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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
651

Taguchi methods in internal combustion engine optimisation

Green, Jeremy James 12 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Statistical experimental design techniques are powerful tools that are often approached with suspicion and apprehension by experimenters. The trend is to avoid any statistically structured and designed experimentation program, and to rather use the traditional method of following ones "gut feel". This approach, more often than not, will supply a satisfactory solution, but there is so much more information availablefor the same amount of effort. This thesis strives to outline the method and application of the Taguchi methodology of experimental design. The Taguchi method is a practical, statistical experimental design technique that does not rely on the designer's knowledge of the complex statistics typicallyneeded to design experimental programs, a fact that tends to exclude design of experiments from the averageengineers' toolbox. The essence of the statistical design of experiments is this: The traditional method of varying one variable at a time and investigating its effect on an output is no longer sufficient. Instead all the input variables are varied at the same time in a structured manner. The output trends resulting from each input variable are then statisticallyextracted from the data in the midst of the variation. Taguchi method achieves this by designing experiments where every level of every input variable occurs an equal number of times with every level of every other input variable. The experimental designs are represented in orthogonal arrays that are chosen and populated by the experimenter by following a simple procedure. Four case studies are worked through in this text and, where possible, compared to the "traditional" approach to the same problem. The case studies show the additional information and time savings availablewith the Taguchi method, as well as clearlyindicating the importance of using a stable system on which to do the experiments. The Taguchi method generated more information in fewer experiments than the traditional approaches as well as allowing analysis of problems too complex to analysewithout a statisticaldesign of the experimentation procedure. / AFRIKAANSE OPSOMMING: Statistiese eksperimentele ontwerptegnieke is besonder kragtige instrumente wat baie keer met agterdog deur ekspermenteerders beheen word. Die neiging is om enige statistiese gestruktureerde and ontwerpte eksperimentele program te vermy, en om liewer die tradisionele metode, wat op 'n mens se intuïsie staatmaak, te gebruik. Hierdie benadering sal baie keer 'n bevredigende oplossing gee, maar daar is veel meer inligting vir dieselfde hoeveelheid inspanning verkrygbaar, wanneer die Taguchimetode gebruik word. Hierdie tesis strewe om die metode en toepassing van die Taguchimetodologie van eksperimentele ontwerp voor te lê. Die Taguchimetode is 'n praktiese statistiese eksperimentele ontwerptegniek .wat nie op die ontwerper se kennis van komplekse statistiek om eksperimentele programme te ontwerp berus nie. Hierdie komplekse statistiek neig ook om eksperimentele ontwerp van die gemiddelde ingenieursvaardigehede uit te sluit. Die kern van statistiese eksperimentele ontwerp is die volgende: Die tradisionele metode van een veranderlike op 'n slag te varieer om die effek op die uitset te ondersoek, is onvoldoende. In plaas daarvan, word al die insetveranderlikes gelyktydig gevarieer in 'n gestruktureered manier. Die neigings van elke veranderlike is dan statisties ontleed van die data ten midde van die variasie van al die ander veranderlikes. Die Taguchimetode bereik die ontwerpte eksperimente deur elke vlak van elke insetveranderlik in 'n gelyke aantal keer met elke vlak van elke ander insetveranderlike te varieer. Hierdie is verteenwoordig deur ortogenale reekse wat gekies en gevul is deur 'n eenvoudige wisselpatroon te volg. Vier gevallestudies is deurgewerk en, waar moontlik, vergelyk met die tradisonele siening van dieselfde probleem. Die gevallestudies wys hoe toereikbaar die additionele inligting in die Taguchimethode toepassings is. Hulle beklemtoon ook die belangrikheid van 'n stabiele sisteem waarop die eksperimente berus. Die Taguchimetode het meer inligting verskaf met minder eksperimente as die tradisionele toenaderings, en ook toegelaat dat die analise van probleme, te kompleks om te analiseer sonder om 'n statistiese ontwerp van eksperimentele prosedure te volg, opgelos kon word.
652

Effect of service-quality dimensions on customer patronage at Jaguar Land Rover dealerships in Gauteng

Theron, Daniell. January 2015 (has links)
M. Tech. Business Administration / The study assesses the dimensions of service quality within a Jaguar Land Rover dealership in Gauteng. The first objective is to determine the importance of each service quality and the second is to measure the effect of the service quality at the dealerships.
653

Observation-driven configuration of complex software systems

Sage, Aled January 2004 (has links)
The ever-increasing complexity of software systems makes them hard to comprehend, predict and tune due to emergent properties and non-deterministic behaviour. Complexity arises from the size of software systems and the wide variety of possible operating environments: the increasing choice of platforms and communication policies leads to ever more complex performance characteristics. In addition, software systems exhibit different behaviour under different workloads. Many software systems are designed to be configurable so that policies (e.g. communication, concurrency and recovery strategies) can be chosen to meet the needs of various stakeholders. For complex software systems it can be difficult to accurately predict the effects of a change and to know which configuration is most appropriate. This thesis demonstrates that it is useful to run automated experiments that measure a selection of system configurations. Experiments can find configurations that meet the stakeholders' needs, find interesting behavioural characteristics, and help produce predictive models of the system's behaviour. The design and use of ACT (Automated Configuration Tool) for running such experiments is described, in combination a number of search strategies for deciding on the configurations to measure. Design Of Experiments (DOE) is discussed, with emphasis on Taguchi Methods. These statistical methods have been used extensively in manufacturing, but have not previously been used for configuring software systems. The novel contribution here is an industrial case study, applying the combination of ACT and Taguchi Methods to DC-Directory, a product from Data Connection Ltd (DCL). The case study investigated the applicability of Taguchi Methods for configuring complex software systems. Taguchi Methods were found to be useful for modelling and configuring DC-Directory, making them a valuable addition to the techniques available to system administrators and developers.
654

Kvalitetsgranskning av flödesdata från vattenledningsnätet / Quality control of flow meter data from water supply networks

Eliasson, Victor January 2016 (has links)
In an attempt to revise the guidelines which are the basis of today’s design of water and sewage systems, Tyréns carries out a project for Swedish Water & Wastewater Association (SWWA). This SWWA project aims to, based on flow meter data, map out the behavior pattern regarding water consumption for certain types of consumers, such as industrial or individual users. The overall goal is to get a better support for the dimensioning process. A prerequisite for SWWA study is that the data to be analyzed are of good quality. Therefore this thesis will be included as a sub-study for the SWWA project with the goal to find and test methods for quality control of the flow meter data. This thesis showed some methods to statistically validate the data. A method is for instance presented that is used to detect changes in the statistical distribution for the sets of flow meter data. The changes that were studied were either changes in mean or variance. The latter turned out to be able to detect sequences, mostly during the summer, when the daily variations in water demand is different than during the rest of the year. Furthermore, some outliers could be identified using regression analysis. Some measurement errors, such as repeated flow values, could also be detected using run length encoding. In identifying anomalies and outliers, some types of those were possible to explain as false flow observation or non-representative for the data series as a whole for further analysis in the SWWA project. Other suspected observations were not possible to declare as true erroneous and have therefore been flagged for further investigation with support by an expert in the field. / I ett försök att revidera de riktlinjer som ligger till grund för dagens dimensionering av vatten- och avloppsledningsnät, genomför Tyréns ett projekt för Svenskt Vatten Utveckling (SVU). Detta SVU-projekt syftar till att utifrån flödesdata från vattenledningsnätet kartlägga beteendemönster hos olika förbrukartypers vattenförbrukning, såsom storförbrukare och enskilda brukare, för att på så vis kunna erhålla bättre och mer aktuella underlag för dimensioneringen. En förutsättning för SVU-studien är att det mätdata som ska analyseras håller god kvalitet. Därför kommer detta examensarbete att ingå som en understudie till SVU-projektet med syftet att finna en metod för att kvalitetsgranska flödesdata. Detta examensarbete visade metoder för att statistiskt granska flödesdatat med avseende på outliers och anomalier. Bland annat presenterades en metod för att finna förändringar i mätseriernas statistiska fördelning. De förändringar som studerades var antingen förändring av medelvärde eller en förändring av variansen. Den senare visade sig kunna detektera sekvenser, framförallt under sommaren, där dygnsvariationen i vattenförbrukningen ofta var annorlunda mot resten av året. Vidare kunde outliers detekteras med hjälp av regressionsanalyser på mätserierna.  Olika mätfel, exempelvis mätvärden som upprepas, kunde även identifieras med hjälp av skurlängdskodning. Vid identifiering av anomalier eller outliers har vissa typer kunnat detekteras och förklarats som felaktiga värden eller icke representativa för mätserien för vidare analyser. Andra identifierade suspekta mätvärden har inte kunnat förklaras eller det har inte kunnat säkerställas att de är felaktiga. Dessa har markerats och bör studeras av en expert inom ämnesområdet.
655

Targeting Non-obvious Errors in Death Certificates

Johansson, Lars Age January 2008 (has links)
Mortality statistics are much used although their accuracy is often questioned. Producers of mortality statistics check for errors in death certification but current methods only capture obvious mistakes. This thesis investigates whether non-obvious errors can be found by linking death certificates to hospital discharge data. Data: 69,818 deaths in Sweden 1995. Paper I: Analysing differences between the underlying cause of death from the death certificate (UC) and the main discharge condition from the patient’s last hospitalization (MDC). Paper II: Testing whether differences can be explained by ICD definitions of UC and MDC. Paper III: Surveying methods in 44 current studies on the accuracy of death certificates. Paper IV: Checking death certificates against case summaries for: i) 573 deaths where UC and MDC were the same or the difference could be explained; ii) 562 deaths where the difference could not be explained. Results: In 54% of deaths the MDC differed from the UC. Almost two-thirds of the differences were medically compatible since the MDC might have developed as a complication of the UC. Of 44 recent evaluation studies, only 8 describe the methods in such detail that the study could be replicated. Incompatibility between MDC and UC indicates a four-fold risk that the death certificate is inaccurate. For some diagnostic groups, however, death certificates are often inaccurate even when the UC and MDC are compatible. Conclusion: Producers of official mortality statistics could reduce the number of non-obvious errors in the statistics by collecting additional information on incompatible deaths and on deaths in high-risk diagnostic groups. ICD conventions contribute to the quality problem since they presuppose that all deaths are due to a single underlying cause. However, in an ageing population an increasing number of deaths are due to an accumulation of etiologically unrelated conditions.
656

Adaptive process control for stabilizing the production process in injection moulding machines

Schiffers, Reinhard, Holzinger, Georg P., Huster, Gernot 02 May 2016 (has links) (PDF)
Plastic injection moulding machines are a positive example of the possibilities in terms of performance and energy efficiency of modern hydraulic drives technology. In addition to the performance and energy efficiency of the machines, the quality of the plastic mouldings and an easy to use machines control is the focus. To ensure a constant plastics part quality the set process parameters of the injection moulding machines are kept constant by appropriate closed loop control strategies today. Assuming a constant quality of the processed plastic raw material, this strategy is effective. If it comes to a qualitative variation in the processed plastics, which often leads to a change in viscosity of the plastics melt, keeping processing parameters constant will not lead to a constant quality of the moulded parts. The deviations in the plastics viscosity have such a great influence on the moulding process that the relevant process parameters have to be adjusted manually in many cases. Often the stroke of the reciprocating screw system has to be adapted to reach a constant filling volume of the cavity and therefore avoid burr formation or short shots. In this paper an approach for adaptive process control is introduced. This control loop is able to correct the set points of specific machines parameters online within the production cycle and therefore is able to avoid changes in the produced parts quality.
657

Working towards the implementaion of an international accreditation programme in a Nuclear Medicine Department of a South African teaching hospital

Eiselen, Thea 04 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: Introduction: Quality assurance in Nuclear Medicine is of utmost importance in order to ensure optimal scintigraphic results and correct patient management. A customised Quality Management System (QMS) should be documented and implemented by following the international guidelines set by the International Standardisation Organization (ISO). Materials & Methods: A Quality Control Manual (QCM), defining the departmental quality policy, mission, vision and objectives was customised following the framework of a tried and tested design. As ISO focuses on client satisfaction and staff harmony, the following departmental objectives were audited in working towards the accreditation of the Nuclear Medicine Department of Tygerberg Hospital: referring physician satisfaction, patient satisfaction as well as staff satisfaction and harmony. Information was collected by means of questionnaires completed by referring physicians and staff members. One-on-one interviews were executed on patients. An international ISO accredited Nuclear Medicine department was visited to establish the suggested path to follow en route to successful ISO accreditation and certification. Results: Referring physicians indicated overall satisfaction with service provision, but a need for electronic report and image transfers seemed too dominant. The patient satisfaction survey resulted into overall satisfaction with personal service providing, but the provision of written and understandable information, long waiting times and t equipment must receive attention. Staff questionnaires indicated a general lack of communication between different professional groups and the need for interpersonal loyalty and team building. Improvement measures were identified to ensure the continuous improvement of the QMS by focusing on these quality parameters. Conclusion: The department has QA procedures in place, but does not meet all criteria for external accreditation. In order to ensure departmental harmony and sustainability of client and staff satisfaction, the departmental objectives in measured and improved where needed. The successful implementation and continuous improvement of a customised QMS, following the guidelines outlined in the QCM will lead to successful accreditation. / AFRIKAANSE OPSOMMING: Inleiding: Die belangrikheid van kwaliteit versekering in Kerngeneeskunde vir die versekering van optimale flikkergrafiese resultate en korrekte pasient handtering kan nie onderskat word me. 'n Klantgerigte Kwaliteitsbeheersisteem (KBS) moet gedokumenteer en geimplimenteer word vir die Kerngeneeskunde Departement deur die riglyne te volg soos uiteengesit deur die Internationale Standardiserings Organisasie (ISO). Materiale & Metodes: 'n Kwaliteitskontrol handleiding (KB), wat die departementele kwaliteitsbeleid, die missie en visie asook die departementele doelwitte definieer is ontwerp en saamgestel vir die Kerngeneeskunde departement van Tygerberg Hospitaal. Hierdie ontwerp is gebaseer op die raamwerk van 'n aanvaarde kwalteitsbeheersisteem. ISO fokus op klante tevredenheid asook personeel harmonie en tevredenheid. Vir hierdie rede is daar 'n tevredenheidpeiling uitgevoer op die klante en personeel in die strewe na ISO akkreditasie en sertifikasie. Inligting was versamel deur vraelyste wat ingevul was deur die verwysende geneeshere, pasiente en personeel. Resultate: 'n Kwaliteitskontrole handleiding was saamgestel VIr gebruik in die Kerngeneeskunde department. Die interne audit resultate het aangedui dat die verwysende geneeshere tevrede is met die algehele dienslewering. Die behoefde aan elektronies versende verlae en beelde was dominerend. Die pasient tevredenheidspeiling het bevestig dat die pasiente tevrede is met persoonlike dienslewering, maar 'n tekort aan verstaanbare en geskrewe inligting was geidentifiseer. Die lang wagtye en stukkende apparaat is ook gebiede wat verbertering benodig. Algemene gebrek aan komminukasie tussen die verskillende beroepsgroepe, die behoefte aan interpersoonlike lojaliteit en span werk was die hoof bevindinge van die personeel tevredenheidspeiling. Verbeterings maatreels, gefokus op hierdie departementele doelwitte, was geidentifiseer ten eide te verseker dat die KBS voordurend verbeter en in stand gehou word. Samevatting: Alhoewel die departement wel KB prosedures in plek het, voldoen dit nie aan al die criteria vir eksterne akkreditasie nie. Ten einde departementele harmonie en kliente tevredenheid te verseker, met die oog op ISO sertifikasie, moet die departmenteIe doelwitte deurlopend gemeet en verbeter word.
658

Assessing the contribution of quality and efficiency initiatives to reduce productions costs at Distell's Green Park

Smit, Wiehahn 12 1900 (has links)
Thesis (MBA (Business Management))--Stellenbosch University, 2008. / ENGLISH ABSTRACT: Manufacturers can gain a competitive advantage through lower production cost, better quality, better efficiencies and being more flexible and dependable than its competitors. Lower production cost can be a result of first-time-right quality products and efficient production processes in terms of throughput. Low production cost is not a destination but a journey where the goalpost will always move as competitors will continuously come up with ideas to lower prices and margins have to be cut in order to stay competitive. This is where manufacturers must come up with initiatives to continuously drive its operational metrics to remain competitive. This research report will explain how Distell's biggest bottling plant, Green Park, successfully introduced Process Control to increase its quality operational metric and a Six Sigma project to reduce downtime to increase its efficiency operational metric to drive its operational costs down. Process Control was introduced as a TOM initiative with a subsequent reduction in rework due to poor quality (thousands) from R1 585 to R484. This contributed to 'first-time-right' production, better efficiencies and not tying up valuable production time with reworks. The Six Sigma principles were used on a production line to introduce initiatives to reduce changeovers and unplanned downtime to improve its GEE. This initiative has a projected benefit of R687 (thousands). The report also indicated that a 1% increase in Green Park's overall GEE will result in 1% saving of production hours resulting in a 1% saving of variable cost. This will result in an OEE of 63% that will save 226 hours and R410(thousands). / AFRIKAANSE OPSOMMING: Vervaardigers kan 'n kompeterende voorsprong verkry deur laer produksiekoste, beter gehalte en groter doeltreffendheid te bewerkstellig en deur meer buigbaar en betroubaar as hul teestanders te wees. Goeie gehalte produkte wat die eerste keer reg is en doeltreffende produksieprosesse vir verwerkingskapasiteit kan laer produksiekoste tot gevolg het. Lae produksiekoste is nie 'n bestemming nie, maar 'n reis waartydens die doelpale sal skuif met teestanders wat deurgaans met idees om pryse te verjaag, vorendag sal kom. Winsgrense sal moet verklein word om kompeterend te bly. Hier moet vervaardigers inisiatief aan die dag lê om hul operasionele meetbares te dryf om kompeterend te bly. Hierdie navorsingsverslag sal verduidelik hoe Distell se grootste botterings aanleg, Green Park, prosesbeheer (Process Control) suksesvol in werking gestel het om sy meetbares wat operasionele gehalte betref, te verhoog, en 'n Six Sigma-projek ingestel het om staantyd te verminder sodat sy meetbares wat operasionele doeltreffendheid betref, kan verhoog en sy operasionele koste sodoende besnoei word. Prosesbeheer is as algehele gehaltebestuursinisiatief ingestel met 'n gevolglike vermindering van herverwerking weens swak gehalte (duisende) van R1 585 na R484. Dit het bygedra tot groter doeltreffendheid met produksie wat uit die staanspoor reg is, en verhoed dat kosbare produksietyd op herverwerking gespandeer word. Die Six Sigma-beginsels is in 'n produksielyn gebruik om inisiatiewe in werking te stel om oorskakelings en onbeplande staantyd ter verbetering van die algehele toerustingsdoeltreffendheid (OEE), te verminder. Hierdie inisiatief hou 'n geprojekteerde voordeel van R687 (duisende) in. Die verslag dui verder aan dat 'n 1%-verhoging in Green Park se algehele OEE sal lei tot 'n 1% besparing in produksie-ure, wat 'n 1% besparing op veranderlike koste tot gevolg het. Dit sal tot 'n OEE van 63% lei, wat 226 uur en R410 (duisende) sal spaar.
659

Managing product quality risks through the supply chain

Malgas, Yolanda 03 1900 (has links)
Thesis (MBA)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: With globalisation and the accompanying increase in international trade there is a great drive towards performing risk assessments on the quality of products. Such assessments are of particular importance within the food and drug industry, so much that this approach is also being adapted by the FDA in their analysis of the quality of products and probable risks to it. The pharmaceutical industry is heavily regulated to reduce or eliminate the production and distribution of poor quality products. Pharmaceuticals have to be of high quality as people's lives depend on it. Many pharmaceutical companies import raw materials from international manufacturers or international agents. In most cases the raw material or the products have to go through a long and complicated supply chain. The more parties involved in the supply chain, the greater the risk to product quality. Supply chain partnerships have therefore become critical to manage these risks to product quality throughout the supply chain. In order to manage risks to product quality, it has become vital to perform product quality risk assessments, especially through the supply chain. In this study the Failure Mode Effect Analysis (FMEA) is used to perform a risk assessment of risks to product quality throughout the supply chain. To obtain the criticality of the risks the Failure Mode Effect and Criticality Analysis (FMCEA) is applied. Quality improvement systems which contribute towards managing the risks to product quality are also discussed in this report. By managing quality risks to pharmaceutical products along with using quality as a strategy, the pharmaceutical company contributes towards improved health for patients as well as customer satisfaction, business success and excellence. / AFRIKAANSE OPSOMMING: Die toepassing van die analise van die risiko op produkte is vinnig besig om te vermeerder. Die FDA gaan dit toepas in hulle analise van die kwaliteit van produkte en die risiko wat daarmee gepaard gaan, in die voedsel en medisyne bedryf. Die farmaseutiese industrie word baie streng gereguleer om te verhoed dat die produksie en distribusie van swak kwaliteit produkte ervaar word. Farmaseutiese produkte moet van hoë gehalte wees, omdat die gesondheid van pasiënte daarvan afhang. Baie farmaseutiese maatskappye bestel rou materiale van oorsese makelaars en in baie gevalle moet die rou materiale deur 'n lang en gekompliseerde voorsieningsketting gaan. Hoe meer agente betrokke is, hoe hoër word die risiko met respek tot die kwaliteit van die produk. Die voorsieningsketting speel 'n kritiese rol om te verseker dat risikos beheer kan word, omdat elke party verantwoordelik is vir die lewering van kwaliteitsprodukkte. Om te verseker dat risikos beheer word, het dit belangrik geword om risiko analise te doen op die kwaliteit van produkte, veral wanneer in die voorsieningsketting. In hierdie studie word die "Failure Mode Effect Analysis (FMEAJ' gebruik om 'n risiko analise te doen met betrekking tot risikos op 'n produk se kwaliteit wanneer in die voorsieningsketting. Die "Failure Mode Effect, and Criticality Analysis (FMECAJ', word ook toegepas om te bereken hoe krities die risiko is. Verbeteringstelsels wat bydra tot die beheer en kontrole van risikos vir produk kwaliteit word ook in hierdie studie bespreek. Deur die risikos te beheer op die kwaliteit van produkte, dra die farmaseutiese maatskappy by tot beter gesondheid vir pasiente, en verseker klient satisfaksie en suksesvolle besigheid.
660

A critical process analysis of wine production to improve cost efficiency, wine quality and environmental performance

Sheridan, Craig 03 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Wine cellars are diverse in terms of equipment types and process configurations. Whilst other food production processes have, in many cases, been properly analysed and modelled, this process diversity has resulted in an absence of process analyses in the wine industry. Each wine cellar is unique and represents a fully integrated agro-business, starting with a raw material (grapes) and extending to marketing and selling of the final product (wine). This makes the wine industry unique in this context. This study is the first attempt to analyse winemaking procedures in the form of a process audit. The study was approached in the following manner: • A questionnaire was developed to assess cellar configurations and conditions. This questionnaire was submitted to a statistically significant number of cellars, and a statistically significant number of questionnaires were returned. • The data collected from the questionnaire were statistically analysed and associations between equipment or procedures and wine faults were identified. • Three cellars were studied in depth. These three cellars had their processes audited and their effluent characterised. Additional data were obtained from current sampling projects and these data were analysed to complement the data obtained from the questionnaire • A preliminary input/output model was developed. The major results of this study are: • It was found that certain faults that appear in wine might be associated with equipment and/or process faults. These associations are statistically significant and they show that cellar hygiene is of critical importance when assessing these wine faults. The most important of these faults are VA, microbial contamination of the wine, sluggish and stuck fermentations. A risk hierarchy was derived to indicate which events are associated with others most strongly. • It was found that few wineries measure water consumption and even fewer wineries measure the quantity of effluent produced. • Correlations have been developed to predict winery parameters in terms of tons of grapes pressed per annum. These parameters include water and electricity consumed, wine produced and the quantity of effluent produced. Effluent characteristics have also been correlated to the tons of grapes pressed per annum. These characteristics include chemical oxygen demand, sodium absorption ratio and total dissolved solids in solution. Chemical oxygen demand was identified as the most important contributing factor in winery effluent. It was shown that all variables rise with an increase in cellar size, but the rise is not linear. This implies that large cellars have greater quantities of effluent of lower quality than small cellars. Most cellars have effluent concentrations that require some form of effluent treatment. The characterisation of effluent shows that the most widely used disposal practice is irrigation, and that the effluent disposed in this manner does not meet legislative requirements. • A preliminary input/output model was developed in order to enable wineries that have not measured the relevant parameters to predict the abovementioned variations. The resolution of these predictions is low but the model serves to provide an initial estimate if there are no data available. The model will give industrial averages for any given cellar size. • An economic balance was performed using this preliminary model. It was shown that if cellars were to lower the consumption of utilities and to reduce the strength of their effluent (using cleaner practices and not dilution) the reduction of operating costs could be reduced by 14% for smaller cellars to 17% for larger cellars. This study has shown that it is possible to make wine in a more environmentally friendly manner, producing better quality wines, without incurring extra costs. / AFRIKAANSE OPSOMMING: Wynkelders is diverse eenhede ten opsigte van die tipe toerusting en prosesse wat gebruik word. Terwyl ander prosesse rondom voedselproduksie in baie gevalle reeds geanaliseer en gemodelleer is, het die diversiteit in die wynindustrie gelei tot 'n afwesigheid van prosesanalises. Elke wynkelder is uniek en verteenwoordig 'n ten voile geintegreerde agro-besigheid wat begin met die rou materiaal (druiwe) en lei tot die bemarking en verkope van die finale produk (wyn), 'n eienskap wat die wynindustrie uniek maak in hierdie verband. Hierdie studie is die eerste poging om die wynmaakproses in die vorm van ‘n proses-oudit te analiseer. Die studie is soos volg aangepak: • ‘n Vraelys is ontwikkel om kelderkonfigurasies en -toestande te ondersoek. Die vraelys is aan ‘n statisties betekenisvolle aantal kelders voorgele, en ‘n statisties betekenisvolle aantal vraelyste is terugontvang. • Die data wat uit die vraelyste ontvang is, is statisties ontleed en verwantskappe tussen toerusting of prosesse en wyngebreke is geidentifiseer. • Drie kelders is in diepte bestudeer. Hierdie drie kelders se prosesse is geoudit en die afvloeiwater is gekarakteriseer. Addisionele data is verkry van huidige projekte en hierdie data is ge-analiseer om die data van die vraelys aan te vul. • ‘n Voorlopige inset / uitset model is ontwikkel. Die belangrikste resultate van hierdie studie is: • Dit is bevind dat sekere gebreke wat in wyn voorkom geassosieer kan word met tekortkominge in toerusting en/of prosesse in die kelder. Hierdie assosiasies is statisties betekenisvol en toon dat kelderhigtene van kritiese belang is wanneer gebreke in wyn ondersoek word. Die mees belangrike gebreke wat voorkom is vlugtige suur, mikrobiese kontaminasie van wyn, slepende en gestaakte fermentasie. ‘n Risikohierargie is afgelei om die gebeure te toon wat die sterktste met mekaar geassosieer word. • Dit is gevind dat min wynkelders waterverbruik meet. Selfs minder kelders meet die hoeveelheid afvloeiwater wat geproduseer word. • Korrelasies is ontwikkel om kelderparameters te voorspel in terme van ton druiwe gepars per jaar. Hierdie parameters sluit in water- en elektrisiteitsverbruik, wyn geprosuseer en hoeveelheid afvloeiwater geproduseer. Eienskappe van afvloeiwater is ook gekorreleer met die ton druiwe wat per jaar gepars word. Hierdie eienskappe sluit in chemiese suurstofbehoeftes, natrium absorpsieverhoudings en totale opgeloste soliede materiaal in oplossing. Chemiese suurstofbehoeftes is geidentifiseer as die mees belangrike bydraende faktor tot afvloeiwater in kelders. Dit is getoon dat alle veranderlikes verhoog hoe groter die kelder, maar hierdie verhoging is nie lineer nie. Dit impliseer dat groter kelder meer afvloeiwater van ‘n laer kwaliteit produseer. Die meeste kelders produseer afvloeiwater van sodanige konsentrasies dat behandeling daarvan nodig is. Die ondersoek van hierdie afvloeiwater toon dat die mees algemene wyse van wegdoening van afvloeiwater besproeiing is, en dat afvloeiwater wat op hierdie manier weggedoen word, nie voldoen aan die wetgewing se vereistes nie. • 'n Voorlopige inset/uitset model is ontwikkel om kelders wat nie die toepaslike parameters gemeet het nie in staat te stel om hierdie parameters te voorspel. Die akuraatheid van hierdie voorspellings is nie hoog nie, maar die model verskaf ‘n aanvanklike skatting waar daar geen data beskikbaar is nie. Die model verskaf industriele gemiddeldes aan kelders van enige grootte. • ‘n Ekonomiese balans is uitgevoer deur van hierdie model gebruik te maak. Dit is getoon dat indien kelders die gebruik van water en elektrisiteit verminder en die konsentrasie van afvloeiwater verlaag (deur van skoner paktyke gebruik te maak, en nie verdunning nie) die bestuurskoste met 14% vir kleiner kelders tot 17% vir groter kelders verlaag kan word. Die studie het getoon dat dit moontlik is om wyn te maak op ‘n meer omgewingsvriendelike wyse, en sodoende beter kwaliteit wyn te produseer sonder addisionele kostes.

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