Assessment of arsenic exposure from groundwater and rice in Bengal Delta Region, West Bengal, India

Arsenic (As) induced identifiable health outcomes are now spreading across Indian subcontinent with continuous discovery of high As concentrations in groundwater. This study deals with groundwater hydrochemistry vis-à-vis As exposure assessment among rural population in Chakdaha block, West Bengal, India. The water quality survey reveals that 96% of the tubewells exceed WHO guideline value (10 μg/L of As). The groundwaters are generally anoxic (−283 to −22 mV) with circum-neutral pH (6.3 to 7.8). The hydrochemistry is dominated by HCO₃⁻ (208 to 440 mg/L), Ca²⁺ (79 to 178 mg/L) and Mg²⁺ (17 to 45 mg/L) ions along with high concentrations of As_T (As total, below detection limit to 0.29 mg/L), Fe_T (Fe total, 1.2 to 16 mg/L), and Fe(II) (0.74 to 16 mg/L). The result demonstrates that Fe(II)-Fe(III) cycling is the dominant process for the release of As from aquifer sediments to groundwater (and vice versa), which is mainly controlled by the local biogeochemical conditions. The exposure scenario reveals that the consumption of groundwater and rice are the major pathways of As accumulation in human body, which is explained by the dietary habit of the surveyed population. Finally, regular awareness campaign is essential as part of the management and prevention of health outcomes.     

Robust nonlinear analytic redundancy for fault detection and isolation in mobile robot

A robust nonlinear analytical redundancy (RNLAR) technique is presented to detect and isolate actuator and sensor faults in a mobile robot. Both model-plant-mismatch (MPM) and process disturbance are considered during fault detection. The RNLAR is used to design primary residual vectors (PRV), which are highly sensitive to the faults and less sensitive to MPM and process disturbance, for sensor and actuator fault detection. The PRVs are then transformed into a set of structured residual vectors (SRV) for fault isolation. Experimental results on a Pioneer 3-DX mobile robot are presented to justify the effectiveness of the RNLAR scheme.     

Updated Assessment of Possibilities and Limits for Solar Cells

The remarkable advances over the past few years in performance of photovoltaic cells, including the advent of new absorber materials, call for an update to the previous assessment of prospects for future progress. The same simple criteria with some refinements, based on cell and module performance data, serve to evaluate and compare most types of solar cells. Apart from Si and InP, for all types the “best cells” have improved in conversion performances (and crystalline Si modules have made major strides in cost reduction). New cell types, such as “perovskite”, sustainable chalcogenide, and quantum dot cells, are included. CdTe results bring those cells in line with other well‐developed ones, lending some credence to the idea that the criteria provide the reader with knowledge, useful for gauging possible future technological developments. Additionally, the developments of the past few years show that, while the advent of more new cell types cannot be predicted, it can be aided and stimulated by innovative, daring, and creative new materials research.     

Partitioning 1-variable Boolean functions for various classification of n-variable Boolean functions

This paper addresses all possible equivalence classes of 1-variable Boolean functions and from these classes using recursion and Cartesian product of sets, 15 different ways of classifications of n-variable Boolean functions are obtained. The properties with regard to the size and the number of classes for these 15 different ways are also elaborated.     

Probabilistic model validation for uncertain nonlinear systems

This paper presents a probabilistic model validation methodology for nonlinear systems in time-domain. The proposed formulation is simple, intuitive, and accounts both deterministic and stochastic nonlinear systems with parametric and nonparametric uncertainties. Instead of hard invalidation methods available in the literature, a relaxed notion of validation in probability is introduced. To guarantee provably correct inference, algorithm for constructing probabilistically robust validation certificate is given along with computational complexities. Several examples are worked out to illustrate its use.     

Tuning the pH Response of i‐Motif DNA Oligonucleotides

Cytosine‐rich single‐stranded DNA oligonucleotides are able to adopt an i‐motif conformation, a four‐stranded structure, near a pH of 6. This unique pH‐dependent conformational switch is reversible and hence can be controlled by changing the pH. Here, we show that the pH response range of the human telomeric i‐motif can be shifted towards more basic pH values by introducing 5‐methylcytidines (5‐MeC) and towards more acidic pH values by introducing 5‐bromocytidines (5‐BrC). No thermal destabilisation was observed in these chemically modified i‐motif sequences. The time required to attain the new conformation in response to sudden pH changes was slow for all investigated sequences but was found to be ten times faster in the 5‐BrC derivative of the i‐motif.     

Effective Mass Model Supported Band Gap Variation in Cobalt-Doped ZnO Nanoparticles Obtained by Co-Precipitation

Semiconductors - Zn1 –xCoxO (x = 0, 0.01, 0.03, 0.05) nanoparticles were synthesized using co-precipitation method. Shift in peaks of XRD patterns for 2θ values has been observed. The...