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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Fostering Homefulness

Pollack, Shelby Marie 18 November 2022 (has links)
The mental health crisis is one of the many pandemics that the world is facing. For years it has been something that has been looked down upon as something that only people in mental institutions deal with, but in fact it is much more widespread than previously thought. The recent Covid-19 pandemic has brought to light the many struggles that people face and has led to a push for a focus on healing these invisible ailments. Often we think of doctors as the people who are responsible for anything health related, but as people spend a vast majority of their time indoors, that responsibility really falls on architects. The design world seems to support this theory as trends have led towards the incorporation of more natural elements into buildings, often referred to as, 'biophilia' and 'wellness' principles. While we enjoy the views of nature and fresh air in our daily lives, there is also scientific evidence to prove that these elements are beneficial to the physical and mental health of living beings. Thus, as architects we have the ability to go beyond creating a merely visually appealing and functionally operating spaces, and should use our skills to create environments that have a positive impact on the users' well-being. For this thesis, I redesigned the way in which group homes are designed for teens in Foster Care with these principles in mind. Teens are often the hardest to place with families, as many foster parents don't want to deal with the effects that childhood trauma has had on these individuals, so many of them end up in group homes. These institutions often provide resources, but unfortunately lack the individualized attention and home-like feeling that living with a family does, in the best-case scenario. It has been my mission to design a place that provides the residents with the comforts of a home, as well as wellness and nature-based spaces to ensure that they have the time and space to heal and grow. / Master of Architecture / Many teens in foster care end up in group housing. While these spaces provide shelter and the ability for social workers to stop by, they lack the consistent support and resources of living in a home with a family. My thesis dives into what makes a new space feel like home and how various methods of architecture and interior design can integrate therapeutic elements into living spaces used by teens to help them heal from childhood trauma. The existing building (Bundy School) contains an organization called Safe Shores, which provides children with a safe space to report abuse; it gives them access to legal, forensic, and mental health resources to help them get justice and handle the trauma that they have been through. The existing building doesn't currently provide any housing resources for the victims. My thesis is a renovation of the existing office spaces, as well as the addition of a new building providing housing for teens in foster care, victims of abuse, or any teens who are in need of housing in a long or short term capacity.
102

Horizontal natural frequency in a 10 story building : A comparison between CLT and concrete using estimate calculations / Horisontell egenfrekvens i ett 10-våningshus : En jämförelse mellan KL-trä och betong med hjälp av överslagsberäkningar

Eriksson, Jennifer January 2018 (has links)
Tall slender buildings are easily set in motion by wind and earthquakes but by estimating the buildings horizontal natural frequencies in the design phase, these motions can be kept within acceptable boundaries. There are many parameters that decides the natural frequency of a building and it can therefore be difficult to calculate it. There are a few ways though to estimate horizontal natural frequencies of tall buildings and two methods have been tested in this report. Both methods give the frequency of a clamped-free cantilever but one of them requires a single degree of freedom system whilst the other handles a multi degree of freedom system. The methods are called SDOF method and MDOF method in this report. A fictional building was created for this project to be the reference object in the comparison between the two methods SDOF and MDOF. The walls and floors of the building was designed with the support of both an acoustic engineer and a structural engineer to create a realistic building. A building’s natural frequency is dependent of the self-weight, stiffness and height of the building and it was therefore important to design these components with care. The fictional building is called House 1 and is a 10 story, almost square building about 20 m wide and broad and 30 m high. This report does not only compare the natural frequencies obtained from the two different calculation methods, but it also shows the difference in frequency in timber and concrete structures. Shear walls constitutes the horizontal stabilization system of the fictional building and both a CLT core and a concrete core is designed and compared. It is only the walls that comes in two different versions, the floorings consist of CLT boards for both structures tested. The horizontal natural frequencies of House 1 were about 2 Hz and 3 Hz for the CLT version and concrete version respectively. It was expected to get frequencies within that range considering the height of House 1. The CLT core having a lower frequency than the concrete core was also expected since concrete is a stiffer material than wood. To be able to make a fair comparison between the SDOF method and the MDOF method, House 1 was designed with the same dimensions and stiffness on all floors because the SDOF method requires that. The results from the two methods are almost identical with only 0.3 Hz and 0.4 Hz difference for the concrete and CLT respectively. For a shear wall structure with a consistent stiffness, weight and dimension, any of the two methods can be used to estimate the horizontal natural frequency. However, it is not realistic for a building of 30 m or higher, to have the same dimensions on the load bearing structure on all floors which makes the MDOF method more accurate in more cases than the SDOF method. / Höga slanka byggnader kan sättas i svajande rörelser av vind och jordbävningar, men genom att uppskatta byggnadernas horisontella egenfrekvenser i den tidiga konstruktionsfasen kan dessa rörelser hållas inom acceptabla gränser. Det är många parametrar som bestämmer byggnadens egenfrekvens och det kan därför vara svårt att beräkna den. Det finns dock några sätt att uppskatta horisontella egenfrekvenser hos höga byggnader och två metoder har testats i denna rapport. Båda metoderna ger frekvensen av en fast inspänd konsolbalk men en av dem kräver ett enfrihetsgradsystem medan den andra kan hantera ett system med flera frihetsgrader. Metoderna kallas SDOF-metoden och MDOF-metoden i denna rapport. En fiktiv byggnad skapades i detta projekt för att vara referensobjekt i jämförelsen mellan de två metoderna SDOF och MDOF. Byggnadens väggar och golv konstruerades med stöd av både en akustiker och en konstruktör för att skapa en realistisk byggnad. Byggnadens egenfrekvens är beroende av byggnadens egenvikt, styvhet och höjd och det var därför viktigt att utforma dessa komponenter med omsorg. Den fiktiva byggnaden kallas House 1 och är en 10 vånings-, nästan fyrkantig byggnad ca 20 m lång och bred och 30 m hög. Denna rapport jämför inte bara egenfrekvenserna erhållna från de två olika beräkningsmetoderna, den visar även skillnaden i frekvens i trä- och betongkonstruktioner. Skjuvväggar utgör det horisontella stabiliseringssystemet för den fiktiva byggnaden och både en KL-kärna och en betongkärna har utformats och jämförts. Det är bara väggarna som skiljer de två olika versionerna åt, bjälklagen består av KL-skivor i båda fallen. De horisontella egenfrekvenserna hos House 1 var ca 2 Hz och 3 Hz för KL-version respektive betongversion. Frekvenser inom detta område var väntade med tanke på höjden av House 1. Att KL-kärnan skulle ha en lägre frekvens än betongkärnan förväntades också eftersom betong är ett styvare material än trä. För att kunna göra en rättvis jämförelse mellan SDOF-metoden och MDOF-metoden, var House 1 utformad med samma dimension och styvhet på alla våningsplan eftersom SDOF-metoden kräver det. Resultaten från de två metoderna är nästan identiska med endast 0,3 Hz och 0,4 Hz skillnad för betong respektive KL. För en skjuvväggskonstruktion med en kontinuerlig styvhet, vikt och dimension kan båda de två metoderna användas för att uppskatta den horisontella egenfrekvensen. Det är dock inte realistiskt för en byggnad på 30 m eller högre att ha samma dimensioner på den lastbärande konstruktionen på alla våningar vilket gör MDOF-metoden mer korrekt i fler fall än SDOF-metoden.
103

En jämförelse mellan KL-trä och betong som bjälklagssystem : Ett experiment med multikriterieanalys / A Comparison Between CLT-wood and Concrete as a Structrural Floor System : An Experiment with Multicritery Analasys

Gustavsson, Anton, Gudjonsson, Julius January 2021 (has links)
Syfte: Miljömedvetet och prisvärt byggande har länge varit två uttryck som använts ibyggbranschen. Betong har använts och är väl beprövat. Trä och framförallt KL-trä ärdäremot ett material som växt fram det senaste decenniet. Frågan är, när är det bäst attbygga med de olika materialen och vad är materialens respektive klimatavtryck? Målet med denna rapport är att jämföra två bjälklagssystem, ett i KL-trä och ett i betong, utifrån ett sammanvägt kostnads-, dimensions- och miljöperspektiv och hur de förhåller sig mellan spännvidderna fyra, sex och åtta meter. ▪ Hur stor är den procentuella kostnadsskillnaden mellan dessa bjälklagssystem? ▪ Hur stor är den procentuella skillnaden i koldioxidutsläpp under produktionen avdessa bjälklagssystem ▪ Hur stor är den procentuella dimensionsskillnaden mellan dessa bjälklagssystem? ▪ Vilket bjälklagssystem är det bästa valet utifrån en multikriterieanalys? Metod: Studien består av flera experiment för att få ut empiri till en kvotmätning.Denna metod användes för att få fram primärdata till arbetet.Sekundärdata samlades in via dokumentstudier av lagar och krav för byggnation inombrand, ljud och dimensionering. Resultat: Studien visar resultaten av en jämförelse mellan bjälklagssystem med olikamaterial och spännvidder. En multikriterieanalys används för att rangordna resultatenför att visa det mest fördelaktiga alternativet. Konsekvenser: Vid användning av KL-trä bör dimensionering tas i beaktande dådimensionerna blir relativt stora jämfört med betong. Kostnaden av materialen skiljersig markant. Detta speglar dock inte totalkostnad då produktion, leveranser, montering,etcetera ej är medräknat. Att använda en multikriterieanalys vid jämförelser ger entydlig bild på fördelaktigt alternativ samt hur stor skillnad det är mellan alternativen. Begränsningar: Då det endast är en del i totalkostnaden som berörs speglar interesultatet rättvis kostnadsbild och kan därför inte användas som referenspunkt. Resultatfungerar endast som ett hjälpmedel vid delberäkning av totalkostnad. Nyckelord: Betong, KL-trä, Plattbärlag, Plattbjälklag, Kassettbjälklag,Multikriterieanalys, Dimensionering, Kostnad, Koldioxidutsläpp / Purpose: Environmental and affordable construction has long been two terms used in theconstruction industry. Concrete has been used and is well proven. Wood and especiallyCLT wood, on the other hand, is a material that has emerged in the last decade. The questionis, when is it best to build with the different materials and what are their respective climatefootprints? The aim of this report is to compare two structural floor systems, one in CLT wood and onein concrete, based on a balanced cost, dimension and environmental perspective and howthey relate between the spans of four, six and eight meters. ▪ What is the percentage cost difference between these structural floor systems? ▪ What is the percentage difference in carbon dioxide emissions during theproduction of these structural floor systems? ▪ What is the percentage dimensional difference between these structural floorsystems? ▪ Which structural floor system is the best choice based on a multi-criteria decisionanalysis? Method: The study consists of several experiments to obtain empirical data for a quotameasurement. This method was used to obtain primary data for the work. To obtain secondary data consisting of standards, calculation models and requirements, adocument study was used. Secondary data were collected via document studies of laws and requirements forconstruction in fire, acoustics and dimensioning. Findings: The study shows the results of a comparison between structural floor systemswith different materials and spans. A multi-criteria decision analysis is used to rank theresults to show the most advantageous alternative. Implications: When using CLT-wood, dimensioning should be taken into account as thedimensions will be relatively large compared to concrete. The cost of the materials differsmarkedly. However, this does not reflect the total cost as production, deliveries, assembly,etcetera are not included. Using a multi-criteria decision analysis in comparisons gives aclear picture of a favorable alternative and how large a difference there is between thealternatives. Limitations: As only a part of the total cost is affected, the result does not reflect a faircost picture and can therefore not be used as a reference point. The results only serve as anaid in the partial calculation of total cost. Keywords: Concrete, CLT-wood, Prefabricated Concrete Slab Joist, CLT Flat Joist,Rib Elements, Multi-Criteria Decision Analysis, Cost, Carbon Dioxide Emissions
104

Sportovní centrum / Sports Centre

Hentschelová, Tereza January 2020 (has links)
The goal of this thesis is to elaborate project documentation of new sports centre. The building is situated on a plot No. 1930/48 of the cadastre territory in the town of Pacov. It is a building without cellar with two above-ground floors part on the area of 595,6 m2. The first floor part circuit structure consist of reinforced concrete walls with an outdoor climbing wall. The roofing is the mono-pitches roof with glue laminated timber beam and purlin with metal roofing. The building features an indoor climbing wall and a bar with seating. The second floor part is made of wooden CLT panels, the roof is designed as a green flat roof. This section provides facilities for athletes and staff and exercise halls. There are 50 parking spaces for cars in the building.
105

Katedrála v současnosti / Cathedral today

Král, David January 2020 (has links)
Theme of the thesis is a construction that is considered to be one of the most spectacular examples of a French gothic architecture. Notre-Dame Cathedral lies on the Eastern half of a Parisian island Île de la Cité on the river Seina. On April 15, 2019, roof of the cathedral caught on fire. It was completely destroyed, including its pinnacle. The thesis offers a solution how to restore the roof and what opportunities the new design brings. Aim of the proposal is enrichment of the Notre-Dame community through offering a new refuge, which will be for both, internal growth and spiritual practice itself. The design provides spaces that capture the path to God in them. I perceive the very path to God as a thorough inner work. That is why I am placing 36 contemplation booths in there, in addition to other 8 cabins. The light is removed from those, in order to extend the perception of consciousness. Spaces for individuals will be amended by 3 chapels for a group practice. Each chapel has its typical content - joint contemplation chapel, chapel that worships the Jesus Christ’s crown of thorns and a community chapel with a variable arrangement.
106

Materialtester på KL-trä : Undersökning av KL-träets tryckkraftskapacitet och tryckhållfasthet samt teoretiska beräkningar och praktiska tester av en KL-trä bräda. / Material tests on CLT : Examination of CLTs compressive force capacity and compressive strength and theoretical calculations and practical tests of a CLT-board.

Eriksson, Andreas, Ågren, Gabriel January 2021 (has links)
Belastningen vid tryck vinkelrätt mot fiberriktningen är ett problem vid höga träbyggnader med träregelstomme vid till exempel mötet mellan regel och syll. Ettmaterial som blivit alltmer populärt i Sverige är korslimmat trä, som benämns som KL-trä, där lameller korsvis limmas samman till en skiva. Experiment har tidigare utförts på materialet och det har visat att en bräda av KL-trä, som idag inte tillverkas, klarar ett högre stämpeltryck än en vanlig bräda av konstruktionsvirke, vilket skulle kunna vara en lösning på problemen vid tryck vinkelrätt fiberriktningen i höga träbyggnader. Syftet med detta examensarbete är att bestämma KL-träets karakteristiska tryckkraftskapacitet och tryckhållfasthet för två uppställningar av KL-trä där andelar vinkelräta och parallella lameller som belastas i tvärsnittet skiljer sig åt. Det undersöks också hur lasten fördelar sig på lamellerna som belastas parallellt med fiberriktningen och vinkelrätt mot fiberriktningen i en bräda av KL-trä samt att teoretiska beräkningar av tryckkraftskapaciteten utfördes i mitten och i änden på brädan. Examensarbetet omfattades av tre olika metoder där standarden SS-EN 408 för tryck vinkelrätt mot fiberriktningen användes för att bestämma tryckkraftskapacitet och tryckhållfasthet för de två uppställningarna av KL-trä genom materialtester i en hydraulisk press. Lastfördelningen mellan lamellerna i en KL-trä bräda undersöktes genom stämpeltrycktester i änden på brädan och återspeglar ett verkligt möte mellan regel och syll. En solid bräda av KL-trä, en bräda där de vinkelräta lamellerna sågats bort samt en bräda av konstruktionsvirke belastades för att undersöka differensen i stämpeltryck. Teoretiska beräkningar utfördes på KL-trä brädorna både i mitten och i änden genom att de olika lamellerna beräknades som enskilda brädor enligt Eurokod 5 samt EKS11 och därefter summerades alla lameller för KL-trä brädan. Resultaten visade att den uppställningen av KL-trä med störst andel lameller som belastades parallellt med fiberriktningen erhöll störst tryckkraftskapacitet och fick högst tryckhållfasthet. I brädan av KL-trä tog de lameller som belastades parallellt med fiberriktningen upp ungefär fyra femtedelar av lasten i tvärsnittet som belastades. De teoretiska beräkningarna som utfördes gav en lägre tryckkraftskapacitet än resultaten från de experimentella testerna. För materialtest 1 där lamellerna fördelade sig 58 % vinkelräta lameller och 42 % parallella lameller erhölls karakteristiska värden på 79,7 kN på tryckkraftskapacitet och 18,6 MPa på tryckhållfasthet. För materialtest 2 där lamellerna fördelade sig 42 % vinkelräta lameller och 58 % parallella lameller erhölls karakteristiska värden på 114,6 kN på tryckkraftskapacitet och 26,8 MPa på tryckhållfasthet. Belastningsfördelningen i KL-trä brädan visade att de parallellt belastade lamellerna tog upp en last motsvarande 80,8 % och de vinkelräta lamellerna tog upp en last motsvarande 19,2 %. De teoretiska beräkningarna utnyttjades till 57 % i jämförelse mot maxlasten från de experimentella testerna, både i mitten och på brädans ände. / Compression perpendicular to the grain is today a problem with tall wood buildings with timber-frame at, for example, the meeting between timber stud and the bottom rail. A material that has become increasingly popular in Sweden is cross-laminated timber, which is referred to as CLT, where lamellae are glued together crosswise to a board. Experiments have previously been performed on the material and it has shownthat a board made of CLT, which is not manufactured today, can withstand a higher pressure than an ordinary board made of structural timber, which could be a solution to the problems with compression perpendicular to the grain in tall wood buildings. The purpose of this thesis is to determine the CLTs characteristic compressive force capacity and compressive strength for two formations of CLT where proportions of perpendicular and parallel lamellae that are loaded in the cross section differ. It will also be investigated how loads are distributed on the lamellae which are loaded parallel to the grain and perpendicular to the grain in a board made of CLT and that theoretical calculations of the compressive force capacity were performed in the middle and at the end of the board. The thesis was comprised of three different methods where the standard SS-EN 408 for compression perpendicular to the grain was used to determine compressive forcecapacity and compressive strength for the two formations of CLT through material tests in a hydraulic press. The load distribution between the lamellae in a CLT-boardwas examined by compression tests at the end of the board and reflects a real meeting between a timber stud and the bottom rail. A solid board made of CLT, a board where the perpendicular lamellae were sawn off and a board made of structural timber were loaded to investigate the difference in compression. Theoretical calculations were performed on the CLT-boards both in the middle and at the end through calculating the different lamellae as individual boards according to Eurocode 5 and EKS11 and then all lamellae for the CLT-board were summed. The results showed that the arrangement of CLT with the largest proportion of lamellae parallel to the grain obtained the largest compressive force capacity and had the highest compressive strength. In the CLT-board, the parallel-loaded lamellae took up about four-fifths of the load in the cross-section that was loaded. The theoretical calculations performed gave a lower compressive force capacity than the results of the experimental tests. For material test 1 where the lamellae were distributed 58% perpendicular lamellaeand 42% parallel lamellae, characteristic values of 79.7 kN on compressive capacity and 18.6 MPa on compressive strength were obtained. For material test 2 where the lamellae were distributed 42% perpendicular lamellae and 58% parallel lamellae, characteristic values of 114.6 kN on compressive capacity and 26.8 MPa on compressive strength were obtained. The load distribution in the CLT-plank shown that the parallel-loaded lamellae took up a load corresponding to 80.8% and the perpendicular lamellae took up a load corresponding to 19.2%. The theoretical calculations were used to 57% in comparison with the maximum load from the experimental test, both in the middle and at the end of the board.
107

Brandskydd i byggnader med exponerad stomme av KL-trä : En kartläggning av olika brandtekniska lösningar för flerbostadshus

Öberg, Andreas, Lejdström, Fredrik January 2021 (has links)
Purpose: The purpose with this work has been to investigate and map selected fireprotection methods in a number of projects. The possibilities and limitations with exposedCLT have been investigated. Method: The method consists of a literature study, interviewstudy, construction site visit and survey. The literature study has been carried out with theaim of presenting relevant facts to the subject and creating a basis for the interview study.The interviews were conducted with fire consultants for the work´s investigated projects.Two of the projects also included construction site visit, of which one of the projects belongsto the partner of this work, Peab. During the visits of the construction sites a tour of thebuilding were carried out and shown where the exposed CLT was placed. The results from theinterviews and construction sites visits are the basis for the survey. Results: The resultsshow that analytical dimension of the fire protection is required when constructing multistory residence with internally exposed CLT. Limitations with exposed CLT are due, amongother things, to the fact that untreated wood does not fulfils the requirements set in BBR forthe surface layer. Delamination contributes to increased fire load as the underlaying slats areexposed to fire. The current study contains two projects carried out with exposed CLT,Notuddsparken and ETC apartment buildings. The projects have dimensioned each withanalytical dimension but with different fire protection methods. Notuddsparken has beenconstructed with automatic sprinkler systems and the ETC apartment buildings have beenconstructed with fire protection impregnation of the exposed CLT. Conclusions:Conclusions established in the work shows that when using exposed CLT analyticaldimension of the fire protection is required. Most of the fire consultants in this work haveexpressed that they do not feel comfortable with dimensioning fire protection for buildingswith exposed CLT, based on the current state of knowledge.
108

The association between fibrinolysis markers and body composition in black adults in the North West Province of South Africa / Philna Eksteen

Eksteen, Philna January 2014 (has links)
INTRODUCTION - Plasminogen activator inhibitor type-1 (PAI-1) has a known relationship with obesity and more specifically with central obesity. Traditionally the physiological contribution of PAI-1 is seen as an indicator of fibrinolysis with increased PAI-1 levels contributing to decreased fibrinolysis. In more recent years, assays have been developed that not only uses proxy markers, such as PA-1, which is considered to be representative of fibrinolysis , but global assays that report on the global fibrinolytic potential of an individual, often reported as clot lysis time (CLT). Investigations into the relationship of CLT with obesity are scarce. Preliminary evidence shows that the relationship of CLT with obesity may differ from that of PAI-1 with obesity although in depth investigations in this regard are lacking. Therefore, the aim of this study was to investigate the association between fibrinolysis markers (PAI-1act and CLT) and various markers of body composition in the South African Prospective Urban and Rural Epidemiology (PURE) data collected during 2010. METHODS - Data collected in the PURE study in 2010 were cross-sectionally analysed. The participants (n = 1288) were apparently healthy black South-African men and women 35 years and older, residing in urban and rural settlements in the North-West Province. Experimental methods included anthropometric measurements such as height, weight, hip circumference, waist circumference, skinfolds (triceps, chest, abdominal, thigh and supra iliac skinfolds) and body composition measurements by means of air-displacement plethysmography and biolelectrical impedance analysis. Laboratory analysis of fibrinolysis markers, PAI-1act and CLT were also performed. MAIN FINDINGS - In men, similarities were seen regarding the relationship between PAI-1act and body composition markers and the relationships observed between CLT and body composition markers. In contrast, in the women more and stronger associations were observed between CLT and body composition markers compared to that observed between PAI-1act and body composition markers. CLT showed a linear relationship with body composition markers where PAI-1act levels plateaued at higher body composition categories. Possible reasons for the observed differences may be related to differences in adipose tissue distribution and sequence of accumulation between men and women. PAI-1 is associated with visceral adipose tissue (VAT) where high amounts of stromal cells are found. In men preferential accumulation of VAT may explain similarities in the relationship of PAI-1act with body composition and that of CLT with body composition. Proportionally less VAT, but more subcutaneous adipose tissue in women may explain the observed increase in CLT compared to PAI-1act levels that plateaued over body composition tertiles and categories. CONCLUSION - PAI-1act has a stronger association with central obesity while CLT has a stronger association with total body fat. In women PAI-1act and CLT showed different associations with body composition markers, whereas associations of PAI-1act and CLT with body composition were similar in men. PAI-1act is strongly influenced by type of body fat accumulation whereas CLT is associated with obesity independent of type and sequence of body fact accumulation. Significant associations observed between CLT and body composition variables are, therefore, at least in part, independent of PAI-1act. Additional factors such as, thrombin activatable fibrinolysis inhibitor (TAFI), α-2-antiplasmin, plasminogen, prothrombin and fibrin clot structure that influence CLT and are also related to obesity may additionally contribute to the link between CLT and obesity. / MSc (Dietetics), North-West University, Potchefstroom Campus, 2014
109

The association between fibrinolysis markers and body composition in black adults in the North West Province of South Africa / Philna Eksteen

Eksteen, Philna January 2014 (has links)
INTRODUCTION - Plasminogen activator inhibitor type-1 (PAI-1) has a known relationship with obesity and more specifically with central obesity. Traditionally the physiological contribution of PAI-1 is seen as an indicator of fibrinolysis with increased PAI-1 levels contributing to decreased fibrinolysis. In more recent years, assays have been developed that not only uses proxy markers, such as PA-1, which is considered to be representative of fibrinolysis , but global assays that report on the global fibrinolytic potential of an individual, often reported as clot lysis time (CLT). Investigations into the relationship of CLT with obesity are scarce. Preliminary evidence shows that the relationship of CLT with obesity may differ from that of PAI-1 with obesity although in depth investigations in this regard are lacking. Therefore, the aim of this study was to investigate the association between fibrinolysis markers (PAI-1act and CLT) and various markers of body composition in the South African Prospective Urban and Rural Epidemiology (PURE) data collected during 2010. METHODS - Data collected in the PURE study in 2010 were cross-sectionally analysed. The participants (n = 1288) were apparently healthy black South-African men and women 35 years and older, residing in urban and rural settlements in the North-West Province. Experimental methods included anthropometric measurements such as height, weight, hip circumference, waist circumference, skinfolds (triceps, chest, abdominal, thigh and supra iliac skinfolds) and body composition measurements by means of air-displacement plethysmography and biolelectrical impedance analysis. Laboratory analysis of fibrinolysis markers, PAI-1act and CLT were also performed. MAIN FINDINGS - In men, similarities were seen regarding the relationship between PAI-1act and body composition markers and the relationships observed between CLT and body composition markers. In contrast, in the women more and stronger associations were observed between CLT and body composition markers compared to that observed between PAI-1act and body composition markers. CLT showed a linear relationship with body composition markers where PAI-1act levels plateaued at higher body composition categories. Possible reasons for the observed differences may be related to differences in adipose tissue distribution and sequence of accumulation between men and women. PAI-1 is associated with visceral adipose tissue (VAT) where high amounts of stromal cells are found. In men preferential accumulation of VAT may explain similarities in the relationship of PAI-1act with body composition and that of CLT with body composition. Proportionally less VAT, but more subcutaneous adipose tissue in women may explain the observed increase in CLT compared to PAI-1act levels that plateaued over body composition tertiles and categories. CONCLUSION - PAI-1act has a stronger association with central obesity while CLT has a stronger association with total body fat. In women PAI-1act and CLT showed different associations with body composition markers, whereas associations of PAI-1act and CLT with body composition were similar in men. PAI-1act is strongly influenced by type of body fat accumulation whereas CLT is associated with obesity independent of type and sequence of body fact accumulation. Significant associations observed between CLT and body composition variables are, therefore, at least in part, independent of PAI-1act. Additional factors such as, thrombin activatable fibrinolysis inhibitor (TAFI), α-2-antiplasmin, plasminogen, prothrombin and fibrin clot structure that influence CLT and are also related to obesity may additionally contribute to the link between CLT and obesity. / MSc (Dietetics), North-West University, Potchefstroom Campus, 2014
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Fluctuations de fonctionnelles spectrales de grandes matrices aléatoires et applications aux communications numériques.

Kharouf, Malika 19 June 2010 (has links) (PDF)
La théorie des matrices aléatoires présente un ensemble d'outils mathématiques efficaces pour l'étude de performances des systèmes de communications numériques. L'objectif de cette thèse est de développer des résultats analytiques basés sur la théorie des matrices aléatoires pour étudier les fluctuations de quelques indices de performances pour les systèmes de communications sans fil. Nous étudions dans un premier temps, les fluctuations de formes quadratiques aléatoires. Basés sur l'approche REFORM, nous montrons les fluctuations gaussiennes des formes quadratiques associées à des matrices aléatoires. De point de vue applicatif, le SINR (rapport signal sur bruit), indice de performance mesuré à la sortie d'un récepteur linéaire de Wiener, peut être modélisé sous forme de formes quadratiques aléatoires. Nous nous intéressons également à l'établissement d'un théorème central limit pour une fonctionnelle spectrale de matrices de Gram pour un modèle de matrices dont les entrées sont indépendantes non centrées et non identiquement distribuées. Sur le plan applicatif, cette fonctionnelle modélise la capacité d'un canal de transmission dans le cadre des systèmes de transmission multi-antennes.

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