As usinas termelétricas a ciclo combinado empregadas na geração de energia elétrica são compostas basicamente por três elementos ou sistemas: a Turbina a Gás, a Caldeira de Recuperação e a Turbina a Vapor. A Turbina a Gás é responsável pela transformação da energia química do combustível em energia mecânica para acionar os geradores, e os gases de escapamento com alta temperatura são responsáveis pela geração de vapor para as turbinas de vapor nas caldeiras de recuperação. É por estes motivos que é importante manter disponível a Turbina a Gás. A disponibilidade de um sistema está relacionada com a confiabilidade dos seus componentes e com as políticas de manutenção associadas aos mesmos, que não só influenciam no tempo de retorno à operação após uma ação de manutenção programada ou não programada, como também na degradação da confiabilidade do sistema. Este trabalho apresenta um método de análise empregado para a estimativa da confiabilidade e disponibilidade de Turbinas a Gás empregadas em usinas termelétricas a ciclo combinado, baseado nos conceitos de Confiabilidade e Manutenção Centrada em Confiabilidade. O método baseia-se na avaliação dos tempos entre falhas das causas destas falhas, e dos tempos de reparo associados a cada uma das intervenções de operação associadas à ocorrência de falhas. Adicionalmente, apresenta-se uma aplicação deste método para Turbinas a Gás de grande porte, com potência nominal de 150MW instaladas em uma Usina Termelétrica com capacidade de geração superior a 500MW. Verifica-se a existência da diferencia na disponibilidade das duas turbinas instaladas na usina obtendo um valor de 99,35% e 96%, considerando um período de operação de 8760 horas. Finalmente, apresentam-se as principais conclusões do trabalho e uma discussão sobre a viabilidade de aplicação do método proposto. / The combined cycle thermoelectric power station presents three main equipments: the Gas Turbine, the Heat Recovery Steam Generator and the Steam Turbine. The Gas Turbine transforms the chemical energy generated by combustion in mechanical energy unit to rotate the generator\'s shaft and the exhaust gas in high temperature is used to heat water at the Heat Recovery Steam Generator to generate steam for the Steam Turbine. Taking in view the great importance of the gas turbine for power generation, its availability should be carefully evaluated to guarantee the power station full operational availability. The availability of a system is strongly associated with the parts reliability and their maintenance policy. That policy not only has influence on the parts repair time but also on the parts reliability, affecting the system degradation and availability. This study presents a method for reliability and availability evaluation of gas turbines installed in a combined cycle thermoelectric power station, based on system Reliability concepts and Reliability-Centered Maintenance. The methodology depended on time between failures, failure modes and time to repair associated to each failure that operation interruption. The method is applied on the analysis of a gas turbine with more than 150MW nominal output installed in a 500MW power plant. A difference between the gas turbines availability are identified. The calculator values are 99,35 % and 96 % for 8760 hours operation period. Finally, the main conclusions and a discussion about feasibility of application of the considered method are present at the end of the study.

Architectural design decisions are known to be crucial for the success of a system in development. An early design decision will most likely be expensive to change at a later stage of the development if the software engineers needs to get back to the drawing board. If a quality attribute has been neglected during architectural design it may ruin the entire project. This work describes a way of increasing the availability of a software service, that have already been put into use, by adding a middle layer of replication logics represented by third party application servers and replicated Enterprise JavaBeans. The approach called Three-tier replication is assessed and compared to the origin architectural design by using a qualitative scenario based assessment. In addition, we have also implemented the new architectural design to be able to validate the assessment results. The validation is done by testing the scenarios on the two architectures. The software service used is an industrial system for sending text messages from computers to mobile phones. / Tidiga designbeslut är extremt viktiga för utgången av ett utvecklingsprojekt. Felaktiga beslut kommer att kosta företaget eller organisationen mycket tid och pengar om det visar sig att de måste omarbetas. Detta arbetet beskriver ett sätt att öka åtkomsten på en tjänst genom att lägga till ett mellan-lager som sköter replikering av tjänstenoden. Relplikeringslogiken sköts av applikationsservrar och Enterprise Javabeans. Vi har använt ett befintligt industriellt system för att utveckla och jämföra metoden. Tjänsten ifråga är en SMS-tjänst för kommunikation mellan dator och mobil-telefon och vise versa.

The increased demand for interoperability among Emergency Responders (ERs) and timely accessibility to a large amount of reliable, accurate, context and location aware, and privacy-preserved data (e.g., environmental data, health records, building plan, etc.), mandates the emergence of dedicated Public Safety Broadband Networks (PSBNs). However, realizing PSBNs and addressing such requirements encounters substantial challenges. For example, several security and privacy vulnerabilities have been detected in the Long Term Evolution (LTE) which is the leading enabler of PSBNs. Nonetheless, the more significant challenge lies under the corresponding data requirements. This is because data is unstructured, its volume is enormous, and it includes inaccurate, irrelevant, and context-free data. Moreover, the data sources are heterogeneous and may not be reachable in an emergency. Furthermore, the data contains personally identifiable information for which privacy and access authorization should be respected. In this thesis, we investigate and address the aforementioned challenges. Here, we propose an efficient and secure algorithm to mitigate the main security and privacy vulnerability of LTE. In addition, to provide context and location aware data availability during an emergency, we propose a secure data storage structure and privacy-preserving search scheme. Furthermore, we propose a location-aware data access model to filter irrelevant data with regards to an incident and prevent unauthorized data access. To envision our access model, we propose a location-aware fine grained access authorization scheme. Our security analysis shows that our search scheme is secure against a chosen keyword attack and the proposed authorization scheme is formally proven secure against a selective chosen ciphertext attack. Concerning performance efficiency, our search scheme requires minimal data search and retrieval delay and the proposed authorization scheme imposes constant communication and decryption computation overheads. Finally, we propose a context-aware framework, which fully complies with emergency response requirements, based on the concept of trust to filter-out inaccurate and irrelevant data. The integration of our contributions promises highly reliable, accurate, context and location aware, and privacy-preserved data availability and timely data accessibility.

Microbial electrochemical technologies (MET) exploit the bioelectrocatalytic activity of microorganisms, with a main focus on waste-to-resource recovery. Electromethanogenesis, a type of MET, describes the process of CO2 reduction specifically to methane, catalyzed by methanogens that utilize the cathode directly as an electron donor or through H2 evolving from the cathode surface. Applications are mainly in the direction of bioelectrochemical power-to-gas, as well as biogas upgrading and carbon capture and utilization. As the cathode and its associated microbial consortia are key to the process, larger scale applications require improvements especially in terms of optimal operational parameters, cathode materials and the dynamics of the effect of electron transfer within the cathodic biofilm. The focus of this dissertation is to improve the understanding of the dynamics and function of methaneproducing biofilms grown on cathodes in electromethanogenic reactors in the presence of two different electron donors: the cathode and the H2 evolving from the cathode surface. The spatial homogeneity of the microbial communities across the area of the cathode was demonstrated, which is relevant for large scale applications where reproducibility is required for predictable engineered systems. Metagenomic and metatranscriptomic methods were applied to elucidate the short-term changes in the actively transcribed methanogenesis and central carbon assimilation pathways in response to varying the availability of electrons by changing the set cathode potential in a novel Methanobacterium species enriched from electromethanogenic biocathodes. Although changes in functional performance were evident with varying potential, no significant differential expression was observed and genes from the methanogenesis and carbon assimilation pathways were highly expressed throughout. Indium tin oxide (ITO) as a potentially hydrogen evolution reaction (HER) – inert cathode material was evaluated using the mixotrophic Methanosarcina barkeri in an attempt to develop a simplified material-science driven approach to future electron transfer studies. It was found to be electrochemically unstable under the tested conditions, losing its conductivity over time. Overall, the findings from these studies provide new knowledge on the effects of electron donor availability on the functional performance and the biocathode community dynamics. The understandings derived from the study are relevant to methanogenic processes and should aid in system scaleup design.

Introduction: Palliative care is the approach to the care of patients with life-threatening illnesses. An important part of this is the rational use of a pharmacological approach to relieve suffering by addressing the symptom burden of the patient. Palliative care symptoms contribute a great deal to the suffering of the patient and affects quality of life. Different studies across several countries on the palliative care symptoms have identified common symptoms with pain being the most frequent. The WHO Public Health Strategy for palliative care outlines four components: policy, education, implementation and drug availability. These components interlink and each one affects the others. The drugs used for palliative care symptoms should be classified as essential medicines and be available to all patients who need this treatment. Factors influencing the effective pharmacological management of palliative care symptoms include drug availability, policy and the approach of the prescribers. Studies have shown that developing countries rank low in the use of the essential palliative care drugs especially morphine. Aim: The aim of this study was to describe the prevalence of palliative care symptoms and the prescribing and administration patterns in oncology and haematology patients at PGH, as well as exploring the health workers' opinions on the pharmacological approach to these symptoms. Methods: A mixed method approach was used to qualitatively look at the health workers' responses using inductive thematic analysis and quantitatively obtain information on palliative care symptom management from the health workers and patient records. Results: Pain was the commonest palliative care symptom identified by health workers, and evident in the patient records. A list of other palliative care symptoms, and the frequency at which they occurred was compiled in this study. The health workers highlighted drug availability, palliative care education and need to engage some nurses in prescribing some of the palliative care drugs. Fewer than half of the patient records assessed as being in need of palliative care (N = 247) were given medications from the recognized palliative care drug list (N = 101). Conclusion: This study showed that essential medicines for palliative care symptoms are not easily available in Zimbabwe for various reasons that include cost, policy, education and training. Pain and other palliative care symptoms are not adequately managed. Therefore, palliative care is not yet integrated into the health care system in Zimbabwe as mandated by the WHO. Recommendations to improve palliative care symptom treatment are suggested.

This essay deal with implementation of the Incident management as one of the possible means to minimize risks and losses arising from failures in the organization’s infrastructure and inaccessibility of their "business-critical" applications. It focuses primarily on the organization focused on electronic commerce.

Soils in the vicinity of Křemže in the Southern Bohemia are developed on altered ultrabasic rocks. The occurrence of Ni-hydrosilicate and Fe-rich ores in this area lead to their mining mainly during 19th century, then during the World War II. This thesis is focused on distribution and availability of Ni, Cr and Co and accompanying elements in soils at former mine and prospection sites (2 soil profiles and 32 topsoil samples at historical surface mine area). In all soil samples, physico-chemical parameters (pH, TOC, TS) and bulk concentrations of Al, Ca, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn were measured. In addition, deionised water, DTPA and EDTA extracts were used to determine the (bio)availability and mobility of these elements. Some of trace elements were found in elevated concentrations in the mining area topsoils; mean Ni: 1175 mg/kg (range 545-2849 mg/kg), mean Cr: 416 mg/kg (240-849 mg/kg), mean Co: 127 mg/kg (65-238 mg/kg), mean Fe: 49155 mg/kg (30460-113800 mg/kg), mean Mg: 12648 mg/kg (8795-18770 mg/kg) and mean Mn: 1480 mg/kg (1028-2319 mg/kg). In soil profiles the Ni availability decreased with depth. In the uppermost organic O horizon in forest soil profile, 19.5 % and 23.8 % of total Ni was extracted by DTPA and EDTA, respectively. The extractabilities are decreasing down to mineral...

Background: The maintenance process is crucial for production activities to supply continuity and productivity. With Industry 4.0 advent, opportunities to create a huge amount of data and use this data to improve production and maintenance performance indicators became a topic that is necessary to make decisions. Most importantly, before applying these technologies, there is a need to integrate all systems to create a common language. Purpose: The first aim is to explore the influence of system integration within production and maintenance in measuring machine availability. Secondly, to review in detail the procedure of calculating machine availability among several production units in a manufacturing company. Research Question 1 (RQ1): What are the values of system integration among maintenance and production decisions in measuring machine availability? Research Question 2 (RQ2): Which parameters or indicators can be taken into consideration to calculate machine availability among several production units in a manufacturing company? Methodology: The study is based on a case study that primarily relies on qualitative data from interviews, survey, and observations, as well as quantitative calculation of availability data. An exploratory research design was used in the beginning of the study, followed by an abductive approach which means both inductive and deductive approach were used. The total process can be broken down into two parts: theoretical background/literature review and Scania empirical research. Conclusions: With the integration of different systems, it is shown that the real availability numbers differ compared with assumed numbers. The manufacturing industry is undergoing paradigm shifts, and many manufacturing companies worldwide are currently updating their maintenance strategies aligned with smart maintenance. With the aim of securing productive, robust, and sustainable production systems through the implementation of the smart maintenance concept. Therefore, it can be suggested that before implementings mart maintenance technologies, starting to create collaboration within a common database in association with production units about production data sharing matter is crucial step for the case company.

Deploying virtual network functions (VNFs) such as WAN accelerators, network address translators (NATs) and 5G functions at the network edge (NE) can significantly reduce the experienced latency of delay-ultrasensitive applications (e.g., autonomous vehicles and Internet of things). Nonetheless, a major challenge to their anticipated large-scale deployment is the ability to efficiently allocate and manage the scarce NE resources hosting these functions. In this thesis, we describe a novel containerized infrastructure manager (cIM) that extends current managers, such as Kubernetes, with the necessary building blocks to provide an accurate yet elastic resource allocation service to containerized VNFs at scale. The proposed cIM treats the main modules of the VNFs, i.e., the containerized VNF components (cNFCs), as atomic special-purpose functions that can be rapidly deployed to form complex network services. The main component of the proposed cIM, the resource reservation manager (RRM), employs concepts of risk pooling in the insurance industry to accurately reserve the needed resources for the hosting containers. More precisely, to meet anticipated cNFCs demand fluctuation, the RRM accurately reserves a quota of additional resources that are shared by the containerized functions collected together in clusters. The reserved quota of resources ensures the desired availability level of the cNFCs without over-provisioning the scarce resources of the NE. The RRM considers three different situations namely that of a cNFC instance, a cluster of cNFCs or multiple cNFC clusters sharing the reserved resources. Different allocation approaches are then presented for each of these three situations. Simulation experiments are conducted to evaluate the performance of our reservation schemes from different aspects. The corresponding experimental results demonstrate that our proposed cIM can significantly improve the performance of the cNFCs and guarantee their desired availability with minimal resource reservation. Optimal allocation solutions of the resource pools are further proposed considering the desired availability level and the limit of resource pools. The evaluation results demonstrate that our optimization models and solutions obtain the best performance of relevant testing parameters, e.g., availability.

Fresh-harvested Gambel oak (Quercus gambelii) browse was mixed with chopped alfalfa hay to formulate six diets , varying in oak content at two phenological stages. Diets included juvenile oak (65 ,80,95%), mature oak (40,80\), and an alfalfa control . Diets we re evaluated for goats using a series of total-collection dige st ion balance trials . Dry matter intake was highest for animal s on mature oak diets, and lowest on diets containing a high percentage of juvenile oak, possibly due to differences in diet dry matter content . Apparent digestibility of dry matter and cell wall components was lowest for mature oak diets, and highest for diets high in juvenile oak. Nitrogen and energy balances were positive in all cases , and all diets provided nitrogen and energy in excess of rnaintenance requirements. This was reflected by weight gains for all animal s in every trial. Fecal and urinary nitrogen losses did not appear to be related to tannin content of the diets, because high-percentage juvenile oak diets resulted in reduced nitrogen outputs , presumably due to reduced nitrogen intakes for these diets. In comparison with previous data using pelleted formulations, the fresh-fed material was consistently higher in digestibility of the various fractions, and associated with lower dry matter intakes.