kasim, Khairul Nizar Ismail, Che Mohd Ruzaidi Ghazali, Kamarudin Hussin, Saiful Azhar Saad, et al.
    Journal of Nuclear and Related Technologies, 2007;2007(1):71-74.
    MyJurnal
    Batu Reput’ is primary sediment mineral and abundantly found in Perlis. Perlis is one of the major producers of ‘Batu Reput’ in Malaysia that content large deposit of high-purity dolomite [CaMg (CO3)2]. Pure samples of ‘Batu Reput’ recently explored in the Koperasi Rimba Mas Padang Besar Quarry were investigated for their physical, chemical and mineralogical composition. SEM and XRD analysis methods were applied. The potential of ‘Batu Reput’ as a raw material in fertilizer production was investigated in this paper.
    Matched MeSH terms: Magnesium
  2. Fulltext Zamzam water: influence of containers on ionic concentration and in-vitro cytotoxic effects on U87 cell line
    Nasir Mohamad, Shariff Halim, Mohd Ekhwan Toriman, Nor Hidayah Abu Bakar, Ahmad Zubaidi A. Latif
    Malaysian Journal of Applied Sciences, 2018;1(1):68-72.
    MyJurnal
    Zamzam is holy water believed by Muslim to have remedial power for all kinds of diseases. It contains
    many electrolytes and the concentration of the electrolytes may be affected by the types of container
    used for its storage. This study was carried out to determine the difference in ions concentration of
    Zamzam water stored in plastic and glass containers, and to determine cytotoxicity effects of Zamzam
    water against U-87 cell line (human primary glioblastoma cell line). Ion Chromatography (IC) was used
    to analyze the concentration. The analyzed anions in the Zamzam water include bromide, chloride,
    phosphate, nitrite, nitrate, sulfate and fluoride whereas the cations were ammonium, lithium, potassium,
    sodium, calcium and magnesium. Subsequently, MTT assay was used to determine the cytotoxicity of
    Zamzam water on U-87 cell line. This study reveals that Zamzam water anions and cations
    concentration was not statistically significant neither in plastic nor glass container. In addition, the
    Zamzam water did not cause any toxicity on the U87 cell line. We postulate that types of container do
    not have much influence on the ion concentration of Zamzam water and it is non-toxic on U87 cell line.
    Matched MeSH terms: Magnesium
  3. Yield and nutritional composition of oyster mushrooms: an alternative nutritional source for rural people
    Mostak Ahmed, Noorlidah Abdullah, Nuruddin MM
    Sains Malaysiana, 2016;45:1609-1615.
    In recent decades, minimizing the frequency of nutrient deficiency and malnutrition in rural areas of developing
    countries becomes an alarming issue. Oyster mushrooms are rich source of both macro and micro nutrients. The
    objective of this paper was to evaluate the yield of newly introduced oyster mushroom strains viz. Pleurotus sajorcaju
    (PSC), Pleurotus flabellatus (FLB), Pleurotus florida (FLO), Pleurotus ostreatus (PO2
    and PO3
    ), Pleurotus ostreatus
    (HK-51) and Pleurotus geesteranus (PG1
    and PG3
    ) and to justify their nutritional values when grown in the climatic
    condition of Bangladesh. Strain HK-51 produced the highest amount of fresh sporophore (197.80 g). In contrast, the
    highest number of fruiting body was obtained from the strain FLO (82 g) followed by strain PSC (69 g). Strain PG1 has
    recorded the highest biological yield (278 g), productivity (55%) and biological efficiency (96%). Nutrient and mineral
    analysis of sporophore of strain PG1 showed protein (31.80%), lipid (3.6%), potassium (1.3 mg/100 g), phosphorus
    (0.8 mg/100 g), calcium (32 mg/100 g), iron (43 mg/100 g), magnesium (12 mg/100 g), copper (3.5 mcg/100 g), zinc
    (12.5 mcg/100 g) and manganese (2.3 mcg/100 g). This study showed that the strain PG1
    performed well with regard to
    quality and productivity as compared to other strains. Hence, oyster mushroom strain PG1
    is a potential cheap source
    of nutrients and minerals to combat socioeconomic problems including malnutrition, diseases linked to malnutrition,
    poverty reduction and agricultural diversity.
    Matched MeSH terms: Magnesium
  4. Waste bones ash as an alternative source of P for struvite precipitation
    Darwish M, Aris A, Puteh MH, Jusoh MNH, Abdul Kadir A
    J Environ Manage, 2017 Dec 01;203(Pt 2):861-866.
    PMID: 26935149 DOI: 10.1016/j.jenvman.2016.02.033
    Struvite precipitation has been widely applied for the removal of ammonium-nitrogen (NH4-N) from wastewater. Due to the high cost of phosphorus (P) reagents, the current research trend was directed to find alternative sources of P, in order to maintain a sustainable NH4-N removal process. The current study investigated waste bones ashes as alternative sources of P. Different types of bones' ashes were characterized, in which the ash produced from waste fish bones was the highest in P content (17%wt.). The optimization of the factors affecting P extraction from ash by acidic leaching showed that applying 2M H2SO4 and 1.25 kg H2SO4/kg ash achieved the highest P recovery (95%). Thereafter, the recovered P was successfully used in struvite precipitation, which achieved more than 90% NH4-N removal and high purity struvite.
    Matched MeSH terms: Magnesium Compounds
  5. Fulltext Vitamin E improved bone strength and bone minerals in male rats given alcohol
    Zakaria S, Mat-Husain SZ, Ying-Hwey K, Xin-Kai K, Mohd-Badawi A, Abd-Ghani NA, et al.
    Iran J Basic Med Sci, 2017 Dec;20(12):1360-1367.
    PMID: 29238472 DOI: 10.22038/IJBMS.2017.9610
    Objectives: Alcohol consumption induces oxidative stress on bone, which in turn increases the risk of osteoporosis. This study determined the effects of vitamin E on bone strength and bone mineral content in alcohol-induced osteoporotic rats.

    Materials and Methods: Three months old Sprague Dawley male rats were randomly divided into 5 groups: (I) control group; (II) alcohol (3g/kg) + normal saline; (III) alcohol (3g/kg) + olive oil; (IV) alcohol (3g/kg) + alpha-tocopherol (60mg/kg) and (V) alcohol (3g/kg) + palm vitamin E (60mg/kg). The treatment lasted for three months. Following sacrifice, the right tibia was subjected to bone biomechanical test while the lumbar (fourth and fifth lumbar) and left tibia bones were harvested for bone mineral measurement.

    Results: Alcohol caused reduction in bone biomechanical parameters (maximum force, ultimate stress, yield stress and Young's modulus) and bone minerals (bone calcium and magnesium) compared to control group (P<0.05). Palm vitamin E was able to improve bone biomechanical parameters by increasing the maximum force, ultimate stress and Young's modulus (P<0.05) while alpha-tocopherol was not able to. Both alpha-tocopherol and palm vitamin E were able to significantly increase tibia calcium and magnesium content while only alpha-tocopherol caused significant increase in lumbar calcium content (P<0.05).

    Conclusion: Both palm vitamin E and alpha-tocopherol improved bone mineral content which was reduced by alcohol. However, only palm vitamin E was able to improve bone strength in alcohol treated rats.

    Matched MeSH terms: Magnesium
  6. Variation of Ca, Sr, Ba and Mg in the otolith of mudskipper in west coast of Peninsular Malaysia
    Sarimin AS, Ghaffar MA, Mohamed CA
    Pak J Biol Sci, 2009 Feb 01;12(3):231-8.
    PMID: 19579951
    A study on elemental composition in the otolith of giant mudskipper, Periophthalmodon schlosseri, was done from June to October 2003. Specimens were obtained from the mangrove areas of Kuala Selangor, Sepang and Melaka in the west coast of Peninsular Malaysia. A total of 70 sagitta otoliths were analyzed to detect variation of Sr, Ba and Mg, replacing the natural chemical composition of the otolith, which is the calcium carbonate (CaCO3). The average ratio of Sr:Ca was 0.11 x 10(-4), Ba:Ca was 5.7 x 10(-3) and Mg:Ca was 0.2 x 10(-3). Strong correlation (R > 0.8) between fish body size and otolith weight ofmudskipper (p < 0.01) also found during this study.
    Matched MeSH terms: Magnesium/analysis*
  7. Fulltext Utilization of magnesium-rich synthetic gypsum as magnesium fertilizer for oil palm grown on acidic soil
    Ayanda AF, Jusop S, Ishak CF, Othman R
    PLoS One, 2020;15(6):e0234045.
    PMID: 32544208 DOI: 10.1371/journal.pone.0234045
    A study was conducted to determine the impact of applying different sources of Mg, namely kieserite, ground magnesium limestone (GML) and Mg-rich synthetic gypsum (MRSG) on an acid tropical soil, oil palm growth and production. Besides high amount of Mg and Ca, MRSG contains S. Exchangeable Ca in the untreated soil of the plantation was 0.64 cmolc kg-1, but its critical level to sustain oil palm growth was 0.9 cmolc kg-1. MRSG was applied in the plantation as Mg-fertilizer; however, since Ca is also a limiting nutrient, oil palm growth was correlated (r = 0.69) with Ca supplied by the MRSG. Mg needed to sustain oil palm production is normally supplied by kieserite. Its requirement can be met at a lower cost compared to that of the kieserite by using MRSG. Due to MRSG treatment, exchangeable Ca in the soil increased steadily to satisfy the requirement of oil palm for fruit bunches production. From the glasshouse and field study, it was observed that MRSG applied at 1.5 times the recommended rate gave results comparable to that of the kieserite. MRSG treatment resulted in the increase of soil pH to >5 that precipitated Al3+ as inert Al-hydroxides, which eventually enhanced oil palm seedlings growth. Thus, MRSG can also replace GML to increase soil pH and satisfy the Ca and Mg requirement of oil palm. It can be concluded that MRSG has the potential to be used as a source of Mg as well as Ca for oil palm grown on acidic soil.
    Matched MeSH terms: Magnesium/chemistry*
  8. Utilization of greenhouse gases through dry reforming: screening of nickel-based bimetallic catalysts and kinetic studies
    Fan MS, Abdullah AZ, Bhatia S
    ChemSusChem, 2011 Nov 18;4(11):1643-53.
    PMID: 22191096
    A series of bimetallic catalysts containing nickel supported over MgO-ZrO2 were tested for activity in the dry reforming of carbon dioxide. A nickel-cobalt bimetallic catalyst gave the best performance in terms of conversion and coke resistance from a range of Ni-X bimetallic catalysts, X=Ca, K, Ba, La, and Ce. The nitrogen-adsorption and hydrogen-chemisorption studies showed the Ni-Co bimetallic supported catalyst to have good surface area with high metal dispersion. This contributed to the high catalytic activity, in terms of conversion activity and stability of the catalyst, at an equimolar methane/carbon dioxide feed ratio. The kinetics of methane dry reforming are studied in a fixed-bed reactor over an Ni-Co bimetallic catalyst in the temperature range 700-800 °C by varying the partial pressures of CH4 and CO2. The experimental data were analyzed based on the proposed reaction mechanism using the Langmuir-Hinshelwood kinetic model. The activation energies for methane and carbon dioxide consumption were estimated at 52.9 and 48.1 kJ mol(-1), respectively. The lower value of CO2 activation energy compared to the activation energy of CH4 indicated a higher reaction rate of CO2, which owes to the strong basicity of nanocrystalline support, MgO-ZrO2.
    Matched MeSH terms: Magnesium Oxide/chemistry
  9. Uranium in well drinking water of Kabul, Afghanistan and its effective, low-cost depuration using Mg-Fe based hydrotalcite-like compounds
    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: Magnesium/pharmacology; Magnesium/chemistry*; Magnesium Hydroxide/pharmacology; Magnesium Hydroxide/chemistry*
  10. Upgrading producer gas quality from rubber wood gasification in a radio frequency tar thermocatalytic treatment reactor
    Anis S, Zainal ZA
    Bioresour Technol, 2013 Dec;150:328-37.
    PMID: 24185417 DOI: 10.1016/j.biortech.2013.10.010
    This study focused on improving the producer gas quality using radio frequency (RF) tar thermocatalytic treatment reactor. The producer gas containing tar, particles and water was directly passed at a particular flow rate into the RF reactor at various temperatures for catalytic and thermal treatments. Thermal treatment generates higher heating value of 5.76 MJ Nm(-3) at 1200°C. Catalytic treatments using both dolomite and Y-zeolite provide high tar and particles conversion efficiencies of about 97% on average. The result also showed that light poly-aromatic hydrocarbons especially naphthalene and aromatic compounds particularly benzene and toluene were still found even at higher reaction temperatures. Low energy intensive RF tar thermocatalytic treatment was found to be effective for upgrading the producer gas quality to meet the end user requirements and increasing its energy content.
    Matched MeSH terms: Magnesium/chemistry
  11. Understanding the performance and mechanism of Mg-containing oxides as support catalysts in the thermal dry reforming of methane
    Khairudin NF, Sukri MFF, Khavarian M, Mohamed AR
    Beilstein J Nanotechnol, 2018;9:1162-1183.
    PMID: 29719767 DOI: 10.3762/bjnano.9.108
    Dry reforming of methane (DRM) is one of the more promising methods for syngas (synthetic gas) production and co-utilization of methane and carbon dioxide, which are the main greenhouse gases. Magnesium is commonly applied in a Ni-based catalyst in DRM to improve catalyst performance and inhibit carbon deposition. The aim of this review is to gain better insight into recent developments on the use of Mg as a support or promoter for DRM catalysts. Its high basicity and high thermal stability make Mg suitable for introduction into the highly endothermic reaction of DRM. The introduction of Mg as a support or promoter for Ni-based catalysts allows for good metal dispersion on the catalyst surface, which consequently facilitates high catalytic activity and low catalyst deactivation. The mechanism of DRM and carbon formation and reduction are reviewed. This work further explores how different constraints, such as the synthesis method, metal loading, pretreatment, and operating conditions, influence the dry reforming reactions and product yields. In this review, different strategies for enhancing catalytic activity and the effect of metal dispersion on Mg-containing oxide catalysts are highlighted.
    Matched MeSH terms: Magnesium
  12. Fulltext Ultrathin Assembles of Porous Array for Enhanced H2 Evolution
    Islam A, Hwa Teo S, Awual MR, Taufiq-Yap YH
    Sci Rep, 2020 Feb 11;10(1):2324.
    PMID: 32047187 DOI: 10.1038/s41598-020-59325-4
    Since the complexity of photocatalyst synthesis process and high cost of noble cocatalyst leftovers a major hurdle to producing hydrogen (H2) from water, a noble metal-free Ni-Si/MgO photocatalyst was realized for the first time to generate H2 effectively under illumination with visible light. The catalyst was produced by means of simple one-pot solid reaction using self-designed metal reactor. The physiochemical properties of photocatalyst were identified by XRD, FESEM, HRTEM, EDX, UV-visible, XPS, GC and PL. The photocatalytic activities of Ni-Si/MgO photocatalyst at different nickel concentrations were evaluated without adjusting pH, applied voltage, sacrificial agent or electron donor. The ultrathin-nanosheet with hierarchically porous structure of catalyst was found to exhibit higher photocatalytic H2 production than hexagonal nanorods structured catalyst, which suggests that the randomly branched nanosheets are more active surface to increase the light-harvesting efficiency due to its short electron diffusion path. The catalyst exhibited remarkable performance reaching up to 714 µmolh-1 which is higher among the predominant semiconductor catalyst. The results demonstrated that the photocatalytic reaction irradiated under visible light illumination through the production of hydrogen and hydroxyl radicals on metals. The outcome indicates an important step forward one-pot facile approach to prepare noble ultrathin photocatalyst for hydrogen production from water.
    Matched MeSH terms: Magnesium Oxide
  13. Twenty-four-hour urine constituents in stone formers: a study from the northeast part of Peninsular Malaysia
    Hussein NS, Sadiq SM, Kamaliah MD, Norakmal AW, Gohar MN
    Saudi J Kidney Dis Transpl, 2013 May;24(3):630-7.
    PMID: 23640651
    Urolithiasis is a common disease with increasing incidence and prevalence world-wide, probably more common in industrialized countries. The metabolic evaluation of 24-h urine collection has been considered as part of the management of urinary stone patients. The aim of this study was to evaluate the 24-h urine constituents in stone formers and its relation to demographic data in the northeast part of Peninsular Malaysia. One hundred and six patients were recruited in this study from two hospitals in the same geographical region; 96 patients fulfilled the inclusion criteria and an informed consent was obtained from all subjects. The 24-h urine was collected in sterile bottles with a preservative agent and calcium, oxalate, citrate, uric acid, magnesium and phosphate were tested using commercial kits on a Roche Hitachi 912 chemistry analyzer. The age (mean ± SD) of 96 patients was 56.45 ± 13.43 years and 82.3% of the patients were male while 17.7% were female. The 24-h urine abnormalities were hypercalciuria (14.5%), hyperoxaluria (61.4%), hypocitraturia (57.2%), hyperuricouria (19.7%), hypomagnesuria (59.3%) and hyperphosphaturia (12.5%). Hyperoxaluria (61.4%) was the most common abnormality detected during the analysis of 24-h urine constituents in contradiction to industrial countries, where hypercalciuria was the most common finding. The high frequencies of hypomagnesuria and hypocitraturia reflect the important role of magnesium and citrate in stone formation and their prophylactic role in the treatment of urinary stone disease in the given population.
    Matched MeSH terms: Magnesium/urine
  14. Twenty-four hour and spot urine metabolic evaluations: correlations versus agreements
    Hong YH, Dublin N, Razack AH, Mohd MA, Husain R
    Urology, 2010 Jun;75(6):1294-8.
    PMID: 19914693 DOI: 10.1016/j.urology.2009.08.061
    OBJECTIVES: To investigate the correlations and agreements between the solute/creatinine ratios from the 24-hour and early morning spot urine samples for metabolic evaluation in stone-formers given the various pitfalls with the 24-hour urinary metabolic evaluation in stone-formers.
    METHODS: 30 urinary stone-formers out of an initial 62 recruited provided a complete 24-hour urine and early morning spot urine samples for metabolic evaluation. Pearson correlation and Bland and Altman Test were used to assess the correlations and agreements.
    RESULTS: Significant correlations were established between the 24-hour urinary solute excretions and the corresponding early morning spot urine solute/creatinine ratios for calcium, magnesium, urate, potassium, oxalate, citrate, and the Differential Gibb's free energy value of calcium oxalate DG(CaOx) values. However, all these solute/creatinine measurements between the 24-hour and early morning spot urine samples were judged to be not within the acceptable limits based on the estimated "limit of agreement" by the Bland and Altman Test of Agreement. Diurnal circadian rhythm and postprandial excretion surge are thought to be responsible for the disagreements.
    CONCLUSIONS: Thus, the early morning spot urine is not suitable to be used interchangeably to replace the 24-hour urine collection in the evaluation of urinary metabolic abnormalities in stone-formers. A good correlation does not translate to an agreement between the 2 measurements.
    Matched MeSH terms: Magnesium/urine
  15. Fulltext Treatment of river water of Sg. Pusu by using magnesium oxide (MGO) coated with chitosan
    Nik Nur Syafika Pahri, Nur Huda Syazwani Jafri, Husna Ahmad Tajuddin, Yusilawati Ahmad Nor
    Biological and Natural Resources Engineering Journal, 2019;2(1):10-25.
    MyJurnal
    Effective treatment of wastewater is crucial in order to achieve a sustainable development. For instance, highly efficient treatment processes with low capital requirements are the major prerequisite for implementation of the advanced wastewater treatment operations. Among various available treatment methods, the application of coagulation-flocculation process by using natural coagulant; chitosan has vast advantages such as low operating cost, environmental friendly and highly effective in the wastewater treatment operations. The application of nanotechnology in numerous treatment techniques are considered as the most significant advances in water and wastewater treatment practices. The utilization of magnesium oxide (MgO) as nano-adsorbent has recently gained attention as a potential treatment method in water remediation particularly for treating effluents with high amount of organic dyes and heavy metals due to its high treatment efficiency, low cost, versatility and environment compatibility. The purpose of this study was to determine the effectiveness of coagulation-flocculation process when using novel coagulant in which MgO coated with chitosan by investigating the percentage removal of several significant parameters which were turbidity, chemical oxygen demand (COD) and suspended solid. The removal efficiencies were determined throughout a series of experiments carried out using a standard jar test procedure in which three different coagulants; chitosan, MgO coated with chitosan and MgO were tested on water samples taken from Sg. Pusu. In addition, a set of experiments was designed using response surface methodology (RSM) in order to optimize adsorption of chitosan into MgO. The experiments were conducted at various concentrations of chitosan (10-30 mg/ml) and selected MgO dosage ranges (10-30 mg). From the obtained results, it was found that chitosan-MgO coagulant has good removal efficiencies of turbidity, chemical oxygen demand (COD) and suspended solids at 92%, 91%, and 98% respectively from the optimization of adsorption of chitosan-MgO. The MgO coated with chitosan is the best coagulant in this study compared to chitosan and MgO alone because of the ability of treating the river water with up to 90 % removal for all the main parameters. The results showed that coagulation-flocculation is effective as a treatment for treating river water.
    Matched MeSH terms: Magnesium; Magnesium Oxide
  16. Fulltext Transport and retention of engineered Al2O3, TiO2, and SiO2 nanoparticles through various sedimentary rocks
    Bayat AE, Junin R, Shamshirband S, Chong WT
    Sci Rep, 2015;5:14264.
    PMID: 26373598 DOI: 10.1038/srep14264
    Engineered aluminum oxide (Al2O3), titanium dioxide (TiO2), and silicon dioxide (SiO2) nanoparticles (NPs) are utilized in a broad range of applications; causing noticeable quantities of these materials to be released into the environment. Issues of how and where these particles are distributed into the subsurface aquatic environment remain as major challenges for those in environmental engineering. In this study, transport and retention of Al2O3, TiO2, and SiO2 NPs through various saturated porous media were investigated. Vertical columns were packed with quartz-sand, limestone, and dolomite grains. The NPs were introduced as a pulse suspended in aqueous solutions and breakthrough curves in the column outlet were generated using an ultraviolet-visible spectrophotometer. It was found that Al2O3 and TiO2 NPs are easily transported through limestone and dolomite porous media whereas NPs recoveries were achieved two times higher than those found in the quartz-sand. The highest and lowest SiO2-NPs recoveries were also achieved from the quartz-sand and limestone columns, respectively. The experimental results closely replicated the general trends predicted by the filtration and DLVO calculations. Overall, NPs mobility through a porous medium was found to be strongly dependent on NP surface charge, NP suspension stability against deposition, and porous medium surface charge and roughness.
    Matched MeSH terms: Magnesium
  17. TiO₂ nanoparticle transport and retention through saturated limestone porous media under various ionic strength conditions
    Esfandyari Bayat A, Junin R, Derahman MN, Samad AA
    Chemosphere, 2015 Sep;134:7-15.
    PMID: 25889359 DOI: 10.1016/j.chemosphere.2015.03.052
    The impact of ionic strength (from 0.003 to 500mM) and salt type (NaCl vs MgCl2) on transport and retention of titanium dioxide (TiO2) nanoparticles (NPs) in saturated limestone porous media was systematically studied. Vertical columns were packed with limestone grains. The NPs were introduced as a pulse suspended in aqueous solutions and breakthrough curves in the column outlet were generated using an ultraviolent-visible spectrometry. Presence of NaCl and MgCl2 in the suspensions were found to have a significant influence on the electrokinetic properties of the NP aggregates and limestone grains. In NaCl and MgCl2 solutions, the deposition rates of the TiO2-NP aggregates were enhanced with the increase in ionic strength, a trend consistent with traditional Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Furthermore, the NP aggregates retention increased in the porous media with ionic strength. The presence of salts also caused a considerable delay in the NPs breakthrough time. MgCl2 as compared to NaCl was found to be more effective agent for the deposition and retention of TiO2-NPs. The experimental results followed closely the general trends predicted by the filtration and DLVO calculations. Overall, it was found that TiO2-NP mobility in the limestone porous media depends on ionic strength and salt type.
    Matched MeSH terms: Magnesium Chloride/chemistry
  18. Thermoluminescence properties of lithium magnesium borate glasses system doped with dysprosium oxide
    Mhareb MH, Hashim S, Ghoshal SK, Alajerami YS, Saleh MA, Razak NA, et al.
    Luminescence, 2015 Dec;30(8):1330-5.
    PMID: 25828828 DOI: 10.1002/bio.2902
    We report the impact of dysprosium (Dy(3+)) dopant and magnesium oxide (MgO) modifier on the thermoluminescent properties of lithium borate (LB) glass via two procedures. The thermoluminescence (TL) glow curves reveal a single prominent peak at 190 °C for 0.5 mol% of Dy(3+). An increase in MgO contents by 10 mol% enhances the TL intensity by a factor of 1.5 times without causing any shift in the maximum temperature. This enhancement is attributed to the occurrence of extra electron traps created via magnesium and the energy transfer to trivalent Dy(3+) ions. Good linearity in the range of 0.01-4 Gy with a linear correlation coefficient of 0.998, fading as low as 21% over a period of 3 months, excellent reproducibility without oven annealing and tissue equivalent effective atomic numbers ~8.71 are achieved. The trap parameters, including geometric factor (μg), activation energy (E) and frequency factor (s) associated with LMB:Dy are also determined. These favorable TL characteristics of prepared glasses may contribute towards the development of Li2O-MgO-B2O3 radiation dosimeters.
    Matched MeSH terms: Magnesium Compounds/chemistry*
  19. Thermoluminescence properties of Li2CO3-K2CO3-H3BO3glass system co-doped with CuO and MgO
    Alajerami YS, Hashim S, Ramli AT, Saleh MA, Kadni T
    Radiat Prot Dosimetry, 2013 Jun;155(1):1-10.
    PMID: 23193136 DOI: 10.1093/rpd/ncs310
    The thermoluminescent properties of boric glass modified with lithium and potassium carbonates (LKB) and co-doped with CuO and MgO are reported for the first time. Two techniques are applied to investigate the effect of dopants and co-dopants on the thermal stimulation properties of LKB. The induced TL glow curves of a CuO-doped sample are found to be at 220°C with a single peak. An enhancement of about three times is shown with the increment of 0.1 mol % MgO as a co-dopant impurity. This enhancement may contribute to the ability of magnesium to create extra electron traps and consequently the energy transfer to monovalent Cu(+) ions. LKB:Cu,Mg is low Z material (Zeff=8.55), and observed 15 times less sensitive than LiF: Mg, Ti (TLD-100). The proposed dosemeter showed good linearity in TL dose-response, low fading and excellent reproducibility with a simple glow curve, and thus, can be used in the radiation dosimetry.
    Matched MeSH terms: Magnesium Oxide/chemistry*
  20. Thermocatalytic treatment of biomass tar model compounds via radio frequency
    Anis S, Zainal ZA, Bakar MZ
    Bioresour Technol, 2013 May;136:117-25.
    PMID: 23567671 DOI: 10.1016/j.biortech.2013.02.049
    A new effective RF tar thermocatalytic treatment process with low energy intensive has been proposed to remove tar from biomass gasification. Toluene and naphthalene as biomass tar model compounds were removed via both thermal and catalytic treatment over a wide temperature range from 850 °C to 1200 °C and 450 °C to 900 °C, respectively at residence time of 0-0.7 s. Thermal characteristics of the new technique are also described in this paper. This study clearly clarified that toluene was much easier to be removed than naphthalene. Soot was found as the final product of thermal treatment of the tar model and completely removed during catalytic treatment. Radical reactions generated by RF non-thermal effect improve the tar removal. The study showed that Y-zeolite has better catalytic activity compared to dolomite on toluene and naphthalene removal due to its acidic nature and large surface area, even at lower reaction temperature of about 550 °C.
    Matched MeSH terms: Magnesium/chemistry
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