In South Africa there is currently no notable use of modern small-scale hydrokinetic (HK) energy systems, mainly due to formerly low-cost coal-powered electricity. This renewable energy option makes ...use of the kinetic energy from flowing water, rather than potential energy, which is more ofen used in conventional hydropower. Updated refined versions of this technology are now being investigated and manufactured due to the global drive towards reducing carbon emissions and increasing energy efficiency. These modular units allow for installation of HK turbines into existing water infrastructure with very little civil works. The study's objective was to develop a simplified design and implementation process for HK devices within the South African legislative and regulatory environment. Approximately 66% of South Africa's water supply is used by the agricultural sector with more than 6 500 km of canal systems running through many areas which could benefit from alternative energy sources. The recent electricity crisis in the country allowed for problem resolution through funding opportunities and thereby an introduction of an innovative and sustainable technology to provide renewable electricity where otherwise not feasible. A pilot HK project was implemented in an applicable section on the Boegoeberg irrigation canal in the Northern Cape Province and tested for optimum functionality and correct application. This process allowed evolution of a development process for the implementation of HK devices in existing water infrastructure.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This paper presents the optimization of a dry machining process where thermomechanical effects like shape deviations and a time-dependent domain are major challenges. First, the simulation model to ...compute finite element approximations to a general milling process is presented. The model includes a submodel (dexel model) for material removal and process forces and heat flux introduced by the machining tool. In a second part, we present a multiobjective optimization algorithm based on metamodels that serve as a tool to identify the process parameters that improve processes with different performance measures that exhibit conflicting behavior. With this metamodel-based optimization method, we avoid the use of a large number of high-fidelity computer simulations, which are commonly computationally expensive. The approach is tested on two case studies for optimizing (a) workpiece deformation and equivalent stress after milling, and (b) shape error and tool wear.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The measurement of the jet cross sections by the H1 collaboration had been compared to various predictions including the next-to-next-to-leading order (NNLO) QCD calculations which are corrected in ...this erratum for an implementation error in one of the components of the NNLO calculations. The jet data and the other predictions remain unchanged. Eight figures, one table and conclusions are adapted accordingly, exhibiting even better agreement between the corrected NNLO predictions and the jet data.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Wastewater treatment facilities are often overlooked as a valuable and sustainable energy source with limited literature available on the methodologies used for identifying energy recovery potential ...at these locations. The lack of research on methodologies to identify potential for energy recovery with limited available data is especially prevalent. This paper aims to address this gap in research by reviewing previous studies that have evaluated the hydropower potential, with a focus specifically on the evaluation of hydropower potential at wastewater treatment works and the technologies most suitable for these sites. Additionally a new methodology was proposed for the assessment of South African wastewater treatment works with the aim of quantifying the potential of this unconventional opportunity when limited access to data poses a challenge. The developed wastewater treatment works evaluation framework was applied to all municipal wastewater treatment works in the Gauteng province to identify a first order estimate of 130 kW–884 kW hydropower potential available in the province.
•Review of hydropower evaluation methods.•Review of hydropower technologies at wastewater treatment works.•Generic wastewater treatment works evaluation framework to quantify potential.•Criteria within the framework alleviate problems associated with limited data.•Framework criteria are validated according to the study area under investigation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Otobius megnini (Dugès), often referred to as the spinose ear tick, is a one-host tick infesting the ear canal of a variety of ungulate species. The objective of this study was to develop sampling ...methods for collecting free-living stages of O. megnini and to collect preliminary data on habitat distribution. Sampling occurred during 2010 and 2011 at Fossil Rim Wildlife Center (FRWC) near Glen Rose, TX, where tick presence has been observed in the ears of a variety of ungulates. To sample for nonfeeding adult stage presence, a debris-filtering method was developed using screens of varying gauges. To sample host-seeking larval-stage tick presence, a carbon dioxide (CO2 ) trap was developed using compressed CO2 released through tubing along with cotton fabric used for tick attachment. Both methods proved successful with adults and larvae collected from animal shelters, with larvae also collected from oak leaf litter away from any structure. Locating both life stages off the host is the first crucial step toward the management of this tick species at facilities such as FRWC.
Large incisional hernias are a permanent problem for surgeons in a growing number of operations. For the treatment of complex hernias, there are no internationally accepted evidence-based ...recommendations regarding the restoration of abdominal wall integrity. In this paper, we are reviewing the development of different component separations (CS) and other techniques used in treating such conditions. A literature review was carried out to describe some important techniques to treat giant hernias. After a detailed description of the CS and its important modifications, we are describing and discussing the relatively new fascial traction technique with its modification. With these reviews of the mentioned studies, we are questioning the extent to which the CS is still indicated in treating giant hernias and point out the importance of further comparison studies evaluating different techniques.
The hydrokinetic industry has advanced beyond its initial testing phase with full-scale projects being introduced, constructed and tested globally. However primary hurdles such as reducing the cost ...of these systems, optimizing individual systems and arrays and balancing energy extraction with environmental impact still requires attention prior to achieving commercial success. The present study addresses the advances and limitations of near-zero head hydrokinetic technologies and the possibility of increased potential and applicability when enhancement techniques within the design, implementation and operational phases are considered. Its goal is threefold: to review small-scale state-of-the-art near-zero hydrokinetic-current-energy-conversion-technologies, to assess barriers including gaps in knowledge, information and data as well as assess time and resource limitations of water-infrastructure owners and operators. A case study summarizes the design and implementation of the first permanent modern hydrokinetic installation in South Africa where improved outputs were achieved through optimization during each design and operation phase. An economic analysis validates a competitive levelized cost of energy and further emphasizes the broad potential that is relatively unexplored within existing water-infrastructure.
•Relatively unexplored potential within water infrastructure exists for zero-head technologies.•Careful selection of an optimal hydrokinetic installation site is a critical challenge.•Hydrokinetic development phase enhancement measures allow an optimized system.•Standards development is a critical need to advance hydrokinetic project development.•Lack of awareness of hydrokinetic resource potential is a large development barrier.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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