published_or_final_version / Economics / Master / Master of Philosophy

Η φωτοκαταλυτική διάσπαση υδατικών διαλυμάτων του Acid Orange 7 (ΑΟ7), ενός αζωχρώματος που αποτελεί τυπικό δείγμα των μη-βιοαποδομήσιμων χρωστικών ουσιών που απαντώνται στα υγρά απόβλητα βιομηχανιών υφαντουργίας, μελετήθηκε με χρήση καταλύτη TiO2 και τεχνητής ηλιακής ή ορατής (>400 nm) ακτινοβολίας. Βρέθηκε ότι όταν χρησιμοποιείται ηλιακή ακτινοβολία, η διάσπαση των μορίων του ΑΟ7 λαμβάνει χώρα στην επιφάνεια του φωτοκαταλύτη μέσω μιας σειράς βημάτων οξείδωσης που οδηγούν στον σχηματισμό ενδιαμέσων, κυρίως αρωματικών και αλειφατικών οξέων, τα οποία στη συνέχεια οξειδώνονται περαιτέρω προς ενώσεις με προοδευτικά μικρότερο μοριακό βάρος. Τελικά, επιτυγχάνεται πλήρης αποικοδόμηση του αζωχρώματος, με σχηματισμό CO2 στην αέρια φάση και ανόργανων ιόντων στο διάλυμα. Όταν χρησιμοποιούνται φωτόνια ορατού φωτός, τα ενδιάμεσα της αντίδρασης είναι παρόμοια με αυτά που παρατηρήθηκαν με τη χρήση ηλιακής ακτινοβολίας, αλλά ο αποχρωματισμός λαμβάνει χώρα με μικρότερους ρυθμούς. Επιπλέον, μετά τον αποχρωματισμό του διαλύματος, το COD δεν μειώνεται περαιτέρω και τα ενδιάμεσα της αντίδρασης μένουν σταθερά με το χρόνο ακτινοβόλησης υποδεικνύοντας ότι, στην περίπτωση αυτή, η φωτοκαταλυτική διάσπαση με χρήση ορατής ακτινοβολίας λαμβάνει χώρα μέσω του μηχανισμού “φωτοευαισθητοποίησης”. Σύμφωνα με τα αποτελέσματα της κινητικής μελέτης του συστήματος, ο αρχικός ρυθμός αποχρωματισμού εξαρτάται από την ένταση και το μήκος κύματος της προσπίπτουσας ακτινοβολίας, από την κάλυψη της επιφάνειας, από την αρχική συγκέντρωση του αζωχρώματος, από τη συγκέντρωση του TiO2 και από το αρχικό pH. Από την κινητική μελέτη προκύπτει κινητικό μοντέλο το οποίο περιγράφει ικανοποιητικά τα πειραματικά δεδομένα. Μελετάται η επίδραση των φυσικοχημικών ιδιοτήτων του φωτοκαταλύτη, όπως κρυσταλλογραφική δομή, ειδική επιφάνεια, μέσο μέγεθος κρυσταλλιτών, απορρόφηση στη UV/vis περιοχή και μορφολογία, καθώς και της μεθόδου παρασκευής του TiO2 στον ρυθμό αποχρωματισμού. Τέλος, διερευνάται η δυνατότητα βελτίωσης των φωτοκαταλυτικών ιδιοτήτων του TiO2 με ενίσχυση με διάφορα ετεροσθενή κατιόντα και με διασπορά μετάλλου στην επιφάνειά του. / The photocatalytic degradation of aqueous solutions of Acid Orange 7 (AO7), a model non-biodegradable textile azo-dye, is investigated with the use of TiO2 photocatalyst and artificial solar- or visible (>400 nm)-light irradiation. It is shown that when the full solar spectrum is utilized, the dye molecules adsorbed on TiO2 surface undergo a series of oxidation steps, which lead to rapid decolorization and formation of a number of intermediates, mainly aromatic and aliphatic acids, which are further oxidized toward compounds of progressively lower molecular weight and, eventually, to CO2 and inorganic ions. Under these conditions, complete decolorization and mineralization of the solution is achieved with appreciable reaction rates. When the solution is irradiated with visible light (λ> 400 nm), reaction intermediates are similar to those observed under artificial solar-light irradiation but decolorization takes place with much lower rates. In addition, when the solution is bleached, the COD does not further decrease with time of irradiation and reaction intermediates remain unchanged, indicating that the visible-light induced photocatalytic degradation of AO7 is governed by the “photosensitization mechanism”. Kinetic results show that the initial rate of decolorization depends on the intensity and the wavelength of incident light irradiation, the surface coverage, the initial concentration of the azo-dye, the concentration of the photocatalyst and the initial pH of the solution. From the kinetic investigation, a kinetic model is obtained which fits well the experimental data. The influence of the physicochemical properties of the photocatalyst such as crystal structure, specific surface area, average crystallite size, absorption in the UV/vis region and morphology, as well as the preparation method of TiO2 on the rate of decolorization is investigated. The improvement of the photocatalytic activity of semiconductor photocatalysts by doping with different altervalent cations and by deposition of noble metals onto the TiO2 surface is studied.

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No abstract available. / Thesis (M.S.U.R.P.)-University of Natal, Durban, 1998.

The overarching objective of this study was to establish the extent to which the Multi-Fiber Arrangement impacted on the garment industry of the Kingdom of Lesotho. The quota system which controlled access to the world's biggest textile and clothing markets in the United States (US) and European Union (EU) namely Multi-fiber Arrangement (MFA) was incorporated in 1974. Nonetheless, with the thrust towards the increasingly liberal world market, MFA was abolished on 1 January 2005. As a result countries such as Lesotho had to compete on an equal footing with developed countries. Lesotho depends heavily on textile and clothing exports, thus, it is potentially vulnerable to this change in competitiveness. There have been predictions that the garment industry will suffer as a result of quota abolition and spell the end of thousand of jobs. This study was conducted to understand the various implications of Multi-Fibre Arrangement phase out on the Lesotho garment industry. The study first examines the impact of MFA on the economic growth and employment in Lesotho. Then it determines the consequences of MFA phase out on workers and the garment industry, that is, whether this elimination badly affected the industry and workers. Lastly, it establishes if adequate actions or efforts have been undertaken to attenuate potential negative impacts on workers. The results strongly indicate that MFA had contributed enormously to the Lesotho economic growth. The phasing out has led to job losses and disruption in the industry. However, programs have been put in place to mitigate and manage the negative impacts on workers such as providing training to workers with the aim of improving productivity. By the same token, recommendations have been suggested in order to address the impacts, such as to integrate vertically the industry to enhance production times. / Thesis (MBA)-University of KwaZulu-Natal, Durban, 2006.

No description available.

No description available.

The British market has until now received little of the credit due it as the chief support of the cotton industry during the final fifty years of the eighteenth century. The manner in which this support was extended involved a restructuring of the economy, as illustrated by a qualitative change in the consumer habits of the population; the advent of a mass consumer society. The demand for cotton textiles was a distillation of many amorphous desires and aspirations that flourished in eighteenth century Britain. This was not a frivolous whim on the part of a small host of women, but a powerful economic force which might be tapped through the female section of the society, but which involved the entire society on a fundamental level. When the fashionable urge was translated into a demand for inexpensive, attractive cottons the industry was tied to one of the most potent commercial forces of that period. As a result of recent research, historians are coming to recognize a feature of economic development in the last half of the eighteenth century never before sufficiently acknowledged. This quality in the economic life of the nation set it off from all previous eras. During that time an economy developed and prospered that was geared to the profits of popular fashions, produced cheaply and in quantity for the mass market. Never before had a trade developed so quickly, exclusively on popular demand for mass-produced fashionable textiles. The provision of news on current fashions throughout the nation sparked generalized interest in British manufacturers among the middle and working classes. These classes were the basis of the market on which the cotton. industry depended for its vitality; it was among these sections of society that the creations of the cotton industry found the great new markets of the eighteenth century. Institutionalized dessimination of fashion information in print; a homogeneity of demand throughout the nation and the ranks of the nation; and the diversification and development of cotton products in response to this demand were the principal characteristics of this economic and social phenomenon.

Corporate Social Responsibility is attracting more public attention in business world nowadays. It has evolved well in developed countries while there still remains some CSR issues in emerging economies such as China and Turkey. Thus, when some multi- national enterprises select suppliers in China and Turkey they come with CSR requirements and pressure. In this supplier-buyer context, less study has been carried out from suppliers’ perspective on how they implement the CSR pressure and whether it has positive or negative impact on their relationship with the buyer and impact on themselves. In addressing this problem in this particular supplier-buyer environment, the purpose of this study is to explore the perspectives and practices of suppliers regarding CSR in emerging economies like China and Turkey with strong export relationships to companies in developed countries. In order to achieve this purpose, this thesis presents a qualitative study supported by primary data gathered by interviews and secondary data gathered by examining company documents. One Chinese supplier and one Turkish supplier were chosen as two cases in this study. Both have supplier-buyer relationships with the same buyer which has a large role in the textile industry. Interviews were conducted with two suppliers respectively to gain research data. The result of the study shows that: (1) CSR is perceived differently by Turkish and Chinese supplier. The Chinese supplier emphasizes their CSR perspectives on only economic and philanthropic levels while the Turkish supplier includes also ethical and legal levels. (2) In supply chains, both suppliers comply with codes of conduct from the buyer and additionally conduct CSR activities voluntarily. Both suppliers focus on philanthropy and community contribution but the Turkish supplier work on environmental friendly products. (3) There is no direct positive impact linked with CSR compliance in terms of supplier-buyer relationship for both suppliers. In other words, requirements on CSR from the buyer do not contribute much to their supply chain relationships. (4) CSR practices bring competitive advantages for both suppliers. Those competitive advantages include innovation capability and positive corporate reputation.

How does technological change alter the position and the configuration of groups of producers in an industry? This dissertation examines the transformations in the strategic groups of two manufacturing industries that introduced radically new manufacturing processes. The primary textile market during the period 1958 to 1978 with the introduction of synthetic fibers, introduced a large-scale process production. In the steel industry during the period 1965 to 1985, small-scale process production was introduced with the technology of mini-mills. / The impact of new manufacturing processes on the economic position of producers in the industry has been examined conventionally by the research in strategic management, which used with the set of business strategies developed by the positioning school (i.e., cost leadership, differentiation and focus). Where the cost structure is the determinant of the profitability of a manufacturer, strategic groups are expected to establish their position in terms of scale and scope (Porter 1980, Aaker, 1984, Day, 1990). / Our findings lead us to introduce a different view of the topic by focusing on competition between strategic groups having different centers of gravity. A center of gravity has been defined by Galbraith (1983) as the primary location of a producer in the economic chain of transformation. We found that large-scale and small-scale manufacturing processes have radically different impacts since these processes are intimately associated with specific centers of gravity. / Large-scale manufacturing processes create conditions for the formation of generalists with a strong center of gravity at the upstream primary manufacturing stage engaged in processes such as casting, cutting and forming. This strategic group of generalists establishes a dominant position in the industry in two stages: a cost leadership strategy followed by integrative strategies such as upstream and downstream vertical integration and ultimately, product diversification. Since manufacturers serve the same geographical market, we have a configuration of competing strategic groups. / Small-scale manufacturing processes create conditions for the formation of mid-size producers that we have called semi-generalists and semi-specialists. These strategic groups have a strong center of gravity at the downstream manufacturing stage and are engaged in processes such as as assembling and finishing. They have smaller scale facilities, are not vertically integrated, and sell a narrower product range than generalists. Since they are located closer to industrial centers and dedicated to specific industries, they compete on factors other than price, such as geographic location, product differentiation, service, etc. These strategic groups of medium-size producers challenge the dominance of generalists by restructuring the market into a set of regional markets. The configuration of strategic groups is shaped by generic groups of manufacturers competing in different geographical markets. / The set of business strategies proposed by the positioning school was adequate for large-scale processes. However, this set of strategies was largely inappropriate in a context where small-scale processes are introduced.