Displaying publications 61 - 80 of 230 in total

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  1. Fulltext Indian jujuba seed powder as an eco-friendly and a low-cost biosorbent for removal of acid blue 25 from aqueous solution
    Krishna LS, Reddy AS, Zuhairi WY, Taha MR, Reddy AV
    ScientificWorldJournal, 2014;2014:184058.
    PMID: 25383360 DOI: 10.1155/2014/184058
    Indian jujuba seed powder (IJSP) has been investigated as a low-cost and an eco-friendly biosorbent, prepared for the removal of Acid Blue 25 (AB25) from aqueous solution. The prepared biomaterial was characterized by using FTIR and scanning electron microscopic studies. The effect of operation variables, such as IJSP dosage, contact time, concentration, pH, and temperature on the removal of AB25 was investigated, using batch biosorption technique. Removal efficiency increased with increase of IJSP dosage but decreased with increase of temperature. The equilibrium data were analyzed by the Langmuir and the Freundlich isotherm models. The data fitted well with the Langmuir model with a maximum biosorption capacity of 54.95 mg g(-1). The pseudo-second-order kinetics was the best for the biosorption of AB25 by IJSP, with good correlation. Thermodynamic parameters such as standard free energy change (ΔG(0)), standard enthalpy changes (ΔH(0)), and standard entropy changes (ΔS(0)) were analyzed. The removal of AB25 from aqueous solution by IJSP was a spontaneous and exothermic adsorption process. The results suggest that IJSP is a potential low-cost and an eco-friendly biosorbent for the AB25 removal from synthetic AB25 wastewater.
    Matched MeSH terms: Powders/pharmacology; Powders/chemistry
  2. Sintering behaviour of hydroxyapatite bioceramics
    Ramesh S, Tan CY, Aw KL, Yeo WH, Hamdi M, Sopyan I, et al.
    Med J Malaysia, 2008 Jul;63 Suppl A:89-90.
    PMID: 19024998
    The sintering behaviour of a commercial HA and synthesized HA was investigated over the temperature range of 700 degrees C to 1400 degrees C in terms of phase stability, bulk density, Young's modulus and Vickers hardness. In the present research, a wet chemical precipitation reaction was successfully employed to synthesize a submicron, highly crystalline, high purity and single phase stoichiometric HA powder that is highly sinteractive particularly at low temperature regimes below 1100 degrees C. It has been revealed that the sinterability of the synthesized HA was significantly greater than that of the commercial HA. The temperature for the onset of sintering and the temperature required to achieve densities above 98% of theoretical value were approximately 150 degrees C lower for the synthesized HA than the equivalent commercial HA. Nevertheless, decomposition of HA phase upon sintering was not observed in the present work for both powders.
    Matched MeSH terms: Powders/chemical synthesis; Powders/chemistry*
  3. Effect of powder calcination on the sintering of hydroxyapatite
    Tan CY, Ramesh S, Aw KL, Yeo WH, Hamdi M, Sopyan I
    Med J Malaysia, 2008 Jul;63 Suppl A:87-8.
    PMID: 19024997
    The sintering behaviour of synthesized HA powder that was calcined at various temperatures ranging from 700 degrees C to 1000 degrees C was investigated in terms of phase stability, bulk density, Young's modulus and Vickers hardness. The calcination treatment resulted in higher crystallinity of the starting HA powder. Decomposition of HA phase to form secondary phases was not observed in all the calcined powders. The results also indicated that powder calcination (up to 900 degrees C) prior to sintering has negligible effect on the sinterability of the HA compacts. However, powder calcined at 1000 degrees C was found to be detrimental to the properties of sintered hydroxyapatite bioceramics.
    Matched MeSH terms: Powders/chemical synthesis; Powders/chemistry*
  4. Influence of manganese doping into HA powders on the properties of its dense bodies
    Natasha AN, Sopyan I, Mel M, Ramesh S
    Med J Malaysia, 2008 Jul;63 Suppl A:85-6.
    PMID: 19024996
    The effect of Manganese (Mn) addition on the Vickers hardness and relative density of nanocrystalline hydroxyapatite (HA) dense bodies were studied. The starting Mn doped HA powders was synthesized via sol-gel method with Mn concentration varies from 2 mol% up to 15 mol% Mn. The Mn doped HA disc samples were prepared by uniaxial pressing at 200MPa and subsequently sintered at 1300 degrees C. Characterization was carried out where appropriate to determine the phases present, bulk density, Vickers hardness of the various content of Mn doped HA dense bodies. The addition of Mn was observed to influence the color appearance of the powders and dense bodies as well. Higher Mn concentration resulted in dark grey powders. It was also found that the hardness and relative density of the material increased as the Mn content increased and influenced by the crystallinity of the prepared Mn doped HA powders.
    Matched MeSH terms: Powders/chemical synthesis; Powders/chemistry*
  5. Fulltext Viability and Antioxidant Effects of Traditional Cooling Rice Powder (bedak sejuk) Made from Oryza sativa ssp. Indica and Oryza sativa ssp. japonica on UVB-Induced B164A5 Melanoma Cells
    Ghazali AR, Muralitharan RV, Soon CK, Salyam T, Ahmad Maulana NN, Mohamed Thaha UAB, et al.
    Asian Pac J Cancer Prev, 2020 Nov 01;21(11):3381-3386.
    PMID: 33247699 DOI: 10.31557/APJCP.2020.21.11.3381
    BACKGROUND: Traditional cooling rice powder (bedak sejuk) is a fermented rice-based cosmetic that is applied topically on one's skin, as an overnight facial mask. According to user testimonies, bedak sejuk beautifies and whitens skin, whereby these benefits could be utilised as a potential melanoma chemopreventive agent.

    OBJECTIVE: Hence, this study aimed to determine the effects of bedak sejuk made from Oryza sativa ssp. indica (Indica) and Oryza sativa ssp. japonica (Japonica) on UVB-induced B164A5 melanoma cells, and also identify the antioxidant capacities of both types of bedak sejuk.

    METHODS: The optimum dose of Indica and Japonica bedak sejuk to treat the cells was determined via the MTT assay. Then, the antioxidant capacities of both types of bedak sejuk were determined using the FRAP assay.

    RESULTS: From the MTT assay, it was found that Indica and Japonica bedak sejuk showed no cytotoxic effects towards the cells. Hence, no IC50 can be obtained and two of the higher doses, 50 and 100 g/L were chosen for treatment. In the FRAP assay, Indica bedak sejuk at 50 and 100 g/L showed FRAP values of 0.003 ± 0.001 μg AA (ascorbic acid)/g of bedak sejuk and 0.004 ± 0.0003 μg AA/g of bedak sejuk. Whereas Japonica bedak sejuk at 50 g/L had the same FRAP value as Indica bedak sejuk at 100 g/L. As for Japonica bedak sejuk at 100 g/L, it showed the highest antioxidant capacity with the FRAP value of 0.01 ± 0.0007 μg AA/g of bedak sejuk which was statistically significant (p < 0.05) when compared to other tested concentrations.

    CONCLUSION: In conclusion, Japonica bedak sejuk has a higher antioxidant capacity compared to Indica bedak sejuk despite both being not cytotoxic towards the cells. Regardless, further investigations need to be done before bedak sejuk could be developed as potential melanoma chemoprevention agents.

    Matched MeSH terms: Powders/pharmacology*; Powders/chemistry
  6. Synthesis and characterization of magnesium doped biphasic calcium phosphate
    Toibah AR, Sopyan I, Mel M
    Med J Malaysia, 2008 Jul;63 Suppl A:83-4.
    PMID: 19024995
    The incorporation of magnesium ions into the calcium phosphate structure is of great interest for the development of artificial bone implants. This paper investigates the preparation of magnesium-doped biphasic calcium phosphate (Mg-BCP) via sol gel method at various concentrations of added Mg. The effect of calcinations temperature (ranging from 500 degrees C to 900 degrees C) and concentrations of Mg incorporated into BCP has been studied by the aid of XRD, TGA and infrared spectroscopy (IR) in transmittance mode analysis. The study indicated that the powder was pure BCP and Mg-BCP with 100% purity and high crystallinity. The results also indicated that beta-tricalcium phosphate (beta-TCP) phase can be observed when the powder was calcined at 800 degrees C and above.
    Matched MeSH terms: Powders/chemical synthesis; Powders/chemistry*
  7. Absorption and Bioavailability of Nano-Size Reduced Calcium Citrate Fortified Milk Powder in Ovariectomized and Ovariectomized-Osteoporosis Rats
    Erfanian A, Mirhosseini H, Rasti B, Hair-Bejo M, Bin Mustafa S, Abd Manap MY
    J Agric Food Chem, 2015 Jun 24;63(24):5795-804.
    PMID: 26022498 DOI: 10.1021/acs.jafc.5b01468
    The aim of this study was to evaluate the effects of fortification and nano-size reduction on calcium absorption and bioavailability of milk powder formula in sham, ovariectomized, and ovariectomized-osteoporosis rats as a menopause and menopause-osteoporosis model. Skim milk powder and skim milk powder fortified with calcium citrate and the suitable doses of inulin, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and vitamins D3, K1, and B6 were formulated based on the North American and Western European recommended dietary allowances. Optimization on cycle and pressure of high-pressure homogenizer was done to produce nano-fortified milk powder. In vivo study demonstrated that fortification and calcium citrate nano-fortified milk powder increased absorption and bioavailability of calcium, as well as bone stiffness and bone strength in sham, ovariectomized, and ovariectomized-osteoporosis rats. This study successfully developed an effective fortified milk powder for food application.
    Matched MeSH terms: Powders/metabolism; Powders/chemistry
  8. Incorporation of dietary fibre-rich oyster mushroom (Pleurotus sajor-caju) powder improves postprandial glycaemic response by interfering with starch granule structure and starch digestibility of biscuit
    Ng SH, Robert SD, Wan Ahmad WA, Wan Ishak WR
    Food Chem, 2017 Jul 15;227:358-368.
    PMID: 28274444 DOI: 10.1016/j.foodchem.2017.01.108
    The purpose of this study was to determine the effects of Pleurotus sajor-caju (PSC) powder addition at 0, 4, 8 and 12% levels on the nutritional values, pasting properties, thermal characteristics, microstructure, in vitro starch digestibility, in vivo glycaemic index (GI) and sensorial properties of biscuits. Elevated incorporation levels of PSC powder increased the dietary fibre (DF) content and reduced the pasting viscosities and starch gelatinisation enthalpy value of biscuits. The addition of DF-rich PSC powder also interfered with the integrity of the starch granules by reducing the sizes and inducing the uneven spherical shapes of the starch granules, which, in turn, resulted in reduced starch susceptibility to digestive enzymes. The restriction starch hydrolysis rate markedly reduced the GI of biscuits. The incorporation of 8% PSC powder in biscuits (GI=49) could be an effective way of developing a nutritious and low-GI biscuit without jeopardizing its desirable sensorial properties.
    Matched MeSH terms: Powders/metabolism; Powders/chemistry
  9. Optimization of headspace solid-phase microextraction technique for extraction of volatile smokeless powder compounds in forensic applications
    Chang KH, Yew CH, Abdullah AF
    J Forensic Sci, 2014 Jul;59(4):1100-8.
    PMID: 24611488 DOI: 10.1111/1556-4029.12440
    Smokeless powders are low explosives and are potentially found in cases involving firearms and improvised explosive devices. Apart from inorganic compound analysis, forensic determination of organic components of these materials appears as a promising alternative, especially the chromatographic techniques. This work describes the optimization of a solid-phase microextraction technique using an 85 μm polyacrylate fiber followed by gas chromatography-flame ionization detection for smokeless powder. A multivariate experimental design was performed to optimize extraction-influencing parameters. A 2(4) factorial first-order design revealed that sample temperature and extraction time were the major influencing parameters. Doehlert matrix design has subsequently selected 66°C and 21 min as the compromised conditions for the two predetermined parameters. This extraction technique has successfully detected the headspace compounds of smokeless powders from different ammunition types and allowed for their differentiation. The novel technique allows more rapid sample preparation for chromatographic detection of smokeless powders.
    Matched MeSH terms: Powders
  10. Development and applications of remote stereocontrol using allylic organobismuth reagents
    Basar N, Donnelly S, Sirat HM, Thomas EJ
    Org Biomol Chem, 2013 Dec 28;11(48):8476-505.
    PMID: 24212203 DOI: 10.1039/c3ob41931b
    Reactions of 5-benzyloxy-4-methylpent-2-enyl(tributyl)stannane with aldehydes promoted by bismuth(III) iodide were usefully stereoselective in favour of the (E)-1,5-anti-6-benzyloxy-5-methylalk-3-en-1-ols. Similar stereoselectivity was observed for reactions of analogous 5-benzyloxy-4-methylpent-2-enyl bromides with aldehydes when promoted by a low valency bismuth species prepared by reduction of bismuth(III) triiodide with powdered zinc so providing a "tin-free" procedure. The analogous reactions of 4-benzyloxypent-2-enyl(tributyl)stannane with aldehydes promoted by bismuth(III) iodide were also stereoselective but gave lower yields. Attempted 1,6-stereocontrol using these reactions resulted in only modest stereoselectivities. Aspects of the chemistry of the products were studied in particular their stereoselective conversion into aliphatic compounds with methyl bearing stereogenic centres at 1,5,9,13- and 1,3,5-positions along the aliphatic chain. Mechanistically, allylic organobismuth species may be involved in both sets of reactions but this was not confirmed although the similar stereoselectivities observed for both the bismuth(III) iodide mediated reactions of the pent-2-enylstannanes and the low-valency bismuth promoted reactions of the pent-2-enyl bromides are consistent with participation of similar intermediates.
    Matched MeSH terms: Powders
  11. Fulltext Dataset on applying HPMC polymer to improve encapsulation efficiency and stability of the fish oil: In vitro evaluation
    Zaidul ISM, Fahim TK, Sahena F, Azad AK, Rashid MA, Hossain MS
    Data Brief, 2020 Oct;32:106111.
    PMID: 32904423 DOI: 10.1016/j.dib.2020.106111
    Data examines the effect of hydroxypropyl methylcellulose (HPMC) HPMC15 cP, and HPMC 5 cP polymer composition on the physicochemical traits of encapsulated oil made using lab scale spray drying (180 °C). The data found showed that the properties of the reconstituted fish oil powder are significantly affected by the polymer's composition and ratio (p < 0.05). In this experiment, powder with the particle sizes below 60 μm was produced and it was observed that HPMC is a good emulsifier for all formulations and the encapsulation efficiency is high with 75.21% for AF1 formulation. It was also observed that the process of fish oil encapsulation employed by HPMC 5 cP produce a more volatile oil powder, while encapsulation with HPMC 15 cP produced a more stable fish oil powder. These finding shows that the utilisation of HPMC as a polymer to encapsulate fish oil can produce a more efficient and stable compound.
    Matched MeSH terms: Powders
  12. Fulltext An investigation of microstructural, magnetic and microwave absorption properties of multi-walled carbon nanotubes/Ni0.5Zn0.5Fe2O4
    Mustaffa MS, Azis RS, Abdullah NH, Ismail I, Ibrahim IR
    Sci Rep, 2019 Oct 29;9(1):15523.
    PMID: 31664142 DOI: 10.1038/s41598-019-52233-2
    The enhancement of microwave absorbing properties in nickel zinc ferrite (Ni0.5Zn0.5Fe2O4) via multiwall carbon nanotubes (MWCNT) growth is studied in this research work. Ni0.5Zn0.5Fe2O4 was initially synthesized by mechanical alloying followed by sintering at 1200 °C and the microstructural, electromagnetic and microwave characteristics have been scrutinized thoroughly. The sintered powder was then used as a catalyst to grow MWCNT derived from chemical vapor deposition (CVD) method. The sample was mixed with epoxy resin and a hardener for preparation of composites. The composite of multi-walled carbon nanotubes/Ni0.5Zn0.5Fe2O4 shown a maximum reflection loss (RL) of -19.34 dB at the frequency and bandwidth of 8.46 GHz and 1.24 GHz for an absorber thickness of 3 mm for losses less than -10 dB. This acquired result indicates that multi-walled carbon nanotubes/Ni0.5Zn0.5Fe2O4 could be used as a microwave absorber application in X-band.
    Matched MeSH terms: Powders
  13. Fulltext Investigation on the Electrochemical Performances of Mn2O3 as a Potential Anode for Na-Ion Batteries
    Yusoff NFM, Idris NH, Din MFM, Majid SR, Harun NA, Rahman MM
    Sci Rep, 2020 Jun 08;10(1):9207.
    PMID: 32513958 DOI: 10.1038/s41598-020-66148-w
    Currently, the development of the sodium-ion (Na-ion) batteries as an alternative to lithium-ion batteries has been accelerated to meet the energy demands of large-scale power applications. The difficulty of obtaining suitable electrode materials capable of storing large amount of Na-ion arises from the large radius of Na-ion that restricts its reversible capacity. Herein, Mn2O3 powders are synthesised through the thermal conversion of MnCO3 and reported for the first time as an anode for Na-ion batteries. The phase, morphology and charge/discharge characteristics of Mn2O3 obtained are evaluated systematically. The cubic-like Mn2O3 with particle sizes approximately 1.0-1.5 µm coupled with the formation of Mn2O3 sub-units on its surface create a positive effect on the insertion/deinsertion of Na-ion. Mn2O3 delivers a first discharge capacity of 544 mAh g-1 and retains its capacity by 85% after 200 cycles at 100 mA g-1, demonstrating the excellent cyclability of the Mn2O3 electrode. Therefore, this study provides a significant contribution towards exploring the potential of Mn2O3 as a promising anode in the development of Na-ion batteries.
    Matched MeSH terms: Powders
  14. Effect of mixing process parameters and suitability of backbone polymer for aluminum powder injection molding feedstock
    Abdullahi A, Choudhury I, Azuddin M, Nahar N
    Sains Malaysiana, 2017;46:477-483.
    A suitable and cost-effective microfabrication technique for processing aluminum micropart is required, as the choice
    of aluminum microparts for aerospace, electronics and automobile components is preferred over other metals due to its
    excellent properties. Meanwhile, powder injection molding (PIM) is identified as an economical manufacturing technique
    for processing ceramic and micro-metal powders into microparts and or components. Therefore, this study investigates
    formulation and processing of aluminum PIM feedstock using a custom-made machine. The investigation is focused on
    the effect of mixing process parameters (powder loading, rotor speed and mixing temperature) and the suitability of
    the backbone polymer. The formulated PIM feedstock constituents are paraffin wax (PW), stearic acid (SA), high-density
    polyethylene (HDPE)/ medium-density polyethylene (MDPE) alternatively and aluminum micro-metal powder. Taguchi
    method is used for the design of experiments (DOEs) and analysis. In addition, response surface methodology (RSM) is
    employed to develop empirical viscosity models. The optimum powder-binder mixing ratio of 58:42 vol. % with rotor
    speed of 43 rpm were determined for preparing aluminum PIM feedstock using mini-lab mixer developed. The empirical
    model developed for aluminum PIM feedstock viscosity shows a good fit with R2
    values of 0.84 using HDPE and 0.96 for
    MDPE binder system. This investigation demonstrates preparation and suitability of aluminum PIM feedstock using waxbased
    binder system.
    Matched MeSH terms: Powders
  15. Fulltext Preparation, Characterization, Morphological and Particle Properties of Crystallized Palm-Based Methyl Ester Sulphonates (MES) Powder
    Abd Maurad Z, Abdullah LC, Anuar MS, Abdul Karim Shah NN, Idris Z
    Molecules, 2020 Jun 05;25(11).
    PMID: 32516971 DOI: 10.3390/molecules25112629
    Methyl ester sulphonates (MES) have been considered as an alternative green surfactant for the detergent market. Investigation on the purification of methyl ester sulphonates (MES) with various carbon chains of C12, C14, C16 and C16-18 derived from palm methyl ester is of great interest. These MES powders have been repeatedly crystallized with ethanol and the purity of MES has increased to a maximum of 99% active content and 96% crystallinity index without changing the structure. These crystallized MES with high active content have 1.0% to 2.3% moisture content and retained its di-salt content in the range of 5%. The crystallized MES C16 and C16-18 attained excellent flow characteristics. Morphology, structural and its crystallinity analyses showed that the crystals MES had good solubility properties, stable crystal structure (β polymorphic) and triclinic lateral structure when it is in high active content. The brittleness of MES crystals increased from a β' to a β subcell. Crystal with high brittleness has the potential to ease production of powder, which leads to a reduction in the cost of production and improves efficiency.
    Matched MeSH terms: Powders
  16. Fulltext Optimization of spray drying parameters for white dragon fruit (Hylocereus undatus) juice powder using response surface methodology (rsm)
    Norzaida Yusof, Noranizan Mohd Adzahan, Kharidah Muhammad
    Malaysian Journal of Applied Sciences, 2020;5(2):45-56.
    MyJurnal
    This study was conducted to optimize the production of spray-dried white dragon fruit (Hylocereus undatus) powder using resistant maltodextrin as wall material. The inlet air temperature (140 °C, 150 °C and 160 °C), outlet temperature (75 °C, 80 °C and 85 °C) and resistant maltodextrin concentrations (20%, 25% and 30%) were tested as independent variables. Process yield, moisture content, water activity, solubility, hygroscopicity and bulk density of the powders were analysed as responses. Process yield significantly (p
    Matched MeSH terms: Powders
  17. Fulltext Morphological and compositional changes exhibited by rice husk when subjected to synergistic thermochemical treatments
    Revathi Rajan, Yusmazura Zakaria, Shaharum Shamsuddin, Nik Fakhuruddin Nik Hassan
    Malaysian Journal of Medicine and Health Sciences, 2020;16(101):1-7.
    MyJurnal
    Introduction: Rice husk has portrayed great potential in becoming a sustainable biomass source in producing silica, cellulose and carbon materials, which garnered widespread interest among researchers. The objective of the current study is to determine the morphological and compositional changes in rice husk due to the synergistic effects of ther- mochemical treatment. Methods: Washed and dried rice husk was blended into a fine powder and then subjected to step-wise heat treatment and acid digestion to produce white ash. The intermittent products, as well as the original rice husk and the final ash product, were characterised using analytical instruments to document the morphologi- cal and chemical composition changes. Results: This report highlights the production of pure rice husk ash using a step-wise treatment using a combination of thermochemical treatment and carbonisation. The results showed that a partial breakdown of the lignocellulose components was achieved using directed thermal treatment at low tem- perature. The ionic impurities were leached out in subsequent heated acid treatment. Thereafter, the carbonaceous organic matter was completely converted to carbon during the carbonisation of the sample and the remaining carbon residue was removed during calcination. High purity ash contained agglomerated and nanostructured silica in the dimensions of 20 to 50 nm in the amorphous form. Conclusion: The step-wise treatment allowed systematic removal of each compound while maintaining the amorphous mineral phase of silica and avoiding carbon fixation. Under- standing the effect of each treatment offers insight to produce purer silica from rice husk.
    Matched MeSH terms: Powders
  18. Fulltext Novel Carbon Quantum Dots/Silver Blended Polysulfone Membrane with Improved Properties and Enhanced Performance in Tartrazine Dye Removal
    Gan JY, Chong WC, Sim LC, Koo CH, Pang YL, Mahmoudi E, et al.
    Membranes (Basel), 2020 Aug 03;10(8).
    PMID: 32756315 DOI: 10.3390/membranes10080175
    This study produced a novel polysulfone (PSF) membrane for dye removal using lemon-derived carbon quantum dots-grafted silver nanoparticles (Ag/CQDs) as membrane nanofiller. The preparation of CQDs was completed by undergoing hydrothermal treatment to carbonize the pulp-free lemon juice into CQD solution. The CQD solution was then coupled with Ag nanoparticles to form Ag/CQDs nanohybrid. The synthesized powders were characterized in terms of morphologies, functional groups and surface charges. A set of membranes was fabricated with different loadings of Ag/CQDs powder using the nonsolvent-induced phase separation (NIPS) method. The modified membranes were studied in terms of morphology, elemental composition, hydrophilicity and pore size. In addition, pure water flux, rejection test and fouling analysis of the membranes were evaluated using tartrazine dye. From the results, 0.5 wt % of Ag/CQD was identified as the optimum loading to be incorporated with the pristine PSF membrane. The modified membrane exhibited an excellent pure water permeability and dye rejection with improvements of 169% and 92%, respectively. In addition, the composite membrane also experienced lower flux decline, higher reversible fouling and lower irreversible fouling. This study has proven that the addition of CQD additives into membrane greatly improves the polymeric membrane's properties and filtration performance.
    Matched MeSH terms: Powders
  19. Effect of different dextrose equivalents of maltodextrin on oxidation stability in encapsulated fish oil by spray drying
    Abd Ghani A, Adachi S, Shiga H, Neoh TL, Adachi S, Yoshii H
    Biosci Biotechnol Biochem, 2017 Apr;81(4):705-711.
    PMID: 28114864 DOI: 10.1080/09168451.2017.1281721
    Encapsulating fish oil by spray drying with an adequate wall material was investigated to determine if stable powders containing emulsified fish-oil-droplets can be formed. In particular, the dextrose equivalent (DE) of maltodextrin (MD) affects the powder structure, surface-oil ratio, and oxidative stability of fish oil. The carrier solution was prepared using MD with different DEs (DE = 11, 19, and 25) and sodium caseinate as the wall material and the emulsifier, respectively. The percentage of microcapsules having a vacuole was 73, 39, and 38% for MD with DE = 11, 19, and 25, respectively. Peroxide values (PVs) were measured for the microcapsules incubated at 60 °C. The microcapsules prepared with MD of DE = 25 and 19 had lower PVs than those prepared with MD of DE = 11. The difference in PV can be ascribed to the difference in the surface-oil ratio of the spray-dried microcapsules.
    Matched MeSH terms: Powders
  20. Fulltext Hybrid Mold: Comparative Study of Rapid and Hard Tooling for Injection Molding Application Using Metal Epoxy Composite (MEC)
    Hussin R, Sharif S, Nabiałek M, Zamree Abd Rahim S, Khushairi MTM, Suhaimi MA, et al.
    Materials (Basel), 2021 Feb 01;14(3).
    PMID: 33535504 DOI: 10.3390/ma14030665
    The mold-making industry is currently facing several challenges, including new competitors in the market as well as the increasing demand for a low volume of precision moldings. The purpose of this research is to appraise a new formulation of Metal Epoxy Composite (MEC) materials as a mold insert. The fabrication of mold inserts using MEC provided commercial opportunities and an alternative rapid tooling method for injection molding application. It is hypothesized that the addition of filler particles such as brass and copper powders would be able to further increase mold performance such as compression strength and thermal properties, which are essential in the production of plastic parts for the new product development. This study involved four phases, which are epoxy matrix design, material properties characterization, mold design, and finally the fabrication of the mold insert. Epoxy resins filled with brass (EB) and copper (EC) powders were mixed separately into 10 wt% until 30 wt% of the mass composition ratio. Control factors such as degassing time, curing temperature, and mixing time to increase physical and mechanical properties were optimized using the Response Surface Method (RSM). The study provided optimum parameters for mixing epoxy resin with fillers, where the degassing time was found to be the critical factor with 35.91%, followed by curing temperature with 3.53% and mixing time with 2.08%. The mold inserts were fabricated for EB and EC at 30 wt% based on the optimization outcome from RSM and statistical ANOVA results. It was also revealed that the EC mold insert offers better cycle time compared to EB mold insert material.
    Matched MeSH terms: Powders
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