Search results for: Njabulo S. Mdlulia
4 Adsorptive Removal of Ba, Na, Ni and V From Fuel Oils Using Low-cost Fe3O4@Cellulose Nanocrystals: Adsorption Kinetics, Isotherm, Thermodynamic and Recyclability Studies
Authors: Njabulo S. Mdlulia, Masixole Sihlahlaa, Vusimuzi Pakadea, Philiswa N Nomngongob, Nomvano Mketoa
Abstract:
The removal of Ba, Na, Ni and V metals in crude oil, gasoline, diesel and kerosine was achieved by using Fe3O4@cellulose. The Fe3O4@cellulose was synthesized by using the co-precipitation method and was then characterized using the scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer-Emmentt-Teller (BET), zeta potential and Transmission electron microscopy (TEM). To obtain the optimum adsorption conditions, multivariate optimization tools such as a two-level full factorial and a central composite were used. The optimum conditions for the adsorptve removal of Ba, Na, Ni and V in the fuel oils were found to be 4.5, 1.5 M of HNO3, 40 minutes, 0.15 g and 0.15 g for pH, eluent concentration, extraction time, adsorbent mass and sample mass (model oil concentration). The adsorption method developed was very sensitive as it reported MLOD ranging from 0.022-1.51 µg/g while MLOQ ranged from 0.072-5.03 µg/g for metals under study. The optimum conditions were then applied to real fuel samples, which were crude oil, gasoline, kerosene and diesel.Keywords: adsorption kinetics, F=fuel oils, isotherms, metals, thermodynamics
Procedia PDF Downloads 03 Fragmentation of The Multilateral Trading System: The Impact of Regionalism on WTO Law
Authors: Musa Njabulo Shongwe
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The multilateral trading system is facing a great danger of fragmentation. Its modus operandi, multilateralism, is increasingly becoming clogged by trade barriers created by the proliferation of preferential regional trading blocs. The paper explores the fragmentation of the multilateral trade regulation system (WTO law) by analysing whether and to what extent Regional Trade Agreements (RTAs) have conflicted with the Multilateral Trading System. The paper examines the effects of RTA dominance in view of the WTO's quest for trade liberalization. This is an important inquiry because the proliferation of RTAs implies the erosion of the WTO law’s core principle of non-discrimination. The paper further explores how the proliferation of RTAs has endangered the coherence of the multilateral trading system. The study is carried out with the initial assumption that RTAs could be complementary and coherent with WTO law, and thus facilitate international trade and enhance development prospects. There is evidence that is tested by this study which suggests that RTAs can be divergent and hence undermine the WTO multilateral rules of regulating international trade. The paper finally recommends legal tools of regulating and managing the WTO-RTA interface, as well as other legal means of ensuring a harmonious existence between the WTO and regional trade arrangements.Keywords: fragmentation of international trade law, regionalism, regional trade agreements, WTO law
Procedia PDF Downloads 3812 Living Heritage(s) And Decoloniality: A Situational Analysis of the Great Zimbabwe World Heritage Site
Authors: Revai Boterere
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The study explores the decolonial theory in the context of engaging with living heritages in the formally colonised through the case of the Great Zimbabwe World Heritage Site. It followed a qualitative research paradigm in the form of a situational analysis, with both primary and secondary data sources examined to enable an analysis focusing on the decolonial discourse and practice at Great Zimbabwe. Unlike the dominant model (in terms of interpretation) used at Great Zimbabwe, that of Thomas Huffman, which views the site as ruins, new literature (Ashton Sinamai, 2017, 2020; Webber Ndoro, 1994, 2005; ShadreckChirikure 2008, etal 2016; Njabulo Chipanguraetal 2019) on zimbabwe culture, Great Zimbabwe World Heritage Site is a living site, a shrine, and a cultural landscape. it argue that the new literature, perhaps decolonial, remain in the hands of academics and not synthesised down to the interpreters. This is a problem, and it needs to be addressed. There is need of a pragmatic thrust to decolonisation at the Great Zimbabwe World Heritage Site. Though there are efforts to involve local communities at Great Zimbabwe as a decolonial approach, there is need to reorder the current system of producing knowledge in place. This paper will unpack these debates of decoloniality between what Huffman’s propositions of the interpretation of Great Zimbabwe vis-a-vis the new decolonial school of thought by local researchers.Keywords: cultural tourism, decoloniality, living heritage, local community
Procedia PDF Downloads 1121 On the Survival of Individuals with Type 2 Diabetes Mellitus in the United Kingdom: A Retrospective Case-Control Study
Authors: Njabulo Ncube, Elena Kulinskaya, Nicholas Steel, Dmitry Pshezhetskiy
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Life expectancy in the United Kingdom (UK) has been near constant since 2010, particularly for the individuals of 65 years and older. This trend has been also noted in several other countries. This slowdown in the increase of life expectancy was concurrent with the increase in the number of deaths caused by non-communicable diseases. Of particular concern is the world-wide exponential increase in the number of diabetes related deaths. Previous studies have reported increased mortality hazards among diabetics compared to non-diabetics, and on the differing effects of antidiabetic drugs on mortality hazards. This study aimed to estimate the all-cause mortality hazards and related life expectancies among type 2 diabetes (T2DM) patients in the UK using the time-variant Gompertz-Cox model with frailty. The study also aimed to understand the major causes of the change in life expectancy growth in the last decade. A total of 221 182 (30.8% T2DM, 57.6% Males) individuals aged 50 years and above, born between 1930 and 1960, inclusive, and diagnosed between 2000 and 2016, were selected from The Health Improvement Network (THIN) database of the UK primary care data and followed up to 31 December 2016. About 13.4% of participants died during the follow-up period. The overall all-cause mortality hazard ratio of T2DM compared to non-diabetic controls was 1.467 (1.381-1.558) and 1.38 (1.307-1.457) when diagnosed between 50 to 59 years and 60 to 74 years, respectively. The estimated life expectancies among T2DM individuals without further comorbidities diagnosed at the age of 60 years were 2.43 (1930-1939 birth cohort), 2.53 (1940-1949 birth cohort) and 3.28 (1950-1960 birth cohort) years less than those of non-diabetic controls. However, the 1950-1960 birth cohort had a steeper hazard function compared to the 1940-1949 birth cohort for both T2DM and non-diabetic individuals. In conclusion, mortality hazards for people with T2DM continue to be higher than for non-diabetics. The steeper mortality hazard slope for the 1950-1960 birth cohort might indicate the sub-population contributing to a slowdown in the growth of the life expectancy.Keywords: T2DM, Gompetz-Cox model with frailty, all-cause mortality, life expectancy
Procedia PDF Downloads 121