Displaying publications 61 - 80 of 180 in total

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  1. Fulltext Nutritional values and cooking quality of defatted Kenaf seeds yellow (DKSY) noodles
    Zawawi, N., Gangadharan, P., Ahma Zaini, R., Samsudin, M.G., Karim, R., Maznah, I.
    International Food Research Journal, 2014;21(2):603-608.
    MyJurnal
    Kenaf (Hibiscus cannabinus) seeds have always being wasted as agricultural waste. Recent studies revealed that the seeds contain high fiber. The purpose of this study is to develop defatted kenaf seeds yellow noodles (DKSY) and assess the nutritional and physicohemical properties of the noodles. Defatted kenaf flour at 25% and 75% were used to make DKSY noodles and compared to wheat yellow noodles (Control). Fresh DKSY noodles were analyzed for their nutritional and physiochemical properties. The ash and fiber contents increased in order of Control > 25% DKSY > 75% DKSY noodles. While total phenolic contents (TPC) was found to be higher in 75% DKSY noodles (138.30 ± 1.63 mg GAE/100 g) than Control noodles. Colour (L, b) and hardness decreased in order of Control > 25% DKSY > 75% DKSY indicating that DKSY noodles developed less quality than Control noodles. However, cooking loss values were found to be in the same order while cooking values exist in the opposite order indicating that. DKSY noodles have better noodle cooking quality. In conclusion, nutritional properties and noodle cooking quality of yellow noodles increased with higher concentration of defatted kenaf flour but the physicochemical properties were compromised. More research needs to be done in order to develop a formulation that can increase all of the attributes studied.
    Matched MeSH terms: Hardness
  2. Fulltext Assessments of Process Parameters on Cutting Force and Surface Roughness during Drilling of AA7075/TiB2 In Situ Composite
    Parasuraman S, Elamvazuthi I, Kanagaraj G, Natarajan E, Pugazhenthi A
    Materials (Basel), 2021 Mar 31;14(7).
    PMID: 33807476 DOI: 10.3390/ma14071726
    Reinforced aluminum composites are the basic class of materials for aviation and transport industries. The machinability of these composites is still an issue due to the presence of hard fillers. The current research is aimed to investigate the drilling topographies of AA7075/TiB2 composites. The samples were prepared with 0, 3, 6, 9 and 12 wt.% of fillers and experiments were conducted by varying the cutting speed, feed, depth of cut and tool nose radius. The machining forces and surface topographies, the structure of the cutting tool and chip patterns were examined. The maximum cutting force was recorded upon increase in cutting speed because of thermal softening, loss of strength discontinuity and reduction of the built-up-edge. The increased plastic deformation with higher cutting speed resulted in the excess metal chip. In addition, the increase in cutting speed improved the surface roughness due to decrease in material movement. The cutting force was decreased upon high loading of TiB2 due to the deterioration of chips caused by fillers. Further introduction of TiB2 particles above 12 wt.% weakened the composite; however, due to the impact of the microcutting action of the fillers, the surface roughness was improved.
    Matched MeSH terms: Hardness
  3. Fulltext Effects of partial sugar replacement on the physicochemical and sensory properties of low sugar cookies
    Ho, L. H., Pulsawat, M. M.
    International Food Research Journal, 2020;27(3):557-567.
    MyJurnal
    The aim of the present work was to produce low sugar cookies by partial substitution with a
    sugar replacer (i.e. maltitol, sorbitol, and isomalt) for sucrose. Four different types of cookies
    were prepared. Sucrose was replaced by maltitol, sorbitol, and isomalt at 50% level (based on
    relative degree of sweetness of sucrose) to produce CMAL50, CSOR50, and CISO50, respectively. Cookies that contained sucrose represented the control. All the cookies produced were
    analysed for chemical properties, physical properties, and sensorial acceptance. The chemical
    analysis results indicated that CMAL50, CSOR50, and CISO50 had higher moisture, crude
    fibre, and the total carbohydrate content, but with lower ash, crude protein, crude fat, calories,
    and total sugar content than the control. CSOR50 showed the lowest total sugar content; thus,
    could be denoted as ‘low sugar’ cookies. Cookies containing maltitol and isomalt presented
    good physical quality. The hardness value of cookies decreased with 50% substitution of
    sorbitol and isomalt for sucrose. CISO50 showed the lowest lightness and yellowness values
    than other cookie samples. The sensory evaluation results showed that the cookies incorporated with maltitol and isomalt did not influence the overall acceptability of cookies. In conclusion, the replacement of sucrose with maltitol, sorbitol, and isomalt could reduce sugar and
    daily calorie intake. However, sorbitol substitution at 50% level is feasible to produce ‘low
    sugar’ cookies, and this cookie could provide benefits to weight and health-conscious
    consumers.
    Matched MeSH terms: Hardness
  4. Fulltext Influence of light and laser activation of tooth bleaching systems on enamel microhardness and surface roughness
    Yusof EM, Abdullah SA, Mohamed NH
    J Conserv Dent, 2021 02 10;23(5):473-478.
    PMID: 33911356 DOI: 10.4103/JCD.JCD_509_20
    Objective: The objective of this study was to compare the effects of light and laser activation of in-office tooth bleaching systems on enamel microhardness and surface roughness.

    Materials and Methods: Twenty-five enamel slabs were divided into three treatment groups: light-activated bleaching, laser-activated bleaching, and control. The baseline data were recorded for enamel microhardness (Vickers microhardness [VMH]) and surface roughness (Roughness average, Ra). The specimens were cured for 10 min upon hydrogen peroxide application for the light-activated bleaching group and activated with a laser source, 8 cycles, 10 s per cycle for the laser-activated group. The changes in VMH and Ra at days 1, 7, and 28 were evaluated. Kruskal-Wallis, Friedman, Wilcoxon, and Mann-Whitney tests were used to analyze both VMH and Ra between the treatment groups at different time intervals.

    Results: There were a significant reduction in VMH values and significant differences between days 1, 7, and 28 against the baseline in the light-activated bleaching group (P = 0.001). The Ra values revealed significant differences in both light- (P = 0.001) and laser-activated (P = 0.033) groups.

    Conclusion: Light activation of a bleaching agent caused a reduction in enamel microhardness and an increase in surface roughness when compared to laser activation.

    Matched MeSH terms: Hardness
  5. Fulltext Experimental data on the properties of pelletization of palm kernel shell using sago starch and sodium acetate
    Halim SA, Razali N, Mohd N
    Data Brief, 2020 Dec;33:106535.
    PMID: 34026955 DOI: 10.1016/j.dib.2020.106535
    Pellet mixed with 5 wt% and 10 wt% of binders was tested. The pelleting process was performed using a pellet mill operated at 100 °C and at 50 MPa. The physical and chemical characteristics including hardness, high heating value and proximate analysis of pellet produces were obtained using durometer and through thermographic analysis and the results were reported in this paper. Bulk and unit density were determined according to ASABE standard. The dataset presented here are the data of palm kernel shell pellet prepared using two types of binder; (1) sago starch and (2) sodium acetate. The pelletization of palm kernel shell aimed to increase the density and strength of the palm kernel shell pellet and consequently provide better thermal degradation characteristics.
    Matched MeSH terms: Hardness
  6. Optimizing palm oil and palm stearin utilization for sensory and textural properties of chicken frankfurters
    Tan SS, Aminah A, Zhang XG, Abdul SB
    Meat Sci, 2006 Mar;72(3):387-97.
    PMID: 22061722 DOI: 10.1016/j.meatsci.2005.07.012
    This study was designed to explore the potential of refined, bleached and deodorized (RBD) palm oil (PO) and palm stearin (POs) utilization in chicken frankfurters. A 10 points augmented simplex-centroid design was used to study the effect of chicken fat (CF), PO and POs as well as the interaction of these fats on the emulsion, textural and sensory properties of chicken frankfurters. All frankfurters were formulated to contain approx 25% fat, 52% moisture and 10% protein. No significant difference was found in end chopping temperatures of all meat batters even though the temperature of PO and POs upon incorporation into meat batters was 50°C higher than CF. Strong emulsions were formed as no fluid losses were observed in all the meat batters tested after heating. Texture profiles of the frankfurters containing PO and/or CF were quite similar, but increment of POs raised hardness, chewiness, and shear hardness of the frankfurters. Acceptability of the frankfurters was evaluated using hedonic test. Panelists found no difference in hardness preference between frankfurters made from totally CF and PO, while frankfurters made from POs were rated as hard and brittle. CF was important in determining acceptability of the frankfurters, as reduction of CF in formulation resulted in lower scores in chicken flavor, juiciness, oiliness and overall acceptance of the frankfurters. Frankfurters with sensory acceptability comparable to a commercial one were found to comprise of more than 17% CF, and less than 67% PO and 17% POs of the fat blend.
    Matched MeSH terms: Hardness
  7. Fulltext Physicochemical and Sensory Properties of Red Ginseng Extracts or Red Ginseng Hydrolyzates-added Asiago Cheese during Ripening
    Choi KH, Min JY, Ganesan P, Bae IH, Kwak HS
    Asian-Australas J Anim Sci, 2015 Jan;28(1):120-6.
    PMID: 25557683 DOI: 10.5713/ajas.14.0056
    This study was carried out to investigate physicochemical properties of different concentrations (0.1%, 0.3%, and 0.5%) of red ginseng hydrolyzates (RGH)- or red ginseng extract (RGE)-added Asiago cheeses (AC) during ripening at 14°C for 4 months. The moisture content significantly increased with increasing concentrations of both RGH- and RGE- added AC (p<0.05). While RGHAC and RGEAC were more yellow and darker with increasing concentrations than that of control (p<0.05), the color was not influenced from the hydrolysis. In texture analysis, hardness, cohesiveness, and chewiness of RGHAC and RGEAC significantly decreased compared to the control during the ripening (p<0.05). In sensory analysis, bitterness and ginseng flavor and taste scores increased significantly with increasing the concentrations of RGH and RGE during ripening (p<0.05). In conclusion, the addition of RGH and RGE into cheese slightly influenced the properties of Asiago cheese, and similarities were observed between RGHAC and RGEAC. Thus, the lower concentrations (0.1% to 0.3%) of RGH and RGE added to AC were preferred for color, texture, and sensory during the ripening, therefore, these cheeses would be worth developing commercially.
    Matched MeSH terms: Hardness
  8. Effect of Milling Time on the Microstructure, Physical and Mechanical Properties of Al-Al₂O₃ Nanocomposite Synthesized by Ball Milling and Powder Metallurgy
    Toozandehjani M, Matori KA, Ostovan F, Abdul Aziz S, Mamat MS
    Materials (Basel), 2017 Oct 26;10(11).
    PMID: 29072632 DOI: 10.3390/ma10111232
    The effect of milling time on the morphology, microstructure, physical and mechanical properties of pure Al-5 wt % Al₂O₃ (Al-5Al₂O₃) has been investigated. Al-5Al₂O₃ nanocomposites were fabricated using ball milling in a powder metallurgy route. The increase in the milling time resulted in the homogenous dispersion of 5 wt % Al₂O₃ nanoparticles, the reduction of particle clustering, and the reduction of distances between the composite particles. The significant grain refining during milling was revealed which showed as a reduction of particle size resulting from longer milling time. X-Ray diffraction (XRD) analysis of the nanocomposite powders also showed that designated ball milling contributes to the crystalline refining and accumulation of internal stress due to induced severe plastic deformation of the particles. It can be argued that these morphological and microstructural variations of nanocomposite powders induced by designated ball milling time was found to contribute to an improvement in the density, densification, micro-hardness (HV), nano-hardness (HN), and Young's modulus (E) of Al-5Al₂O₃ nanocomposites. HV, HN, and E values of nanocomposites were increased by ~48%, 46%, and 40%, after 12 h of milling, respectively.
    Matched MeSH terms: Hardness
  9. Experimental and theoretical approach on the optical properties of zinc borotellurite glass doped with dysprosium oxide
    Halimah MK, Ami Hazlin MN, Muhammad FD
    Spectrochim Acta A Mol Biomol Spectrosc, 2018 Apr 15;195:128-135.
    PMID: 29414569 DOI: 10.1016/j.saa.2017.12.054
    A series of glass samples with chemical formula {[(TeO2)0.7(B2O3)0.3]0.7(ZnO)0.3}1-x(Dy2O3)xwhere x=0.01, 0.02, 0.03, 0.04 and 0.05M fraction were synthesized through conventional melt-quenching method. The most common way to fabricate a glass material is by fusion of two or more component oxides followed by their quenching. This technique is known as melt-quenching technique. Kaur et al. (2016) [1] highlighted that the melt-quenching method able to enhance the mechanical properties like hardness and flexural strength of the material. The nature of the glass systems is proven to be amorphous based on the XRD pattern. The FTIR spectra of the glass systems confirm the existence of five bands which are assigned for the BO4, BO3,TeO4and TeO3vibrational groups. The density of the glass systems is increased with the addition of Dy2O3while the molar volume is found to be inversely proportional to the density of the proposed glass. The optical properties of the glasses are determined through the absorption spectra obtained from the UV-VIS spectrophotometer. From the absorption spectra, the indirect and direct optical band gaps and the Urbach energy are found to be inversely proportional to each other. As the molar fraction of the Dy2O3increased, the optical band gaps are observed to increase as opposed to the Urbach energy. For this glass system, the values of refractive index, electronic polarizability, oxide ion polarizability and the optical basicity are found to decrease as the addition of the dysprosium oxide is increased. From the emission spectra, two intense blue and yellow emission bands are observed, which correspond to the4F9/2→6H15/2and4F9/2→6H13/2transitions of Dy3+ions respectively. The CIE chromaticity coordinates of the zinc borotellurite glass systems are found to be located in the white light region.
    Matched MeSH terms: Hardness
  10. Fulltext Hard rock landforms generate 130 km ice shelf channels through water focusing in basal corrugations
    Jeofry H, Ross N, Le Brocq A, Graham AGC, Li J, Gogineni P, et al.
    Nat Commun, 2018 11 01;9(1):4576.
    PMID: 30385741 DOI: 10.1038/s41467-018-06679-z
    Satellite imagery reveals flowstripes on Foundation Ice Stream parallel to ice flow, and meandering features on the ice-shelf that cross-cut ice flow and are thought to be formed by water exiting a well-organised subglacial system. Here, ice-penetrating radar data show flow-parallel hard-bed landforms beneath the grounded ice, and channels incised upwards into the ice shelf beneath meandering surface channels. As the ice transitions to flotation, the ice shelf incorporates a corrugation resulting from the landforms. Radar reveals the presence of subglacial water alongside the landforms, indicating a well-organised drainage system in which water exits the ice sheet as a point source, mixes with cavity water and incises upwards into a corrugation peak, accentuating the corrugation downstream. Hard-bedded landforms influence both subglacial hydrology and ice-shelf structure and, as they are known to be widespread on formerly glaciated terrain, their influence on the ice-sheet-shelf transition could be more widespread than thought previously.
    Matched MeSH terms: Hardness
  11. Fulltext Simultaneous use of adzuki beans (Vigna angularis) flour as meat extender and fat replacer in reduced-fat beef meatballs (bebola daging)
    Aslinah LNF, Mat Yusoff M, Ismail-Fitry MR
    J Food Sci Technol, 2018 Aug;55(8):3241-3248.
    PMID: 30065435 DOI: 10.1007/s13197-018-3256-1
    Adzuki bean is high in protein and fiber with a potential to be used as meat extender and fat replacer in the meat product. Replacement of both the corn flour and fat with different percentages of adzuki beans flour (ABF) has successfully produced acceptable reduced fat meatballs. Meatballs with 100% (w/w) ABF replacement exhibited highest cooking yield and higher moisture content compared to meatballs without the flour, which indicates its ability to bind water. Increasing the ABF content also increased the hardness and chewiness of the meatballs, whilst decreasing their lightness and yellowness. Replacing the corn flour and fat contents with ABF has obviously decreased the fat and calorie contents of the meatballs, yet their protein and carbohydrate contents remained the same compared to control. The sensory test revealed that meatball samples with 25% (w/w) and 50% (w/w) ABF showed no significant difference compared to control but received highest overall acceptability among the panelists. This indicates that replacement of corn flour and fat with ABF especially at 50% (w/w) in the production of reduced fat meatballs resulted with better physicochemical properties and acceptable sensory compared to original meatballs.
    Matched MeSH terms: Hardness
  12. Fulltext Development and characterisation of Vitex negundo Linn. noodles
    Tan, L.S., Leila, M., Rabeta, M.S.
    Food Research, 2018;2(1):68-75.
    MyJurnal
    Formulation 2 (1 g w/w) was the most favourable and was chosen for further analyses to
    compare its composition with that of a control (0 g w/w). Total phenolic content (TPC) of
    the fresh noodles remained higher than that of the control even after cooking. However,
    after cooking, the carbohydrate and protein contents showed significant increases. The
    results showed that the lemuni-supplemented noodles have a longer shelf life compared to
    the control. The colour parameters L* and a* also showed significant differences as the
    lightness decreased, and the redness increased after the substitution. The L*, a* and b*
    values decreased significantly after the noodles of both formulations were cooked. The
    tensile strength, adhesiveness, and hardness of the lemuni noodles were significantly
    higher than those of the control. Thus, the Vitex negundo Linn. leaf has the potential to
    increase the health benefits of food products.
    Matched MeSH terms: Hardness
  13. Kesan Komposisi Gentian dan Kaedah Pemprosesan ke atas Sifat Mekanik Komposit NR/LLDPE diperkuat Twaron (Effect of Fiber Composition and Processing Methods on the Mechanical Properties of Twaron Reinforced NR/LLDPE Composites)
    Ishak Ahmad, Mohd Khairil Saat, Ibrahim Abdullah, Azizah Baharum
    Sains Malaysiana, 2004;33.
    Blends of fibre-reinforced rubber based on natural rubber-thermoplastic (NR/LLDPE) reinforced by aramid fibre have been done using melt blending process. Two different processing methods were used; internal mixer and extrusion compounding in twin screw extruder. Twaron loading in the system was varied from 0 to 30%. It was found that increasing the amount of aramid fibre led to an increase in the tensile strength, tensile modulus and hardness of the composites while the strain decreased rapidly. The results showed that the optimum composition of filler loading in NR/LLDPE blend is 20%. The ,echanical behaviour was caused by the strong Twaron-matrices interaction in the composites and effective stress concentrating function of Twaron. Composites prepared using the twin-screw extruder have a higher tensile strength and tensile using the twin-screw extruder have a higher tensile stength and tensile modulus but lower impact strength compared to those prepared using internal mixer. Study of the fracture surface by scanning electron microscopy showed that the composite prepared using the internal mixer produced random fiber orientation while the twin-screw extruder produced the fibers aligned to the longitudinal direction. The results indicate that the mechanical properties of the composite were significantly influenced by the processing technique.
    Penyediaan komposit getah asli termoplastik daripada NR/LLDPE yang diperkuat gentian Twaron telah dijalankan melalui proses adunan leburan. Dua kaedah penyediaan yang berbeza digunakan iaitu menggunakan mesin pencampur dalaman manakala kaedah kedua menggunakan pengekstrud skru kembar. Kandungan Twaron di dalam komposit telah diubah daripada 0 hingga 30%. Keputusan menunjukkan bahawa penambahan Twaron telah meningkatkan nilai tegasan maksima, modulus Young dan kekuatan hentaman komposit tetapi menurunkan nilai terikan maksima. Kandungan Twaron yang optimum adalah 20%. Kehadiran Twaron telah membentuk satu jaringan saling tindak gentian-matriks menyebabkan kekuatan regangan komposit meningkat. Twaron juga berfungsi sebagai penyerap hentaman yang berkesan. Penyediaan komposit menggunakan pengekstrud skru berkembar telah menghasilkan nilai kekuatan regangan yang lebih tinggi berbanding penggunaan pencampur dalaman sebaliknya kekuatan hentaman yang lebih rendah. Kajian morfologi menggunakan mikroskop imbasan elektron mendapati komposit yang disediakan menggunakan pencampur dalaman menghasilkan gentian dengan orientasi rawak manakala pengekstrud skru kembar menghasilkan orientasi gentian yang selari. Keputusan ini menunjukkan bahawa sifat mekanik komposit NR/LLDPE yang diperkuat Twaron sangat dipengaruhi oleh teknik pemprosesan.
    Matched MeSH terms: Hardness
  14. Mechanical properties of natural fibre reinforced PVC composites: a review
    Wirawan R, Zainudin E, Sapuan S
    Sains Malaysiana, 2009;38.
    Poly (vinyl chloride), which is commonly abbreviated as PVC, is widely used due to it being inexpensive, durable, and flexible. As a hard thermoplastic, PVC is used in the applications such as in building materials pipe and plumbing. The factors that should be considered in using PVC is safety and environmental issues. Mixing PVC with natural fibres is an interesting alternative. The main challenge in the research on natural fibre/polymer composites is the poor compatibility between the fibres and the matrix because this will affect their bonding strength. During the mixing with PVC, some natural fibres may acts as reinforcing materials while other natural fibres only act as filler, which contribute less to mechanical strength improvement. However, generally natural fibres also give positive outcome to the stiffness of the composites while decreasing the density.
    Matched MeSH terms: Hardness
  15. Dry sliding wear behaviour of talc-reinforced UHMWPE composite for implant application
    Chang BP, Hazizan Md Akil, Ramdziah bt Md Nasir
    Sains Malaysiana, 2015;44:819-825.
    As of today, ultra-high molecular weight polyethylene (UHMWPE) is a thermoplastic material normally used as bearing
    components for human joint replacements. However, formation of wear debris from UHMWPE after certain service
    periods may cause adverse effects which remain as unresolved issues. In this study, mechanical and dry sliding wear
    properties of UHMWPE reinforced with different loading of talc particles were investigated. The wear test was carried
    out using Ducom TR-20 pin-on-disc tester at different pressure velocity (pv) factors under dry sliding conditions. The
    worn surfaces and transfer films of pure UHMWPE and talc/UHMWPE composites were observed under scanning electron
    microscope (SEM). The experimental results showed that the microhardness increased with the increase of talc loadings
    in UHMWPE. The 20 wt. % talc/UHMWPE composites showed a 17% increment in microhardness as compared with pure
    UHMWPE. The dry sliding wear behaviour of UHMWPE was also improved upon the reinforcement of talc. The wear rate
    of UHMWPE decreased after incorporation of talc particles. The coefficient of friction (COF) increased slightly under low
    pv conditions. At high pv conditions, the COF decreased in values with increasing talc loadings. The improvement in
    wear behaviour may be attributed to the increase in load-carrying capacity and surface hardness of the talc/UHMWPE
    composites. SEM micrographs on worn surfaces showed that plastic deformation and grooving wear were dominant for
    UHMWPE. The plastic deformation and grooving wear were reduced upon the reinforcement of talc particles. The talc/
    UHMWPE composites produced smoother and uniform transfer films as compared to pure UHMWPE.
    Matched MeSH terms: Hardness
  16. Mechanical properties of alumina trihydrate filled polypropylene/ethylene propylene diene monomer composites for cable applications
    Reza Hashemi Farzad, Azman Hassan, M. Jawaid, M.A.M. Piah
    Sains Malaysiana, 2013;42:801-810.
    Polymeric materials such as polypropylene (PP), polyethylene (PE) and ethylene propylene diene monomer (EPDM) are widely used as insulators for cable applications. We investigated the effect of alumina trihydrate (ATH) loading on the mechanical properties of PP/EPDM blend. Preliminary study showed that PP/EPDM (60:40) was the optimum composition. ATH filled PP/EPDM composites was prepared by using twin screw extruder. In this study, the tensile properties and hardness of the composites were evaluated. The tensile modulus and hardness increased while elongation at break and tensile strength decreased with increasing ATH content. Scanning electron microscope was used to study the morphology of ATH in PP/EPDM blend.
    Matched MeSH terms: Hardness
  17. Fulltext Assessment of Nano-Indentation Method in Mechanical Characterization of Heterogeneous Nanocomposite Materials Using Experimental and Computational Approaches
    Karimzadeh A, R Koloor SS, Ayatollahi MR, Bushroa AR, Yahya MY
    Sci Rep, 2019 10 31;9(1):15763.
    PMID: 31673118 DOI: 10.1038/s41598-019-51904-4
    This study investigates the capacity of the nano-indentation method in the mechanical characterization of a heterogeneous dental restorative nanocomposite using experimental and computational approaches. In this respect, Filtek Z350 XT was selected as a nano-particle reinforced polymer nanocomposite with a specific range of the particle size (50 nm to 4 µm), within the range of indenter contact area of the nano-indentation experiment. A Sufficient number of nano-indentation tests were performed in various locations of the nanocomposite to extract the hardness and elastic modulus properties. A hybrid computational-experimental approach was developed to examine the extracted properties by linking the internal behaviour and the global response of the nanocomposite. In the computational part, several representative models of the nanocomposite were created in a finite element environment to simulate the mechanism of elastic-plastic deformation of the nanocomposite under Berkovich indenter. Dispersed values of hardness and elastic modulus were obtained through the experiment with 26.8 and 48.5 percent average errors, respectively, in comparison to the nanocomposite properties, respectively. A disordered shape was predicted for plastic deformation of the equilateral indentation mark, representing the interaction of the particles and matrix, which caused the experiment results reflect the local behaviour of the nanocomposite instead of the real material properties.
    Matched MeSH terms: Hardness
  18. Fulltext Effect of Tilt Angle and Pin Depth on Dissimilar Friction Stir Lap Welded Joints of Aluminum and Steel Alloys
    Chitturi V, Pedapati SR, Awang M
    Materials (Basel), 2019 Nov 26;12(23).
    PMID: 31779107 DOI: 10.3390/ma12233901
    Automobile, aerospace, and shipbuilding industries are looking for lightweight materials for cost effective manufacturing which demands the welding of dissimilar alloy materials. In this study, the effect of tool rotational speed, welding speed, tilt angle, and pin depth on the weld joint were investigated. Aluminum 5052 and 304 stainless-steel alloys were joined by friction stir welding in a lap configuration. The design of the experiments was based on Taguchi's orthogonal array for conducting the experiments with four factors and three levels for each factor. The microstructural analysis showed tunnel defects, micro voids, and cracks which formed with 0° and 1.5° tilt angles. The defects were eliminated when the tilt angle increased to 2.5° and a mixed stir zone was formed with intermetallic compounds. The presence of the intermetallic compounds increased with the increase in tilt angle and pin depth which further resulted in obtaining a defect-free weld. Hooks were formed on either side of the weld zone creating a mechanical link for the joint. A Vickers hardness value of HV 635.46 was achieved in the mixed stir zone with 1000 rpm, 20 mm/min, and 4.2 mm pin depth with a tilt angle of 2.5°, which increased by three times compared to the hardness of SS 304 steel. The maximum shear strength achieved with 800 rpm, 40 mm/min, and a 4.3 mm pin depth with a tilt angle of 2.5° was 3.18 kN.
    Matched MeSH terms: Hardness
  19. Fulltext Comparative Study of Aromatic and Cycloaliphatic Isocyanate Effects on Physico-Chemical Properties of Bio-Based Polyurethane Acrylate Coatings
    Mudri NH, Abdullah LC, Aung MM, Salleh MZ, Awang Biak DR, Rayung M
    Polymers (Basel), 2020 Jul 03;12(7).
    PMID: 32635384 DOI: 10.3390/polym12071494
    Crude jatropha oil (JO) was modified to form jatropha oil-based polyol (JOL) via two steps in a chemical reaction known as epoxidation and hydroxylation. JOL was then reacted with isocyanates to produce JO-based polyurethane resin. In this study, two types of isocyanates, 2,4-toluene diisocyanate (2,4-TDI) and isophorone diisocyanate (IPDI) were introduced to produce JPUA-TDI and JPUA-IPDI respectively. 2,4-TDI is categorised as an aromatic isocyanate whilst IPDI is known as a cycloaliphatic isocyanate. Both JPUA-TDI and JPUA-IPDI were then end-capped by the acrylate functional group of 2-hydroxyethyl methacrylate (HEMA). The effects of that isocyanate structure were investigated for their physico, chemical and thermal properties. The changes of the functional groups during each synthesis step were monitored by FTIR analysis. The appearance of urethane peaks was observed at 1532 cm-1, 1718 cm-1 and 3369 cm-1 while acrylate peaks were detected at 815 cm-1 and 1663 cm-1 indicating that JPUA was successfully synthesised. It was found that the molar mass of JPUA-TDI was doubled compared to JPUA-IPDI. Each resin showed a similar degradation pattern analysed by thermal gravimetric analysis (TGA). For the mechanical properties, the JPUA-IPDI-based coating formulation exhibited a higher hardness value but poor adhesion compared to the JPUA-TDI-based coating formulation. Both types of jatropha-based polyurethane acrylate may potentially be used in an ultraviolet (UV) curing system specifically for clear coat surface applications to replace dependency on petroleum-based chemicals.
    Matched MeSH terms: Hardness
  20. Fulltext The roles of banana peel powders to alter technological functionality, sensory and nutritional quality of chicken sausage
    Zaini HBM, Sintang MDB, Pindi W
    Food Sci Nutr, 2020 Oct;8(10):5497-5507.
    PMID: 33133552 DOI: 10.1002/fsn3.1847
    Chicken sausages included with three different quantities of banana (Musa balbisiana) peel powder. The technological properties (cooking yield, texture, water-holding capacity, color, rheology, and texture), composition, and sensory acceptability were assessed. In storage study, lipid oxidation of the best formulation from the sensory score was evaluated. The inclusion of banana peel powder (BPP) raises the nutritional value with regard to an increase in dietary fiber and a reduction in the sausage fat content. The addition of BPP also causes a significant increase in the cooking yield and water-holding capacity. Additionally, storage modulus values increase with the increase in the BPP's concentration. However, with BPP incorporation, a hard texture and darkening of the sausage were observed. Interestingly, our findings exhibit the compromise in microstructural of chicken sausage with high percentage of BPP manifested by the high storage modulus and hardness but with low resistance toward stress, short linear viscoelastic region. This aspect also caused a significant change in the sensory score. The TBA value in the sausage containing 2% BPP exhibited a delay in lipid oxidation up to 55%, prompting its antioxidant potential. Generally, the incorporation of BPP to chicken sausage changes its properties. BPP has been a potential candidate as a value-adding ingredient that may be used during meat preparation since it positively influences the nutritional value and specific technological properties of the food.
    Matched MeSH terms: Hardness
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