Microrheological Studies of Regenerated Silk Fibroin Solution by Video Microscopy

We have carried out studies on the rheological properties of regenerated silk fibroin (RSF) solution using video microscopy. The degummed silk from the Bombyx mori silkworm was used to prepare RSF solution by dissolving it in calcium nitrate tetrahydrate-methanol solvent. Measurements were carried out by tracking the position of an embedded micron-sized polystyrene bead within the RSF solution through video imaging. The time dependent mean squared displacement (MSD) of the bead in solution and hence, the complex shear modulus of this solution was calculated from the bead's position information. An optical tweezer was used to transport and locate the bead at any desired site within the micro-volume of the sample, to facilitate the subsequent free-bead video analysis. We present here the results of rheological measurements of the silk polymer network in solution over a frequency range, whose upper limit is the frame capture rate of our camera, at full resolution. By examining the distribution of MSD of beads at different locations within the sample volume, we demonstrate that this probe technique enables us to detect local inhomogeneties at micrometer length scales, not detectable either by a rheometer or from diffusing wave spectroscopy.Comment: 5 page

Application of Experimental and Numerical Techniques to Microscale Devices

Two of the areas that have become relevant recently are the areas of mixing in micro-scale devices, and manufacturing of functional nanoparticles. MicroPIV experiments were performed on two different mixers, one a wide microchannel with the surface grooves, in the laminar regime, and the other, a confined impinging jets reactor, in the laminar and turbulent regimes. In the wide microchannel with surface grooves, microPIV data were collected at the interface and the midplane at the Reynolds numbers of 0.08, 0.8, and 8. The experiments were performed on three internal angles of the chevrons, namely 135°, 90°, and 45°. The normalized transverse velocity generated in the midplane due to the presence of the grooves, is the strongest for the internal angle of 135°, and in that, the normalized transverse velocity is maximum at the Reynolds numbers of 0.08 and 0.8. MicroPIV experiments were performed in a confined impinging jets reactors at Reynolds numbers of 200, 1000, and 1500. The data was collected in the midplane, and turbulent statistics were further computed. The high velocity jets impinge along the centerline of the reactor. Upon impinging, part of the fluid turns towards the top wall and the majority of it turn towards the outlet. This high velocity impingement causes and unstable zone called the impingement zone, which moves about the centerline line, causing the jets to flap back and forth. Spatial correlations were computed to get an estimate of the size of the coherent structures. Large eddy simulation was performed on the CIJR for the Reynolds numbers of 1000 and 1500, using OpenFOAM. The Reynolds number is based on the inlet jet hydraulic diameter. Excellent agreement was found with the experimental and simulation data. Turbulent reactive mixing in a rectangular microscale confined impinging-jets reactor (CIJR) was investigated using the pH indicator phenolphthalein in this study for three di_erent jet Reynolds numbers of 25, 1000 and 1500. Laminar flow regime was observed at Reynolds number of 25 whereas the flow was turbulent at Reynolds numbers of 1000 and 1500. An image processing technique was applied to instantaneous images to extract quantitative mixing data by identifying regions with pH ≥ 9.3 and regions with pH \u3c 9.3. The ensemble-averages were computed using these thresholded images to compare mixing performance between different Reynolds numbers. Finally, the spatial auto-correlation fields of the thresholded images fluctuations were evaluated, based on which large-scale turbulent structure were analyzed

Multivariate analysis to evaluate geochemistry of groundwater in Varahi river basin of Udupi in Karnataka (India)

The Varahi Irrigation project dam site is located at approx. 6 km from Siddapura, Kundapura taluk, Udupi district with latitude of 13°39' 15" N and a longitude of 74°57'E. Groundwater quality in the study area was evaluated for its suitability for drinking and irrigation purposes by collecting 36 samples during pre-​monsoon period of the year 2005. The quality assessment was made by estg. physico-​chem. parameters, major cations and anions, besides irrigation quality parameters like SAR,​% Na and RSC. It was also noticed that alk. earth elements exceeded alkalies concn. and weak acids exceeded the strong acid element and HCO3-​was the predominant among anions, while Ca-​Mg dominates cations. Classification of water samples based on SAR and Salinity Hazard revealed that majority of the samples were under excellent (S1, 88.88​%) and excellent (C1, 80.56​%) to good (C2, 8.33​%) categories resp. Gibbs' ratio illustrates that majority of water samples fall in the pptn. dominance field, giving an indication that the aquifer recharging is by means of rain​/river water

Spatial distribution of macronutrients in soils of Markandeya river basin, Belgaum(d)​, Karnataka(s)​, India

Markandeya River basin stretches geog. from 15° 56' to 16° 08' N latitude and 74° 37' to 74° 58' E longitude, positioned in the midst of Belgaum district in the northern part of Karnataka state. Spatial distributions for twenty different soil quality characteristics were analyzed in the soil samples collected from 30 selected agricultural fields in the study area. Nutrient index reflected the nutrient status of soil and hence it was calcd. by using already detd. chem. parameters like org. C, available N, available phosphorus, and available potash. The present study revealed that there is not much variation in soil fertility status of soils developed on various landforms in the area. The soils had variable org. matter content and decompn. rates accounting to 0.06 to 1.5 % of org. carbon. Further, it is evident that all the soil samples were having low available nitrogen (29.1-​189.5 Kg​/ha) content, 50​% of the samples has low to medium available P (0.96 to 15.1 Kg​/ha) and 90​% of the samples showed adequate supply of available potash (313.3-​1500.8 Kg​/ha)​. Sodium Absorption Ratio (SAR) and Exchangeable Sodium Percentage (ESP) indicated that the soils were excellent for irrigation

Geochemistry of groundwater, Markandeya River Basin, Belgaum district, Karnataka State, India

The Markandeya River Basin stretches geog. from 15°56' to 16°08' N latitude and 74°37' to 74°58' E longitude, positioned in the midst of Belgaum district, in the northern part of Karnataka. The groundwater quality of 54 pre-​monsoon samples in the Markandeya River Basin was evaluated for its suitability for drinking and irrigation purposes by estg. pH, EC, TDS, hardness and alky. besides major cations (Na+, K+, Ca2+, Mg2+) and anions (HCO3 -​, Cl-​, SO4 2-​, PO4 3-​, F-​, NO3 -​)​, boron, SAR, % Na, RSC, RSBC, chlorinity index, SSP, non-​carbonate hardness, Potential Salinity, Permeability Index, Kelley's ratio, Magnesium hazard and Index of Base Exchange. Neg. Index of Base Exchange indicates the chloro-​alk. disequil. in the study area and the majority of water samples fall in the rock dominance field based on Gibbs' ratio. Permeability indexes of classes I and II suggest suitability of groundwater for irrigation. Based on Cl, SO4, HCO3 concns., water samples can be classified as normal chloride (96.3​%) and normal sulfate (94.4​%) and normal bicarbonate (44.4​%) water types

Future Prediction of Land Covers in Devikulam Taluk, Kerala

Land Cover of the Earth is undergoing significant transformation due to natural and human induced interventions. Information about land use change is very essential for planning, monitoring and management of natural resources. Prediction of natural and social causes of land cover change through spatially explicit models is made possible by GIS and other computer based techniques which can define and test relationships between environment and social variables using a combination of existing data, observations on the ground and the data from remote sensing. This study is proposed with an objective to inventory various land cover classes in Devikulam Taluk, Kerala. With the help of temporal data sets, the dynamics of the different land use classes in the study area has also been attempted. An attempt is made to correlate each land cover class for the Land Transformation Model (LTM) developed based upon Markov and Cellular Automata. Using the developed LTM, generation of the future scenario of land cover of the study area has been attempted. This information is expected to be useful for the assessment of land cover change and plan for better land management strategies after a review of the future trends in the land cover patterns. This study shows the extent of forest area which is degraded and converted to other land cover classes

Seasonal Variation of Fluoride, Nitrate and Boron in Ground Water of Hebbal and Challaghatta Basins, Bangalore, Karnataka

Present paper focuses on physico-chemical characteristics of Hebbal and Challaghatta basins, Bangalore with special reference to fluoride, nitrate and boron concentration. During the pre-monsoon of 2011, the NO^sub 3^^sup -^ content is as high as (100 mg/l) in 12% of wells having depth of less than 42 feet, whereas 88% of samples from wells having depth of more than 799 feet showed < 100 mg/l of NO^sub 3^^sup -^. The higher NO^sub 3^^sup -^ along shallow open wells is therefore attributed to sewage contamination. Pesticides and fertilizers used in agricultural activities are also contributing significant amounts of fluoride to the groundwater regime in Hebbal and Challaghatta aquifers. In the Hebbal and Challaghatta valleys, the industrial applications of boron that apparently could affect the groundwater system are washing powder and agricultural applications of boron-fertilizers and boron-pesticides. The high content of boron in several water sources is signal for restricting the use of washing powder containing boron

Multispectral Monitoring of Vegetation Cover of Bangalore Metropolitan Area

Urban vegetation plays significant role in one’s judgment for quality of place in a neighborhood, which is one of the important implication areas of urban image classification technique. In the present study Quick Bird and LISS III imageries of 2005 are used for comparative study of NDVI and TNDVI indices for estimating vegetation cover in Greater Bangalore also called Bruhat Bangalore Mahanagara Palike (BBMP) which is administratively divided into 8 zones. Both NDVI and TNDVI showed highly significant variation in their values between LISS III and Quick Bird imageries. The NDVI values range between -0.2 and 0.31797 in LISS III and –0.99595 and 0.92857 in Quick Bird. In case of TNDVI the variation is between 0 and 1.01145 for Quick Bird and 0 and 0.90442 for LISS III. A strong linear relationship was observed between NDVI and TNDVI of both imagery data set. The validation of results according to ground truth revealed that NDVI is much better tool for monitoring vegetation cover in urban environment in LISS III and Quick Bird data set. This study helps to demonstrate the difference between two imageries in depiction of the vegetation distribution across greater Bangalore. It also show the multipurpose utility of RS data for many application like land cover change, vegetation cover, planning and policy making, which are of particular importance in a large rapidly growing urban area with complex pattern of land use and many diverse environment

Assessment of Vegetation Cover through NDVI, Bangalore India

This paper assesses the distribution of vegetation in eight zones of BBMP also called Bruhat Bangalore Mahanagar Palike, and compares their condition with indicators of vegetative health for the city as a whole. The evaluation is based on use of the normalized difference vegetation index (NDVI) deliberated from 2004 Quick Bird satellite imagery. In our application, we examine spatial variation and mean NDVI for each zones. We then compare these results to the mean NDVI for different zones and discuss implications for use of the NDVI in Vegetation assessment of BBMP. Our results indicate that significant differences of mean NDVI values between the zones. Among eight zones high mean NDVI value was observed in Byatarayanpura and Dasarahalli zone showed lowest. In the current study vegetation assessment across the zones can epitomize how urban vegetation cover and its associated benefits vary across the BBMP and this data can be used to compare urban vegetation cover between the zone

Evaluation of Nutrient Index Using Organic Carbon, Available P and Available K Concentrations as a Measure of Soil Fertility in Varahi River Basin, India

Varahi River basin is in the midst of Udupi district in the western part of Karnataka state, covering parts of Kundapura and Udupi taluks in Udupi District, Karnataka, India. Spatial distributions for twenty physical and chemical properties were examined in the soil samples of selected agricultural fields in 28 different locations in Varahi River basin. The present study revealed that there is not much variation in soil fertility status of soils developed on various landforms in the area as the soils were having low to medium in organic carbon (0.06 to 1.20 %) and available nitrogen (6.27 to 25.09 Kg/ha) content; low to medium in available P (2.24 to 94.08 Kg/ha) and deficient to doubtful in available K (20.10 - 412.3 Kg/ha) contents. The soils of Varahi River basin were characterized as low-medium-low (LML) category based on the nutrient index calculated w.r.t. available organic carbon, available P and available K. Further, Sodium Absorption Ratio (SAR) and Exchangeable Sodium Percentage (ESP) indicated that the soils were excellent for irrigation