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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Floodplain filtration for treating municipal wastewaters

Kunjikutty, Sobhalatha Panangattu. January 2006 (has links)
The effectiveness of a cheap, low-tech, environmentally and technically favorable treatment of secondary treated municipal wastewater by contaminant removal through a floodplain-soil filter was evaluated using floodplain-simulating field lysimeters, packed with a sandy soil in 2002 and sand in 2003 and 2004. Secondary treated wastewaters from Vaudreuil (2002 and 2003) and Pincourt (2004) Wastewater Treatment Plants were used as influent. This was applied at rates of 0.06, 0.19, and 0.31 m3 m-2 d -1 to vegetated lysimeters, and at a rate of 0.19 m3 m-2 d-1 to bare-soil lysimeters. / Removal of NH4+-N, NO3--N, and COD from the influent was studied in all three years. Irrespective of flow rate or year, the system removed 62~84%, 96~99%, and 6~67% of TKN, NH4+-N, and COD, respectively, from the influent. Under 0.19 m3 m-2 d-1 flow rate, vegetated systems removed slightly more of these constituents from the influent, than did bare-soil lysimeters. Organic degradation mainly occurred in the top 0.1 m soil depth. Degradation of organic and inorganic influent nitrogen increased NO3--N levels in the effluent. Only minimal increases in soil-N levels and N2O emissions occurred with increasing application rates. The nitrogen mass balance accounted for 85∼98% (2003) and 67∼96% (2004) of input nitrogen (through leaching, soil retention, and N2O emissions), the remaining portion being attributable to vegetative effects and volatilization of non-N2O nitrogenous gases. The under established vegetation on the lysimeters reduced nitrogen leaching through soil, being 6% (2003) and 60% (2004) more effective than bare soil. / Effluent water quality improved with decreasing levels of heavy metals. Compared to influent levels, in vegetated lysimeters, under all flow rates, mean effluent As, Cd, Cu, Ni, Pb, and Zn levels had dropped by 58%, 9%, 3%, 37%, 63%, and 52% in 2003, and by 20%, 63%, 5%, 23%, 18%, 57%, and 79% for As, Cd, Cr, Cu, Ni, Pb, and Zn, in 2004. In both years, similar decreases in heavy metal levels occurred in the bare soil lysimeters. Across all flow rates and influent concentrations, soil heavy metal levels increased. In 2004, even low heavy metal content influent further increased (6∼179%) their accumulation in soil. As inputs of heavy metals to the soil increased with the increase in application rates, their associated times to reach maximum permissible limits also decreased. / LEACHN simulation of NO3--N in leachate arising from wastewater application, showed lowered levels with increasing flow rates, due to enhanced denitrification in the resulting anoxic upper soil zones. The simulation under continuous wastewater application at different range of nitrogen concentrations (low, medium, high) showed an increase of NO 3--N levels in the leachate with increasing N-levels. For all flow rates, and under tropical or humid conditions, the effluent NO 3--N levels remained below permissible limits for the low-N content wastewater applications. Intermittent applications, under all wastewater N-contents and flow rates, reduced NO3--N levels in the leachate by 51∼89% compared to continuous wastewater application, and permissible limits were not exceeded. Hence, wastewater with high levels of nitrogenous compounds, as occurs in most developing countries, could be treated by land under an intermittent application pattern, allowing a considerable reduction in nitrate pollution.
62

The short term relative effectiveness of two manual interventions in the management of chronic moderate asthma

Rampersad, Shekaar Ramesh January 2008 (has links)
Dissertation submitted in partial compliance with the requirements for the Masterà ¢ s Degree in Technology: Chiropractic, Durban University of Technology, 2008. / Objectives: To determine the short-term effect of an inhaled, short-acting 2-agonist bronchodilator on chest wall expansion (cm) and lung function parameters (FEV1, FVC and FEV1/FVC%) in chronic moderate asthmatics. To determine the short-term effect of spinal manipulation (SMT) and ribcage mobilisation on chest wall expansion (cm) and lung function parameters (FEV1, FVC and FEV1/FVC%) in chronic moderate asthmatics. To determine the short-term effect of a combination of SMT, ribcage mobilisation and an inhaled, short-acting 2-agonist bronchodilator on chest wall expansion (cm) and lung function parameters (FEV1, FVC and FEV1/FVC%) in chronic moderate asthmatics. Methods: Forty-five chronic moderate asthmatics who met all the inclusion criteria of the study were divided into three groups of fifteen each. Group A received a short-acting 2-agonist bronchodilator, Group B received SMT and ribcage mobilisation and Group C received a combination of SMT, ribcage mobilisation and a short-acting 2-agonist bronchodilator. Baseline measurements and testing included chest wall expansion and the lung function parameters FEV1, FVC and FEV1/FVC%. These measurements were repeated 15 minutes post-intervention. Data was analyzed using SPSS version 15.0. Results: There were no statistically significant changes between pre- and post-intervention in the short-acting 2-agonist bronchodilator group with respect to any of the chest wall expansion measurements. There was a statisticallly significant increase in FEV1 between pre- and post-intervention in the short-acting 2-agonist bronchodilator group (p = 0.008). There was a statistically significant increase in the mean pre- and post-intervention axillary chest wall expansion (p = 0.014) as well as the mean of the half-way measurement (p = 0.014) and the overall mean chest wall expansion value (p = 0.001) following SMT and ribcage mobilisation. There were no statistically significant changes in any of the lung function parameter values following SMT and ribcage mobilisation. There was a significant increase for the half-way measurement in chest wall expansion (p = 0.018) in the combination of SMT, ribcage mobilisation and the inhaled, short-acting 2-agonist bronchodilator group. There were no statistically significant changes in any of the lung function parameter values in the combination of SMT, ribcage mobilisation and an inhaled, short-acting 2-agonist bronchodilator. For FEV1, the effect in the short-acting 2-agonist bronchodilator group vs. the SMT and ribcage mobilisation group was statistically significant (p = 0.018). There was no statistical difference in any of the chest wall expansion measurements and FVC and FEV1/FVC% parameters between all three groups. Conclusions The results did not point specifically to one intervention over another for all outcomes. SMT and rib mobilisation had no effect on the lung function parameters, at least in the short term. There was a statisticallly significant increase in FEV1 between pre- and post-intervention in the short-acting 2-agonist bronchodilator group.
63

Treatment retention in methadone maintenance programs in Indonesia: towards evidence-informed drug policy.

Sarasvita, Riza January 2010 (has links)
Indonesia has been implementing methadone maintenance treatment (MMT) since January 2003 as a strategy to minimize HIV transmission among injecting drug users (IDU). Previous studies have shown the effectiveness of the program and also showed that the program had attracted many IDU to participate. However, the dropout rate, particularly in Jakarta clinics, was relatively high. The first aim of this study was to investigate the MMT retention rate and its predictive variables. The second aim was to examine the effects of remaining in the program on treatment outcomes. A six-month longitudinal prospective cohort study was conducted at the client level and a cross-sectional survey was carried out at the clinic level. Information from this study provides significant inputs for developing drug treatment policy and improving its quality of service in Indonesia. It also contributes to a better understanding of the substitution treatment implementation in Indonesia. The average 3-month treatment retention rate was 74.2 percent and the 6-month retention rate was 61.3 percent. There was no significant difference in retention rates between clinics. Significant predictors of treatment retention in MMT in Indonesia were size of dose, the interaction between take-home dose and clinic experience, age of participant, participant’s belief towards the program and perceived accessibility, while a variable representing perceived peer support unexpectedly predicted an increased likelihood of prematurely leaving the treatment. This study showed a marked reduction in the use of heroin and depression status and a significant improvement of self-efficacy at the follow up times among participants who continued in treatment. There were no significant differences in criminal involvement and physical health status between those who remained in treatment and the treatment dropouts in both follow-up interviews. Nevertheless, there was a significant improvement in physical health from baseline to follow-up in both groups. The study concluded that retention rates of MMT in Indonesia were comparable to those of similar programs in other countries. As previously reported in other settings, dose was the primary predictor of treatment retention in Indonesia. A policy of providing take-home doses, prescribed in experienced clinics,was also found to be a significant predictor of remaining in treatment. Further research, however, is still needed to explain some of the unexpected observations. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1522114 / Thesis (Ph.D.) -- University of Adelaide, School of Medical Sciences, 2010
64

Soil Solution Dynamics in Response to Elevated Nitrogen and Sulfur Treatments at the Bear Brook Watershed in Maine

Szillery, Johanna January 2003 (has links) (PDF)
No description available.
65

The Effects of Stress Induction on Pre-attentive and Attentional Bias for Threat in Social Anxiety

Maki, Kristen M. January 2003 (has links) (PDF)
No description available.
66

Wastewater treatment by filamentous macroalgae

Ross, Michael Eric January 2018 (has links)
An increase in anthropogenic activity has led to the heightened levels of pollution entering aquatic systems. These excessive concentrations of heavy metals, nitrogen (N), and phosphorus (P) in water bodies can lead to several adverse impacts, such as eutrophication and human health risks. Therefore, the removal of pollutants from wastewaters, prior to their discharge into the natural environment, is of paramount importance. However, conventional wastewater treatment (WWT) technologies have their limitations; for instance, large capital/operational costs, and incomplete removal of contaminants. Therefore, innovative and more effective treatment technologies are required. Macro-algae typically have high growth and solar energy conversion rates, and are able to sequester nutrients, utilise CO2, and adsorb metals from aquatic environments. Therefore, algae may have potential applications in WWT. Furthermore, costs could be negated by the production of renewable algal biomass which may have a variety of commercially exploitable applications. However, issues such as poor selection of species or cultivation systems, and a lack of understanding of the influence of biological, chemical and physical factors, particularly in a highly dynamic wastewater environments, has led to varied results and prevented algal WWT becoming a widespread reality. In this thesis the algae Cladophora coelothrix and Cladophora parriaudii were studied as potential organisms for implementation into WWT. In addition to the features mentioned above, Cladophora was selected due to its ubiquity, filamentous morphology, which minimises harvesting costs, as well as their natural dominance and bloom forming behaviour in nutrient-rich environments. The influence of dewatering techniques, environmental factors, and nutrient regime upon the growth, nutrient/metal removal, and biochemical composition of the biomass were assessed. The first aspect of the thesis was an abiotic screening process, in order to investigate the robustness of Cladophora and its suitability for WWT applications on a fundamental level. Good rates of growth (4-13.3% d-1) and nutrient removal (45.2-99.9%) were observed throughout the screening process, except under the most extreme of conditions, e.g. pH 3. This indicated that Cladophora are potentially suitable for treating a broad range of wastewaters and merit further research to improve its potential applicability for WWT applications and commercial realisation. For instance, developing a reliable and accurate method for fresh weight (FW) assessment and hence productivity estimation. The determination of growth rate via FW measurement is one of the most basic aspects of algal biology, yet no standardised method exists for filamentous macro-algae. A variety of FW methods were systematically assessed in terms of accuracy and physiological impact. Methods involving mechanical pressing to dewater the biomass resulted in >25% reduction in the final biomass yield, compared to control cultures. The best method for FW determination employed a reticulated spinner, which was rapid, reliable, and easily standardised. Furthermore, this approach ensured accurate growth estimation with minimal physiological impact, measured as growth, maintenance of structural integrity and nutrient removal. This indicates that the method developed has the potential for widespread application in macro-algal cultivation, as such the method was employed throughout this thesis. The influence of nutrient regime on growth, biochemical composition, and bioremediation capacity was studied for both species of Cladophora. The nutrient regimes tested, representative of a broad variety of wastewaters, included four different N/P ratios, four N sources (ammonium, nitrate, nitrite and urea), and six different equimolar N source combinations provided at two N/P ratios. There were clear differences in performance between the two species, with higher rates of growth observed in all instances by C. parriaudii (4.75-11.2% d-1 vs. 3.98-7.37% d-1). Furthermore, ammonium was removed preferentially, whereas urea was removed secondarily. However, the presence of urea in the medium enhanced growth and uptake of the other co-existing N-forms, and yielded a carbohydrate-rich biomass (37.6-54% DW). These findings demonstrate that algal strain selection is important for treating wastewaters with specific nutrient profiles. In addition, results from this study suggest that nutrient regimes can be tailored to produce biomass with certain properties or characteristics, which make it suitable for further, potentially commercially viable, applications, such as metal biosorption. Since the biochemical characteristics of algal biomass were shown to be affected by nutrient regime, the final chapter describes research investigating the influence of nutritional history on metal biosorption. C. parriaudii was cultivated under different nutrient regimes to produce biomass of varying biochemical composition. This biomass was then used for metal removal, with maximum removal rates ranging from 1.08-2.35 mmol g1, 0.3-0.62 mmol g-1, 0.22-0.48 mmol g-1, and 0.43-0.61 mmol g-1 for Al2+, Cu2+, Mn2+, and Pb2+, respectively. Observations from this work indicate that metal removal is achieved by various mechanisms including adsorption, ion exchange, complexation and micro-precipitation, and that the biosorption efficacy is dependent upon the number and type of functional groups present, which are in turn influenced by the cultures nutrient regime. Overall, this study demonstrates the inter-relatedness of biological, chemical, and physical factors on algal growth, nutrient removal, biochemical composition, and metal biosorption. Results from this work have highlighted the need for standardisation in protocols, increased understanding of the influence of algal selection and nutrient characteristics in bioremediation, and highlighted the importance of considering biological aspects, specifically nutritional history, in biosorption studies.
67

The efficacy of Cat hair 9cH and Histaminum 9cH in treating the symptoms of cat allergy

Alexander, Dalen 24 October 2012 (has links)
M.Tech. / Cat allergy is the allergic reaction of a person’s body when exposed to allergens borne in the cat’s dander (shed skin cells), saliva or urine. The major cat allergen, called Fel d 1, is found in cat saliva, dander from sebaceous glands in the skin, fur and anal sebaceous glands. Symptoms of cat allergies may include sneezing, itchy and watery eyes, coughing and wheezing and in rare circumstances anaphylaxis occurs. The aim of this study was to determine the efficacy of the homoeopathic complex Cat hair 9cH and Histaminum 9cH in treating the symptoms of cat allergy using the skin prick test and a symptom score card which rates the severity, frequency and duration of symptoms experienced. This was a four-week double blind, placebo-controlled study in which thirty participants, male and female between the ages of 18 and 45 were randomly divided into two groups. Advertisements was placed at the University of Johannesburg Doornfontein campus and at the Weleda pharmacy (Fourways). Potential participants that meet the inclusion criteria were requested to sign the Participant Information and Consent Form. This study had to form part of a group study related to cat allergy analysis. Participants were requested to report to Ampath laboratories to undergo a skin prick test to establish the presence of a cat allergy. Those participants that tested positive for cat allergies were to undergo an initial consultation involving a case history and a focused physical examination. Participants were given a score card each week to evaluate their severity, frequency and duration of their symptoms to be completed at the end of each week. Participants were given a 25ml bottle of either the homoeopathic complex of Cat hair 9cH and Histaminum 9cH or the placebo in tablet form, and each participant was instructed to take two tablets twice daily throughout the four week study. At the second consultation the physical exam was repeated and a second bottle of medication were given. At the end of week four, participants had to report to Ampath laboratories for the final skin prick test. This was to be followed by the third and final consultation, where the physical examination was done and all score cards collected. All data will be analysed using the Shapiro Wilk test, Mann-Whitney test, Friedman test and Wilcoxon test. With the aid of results from each participant the researcher arrived at the conclusion that the homoeopathic complex Histaminum 9cH and Cat Hair 9cH was effective on alleviating the symptoms of cat allergy.
68

Substance abuse among adolescents in the Limpopo province

Rikhotso, Tinyiko Nelly 13 May 2014 (has links)
M.Cur. (Psychiatric Nursing) / Globally, the use of substances which seem to be harmful in all life dimensions appear to be an alarming problem. Recent studies indicate that the use and abuse of these substances is more prevalent among adolescents than any other age group. This is so because there are enormous changes to the physical, psychological and social dimensions at this stage. The use of these substances is a daily occurrence and reality for many people. However, for some individuals, the use of drugs can become overwhelming and be the focus of their lives and their existence. Among all abused substances, alcohol remains the dominant substance of abuse across sites. In South Africa too, adolescents abuse substances than other age groups. Substance abuse is commonly observed among adolescents who dropped out of school before completion of matric, those who completed matric but failed to go for tertiary education due to financial constraints, and those who are already in tertiary institutions thus making it difficult for them to complete their careers. Adding up on alcohol as commonly used substances are marijuana and hallucinogens. Some contributing factors of adolescent substance abuse have been identified as family environment factors, conflicting parental monitoring, peer group influence, psychiatric conditions and attention. To explore this problem of adolescents, the researcher conducted a study on the life stories of adolescents who abuse substances. The objectives of the study were to:- -Explore and describe the life stories of adolescents who abuse substances. -Describe the guidelines for advanced psychiatric nurses to facilitate the mental health of adolescents who abuse substances. This study was undertaken within the framework of Caplan's model of health promotion and prevention of illness based on the resources of community mental health care (Kaplan & Sadock 2003:1376). A qualitative, explorative and descriptive research design was used to answer the research questions. In depth, semi-structured phenomenological interviews were conducted with adolescents who met the sample criteria. Steps were taken throughout the research to ensure trustworthiness. Data analysis was done according to (Cresswell 1994:155) Tech's model. The results of this study indicate that adolescents abuse substances in certain behaviours which lead to substance abuse, face challenges in the physical, social and psychological dimensions. However, positive feelings of determination and courage to quit the substance abuse behaviour are also expressed. Conclusions were drawn and recommendation made concerning psychiatric nursing practice, nursing education and nursing research.
69

Correlates of Treatment Preference in a Randomized Trial Comparing Mindfulness Meditation versus Cognitive-Behavioral Therapy

Dowell, Amelia January 2018 (has links)
Purpose: There is growing interest in the clinical application of mindfulness meditation. However, little is known about the extent to which clients prefer mindfulness-based interventions (MBI) over conventional psychological therapies. The present study examined predictors of treatment preference and credibility in individuals with social anxiety disorder (SAD) who participated in a randomized trial of a mindfulness intervention adapted for SAD (MBI-SAD) versus a conventional psychological therapy (cognitive behavior group therapy; CBGT). Method: The sample included 97 adults who met DSM-5 criteria for SAD. Binary logistic and multiple linear regressions were conducted to examine baseline sociodemographic and clinical predictors of treatment preference for the MBI-SAD and perception of treatment credibility. Analysis of variance was used to compare levels of trait mindfulness across treatment preference groups. Results: The majority of participants (49%) reported a preference for the MBI-SAD. Ratings of treatment credibility were comparable for the two interventions. Employment status significantly predicted preference for CBGT versus the MBI-SAD, whereas younger age predicted preference for CBGT. Higher household income, a history of psychotherapy, elevated scores on clinician ratings of depression and social anxiety, and lower scores on self-report depression predicted no treatment preference. Higher household income predicted greater perceived credibility of treatment. Trait mindfulness did not differ across the treatment preference groups or predict treatment credibility. Discussion: Mindfulness meditation appears to be an acceptable and credible treatment for SAD. However, few baseline demographic and clinical characteristics predicted preference for the MBI-SAD. Additional research is needed to explore factors that shape preference and beliefs about mind-body interventions.
70

The efficacy of Cat saliva 9cH and Histaminum 9cH in the desensitization of cat allergy

Du Plessis, Erin 18 April 2013 (has links)
M.Tech. (Homoeopathy) / Cat allergy is an Immunoglobulin E (IgE) response by the body in hypersensitive individuals, triggered by exposure to cat allergen, which can be found in cat saliva and cat dander. Cat allergy produces a number of symptoms which negatively influence daily living and may be exacerbated in hypersensitive individuals to halt daily functioning. Conventional treatment for cat allergy comprises of antihistamines, anti-inflammatories, leukotrine blockers and decongestants, which have many adverse effects, are not always effective and may lead to drug tolerance. To date, research has been conducted by Naidoo et al., (2011) on the efficacy of the homoeopathic complex of Cat saliva 9cH and Histaminum 9cH in treating the symptoms of cat allergy, which yielded positive and statistically significant results according to the skin prick test. The desensitising effect of this complex on blood IgE levels has not yet been studied. The aim of this study was to determine the efficacy of Cat saliva 9cH and Histaminum 9cH in the desensitization of cat allergy, by use of cat specific RAST tests and a symptom score card. The complex of Cat saliva 9cH and Histaminum 9cH was prepared according to homoeopathic principles and prescribed according to isopathic principles. Thirty male and female participants between the ages of 18 and 45, who had a positive RAST test result for cat allergy, were selected for this four week, double-blind, placebo-controlled study. The RAST tests were performed at the beginning of the study (week 1) and at the end of the study (week 4). The participants were randomly divided into treatment and control groups. The treatment group received the homoeopathic complex of Cat saliva 9cH and Histaminum 9cH and the control group received the placebo. Participants were asked to take two tablets in the morning and two tablets at night sublingually for the duration of the study period. Each participant received a symptom score card which was to be completed at the end of each week. The symptom score card rated the severity, frequency and duration of their symptoms. The results were statistically analysed using, the Friedman-K Related Samples Test, the Wilcoxon Signed Ranks Test and the Mann-Whitney U Test. The results showed that the homoeopathic complex of Cat saliva 9cH and Histaminum 9cH did not improve the IgE levels or IgE grading in the treatment group. When looking at the symptoms, the treatment group had a statistically significant improvement in the severity, duration and frequency of the symptom “red itchy eyes”, as well as improved duration of the symptoms “runny itchy stuffy nose” and “sneezing”; while the control group was found to have a statistically significant improvement in the frequency of the symptom “red itchy eyes”, “scratchy throat”, as well as the duration of “red itchy eyes”. In conclusion it can be said that the homoeopathic complex of Cat saliva 9cH and Histaminum 9cH did not produce desensitization to cat allergen, thus leading to the rejection of the hypothesis and the acceptance of the null hypothesis.

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