Displaying publications 81 - 100 of 767 in total

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  1. Nurul Syafiqah Hirman, Nur Athirah Mohd Taib
    MyJurnal
    A simple and low-cost Fiber Optic Displacement Sensor (FODS) using reflective intensity modulation technique was developed to analyze various concentrations of Pb2+, a compound classified under heavy metal ions. Lead is harmful to the environment including to human but is used in the cosmetic field for beauty without realizing and considering the hazardousness of lead as it would cause a long-term effect. Therefore, a feasible way has been identified in this study to demonstrate the level of Pb2+ concentration in cosmetics field by employing the theory of modulation of intensity as a function of displacement sensor. The permissible limit according to Malaysian Cosmetics Guidelines and ASEAN Cosmetic Directive was 20 ppm. The concentration sensor’s system exhibits 0.0018 V/ppm sensitivity with a linearity of 96% and 94% respectively, for both peaks. Meanwhile, the sensitivity was 0.034 V/ppm for the first peak and 27.72 V/ppm for the second peak, with slope linearity of more than 96% for surface tension parameter. The credibility of these optical response curves data might be useful, especially in the cosmetic’s industrial application.

    Matched MeSH terms: Metals, Heavy
  2. Bujang JS, Zakaria MH, Ramaiya SD
    PLoS One, 2021;16(2):e0247327.
    PMID: 33626109 DOI: 10.1371/journal.pone.0247327
    Currently, bee-gathered pollen (bee pollen) is commonly used worldwide as a dietary supplement and is recognized for its curative properties. Floral pollen is also important but is less recognized due to a lack of investigation. This study aims to determine the morphological characteristics and nutritional and phytochemical properties of floral maize pollen. Fresh pollen grains harvested from a farm of maize plants are yellow in colour and spheroid in shape. They change to amber and indented prismatic solid shapes when dehydrated. The main composition of floral maize pollen is carbohydrates (44.30±3.73%), followed by moisture (23.38±5.73%), crude proteins (17.16±3.13%), crude fibres (9.56±0.92%), and ash (4.98±0.11%), while the lowest content is observed for crude fats (0.62±0.06%). The predominant mineral is potassium (768.50±11.40 mg 100 g-1), followed by sodium (695.10±9.70 mg 100 g-1), calcium (147.20±12.60 mg 100 g-1), and magnesium (97.30±2.9 mg 100 g-1). The microelements (with average values) consist of iron (49.50±3.30 mg 100 g-1) and zinc (30.00±3.70 mg 100 g-1). Excellent phytochemical properties add value to floral maize pollen. Maize pollen contains a high total phenolic content (TPC) and total flavonoid content (TFC) of 783.02 mg GAE 100 g-1 and 1706.83 mg QE 100 g-1, respectively, and possesses strong antioxidant activity of 10.54 mg mL-1. Maize floral pollen and derived products can serve as future food resources for human consumption and as a source of functional and bioactive compounds in nutraceutical and pharmaceutical industries.
    Matched MeSH terms: Metals/isolation & purification; Metals/chemistry
  3. Khalid AM, Hossain MS, Ismail N, Khalil NA, Balakrishnan V, Zulkifli M, et al.
    Polymers (Basel), 2020 Dec 30;13(1).
    PMID: 33396583 DOI: 10.3390/polym13010112
    In the present study, magnetic oil palm empty fruits bunch cellulose nanofiber (M-OPEFB-CNF) composite was isolated by sol-gel method using cellulose nanofiber (CNF) obtained from oil palm empty fruits bunch (OPEFB) and Fe3O4 as magnetite. Several analytical methods were utilized to characterize the mechanical, chemical, thermal, and morphological properties of the isolated CNF and M-OPEFB-CNF. Subsequently, the isolated M-OPEFB-CNF composite was utilized for the adsorption of Cr(VI) and Cu(II) from aqueous solution with varying parameters, such as pH, adsorbent doses, treatment time, and temperature. Results showed that the M-OPEFB-CNF as an effective bio-sorbent for the removal of Cu(II) and Cr(VI) from aqueous solution. The adsorption isotherm modeling revealed that the Freundlich equation better describes the adsorption of Cu(II) and Cr(VI) on M-OPEFB-CNF composite. The kinetics studies revealed the pseudo-second-order kinetics model was a better-described kinetics model for the removal of Cu(II) and Cr(VI) using M-OPEFB-CNF composite as bio-sorbent. The findings of the present study showed that the M-OPEFB-CNF composite has the potential to be utilized as a bio-sorbent for heavy metals removal.
    Matched MeSH terms: Metals, Heavy
  4. Gao P, Mohd Noor NQI, Md Shaarani S
    PMID: 33356490 DOI: 10.1080/10408398.2020.1866490
    Food safety issues associated with aquatic food products become more important with the increasing consumption and followed by its ongoing challenges. The objective of this paper is to review the food safety hazards and health risks related to aquatic food products for the Southeast Asian region. These hazards can be categorized as microplastics (MPs) hazard, biological hazards (pathogenic bacteria, biogenic amines, viruses, parasites), and chemical hazards (antimicrobial, formaldehyde, heavy metal). In different Southeast Asian countries, the potential health risks of aquatic food products brought by food hazards to consumers were at different intensity and classes. Among all these hazards, pathogenic bacteria, antimicrobials, and heavy metal were a particular concern in the Southeast Asian region. With environmental changes, evolving consumption patterns, and the globalization of trade, new food safety challenges are created, which put forward higher requirements on food technologies, food safety regulations, and international cooperation.
    Matched MeSH terms: Metals, Heavy
  5. Lim TW, Ab Ghani SM, Mahmud M
    J Prosthet Dent, 2020 Dec 02.
    PMID: 33279159 DOI: 10.1016/j.prosdent.2020.06.034
    STATEMENT OF PROBLEM: Resin-bonded fixed partial dental prostheses (RBFPDPs) cemented at an increased occlusal vertical dimension (OVD) (the Dahl concept) to create space for a metal retainer remain controversial because of the lack of reported clinical studies. This study evaluated RBFPDPs by applying the Dahl concept.

    PURPOSE: The purpose of this retrospective study was to investigate the clinical factors affecting the occlusal re-establishment and short-term complications of RBFPDPs cemented at an increased OVD.

    MATERIAL AND METHODS: Occlusal re-establishment and clinical complications were reviewed in 109 participants (155 RBFPDPs) treated at the Faculty of Dentistry, Universiti Teknologi MARA from January 2013 to May 2018. Types of complications and risk factors were assessed from clinical data. Demographic factors, clinical factors, and prosthesis factors were distinguished and their association with occlusal re-establishment analyzed by using multiple regression analysis.

    RESULTS: A total of 155 RBFPDPs (42 anterior, 113 posterior) were placed in 109 participants. All achieved occlusal re-establishment, 89.9% complete occlusal re-establishment and 10.1% partial occlusal re-establishment, a minimum of 4 months after the RBFPDPs had been placed at an increased OVD. The design of the metal retainer coverage was found to be a significant factor affecting occlusal re-establishment and decementation (P

    Matched MeSH terms: Metals
  6. Arifin MH, Kayode JS, Ismail KI, Abdullah M, Embrandiri A, Nazer SM, et al.
    Data Brief, 2020 Dec;33:106595.
    PMID: 33318980 DOI: 10.1016/j.dib.2020.106595
    Industrial, and municipal wastes are part of the main sources of environmental hazards as well as groundwater and surface water pollutions. If not well composed, treated, and safely disposed, it could permeate through the subsurface lithologies by reaching down to the underground water aquifers, particularly in zones of unprotected aquifer units. Pollutants, most especially the landfills leachates that encompassed organic contaminants, ammonia, nitrates, total nitrogen, suspended solids, heavy metals and soluble inorganic salts, i.e., soluble nitrogen, sulphur compound, sulphate and chlorides, could posed undesirable environmental impacts due to inappropriate disposals that may give rise to gaseous fumes and leachate formations. An electrical resistivity geophysical technique utilizing the RES2D no-invasive, cost-effective and rapid method of data collection was integrated with the 3D Oasis Montaj software to approximate the volume of the generated rectangular prism model of the contaminants delineated from mixtures of the industrial, and municipal wastes plumes to be 312,000 m 3.
    Matched MeSH terms: Metals, Heavy
  7. Rajendran SD, Wahab SN, Yeap SP
    Saf Health Work, 2020 Dec;11(4):537-542.
    PMID: 33329921 DOI: 10.1016/j.shaw.2020.06.007
    Background: Personal protective equipment (PPE) has been designed in such a way to reduce accident rates. Unfortunately, existing PPE is rather ineffective as it is not able to provide warning signals when hazard is around. The integration of intelligent systems is envisaged to increase the efficiency of existing PPE.

    Methods: This project designed a safety vest incorporated with metal detectors which can provide immediate warning to the field workers when there is metal hazard around. This product has greater freedom of design via smart manufacturing as it involves the assembly of few commercially available parts into a single entity. Briefly, the metal detector is a do it yourself (DIY) kit, and the safety vest is purchasable from any local market. The DIY kit was connected to a copper coil and being sewed into the safety vest.

    Results: The metal detector induces beeping sound when there is metal hazard around. A total of 121 engineering students were introduced to the prototype before being requested to answer a survey associated with the design. Respondents have rated >3.00/5.00 for the design simplicity, ease of usage, and light weight. Meanwhile, respondents suggested that the design should be further improved by increasing the metal detection range.

    Conclusion: It is envisaged that the introduction of this smart safety vest will allow the workers to carry out their duties securely by reducing the accident rates. Particularly, such design is expected to reduce workplace accident especially during night time at construction sites where the visibility is low.

    Matched MeSH terms: Metals
  8. Nizar SA, Kobayashi T, Mohd Suah FB
    Luminescence, 2020 Dec;35(8):1286-1295.
    PMID: 32525612 DOI: 10.1002/bio.3890
    This paper describes the synthesis of poly(1-aminonaphthalene) and its application as a chemosensor for detection of Fe3+ using the naked eye and a fluorimetric method. The conjugated polymer was synthesized by chemical oxidative polymerization using FeCl3 as a catalyst. The response of the polymer towards various metal ions was investigated using colorimetric detection, and ultraviolet-visible and fluorescence spectroscopies. The polymer displayed high selectivity and sensitivity towards Fe3+ compared with other metal ions. A significant colour change from purple to yellow was observed upon addition of Fe3+ by the naked eye. The polymer also showed a high selectivity and sensitivity 'turn-off' fluorescence response towards Fe3+ ions. A good linear response was obtained for Fe3+ concentrations in the range 10-50 mg L-1 with a detection limit of 1.04 mg L-1 . The proposed chemosensor was applied for determination of Fe3+ content in water samples and satisfactory results were obtained.
    Matched MeSH terms: Metals
  9. Khan FSA, Mubarak NM, Tan YH, Karri RR, Khalid M, Walvekar R, et al.
    Environ Sci Pollut Res Int, 2020 Dec;27(35):43526-43541.
    PMID: 32909134 DOI: 10.1007/s11356-020-10482-z
    Substantial discharge of hazardous substances, especially dyes and heavy metal ions to the environment, has become a global concern due to many industries neglecting the environmental protocols in waste management. A massive discharge of contaminantsfrom different anthropogenic activities, can pose alarming threats to living species and adverse effect to the ecosystem stability. In the process of treating the polluted water, various methods and materials are used. Hybrid nanocomposites have attained numerous interest due to the combination of remarkable features of the organic and inorganic elements in a single material. In this regards, carbon and polymer based nanocomposites have gained particular interest because of their tremendous magnetic properties and stability. These nanocomposites can be fabricated using several approaches that include filling, template, hydrothermal, pulsed-laser irradiation, electro-spinning, detonation induced reaction, pyrolysis, ball milling, melt-blending, and many more. Moreover, carbon-based and polymer-based magnetic nanocomposites have been utilized for an extensive number of applications such as removal of heavy metal and dye adsorbents, magnetic resonance imaging, and drug delivery. This review emphasized mainly on the production of magnetic carbon and polymer nanocomposites employing various approaches and their applications in water and wastewater treatment. Furthermore, the future opportunities and challenges in applying magnetic nanocomposites for heavy metal ion and dye removal from water and wastewater treatment plant.
    Matched MeSH terms: Metals, Heavy*
  10. Jairoun AA, Shahwan M, Zyoud SH
    Sci Rep, 2020 11 02;10(1):18824.
    PMID: 33139833 DOI: 10.1038/s41598-020-76000-w
    A specific safety concern is the possibility that a dietary supplement could be contaminated with heavy metals. This research was undertaken to investigate the daily exposure levels of heavy metals in dietary supplements available in the UAE and to explore the factors associated with the contamination of dietary supplements with heavy metals. A total of 277 dietary supplement samples were collected from the UAE market and prepared for the analysis of selected heavy metal contamination. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the presence of heavy metals. The average daily intake of cadmium was 0.73 μg [95% CI 0.61-0.85], compared to the acceptable daily intake (ADI) of 6 μg; the daily intake of lead was 0.85 μg [95% CI 0.62-1.07], compared to the acceptable daily intake (ADI) of 20 μg; and the daily intake of arsenic was 0.67 μg [95% CI 0.57-0.78], compared to the acceptable daily intake of 10 μg. Although the dietary supplements available in the UAE have low levels of heavy metal contamination, numerous individuals are consuming a number of different dietary supplements every day and thereby may experience a cumulative level of toxic exposure. Dietary supplements formulations (Categories), dosage forms and country of origin are strong determents of heavy metal contamination in dietary supplements products.
    Matched MeSH terms: Metals, Heavy/adverse effects*; Metals, Heavy/analysis*
  11. Praveena SM, Rashid U, Rashid SA
    Environ Technol, 2020 Nov;41(25):3363-3374.
    PMID: 31002023 DOI: 10.1080/09593330.2019.1609590
    There is limited information on the optimal processes to remove heavy metals in greywater. A Response Surface Methodology (RSM) via the Box-Behnken Design (BBD) approach was applied in this study to investigate and optimise the process variables of activation time (1.5-2.5 h), impregnation ratio (0.25-0.75) and zinc chloride (ZnCl2) percentage (20-60%) for the removal of heavy metal ions (Cd, Cu, Pb and Ni) associated with greywater treatment. The quadratic model was chosen to describe the effects of the process variables (activation time, impregnation ratio, ZnCl2 percentage) on predicting the responses (heavy metal ions removal) with low p-values (
    Matched MeSH terms: Metals, Heavy*
  12. Brindha K, Paul R, Walter J, Tan ML, Singh MK
    Environ Geochem Health, 2020 Nov;42(11):3819-3839.
    PMID: 32601907 DOI: 10.1007/s10653-020-00637-9
    Monitoring the groundwater chemical composition and identifying the presence of pollutants is an integral part of any comprehensive groundwater management strategy. The present study was conducted in a part of West Tripura, northeast India, to investigate the presence and sources of trace metals in groundwater and the risk to human health due to direct ingestion of groundwater. Samples were collected from 68 locations twice a year from 2016 to 2018. Mixed Ca-Mg-HCO3, Ca-Cl and Ca-Mg-Cl were the main groundwater types. Hydrogeochemical methods showed groundwater mineralization due to (1) carbonate dissolution, (2) silicate weathering, (3) cation exchange processes and (4) anthropogenic sources. Occurrence of faecal coliforms increased in groundwater after monsoons. Nitrate and microbial contamination from wastewater infiltration were apparent. Iron, manganese, lead, cadmium and arsenic were above the drinking water limits prescribed by the Bureau of Indian Standards. Water quality index indicated 1.5% had poor, 8.7% had marginal, 16.2% had fair, 66.2% had good and 7.4% had excellent water quality. Correlation and principal component analysis reiterated the sources of major ions and trace metals identified from hydrogeochemical methods. Human exposure assessment suggests health risk due to high iron in groundwater. The presence of unsafe levels of trace metals in groundwater requires proper treatment measures before domestic use.
    Matched MeSH terms: Metals/analysis*
  13. Keirudin AA, Zainuddin N, Yusof NA
    Polymers (Basel), 2020 Oct 24;12(11).
    PMID: 33114335 DOI: 10.3390/polym12112465
    In the present study, CMSS (carboxymethyl sago starch)-based hydrogel was synthesized by crosslinking with citric acid via esterification and then applied as a metal sorbent to overcome excessive heavy metal pollution. The CMSS/CA (carboxymethyl sago starch/citric acid) hydrogel was characterized by Fourier Transform Infrared (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The absorption band at 1726 cm-1 was observed in the FT-IR spectrum of CMSS/CA hydrogel and indicated ester bonds formed. Further findings show that the cross-linkages in the CMSS/CA hydrogel increased the thermal stability of CMSS and various sizes of pores were also shown in the SEM micrograph. Conversely, the removal of heavy metals was analyzed using Inductively Coupled Plasma-Optic Emission Spectra (ICP-OES). The effects of the pH of the metal solution, contact time, initial concentration of the metal ions and temperature on the sorption capacity were investigated. Under optimum condition, the sorption capacity of Pb2+, Cu2+, Ni2+ and Zn2+ onto CMSS/CA hydrogel were 64.48, 36.56, 16.21, 18.45 mg/g, respectively. The experiments demonstrated that CMSS/CA hydrogel has high selectivity towards Pb2+ in both non-competitive and competitive conditions. In conclusion, the CMSS/CA hydrogel as a natural based heavy metal sorption material exhibited a promising performance, especially in the sorption of Pb2+ for wastewater treatment.
    Matched MeSH terms: Metals, Heavy
  14. Adil M, Lee KC, Zaid HM, Manaka T
    Nanomaterials (Basel), 2020 Oct 06;10(10).
    PMID: 33036153 DOI: 10.3390/nano10101975
    The utilization of metal-oxide nanoparticles in enhanced oil recovery (EOR) has generated considerable research interest to increase the oil recovery. Among these nanoparticles, alumina nanoparticles (Al2O3-NPs) have proved promising in improving the oil recovery mechanism due to their prominent thermal properties. However, more significantly, these nanoparticles, coupled with electromagnetic (EM) waves, can be polarized to reduce water/oil mobility ratio and create disturbances at the oil/nanofluid interface, so that oil can be released from the reservoir rock surfaces and travelled easily to the production well. Moreover, alumina exists in various transition phases (γ, δ, θ, κ, β, η, χ), providing not only different sizes and morphologies but phase-dependent dielectric behavior at the applied EM frequencies. In this research, the oil recovery mechanism under EM fields of varying frequencies was investigated, which involved parameters such as mobility ratio, interfacial tension (IFT) and wettability. The displacement tests were conducted in water-wet sandpacks at 95 °C, by employing crude oil from Tapis. Alumina nanofluids (Al2O3-NFs) of four different phases (α, κ, θ and γ) and particle sizes (25-94.3 nm) were prepared by dispersing 0.01 wt. % NPs in brine (3 wt. % NaCl) together with SDBS as a dispersant. Three sequential injection scenarios were performed in each flooding scheme: (i) preflushes brine as a secondary flooding, (ii) conventional nano/EM-assisted nanofluid flooding, and (iii) postflushes brine to flush NPs. Compared to conventional nanofluid flooding (3.03-11.46% original oil in place/OOIP) as incremental oil recovery, EM-assisted nanofluid flooding provided an increase in oil recovery by approximately 4.12-12.90% of OOIP for different phases of alumina. It was established from these results that the recovery from EM-assisted nanofluid flooding is itself dependent on frequency, which is associated with good dielectric behavior of NPs to formulate the oil recovery mechanism including (i) mobility ratio improvement due to an electrorheological (ER) effect, (ii) interfacial disturbances by the oil droplet deformation, and (iii) wettability alteration by increased surface-free energy.
    Matched MeSH terms: Metals
  15. Hussein HA, Maulidiani M, Abdullah MA
    Heliyon, 2020 Oct;6(10):e05263.
    PMID: 33102866 DOI: 10.1016/j.heliyon.2020.e05263
    Heavy metal pollution has become a major concern globally as it contaminates eco-system, water networks and as finely suspended particles in air. In this study, the effects of elevated silver nanoparticle (AgNPs) levels as a model system of heavy metals, in the presence of microalgal crude extracts (MCEs) at different ratios, were evaluated against the non-cancerous Vero cells, and the cancerous MCF-7 and 4T1 cells. The MCEs were developed from water (W) and ethanol (ETH) as green solvents. The AgNPs-MCEs-W at the 4:1 and 5:1 ratios (v/v) after 48 and 72 h treatment, respectively, showed the IC50 values of 83.17-95.49 and 70.79-91.20 μg/ml on Vero cells, 13.18-28.18 and 12.58-25.7 μg/ml on MCF-7; and 16.21-33.88 and 14.79-26.91 μg/ml on 4T1 cells. In comparison, the AgNPs-MCEs-ETH formulation achieved the IC50 values of 56.23-89.12 and 63.09-91.2 μg/ml on Vero cells, 10.47-19.95 and 13.48-26.61 μg/ml on MCF-7; 14.12-50.11 and 15.13-58.88 μg/ml on 4T1 cells, respectively. After 48 and 72 h treatment, the AgNPs-MCE-CHL at the 4:1 and 5:1 ratios exhibited the IC50 of 51.28-75.85 and 48.97-69.18 μg/ml on Vero cells, and higher cytotoxicity at 10.47-16.98 and 6.19-14.45 μg/ml against MCF-7 cells, and 15.84-31.62 and 12.58-24.54 μg/ml on 4T1 cells, respectively. The AgNPs-MCEs-W and ETH resulted in low apoptotic events in the Vero cells after 24 h, but very high early and late apoptotic events in the cancerous cells. The Liquid Chromatography-Mass Spectrometry-Electrospray Ionization (LC-MS-ESI) metabolite profiling of the MCEs exhibited 64 metabolites in negative ion and 56 metabolites in positive ion mode, belonging to different classes. The microalgal metabolites, principally the anti-oxidative components, could have reduced the toxicity of the AgNPs against Vero cells, whilst retaining the cytotoxicity against the cancerous cells.
    Matched MeSH terms: Metals, Heavy
  16. Jaafar NR, Khoiri NM, Ismail NF, Mahmood NAN, Abdul Murad AM, Abu Bakar FD, et al.
    Enzyme Microb Technol, 2020 Oct;140:109625.
    PMID: 32912685 DOI: 10.1016/j.enzmictec.2020.109625
    Endo-β-1,3-glucanase from alkalophilic bacterium, Bacillus lehensis G1 (Blg32) composed of 284 amino acids with a predicted molecular mass of 31.6 kDa is expressed in Escherichia coli and purified to homogeneity. Herein, Blg32 characteristics, substrates and product specificity as well as structural traits that might be involved in the production of sugar molecules are analysed. This enzyme functions optimally at the temperature of 70 °C, pH value of 8.0 with its catalytic activity strongly enhanced by Mn2+. Remarkably, the purified enzyme is highly stable in high temperature and alkaline conditions. It exhibits the highest activity on laminarin (376.73 U/mg) followed by curdlan and yeast β-glucan. Blg32 activity increased by 62% towards soluble substrate (laminarin) compared to insoluble substrate (curdlan). Hydrolytic products of laminarin were oligosaccharides with degree of polymerisation (DP) of 1 to 5 with the main product being laminaritriose (DP3). This suggests that the active site of Blg32 could recognise up to five glucose units. High concentration of Blg32 mainly produces glucose whilst low concentration of Blg32 yields oligosaccharides with different DP (predominantly DP3). A theoretical structural model of Blg32 was constructed and structural analysis revealed that Trp156 is involved in multiple hydrophobic stacking interactions. The amino acid was predicted to participate in substrate recognition and binding. It was also exhibited that catalytic groove of Blg32 has a narrow angle, thus limiting the substrate binding reaction. All these properties and knowledge of the subsites are suggested to be related to the possible mode of action of how Blg32 produces glucooligosaccharides.
    Matched MeSH terms: Metals/chemistry
  17. Revathi M, Sivagaami Sundari G, Ahmed Basha C, Alam M, Sagadevan S, Ahmad N
    J Nanosci Nanotechnol, 2020 10 01;20(10):6547-6554.
    PMID: 32385012 DOI: 10.1166/jnn.2020.18562
    This investigation aims at the reclamation of Cr(VI) from synthetic electroplating industrial effluent by electroextraction process namely electrochemical ion exchange (EIX). An electrochemical ion exchange reactor of desired dimensions was fabricated with the help of ion-permeable membranes, stainless steel cathode and PbO₂ coated Ti expanded mesh anode. The performance of the reactor was studied in batch recirculation mode, continuous flow mode at different experimental conditions. The influence of various experimental factors, for instance, initial metal ion concentration (20, 300, 1000 mg/L of Cr(VI)), applied voltages (2.5 V, 5 V, 7.5 V, 10 V) and flow rates of the process stream (2, 4, 6, 8, 10, 12 and 14 ml/min) on removal/reclamation efficiency was deliberated. For comparison purposes, an electrodialysis process was conducted at the same optimal conditions. It was found that the EIX process with three compartments has more removal efficiency at optimum experimental conditions than the electrodialysis process. The continuous flow process of the reactor with 300 mg/L of Cr(VI) as inlet concentration has studied to predict the breakeven point of the reactor. It was noted that Cr(VI) ion concentration in the treated wastewater is almost zero up to the discharge of 20 liters of treated rinse water.
    Matched MeSH terms: Metals
  18. Usman UA, Yusoff I, Raoov M, Hodgkinson J
    Environ Geochem Health, 2020 Oct;42(10):3079-3099.
    PMID: 32180058 DOI: 10.1007/s10653-020-00543-0
    The research study was carried out to evaluate trace metals (Pb, Cd, Se, Al, Mn, Cu, Zn, Fe, As, Ni, Cr, and Ag) concentrations in groundwater of Lorong Serai 4, Hulu Langat, Selangor, Malaysia. Additionally, the research study focused on determining non-carcinogenic and carcinogenic health risks, sources of the contaminants, and effective remediation methods. The results show that the concentration levels of Pb, Cd, Se, Al, Cu, Zn, Ni, Cr, and Ag are lower than their corresponding permissible limits, while Fe, Mn, and As concentrations exceed their acceptable limit. The hazard index of the groundwater in the area exceeded the acceptable limit, showing the rate of carcinogenic and non-carcinogenic health effects associated with the water. The findings also indicate that the lifetime cancer risk is high compared to the maximum limits of lifetime cancer risk from the drinking water (10-6 to 10-4). The groundwater geochemical data of the area are used in establishing the source of Fe, Mn, and As metal ions. Evaluation of Fe2+/Fe3+ and S2-/SO42- redox couples and thermodynamic modelling indicates that the groundwater of the area is in redox disequilibrium. The groundwater samples contain aqueous iron sulphate, which is supersaturated, ferrous carbonate and aluminium sulphate that are saturated. The main state of redox disequilibrium is governed by mineral precipitation and dissolution. Aqueous arsenic and manganese are possibly derived from the dissolution of pyrite (arsenopyrite) and amorphous oxide-hydroxides, respectively. The high concentration of iron in the shallow groundwater in the area is primarily the result of silicate rock weathering of ferroan igneous and metamorphic minerals with a minor contribution from the oxidation of iron sulphides. Magnetite coated with graphene oxide (Fe3O4-GO) nanoparticles (NPs) was synthesized and characterized, and the adsorption preliminary experiments were carried out; and the Fe3O4-GO NPs show enhanced removal (Fe > As > Mn) capacity over graphene oxide (GO).
    Matched MeSH terms: Metals/analysis*
  19. Pui LP, Mohammed AS, Ghazali HM
    Acta Sci Pol Technol Aliment, 2020 9 27;19(3):319-331.
    PMID: 32978914 DOI: 10.17306/J.AFS.0804
    BACKGROUND: 5'-Phosphodiesterase (5'-PDE) is an enzyme that hydrolyzes RNA to form 5'-inosine monophosphate (5'-IMP) and 5'-guanosine monophosphate (5'-GMP). These 5'-nucleotides can function as flavor enhancers. Adzuki beans (Vigna angularis L.) are found to be high in 5'-PDE.

    METHODS: 5'-phosphodiesterase (5'-PDE) enzyme was characterized from adzuki beans, in which the optimum pH and temperature were determined. In addition, the stability of 5'-PDE was assessed at different pH and temperature. The effects of cations and EDTA were evaluated to characterize the 5'-PDE enzymes further.

    RESULTS: The alkaline 5'-phosphodiesterase has an optimum pH of 8.5. This enzyme is also thermostable, with an optimum temperature of 80°C. The stability in terms of temperature and pH was also determined, and was found to be stable in the pH range of 7.0-8.5. This enzyme was found to retain more than 80% of its activity for 4 days at 60 and 65°C. In addition, the effects of 14 different metal ions, 4 types of detergents and ethylenediaminetetraacetic acid (EDTA) on 5'-PDE were studied. Ca2+, K+, Mg2+ and Li+ activated 5'-PDE while Na+, Zn2+, Ni+, Hg+, Cu2+, Pb2+, Fe2+, Al3+, Ba2+ and Co2+ were inhibitory. EDTA, Triton X-100 and sodium dodecyl sulfate (SDS) were strong inhibitors of 5'-PDE, while Tween 80 and Tween 20 were slightly inhibitory. The effects of cations and EDTA suggest that 5'-PDE from adzuki beans is a metalloenzyme.

    CONCLUSIONS: Although 5'-PDE from adzuki beans has a high temperature optimum of 80°C, the enzyme is more stable at 60°C, and different cations affected the activity of the enzyme differently.

    Matched MeSH terms: Metals
  20. Bassiri Nia A, Xin L, Yahya MY, Ayob A, Farokhi Nejad A, Rahimian Koloor SS, et al.
    Polymers (Basel), 2020 Sep 19;12(9).
    PMID: 32961655 DOI: 10.3390/polym12092139
    The present study investigates the effects of close-range blast loading of fibre metal laminates (FMLs) fabricated from woven glass polypropylene and aluminium alloy 2024-T3. The polypropylene layers and anodized aluminium are stacked in 3/2 layering configuration to investigate the impact energy absorbed through deformation and damage. In order to study the blast responses of FMLs, a 4-cable instrumented pendulum blast set-up is used. Effects of blast impulse and stand-off distance were examined. Investigation of the cross-section of FMLs are presented and damages such as fibre fracture, debonding, and global deformation are examined. Increasing stand-off distance from 4 to 14 mm resulted in a change of damage mode from highly localized perforation to global deformation.
    Matched MeSH terms: Metals
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