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Komplexitet med hantering och utveckling av cyberfysiska system (CPS) i sjukhusmiljö / The complexity of managing and developing CPS in a hospital environmentBakeleh, Majd January 2023 (has links)
Denna rapport närmar sig cyberfysiska system (CPS) ur både användnings- och utvecklingsperspektiv, med särskilt fokus på utmaningarna i en sjukhusmiljö. Vikten av en kontinuerlig utveckling för att optimera teknologins prestanda och användbarhet betonas, och de specifika utmaningar som är unika för en sjukhusmiljö belyses. Studien undersöker hantering av komplexitet kopplat till CPS i form av automatiserade transportsystem på Nya Karolinska Universitetssjukhuset, Stockholm, Sverige. Målet är att ge framtida sjukhusprojekt en klar beskrivning av erfarenheterna av att utveckla och hantera CPS i sjukhusmiljö. Genom att titta på både möjligheter och utmaningar kommer rapporten att bidra till en ökad förståelse för CPS och dess förmåga att förbättra vården. Resultaten visar att utmaningarna inkluderar höga säkerhetskrav, integrering med personal, noga övervakning för att undvika driftstörningar och behovet av samarbete och flexibilitet. Rapporten drar slutsatsen att samarbete, proaktiv inställning och kontinuerlig utveckling är nödvändiga för att optimera prestanda och användbarhet hos CPS. Användare och kunder bör också vara aktiva i att dokumentera och rapportera systemets beteende för en kontinuerlig förbättring. Utvecklingen av CPS inom sjukhusmiljöer kräver också kontinuerlig testning och utbildning av personal samt ett koordinerat och strategiskt förhållningssätt för att säkerställa god samverkan mellan systemets olika aspekter. / This report approaches CPS technology from both usage and development perspectives, with a particular focus on the challenges in a hospital environment. The importance of continuous development to optimize the technology's performance and usability is explored, as well as the specific challenges that are unique to a hospital environment. The study investigates the complexity management of CPS in the form of automated transport systems at the New Karolinska University Hospital in Stockholm, Sweden. The goal is to provide future hospital projects with a clear description of the experiences of developing and managing CPS in a hospital environment. By looking at both opportunities and challenges, the report contributes to a greater understanding of CPS and its ability to improve health care. The study shows that the challenges include high security requirements, integration with staff, careful monitoring to avoid disruptions, and the need for cooperation and flexibility. The report concludes that cooperation, proactive attitude and continuous development are necessary to optimize the performance and usability of CPS. Users and customers should be active in documenting and reporting the system's behavior for continuous improvement. The development of CPS in hospital environments also requires continuous testing and training of staff and a coordinated and strategic approach to ensure cooperation between the system's different aspects.
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Data Aggregation in Time Sensitive Multi-Sensor Systems : Study and Implementation of Wheel Data Aggregation for Slip Detection in an Autonomous Vehicle ConvoyHellman, Hanna January 2017 (has links)
En övergång till bilar utrustade med avancerade automatiska säkerhetssystem (ADAS) och även utvecklingen mot självkörande fordon innebär ökad trafik på den lokala databussen. Det finns således ett behov av att både minska den faktiska mängden data som överförs, samtidigt som värdet på datat ökas. Data aggregation tillämpas i dagsläget inom områden såsom trådlösasensornätverk och mindre mobila robotar (WMR’s) och skulle kunna vara en del av en lösning. Denna rapport avser undersöka aggregation av sensordata i ett tidskänsligt system. För ett användarfall gällande halka under konvojkörning testas en aggregationsstrategi genom implementation på en fysisk demonstrator. Demonstratorn består av ett autonomt fordon i mindre skala som befinner sig i en konvoj med ett annat identiskt fordon. Resultaten pekar mot att ett viktat medelvärde, som i realtid anpassar sin viktning baserat på specifika sensorers koherens, med fördel kan användas för att estimera fordonshastighet baserat på individuella hjuls sensordata. Därefter kan en slip ratio beräknas, vilket avgör om fordonet befinner sig i ett tillstånd av halka eller ej. Begränsningar för den undersökta strategin inkluderar antalet icke-halkande hjul som behövs för tillförlitliga resultat. Simulerade resultat antyder att extra hastighetsreferenser behövs för tillförlitliga resultat. Relaterat till användarfallet konvojkörning föreslås att andra fordon används som hastighetsreferens. Detta skulle innebära en ökad precision för estimeringen av fordonshastigheten samt utgöra en intressant sammanslagning av områdena samarbetande cyberfysiska system (CO-CPS) och dataaggregation. / With an impending shift to more advanced safety systems and driver assistance (ADAS) in the vehicles we drive, and also increased autonomousity, comes increased amounts of data on the internal vehicle data bus. There is a need to lessen the amount of data and at the same time increase its value. Data aggregation, often applied in the field of environmental sensing or small mobile robots (WMR’s), could be a partial solution. This thesis choses to investigate an aggregation strategy applied to a use case regarding slip detection in a vehicle convoy. The approach was implemented in a physical demonstrator in the shape of a small autonomousvehicle convoy to produce quantitative data. The results imply that a weighted adaptive average can be used for vehicle velocity estimation based on the input of four individual wheel velocities. There after a slip ratio can be calculated which is used to decide if slip exists or not. Limitations of the proposed approach is however the number of velocity references that is needed since the results currently apply to one-wheel slipon a four-wheel vehicle. A proposed future direction related to the use case of convoy driving could be to include platooning vehicles as extra velocity references for the vehicles in the convoy, thus increasing the accuracy of the slip detection and merging the areas of CO-CPS and data aggregation.
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Network simulation for the monitoring of water distribution infrastructureXia, Jing January 2021 (has links)
The smart society, including smart infrastructures is developing quickly. The smart monitoring of the water distribution systems is a significant part of this development, trying to address possible problems in the Water Distribution Networks (WDNs) such as water leakages, pressure instability and water contamination. By sampling and sensing important parameters in the water distribution infrastructure and sending these data to control systems through a low power wide area network (LPWAN), a Cyber Physical System (CPS) of a digitalized WDN can be built. This thesis provides support for the design of such a CPS, by the design of a simulation framework, which includes coordinated WDN and communication network simulators. First, we make a selection on the communication network simulators and protocol stacks. Network simulator 3 (NS-3) is chosen as the simulation tool and Long Range (LoRa)/long range wide-area network (LoRaWAN) is chosen as the network protocol. The EPANET software is used as WDN simulator. Then, the existing implementation of the LoRaWAN protocol stack in NS-3 is modified, to allow the network simulator run parallel to the WDN simulator, and to transmit WDN sampling data to a control center. Finally, the effect of the communication network properties on the performance of the WDN monitoring system is evaluated, and it is shown that the communication delays can affect the monitoring performance even in small systems. The thesis provides the first steps of the development of a simulation environment of the cyber physical system of digitalized water distribution networks, and is expected to support further research in the area. / Det smarta samhället, inklusive smarta infrastrukturer, utvecklas snabbt. Den smarta övervakningen av vattendistributionssystemen är en betydande del av denna utveckling, som försöker lösa eventuella problem i vattendistributionsnäten (WDN) såsom vattenläckage, tryckinstabilitet och vattenförorening. Genom att ta prov och känna av viktiga parametrar i vattendistributionsinfrastrukturen och genom att skicka dessa data till ett kontrollsystem via ett LPWAN, kan ett CPS av ett digitaliserat WDN byggas. Detta examensarbete ger stöd för designen av en sådan CPS, genom utformningen av ett simuleringsramverk, som inkluderar koordinerade simulatorer för WDN och kommunikationsnätverk. Först gör vi ett urval på simulatorer för protokollstackar och kommunikationsnätverk. NS-3 väljs som simuleringsverktyg och LoRa/LoRaWAN väljs som nätverksprotokoll. EPANET-mjukvaran används som WDN-simulator. Sedan modifieras den befintliga implementeringen av LoRaWAN-protokollstacken i NS-3, för att tillåta nätverkssimulatorn att köras parallellt med WDN-simulatorn och för att överföra WDN-samplingsdata till ett kontrollcenter. Slutligen utvärderas effekten av kommunikationsnätverkets egenskaper på prestandan hos WDN-övervakningssystemet, och det visas att förseningarna i kommunikationsnätet kan påverka övervakningsprestandan även i små system. Avhandlingen ger de första stegen i utvecklingen av en simuleringsmiljö av det cyberfysiska systemet för digitaliserade vattendistributionsnät, och förväntas stödja ytterligare forskning inom området.
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Implementing Bayesian Networks for online threat detectionPappaterra, Mauro José January 2018 (has links)
Cybersecurity threats have surged in the past decades. Experts agree that conventional security measures will soon not be enough to stop the propagation of more sophisticated and harmful cyberattacks. Recently, there has been a growing interest in mastering the complexity of cybersecurity by adopting methods borrowed from Artificial Intelligence (AI) in order to support automation. Moreover, entire security frameworks, such as DETECT (Decision Triggering Event Composer and Tracker), are designed aimed to the automatic and early detection of threats against systems, by using model analysis and recognising sequences of events and other tropes, inherent to attack patterns. In this project, I concentrate on cybersecurity threat assessment by the translation of Attack Trees (AT) into probabilistic detection models based on Bayesian Networks (BN). I also show how these models can be integrated and dynamically updated as a detection engine in the existing DETECT framework for automated threat detection, hence enabling both offline and online threat assessment. Integration in DETECT is important to allow real-time model execution and evaluation for quantitative threat assessment. Finally, I apply my methodology to some real-world case studies, evaluate models with sample data, perform data sensitivity analyses, then present and discuss the results.
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Transformação digital na indústria: indústria 4.0 e a rede de água inteligente no Brasil. / Digital transformation in the industry: industry 4.0 and the smart network water on Brasil.Azevedo, Marcelo Teixeira de 10 March 2017 (has links)
Atualmente vive-se uma transformação digital na indústria, que está sendo referenciada como uma nova revolução e conhecida como a quarta revolução industrial. Essa nova revolução foi precedida por três anteriores, sendo que a primeira foi baseada no carvão como fonte de energia, impulsionando, assim, as máquinas a vapor e transformando o trabalho artesanal em automatizado; posteriormente, houve a segunda revolução industrial, baseada em conceitos de eletricidade para atingir a produção em massa; já a terceira revolução industrial baseou-se em sistemas eletrônicos e computacionais, tendo como o seu maior expoente os sistemas Supervisory Control and Data Aquisition (SCADA), que foram utilizados para aprimoramento e eficiência da linha de produção. Hoje, vive-se no limiar da quarta revolução industrial, que se apoia fortemente nas tecnologias habilitadoras, tais como: Internet of Things (IoT), machine learning, big data analytics, cyber-physical systems (CPS), machine-to-machine (M2M) e cloud computing. Essas tecnologias, trabalhando cooperativamente, são utilizadas para promover a transformação digital descrita nas visões ao redor do mundo, entre as quais se destacam: Industry 4.0, Industrial Internet Consortium e Manufatura Avançada. A presente pesquisa visa caracterizar as tecnologias habilitadoras, as visões da transformação digital e o cenário Brasil para esta nova realidade. O objetivo central é a definição de uma plataforma de transformação digital aplicada ao cenário da indústria de Utilities. Para a identificação do setor industrial, optou-se pela aplicação de um questionário direcionado às indústrias da região metropolitana de Campinas. Esse questionário serviu para traçar o nível de conhecimento, aderência e perfil profissional desejado pelas empresas relacionadas com a transformação digital. Na análise do questionário para o grupo estudado, verificou-se desconhecimento estratégico sobre a transformação digital e resistência para aplicação dos novos conceitos na cadeia de suprimentos existente. Para suprir esta necessidade e como prova de conceito foi proposta uma plataforma para transformação digital para a questão da água, com o objetivo de alcançar uma gestão eficiente dos recursos atrelada ao uso racional da água. Para a definição da plataforma foi realizado o levantamento de todo o processo de uma planta de tratamento de água, implantada nos moldes da terceira revolução industrial, de modo a melhorar o processo aplicando-se os conceitos da transformação digital na nova plataforma definida. Como resultado, o estudo de caso contribuiu para o projeto PURA-USP juntamente com o projeto SafeCity, do convênio Huawei-USP no âmbito do conceito de cidades inteligentes, integrando a transformação digital na gestão eficiente dos recursos hídricos no campus USP da capital. Adicionalmente, inseriu-se a capacitação técnica também no projeto Huawei-USP, denominada Centro de Internet do Futuro, habilitando e capacitando os profissionais para as novas tecnologias. / Nowadays, there´s a digital transformation in the industry, which is being referred to as a new revolution, known as the fourth industrial revolution. This new revolution was preceded by three previous ones, the first one was based on coal as a way of source energy, boosting the steam engines and turning the manual labor into automated; posteriorly the second industrial revolution was based on electricity concepts to achieve mass production; and the third industrial revolution, which was based on electronics and computer systems, having as its greatest exponent the systems Supervisory Control and Data Acquisition (SCADA) and programmable logic controllers (PLC), which were used for improvement and production line efficiency. Today we are on the bound of the fourth industrial revolution, which strongly supports itself at enabling technologies, such as: Internet of Things (IoT), big data analytics, cyber-physical systems (CPS), machine-to-machine (M2M) and cloud computing. These technologies are working cooperatively used to promote digital transformation described in the sights around the world, between them are: Industry 4.0, Industrial Internet Consortium and Advanced Manufacturing. This research aims to characterize the enabling technologies, the visions of the digital transformation and Brazil scenario for this new reality. The main objective is the definition of a digital transformation platform applied in the industry scenario. To identify the industry it was chosen the application of a questionnaire targeting the industries at the metropolitan region of Campinas. This questionnaire was used to trace the level of knowledge, adherence and professional profile required of companies related to digital transformation. In the questionnaire analysis for the group in the scope there was strategic unfamiliarity about the digital transformation and resistance to application of new concepts in the existing supply chain. To meet this need and as a proof of concept, a platform for digital transformation for the water issue was proposed with the objective of achieve an efficient management of resources linked to the rational use of water. For the platform definition was performed a survey of the whole process of a water treatment plant that was implemented along the lines of the third industrial revolution and improved the process by applying the concepts of digital transformation in the new set platform. The case study aimed to contribute to the PURA-USP project, integrating the digital transformation in the efficient management of water resources on campus USP capital. Additionally, technical training was also included in the Huawei-USP project, denominated the Future Internet Center, enabling and training professionals for new technologies.
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Cyber Physical System for Continuous Evaluation of Fall Risks to Enable Aging-In-PlaceJagtap, Vinayak 29 April 2015 (has links)
Every year, one out of three adults over the age of 65 falls, and about 30% of the falls result in moderate to severe injuries. The high rate of fall-related hospitalizations and the fact that falls are a major source of morbidity and mortality in older adults have motivated extensive interdisciplinary clinical and engineering research with a focus on fall prevention. This research is aimed at developing a medical Cyber Physical System (CPS) composed of a human supervised mobile robot and ambient intelligence sensors to provide continuous evaluation of environmental risks in the home. As a preventive measure to avoid falls, we propose use of mobile robots to detect possible fall risks inside a house. As a step-up to that, we also define a control framework for intelligent, networked mobile robots to semi-autonomously perform assistive and preventive tasks. This framework is integrated in a smart home that provides monitoring and control capabilities of environmental conditions such as objects blocking pathways or uneven surfaces. The main outcome of this work is the realization of this system at Worcester Polytechnic Institute's (WPI) @Home testbed.
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Interferômetros coplanares de micro-ondas para aplicação em sistemas de detecção instantâneaGomes Moura de Oliveira, Bruno 31 January 2009 (has links)
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Previous issue date: 2009 / Companhia Hidro Elétrica do São Francisco / Os sistemas IFM (do inglês Instantaneous Frequency Measurement) são largamente usados na eletrônica para fins militares e em sistemas inteligentes para a detecção de sinais desconhecidos com velocidade e precisão ao longo de uma larga banda do espectro de frequências. Além disso, o aumento da quantidade de sistemas irradiantes faz crescer a importância de dispositivos para identificação de sinais desconhecidos. O sistema IFM monitora, de forma simultânea, todas as frequências da banda para a qual foi projetado, sem a necessidade de fazer uma varredura de espectro, detectando instantaneamente os sinais desconhecidos. Nos sistema IFM existem os circuitos discriminadores de fase. Os sinais de saída dos discriminadores de fase servem para formar um código binário que associa uma palavra binária a uma sub-banda de frequência. Neste trabalho, será demonstrado, através de equações de projeto, simulações eletromagnéticas e medições experimentais, o comportamento de interferômetros coplanares de micro-ondas atuando como discriminadores em um sistema IFM simples de 4 bits. Esse sistema é projetado para operar na banda de 5 a 6 GHz, com uma resolução de 62,5 MHz, identificando 16 sub-bandas distintas de frequência. Os interferômetros coplanares são implementados com circuitos de micro-ondas em CPS (do inglês Coplanar Strips) e CPW (do inglês Coplanar Waveguide), seus resultados experimentais são comparados aos teóricos e simulados
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Transformação digital na indústria: indústria 4.0 e a rede de água inteligente no Brasil. / Digital transformation in the industry: industry 4.0 and the smart network water on Brasil.Marcelo Teixeira de Azevedo 10 March 2017 (has links)
Atualmente vive-se uma transformação digital na indústria, que está sendo referenciada como uma nova revolução e conhecida como a quarta revolução industrial. Essa nova revolução foi precedida por três anteriores, sendo que a primeira foi baseada no carvão como fonte de energia, impulsionando, assim, as máquinas a vapor e transformando o trabalho artesanal em automatizado; posteriormente, houve a segunda revolução industrial, baseada em conceitos de eletricidade para atingir a produção em massa; já a terceira revolução industrial baseou-se em sistemas eletrônicos e computacionais, tendo como o seu maior expoente os sistemas Supervisory Control and Data Aquisition (SCADA), que foram utilizados para aprimoramento e eficiência da linha de produção. Hoje, vive-se no limiar da quarta revolução industrial, que se apoia fortemente nas tecnologias habilitadoras, tais como: Internet of Things (IoT), machine learning, big data analytics, cyber-physical systems (CPS), machine-to-machine (M2M) e cloud computing. Essas tecnologias, trabalhando cooperativamente, são utilizadas para promover a transformação digital descrita nas visões ao redor do mundo, entre as quais se destacam: Industry 4.0, Industrial Internet Consortium e Manufatura Avançada. A presente pesquisa visa caracterizar as tecnologias habilitadoras, as visões da transformação digital e o cenário Brasil para esta nova realidade. O objetivo central é a definição de uma plataforma de transformação digital aplicada ao cenário da indústria de Utilities. Para a identificação do setor industrial, optou-se pela aplicação de um questionário direcionado às indústrias da região metropolitana de Campinas. Esse questionário serviu para traçar o nível de conhecimento, aderência e perfil profissional desejado pelas empresas relacionadas com a transformação digital. Na análise do questionário para o grupo estudado, verificou-se desconhecimento estratégico sobre a transformação digital e resistência para aplicação dos novos conceitos na cadeia de suprimentos existente. Para suprir esta necessidade e como prova de conceito foi proposta uma plataforma para transformação digital para a questão da água, com o objetivo de alcançar uma gestão eficiente dos recursos atrelada ao uso racional da água. Para a definição da plataforma foi realizado o levantamento de todo o processo de uma planta de tratamento de água, implantada nos moldes da terceira revolução industrial, de modo a melhorar o processo aplicando-se os conceitos da transformação digital na nova plataforma definida. Como resultado, o estudo de caso contribuiu para o projeto PURA-USP juntamente com o projeto SafeCity, do convênio Huawei-USP no âmbito do conceito de cidades inteligentes, integrando a transformação digital na gestão eficiente dos recursos hídricos no campus USP da capital. Adicionalmente, inseriu-se a capacitação técnica também no projeto Huawei-USP, denominada Centro de Internet do Futuro, habilitando e capacitando os profissionais para as novas tecnologias. / Nowadays, there´s a digital transformation in the industry, which is being referred to as a new revolution, known as the fourth industrial revolution. This new revolution was preceded by three previous ones, the first one was based on coal as a way of source energy, boosting the steam engines and turning the manual labor into automated; posteriorly the second industrial revolution was based on electricity concepts to achieve mass production; and the third industrial revolution, which was based on electronics and computer systems, having as its greatest exponent the systems Supervisory Control and Data Acquisition (SCADA) and programmable logic controllers (PLC), which were used for improvement and production line efficiency. Today we are on the bound of the fourth industrial revolution, which strongly supports itself at enabling technologies, such as: Internet of Things (IoT), big data analytics, cyber-physical systems (CPS), machine-to-machine (M2M) and cloud computing. These technologies are working cooperatively used to promote digital transformation described in the sights around the world, between them are: Industry 4.0, Industrial Internet Consortium and Advanced Manufacturing. This research aims to characterize the enabling technologies, the visions of the digital transformation and Brazil scenario for this new reality. The main objective is the definition of a digital transformation platform applied in the industry scenario. To identify the industry it was chosen the application of a questionnaire targeting the industries at the metropolitan region of Campinas. This questionnaire was used to trace the level of knowledge, adherence and professional profile required of companies related to digital transformation. In the questionnaire analysis for the group in the scope there was strategic unfamiliarity about the digital transformation and resistance to application of new concepts in the existing supply chain. To meet this need and as a proof of concept, a platform for digital transformation for the water issue was proposed with the objective of achieve an efficient management of resources linked to the rational use of water. For the platform definition was performed a survey of the whole process of a water treatment plant that was implemented along the lines of the third industrial revolution and improved the process by applying the concepts of digital transformation in the new set platform. The case study aimed to contribute to the PURA-USP project, integrating the digital transformation in the efficient management of water resources on campus USP capital. Additionally, technical training was also included in the Huawei-USP project, denominated the Future Internet Center, enabling and training professionals for new technologies.
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The Collaborative Problem-Solving Approach with Traumatized Children: Its Effectiveness in the Reduction of Locked Seclusion in an Inpatient Psychiatric SettingFinnie, Halana M. 09 April 2015 (has links)
Aggressive or explosive behaviors in children typically occur within the context of a variety of psychiatric diagnoses and pose additional challenges when children present with histories of abuse. These behaviors are often interpreted as deliberate or noncompliant and management of these extreme behaviors often results in locked seclusion in most inpatient psychiatric settings. Locked seclusion remains controversial at best and raises legal and ethical issues regarding its safe and therapeutic use. <br>This retrospective quantitative study evaluated the effectiveness of the Collaborative Problem-Solving (CPS) approach as a less restrictive behavioral intervention on an inpatient child psychiatric unit with children ages 5-12 years that introduced the CPS approach during a nine month performance improvement project from July 1, 2006 - March 31, 2007. This study sought to determine what variables, if any, impacted the use of locked seclusion before, during, and after CPS implementation and whether children with histories of abuse were placed in locked seclusion at a significantly different rate relative to admissions of children who did not have histories of abuse. Erik Erikson's Theory of Psychosocial Development served as the theoretical framework.<br>The closed medical record review involved 197 admissions and 167 children. All data were analyzed in two parts: the entire nine month period of 197 admissions and by time period, based on when the CPS intervention was introduced and implemented on the unit. <br>Length of stay was the only variable statistically significant during the nine month period (n=197) and third time period of January -March 2007 (n=65) when CPS was fully implemented and assessed. This finding suggests that a child's longer length of stay may have had a relationship with being placed in locked seclusion. When length of stay was controlled as an influence with history of abuse, the variable of interest for this study, children with histories of abuse for the nine month period were not significantly more likely of being placed in locked seclusion than children without histories of abuse; for the third time period, they were found to be almost eight times less likely of being placed in locked seclusion with an odds ratio of 7.81.<br>Although these findings suggest a favorable response to the CPS approach and that behaviors associated with traumatized children were normalized to that of their peer group, the results must be considered with caution. There were many limitations to the initial project and any inferred success with abused children and the CPS approach is based on statistical outcomes only. Other variables not measured or controlled must be considered as potential influences that may have impacted these outcomes. As such, future research evaluating CPS effectiveness with traumatized children is recommended. / School of Nursing; / Nursing / PhD; / Dissertation;
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Sources, emissions, and occurrence of chlorinated paraffins in Stockholm, SwedenFridén, Ulrika E. January 2010 (has links)
Chlorinated paraffins (CPs) are ubiquitous environmental contaminants. They fulfill all of the criteria (persistent, toxic, and subject to long-range transport) for persistent organic pollutants (POPs) according to the United Nations Economic Commission for Europe (UNECE). CPs are also under consideration for inclusion in the Stockholm Convention on POPs. Their presence has been shown in various environmental matrices in the industrialized parts of the world, as well as in remote regions such as the Arctic. The aim of this thesis was to increase the limited knowledge of the presence of CPs in the environment, their sources to the environment, and the resulting human exposure. An analytical procedure for the determination of CPs in environmental samples based on gas chromatography coupled to electron capture detection (GC-ECD) has been developed. GC-ECD is a relatively inexpensive instrument that is fast and easy to operate. These advantages open up the possibility for a comprehensive screening of the occurrence of CPs in the environment, including developing countries. Furthermore, the occurrence of CPs in ambient air and in indoor air and dust was studied. Elevated CP concentrations in indoor air (<5-210 ng/m3) were observed compared to ambient air (0.7-33 ng/m3), which is indicative of the presence of indoor emission sources. Indoor air and dust concentrations were used to estimate the human exposure to CPs via the indoor environment. Comparison of the estimates to available dietary intake estimates indicated that the indoor exposure pathways are not negligible. CP concentrations in ambient air from urban Stockholm were higher than in rural Aspvreten, Sweden. This indicates the presence of additional (emission) sources in urban areas compared to rural sites. Additionally, a seasonal variation of air concentrations was observed at both locations, suggesting temperature dependent emission sources for CPs. These observations were supported by a substance flow analysis of CPs performed for Stockholm. This study estimated the major emission sources of CPs to the Stockholm environment to be emissions from painted surfaces and in-place sealants. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.
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