A Novel Method to Choose the Experimental Parameters in Large Amplitude Oscillatory Shear Rheology

Large Amplitude Oscillatory Shear (LAOS) rheology is a technique to analyze materials that are viscoelastic in nature. The raw values of stress and strain that were taken out from rheometer during the large amplitude oscillatory shear test are used in the constitutive models. The model parameters from the constitutive model are then analyzed on the materials being tested. Various test protocols and geometries will be used to analyze the materials of interest during LAOS rheological examination. The selection of test protocols and usage of geometry are less studied in testing various kinds of materials using LAOS. Cone and plate and parallel plate geometries are generally used for LAOS. The test protocols would be varying amplitude and varying frequencies. In the present work, quantification of relative performance of test protocols and geometry that have been used during the analysis of cross-linked poly vinyl alcohol hyaluronic acid (PVAHA) gels as material systems are studied using data envelopment analysis (DEA). The methodological approach using output oriented constant return to scale (CRS) and output oriented variable return to scale (VRS) are tested with the decision making units (DMU) as the geometry and test protocols used. These results are then combined with the Shannon's entropy to rank the efficient DMUs. Using Shannon's entropy combined with CRS and VRS, it is suggested that the use of parallel plate geometry with the test protocol of 0.5 rad/s and 50 frequency is best suitable for the cross-linked hyaluronic acid and poly vinyl alcohol gels examined.

Urban Sprawl Analysis using GIS Application of Bhagur City

The word “Urban Sprawl” means growth is more than the normal and the criteria that makes it different from urban growth is this excessive nature. Cities grow continuously and planned growth is achieved when there is a right balance between urban growth and urbanization. But when growth is above normal its pressure on the region and the city will face major new challenges. Urban sprawl is unrestricted growth in many urban housing areas, business development and roads in large parts of the world, without worrying about urban planning. Urban Sprawl are of three types i.e., linear growth, cluster growth and leapfrog growth. This paper inspect the use of Remote Sensing and GIS in mapping of urban sprawl (1990-2021) and landuse/ landcover change detection to detect changes that has been taken place between these periods in Bhagur city. The paper helps to study the software such as ArcGIS, used to classify between built up and agricultural land using temporal signatures obtained from satellite images. To numerically understand the growth pattern Shannon’s entropy is used. Shannon’s entropy is used as an index to quantify the degree of dispersion or concentration of built-up areas. Entropy approach shows concentration growth pattern in Bhagur city. Keywords: Urban Sprawl, GIS, Remote sensing, Land use/ Land cover, Shannon’s entropy.

A Comparative Study of Frequency Ratio, Shannon’s Entropy and Analytic Hierarchy Process (AHP) Models for Landslide Susceptibility Assessment

Landslide susceptibility maps are very important tools in the planning and management of landslide prone areas. Qualitative and quantitative methods each have their own advantages and dis-advantages in landslide susceptibility mapping. The aim of this study is to compare three models, i.e., frequency ratio (FR), Shannon’s entropy and analytic hierarchy process (AHP) by implementing them for the preparation of landslide susceptibility maps. Shimla, a district in Himachal Pradesh (H.P.), India was chosen for the study. A landslide inventory containing more than 1500 landslide events was prepared using previous literature, available historical data and a field survey. Out of the total number of landslide events, 30% data was used for training and 70% data was used for testing purpose. The frequency ratio, Shannon’s entropy and AHP models were implemented and three landslide susceptibility maps were prepared for the study area. The final landslide susceptibility maps were validated using a receiver operating characteristic (ROC) curve. The frequency ratio (FR) model yielded the highest accuracy, with 0.925 fitted ROC area, while the accuracy achieved by Shannon’s entropy model was 0.883. Analytic hierarchy process (AHP) yielded the lowest accuracy, with 0.732 fitted ROC area. The results of this study can be used by engineers and planners for better management and mitigation of landslides in the study area.