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Attempted synthesis of a (14)annuleno(14)annulene and conformational studies of some dithia(3.1.3.1)metacyclophanes, (2.1.2.1)metacylophanes and (2.1.2.1)metacyclophanedienesLai, Yee-Hing 07 April 2014 (has links)
Graduate / 0485
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Attempted synthesis of a (14)annuleno(14)annulene and conformational studies of some dithia(3.1.3.1)metacyclophanes, (2.1.2.1)metacylophanes and (2.1.2.1)metacyclophanedienesLai, Yee-Hing 07 April 2014 (has links)
Graduate / 0485
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Renewable energies management strategy challenges in the Arabian Gulf countriesAloughani, Muhammad January 2015 (has links)
The main source of energy in the Gulf Cooperation Council (GCC) remains fossil fuels (oil and gas). The massive and accelerated used of such sources of energy not only depletes the traditional energy sources in those states and thus undermines exports and long-term prosperity; it also causes devastating damages to the environment and to human health. The nature of the Arabian Peninsula is very suitable for renewable energy sources (RES), thus many GCC states have started to consider those resources for their future energy plans. Like any technology, renewable energy technologies (RET) face many challenges such as economic, technical, social and environmental. This research analyses renewable energy (RE) possibilities and barriers in the GCC states in depth, using Kuwait as a case study. Questionnaires were distributed to three different groups to measure their attitudes and knowledge with regard to RE. Moreover, this research investigates the economic and environmental implications of RES adoption for Kuwait. A cost analysis between the traditional energy generated by the Ministry of Electricity and Water (MEW) using oil and gas, and RE energy generated by Al- Shagaya project has been carried out. It was found that most participants were environmentally aware of fuel issues and supported RE; they were prepared to forego subsidies on traditional energy to promote RE, but they doubted the government’s ability to implement RE successfully. Although Al-Shagaya Project was targeted to contribute up to 15% of Kuwait’s total power production by 2030, the cost analysis presented in this thesis revealed that the energy generated from the Al-Shagaya Project accounts for only 2% the energy needs projected at 2030, therefore current plans would only reduce CO2 emissions by 2% by 2030, but a program was proposed whereby larger investment would cause a 92% reduction in costs and reduce CO2 emissions to zero within the same timeframe.
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Simulation of Crystal Nucleation in Polymer MeltsKawak, Pierre 03 August 2022 (has links)
Semicrystalline polymers are an important class of materials for their prevalence in today's markets and their desirable properties. These properties depend on the early stages of the polymer crystallization process where a crystal nucleates from the polymer melt. This nucleation process is conventionally understood via an extension of Classical Nucleation Theory to polymers (CNTP). However, recent experimental and simulation evidence points to nucleation mechanisms that do not agree with the predictions of CNTP. Specifically, these experiments suggest a previously unrecognized role of nematic phases in mediating the melt"“crystal transtion. To explain these observations, several new theories of nucleation alternate to CNTP have emerged in the literature, all of which suggest specific modifications to the free energy landscape (FEL) near-equilibrium. To address these theoretical controversies, this dissertation aimed to study the equilibrium phase behavior of polymers via Monte Carlo (MC) simulations. Simulating equilibrium phase behavior of polymer melts is not a trivial task due to the large free energy barriers involved. Throughout this research, we employed a combination of strategies to speed up these molecular simulations. First, we employed a domain decomposition to divide the simulation box into multiple independent simulations that execute independent MC trajectories in parallel. The novel GPU-accelerated MC algorithm successfully and accurately simulated the phase behavior of bead spring chains. Additionally, it sped up MC simulations of Lennard Jones chains by up to 10 times. In its current form, the GPU-accelerated algorithm did not achieve significant speedups to improve outcomes of simulating large polymer melts with detailed potentials. We recommended various strategies to improving the current algorithm. This reality motivated the use of biased MC simulations to study the phase behavior of polymers more expediently without the need for GPU acceleration. Specifically, the latter part of the Dissertation employed Wang Landau MC (WLMC) simulations to build phase diagrams and expanded ensemble density of states (EXEDOS) simulations to construct FELs. Phase diagrams from WLMC simulations divided volume-temperature space into melt, nematic and crystal phases. Then, FELs from EXEDOS simulations at equilibrium provided direct access to the relative stability and minimum free energy paths between coexistant states. By employing a two-dimensional EXEDOS sampling in both crystal and nematic order for hard bead semiflexible oligomers with a stepwise bending stiffness, we built FELs that show that the crystalline transition cooperatively and simultaneously formed crystal and nematic order. This nucleation mechanism was not in agreement with predictions from CNTP or newer theoretical formulations. To investigate the sensitivity of the phase behavior to the employed polymer model, we then employed WLMC simulations to build phase diagrams for a number of different polymer models to ascertain their impact on the resulting nucleation mechanism. We found that the phase behavior was sensitive to the form of the bending stiffness potential used. Chains with a stepwise bending stiffness yielded the previously mentioned cooperative and simultaneous crystal and nematic ordering. In contrast, chains with a harmonic bending stiffness potential crystallized via a two-step nucleation process, first forming a nematic phase that nucleates the crystal. The latter nucleation mechanism was in line with predictions from new theories of nucleation that incorporate the nematic phase as a precursor. Furthermore, we found that it is important to correct for excluded volume differences when comparing chains with soft and hard beads or chains with differing bending stiffnesses.
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Energy Services in ShanghaiDe Geer, André, Melander, Mathias January 2013 (has links)
The People’s Republic of China (PRC) is one of the fastest growing economies in the world. However, the economic expansion is not without complications. Improved standard of living and a growing industrial sector have led to an increased demand of energy, which in turn is contributing to air pollution and land contamination. The research problem of the study is what is keeping existing Energy Services (ES) in Shanghai from being used more frequently. To answer this, a sequential mixed method study is conducted, divided into a qualitative and quantitative part. The literature study indicates a great potential for ES in Shanghai. This is mainly due to great efforts taken in Energy Efficiency (EE), an attempt to face the rapidly increasing population by reducing the usage of energy. A number of barriers for ES are found throughout the existing literature, including market, financial, institutional as well as technological barriers. To further investigate barriers and opportunities on the ES market in Shanghai, 14 semi-structured interviews with relevant stakeholders and academics were conducted. Hypothesizes were formulated based on results from the interview and literature study as well as an expert panel. To test the hypotheses a questionnaire was sent out to real estate developers in Shanghai. This study discovers the need of bringing several in the literature identified barriers to ES in Shanghai up to date. Some barriers were found to be invalid while others were not identified at all. The newly found barriers include market barriers, such as ES having low priority, poor technological understanding among clients, and complications approaching and communicating with potential clients. For institutional barriers, it was found that the prevalence of low margins in the Chinese industries is holding back stricter regulations. Furthermore, the Energy Service Companies’ (ESCO) lack of understanding of ES from a system perspective is considered a technology barrier. In addition to the barriers, a number of opportunities were found. Improved communication between real estate stakeholders and ESCOs contribute to greater awareness and knowledge, which in turn leads to a higher degree of investment in ES. Differentiation of the services offered by ESCOs may attract new customers who previously were not interested, e.g. companies with short investment horizon. In Shanghai, there are a significant number of subsidies, regulations and laws favoring ES. Moreover, the rapid growth of Shanghai is considered one of the greater opportunities. To conclude, it was found that the maturity level among ESCOs in Shanghai was having large impact on the overall usage of ES. Fixed barriers, i.e. barriers nearly impossible to overcome, together with the large amount of small and inexperienced ESCOs is found to be hindering ES in the Shanghai commercial real estate sector from being used more frequently. / Kina ett är en av de snabbast växande ekonomierna i världen. Den ekonomiska expansionen är emellertid inte helt utan problem. Med bättre levnadsstandard och en allt större industrisektor ökar behovet av energi explosionsartat med förorenad mark och luft som följd. Studiens problemformulering är vad det är som hindrar befintliga energitjänster i Shanghais byggnadssektor från att användas oftare. För att svara på denna fråga användes en sekventiellt multidisciplinär metod uppdelad i en kvalitativ och- kvantitativ studie. Utifrån litteraturen är det uppenbart att det finns en stor potential för användning av energitjänster i Shanghai. Främst till följd av stora satsningar på energieffektivitet i ett försök att möta den snabbväxande befolkningen med högre krav på levnadsstandard genom att minska energianvändningen. Ett antal hinder existerar emellertid inom Shanghais energitjänstemarknad. Inom dessa inkluderas allt ifrån marknads- och finansiella problem till institutionella och teknologiska komplikationer. För att vidare undersöka vilka problem och möjligheter det finns för energitjänster i Shanghai genomfördes 14 semi-strukturerade intervjuer med involverade aktörer och akademiker i Shanghai. Baserat på resultatet från intervjuerna tillsammans med litteraturstudien och en expert panel formulerades hypoteser härrörande energitjänstesituationen. För att testa hypoteserna genomfördes en enkätundersökning riktad till fastighetsutvecklare i Shanghai. Studien visade att många av de tidigare utpekade hindren för energitjänster i Shanghai behövdes uppdateras, varav vissa visade sig vara obsoleta och några inte gick att verifiera. Bland de nyfunna barriärerna kan nämnas marknadsbarriärer som låg prioritering för energitjänster, låg teknisk kompetens bland fastighetsägare samt svårigheter för energitjänstebolag att närma och kommunicera med potentiella kunder. För de institutionella barriärerna framgick att låga marginaler inom den kinesiska industrin håller tillbaka hårdare regleringar. Inom de tekniska barriärerna framkom att energitjänstebolag generellt sett brister i deras kunskap om energitjänster som kan tillgodose hela byggnaders energisystem. Utöver problemen identifierades även betydande möjligheter. Ökad kommunikation mellan aktörerna bidrar till större kunskap vilket i sin tur leder till en högre grad av energitjänsteinvesteringar. Genom att differentiera de tjänster energitjänsteföretag erbjuder kan de hitta nya kunder som tidigare inte varit intresserade, framförallt sådana med kort investeringshorisont. I Shanghai finns det ett betydande antal subventioneringar, regler och lagar som gynnar energitjänster. Även Shanghais tillväxt ses som en av de stora möjligheterna. Studien kommer fram till att en låg mognadsgraden bland energitjänstebolag i Shanghai negativt påverkan användningen av energitjänster. Existensen av flera fasta barriärer, barriärer som är svåra att påverka, tillsammans med det faktum att majoriteten av energitjänstebolag är små och oerfarna ses som den främsta orsaken till att energitjänster inte används i större utsträckning i Shanghai.
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