Displaying publications 21 - 40 of 237 in total

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  1. Fulltext Nutritional composition of ready-to-eat cereals in the Malaysian market
    Suraiami, M., Mohd Fairulnizal, M.N., Norhayati, M.K., Zaiton, A., Norliza, A.H., Wan Syuriahti, W.Z., et al.
    Malays J Nutr, 2014;20(3):417-427.
    MyJurnal
    Introduction: This study aimed to determine the nutrient content of cornflakes and muesli, ready-to-eat cereal products available in the Malaysian market. Cornflakes and muesli were chosen due to their popularity as a breakfast meal especially in urban areas. Methods: A total of six brands each for cornflakes and muesli were purchased from supermarkets in the Klang Valley using stratified random sampling. All samples were analysed using AOAC official methods of analysis. The validity of the test data was monitored with the application of internal quality controls in line with the requirements of ISO 17025. Results: Proximate analysis revealed significantly higher mean levels of carbohydrate (86.94 ± 0.59 mg/lOOg), minerals such as iron (8.48±1.72 mg/lOOg) and sodium (674.83±102.99 g/lOOg), B3 as niacinamide (25.87 ± 6.14 g/lOOg) and sucrose (5.10 ± 0.90 mg/lOOg) in cornflakes than in muesli. However, muesli contained significantly more mean moisture (10.23 ± 0.72 mg/lOOg), protein (10.07 ± 0.79 mg/lOOg), total dietary fibre (12.49 ± 1.44 mg/lOOg), magnesium (113.22 ± 7.93 mg/lOOg), zinc (1.65 ± 0.16 mg/lOOg), copper (0.25 ± 0.02 mg/lOOg), total sugar (18.75 ± 2.05 mg/lOOg), glucose (7.70±1.77 mg/lOOg) and fructose (8.68±1.76 mg/lOOg) than cornflakes. Most of the fatty acids analysed were not detected or of low value in both the cereal products. Conclusion: The nutrient analysis of cornflakes and muesli suggests that both ready-to-eat cereals are nutritionally good choice as breakfast for consumers as it provides carbohydrate, minerals, fibre and vitamins. The data provides additional information to the Malaysian Food Composition Database.
    Matched MeSH terms: Minerals
  2. Fulltext The Hippocratic commitment to patients: A declining trend in modern medicine
    Suleiman AB
    International e-Journal of Science, Medicine & Education, 2015;9(1):3-8.
    MyJurnal
    In ancient times, before Hippocrates, disease and illness were attributed as a sign of divine dismay, and the Gods needed to be appeased to achieve a cure. Hippocrates and his followers showed courage in breaking away from this paradigm. They moved away from the divine and supernatural, to focus on the biology of the body. In the process they put the patient at the centre of their focus. They collected detailed case histories, dismissed religious and supernatural explanations and developed remedies in the form of diets, exercise and mixed minerals and herbs based on their understanding of ill health.
    Matched MeSH terms: Minerals
  3. Effect of high-speed parameters on uncoated carbide tool in finish turning titanium Ti-6A1-4V ELI
    Sulaiman M, Cbe Haron C, Ghani J, Kasim M
    Sains Malaysiana, 2014;43:111-116.
    In this work, the Sandvik uncoated carbide insert, CNGG 120408-SGF-H13A was used as a cutting tool in high-speed turning of titanium alloy Ti-6A1-4V EH (extra-low interstitial) with hardness of 32 HRC. Wear is one of the problems that cannot be avoided in machining process. Therefore, the objective of this paper was to investigate tool-wear behavior of various cutting-speed values (high-speed range) on the tool life of the cutting tools, especially in finishing titanium alloy. The experiments were performed under flooded coolant condition using water-based mineral-oil. The cutting speeds employed were 120, 170 and 220 mlmin. The feed rate was constant at 02 mm/rev and the depth of cut was 0.4 mm. Based on the results, the highest cutting speed of 220 m/min caused the highest wear rate. By linking the machine operations and the tool life curves obtained using flank wear data, the wear behavior of uncoated carbide was described.
    Matched MeSH terms: Minerals
  4. Fulltext Calculating in-vivo short-term precision error of dual-energy x-ray absorptiometry in human and animal: a technical report
    Subramaniam S., Mohamad, N.V., Chan, C.Y., Soelaiman, I.N., Chin, K.Y.
    Medicine & Health, 2020;15(1):70-77.
    MyJurnal
    Pengukuran ketumpatan mineral tulang oleh 'Dual-energy X-ray Absorptiometry' (DXA) adalah penting untuk mengenalpasti osteoporosis. Ralat ketepatan DXA adalah ukuran yang penting untuk menentukan perubahan sebenar dalam nilai ketumpatan mineral tulang. Kajian ini bertujuan untuk mengkaji pekali variasi jangka pendek mesin QDR Wi DXA Discovery Hologic. Ketumpatan mineral tulang pinggul dan tulang belakang untuk lima belas sukarelawan (purata umur: 30.67 + 10.41 tahun) dan ketumpatan tulang keseluruhan badan untuk lima belas ekor tikus Sprague-Dawley betina (berusia tiga bulan) diimbas menggunakan mesin HDR Discover QDR Wi DXA. Setiap sukarelawan dan tikus menjalani imbasan sebanyak tiga kali untuk menilai kebolehulangan nilai ketumpatan tulang. Imbasan untuk subjek manusia dilakukan dalam tempoh 1 hingga 12 minggu. Untuk sampel haiwan, imbasan diulang pada hari yang sama selepas posisi semula. Ralat kepersisan dinyatakan sebagai peratusan pekali variasi (%CV). %CV diperolehi untuk tulang belakang lumbar adalah 1.8% dan 1.2% untuk tulang pinggul. %CV untuk keseluruhan BMD tikus adalah 1.4%. %CV jangka pendek yang ditunjukkan untuk kedua-dua manusia dan haiwan dalam kajian ini adalah setanding. Ralat kepersisan DXA mesti dipantau untuk memastikan prestasi yang optimum.
    Matched MeSH terms: Minerals
  5. Fulltext Gypsum-Based Material for Dental Pulp Capping: Effect of Chitosan and BMP-2 on Physical, Mechanical, and Cellular Properties
    Subhi H, Reza F, Husein A, Al Shehadat SA, Nurul AA
    Int J Biomater, 2018;2018:3804293.
    PMID: 30147725 DOI: 10.1155/2018/3804293
    Effective pulp capping material must be biocompatible and have the ability to induce dentin bridge formation as well as having suitable physical and mechanical properties; however, many current materials do not satisfy the clinical requirements. This study aimed to assess the physical and mechanical properties of gypsum-based chitosan material (Gp-CT) and to evaluate its effects on cellular properties of stem cells from human exfoliated deciduous teeth (SHED). The experimental material was prepared with different concentrations of chitosan (CT) with or without BMP-2. Then, setting time, compressive strength, and pH were determined. In addition, cell viability, alkaline phosphatase (ALP) activity, and cell attachment were assessed. The setting time, compressive strength, and pH obtained were 4.1-6.6 min, 2.63-5.83 MPa, and 6.5-5.7, respectively. The cell viability to gypsum (Gp) with different CT concentrations was similar to that of the control on day 1 but statistically different from that of Gp alone on day 3. The ALP activity of SHED was significantly higher (p < 0.05) in CT- and BMP-2-containing materials than those in the control and Dycal at days 3 and 14. The scanning electron microscopy (SEM) image revealed that flattened cells were distributed across and adhered to the material surface. In conclusion, Gp-CT material shows promise as a potential material for direct pulp capping.
    Matched MeSH terms: Minerals
  6. Impacts of forestry planting on primary production in upland lakes from north-west Ireland
    Stevenson MA, McGowan S, Anderson NJ, Foy RH, Leavitt PR, McElarney YR, et al.
    Glob Chang Biol, 2016 Apr;22(4):1490-504.
    PMID: 26666434 DOI: 10.1111/gcb.13194
    Planted forests are increasing in many upland regions worldwide, but knowledge about their potential effects on algal communities of catchment lakes is relatively unknown. Here, the effects of afforestation were investigated using palaeolimnology at six upland lake sites in the north-west of Ireland subject to different extents of forest plantation cover (4-64% of catchment area). (210) Pb-dated sediment cores were analysed for carotenoid pigments from algae, stable isotopes of bulk carbon (δ(13) C) and nitrogen (δ(15) N), and C/N ratios. In lakes with >50% of their catchment area covered by plantations, there were two- to sixfold increases in pigments from cryptophytes (alloxanthin) and significant but lower increases (39-116%) in those from colonial cyanobacteria (canthaxanthin), but no response from biomarkers of total algal abundance (β-carotene). In contrast, lakes in catchments with <20% afforestation exhibited no consistent response to forestry practices, although all lakes exhibited fluctuations in pigments and geochemical variables due to peat cutting and upland grazing prior to forest plantation. Taken together, patterns suggest that increases in cyanobacteria and cryptophyte abundance reflect a combination of mineral and nutrient enrichment associated with forest fertilization and organic matter influx which may have facilitated growth of mixotrophic taxa. This study demonstrates that planted forests can alter the abundance and community structure of algae in upland humic lakes of Ireland and Northern Ireland, despite long histories of prior catchment disturbance.
    Matched MeSH terms: Minerals
  7. Physicochemical Properties, Minerals, Trace Elements, and Heavy Metals in Honey of Different Origins: A Comprehensive Review
    Solayman M, Islam MA, Paul S, Ali Y, Khalil MI, Alam N, et al.
    Compr Rev Food Sci Food Saf, 2016 Jan;15(1):219-233.
    PMID: 33371579 DOI: 10.1111/1541-4337.12182
    Honey is a popular natural food product with a very complex composition mainly consisting of both organic and inorganic constituents. The composition of honey is strongly influenced by both natural and anthropogenic factors, which vary based on its botanical and geographical origins. Although minerals and heavy metals are minor constituents of honey, they play vital role in determining its quality. There are several different analytical methods used to determine the chemical elements in honey. These methods are typically based on spectroscopy or spectrometry techniques (including atomic absorption spectrometry, atomic emission spectrometry, inductively coupled plasma mass spectrometry, and inductively coupled plasma optical emission spectrometry). This review compiles available scientific information on minerals and heavy metals in honey reported from all over the world. To date, 54 chemical elements in various types of honey have been identified and can be divided into 3 groups: major or macroelements (Na, K, Ca, Mg, P, S, Cl), minor or trace elements (Al, Cu, Pb, Zn, Mn, Cd, Tl, Co, Ni, Rb, Ba, Be, Bi, U, V, Fe, Pt, Pd, Te, Hf, Mo, Sn, Sb, La, I, Sm, Tb, Dy, Sd, Th, Pr, Nd, Tm, Yb, Lu, Gd, Ho, Er, Ce, Cr, As, B, Br, Cd, Hg, Se, Sr), and heavy metals (trace elements that have a specific gravity at least 5 times higher than that of water and inorganic sources). Chemical elements in honey samples throughout the world vary in terms of concentrations and are also influenced by environmental pollution.
    Matched MeSH terms: Minerals
  8. Macro-nutrients recovery from liquid waste as a sustainable resource for production of recovered mineral fertilizer: Uncovering alternative options to sustain global food security cost-effectively
    Sniatala B, Kurniawan TA, Sobotka D, Makinia J, Othman MHD
    Sci Total Environ, 2023 Jan 15;856(Pt 2):159283.
    PMID: 36208738 DOI: 10.1016/j.scitotenv.2022.159283
    Global food security, which has emerged as one of the sustainability challenges, impacts every country. As food cannot be generated without involving nutrients, research has intensified recently to recover unused nutrients from waste streams. As a finite resource, phosphorus (P) is largely wasted. This work critically reviews the technical applicability of various water technologies to recover macro-nutrients such as P, N, and K from wastewater. Struvite precipitation, adsorption, ion exchange, and membrane filtration are applied for nutrient recovery. Technological strengths and drawbacks in their applications are evaluated and compared. Their operational conditions such as pH, dose required, initial nutrient concentration, and treatment performance are presented. Cost-effectiveness of the technologies for P or N recovery is also elaborated. It is evident from a literature survey of 310 published studies (1985-2022) that no single technique can effectively and universally recover target macro-nutrients from liquid waste. Struvite precipitation is commonly used to recover over 95 % of P from sludge digestate with its concentration ranging from 200 to 4000 mg/L. The recovered precipitate can be reused as a fertilizer due to its high content of P and N. Phosphate removal of higher than 80 % can be achieved by struvite precipitation when the molar ratio of Mg2+/PO43- ranges between 1.1 and 1.3. The applications of artificial intelligence (AI) to collect data on critical parameters control optimization, improve treatment effectiveness, and facilitate water utilities to upscale water treatment plants. Such infrastructure in the plants could enable the recovered materials to be reused to sustain food security. As nutrient recovery is crucial in wastewater treatment, water treatment plant operators need to consider (1) the costs of nutrient recovery techniques; (2) their applicability; (3) their benefits and implications. It is essential to note that the treatment cost of P and/or N-laden wastewater depends on the process applied and local conditions.
    Matched MeSH terms: Minerals
  9. Fulltext Evaluation of calcium and phosphorus content in virgin coconut oil, coconut milk and coconut water using icpms- assessment of remineralization potential for tooth enamel
    Siti Fatimah Rahamat, Zurainie Abllah, Wan Nor Hayati Wan Abd Manan, Anil Azura Jalaludin, Intan Azura Shahdan
    International Medical Journal Malaysia, 2017;16(21):23-23.
    MyJurnal
    Dental decays happened due to demineralization of dental minerals because of oral
    acidic environment. The minerals that usually dissolved out from the enamel are calcium (Ca) and
    phosphorus (P). To ensure more Ca and P absorbed via remineralization, high Ca and P content in
    daily diet supply are required. In Malaysia, virgin coconut oil (VCO), coconut milk (CM) and coconut
    water (CW) are a few of many major diet component of daily diet. The aim for this study is to
    evaluate the Ca and P content of VCO, CM and CW. (Copied from article).
    Matched MeSH terms: Minerals
  10. Fulltext Geochemical and organic petrographic characteristics of high bituminous shales from Gurha mine in Rajasthan, NW India
    Singh AK, Hakimi MH, Kumar A, Ahmed A, Abidin NSZ, Kinawy M, et al.
    Sci Rep, 2020 12 17;10(1):22108.
    PMID: 33335176 DOI: 10.1038/s41598-020-78906-x
    A high bituminous shale horizon from the Gurha mine in the Bikaner sub-basin of the Rajasthan District, NW India, was studied using a collection of geochemical and petrological techniques. This study investigated the nature and environmental conditions of the organic matter and its relation to the unconventional oil-shale resources of the bituminous shale. The analyzed shales have high total organic carbon and total sulfur contents, suggesting that these shale sediments were deposited in a paralic environment under reducing conditions. The dominant presence of organic matter derived from phytoplankton algae suggests warm climatic marine environment, with little connection to freshwater enhancing the growth of algae and other microorganisms. The analyzed bituminous shales have high aquatic-derived alginite organic matters, with low Pr/Ph, Pr/n-C17, and Ph/n-C18 ratios. It is classified as Type II oil-prone kerogen, consistent with high hydrogen index value. Considering the maturity indicators of geochemical Tmax (
    Matched MeSH terms: Minerals
  11. Fulltext Does cooking affect the phytate content in local soy based dishes?
    Shimi, G., Hasnah, H.
    International Food Research Journal, 2013;20(5):2873-2880.
    MyJurnal
    This study aimed to determine the effect of cooking on phytate content and the inhibitory effects of phytate on the bioavailability of minerals in eight Malaysian soy based dishes. Phytate was analyzed by using anion-exchange chromatography while minerals were analyzed by using Atomic Absorption Spectrophotometer. Molar ratios were obtained by dividing the mole of phytate to minerals. Phytate content was reduced in cooked dishes compared to the raw ones but it was not significantly different (P > 0.05). Raw, cooked and whole dish soy products contained 257.14-900.00, 182.14-803.57 and 289.29-910.71 mg/100 g phytate, respectively. Boiling and steaming have reduced most phytate content in the food samples. Molar ratios for phytate/minerals in these samples (phytate/Ca >0.17; phytate/Fe >1) indicated that phytate content inhibited the absorption of calcium and iron. However, the ratio for Ca × phytate/Zn in all samples was less than 200 which showed that phytate did not affect the bioavailability of zinc.
    Matched MeSH terms: Minerals
  12. Fulltext Identification of the hydrogeochemical processes in groundwater using classic integrated geochemical methods and geostatistical techniques, in Amol-Babol Plain, Iran
    Sheikhy Narany T, Ramli MF, Aris AZ, Sulaiman WN, Juahir H, Fakharian K
    ScientificWorldJournal, 2014;2014:419058.
    PMID: 24523640 DOI: 10.1155/2014/419058
    Hydrogeochemical investigations had been carried out at the Amol-Babol Plain in the north of Iran. Geochemical processes and factors controlling the groundwater chemistry are identified based on the combination of classic geochemical methods with geographic information system (GIS) and geostatistical techniques. The results of the ionic ratios and Gibbs plots show that water rock interaction mechanisms, followed by cation exchange, and dissolution of carbonate and silicate minerals have influenced the groundwater chemistry in the study area. The hydrogeochemical characteristics of groundwater show a shift from low mineralized Ca-HCO3, Ca-Na-HCO3, and Ca-Cl water types to high mineralized Na-Cl water type. Three classes, namely, C1, C2, and C3, have been classified using cluster analysis. The spatial distribution maps of Na(+)/Cl(-), Mg(2+)/Ca(2+), and Cl(-)/HCO3 (-) ratios and electrical conductivity values indicate that the carbonate and weathering of silicate minerals played a significant role in the groundwater chemistry on the southern and western sides of the plain. However, salinization process had increased due to the influence of the evaporation-precipitation process towards the north-eastern side of the study area.
    Matched MeSH terms: Minerals/analysis; Minerals/chemistry
  13. Foliar Boron spray for improved yield, oil quality and water use efficiency in water stressed sunflower
    Shehzad MA, Maqsood M, Abbas T, Ahmad N
    Sains Malaysiana, 2016;45:1497-1507.
    Boron (B) is a mineral considered essential for improving sunflower (Helianthus annuus L.) resistance to drought. B supplements (0, 15-, 30- and 45 mg L-1) under well-watered and variable water deficit levels (64 and 53 mm irrigation depths) were evaluated for their effects on growth, oil quality and water use efficiency (WUE) in a field study for two consecutive years (i.e. 2011 and 2012). The duration of 50% inflorescence emergence, 50% flowering and 50% maturity stages were reduced with increasing moisture stress. All B application rates improved sunflower growth compared to no B control treatment. The moisture deficit treatments of 64 and 53 mm irrigation depths significantly (p<0.05) reduced the yield-related components. Achenes/head, achenes weight and achene yield under water stress conditions were considerably improved by foliar application of B at 30 mg L-1. An increase in protein contents and a decrease in oil contents were observed with B foliar application under moisture deficit treatments. Foliar application of B (30 mg L-1) on water stressed plants also resulted in increased WUE. The highest net benefits were achieved with B concentration of 30 mg L-1 under well-watered and mild deficit water level of 64 mm irrigation depth. The highest application rate of B (45 mg L-1) gave the best results at the most severe water deficit level. In conclusion, the B rates of 30 and 41 mg L-1 performed best for improving drought tolerance in terms of higher sunflower productivity under mild and higher water deficit conditions
    Matched MeSH terms: Minerals
  14. Fulltext Landslide factors and susceptibility mapping on natural and artificial slopes in Kundasang, Sabah
    Sharir K, Roslee R, Lee KE, Simon N
    Sains Malaysiana, 2017;46:1521-1540.
    This study was carried out on the hilly topographic area in Kundasang, Sabah. This area is known to be extremely prone to landslides that occurred either naturally or by human interference to natural slopes. Aerial photographs interpretation was conducted in order to identify landslide distributions across three assessment years (2012, 2009 and 1984). These datasets were classified into two landslides groups based on their occurrences; natural and artificial. A total of 362 naturally occurring landslides were identified and another 133 are artificial slope landslides. Physical parameters which include lithology, slope angle, slope aspect and soil series were analyzed with each landslide group to examine the different influence of these parameters on each of the group. From the analysis, the landslide density for the natural landslide group shows that more than 35° slope angle and slope aspect facing east and southwest are prone to landslides. In terms of geological materials, high landslide density is recorded in the phyllite, shale, siltstone and sandstone lithologies group and the Pinosuk, Kepayan and Trusmadi soil series. In contrast, for the artificial
    slope landslide, high landslide density is observed in the 25°-35° slope angle and similar density in every slope aspect classes. The geological materials however have similar landslide density across their factors’ classes. The landslide density technique was also used to generate the landslide susceptibility maps for both landslide conditions. Validation of the maps shows acceptable accuracy of 71% and 74%, respectively, for both natural and artificial slope landslide susceptibility maps and this shows that these maps can be used for future land use planning.
    Matched MeSH terms: Minerals
  15. Nutritional values of Baccaurea pubera and comparative evaluation of SHS treatment on its antioxidant properties
    Shaharuddin S, Husen R, Othman A
    J Food Sci Technol, 2021 Jun;58(6):2360-2367.
    PMID: 33967332 DOI: 10.1007/s13197-020-04748-0
    Baccaurea pubera is a blood red coloured fruit found exclusively in Borneo. This study was conducted to evaluate the effect of superheated steam treatment on its antioxidant properties and mineral content as well as to determine nutritional values of the fruit. The fruits were treated with superheated steam at 170 °C for 15 min prior to extraction and freeze drying. The results showed that, in comparison to the control, superheated steam treatment enhanced the total phenolic content by 147.8% (287.16 mg GAE/100 g vs. 115.87 mg GAE/100 g) and DPPH radical scavenging activity by 23.7% (66.94% vs. 54.13%). However, there were reductions, as compared to the control treatments, in total flavonoid content by 16.5% (8.29 mg QE/100 g vs. 9.93 mg QE/100 g), lycopene content by 28.6% (0.020 μg/100 g vs. 0.028 μg/100 g) and ferric reducing antioxidant power by 22.2% (844.41 mg TE/100 g vs. 1085.15 mg TE/100 g). The superheated steam treatment was also observed to reduce the mineral content of the fruit, from as little as 3.6% to as high as 52% depending upon the specific mineral.
    Matched MeSH terms: Minerals
  16. Fulltext Sodium content in sauces-a major contributor of sodium intake in Malaysia: a cross-sectional survey
    Shahar S, You YX, Zainuddin NS, Michael V, Ambak R, Haron H, et al.
    BMJ Open, 2019 05 27;9(5):e025068.
    PMID: 31133578 DOI: 10.1136/bmjopen-2018-025068
    OBJECTIVE: To investigate the sodium content in sauces sold in Malaysian supermarkets.

    METHODS: A cross-sectional market survey was conducted in 2017 of 233 sauces sold in Malaysian supermarkets. Information on the sodium content was collected from the product packaging and nutrient information panels of the sauces sold in the seven top supermarkets in the capital of Malaysia.

    RESULTS: Of the 233 sauces surveyed, 116 did not include sodium content information on the nutrient information panel (49.8%). Soy sauce (particularly sweet soy sauce) and ketchup (particularly chilli sauce) were found to be the highest number of products surveyed in the analysis (N=54 and N=48, respectively). The highest sodium content information was displayed by fish/prawn sauce (budu/cencalok) (5192±3228 mg/100 g) which was followed by the light/thin soy sauce (5116±2084 mg/100 g), and followed by salty soy sauce (4780±988 mg/100 g). The sodium content information of the imported sauces was higher compared with local products produced in Malaysia. However, for sweet soy sauce, the sodium content information of the local products was higher compared with the imported products. Of the 116 sauces which displayed information regarding their sodium content, only 18.2% of the salty soy sauce and 25% of the light/thin soy sauce were found to be below the 2017 Malaysian sodium guidelines. Furthermore, only 21.7% of chilli ketchup and no tomato ketchup were below the 2017 UK salt guidelines.

    CONCLUSIONS: Almost half of the sauces surveyed did not include sodium content information on the nutrient information panel. It is recommended that sodium content information is provided on all sauces sold in Malaysia. Also, manufacturers should be urged to reduce the sodium content level of their sauces to a minimum of 5%.

    Matched MeSH terms: Minerals
  17. Fulltext Pore Structure Changes Occur During CO2 Injection into Carbonate Reservoirs
    Seyyedi M, Mahmud HKB, Verrall M, Giwelli A, Esteban L, Ghasemiziarani M, et al.
    Sci Rep, 2020 Feb 27;10(1):3624.
    PMID: 32107400 DOI: 10.1038/s41598-020-60247-4
    Observations and modeling studies have shown that during CO2 injection into underground carbonate reservoirs, the dissolution of CO2 into formation water forms acidic brine, leading to fluid-rock interactions that can significantly impact the hydraulic properties of the host formation. However, the impacts of these interactions on the pore structure and macroscopic flow properties of host rock are poorly characterized both for the near-wellbore region and deeper into the reservoir. Little attention has been given to the influence of pressure drop from the near-wellbore region to reservoir body on disturbing the ionic equilibrium in the CO2-saturated brine and consequent mineral precipitation. In this paper, we present the results of a novel experimental procedure designed to address these issues in carbonate reservoirs. We injected CO2-saturated brine into a composite core made of two matching grainstone carbonate core plugs with a tight disk placed between them to create a pressure profile of around 250 psi resembling that prevailing in reservoirs during CO2 injection. We investigated the impacts of fluid-rock interactions at pore and continuum scale using medical X-ray CT, nuclear magnetic resonance, and scanning electron microscopy. We found that strong calcite dissolution occurs near to the injection point, which leads to an increase in primary intergranular porosity and permeability of the near injection region, and ultimately to wormhole  formation. The strong heterogeneous dissolution of calcite grains leads to the formation of intra-granular micro-pores. At later stages of the dissolution, the internal regions of ooids become accessible to the carbonated brine, leading to the formation of moldic porosity. At distances far from the injection point, we observed minimal or no change in pore structure, pore roughness, pore populations, and rock hydraulic properties. The pressure drop of 250 psi slightly disturbed the chemical equilibrium of the system, which led to minor precipitation of sub-micron sized calcite crystals but due to the large pore throats of the rock, these deposits had no measurable impact on rock permeability. The trial illustrates that the new procedure is valuable for investigating fluid-rock interactions by reproducing the geochemical consequences of relatively steep pore pressure gradients during CO2 injection.
    Matched MeSH terms: Minerals
  18. Efficacy of guided bone regeneration using composite bone graft and resorbable collagen membrane in Seibert's Class I ridge defects: radiological evaluation
    Saravanan P, Ramakrishnan T, Ambalavanan N, Emmadi P, John TL
    J Oral Implantol, 2013 Aug;39(4):455-62.
    PMID: 23964779 DOI: 10.1563/AAID-JOI-D-10-00211
    The purpose of the study was to evaluate radiologically the efficacy of guided bone regeneration using composite bone graft (autogenous bone graft and anorganic bovine bone graft [Bio-Oss]) along with resorbable collagen membrane (BioMend Extend) in the augmentation of Seibert's class I ridge defects in maxilla. Bone width was evaluated using computerized tomography at day 0 and at day 180 at 2 mm, 4 mm, and 6 mm from the crest. There was a statistically significant increase in bone width between day 0 and day 180 at 2 mm, 4 mm, and 6 mm from the crest. The results of the study demonstrated an increase in bone width of Seibert's class I ridge defects in the maxilla of the study patients.
    Matched MeSH terms: Minerals
  19. Fulltext Radiological hazard associated with amang processing industry in Peninsular Malaysia and its environmental impacts
    Sanusi MSM, Ramli AT, Hashim S, Lee MH
    Ecotoxicol Environ Saf, 2021 Jan 15;208:111727.
    PMID: 33396058 DOI: 10.1016/j.ecoenv.2020.111727
    Continuous depletion in tin productions has led to a newly emerging industry that is a tin by-product (amang) processing industry to harness mega tons of tin by-products produced in the past. Amang composed of profitable multi-heavy minerals and rare-earth elements. With poorly established safety and health practices in operating plant, amang poses extremely high radioactivity problem associated with high occupational ionizing radiation exposures to workers and continuously impacting the local environment with radioactive contamination from industrial effluent and solid waste into lithosphere and water bodies. The radioactivity level of 238U and 232Th series in the mineral varies from few hundreds up to ~200,000 and ~400,000 Bq kg-1 respectively and are potential to yield more than ~ 30,000 nGy h-1 of gamma (γ) radiation exposure to plant workers. The study found out that for 8 h of work time, a worker is estimated to receive an average effective dose of 0.1 mSv per day from external γ radiation source with a maximum up to 2 mSv per day for extreme exposure situation. Interferences of different exposure routes for examples inhalation of equivalent equilibrium concentration (ECC) of 222Rn and 220Rn progenies and airborne long-lived α particles from the dusty working environment could pose a higher total effective dose as much as 5 mSv per day and 115 mSv per year. The value is 5 times higher than the annual dose limit for designated radiation worker (20 mSv) in Peninsular Malaysia. The study found that 41% of the total received an effective dose received by a worker is contributed by 222Rn, 32% of airborne particulates and dust, 23% from external γ exposure and 4% from 220Rn. Based on radioecological risk assessment, the study found out that the aquatic environment is the highly exposed group to ionizing radiation from industrial effluent discharge and sand residues. With the impotent establishment of radiation protection in the industry, plus the country newly introduced long-term plan to revive tin mining as well as its accessory amang mineral, it is necessary for the government to harmonize current regulation to improve the worker safety and health as well as sustaining local environment.
    Matched MeSH terms: Minerals
  20. Fulltext Major elements and heavy metal composition of soils surrounding limestone hills in Perlis. [Komposisi unsur-unsur utama dan logam berat dalam tanih di sekitar bukit batu kapur di Perlis]
    Sahibin Abd. Rahim, Zulfahmi Ali Rahman, Muhd Barzani G, Wan Mohd Razi Idris, Mohamad Md. Tan
    Sains Malaysiana, 2008;37(4):341-350.
    Sixteen topsoil samples from Bukit Jernih, Gua Kelam and Bukit Merah were analysed for their major elements and heavy metal composition, together with several physico-chemical parameters. Major elements determined were SiO2, TiO2, Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O, P2O5, whereas heavy metals determined were As, Co, Cu, Cr, Ni, Pb and Zn. Physico-chemical parameters determined were percentage of organic matter, clay, silt and sand composition, pH and electrical conductivity. The results showed that the average soil pH in limestone soil was between 6.38 to 6.93, whereas average soil pH in quartzite soil was 6.23. The average soil electrical conductivity for all sampling stations was below 1.7 mScm-1. High organic matter content average was shown in soil samples from Bukit Jernih (7.45%), followed by Gua Kelam (5.21%) and Bukit Merah (3.31%). Soil samples from Bukit Jernih and Gua Kelam showed a clayey texture with more than 35% clay content, whereas soil from Bukit Merah was sandy in texture with more than 67% sand content. In general, soil samples from limestone area of Bukit Jernih and Gua Kelam recorded higher content of heavy metals compared to quartzite soil from Bukit Merah. The average concentration of Cr and Co at Bukit Jernih at 413 µg/g and 88 µg/g, respectively, whereas the concentration at Gua Kelam was 152 µg/g dan 76 µg/g. These concentrations exceeded the potential toxic concentration in soil. The main major elements were SiO2 followed by Al2O3 and Fe2O3. SiO2 content in quartzite soil from Bukit Merah(89.45%) was higher compared to limestone soil from Bukit Jernih (59.74%) and Gua Kelam (53.16%). Nevertheless, Al2O3 and Fe2O3 content in limestone soil was higher compared to quartzite soil. The percentage of easily ignited content in limestone soil was two fold higher than quartzite soil. Other major elements were less than 2.5%. The study showed that enrichment of Cr, Zn, Pb, Ni and Cu in soil was influenced by the presence of SiO2, Al2O3 and Fe2O3.
    Keywords: Enrichment; heavy metals; limestones hill; major elements; toxicity
    Matched MeSH terms: Minerals*
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