754 research outputs found
Electrification financing and tariffs: international literature review
This report was commissioned by the National Electrification Forum (NELF}. It is a review of international experience in electricity pricing, funding and financial management. The purpose of the report is to assess how these issues have affected electrification programmes in developing countries and to draw conclusions which will assist NELF in establishing appropriate electricity pricing and financing policies for South Africa. A successful electrification programme which enables widened access to electricity is ultimately dependent on the creation and maintenance of a financially viable electricity distribution industry. Financial viability is, in tum, crucially dependent on appropriate pricing and financing policies and financial management practices. The report is based on an extensive review of international literature. The review of electricity pricing commences with a discussion on pricing policies, the principles of economic efficiency and marginal cost-based prices. Some of the difficulties of this approach are highlighted, and additional, often more pressing, pricing objectives are noted, including the imperative of prices which will allow financial viability and prices which will achieve greater equity. Actual practice in developing countries is then examined with regard to tariff levels and structures. Tariff levels are compared with long run marginal costs, generally being much lower in developing countries. The tariff structures discussed include inclining block, single flat rate, two-part, unmetered and time-of-use tariffs. The question of subsidies is raised as well as the problems of implementing equitable life-line tariffs
Development of Onchocerca volvulus in humanized NSG mice and detection of parasite biomarkers in urine and serum.
BACKGROUND: The study of Onchocerca volvulus has been limited by its host range, with only humans and non-human primates shown to be susceptible to the full life cycle infection. Small animal models that support the development of adult parasites have not been identified.
METHODOLOGY/PRINCIPAL FINDINGS: We hypothesized that highly immunodeficient NSG mice would support the survival and maturation of O. volvulus and alteration of the host microenvironment through the addition of various human cells and tissues would further enhance the level of parasite maturation. NSG mice were humanized with: (1) umbilical cord derived CD34+ stem cells, (2) fetal derived liver, thymus and CD34+ stem cells or (3) primary human skeletal muscle cells. NSG and humanized NSG mice were infected with 100 O. volvulus infective larvae (L3) for 4 to 12 weeks. When necropsies of infected animals were performed, it was observed that parasites survived and developed throughout the infection time course. In each of the different humanized mouse models, worms matured from L3 to advanced fourth stage larvae, with both male and female organ development. In addition, worms increased in length by up to 4-fold. Serum and urine, collected from humanized mice for identification of potential biomarkers of infection, allowed for the identification of 10 O. volvulus-derived proteins found specifically in either the urine or the serum of the humanized O. volvulus-infected NSG mice.
CONCLUSIONS/SIGNIFICANCE: The newly identified mouse models for onchocerciasis will enable the development of O. volvulus specific biomarkers, screening for new therapeutic approaches and potentially studying the human immune response to infection with O. volvulus
Optimization of Slag Mobility of Biomass Fuels in a Pilot‐scale Entrained‐Flow Gasifier
The bioliq® process, developed at the Karlsruhe Institute for Technology, aims at the production of synthetic fuels and chemicals from biomass. The bioliq® technology is based on a two-step process with decentral pyrolysis for the production of a transportable slurry from residual biomass and the central entrained-flow gasification of the slurry by using biomass-to-liquid technology. This study is focused on the slag, which is formed by melting the inorganic ash components during gasification. To operate the gasifier smoothly, a range of desired viscosity has to be defined. A structure-based viscosity model was used to predict the viscosity of the slags at the gasifier outlet. A good agreement between experimental and calculated viscosities is achieved for fully liquid slag systems
A Highspeed‐Camera Based Measurement System for the High‐Pressure Entrained‐Flow Gasification
The coin beneath the crust : a pilot study of coins from the Mediterranean coast of Israel
We describe the application of synchrotron X-ray diffraction and neutron micro-tomography to three ancient bronze coins from the Mediterranean coast of Israel. Key questions are whether neutron tomography can contribute to the reading of features on corroded coins by allowing the corrosion crust to be stripped away in cyber-space using surface and volume rendering techniques, and to what extent this type of non-destructive measurement can inform possible conservation action. In addition, the X-ray diffraction experiments allow the main composition of the varicoloured surface corrosion to be deduced. We show that both X-ray and neutron data are of considerable help to numismatic study of the coins
Viability of Baylisascaris procyonis Eggs
Infection with Baylisascaris procyonis roundworms is rare but often fatal and typically affects children. We attempted to determine parameters of viability and methods of inactivating the eggs of these roundworms. Loss of viability resulted when eggs were heated to 62°C or desiccated for 7 months but not when frozen at –15°C for 6 months
Macro economic reforms and sustainable development in Southern Africa. Report 5: Electricity production
- …