Minimum energy wireless sensor networks

PhD programme overviewHere, on-off keying modulation is used as a means of reducing the transmit energy requirements whilst exploiting inherent channel coding, which sets the scene of this PhD study

Macro Determinants of Total Factor Productivity in Pakistan

By utilizing the conventional growth accounting framework, this study first estimates the Total Factor Productivity (TFP) in Pakistan and then establishes its macro determinants. Covering the sample from 1960 to 2003, the results confirm that macroeconomic stability, foreign direct investment, and financial sector development play an important role in the increase of TFP. Interestingly, education expenditures turn out to be insignificant.Growth Accounting, Total Factor Productivity, Macro Determinants,Pakistan

Linearizability of Systems of Ordinary Differential Equations Obtained by Complex Symmetry Analysis

Five equivalence classes had been found for systems of two second-order ordinary differential equations, transformable to linear equations (linearizable systems) by a change of variables. An "optimal (or simplest) canonical form" of linear systems had been established to obtain the symmetry structure, namely with 5, 6, 7, 8 and 15 dimensional Lie algebras. For those systems that arise from a scalar complex second-order ordinary differential equation, treated as a pair of real ordinary differential equations, a "reduced optimal canonical form" is obtained. This form yields three of the five equivalence classes of linearizable systems of two dimensions. We show that there exist 6, 7 and 15-dimensional algebras for these systems and illustrate our results with examples

Biocementation of an Organic Soil with Electrokinetics

This thesis assesses the feasibility of biocementation of a problematic organic foundation soil of many embankments of the East Anglia railway network. Biocementation has recently attracted the interest of the researchers worldwide as an emerging soil stabilisation technique, proposed as environmentally friendlier and more sustainable than other soil stabilisation techniques; however, evidence of its effectiveness as a stabilisation technique for soils other than sands is limited. In this research indigenous, non-pathogenic and ureolytic bacterial strains were screened and isolated from the in situ soil. Four strains (Bacillus licheniformis, Rhodococcus erythropolis, Micrococcus luteus, and Lysinibacillus fusiformis) were selected based on their ability to grow at different temperatures, pH, soil moisture content and to precipitate CaCO3 through urea hydrolysis. For the implementation of the biocementation treatment, laboratory scale models were designed for pressure flow column and electrokinetic injection. The latter method was of particular interest in this study as a potential in situ implementation method under existing embankments. After a first series of pressure flow soil column experiments, with all strains, which studied parameters such as bacterial population and cementation reagent concentration and curing time. Following these, the best performing strain (Bacillus licheniformis) in terms of Unconfined Compressive Strength (UCS) and CaCO3 precipitation (in the flow column tests) was used for further testing and the electrokinetic experiments. Unconfined Compressive Strength (UCS) and oedometer testing results supported by CaCO3 measurements, NH4 + concentration measurements and pH change measurements, as well as microstructural SEM-EDS analysis, proved that biocementation did occur for both implementation methods and for a number of treatment combinations. EK was the most successful implementation method and was proven effective for degrees of saturation of 85-95%. Whilst treatment non-uniformity when bacteria were injected electrokinetically still needs to be addressed, there is promise that EK could be a viable technique for treating foundation soil under existing infrastructure, which is a major challenge for engineers

EFFICIENT MARKETING OF BLUEBERRIES IN MISSISSIPPI AND LOUISIANA

Fresh blueberries are sold through a marketing cooperative of the blueberry industry in Mississippi and Louisiana. Blueberry producers have numerous alternatives in assembling blueberries, and the cooperative needs to know the costs of different systems for assembling berries in order to provide better services to its members. The main objective of this study was to determine an efficient system for handling blueberries in Mississippi and Louisiana. Sixteen models with different combinations of drop stations and shipping points were evaluated. The results of this study will help the Miss-Lou Association and farmers to better develop strategies for handling and marketing blueberries in the future. It will assist the Miss-Lou Association in determining the number, size, and locations of drop stations/shipping points with change in production each year.Marketing,