Nutrient Removal From Urban Stormwater Using Floating Treatment Wetland System

Despite the technology advancement, degradation of water quality due to stormwater continues to be a significant threat to the water and ecosystems due to the exponential growth of industries and agricultural enterprises that discharge stormwater. These anthropogenic activities are the sources of high nitrogen and phosphorus quantities in stormwater, which is responsible for eutrophication phenomena and deterioration of public health. Floating Treatment Wetlands (FTWs) are a potential solution to this problem. Both microcosm and mesocosm level studies were conducted for the effective removal of nutrients in stormwater wet detention ponds with different sorption media under varying nutrient concentrations and weather conditions. Water depth, percent area coverage of the FTWs and littoral zone emergent plants were varied in order to determine nutrient removal efficiency before implementing in an actual pond. Focus has also been placed on the observations of macrophyte-epiphyte-phytoplankton interactions in order to understand temporal characteristics of ecological phenomena. Water quality parameters included Total Nitrogen, Total Phosphorus, Orthophosphate, Nitrate-Nitrogen, and Ammonia-Nitrogen in addition to in-situ parameters such as pH, Dissolved Oxygen, Temperature and Chlorophyll-a. Results clearly indicate that an FTW filled with sorption media of 80% expanded clay and 20% tire crumb can significantly promote the biomass growth. Different levels of nutrient concentrations did affect the plants’ growth and cold temperature in late winter was detrimental to growth. To make the system more viable irrespective of the seasonal weather conditions, the adoption of mixed vegetation is highly recommended in the FTWs implementation. It is also recommended that, the positioning of the floating wetlands should not be in the vicinity of the outlet of the pond as assimilated nutrient under the mat might increase the nutrient concentration in the discharged water. Finally, One-way ANOVA test is performed to check whether or not iv these grouped microcosms and mesocosms with differing experimental setup can be deemed statistically significan

Food Retailing and Its Contribution Towards FDI, Economic Growth and Employment in Bangladesh

The food retail industry in Bangladesh is fragmented and underdeveloped compared to other South Asian countries. In fact, the food retail industry in Bangladesh is facing several major challenges. For instance, there is a shortage of experienced manpower, very high cost of capital, supply chain management problems, and so forth. Many organisations in Bangladesh folded their operations because they were burdened by losses. More interestingly, there is limited academic research that addresses these concerns. Therefore, this research will contribute to fulfil the existing gaps. The objective of this paper is twofold: first, to provide an overview of food retail sector in Bangladesh and key issues and problems it faces; second, to analyse the contribution food retail industry towards foreign direct investment (FDI), economic growth, and labour force in Bangladesh. This study is informed by secondary data sets which were already available in the public domain and were analysed using associative techniques. The findings of the study suggest that despite the industry is suffering uphill challenges but, there is a significant interconnection between the performance of the food retail industry in Bangladesh, FDI, GDP growth and total labour force of the country. Moreover, the industry has the opportunity to overcome these challenges and thereby contribute further towards FDI, economic growth, and labour force in Bangladesh. The results of the study and will make the policy makers aware regarding existing problems within the industry and will help managers to think more deeply about re-organising the food retail industry. Keywords: Bangladesh, FDI, Food retailing, Economic growth, Labour force

Vote Choice of Minority Groups: Emphasizing Their Issue Preferences

In explaining vote choice of minority groups, scholars of American politics often characterize them as natural democrats. They argue that they have become natural Democrats because of their minority identity and the constraints they faced throughout the history of the United States. However, this thesis questions the characterization and highlights the issue preferences of minority groups; it analyzes whether their issue preferences have an impact on shaping their vote choice. By analyzing the Cooperative Congressional Election Study (CCES) 2016 survey, this thesis has explored that minority groups vote for candidates who pay greater emphasis on the issues they care about. Moreover, their political ideology and party identification are being greatly influenced by their issue preferences

Dynamic Scaling, Data-collapse and Self-Similarity in Mediation-Driven Attachment Networks

Recently, we have shown that if the $i$th node of the Barab\'{a}si-Albert (BA) network is characterized by the generalized degree $q_i(t)=k_i(t)t_i^\beta/m$, where $k_i(t)\sim t^\beta$ and $m$ are its degree at current time $t$ and at birth time $t_i$, then the corresponding distribution function $F(q,t)$ exhibits dynamic scaling. Applying the same idea to our recently proposed mediation-driven attachment (MDA) network, we find that it too exhibits dynamic scaling but, unlike the BA model, the exponent $\beta$ of the MDA model assumes a spectrum of value $1/2\leq \beta \leq 1$. Moreover, we find that the scaling curves for small $m$ are significantly different from those of the larger $m$ and the same is true for the BA networks albeit in a lesser extent. We use the idea of the distribution of inverse harmonic mean (IHM) of the neighbours of each node and show that the number of data points that follow the power-law degree distribution increases as the skewness of the IHM distribution decreases. Finally, we show that both MDA and BA models become almost identical for large $m$.Comment: 8 pages, 8 captioned figure

An efficient approach of face detection and recognition from digital images for modern security and office hour attendance system

This thesis report is submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in Computer Science and Engineering, 2015.The purpose of this project is to make an efficient security system for university safety measurement which can also be used to calculate the office hours of Student Tutors by face detection and recognition. By using surveillance cameras, attached at all the entrance of university main buildings, the system can detect human faces and then it can recognize people. First, the system captures the image of a person who enters into the building and then detects the face from the image. Then the recognition system matches that image with the given database of images with valid information. After matching that image if the system recognize that face it gives a green signal to allow that person. Otherwise, if the system cannot recognize that face it gives an alert signal to block that person as an intruder. Also, this system calculates the office hours of the Student Tutors. By using face recognition the system takes the starting time and ending time of the Student Tutors individually and then gives the result as output by calculating the time duration

Reliability Analysis of Public Transit Systems Using Stochastic Simulation

Unreliable public transport systems cause excessive waiting times, late or early arrivals at destinations and missed connections for passengers. Also, unreliability results in economic losses to transit operators through under utilization of vehicles, equipment and work force. The reliability analysis of bus transit, covered in this paper, is based on numerical estimation of headway variations at different bus stops along the route. A number of simulations are conducted to determine the variation of performance of bus operation due to the variability of departure headways. The average waiting time of passengers is used as an indicator of operational performance. Simulation results show that the spread of passenger waiting times widens as the headway variation increases. Impact of size of vehicle on waiting time distributions is also investigated. Irregular headways lead to uneven passenger loads on buses. Such variation in passenger counts result in some buses becoming full and being unable to serve certain stops. Thus, average waiting time increases with smaller bus size. Simulation also reveals that the average waiting time increases for passengers waiting further along the route

Tourist-Group Consideration in Tourism Carrying Capacity Assessment: a New Approach for Saint Martin’s Island, Bangladesh

Everything has a capacity that it can tolerate or afford, beyond which it cannot serve. Tourism development and management should also be based on the recognition of the limits of a destination. As a result, tourist destinations must have their carrying capacity assessed and managed accordingly with a view to protecting them from getting exploited. In assessing tourism carrying capacity of a particular destination, the formulae given by Cifuentes (1992) and recommended by IUCN (Ceballos-Lascuráin, 1996) are widely used around the world. The formulae recognize the ‘necessary distance between two tourists’ as a factor that affects tourist satisfaction; and thus, consider it in assessing physical carrying capacity (PCC) of a destination. But Tran Nghi et al. (2007) argue that, the necessary distance between two groups on a route, as well as distance between two people, affects tourist's comfort and should be considered when assessing tourism carrying capacity (TCC). Tran Nghi et al. (2007) tried to make some adjustments to the formulae and used some techniques to consider tourists as in separate groups- not as an individual in a mass. When it is about assessing carrying capacity of a trekking trail or walking route where tourists have to be in a line one behind another, carrying capacity can be calculated for group of tourists using this adjusted formula. But when it is about a beach or a park where tourists are not in queues or lines- rather scattered in the whole area, carrying capacity cannot be calculated based on tourist-group, -rather as a mass. To calculate TCC of such destinations (beach/park) a new technique is proposed and used on the basic formulae of Cifuentes in this study.  This new technique is applied in calculating the TCC of the Saint Martin’s Island, the only coral island of Bangladesh, as a case study. Keywords: tourism carrying capacity (TCC), Cifuentes' methodology, tourist-group, Saint Martin’s Island