Geosynthetic-sheet pile reinforced foundation for mitigation of earthquake and tsunami induced damage of breakwater

Earthquake and tsunami impose great threats on the stability of a breakwater. Foundation of the breakwater is weakened by these forces, and it may result in collapse of the breakwater. Lateral flow of seabed soils take place beneath the breakwater, and excess pore water pressure is generated in the foundation by an earthquake that precedes tsunami. These factors may lead to excessive settlement and horizontal displacement of the breakwater. Tsunami introduces additional instability to the deformed breakwater. Due to water level difference between seaside and harborside of the breakwater during a tsunami, seepage occurs through its foundation, and it may cause pipping of seabed soils. Tsunami induced scouring of mound is also a big problem for the stability of the breakwater foundation. Finally, these result in failure of the breakwater foundation. Due to failure of its foundation, the breakwater may collapse and cannot block the tsunami. It results in entering of the tsunami in coastal areas. In order to make a breakwater resilient against earthquake and tsunami induced damage, reinforcing countermeasures were developed for foundation of a breakwater. Geogrid, gabions and sheet piles were used for reinforcing a foundation model. The effectiveness of the model is evaluated through physical modeling for mitigating the earthquake and tsunami induced damage. Shaking table tests were performed to determine the effectiveness of the reinforced model under different earthquake loadings. Tsunami overflow test was conducted on the same deformed model in order to see the effects of tsunami on the model. Comparisons were made between the unreinforced and reinforced foundations, and it was observed during the tests that the reinforced foundation performed well in reducing the damage of the breakwater brought by the earthquake and tsunami. Overall, this study is useful for practice engineering, and the reinforced foundation model can be adopted for designing a breakwater foundation to reduce damage triggered by an earthquake and tsunami in the future.     

Development of Apparels from Silk Waste and Pineapple Leaf Fiber

The degummed mulberry silk waste and eri silk waste were blended with degummed and bleached pineapple leaf fibers (PALF) at fiber stage in different proportions, and spun into yarn in a jute spinning system. The 90-tex blended yarn thus developed was analyzed for different physico-mechanical properties. Properties of fabric developed in a traditional handloom using 2/40-s cotton as warp and blended yarn as weft were also analyzed. The quality parameters, viz., tensile property, crease recovery, fabric cover, stiffness, drape, and thickness of the developed fabric, met essential apparel requirements. A comparative subjective evaluation of the fabric quality, viz., aesthetic appearance, luster, and texture, was made with the help of a group of people from different age, educational, and occupational background to examine its marketability; all respondents felt that appearance of PALF with silk waste was excellent. Texture and luster were found to be from medium to moderate. About 95% of respondents felt that fabric was crispy.     

Chemical characterisation of CTC black tea of northeast India: correlation of quality parameters with tea tasters' evaluation

BACKGROUND: Consumers have different regional perceptions of tea quality. Objective evaluation based on biochemical data for different regions has been needed for a long time. Biochemical factors regulating this variation would help to remove regional disparities. This study was undertaken on CTC (crust, tear and curl) black tea to generate the biochemical data responsible for quality along with tea tasters' evaluation of three geographical regions of northeast India and to determine the reason for the variation. RESULTS: Brahmaputra valley teas had highest theaflavin (TF), thearubigin (TR), brightness (BR) and total colour (TC) and low crude fibre content (CFC) and total polyphenol (TPP). Brahmaputra valley and Dooars region teas showed high total soluble solid (TSS). Barak valley teas had highest CFC and low TSS, caffeine (CA), TF, TR and TC. Dooars region teas had high CA and TPP and low BR. Dooars region and Barak valley teas contained higher levels of residual catechin than Brahmaputra valley teas. CONCLUSION: Overall quality as evaluated by tea tasters was found to be highest for Brahmaputra valley teas followed by Dooars region and Barak valley teas. This high evaluation can be attributed to higher levels of TF, TR, BR and TSS. Barak valley and Dooars region teas contained high residual catechin, indicating limitation in oxidation during processing. Copyright © 2009 Society of Chemical Industry     

An experimental study on the shattering behavior of a high strength armour steel under blast and long rod penetrator impact

Armour steel plates with drilled holes are filled with explosive and subjected to single or multiple blasts to induce shattering. The critical diameter for shattering under explosive detonation, found from the experiments matches closely with that of the long rod penetrator impacted plates. The damage pattern and fracture surface of the tested samples under blast effect have been compared with plates impacted with long rod penetrators for matching the observed shattering behavior. Difference in the shattering behavior of the armour steel subjected to single and multiple blasts has also been presented.     

Characterisation of a Schottky ISFET as Hg-MOSFET and as cytochrome P450-ENFET

A cost-effective and simple method is proposed wherein a Schottky ion sensitive field effect transistor (Schottky ISFET)-based sensor is characterised as metal oxide semiconductor and enzyme field effect transistor (ENFET). This technique involves deposition of mercury (Hg) as gate material over the sensing layer mitigating the complexity of fabrication process, thereby eliminating the need of refabricating an identical device. A Schottky-based ISFET simplifies the fabrication process as the requisite for doping of source and drain regions becomes redundant. Steps involved in lithography process for fabricating metal oxide semiconductor field effect transistor (MOSFET) are reduced with the use of liquid metal Hg as gate over layer. Such a device can be transformed back to an ISFET without any additional etching process. Furthermore, the same ISFET device can be utilised as an ENFET when the former is used in conjunction with a biological element. In this work, a Schottky-based ISFET has been characterised as Hg-MOSFET and as cytochrome P450-ENFET. Multiple tests on the device exhibit that the same ISFET sensor can be used both as a MOSFET and an ENFET with good repeatability and versatility without losing its sensitivity.     

Biomechanical Energy‐Harvesting Wearable Textile‐Based Personal Thermal Management Device Containing Epitaxially Grown Aligned Ag‐Tipped‐NixCo1−xSe Nanowires/Reduced Graphene Oxide

Energy consumption is increasing with the rapid growth of externally powered electronics. A vast amount of energy is needed for indoor heating, and body heat is dissipated to the surroundings. Recently, wearable heaters have attracted interest for their efficiency in providing articular thermotherapy. Herein, the fabrication of a personal thermal management device with a self‐powering ability to generate heat through triboelectricity is reported. Composites are prepared with vertically aligned silver tipped nickel cobalt selenide (Ag@Ni_xCo_1?xSe) nanowire arrays synthesized on the surface of woven Kevlar fiber (WKF) sheets and reduced graphene oxide (rGO) dispersed in polydimethylsiloxane (PDMS). The Ag@Ni_xCo_1?xSe with rGO induces effective Joule heating in the composites (79 °C at 2.1 V). The WKF/Ag@Ni_xCo_1?xSe/PDMS composite shows higher infrared reflectivity (98.1%) and thermal insulation (54.8%) than WKF/PDMS. The WKF/Ag@Ni_xCo_1?xSe/PDMS/rGO composite has an impact resistance and tensile strength that are 152.2% and 92.1% higher, respectively, than those of WKF/PDMS. A maximum output power density of 1.1 mW cm^?2 at a low frequency of 5 Hz confirms efficient mechanical energy harvesting of the composites, which enables self‐heating. The high flexibility, breathability, washability, and effective heat generation achieved during body movement satisfy the wearability requirement and can address global energy concerns.     

Thermal analysis of a constructal T-shaped porous fin with simultaneous heat and mass transfer

The present work establishes an analytical model for computing the temperature distribution,fin efficiency and optimum design parameters of a constructal T-shaped porous fin operating in fully wet condition.For more practical results,this study considers a cubic polynomial relationship between the humidity ratio of saturated air and the corresponding fin surface temperature.The temperature distribution has been determined by solving the highly non-linear governing equations using a semi-analytical transformation technique called Differential Transform Method.A comparison of the results with that of a numerical model shows that this transformation method is a very efficient and convenient tool for solution of non-linear problems.The effects of various geometric,thermo-physical and psychometric parameters on the temperature distribution,fin efficiency and optimum design condition have been investigated.Also,a comparison has been presented between solid and porous fins and the results point out that by selecting an appropriate value of porosity,the heat transfer rate can be increased than the corresponding solid fin.     

Biochemical Synthesis and Manipulation of a 70 nm DNA Linker for the Assembly of DNA‐Functionalized Gold Nanoparticles

DNA oligonucleotides are extraordinarily well suited as linkers for the programmable assembly of nanoparticles. To extend the scope of DNA‐directed particle assembly, a 70 nm DNA linker molecule for the DNA‐directed assembly of gold nanoparticles is synthesized by biochemical reactions. In particular, polymerase chain reaction (PCR) and subsequent restriction and ligation reactions are employed to synthesize the DNA linker, comprising a 178 base pair (bp) double helical core region supplemented with two sticky‐end binding sites of 12 nucleotides in length, attached to one of the core‐forming strands. The linker is used for the assembly of DNA‐functionalized gold nanoparticles employing yet another biochemical reaction, namely covalent linkage through the enzyme DNA ligase. The resulting nanoparticle assemblies are characterized by using atomic force microscopy. The methodology described here represents a general way of synthesizing programmable DNA linker molecules with dimensions that exceed those presently available by using chemical synthetic methods, and thus, supplements the synthetic toolbox of nanobiotechnology to asses complex and functional nanoparticle/linker architectures for potential applications in sensing and materials science.