Advanced Materials Research Vol. 910

Abstract: In order to study the mechanical property for the combining yarn of BF/GF and polypropylene, 8 groups of combining yarn were designed and prepared. Through testing the mechanical property of the yarns, the affection of some parameters on the property of the yarns was analyzed. And following conclusions can be gotten. For BF/polypropylene combining yarn, when the fiber content of basalt is about 50.7%, the mechanical property of the yarn is the best. When the fiber content of basalt is about 43.7%, the mechanical property of the yarn is the worst. For GF/polypropylene combining yarn, the optimal and worst ratio is 55.42% and 44.4%, respectively.

Abstract: With the extensive application of composite materials in aircraft structure, effect of the installing process of strain gauge on the strain measuring results of composite structure need to be researched experimentally. In this paper, the composite (T700/LT-03A) was selected to made specimens, and the different grinding manners, surface cleaning agents and bonding agents were adopted respectively as one of strain gauge installing processes. In order to identify influence of the different installing processes on the measuring data accuracy, measured strain data repeatability, linearity and characteristics of measured value oscillation are served as test standard. The compared test results show that the strain installing processes adopted in strength test on traditional metal also apply to the composite (T700/LT-03A) structures strength test.

Abstract: Three Lactobacillus strains were screened on the basis of probiotic characteristics (i.e., resistance to low pH and bile salts, adhesion to the human gastrointestinal tract, inhibition of pathogenic strains). They further exhibited producing antimicrobial activities of non-acid molecule (s). In addition, antibacterial peptides were isolated and purified from the cell-free culture supernatants of these three probiotic strains. Based on TricineSDSPAGE, the antimicrobial peptide was approximately 10 kDa in size. After analyzing the sequence of the 16SrDNA regions of these three strains, they were identified as Lactobacillus crispatus Lactobacillus rhamnosus and Lactobacillus rhamnosua GG. Using an in vitro system simulating gastric transit, our findings indicated that the three probiotic strains had the ability to tolerate gastroenteric environment and the adhesive capacity to HT-29 cells. It was demonstrated that the probiotic strains inhibited subsequent adhesion of E. coli to the HT-29 cell. Among the selected strains, L. rhamnosus F1333 showed a high probiotic potential and could be used in health-promoting food products.

Abstract: In this study, five selected Lactobacillus of fecal origin were investigated for their probiotic properties. They were preliminarily identified by partial 16S rDNA gene sequencing and characterized in vitro for their resistance to low pH and bile salts. Here, we assessed the adhesive properties and the ability to inhibit the adhesion and to displace pathogens of five selected Lactobacillus strains using HT-29 cells model through a process which may be related to specific components of the baterial surface. Surface-layer proteins are located in a paracrystalline layer outside the bacterial cell wall and are thought to play a role in tissue adherence. Removal of S-layer proteins from the Lactobacillus (treated with 5 M LiCl) reduced adhesion to Caco-2 cells. Under such conditions, inhibition activity was also decreased in all five strains, as revealed in competition assays, which suggested that S-layer protein had involved in the adhesion of probiotics. SDS-PAGE analysis confirmed the presence of S-layer proteins with dominant bands of was approximately 60 kDa. Our findings also indicate that the surface layer proteins contributed to its increased adhesion to the cultured cells and competitive exclusion of pathogens.

Abstract: When the bone tissues suffer from an impaired area that is greater than their self-healing size limit, the impairment may not heal or heal incompletely. With the purpose of developing artificial bone scaffolds for the recovery of bone tissues, this study twists 3-ply polyvinyl alcohol (PVA) fibers into plied yarns, which are then braided into PVA bone scaffolds using a braiding technique. Afterward, the braids are cross-linked with glutaraldehyde in order to improve their structure and their water stability. The experiment results show that a cross-linking by glutaraldehyde does not significantly influence the surface morphology of the braids. However, a cross-linking by high concentration glutaraldehyde provides the braids with a swelling phenomenon, which in turn causes a dense internal feature of the braids, and namely a lower porosity. This study successfully prepares braided PVA bone scaffolds with water stability, through a glutaraldehyde cross-linking.

Abstract: With similar components to human bone, hydroxyapatite (HAp) has been commonly used in dental and orthopedics practice. Calcium phosphate cement (CPC) can be made into porous HAp scaffolds through reaction; therefore, this study aims to examine how reaction temperatures influence CPC. CPC powder and NaCl are blended, and after diammonium phosphate (DAP) is added, they are infused into a mold for a hydration reaction under a saturated vapor pressure to form CPC scaffolds. XRD and FTIR are used to determine the influence of reaction temperatures on crystallization and functional groups. A scanning electron microscope (SEM) observes the structures of the CPC scaffolds. Test results show that when the temperature of a saturated vapor pressure is 70 °C, the CPC scaffolds have significant crystalline conversion and functional group peaks. SEM observation indicates that the temperature of a saturated vapor pressure does not affect the formation of the CPC scaffolds structure.

Abstract: This study uses carbon fibers (CF) to reinforce polylactic acid (PLA) matrices to form CF/PLA biocomposites. Tensile test, flexural test, and impact test are performed on biocomposites to evaluate their mechanical properties. The results of tests show that an increment of the CF content results in an increase in tensile strength, flexural strength, flexural modulus, and impact strength. The combination of 15 wt% CF provides the resulting biocomposites with a 72 % increase in tensile strength, a 322 % increase in flexural modulus, and a 96 % increase in impact strength.

Abstract: This study examine the influence of gelatain with different concentrations on the physical property of the PET/Gelatin composite tubular braids. PET fibers are braided into tubular braids on a braider, and then immersed in gelatin solution with various concentrations to form PET/Gelatin composite tubular braids. The tensile strength and water contact angle of the braids are then tested to determine the their physical properties. The experiment results show that an increasing concentration of gelatin does not result in a significant varation in tensile strength, but a decreased displacement only.

Abstract: This study aims to examine the thickness of a sandwich structure and the lamination number of the Kevlar nonwoven fabrics o n the punch resistance strength and impact resistance strength of the nonwoven composites. Kevlar nonwoven fabrics and Nylon/low-melting-point polyethylene terephthalate (LPET) nonwoven fabrics are laminated with various combinations to form sandwich-structured nonwoven composites. The experiment results show that an increasing number of Kevlar nonwoven fabrics results in low dynamic and constant rate puncture resistance but high impact strength; and conversely, an increasing thickness of sandwich-structured nonwoven composites causes high dynamic and constant rate puncture resistances but low impact strength.

Abstract: Polylactic acid (PLA) is a synthetic polymer that has biocompatibility and biodegradation. This study aims to examine the influence of manufacturing parameters on the physical properties of tubular PLA/Spandex/Gelatin composite braids. PLA fibers and spandex are combined, braided and then immersed in gelatin solution to form tubular PLA/Spandex/Gelatin composite braids. The tensile strength, bursting strength, and porosity of the resulting braids are tested, and the experiment results show that a greater twist per inch (T.P.I.) causes a higher tensile strength and bursting strength, but does not change the porosity distinctively.