Design of System Level Control for a Residential Power Router

This thesis presents the overall power flow and load management system for a 2 kW residential power router. The objective is to satisfy the residential load demand with cost savings by managing the energy sources including PV, battery, generator, and grid. The power flow management system algorithm is developed both for grid-connected mode and island mode. This algorithm involves the battery state of charge estimation, available PV power, load demand and electricity grid pricing. The residential load management algorithm is also developed using PV power prediction and load power prediction acquired for a day.¬ A Labview GUI is also developed for this load management

The Double Edged Blade of Consumerism & the Impossible Trinity – Bangladesh

This paper demonstrates how a change in monetary policy by lowering the interest rates can lead to a decline in savings in the short run. Almost perfect correlation coefficient exists between declined marginal savings and increased household desire to either invest or spend; hoarding proves to be minimal but there are limits to household investments. Corporate investment is also possibly affected by the new policy as consumerism and lower cost of capital encourages the firms to invest. Consumption also leads to indebtedness. However, the consumption patterns, capital flight and borrowing motives proves to be of alarming significance to the policy makers. In the long-run, monetary expansionary policy is forecasted to be ineffective. Keywords: Monetary policy, interest rate, Saving-Consumption-Investment Imbalance, Product Influx, Impossible Trinity, Consumption Pattern, Debt Motivations, Capital Fligh

A Computational Approach to Evaluate the Effect of Shelter Construction Material and Fuel Load on the Fire Spread Behavior in Rohingya Refugee Camp

Numerous fires break out, especially from January to March every year, destroying thousands of shelters in the Rohingya Refugee Camps. In this study, a computational approach has been taken to analyze the fire dynamic behavior of informal settlements (ISs) in Rohingya Refugee Camps. The design parameters for the mathematical model are determined based on a comprehensive survey carried out in Rohingya Refugee Camps in Cox's Bazar, Bangladesh. This survey is conducted on three camps having distinctive fuel features, i.e., Kutupalong Registered Camp (KRC), Camp 5, and Camp 4 Extension (Ex), in order to accumulate data on the type, density, arrangement of fuel, etc. Using the dataset of almost 500 shelters having 42 fuel characteristics features, simplified small scale representation of each camp under fire had been modelled in Fire Dynamic Simulator (FDS). It is found that Camp 5 is more vulnerable to fire hazard than Camp 4 Ex and KRC because of the dense fuel arrangement, bamboo structure and negligible separation distance between ISs. KRC's brick exterior acts as a fire barrier, and thereby despite having the largest internal fuel load of all three camps, prevents further spreading of fire from the ignited enclosure. It is also found that type of building material and separation distance are crucial for fire spread and increasing fuel load density causes the ceiling temperature to rise higher and the flashover point to approach faster. The findings of our study can be helpful for informed decision making of fire safety measures in the Rohingya Refugee Camps

The Outcome of Using a Jamshidi Biopsy Trocar Needle in a Novel Technique for Bone Grafting in Percutaneous Internal Fixation of Scaphoid Non-Union

INTRODUCTION: We report the outcome of using a novel technique of minimally invasive internal fixation and distal radius bone grafting using the Jamishidi Trephine needle and biopsy/graft capture device.METHODS: The technique utilises a 8 mm incision at the distal pole of the scaphoid. The non-union is excavated using the standard Acutrak drill. An 8 gauge Jamshidi trephine needle is used to harvest bone graft from the distal radius which is impacted into the scaphoid and fixed with an Acutrak screw. Fifteen patients were available for retrospective review, 14 male, age mean 29.5 (15-56). Average time from injury to surgery was 167 days (45-72). Fractures classified according to Herbert giving 7 D1 and 8 D2 fractures, 14 waist and 1 proximal pole fractures, all of which had no humpback deformity.RESULTS: Sixty-six percentages of the fractures went onto unite, 4/7 D1 and 6/8 D2 united (p > 0.05). Seventy-five percentages of fracture that had surgery in less than 3 months from time of injury went onto unite, whereas only 63% united in patients who had surgery later than 3 months (p > 0.05). DASH outcome for all patients improved from 86 down to 32 (p < 0.05). With those that united going down from 90 to 6. Those that did not unite went from 81 to 61.CONCLUSION: The Jamshidi bone grafting technique shows comparable results (union rate 66%) to other techniques published in the literature (27-100%) providing the surgeon with an alternative and less demanding procedure than open scaphoid non-union surgery

Modification and Characterization of Biodegradable Chitosan/ Starch-Based Films with Monomer 1,4-Butanediol Diacrylate (BDDA) by Gamma Radiation

Chitosan reinforced starch-based biodegradable films were prepared by solution casting. Tensile strength (TS), tensile modulus (TM), elongation at break (%), and water vapor permeability (WVP) of the 50% chitosan containing starch-based films were found to be 47 MPa, 550 MPa, 16%, and 2.45 g·mm/m2·day·kPa, respectively.Monomer 1,4 butanediol diacrylate (BDDA) was added (0.25-1% by wt) to the starch/chitosan (50:50) based film formulation. Then, films were cast and gamma irradiated from a radiation dose varied from 1 kGy to 25 kGy. Then mechanical and barrier properties were evaluated. The highest TS (80 MPa) and TM (880 MPa) of the films were found by using 0.5% monomer at 5 kGy dose. The WVP of the films were found to be 1.50 g·mm/m2·day·kPa which is 38.77% lower than control starch/chitosan-based films. Molecular interactions due to incorporation of BDDA were supported by Fourier transform infra red (FTIR) spectroscopy. The water uptake of the films pointed out better hydrophobic character due to incorporation of BDDA in starch/chitosan-based films. Surface morphologies of BDDA treated films were examined by scanning electron microscope (SEM) and suggested better morphologies due to BDDA treatment with starch/chitosan-based biodegradable films