Comparison of Liquefaction Potential Evaluation Based on Different Field Tests

The lowlands of India are vulnerable to possible future large earthquakes. The liquefaction strength is estimated using in-situ tests and the factor of safety against liquefaction by comparing the liquefaction strength with cyclic shear stress ratio developed in the deposit during an earthquake. Standard Penetration test (SPT) and Cone Penetration test(CPT) have been most commonly used in-situ tests for characterization of liquefaction resistance. In this study, liquefaction potential is evaluated based on SPT as well as CPT data obtained from the three different locations situated in alluvial lowlands. A large difference in factor of safety against liquefaction is found based on SPT and CPT data. It is observed that CPT data is more reliable for liquefaction potential evaluation because there is no concrete method available in India to convert measured SPT N-value to (N1)60

Inter- and transgenerational inheritance of behavioral phenotypes

Adult animal behaviors are determined by complex and dynamic changes in gene expression in different brain regions and are influenced by life experiences and environmental exposures. These stimuli affect gene expression through intricate mechanisms of regulation that largely implicate epigenetic factors, such as, DNA methylation, histone post-translational modifications, and non-coding RNAs (ncRNAs). Through these molecular pathways, some of the behavioral phenotypes associated with life experiences can be stably transmitted to descendants, sometimes across several generations. Rodent studies indicate that parental stressful and traumatic experiences can lead to behavioral despair, risk-taking behaviors, altered sociability and atypical responses to stressful stimuli in the offspring, whereas parental environmental enrichment has been associated with improved cognition and stress resilience in the offspring. Similar observations have been made in humans; children and grandchildren of genocide survivors show increased psychopathology and emotional disturbances. At the molecular level, changes in germline ncRNAs have been identified as likely vectors of transmission in rodents. The mechanisms linking behavioral stimuli to the germline, and factors responsible for these changes and their persistence across generations remain, however, largely unidentified

Mechanical performance of roselle/sugar palm fiber hybrid reinforced polyurethane composites

The effect of sugar palm fiber (SPF) loading was studied relative to the mechanical properties of roselle (RF)/SPF/thermoplastic polyurethane (TPU) hybrid composites. RF/SPF/TPU hybrid composites were fabricated at different weight ratios (100:0, 75:25, 50:50, 25:75, and 0:100) by melt mixing and hot compression. The mechanical (tensile, flexural, and impact test) and morphological properties of tensile fractured samples were examined using a universal testing machine, impact machine, and scanning electron microscope. It was found that the hybridization of RF/SPF increased its impact strength corresponding to the increases in the SPF content of the composites. The tensile and flexural properties of the hybrid composites decreased due to poor interfacial bonding between the fiber and matrix. Scanning electron micrographs of the tensile fractured surface of the RF/SPF hybrid composites revealed fiber pullouts and poor adhesion bonding. In conclusion, the hybridization of SPF with RF/TPU composites enhanced its impact strength while decreasing the tensile and flexural strength

Mechanical and thermal properties of sugar palm fiber reinforced thermoplastic polyurethane composites: effect of silane treatment and fiber loading

The aim of the present study was to develop sugar palm fiber (SPF) reinforced thermoplastic polyurethane (TPU) composites and to investigate the effects of fiber surface modification by 2% silane treatment and fiber loading (0, 10, 20, 30, 40 and 50 wt%) on the mechanical and thermal properties of the obtained composites. Surface treatment was employed to improve the fiber-matrix interface, which was expected to boost the mechanical strength of the composites, in terms of tensile, flexural and impact properties. Thermal properties were also investigated by thermal gravimetric analysis (TGA) and dynamic mechanical analysis (DMA) to assess the thermal stability of the developed composites. Furthermore, scanning electron microscopy (SEM) was used to study the tensile fracture samples of composites with a view towards evaluating the effects of fiber surface treatments on the fiber/matrix interfacial bonding. The findings of this study reveal that the silane treatment has determined good bonding and linkage of the cellulose fiber to the TPU matrix, hence contributing to enhanced mechanical and thermal properties of the composites. The composite formulation with 40 wt% sugar palm fiber loading showed optimum values such as 17.22 MPa for tensile, 13.96 MPa for flexural, and 15.47 kJ/m2 for impact strength. Moreover, the formulations with higher fiber content exhibited satisfactory values of storage modulus and thermal degradation, while their good interfacial adhesion was evidenced by SEM images

Effect of natural rubber/epoxidized natural rubber (90/10) on mechanical and thermal properties of linear low density polyethylene.

The effects of blending different amounts of (90/10) natural rubber/epoxidized natural rubber (NR/ENR-50) with metallocene linear low density polyethylene (mLLDPE) on the tensile strength, elongation at yield point, Young’s modulus, hardness and thermal properties were investigated. In this study, N, N-m-phenylenebismaleimide (HVA-2) was used as compatibilizer for the blends. The highest tensile strength was observed in the blend of 90/(9/1) mLLDPE/NR/ENR-50. With increasing mixed rubber content, the tensile modulus is found to decrease continuously, but interestingly the hardness and elongation at yield point is shown to increase. The crystallinity percentage of 10% rubber/mLLDPE was the lowest percentage. The maximum physical crosslinks occur in 90/(9/1) mLLDPE/NR/ENR-50 composite blend. The FTIR showed that the epoxy and double bond groups were found to be absent in all blends indicating thermal stability and compatibility of mLLDPE/rubber blends were improved by addition of 10 and 30% loading of rubber, in the presence of HVA-2 as compatibilizer

Development and characterization of sugar palm starch and poly(lactic acid) bilayer films

The development and characterization of environmentally friendly bilayer films from sugar palm starch (SPS) and poly(lactic acid) (PLA) were conducted in this study. The SPS-PLA bilayer films and their individual components were characterized for their physical, mechanical, thermal and water barrier properties. Addition of 50% PLA layer onto 50% SPS layer (SPS50-PLA50) increased the tensile strength of neat SPS film from 7.74 to 13.65MPa but reduced their elongation at break from 46.66 to 15.53%. The incorporation of PLA layer significantly reduced the water vapor permeability as well as the water uptake and solubility of bilayer films which was attributed to the hydrophobic characteristic of the PLA layer. Furthermore, scanning electron microscopy (SEM) image of SPS50-PLA50 revealed lack of strong interfacial adhesion between the SPS and PLA. Overall, the incorporation of PLA layer onto SPS films enhances the suitability of SPS based films for food packaging

A Review on Pineapple Leaves Fibre and Its Composites

Natural fibre based composites are under intensive study due to their ecofriendly nature and peculiar properties.The advantage of natural fibres is their continuous supply, easy and safe handling, and biodegradable nature. Although natural fibres exhibit admirable physical and mechanical properties, it varies with the plant source, species, geography, and so forth. Pineapple leave fibre (PALF) is one of the abundantly available wastes materials of Malaysia and has not been studied yet as it is required. A detailed study of chemical, physical, and mechanical properties will bring out logical and reasonable utilization of PALF for various applications. Fromthe socioeconomic prospective, PALF can be a newsource of rawmaterial to the industries and can be potential replacement of the expensive and nonrenewable synthetic fibre. However, few studies on PALF have been done describing the interfacial adhesion between fibres and reinforcement compatibility of fibre but a detailed study on PALF properties is not available. In this review, author covered the basic information of PALF and compared the chemical, physical, and mechanical properties with other natural fibres. Furthermore, it summarizes the recent work reported on physical, mechanical, and thermal properties of PALF reinforced polymer composites with its potential applications

Study on characterization of Furcraea foetida new natural fiber as composite reinforcement for lightweight applications

The exploration of new natural fibers in the field of polymer composites can contribute to increase the invention of natural reinforcements and expand their use in possible applications. In the present work, the physico-chemical, thermal, tensile and morphological properties of Furcraea foetida (FF) fiber are presented for the first time. Chemical analysis results shows that FF has relatively higher cellulose (68.35%) with lower hemicelluloses (11.46%) and lignin (12.32%). Structural analysis of FF was conducted by Fourier transform infrared and 13C (CP-MAS) nuclear magnetic resonance spectroscopy. X-ray diffraction (XRD) analysis evidenced that FF has crystallinity index of 52.6% with crystalline size of 28.36 nmThe surface morphology of FF was investigated by scanning electron microscopy (SEM), energy dispersive X-ray micro analyzer (EDX) and atomic force microscopy (AFM). The thermogravimetric analysis (TGA) reveals thermal constancy of the fiber upto 320.5 °C with the kinetic activation energy of 66.64 kJ/mol, which can be used as reinforcements in thermoplastic green composite whose working temperatures is below 300 °C. The FF results were compared with those of other natural fibers, and indicated as a suitable alternative source for composite manufacture