Short-term supply responde to a devaluation : a model's implications for primary commodity-exporting developing countries

The authors evaluate whether, in the short run, a devaluation could be contractionary in developing countries that export primary commodities. To do so, they use a model capturing the principal features of those economies. The two most important channels for transmitting the change in parity are (1) a supply effect with the supply response for tradables essentially a function of labor costs relative to the export commodity price, and (2) a demand effect, with the supply responds for the semitradabless essentially a function of the real wage. They simulated the model for a middle-income and a low-income country. The economic structure of the low-income country is less flexible (lower supply elasticity in production, lower elasticity of substitution between domestic production and imported inputs) than in the middle-income country. The model is meant not for use as a forecasting tool but to show the relative magnitude of various effects that are relevant in countries where the initial supply response to a devaluation would come mostly form increased production of an export commodity. In particular, the authors analyze the difference between the producer's response under"wrong"timing (the predevaluation price is the price signal on which production decisions are based) and under the presence of middlemen (rentiers in the export sector whose presence affects the devaluation's pass-through to procuders). Their findings: (a) For devaluation to succeed, there must be little wage indexing. Devaluation is more likely to be expansionary in the middle-income than in the low income country. (b) The devaluation's timing with the production cycle of the primary commodity export matters, especially in the middle-income country. (c) Debt relief is more effective where wage indexing is low and can help offset the negative effects of"wrong"timing by increasing output. But debt relief has an asymmetric effect on exportable and semitradables sectors, as the production of semitradables increases while that of exportable decreases. (d) With a tariff reduction, the devaluation implies more expansion in tradable. But this is not enough to compensate for the relative decrease in the growth rate of production of nontradables, so the growth of total output declines. (e) Finally unless the timing is"right,"the effects of redistribution (which income being"transferred"from producers to middlemen with a higher propensity to consume imported goods) can have contractionary effects that cannot be offset by debt relief.Payment Systems&Infrastructure,Economic Theory&Research,Environmental Economics&Policies,Fiscal&Monetary Policy,Labor Policies,Economic Theory&Research,Environmental Economics&Policies,Fiscal&Monetary Policy,Health Economics&Finance,Inequality

Asymptotic giant branch variables in NGC 6822

Includes bibliographical references (p. 71-75).NGC 6822, a Local Group dwarf irregular galaxy, was observed in the nearinfrared JHKS bands using the Japanese-SAAO Infrared Survey Facility (IRSF) telescope over a period of about four years. An extensive search for large amplitude asymptotic giant branch variables over the observed 7.5' x 21.1' area of NGC 6822 found 162 probable variables. In particular, 30 Miras and 9 semiregulars have been identified and characterised

A VISION-BASED QUALITY INSPECTION SYSTEM FOR FABRIC DEFECT DETECTION AND CLASSIFICATION

Published ThesisQuality inspection of textile products is an important issue for fabric manufacturers. It is desirable to produce the highest quality goods in the shortest amount of time possible. Fabric faults or defects are responsible for nearly 85% of the defects found by the garment industry. Manufacturers recover only 45 to 65% of their profits from second or off-quality goods. There is a need for reliable automated woven fabric inspection methods in the textile industry. Numerous methods have been proposed for detecting defects in textile. The methods are generally grouped into three main categories according to the techniques they use for texture feature extraction, namely statistical approaches, spectral approaches and model-based approaches. In this thesis, we study one method from each category and propose their combinations in order to get improved fabric defect detection and classification accuracy. The three chosen methods are the grey level co-occurrence matrix (GLCM) from the statistical category, the wavelet transform from the spectral category and the Markov random field (MRF) from the model-based category. We identify the most effective texture features for each of those methods and for different fabric types in order to combine them. Using GLCM, we identify the optimal number of features, the optimal quantisation level of the original image and the optimal intersample distance to use. We identify the optimal GLCM features for different types of fabrics and for three different classifiers. Using the wavelet transform, we compare the defect detection and classification performance of features derived from the undecimated discrete wavelet and those derived from the dual-tree complex wavelet transform. We identify the best features for different types of fabrics. Using the Markov random field, we study the performance for fabric defect detection and classification of features derived from different models of Gaussian Markov random fields of order from 1 through 9. For each fabric type we identify the best model order. Finally, we propose three combination schemes of the best features identified from the three methods and study their fabric detection and classification performance. They lead generally to improved performance as compared to the individual methods, but two of them need further improvement

Simplification of Complex WWTP Models into Simple Design and Evaluative WRRF Tool

Wastewater treatment plant (WWTP) steady-state models have been used, historically, by consulting engineers and researchers for design, process optimisation, and to study and evaluate various operating scenarios. These models have, however, been generally developed for single unit process which limits their use. In addition, there have been three recent shifts in the past two decades from conventional design and modelling of WWTPs. Firstly, the shift from single unit to plant-wide modelling. Secondly, WWTPs are considered as water and resource recovery facilities (WRRFs). Lastly, there has been a growing interest to use the developed plant-wide steady-state models by stakeholders i.e., plant operators, designers and decision-makers who have limited technical expertise in WWTP modelling. These stakeholders use these models for design, evaluation and optimisation of scenarios. The later shift has raised the debate of complexity versus simplicity of the developed steady-state models. In addition to the aforementioned shifts, there has been limited research on the impact of sludge return liquors on the overall plant performance especially in the context of South African WWTPs. Wastewater treatment plants treat influent wastewater to a specified effluent quality, through several processes, before discharging it into the receiving water bodies. One of the by-products of these treatment processes is a nitrogen (N) and phosphorus (P) rich dewatering liquor (DWL). Generally, South African WWTPs recycle the DWL to the mainstream treatment process without first undergoing any side-stream treatment process (SSTP). The recycling of such N and P rich DWLs to the mainstream process, without first going through any SSTP and/or addition of organics to the mainstream process (organics have a role to play in nutrient removal, through the provision of substrate for biomass growth and provision of electron donors in the process of denitrification) poses a problem to the treatment process. Consequently, the reactor is overloaded with nutrients without sufficient organics to remove them; hence, the plant produces poor effluent quality i.e., high N and P concentrations at high operational cost. A simplified full-scale steady-state WWTP simulation tool, namely, plant performance evaluation tool (PPET), with a user-friendly interface was developed, based on principles of sound mass balance and kinetic and stoichiometric relations over the full-scale plant, to bridge the gap between the complexity of WWTP models and the lack of technical expertise of the stakeholders. This simulation tool analyses the impact of recycling sludge dewatering liquors on the overall plant performance. Furthermore, it gives the user a platform to analyse different scenarios and provides uncompromised results that enable the user to make better design and operation decisions. The bio-augmentation batch enhanced (BABE) and struvite precipitation SSTPs, and plant performance indices i.e., effluent quality and operational cost indices, EQI and OCI, respectively, were incorporated into PPET to analyse case studies on South African plants. It was found that there are added benefits of using a SSTPs to mitigate the detrimental impacts of recycled DWL when the capacity of the plant has been exceeded. However, both BABE and struvite precipitation processes achieve different results based on the composition of the DWL that is being treated i.e., for DWL from an anaerobic digester treating waste activated sludge that is not P rich (with low EBPR), then the recommended SSTP operation would be BABE process rather than struvite precipitation. Due to the different treatment systems (i.e., with variations in influent loads, system configurations and priority end products required - energy, water, phosphorus, etc.), further investigations are required on strategies for implementation of the various SSTPs

Cost comparison of hydropower options for rural electrification in Rwanda

The decision to develop a hydropower plant depends on several factors, which cost is the most significant. This thesis, entitled "Cost comparison of hydropower options for rural electrification in Rwanda" intends to show that the use of a large number of mini hydropower plants for electrification of sparse rural areas in Rwanda is the least cost option when compared to installing either a single small or large hydropower plants. This is done by considering rural households to be randomly distributed and the model composed by 98 rural villages having three different population densities is used to test the validity of the hypothesis. Three different hydropower options providing the same level of service to rural households were used for the cost comparison. The relationship between the electrification cost per household versus the population density is deduced. Many distribution technologies can be used in rural areas and the accurate selection of the appropriate distribution technology is the main concern as it affects the cost of the whole distribution system. The rural network should be carefully designed so that the sizing of conductors to be used for LV and MV network is properly done at a low cost. The high distribution cost depends largely on the size of power to be delivered. Based on these findings, the cost comparison of mini, small and large hydropower schemes for rural electrification in Rwanda is discussed

The role of vitamin D in the development and progression of experimental abdominal aortic aneurysm

Vianne Nsengiyumva conducted experimental investigations into the role of vitamin D on abdominal aortic aneurysms (AAA). Vitamin D supplementation to achieve optimal circulating levels slowed the growth of AAA. Findings from this thesis are supportive of clinical trials to examine regulating vitamin D levels in AAA patients

INVESTIGATING THE EFFECTS OF SINGLE-EVENT UPSETS IN STATIC AND DYNAMIC REGISTERS

Radiation-induced single-event upsets (SEUs) pose a serious threat to the reliability of registers. The existing SEU analyses for static CMOS registers focus on the circuit-level impact and may underestimate the pertinent SEU information provided through node analysis. This thesis proposes SEU node analysis to evaluate the sensitivity of static registers and apply the obtained node information to improve the robustness of the register through selective node hardening (SNH) technique. Unlike previous hardening techniques such as the Triple Modular Redundancy (TMR) and the Dual Interlocked Cell (DICE) latch, the SNH method does not introduce larger area overhead. Moreover, this thesis also explores the impact of SEUs in dynamic flip-flops, which are appealing for the design of high-performance microprocessors. Previous work either uses the approaches for static flip-flops to evaluate SEU effects in dynamic flip-flops or overlook the SEU injected during the precharge phase. In this thesis, possible SEU sensitive nodes in dynamic flip-flops are re-examined and their window of vulnerability (WOV) is extended. Simulation results for SEU analysis in non-hardened dynamic flip-flops reveal that the last 55.3 % of the precharge time and a 100% evaluation time are affected by SEUs

Genetic Analysis of the Role of GRP170B (T14G8.3) During Toxin Induced Protein Folding Stress in Caenorhabditis elegans

Chaperones maintain cellular homeostasis by facilitating protein folding. However, under standard cultured conditions, Caenorhabditis elegans strains genetically deficient for the ER chaperone GRP170B (encoded by the T14G8.3 locus) seems unaffected by the loss of this large chaperone. For most ER chaperones, the loss of GRP170B chaperone increases sensitivity to toxins that disrupt protein folding in the ER. I hypothesized that GRP170B’s role may involve mediating the nematodes response to ER protein folding stress. To investigate a stress role for GRP170B chaperone, I analyzed the effect of toxins that are known to effect ER protein folding on nematodes deficient for the chaperone. The three toxins tested I tested were: 1. tunicamycin (TM), an ER glycosylation inhibitor, 2. dithiothreitol (DTT), a disrupter of disulfide bond formation and 3. thapsigargin (TG) an inhibitor of an ER calcium pump which disrupts protein folding by interfering with the activity of calcium dependent ER chaperones. Eggs of nematodes deficient for GRP170B (strain BSC06) and the control strain (N2) were cultured at varying doses of each toxin, and the development of the nematodes was monitored. At 80-320 mg/μl of TM, the GRP170B deficient worms were less sensitive to the toxin than the control strain. This was similar to a previous study which found that nematodes deficient for GRP170B were less sensitive to 3 μg/ml TM. At the highest dose of TM tested (640 μg/μl), development was similar in nematodes with and without GRP170B. Results showed that at low doses of the second toxin DTT (80-320 mg/μl), development was similar in nematodes with and without GRP170B. However, at highest dose (640 mg/μl) GRP170B deficient worms were more sensitive to the toxin and none of them developed to L4/adult stages. For the third toxin tested, TG there was a notable experimental variation across all treatments from 0.5 mM to 1.25 mM. The effect of TG on development of nematodes deficient for GRP170B was also tested. Thapsigargin doses(0.5 nM to 5 nM) did not affect the development of either strain. These data demonstrate that GRP170B deficient worms are not being affected specifically with one toxin versus the other. These data revealed that GRP170B has a critical role during normal C. elegans physiology role and during stress physiology with the use TM. However, the role of GRP170B could not be determined using DTT and TG at the tested doses

The enslaved family as reflected in Post-colonial African Drama: Ngugi and Ngugi’s I Will Marry When I Want

In literary studies, critics demonstrate authors’ role to depict human life using characters and themes affecting them through various literary forms viz prose fiction, poetry and drama. The latter tells a story by engaging dialogue and conflicts among characters. Driven by the didactic literary theory, the researchers carry out a literary analysis of Ngugi wa Thiong’o and Ngugi wa Mirii’s morality play “I Will Marry When I Want”; and explore the situation of an enslaved family reflected in the impossible promise of the land grabber and exploiter targeting a one and half acres of land that the family was living on. Discussion centers on character victims in the story, leading to the conclusion that the play depicts the hypocrisy and power of the elite - haves at the expense of the poor in post-colonial Africa. The Kioi’s malice unbeknown to Kiguunda’s family is one of many cases of human bad manners that affect society members due to their poor life background rooted in the effects of exploitation and oppression; resulting in the victim’s wrong choice motivated by the stopgap altogether