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Bending Modulus (bending + modulus)
Selected AbstractsMechanical and fracture properties for predicting cracking in semi-sweet biscuitsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2005Qasim Saleem Summary Mechanical and fracture properties required for predicting crack development in semi-sweet (,rich tea') biscuits have been experimentally determined. Pilot-scale biscuits of different fat concentrations were prepared and studied with commercial biscuits at different moisture contents. Bending modulus, fracture stress and strain were measured using three-point bending tests. All biscuit types showed considerable dependence on moisture content over a range of 4,12%. Young's modulus and failure stress showed a uniform decrease and failure strain showed an increase with increasing moisture content. For pilot-scale biscuits of different fat concentrations, an increase in fat level caused a decrease in modulus and failure stress values; however, the failure strains were very similar for all the fat types. The testing of the samples with top surface up and top surface down revealed that the sample orientation does not affect the measured parameters. The measured parameters also did not show any directional dependence within the plane, thus assuring that the assumption of an isotropic material would be valid for modelling. The mechanical and fracture properties measured in this study will serve as a very useful set of data to predict the stress state and cracking of the checked biscuits. [source] Microfluidic Endoskeletons: Materials of Controlled Shape and Stiffness with Photocurable Microfluidic Endoskeleton (Adv. Mater.ADVANCED MATERIALS, Issue 27 200927/2009) Photocurable microfluidic channel networks in thin layers of polydimethylsiloxane can act as on-demand endoskeletons to lock-in specific shapes, report Orlin Velev and co-workers on p. 2803. The light-induced solidification of photopolymer inside the microchannel networks leads to drastic increases in the elastic and bending moduli of the elastomeric material. The fabrication process is simple and scalable, and could make use of other shape-memory materials, creating the potential to fabricate custom shapes (e.g., containers, protective exoskeletons, or supports) using simple heat, light, or magnetic/electric field triggers. [source] Materials of Controlled Shape and Stiffness with Photocurable Microfluidic EndoskeletonADVANCED MATERIALS, Issue 27 2009Suk Tai Chang Photocurable microfluidic channel networks in thin layers of polydimethylsiloxane can act as on-demand endoskeletons to lock-in specific shapes. The light-induced solidification of photopolymer inside the microchannel networks leads to drastic increases in the elastic and bending moduli of the elastomeric material. [source] Curvature properties of novel forms of phosphatidylcholine with branched acyl chainsFEBS JOURNAL, Issue 10 2000Richard M. Epand We studied the properties of a series of phosphatidylcholine molecules with branched acyl chains. These lipids have previously been shown to have marked stimulatory effects on the side-chain cleavage activity of cytochrome P450SCC (CYP11A1), an enzyme of the inner mitochondrial membrane. The synthetic lipids used were diacyl phosphatidylcholines with the decanoyl, dodecanoyl or tetradecanoyl chain having a hexyl, octyl or decyl straight chain aliphatic branch at the 2-position. All three lipids lowered the bilayer to hexagonal phase transition temperature of dielaidoyl phosphatidylethanolamine, the lipids with longer acyl chains being more effective in this regard. As pure lipids all of the forms were found by X-ray diffraction to be predominantly in the hexagonal phase (HII) over the entire temperature range of 7,75 °C. The properties of the HII phase were unusual with regard to the small size of the lattice spacings and the small temperature dependence of the spacings. We used tetradecane to relieve hydrocarbon packing constraints to determine the intrinsic radius of curvature of the lipid monolayer. The elastic bending modulus was measured in the presence of tetradecane by introducing an osmotic gradient across the hexagonal phase cylinders with aqueous solutions of poly(ethylene glycol). The elastic bending modulus was found to be higher than that observed with other lipids and to increase with temperature. Both the small intrinsic radius of curvature and the high elastic bending modulus indicate that the presence of these lipids in bilayer membranes will impose a high degree of negative curvature strain. [source] Influence of yarn texture on the mechanical properties of textile composite castingsPOLYMER COMPOSITES, Issue 2 2010A. Zadhoush In this research, mechanical properties of textile composite castings used for immobilizing a damaged limb have been studied. For this purpose, a fabric composite was made using a new knitted fabric and textured yarn for the first time. This composite possesses suitable mechanical properties. Mechanical and physical properties such as tensile, bending, and thickness of materials were studied. Results indicate that the use of textured yarns instead of flat yarns increases the amount of resin retainment in fabrics. Furthermore, it decreases tensile modulus and bending modulus of fabrics. Properties of the castings produced were compared with a valid commercial casting. Sample with textured warp and weft, with linear density of 1,500 den of weft, had the best physical and mechanical properties among produced samples. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers [source] Compatibilizing effect of ethylene,propylene,diene grafted maleic anhydride terpolymer on the blend of polyamide 66 and thermal liquid crystalline polymerPOLYMER COMPOSITES, Issue 6 2006Qunfeng Yue Polyamide 66,thermal liquid crystalline polymer (PA66/TLCP) composites containing 10 wt% TLCP was compatibilized by ethylene,propylene,diene-grafted maleic anhydride terpolymer (MAH- g -EPDM). The blending was performed on a twin-screw extrusion, followed by an injection molding. The rheological, dynamic mechanical analysis (DMA), thermal, mechanical properties, as well as the morphology and FTIR spectra, of the blends were investigated and discussed. Rheological, DMA, and FTIR spectra results showed that MAH- g -EPDM is an effective compatibilizer for PA66/TLCP blends. The mechanical test indicated that the tensile strength, tensile elongation, and the bending strength of the blends were improved with the increase of the content of MAH- g -EPDM, which implied that the blends probably have a great frictional shear force, resulting from strong adhesion at the interface between the matrix and the dispersion phase; while the bending modulus was weakened with the increase of MAH- g -EPDM content, which is attributed to the development of the crystalline phase of PA66 hampered by adding MAH- g -EPDM. POLYM. COMPOS., 27:608,613, 2006. © 2006 Society of Plastics Engineers [source] Effects of organically modified clay loading on rate and extent of cure in an epoxy nanocomposite systemPOLYMER INTERNATIONAL, Issue 11 2008Sharon E Ingram Abstract BACKGROUND: Cloisite 30B was added to diglycidyl ether of bisphenol F and cured with diaminodiphenylsulfone to investigate how the organoclay influenced the extent of cure. RESULTS: A substantial increase in the extent of cure was found with the addition of Cloisite 30B, when lower cure temperatures were employed. Cloisite 30B at 2 wt% resulted in a 40 °C increase in glass transition temperature and an increase in the magnitude of the bending modulus even though a high level of intercalated material was detected. CONCLUSIONS: It was observed that the addition of Cloisite 30B to the epoxy system increased the level of cure in the polymer, and was particularly prominent at low cure temperatures. Copyright © 2008 Society of Chemical Industry [source] | |||||||||||||