AN ENGINEERING GEOLOGICAL ANATOMY OF THE PADMA RIVER BANK FAILURE AND EROSION, 2018: A CASE STUDY OF NARIA BANK SECTION, BANGLADESH

The Naria town of Bangladesh is developed on the right bank of the Padma River. The bank is an old natural levee of Meghna River. The Holocene-Recent geology of Naria is actively dominated by the fluvial processes of Ganges-Brahmaputra-Meghna River system where the deltaic sediments are characterized as unconsolidated fine sand and silt, covered by thin veneer of clayey silt and loam. The annual volume of water discharge and flow dynamics are dependent on the intensity of the rainfall, runoff and the length of dry winter. Excessive river bank erosion, channel avulsion, renewed submergence of floodplains, and formation of natural levees and channel-bars are due to natural geomorphological processes that impact the area by inevitable ground failures. The geological attributes of ground condition and drastic variations in water levels make the area extremely vulnerable to severe bank failures and erosion. A unique erosion phenomenon prevailing in this part of Bengal delta prompted this study. During Aug-Sept, 2018 a sudden complex attenuation of current, wave and vortex in the Padma water flow caused an extraordinary disaster and made more than 5000 people homeless overnight by devouring away houses including concrete buildings, factories and markets. It is observed that geologically the Padma River remained confined within a width of 5 miles striking NW-SE trend following the margins of older alluvium and Faridpur Trough. The river tends to a meandering pattern consisting of deep vertical trenches along the Naria curvature. The deep trenches form along right bank and render the ground increasingly more vulnerable to subaqueous slope failure due to presence of thick (~200 ft.) alternating cross-bedded silt and micaceous fine sand of very high dilatancy and low angle of friction. The present study identifies some application of technological advancement for developing real-time engineering geological mapping systems for monitoring and managing complex river bank erosion. Large scale 3D engineering geological map coupled with air-borne photogrammetric and radar inferrometry methods can be applied for real-time monitoring and prediction of differential settlements, subaqueous failures and ground movement. The point cloud maps developed using data from these systems can refine engineering geological maps for decision makers and improve the design of protective measure and sustainable engineering structures

Modelling of lightly doped collector of a bipolar transistor operating in quasi-saturation region

A physical model taking into consideration the effects of finite collector minority carrier lifetime and minority carrier blocking property of the low-high (n−n+) junction is proposed for predicting the bipolar transistor dc characteristics covering saturation and quasi-saturation operations. Solution for the electron and hole carrier profiles, recombination, drift and diffusion current densities, electric field distributions and voltage drops as a function of the collector current density is presented. The low-level injection model neglecting collector minority carrier recombination current within the injection region is also present. The validity of the complete model is verified by comparing the results obtained by the present analysis with experimental results available in the literature

Gender, Race, and Experiences of Workplace Incivility in Public Organizations

Workplace incivility can have deleterious effects on individuals and organizations such as decreased job satisfaction and commitment, employee turnover, and reductions in morale and performance. Moreover, these effects can be exacerbated for women and employees of color. However, few studies have examined predictors of incivility in public sector organizations. This study explores how public employees' incivility experiences vary across social categories, specifically by gender and race. Data were collected with a survey from all employees of four local governments in North Carolina. The results of hierarchical linear modeling show that women experience more incivility than men, and that men and women of color experience fewer incidences of incivility than White men and women. We also find that race moderates the relationship between gender and workplace incivility. Specifically, women of color experience more incivility than men of color, but less incivility than White women. Finally, women are more likely than men to experience incivility in departments where women constitute the majority of the workforce. Implications of these results for human resource management in public organizations are discussed

Farmers’ Preference, Yield, and GGE-Biplot Analysis-Based Evaluation of Four Sweet Potato (Ipomoea batatas L.) Varieties Grown in Multiple Environments

The study aimed to select high-yielding, farmers-preferred quality sweet potato varieties that are suitable to grow in various environmental conditions in Bangladesh. In this context, four popular sweet potato varieties (viz., ‘BARI Mistialu-8′, ‘BARI Mistialu-12′, ‘BARI Mistialu-14′, and ‘BARI Mistialu-15′) were used in the study. These varieties were released by Bangladesh Agricultural Research Institute (BARI). In the first season (2018–2019), these varieties were evaluated at nine locations, and in the second season (2019–2020), the same varieties were tested further, but only in three locations. The trial was set up in a randomized complete block design and repeated three times. After two years of observation, it was found that the fresh root yield was varied significantly due to the environment (E), genotypes (G), and their (G × E) interaction (p ≤ 0.01) by using genotype and genotype x environment (GGE) biplot analysis. The E and G × E interaction effects were found to the greater than the genotypes effect solely. In the first year, three varieties, namely ‘BARI Mistialu-8′, ‘BARI Mistialu-12′ and ‘BARI Mistialu-14′, were identified as balanced and comparatively higher in yield in nine locations. These three varieties also showed a similar trend with respect to root yield in tested three locations in the second year. Among the four varieties, ‘BARI Mistialu-12′ was found to be the highest root yielder, followed by ‘BARI Mistialu-8′ and ‘BARI Mistialu-14′. Across the locations, these varieties showed 57.89%, 61.50% and 44.30% higher yield than the local check cultivar. Therefore, these three varieties may be recommended as the best varieties of sweet potato throughout the country