Dissertations / Theses on the topic 'Energetic evaluation'

In this study, a cylinder expansion test was performed using a square prism OFHC copper with a cylindrical extrusion filled with Comp B explosive charge. A Valyn VISAR was used as a measuring tool to record the expansion history of the cylinder by Doppler shift of the light reflected off its surface, which subsequently was used to obtain the velocity history of the square prism cylinder. Quadrature fringe signals obtained from the square prism cylinder test were analysed using the results still showing some traces of fringe jumps. Whereas the hands-on calculations were more precise in correcting the jumps. This introduced some shifts in the velocity results VISAR Push-Pull reduction software and hands-on calculations. The outcome of the two velocity graphs (reduction software and manual) did not correspond. This might be due to the software velocity which caused the variation in the two velocity results. Overall, both software and manual methods resulted in velocity values that were difficult to draw conclusions from. In an attempt to further understand the test results, the displacement curve were also reduced from the velocity graphs. Although the trend of the displacement graph obtained from the reduction software is comparable to the displacement graph published in literature for the same test, the magnitudes of the values are still difficult to explain. The cylinder design used in this study was tested for the first time and numerous challenges rose up during setup and execution and are discussed. It is important for another test to be conducted with an improved setup in order to achieve a reliable interpretation of the cylinder test results.
Dissertation (MSc)--University of Pretoria, 2020.
Physics
MSc
Unrestricted

The aim of this study was to evaluate the growth supporting value of DE derived from gut fermentation in growing pigs. Unmolassed sugar beet pulp (SBP) was selected as a model material for fermentation. For a reference material which would be digested in the small intestine by the endogenous enzymes, maize starch (MS) was selected. A cereal-based control diet was formulated to fulfil the needs of pigs for all essential nutrients apart from energy. To this control diet, either SBP (150 & 300 g/kg) or MS (100 & 200 g/kg) were added. The study consisted of two phases. The first phase (digestion trial and growth trial) was devoted to studying the digestion of these diets and to comparing the effects on growth of pigs of the two DE sources (SBP and MS). The second phase was to determine the production of VFA resulting from the fermentation of SBP. Methods used included stoichiometric calculations based on measurements of the molar proportions of VFA combined with CH4 production, and a direct assessment of the true fermented materials using antibiotics to suppress fermentation. The results of the first phase showed that the energy in SBP and MS had an apparent digestibility of 0.74 and 0.98. The DE from SBP was used for supporting carcass gain with an efficiency of 0.57 of the DE from MS. The results of the second phase indicated that measurements of methane production alone or even with inclusion of free hydrogen could underestimate the extent of fermentation in the gut of pigs. The results also suggest that with the cereal-based control diet, fermentation could supply up to 13.6% of the dietary DE in the form of VFA or 18.0% in the form of fermented energy. For this control diet incorporating 30% SBP, the respective values were 25.4% and 33.4%. The absorbed VFA resulting from the fermentation of SBP had a growth supporting value of 0.763 of that of absorbed glucose from MS.

Doutoramento em Engenharia Mecânica
The PhD project addresses the potential of using concentrating solar power (CSP) plants as a viable alternative energy producing system in Libya. Exergetic, energetic, economic and environmental analyses are carried out for a particular type of CSP plants. The study, although it aims a particular type of CSP plant – 50 MW parabolic trough-CSP plant, it is sufficiently general to be applied to other configurations. The novelty of the study, in addition to modeling and analyzing the selected configuration, lies in the use of a state-of-the-art exergetic analysis combined with the Life Cycle Assessment (LCA). The modeling and simulation of the plant is carried out in chapter three and they are conducted into two parts, namely: power cycle and solar field. The computer model developed for the analysis of the plant is based on algebraic equations describing the power cycle and the solar field. The model was solved using the Engineering Equation Solver (EES) software; and is designed to define the properties at each state point of the plant and then, sequentially, to determine energy, efficiency and irreversibility for each component. The developed model has the potential of using in the preliminary design of CSPs and, in particular, for the configuration of the solar field based on existing commercial plants. Moreover, it has the ability of analyzing the energetic, economic and environmental feasibility of using CSPs in different regions of the world, which is illustrated for the Libyan region in this study. The overall feasibility scenario is completed through an hourly analysis on an annual basis in chapter Four. This analysis allows the comparison of different systems and, eventually, a particular selection, and it includes both the economic and energetic components using the “greenius” software. The analysis also examined the impact of project financing and incentives on the cost of energy. The main technological finding of this analysis is higher performance and lower levelized cost of electricity (LCE) for Libya as compared to Southern Europe (Spain). Therefore, Libya has the potential of becoming attractive for the establishment of CSPs in its territory and, in this way, to facilitate the target of several European initiatives that aim to import electricity generated by renewable sources from North African and Middle East countries. The analysis is presented a brief review of the current cost of energy and the potential of reducing the cost from parabolic trough- CSP plant. Exergetic and environmental life cycle assessment analyses are conducted for the selected plant in chapter Five; the objectives are 1) to assess the environmental impact and cost, in terms of exergy of the life cycle of the plant; 2) to find out the points of weakness in terms of irreversibility of the process; and 3) to verify whether solar power plants can reduce environmental impact and the cost of electricity generation by comparing them with fossil fuel plants, in particular, Natural Gas Combined Cycle (NGCC) plant and oil thermal power plant. The analysis also targets a thermoeconomic analysis using the specific exergy costing (SPECO) method to evaluate the level of the cost caused by exergy destruction. The main technological findings are that the most important contribution impact lies with the solar field, which reports a value of 79%; and the materials with the vi highest impact are: steel (47%), molten salt (25%) and synthetic oil (21%). The “Human Health” damage category presents the highest impact (69%) followed by the “Resource” damage category (24%). In addition, the highest exergy demand is linked to the steel (47%); and there is a considerable exergetic demand related to the molten salt and synthetic oil with values of 25% and 19%, respectively. Finally, in the comparison with fossil fuel power plants (NGCC and Oil), the CSP plant presents the lowest environmental impact, while the worst environmental performance is reported to the oil power plant followed by NGCC plant. The solar field presents the largest value of cost rate, where the boiler is a component with the highest cost rate among the power cycle components. The thermal storage allows the CSP plants to overcome solar irradiation transients, to respond to electricity demand independent of weather conditions, and to extend electricity production beyond the availability of daylight. Numerical analysis of the thermal transient response of a thermocline storage tank is carried out for the charging phase. The system of equations describing the numerical model is solved by using time-implicit and space-backward finite differences and which encoded within the Matlab environment. The analysis presented the following findings: the predictions agree well with the experiments for the time evolution of the thermocline region, particularly for the regions away from the top-inlet. The deviations observed in the near-region of the inlet are most likely due to the high-level of turbulence in this region due to the localized level of mixing resulting; a simple analytical model to take into consideration this increased turbulence level was developed and it leads to some improvement of the predictions; this approach requires practically no additional computational effort and it relates the effective thermal diffusivity to the mean effective velocity of the fluid at each particular height of the system. Altogether the study indicates that the selected parabolic trough-CSP plant has the edge over alternative competing technologies for locations where DNI is high and where land usage is not an issue, such as the shoreline of Libya.
O projeto de Doutoramento aborda o potencial de usar centrais de energia solar concentrada (CSP) como um sistema de produção de energia alternativa disponível na Líbia. Uma análise nas vertentes exergética, energética, económica e ambiental foi realizada para um tipo particular destas centrais – um sistema de 50 MW com receção parabólica, porém ela é suficientemente geral para ser aplicada a outras configurações. A originalidade do estudo, para além da modelação e análise da configuração selecionada encontra-se na utilização do estado da arte em termos da análise exergética combinada com a avaliação do ciclo de vida (LCA). A modelação e simulação da central CSP selecionada são efetuadas no terceiro capítulo tendo em consideração as duas componentes: ciclo de potência e campo de coletores solar. O modelo computacional para a análise do sistema foi desenvolvido com base em equações algébricas que descrevem o sistema, e que são resolvidas usando o software EES. Deste modo, são definidas as propriedades em cada ponto de interesse para os diferentes elementos do sistema, o que assim permite determinar as energias, eficiências e irreversibilidades desses elementos. O modelo desenvolvido tem o potencial de se tornar uma ferramenta de grande utilidade para o projeto preliminar de engenharia de centrais CSP, e também para a avaliação da eventual reconfiguração de centrais elétricas solares comerciais em operação. Além disso, o modelo pode ser utilizado no estudo de viabilidade da operação de centrais CSP, através da análise energética, económica e ambiental, para regiões diferentes da que foi escolhida no presente estudo -Trípoli (Líbia). O cenário total da viabilidade da operação da central CSP é completado através da análise horária com base anual apresentada no quarto capítulo. Esta análise permite a comparação de diferentes sistemas e, eventualmente permite fazer a seleção com base nas componentes económicas e energéticas, que são determinadas dentro do contexto do software greenius. A análise também toma em conta o impacto de financiamento e incentivos dados aos projetos no custo da produção de energia. O principal resultado desta análise é a verificação que o desempenho é mais elevado, com o consequente menor custo nivelado da eletricidade, para a Líbia em comparação com o Sul da Europa (Espanha). Assim a Líbia tem o potencial de se tornar um candidato atrativo para o estabelecimento de centrais CSP com o objetivo, como foi considerado em várias iniciativas europeias, de exportar eletricidade gerada através de fontes de energia renováveis de países do Norte de África e Médio Oriente para a Europa. A análise apresenta uma breve revisão do custo corrente da eletricidade e o potencial para reduzir o custo da energia a partir da tecnologia de receção parabólica de centrais CSP. A avaliação do ciclo de vida com base exergética (ELCA) e a avaliação do ciclo de vida convencional são realizadas para a centrais CSP específicas no quinto capítulo. Os objetivos são 1) avaliar o impacto ambiental e custo, em termos de do ciclo iv de vida exergético do sistema; 2) identificar pontos fracos em termos da irreversibilidade dos processos; e 3) verificar se as centrais CSP podem reduzir o impacto ambiental e o custo de geração de eletricidade em comparação com centrais que consomem combustível fóssil. O capítulo ainda apresenta uma análise termoeconómica com base na metodologia do custo específico da exergia (SPECO), que avalia o custo relacionado com a destruição de exergia. A análise verificou que o impacto mais importante é a contribuição apresentada pelo campo solar (79%), e os materiais com maior impacto são: aço (47%), sal fundido (25%) e óleo sintético (21%). A análise ELCA mostra que a maior demanda de exergia é devida ao aço (47%); a análise existe uma considerável demanda de exergia relacionada com o sal fundido e ainda o óleo sintético. Em comparação com as centrais que consomem combustível fóssil (NGCC e óleo) a central sistema CSP apresenta menor impacto ambiental, enquanto o pior desempenho ambiental é o da central com queima de óleo seguida pela central a gás natural (NGCC). Na central CSP, o campo solar apresenta o custo mais elevado, enquanto o gerador de vapor, entre os componentes do ciclo de potência, apresenta o maior custo. O armazenamento de energia térmica permite que as centrais CSP superem a intermitência de radiação solar para responder à procura de energia elétrica independentemente das condições climáticas, e também possam estender a produção de eletricidade para além da disponibilidade da radiação solar diária. A análise numérica do transiente térmico de um sistema de armazenamento de gradiente térmico é realizada durante a fase de carregamento. O sistema de equações que descreve o modelo numérico é resolvido através da utilização de diferenças finitas implícitas no tempo usando o software Matlab. Os resultados da análise indicam que as previsões estão em boa concordância com os dados experimentais para a evolução no tempo da região de gradiente térmico, em particular para regiões mais afastadas da entrada. Nesta região os desvios observados são provavelmente causados pelo alto nível de turbulência devido à penetração do jato no seio do tanque de armazenamento. O modelo analítico simples para simular a turbulência que foi desenvolvido melhora os resultados. Esta abordagem não requer esforço computacional adicional e determina a difusidade térmica efetiva ao longo do tanque.

Cetaceans have been suggested as ideal ocean sentinels for the evaluation of ecosystem health because they are long-lived, higher trophic foragers, often with high site-fidelity. The body condition of cetaceans provides an integrated picture of foraging success and energy expenditure and thus represents an effective ‘sentinel parameter’ for ecosystem monitoring. In addition, the body condition of an individual can serve as a predictor of reproductive success and offspring survival. The ability to monitor the body condition of cetaceans is therefore of direct relevance for conservation biology. Despite the value of this parameter, there is currently a lack of reliable, standardized, non-lethal methodologies for its evaluation across species and age-categories. The introduction chapter describes the natural history of the humpback whale (Megaptera novaeangliae) in the context of its Antarctic ecosystem and its energetic requirements. It sets out that the species is among the most vulnerable in a changing environment due to it being a specialised feeder depending on Antarctic krill. Krill is the keystone of the Antarctic ecosystem and is presently facing numerous threats. Humpback whales are capital breeders that spend summers feeding in high latitude feeding grounds, building up their energy reserves reflected in their body condition. During winter they migrate to tropical waters to reproduce, a journey that is fuelled by the energy stores previously accumulated. The seasonal dynamics of intensive feeding and lipid deposition, followed by high energy activities that are accompanied by fasting and lipid mobilisation, render the species ideal for the study of possible biomarkers of fluctuating energy stores. This thesis focuses on the evaluation of fluctuating adiposity of southern hemisphere humpback whales. The second chapter presents a critical review of the available approaches of assessing cetacean body condition. Currently the methodologies can be divided into four groups, namely: Blubber Measures, Body Composition, Body Morphometry, and Biochemical and Chemical Biomarkers. The last category is dedicated mainly to new developments and explores the emerging methodologies. This chapter describes and analyzes their applications as well as their respective strengths and weaknesses. The chapter concludes by advocating research priorities that fill the critical technical research needs for a reliable, non-lethal and standardized methodology that is applicable across species and age-categories and for large numbers of individuals. In response to the research need identified in chapter two, chapter three investigates adipocyte metrics as a potential biomarker of adiposity in humpback whales. Blubber is composed of adipocytes, which are filled with lipids according to the individual energy reserves. This means that a change in total energy reserve impacts the volume of individual adipocytes. Two adipocyte metrics were assessed histologically: the two-dimensional adipocytes area and the relative proportion of adipocyte space in the blubber tissue which is termed the adipocyte index. Both adipocyte metrics exceed the sensitivity of the most widely used proxy for energetic reserves, blubber lipid percentage, thus validating the implementation of adipocyte area and the adipocyte index as energetic reserve biomarkers. This published work therefore advocates the inclusion of these measures, obtained from superficial blubber biopsies, in long-term monitoring programs as a means of improving evaluation of fluctuating energy reserves. Following the molecular techniques’ potential to assessing body condition identified in the second chapter, chapter four explores the RNA extraction from humpback whale blubber for downstream applications. Good quality RNA is a prerequisite for successful downstream applications, however its extraction can be difficult, especially if the starting material is high in lipids. This chapter describes the strategic approach taken for method optimization and the difficulties encountered. The fifth chapter provides a theoretical basis for the use of blubber proteins “adipokines” as biomarkers of adiposity. The main physiological role of blubber is energy storage; however, the tissue is highly integrated into the overall physiological and metabolic control systems of mammals. This mechanism is carried out through the secretion of proteins, synthesized in the adipose tissue and actively involved in the lipid dynamics, with a profound effect on food intake and energy expenditure in model species. The different concentrations of these proteins, such as leptin and adiponectin inform the hypothalamus of the amount of energy stored. However, very little is known about the operation of adipokines in animals that experience extreme fluctuations in their energy reserves while at the same time using adipose tissue as insulation as cetaceans do. This chapter explores the possibility that the gene expression profile of selected adipokines may provide insight into the fluctuating energetic health of cetaceans. This chapter also outlines trialled approaches and advocates future priorities. The key findings and implications of this work are discussed in the concluding chapter. In summary, this study makes clear the importance of the energy reserves measurement and its ecological scope. It identifies the priorities for the improvement and standardization of the current methodologies and highlights the importance of new developments, pointing towards possible areas for further development. It proposes a simple and easily applicable methodology that improves precision and accuracy of the current method. In addition, it proposes advances in the optimization of the extraction of good quality RNA from blubber for downstream application. Finally, it explores the gene profile of the adipokines leptin and adiponectin, leaving the theoretical bases and some progress in the study of adipokines gene expression from humpback whale blubber.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
Full Text

El consum energètic representa un 30 % dels costos d'operació en sistemes intensius de tractament d'aigües residuals urbanes. En depuradores convencionals que utilitzin un sistema de fangs activats, entorn al 15-20 % de l'energia és consumida en la línia dels fangs, que inclou el bombeig, l'espessiment, l'estabilització i la deshidratació. Per tant, la optimització de la gestió dels fangs pot contribuir substancialment en la reducció dels costos de tractament d'aigües residuals. La digestió anaeròbia termofílica és més eficient que la mesofílica i pscicrofílica, en termes de producció de biogàs i metà, eliminació de sòlids volàtils (SV) i destrucció de patògens. El procés es pot accelerar mitjançant el pre¬tractament dels fangs, afavorint la seva solubilització i hidròlisi.
L'objecte d'aquesta Tesi Doctoral fou estudiar l'impacte dels paràmetres del procés en la digestió anaeròbia termofílica dels fangs de depuradora urbana, avaluar l'efecte del pre-tractament tèrmic dels fangs a baixa temperatura, i valorar processos alternatius des del punt de vista energètic.
Els resultats experimentals presentats s'obtingueren mitjançant l'operació de dos reactors de laboratori durant prop de dos anys. En aquest període es va estudiar l'efecte de la temperatura del procés, del temps de retenció dels fangs (TRF), de la velocitat de càrrega orgànica (VCO) i del pre-tractament a 70 ºC en la digestió anaeròbia dels fangs de depuradora. El procés fou avaluat en termes de la producció d'energia (biogàs i metà) i de la qualitat del fang digerit (contingut de SV i d'àcids grassos volàtils (AGV), facilitat de deshidratació i higienització). S'analitzà l'estabilitat del procés a mesura que es reduïa el TRF i s'incrementava la VCO, i es comparà l'eficiència en períodes d'estabilitat corresponents a les diferents condicions operacionals. Finalment, s'avaluaren els resultats des del punt de vista energètic, mitjançant el càlcul de balanços i ratis energètics teòrics, que es compararen amb els resultats obtinguts a partir de dades experimentals d'altres estudis. També s'utilitzà un model cinètic de primer ordre. Les conclusions que es desprenen d'aquest treball es resumeixen a continuació:
Durant la digestió anaeròbia dels fangs, la transició d'un reactor mesophilic (43 ºC) a termofílic (50 ºC) es podria dur a terme sense alterar el procés, treballant a TRF elevats (≥ 30 dies) i VCO baixes (≤ 0.5 kg SV m-3reactor d-1). En aquestes condicions, les principals diferències entre reactors termofílics (50-55 ºC) i mesofílics (38-43 ºC) fan referència a una certa acumulació d'AGV (0.5-2.5 g L-1) i millora de la destrucció de patògens (E. coli ≤ 102 UFC mL-1). La digestió termofílica a 50 ºC i 55 ºC dóna lloc a resultats similars pel que fa a la producció de biogàs, estabilització, higienització i facilitat de deshidratació de l'efluent, si no varien els altres paràmetres operacionals.
La producció de metà tendeix a incrementar proporcionalment a la VCO, és a dir al TRF i el contingut de SV als fangs alimentats. Així mateix, la qualitat de l'efluent (contingut de SV i AGV, facilitat de deshidratació dels fangs) també depèn de la VCO. D'acord amb els resultats obtinguts a 55 ºC, la producció de metà s'incrementà 2-3 vegades (de 0.2 a 0.4-0.6 m3CH4 m3reactor d-1) en disminuir el TRF de 30 a 15-10 dies, incrementant la VCO de 0.5 a 2.5-3.5 kg SV m3reactor d-1. En canvi, el procés es desestabilitzà amb la reducció del TRF a 6 dies i VCO per sobre de 5 kg SV m3reactor d-1. Les següents concentracions poden ser útils per detectar i prevenir la desestabilització d'un digestor termofílic de fangs: AGV totals
(2.5 g L-1), acetat (0.5 g L-1), rati acetat/propionat (0.5), alcalinitat intermèdia (1.8 g CaCO3 L-1), rati alcalinitat intermèdia/alcalinitat parcial (0.9), rati alcalinitat intermèdia/alcalinitat total (0.5), contingut de metà al biogàs (55 %).
El pre-tractament a 70 ºC afavoreix la solubilització dels fangs, incrementant la proporció de matèria orgànica soluble respecte la matèria orgànica total del 5 % al 50 % en 9-24 h; seguit d'una progressiva generació d'AGV després de 24h. Durant la subseqüent digestió anaeròbia de fangs pre¬tractats (9-48 h), s'incremetà la producció de biogàs en un 30-40 %, treballant a 55 ºC i 10 dies de TRF. El rendiment de producció de biogàs fou un 30 % superior amb fangs pre-tractats (0.28-0.30 vs. 0.22 L·gVS¬1) i el contingut de metà al biogàs també fou superior (69 % vs. 64 %).
La digestió anaeròbia termofílica de fangs pot donar lloc a una producció neta d'energia, durant estacions fredes i càlides, si s'utilitzen reactors amb aïllament tèrmic de les parets i amb recuperació energètica a partir del biogàs i dels fangs digerits. En aquest cas, l'eficiència energètica de reactors termofílics treballant a la meitat de TRF (10-15 dies) que reactors mesofílics (20-30 dies) seria similar, per la qual cosa el cabal diari podria ser doblat, o el volum del reactor reduït, amb el conseqüent estalvi en el cost de tractament dels fangs. A més, un sistema en dues etapes (70/55 ºC) produiria més energia neta que un sistema en una sola etapa (55 ºC) amb un TRF de 10 dies. De totes maneres, la quantitat d'energia neta generada augmenta amb el volum del digestor donat que, malgrat la disminució en la producció de metà a TRF creixents, la producció d'energia segueix essent superior al consum, i per tant com més quantitat de fangs hi hagi al digestor, més energia es produirà.
Energy consumption accounts for some 30 % of the total operating costs of intensive sewage treatment systems. In conventional wastewater treatment plants employing an activated sludge process, around 15-20 % of this energy is used in the sludge treatment line, including sludge pumping, thickening, stabilisation and dewatering. Therefore, optimisation of sludge management can substantially contribute in the reduction of wastewater treatment costs. Thermophilic anaerobic digestion is more efficient than mesophilic anaerobic digestion, in terms of biogas production, volatile solids (VS) removal and pathogens destruction. The process might be further accelerated by sludge pre-treatment, promoting sludge solubilization and hydrolysis.
The aim of this PhD Thesis was to study the impact of process parameters on the thermophilic anaerobic digestion of sewage sludge, to evaluate the effect of implementing a low temperature pre¬treatment step, and to assess alternative processes from an energy perspective.
The experimental results presented were obtained by operating two lab-scale reactors for almost two years. During this period, the effect of process temperature, sludge retention time (SRT), organic loading rate (OLR) and 70 ºC sludge pre-treatment on the anaerobic digestion of sewage sludge was studied. The process was evaluated in terms of energy production (i.e. biogas and methane production) and the quality of the effluent sludge (i.e. VS and volatile fatty acids (VFA) content, sludge dewaterability and hygienisation). Focus was put on the stability of the process at decreasing SRT and increasing OLR. Process efficiency during stable performance under each operating condition assayed was compared. Finally, the results were assessed from an energy perspective, by means of theoretical energy balances and ratios; and compared to the results obtained with experimental data from other studies. A first order kinetic model was also used. The conclusions drawn from the different issues dealt in this work are summarised as follows:
During anaerobic sludge digestion, the transition from a mesophilic (43 ºC) to a thermophilic operation (50 ºC) may be carried out without disturbing the process, by operating the reactors at high SRT ( ≥ 30 days) and low OLR (≤ 0.5 kg VS m-3reactor d-1). Under such conditions, some VFA accumulation (0.5-2.5 g L-1) and enhanced pathogen destruction (residual E. coli ≤ 102 CFU mL-1) would be the main differences of thermophilic (50-55 ºC) compared to mesophilic (38-43 ºC) reactors. Thermophilic sludge digestion at 50 ºC and 55 ºC should be similar in terms of biogas production and effluent stabilisation, hygienisation and dewaterability; provided that other process parameters are the same.
Methane production rate tends to increase proportionally to the OLR, thus to the SRT and VS concentration in the feed sludge. Similarly, the quality of the effluent sludge (VS content, VFA content and sludge dewaterability) is also affected by the OLR. According to the results obtained at 55 ºC, methane production rate increased by 2-3 times (from 0.2 to 0.4-0.6 m3CH4 m3reactor d-1) by decreasing the SRT from 30 to 15-10 days; increasing the OLR from 0.5 to 2.5-3.5 kg VS m3reactor d-1. However, process unbalance resulted from SRT reduction to 6 days, with OLR above 5 kg VS m3reactor d-1. The following concentrations might be useful to detect and prevent digester failure during thermophilic sludge digestion: total VFA (2.5 g L-1), acetate (0.5 g L-1), acetate/propionate ratio (0.5), intermediate alkalinity (1.8 g CaCO3 L-1), intermediate alkalinity/partial alkalinity ratio (0.9), intermediate alkalinity/total alkalinity ratio (0.5), methane content in biogas (55 %).
The 70 ºC sludge pre-treatment may initially promote sludge solubilization, increasing the concentration of soluble to total organic matter from 5 to 50 % within 9-24 h; which is followed by a progressive VFA generation after 24 h. Subsequent anaerobic digestion of pre-treated sludge samples (9¬48 h) could increase biogas production by 30-40 % working at 55 ºC with a SRT of 10 days. Biogas yield is some 30 % higher with pre-treated sludge (0.28-0.30 vs. 0.22 L·gVSfed-1) and methane content in biogas is also higher with pre-treated sludge (69 vs. 64 %).
Thermophilic anaerobic sludge digestion would result in net energy production, during cold and warm seasons, provided that digesters with wall insulation and with energy recovery from both the biogas produced and the effluent sludge are used. In this case, the energetic efficiency would be similar for thermophilic digesters working at half the SRT (10-15 days) of mesophilic digesters (20-30 days), meaning that the sludge daily flow rate could be doubled, or the reactor volume reduced, with subsequent savings in terms of sludge treatment costs. Furthermore, two-stage systems (70/55 ºC) may result in higher net energy production compared to single-stage systems (55 ºC) at 10 days SRT. However, the amount of surplus energy generated increases with digester volume. In spite of the decrease in methane production rate at increasing SRT, energy production is still higher than energy consumption, and therefore the bigger the amount of sludge in the digester, the higher the energy production.

Différentes approches ont été utilisées pour évaluer les effets de deux formes de nanoparticules de carbone (NPC), nanotubes et graphène, afin de comprendre les mécanismes de la réponse générée par la diatomée benthique d'eau douce Nitzschia palea. Les effets à l'échelle de la communauté ont démontré un impact temporaire sur la croissance du biofilm et une accumulation des NPC dans la matrice extracellulaire. L'application d'une étude transcriptomique a mis en évidence l'importance de l'interaction physique, à l'origine d'altération du frustule, dans la mise en place de cette réponse extracellulaire se traduisant par une surproduction des substances exo-polymériques (EPS). Cette approche a également révélé l'impact des NPC sur l'activité photosynthétique des diatomées et une modification du métabolisme énergétique, suggérant une allocation énergétique en faveur de la production d'EPS. L'étude du protéome extracellulaire a permis d'avoir un premier aperçu de la composition de la matrice extracellulaire, principalement constituée de protéines à caractère hydrophobe. Lors de l'exposition aux NPC, les diatomées semblent produire un système adhésif complexe permettant de renforcer la matrice extracellulaire et d'augmenter la stabilité du biofilm tout en piégeant les NPC. L'exposition des diatomées face au deux formes de NPC induit une réponse présentant une forte similitude notamment pour les plus fortes concentrations testées
Different approaches were used to assess the effect of two forms of carbon-based nanoparticles (CNP) nanotubes and graphene, in order to determine the mechanism of the response generated by the benthic freshwater diatom Nitzschia palea. The effect at the cellular community scale demonstrated a temporary impact on biofilm growth and an accumulation of NPC in the extracellular matrix. The use of transcriptomic study evidenced the role of the physic interaction, causing alteration of the frustule, in the extracellular response leading to an overexcretion of exopolymeric substances (EPS). This approach also revealed the impact of NPC on the photosynthetic activity of diatoms and a modification of the energetic metabolism suggesting an energetic allocation for the EPS production. The study of the extracellular proteome allowed to have a first insight of the extracellular matrix composition, in majority composed of hydrophobic-like proteins. In NPC exposure, diatoms seemed to produce an adhesive system allowing to strengthen the extracellular matrix and increase the biofilm stability while trapping NPC. The exposition of diatoms to the two NPC forms induce a response greatly similar for the highest tested concentration

The diploma thesis contains an energy audit of the figure skating hall. In the first part I focused on the analysis of the topic, fire regulations and laws relating to given theme, recent technical, theoretical and experimental solutions in practice. In the next part, I compiled the of building energy audit of building, including its mandatory annexes. In the last part, I presented the results of measurements in the evaluated object.

Master´s thesis solves problematic of energy evaluation of residential building in Kyjov. The theoretical part analyzes the legislative requirements, the practical part includes energy audit of brick residential building with 9 apartments for 18 inhabitants.

Master's thesis deals economy evaluation of biogas station. As evaluating mechanism was elected energy audit. It tries to show all effects and economy and energy influences. Output evaluation recommend the best option of project. Master's thesis also solves project documentation. It contains implementation drawings and scripts. Thesis thinks about global reason production of electric energy in biogas stations.

Contain of master´s thesis is a energy assessment of multifunctional building in Komňátka. The theoretical part deals with the analysis of legislativ documents, current technical solution and practical application to the specified building. In the practical part thesis focus on experimental determination of the heat transfer coefficient using thermography.

The thesis deals with the project of the construction of the Temelin Nuclear Power Plant, as an optimal new production source of electrical energy to ensure the majority of the coverage of the growing electric consumption in the Czech Republic and to ensure the state energy independence in the future. The main part of the thesis is dedicated to the methods of strategic investments evaluation. Emphasis is placed on the dynamic methods, which are also working with the factors of time and risk, which are relevant in this case, because the project time horizon is 70 years. The investment project is evaluated from the perspective of owners, as well as from the overall perspective of owners and creditors. The Monte-Carlo method was implemented into the model to support the decision-making process and to move closer to reality. The method assigns the relevant distribution division to the model input values. The output is the set of available values, and the probability of their occurrence. The main thesis objective lies in the decision of the decision maker with a neutral attitude to risk, whether accept the investment or not.

This master thesis offers two cost-saving measures to reduce the energy consumption of a residential building. These measure include insulation of the building envelope, domestic hot water by solar colectors and heat recovery.

The aim of thesis is the energy evaluation of building for public facilities - kindergarten. From the beginning work deals with the analysis of a given topic, standard and legal regulations associated with the topic. This knowledge is further applied to a specific building. It follows by evaluation of the current state of the building, its systems, internal environment and analysis of measures leading to energy savings and ensuring the quality of the indoor environment of building. Work also deals with experimental measurements of selected parameters of the internal environment.

More than 30% of the final energy uses in the European Union are due to the building energy consumptions. In order to reduce their energy impact and improve their efficiency, the design activity has been given a large importance, both for new buildings or refurbishment projects. Moreover, besides these goals, during the last years the indoor comfort conditions have assumed a more and more relevant significance for professionals in the building design. That required the development of properly detailed instruments of analysis, such as building energy simulation tools (BES). Generally, the more complex a tool, the higher the number of required inputs but not all of them are always available in the early design stages. For this reason, BES codes have been used also to elaborate simpler models. This research analyses the possibilities given by an extensive use of the BES for the evaluation of the building envelope energy performance and some of the different issues related to BES. The first topic discussed is related to the external boundary conditions in BES, in particular the definition of a representative weather file for the description of the external environment and of the modelling of the heat transfer through the ground. The second topic analyses the problems of the validation of the results provided by BES tools and the relative accuracy introduced by the choice of a specific code. The comparison between BES software is carried out both considering the outputs of a whole thermal zone, such as heating and cooling energy needs and peak loads and the time of their occurrences, and the response of a single component (i.e., opaque walls and glazings). Finally, the coherence between the energy needs elaborated by means of BES tools and those by the quasi-steady state model presented in the technical Standard EN ISO 13790:2008 is studied and some correction factors are proposed for this simplified method.
Più del 30% degli impieghi finali di energia nell’Unione Europea è dovuto ai consumi energetici degli edifici. Al fine di ridurre il loro impatto energetico e migliorare la loro efficienza, è stata data una sempre maggiore importanza all’attività di progettazione, sia in merito ai nuovi edifici sia per gli interventi di riqualificazione. Inoltre, in aggiunta a questi obiettivi, durante gli ultimi anni le condizioni di comfort nell’ambiente confinato hanno assunto una sempre maggiore significatività per i progettisti edili. Ciò ha richiesto lo sviluppo di strumenti di analisi adeguatamente dettagliati, come i simulatori dinamici dell’edificio. In generale, più è complesso uno strumento, maggiore è il numero di input richiesti ma non tutti sono sempre disponibili nelle fasi iniziali della progettazione. Per questa ragione, i codici di simulazione dinamica sono stati impiegati anche per sviluppare modelli semplificati. Questa ricerca analizza le possibilità date da un uso estensivo della simulazione dinamica per la valutazione delle prestazioni energetiche dell’involucro edilizio e alcune problematiche relative ad essa. Il primo argomento discusso riguarda le condizioni al contorno nella simulazione dinamica, in particolare la definizione di un file climatico rappresentativo per la descrizione dell’ambiente esterno e la modellazione dello scambio di calore attraverso il terreno. Il secondo argomento analizza i problemi della validazione dei risultati forniti dagli strumenti di simulazione dinamica e l’accuratezza introdotta dalla scelta di uno specifico codice. Il confronto tra i software di simulazione dinamica è condotto sia a livello degli output di un’intera zona termica, quali i fabbisogni di riscaldamento e raffrescamento, i carichi di picco e l’istante in cui si verificano, e la risposta di un singolo componente (i.e., le pareti opache e quelle vetrate). Infine, viene studiata la coerenza tra i fabbisogni energetici elaborati dagli strumenti di simulazione dinamica e quelli ottenuti tramite il modello semi-stazionario presentato nella normativa EN ISO 13790:2008 e vengono proposti alcuni fattori correttivi per questo metodo semplificato.

The theme of this diploma thesis are the issue of energy evaluation of buildings and the reduction of energy consumption in the Czech legal system in the theoretical part, an analysis of energy consumption of the judged building in an old and new state in the calculation part and an energy audit of the main building of SRC Lihovar in Třemošnice according to Decree no. 480/2012 Coll. The three-storey main building of sports and rehabilitation center is located on the southern edge of city Třemošnice and it used to be a distillery until it has been renovated in 2013. There is a restaurant with a bowling room, hotel with two conference lounges, wellness, fitness and a swimming pool. The heat source for this building are two gas boilers, three heat pumps and solar collector array. There is partly forced and partly natural ventilation installed in the building.

The main content of this thesis is a design and an assessment of energy-saving measures with an objective of energy economical optimization of a particular family house. The theoretical part of the thesis describes problems of the energy performance of the building. The calculating part is devoted to economical and environmental assessment of two solving options with a use of a computer program which enables a monthly calculating measure. One part constitutes a design of air-conditioning systems, heating and drawing up an Energy Performance Certificates. The part of the thesis which is focused on a computer technology application deals with energy performance optimization with a use of a program which enables a daily calculating measure and making models of pictures of flowing with a use of CFD methods.

3. Methodenband der Querschnittsarbeitsgruppe "Energetisch-wirtschaftliche Bilanzierung" des Spitzentechnologieclusters eniPROD
3rd workbook of the cross-sectional group 'Energy-related technologic and economic evaluation' of the Cluster of Excellence eniPROD

Creating the concept of buildings is the primary task of architects, designers in the field of architecture and engineering. Although the basic requirements remain the same across time , possibilities of their solution are constantly evolving and changing. In addition, with the increasing globalization, in context of the housing and the architecture is expected new requirements go beyond the horizons of the interests of bouth investor and designer. Global view of each project and the evaluation of its traces left in our environment and society, although is much discussed but rarely taken into account or even just considered. In this context, we are witnessing the development of new trends of the concepts of buildings, consisting in the use of natural materials, in reducing the environmental burden of a surroundings, in reducing energy demands, or even in an effort to achieve energy independence thus trends, whose common denominator is sustainable construction, hence sustainable development in general. Feasibility of the creation of the concept of energy self-sufficient building doesn´t consist only in the precise solution of the assigned task from the perspective of the designer or investor, but also in finding such a solution which, even with using new trends and principles, will not go against the initial idea itself. The present instrument processed and presented in this dissertation has the ambition to move global view of the project into the perspective of a particular individual design process and in small way contribute to the creation of better projects from the perspective of sustainable development The term of energy self-sufficient buildings are not clearly defined. To work with them it was necessary to determine their basic definition that describes their diverse conceptual variations and allows precisely define the solution area. To correctly select the optimal solution in terms of sustainable development is necessary the assessment and mutual comparison since the beginning. As a basic tool for this assessment was used and partially modified SBTool, which is built on three basic pillars of sustainable development - SOCIAL - ENVIRONMENTAL - ECONOMIC. SBTool tries to determine the degree of left traces of the approach from the perspectives of these three aspects and evaluate the effectiveness of the selected solution. This tool allow to compare the different concepts for the same project among themselves, their parts but also various projects among each other. All of course with regard to the development of various aspects in the time.

Main task of this final thesis is to analyse experimental measured data of prototype unit with output of 1 MW for energic biomass utilization. Furthermore the aim is to get acquainted with energic biomass problems utilization in middle output kettles and with stationary source legislation. To transfer measured value due to legislative conditions this diploma work solves the conversion procedure which is necessary to evaluate emission limits for measured concentration CO, SO2, NOX and stiff contaminating matters. My final work put emphasis on graphics processing in general tables and graphs with trends describtions. Endeavour is achieve discussion bilateral connection.

Tagungsbände des 1. und 2. Methodenworkshop der Querschnittsarbeitsgruppe 1 "Energetisch-wirtschaftliche Bilanzierung" des Spitzentechnologieclusters eniPROD
Proceedings of the 1st and the 2nd workshop of the cross-sectional group 1 'Energy-related technologic and economic evaluation' of the Cluster of Excellence eniPROD

Nowadays, carbon capture and sequestration technologies can be considered as the most useful method in order to stop global warming which is caused by the increase of CO2 emissions. This innovative strategy exploits of the underground formations capacity to storage carbon dioxide safely. We are managing to reduce the 38 gigatonnes of CO2 annually emitted to reach the Paris agreement conditions. Scotland will start in short time a new CCS plant in the North Sea. This project is known as ACT ACORN and it involves storing about 150 megatonnes of CO2. The average sequestration cost will be about 1,1 euros per tonne of CO2. In Italy, a CCS project was supposed to start in 2011 in province of Piacenza but it did not happen due to external reasons (earthquake). In Cortemaggiore plant, 24ktonnes of CO2 would have been stored into a depleted gas field for a total investment cost worthing about 42 millions. Both of these projects are showing that CCS methods cannot be ignored. It is an available and consolidated technology, made by a capture-transport and compression structures. Thus, this project has received plenty of European Authorities fundings. It has to be overpassed the pubblic acceptance which is negletting this possibility because of the scare of leaking CO2 from natural reservoirs could risk their lifes. Furthermore, scientific opinion has to be cohesive in order to convince people and Public Institutions this is the right way to follow to achieve global warming targets . In the time this thought to be common, few alternatives can be evaluated to reuse the captured CO2 instead of emitting it in the atmosphere. A plenty of biogas plants are spreading worldwide to encourage biofuels distribution. Also, the solution to plant trees around factories could be a quick option to start the CO2 sequestration phase waiting for the CCS technology affirming worldwide.

The following work is the result of an internship carried out at STC POWER Company, in the proposal office, with the aim to make a technical comparison of two combustion technologies, Moving Grate (MG) and Circulating Fluidized Bed (CFB), in order to find out which is the optimal solution for a specific biomass power plant. After a preliminary description of the fuel considered (biomass) and an overview of the operating principle of a combined heat and power (CHP) plant, the attention has been paid to the main differences of the two boilers, focusing on: fuel characteristics, pollutant emissions, corrosion and fouling problems, performances and auxiliaries. Then, the technical comparison has been applied to a biomass CHP plant that will be realized in France following a tendering process to which STC Power is participating. The overall power plant has been simulated with the software Thermoflex both with MG boiler and CFB boiler and, after several optimizations, the results in terms of performances and efficiencies have been compared. Particularly critical has been the corrosion problem, caused by the fuel composition, that has led to a limitation on the maximum temperature of the steam produced with MG boiler, thus limiting also the overall efficiency of the plant. After the technical analysis, also the economic aspects have been evaluated, with a comparison of the main costs (CAPEX and OPEX) of MG and CFB boilers. Finally, the reasons that have led to choose one specific boiler instead of the other have been explained.

The thesis deals with the environmental assessment of buildings, concrete objects Letní lázně at Karlova Studánka. The first part describes the issue and legislation. There is also described a method of experimental measurement and methods of moisture measurement. The second part deals with the analysis of the specified object, description of selected renewable sources and description of possible modifications of the object. The third part is devoted to modeling and simulation of the specified object in DesignBuilder. Using the model were created various simulations with various modifications in order to reduce energy intensity of the object. Results were then evaluated and compared.

Telemetry system, Optimisation, Sensoric networks, Smart Grid, Internet of Things, Sensors, Information security, Cryptography, Cryptography algorithms, Cryptosystem, Confidentiality, Integrity, Authentication, Data freshness, Non-Repudiation.

Thesis is intent on economic analysis and risk analysis building technology, used at reducing energy costingness. Basic goal of this thesis is evaluating selection energy - saving building technology for concrete investment project at authority two principles. First principle is complying with time influence namely how in view of financial resources, so in view of price energy. Second principle is consequential complying with risk and uncertainties particular factors. In case of these thesis it means simulation crucial factors as a stochastic model. To these purposes will be used method Monte Carlo. Theoretical part of thesis be engaged in characterization economics analyses and risk analyses investment project. Information betray into theoretic parts will applied on concrete investment project, reconstruction residential building using energy - saving technology that contribute by to decrease energy costingness of all building. Fundamental of the investment project is reducing costs on heat a hot water. Goal of practical parts this thesis is give to data for decision making house owners about reconstruction house, regarding particular building technologies.

Questo elaborato tratta il reattore di ricerca MYRRHA, in fase di sviluppo presso il centro di ricerca belga SCK CEN. In particolare si focalizza sullo studio della circolazione naturale del refrigerante, ovvero l'LBE (Lead-Bismuth Eutectic), utilizzata come sistema passivo di sicurezza dopo lo shutdown del reattore in caso di mancato funzionamento delle pompe. Lo scopo di questo lavoro è la creazione di un modello in scala ridotta del reattore per simulare la circolazione naturale dell'LBE. Lo scaling down del reattore viene effettuato tramite lo studio dei numeri adimensionali e la scelta di mantenere costante il coefficiente di scambio termico tra il reattore e il modello in scala. Questa scelta viene fatta al fine di avere sufficiente similarità tra i due per quanto concerne lo scambio termico, in modo che il comportamento del fluido sia lo stesso di quello all'interno del reattore. Nella prima parte vengono effettuate simulazioni 2D, tramite ANSYS 2020, per confrontare la circolazione naturale di fluidi caratterizzati da diverso numero di Prandtl. Viene, inoltre, effettuato un confronto tra i coefficienti di scambio termico ottenuti dalla simulazione e quelli ottenuti tramite calcoli a mano, al fine di verificare che la simulazione possa ben rappresentare il comportamento reale del fluido. Vengono poi calcolate le temperature che si hanno all'interno del reattore rimuovendo una potenza di 1MW, i relativi numeri adimensionali, quali Pr, Gr, Ra e Nu, e i coefficienti di scambio termico dell'LBE per ciascuna area, attraverso un modello semplificato per poter ricavare le dimensioni del modello in scala. Dopo aver disegnato uno sketch del modello, sono state infine effettuate delle simulazioni 3D del modello in scala per verificarne il comportamento, rispetto a quello reale. Le simulazioni 3D hanno dimostrato che il modello rispecchia correttamente il comportamento reale del fluido e che la circolazione naturale può essere usata per raffreddare il reattore.

Buildings are at the centre of our social and economic activity. Not only do we spend most of our lives in buildings, we also spend most of our money on buildings. The built environment is not only the largest industrial sector in economic terms, it is also the largest in terms of resource flow1. The rising energy costs, the growing concern about environmental issues and the approaching exhaustion of world energy resources are urging the entire European Community and the several national governments to improve energy management. Special attention is usually paid to public administrations, as European and national legislations often point out that these bodies must provide energy efficiency measures, as well as for the reasons mentioned above, also in order to represent an example for the entire community and for citizens as well. But it is also very important to find out how to foster and encourage energy efficiency improvements and saving measures in private dwellings to achieve the double advantage of reducing the global energy consumption level within the private sector and increasing investments, favoring the creation of additional cash flows as well. The possible combination of such multiple benefits makes the building sector a crucial field for policy makers at EU and national levels. Hence a policy framework that supports national markets in unlocking these potentials is strongly needed. With overall European policy aimed at significantly decarbonizing its economy by 80% to 95% by 2050, the building sector must undoubtedly play a key role. And any strategy to tackle the challenge in this field will clearly require both a significant amount of financial investments and long-term political commitments. The main goal of the present research is to propose an optimized methodology and cost effective decision-making process - based on the main facts emerging from the adoption of the key energy policies and financial instruments currently in force at European level (particularly in Italy and Denmark) - also to outline the next policy steps in improving the energy performance of buildings. After a global overview of the policies adopted at European level, the analysis focuses on the two different regulations implemented at the national level by Italy and Denmark. Furthermore, to define the best mixture of energy retrofit measures for the different geographical areas of Italy - applying a methodology based on simple and available data to improve residential buildings' energy efficiency - the work started with the analysis of the several reports produced by ENEA (the Italian Research Agency for Energy Efficiency) since year 2007. These were based on the data collection performed in order to assess the effectiveness of the Italian government’s financial policies established to support energy saving actions in private dwellings. The first steps of such a top-down analysis are then carried out both through manual cost/benefit spreadsheets, as well as with the implementation of a linear programming analysis tool. The study defines different linear programming models, depicting different optimization problems (e.g. energy saving maximization vs. retrofit cost minimization), along with the respective different background scenarios. Such investigations are therefore carried out through the implementation and development of Dantzig's simplex algorithm. Moreover, to carry out a global comparison between the overall Italian and Danish situations, also achieving a deeper single-dwelling-focused analysis, further studies are developed through a Building Energy Optimization tool, implementing the EnergyPlus dynamic energy simulation software. Thence, the research moves on to a more specific analysis, shifting to a bottom-up approach and involving in the enquiry a comparison between the different assessment settings (climatic, political, economic, cultural) depicted both by Italy and Denmark. Two different dwelling models are defined for the above countries, focusing the analysis on those building typologies most representative of such European nations and thence different retrofit solutions are depicted and analyzed. The results obtained by means of this dynamic assessment are then used to group the respective energy savings vs. retrofit cost considerations within a global cost-effectiveness assessment. Finally, some “guidelines” are outlined to address the challenge of renovating the existing building stock, also in order to keep pace with the aims of both the nations and the European Union.

This dissertation analyzes the effect of insulation on the price of housing units in Opava city. In the theoretical part of the dissertation deals with the subject of appraisement, the energy intensity of buildings and technical-economic evaluation. In the practical part sets the prices of selected housing units by direct comparison, the comparative method by regulation and yield value. It assesses whether the possible range in the valuation regulations (5%) reflects the fact that the recognized building insulated in accordance to the current legislation. It detects the energy nature of a apartment building in which they are placed selected apartments. The goal is to determine a price increase of housing units due to insulation and evaluates the appropriateness and inappropriateness of buying from the investor's perspective.

This Ph.D. project has been addressed to evaluate the potential of microalgal technology for biofuel production. Different steps of the process, as well as technologies and concepts have been analyzed experimentally and by process simulations in order to assess the sustainability of the production of biofuel from microalgae. An experimentation work on microalgae cultivation in untreated wastewaters is reported, including the selection of the optimal wastewater process stream, the nutrients removal efficiencies and the removal rates. Also, the effects of temperature, day/night irradiation and bacterial competition in steady-state biomass production are evaluated in order to integrate both technologies. Downstream processing has been investigated with respect to anaerobic digestion and hydrothermal liquefaction (HTL) of microalgae biomass. The production of biogas is evaluated using whole and de-oiled microalgae, as a function of inoculum typology and biomass concentration, and the effect of the solvent used for oil extraction is tested. For HTL, the recovery and reuse of the water process is investigated, by recycling it into the HTL system, testing the effects of temperature and the number of recycles on the product yields. An energy analysis of the entire process, considering several process routes and conditions is presented to verify and optimize its energy profits with respect to EROEI, and eventually a process which is energetically self-sufficient is proposed. Finally a techno-economic analysis of a large-scale plant of biocrude is reported, where data from experimental results and process simulations are used to calculate the oil selling price to achieve revenues from the production of biofuel from microalgae.
I biocarburanti provenienti da biomassa microalgale sono considerati come una delle alternative migliori e più a breve termine per produrre energia pulita. Le microalghe sono microorganismi capaci di convertire l’energia solare in energia chimica che può essere sfruttata come combustibili di diverse tipologie sia liquida sia gassosa. L’obiettivo della ricerca presentata in questa Tesi é di valutare il potenziale della tecnologia per la produzione di olio da microalghe, analizzando diverse alternative e concetti sia in modo sperimentale che tramite simulazioni del processo. Il Capitolo 1 é una discussione introduttiva sulla situazione mondiale delle microalghe, recenti studi e gli ultimi risultati riportati su questa tecnologia. Dal punto di vista sperimentali, nei Capitoli 2 e 3 di questa tesi si sono approfonditi, la coltivazione di microalghe in acque reflue e la capacità che presentano alcune specie di microalghe di crescere in acque reflue non trattate, verificata con la microalga Chlorella protothecoides. La crescita é stata valutata in acque provenienti da diversi step del di trattamento delle acque, per selezionare la stream ottimale per la crescita delle microalghe. Inoltre, é stata testata la efficienza nella rimozione di nutrienti e i tassi di rimozione in acque reflue reali. Nel Capitolo 2 si riportano anche la produzione di biomassa in stato stazionario con alimentazione continua del effluente. Nel Capitolo 3 sono stati studiati gli effetti della temperatura, l’irradiazione in ciclo giorno/notte e la competizione batterica sulla crescita di C. protothecoides, e la rimozione dei nutrienti con l’obiettivo d’integrare entrambe tecnologie in un approccio realistico. É stato infine proposto uno schema modificato dell’impianto di depurazione. Il Capitolo 4 presenta il lavoro sperimentale per la valutazione della capacità di produzione di biogas da microalghe e le loro velocità di degradazione nel processo di digestione anaerobica: sono state testate diverse condizioni come la tipologia del’inoculo batterico e la concentrazione della biomassa algale all’inizio delle prove. Inoltre, questo capitolo riporta anche la ricerca nel recupero del contenuto energetico dalla biomassa residua dopo l’estrazione di olio, dimostrando che il metodo di estrazione dell’olio é un fattore importante. La produzione di biogas e sua corrispondente frazione di metano sono stati testati considerando l’effetto della miscela di solvente usato nella estrazione, e i risultati sono stati confrontati con quelli della biomassa microalgale prima della estrazione. Il Capitolo 5 é focalizzato sulla conversione di biomassa mediante il processo di liquefazione idrotermica (HTL) che viene svolto a temperature tra 200 C e 375 C (la pressione é quella necessaria per mantenere l’acqua in stato liquido), ed é caratterizzato da alte rese. Tuttavia, uno dei sottoprodotti é una fase acquosa con alto contenuto di componenti organici che deve essere trattata adeguatamente per evitare ulteriori costi. In questo capitolo si riporta il lavoro sperimentale svolto con l’obiettivo di recuperare e riutilizzare l’acqua di processo mediante un riciclo nel sistema stesso. Inoltre si é misurato l’effetto della temperatura e del numero di ricicli nelle rese di produzione di olio, gas, residuo solido e la fase acquosa e la composizione dei prodotti. Nel Capitolo 6 si riporta l’analisi energetica del processo per la produzione di biocrudo: lo studio é stato svolto considerando diverse tipologie e condizioni di processo, i quali sono stati modellati e simulati dal simulatore di processo Aspen PlusTM, col fine di verificare e ottimizzare i profitti energetici rispetto all’analisi del EROEI, e di proporre un processo energeticamente autosufficiente. Dei diversi processi studiati per ottenere energia della biomassa quello che utilizza la combustione di biomassa dopo estrazione dell’olio é risultato il più favorevole in termini energetici. In particolare, due casi di questo processo sono stati confrontati con un caso base, variando la provenienza dei requisiti energetici (calore ed elettricità), fornendoli sia da fonti esterne che dal processo steso. In ultimo, nel Capitolo 7 si riporta una valutazione tecnica di un impianto per la produzione di biodiesel da microalghe in cui si propone una nuova configurazione della sezione di crescita, un fotobioreattore ibrido, il Closed Pond Reactor (CPR). L’intero processo é stato simulato Aspen PlusTM e ottimizzato per ottenere i migliori benefici in termini energetici. La progettazione e il dimensionamento delle attrezzature tecnologiche sono stati effettuati per ottenere una stima realistica dei costi, considerando sia CAPEX (costi di capitale) e OPEX (costi operativi). Nell’analisi economica si é valutata, la redditività del processo su scala industriale e sono stati calcolati i prezzi di vendita corrispondenti dell’olio e del biodiesel necessario per rendere la produzione economicamente sostenibile.

La performance d’un module photovoltaïque est conditionnée par l’environnement dans lequel il est installé. En effet, la quantité d’énergie solaire convertie en électricité dépend de l’irradiance incidente sur le module. Les progrès dans l’intégration des modules photovoltaïques sur bâtiment et la diminution de leurs coûts amènent à considérer le potentiel solaire en milieu urbain, en toiture mais aussi en façade. En milieu urbain, la densité des bâtiments limite les apports solaires en façade par la présence de masques. La volonté publique encourage une augmentation de la production locale d’énergies renouvelables. Il est alors nécessaire de se doter d’outils numériques permettant d’évaluer avec précision le potentiel solaire en ville, et ainsi évaluer la rentabilité d’installations photovoltaïques. Il s’agit en particulier d’évaluer les apports solaires issus des réflexions sur les différentes surfaces composant la scène urbaine. Les problématiques d’intégration visuelle, soulevant la question des couleurs et des spectres incidents sur les surfaces dans différentes gammes de longueurs d’ondes doivent également être considérées Enfin, ces outils doivent également permettre d’évaluer l’impact d’une intégration photovoltaïque en milieu urbain afin d’éviter de renforcer les phénomènes d’îlot de chaleur. Les travaux de thèse se sont donc focalisés sur les méthodes de simulation d’ensoleillement en milieu urbain, au travers du développement de deux stratégies de modélisation (radiosité et lancer de rayons). Les modèles de simulation sont comparés sous des hypothèses de réflexions optiques équivalentes, permettant une validation des hypothèses utilisées dans chacune des méthodes. Parallèlement, une qualification des propriétés optiques de matériaux typiques de l’environnement urbain permet la construction de modèles de réflexion optiques basés sur les distributions de réflectivité bidirectionnelles (BRDF en anglais). Ces modèles, injectés dans les modèles d’irradiance, permettent d’évaluer la part d’énergie issue des différents modes de réflexion. Par ailleurs, des mesures d’irradiances sont réalisées en milieu extérieur. Un banc de test est conçu de sorte à mesurer les irradiances perçues en façade et au sol. Différentes configurations sont testées dans via cette maquette. Les mesures obtenues sont alors confrontées aux résultats numériques sous conditions réelles, permettant une validation des modèles
The performance of a photovoltaic module is conditioned by the environment in which it is installed. Indeed, the amount of solar energy converted into electricity depends on the incident irradiance on the module. Progress in the integration of photovoltaic modules on buildings and the reduction of their costs leads us to consider the solar potential in urban environments, both on roofs and facades. In an urban environment, the density of buildings limits solar gain on the facade by the presence of masks. Public institutes encourages an increase in the local production of renewable energies. It is therefore necessary to acquire digital tools to accurately assess the solar potential in cities, and thus evaluate the profitability of photovoltaic installations. In particular, it is necessary to evaluate the solar contributions resulting from reflections on the various surfaces that make up the urban scene. Visual integration issues, raising the question of colours and incident spectra on surfaces in different wavelength ranges must also be considered. Finally, these tools must also make it possible to assess the impact of photovoltaic integration in an urban environment in order to avoid reinforcing heat island phenomena. The PhD work is therefore focused on methods for simulating sunshine in an urban environment, through the development of two modelling strategies (radiosity and ray throwing). The simulation models are compared under the hypotheses of equivalent optical reflections, allowing a validation of the hypotheses used in each of the methods. At the same time, a qualification of the optical properties of typical materials from the urban environment allows the construction of optical reflection models based on Bidirectional Reflectivity Distributions Functions (BRDF). These models are integrated into the irradiance models. Therefore, it possible to evaluate the ratio of energy resulting from the different reflection modes. In addition, irradiance measurements are carried out in an external environment. A test bench is designed to measure the irradiances perceived on the facade and on the ground. Different configurations are tested using this mock-up. The measurements obtained are then compared with the numerical results under real conditions, enabling the models to be validated

Thesis 'Analysis of non-current tangible assets in selected entities ' deals with the non-current tangible assets from the point of view of the Czech legislation and IFRS. The theoretical part of the thesis characterises non-current tangible assets in terms of IFRS, which together with examples concern with the issues of definition and evaluation. The Czech legislation is compared with IFRS and the main differences are marked out that prevent a unified view of non-current tangible assets adjusted according to IFRS and the Czech accounting standards. The practical aspect is reflected in an empirical research that analyses non-current tangible assets in entities operating in the area of power and food industries.

This master’s thesis is dealing with the plan of reconstruction of the house in an effort to get closer to "near zero building". Total heat loss along with calculation of the cost of the house operation and the energy performance of buildings were computed for the given house. Then we have enclosed suggestions of individual methods of building´s insulation (replacing of windows, doors and gates, insulation of exterior walls, roof and ceiling between floor and attic) and a draft of a new technical building services (forced ventilation with heat recovery, photovoltaic system and heat pump). Furthermore, the suitability of the original heating system was evaluated and the also the energy performance for the renovated building was analyzed during the reconstruction. An economic evaluation was calculated for each method of reconstruction, together with the new green subsidy programme. At the end of the dissertation is drawn up the economic evaluation of the whole proposed reconstruction, together with an assessment, what class of the building we have achieved according to its the energy intensity.

Energetická náročnost a ekonomická životaschopnost jsou často skloňované pojmy spojené s aquaponickým způsobem produkce potravin. Tato práce si klade za cíl nalézt opatření, která by zvýšila ziskovost podnikání v oblasti aquaponie a zároveň by snížila energetickou náročnost procesu a spotřebu dalších zdrojů. Součástí práce je následné ověření vybraných opatření na zkušební aquaponické farmě. K vyřešení otázky úspory energie a vody byly použity optimalizační metody vycházející z procesního inženýrství. Pro účely automatického monitoringu růstu rostlin, jakožto hlavního zdroje příjmů v aquaponii, byla využita technologie počítačového vidění. Za využití optimalizační metody zvané P-graph, integrace procesů a hledání procesních alternativ bylo nalezeno nejlepší možné uspořádání procesní sítě, které vykazovalo více než devítinásobný čistý roční příjem ve srovnání se současným uspořádáním procesních zařízení v aquaponické farmě. Dalších úspor energie a vody bylo dosaženo instalací reflexních fólií na okraje pěstebních boxů a dalším využitím odpadní vody z aquaponické části farmy v hydroponické sekci určené k pěstování sazenic. Tato opatření mohou napomoci aquaponickým farmám zvýšit konkurenceschopnost a snížit jejich dopad na životní prostředí.

The use of gas microturbines as a primary unit in CHP is still weak in the industrial process. It gives the driving force to the main aim of this master thesis, which is the technical and economic evaluation of the gas microturbines waste heat recovery system, which is the key factor for their economic sustainability. Assignment contains description of CHP system that was gradually built in LENP laboratory, part of NETME Centre. The author has joined the final work before start-up of the CHP system. He presents and describes results of the first experiments on this unit. The flue gas of a microturbine was used for heating water by heat exchanger flue gas–water and for direct linen drying. The case study of laundry with capacity 10 tons per shift was developed in cooperation with companies in laundry care. Results of those tests were used to process integration and utilization of this professional industrial laundry All obstacles found and opportunities of the use of microturbines are comprehensively described and tested in case studies, which are simulated in Chemstation Chemcad Software. Results of the thesis are expected to be useful these fields: the use of gas microturbines in industry & energy savings in industrial laundries.

In 2007, in June the company Europrojekt entered the project with the requirement of the formulation and implementation of heating motherly school by heat pumps in the village Hluk. The projekt was ordered by the management of this motherly school. This is a total reconstruction of the heating system building motherly school, including the use of residual heat for heating the pool water in an open swimming pool, which is located near this motherly school. The requirement is also given to reduce environmental pollution and achieve energy savings. This diploma thesis solves the detailed description of solutions and calculations for each part. In first, the introductory part of the work is focused on getting the project, a description of the object motherly school and a proposal for the energy measure before the realization. Second section is devoted to the selection and design of the system of heat pumps and solar collectors. Next part of work is the use of the residual heat for heating the pool water in the transitional months, i.e. May, September and the main months June, July, and August, when should be the visit of the swimming pool the biggest. In addition, resolving heat recovery through plate exchangers, the calculation of storage tanks, valves insurance proposal, the expansion tank, circulation pumps, etc. The last part thesis addresses the energy and economic assessment of the whole project.

The master’s thesis on the topic Low- energy kindergarten is processed in the form of project documentation for the implementation of the new building. The building is designed on a plot of 1350/5 in the cadastral Karviná. It is the kindergarten with a basement and two floors. The building contains two classes for a total of 48 children. Food is provided by imports.

Biofuels started to raise interest almost 40 years ago, when the Arab oil embargo pushed oil prices up and therefore spurred the research towards new forms of energy. Nevertheless, biofuel production has not really taken off until recently, when the combination of high oil prices, concern about greenhouse gas emissions, and the progressive reduction of oil reserves induced many countries across the world to implement policies encouraging biofuels production. At the beginning of the 2000s, biofuels were seen as a panacea for energy security (domestic energy source, highly reliable), economic stability (energy price stability, rural development, employment generation, reduce supply-demand gap for agricultural commodities), and for environment protection (better waste utilization, GHG emissions reduction), especially after the drawing up of the Kyoto protocol, according to which signatory countries had to reduce their GHG emissions by about 5% from their 1990 levels, by 2012. Biofuels are currently produced from agricultural commodities, therefore their repercussions on the agricultural and food sector might be substantial. In this framework it is clear that the responsibility that big countries (those able to affect world prices) have is substantial. Countries like the US, Brazil, and the EU have been encouraging biofuel production in recent years and ended up artificially creating a new market for agricultural commodities without fully understanding, a priori, the possible negative consequences of such decision. They decided to subsidize renewables because of the increased pressure by the public opinion towards greenhouse gas emissions reduction, reduce dependency on oil imports, and the need to meet the targets set by both the Kyoto protocol. Biofuel expansion took place not only in a controversial manner, without coordination at international level, but also in a critical historical moment. The past two decades have been characterized by a strong increase in world food demand, mainly due to economic expansion in emerging economies like China, India, Brazil, and some South East Asian countries. The strong increase in demand faces an agricultural supply that in the short period is inevitably inelastic, which results in higher prices and higher volatility (due to reduced stocks). Much of the initial enthusiasm towards biofuels has been declining in the last few years. First of all, biofuel expansion has increased the demand for many agricultural commodities, which, in a framework of increasing food demand in the world, triggered a sharp increase in agricultural prices with strong negative implications for poor people especially in developing countries. Many doubts have also been raised concerning the real effectiveness of biofuels in reducing GHG emissions. Emission-computing methodologies are not always accurate and sometimes are difficult to put in practice. Agriculture intensification and land use changes, both consequences of biofuel expansion, are two of the factors more likely to have increased GHG emissions rather than reduced. Furthermore, biofuel policies have been designed and implemented by countries on an individual basis, without the coordination at international level that would have been needed to avoid the numerous side-effects that biofuels have been having on international food markets and on the environment. My doctorate research analyzes all aspects of the biofuel sector at world level with special emphasis on its sustainability under an economic, environmental, and ethical point of view. The research starts with a description of what biofuels are and in which sub-categories they can be divided. Then, it provides a review of biofuel policies around the world and data on production, prices and trade. The work also provides figures on production, prices and trade of the main agricultural commodities used for biofuel production and the evolution of cropped and forest areas worldwide in the last twenty years. Main biofuel producers are the US, Brazil and the EU. In the first two countries is ethanol the main biofuel produced (obtained from corn in the US and from sugarcane in Brazil), while in the EU the leasing biofuel is biodiesel (from vegetable oils). In 2011, 51.8% of Brazilian sugarcane production and 42.2% of US corn production were used to produce ethanol. Areas cropped with sugarcane and corn, in the two countries were 4.2 and 15.5 million hectares in 2011, which correspond to 1.5% and 16% of total agricultural area respectively. By 2021 ethanol production will absorb almost 61% of Brazilian sugarcane production and 57% of US corn production, ceteris paribus. In 2021 the amount of land needed to grow all sugarcane needed to produce ethanol in Brazil will be more than 8 million hectares, almost equal to the entire current sugarcane area in the South American country. In the US the area that will be needed to cultivate corn for ethanol production will grow to slightly less than 20 million hectares, equal to 53% of current corn area in the US and 20% of current total agricultural area. These data highlight the different impact sugarcane- and corn-based ethanol have on agricultural production. Brazilian and American ethanol production was 22.9 and 52.8 million m3 in 2011 respectively, implying an “ethanol yield” of 5.5 m3/hectare for sugarcane ethanol and of 3.4 m3/hectare for corn-ethanol. This means that producing ethanol from sugarcane is more efficient and less consuming in terms of land than corn-ethanol. Considering also biodiesel, the amount of land needed to crop biofuel feedstocks, in Brazil and the US grows to 3 and 18.4% of total agricultural land. These areas are forecasted to increase to 6.3 and 23% by 2021, implying an increasing competition for land. In 2011 the EU used 5.4 million tons of domestically produced rapeseed oil and at least 3.9 million tons of imported palm oil to make biodiesel. The amount of land needed to grow rapeseed within the Union and oil palm in third countries (mainly Indonesia and Malaysia) was 5.2 and 1.3 million hectares respectively. The area needed to crop rapeseed for biodiesel production, in the EU, was equal to 5.2% of total agriculture area. Assuming that the percentage of rapeseed oil on total vegetable oil production in the EU will remain the same of 2011 and that the share of it employed in the food sector will also remain unchanged, it is possible to forecast that, in 2021, the EU will need 6.6 million tons of rapeseed oil and at least 10 million tons of palm oil from third countries to meet its consumption targets. This means that at least 3.4 million hectares of land, in South East Asia will be needed to produce palm oil destined to the EU. The core of the thesis is the analysis of the sustainability of biofuels on one hand, and of biofuels’ implications on food production on the other. The sustainability of biofuel production is analyzed through a literature review and re-interpretation of the existing literature on the topic, encompassing effects of mass biofuel production on the environment, GHG emissions, land use changes, water availability, and implications for developing countries. One of the most important aspects of biofuel sustainability is their effects on agricultural production and agricultural prices. The empirical part of this thesis employs econometric tools to assess the degree of integration between energy and agricultural markets in the main biofuel producing countries and price transmission elasticity between international and EU agricultural markets before and after the last reform of the CAP. In the US and in Brazil energy and agricultural prices move together in the long-run and the influence of oil prices has been growing over time. This means that policy-makers, in the future, will have to pay great attention to the mutual influence energy and agricultural policies can have on each other. In Europe this close relationship between energy and agricultural prices was not detected, however European agricultural markets have been influenced by biofuel policies in the US, and to a lesser extent Brazil, indirectly, through their effects on international commodity prices. What emerges from this work is that biofuels, in the current political, economic demographic, situation are, for many aspects, not sustainable. Side-effects of biofuel production are many and often even difficult to quantify. Solutions provided are often utopic or, even if good in theory, very difficult to implement. Biofuel production has been having negative effects on food production and prices, biodiversity and social welfare in the last decade, inside and outside the countries of production. The “original sin” was the initial lack of coordination between policies issued unilaterally by different countries, something that now seems extremely difficult to fix. Governments should, as it has been recently suggested by the United Nations, consider the option of modifying their biofuel programs because of their negative consequences on food security in many low-income countries. Also the promotion and implementation of biofuel policies in developing countries should be avoided as a measure for fostering development. It is very unlikely that rural poor will benefit from policies subsidizing the biofuel sector since most of the land in developing countries is owned by big multinational companies or by foreign states (land grabbing). The development of the biofuel sector would also increase food prices even in countries where such increase has been marginal so far because of scarce price transmission from the world market. Poor people living in urban areas would be worse off by higher food prices as well as small farmers who, in developing countries, are often net-purchasers of food. It has been suggested by many scholars and international organizations that, in order to become sustainable, biofuel production should shift from first-generation to second-generation technologies (those that allow the use of non-food crops or wastes for biofuel production). This will not be easy to achieve. Current second-generation biofuel production is still very small and will not grow substantially unless major investments are made by governments and, under the right conditions, private companies. Moreover it is not governments nor policy-makers who decides whether is profitable to put marginal land under cultivation and to crop non-food biofuel crops on it. Farmers are those making such decisions and they will not do it unless it is profitable. Current record-high agricultural commodity prices raise many doubts on the fact that farmers will shift from food to non-food crops without substantial government subsidies. An increase in subsidies to the agricultural sector, even just for energy crops, is unlikely to happen anytime soon because of the financial and economic crisis that hit many countries around the world and because of pressure by the WTO and other international organizations to reduce the degree of protection. In case it will be decided to keep subsidizing biofuels, new polices will have to be designed and implemented at world level, needing a very high degree of coordination between countries and flexibility, which is difficult to imagine can be reached in the short or even the medium term. An emblematic case, in this sense, is GHG emission accounting mechanisms that currently are based on life-cycle assessment analysis and that are often incomplete (i.e. limited to a single country or region) or unable to take all factors into account (i.e. indirect land-use changes). Research, in the next years, will have to focus on two main topics. On one hand second- and third-generation techniques for biofuel production will have to be refined and made economically (but also environmentally and socially) viable, possibly together with progressive reduction in the support in favor of first-generation biofuels. On the other hand, a better definition of the methodologies to assess the environmental, economic and social impacts of biofuel production will be crucial in order to correctly evaluate the sustainability of biofuel programs. In particular, the development of reliable methodologies to assess the environmental impact of biofuel production is very important since, in the future, subsidies could be calculated in a way to reward the production of biofuels able to provide (proved) positive externalities to the environment as well as increase social welfare.
Di biocarburanti si iniziò a parlare circa 40 anni fa, in concomitanza con la crisi petrolifera determinata dall’embargo da parte dei paesi OPEC. Il conseguente forte aumento del prezzo del petrolio stimolò infatti la ricerca nel campo delle forme di energia alternative. La produzione di biocarburanti è tuttavia decollata solo di recente, grazie all’azione combinata di molteplici fattori: elevate quotazioni del petrolio, necessità di contenere le emissioni di gas serra e la riduzione delle scorte di combustibili fossili; tutte cose che hanno indotto molti paesi a mettere a punto programmi volti allo sviluppo del settore dei biocarburanti. All’inizio degli anni 2000 i biocarburanti venivano considerati la soluzione ideale per risolvere i problemi dell’approvvigionamento energetico, della stabilità economica (stabilizzazione dei prezzi dell’energia, sviluppo rurale, creazione di posti di lavoro, aumento della domanda di materie prime agricole) e della protezione dell’ambiente (utilizzazione più efficiente dei rifiuti e riduzione delle emissioni di gas serra). Un impulso decisivo allo sviluppo delle politiche fu dato dalla stipula del Protocollo di Kyoto nel quale i paesi firmatari si impegnavano a ridurre le proprie emissioni di gas serra del 5% rispetto ai livelli del 1990 entro il 2012. Al momento attuale i biocarburanti vengono in larga parte prodotti a partire da materie prime agricole, quindi le ripercussioni della loro produzione sul settore agricolo possono essere rilevanti. In tale àmbito appare chiara la forte responsabilità, in termini di effetti sui mercati agricoli mondiali, che hanno i paesi che più di tutti hanno sovvenzionato il settore: Stati Uniti, Brasile e Unione Europea. Tali paesi, tramite le loro politiche, hanno creato un nuovo mercato di sbocco per molte materie prime agricole, senza capire a fondo, a priori, le conseguenze di tale azione. Le principali motivazioni addotte dai decisori politici per giustificare le sovvenzioni al settore dei biocarburanti furono la necessità di ottemperare ai dettami del Protocollo di Kyoto, aumentare l’indipendenza energetica, creare nuovi posti di lavoro, migliorare il reddito degli agricoltori e stabilizzare i prezzi dell’energia. L’espansione del settore dei biofuel è avvenuta non solamente in maniera quantomeno controversa, senza coordinazione a livello internazionale, ma anche in un momento storico molto delicato. Gli ultimi venti anni sono stati infatti caratterizzati da un grande aumento della domanda mondiale di cibo, soprattutto a causa della forte crescita economica dei cosiddetti paesi emergenti: Cina, India, Brasile e paesi del Sud-Est asiatico. Il forte aumento della domanda si scontra contro un’offerta di materie prime agricole giocoforza rigida nel breve termine, cosa che genera forti aumenti di prezzo e della volatilità delle quotazioni (soprattutto a causa del forte ridimensionamento delle scorte). Negli ultimi anni gran parte dell’entusiasmo iniziale nei confronti dei biocarburanti è andato scemando. Per prima cosa l’espansione del settore dei combustibili “verdi” ha aumentato la domanda per molte materie prime agricole che, in un contesto contraddistinto da un forte aumento della domanda mondiale, ha generato un sensibile aumento dei prezzi alimentari, con ripercussioni particolarmente negative per le fasce più povere della popolazione, soprattutto nei paesi meno sviluppati. Anche l’effettiva efficacia dei biocarburanti nel ridurre le emissioni di gas serra è stata fortemente messa in dubbio. Le metodologie utilizzare per il conteggio delle emissioni non sono sempre accurate o di facile attuazione. L’intensivizzazione dei processi agricoli e i cambiamenti d’uso dei suoli, entrambi conseguenza dell’aumento della produzione agricola, sono due fattori che molto probabilmente hanno causato un aumento delle emissioni di gas serra invece che una diminuzione. Inoltre, le politiche a favore del settore delle energie rinnovabili sono state progettate e messe in pratica in maniera spesso unilaterale da parte dei vari paesi, senza quella coordinazione a livello internazionale che sarebbe stata essenziale a evitare le conseguenze negative sui mercati agricoli e sull’ambiente. La mia ricerca di dottorato analizza tutti gli aspetti del settore dei biocarburanti a livello mondiale con particolare attenzione a quelli della sostenibilità: economica, ambientale e sociale. La ricerca inizia con una descrizione delle varie tipologie di biocarburanti attualmente prodotti a livello mondiale e prosegue con una rassegna delle politiche a favore dei biocarburanti nei principali paesi. In séguito vengono analizzate le produzioni, i prezzi e il commercio internazionale di biocarburanti e delle materie prime dalle quali sono ottenuti. I principali paesi produttori di biocarburanti sono gli Stati Uniti, il Brasile e l’Unione Europea. Nei primi due viene prodotto principalmente etanolo (a partire dal mais negli Stati Uniti e dalla canna da zucchero in Brasile), mentre nell’Unione Europea è il biodiesel il biocarburante di riferimento (prodotto a partire da oli vegetali). Nel 2011, il 51,8% della produzione brasiliana di canna da zucchero e il 42,2% di quella statunitense di mais sono state usate per produrre etanolo. Le superfici necessarie, nei due paesi, per la coltivazione della materia prima per la produzione del biocarburante sono state pari a 4,2 e 15,5 milioni di ettari, che rappresentano l’1,5 e il 16% della superficie agricola totale dei due paesi. Nel 2021, ceteris paribus, la produzione di etanolo assorbirà circa il 61% della produzione brasiliana di canna da zucchero e il 57% di quella statunitense di mais. Sempre nel 2021, in Brasile, le superfici necessarie per coltivare canna da zucchero destinata la settore dell’etanolo raggiungeranno gli 8 milioni di ettari, pari a tutta l’area attualmente coltivata a canna da zucchero nel paese sudamericano. Negli Stati Uniti le superfici necessarie a coltivare il granturco per la produzione di etanolo cresceranno fino a sfiorare i 20 milioni di ettari, un’estensione pari al 53% dell’area attualmente investita a mais e al 20% della superficie agricola totale del 2011. Da questi dati è possibile osservare la forte differenza, in termini di impatto sulle produzioni agricole, tra la produzione di etanolo brasiliana (imperniata sulla canna da zucchero) e quella statunitense (basata sul mais). La produzione brasiliana e statunitense di etanolo, nel 2011, è stata rispettivamente di 22,9 e 52,8 milioni di metri cubi, implicando una “resa” in etanolo di 5,5 e 3,4 metri cubi a ettaro. Ciò significa che la produzione di etanolo a partire dalla canna da zucchero è più efficiente in termini di superfici necessarie alla coltivazione della materia prima. Tenendo in considerazione anche il biodiesel, in rapida espansione in entrambi i paesi (dove viene ottenuto a partire dall’olio di soia), l’incidenza percentuale delle superfici utilizzate per coltivare la materia prima per la produzione di biocarburanti (etanolo e biodiesel) cresce fino a raggiungere il 3% del totale della superficie agricola in Brasile e il 18,4% negli Stati Uniti. Tali percentuali sono destinate a raggiungere il 6,3 e il 23% entro il 2021. Nel 2011 l’Unione Europea ha impiegato 5,4 milioni di tonnellate di olio di colza (prodotto all’interno dell’Unione) e almeno 3,9 milioni di olio di palma (importato da Indonesia e Malesia) per produrre biodiesel. Le superfice necessaria, all’interno dell’UE, per la coltivazione della colza usata nel settore dei biocarburanti è stata di 5,2 milioni di ettari nel 2011, mentre quella impiegata per la produzione di olio di palma nei paesi terzi di almeno 1,3 milioni di ettari. Sempre nel 2011, il 5,2% della superficie agricola totale dell’Unione è stato utilizzato per la coltivazione di colza da destinare alla produzione di biocarburanti. Assumendo che la percentuale di olio di colza impiegata nel settore alimentare nell’Unione Europea rimarrà la stessa anche negli anni a venire, è possibile prevedere che, nel 2021, l’UE avrà bisogno di 6,6 milioni di tonnellate di olio di colza e di almeno 10 milioni di tonnellate di olio di palma (importato da paesi terzi) per raggiungere i suoi obiettivi di consumo in materia di biodiesel. Ciò implica che almeno 3,4 milioni di ettari di terreni, presumibilmente in Indonesia e Malesia, saranno necessari per produrre tutto l’olio di palma di cui il settore del biodiesel comunitario avrà bisogno. Il fulcro di questa tesi è l’analisi della sostenibilità della produzione di biocarburanti e le sue conseguenze sulla produzione di materie prime agricole. La sostenibilità dei biocarburanti viene esaminata attraverso una revisione della letteratura esistente sull’argomento, con particolare enfasi sugli effetti della forte espansione del settore dei carburanti “verdi” sull’ambiente, sulle emissioni di gas serra, i cambiamenti d’uso del suolo, la disponibilità idrica e le implicazioni per i paesi in via di sviluppo. In termini di sostenibilità, uno degli aspetti più importanti riguarda gli effetti del forte aumento della produzione di biofuel sulla produzione e sui prezzi delle materie prime agricole. Questa tesi, nella sua parte empirica, utilizza tecniche econometriche per misurare il livello di integrazione tra i mercati energetici e quelli agricoli nei principali paesi produttori. Viene inoltre anche stimata l’elasticità di trasmissione dei prezzi tra il mercato mondiale e quello comunitario nel caso delle principali materie prime agricole, prima e dopo l’ultima riforma della Politica agricola comune (Riforma Fischler). Negli Stati Uniti e in Brasile i prezzi agricoli e quelli dell’energia (petrolio ed etanolo) condividono il medesimo trend di lungo periodo, con l’influenza del prezzo del petrolio che è andata crescendo negli ultimi anni. Ciò implica che i decisori politici dovranno, in futuro, prestare grande attenzione agli effetti che le politiche energetiche hanno sui mercati agricoli e viceversa. In Europa non è stato possibile dimostrare la presenza di una relazione diretta tra prezzi agricoli e prezzo del petrolio, tuttavia è possibile affermare che i mercati agricoli europei subiscano le conseguenze delle politiche a favore dei biocarburanti di altri paesi, in particolare degli Stati Uniti, in maniera indiretta, cioè tramite l’effetto di tali politiche sui prezzi internazionali. Ciò che merge da questo lavoro è che i biocarburanti, nella situazione economica, politica e demografica attuale, sono, per molti aspetti, non sostenibili. Gli effetti collaterali della produzione di biofuel sono numerosi e spesso difficili da quantificare. Le soluzioni proposte dalla letteratura sono spesso utopiche o, seppur corrette dal punto di vista teorico, molto difficili da applicare. L’espansione del settore dei biocarburanti sta avendo effetti negativi sulla produzione e sui prezzi delle materie prime agricole, sulla biodiversità e sul benessere sociale, sia all’interno dei principali paesi produttori che all’esterno di essi. Il “peccato originale” è stato la mancanza di coordinazione iniziale tra le varie politiche, progettate e messe in pratica in maniera unilaterale dai vari paesi; una cosa alla quale, oggi, è molto difficile porre rimedio. I governi dovrebbero, come è stato recentemente raccomandato dalle Nazioni Unite, considerare la possibilità di modificare in maniera sostanziale i propri programmi di sviluppo del settore dei biocarburanti a causa soprattutto delle pesanti conseguenze che hanno sulla sicurezza alimentare nei paesi a basso reddito. Per questa ragione l’utilizzo dei biocarburanti come misura volta a stimolare lo sviluppo nei paesi poveri dovrebbe essere evitata. È altamente improbabile che i poveri nelle zone rurali traggano alcun beneficio dallo sviluppo del settore dei biocarburanti nei loro paesi poiché gran parte della terra è posseduta da grandi compagnie multinazionali o, in alcuni casi, da paesi terzi (land grabbing). Lo sviluppo del settore dei biocarburanti nei paesi in via di sviluppo contribuirebbe, dall’interno, a mantenere elevati i prezzi dei generi alimentari anche dove finora tale effetto, a causa del basso livello di trasmissione dei prezzi agricoli mondiali, è stato marginale. L’aumento dell’inflazione alimentare causato dalla produzione di biocarburanti avrebbe effetti negativi sia sui poveri delle aree urbane che sue quelli delle aree rurali poiché in molti casi i piccoli coltivatori, nei paesi in via di sviluppo, sono compratori netti di generi alimentari. Molti studi, anche da parte di organizzazioni governative internazionali, mettono in risalto il fatto che la produzione di biocarburanti possa diventare sostenibile solo attraverso lo sviluppo delle cosiddette tecnologie di seconda o terza generazione (cioè quelle che permettono l’uso di materia prima non-food per la produzione di biocarburanti) e l’uso di terreni degradati e marginali per la coltivazione delle materie prime. Tuttavia, tutto ciò è di difficile realizzazione. Attualmente i biocarburanti di seconda o terza generazione sono ancora in fase di sviluppo e la loro produzione non crescerà in maniera sostanziale se non tramite forti investimenti da parte dei vari governi e, in determinate circostanze, di investitori privati. Va ricordato che non sono i governi quelli che decidono se la coltivazione di materia prima per la produzione di biocarburanti in aree degradate o marginali sia economicamente conveniente: sono infatti i coltivatori quelli che prendono le decisioni ed essi non lo faranno se non vi troveranno alcun beneficio economico. L’attuale livello, molto elevato, dei prezzi agricoli pone seri dubbi sul fatto che i coltivatori siano disposti a passare dalla produzione di materie prime food a quelle non-food in assenza di forti incentivi pubblici in tal senso. Tuttavia, un aumento del livello di supporto all’agricoltura, anche solo nel caso delle colture energetiche, difficilmente avverrà nel breve termine, a causa soprattutto della crisi economica, che ha ristretto i budget di spesa di molti paesi, e le pressioni, in sede WTO, per una riduzione del livello di protezione dei mercati. Nel caso in cui si decida di mantenere gli aiuti di stato al settore dei biocarburanti, sarà necessario progettare e sviluppare nuove politiche, questa volta a livello sovranazionale, cosa che implicherebbe un elevato livello di coordinazione e di flessibilità tra i vari paesi, oltre che difficile da raggiungere nel breve o medio termine. Un caso emblematico, in tal senso, è rappresentato dalle metodologie di conteggio delle emissioni di gas serra che sono attualmente basate sull’analisi del ciclo di vita e che sono molto spesso incomplete (limitate, ad esempio, a determinati paesi o regioni) o ancora non in grado di considerare il ruolo di tutti i fattori (es. cambiamenti indiretti d’uso del suolo). La ricerca, negli anni a venire, dovrà focalizzarsi su due argomenti principali. Da una parte, le tecniche di produzione dei biocarburanti di seconda e terza generazione dovranno essere raffinate, rese economicamente convenienti e sostenibili dal punto di vista sociale e ambientale. Possibilmente ciò dovrà avvenire di pari passo con la progressiva riduzione del livello di supporto ai biocarburanti di prima generazione. Dall’altra parte, sarà necessario definire meglio le metodologie di quantificazione dell’impatto dei biocarburanti in termini ambientali, economici e sociali, in modo da determinare con certezza la loro sostenibilità e da consentire lo sviluppo di politiche più appropriate. In particolare, la messa a punto di metodologie affidabili per la valutazione dell’impatto dei vari biocarburanti è molto importante poiché, in futuro, le sovvenzioni potrebbero essere calcolate in maniera tale da premiare la produzione di quei biocarburanti in grado di fornire esternalità positive per l’ambiente e il benessere sociale.

The subjects of this thesis are low-energy and passive houses. The main objective is to compare the acquisition costs and operating cost of the low energy and passive houses with conventional construction of houses offering the real estate market, respectively evaluating of investments in energy-efficient buildings. Furthermore, the work focuses on the history, properties and basic problems of designing energy efficient buildings with subsequent by an assessment of the advantages and disadvantages of their implementation. Klíčová slova

Despite significant efforts have been directed toward reducing waste generation and encouraging alternative waste management strategies, landfills still remain the main option for Municipal Solid Waste (MSW) disposal in many countries. Hence, landfills and related impacts on the surroundings are still current issues throughout the world. Actually, the major concerns are related to the potential emissions of leachate and landfill gas into the environment, that pose a threat to public health, surface and groundwater pollution, soil contamination and global warming effects. To ensure environmental protection and enhance landfill sustainability, modern sanitary landfills are equipped with several engineered systems with different functions. For instance, the installation of containment systems, such as bottom liner and multi-layers capping systems, is aimed at reducing leachate seepage and water infiltration into the landfill body as well as gas migration, while eventually mitigating methane emissions through the placement of active oxidation layers (biocovers). Leachate collection and removal systems are designed to minimize water head forming on the bottom section of the landfill and consequent seepages through the liner system. Finally, gas extraction and utilization systems, allow to recover energy from landfill gas while reducing explosion and fire risks associated with methane accumulation, even though much depends on gas collection efficiency achieved in the field (range: 60-90% Spokas et al., 2006; Huitric and Kong, 2006). Hence, impacts on the surrounding environment caused by the polluting substances released from the deposited waste through liquid and gas emissions can be potentially mitigated by a proper design of technical barriers and collection/extraction systems at the landfill site. Nevertheless, the long-term performance of containment systems to limit the landfill emissions is highly uncertain and is strongly dependent on site-specific conditions such as climate, vegetative covers, containment systems, leachate quality and applied stress. Furthermore, the design and operation of leachate collection and treatment systems, of landfill gas extraction and utilization projects, as well as the assessment of appropriate methane reduction strategies (biocovers), require reliable emission forecasts for the assessment of system feasibility and to ensure environmental compliance. To this end, landfill simulation models can represent an useful supporting tool for a better design of leachate/gas collection and treatment systems and can provide valuable information for the evaluation of best options for containment systems depending on their performances under the site-specific conditions. The capability in predicting future emissions levels at a landfill site can also be improved by combining simulation models with field observations at full-scale landfills and/or with experimental studies resembling landfill conditions. Indeed, this kind of data may allow to identify the main parameters and processes governing leachate and gas generation and can provide useful information for model refinement. In view of such need, the present research study was initially addressed to develop a new landfill screening model that, based on simplified mathematical and empirical equations, provides quantitative estimation of leachate and gas production over time, taking into account for site-specific conditions, waste properties and main landfill characteristics and processes. In order to evaluate the applicability of the developed model and the accuracy of emissions forecast, several simulations on four full-scale landfills, currently in operative management stage, were carried out. The results of these case studies showed a good correspondence of leachate estimations with monthly trend observed in the field and revealed that the reliability of model predictions is strongly influenced by the quality of input data. In particular, the initial waste moisture content and the waste compression index, which are usually data not available from a standard characterisation, were identified as the key unknown parameters affecting leachate production. Furthermore, the applicability of the model to closed landfills was evaluated by simulating different alternative capping systems and by comparing the results with those returned by the Hydrological Evaluation of Landfill Performance (HELP), which is the most worldwide used model for comparative analysis of composite liner systems. Despite the simplified approach of the developed model, simulated values of infiltration and leakage rates through the analysed cover systems were in line with those of HELP. However, it should be highlighted that the developed model provides an assessment of leachate and biogas production only from a quantitative point of view. The leachate and biogas composition was indeed not included in the forecast model, as strongly linked to the type of waste that makes the prediction in a screening phase poorly representative of what could be expected in the field. Hence, for a qualitative analysis of leachate and gas emissions over time, a laboratory methodology including different type of lab-scale tests was applied to a particular waste material. Specifically, the research was focused on mechanically biologically treated (MBT) wastes which, after the introduction of the European Landfill Directive 1999/31/EC (European Commission, 1999) that imposes member states to dispose of in landfills only wastes that have been preliminary subjected to treatment, are becoming the main flow waste landfilled in new Italian facilities. However, due to the relatively recent introduction of the MBT plants within the waste management system, very few data on leachate and gas emissions from MBT waste in landfills are available and, hence, the current knowledge mainly results from laboratory studies. Nevertheless, the assessment of the leaching characteristics of MBT materials and the evaluation of how the environmental conditions may affect the heavy metals mobility are still poorly investigated in literature. To gain deeper insight on the fundamental mechanisms governing the constituents release from MBT wastes, several leaching experiments were performed on MBT samples collected from an Italian MBT plant and the experimental results were modelled to obtain information on the long-term leachate emissions. Namely, a combination of experimental leaching tests were performed on fully-characterized MBT waste samples and the effect of different parameters, mainly pH and liquid to solid ratio (L/S,) on the compounds release was investigated by combining pH static-batch test, pH dependent tests and dynamic up-flow column percolation experiments. The obtained results showed that, even though MBT wastes were characterized by relatively high heavy metals content, only a limited amount was actually soluble and thus bioavailable. Furthermore, the information provided by the different tests highlighted the existence of a strong linear correlation between the release pattern of dissolved organic carbon (DOC) and several metals (Co, Cr, Cu, Ni, V, Zn), suggesting that complexation to DOC is the leaching controlling mechanism of these elements. Thus, combining the results of batch and up-flow column percolation tests, partition coefficients between DOC and metals concentration were derived. These data, coupled with a simplified screening model for DOC release, allowed to get a very good prediction of metal release during the experiments and may provide useful indications for the evaluation of long-term emissions from this type of waste in a landfill disposal scenario. In order to complete the study on the MBT waste environmental behaviour, gas emissions from MBT waste were examined by performing different anaerobic tests. The main purpose of this study was to evaluate the potential gas generation capacity of wastes and to assess possible implications on gas generation resulting from the different environmental conditions expected in the field. To this end, anaerobic batch tests were performed at a wide range of water contents (26-43 %w/w up to 75 %w/w on wet weight) and temperatures (from 20-25 °C up to 55 °C) in order to simulate different landfill management options (dry tomb or bioreactor landfills). In nearly all test conditions, a quite long lag-phase was observed (several months) due to the inhibition effects resulting from high concentrations of volatile fatty acids (VFAs) and ammonia that highlighted a poor stability degree of the analysed material. Furthermore, experimental results showed that the initial waste water content is the key factor limiting the anaerobic biological process. Indeed, when the waste moisture was lower than 32 %w/w the methanogenic microbial activity was completely inhibited. Overall, the obtained results indicated that the operative conditions drastically affect the gas generation from MBT waste, in terms of both gas yield and generation rate. This suggests that particular caution should be paid when using the results of lab-scale tests for the evaluation of long-term behaviour expected in the field, where the boundary conditions change continuously and vary significantly depending on the climate, the landfill operative management strategies in place (e.g. leachate recirculation, waste disposal methods), the hydraulic characteristics of buried waste, the presence and type of temporary and final cover systems.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. August 2014.
Human immunodeficiency virus (HIV), the causative agent of the acquired immunodeficiency syndrome (AIDS), remains a topic of global concern even though great strides have been made to combat the virus. The high replicative rate of the virus and recombination of the variety of viral strains complicate the treatment of AIDS. There has been an increasing prevalence of African HIV strains in the Americas and Europe. The viral protease (PR) is vital for the propagation of the virus; and thus, is a major target in antiviral therapy. The HIV-1 PR enzyme from the subtype C strain; which predominates in sub- Saharan Africa, has been greatly under-investigated in comparison to the protease from the subtype B strain which predominates in North America and Europe. Enzyme activity data which were part of this work suggested that the South African HIV-1 subtype C protease (CSA PR) displays improved substrate turnover in comparison to the subtype B PR. Thermodynamics and inhibition kinetics of drug binding showed that the C-SA PR is less susceptible to certain clinically-used protease inhibitors when compared to the subtype B PR. A crystal structure of the C-SA PR was solved and showed no difference to the global structure of the subtype B PR. Molecular dynamics simulations showed that the C-SA PR exhibits a wider range of open conformations. Hydrogen/deuterium exchange-mass spectrometry (HDX-MS) was performed to elucidate the mechanism of reduced drug susceptibility displayed by the C-SA PR. HDX-MS data provided insights into the basis of the increased preference for open conformers displayed by the C-SA PR and the stability of the terminal dimer interface which is a target in protease inhibition.

博士
雲林科技大學
工程科技研究所博士班
98
This study was role of the green thermal analysis technology in promoting the use of resources, preventing pollution, reducing energy consumption and protecting the ecology and environment. A reaction kinetic model on thermal decomposition properties for energetic materials, such as 2,4,6,8,10,12-hexanitro- 2,4,6,8,10,12-hexaaza-isowurtzitane (HNIW), octahydro-1,3,5,7-tetranitro-1,3,5,7- tetrazocine (HMX), l,3,5-trinitro-l,3,5-triazmane (RDX), tert–butyl peroxybenzoate (TBPB), and multi-walled carbon nanotubes (MWCNTs) via differential scanning calorimetry (DSC) by well-known kinetic equations, curve-fitting approach, and kinetics evaluation simulations was created. Our objective was to analyze the thermokinetic parameters of various scanning rates for energetic materials by DSC, and then to compare thermal decomposition energy parameter simulations under various conditions by the kinetic model. Experimental results obtained strongly depended on the reliability of the kinetic model applied, which is essentially defined by the proper choice of a mathematical model of a reaction and the correctness of the methods used for kinetics evaluation. Moreover, this study established the models of thermal decomposition and thermal explosion hazard for energetic materials. Differential scanning calorimetry (DSC) data were used for parameters determination of the thermokinetic models, and then these models were employed for green simulation of thermal explosion. Experimental results indicating the best storage conditions to avoid any violent runaway reaction of energetic materials were also discovered. In addition, this study investigated the thermokinetic parameters of liquid of energetic materials by isothermal kinetic algorithm and non-isothermal kinetic equation by thermal activity monitor III (TAM III) and differential scanning calorimetry (DSC), respectively. Moreover, to simulate thermokinetic parameters, 5 gallon, 55 gallon, and 6 ton reactors of liquid thermal explosion models were created in this study. Our approach was to develop a precise and effective procedure on thermal decomposition, runaway and thermal hazard parameters, such as heat of decomposition (∆Hd), activation energy (Ea), isothermal time to maximum rate (TMRiso), time to conversion limit (TCL), self-accelerating decomposition temperature (SADT), control temperature (CT), emergency temperature (ET), and critical temperature (TCR), etc., for a reactor containing energetic materials. From experimental results, the best conditions for avoiding any violent runaway reaction of energetic materials were obtained by green analysis technology.

Reactive chemicals are presented widely in the chemical and petrochemical process industry. Their chemical reactivity hazards have posed a significant challenge to the industries of manufacturing, storage and transportation. The accidents due to reactive chemicals have caused tremendous loss of properties and lives, and damages to the environment. In this research, three classes of reactive chemicals (unsaturated hydrocarbons, self-reacting chemicals, energetic materials) were evaluated through theoretical and experimental methods. Methylcyclopentadiene (MCP) and Hydroxylamine (HA) are selected as representatives of unsaturated hydrocarbons and self-reacting chemicals, respectively. Chemical reactivity of MCP, including isomerization, dimerization, and oxidation, is investigated by computational chemistry methods and empirical thermodynamic–energy correlation. Density functional and ab initio methods are used to search the initial thermal decomposition steps of HA, including unimolecular and bimolecular pathways. In addition, solvent effects are also examined using water cluster methods and Polarizable Continuum Models (PCM) for aqueous solution of HA. The thermal stability of a basic energetic material, Nitroethane, is investigated through both theoretical and experimental methods. Density functional methods are employed to explore the initial decomposition pathways, followed by developing detailed reaction networks. Experiments with a batch reactor and in situ GC are designed to analyze the distribution of reaction products and verify reaction mechanisms. Overall kinetic model is also built from calorimetric experiments using an Automated Pressure Tracking Adiabatic Calorimeter (APTAC). Finally, a general evaluation approach is developed for a wide range of reactive chemicals. An index of thermal risk is proposed as a preliminary risk assessment to screen reactive chemicals. Correlations are also developed between reactivity parameters, such as onset temperature, activation energy, and adiabatic time to maximum rate based on a limited number, 37 sets, of Differential Scanning Calorimeter (DSC) data. The research shows broad applications in developing reaction mechanisms at the molecular level. The methodology of reaction modeling in combination with molecular modeling can also be used to study other reactive chemical systems.

碩士
國立臺灣大學
藥學研究所
96
Accurate methods for predicting the affinity of a small molecule with a protein or other biomolecule play a crucial role in computational drug design because these predictions can speed the lead generation or lead optimization. Nowadays these methods can be categorized as docking and scoring and free energy method. Free energy method, in contrast with docking and scoring, which focus on a single bound conformation use conformation sampling to generate thermodynamic averages. Therefore, free energy methods are required more computer time than docking and scoring approaches. We consider that the dynamic effect of the protein-ligand complex should be still included in evaluating binding affinities because in the binding process, protein and ligand are flexible. Therefore, our study started from the linear interaction energy (LIE) method, which is one free energy method and only required two simulations, complex and ligad only. Besides that, it is also more economical than other free energy methods, such as the FEP and the MM-PBSA method. In our study, we used GROMACS to perform simulations with GROMACS force field parameters. For predicting the free energy of binding, we not only used the original LIE equation, but also we added ligand-ligand interaction into the evaluating scheme trying to obtain a better prediction model. In addition, we used several scoring functions, ChemScore, DrugScore, XScore, etc, to compare with our results.

The purpose of this study was to compare the external load of the different age-groups within a professional football club through innovative measuring systems based on the studies conducted by Prof. Di Prampero on Metabolic Power. We can confirm that both quantity and intensity of physical work are discriminative traits of the age groups we have analyzed. The approach to practice, quality of players, and technical-tactical-physical-psychological objectives are all variables that carry fundamental importance on the variation of work load amongst different teams; we can say that the team with the highest parameters is the U17-18. Surprisingly their values/data are higher than the first team’s (on all the tests taken into account) in terms of volume and intensity ( > 20 w/ > maximal aerobic power) over the exact number of days of practice. Even the U16, (with one day less of practice) registered the same volume of work as the first team, with higher results in high intensity CoDs. The U15 are the group that developed less volume of work and intensity over the week(considering they practice one day less a week compared to the U16 and two days less a week compared to the U17-18 and the first team).