Aggregate demand for electricity in South Africa: An analysis using the bounds testing approach to cointegration

Electricity demand in South Africa has grown at a very rapid rate over the past decade. As part of reform initiatives to enhance long-term sustainability of the country's electricity industry, South Africa's authorities have in recent years sought to develop an electricity pricing framework that is cost reflective and forms the cornerstone of demand management schemes meant to foster changes in consumption behaviour and enhance efficiency in resource use. The effects of any pricing policy on aggregate electricity consumption will depend on a useful understanding of the factors that influence electricity demand, and the magnitude to which electricity demand responds to changes in such factors. In this context, this paper applies the bounds testing approach to cointegration within an autoregressive distributed lag framework to examine the aggregate demand for electricity in South Africa during the period 1960–2007. The results indicate that in the long run, income is the main determinant of electricity demand. With electricity prices having an insignificant effect on aggregate electricity demand, future pricing policies will need to ensure that electricity prices are cost reflective and enhance efficiency of electricity supply and use.     

Effects of Pretreatment on Properties of Gelatin from Perch (Lates Niloticus) Skin

Fish gelatins obtained from perch fish skin pretreated with various solutions containing acetic acid, sodium hydroxide (NaOH) and sodium chloride (NaCl) were successfully characterized for their nanostructure pattern using field emission scanning electron microscopy. Each pretreatment transformed collagen to gelatin with fibril, zigzag cracks, straight rods, and cross-linked rods nanostructure patterns. Pretreatment solutions also affect the gel yield, gel strength, amino acid profile, and functional groups in perch gelatin as analyzed by Fourier transform infrared spectroscopy. Samples pretreated with NaCl, NaOH, and acetic acid solution showed the highest gel yield (22.84%) and gel strength (179.84 g). Fourier transform infrared spectra for perch gelatins also revealed weak C–N amide II and III bond stretches as well as weak C=O bond stretch.     

Scattered doses to different parts of cancer patients during radiotherapy treatment in Nigeria

The doses over various parts of the body of 7 patients with cancers of the pharynx, breast and cervix during radiotherapy treatment with a megavoltage 60Co therapy machine were measured using LiF TL dosemeters. The doses on the surface of the patients outside the primary beam were found to vary with a maximum of 366 mGy at the abdomen of a cervix cancer patient to a minimum value of 1.1 mGy at the left arm and left leg of a pharynx cancer patient. The observed variations in the doses were attributed to the difference in patients' tumour location, exposure and anatomy. In the treatment of pregnant women and women of childbearing age, the results presented will be a good starting point for estimation of fetus doses and doses to organs outside the planning region.     

Quantitative Assessment of Interdisciplinarity in Water Science Programs

Water occupies a prominent role in global environmental change research as a result of its importance in the efficient functioning of the Earth System, and its role in socioeconomic development. Anthropogenic and natural factors have led to unparalleled changes in the global water system, necessitating integrative, interdisciplinary and holistic research paradigm for water resources management. A meta-analysis of water science projects shows that water research activities fall into HUMAN, ECOLOGY, PROCESS, and CLIMATE-BIOGEOCHEMISTRY clusters. Research themes within the clusters suggest that each research project set priorities along the lines of certain scientific disciplines. Statistical analysis further reveals low level of integration between the research clusters. The persistence of a disciplinary perspective could hinder science from effectively informing policy for sustainable water resources management. A proper integration of knowledge generated from different disciplinary epistemologies through partnership and collaboration of research projects is required for effective water management.     

Synthesis and characterization of polylactic acid-lecithin-starch bioplastic film

Plastic-induced environmental issues could be solved using biomaterials, such as polylactic acid (PLA) film. PLA film is a costly solution suggesting the need to add less expensive starch. However, PLA and starch do not mix due to their diverging water behavior. In this study, we evaluated the impact of lecithin as a compatibilizer in varying ratio of PLA and starch film. The results show that inclusion of lecithin in PLA/starch composite leads to enhanced mechanical properties compared with the composite without lecithin. All films' thermal properties were stable but the thermograph of PLA/starch display two peaks whose distance is impacted by lecithin. In addition, morphology and functional group fingerprints revealed that the addition of lecithin improved the interfacial adhesion between the two polymers. Lecithin influenced the positioning and dispersion pattern of starch granules and distinct transmittance characteristics. The improved compatibility of PLA/starch makes the resulting films less susceptible to water penetration and dissolution. This work demonstrated the possibility of using lecithin as emulsifier between PLA and starch which could expand the application of PLA/starch film especially in packaging industries and bale net wrapping.     

Albumin-based biomaterial for lung tissue engineering applications

The role of albumin-based biomaterials in tissue engineering (TE) cannot be overemphasized. The authors review the role of albumin in lungs scaffold grafting, which promotes cell seeding. Albumin grafted on decellularized lungs scaffold is presented as a great support material for cell-tissue interaction as well as for ease in attachment, growth, and differentiation when seeded with different types of cells. Albumin scaffold fabrication from different sources is a promising approach that may facilitate medical treatments from bench-to-bed, although the role of this scaffold in lungs surfactant proteins regeneration and binding needs to be fully elucidated.     

The era of sustainable agricultural development in Africa: Understanding the benefits and constraints

Sustainable agriculture has the potential to address some of the fundamental challenges facing agricultural practices in Africa especially in Sub-Saharan Africa (SSA). The agriculture sector plays an important role as the engine of economic growth in SSA. In this article, we ask the following key question: Can sustainable agriculture save Africa from poverty and food insecurity? To address this fundamental question, we examine and critique evidence of the benefits and challenges associated with the adoption of sustainable agricultural practices in Africa. Improving agricultural sustainability is fundamental to food security and poverty reduction, particularly in achieving elements of the sustainable development goals (SDGs) by 2030, but it will not solve all these problems alone. In consort, African governments and the international community must increase their efforts in tackling problems such as conflicts, civil war, political instability, and disease. Therefore, agricultural policy at the national, regional, and local levels and institutional reforms must be designed to benefit food security, poverty reduction, and income growth at the household level.