Narrow Results

Collection and synthesis of evidence is a key task in the development of the simulation models required for health technology assessment (HTA). The implementation of some of these models, such as discrete event simulation (DES) models, presents technical difficulties and requires higher technical skills. This work presents a method to extract the knowledge stored in an ontology, Rare Disease Ontology for Simulation (RaDiOS), to generate a DES model. RaDiOS is a domain ontology focused on collecting evidence on rare diseases for simulation models. We reviewed and enhanced the ontology to increase its semantic expressiveness. Besides, we developed a transformation tool (RaDiOS-MTT) to automatically generate DES models from the knowledge stored in the ontology. We defined a set of “synthetic” diseases, with simple natural histories, represented them in RaDiOS, and compared the results of the automatically generated simulation models with their manually created counterparts. Afterwards, we used a case study on a real intervention (newborn screening for profound biotinidase deficiency) to validate our approach. The automatically generated models for the synthetic diseases mimicked their programmatic counterparts in structure and results. The same happened to the model for profound biotinidase deficiency.

In today’s rapidly evolving manufacturing industry, researchers and engineers are constantly seeking innovative methods to improve machining processes. One such area of interest is the use of electrical discharge machining (EDM) for difficult-to-machine metals like SS316. This research compares the performance and economic aspects of traditional EDM and powder-mixed EDM when machining SS316 using copper electrode. Graphite powder dispersed in biodegradable palm oil is investigated as a dielectric media with the aim of enhancing EDM performance. According to the findings, the analysis of the cutting performance of different machinability aspects revealed that using graphite powder mixed with palm oil as a dielectric in EDM outperformed conventional EDM relating to material removal, surface finish, surface hardness, electrode wear rate and hole overcut. The flushing condition and unique properties of graphite powder and palm oil, such as cooling, and thermal conductivity, contributed to the improved performance observed in EDM processes. These findings highlight the potential of graphite powder mixed with palm oil as a promising alternative dielectric in EDM, offering enhanced machining capabilities and improved surface quality. The total machining expenditure per part under PMEDM (INR 505.50) is lowered by 9.2% than expenditure under conventional EDM (INR 525). The surface microhardness of the machined component attained using graphite powder-mixed EDM is enhanced in comparison to that achieved using standard EDM due to the creation of a carbon-rich re-solidified layer.

The aims of this paper are to determine the composition of municipal solid waste (MSW) at the Robinson Deep landfill site (LS) and estimate the economics of setting up a recycling facility. The waste composition study was conducted during the summer period of 2015 at the LS. This was done to determine the quantity of organic wastes that are generated daily as a basis for the waste to energy (WtE) proposition and the quantities of the entire wastes generated for the recycling facilities plan in the City of Johannesburg (CoJ). The samples were classified into nine broad categories. The categories include; paper, organics, plastics, metals, glasses, textiles, construction and demolition (C&D), special care and other wastes. The results of the analysis were classified into two services. The services are Dailies refuse (DR) non-compacted and Round collected refuse (RCR) compacted wastes. The results obtained showed organic wastes to be 14% for the DR and 34% for the RCR. The 14% organic waste generated from the DR was attributed to the consumption patterns of people mostly at work. People in offices tend to buy more packaged food items and a smaller amount of organics are disposed of since wastages are less. The 34% organic wastes from the RCR was attributed to the fact that the majority of the people tend to prepare every of their basic meal from their homes and surplus are made; hence, when the surplus could not be consumed, it is disposed of, as a result, more organics are generated. The economic valuation of the recycling facility was also carried out and this was done on all the waste components to estimate the total cost of setting up a facility to divert all the entire MSWs generated. Based on the results obtained, the total capital investment (TCI) was R 35,643,262.73.