Additive Manufacturing (AM) refers to the use of a group of technologies capable of combining material layer-by-layer to manufacture geometrically complex products in a single digitally controlled process step, entirely without moulds, dies or other tooling. AM is a parallel manufacturing approach, allowing the contemporaneous production of multiple, potentially unrelated, components or products. This thesis contributes to the understanding of the economic aspects of additive technology usage through an analysis of the effect of AM s parallel nature on economic and environmental performance measurement. Further, this work assesses AM s ability to efficiently create complex components or products. To do so, this thesis applies a methodology for the quantitative analysis of the shape complexity of AM output. Moreover, this thesis develops and applies a methodology for the combined estimation of build time, process energy flows and financial costs. A key challenge met by this estimation technique is that results are derived on the basis of technically efficient AM operation. Results indicate that, at least for the technology variant Electron Beam Melting, shape complexity may be realised at zero marginal energy consumption and cost. Further, the combined estimator of build time, energy consumption and cost suggests t AM process efficiency is independent of production volume. Rather, this thesis argues that the key to efficient AM operation lies in the user s ability to exhaust the available build space.

Till följd av EU:s miljömål 2020 har svenska statliga och kommunala miljömål satts upp för att minska energianvändningen. EU:s 2020-mål syftar till att minska energianvändningen i Europa med 20 procent fram till år 2020 från det att målet sattes upp 2010. På kommunal nivå har detta inneburit att fastighetsbolag, privata men främst kommunala aktörer, har tvingats att se över sin energianvändning. Arbetet i denna rapport föranleds av en av de besparingsåtgärder som har vidtagits nämligen att komplettera befintliga fjärrvärmeuppvärmningssystem med värmepumpar. Uppdraget avser utveckling och utvärdering av en beräkningsmodell för denna typ av system. För att skapa ett pålitligt beslutsunderlag i arbetet med att minska energianvändningen krävs välgrundade beräkningar. Befintliga beräkningsmodeller lägger stor vikt vid ekonomiska faktorer och tar därmed liten hänsyn till tekniska aspekter och omgivande faktorer. Målet med arbetet har varit att skapa en beräkningsmodell vilken i större utsträckning speglar den faktiska situationen och påvisar ett mer välgrundat beslutsunderlag. Arbetet inleddes med en litteraturstudie vilken innefattade relevant forskning och grundläggande fakta om värmepumpar och fjärrvärmesystem. Beräkningsmodellen har utvecklats löpande under projektet där nya funktioner samt ny information ständigt tillkommit. Projektet har resulterat i en fungerande beräkningsmodell vilken innefattar fler parametrar än tidigare motsvarigheter. Tillsammans med uppdragsgivaren sattes tre olika mål upp för beräkningsmodellen, dessa var:  Att på ett intuitivt sätt presentera information och data.  Att skapa en transparent struktur vilken är enkel att följa.  Att skapa ett flöde genom modellen vilket följer en önskad arbetsgång. Dessa mål anses ha blivit uppfyllda, dock finns möjlighet till vidareutveckling. Modellen skulle exempelvis kunna kompletteras med mer automatiserade optimeringsberäkningar och justeras för att hantera andra typer av systemlösningar. / As a result of the EU's environmental 2020 goal, the Swedish government and municipal boards has put up internal goals to reduce energy consumption. EU 2020 goal aims to reduce energy consumption in Europe by 20 percent by the year 2020 from that the target was set in 2010. At the municipal level, this has meant that private but mainly public housing properties have been required to review their energy use. The work in this report is based on one of the savings measures that have been taken, which is to supplement existing district heating systems with exhaust air heat pumps. The project aims to develop a calculation model for evaluation and computation for this type of system. To create a reliable basis for decisions, efforts were made to produce just calculations. Existing computational models are focused on economic factors and thus takes little consideration of technological aspects and environmental factors. The aim of the work has been to create a computational model which more closely reflects the real situation and demonstrates a more informative decision basis. The work began with a literature review which included relevant research and basic facts about exhaust air heat pumps and district heating systems. The calculation model has been developed continuously during the project in which new functions and new information constantly has been added. The project has resulted in a working computational model which includes many more parameters than previous reviewed models. Together with the client three sub goals were set up for the model, these were:  To intuitively present information and data.  To create a transparent structure which is simple to follow.  To create a flow through the model, which follows a desired work process. These goals are considered to have been fulfilled in the developed calculation model, however, it's possible to further develop this model. The model could, for example, be supplemented with more automated optimization calculations and be adjusted to handle other kinds of heating systems.

Data fusion in wireless sensor networks can improve the performance of a network by eliminating redundancy and power consumption, ensuring fault-tolerance between sensors, and managing e®ectively the available com- munication bandwidth between network components. This thesis considers a data fusion approach applied to wireless sensor networks based on fuzzy logic theory. In particular, a cluster-based hierarchical design in wire- less sensor networks is explored combined with two data fusion methods based on fuzzy logic theory. A data fusion algorithm is presented and tested using Mamdani and Tsukamoto fuzzy inference methods. In addition, a concept related to the appropriate queuing models is presented based on classical queuing theory. Results show that the Mamdani method gives better results than the Tsukamoto approach for the two implementations considered. We noted that the proposed algorithm requires low processing and computational power. As a result, it can be applied to WSNs to provide optimal data fusion and ensures maximum sensor lifetime and minimum time delay.

Purpose: The purpose of this study is to contribute with knowledge about how the warming effects of climate change may affect indoor living standards, considering that we are already living with some over-temperatures during the summer time. The specific aim is therefore to show how thermal climate in warm passive houses will be perceived, and how specific energy consumption will be affected, within the near future in southern Sweden. Method: To order to achieve the aim, a specific scenario of future temperatures had to be defined. Official climate data for the year 2050 in Gothenburg was collected and compiled. A certified passive house was theoretically exposed to the expected future climate and indoor temperature as well as energy consumption was calculated. Calculations were made using the energy calculation software BV2 for reference conditions and adaptions of both climate as well as technical solutions for greater thermal comfort. Findings: A climate scenario for Gothenburg during year 2050 illustrates that the average year-temperature increases from +7.7°C to +9.9°C. The largest change can be observed during the winter, with an increase peaking at +2.5 ºC. The results show an increase from 65 to 107 number of days during the year in which the studied passive house has an inadequate indoor temperature, as a consequence of over-temperatures. One method for thermal climate enhancing, using a combination of sun screening and air conditioning powered by solar cells, showed having good impact without considerably affecting the specific energy consumption. Implications: In a passive house without air conditioning, the thermal indoor climate will reach an unacceptable level for the tenants, more often in the year 2050, than during the reference period, due to warmer outside temperatures. The method which has the smallest impact upon the energy consumption is sun screening, while air conditioning is the most effective, but also very energy consuming. In order to optimally conserve the thermal indoor climate without decreasing the free energy during the winter, one should install both sun screening and air conditioning in their passive house. Limitations: The result is applicable on passive houses within climate zone III, but the general conclusions made applies for all passive houses in Sweden. Using different methods of calculating the indoor temperature may result in variable results. Keywords: Climate change, Passive house, Indoor climate, Thermal comfort, Energy consumption

The thesis compares and analyses the development of production/consumption of energy in the EU28, in selected countries (Austria, Czech Republic, Slovakia, Poland, Hungary, Slovenia), and especially in the Czech Republic and Slovakia in the context of accepting and development (change) of energy policies. The main aspect of the work was to analyze trends in energy consumption and (in) dependence, structure of energy production/consumption, particularly with the application potential of alternative energy sources and energy savings. This thesis confirmed that there are significant differences in achieving the main objectives of EU energy policy among states. Statistical (correlation) analysis did not confirmed a significant dependence between the energy (in) dependence, the energy saving rates and the share of alternative energy sources. Synthetic index of energy change has evaluated Hungary and Slovakia from selected countries with the best energy progress since 2004. It was not proved that Slovakia or Czech Republic have a consistent long-term energy policy that they would explicitly followed. Key words: energy policy, energy savings, energy consumption, energy dependence, European Union

This master thesis aims to examine the relationship between energy consumption and economic growth and between energy consumption and greenhouse emissions for the EU countries, using a panel time series data from 1996 to 2012 within a multivariate framework for 26 EU countries. The energies are composed from oil consumption, natural gas consumptions, and renewable energies including the biomass as a distinct part. To do that, Unit Root Tests, cointegration test, Pairwise Granger causality tests, and Error Correction Model are employed to find out the type of the causal relationship. The main results to denote are that, there is in the short run, a positive unidirectional causal relationship running from oil consumption to economic growth. We can as well denote a positive bidirectional causal relationship between renewable energies and economic growth and between greenhouse emissions and economic growth. However, there is an unexpected negative bidirectional causal relationship between biomass consumption and gas consumption. From the greenhouse emissions perspective, we can see in the short run, a negative bidirectional causal relationship between greenhouse emissions and renewable energies, and a positive unidirectional causal relationship running from both oil consumption and biomass consumption...

Context: Wireless Mesh Network (WMN) is a form of ad-hoc network with flexible backhaul infrastructure and configuration, provides adaptive wireless internet connectivity to end users with high reliability. WMN is a wireless network consisting of mesh clients, mesh routers and gateways which are organized in a mesh topology with decentralized nature can consume more energy for data transmission. The networking performance of WMNs can be degraded due to the fact of high energy consumption for data transmission. Therefore, energy efficiency is the primary factor for attaining eminent performance. Organizing efficient routing and proper resource allocation can save huge amount of energy. Objectives: The main goal of this thesis is to reduce the energy consumption in WMNs. To do this, a new energy efficient routing algorithm is suggested. Adaptive rates based on rate allocation strategy and end to end delay metric are used mainly for optimal path selection in routing, which may in turn reduces the resource utilization and energy consumption. Method: An energy efficient routing algorithm is implemented by using the Ad hoc OnDemand Distance Vector (AODV) routing protocol. The RREQ packet in AODV is modified by adding a new field known as delay parameter which measures end to end delay between nodes. Adaptive rates obtained from Rate allocation policy are considered in the routing process to reduce energy consumption in the network. Energy measurement of the WMN and its performance is evaluated by measuring the metrics such as Throughput, End-to-End delay, Packet Delivery Ratio (PDR). For performing the simulation process, in this thesis, Network Simulator - 3 (NS-3) which is an open source discrete-event network simulator in which simulation models can be executed in C++ and Python is used. Using NetAnim-3.107 animator in NS-3-25.1, traffic flows between all the nodes are displayed. Results: The results are taken for existing algorithm and proposed algorithm for 25,50,75 and 100 nodes. Comparison of results shows that the total energy consumption is reduced for proposed algorithm for in all four scenarios. Conclusion: Energy efficient routing algorithm is implemented in different scenarios of radio access networks and energy is saved. Due to this algorithm even the performance metrics, Throughput, End-to-End delay, Packet Delivery Ratio (PDR) have shown eminent performance.

M.Com. (Business Management) / The residential demand profile for electricity shows that this segment of the market has. a great demand in the morning and early evening. Due to a shortage of generation capacity during these peak consumption periods, different strategies are now needed to persuade customers to use their electricity in the periods when there is not a great demand. One way in which this can be achieved is to give the customers a time differentiated tariff i.e. a time-of-use (TOU) tariff, whereby the customer will pay a high energy rate in the peak periods, and lower energy rates in the off-peak and standard periods. The overall goal of this study was to determine to what extent residential customers would respond to such a tariff The study covered three consumption groups i.e. customers using more than 1500 kWh per month, between 600 and 1000 kWh per month, and between 300 and 600 kWh per month. All the customers taking part in the study were direct Eskom customers. Once the customers had agreed to participate in the study, they had TOU measuring equipment installed in their homes, which measured their consumption according to the time of day it was consumed.

This dissertation contains three studies examining aspects of energy use by data centers and other information and communication technology (ICT) infrastructure necessary to support the electronic services that now form such a pervasive aspect of daily life. The energy consumption of ICT in general and data centers in particular has been of growing interest to both industry and the public, with continued calls for increased efficiency and greater focus on environmental impacts. The first study examines the metrics used to assess data center energy performance and finds that power usage effectiveness (PUE), the de facto industry standard, only accounts for one of four critical aspects of data center energy performance. PUE measures the overhead of the facility infrastructure but does not consider the efficiency of the IT equipment, its utilization, or the emissions profile of the power source. As a result, PUE corresponds poorly with energy and carbon efficiency, as demonstrated using a small set of empirical data center energy use measurements. The second study lays out a taxonomy of indirect energy impacts to help assess whether ICT’s direct energy consumption is offset by its energy benefits, and concludes that ICT likely has a large potential net energy benefit, but that there is no consensus on the sign or magnitude of actual savings, which are largely dependent upon implementation details. The third study estimates the potential of dynamic load shifting in a content distribution network to reduce both private costs and emissions-related externalities associated with electricity consumption. Utilizing variable marginal retail prices based on wholesale electricity markets and marginal damages estimated from emissions data in a cost-minimization model, the analysis finds that load shifting can either reduce data center power bills by approximately 25%–33% or avoid 30%–40% of public damages, while a range of joint cost minimization strategies enables simultaneous reduction of both private and public costs. The vast majority of these savings can be achieved even under existing bandwidth and network distance constraints, although current industry trends towards virtualization, energy efficiency, and green powermay make load shifting less appealing.

ABSTRACT This work applies the concepts of the attainable region for process synthesis in comminution. The attainable region analysis has been successfully applied for process synthesis of reactor networks. The Attainable Region is defined as the set of all possible output states for a constrained or unconstrained system of fundamental processes (Horn, 1964). A basic procedure for constructing the attainable region for the fundamental processes of reaction and mixing has been postulated in reaction engineering (Glasser et al., 1987). This procedure has been followed in this work to construct the candidate attainable region for size reduction processes as found in a size reduction environment. A population balance model has been used to characterise the evolution of particle size distributions from a comminution event. Herbst and Fuerstenau (1973) postulated the dependency of grinding on the specific energy. A specific energy dependent population balance model was used for the theoretical simulations and for the fitting of experimental data. A new method of presenting particle size distributions as points in the Euclidian space was postulated in place of the traditional cumulative distribution. This allows successive product particle size distributions to be connected forming a trajectory over which the objective function can be evaluated. The curve connects products from successive batch grinding stages forming a pseudo-continuous process. Breakage, mixing and classification were identified as the fundamental processes of interest for comminution. Agglomeration was not considered in any of the examples. Mathematical models were used to describe each fundamental process, i.e. breakage, mixing and classification, and an The application of the attainable region analysis in comminution Abstract algorithm developed that could calculate the evolution of product particle size distributions. A convex candidate attainable region was found from which process synthesis and optimisation solutions could be drawn in two dimensional Euclidian space. As required from Attainable Region Theory, the interior of the bounded region is filled by trajectories of higher energy requirements or mixing between two boundary optimal points. Experimental validation of the proposed application of the attainable region analysis results in comminution was performed. Mono-sized feed particles were broken in a laboratory ball mill and the products were successfully fitted using a population balance model. It was shown that the breakage process trajectories were convex and they follow first order grinding kinetics at long grind times. The candidate attainable region was determined for an objective function to maximise the mass fraction in the median size class 2. It was proved that the same specific energy input produces identical products. The kinematic and loading conditions are supposed to be chosen as a subsequent event after the required specific energy is identified. Finally the fundamental process of classification was added to the system of breakage and mixing. The attainable regions analysis affords the opportunity to quantify exactly the reduction in energy consumption due to classification in a comminution circuit, thus giving optimal targets. Classification showed the potential to extend the candidate attainable region for a fixed specific energy input. The boundary of the attainable region is interpreted as pieces of equipment and optimum process conditions. This solves both the original process synthesis and successive optimisation problems.