Acidogenic activities, as part of anaerobic digestion, have been discovered since the beginning of the century. Still it was mid '60's when it was initially stated in the literature that engineered phase separation would increase stability in anaerobic reactors and possibly increase substrate digestion rates. Pioneering research in the early '70's, with the first report on two-phase digestion of sludges, came as practical proof of those past assumptions. Today phase separation is a proposed option to single-stage digestion, due to the many advantages over conventional operation. Such an application utilises the different steady-state kinetic rates in the two main bacterial groups in anaerobic digestion. Furthermore, the process benefits through differences of these two groups, in relation to changing conditions. The overall result of two-phase applications is lower operational costs, with higher treatment efficiency and energy recovery. In recent decades much research work has created a positive image for two-phase applications, compared to single-stage digestion. Still until today, many consultants in the field of anaerobic processes, are not provided with sufficient knowledge to utilise fully the potential of the twophase process. It seems often the case that leading companies in the design and construction of anaerobic plants, will design pre-acidification tanks without understanding the uncontrolled acidogenic activities taking place in them. Therefore, design is based on an empirical approach or lack of knowledge of the effects of reactor design parameters on acidogenesis. Although data on acidification of industrial wastewaters is in high demand, few studies have been carried out previously to assess the effects of the whole range of engineered reactor design parameters on acidification of industrial wastewater. Out of these few studies none has examined the whole range of design parameters on freshly collected agro-industrial wastewater. Apparently, most studies have been made on synthetic versions of wastewaters or simple compounds. Additionally since the '80's anaerobic processes have been extensively applied for the treatment of agro-industrial wastewaters. Obviously the extent of information provided from this study, was particularly required to clarify many issues related to the role of acidification in the pre-treatment of agro-industrial wastewaters. The research project presented in this thesis is based on a 3-year laboratory study. Some early conclusions of this study have been presented previously in a number of papers on preacidification discussing design guidelines, advantages of two-phase applications and methods to assess acidogenesis. This thesis is focused on the complete range of findings related to the effects of various reactor design parameters, namely: temperature (from ambient to thermophilic); pH (from 4.5 to 7.0); HRT (from 6 to 12 hrs, with and without variations in the organic loading rate); addition of commercial micro-nutrients; and mixing the reactor contents. The two wastewaters studied are slaughterhouse, collected fresh each week; and synthetic instant coffee production. They are both considered as high strength wastewaters. Slaughterhouse wastewaters are found everywhere, as they are connected with daily human activities, while they are easily biodegradable wastewaters for high-rate digestion. On the other hand instant coffee production wastewaters, although not a common global industrial activity, involves more complexity for high-rate digestion, due to various recalcitrant and inhibitory compounds present in the composition of coffee. Results are based on analyses for: VFA concentration and composition (Acetic to Caproic acid). Tot. and Filt.COD, Tot.BOD, TS, VS, SS, VSS, TKN, NH 3-N, PO4-P, gas composition and for slaughterhouse wastewaters protein concentrations. In particular, results on VFA are presented as concentration, COD of the acids, composition and in relation to the influent and effluent COD. Assessment of the effects of design parameters on the performance of acidogenic biomass are based on: VFA production and composition; acidified COD; and overall effluent quality in relation to methanogenic treatment requirements. This study provides information on all design requirements needed to use acidogenic phenomena to convert organic matter into simple carbon source (i.e. VFA). Such a conversion appears to benefit biological wastewater treatment when used as pre-treatment for anaerobic digestion, but also for its potential in aerobic processes and nutrient removal processes. The process proves to have great low-cost pre-treatment potential, but can also be used for advanced wastewater treatment. Finally, the extensive data collected is used to present various guidelines for process engineers. which should be considered in order to design anaerobic plants. Also, they should be even further used for the overall assessment of the treatment or pre-treatment potential of pre-acidification for agro-industrial wastewaters.

Thesis (Ph. D.)--University of Texas at Dallas, 2007. / Includes vita. Includes bibliographical references (leaves 117-122)

Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: After its introduction in 1993, the use of the NEC is still limited in the civil engineering industry of South Africa. The benefits of the NEC however appear to be promising. This research identifies the barriers of a NEC adoption. Moreover, in order to recommend strategies and measures to achieve a better NEC adoption, required success factors for a NEC implementation are investigated. Beneficial insights for South Africa are gained from the Dutch UAV-GC introduction experiences. A literature study is conducted to define the research needs and focus. Both contracts are analysed and compared. These findings are then used to validate the assumed advantages of the NEC by correlating them to the contract content. Subsequently, expert interviews are conducted in which the advantages, disadvantages, barriers for adoption and success factors for implementation of the NEC are explored. Interviews with seven South African experts also contained a short-questionnaire. The short-questionnaire gave a quantitative context as validation for the qualitative advantages. In addition, three interviews with Dutch experts were conducted. In this manner the Dutch UAVGC introduction experiences were explored. In the research synthesis, findings from the various sources are validated. This is achieved through a comparison of the different methods applied in the study. The barriers identified as the main cause of obstruction to the NEC adoption are a lack of knowledge, understanding, education, effective training courses and skills in procurement strategy, contract management and general project management. Furthermore, there is a resistance from industry because of the preference for the South African contract forms. Another resistance is from employers, due to the desire for some grey area in their contract form. Principal success factors necessary for the implementation of the NEC are education, training, promotion, and a proper understanding of the NEC as well as its philosophy and benefits. Consequently, a culture change towards collaborations would be necessary. In addition employers must apply and improve their procurement strategies. As a result, the NEC would be identified as their best tool for procurement. A helpful success factor, extracted from the Dutch experience, is the requirement for knowledge sharing between governmental bodies in order to guide innovations. For optimum industry performance by the more frequent use of the NEC, this research has resulted in the following recommendations: • The industry should not be afraid to question tradition and to initiate the required cultural change towards increasing collaboration • An in uential South African institute should take responsibility for the promotion, monitoring and training of the NEC • Educate students on the NEC and other contracts based on all possible procurement strategies • An adoption strategy should be applied for inexperienced NEC parties • NEC should be used as the stimulator for improvement of South African project management practices in construction projects • Organize regular knowledge sharing meetings between governmental departments to stimulate and improve innovations • Employers should improve their procurement practices. / AFRIKAANSE OPSOMMING: Na sy bekendstelling in 1993, is die gebruik van die NEC steeds beperk in die Suid- Afrikaanse ingenieursbedryf. Die voordele vir die gebruik daarvan blyk egter tog belowend te wees. Hierdie navorsing identifiseer die hindernisse wat gepaard gaan met die gebruik van die NEC in die bedryf. Die studie ondersoek ook die faktore wat 'n rol speel by die implementering van die NEC, om sodoende strategieë vir 'n meer omvattende gebruik van die NEC aan te beveel. Lesse om 'n nuwe kontrakdokument in die bedryf in te bring word geleer uit die Nederlandse ervaring met die UAV-GC. 'n Literatuurstudie is uitgevoer om die behoeftes en fokus van die navorsing te definieer. Beide kontrakvorms is geanaliseer en met mekaar vergelyk. Hierdie bevindinge is daarna gebruik om die voor- en nadele wat die NEC inhou te bevestig, deur dit te vergelyk met die inhoud van die kontrak. Onderhoude is gevolglik gevoer met industriedeelnemers waarin die voordele, nadele, hindernisse vir en die suksesfaktore vir die implementering van die NEC ondersoek is. Die sewe onderhoude wat met Suid-Afrikaanse deskundiges gevoer is, het elk 'n kort vraelys ingesluit. Die kort vraelys verleen 'n kwantitatiewe bevestiging van die bevindinge. Aansluitend is daar ook drie onderhoude met Nederlandse deskundiges gevoer. Op hierdie wyse is die Nederlandse ervarings ondersoek met die inlywing van die UAV-GC. In die navorsingsintese word die bevindinge van die verskillende bronne bevestig. Dit word bereik deur 'n vergelyking van die resultate van die verskillende metodes wat in die studie gebruik is. Hindernisse wat geïdentifiseer is as die hoof oorsaak vir die beperkte inlywing van die NEC in die bedryf, is die tekort aan kennis, begrip, opvoeding, effektiewe opleidingskursusse, vaardighede in aankoopstrategieë, tekort aan kennis oor kontrakbestuur en ook algemene projekbestuur. Boonop is daar teëstand van die bedryf weens die voorkeur vir Suid-Afrikaanse kontrakvorms. Verdere teëstand word verkry deur werkgewers vanweë die behoefte na grys area in hul kontrakte. Die belangrikste faktore wat benodig word vir die suksesvolle implementering van die NEC is opleiding, kennis en begrip van die NEC, asook begrip van sy filosofie en voordele. 'n Kultuur verandering, met die fokus op samewerking tussen partye, is noodsaaklik. Werkgewers moet verder hul aankoopstrategieë verbeter. 'n Nuttige faktor vir die suksesvolle inlywing van die NEC, verkry uit die Nederlandse ervaring, is die vereiste vir die uitruil van kennis onder staatsdepartemente om sodoende die veranderinge te lei. Om die gebruik van die NEC optimaal by die Suid-Afrikaanse ingenieursbedryf in te lei, het die navorsing tot die volgende gevolgtrekkings gelei: • Die bedryf moet nie huiwer om tradisie te bevraagteken nie. Dit is nodig dat kultuurveranderinge gemaak word om samewerking tussen partye te bewerkstellig • 'n Invloedryke Suid-Afrikaanse instituut moet verantwoordelikheid neem vir die bevordering, die monitering en opleiding vir die gebruik van die NEC • Studente moet opgelei word met blootstelling aan die NEC asook blootstelling aan 'n verskeidenheid van aankoopstrategieë • 'n Strategie moet ontwikkel word om partye wat onbekend is met die NEC daarvan bewus te maak • Die NEC moet gebruik word as bron wat die Suid-Afrikaanse projekbestuurs- en kontrakbestuuromgewings kan verbeter • Daar moet skakeling wees tussen staatsdepartemente om sodoende verandering te bevorder en te verbeter in aankoopstrategieë • Werkgewers moet hulle aankoopstrategieë en praktyke verbeter.

Abstract Throughout the engineering in Taiwan, due to the rapid development of engineering technology, engineering increasingly large scale, business has been facing ever faster and greater impact; however, SMEs have long played the Taiwan's driving force in economic growth. Therefore, facing the situation of global competition, companies how to respond to times changing and overcome difficulties then evolve, strategically transformation is even more important. The researchers involved in heavy machine engineering professional installation industry up to thirty years long. In the professional installation of mechanical engineering project management experience, have deeply realized that the heavy machine construction industry is largely impacted by the economic cycle and national policies. Heavy machine engineering industry is the services provider in the industry supply chain for the steel industry, shipbuilding and petrochemical industry, energy industry and environmental protection products industry. The current Taiwan industrial development status in today's perspective, the petrochemical industry is the heavy machine construction industry to the biggest support industry. Case studied company is a local medium-sized heavy mechanical machine installation company provides functional products for the industrial market. Because the client faces international risk management and international competitiveness thinking, the future business risk changes and uncertainties will be bound by potential clients and constraints. Such as South Korea's Samsung, Japan¡¦s CHOYOTA, etc., as a long-term business perspective, they will definitely affect and raise this company's international operations threshold and entrance barriers. Furthermore, medium-sized engineering company as like large engineering companies is also required constantly cost-price competition. Resources are not as much as large companies in economies scale financial size and human resources, how to find core competition of medium-sized engineering manufacture company and implement transformation of organizational change strategies are the main motivations of this thesis study. This thesis study takes the interview to study the case company, first of all to understand of the domestic small and medium sized engineering manufacture industry profile, case company operating situation, finally analysis the transformation operate strategy of the case company, the result appears that the case company "the problems change faced by the company" and the "Innovation Challenge of Development " are two key factors for the company transformation strategy. The research result is sufficient to provide small and medium sized engineering manufacturing industry as a future strategic policy reference. For the medium-sized engineering manufacturing industry in the industry sector in the value of the core competitiveness, supply chain management for reviewing source of corporate competitiveness. Keywords¡G Engineering industry, business transformation strategy, heavy industry, industrial development

Thesis (Ph. D.)--University of Texas at Dallas, 2007. / Includes bibliographical references (leaves 117-122) Abstract and preview also issued online.

The climate change is driving a change in technology and promotes intermittent electricity; solar and wind, and also promotes new technology such as electrical vehicles. The increased share of intermittent  power and changed patterns of using power causes large strain on the powergrids during critical hours of the year. The system The Eergimarknadsinspektionen as well as the European transmission system operators are therefore requesting that electricity users adapt their power consumption to when power is generated. This is rather opposite to the present situation where the TSO’s respond to the customers demand by increasing their power generation. This new change of customers adapting to the current power available is called Demand response (DR). The thesis investigates drivers, barriers and potential for demand response within the engineering industry. It is based on interviews with representatives from enginering industries, system operators as well as a case study on Volvo Group Trucks Operations Powertrain Production in Köping. The potential is also determined through a simulation carried out in collaboration with Johan Norberg, a masterstudent at the Royal Technical Highschool. The conclusion states that it is possible for Volvo Pwertrain to participate in DR events, however the economical compensation identified in this thesis is not enough.

No description available.

Today organizations are facing different kinds of challenges as they are operating in a dynamic global market. Due to the lack of proper knowledge and skill in management, shortage of capital, weak infrastructure etc. the challenge is more intensive for organizations situated in developing countries like Ethiopia. Therefore, such organizations have to seek for alternative ways to improve their business activities in order to compete in the global market. Supply Chain Management (SCM) is one of the most effective ways that many organizations like Wall-Mart have managed to achieve best organizational performance. In the Ethiopian business context, especially in Basic Metal and Engineering Industries (BMEIs), the concept of SCM should be well understood and practiced because these industries are the backbone of other growing industries in the country. The basic objectives of this research are (1) to assess the level of implementation of SCM practices in Ethiopian BMEIs, and (2) to analyze the relationship between SCM practices and organizational performance in the same industries.

Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Sustainability is becoming an increasingly important aspect in all facets of engineering. It is in particular an important consideration in the structural engineering industry, due to the prominence of the negative impact this industry has on the environment, both on a national and international scale. The problem, however, is that sustainability is a mostly unknown and highly debated topic. It is not only difficult to quantify, but even difficult just to define. In the field of structural engineering it is an especially difficult task to consider sustainability. It is still a very new field of research and difficult to apply. It is therefore important that continued research be done in order for there to be a better understanding of how sustainability should be considered and applied in the context of structures. In an attempt to assess the environmental impact of building structures, there are two basic approaches that are followed. The first, the application-oriented method, is a simple, points-based system. The second, the analysis-oriented method, makes use of detailed indices and factors to quantify the impact. This study aims to develop an analysis-oriented method, specifically designed for the complete life cycle of buildings in the South African environment. This is accomplished by continuing the work that was started by Brewis (2011), and continued by Brits (2012). Brewis developed the approach for the pre-use phase, while Brits developed the approach for the end-of-life phase. Both focussed their application on low-cost housing development. However, the approach is defined for the use of the analysis of a building envelope. The details of developing the environmental life cycle assessment (LCA), as well as the approaches for the pre-use phase and the end-of life phase are discussed in Chapter 3. The study develops the use phase of the proposed environmental life cycle assessment for buildings in Chapter 4. It discusses in detail the two main components of the use phase, namely maintenance and operation. While maintenance is concerned with the replacement of building materials in the structure, the operation component is concerned with the energy needs during the use phase. It is determined that the energy use that is directly related to the building envelope is the energy required for the space heating and cooling of the building. This is due to the fact that the thermal properties of the building envelope influence the thermal environment within the building, and thereby impact the use of energy to regulate that thermal environment. In order to make the most use of both of these components within the application of the proposed LCA, it was decided to model a residential building structure that uses consistent energy to regulate the thermal environment within the structure. However, it is not only the objective to use the proposed LCA as an assessment tool, but also as a comparative and optimisation tool. Therefore one component, the external walls, was selected as a variable component. This component was varied to form a total of nine different buildings. These nine buildings were then used in a comparative study in order to try to determine an optimum choice of external walling system, based on the results of the environmental impacts determined in the LCA. It is also used to try to explain exactly how and to what extent the external walling system contributes to the environmental impact, and what useful application value we can gain from this knowledge. The results showed that a minor increase in the materials impact (due to attempts to improve the thermal capacity of the external walls) were in most cases countered by a decrease in the energy impact, which in seven of the eight alternative external walling systems led to a net decrease in environmental impact (EI) categories one to four. It was also found that with the increase of the R-value of the external walling systems, the environmental impact of the building steadily decreased, in terms of four of the five impact categories. The only exception to these trends was found in the fifth impact category: waste generation. The reason for this is the fact that energy impact in this environmental impact category is negligible, and therefore does not contribute much to the net change in environmental impact. / AFRIKAANSE OPSOMMING: Die belangrikheid van volhoubaarheid neem al hoe meer toe in alle aspekte van ingenieurswese. In die industrie van struktuuringenieurswese is dit van besonderse belang as gevolg van die prominente negatiewe impak van hierdie industrie op die omgewing, op beide ’n nasionale en internasionale skaal. Die probleem is egter dat volhoubaarheid nog meestal gesien word as ʼn onderwerp wat onbekend en hoogs debatteerbaar is. Dit is nie net moeilik om te kwantifiseer nie, maar selfs moeilik om dit net te definieer. In struktuuringenieurswese is dit veral ʼn moeilike taak om volhoubaarheid in ag te neem. Dit is nog ʼn baie jong studieveld wat moeilik is om toe te pas. Dit is dus van uiterse belang dat verdere navorsing gedoen word sodat daar ʼn beter begrip kan wees van hoe volhoubaarheid op die lewensiklus van strukture toegepas kan word. In 'n poging om die omgewingsimpak van die geboustrukture te evalueer, is daar twee basiese benaderings wat gevolg kan word. Die eerste, die toepassingsgeoriënteerde metode, is 'n eenvoudige, punte-gebaseerde stelsel. Die tweede, die analise-georiënteerde metode maak gebruik van gedetailleerde indekse en faktore om die omgewingsimpak te kwantifiseer. Hierdie studie beoog om 'n analise-georiënteerde metode te ontwikkel, wat spesifiek ontwerp is vir die analise van die volledige lewensiklus van geboue in die Suid-Afrikaanse omgewing. Dit word gedoen deur die voortsetting van die werk wat begin is deur Brewis (2011), en voortgesit is deur Brits (2012). Brewis het die benadering vir die eerste fase (voor-gebruik) ontwikkel, terwyl Brits die benadering vir die finale fase (einde-van-lewe) ontwikkel het. Beide het die fokus van hul toepassings geplaas op lae-koste behuising. Die benaderings is egter gedefinieer vir die algemene analise van ʼn gebou se raamwerk. Die besonderhede van die ontwikkeling van die omgewingslewensiklus analise (OLA), asook die benaderings vir die eerste en finale fases, word in Hoofstuk 3 bespreek. Die studie ontwikkel die gebruiksfase van die voorgestelde omgewingslewensiklus analise vir geboue in Hoofstuk 4. Dit bespreek die twee hoofkomponente van die gebruiksfase, naamlik die instandhouding en bedryf. Terwyl instandhouding gemoeid is met die vervanging van boumateriale in die struktuur, is die bedryfskomponent gemoeid met die energie behoeftes tydens die gebruiksfase. Dit word bepaal dat die energie verbruik wat ʼn direkte verband het met die gebou se raamwerk, die energie is wat nodig is vir die verhitting en verkoeling van die gebou. Dit is te danke aan die feit dat die termiese eienskappe van die gebou se raamwerk die termiese omgewing binne die gebou beïnvloed, en sodoende 'n impak het op die energie wat benodig word om die temperatuur te reguleer. In ʼn poging om die spektrum van die voorgestelde OLA ten volle te benut, is dit besluit om die toepassing daarvan te illustreer op 'n residensiële gebou wat van konsekwente energieverbruik gebruik maak om die termiese omgewing binne die gebou te reguleer. Dit is egter nie net die doel om die voorgestelde OLA te gebruik as 'n assesseringsinstrument nie, maar ook om die OLA se funksie as ’n vergelykende en optimaliseringshulpmiddel te illustreer. Dus is een komponent, die eksterne mure, gekies as 'n veranderlike komponent. Hierdie komponent is gewissel om 'n totaal van nege verskillende geboue te vorm. Hierdie nege geboue is gebruik in 'n vergelykende studie in 'n poging om 'n optimale keuse van eksterne mure te bepaal, gebaseer op die resultate van die omgewingsimpak wat in die OLA te bepaal is. Dit word ook gebruik om te probeer om te verduidelik presies hoe en tot watter mate die eksterne mure bydra by tot die omgewingsimpak, en watter nuttige toepassingswaarde geput kan word uit hierdie kennis. Die resultate het getoon dat 'n toename in die materiaal impak (weens pogings om die termiese kapasiteit van die eksterne mure te verbeter) in die meeste gevalle teengewerk is deur 'n afname in die energie impak. In sewe van die agt alternatiewe eksterne muurstelsels het dit gelei tot 'n netto afname in omgewingsimpak vir kategorieë een tot vier. Dit is ook gevind dat die omgewingsimpak van die gebou stelselmatig gedaal het met die toename van die Rwaarde van die eksterne muurstelsels, ook in terme van kategorieë een tot vier. Die enigste uitsondering op hierdie tendense is gevind in die vyfde impak kategorie: die afval wat gegenereer word. Die feit dat die effek van energie verbruik gering is in hierdie omgewingsimpak kategorie, lei tot die feit dat dit nie veel bydra tot die netto verandering in die omgewingsimpak nie.

Effective estimation, planning, and control of the functions, operations, and resources of a project are among the most challenging tasks faced by the management of today's engineering and construction organisations. The increase in size and complexity of modern projects demand a sound organisational structure and a rational approach. The main objectives of the present study are two-fold. Firstly to report and critically review theoretical and practical developments of different aspects of the management of engineering and construction projects. Secondly to further develop conceptual, practical techniques and processes; also to provide Guidelines to make more effective use. of resources and systems. To achieve these objectives the present research was carried out in close collaboration with various indurtrial organisations. The current literature on project management is critically examined from the point of View of project cost estimation, planning and control. Various existing and recommended procedures, approaches and techniques are reviewed with particular emphasis on using probabilistic techniques. As the problems of scale are increasing, progressively more industries are adopting systems and project management approaches. Problems, deficiencies and gaps in the existing systems are identified. An analysis of a questionnaire survey on Systems-Caps is carried out and the results of the analysis are reported. . S-curves (or progress curves) are widely used in the plauaing and control of cost, time and resources. A mathematical model for the S-curve is adopted for this purpose. Expenditure data on a number of ii recent projects is analysed and fitted to two S-curve models suggested by Keller-Singh and the Department of Health and Social Security (D. H. S. S. ). A comparative study of the models is carried out. A set of standard parameters for the models is obtained and the predicting accuracy of these models for forecasting expenditure for future similar projects investigated. Quantification aspects of risk involved with the completion time of a project are studied. 'A number of stochastic distributions arc fitted for this purpose to the programed and actual durations for the different activities of a housing project. The maximum likelihood method is used for the estimation of parameters of the fitted distributions. Due to the increasing use of indices in the construction industry, building cost and tender price indices, their application, limitations and methods of formation are discussed. Box-Jenkins models are employed to study past behaviour and to forecast future trends for labour, materials and building cost indices. Finally, general conclusions derived from the present regearch are sunmarised and areas requiring further research are proposed.