SuperNEC is a method of moments (MoM) electromagnetic eld solver based on the Numerical Electromagnetics Code (NEC). Much of the simulation time can be attributed to the lling of the impedance matrix, which is performed at each frequency point of interest. Impedance matrix interpolation methods have been implemented in SuperNEC to reduce the computational time required to ll the impedance matrix [Z]. Elements in [Z] vary predictably over frequency and can be approximated by a second order polynomial. A second improved method is implemented where the dominant frequency variation term is removed prior to calculating the tting function. A method of determining the optimum sample range relative to simulation range and maximum interaction distance has been developed. Given the correct choice of sample range the mean error in the MoM solution is less than 10% over the frequency range and the input impedance can be reproduced with good agreement over a wide bandwith. Improvement in the simulation e ciency of 1.7 times can be expected if su cient frequency points are of interest to account for the computational time required to sample the matrix and determine tting function coe cients. This method has been applied to a dipole antenna, an LPDA and a horn antenna. To increase the simulation bandwidth and retain an acceptable level of accuracy, the bandwidth is split into multiple sub-bands.

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Os sistemas de controle solar auxiliam no controle da radiação solar incidente no envoltório, e, de acordo com a NBR 15220-3, é recomendável seu uso para a zona bioclimática 3, na cidade de Porto Alegre. Assim, com a ação de retrofitting, é possível utilizar os sistemas de controle solar como modo de adaptar o envoltório das edificações ao clima local e aos padrões de consumo atuais. Dessa forma, o retrofitting do envoltório pode contribuir com a redução do consumo energético e a dependência de sistemas de refrigeração e aquecimento mecânico. Logo, o objetivo da dissertação é qualificar e quantificar energeticamente os sistemas de controle solar com vistas à redução do consumo energético nos ambientes construídos. Um estudo de caso foi realizado na cidade de Porto Alegre, onde um edifício foi selecionado perante um conjunto de edificações existentes. Com o auxílio de um método expedito de cálculo energético, foi realizada a avaliação energética do envoltório da edificação atual e do seu retrofitting proposto. A edificação passou de nível energético E para nível A, comprovando o êxito do estudo de retrofitting aplicado. A pesquisa concluiu que, alinhado com o encontrado na revisão da literatura, as edificações com grandes aberturas orientadas para oeste são um equívoco de projeto no clima de Porto Alegre e que as ações de retrofitting são uma alternativa de adaptação ao clima local, tornando os edifícios eficientes energeticamente. / Shading systems help to control the incident solar radiation on the envelope, and, according to NBR 15220-3, its use is recommended for the bioclimatic zone 3, in the city of Porto Alegre. Hence, with retrofitting, it is possible to use shading systems as a way of adapting the building envelope to the local climate and current consumption patterns. Thus, the retrofitting of the envelope can contribute to the reduction of the energy consumption and of the dependence on systems of refrigeration and mechanical heating. Therefore, the objective of this dissertation is to qualify and quantify the energy of shading systems in order to reduce energy consumption in built environments. Thus, a case study was conducted in the city of Porto Alegre, where a building was selected from a set of existing buildings. We performed an energetic evaluation of current envelope of buildings and its proposed retrofitting by using a facilitated method for energy calculation. The buildings moved from energy level E to level A, proving the success of the study on the applied retrofitting. We conclude that, as also shown in literature review; buildings with large openings oriented to the west in Porto Alegre are a design misconception due to the city’s climate. Thus, retrofitting actions are alternative ways to adapt to the local climate so that buildings are energy efficient.

Overreliance on energy from fossil fuels is unsustainable because of their regional depletion and associated environmental impacts. The British industrial sector accounts for around one fifth of final energy demand and one third of carbon emissions nationally. This thesis attempts to quantify the potential for industrial energy efficiency from the current baseline, by adopting thermodynamic and economic perspectives. The methodology involves a top-down analysis of energy trends within the manufacturing sector to determine the baseline against which changes are measured, leading to bottom-up case studies which explicitly consider the detailed mechanisms affecting energy demand. Top-down analysis highlights the diversity between industrial sectors, for which a sectoral classification based on process homogeneity is proposed. It also enables the long term, systemic potential for efficiency improvements to be estimated and identifies the barriers to uptake. Bottom-up case studies are better suited to identifying the sectoral potential in the short to medium term. Firstly, the technical potential for heat recovery from industrial sectors is quantified by recourse to thermodynamic quality and spatial considerations. Secondly, an energy and exergy analysis of a glass furnace enables a distinction between avoidable and unavoidable losses, leading to the identification of economic savings. Thirdly, a process integration study at a pulp and paper mill based on a pinch analysis and optimisation of a heat exchanger network highlights economic efficiency improvements. This thesis demonstrates that realising the full industrial energy efficiency potential requires improvements to public policy intended to overcome market-related barriers, especially the EU Emissions Trading Scheme and the Carbon Trust, with additional scope for a mandatory efficiency standard relating to motors. Energy efficiency has to part of a company’s overall strategy to be effective. Future work should focus on heterogeneous sectors and the broader effects on industrial energy efficiency of globalisation and the shift towards services.

Digitized by Kansas Correctional Industries

Optimizing the production of useful macromolecules from transgenic microorganisms is crucial to biopharmaceutical companies. Improving bacterial growth and replication depends largely on the efficiency of translation, which is rate-limited by initiation. Among the most important interactions between the mRNA translation initiation region (TIR) and the translation machinery is the association between the Shine-Dalgarno (SD) sequence in the TIR and the complementary anti-SD (aSD) sequence which is located within a short unstructured segment that includes the 3’ terminus (3’ TAIL) of the mature 16S rRNA. However, the mature 3’ TAIL has been poorly characterized in the majority of bacteria, rendering optimal SD/aSD pairing unclear in these species. In light of this, we established a novel strategy to characterize the mature 3’ TAILs of bacterial species that leverages the availability of publically stored RNA sequencing (RNA-Seq) data. In chapter 2, we devised a RNA-Seq-based approach to successfully recover the experimentally verified 3’ TAIL in E. coli (5’-CCUCCUUA-3’) and resolve inconsistencies surrounding the identity of the 3’ TAIL in Bacillus subtilis. In chapter 3 we improve the method introduced in chapter 2 to clearly and more reliably define the 3’ TAIL termini for 13 bacterial species with available protein abundance data. Our results reveal considerable heterogeneity in the termini of 3’ TAILs among closely related species and that sites downstream of the canonical CCUCC aSD motif are more important to initiation than previously believed. My research contributes to advance our understanding in microbial translation efficiency in two significant ways: 1) providing an RNA-Seq-based approach to characterize rRNA transcripts, and 2) elucidating optimal recognition between protein-coding genes and the rRNA translation machinery.

This study is an exposition of research into the effect of operational efficiency to global competitiveness, with the Richards Bay Dry Bulk Terminal (DBT) being the case study. The Richards Bay DBT is the main dry bulk terminal in the South African ports, operated by Transnet Ports Terminals (TPT), which is a division of the state-owned Transnet Ltd. Because of the strategic position of the DBT as the main dry bulk terminal of the country and also that it is a state owned entity, its competitiveness or otherwise is a reflection of South Africa the country as a trade destination. The research seeks to investigate the problem of the declining volumes handled by the DBT, which is traced to the possible operational inefficiencies and is likely to impede competitiveness of the DBT. While this study will not propose the ultimate solutions to the DBT’s problems, it will identify the root causes and symptoms of the problems, which will ultimately guide what needs to be tested as a better solution. Based on this, it is argued that this topic should generate a lot of interest to the stakeholders both locally and internationally.

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Bibliography: leaves 97-98. / by Andrew David Reamer. / M.C.P.

Nowadays, many organizations choose to increasingly implement the cloud computing approach. More specifically, as customers, these organizations are outsourcing the management of their physical infrastructure to data centers (or cloud computing platforms). Energy consumption is a primary concern for datacenter (DC) management. Its cost represents about 80% of the total cost of ownership and it is estimated that in 2020, the US DCs alone will spend about $13 billion on energy bills. Generally, the datacenter servers are manufactured in such a way that they achieve high energy efficiency at high utilizations. Thereby for a low cost per computation all datacenter servers should push the utilization as high as possible. In order to fight the historically low utilization, cloud computing adopted server virtualization. The latter allows a physical server to execute multiple virtual servers (called virtual machines) in an isolated way. With virtualization, the cloud provider can pack (consolidate) the entire set of virtual machines (VMs) on a small set of physical servers and thereby, reduce the number of active servers. Even so, the datacenter servers rarely reach utilizations higher than 50% which means that they operate with sets of longterm unused resources (called 'holes'). My first contribution is a cloud management system that dynamically splits/fusions VMs such that they can better fill the holes. This solution is effective only for elastic applications, i.e. applications that can be executed and reconfigured over an arbitrary number of VMs. However the datacenter resource fragmentation stems from a more fundamental problem. Over time, cloud applications demand more and more memory but the physical servers provide more an more CPU. In nowadays datacenters, the two resources are strongly coupled since they are bounded to a physical sever. My second contribution is a practical way to decouple the CPU-memory tuple that can simply be applied to a commodity server. Thereby, the two resources can vary independently, depending on their demand. My third and my forth contribution show a practical system which exploit the second contribution. The underutilization observed on physical servers is also true for virtual machines. It has been shown that VMs consume only a small fraction of the allocated resources because the cloud customers are not able to correctly estimate the resource amount necessary for their applications. My third contribution is a system that estimates the memory consumption (i.e. the working set size) of a VM, with low overhead and high accuracy. Thereby, we can now consolidate the VMs based on their working set size (not the booked memory). However, the drawback of this approach is the risk of memory starvation. If one or multiple VMs have an sharp increase in memory demand, the physical server may run out of memory. This event is undesirable because the cloud platform is unable to provide the client with the booked memory. My fourth contribution is a system that allows a VM to use remote memory provided by a different rack server. Thereby, in the case of a peak memory demand, my system allows the VM to allocate memory on a remote physical server.

The primary objective of this work is to determine the Kalina cycle's suitability for thermal power conversion from a pressurized water reactor. Several previous papers have examined this application, but these either lack proof of concept or make unfeasible assumptions. This work expands current knowledge by simulating the Kalina cycle and comparing it to current pressurized water reactor Rankine cycles in order to identify which is more efficient. Prerequisite to the modeling is a simulation tool capable of modeling the thermodynamics of ammonia/water mixtures. Instead of using an existing program, a new one called Clearwater is used. This tool is based on a preexisting Gibbs free energy "super" equation of state. Algorithms for vapor-liquid equilibrium calculations and phase identification are presented. Clearwater will be distributed online as open-source code to aid future developers of ammonia/water power and refrigeration cycles. A comparison of single-stage Kalina and Rankine cycles driven by heat from PWR core coolant suggests that the Kalina cycle is not well suited to the application. Any benefit from the Kalina cycle's ability to match temperature profiles in the boiling region of the steam generator is outweighed by other drawbacks. These include the cycle's 1) increased turbine exhaust pressure and 2) lower average heat absorption temperature caused by its working fluid's relatively high liquid heat capacity, both of which lower efficiency. Having concluded this, an attempt is made to quantify the conditions under which the Kalina cycle produces more power than the Rankine cycle. Both cycles are optimized for a range of heat source inlet and outlet temperatures between 350 ℃ and 525 ℃. When both cycles absorb the same amount of heat from the source"”i.e., when source outlet temperature is constrained"” the Kalina cycle is less effective for small source temperature drops. When outlet temperature is unconstrained, the Kalina cycle outperforms the Rankine cycle for all but the lowest inlet temperature. This is due to the Kalina cycle's non-isothermal boiling profile, which allows it to absorb low temperature heat at relatively high pressure. Because of its isothermal boiling profile, the Rankine cycle cannot capture low temperature heat as effectively, so it performs worse over large, unconstrained source temperature drops.