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Abstract This paper examines the effects of foreign trade and foreign direct investment (FDI) on CO 2 emissions in Turkey. We consider linear and nonlinear ARDL models and find significant asymmetric effects of exports, imports and FDI on CO 2 emissions per capita. However, FDI has no statistically significant long-run effects. In the long run, decreases in exports reduce CO 2 emissions per capita but increases in exports have no statistically significant effects. Increases in imports push up CO 2 emissions per capita, while decreases in imports have no long-run effects. On the other hand, CO 2 intensity, which measures CO 2 emissions per unit of energy, is not influenced by exports and imports, nor by FDI. Instead, it is affected positively by financial development and urbanization. Also, we find that an environmental Kuznets curve is present for both CO 2 measures so that increases in real GDP per capita have led to reductions in CO 2 emissions for at least the most recent decade, controlling for other confounding factors. Furthermore, the sectoral shares of CO 2 emissions in total CO 2 emissions change asymmetrically with foreign trade for two of four sectors, with export increases leading to lower CO 2 shares and imports having the opposite effect.

Engineered cementitious composites (ECCs) are special types of fibre-reinforced cementitious composites (FRCC) with higher strain capacity which can be achieved with low fibre volume as low as 2% and total elimination of coarse aggregates. Due to the outstanding performance of ECCs, they are suitable for various construction and repair applications. However, in order for ECCs to achieve their properties; a high amount of binder which is primarily composed of Portland cement (PC) is used alongside a special type of ultrafine silica sand (USS) which is different from the conventional natural fine aggregates. The production of PC is known to be detrimental to the environment due to its high carbon dioxide emissions coupled with the high consumption of natural resources. Thus, the high use of PC content in ECCs posed a sustainability threat. Similarly, the USS used in ECCs are not readily available everywhere and are expensive. The processing of the USS coupled with its transportation over long distances would also increase the cost and embodied carbon of ECCs. Hence, in order to promote more development and applications of ECCs for various applications; this dissertation aims to provide innovative ways to improve the sustainability of ECCs and their performances. This dissertation offers four solutions to improve the sustainability of ECCs which are (i) use of unconventional industrial by-products as partial replacement of PC (ii) total replacement of PC in ECCs with alternative sustainable binders (iii) replacement of USS in ECCs with recycled materials and (iv) the use of supplementary cementitious materials to replace a high volume of PC. The findings from this study revealed sustainable ECCs with acceptable mechanical and durability performance can be achieved with the use of alternative binders or replacement of the conventional USS used in ECC mixtures. The sustainability and cost assessment of the ECCs indicated that the incorporation of industrial by-products such as blast furnace slag (BFS) especially at higher content is beneficial to reducing the negative environmental impact and economic burden associated with ECCs compared to the conventional ECC. The sustainability index and cost index of the ECCs further showed that the use of BFS is more beneficial when the sustainability and cost of the ECCs are compared with the corresponding performance. Similarly, the use of recycled materials as an alternative to USS was found to result in a significant reduction in the embodied carbon and cost of ECCs. The use of recycled materials such as expanded glass (EG) as aggregates in ECCs was also found to improve the thermal insulation properties of ECCs making such ECC suitable for the production of building envelope elements.

THERMODYNAMIC AND ECONOMIC ANALYSIS OF COMBINED HEAT AND POWER (COGENERATION) STEAM CYCLES SUMMARY Thermodynamic models for twoprocess heating, cogeneration steam cycles were developed in this study. These cycles are an extraction-condensing turbine cycle and a back pressure turbine cycle. Heat and electric outputs were calculated for inlet conditions ranging from 3 MPa, 250 C to 12 MPa, 535 C and process heat supply temperatures ranging from 80 C to 160 C. Furthermore, the performance of these cycles at 0 to 100 percent of their maximum heat outputs were examined. A simple method of economic analysis based on the annual costs was developed. This method can take part load into consideration. An extraction-condensing system and a back pressure system were compared by using this method. Process heating with cogeneration is a thermodinamically effective way of supplying heat and power to the industry. In a central plant, fuel can be burned more efficently, environmental controls can be applied more easily and economies of scale can be used to advantage. Furthermore, producing electricity as a byproduct in such plants is less expensive than producing electricity in power stations. In the extraction-condensing type, steam is expanded to condenser pressure and an extraction is made at the saturation pressure corresponding to the process heat supply temperature. In the back pressure type, steam is expanded only to the saturation pressure correspoding to the process heat supply temperature. The extraction-condensing turbines have the advantage that the electric output can be increased at partial heat loads. On the other hand, back- pressure turbines have a simpler mechanism of load control and lower initial costs. Detailed thermodynamic analysis of these systems appears to be lacking [14]-. For example, information on the variation of heat and electric outputs and thermal efficiencies of different configurations with changes in load and inlet steam conditions is essantial for the initial planning stage. viIn this study, computer modelling and simulation of two steam turbine based cogeneration cycles is made. Nu merical experiments were performed for various steam inlet conditions. Heat and electric outputs of cycles, heat input to the cycles and various parameters based on these thermodynamic quantities were calculated at full load and part load conditions. Partial loads ranging from 0 to 100 percent of full load were considered for the extraction-condensing cycle and partial loads of 37.5 to 100 percent were considered for the back pressure cycle. Thermodynamic Analysis The extraction-condensing turbine cycle consists of steam generator, turbine, condenser, heating condenser, feedwater heaters and pumps. The following assumptions are made regarding this cycle: The condenser is assumed to operate at 10 kPa. Extractions from the turbine to the feedwater heaters, heating condenser and the condenser is assumed to occur with a pressure loss equal to 5 persent of the exraction pressure. Pressure loss in the steam generator is assumed to be 25 percent of the turbine inlet pressure. Enthalpy rise of the feedwater is taken as 70 percent of the theoretically optimum value [13- This value is given by Ahopt = n/n+1 (hab - he) (1) where: n is the number of feedwater heaters, hs*> is the boiler drum satureted liquid enthalpy he is the enthalpy of satureted liquid leaving the condenser The loses in the expansion process through the turbine are accounted for by using an isentropic efficiency, r/, defined as : hi- ho r, = - t- r (2) h>- - hos where : hi is the enthalpy before expansion ho is the enthalpy after expansion hos is the enthalpy after an isentropic expansion This value is taken as 0.8 for the high pressure section of the turbine. The isentropic expansion efficiency for the flow between the heating condenser extraction and the turbine exhaust decreases linearly from 0.8 to 0.5 as the flow to the condenser decreases. Isentropic efficiency or compression in all of the pumps is asumed to be 0.7. viiThe calculations performed in the computer program are summarized in the block diagram of figure 1. Application of the first law of thermodynamics and the conservation of mass to each of the components of the cycle yield the exraction mass flows, work in the turbines and in the pumps, heat transfer in the boiler, heating condenser and in the condenser. Heat output is assumed to be primary output from the cycle. Electric output is considered to be a byproduct. Variation of the heat output is achieved by controlling the flow passing through the condenser. At 100 percent heat output, only the cooling steam flows to the condenser. At no heat output, there is no flow through the heating condenser. Cycle calculations have been performed for 100, 75, 50, 25, and 0 percent of the maximum heat output. Assumptions calculation procedures outlined above for the extraction-condensing cycle also apply for back- pressure cycle. The control of heat output, however, is different. The heat output of the back pressure cycle is varied by changing the mass flow rate through the turbine. Calculations have been performed for 100 to 37.5 percent of the maximum heat output. Properties of water required in the computer programs were computed using the equation and procedures given in [3]- Economic Analysis It is the economic consideration which will determine whether or not a cogeneration plant should be built. A simple method is presented here for determining the economic feasibility of a cogeneration plant. In this method all costs and revenues are expressed on an annual basis for comparison. Two assumption are made. First the heat demand is assumed to be supplied by other means if a cogeneration plant is not built. Therefore only the additional or incremental cost is considered. This includes the turbo generator set, condensers, feedwater heaters, steam generators, additional piping, fuel handling, exhaust cleaning measures, building and consruction costs as well as engineering cost. The second assumption is that all of the byproduct electricity produced can be utilised. A numerical example using this method shows that an extinction condensing cycle should bepreferred if the system is to operate at partial heat loads for long periods of time. Back-pressure cycle will be economically feasible only if the system operates at full load more than 90 percent of the time. However the most economic operation for the extraction-condensing cycle is also realized at full load. vmResults Results of the computer simulation of the two cycles discussed above. The key parameters on which the results are based, are explained below. Heat output per unit mass of steam entering the turbine has a maximum value for a given throttle condition and process heat supply temperature. Heat output from the cycle for a given set of turbine inlet conditions was varied as explained in the thermodinamic a na lysis. It was also found that the thermal efficiency of these cycles, defined as net work output over the heat input. Increasing the process heat supply temperature decreases the electric to heat ratio and the electric out put, increases the heat output. IXEnter the type of the system Turbine inlet pressure and temperature Process heat supply temperature Deter mine feedwater enthalpy rise and Turbine exraetion pressure Determine for the case of no heat output mass flow to the feed water heaters and the condenser r* Select a heat load as a percent of full load L-. Determine mass flows to the feedwater heaters, process heating condenser, condenser, net work, electric output heat output, heat input Figure 1. Block diagram of calculation procedure xi ÖZET Birleşik ısı ve güç çevrimlerinin endüstride kullanımının yaygınlaşması bu konudaki araştırmalara yeni boyutlar kazandırmaktadır. Bu durum göz ününe alınarak endüstride kullanılan buharlı birleşik ısı -güç çevrimleri ne ait termodinamik ve ekonomik çözümlemelerin yapıldığı bu çalışmada beş bölüm bulunmaktadır. Birinci bölümde, yapılan çalışmanın amacı açıklanmış, literatürdeki yerine ve önemine değinilmiştir. Konu ile ilgili kabullerden bahsedilmiştir. ikinci bölümde, buharlı güç çevrimleri hakkında genel bilgi verilmiştir. Çevrimlere ait T-s ve akis diyagramlarının yer aldığı bu bölümde çalışmada dikkate alınan değişkenlerin değişim aralığından bahsedilmiştir. Uçüncü bölümde, termodinamik çözümleme yapılarak, kısmi ve tam yükte ısı ve elektirik enerjisinin değişimi ile proses için gereken ısı enerjisi değeri hesaplanmıştır Dördüncü bölümde yakıt fi ati arı ve yakıt türleri yanısıra isletmelerin ihtiyaç duyduğu güç değerleri ve çalışma süreleri esas alınarak bu çevrimlerin ekonomik analizi yapılmıştır. Son bölümde sonuçların grafiklerle kıyaslama ve tartışması yapılarak her iki çevrime ait değişik değerlerin irdelemesi yapılmıştır. 69

SUMMARY A NEW METHOD FOR THE ORIENTATION AND DESIGN OF A BUILDING OF MINIMAL ENERGY CONSUMPTION Substitution of passive solar systems for the `dirty` combustion of fossil fuels for energy use in buildings to keep the environment biologically clean, can make important contributions to the health, both of individuals and of the global ecosystem, as well as contributing to the energy economy. Local outdoor chemical pollution, with all the damage it causes, can also be reduced with energy-cone ious design. A new method for design and orientation of an energy conservative building is presented for the use of architectural, urban planning, and energy engineering purposes. The precedure of the thesis is explained in five chapters. The concept of the energy conservative building is given in passive systems' methodology in Chapter 1. Also in the same chapter, the climatological effects on the building envelope and a review of current calculation procedures and computer programs with solar heating and cooling system capabilities are included. Successful passive solar architecture integrates energy conservation with passive solar heating, natural cooling and day lighting. The result can be a comfortable and economic building that uses 50%-90% less operating energy than most contemporary buildings. A world wide interest in passive solar architecture has developed since last five years because it provides an alternative to the trend toward an overdependence on lighting, heating, ventilating, and air conditioning equipment to maintain a livable and productive indoor environment in modern building. Building practitioners in many devoloping countries are interested in passive solar methods which may be integrated into the building design using familiar and readily available materials. Passive solar architecture has emphasized heating of residences in temperate climates; however, passive strategies have now spread to nearly all building types and most climates. The process is more complex for institutional and commercial buildings than for residential, but the same concepts always apply. viiiHour-by-hour simulation provides the backbone for design analysis. For smaller or simpler buildings simplified methods are usually based on monthly analysis. For larger or more complex buildings, the trend is to take full advantage of the inceased computing power of the current generation of powerful microcomputers in order to use simulation directly for design. Convenient design tools based on simulation are becoming available. The entire area of design tools appropriate to passive solar architecture needs much additional effort. Rasearch in the software design area, with powerful microcomputers, expert systems, and computer aided design techniques, promises to aid greatly in the spread of passive solar strategies. The second chapter is a review of the methods of estimation of hourly beam, diffuse and reflected solar radiation data for vertical and horizontal surfaces; whereas in this chapter Liu-Jordan's equations have a significant emphasis and are explained in full detail. There is evidence with the increasing emphasis on the use of solar energy in buildings, that much of the past solar radiation data will be rehabiliated and additional data will be collected in the future; however, it is unlikely that the hourly data to be taken will be extended to cover surfaces other than the horizontal for the majority of the stations. Liu and Jordan conducted extensive analyses during the early I960' s on the available solar radiation data and developed several emperical correlations that can be used to estimate the available solar radiation on `average` days for each month of the year and for a larger number of locations in the United States and Canada. Using the correlations, it is possible to take the monthly average daily total radiation on a horizontal surface, divide the daily total into direct and diffuse components, convert each component into hourly values, and then compute the hourly value of either component on a surface of any orientation desired. In the third chapter shadow analysis techniques for window and building energy studies are examined in detail. These techniques are examined under two parallel groups of classification. In the first group, roughly, the methods deal either with the building as a whole or only with the windows. In the second group, however, the methods are classified according to the first or second position of the observer. ixShading and solar influences on a building can be understood from two different observer positions. At the first position the observer stands at the ground or the building element and looks toward the Sun. The entire yearly movements of the Sun and relationship to the modifying intermediate conditions are seen at one time j thus, from the single station point, the observer has a yearly picture of solar movement. The disadavantage of this technique is that every position of the subject surface must be seperately analysed with a a new drawing and accompanying calculations. For a total analysis, a continious three-dimentional site volume must necessarily be broken into discrete representative points each of which is seperately analysed. Without intermediate obstructions any point on a site is equivalent in a solar analysis, since solar rays are parellel. However when the obstruction is large or close, its influence on different station points may be quite varied, such as on an urban. Since the proximity of the obstruction determines the the degree of variation in complex situations, differences may be considerable. Therefore, the movement or location of shadows is impossible to analyze, for only by accident can one determine whether the discrete object point is at a shadow edge. The crucial issue of total overshadowing effects and shadow patterns cannot be seen, nor can the entire building be examined at one time. In the second position, as used in the new method, the observer is located at a spot between the Sun and the building. By considering both the Sun and the entire building at once, all surfaces in any orientation can be observed under solar illumination. In this position, the relationship of of one portion of the site can be understood acting on another portion of the site. It is clearly seen from the examples that in the methods dealing only with the windows, the observer is, generally, in the first position, whereas in the methods which consider the building as a whole, the observer is in the latter position. The method is explained in details and step by step with a set of examples in Chapter 4. The method is an optimisation of the total percent of the sunlit area and the thermal effect due to the beam component of total solar energy on the vertical exterior surfaces of a building of minimal energy consumption, in Olgyay's bioclimatic chart which considers temperature, solar energy, wind, precipitation, relative humidity and vapor pressure. In other words, the method is a new and comprehensive interpretation of Olgyay's well known Overheated period charts. By replacing the secondposition of the observer in hourly simulation by the original gnomonic diagrams based on the first position of the observer, the metod gets closer to the aims of Olgyays' in the interpretation of architectural principles, site selection, sol-air orientation, solar control, environment and building forms, wind effects and air-flow patterns, and finally the thermal effects of materials. The method assumes that solar radiation does not penetrate the building; therefore it deals neither with the heat transfer problems nor the thermal storage capacity of the building, for the time being. The method does, however, generate relaible kernel data base for future research work on building heat transfer problems. The method is composed of two parts, the second being based on the first. The first part of the method deals with the changes in the sums of the total annual percents of sunlit areas (sunny portion of total exterior walls/total area of exterior walls) of a building at any location, relative to the changes in the orientation. In the second part, the thermal energy of the direct component is added to the variables mentioned above; e.i., location, geometrical design and orientation of the building. Thus, each wall is taken into consideration seperately, with the changes of intensity of solar energy and the percentages of sunlit area on it, due to the changes of the orientation of the building. The method is compiled in ten steps, of which the first five build the primary part, and the last five the secondary. The steps are as follows: 1. Olgyays' bioclimatic chart is adapted to the geographical place. The Overheated and the Underheated periods for selected hours of daytime are marked for selected days. For the selected hours of the selected days 2. percentages of sunlight on the walls of the building of a given orientation are computed, with any shading algorithm of parallel projection. 3. areas of sunlight (mE) on the walls of the building of a given orientation are computed, 4. total percentage of sunlight on the building is computed and grouped under two intensities, e.i. the Overheated and the Underheated. xi5. The annual sums of the total percentages of sunlight for the Overheated and Underheated periods are devided by the number of the Overheated and Underheated daytime hours respectively. 6. Solar thermal energy due to the beam component of hourly radiation is computed for each orientation (KJ/mz.h). 7. Solar thermal energy due to the beam component of hourly radiation is computed for each wall (KJ/h). 8. Total solar thermal energy gain of the building due to the beam component of hourly radiation is computed (KJ/h). 9. Hourly total solar thermal energy gains of the building are grouped under two intensities, the Overheated and the Underheated. 10. The annual sums of total solar thermal energy gains of the building for the Overheated and Underheated groups are devided by the number of Overheated and Underheated daytime hours respectively. application of the first part of the method is done by three blocks of passive apartment houses of the same area and hight, but of different design, for istanbul and Antalya, and for 1., 11., and 21. days of the months. For the second part, however, only the second block is examined for istanbul, and only for 21. days of the months. Hence comparisons of two sets of meteorological data and all the parameters mentioned above may be seen clearly from the graphics relative to the changes in eight orientations, e.i., North, North-East, East, South- East, South, South-West, West, and North-West. A minor modification was made in Olgyay's Overheated period charts in order to eliminate what was believed to be erroneous results by the use of Liu-Jordan equations near the sunrise and sunset hours for the application of the second part of the method. Although percentages of sunlight on the vertical exterior walls are computed with a shading technique based on Conlon's JPCSHAD parallel projection algorithm and the inclusion of the thermal effect mentioned above is done by Liu-Jordan's well known equations, the method is still applicable to other scientists' formulae and shadow analysis models as well. At the last chapter, the method is evaluated and further possible reseach work are pointed out. xiiThe method may be used to generate a wide variety of building blocks. The irradiance load on external surfaces of building blocks of any rectangular design may be evaluated for any orientation, time of day and for different localities. This evidently provides the designer with useful information, guide lines and design aids expanding his ability to manipulate the parameters of form for the control of solar environment and to develop practical indicators and building regulations for planning control. The method may furter be used in a generative process to define alternative proportion of block's sides, configuration of surroundings, street widths, physical characteristics of building surfaces for appropriate solar load criteria. Thus the method may be employed directly in conjunction with other performance criteria for a sythesis of an integrated architectural solution. xiii ÖZET Yapıların, enerji korunumu için yönlendirilmesi ve biçimlendirilmesinde, dış kabuk düşey yüzlerindeki doğrudan güneş ışınımına bağlı, güneşlenme yüzdeleri ve ısıl etkilerin Olgyay konfor bölgelerinde gözlemcinin 2. durumuna göre optimizasyonunun yapıldığı bu metod, iki kademeden meydana gelmektedir: Birinci kademede herhangi bir enlem, boylam ve biçimdeki yapının, düşey dış kabuk elemanları üzerindeki yıllık ortalama toplam güneşlenme yüzdeleri (güneşli alan/toplam alan), güneş ışınımı, bağıl nem, sıcaklık ve hava hareketlerine bağlı Olgyay konfor bölgelerindeki iki şiddet grubu, En Az Sıcak Dönem (EASD) ve En Sıcak Dönem (ESD) altında toplanmakta ve bu değerlerin yönlendirilişe göre değişimi incelenmektedir. Başka bir deyişle, yer, biçim ve yön değişkenlerinin birbirleri üzerindeki etkileri güneşlenme yüzdelerindeki farklılıklar ile belirlenmektedir. ikinci kademede yukarıdaki değişkenlere doğrudan güneş ışınımının düşey yüzeylerdeki ısıl etkileri de eklenmekte ve yapının bütünü ile ilgili, yer, biçim ve yön değişkenlerinin etkileşimine, beher duvarın konumuna ve üzerindeki saatlik güneşlenme yüzdelerine bağlı enerji kazançlarındaki farklılıkların ortalamaları da katılmaktadır. ikinci kademenin uygulamasında Liu- Jordan denklemleri, dünya sathında denenmiş ve kusurları ortaya çıkmış olduğu için, tercih edilmiş; ancak metod diğer araştırıcıların bağıntılarına da açık bırakılmıştır. Yeni metodun gelişimini hazırlayan konular başlıca üç bölüm içinde incelenmiştir. Birinci bölümde enerji korunumlu yapının tanımı pasif sistem metodolojisi içinde verilmekte; aynı bölümde, yapının dış kabuğunu etkileyen iklim elemanları kısaca ve bilgisayarlı ısıl enerji analiz metodları tarihsel gelişim içinde, ikinci bölümde metodun 2. kademesi için önem taşıyan güneş enerjisi verilerinin elde ediliş yolları incelikleri ile açıklanmaktadır, üçüncü bölümde ise yapılarda uygulanan gölge analizi metodları gözlemcinin durumuna göre tanıtılmaktadır. Dördüncü bölümde metod ve inceliklerinin anlaşılabilmesi için bir dizi uygulama sunulmakta, ayrıca birinci kademenin uygulanmasında yararlanılan JPCSHAD gölge algoritması tanıtılmakta ; sonuç bölümünde ise metod değerlendirilmekte ve ileriye dönük araştırmalar için önerilerde bulunulmaktadır. vii 145

AbstractTransition to a bio‐based economy will create new demand for biomass, e.g. the increasing use of bioenergy, but the impacts on existing markets are unclear. Furthermore, there is a growing public concern on the sustainability of biomass. This study proposes a methodological framework for mapping national biomass flows based on domestic production‐consumption and cross‐border trade, and respective share of sustainably‐certified biomass. A case study was performed on the Netherlands for 2010‐2011, focusing on three categories: (i) woody biomass, (ii) oils and fats, and (iii) carbohydrates. Between 2010‐2011 few major shifts were found, besides the increasing biofuel production. The share of sustainably‐certified feedstock is growing in many categories. Woody biomass used for energy amounted to 3.45 MT, including 1.3 MT imported wood pellets ( >85% certified). About 0.6 MT of oils and fats and 1.2 MT (estimation) of carbohydrates were used for biofuel production. It is assumed that only certified materials were used for biofuel production. For non‐energy purpose, more than 50% of woody biomass used was either certified or derived from recycled streams. Certified oils has entered the Dutch food sector since 2011, accounted for 7% of total vegetable oils consumption. It is expected that carbohydrates will also be certified in the near future. Methodological challenges encountered are: inconsistency in data definitions, lack of coherent cross‐sectorial reporting systems, low reliability of bilateral trade statistics, lack of transparency in biomass supply chains, and disparity in sustainability requirements. The methodology may be expanded for future projection in different scenarios. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd

Esta dissertação oferece contribuições para o campo da energia eólica, e fornece um roteiro claro para a tomada de decisão baseada em dados, bem como orientações práticas para otimizar a operação e manutenção. No contexto atual da transformação digital e crescente demanda energética surge a necessidade de soluções inovadores e sustentáveis em larga escala, como a energia eólica offshore. A energia eólica é uma fonte de energia renovável que tem o potencial de contribuir significativamente para a matriz energética global. A implementação e operação de projetos eólicos offshore são desafiadores devido aos custos elevados e à natureza intrínseca dos riscos no ambiente marítimo, por isso necessitam operar em sua máxima eficiência e desempenho, tendo em vista a viabilidade económica. Este trabalho tem como objetivo a compreensão dos fatores principais que influenciam o desempenho energético dos aerogeradores através dos dados que revelam as interrupções e falhas de sistemas. Os resultados obtidos nesta pesquisa destacam a necessidade de uma abordagem integrada, buscando o conhecimento técnico especializado com a aplicação de tecnologias de monitoramento em tempo real e análise de dados. Ao reconhecer os padrões de falhas e as lacunas de eficiência, os gestores podem direcionar seus esforços para aprimorar a fiabilidade, a disponibilidade e a performance geral dessas unidades geradoras de energia elétrica. Através da implementação das recomendações resultantes deste estudo, espera-se que as instituições possam alcançar uma expressiva rentabilidade e sustentabilidade, alinhando-se de forma eficaz com as demandas atuais, garantindo uma posição sólida no ambiente empresarial e contribuindo para um futuro energético mais equilibrado.

Extreme summer droughts are expected to occur more often in the future in NW Europe due to climate change. These droughts might accelerate the rate of peat oxidation in drained peat areas, with impacts on soil subsidence, GHG emission and water quality. This study aimed at providing more insight in the oxidation of deep peat layers that had not previously been exposed to air, the so-called secondary decomposition. We incubated two types of peat (eutrophic and oligotrophic), sampled from permanently anoxic peat layers from nature reserves and agricultural peat meadows. Peat samples were incubated for thirteen weeks under anoxic conditions, but were exposed to air for one to eight weeks. The production of CO2 and CH4 was quantified as a proxy for decomposition; concentrations of soluble nutrients and phenolic compounds were also measured. The results showed that oxygenation led to a steep increase in the rate of decomposition, indicated by higher carbon loss rates during and after oxygenation compared to non-oxygenated samples. Carbon loss rates increased more for eutrophic peat (agricultural area: 352%, nature reserve: 182%) than for oligotrophic peat (83% and 159% respectively). Most peat samples investigated showed higher post-oxygenation CO2 and/or CH4 production compared to the anoxic pre-oxygenation period. This indicates that oxygenation stimulates decomposition, even after anoxic conditions have returned. Contrary to the enzymic latch theory, no effects of oxygenation on the concentrations of soluble or condensed phenolic compounds were detected. Soluble nutrient concentrations did not change due to oxygenation either. Noteworthy is the occurrence of pyrite mineralization and associated acidification in eutrophic peat. Thus, low summer water levels, for example due to climate change, should be avoided in order to limit exceptionally high decomposition rates and associated problems such as increasing subsidence rates, greenhouse gas emission, sulfate release and acidification.

In industrialized countries, large amounts of mineral wastes are produced. They are re-used in various ways, particularly in road and earth constructions, substituting primary resources such as gravel. However, they may also contain pollutants, such as heavy metals, which may be leached to the groundwater. The toxic impacts of these emissions are so far often neglected within Life Cycle Assessments (LCA) of products or waste treatment services and thus, potentially large environmental impacts are currently missed. This study aims at closing this gap by assessing the ecotoxic impacts of heavy metal leaching from industrial mineral wastes in road and earth constructions. The flows of metals such as Sb, As, Pb, Cd, Cr, Cu, Mo, Ni, V and Zn originating from three typical constructions to the environment are quantified, their fate in the environment is assessed and potential ecotoxic effects evaluated. For our reference country, Germany, the industrial wastes that are applied as Granular Secondary Construction Material (GSCM) carry more than 45,000 t of diverse heavy metals per year. Depending on the material quality and construction type applied, up to 150 t of heavy metals may leach to the environment within the first 100 years after construction. Heavy metal retardation in subsoil can potentially reduce the fate to groundwater by up to 100%. One major challenge of integrating leaching from constructions into macro-scale LCA frameworks is the high variability in micro-scale technical and geographical factors, such as material qualities, construction types and soil types. In our work, we consider a broad range of parameter values in the modeling of leaching and fate. This allows distinguishing between the impacts of various road constructions, as well as sites with different soil properties. The findings of this study promote the quantitative consideration of environmental impacts of long-term leaching in Life Cycle Assessment, complementing site-specific risk assessment, for the design of waste management strategies, particularly in the construction sector.

II ABSTRACT Climate change is expected due to the increasing atmospheric concentrations of carbondioxide and other trace gasses, which lead to changes in the radioactive balance of the atmosphere. Such changes propagate further to those in temperature i and other climatic variables. Hydrologic systems and water resources are likely to be seriously impacted by global climate change. Such processes as surface runoff, precipitation, soil moisture, groundwater, water quality, and sea levels will be significantly exposed to effects of climate change. Eventually, these effects will have to be considered in water resources planning and management. The study presented stems from the above needs and addresses the problem of climate change-water resources interactions. It is intended here to investigate the possible effects of climate change on watershed scale hydrologic processes and water demand. Within this context, the current methods used in developed countries are applied to the case of the Gediz River Basin, and possible impacts of changes in climatic variables, i.e., precipitation and temperature, are investigated as they relate to runoff The results of the study should not considered as exact values to represent the effects of climate change. They are essentially `estimates` on `likely` effects of an expected climate change. However, the results also show that, if the prescribed climate change scenarios do occur in the future, they will have significant effects on the hydrology of the basin which, in turn, affects water demand for various water resources development plans. Accordingly, the study presented should be considered as an initial step towards assessment of climate change impacts and should be reaccomplished in future attempts towards any planning or management activity in the basin. ÖZET İklim değişikliği, atmosferdeki karbondioksit (CO2) ve diğer antropojen sera gazı konsantrasyonlarının giderek artması sonucu beklenmektedir. İklim değişikliğinin sonucunda beklenen en önemli olgu, sıcaklık, yağış, evapotranspirasyon, akış gibi temel iklimsel ve hidrolojik değişkenlerdeki muhtemel değişimlerdir. Bu etkilerin su kaynakları planlama ve yönetiminde değerlendirilmesi gerekmektedir. Sunulan çalışma, iklim değişikliğinin su kaynakları ile olan ilişkisini incelemektedir. Bu değişimlerden hidrolojik çevrimin ve su kaynaklarının gerek miktarı ve gerekse kalitesinin de etkilenmesi beklenmektedir. Dolayısıyla, küresel iklim değişikliğinin havza su dengesine ve su kaynaklarının planlama ve yönetimine de yansıması söz konusudur. Bu kapsamda sunulan çalışmada alt havza bazında sıcaklık ve yağış gibi iklim parametrelerinin, akıma olan etkileri incelenmiş ve duyarlılık analizi ile sonuçlar değerlendirilmiştir. 75