Displaying publications 81 - 100 of 135 in total

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  1. Mechanical and microarchitectural analyses of cancellous bone through experiment and computer simulation
    Syahrom A, Abdul Kadir MR, Abdullah J, Öchsner A
    Med Biol Eng Comput, 2011 Dec;49(12):1393-403.
    PMID: 21947767 DOI: 10.1007/s11517-011-0833-0
    The relationship between microarchitecture to the failure mechanism and mechanical properties can be assessed through experimental and computational methods. In this study, both methods were utilised using bovine cadavers. Twenty four samples of cancellous bone were extracted from fresh bovine and the samples were cleaned from excessive marrow. Uniaxial compression testing was performed with displacement control. After mechanical testing, each specimen was ashed in a furnace. Four of the samples were exemplarily scanned using micro-computed tomography (μCT) and three dimensional models of the cancellous bones were reconstructed for finite element simulation. The mechanical properties and the failure modes obtained from numerical simulations were then compared to the experiments. Correlations between microarchitectural parameters to the mechanical properties and failure modes were then made. The Young's modulus correlates well with the bone volume fraction with R² = 0.615 and P value 0.013. Three different types of failure modes of cancellous bone were observed: oblique fracture (21.7%), perpendicular global fracture (47.8%), and scattered localised fracture (30.4%). However, no correlations were found between the failure modes to the morphological parameters. The percentage of error between computer predictions and the actual experimental test was from 6 to 12%. These mechanical properties and information on failure modes can be used for the development of synthetic cancellous bone.
    Matched MeSH terms: Elastic Modulus
  2. Mechanical and physical properties of calcium silicate/alumina composite for biomedical engineering applications
    Shirazi FS, Mehrali M, Oshkour AA, Metselaar HS, Kadri NA, Abu Osman NA
    J Mech Behav Biomed Mater, 2014 Feb;30:168-75.
    PMID: 24316872 DOI: 10.1016/j.jmbbm.2013.10.024
    The focus of this study is to investigate the effect of Al2O3 on α-calcium silicate (α-CaSiO3) ceramic. α-CaSiO3 was synthesized from CaO and SiO2 using mechanochemical method followed by calcinations at 1000°C. α-CaSiO3 and alumina were grinded using ball mill to create mixtures, containing 0-50w% of Al2O3 loadings. The powders were uniaxially pressed and followed by cold isostatic pressing (CIP) in order to achieve greater uniformity of compaction and to increase the shape capability. Afterward, the compaction was sintered in a resistive element furnace at both 1150°C and 1250°C with a 5h holding time. It was found that alumina reacted with α-CaSiO3 and formed alumina-rich calcium aluminates after sintering. An addition of 15wt% of Al2O3 powder at 1250°C were found to improve the hardness and fracture toughness of the calcium silicate. It was also observed that the average grain sizes of α-CaSiO3 /Al2O3 composite were maintained 500-700nm after sintering process.
    Matched MeSH terms: Elastic Modulus
  3. Fulltext Mechanical and physical properties of gellan gum (GG) biofilm: effect of glycerol
    Razali, M.H., Ismail, N.A., Osman, U.M., Amin, K.A.M.
    ASM Science Journal, 2018;11(101):158-165.
    MyJurnal
    The aim of this work was to investigate the effect of glycerol concentration on mechanical
    and physical properties of gellan gum (GG) biofilm. The biofilm was prepared using solvent
    casting method and the effective glycerol concentration was found to be within 30-50%
    w/w (based on GG weight). At 60 and 70 w/w% of glycerol, the films started to distort
    because the films was flexible and brittle. As glycerol concentration was increased the tensile
    strength (TS) and Youngs modulus (E) of films decreased. Somehow, elongation at break
    (EAB), water vapor transmission rate (WVTR) and swelling of films was increased. Glycerol
    plasticized GG biofilm was thermally stable and flexible, proposed its can be exploited as
    film-forming material and with optimized glycerol concentration it has good mechanical and
    physical properties for edible biofilm.
    Matched MeSH terms: Elastic Modulus
  4. Fulltext Mechanical properties of wood-wool cement composite board manufactured using selected Malaysian fast grown timber species
    Ahmad, Z., Wee, L.S., Fauzi, M.A.
    ASM Science Journal, 2011;5(1):27-35.
    MyJurnal
    This paper reports the mechanical properties of cement composite boards made using wood-wool from a lesser known Malaysian timber species. A total of 108 specimens were fabricated using Portland cement (Type I) and wood-wool from Kelampayan (Neolamarckia cadamba). The cement to wood ratio of the specimens was 2 to 1 by weight. The aim of the study was to determine the density; flexural, compressive and tensile strength of wood-wool cement composite boards (WWCCB) by studying boards with wood-wool sized 1.5 mm, 2.5 mm and 3.5 mm and board thickness 25 mm, 50 mm and 75mm. The physical and mechanical properties of the boards were evaluated according to ASTM D 1037-96a (Standard testing method for evaluating properties of wood-based fibre and particle panel materials) and MS934:1986. Results showed that mechanical properties of WWCCB were greatly influenced by the density; as the density decreased, the mechanical strengths also decreased. However, the strength properties of the composite boards did not display a similar trend when subjected to different types of loading conditions. The compressive strength increased with thicker boards (50 mm and 75 mm) but the modulus of elasticity and modulus of rupture declined as the thickness of the board was increased.
    Matched MeSH terms: Elastic Modulus
  5. Fulltext Mechanical property and quality aspects of rice dried in industrial dryers
    Sarker MSH, Hasan SMK, Ibrahim MN, Aziz NA, Punan MS
    J Food Sci Technol, 2017 Nov;54(12):4129-4134.
    PMID: 29085156 DOI: 10.1007/s13197-017-2856-5
    The influence of drying methods on selected mechanical properties and qualities of MR219 rice variety has been investigated. The results showed significant effects of drying methods on bending strength and head rice yields while the average bending strength of paddy were 28.6-31.8 MPa. The effect of drying methods on apparent modulus of elasticity of rice was not significant (204.5-222.4 MPa). The fracture energy of rice varied significantly under control drying but not with industrial drying methods. Higher temperature in drying by IBD contributed in making the grains tougher, where the effect of FBD temperature was positive toward the development of fracture energy inside rice kernel. IBD at temperature above 40 °C resulted in lower bending strength in rice kernels which affected head rice yield. Two stage paddy drying practices with FBD using temperature of 115-125 °C as first stage is still acceptable, and inclined bed dryer either as single stage or as second stage after FBD should be operated at temperature of <40 °C to maintain head rice yield. The whiteness and milling recovery of rice achieved from different drying methods were comparable.
    Matched MeSH terms: Elastic Modulus
  6. Fulltext Melt- vs. Non-Melt Blending of Complexly Processable Ultra-High Molecular Weight Polyethylene/Cellulose Nanofiber Bionanocomposite
    Sharip NS, Ariffin H, Yasim-Anuar TAT, Andou Y, Shirosaki Y, Jawaid M, et al.
    Polymers (Basel), 2021 Jan 27;13(3).
    PMID: 33513876 DOI: 10.3390/polym13030404
    The major hurdle in melt-processing of ultra-high molecular weight polyethylene (UHMWPE) nanocomposite lies on the high melt viscosity of the UHMWPE, which may contribute to poor dispersion and distribution of the nanofiller. In this study, UHMWPE/cellulose nanofiber (UHMWPE/CNF) bionanocomposites were prepared by two different blending methods: (i) melt blending at 150 °C in a triple screw kneading extruder, and (ii) non-melt blending by ethanol mixing at room temperature. Results showed that melt-processing of UHMWPE without CNF (MB-UHMWPE/0) exhibited an increment in yield strength and Young's modulus by 15% and 25%, respectively, compared to the Neat-UHMWPE. Tensile strength was however reduced by almost half. Ethanol mixed sample without CNF (EM-UHMWPE/0) on the other hand showed slight decrement in all mechanical properties tested. At 0.5% CNF inclusion, the mechanical properties of melt-blended bionanocomposites (MB-UHMWPE/0.5) were improved as compared to Neat-UHMWPE. It was also found that the yield strength, elongation at break, Young's modulus, toughness and crystallinity of MB-UHMWPE/0.5 were higher by 28%, 61%, 47%, 45% and 11%, respectively, as compared to the ethanol mixing sample (EM-UHMWPE/0.5). Despite the reduction in tensile strength of MB-UHMWPE/0.5, the value i.e., 28.4 ± 1.0 MPa surpassed the minimum requirement of standard specification for fabricated UHMWPE in surgical implant application. Overall, melt-blending processing is more suitable for the preparation of UHMWPE/CNF bionanocomposites as exhibited by their characteristics presented herein. A better mechanical interlocking between UHMWPE and CNF at high temperature mixing with kneading was evident through FE-SEM observation, explains the higher mechanical properties of MB-UHMWPE/0.5 as compared to EM-UHMWPE/0.5.
    Matched MeSH terms: Elastic Modulus
  7. Microfluidic production of bioactive fibrin micro-beads embedded in crosslinked collagen used as an injectable bulking agent for urinary incontinence treatment
    Vardar E, Larsson HM, Allazetta S, Engelhardt EM, Pinnagoda K, Vythilingam G, et al.
    Acta Biomater, 2018 02;67:156-166.
    PMID: 29197579 DOI: 10.1016/j.actbio.2017.11.034
    Endoscopic injection of bulking agents has been widely used to treat urinary incontinence, often due to urethral sphincter complex insufficiency. The aim of the study was to develop a novel injectable bioactive collagen-fibrin bulking agent restoring long-term continence by functional muscle tissue regeneration. Fibrin micro-beads were engineered using a droplet microfluidic system. They had an average diameter of 140 μm and recombinant fibrin-binding insulin-like growth factor-1 (α2PI1-8-MMP-IGF-1) was covalently conjugated to the beads. A plasmin fibrin degradation assay showed that 72.5% of the initial amount of α2PI1-8-MMP-IGF-1 loaded into the micro-beads was retained within the fibrin micro-beads. In vitro, the growth factor modified fibrin micro-beads enhanced cell attachment and the migration of human urinary tract smooth muscle cells, however, no change of the cellular metabolic activity was seen. These bioactive micro-beads were mixed with genipin-crosslinked homogenized collagen, acting as a carrier. The collagen concentration, the degree of crosslinking, and the mechanical behavior of this bioactive collagen-fibrin injectable were comparable to reference samples. This novel injectable showed no burst release of the growth factor, had a positive effect on cell behavior and may therefore induce smooth muscle regeneration in vivo, necessary for the functional treatment of stress and other urinary incontinences.

    STATEMENT OF SIGNIFICANCE: Urinary incontinence is involuntary urine leakage, resulting from a deficient function of the sphincter muscle complex. Yet there is no functional cure for this devastating condition using current treatment options. Applied physical and surgical therapies have limited success. In this study, a novel bioactive injectable bulking agent, triggering new muscle regeneration at the injection site, has been evaluated. This injectable consists of cross-linked collagen and fibrin micro-beads, functionalized with bound insulin-like growth factor-1 (α2PI1-8-MMP-IGF-1). These bioactive fibrin micro-beads induced human smooth muscle cell migration in vitro. Thus, this injectable bulking agent is apt to be a good candidate for regeneration of urethral sphincter muscle, ensuring a long-lasting treatment for urinary incontinence.

    Matched MeSH terms: Elastic Modulus
  8. Fulltext Modeling and simulation of artificial hair cell sensor for underwater applications
    M.N.M. Nawi, A.A. Manaf, M.R. Arshad
    ASM Science Journal, 2013;7(2):144-151.
    MyJurnal
    This article uses finite volume and finite element methods for optimization of the artificial hair cell sensor. The performance of the sensor was investigated for different materials such as sicon and polysilicon and by varying hair cell dimensions including width and length. The silicon material which has low young modulus was proposed based on the simulation performance. The performance of the hair cell sensor was achieved by increasing the hair cell length while increasing the width did not significantly influence the performance. The
    performance of the sensor was studied for its viscous force, deflection, von mises stress and sensitivity. From the simulation, the hair cell with a length of 1600 µm and 80 µm width was suggested for the subsequent analysis. Another way to improve the performance was by modifying the hair cell geometry and it was proved that the modified hair cell was more sensitive, based on the deflection. The angle of flow that hit the hair cell also affected the deflection of the sensor where the zero angle flow which was parallel to the substrate was the most effective angle. The limitations of the performance of hair cell for various fluid velocity were also discussed in this paper.
    Matched MeSH terms: Elastic Modulus
  9. Fulltext Molecular Dynamics Study of Poly(dimethylsiloxane) Nanostructure Distortion in a Soft Lithography Demolding Process
    Abdul Manap AH, Md Izah SS, Mohamed K
    ACS Omega, 2019 Dec 03;4(23):20257-20264.
    PMID: 31815228 DOI: 10.1021/acsomega.9b02547
    This study aims at investigating the distortion of poly(dimethylsiloxane) (PDMS) nanostructures in a soft lithography demolding process using molecular dynamics simulation. Experimental results show that after peeling, PDMS nanopillars became 10-60% longer in height than the mold size. Molecular dynamics simulations have been employed to plot the stress-strain curve of the nanopillars when subjected to uniaxial stress. Three force fields (COMPASS, CVFF, and PCFF) were used for modeling. The demolding process in soft lithography and nanoimprint lithography causes significant deformation in replication. The experimental results show clear signs of elongation after demolding. Molecular dynamics simulations are employed to study the stress-strain relationship of the PDMS nanopillars. The results from the simulation show that a PDMS nanopillar at temperature T = 300 K under tensile stress shows characteristics of flexible plastic under tensile stress and has a lower Young's modulus, ultimate tensile stress, and Poisson's ratio.
    Matched MeSH terms: Elastic Modulus
  10. Fulltext Morphology observation and physical properties of phenolic resin-silicate layered nanocomposites
    Norul Azlin, M.Z., Senin, H.B., Kok Sheng, C.
    Journal of Nuclear and Related Technologies, 2009;2009(1):121-134.
    MyJurnal
    Phenolic resin-silica nanocomposites samples in pellet shape have been successfully prepared by intercalation of polymer solution through the hot pressing method. The phenolic resin is modified with organic elastomers of silica nanoparticles, which is about 20 nanometer in diameter. The change of density and porosity was studied based on the addition of silica content in the phenolic resin composites. The densities of composites increased with the addition of the silica content from 10 wt.% to 40 wt.%. On the other hand, the porosity percentage was decreased with increasing of silica contents. The mechanical properties (Young’s modulus, energy to break and time to failure) of the nanocomposites samples were identified using the Universal Testing Material Machine (UTM). The results of Young’s modulus, energy to break and time to failure of the phenolic resin composites were found to be slightly increased with silica content from 10 wt.% to 30 wt.%. The X-Ray Microtomogaphy (XRM) topographies have shown that the porosity exists on fracture structure for each nanocomposite. The nanocomposites surface structure has been analyzed using Scanning Electron Microscope (SEM). The observation shows that the fracture surface of the pure phenolic resin is relatively smooth and glassy, which is typical for a brittle material, but the phenolic resin- silica composites fracture surface is not smooth at all. The observations indicate the pure phenolic resin is brittle than phenolic resin-silica nanocomposites. Consequently, the physical properties of the phenolic resin-silica nanocomposites were improved with the addition of 10 wt.% to 30 wt.% silica contents, as compared to that of the pure phenolic resin.
    Matched MeSH terms: Elastic Modulus
  11. Nanocrystalline forsterite for biomedical applications: synthesis, microstructure and mechanical properties
    Ramesh S, Yaghoubi A, Lee KY, Chin KM, Purbolaksono J, Hamdi M, et al.
    J Mech Behav Biomed Mater, 2013 Sep;25:63-9.
    PMID: 23726923 DOI: 10.1016/j.jmbbm.2013.05.008
    Forsterite (Mg2SiO4) because of its exceptionally high fracture toughness which is close to that of cortical bones has been nominated as a possible successor to calcium phosphate bioceramics. Recent in vitro studies also suggest that forsterite possesses good bioactivity and promotes osteoblast proliferation as well as adhesion. However studies on preparation and sinterability of nanocrystalline forsterite remain scarce. In this work, we use a solid-state reaction with magnesium oxide (MgO) and talc (Mg3Si4(OH)2) as the starting precursors to synthesize forsterite. A systematic investigation was carried out to elucidate the effect of preparatory procedures including heat treatment, mixing methods and sintering temperature on development of microstructures as well as the mechanical properties of the sintered forsterite body.
    Matched MeSH terms: Elastic Modulus
  12. Fulltext Nanomechanical Behavior of Multi-Walled Carbon Nanotubes Particulate Reinforced Aluminum Nanocomposites Prepared by Ball Milling
    Ostovan F, Matori KA, Toozandehjani M, Oskoueian A, Yusoff HM, Yunus R, et al.
    Materials (Basel), 2016 Feb 26;9(3).
    PMID: 28773261 DOI: 10.3390/ma9030140
    The nanomechanical properties of carbon nanotubes particulate-reinforced aluminum matrix nanocomposites (Al-CNTs) have been characterized using nanoindentation. Bulk nanocomposite specimens containing 2 wt % multiwalled CNTs (MWCNTs) were synthesized by a combination of ball milling and powder metallurgy route. It has been tried to understand the correlation between microstructural evolution particularly carbon nanotubes (CNTs) dispersion during milling and mechanical properties of Al-2 wt % nanocomposites. Maximum enhancement of +23% and +44% has been found in Young's modulus and hardness respectively, owing to well homogenous dispersion of CNTs within the aluminum matrix at longer milling time.
    Matched MeSH terms: Elastic Modulus
  13. Nanomechanical properties, wear resistance and in-vitro characterization of Ta2O5nanotubes coating on biomedical grade Ti-6Al-4V
    Sarraf M, Razak BA, Nasiri-Tabrizi B, Dabbagh A, Kasim NHA, Basirun WJ, et al.
    J Mech Behav Biomed Mater, 2017 02;66:159-171.
    PMID: 27886563 DOI: 10.1016/j.jmbbm.2016.11.012
    Tantalum pentoxide nanotubes (Ta2O5NTs) can dramatically raise the biological functions of different kinds of cells, thus have promising applications in biomedical fields. In this study, Ta2O5NTs were prepared on biomedical grade Ti-6Al-4V alloy (Ti64) via physical vapor deposition (PVD) and a successive two-step anodization in H2SO4: HF (99:1)+5% EG electrolyte at a constant potential of 15V. To improve the adhesion of nanotubular array coating on Ti64, heat treatment was carried out at 450°C for 1h under atmospheric pressure with a heating/cooling rate of 1°Cmin-1. The surface topography and composition of the nanostructured coatings were examined by atomic force microscopy (AFM) and X-ray electron spectroscopy (XPS), to gather information about the corrosion behavior, wear resistance and bioactivity in simulated body fluids (SBF). From the nanoindentation experiments, the Young's modulus and hardness of the 5min anodized sample were ~ 135 and 6GPa, but increased to ~ 160 and 7.5GPa, respectively, after annealing at 450°C. It was shown that the corrosion resistance of Ti64 plates with nanotubular surface modification was higher than that of the bare substrate, where the 450°C annealed specimen revealed the highest corrosion protection efficiency (99%). Results from the SBF tests showed that a bone-like apatite layer was formed on nanotubular array coating, as early as the first day of immersion in simulated body fluid (SBF), indicating the importance of nanotubular configuration on the in-vitro bioactivity.
    Matched MeSH terms: Elastic Modulus
  14. On finite element modeling of single- and multi-walled carbon nanotubes
    Rahmandoust M, Ochsner A
    J Nanosci Nanotechnol, 2012 Oct;12(10):8129-36.
    PMID: 23421189
    In this study, Single-Walled and Multi-Walled Carbon Nanotubes in their perfect forms were investigated by the Finite Element Method. Details on the modeling of the structure are provided in this paper, including the appropriate elements, the element properties that should be defined based on the atomic structure of Carbon Nanotubes and the corresponding chemical bonds. Non-covalent van der Waals interactions between two neighbor atoms as well as the required approximations for the modeling of the structures with this kind of interaction are also presented. Specific attention was dedicated to the necessity of using some time- and energy-consuming steps in the simulation process. First, the effect of simulating only a single ring of the whole structure is studied to find out if it would represent the same mechanical behavior as the long structure. Results show that by applying an appropriate set of boundary conditions, the stiffness of the shortened structure is practically equal to the long perfect structure. Furthermore, Multi-Walled Carbon Nanotube structures with and without defining the van der Waals force are studied. Based on the observations, applying the van der Waals force does not significantly influence the obtained Young's modulus of the structure in the case of a uniaxial tensile test.
    Matched MeSH terms: Elastic Modulus
  15. Fulltext On the Use of OPEFB-Derived Microcrystalline Cellulose and Nano-Bentonite for Development of Thermoplastic Starch Hybrid Bio-Composites with Improved Performance
    Lai DS, Osman AF, Adnan SA, Ibrahim I, Alrashdi AA, Ahmad Salimi MN, et al.
    Polymers (Basel), 2021 Mar 15;13(6).
    PMID: 33803984 DOI: 10.3390/polym13060897
    Thermoplastic starch (TPS) hybrid bio-composite films containing microcrystalline cellulose (C) and nano-bentonite (B) as hybrid fillers were studied to replace the conventional non-degradable plastic in packaging applications. Raw oil palm empty fruit bunch (OPEFB) was subjected to chemical treatment and acid hydrolysis to obtain C filler. B filler was ultra-sonicated for better dispersion in the TPS films to improve the filler-matrix interactions. The morphology and structure of fillers were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). TPS hybrid bio-composite films were produced by the casting method with different ratios of B and C fillers. The best ratio of B/C was determined through the data of the tensile test. FTIR analysis proved the molecular interactions between the TPS and the hybrid fillers due to the presence of polar groups in their structure. XRD analysis confirmed the intercalation of the TPS chains between the B inter-platelets as a result of well-developed interactions between the TPS and hybrid fillers. SEM images suggested that more plastic deformation occurred in the fractured surface of the TPS hybrid bio-composite film due to the higher degree of stretching after being subjected to tensile loading. Overall, the results indicate that incorporating the hybrid B/C fillers could tremendously improve the mechanical properties of the films. The best ratio of B/C in the TPS was found to be 4:1, in which the tensile strength (8.52MPa), Young's modulus (42.0 MPa), elongation at break (116.4%) and tensile toughness of the film were increased by 92%, 146%, 156% and 338%, respectively. The significantly improved strength, modulus, flexibility and toughness of the film indicate the benefits of using the hybrid fillers, since these features are useful for the development of sustainable flexible packaging film.
    Matched MeSH terms: Elastic Modulus
  16. Fulltext Parametric study on volume fraction of representative volume element (rve) CFRP and gfrp towards tensile properties
    Ahmad Fuad Ab Ghani, Mohd Irman Ramli, Ridhwan Jumaidin, Dharmalingam, Sivakumar, Fudhail Abdul Munir, Mohd Syukri Yob
    Malaysian Journal of Applied Sciences, 2020;5(2):17-29.
    MyJurnal
    The study of Representative Volume Element (RVE) on Composite Material has been performed in the aim to obtain the relation and effect of fiber volume fraction on its tensile properties which is one of the important mechanical properties for composite designers in automotive and aerospace community.The properties such as fibre content, orientation, dimension of constituent fibres (diameter), level of intermixing of fibres, interface bonding between fibre and matrix, and arrangement of fibres between different types of fibres, influences the mechanical properties of hybrid composite.Representative Volume Element (RVE) for each constituent Carbon Fiber Reinforced Polymer (CFRP) and Glass Fiber Reinforced Polymer (GFRP) assumed isotropic behavior for carbon fibre, glass fibre and epoxy resin matrix and assumed to be perfectly bonded interface between fibre and matrix region i.e. strain compatibility at the interface. The scope of study on the micro mechanical modelling via representative volume element (RVE) is limited only to unidirectional composites.The result of parametric study performed deduces that incremental volume fraction of carbon and glass respectively will increase the E11 (Modulus of Elasticity in Tensile Direction) and enhance the tensile properties of both CFRP and GFRP.
    Matched MeSH terms: Elastic Modulus
  17. Fulltext Penetration mechanics of elongated female and male genitalia of earwigs
    Matsumura Y, Kamimura Y, Lee CY, Gorb SN, Rajabi H
    Sci Rep, 2021 04 12;11(1):7920.
    PMID: 33846369 DOI: 10.1038/s41598-021-86864-1
    We unveiled the penile penetration mechanics of two earwig species, Echinosoma horridum, whose intromittent organ, termed virga, is extraordinarily long, and E. denticulatum, whose virga is conversely short. We characterised configuration, geometry, material and bending stiffness for both virga and spermatheca. The short virga of E. denticulatum has a material gradient with the stiffer base, whereas the long virga of E. horridum and the spermathecae of both species are homogeneously sclerotised. The long virga of E. horridum has a lower bending stiffness than the spermatheca. The virga of E. denticulatum is overall less flexible than the spermatheca. We compared our results to a previous study on the penetration mechanics of elongated beetle genitalia. Based on the comparison, we hypothesised that the lower stiffness of the male intromittent organ comparing to the corresponding female structure is a universal prerequisite for the penetration mechanics of the elongated intromittent organ in insects.
    Matched MeSH terms: Elastic Modulus
  18. Penyediaan dan pencirian nanokomposit epoksi berpenguat getah ash terepoksida
    Se YEN, Sahrim Armad, Rozaidi Rasid, Yew CH, Lee YS, Tarawneh MA
    Sains Malaysiana, 2014;43:1231-1237.
    Komposit epoksi berpengisi hibrid OMMT (organ-monmorilonit) dan getah asli terepoksida (ENR) telah dihasilkan dengan menggunakan kaedah penyemperitan berskru kembar pusingan searah. Ujian regangan ke atas sistem epoksi yang dihasilkan menunjukkan modulus Young bagi komposit hibrid epoksi adalah lebih tinggi daripada resin tanpa pengisi dan nilai modulus didapati meningkat dengan peningkatan komposisi OMMT dalam matriks (setinggi 40% peningkatan). Hal ini dipercayai adalah disebabkan oleh sifat tegar lapisan MMT. Sementara itu, peningkatan luas permukaan kawasan antara fasa ekoran kehadiran fasa penambah didapati telah mengurangkan tegasan alah dan terikan akhir komposit hibrid yang dihasilkan. Pemeriksaan mikrostruktur komposit hibrid epoksi melalui TEM dan xRD mendedahkan taburan OMMT dalam matriks epoksi dengan susunan interkalasi dan pengelupasan. Analisis DSC ke atas sampel yang termatang menunjukkan bahawa T g sistem komposit hibrid adalah rendah berbanding dengan sistem perduaan (ESB dan ESLE). Pengurangan ketumpatan taut silang disyaki merupakan punca penyusutan T g ini.
    Matched MeSH terms: Elastic Modulus
  19. Fulltext Physical and mechanical properties of cassava-bamboo composite lumber
    Ros Syazmini Mohd Ghani, Razak Wahab, Noor Maisarah Che Musthafa, Nasihah Mokhtar, Mohamad Saiful Sulaiman, Lee, Man Djun
    Journal of Engineering and Science Research, 2018;2(6):6-9.
    MyJurnal
    The study was carried out to determine the physical and mechanical properties of composite lumber made from cassava (Mahinot esculenta Crantz) and bamboo (Bambusa vulgaris) in different ratios which is 100% cassava with 0% bamboo, 75% cassava with 25% bamboo, 50% cassava with 50% bamboo, 25% cassava with 75% bamboo and 0% cassava with 100% bamboo. The tests samples for determining the strength properties were divided into two categories namely mechanical testing and physical testing. Basic density of the samples was carried out for physical testing. The lowest basic density was in samples with 100% cassava which is 0.49 g/cm3 and highest in samples with 100% bamboo which is 0.68 g/cm3. Two tests for the mechanical testing are bending test and compression test. In bending test, modulus of elasticity (MOE) and modulus of rupture (MOR) were both highest for samples with 100% bamboo which the reading of MOE was 16794.03 N/mm2 and 122.52 N/mm2 for MOR. Similar to the bending test, compression test is the highest for the samples with 100% bamboo which are 65.58 N/mm2. From statistical analysis, the basic density, static bending can compression strength give significant value at 95% confidence interval.
    Matched MeSH terms: Elastic Modulus
  20. Physical properties and biocompatibility of oligochitosan membrane film as wound dressing
    Ujang Z, Abdul Rashid AH, Suboh SK, Halim AS, Lim CK
    J Appl Biomater Funct Mater, 2014 Dec 30;12(3):155-62.
    PMID: 24700269 DOI: 10.5301/jabfm.5000190
    BACKGROUND: The physical and biological characteristics of oligochitosan (O-C) film, including its barrier and mechanical properties, in vitro cytotoxicity and in vivo biocompatibility, were studied to assess its potential use as a wound dressing.

    METHODS: Membrane films were prepared from water-soluble O-C solution blended with various concentrations of glycerol to modify the physical properties of the films. In vitro and in vivo biocompatibility evaluations were performed using primary human skin fibroblast cultures and subcutaneous implantation in a rat model, respectively.

    RESULTS: Addition of glycerol significantly influenced the barrier and mechanical properties of the films. Water absorption capacity was in the range of 80%-160%, whereas water vapor transmission rate varied from 1,180 to 1,618 g/m2 per day. Both properties increased with increasing glycerol concentration. Tensile strength decreased while elongation at break increased with the addition of glycerol. O-C films were found to be noncytotoxic to human fibroblast cultures and histological examination proved that films are biocompatible.

    CONCLUSION: These results indicate that the membrane film from O-C has potential application as a wound-dressing material.

    Matched MeSH terms: Elastic Modulus
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