Field Investigation on Ground and Structural Vibrations During Prototype Pile Driving

As the land is very precious in urban areas and coastal regions, many structures are built in close proximity. When the soil is weak and heavy loads are to be carried, pile foundation is adopted for such structures. The impact caused by pile driving is a potential hazard to neighbourhood structures. Berthing structures are constructed using piles and the effect of pile driving on already installed adjacent piles is important. To predict the effect of pile driving on neighbourhood piles, measurement of ground and structural vibrations during prototype pile driving was carried out at a site in the city of Chennai, India. The soil at the site up to a depth of 19 m is mainly fine to medium sand. A driven cast in-situ pile of 600 mm diameter (D) was driven up to a depth of 15.8 m. The 25mm thick mild steel (M.S) tube casing is driven by 4.1t hammer with a drop height of 2.5m. During the pile driving, for every blow of hammer, the acceleration of the ground at various distances 5D, 8.33 D and 25 D from the pile are measured. Piezoelectric acceleration transducers, power amplifiers and taper recorder are used for measurement. The time history of vertical and horizontal ground accelerations as well as time history of vertical acceleration of an already installed pile at a distance of 6.25 m was analysed using PC based data acquisition systems. The time-histories and spectrum of ground and structural accelerations are presented

Valuing life and limb : understanding the risk-return trade-off

This policy brief is based on SANDEE working paper no. 9-04, "Measuring the value of life and limb : estimating compensating wage differentials among workers in Chennai and Mumbai"Across the developing world improvements in public health and environmental safety are becoming an ever-greater priority. One way to understand how the public values improvements in health is by assessing what individuals are willing to pay or forgo for small decreases in risks that may affect their longevity. For example, workers frequently make decisions that trade-off increased work-place risk and higher wages. This estimate of the financial gain required to take on increased risks can be used to assess public policies that seek to decrease the risk of death from environmental factors such as air pollution

Parallel network file systems using authenticated key exchange protocols

The keyestablishment for secure many-to-many communications is very important nowadays. The problem is inspired by the proliferation of large-scale distributed file systems supporting parallel access to multiple storage devices. In this, a variety of authenticated key exchange protocols that are designed to address the issues. This shows that these protocols are capable of reducing the workload of the metadata server and concurrently supporting forward secrecy and escrow-freeness. All this requires only a small fraction of increased computation overhead at the client. This proposed three authenticated key exchange protocols for parallel network file system (pNFS). The protocols offer three appealing advantages over the existing Kerberos-based protocol. First, the metadata server executing these protocols has much lower workload than that of the Kerberos-based approach. Second, two of these protocols provide forward secrecy: one is partially forward secure (with respect to multiple sessions within a time period), while the other is fully forward secure (with respect to a session). Third, designed a protocol which not only provides forward secrecy, but is also escrow-free

Strengthening of Load Bearing Masonry Wall Panels with Externally Bonded Precast Textile Reinforced Concrete Laminate

241-245Textile Reinforced Concrete (TRC) has gained worldwide popularity as a strengthening material for masonry structures in the recent years. As of today, the application of TRC for masonry strengthening is either by cast-in-place methodology or by spraying method. The present work is a first-of-its kind study, which explores the feasibility of using externally bonded precast TRC laminate for strengthening of load bearing brick masonry wall panels. The binder used in TRC itself is used as adhesive for adhering the TRC laminate to masonry wall panels. Experimental investigations were carried out on unstrengthened and strengthened brick masonry wall panels under axial compression and combined axial compression and shear loading. The influence of TRC strengthening system is assessed by examining the performance indicators such as strength, stiffness and deformation. Based on the investigations, the use of externally bonded precast TRC laminate is found to be a feasible solution to strengthen brick masonry walls to have the required structural adequacy

Investigation on behaviour of reinforced geopolymer concrete slab under repeated low velocity impact loading

ABSTRACT: Geopolymers are a novel class of materials that are formed by the polymerisation of silicon, aluminum, and oxygen species to form an amorphous 3-D framework structure. Concrete made out of these binder system possess several advantages compared to conventional ordinary Portland cement concretes (OPCCs). Substantial research work has been reported on the impact behaviour of reinforced concrete structural elements whereas similar studies have not been reported on GPCs. This paper describes the experimental and numerical investigation on the behaviour of reinforced GPC slabs under repeated impact loading. The aim is to study the impact behavior of reinforced GPC slabs with and without steel fibers and compare with that of OPCC slabs. The overall dimensions of the GPC slab are 1m x 1m, with 60mm thickness. Finite element modeling of slab was also carried out using ANSYS software. The Solid 65 element and link 8 elements were used to model the concrete slab and Reinforcement respectively. Displacement boundary conditions are applied at the supports. The measured impact load time history is used to excite the structure. Transient dynamic analysis was carried out. The response was obtained in terms of deflection time histories. The peak acceleration of analytical studies showed a pattern similar to that obtained from experimental results. The failure crack pattern of plain and steel fibre reinforced slabs predicted by Finite Element analyses are compared with experimental results. The studies emphasize that by proper design, GPCC can be used in lieu of OPCC for structural components subjected to low velocity impact

The extent, nature and distribution of child poverty in India

Despite a long history, research on poverty has only relatively recently examined the issue of child poverty as a distinct topic of concern. This article examines how child poverty and well-being are now conceptualized, defined and measured, and presents a portrait of child poverty in India by social and cultural groups, and by geographic area. In December 2006, the UN General Assembly adopted a definition of child poverty which noted that children living in poverty were deprived of (among other things) nutrition, water and sanitation facilities, access to basic health care services, shelter and education. The definition noted that while poverty hurts every human being ‘it is most threatening and harmful to children, leaving them unable to enjoy their rights, to reach their full potential and to participate as full members of the society’. Researchers have developed age-specific and gender-sensitive indicators of deprivation which conform to the UN definition of child poverty and which can be used to examine the extent and nature of child poverty in low and middle-income countries. These new methods have ‘transformed the way UNICEF and many of its partners both understood and measured the poverty suffered by children’ (UNICEF, 2009). This article uses these methods and presents results of child poverty in India based on nationally representative household survey data for India

Unravelling the Therapeutic Potential of Nano-Delivered Functional Foods in Chronic Respiratory Diseases

Chronic inflammation of the respiratory tract is one of the most concerning public health issues, as it can lead to chronic respiratory diseases (CRDs), some of which are more detrimental than others. Chronic respiratory diseases include chronic obstructive pulmonary disease (COPD), asthma, lung cancer, and pulmonary fibrosis. The conventional drug therapies for the management and treatment of CRDs only address the symptoms and fail to reverse or recover the chronic-inflammation-mediated structural and functional damage of the respiratory tract. In addition, the low efficacy and adverse effects of these drugs have directed the attention of researchers towards nutraceuticals in search of potential treatment strategies that can not only ameliorate CRD symptoms but also can repair and reverse inflammatory damage. Hence, there is a growing interest toward investigating the medicinal benefits of nutraceuticals, such as rutin, curcumin, zerumbone, and others. Nutraceuticals carry many nutritional and therapeutic properties, including anti-inflammatory, antioxidant, anticancer, antidiabetic, and anti-obesity properties, and usually do not have as many adverse effects, as they are naturally sourced. Recently, the use of nanoparticles has also been increasingly studied for the nano drug delivery of these nutraceuticals. The discrete size of nanoparticles holds great potential for the level of permeability that can be achieved when transporting these nutraceutical compounds. This review is aimed to provide an understanding of the use of nutraceuticals in combination with nanoparticles against CRDs and their mechanisms involved in slowing down or reversing the progression of CRDs by inhibiting pro-inflammatory signaling pathways.</jats:p