Impacts of mining on land use - A case (study) of Luanshya district, Zambia

Copper mining is the main driver of Zambia’s economic growth and development and plays a significant role in the global supply of materials for electrical, plumbing, heating and transport equipment among other benefits. However, primary production and beneficiation of copper pose serious risks to the mining districts such as environmental pollution, landscape alterations, land degradation and social economic challenges to the host communities. This research looks at the landscape alterations in the mining district of Luanshya, and how these alterations are related to mining and other land uses. Using remote sensing and Geographic Information Systems (GIS), the landscape alterations were mapped and analysed to identify the processes causing these alterations and their impacts on land use. Secondly, stakeholder interviews were conducted to gain a deeper understanding of the mapped landscape alterations, what the approach has been to land use planning and the stakeholder roles in this planning. Analysis of the findings identifies that landscape alterations in the district have been caused by different inter-related mechanisms stemming from a number of causes. These causes include high dependency on copper mining; inadequate enforcement of environmental legislation; lack of state involvement in land use planning of mining districts; and also global factors such as commodity market conditions. As a result, boom and bust commodity cycles have had significant impacts on the wellbeing of both mining communities and the environment. These impacts are not limited to the mine sites alone but extend to entire districts. This research also identifies that while mining plays a vital role in the economic development of Zambia, adequate enforcement of environmental legislation and adoption of inclusive land use planning may stimulate sustainable development of mining districts and foster sustainable land use patterns. Furthermore, this study recommends that future land use planning must be dynamic in terms of adopting postmining restoration of landscapes and infrastructure while also taking the direct and indirect impacts of mining into account

Extraction and separation of zirconium and hafnium using octanol

Zirconium (Zr) and hafnium (Hf) metals have drawn considerable attention due to their various applications, especially in the nuclear industry where zirconium is used as a cladding material for nuclear reactors due its low neutron-capture cross-section and strong resistance to corrosion, whereas hafnium is used as an excellent control rod material for reactors due to its high neutron-absorption capacity. The efficiency of the reactor depends directly on the concentration of hafnium in zirconium. The zirconium should contain a very low concentration of hafnium, not exceeding 100 ppm, for use in the nuclear industry. Due to the fact that zirconium and hafnium occur within the same mineral, there is great interest in separating them in order to produce zirconium and hafnium oxide which can be used in the production of zirconium and hafnium metals appropriate for use in the nuclear industry. Hence, the separation and purification of these elements is of great importance. Solvent extraction techniques are employed to separate and purify these elements on an industrial scale. However, the separation of zirconium and hafnium is a difficult task as both elements exhibit similar chemical and physical properties. The main objective of this investigation was therefore to evaluate the potential of octanol as an alternative extractant to the conventional extractants methyl isobutyl ketone (MIBK) and tributyl phosphate (TBP) due to the problems associated with the latter two extractants. The effect of the different parameters affecting the extraction and separation of these two elements (Zr and Hf) were studied in terms of the initial feed concentration, contact time, extractants, loading capacity, temperature, diluents and stripping agents. It was determined from the results obtained that the different parameters investigated all have important effects on the extraction and separation of zirconium from hafnium. The results indicate that zirconium ions were preferentially extracted over hafnium with undiluted 1-octanol and 2-octanol in 10 % hydrochloric acid and 1.5 M potassium fluoride as feed concentration at a ratio of 1:2. The McCabe-Thiele diagram indicates that four equilibrium stages are required for almost complete extraction of zirconium from the aqueous solution. Sulfuric acid was found to be the most desirable agent for stripping zirconium from the loaded organic solution. A mixture of oxalic acid and nitric acid was considered to be a good stripping agent for hafnium as it could lead to good separation of hafnium from the remaining zirconium. Zirconium and hafnium were neutralized using 25 % ammonium hydroxide solution. After filtration and calcination, the products obtained were characterised using XRD and SEM-EDS analysis. A packed column was also used to compare the effectiveness of the extraction and separation of zirconium from hafnium. It was observed that in order to achieve the optimum mass transfer, greater column height is required.Thesis (PhD)--University of Pretoria, 2019.Chemical EngineeringPhDUnrestricte

Extraction and separation of tantalum and niobium from Mozambican tantalite by solvent extraction in the ammonium bifluoride-octanol system

The principal aim of this research was to determine the optimum conditions of extraction and separation of niobium and tantalum with octanol as solvent, from Mozambican tantalite using ammonium bifluoride as an alternative to hydrofluoric acid. The extraction of niobium and tantalum from tantalite can be divided into three activities, viz., acid treatment of the ore to bring the niobium and tantalum values into solution, separation of niobium and tantalum by solvent extraction and preparation of pure niobium pentoxide and tantalum pentoxide by precipitation followed by calcination. An initial solution was prepared by melting a mixture of tantalite and ammonium bifluoride followed by leaching of the soluble component with water and separation of the solution by filtration. The solution filtered was successfully used after adjustment of the acidity for the extraction and separation of niobium and tantalum. After liquid-liquid extraction highly pure niobium pentoxide and tantalum pentoxide were obtained through precipitation with ammonium hydroxide and calcination. Comparative experiments were performed modifying the following variables: decomposition temperature; decomposition time of the digestion of niobium and tantalum; acid concentration of feed solution; solvent agent; and stripping agent. From the experimental results it was determined that the decomposition temperature, decomposition time of the digestion of niobium and tantalum, the acidity of the feed solution, the solvent agent, and stripping agent, all have an important effect on the extraction and separation of tantalum and niobium. The optimal conditions were determined to be: tantalite-to-ammonium bifluoride 1:30; decomposition temperature 250°C; decomposition time 3 hours; and a water leach period of 10 minutes. Under these conditions the leach recovery of niobium and tantalum was about 95.07% and 98.52%, respectively. For nearly complete extraction of tantalum and niobium with 2-octanol, two and three equilibrium stages, respectively, are required. The equilibrium data were obtained at an aqueous-to-organic ratio (A/O) of 1:1 using: 100% 2 octanol; 6 M H2SO4; 10 minutes contact time at room temperature for tantalum; and 100% 2 octanol, 9 M H2SO4, 10 minutes contact time at room temperature for niobium. Different stripping agents were used and water seems to give good result for both. For the nearly complete stripping process four equilibrium stages are required. From the results obtained an optimum stripping efficiency is achieved after 15 minutes for a 1:1 ratio. Niobium and tantalum were then neutralized using 28% ammonium hydroxide. The precipitate obtained was dried and placed in a muffle furnace for 4 hours at 900°C. After calcinations, pure tantalum pentoxide and niobium pentoxide were obtained and characterized using XRD and SEM. Tantalum pentoxide and niobium pentoxide synthesized contain trace impurities such as iron and titanium which can be removed by incorporating an appropriate intermediate treatment.Dissertation (MSc)--University of Pretoria, 2012.Chemical Engineeringunrestricte

Identification of adapted varieties of groundnuts (Arachis hypogaea L.) in SEKE BANZA area, Democratic Republic of the Congo (DRC)

The present study aimed at identifying the most effective and adapted groundnut varieties to the climatic conditions of SEKE BANZA area, province of Bas Congo, Democratic Republic of Congo (DRC.). Twenty four varieties from IITA /DRC were tested in experimental site of INERA GIMBI. Randomised block design with four replications was used to evaluate grain yields (t/ha), height of plant at the end of flowering(cm), number of days for plant flowering, number of maturity days, stem diameter at the first internodes (mm), Rosette incidence disease(%), Cercospora leaf spots incidence disease (%), Rosette severity (1-5), Cercospora severity (1-5). Compared to controls, ten varieties revealed more effective. Evaluated parameters during season A were higher than during season B. Varieties not released have to be listed on national catalogue before their popularization. In SEKE BANZA area, diseases attack level is low mostly in season A. Number of days for plant maturity was correlated to number of days of plant flowering.Keywords: Arachis hypogaea L., illness, effective variety, yield

Evolution du système national d’information sanitaire de la république démocratique du Congo entre 2009 et 2015

Introduction: Lancé en 1987, le Système national d'information sanitaire (SNIS) de la République Démocratique du Congo (DR Congo) a été évalué en 2009 et 2015 moyennant l'outil HMN (Health metrics network). L'objectif de cette étude était d'estimer les progrès réalisés entre ces deux évaluations.Méthodes: Il s'agissait d'une analyse des données secondaires des évaluations du SNIS, qui a consisté à comparer le degré de satisfaction par rapport aux six composantes de cet outil entre 2009 et 2015, à savoir; les ressources, les indicateurs, les sources de données, la gestion des données, les produits de l'information, la diffusion et l'utilisation des données.Résultats: Entre 2009 et 2015, le degré de satisfaction des répondants a évolués de la manière suivante: 49% contre 61% pour les ressources; 73% vs 88% pour les indicateurs; 52% vs 61% pour les sources de données; 41% vs 45% pour la gestion des données; 74% contre 77% pour les produits de l'information et enfin 51% vs 51% pour la diffusion et l'utilisation des données. Dans l'ensemble, le score moyen est passé de 59% à 64% avec une mention « satisfaisante ».Conclusion: Notre étude a montré que le SNIS de la RD Congo n'a pas significativement évolué entre 2009 et 2015, et n'était pas en mesure de fournir en temps réel l'information sanitaire fiable pour la prise de décision et la planification des programmes de santé.Mots clés: Outil HMN, SNIS, RD CongoEnglish Title: Evolution of the National Health Information System in the Democratic Republic of the Congo between 2009 and 2015English AbstractIntroduction: Launched in 1987, the National Health Information System (NHIS) in the Democratic Republic of the Congo (DR Congo) was evaluated in 2009 and 2015 using the HMN (Health Metrics Network) assessment tool. This study aimed to estimate the progress made between these two evaluations.Methods: We performed an analysis of the secondary data from the evaluations of the NHIS, which was based on the comparison of the satisfaction level between the six components of this tool between 2009 and 2015, namely: resources, indicators, data sources, data management, information products, dissemination and use of data.Results: Between 2009 and 2015, respondents' satisfaction level changed as follow: resouces 49% vs 61%; indicators 73% vs 88%; data sources 52% vs 61%; data management 41% vs 45%; information products 74% vs 77%; dissemination and use of data 51% vs 51%. In general the average score increased from 59% to 64% with "satisfactory" mark.Conclusion: Our study shows that the NHIS in the DR Congo has not changed significantly between 2009 and 2015 and that it couldn't provide real-time reliable health information for decision-making and health program planning.Keywords: HMN tool, NHIS, DR Cong

Report of the International Society of Hypertension (ISH) Hypertension Teaching Seminar organized by the ISH Africa Regional Advisory Group: Maputo, Mozambique, 2016

The International Society of Hypertension (ISH), in fulfilment of its mission of promoting hypertension control and prevention and also of advancing knowledge globally, organizes hypertension teaching seminars or ‘summer schools’ worldwide through the ISH Regional Advisory Groups. In Africa, seven of such seminars have been organized. This is a report of the eighth seminar held in Maputo, Mozambique, April, 2016. The seminar was attended by over 65 participants from 11 African countries. The Faculty consisted of 11 international hypertension experts. The eighth African hypertension seminar was a great success as confirmed by a pre- and post-test questionnaire

LES PROFILS DE L’EMPLOI ET DE L’EMPLOYÉ DE MAISON EN RÉPUBLIQUE DÉMOCRATIQUE DU CONGO

En République Démocratique du Congo, le travail de maison s’apparente au travail au noir. En vue de définir les profils de l’emploi et de l’employé de maison nous avons formulé cinq hypothèses. L’une d’elles est en rapport avec le profil de l’employé et les quatre restantes visent le profil de l’emploi. Leur test a été réalisé avec deux indicateurs statistiques, notamment la médiane et le pourcentage, obtenus après avoir interrogé 190 employés de maison de Kinshasa avec un questionnaire. En effet, le personnel de maison congolais est généralement jeune, de genre féminin, scolarisé et de toute origine régionale et / ou ethnique. Il travaille à proximité de sa résidence. Il est vulnérable, car sans couverture sociale, sans défense de ses intérêts salariaux mais avec un contrat verbal donc impossible à retracer en cas de problème. Son travail est physiquement épuisant et mal rémunéré. Ce pessimiste portrait doit interpeller les législateurs congolais et nécessiter la précision des fondements juridico-sociaux de la relation entre employeur et employé pour protéger socialement l’emploi de maison et son occupant

Analyse rétrospective de la Mortalité périnatale sans facteur de risque préalablement décelé aux Cliniques Universitaires de Kinshasa: Retrospective analysis of Perinatal mortality without risk factor previously detected at Kinshasa University Hospital

Context and objective. Perinatal mortality (PNM) remains high in developing countries. The present study analyzed fetal-maternal parameters associated with PNM with no known risk factor. Methods. The analysis concerned all pregnant women at full term pregnancy, single fetus, without anomaly and alive at the onset of labor, having given birth in Kinshasa University Hospital over a decade. The risk of PNM was modeled in a multiple logistic regression. Results. Of the 4,390 newborns, birth weight 3,085±416g, 52.8% were boys. Gestational age averaged 38.2±1.1 amenorhee week. PNM (n=354; 81 %) was similar for girls and boys (p=0.5111). The BW of deceased and alive babies was also similar (p = 0.219). Maternal weight (p=0.034), height (p<0.0001), number of antenatal care (p=0.0001) and gestational age (p<0.0001) were greater in mothers with deceased infants. The PNM was directly proportional (p<0.0001) to birth weight, number of antenatal care, mode of delivery, and gestional age but negatively (p<0.0001) proportional to Apgar score. The PNM was lower for Apgar “Good” (ORa: 0.005; 95% CI [0.003-0.009]; p<0001) and antenatal care ≥ 4 (ORa: 0.256 [0.126-0.523]; p=0.0004), higher for boys (ORa: 1.692 [1.095-2.616];p=0.0173), non eutocia delivery (ORa: 3.586[2.383–5.396]; p<0001) and higher gestional age (ORa: 5.657 [3.194-10.019]; p<0001). Conclusion. Excessive PNM is linked to gender, mode of delivery and gestional age suggesting early post-maturity onset in African women. Contexte et objectif. La mortalité périnatale (MPN) reste élevée dans les régions en développement. La présente étude a analysé des paramètres fœto–maternels associés à la MPN sans facteur de risque connu. Méthodes. L’analyse a concerné des gestantes avec fœtus unique, normal et vivant à l’entrée en travail, ayant accouché aux Cliniques Universitaires de Kinshasa au cours d’une décennie. Le risque de MPN est modélisé dans une régression logistique multiple. Résultats. Des 4390 nouveau-nés, poids de naissance=3085±416g, 52,8% étaient garçons. L’âge gestationnel était 38,2±1,1 semaines d’amenorhée. La MPN (n=354 ; 81‰) était similaire (p=0,5111) pour filles et garçons ; de même le poids de naissance des nouveau-nés décédés et vivants. Le poids (p=0,034), la taille (p<0,0001), le nombre de consultation prénatale (p=0,0001) et l’age gestationnel (p=0,0001) des mères avec nouveau-nés décédés étaient plus importants. La MPN était directement proportionnelle (p<0,0001) au poids de naissance, au nombre de consultation prénatale, à l’âge gestationnel et au mode d’accouchement et négativement proportionnelle (p<0,0001) au score d’Apgar. La MPN était moindre pour Apgar « Bon » (ORa: 0,005 IC 95% [0,003-0,009]; p<0001) et consultation prénatale ≥ 4 (ORa: 0,256 [0,126-0,523]; p=0,0004), plus élevée pour les garçons (ORa: 1,692[1,095-2,616]; p=0,0173), l’accouchement non eutocique (ORa: 3,586 [2,383–5,396]; p<0001) et l’âge gestationnel important (ORa: 5,657[3,194–10,019]; p< 0001). Conclusion. La MPN excessive est liée au sexe, au mode d’accouchement et à l’âge gestationnel suggérant une post-maturité précoce chez l’africaine

Solvent extraction of Zirconium and hafnium with 1 and 2-octanol: a comparative study

Comparative solvent extraction studies of Zr and Hf were carried out from acidic chloride and potassium fluoride solutions with 1 or 2-octanol as extractants. The extraction process was experimentally investigated as a function of contact time, hydrochloric acid concentration, sulfuric acid concentration, hydrofluoric acid concentration, nitric acid concentration, amount of potassium fluoride added and organic-to-aqueous phase ratio. The results show that zirconium is preferentially extracted into the organic phase. Under the optimal operating conditions of 10 % HCl, 1.5 M KF, 15 minutes and an organic-to-aqueous phase ratio of 2:1, the extraction percentage of zirconium and hafnium is 94.3 % of Zr and 64.3 % of Hf and a separation factor of 9.2 for 2-octanol and 93.1 of Zr and 60.9 % of Hf and a separation factor of 8.7 %. 2-octanol shows a slightly higher extraction percentage and separation factor over 1-octonal.The authors will like to thank the University of Pretoria, the South African Research Foundation (NRF) and the Advanced Metals Initiative of the Department of Science and Technology, for their financial support.The University of Pretoria, the South African Research Foundation (NRF) and the Advanced Metals Initiative of the Department of Science and Technology.http://www.cetjournal.itam2020Chemical Engineerin

Relationship between Younger Age, Autoimmunity, Cardiometabolic Risk, Oxidative Stress, HAART, and Ischemic Stroke in Africans with HIV/AIDS

Background and Purpose. It now appears clear that both HIV/AIDS and antiretroviral therapy (HAART) use are associated with higher risk of cardiovascular disease such as stroke. In this study, we evaluated the prevalence, the risk factors, and the cardiometabolic comorbidities of stroke in HIV/AIDS Central African patients. Methods. This hospital-based cross-sectional study collected clinical, laboratory, and imaging data of black Central African heterosexual, intravenous drug nonuser, and HIV/AIDS patients. Results. There were 54 men and 62 women, with a female to male ratio of 1.2 : 1. All were defined by hypercoagulability and oxidative stress. Hemorrhagic stroke was reported in 1 patient, ischemic stroke in 17 patients, and all stroke subtypes in 18 patients (15%). Younger age <45 years (P = .003), autoimmunity (P < .0001), and metabolic syndrome defined by IDF criteria (P < .0001) were associated with ischemic stroke. Conclusions. Clustering of several cardiometabolic factors, autoimmunity, oxidative stress, and lifestyle changes may explain accelerated atherosclerosis and high risk of stroke in these young black Africans with HIV/AIDS. Prevention and intervention programs are needed