In this study, mixing is identified to be the most crucial step during the pre-processing process of extruded food and feed stocks. This study therefore aimed to investigate different mixing techniques in an effort to identify the most effective method and its feasibility to pilot plant application for food extrusion processing. The study furthermore considered the methods of mixing with the view to incorporating the identified method in a standard portable cargo container. The research included an investigation and the design of an inexpensive pre-processing control system that would also save space in such applications where storing facilities for ingredients are housed. After investigating different mixing solutions, a V-blender was identified to be a feasible option. It is suggested that by adding a third leg to the V-blender, to obtain what is dubbed as a “Y”-blender, the effectiveness of mixing would be improved upon - not only in the specified application but with respect to mixing in general. In order to evaluate and compare the effectiveness of the mixers, rapid prototyping models of a V- and a Y- blender, with capacities of about 7.6 litres each, were produced from medium density fibreboard (MDF) with the aid of a laser cutter. It was found that, for a recipe consisting of 87% fine yellow maize, 12.75% fine sugar and 0.25% colorant, the effectiveness of mixing within the V-blender was greatly influenced by the level to which it was filled. This was not the case for the Y-blender. This therefore suggested that a Y-blender is the ideal solution for the given application. A layout of a pre-processing system that fits in a standard shipping container and can accommodate six funnel-shaped raw material storage bins with a feed conveyor leading to a Y-blender is designed and a rapid prototyping model of the most vital components of the system is produced. A novel control system using the IOIO USB controller coupled to an Andriod device is developed and this sub-system, with dedicated software, is coupled to the prototyped pre-processing set-up and operated successfully. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

In this study, mixing is identified to be the most crucial step during the pre-processing process of extruded food and feed stocks. This study therefore aimed to investigate different mixing techniques in an effort to identify the most effective method and its feasibility to pilot plant application for food extrusion processing. The study furthermore considered the methods of mixing with the view to incorporating the identified method in a standard portable cargo container. The research included an investigation and the design of an inexpensive pre-processing control system that would also save space in such applications where storing facilities for ingredients are housed. After investigating different mixing solutions, a V-blender was identified to be a feasible option. It is suggested that by adding a third leg to the V-blender, to obtain what is dubbed as a “Y”-blender, the effectiveness of mixing would be improved upon - not only in the specified application but with respect to mixing in general. In order to evaluate and compare the effectiveness of the mixers, rapid prototyping models of a V- and a Y- blender, with capacities of about 7.6 litres each, were produced from medium density fibreboard (MDF) with the aid of a laser cutter. It was found that, for a recipe consisting of 87% fine yellow maize, 12.75% fine sugar and 0.25% colorant, the effectiveness of mixing within the V-blender was greatly influenced by the level to which it was filled. This was not the case for the Y-blender. This therefore suggested that a Y-blender is the ideal solution for the given application. A layout of a pre-processing system that fits in a standard shipping container and can accommodate six funnel-shaped raw material storage bins with a feed conveyor leading to a Y-blender is designed and a rapid prototyping model of the most vital components of the system is produced. A novel control system using the IOIO USB controller coupled to an Andriod device is developed and this sub-system, with dedicated software, is coupled to the prototyped pre-processing set-up and operated successfully. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

In recent years, batch processes have been getting more attention due to their suitability for the production of small volume, high value added products. The flexibility of batch plants allows the production of different products within the same facility which mandates equipment sharing. Batch manufacturing is typically used in the pharmaceutical, polymer, food and specialty chemical industries as demands for such products are highly seasonal and are influenced by changing markets. Despite the advantage of batch plants being flexible, they also pose a challenging task to design, synthesize and operate, compared to their continuous counterparts. The profitability of these batch plants is highly dependent on the way the synthesis, design and operation is optimized. Since different types of resources (raw materials, equipment, utilities and manpower) need to be shared by a number of process operations to produce a variety of products, modeling and optimizing the design and operation of batch plants are important for economic benefits. The growing awareness of civil society for the environment and the resulting regulations introduced by national states have resulted in chemical industries considering process integration to reduce their energy and process water requirements. Energy optimization and the optimization of water use have mainly been treated as separate problems in literature. The batch production schedules resulting from each of these formulations do not guarantee that the plant is operated optimally. Consequently, it is required to develop a formulation that caters for opportunities that exist for both wastewater minimization and energy integration. This may result in production schedules that improve the operation of the batch plant when compared to optimizing water and energy separately. Presented in this thesis is a mathematical technique that addresses optimization of both water and energy, while simultaneously optimizing the batch process schedule. The scheduling framework used in this study is based on the formulation by Seid and Majozi (2012). This formulation has been shown to result in a significant reduction of computational time, an improvement of the objective function and leads to fewer time iii points required to solve the scheduling problem. The objective is to improve the profitability of the plant by minimizing wastewater generation and utility usage. From a case study it was found that through only applying water integration the total cost is reduced by 11.6%, by applying only energy integration the total cost is reduced by 29.1% and by applying both energy and water integration the total cost is reduced by 34.6%. This indicates that optimizing water and energy integration in the same scheduling framework will reduce the operating cost and environmental impact significantly. This thesis also presents a mathematical model for design and synthesis of batch plants. The conceptual design problem must determine the number and capacity of the major processing equipment items, pipe connections and storage tanks so as to meet production objectives at the lowest possible capital and operating cost. A recent robust scheduling model based on continuous-time representation is used as a platform for the synthesis and design problem. An improved objective value (revenue) of 228.6% is obtained by this work compared to the recent published models for the design and synthesis problem. Compared with other formulations, the formulation presented in this thesis gives a smaller size mathematical model that required less binary variables, continuous variables and constraints. The presented model also considers costs that arise from the pipe network and consequently, determines the optimal pipe network which should exist between different pieces of equipment. Finally, the medium-term scheduling problem for a multiproduct batch plant is addressed. The intractability of the short-term scheduling models when directly applied to the medium-term scheduling problems is solved by applying a decomposition method. The decomposition method has two level mathematical models. The first level determines the type of products and their amount to be produced in each scheduling subproblem to satisfy the market requirement. The second level determines the detailed sequencing of tasks for the tractable size of the subproblems. The recently published robust short-term scheduling model based on continuous time is extended for solving the scheduling supbroblems of the second level decomposition model. The model is applied in solving the medium-term scheduling problem of a pharmaceutical facility specializing in animal vaccines using the actual plant data. The model effectively solved a makespan minimization problem for the medium-term scheduling horizon of almost 13 weeks. / Thesis (PhD)--University of Pretoria, 2013. / gm2013 / Chemical Engineering / unrestricted

All physical copies are missing page 3 in this thesis. - McMaster Digitization Center / A computer simulation model was developed to simulate the receiving of raw materials at a dock for an integrated steel plant on the North shore of Lake Erie. The model was formulated to study queue build-up, berth waiting time and the effect of various unloading conditions on dock efficiency. A financial analysis, using present value techniques, was then applied to the model results in order to recommend an optimum berth staging plan under various economic conditions. Historical data on raw material receiving at Hilton Works, Hamilton, were collected and used to develop mathematical functions to describe the random nature of vessel arrivals and berth times. It was determined from this data that vessel arrivals are described by a Poisson distribution and berth times are described by an Erlang distribution. The computer model simulates the dock operation by generating random numbers according to these distributions (Monte Carlo Simulation.) Coal and ore vessel arrivals are merged and respective service times generated. Interferences occur and queues grow and diminish as the facility is simulated through the shipping seasons throughout its expected life. Various unloading rates and vessel tonnages are simulated for a single and double berth operation and the associated waiting times and queue lengths are recorded for each alternative. An economic analysis is performed on the alternatives using present value techniques. The economic analysis indicated that the optimum time to expand the dock to a double berth occurs at a tonnage level of 15 million (coal + ore). To reach this level unloading rates of 10,000 TPH for ore and 8,000 TPH for coal would have to be achieved with an average vessel tonnage of 39,000 metric tonnes. Reducing the unloading rates or average vessel tonnage would move forward the required construction of a double berth and would increase the present value for that alternative. This expansion date will also depend on future economic factors such as cost of capital and escalation rate. The other important conclusion drawn from the economic analysis was that the receiving facility should be expanded in minimum feasible increments because of uncertain economic conditions. This concept dictates that conveyors be installed at minimum capacity, i.e. -belt width and drive size, to handle the first stage tonnage only with provision in the equipment to increase capacity by replacing narrow belts with wider ones and adding additional drive units. The timing for the stages is predicted on several factors, such as: life of the initial belt, tonnage forecast, ship delay costs, and most importantly future economic conditions. For example, it would be advantageous to increase the unloading capacity with a wider belt at the time the initial belt is worn out. Belt and drive staging will take place before the expansion to a second berth in order to defer the capital investment as long as possible. The conveyor system for the second berth can be similarily staged. The study indicated that a good planning strategy would be to initially install a 1.8 m wide belt on 2.0 m wide machinery with 3-1,000 H.P. drives. This system would unload ore at approximately 7,000 t/hr. and coal at approximately 5,000 t/hr. This capability could be increased to 10,000 t/hr. for ore and approximately 8,000 t/hr: for coal by adding a 2.0 m wide belt and 1 -1,000 H.P. drive unit. These rates would be compatible with the expected unloading rates of the future fleet. The decision to increase capacity should be considered when the initial belt is worn out or when delay costs and future economics dictate expansion before that time. The study also indicated that it is poor strategy to design the second berth/conveyor system to be restricted to coal receiving only. The Computer simulation indicated ship delay time for the restricted berth to be approximately three times that for a system with capability to receive ore and coal equally at both berths on either conveyor and either stacker. It indicates that ore receiving is the most important capability and should not be restricted. Even though ore pellets unload more quickly the ore tonnage required is twice that for coal. Therefore, it is recommended to design a completely flexible system . with full provision for expansion to higher unloading rates and larger vessels (850 ft.) and with provision to unload equally from either berth to either conveyor and to have the ability to transfer material between converyors at the head end of the stacker conveyor. / Thesis / Master of Engineering (MEngr)

El objetivo de esta propuesta no solo es brindarle a la empresa una herramienta que le permita cumplir con sus obligaciones tributarias, sino también poder comparar los resultados obtenidos en esta investigación con los estados financieros del periodo 2015 y poder analizar si los costos fijos y variables con los que se estimaron los precios de venta para el periodo 2016 son los adecuados, como también medir el grado de eficiencia en que la empresa se encuentra. The objective of this proposal is not only to provide the company with a tool that allows it to comply with its tax obligations, but also to be able to compare the results obtained in this research with the financial statements of the 2015 period and be able to analyze whether the fixed and variable costs with those that were estimated the sale prices for the 2016 period are appropriate, as well as measuring the degree of efficiency in which the company is located.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This research project proposes a supply management model in a consumer goods company in Lima, Peru, to improve stock control and avoid raw materials stockouts and overstock. A Kraljic matrix was used to identify products based on their criticality considering material segmentation, warehouse capacity and times, and ABC segmentation to classify products on each quadrant of the matrix. This project also focuses on defining purchasing and supply strategies in each quadrant of the matrix. This model involves the development of three processes that are related to a new purchasing strategy: economic order quantity, lot-for-lot ordering, and just in time. This new system is based on a more accurate inventory because continuous improvement attracts employees’ attention and engages them in reducing the number of manual notifications made by operators every month. Moreover, after implementing the new procedure for recording inventories, the inventory record was 87% accurate, whereas, in the past, the inventory was not counted and was performed by employees of other areas.

Hominins habitually moved across landscapes to forage for resources, which can be investigated by the probabilistic attribution of stone tools to raw material sources. The sources that were available to Pleistocene hominins at the UNESCO World Heritage Site of Oldupai Gorge (Tanzania) have been studied for over a half-century. However, limited reference collections have prevented detailed investigations on the degree to which hominins transported stone tools. The primary goal of this dissertation was to identify the locations and distances over which Oldowan and Acheulean hominins transported raw materials at Oldupai Gorge and interpret the results in the context of the human evolutionary record. Fieldwork consisted of sampling metamorphic and volcanic outcrops to supplement an existing reference collection. An equally important fieldwork component consisted of conducting excavations at four occupation sites, including, from oldest to youngest, Ewass Oldupa (Oldowan), Elang’ata Oljurusi (Acheulean), Engaji Nanyori (Acheulean), and Emurutoto (Acheulean). Laboratory work consisted of studying artefact collections to obtain general information about toolmaking practices, and characterising geological samples and stone tools at the macroscopic and geochemical levels for comparative analyses using computational statistics. The overarching aim of this dissertation was to investigate whether the shift from Oldowan to Acheulean toolmaking was accompanied by equally more complex landuse strategies amidst progressive aridification. Informed by probabilistic sourcing results, the evidence presented herein indicates that the Oldowan to Acheulean transition in the Oldupai basin was accompanied by more focalised landuse. Yet, both Oldowan and Acheulean hominins altered their mobility to variable environments ranging from woodlands to steppe deserts. These behavioural responses represent possible explanations for the adaptive radiation of hominin populations across, and out of, Eastern Africa during the Early and Middle Pleistocene. / Dissertation / Doctor of Philosophy (PhD) / Hominins habitually moved across landscapes to forage for resources, which can be investigated by sourcing the raw materials that were fashioned into stone tools. The raw material sources at the UNESCO World Heritage Site of Oldupai Gorge (Tanzania) have been studied for over a half-century. However, limited reference collections have prevented thorough investigations on the degree to which hominins transported tools during the Pleistocene. Informed by the systematic sampling of metamorphic and volcanic outcrops, macroscopic and geochemical data were used to source Oldowan and Acheulean artefacts excavated from four occupation sites across the Oldupai Gorge study area. The evidence presented herein indicates that the shift from Oldowan to Acheulean toolmaking was accompanied by more focalised landuse amidst growing aridity. Yet, both Oldowan and Acheulean hominins altered their mobility to variable environments. This represents a plausible explanation for the adaptive radiation of hominin populations into increasingly diverse biogeographic zones through time.

No / This chapter summarises AHRC/EPSRC Science and Heritage Programme-funded research to develop a digital resource to disseminate knowledge of the identification of osseous and keratinous animal hard tissues. The choice of materials in the manufacture of individual artefacts or classes of objects can make a major contribution to understanding their cultural significance and questions of provenance or authenticity. This resource builds on understanding gained through a Fellowship to O’Connor in developing, evaluating and validating identification criteria for these materials in raw, worked and decayed states. The resource concentrates on the non-destructive visual methods of particular relevance to the examination of artworks, historic and archaeological artefacts. The chapter highlights the potential of various visualisation methods and digital technologies to capture and combine 2D images and 3D models and guide the viewer through the multi-scalar visual cues of each material to a reliable identification. By accessing a range of collections, the project has produced a comprehensive and accessible resource, disseminating these findings more widely than could be achieved by a physical reference collection. This resource supports the identification of cultural heritage objects for conservation scientists and heritage professionals and informs the fight against the illegal hunting and trafficking of rare and endangered species. / VAHT was funded through an AHRC-EPSRC Science and Heritage Programme Research Development Award (AH/K006169/1) that developed directly from Sonia O'Connor's AHRC/EPSRC Science & Heritage Programme Fellowship (AH/H032150/1)—Cultural Materials Worked in Skeletal Hard Tissues (COWISHT).

In manufacture of cement-bonded particle boards are in present-days used exclusively wooden particles as filler. This thesis deals with a research of possible substitution of this material, especially of waste emerging by production of CBPB itself. At first is completed a survey of possible substitute fillers and czech and foreign literature, dealing with issues of modification of composition of cement-bonded particle boards. In practical part are tested some treatments of waste and its adding to recipe. Further are analysed the influences of substitution of cement by slag and substitution of wooden particles by recycled fibreglass. By laboratory work with CBPB is monitored the influence of amounts of added wather to fresh mixture and also to properties of finished elements.

Thesis (MBA (Business Management))--Stellenbosch University, 2008. / ENGLISH ABSTRACT: In the highly competitive international wine markets, effective procurement of raw material could prove the difference between success or failure for a wine company. Therefore the researcher embarked on this study to create a model that will assist procurement decision makers in the South African wine industry in the strategic procurement of raw material. In order to create a model for procurement of raw material in the South African wine industry, qualitative research was conducted that included a study of literature, available material, views from experts as well as a content analysis from sample interviews. Procurement officials need to ensure that marketing forecasts are aligned with contracted procurement volumes. Cost, quality and availability should be tightly managed to minimise losses due to unallocated inventory or lack of raw material with sufficient quality or quantity to serve a marketing need. Suppliers should be prioritised in terms of strategic importance and procurement decision-makers should be crystal clear on which strategy to pursue with each quality segment and supplier in order to obtain the right quantity at the desired quantity and most economical price. Procurement decision makers need to evaluate the procurement and market environment for opportunities and threats that might impact on their ability to procure raw material from their supply base, and put measures in place to take control of possible effects of those uncertainties. This includes differentiating between grape procurement and wine procurement to leverage the advantages from both. Procurement officials must establish an action plan to limit the risk of cost, availability and quality by engaging and investing in trusting, loyal relationships with proficient suppliers with capacity. The procurement function should operate in a professional manner, building a track record of pro-active procurement and focus on loyal supplier relationships. / AFRIKAANSE OPSOMMING: In die hoogs kompeterende internasionale wynmarkte kan effektiewe aankope van rou-materiaal die verskil beteken tussen sukses of mislukking vir 'n wynmaatskappy. Daarom het die navorser begin met hierdie studie om 'n model te skep wat besluitnemers van aankope kan bystaan met die strategiese aankoop van roumateriaal in die Suid-Afrikaanse wynbedryf. Om 'n model te skep vir die aankoop van roumateriaal in die Suid-Afrikaanse wynbedryf is kwalitatiewe navorsing gedoen, wat 'n literatuurstudie insluit, sowel as 'n studie van beskikbare materiaal, sienings van kenners en 'n inhoudsanalise van steekproefonderhoude. Aankoopsbeamptes moet verseker dat bemarkingsvooruitskattings en gekontrakteerde aankoopvolumes ooreenstem. Koste, kwaliteit en beskikbaarheid moet streng bestuur word om verliese te beperk wat kan ontstaan deur ongeallokeerde voorraad of 'n tekort aan roumateriaal met genoegsame kwaliteit of hoeveelheid om 'n bemarkingsbehoefte te bevredig. Verskaffers moet prioritiseer word in terme van strategiese belangrikheid en aankoop-besluitnemers moet kristalhelder dink oor watter strategie om te volg met elke kwaliteitssegment en verskaffer, sodat die regte hoeveelheid en volume teen die mees ekonomiese prys aangekoop word. Aankoopbesluitnemers moet die aankoop- en markomgewing evalueer vir geleenthede en bedreigings wat 'n invloed kan hê op hul vermoë om roumateriaal van hul verskaffingskorps aan te koop, en moet maatreëls in plek stel om beheer te neem oor die moontlike effek van daardie onsekerhede. Maatreëls sluit in die differensiasie tussen druifaankope en wynaankope om die voordele van elk maksimaal te benut. Aankoopsbeamptes moet 'n aksieplan vestig om die risiko van koste, beskikbaarheid en kwaliteit te beperk deur in verbintenisse te belê met lojale vertrouensverhoudings met vaardige verkaffers met kapasiteit. Die aankoopsfunksie moet op 'n professionele manier optree, om 'n beeld van pro-aktiewe aankope te bou en 'n fokus op lojale verskafferverhoudings te vestig.