ID: 52042
Title: Novel technologies for sniffing soil and ground water contaminants
Author: Pradeep U. Kurup
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: Contaminants, electronic nose, ground water, site characterization, soil, sensors
Abstract: The presence of hydrocarbons, dense non-aqueous phase liquids, heavy metals and radioactive wastes in soil and ground water represents a serious threat to health and safety. Detecting and delineating these contaminants in the subsurface is a challenging task. Traditional site characterization methods involving drilling and sampling (soil, groundwater, and soil gas), followed by laboratory analysis are time-consuming, laborious, expensive and expose personnel to contaminated media. Recent emphasis has been placed on developing on-site field characterization techniques based on direct push technologies (DPTs) such as the cone penetration test (CPT). A variety of samplers have been deployed in DPTs for collecting soil gas, groundwater and soil samples from desired depths of interest. A variety of in situ sensors have been deployed inside cone penetrometer probes, including load cells, pressure transducers, miniature camera, electrical resistivity, temperature, pH and oxidation reduction potential, laser induced fluorescence, infrared spectroscopy and Raman spectroscopy. This article also describes a novel electronic nose technology that was integrated with an in situ vapour sampling membrane interface probe for sniffing sub surface volatile organic contaminants. This technology has been recently miniaturized and integrated with CPT sensors for comprehensive geotechnical and geoenvironmental investigations.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52041
Title: An approximate approach for nonlinear system response determination under evolutionary stochastic excitation
Author: Ioannis A. Kougioumtzoglou and Pol D. Spanos
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: Monte Carlo simulation, nonlinear system, stochastic process
Abstract: A method based on the concepts of stochastic averaging and equivalent linearization is presented for determining the response of a lightly damped nonlinear single-degree-of-freedom oscillator to a random excitation with an evolutionary broad-band power spectrum. The nonlinearities could be either of the hysteretic or the ' zero-memory ' kind. Approximate analytical relationships for evaluating the response variance are derived for a number of oscillators. The efficiency and accuracy of the approach is demonstrated by pertinent digital Monte Carlo simulations. The significant advantage of the proposed approach relates to the fact that it is readily applicable for excitations possessing even non-separable evolutionary power spectra circumventing ad hoc pre-filtering and pre-processing excitation treatments associated with existing alternative schemes of linearization.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52040
Title: Assimilation of remote sensing and hydrological data using adaptive filtering techniques for watershed modelling
Author: Sat Kumar, M. Sekhar and S. Bandyopadhyay
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: Data assimilation, hydrological model, remote sensing, soil moisture
Abstract: The knowledge of hydrologica variables (e.g. soil moisture, evapotranspiration) are of pronounced importance in various applications including flood control, agricultural production and effective water resources management. These applications require the accurate prediction of hydrological variables spatially and temporally in watershed/basin. Though hydrological models can simulate these variables at desired resolution (spatial and temporal), often they are validated against the variables, which are either sparse in resolution (e.g. soil moisture) or averaged over large regions (e.g. runoff). A combination of the distributed hydrological model (DHM) and remote sensing (RS) has the potential to improve resolution. Data assimilation schemes can optimally combine DHM and RS. Retrieval of hydrological variables (e.g.soil moisture) from remote sensing and assimilating it in hydrological model requires validation of algorithms using field studies. Here we present a review of methodologies developed to assimilate RS in DHM and demonstrate the application for soil moisture in a small experimental watershed in south India.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52039
Title: Is the inverse problem technique appropriate for structural health assessment?
Author: Achintya Haldar
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: Experimental verification, finite element method, structural health assessment, system identification, time domain technique
Abstract: Structural health assessment techniques using system identification-based approaches have recently generated a considerable amount of multidisciplinary research interest. However, in 1979, it was stated that the inverse transformation technique could not identify a system with measured response information. Presence of many sources of error including noise, high frequency content, slope, DC bias, etc. in the measured response information were considered to be the major reasons. However, removing these sources from the measured responses may not be adequate to eliminate the non-convergence problem. In this article, it is conclusively demonstrated that a system can be identified if the amplitude and phase shift errors embedded in the measured responses are mitigated properly. The noise may not be primary reason for the non-convergence. The conclusions made here are primarily based on teh analytical and experimental works completed by the author and his team. Their experience indicates that the system identification-based structural health assessment techniques have unlimited application potential.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52038
Title: Applications of SPH with the acceleration correction algorithm in structural impact computations
Author: Amit Shaw and S.R. Reid
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: Acceleration correction algorithm, artificial viscosity, energy dissipation, smooth particle hydrodynamics
Abstract: How to use artificial viscosity ' properly ' (i.e. without excessively effecting the physics of the response) in smooth particle hydrodynamics (SPH) computations has been a long standing issue. Though SPH has great potential in problems related to dynamic structural mechanics, the loss of kinetic energy due to the ' inaccurate ' choice of artificial viscosity parameters may result in physically unreal phenomena. Recently, the effect of artificial viscosity in SPH computations has been revisited and an acceleration correction algorithm to recover the majority of the ' lost ' kinetic energy has been proposed by Shaw and Reid (2009). The essence of the acceleration correction algorithm is to calculate the change in the acceleration due to the artificial viscosity term and then correct the computed acceleration by subtracting a convex approximation of the ' changed ' acceleration. The energy equation is accordingly modified. In the process, some of the unwanted energy dissipation is removed while retaining the basic effect of the artificial viscosity in order to have a stable computation. The approach used in relatively straightforward and, in due course, this approach will be optimized. In this article, some additional numerical aspects of the acceleration correction algorithm are discussed and the method is further explored in the context of some classical elastic-plastic impact problems. It is shown that, together with the acceleration correction algorithm, SPH can be used as a useful tool in dynamic, inelastic structural mechanics.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52037
Title: Natural analogs for improved understanding of coupled processes in engineered earth systmes: examples from karst system evolution.
Author: Harihar Rajaram, Wendy Cheung and Abhijit Chaudhuri
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: Engineering earth systems, karst system evolution, natural analogs
Abstract: There is an increasing need to understand the behaviour of engineered earth systems, from the viewpoint of safe waste disposal and exploration of renewable energy sources. Often, human activities lead to significant perturbations of the earth systems, involving hydrologic, mechanical, thermal and chemical processes. Prediction of the long-term response of earth systems to large perturbations is critical for evaluating their design, performance and operation. Because many of the processes involved in system response will manifest over decades or centuries, field -testing during the design stage is infeasible. In this connection, we propose that development of coupled process simulators and testing them on natural analogs provided by geologic systems may be fruitful. As example, we illustrate our attempts to simulate the development of two types of cave systems-branchwork in meteoric environments and mazework in hypogene or hydrothermal environments. Our computational models combine hydraulic, thermal and chemical processes in limestone fractures and consider the influence of sub-surface heterogeneity as well.. Our computational results vividly demonstrate the mechanisms by which branchwork patterns develop in meteoric environments and demonstrate how sustained dissolution along upward flow channels can be established in hypogene environments, thus creating favourable conditions for development of maze patterns. Investigations of system sensitivities in both types of environments indicate that a surprisingly robust pattern of behaviour results, thus serving as a target for developing simplified conceptual models of these systems.We also discuss the implications of our resuts for design, operation and risk analysis of engineered earth systems.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52036
Title: Bathymetry prediction over a part of the Bombay High in the western offshore using very high resolution satellite gravity data
Author: R.Bhattacharyya and T. J. Majumdar
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: Bathymetry prediction model, ETOPO2, Gujarat-Maharashtra offshore, GEBCO, high-resolution satellite gravity
Abstract: Bathymetry, when convolved with a response function, yields geoid or gravity. The predictive model as computed using high-resolution satellite gravity, and its downward continuation, is a generalized approach and seems to be satisfactory for bathymetry prediction in a complex region. The predictive model has been modified and applied over the study area in the Western Indian offshore using very high resolution satellite gravity data (data gap ~4km) as obtained from Geosat, Seasat, ERS-1/2 and Topex altimeter data. The area consists of variable bathymetric features, e.g. ridges and trenches, and it has been found to be successful to detect more number of features in comparison to those obtained from the presently available bathymetry data. Results from the predicted model have been compared with ETOPO2, NHO ship-borne and GEBCO bathymetry data and have been found satisfactory for geophysical and oceanographic applications.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52035
Title: Status and distribution of the endangered Gangetic dolphin (Platanista gangetica gangetica ) in the Brahmaputra River within India in 2005
Author: Abdul Wakid
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: Brahmaputra River, conservation, depth, distribution, Gangetic dolphin, population status
Abstract: A population assessment survey of the endangered Ganges river dolphin was made between February and April 2005 in the Brahmaputra River starting from Assam - Arunachal Pradesh border to the India-Bangladesh border. One hundred and ninety seven dolphins were recorded in the entire 856 km river stretch with an encounter rate of 0.23 dolphins per km. Encounter rates of dophin in different sectors were significantly different. Calves and subadult encounter rates were recorded as highest in the Brahmaputra stretch within the Kaziranga National Park. No significant difference was found between the number of calves and subadults, calves and adults as well as subadults and adults. The variations in depth structure of the river were highly significant along different stretches. The number of dolphins occurring in different depths was found to be significantly different and the highest number was found in a depth of 4.1-6m. Gill net encounter rate was significantly different in different stretches of the river with maximum encounter rate recorded from Goalpara to Dhubri. Accidental killing through gill net and poaching of dolphin for oil are the most dangerous threats to the survival of these dolphins. Close monitoring of dolphins and their habitats involving local communities are required for long term conservation of the species in the Brahmaputra River.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52034
Title: Evaluation of changes in oil cells and composition of essential oil in lemongrass (Cymbopogon citratus (D.C) Stapf.) due to supplemental ultraviolet-B irradiation
Author: Rima Kumari, S.B. Agrawal and Abhijit Sarkar
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: Citral, Cymbopogon citratus, essential oil, oil cells, sUV-B
Abstract: Field grown lemongrass (Cymbopogon citratus (D.C) Stapf. ) was exposed for a short duration (3h/day) to supplemental ultraviolet -B (sUV-B) to evaluate its effect on oil cells and chemical composition of essential oils. Histochemical studies showed an increase in number of oil cells in tissues under sUV-B treatment. Estimation of essential oil content also demonstrated an increase of 25.7% in sUV-B treated plants over its control. Gas chromatography-mass spectrometric (GC/MS) analysis of essential oils demonstrated significant variations in qualitative and quantitative expression of oil constituents of sUV-B exposed plants. sUV-B irradiation induced the formation of major compound z-citral within the investigated oil samples by 117.56% as compared to oil obtained from non-irradiated plants. Geraniol formate, pulegol, linalyl formate and other compounds also showed significant variations after sUV-B treatment. Results suggest that sUV-B exposure stimulated the production of oil cells vis-a-vis positive change in quality and percentage of essential oil contents of lemongrass. The results suggest some future prospects for better economical utilization of lemongrass after irradiation with low doses of sUV-B for its commercial exploitation.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52033
Title: Otoliths - the biological CD-ROMs of fish
Author: K.V.Radhakrishnan, W.He. M. Liu and S. Xie
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52032
Title: Mangrove forest cover of Visakhapatnam coast is under threat
Author: P.K. Swain, N. Rama Rao, Chiranjibi Pattanaik
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52031
Title: Guazuma ulmifolia, an abundant tree species in Chennai
Author: D Senthil
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52030
Title: Bioethics, medicine and society-a philosophical inquiry
Author: Vijay Kumar Yadavendu and Deepak Kumar
Editor: P. Balaram
Year: 2009
Publisher: Current Science Association, Vol 97, N0. 8, 25 October 2009
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Current Science
Keywords: Bioethics, philosophy of medicine, society, technological innovations
Abstract: This article is an attempt to see how technological innovations and social developments have led to enormous changes in health and medicine. With ethical complexities and challenges emerging in modern medicine, bioethics seeks ways in which people in societies can work together under the provision of medical care and research. The field is supposed to provide an insight into the issues of moral community, and into how society understands political authority and its appropriate exercise. As a social movement, bioethics developed in the mid-twentieth century as a critical discourse, a response to felt inhumanities in the system of health care and biomedical research. As a response to specific abuses, bioethics has remained practice-oriented; society expects bioethics to solve or at least ameliorate visible problems. Different responses to these different bioethical issues reflect differing views on the philosophy of medicine, which are influenced in turn by the cultural views of those involved.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52029
Title: Fishes
Author: S. Krishnan and S.S. Mishra
Editor: Director, Zoological Survey of India, Kolkata
Year: 2001
Publisher: Zoological Survey of India, September 2001
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Fauna of Godavari Estuary- Andhra Pradesh
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 52028
Title: Echinodermata
Author: D.R.K.Sastry
Editor: Director, Zoological Survey of India, Kolkata
Year: 2001
Publisher: Zoological Survey of India, September 2001
Source: Centre for Ecological Science,Indian Institute of Science, Bangalore-12
Reference: None
Subject: Fauna of Godavari Estuary- Andhra Pradesh
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None