Call number: LD2668 .T4 1955 G37 / Master of Science

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / William P. Winslow III / Synthetic turf has been used extensively for football, soccer, and baseball playing surfaces as a substitute for natural turf because of its increased durability, low maintenance costs, and similar characteristics. The popularity, however, has not extended to golf courses, a seemingly appropriate application. Golf courses are prized for their aesthetic beauty, and their maintenance requires regular, detailed upkeep with particular attention to fairways, tees, greens, hazards, and the surrounding landscape. The combination of regular mowing, watering, grooming, and application of chemicals aim to strengthen the overall appearance of the golf course, but have negative effects on the ecologic and economic values of the golf course. Is it possible to use synthetic turf to reduce the ecologic and economic effects of golf course maintenance, while still providing an aesthetically pleasing playing surface and environment? This study develops three methodologies from the primary areas of concern: ecologic, economic, and aesthetic. The ecologic method uses criteria derived from the Sustainable Sites Initiative. Criteria in the economic method assist in understanding the cost efficiency of synthetic turf over time. Finally, the aesthetic method contains criteria that define characteristics that affect the look of the golf course. These methods are then organized into a metric structure with the respective evaluation criteria. Using the two re-designed options of Lakeside Hills Municipal Golf Course in Olathe, Kansas as the site for application, the methodologies are evaluated for three different scenarios, the traditional turf course, a partial replacement with synthetic turf, and a full replacement, and given a score. This score provides a quantitative value to weigh the ecologic, economic, and aesthetic benefits and constraints of synthetic turf in a golf course application, and important initial step in discovering its viability in the golf course design industry.

Novel mitosenes substituted at the 6-position were synthesized for antineoplastic screening. More than 26 new compounds were made by two synthetic routes. A Nenitzescu-type synthesis provided ethyl 1-acetoxy-2,3-dihydro-5,8-dione-7-methoxy-1H-pyrrolo{1,2-a}indole-9-carboxylate. However, selective reduction of this ester could not be achieved satisfactorily. A more practical route via annelation of a commercially available indole was successful in completing the planned scheme of 6-substituted mitosene congeners. The third ring (pyrrolidine) was added by condensation of ethyl acrylate with ethyl 5-methoxyindole-2-carboxylate. After decarboxylation at position 2, the ketone at position 1 was reduced and acetylated. Then the carbon at the 9 position was introduced by Vilsmeier-Haack formylation and the quinone moiety was synthesized via a nitration, reduction, and oxidation sequence. Subsequently, the aldehyde was most satisfactorily reduced to an alcohol with sodium borohydride and the quinone was regenerated with Fremy's salt. 1-acetoxy-6-desmethyl-7-methoxymitosene was made by forming a carbamate at position 9 by treatment of the 9-alcohol with phenyl chloroformate and displacing the phenoxy group with ammonia. Other 1,6,7-substituted mitosene congeners were made using N-methylcarbamate formation via methyl isocyanate and the 9-alcohol. The 6-chloro and 6-bromo analogs were formed by treatment of the 6-H congener, 1-acetoxy-2,3-dihydro-5,8-dioxo-9-(hydroxymethyl)-7-methoxy-1H-pyrrolo{1,2-a}indole methylcarbamate, with the desired halogen in acetic acid and sodium acetate. The 7-methoxy group could be displaced by ammonia for the 6-bromo compound and by pyrrolidine for the 6-H compound to form respectively the 7-amino-6-bromo and 7-pyrrolidino-6-H 1-acetoxy-2,3-dihydro-5,8-dioxo-9-(hydroxymethyl)-1H-pyrrolo{1,2-a}indole methylcarbamates. The 6-methyl analog (1-acetoxy-7-methoxy-N-methyl-carbamoylmitosene) was made from a previously synthesized precursor. Attempted syntheses of the 6-azido and 6-amino analogs by displacing the 6-bromo substituent with sodium azide were met by gross rearrangement of the resulting adducts. Preliminary antitumor screening against P388 leukemia in mice showed these analogs to be too inactive for use as antineoplastic agents. The 6-methyl substituent was shown to be most potent in bacteriophage induction in E. coli for this series of 6-substituted mitosene analogs.

Cellulose, the most abundant biopolymer on earth, is composed of β – 1,4 – linked glucose units, which in turn form a highly ordered crystalline structure that is insoluble and recalcitrant to degradation. It is the world’s most attractive, abundant and renewable energy resource, representing the bioconversion of carbon dioxide into green plants. Cellulosic biomass, such as agricultural and forestry residues, waste paper and industrial waste can therefore be used as an inexpensive and abundantly available source of sugar for fermentation into fuel ethanol. The combustion of biofuels releases carbon dioxide which is thus recycled and hence the use of these fuels in transportation provides an alternative to fossil fuels, solving many environmental problems. The ability to degrade crystalline cellulose seems to be restricted to a specialized group of microorganisms which includes for example Clostridium, Cellulomonas, Cytophaga, Trichoderma etc. Hence the aim of this project was to create BioBricks using different cellulases from cellulose degraders and express them in different expression hosts like Escherichia coli, Bacillus subtilis, Citrobacter freundii etc., using two different promoters, spac and lac. It was observed that the expression of Cytophaga hutchinsonii cellulases (CHU_2103 and CHU_2802) and dehydrogenases (CHU_1944 and CHU_2315) was toxic to the E. coli host for some unknown reason. Therefore it was decided to use cellulases from Cellulomonas fimi, which are well characterized. BioBricks of cellulases (cenA and cex) from C. fimi were introduced into different expression hosts. It was observed that under our experimental conditions Citrobacter freundii SBS197 gave the best results. Both Pspac and Plac were functional in this organism with expression being higher when Pspac was used. When E. coli JM109 was used as an expression host, activity was only detected when the lac promoter was used to control the expression. Although the expression was higher when E. coli JM109 (containing Plac) was used as an expression host, almost all of this activity was residing within the cells, whereas when C. freundii SBS197 was used as an expression host, considerable activity was detected in the surrounding medium, which is essential for cellulose degradation. Growth curve studies were done to see if heterologous cellulases enable the host to use cellulosic substrates as a source of carbon. It was observed that C. freundii SBS197 expressing cenA and cex was able to use filter paper and Avicel as a source of carbon with maximum growth of up to 8.8×108 cfu/ml and 1.2×109 cfu/ml respectively. This was about 2 – 5 fold higher when compared to the control (vector and/or negative) strains. Filter paper completely disappeared within 3 – 4 days when C. freundii SBS197 was used. Slight degradation was observed when E. coli JM109 was used but there was no physical degradation seen when B. subtilis 168 was used as an expression host. Hence it was concluded that heterologous cellulases impart to C. freundii SBS197 with the ability to use cellulosic substrates as a source of carbon. The maximum growth obtained using these cultures is to our knowledge higher than what has been reported so far for recombinant organisms expressing heterologous cellulases using cellulosic substrates as a source of carbon.

Mitigation of health and heat-build-up issues related to black, granulated crumb rubber infill (GCRI) in synthetic turf fields (STF) while maintaining acceptable impact absorption properties was the central goal of this study. The first step was establishing a STF baseline performance of GCRI samples that originated from several sources while elucidating the synergistic parameters between infill and turf that promulgate acceptable impact performance. Based on the knowledge base built on the GCRI-STF standard, three polymeric waste streams selected for their benign chemical contents, non-black colors and competitive low costs were evaluated as alternate turf infill materials: post-consumer carpet broadloom (PCCB), post-consumer carpet tile (PCCT) and recycled polyethylene terephthalate (PET) drink bottles. For ground PCCB carcass (the base on the carpet construction remaining after the face fibers were removed), the heterogeneous composition of unconfined fine particles and remaining short fibers prevented sufficient material integration to allow sufficient impact energy absorption. The ground PET homogeneous particles alone lacked sufficient impact absorption capabilities, and their synergistic interactions with the turf blade yarns were not sufficient to meet specified levels of impact performance. Only the PCCT infill crumb possessed a heterogeneous structure that effectively filled the STF to yield sufficient impact cushioning comparable to standard GCRI. In conclusion, PCCT was shown to be a technically-viable candidate for GCRI infill replacement, warranting further development to bring it into closer cost competitiveness to GCRI and ensure long-term wear and weathering performance in synthetic turf.

Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: There is a decrease in viscosity when universal colorants are added to the latex coating system. Two different routes were taken to investigate this problem. The first was to investigate the thickening mechanism of the coating system. For this purpose six different hydrophobically modified alkali-soluble (HASE) thickeners were synthesized. The second was to compile new color concentrate formulations. The HASE thickeners consist of acrylic acid and a second associative monomer. The associative monomer (macromonomer) contained a long chain hydrophilic segment, terminated with a hydrophobic group. The hydrophilic segment consists of polyethoxylation, situated between the ethylenic unsaturation at one end of the molecule and the terminal hydrophobe at the other end. Three different macromonomers were prepared by coupling the hydroxyl end groups of three commercially available nonionic surfactants with either acrylic acid or acryloyl chloride. A much higher yield of macromonomer was obtained when the nonionic surfactants were reacted with the acryloyl chloride. Six HASE thickeners were synthesized by means of free radical addition polymerization. The first three HASE thickeners had the same backbone length and each thickener containing one type of hydrophobic macromonmer. The hydrophobic macromonomers differed in the length of their repeating oxyethylene units. They contained either 20, 50 or 100 oxyethylene units. The next three HASE thickeners were very similar to the first three except that 5% of the acrylic acid in the backbone was substituted with a second, phosphated, macromonomer, meaning that these thickeners each contained two types of macromonomers. These thickeners were then introduced into a standard latex coating formulation. By comparing the rheology profiles of the different coatings it was possible to determine the thickening efficiencies of the different thickeners. These coatings were also evaluated for their viscosity stability when tinted with a universal colorant. The HASE thickeners containing the second phosphated macromonomer showed superior thickening efficiency. All six coatings showed excellent stability on tinting with a universal colorant. Following the second route of investigation, eight universal colorant formulations consisting of only one polymeric dispersant in each of the formulations as sole wetting and dispersing additive were made up. A commercially available universal colorant was used as standard against which the new formulations were tested. The colorants were tested for color strength, their compatibility with the different coating groups, and the rheology profiles of the tinted vs. untinted coating systems. The two colorant formulations that contained EFKA 4550 as the polymeric dispersant performed very well in all the coating groups. / AFRIKAANSE OPSOMMING: Daar is 'n afname in viskositeit wanneer universele kleurstowwe by die lateks-bedekkingsisteem gevoeg word. Twee verskillende roetes is gevolg om die probleem te ondersoek. Die eerste was om die verdikkingsmeganisme van die bedekkingsisteem te ondersoek. Vir die doel is ses verskillende hidrofobies gemodifiseerde alkali-oplosbare (HASE)-verdikkers gesintetiseer. Die tweede was om nuwe kleurkonsentraatformulerings saam te stel. Die HASE-verdikkers bestaan uit akrielsuur en 'n tweede assosiatiewe monomeer. Die assosiatiewe monomeer (makromonomeer) bevat 'n langketting-hidrofiliese segment, met 'n hidrofobiese endgroep. Die hidrofiliese segment bestaan uit herhalende oksi-etileen eenhede, tussen die etileniese onversadigdheid aan die een punt van die molekuul en die hidrofobiese endgroep aan die ander punt. Drie verskillende makromonomere is voorberei deur die koppeling van die hidroksiel-endgroepe van drie kommersieel beskikbare anioniese sepe met akrielsuur of akriloielchloried. 'n Baie hoër opbrengs van makromonomere is verkry toe die anioniese sepe met die akriloielchloried gereageer is. Ses HASE-verdikkers is gesintetiseer deur middel van vrye radikaal addisie polimerisasie. Die eerste drie HASE-verdikkers het dieselfde ruggraatlengte en elke verdikker bevat een tipe hidrofobiese makromonomeer. Die hidrofobiese makromonomere verskil in die lengte van hul herhalende oksi-etileen eenhede. Die hidrofobiese makromonomere bevat of 20, 50 of 100 oksietileen eenhede. Die volgende drie HASE-verdikkers stem baie ooreen met die eerste drie behalwe dat 5% van die akrielsuur in die ruggraat vervang is deur 'n tweede, fosfaatbevattende makromonomeer, wat beteken dat hierdie verdikkers elk twee tipes makromonomere bevat. Hierdie verdikkers is in 'n standaard lateks bedekking formulering gevoeg. Deur die vergelyking van die reologie profiele van die verskillende bedekkings was dit moontlik om die verdikkings effektiwitiet van die verskillende verdikkers te bepaal. Hierdie bedekkings is ook geevalueer vir hulle viskositeits stabiliteit as dit met 'n universele kleurstof gekleur word. Die HASE-verdikkers wat die tweede fosfaatbevattende makromonomeer bevat, het uitstekende verdikkings effektiwiteit getoon. Al ses bedekkings het uitstekende stabiliteit getoon tydens kleuring met 'n universele kleurstof. Deur die tweede roete van ondersoek te volg, is agt universele kleurstof formulerings wat bestaan uit slegs een polimeriese dispergeermiddel opgemaak. 'n Kommersieel beskikbare universele kleurstof is gebruik as standaard waarteenoor die nuwe formulerings getoets is. Die kleurstowwe is getoets vir kleursterkte, hul verenigbaarheid met die verskillende bedekkingsgroepe, en die reologie profiele van die gekleurde teenoor die ongekleurde bedekkingsisteme. Die twee kleurstof formulerings wat EFKA 4550 as die polimeriese dispergeer middel bevat, het baie goed gevaar in al die bedekkingsgroepe.

Given the explosion in human genetic data, new high-throughput genetic methods are necessary for studying variants and elucidating their role in human disease. In Chapter I, I will expand on this concept and describe current methods for genetically modifying human cells. In E. coli, Multiplex Automatable Genome Engineering (MAGE) is a powerful tool that enables the targeting of multiple genomic loci simultaneously with synthetic oligos that are recombined at high frequencies in an optimized strain. MAGE as a method has two components: organism-specific optimization of oligo recombination parameters and a protein capable of increasing recombination frequencies.

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Gas cleaning is an essential step in many chemical processes. The reason for cleaning is to remove components that can damage equipment or inhibit further reactions. The treatment can include the removal of particulates, removal of one or more chemical species, or the conversion of one species to another. The gases include natural gases, combustion gases or synthesis gas (syngas). Of particular importance is the hot gas desulphurization (HGD) of syngas after gasification. This method of treatment offers potential energy and raw material savings to traditional ‘wet’ gas cleaning methods, such as physical or chemical absorption. Syngas is a valuable intermediate product because it can be processed into a number of different chemicals. These range from hydrocarbon chains (Fischer-Tropsch reactions), methanol, and ammonia (from hydrogen in the syngas). Methanol and ammonia are important raw materials to produce other chemicals. Syngas can be used for production of electricity via gas turbines in an Integrated Gasification Combined Cycle (IGCC) plant. In this study, a laboratory scale gasification and desulphurization unit was designed and constructed for removal of hydrogen sulphide (H2S) from syngas. The gasifier operates at moderately high temperature (700-900 °C) and low pressure (1-3 bar g) to produce syngas containing H2S (1-6 mol %) from a liquid hydrocarbon fuel mixture and oxygen. Desulphurization occurs in a fixed bed isothermal reactor (300-600 °C) whereby H2S is removed by chemical reaction with a sorbent. The fuel used was a mixture of methanol and ipropanethiol and the sorbent chosen was zinc oxide. The apparatus was tested to obtain a reliable experimental method. A series of experiments were conducted to determine two results: Firstly, to see the performance of the unit during repeated sorbent testing (i.e. a systematic experimental run programme). Secondly, to determine the effect of some process variables (temperature, flowrate and particle size) on the conversion of sorbent. GC analysis of the syngas showed consistent gas composition during the experiment, an important result which justifies this new method of syngas production from a liquid fuel. The final conversions from ZnO to ZnS ranged from 2-12 mole %. However, there was some variation under repeated conditions, which showed the need for additional method development. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.