Bakgrund: Utvecklingen inom informationsteknik (IT) har skapat många möjligheter för samhället, vilket har lett till framgångsrika IT-bolag som erbjuder digitala produkter och tjänster. IT-sektorn har en hög tillväxttakt vilket attraherar investeringar och skapar jobbmöjligheter. Trots detta är risken att misslyckas inom IT-sektorn hög, och många nystartade IT-bolag överlever inte de första åren på grund av den dynamiska och komplexa miljön de verkar i. Inom IT-sektorn finns det tusentals nystartade bolag, och begreppen 'start-up' och 'scale-up' används för att beskriva dessa. Ett start-ups är ett ungt bolag i ett tidigt utvecklingsstadie, medan scale-up är ett bolag som har nått nästa tillväxtfas och strävar efter att öka sin omsättning och etablera sin marknadsposition. Ledarskapet i dessa miljöer har visat sig spela en avgörande roll för framgång i både start-ups och scale-ups, då miljön är ytterst osäker och snabbföränderlig. Däremot är det fortfarande oklart vilken typ av ledare, och mer specifikt vilka ledarskapskompetenser, som bidrar till ett framgångsrikt start-up respektive scale-up. Tidigare forskning pekar även på att ledarskap är högst kontextrelaterat, och att de ledarskapskompetenser som är viktiga i en kontext inte behöver vara densamma i en annan. Ledarskapskompetenser bör därmed identifieras och utvecklas för att säkerställa att ledaren innehar rätt färdigheter, kunskap, beteende och egenskaper som krävs för att nå strategiska mål och prestationsförväntningar i den specifika miljön.  Syfte: Studiens syfte är att undersöka och få en ökad förståelse för vilka ledarskapskompetenser som associeras med framgång vid IT-bolags tillväxtfaser, start-up respektive scale-up. Metod: Studien har ett kvalitativt tillvägagångssätt och utgår från en hermeneutisk ansats eftersom den syftar till att förstå och tolka företeelser inom det valda forskningsområdet. Vidare används en abduktiv ansats, vilket medför att forskare i denna studie växlar mellan empirisk och teoretisk reflektion. För insamling av empiri har semistrukturerade intervjuer nyttjas med noga utvalda respondenter. Insamlad empiri har sedan analyserats genom en tematisk analys. Slutsats: Studiens resultat visar att det inte är någon markant skillnad mellan de ledarskapskompetenser som associeras med framgång i respektive tillväxtfas. Det tillkommer däremot några ledarskapskompetenser när bolaget skalar upp som relaterar till en ökad arbetsstyrka, vilket kräver mer fokus på struktur och omsorg av medarbetare. Vidare så pekar studiens resultat på att de ledarskapskompetenser som krävs i båda faserna kan behövas nyttjas annorlunda och till olika ändamål. De ledarskapskompetenser som anses krävas i båda tillväxtfaserna är visionär, uthållig, riskbenägen, strategisk, kundfokuserad, kunskapsorienterad, rekryteringsförmåga, omhändertagande, anpassningsbar och flexibel. De ledarskapskompetenser som tillkommer i scale-up är strukturförmåga, förtroende, kommunikativ och kunskapsöverförande.

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The cleaning and dewatering of ultrafine (minus 44 micron) coal slurries is one of the biggest challenges faced by coal industry. Existing commercial technologies cannot produce sellable products from these ultrafine streams; therefore, the industry is forced to discard this potential energy resource to waste impoundments. This practice also has the potential to create an environmental hazard associated with blackwater pollution. To address these issues, researchers at Virginia Tech have worked over the past decade to develop a novel separation process that simultaneously removes both mineral matter and surface moisture from fine coal particles. The first stage of the process uses immiscible non-polar liquids, such as straight chain hydrocarbons, to selectively agglomerate fine coal particles in an aqueous medium. The agglomerates are then passed second stage of processing where mild agitation is used to disperse and fully engulf hydrophobic coal particles into the non-polar liquid and to simultaneously reject any residual water and associated hydrophillic minerals entrapped in the agglomerates. The non-polar liquid, which has a low heat of evaporation, is then recovered by evaporation/condensation and recycled back through the process. The research work described in this document focused on the engineering development of this innovative process using batch laboratory and continuous bench-scale systems. The resulting data was used to design a proof-of-concept (POC) pilot-scale plant that was constructed and successfully demonstrated using a variety of fine coal feedstocks. / Ph. D.

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[pt] No presente trabalho foi investigada a microfabricação de reatores fotocatalíticos de polidimetilsiloxano (PDMS) para o estudo comparativo de aumento de escala entre micro- e mesorreatores, e lignocelulósicos de bambu para reação de cicloadição alcino-azida catalisada por cobre(I) (CuAAC) em fluxo contínuo. Nesse cenário, foi desenvolvida uma configuração experimental de scale-up e numbering-up de sistemas meso- e microfluídicos fotocatalíticos, respectivamente, para comparar a eficiência de fotodegradação de TiO2/P25 em rodamina B (RB) e azul de metileno (em inglês, Methylene Blue, MB) sob irradiação UV. Os resultados obtidos sugerem que o aumento do volume (scale-up) reduz os valores de D(por cento), enquanto que numbering-up mantém a eficiência fotocatalítica com redução significativa do tempo de reação. M6-60 (micro)L apresentou melhor desempenho entre os dispositivos, com degradação total do MB (1,2 x 10-5 mol L-1) em apenas 1h, e foto-oxidação total de fenol (1,2 x 10-4 mol L-1) em 4h. Além disto, M6-60 (micro)L apresentou menor consumo de energia elétrica por ordem (0,012 kWh m-3) e maior rendimento quântico (2,6 x 10-2) em comparação com os outros dispositivos. O desenvolvimento de suportes sólidos lignocelulósicos apresentou importantes características para os processos de funcionalização de TEMPO-TAL com íons Cu(II) e Zn(II) e CuNPs. Os suportes foram devidamente caracterizados por MEV/EDS e FT-IR. Os resultados para a reação de CuAAC mostraram rendimentos de 79-82 por cento com reciclabilidade de até 7 vezes e lixiviação média de cobre de 1,30 ppm, e foram importantes para o desenvolvimento do microrreator de bambu. A microfabricação do microrreator lignocelulósicos de bambu (L(micro)R) foi realizada a partir de etapas de cortes, sem utilização de técnicas caras e sala limpa. L(micro)R mostrou fácil prototipagem e rápida oxidação com N-oxil-2,2,6,6-tetrametilpiperidina (TEMPO) e funcionalização com íons cobre (Cu-L(micro)R) e nanopartículas de cobre (CuNPs-L(micro)R). O desempenho de CuAAC em fluxo contínuo do Cu-L(micro)R foi demonstrado através da realização de estudos de reciclabilidade e rendimentos em diferentes taxas de fluxo (0,1 a 0,8 mL min-1). Cu-L(micro)R apresentou rendimentos de 60 por cento a 96 por cento para 5 tipos de reações CuAAC, indicando promissora aplicação na área de catálise em dispositivos microfluídicos. Todas as reações foram realizadas em regime de fluxo com MeOH:H2O (2:1) e lixiviação de cobre inferior a 6,0 ppm, produzindo uma série de 5 derivados de 1,2,3-triazol 1,4-dissubstituídos com boa eficiência em um ambiente com poucos recursos. CuNPs-L(micro)R apresentou limitação para realização de CuAAC por não alcançar as condições ideais de aquecimento, exigidas para ocorrência da reação. / [en] The present work had two main objectives. The first refers to the development of polydimethylsiloxane photocatalytic microreactors (PDMS) for the comparative scale-up study between micro- and mesoreactors. The second focused on the development of bamboo lignocellulosic microreactors for copper(I) catalyzed alkine-azide cycloaddition reaction (CuAAC). In this scenario, an experimental scale-up and numbering-up configuration of photocatalytic meso- and microfluidic systems were developed, to compare, respectively, the photodegradation efficiency of TiO2-P25 in rhodamine B (RB) and methylene blue (MB) under UV irradiation. The obtained results suggest that the scale-up reduces the values of D (percent), while numbering-up maintains the photocatalytic efficiency with a significant reaction time reduction. The best photocatalytic microfluidic system was M6-60 (micro)L, which presented total MB degradation (1.2 x 10-5 mol L-1) in only 1h, and total phenol photo-oxidation (1,2 x 10-4 mol L-1) in 4h. Furthermore, M6-60 (micro)LM6 had lower electrical energy consumption (0,012 kWh m-3) and higher quantum yield (2,6 x 10-2) compared to others. The development of solid lignocellulosic supports showed important characteristics for the TEMPO-TAL functionalization processes with Cu(II), Zn(II) ions and CuNPs. The supports were properly characterized by SEM/ EDS and FT-IR. The results for the CuAAC reaction showed yields of 79-82 percent with recyclability of up to 7 times and average copper leaching of 1.30 ppm, and were important for the development of the bamboo microreactor. The microfabrication of the bamboo lignocellulosic microreactor (L(micro)R) was performed from cutting steps, without using expensive techniques and clean room. L(micro)R showed easy prototyping and rapid oxidation with N-oxyl-2,2,6,6-tetramethylpiperidine (TEMPO) and functionalization with copper ions (Cu-L(micro)R) and copper nanoparticles (CuNPs-L(micro)R). Cu-L(micro)R continuous flow CuAAC performance was demonstrated by conducting recyclability and yield studies at different flow rates (0.1 to 0.8 mL-1). Cu-L(micro)R presented 60 percent to 96 percent yields for 5 types of CuAAC reactions, indicating promising application in the area of catalysis in microfluidic devices. All reactions were performed under a MeOH:H2O (2:1) flow regime and copper leaching below 6.0 ppm, producing a series of 5 efficiently 1,4-disubstituted 1,2,3-triazols derivatives in a resource-poor environment. CuNPs-L(micro)R presented limitation for CuAAC because it did not reach the ideal heating conditions required for the reaction to occur.

Prior to 1998 charter schools in the Commonwealth of Virginia were non-existent. Students who wanted to be educated in ways alternative to public education would need to seek out private schools or homeschooling. The Patrick Henry School of Arts and Sciences (PHSSA), a year round elementary charter school in the City of Richmond, is the first elementary charter school in Virginia. The purpose of this study was to describe and analyze the events and actions that led to the establishment and operation of PHSSA, as a public charter school. The main research question for this study is, what has occurred and had to be overcome in order to enable the first elementary public charter school in the Commonwealth of Virginia to be approved and to continue as a charter, renewed twice for a total existence of 10 years? This research provides recommendations for those seeking to implement and continue the renewal of a charter school where the authorizer is a local school board. Participants interviewed were representatives of the community--parents and community leaders--who were involved in the startup of Patrick Henry at various stages of its existence. A systematic method of document review and structured interviews of key informants was conducted. Analysis revealed the problems and successes of this elementary charter school. Outcomes from the interviews should foster understanding of the creation and continued renewal of charter schools in Virginia. The study may provide counsel for future public charter school endeavors in the Commonwealth. / Doctor of Education / Public charter schools in the Commonwealth of Virginia began with the authorization of public charters in 1998. As written in the Code of Virginia (§ 22.1-212.5): Public charter schools in Virginia are nonsectarian, nonreligious, or non-home-based alternative schools located within a public school division. The Patrick Henry School of Arts and Sciences (PHSSA), a year-round elementary charter school in the city of Richmond, is the first elementary charter school in Virginia. The purpose of this study was to describe and analyze the events and actions that led to the establishment and operation of PHSSA. This study provides recommendations for those seeking to implement and continue the renewal of a charter school. Participants interviewed were representatives of the community--parents and community leaders--who were involved in the startup of PHSSA. Outcomes from the interviews should provide understanding of the creation and continued renewal of charter schools in Virginia. It also may provide guidance for future public charter school endeavors in the Commonwealth. .

No / Mechanochemical synthesis, i.e., reactions conducted by grinding solid reactants together with no or minimal solvent, has been demonstrated as an excellent technique for the formation of both organic and inorganic compounds. Mechanochemistry is viewed as an alternative approach to chemical synthesis and is not always considered when developing manufacturing processes of fine chemicals. Here, recent advances are highlighted regarding mechanochemical synthesis, by utilizing a well‐developed continuous technique – extrusion, and the advantages it offers to further support its use in the manufacturing of these chemicals. To put this work into context, it is shown how extrusion plays a vital role for manufacturing in the food, polymer, and pharmaceutical industries, and how the research carried out by these respective industrialists provides great insight and understanding of the technique, with the results being applicable in the chemical industry. The synthesis of metal–organic frameworks (MOFs) is highlighted herein as an excellent example showcasing the advantages that extrusion provides to the manufacture of these materials, one advantage being the exceptional space time yields (STYs) reported for these processes, at three orders of magnitude greater than conventional (solvothermal) synthesis. / EPSRC. Grant Number: EP/L019655/1

Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Over the last few decades, wave run up prediction has gained the interest of numerous researchers and every newly-published paper has aimed to predict wave run up with greater accuracy. Wave run up is defined as the vertical elevation reached by a wave's, front water edge as it runs up a beach, measured relative to the still water line. Wave run up is dependent on the incidental wave height, the wave period, the beach slope and the wave steepness. The majority of publications incorporate all of these factors, but some do not, which has led to numerous debates. The goal of this study is to do a re-assessment of previously published wave run up formulae, to obtain a more informed understanding about wave run up and the available predictive empirical formulae. The study also seeks to evaluate the Mather, Stretch & Garland (2011) formula. The method for undertaking this objective comprised a physical model test series with 10 regular wave conditions on a constant slope, being 1/24, performed with an impermeable floor. Also, a beach study in the field was done on Long Beach, Noordhoek, where run up measurements were taken for 30 minute intervals, resulting in five test conditions. A numerical model was employed in conjunction with the beach study to determine the local offshore wave parameters transformed from a deep water wave rider. This information was used to correlate the run up measurements with known wave parameters. Firstly, the physical model assessment was performed to provide a proper foundation for run up understanding. Plotting empirical normalised run up values (R2/H0 ) versus the Iribarren number for different formulae, a grouping was achieved with upper and lower boundaries. The physical model results plotted on the lower end of this grouping, resulted in prediction differences of more than 10%. These differences may have been caused by the unevenness of the physical model slope or the fact that only one slope had been tested. Despite this, the results fell within a band of wave run up formulae located on the lower end of this grouping. An assessment of the beach measurements in the field gave a better correlation than the physical model results when compared to normalised predicted wave run up formulae. These measurements also plotted on the lower end of the grouping, resulting in prediction differences of less than 10% for some empirical formulae. When comparing these empirical predictions to one another, the results demonstrate that the formulae comparing best with the beach measurements were Holman (1986) and Stockdon, Holman, Howd, & Sallenger Jr. (2006). Extreme over predictions were found by Mase & Iwagaki (1984), Hedges & Mase (2004) and Douglass (1992). Nielsen & Hanslow (1991) only compared best with the beach measurements and De la Pena, Sanchez Gonzalez, Diaz-Sanchez, & Martin Huescar (2012) only compared best to the physical model results. This study supports the formula proposed by Mather, Stretch, & Garland (2011). Applying their formula to the measured results presented a C constant of 3.3 for the physical model and 8.6 for the beach results. Both values are within the range prescribed by the authors. Further reasearch minimized the array of possible „C‟ values by correlating this coefficient to Iribarren numbers. „C‟ values between 3.0~5.0 is prescribed for low Iribarren conditions (0.25-0.4) and values between 7.0~10 for higher Iribarren conditions are 0.75-0.8. However, this formula is still open for operator erros whereby the „C‟ value has a big influence in the final result. The best formulae to use, from results within this thesis, is proposed by Holman (1986) and Stockdon et.al (2006). These formulae are not open to operator erros and uses the significant wave height, deep water wave length and the beach face slope to calculate the wave run up. / AFRIKAANSE OPSOMMING: Gedurende die afgelope paar dekades, het golf-oploop voorspellings die aandag van talle navorsers gelok en elke nuwe geskrewe voorlegging het gepoog om meer akkurate golf-oploop voorspellings te verwesenlik. golf-oploop kan definieer word as die vertikale elevasie bereik deur 'n golf se voorwaterkant soos dit op die strand uitrol, gemeet relatief vanaf die stilwaterlyn. golf-oploop is afhanklik van die invals-golfhoogte, die golfperiode, die strandhelling en die golfsteilheid. Die oorgrote mederheid publikasies uit die literaturr inkorporeer al hierdie faktore, maar sommige nie, wat groot debatvoering tot gevolg het. Die doel met hierdie studie is om vorige gepubliseerde golf- oploop formules te re-evalueer, om 'n meer ingeligte begrip van golf- oploop en beskikbare voorspellende formules te verkry. Die studie poog terselfdertyd ook om golf-opvolg tendense, uniek aan Suid Afrikaanse strande te evalueer deur die huidige formule wat tans hier gebruik word, te assesseer. Om hierdie doelwit te bereik, is gebruik gemaak van 'n fisiese model toets reeks bestaande uit 10 reëlmatige golfstoestande op 'n konstante ondeurlaatbaare strandhelling van 1/24. 'n Veldstudie was ook uitgevoer op Langstrand, Noordhoek, waar golf-oploopmetings met 30 minute tussenposes uitgevoer is, vir vyf toets-toestande. Tesame met die veldstudie, is 'n numeriese model aangewend om die gemete diepsee data nader ann die strand wat bestudeer is te transformeer. Hierdie inligting is benodig om 'n verband tussen tussen oploop-metings en bekende golf parameters te bepaal. Eerstens is die fisiese model assessering uitgevoer om 'n behoorlike basis vir die begrip van golfoploop in die veld te verkry. Deur die emperiese, genormaliseerde oploop waardes (R₂/H₀) vir verkeie formules teenoor die Iribarren getal te plot, is 'n groepering met hoër en laer grense gevind. Daar is gevind dat die fisiese modelwaardes op die laer grens plot, en het verskille met die emperiese waardes van meer as 10% getoon. Hierdie verskille is moontlik veroorsaak as gevolg van 'n oneweredige fisiese model strandhelling of deur die feit dat slegs een helling getoets is. Ten spyte hiervan, het die model oploop waardes binne die bestek van golf- oploop formules geval. Assessering van die veldmetings het 'n beter korrelasie as die fisiese modelresultate getoon, tydens vergelykings met genormaliseerde golf-oploop formules van die emperiese formules. Die oploop waardes van hierdie metings het ook geplot aan die laer grens van die groepering, met verskille van minder as 10% vir die meeste gevalle van die emperiese formules. Wanneer hierdie emperiese voorspellings vergelyk word, is gevind dat die formules wat die beste ooreenstem met die fisiese model, die van Holman (1986) en Stockdon, Howd, & Sallenger Jr. (2006) is. Die emperiese formules van Mase & Iwagake (1984), Hedges & Mase (2004) en Douglas (1992) het die golf-oploop oorvoorspel. Nielsen & Hanslow (1991) het slegs die beste met die strandmetings vergelyk, terwyl De la Pena, Sanchez Gonzalez, Diaz-Sanchez & Martin Huescar (2012) slegs die beste vergelyk het met die fisiese-model resultaat. Hierdie studie ondersteun die formule voorgestel deur Mather, Stretch, & Garland (2011). Deur hul formules op die gemete bevindings toe te pas, is 'n C konstante van 3.3 vir die fisiese model resultate, en 8.0 vir die stranduitlslae bepaal. Beide waardes lê binne die grense wat deur die outeurs voorgestel is. Verdere navorsing het getoon dat moontlike waardes vir die „C‟ konstante tussen 3.0 en 5.0 moet wees vir Iribarren waardes van tussen 0.25 en 0.4. Vir hoër Iribarren waardes, 0.75-0.8, moet die „C‟ kosntante tussen 7.0 en 10 wees; dog is die formule steeds oop vir operateur foute. Die hoofbevindinge van die tesis is gevind dat die beste golf-oploop formules, om tans te gebruik, die van Holman (1986) en Stockdon et.al (2006) is. Hierdie formules kan glad nie beinvloed word deur operateurs foute nie en maak gebruik van die invals golfhoogte, die golfperiode en die strandhelling om die golf-oploop te bepaal.