Measurement of horticulture produce quality.

The aim of this work was to develop amperometric biosensors, for the detection of key analytes that affect horticulture produce quality. Information was gathered relating to the interaction between key analytes, such as amino acids, organic acids and sugars and their effect on produce quality. Trends of these key analytes changed in the produce over time, thus their measurement can indicate ripeness. A taste panel analysis on six varieties of tomatoes was therefore carried out. The key analytes were then measured by conventional means and the data was subjected to Principal Component Analysis (PCA). The results indicate that total organic acids correlate well with perceived sweetness of tomatoes. Individual amperometric biosensors for the measurement of L-malic acid, D- glucose, L-ascorbic acid, L-amino acids, and L-glutamic acid were developed during the course of this study. These individual biosensors were tested with real samples and the results were compared with standard photometric tests. The biosensors generally gave high precision values. The L-malic acid biosensor showed a high correlation against the standard method (accuracy = > 87.3 % when testing real samples). One of the problems encountered when testing real samples was the effect of interferent species. Therefore, quantification of the interferent effect was achieved by testing the sample with and without enzyme immobilised onto the working electrode. By calculating the difference in current, an accurate concentration of the target analyte could be measured. Finally, it was understood through the course of this work that measurement of only single analytes is insufficient in determining the quality of horticulture produce. Therefore a multianalyte biosensor was constructed. D-glucose, L-malic acid, and L- ascorbic acid, were tested simultaneously using this biosensor array. The average accuracy of this method, as compared to detection of single analytes was 90 %

Essays in financial economics

Chapter 1 explores the recent failure of covered interest parity (CIP) in tranquil markets. By focussing on the term structure of CIP deviations, the chapter shows that imbalances in the demand for and supply of FX hedges exert first order effects on the level of CIP deviations. Fluctuations in FX hedging demand move forward exchange rates out of line with CIP because financial institutions charge premia for provisioning for risks associated with FX derivative exposure. The chapter highlights a fundamental change in the relationship between prices and quantities in the FX derivatives market. Chapter 2 studies the impact of agency on asset prices. The chapter presents a model in which benchmarked money managers tilt their portfolios to low volatility stocks in periods of high market volatility. The tilt by a large segment of the market means that low volatility stocks appear expensive and vice versa for high volatility stocks. The chapter shows that benchmarking constraints result in a steeper security market line (SML) in periods of high market volatility than implied by the Capital Asset Pricing Model (CAPM), that mutual (hedge) fund betas fall (rise) with rising market volatility, and that betas become more dispersed in stressed markets. Chapter 3 explores whether one can use holdings data from the Securities and Exchange Commission (SEC)'s 13F filings to systematically extract hedge fund alpha. Using proprietary data on hedge fund holdings to identify a subset of managers known as 'Fundamental Equity Hedge Funds' (FEHF) that tend to have a longer-term view on stock picks, the chapter shows that portfolio construction in this context must take the 'how' and the 'who' into consideration. The chapter proposes a long-only trading strategy based on conviction and consensus of FEHFs that delivers a Sharpe ratio of 0.86 and a significant six-factor alpha of 0.37% per month.Open Acces

The Administration of Hajj in Brunei under the British Residency (1906 – 1954): A Historical Perspective

This article explores the historical perspective of the administration of hajj in Brunei under the British Residency from 1906 until 1954. The pilgrimage reports were initially issued by the British and the British-Indian Officers. Malaysian pilgrims were previously misclassified as Javanese due to oversimplification of the officers in charge before the 1920s. Nevertheless, Bruneian pilgrims might interrelate with the same problem as they shared the same hajj routes. Eventually in the 1920s, the pilgrimage reports were mainly handled by the Malay Pilgrimage officer who was also known as the Malayan Pilgrimage Commissioner in 1948. The Malayan Pilgrimage Commissioner was responsible in handling the pilgrims from Brunei, Federation of Malaya, Sarawak, North Borneo, and Singapore during the pilgrimage season in Mecca at the time. Even though the Malayan Pilgrimage Commissioner eliminated the misclassification of Malaysian pilgrims, Bruneian pilgrims continued to be enumerated together with pilgrims from Malaysia under the rubric of ‘Malay Pilgrims’. Primary and secondary research method are conducted for this article where various primary and secondary sources related to the administration of hajj in Brunei from 1906 until 1954 are used. This article discusses the roles and duties of the British Residents, local officers, Malayan Pilgrimage Commissioner, Medical Officers, and Sheikh Haji (Hajj Sheikh) in the hajj administration of the pilgrims from Brunei. This article further analyses British interests behind their involvements in the hajj administration

Influence of Product Complexity and Customers Demographics on Co-Design.

Co-design is an emerging trend in new product development that results in more active customer participation in product development than conventional design processes; it connects customers, designers, and engineers throughout product design and development. This dissertation studies the influence of product complexity, frequency of product use, and customer demographics on co-design. Three co-design surveys were conducted with an online community of customers. More than five hundred community members participated in these surveys and provided about two thousand design ideas to improve four different products. The analysis of these ideas showed that frequency of use influences the quantity of design ideas generated for that product. It was also found that product complexity (estimated by number of components and user interfaces) does not affect the novelty of design ideas generated for a product. In addition the data suggests that customers’ dissatisfaction with existing products may lead them to generate novel ideas during co-design. Results from these surveys also showed that customers’ interest in co-design varies significantly with product type. For example customers are five times more interested in co-designing a house than an inkjet printer. Gender also influences co-design. Females are more interested in co-designing clothes than males whereas males are more interested in co-designing cars than females. Age also plays a role in determining customers’ interest in co-design. Finally, a five step framework (5i model) was proposed to implement co-design. These five steps were identified after reviewing latest case studies of co-design efforts for various companies like Dell, Starbucks, and Apple. In addition, the data collected as part of this dissertation also informed the five step framework. The five steps are: invite the customers, interact with them, ideate for new products and services, implement customers’ ideas and then improve the process of co-design. Using these five steps a company can initiate co-design efforts and engage customers in product design and development. It is predicted that in coming years co-design will increasingly augment conventional design processes.Ph.D.Design ScienceUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/91473/1/mshaukat_1.pd

Multiphase flow and hysteresis phenomena in oil recovery by water alternating gas (WAG) injection

Water flooding and gas injection are two widely used improved oil recovery techniques that can be applied individually or combined as water alternating gas (WAG) or simultaneous gas and water (SWAG) injection. Laboratory data on WAG and SWAG injections for non-water-wet systems are very limited especially for near-miscible (very low IFT) gas-oil systems. Near-miscible gas injection represents a number of processes of great importance to reservoir engineers including high pressure hydrocarbon gas injection and CO2 flooding. Simulation of these processes (WAG and SWAG injections) requires three-phase relative permeability (kr) data. Most of the existing three-phase relative permeability correlations (such as Stone-I, Stone-II or Baker) have been developed for water-wet conditions and are unable to adequately account for all the complex multi-phase and multi-physics processes involved in these oil recovery techniques. Another major problem in the prediction of the performance of Water Alternating Gas (WAG) process is the uncertainty associated with the changes in three-phase relative permeability (kr) values of oil, gas and water in different cycles, which is known as cyclic hysteresis. The current approach in the industry (except hysteresis model proposed by Larsen and Skauge) is to use two-phase bounding imbibition and drainage relative permeabilities along with a two-phase hysteresis model (such as Land, Carlson or Killough to generate two-phase scanning curves) and input the result into a three-phase correlation (Stone-I, Stone-II, Baker etc) to simulate hysteresis in WAG injection. The other approach in the industry to account for hysteresis in WAG injection is the WAG-hysteresis model (proposed by Larsen and Skauge) coupled with Stone-I correlation. None of these models and approaches is developed and assessed based for low oil/gas IFT and/or nonwater- wet system. Nevertheless, the majority of oil reservoirs are believed to be mixedwet and hence, prediction of the performance of WAG injection in these reservoirs is associated with significant uncertainties. Accurate determination of relative permeability values and their hysteresis behaviour is crucial for obtaining a reliable prediction of the performance of water-alternating-gas (WAG) injection in oil reservoirs. Performing reliable laboratory experiments is the key to evaluating the performance of these oil recovery techniques under different reservoir and operational conditions. The experimental data can be also used for assessment of different relative permeability and hysteresis models, and developing new methodologies for reliable simulation of WAG and SWAG injections (if required). The content of the thesis can be divided into two sections: a) two-phase flow and b) three-phase flow. I present the results of comprehensive series of two-phase and three-phase (WAG injections) coreflood experiments for a gas/oil system at near-miscible (IFT= 0.04 mN.m-1) conditions. Two different cores; a high-permeability (1000 mD) and a lower permeability (65 mD) core were used in the experiments and both water-wet and mixedwet conditions were examined. Experimental data have been used to obtain reliable relative permeabilities and investigate their cyclic hysteresis behavior. In the first section of the thesis (two-phase flow), effects of different parameters such as permeability, wettability (water-wet and mixed-wet), immobile water and saturation history on two-phase flow of oil and gas at near-miscible condition have been investigated. Contrary to the open literature reports which are based on high IFT oil/gas, the results (for very-low oil/gas IFT) showed the importance of the wettability and immobile water saturation on the recovery profiles and estimated relative permeabilities. In addition contrary to the near-miscible liquid-liquid systems, it was observed significant hysteresis effect in the gas-liquid system. I have also investigated different two-phase systems (gas-oil, gas-water and oil-water) in mixed-wet systems. This is crucial, considering the importance of the two-phase systems as a backbone to better understand three-phase flow as well as their importance as an input to two-phase hysteresis models (for simulation of WAG including hysteresis). The investigation in this study shows that currently available two-phase hysteresis models in simulators (Carlson and Killough) are not able to capture the observed cyclic hysteresis behavior in these systems. The results suggest that for mixed-wet systems, it is necessary to consider irreversible hysteresis loops for both the wetting and non-wetting phases. Such capability currently does not exist in reservoir simulators due to lack of appropriate predictive tools. Results highlight the differences between cyclic hysteresis behaviors of the relative permeabilities in these three systems. In the second section of the thesis, I first evaluated the performance of different injection scenarios in the mixed-wet system. These processes include primary waterflooding (WF), primary gasflooding (GF), WAG injection (either starting with water injection or gas injection), and SWAG injection (with different gas/water ratios). For some of these processes (WF, GF and WAG injection started with primary WF) the effect of wettability was also investigated. The results show that in both the water-wet and mixed-wet cores, the performance of WAG injection is better than water injection and gas injection alone. The results show that in mixed-wet core, oil recovery by the WAG test which had started with water injection was higher than the WAG test started with gas injection. WAG injections had superior performance over SWAG injections. SWAG performed better compared to primary gas injection. However, surprisingly, SWAG resulted in lower oil recovery compared to primary waterflood in the mixed-wet system. Compared to the other injection strategies, a very high pressure drop across the core was observed during SWAG injection indicating injectivity problems with the application of the process in mixed-wet rocks. Using results of the WAG injection experiments, I also investigated the cyclic hysteresis effect on three-phase relative permeabilities of each phase (gas, oil and water). The results show the importance of properly accounting for irreversible kr hysteresis loops in the processes involving cyclic injection under three-phase flow conditions. Gas relative permeability (krg) dropped in successive cycles under both water-wet and mixed-wet conditions. krg hysteresis was larger in the water-wet system compared to the mixed-wet case. The results also reveal saturation history dependency for oil relative permeability (kro), which tends to increase in successive gas injection periods. The improvement in kro was larger in the water-wet system. In both water-wet and mixed-wet systems, the largest krw hysteresis happens for the transition from two-phase (oil/water system) to three-phase system (from 1st water injection into 1st gas injection) and the subsequent WAG cycles does not show much hysteresis for krw in the experiments. I addressed some serious shortcomings of the existing reservoir simulators for reliable simulation of oil recovery processes involving three-phase flow and flow reversal

Impacts of Pandemics on Economy - Focusing on the Measures and Employee Performance in Banking Industry of Pakistan during COVID-19

This study deals with the impacts of pandemics on economy with the focus lying on the banking sector of Pakistan. This work centers on the recent pandemic of Corona Virus that instigated in late 2019. COVID-19 is not the single pandemic observed by the nations. However, the span of its outbreak is larger than those occurred earlier. This occurrence has affected the health and life of people. Besides, it is also causing strokes to the economies. Pakistan is one of the developing nations those came across with the hit. Nevertheless, banks are the only business that is operating with almost its full capacity even though many other businesses are either closed or working partially and lockdown is being observed in the country. Responses from 112 bank employees working in Pakistan obtained regarding their stance during COVID-19 and resultant lockdown. The study explores that bank employees in Pakistan are not satisfied with the financial benefits that must have been provided to work in this situation. Moreover, a significant number of employees is also having trouble due to the non-availability of appropriate conveyance facility because public transport is not available under lockdown. This condition, if prevails further, may cause employees’ demotivation, reduced productivity and economic slowdown in the long run

DEFLUORIDATION TECHNIQUES- A CRITICAL REVIEW

Fluoride in drinking water plays a vital role in dental health. Due to excessive fluoride in water, enamel loses its luster. At lower concentration, it guards our teeth against cavities but at higher concentrations imparts fluorosis in varying concentrations. Excess fluoride in drinking water is reported from more than 35 countries around the globe with India and China. In countries like India, the severe contamination of drinking water with excess fluoride acquired the dimensions of a social economic rather than a public health problem triggering defluoridation research