Transit time estimation of drying springs in Uttarakhand region using environmental tritium concentration.

Many parts of the Uttarakhand state, situated in the hilly terrain of the Himalayan region of India are facing acute water crisis due to the drying up of the perennial springs which are the only source of potable water in those regions. Tritium (3H), the radioactive isotope of hydrogen (half-life of 12.32 years) and also a part of water molecule (in the form of HTO) acts as a very useful tracer in estimating the transit time of the hydrological systems. Tritium concentrations of three springs (S-1, S-2 and S-3) were monitored consecutively for three years (2017-2019) to better constrain the transit time estimation. The tritium concentrations of the springs are found to vary between 3.66 and 4.15 TU. All the springs show gradual decrease in tritium concentration with the passage of time indicating the diminishing percentage of freshly recharged modern water component. Among various lumped parameter models, the piston-flow model (PFM), exponential mixing model (EMM), exponential piston-flow model (EPM) and partial exponential mixing model (PEM) have been employed in this study. The historical record of weighted mean concentration of tritium in precipitation available for the Uttarakhand region is taken as input function in the modelling procedure. The application of various LPMs (PFM, EMM, EPM and PEM) indicates that the transit time of the S-1 spring ranges from 1.26 to 1.46 years whereas for S-2 spring, the transit time is found to vary from 5 months to 1.1 years. The MTT of S-3 spring ranges from 5 months to 11 months. The relatively short residence time of these springs indicates the actively recharged system. The estimation of accurate transit time is thus very crucial for understanding the renewability of the spring water systems.

Unraveling the paleo-marine signature in saline thermal waters of Cambay rift basin, Western India: Insights from geochemistry and multi isotopic (B, O and H) analysis.

Cambay rift basin is the only geothermal province in India that hosts several saline thermal water manifestations having EC values varying from 525 to 10,860 µS/cm. Various ionic ratios (Na/Cl, Br/Cl, Ca/(SO4 + HCO3), SO4/Cl) as well as boron isotopic composition (δ11B = 40.5 to 46 ‰) clearly ascribes the presence of fossil (relics of evaporated seawater) seawater as origin of increased salinity in the majority of thermal waters. Depleted isotopic (δ18O, δ2H) composition of these thermal waters also substantiates the presence of paleowater in these systems. In rest of the thermal waters, agricultural return flow is found to be source of dissolved solutes as confirmed from different bivariate plots such as B/Cl vs. Br/Cl and δ11B vs. B/Cl as well as from ionic ratios. This study thus provides the diagnostic tools to elucidate the source of variable salinity in the thermal waters circulating in the Cambay rift basin, India.

Surface haptic rendering of virtual shapes through change in surface temperature.

Compared to relatively mature audio and video human-machine interfaces, providing accurate and immersive touch sensation remains a challenge owing to the substantial mechanical and neurophysical complexity of touch. Touch sensations during relative lateral motion between a skin-screen interface are largely dictated by interfacial friction, so controlling interfacial friction has the potential for realistic mimicry of surface texture, shape, and material composition. In this work, we show a large modulation of finger friction by locally changing surface temperature. Experiments showed that finger friction can be increased by ~50% with a surface temperature increase from 23° to 42°C, which was attributed to the temperature dependence of the viscoelasticity and the moisture level of human skin. Rendering virtual features, including zoning and bump(s), without thermal perception was further demonstrated with surface temperature modulation. This method of modulating finger friction has potential applications in gaming, virtual and augmented reality, and touchscreen human-machine interaction.

Nanotexture Shape and Surface Energy Impact on Electroadhesive Human-Machine Interface Performance.

With the ubiquity of touch screens and the commercialization of electroadhesion-based surface haptic devices, modeling tools that capture the multiphysical phenomena within the finger-device interface and their interaction are critical to design devices that achieve higher performance and reliability at lower cost. While electroadhesion has successfully demonstrated the capability to change tactile perception through friction modulation, the mechanism of electroadhesion in the finger-device interface is still unclear, partly due to the complex interfacial physics including contact deformation, capillary formation, electric field, and their complicated coupling effects that have not been addressed comprehensively. A multiphysics model is presented here to predict the friction force for finger-surface tactile interactions at the nanoscale. The nanoscopic multiphysical phenomena are coupled to study the impacts of nanotexture and surface energy in the touch interface. With macroscopic friction force measurements as verification, the model is further used to propose textures that have maximum electroadhesion effect and minimum sensitivity to relative humidity and user perspiration rate. This model can guide the performance improvement of future electroadhesion-based surface haptic devices and other touch-based human-machine interfaces.

Application of laser-induced breakdown spectroscopy (LIBS) coupled with PCA for rapid classification of soil samples in geothermal areas.

The Manuguru geothermal area, located in the Telangana state, is one of the least explored geothermal fields in India. In this study, characterization of the soil samples is carried out by laser-induced breakdown spectroscopy (LIBS) coupled with analytical spectral-dependent principal component analysis. A total of 20 soil samples were collected both from near the thermal discharges as well as away from the thermal manifestations. LIBS spectra were recorded for all the collected soil samples and principal component analysis (PCA) was applied to easily identify the emission lines majorly responsible for variety classification of the soil samples. In this submission, a modified PCA was developed which is based on the spectral truncation method to reduce the huge number of spectral data obtained from LIBS. The PCA bi-plot on the LIBS data reveals the presence of two different clusters. One cluster represents the soil samples collected from the close vicinity of the thermal manifestations whereas the other cluster contains the soil samples collected away from the thermal sprouts. PCA performed on the chemical dataset of the soil samples also reveals the same clustering of the soil samples. Both LIBS and chemical analysis data shows that soil samples near the thermal waters are found to be enriched in B, Sr, Cs, Rb, Fe, Co, Al, Si, Ti, Ru, Mn, Mg, Cu, and Eu concentrations compared to the soil samples located away from thermal manifestations. This study demonstrates the potential use of LIBS coupled with PCA as a tool for variety discrimination of soil samples in a geothermal area. LIBS is shown to be a viable real-time elemental characterization technology for these samples, avoiding the rigorous dissolution required by other analytical techniques.

Celiac disease with pure red cell aplasia: an unusual hematologic association in pediatric age group.

Anemia in Celiac disease (CD) is usually hypoproliferative, reflecting impaired absorption of essential nutrients like iron and various vitamins. We report a 2-year-old boy with Celiac disease and severe anemia due to pure red cell aplasia, diagnosed by bone marrow biopsy. This rare, unexplained extra digestive manifestation responded to gluten free diet.

An Atypical form Rhizomelic Chondrodysplasia Punctata in a Newborn.

Rhizomelic Chondrodysplasia punctata (RCDP) is an autosomal recessive metabolic disorder affecting mainly peroxisomal function. We describe a case of RCDP in a 12 days old newborn based on the clinical and radiological ground without any major systemic structural or functional abnormalities.