231 |
A thermofluid network-based methodology for integrated simulation of heat transfer and combustion in a pulverized coal-fired furnacevan Der Meer, Willem Arie 02 March 2021 (has links)
Coal-fired power plant boilers consist of several complex subsystems that all need to work together to ensure plant availability, efficiency and safety, while limiting emissions. Analysing this multi-objective problem requires a thermofluid process model that can simulate the water/steam cycle and the coal/air/flue gas cycle for steady-state and dynamic operational scenarios, in an integrated manner. The furnace flue gas side can be modelled using a suitable zero-dimensional model in a quasi-steady manner, but this will only provide an overall heat transfer rate and a single gas temperature. When more detail is required, CFD is the tool of choice. However, the solution times can be prohibitive. A need therefore exists for a computationally efficient model that captures the three-dimensional radiation effects, flue gas exit temperature profile, carbon burnout and O2 and CO2 concentrations, while integrated with the steam side process model for dynamic simulations. A thermofluid network-based methodology is proposed that combines the zonal method to model the radiation heat transfer in three dimensions with a one-dimensional burnout model for the heat generation, together with characteristic flow maps for the mass transfer. Direct exchange areas are calculated using a discrete numerical integration approximation together with a suitable smoothing technique. Models of Leckner and Yin are applied to determine the gas and particle radiation properties, respectively. For the heat sources the burnout model developed by the British Coal Utilisation Research Association is employed and the advection terms of the mass flow are accounted for by superimposing a mass flow map that is generated via an isothermal CFD solution. The model was first validated by comparing it with empirical data and other numerical models applied to the IFRF single-burner furnace. The full scale furnace model was then calibrated and validated via detailed CFD results for a wall-fired furnace operating at full load. The model was shown to scale well to other load conditions and real plant measurements. Consistent results were obtained for sensitivity studies involving coal quality, particle size distribution, furnace fouling and burner operating modes. The ability to do co-simulation with a steam-side process model in Flownex® was successfully demonstrated for steady-state and dynamic simulations.
|
232 |
"Jag förtjänade inte det där, ingen gör det!" : En kvalitativ studie om generationstillhörighetens betydelse för våldsutsatta kvinnors utträdesprocesser ur våldsamma kärleksrelationer. / “I did not deserve that, nobody does” : A qualitative study about the effect of generational affiliation on abused women’s role exit.Jonsson, Emelie, Tousi, Shirin January 2021 (has links)
Title: “I did not deserve that, nobody does” - A qualitative study about the effect of generational affiliation on abused women’s role exit. Authors: Emelie Jonsson and Shirin Tousi. This study intends to gain understanding about the process of role exit for women who once lived in violent and abusive close relationships, and what the generation the women belong to may mean. The empirical data is based on women’s histories and experiences of living in and leaving violent relationships. The data has been collected through a qualitative method. Semi-structured interviews were conducted with 14 women, of which half took place with women aged 20-30 and half with women aged 50-60. To understand the empirical data three different theoretical perspectives have been chosen. The theories that have been chosen are Yvonne Hirdmans’ (2004) theory about gender structures, Helen Rose Ebaughs’ (1988) theory about the process of role exit and lastly Clary Krekula and Barbro Johansson’s (2017) generational perspective. Some of the theoretical concepts that have been used in order to gain understanding of the women’s experiences are gender relations, hierarchy, dichotomy, gender contract, role exit and generation. The results of this, show that generational affiliation has a notable impact on women’s exit from violent close relationships. The first question is, In what way does generational affiliation affect women's initial thoughts of wanting to leave a violent relationship? The results show that women's generational belonging affected their first initial thoughts about leaving the violent relationship greatly. Women who belong to the younger generation are more individualistic in their way of thinking and acting, whilst women who belong to the older generation are guided and moulded by their close surroundings. The second question in this study is, What significance does generational affiliation have on women’s actual exit from violent relationships? This study’s results show that the generation one belongs to is of great importance for a woman's actual exit from violent relationships, but the effect is expressed differently within the two different generations. The women from the older generation do not act on their own needs and wants but on the needs of their children and family. The women who belong to the younger generation are more individualists and choose to leave the violent relationships as a result of violent incidents that have harmed them personally. The third question discussed in this study is, In what way has one’s generation affected the women after their exit from the violent relationships? The results show that the women from the younger generation have been able to move on after exit from the violent relationships, whilst the women from the older generation have gotten stuck in a hangover identity from their ex-role of being exposed to violence.
|
233 |
Konsultationsteamet : - Arbete och samverkan / Konsultationsteamet : - Work and CooperationKongshöj, Nathalie, Norén, Tilda January 2022 (has links)
Både internationellt och i Sverige har gängkriminaliteten ökat stadigt sedan 2000-talets början. Gängkriminaliteten orsakar stort mänskligt och ekonomiskt lidande, både för de direkta offren och för samhället i stort. Utifrån denna problembild har insatserna varit många för att stoppa gängen däribland interventioner för att få individer att lämna/hoppa av kriminella gäng. Verksamheter som bistår individer att lämna kriminella gäng benämns som avhopparverksamheter. I Malmö finns bland annat avhopparverksamheten Konsultationsteamet, som består av socialsekreterare och poliser och riktar sig till kriminella individer med en stor hotbild och som är i behov av att flytta till en ny stad. Teamet genomför initialt en utredning av avhopparens motivation och hotbild som används som underlag för ett officiellt beslut om insatser. Efter beslutet flyttas avhopparen till ett boende i en annan stad. Aspekten av samverkan har aldrig tidigare studerats i relation till Konsultationsteamet och dess arbete. Därmed syftar den aktuella studien är att undersöka de verksamma aktörernas, i.e. socialsekreterare och polisers, upplevelser och erfarenheter av arbetet inom Konsultationsteamet. Fokus har lagts på informanternas upplevelser av samverkan inom Konsultationsteamet samt samverkan med andra aktörer som deltar i arbetet med avhopparen. Studien syftar även till att studera vad för upplevelser och erfarenheter anställda på boendena har på arbetet och samverkan med Konsultationsteamet. Resultatet visar att arbetet och samverkan i Konsultationsteamet överlag upplevs fungera mycket bra. Informanterna som arbetar på boendena uttrycker även de att arbetet och samverkan med Konsultationsteamet fungerar bra. Vidare har det noterats att kvaliteten på boendena kan variera mycket vilket upplevts vara ett problem. Kontakten med Socialtjänsten skulle även kunna stärkas och förbättras då det noterats vissa brister i rådande kontakt. / The problem of gang criminality has increased substantially both internationally and in Sweden since the beginning of the 21st century. Criminal gangs cause a tremendous amount of harm and suffering, both physically and economically, to the victims of the crime and to society as a whole. The efforts to stop these criminal gangs have been many. Among the interventions aimed to stop criminal gangs are exit programs which aim to help gang members leave their criminal gang. One example of an exit program is Konsultationsteamet in Malmö. Konsultationsteamet is a form of cooperation between social workers and the police. They work with gang members who have an increased level of threat targeted against them and who are in need of a relocation in a new city. The team initially conducts an investigation of the gang member's motivation and the level of threat targeted against the gang member that wants to leave. This information is used as a basis for an official decision on interventions. After the official decision, the gang member is relocated to a new city. Konsultationsteamet has been studied before. However, the aspect of cooperation has never before been investigated in relation to Konsultationsteamet. The aim of this study is therefore to study the informants' experiences of the work in Konsultationsteamet, i.e. the social workers and the police officers. The focus has been on the informants' experiences of the collaboration within Konsultationsteamet as well as collaboration with other actors who participate in the work with the exit programs. The study also aims to investigate the experiences of the employees, who work at the accommodations where the defectors are placed about their thoughts on their work and cooperation with Konsultationsteamet. The results shows that the informants at Konsultationsteamet are very satisfied with the work and cooperation within the team. The employees at the accommodations where the defectors are placed also express that their work and cooperation with Konsultationsteamet is working really well. Furthermore, it has been noted that the quality of the accommodations where the defectors are placed can vary greatly, which is perceived as a problem by all informants. Finally, the results also shows that the contact with the social services could evolve and improve more, as some shortcomings in the current contact have been noted.
|
234 |
Experimental loss measurements in an annular sector cascade at supersonic exit velocitiesLilienberg, László January 2016 (has links)
Efficiency improvement is one of the most important aspects of engineering and especially important in the field of energy production. In the past decades, energy was mostly produced by fossil based technologies involving turbomachines, and the efficiency of these machines nearly quadrupled since the introduction of the first economically viable gas turbines. The progress continues, as there are still areas where improvement can be made. Such area is the High Pressure Turbine stage (HPT), which influences the flow characteristics and losses downstream, which this thesis will examine in more detail. In the open literature it can be found that one of the areas with potential for progress is the external cooling of the nozzle guide vanes (NGV) of the HPT stage. However not many studies go towards supersonic exit velocities even though that is the most common trend followed by the industry these days. The external cooling allows the turbine entry temperature (TET) to go beyond the melting point of the blade material thus increase Carnot efficiency but in the meantime influences the flow characteristics and losses. To understand these influences of the cooling, experiments in an annular sector cascade (ASC) were conducted with exit velocities from Mach 0.95 to 1.2 without and with cooling applied. The findings of the experiments are believed to help the more detailed understanding of the flow behaviour at high exit velocities. When comparing the corresponding runs in the two cases it became obvious that with cooling applied the deviation of the exit flow angle is generally smaller than in the uncooled case. This might be a highly important design feature for designers to work with. From the available data it was concluded that the total pressure distribution across the span is not significantly affected with the introduction of cooling.
|
235 |
"Det värsta har vi tyvärr varit med om, att de blir mördade" : En kvalitativ intervjustudie om yrkesverksammas förståelse för sitt och organisationens arbete med avhoppare som vill lämna kriminella grupperingarAntonsson, Linnea, Sävqvist, Isabelle January 2023 (has links)
Syftet med denna kvalitativa studie har varit att undersöka professionellas förståelse för sitt och organisationens arbete med avhoppare som vill lämna kriminella grupperingar, samt studera hur samverkan fungerar mellan organisationer. För att besvara syftet har semistrukturerade intervjuer genomförts med yrkesverksamma som arbetar med avhoppare. Studiens teoretiska utgångspunkt har varit Travis Hirschis teori om sociala band och samverkansteori. Studiens empiri har tolkats genom tematisk analys. Studien visar på att professionella identifierar ett flertal påverkansfaktorer som är centrala i arbetet med avhoppare. När det gäller processen in i kriminalitet tar yrkesverksamma upp sociala aspekters betydelse, såsom påtryckningar från omgivningen, lojalitet, umgänge och sammanhang. Bristande skolgång och avsaknad av meningsfull fritid, samt individens egna betydelse lyfts också. Gällande processen ut ur kriminalitet betonar yrkesverksamma att akuta händelser, såsom dödsfall eller hot, är centrala aspekter. Många som väljer att lämna kriminaliteten gör det på grund av trauma och att orken att vara kriminell finns inte längre kvar. Nya sammanhang och nya värderingar i livet kan leda till att individer påbörjar avhopparprocessen. Samverkan beskrivs som ytterst nödvändig för att arbetet med målgruppen ska kunna bedrivas. Alla insatser sker genom samverkan och aktörer behöver inta en kompletterande roll gentemot varandra. Yrkesverksamma i arbetet med målgruppen har olika erfarenheter av möjligheter och begränsningar i arbetet. Samverkan och sekretess anses vara både möjliggörande, men även försvårande i arbetet. Att personalen är relationsskapande och personalomsättningen är låg, ger goda förutsättningar för att arbetet med målgruppen ska ge önskade resultat. Psykiatrin lyfts fram som en saknad aktör och ytterligare nationellt stöd efterfrågas för att arbetet i kommunerna ska bli mer samstämmigt. Slutsats kan dras att arbetet med målgruppen behöver fortsätta att vidareutvecklas och inkludera professionella på flera olika nivåer, lokalt, regionalt och nationellt.
|
236 |
Developing New Works For The Stage: An Actor's PerspectiveButler, Lauren 01 January 2013 (has links)
U.S. Theatre is often noted for its commitment to new play development. Since Eugene O’Neill, America has fostered a tradition of celebrating emerging playwrights and their bold, edgy new works through countless development programs such as festivals, new play readings, grant programs, workshops, and world premieres. Although in recent years new-play development has seen a steady decline in funding (Levitow 2), it remains a cornerstone of American identity and an essential medium for pushing boundaries in theatre, both culturally and artistically. New-play development is indispensable for keeping theatre relevant in our everchanging culture. For my thesis, I explore the process of developing a new play from an actor’s perspective. The role of the director, dramaturg and producer of a new play is often discussed; however the importance of the actor throughout the development process is sometimes overlooked. There are many configurations of artistic teams assembled to develop a new play; therefore, I do not suggest there is one type of team that is best or one type of role for the actor to play within the team. My aim was to collaborate with the playwright, director and fellow actors to discover what is required of an actor in all phases of new play development. I applied the principles learned to my own work in the World Premiere of The Exit Interview by William Missouri Downs at the Orlando Shakespeare Theatre in Partnership with The University of Central Florida. As I navigated my way through the artistic process of developing a new work, I discovered some ‘best practices’, which I employed throughout the rehearsal and performance iii process to further my own skills. I will discuss the development process I experienced, as objectively as possible, outlining the key best practices for an actor working in a collaborative team to develop a new play.
|
237 |
Investigations of the Functions of gamma-Tubulin in Cell Cycle Regulation in <i>Aspergillus nidulans</i>Nayak, Tania 11 September 2008 (has links)
No description available.
|
238 |
Estimation of Runway Throughput with Reduced Wake Separation, Runway Optimization, and Runway Occupancy Time ConsiderationLi, Beichen 22 September 2022 (has links)
This thesis estimates potential runway throughput gains using a reduced wake separation based on the 123 most prevalent aircraft in the United States fleet. The analysis considers Runway Occupancy Time (ROT) constraint factors and existing geometric design factors. This research extracts the historic data from Airport Surface Detection Equipment Model X (ASDE-X) for analysis. The Runway Exit Design Interactive Model (REDIM) is used to optimize the runway exit locations and reduce ROT. The runway throughput and safety factors are generated from a Monte Carlo runway simulator.
This thesis focuses on selected US airport runways that could benefit from geometric optimization. The study aims to estimate ROT improvements through improved runway exit locations and the changes in runway throughput considering ROT constraint factors.
The results of the thesis show that Dallas Fort Worth International Airport (DFW) runway 35C and Denver International Airport (DEN) runway 16R have the potential to improve the ROT. After the optimization to locate runway exits, the ROT time of the RECAT group F and G aircraft (greater than 90% of the arrivals) was reduced by three to five seconds (a very significant effect). After the ROT reductions and with the application of reduced wake separation criteria with the ROT constraint factor applied, the arrival-only capacity of DFW runway 35C improved by 3.5 arrivals per hour. The arrival-only capacity on DEN runway 16R improved by 2.14 arrivals per hour. Both runways maintained a probability of violation between time-based separation and ROT time at around 1.5%.
The study concludes that the application of reduced wake separation criteria alone is a necessary but insufficient condition to improve the efficiency of arrival runways. Through careful improvements of runway exit locations, reductions in ROT provide reliability and efficiency to the operation of runways. / Master of Science / This thesis estimates potential runway throughput gains using a reduced wake separation based on the 123 most prevalent aircraft in the United States fleet. The analysis considers Runway Occupancy Time (ROT) constraint factors and existing geometric design factors. This research extracts the historic data from Airport Surface Detection Equipment Model X (ASDE-X) for analysis. The Runway Exit Design Interactive Model (REDIM) is used to optimize the runway exit locations and reduce ROT. The runway throughput and safety factors are generated from a Monte Carlo runway simulator.
This thesis focuses on selected US airport runways that could benefit from geometric optimization. The study aims to estimate ROT improvements through improved runway exit locations and the changes in runway throughput considering ROT constraint factors.
The results of the thesis show that Dallas Fort Worth International Airport (DFW) runway 35C and Denver International Airport (DEN) runway 16R have the potential to improve the ROT. After the optimization to locate runway exits, the ROT time of the RECAT group F and G aircraft (greater than 90% of the arrivals) was reduced by three to five seconds (a very significant effect). After the ROT reductions and with the application of reduced wake separation criteria with the ROT constraint factor applied, the arrival-only capacity of DFW runway 35C improved by 3.5 arrivals per hour. The arrival-only capacity on DEN runway 16R improved by 2.14 arrivals per hour. Both runways maintained a probability of violation between time-based separation and ROT time at around 1.5%.
The study concludes that the application of reduced wake separation criteria alone is a necessary but insufficient condition to improve the efficiency of arrival runways. Through careful improvements of runway exit locations, reductions in ROT provide reliability and efficiency to the operation of runways.
|
239 |
2A-induced ribosome stallingOdon, Valèrie M. N. January 2014 (has links)
Originally 2A was characterised in foot-and-mouth disease virus. Site directed mutagenesis identified a C-terminus consensus motif [D(V/I)ExNPGP] and it is proposed that 2A interacts with the exit tunnel of the ribosome in a way that a specific peptide bond is skipped between the last glycine of 2A and the proline of 2B, thus providing a discontinuity in translation, resulting in release of discrete proteins from one single ORF. 2A was also identified in other picornaviruses, positive, single and double-stranded RNA insect viruses and mammalian rotaviruses. A motif present at the C-terminus of the 2A oligopeptide [D(V/I)ExNPGP] is very highly, though not completely conserved . The sequence upstream of this motif shows, however, no apparent conservation between 2As of different viruses. In this study, extensive site-directed mutagenesis were performed on several 2A sequences and a series of ‘hybrid' 2As comprising different consensus motifs juxtaposed with different upstream contexts were created as part of a detailed analysis of the mechanism of 2A-mediated ribosome stalling. The results demonstrated that a minimal region of twenty to twenty-three amino acids interacts with the exit tunnel of the ribosome to bring about a pause in processivity, alter the peptidyl transferase centre geometry and restrict the ribosome A site via two distinctive stalling mechanisms. Other molecular analyses tested here will require further optimisations or alternative methods: a visual method to explore the dynamics of re-initiation of translation from proline codon, purification of the translation-regulating factors and structural resolution of 2A sequences. Previously, cellular 2As were identified in non-LTR retrotransposons of trypanosomes. It is reported here as part of two other cellular organisms Saccoglossus kowalevskii (acorn worm) and Branchiostoma floridae (amphioxus). In the acorn worm, the nucleotides sequences corresponding to 2A motifs were part of the untranslated genome. In amphioxus, three 2A elements were identified in hypothetical proteins, and at the N-terminus of twenty non-LTR retrotransposons.
|
240 |
Stochastic Simulation of Multiscale Reaction-Diffusion Models via First Exit TimesMeinecke, Lina January 2016 (has links)
Mathematical models are important tools in systems biology, since the regulatory networks in biological cells are too complicated to understand by biological experiments alone. Analytical solutions can be derived only for the simplest models and numerical simulations are necessary in most cases to evaluate the models and their properties and to compare them with measured data. This thesis focuses on the mesoscopic simulation level, which captures both, space dependent behavior by diffusion and the inherent stochasticity of cellular systems. Space is partitioned into compartments by a mesh and the number of molecules of each species in each compartment gives the state of the system. We first examine how to compute the jump coefficients for a discrete stochastic jump process on unstructured meshes from a first exit time approach guaranteeing the correct speed of diffusion. Furthermore, we analyze different methods leading to non-negative coefficients by backward analysis and derive a new method, minimizing both the error in the diffusion coefficient and in the particle distribution. The second part of this thesis investigates macromolecular crowding effects. A high percentage of the cytosol and membranes of cells are occupied by molecules. This impedes the diffusive motion and also affects the reaction rates. Most algorithms for cell simulations are either derived for a dilute medium or become computationally very expensive when applied to a crowded environment. Therefore, we develop a multiscale approach, which takes the microscopic positions of the molecules into account, while still allowing for efficient stochastic simulations on the mesoscopic level. Finally, we compare on- and off-lattice models on the microscopic level when applied to a crowded environment.
|
Page generated in 0.0185 seconds