O objetivo desta pesquisa é apresentar procedimentos de verificação da estabilidade lateral de vigas de concreto em situações transitórias e com eles realizar análises paramétricas. As fases transitórias estudadas são içamento, transporte e pré-serviço com e sem contraventamento nos apoios. As formulações apresentadas contém cálculo de carga crítica de instabilidade lateral, momento crítico e fator de segurança. São apresentados exemplos numéricos e a partir deles realizadas análises paramétricas com intuito de determinar limites de segurança. Os parâmetros variados foram fck, imperfeições geométricas, vão, largura da mesa comprimida e espessura da alma fazendo uma comparação entre vigas I e retangular. Com os resultados, foram obtidas esbeltezes geométricas limite para fases transitórias, relações entre carga crítica e carga devido ao peso próprio e uma relação entre momento crítico elástico e momento último de flexão para a fase transitória anterior à execução do tabuleiro com contraventamento nos apoios, especificamente. Na comparação entre vigas I e retangular, constatou-se que os dois tipos de seção apresentam limites de segurança distintos. As análises mostraram que os limites de esbeltez geométrica recomendados, como lh/bf², geram elementos, de seção transversal I, muito esbeltos. Este parâmetro apresentou uma variação significativa na tentativa de determinar limites nas análises paramétricas. Portanto, pode ser conservador adotar como limite a menor esbeltez obtida nas análises. Conclui-se que a verificação da segurança por esbeltezes geométricas nem sempre é adequada, pois não são considerados parâmetros como imperfeições geométricas e fck que mostraram serem importantes nas análises paramétricas. A esbeltez representada pela razão entre momento último e momento crítico de instabilidade elástico é mais abrangente e a busca por um valor limite deste parâmetro apresentou resultados com pouca variação para as vigas I. Com relação ao limite clássico de segurança que recomenda uma carga crítica maior que quatro vezes a carga de peso próprio, os resultados mostraram que esta recomendação é conservadora. As análises paramétricas mostraram que para vigas I esta razão igual a dois e meio atende a segurança destes elementos. / The objective of this research is to present a contribution to the verification of lateral stability of concrete beams in transient situations through parametric analyzes. The transient phases studied are lifting, transportation and prior to execution of the deck with braced and unbraced supports. Formulations presented contain calculation of buckling load, buckling moment and factor of safety. Numerical examples are presented and parametric analyzes are performed from these aiming to determine safety limits. The varied parameters were fck, geometric imperfections, span, compression flange width and web width by making a comparison between I-beams and rectangular beams. With the results, slenderness limits were obtained for transient phases, relationships between critical load and load due to self-weight and a relationship between elastic critical moment and ultimate moment to the transient situation before the execution of the deck with braced supports, specifically. In the comparison between I-beams and rectangular beams, it was found that the two types of section present different safety limits. Analyzes showed that the geometric slenderness limits recommended, as lh/bf², generate slender elements of I cross section. This parameter showed a significant variation in an attempt to determine limits on parametric analyzes. Therefore adopt the lower slenderness limit obtained in analyzes may be conservative. It is concluded that the safety verification by geometric slenderness is not always adequate, because they do not consider parameters such as geometric imperfections and fck that showed to be important in the parametric analyzes. The slenderness ratio represented by the ultimate moment and elastic critical moment of instability is more comprehensive and the search for a limiting value of this parameter presented results with little variation for the I-beams. With respect to the classical limit of safety which recommends that the critical load is greater than four times the self-weight load, the results showed that this recommendation is conservative. Parametric analyzes showed that for I-beams this ratio equal to two and a half addresses the safety of these elements.

O objetivo desta pesquisa é apresentar procedimentos de verificação da estabilidade lateral de vigas de concreto em situações transitórias e com eles realizar análises paramétricas. As fases transitórias estudadas são içamento, transporte e pré-serviço com e sem contraventamento nos apoios. As formulações apresentadas contém cálculo de carga crítica de instabilidade lateral, momento crítico e fator de segurança. São apresentados exemplos numéricos e a partir deles realizadas análises paramétricas com intuito de determinar limites de segurança. Os parâmetros variados foram fck, imperfeições geométricas, vão, largura da mesa comprimida e espessura da alma fazendo uma comparação entre vigas I e retangular. Com os resultados, foram obtidas esbeltezes geométricas limite para fases transitórias, relações entre carga crítica e carga devido ao peso próprio e uma relação entre momento crítico elástico e momento último de flexão para a fase transitória anterior à execução do tabuleiro com contraventamento nos apoios, especificamente. Na comparação entre vigas I e retangular, constatou-se que os dois tipos de seção apresentam limites de segurança distintos. As análises mostraram que os limites de esbeltez geométrica recomendados, como lh/bf², geram elementos, de seção transversal I, muito esbeltos. Este parâmetro apresentou uma variação significativa na tentativa de determinar limites nas análises paramétricas. Portanto, pode ser conservador adotar como limite a menor esbeltez obtida nas análises. Conclui-se que a verificação da segurança por esbeltezes geométricas nem sempre é adequada, pois não são considerados parâmetros como imperfeições geométricas e fck que mostraram serem importantes nas análises paramétricas. A esbeltez representada pela razão entre momento último e momento crítico de instabilidade elástico é mais abrangente e a busca por um valor limite deste parâmetro apresentou resultados com pouca variação para as vigas I. Com relação ao limite clássico de segurança que recomenda uma carga crítica maior que quatro vezes a carga de peso próprio, os resultados mostraram que esta recomendação é conservadora. As análises paramétricas mostraram que para vigas I esta razão igual a dois e meio atende a segurança destes elementos. / The objective of this research is to present a contribution to the verification of lateral stability of concrete beams in transient situations through parametric analyzes. The transient phases studied are lifting, transportation and prior to execution of the deck with braced and unbraced supports. Formulations presented contain calculation of buckling load, buckling moment and factor of safety. Numerical examples are presented and parametric analyzes are performed from these aiming to determine safety limits. The varied parameters were fck, geometric imperfections, span, compression flange width and web width by making a comparison between I-beams and rectangular beams. With the results, slenderness limits were obtained for transient phases, relationships between critical load and load due to self-weight and a relationship between elastic critical moment and ultimate moment to the transient situation before the execution of the deck with braced supports, specifically. In the comparison between I-beams and rectangular beams, it was found that the two types of section present different safety limits. Analyzes showed that the geometric slenderness limits recommended, as lh/bf², generate slender elements of I cross section. This parameter showed a significant variation in an attempt to determine limits on parametric analyzes. Therefore adopt the lower slenderness limit obtained in analyzes may be conservative. It is concluded that the safety verification by geometric slenderness is not always adequate, because they do not consider parameters such as geometric imperfections and fck that showed to be important in the parametric analyzes. The slenderness ratio represented by the ultimate moment and elastic critical moment of instability is more comprehensive and the search for a limiting value of this parameter presented results with little variation for the I-beams. With respect to the classical limit of safety which recommends that the critical load is greater than four times the self-weight load, the results showed that this recommendation is conservative. Parametric analyzes showed that for I-beams this ratio equal to two and a half addresses the safety of these elements.

Im Freistaat Sachsen ist der Umbau der Nadelbaum-Reinbestände in Mischbestände standortsgerechter Baumarten ein wichtiges forstpolitisches Ziel. Um dieses Zieles zu erreichen, werden in den sächsichen Berglagen seit mehr als 25 Jahren Rot-Buchen (Fagus sylvatica L), Weiß-Tannen (Abies alba Mill), Berg-Ahorn (Acer pseudoplatanus L.) sowie weitere Laub- und Nadelbaumarten künstlich eingebracht. Mit 18 Versuchsanlagen begleitet das Kompetenzzentrum für Wald und Forstwirtschaft im Staatsbetrieb Sachsenforst den Voranbau der genannten drei Baumarten in Fichtenaltbeständen. Im Rahmen dieser Arbeit werden die vorliegenden 137 Aufnahmen von Ober- und Unterstand von 576 Parzellen ertragskundlich ausgewertet und verschiedene Modelle zur Abbildung des Höhenwachstums, der Wuchsleistungen und des Schlankheitsgrades an die Daten angepasst. Bisher bildet nur ein Teil der einzelbaumbasierten Wachstumssimulatoren die Entwicklung von Voranbauten ab. Die sächsische Variante BWINPro-S enthält hierfür ausschließlich ein Modell für das Wachstum von Rot-Buchen unter Fichtenschirm welches bisher nicht evaluiert wurde. Zur Evaluation dieses Unterstandsmodells wurden parzellenübergreifend Verteilungsfunktionen angepasst und deren Lagemaße als quasireale Bäume genutzt. Für den Einzelbaum wurden entsprechend den in der DESER-Norm (Johann, 1993) beschriebenen Methoden Beziehungen von Durchmesser-Höhe-Alter hergeleitet und miteinander verglichen. Im Fokus stand dabei ihre Anwendung im UST, wo die Verjüngungs- und Schirmdichte die Baumallometrie beeinflussen. Neben den ertragskundlich gebräuchlichen Methoden DHA-2 und DHA-3 wurden hier gemischte nichtlineare Modelle als Variante DHA-4 angepasst. Die versuchsübergreifende Anpassung der gemischten nichtlinearen Modelle vereint die mit dem Parameterausgleichs von DHA-3 erreichten plausiblen Kurvenscharen mit der Anpassungsgüte von DHA-2. Für seltene Baumarten, die bei den anderen Ansätzen oftmals der Hauptbaumart zugeordnet werden, sind die Vorteile am deutlichsten. Zudem sind nur mit DHA-4 zuverlässige Schätzungen bei fehlenden Höhenmessungen möglich. Die gemischten linearen Modelle zur Schätzung des Schlankheitsgrades sind eine weitere Möglichkeit zur Ergänzung fehlender Baumhöhen im UST. Die doppelte logarithmische Transformation der Daten gibt die nichtlinearen Beziehungen nur unzureichend wieder, sodass sich im Vergleich zur nichtlinearen BHK unter Berücksichtigung zufälliger Effekte keine Vorteile ergeben. Die Modelle zur Schätzung der H:D-Relation zeigen, genauso wie das DHA-4 Modell, den Einfluss von Dichtstand und Überschirmung auf morphologische Anpassungen im UST. Die gute Anpassung des HDR-Modells wird deutlich, wenn ausschließlich die festen Effekte betrachtet werden. Dann lassen sich über H:D-Relation genauere Höhen schätzen, als mit der BHK im DHA-4 Ansatz. Allerdings erreichen die HDR-Modelle auf der Ebene einzelner Bäume auch unter Berücksichtigung räumlicher Varianzkoeffizienten nicht die für Inferenzstatistiken notwendige Unabhängigkeit. Die fehlende räumliche Unabhängigkeit ist bei der Parametrisierung von Einzelbaummodellen kein Einzelfall und stellt den wesentlichen Kritikpunkt bei der Evaluation des Höhenzuwachsmodells der Buche unter Fichte von BWINPro-S dar. Auf der Ebene von Baumkollektiven konnten plausible standortsensitive Modelle für Wuchsleistungen und das Höhenwachstum angepasst werden. Der auf Alter von maximal 26 Jahren stringierte Datensatz stellt dabei eine erhebliche Einschränkung dar. Gute Schätzung der Oberhöhen (H300) der Voranbauten wurden mit der logistischen Funktion des R-Packetes nlme und der Funktion von Gompertz (1825) erreicht. Allerdings sind Extrapolationen der weiteren Entwicklung nicht möglich, bzw. auf wenige Jahre begrenzt. Die Funktion nach Schumacher (1939) passt sich zwar weniger gut an die frühen Höhenmessungen an, ermöglicht jedoch deutlich längere und plausible Abschätzungen des weiteren Höhenwachstums. In der Zusammenschau der verschiedenen Modellansätze wird der Vorteil gemischter Modelle an verschiedenen Stellen (DHA, Höhenwachstum BWINPro-S) ersichtlich. Mit Blick auf die bei allen Baumarten festgestellten morphologischen Anpassungen an die Überschirmung spielen bei der Betrachtung einzelner Dimensionen des Wachstums – BHD oder Höhe – die Dynamik der Baumallometrie eine nicht unerhebliche Rolle. Gerade im Zuge der Nachlichtungen des OST oder dem Übergang vom UST zum OST, den die vorwüchsigen Bäume in den nächsten Jahren vollziehen, ändert sich die Allokationen von Stoffwechselprodukten, was zu veränderten Durchmesser- und Höhenzuwachsraten führt. In den Höhenwachstumsmodellen führen wenige klimatische und edaphische Faktoren zur Differenzierung der Wachstumsverläufe. Der Einfluss der Schirmdichten liegt in der gleichen Größenordnung wie die Streuung von pH-Wert, die Kalkungsintensität oder das C:N-Verhältnis. Der Einfluss der Höhenlage, bzw. der mit ihr gekoppelten klimatischen Parameter wie Jahresmitteltemperatur, Ariditätsindex, Sonnenscheindauer und klimatische Wasserbilanz, ist der Haupteffekt für das Höhenwachstum. Kalkungen und die klimatischen Änderungen üben einen merklichen Einfluss auf Leistungsfähigkeit der Bestände, die Konkurrenzverhältnisse der Baumarten und damit auch das ökosystemare Gefüge aus. Entsprechend dem Höhenwachstumsmodell profitiert die Rot-Buche gegenüber dem Berg-Ahorn und der Weiß-Tanne von dichteren Schirmen und wärmeren klimatischen Bedingungen. Mit Blick auf die positiven Wirkungen der Überschirmung auf die Qualität sind längere und dichtere Schirmhaltungen als waldbauliche Zielstellung obligat. Mit ihrem vergleichbar hohem Schattenerträgnis vermag die Weiß-Tanne auch unter dichtem Schirm zu überdauern. Allerdings wird damit die Möglichkeit eines raschen Jugendwachstums nicht genutzt und das Risiko von Anpassungsproblemen der Schattnadeln an plötzliche Freiflächenbedingungen steigt an. Aus diesem Grund werden für einzelne Verjüngungselemente lichtere Schirme und kürzere Überschirmungszeiträume empfohlen. Der Berg-Ahorn sollte vorzugsweise auf kleineren Lücken angebaut werden. Hier vermag er in wenigen Jahrzehnten die aus der Vorratsabsenkung resultierende Zuwachsreduktion auszugleichen. Für die statische Stabilität kritische H:D-Relationen werden damit genauso vermieden, wie die durch unterschiedliche Mykorrhizatypen und die daraus folgenden Stoffumsätze im Oberboden resultierende zwischenartliche Konkurrenz. Insgesamt stellte sich die Bodenbearbeitung bei der Begründung der Voranbauten als vorteilhaft heraus. Rot-Buche, Berg-Ahorn und Weiß-Tanne erwiesen sich auf einer großen standörtlichen Breite in den sächsichen Berglagen als anbauwürdig. Die ebenfalls vorangebaute Gemeine Esche (Fraxinus exelsior L.), Douglasie (Pseudotsuga menziesii Franco) und Berg-Ulme (Ulmus glabra Huds.) leiden dagegen unter phytopathologischen Problemen und wurden bei der Modellanpassung nicht berücksichtigt. Für die periodischen Wuchsleistungen ist der Vorrat des Fichtenaltbestandes – stellvertretend für die vorhandene Biomasse – die entscheidende Einflussgröße. Er modifiziert die verjüngungsökologischen Bedingungen, wobei trotz morphologischer Anpassungen der Bäume im UST die Konkurrenz gegenüber der Faszilitation überwiegt. So werden auf Bestandeslücken, die in den Versuchen zwischen 0,02 und 0,5 ha groß waren, die größten Baumhöhen des Voranbaus erreicht.:1 Einleitung 2 Material und Methoden 3 Charakteristik der Zwischenergebnisse und Prädiktoren 4 Ergebnisse 5 Diskussion 6 Schlussfolgerungen und Handlungsempfehlungen 7 Zusammenfassung 8 Summary 9 Abbildungsverzeichnis 10 Tabellenverzeichnis 11 Literaturverzeichnis

The use of nonmetallic reinforcement in concrete aims at the decrease in material consumption by reducing the component sizes when compared to conventional reinforced concrete structures, which inherently results in very filigree structures. Although intensive basic research has been carried out on textile-reinforced concrete for about 30 years, the subject of stability behavior has hardly been investigated so far. This study focuses the fundamental understanding of the structural behavior of slender carbon-reinforced concrete (CRC) structures subjected to axial compression. Therefore, buckling experiments have been carried out in order to quantify the influence of two parameters: the slenderness ratio of the specimens (varying between 60 and 130) and the load eccentricity (0, 2, and 4 mm). The results of the specimens that were tested with the initial load eccentricities revealed a good overall agreement with those obtained by a second-order theory approach throughout all of the investigated slenderness ratios. For the centrally pressed samples that featured high slenderness ratios, the failure stresses could successfully be predicted with Euler’s buckling formula, whereas this theory overestimated the results of the specimens with intermediate to low slenderness ratios due to the plastic buckling phenomenon. The presented study emphasizes that the consideration of the stability problem is inevitable when designing material-efficient structures made of textile-reinforced concrete.

The thesis "The Influence of Media on Body Image with Emphasis on the Issue of Eating Disorders" deals with the impact of media on body perception regarding the current beauty ideal, the cult of slenderness as well as the causes of eating disorder spreading in today's world. This thesis aims to determine how media influences body image of the current society and what part it has in the origin of eating disorders. In terms of this aim, the thesis is divided into theoretical background, a part about body image, followed by the part about beauty ideal, then eating disorders and research. The theoretical part discusses the theory of social and media reality, expected media impacts on people as well as selected theories concerning the media impact on body image. The next part deals with the term body image. The third part involves discussion about the ideal of beauty and introduces three current theories about direct impact of media on body image. It also shows some examples from today's media concerning the topic. The fourth part deals with the eating disorders and their media discourse, followed by few examples of their spreading trend and also campaigns against them. The quantitative analysis aims to find out about today's population body image, the importance of appearance and connection between media...

The purpose of this study is to explore haw thinning planning standards agree with standards of estimation. Study was carried out in Kretinga forest enterprise Grūšlaukė forestry. Study of ratio of stands medial diameter and medial high was carried out in 11 – 60 years old pure spruce. The main purpose of thinning is to increase total productivity of forest stands and to form desirable structure and closeness of stands. It is important that all kinds of forest thinning concern biodiversity, increase resistance to wind and snow damage of forest stands, improve the quality of growing timber. Forests thinning use that timber part which rots in forests and gives no profit. To reach all these purpose forests thinning must be planned. Planning standard must be definite as it possible. It is important that these standards be suit with forests thinning normative. It was estimated that both standards has different rates and they are not matched. Thinning is planning by thickness of stands, but they are estimating by the number of trees in one hectare of stands. It was estimated that the ratio of forest stands medial diameter and medial high can be used in thinning planning. In pure spruce stands thinning must planned until ratio of medial diameter and medial high reach value: 0,8 in 11 – 20 years old stands; 0,9 in 21 – 40 years old stands; 1,0 in 41 – 60 years old stands.

The aim of this thesis is to assess the suitability of cold-formed rectangular hollow sections (RHS) for plastic design. The project involved an extensive range of tests on cold-formed Grade C350 and Grade C450 (DuraGal) RHS beams, joints and frames. A large number of finite element analyses was also carried out on models of RHS beams. The conclusion is that cold- formed RHS can be used in plastic design, but stricter element slenderness (b/t) limits and consideration of the connections, are required. Further research, particularly into the effect of axial compression on element slenderness limits, is required before changes to current design rules can be finalised. Bending tests were performed on cold-formed RHS to examine the web and flange slenderness required to maintain the plastic moment for a large enough rotation suitable for plastic design. The major conclusions of the beam tests were: (i) Some sections which are classified as Compact or Class 1 by current steel design specifications do not maintain plastic rotations considered sufficient for plastic design. (ii) The current design philosophy, in which flange and web slenderness limits are independent, is inappropriate. An interaction formula is required, and simple formulations are proposed for RHS. Connection tests were performed on various types of knee joints in RHS, suitable for the column - rafter connection in a portal frame. The connection types investigated were welded stiffened and unstiffened rigid knee connections, bolted plate knee joints, and welded and bolted internal sleeve knee joints, for use in RHS portal frames. The ability of the connections to act as plastic hinges in a portal frame was investigated. The most important finding of the joint tests was the unexpected fracture of the cold-formed welded connections under opening moment before significant plastic rotations occurred. The use of an internal sleeve moved the plastic hinge in the connection away from the connection centre- line thus eliminating the need for the weld between the RHS, or the RHS and the stiffening plate, to carry the majority of the load. The internal sleeve connections were capable of sustaining the plastic moment for large rotations considered suitable for plastic design. Tests on pinned-base portal frames were also performed. There were three separate tests, with two different ratios of vertical to horizontal point loads, simulating gravity and horizontal wind loads. Two grades of steel were used for comparison. The aims of the tests were to examine if a plastic collapse mechanism could form in a cold-formed RHS frame, and to investigate if plastic design was suitable for such frames. In each frame, two regions of highly concentrated curvature were observed before the onset of local buckling, which indicated the formation of plastic hinges and a plastic collapse mechanism. An advanced plastic zone structural analysis which accounted for second order effects, material non-linearity and member imperfections slightly overestimated the strength of the frames. The analysis slightly underestimated the deflections, and hence the magnitude of the second order effects. A second order plastic zone analysis, which did not account for the effects of structural imperfections, provided the best estimates of the strengths of the frames, but also underestimated the deflections. While cold-formed RHS did not satisfy the material ductility requirements specified for plastic design in some current steel design standards, plastic hinges and plastic collapse mechanisms formed. This suggests that the restriction on plastic design for cold-formed RHS based on insufficient material ductility is unnecessary, provided that the connections are suitable for plastic hinge formation, if required. A large number of finite element analyses were performed to simulate the bending tests summarised above, and to examine various parameters not studied in the experimental investigation. To simulate the experimental rotation capacity of the RHS beams, a sinusoidally varying longitudinal local imperfection was prescribed. The finite element analysis determined similar trends as observed experimentally, namely that the rotation capacity depended on both the web slenderness and flange slenderness, and that for a given section aspect ratio, the relationship between web slenderness and rotation capacity was non-linear. The main finding of the finite element study was that the size of the imperfections had an unexpectedly large influence on the rotation capacity. Larger imperfections were required in the more slender sections to simulate the experimental results. There should be further investigation into the effect of varying material properties on rotation capacity.

The aim of this thesis is to assess the suitability of cold-formed rectangular hollow sections (RHS) for plastic design. The project involved an extensive range of tests on cold-formed Grade C350 and Grade C450 (DuraGal) RHS beams, joints and frames. A large number of finite element analyses was also carried out on models of RHS beams. The conclusion is that cold- formed RHS can be used in plastic design, but stricter element slenderness (b/t) limits and consideration of the connections, are required. Further research, particularly into the effect of axial compression on element slenderness limits, is required before changes to current design rules can be finalised. Bending tests were performed on cold-formed RHS to examine the web and flange slenderness required to maintain the plastic moment for a large enough rotation suitable for plastic design. The major conclusions of the beam tests were: (i) Some sections which are classified as Compact or Class 1 by current steel design specifications do not maintain plastic rotations considered sufficient for plastic design. (ii) The current design philosophy, in which flange and web slenderness limits are independent, is inappropriate. An interaction formula is required, and simple formulations are proposed for RHS. Connection tests were performed on various types of knee joints in RHS, suitable for the column - rafter connection in a portal frame. The connection types investigated were welded stiffened and unstiffened rigid knee connections, bolted plate knee joints, and welded and bolted internal sleeve knee joints, for use in RHS portal frames. The ability of the connections to act as plastic hinges in a portal frame was investigated. The most important finding of the joint tests was the unexpected fracture of the cold-formed welded connections under opening moment before significant plastic rotations occurred. The use of an internal sleeve moved the plastic hinge in the connection away from the connection centre- line thus eliminating the need for the weld between the RHS, or the RHS and the stiffening plate, to carry the majority of the load. The internal sleeve connections were capable of sustaining the plastic moment for large rotations considered suitable for plastic design. Tests on pinned-base portal frames were also performed. There were three separate tests, with two different ratios of vertical to horizontal point loads, simulating gravity and horizontal wind loads. Two grades of steel were used for comparison. The aims of the tests were to examine if a plastic collapse mechanism could form in a cold-formed RHS frame, and to investigate if plastic design was suitable for such frames. In each frame, two regions of highly concentrated curvature were observed before the onset of local buckling, which indicated the formation of plastic hinges and a plastic collapse mechanism. An advanced plastic zone structural analysis which accounted for second order effects, material non-linearity and member imperfections slightly overestimated the strength of the frames. The analysis slightly underestimated the deflections, and hence the magnitude of the second order effects. A second order plastic zone analysis, which did not account for the effects of structural imperfections, provided the best estimates of the strengths of the frames, but also underestimated the deflections. While cold-formed RHS did not satisfy the material ductility requirements specified for plastic design in some current steel design standards, plastic hinges and plastic collapse mechanisms formed. This suggests that the restriction on plastic design for cold-formed RHS based on insufficient material ductility is unnecessary, provided that the connections are suitable for plastic hinge formation, if required. A large number of finite element analyses were performed to simulate the bending tests summarised above, and to examine various parameters not studied in the experimental investigation. To simulate the experimental rotation capacity of the RHS beams, a sinusoidally varying longitudinal local imperfection was prescribed. The finite element analysis determined similar trends as observed experimentally, namely that the rotation capacity depended on both the web slenderness and flange slenderness, and that for a given section aspect ratio, the relationship between web slenderness and rotation capacity was non-linear. The main finding of the finite element study was that the size of the imperfections had an unexpectedly large influence on the rotation capacity. Larger imperfections were required in the more slender sections to simulate the experimental results. There should be further investigation into the effect of varying material properties on rotation capacity.

The thesis has both a theoretical and a practical part. Within the theoretical part it deals with problems and the characteristics of food intake failures, especially with the perception of her/his body during maturation, pubescence, adolescence, early adulthood and middle adulthood and the impact of psychological and social factors and risk factors. It points out the possibilities of a probable occurrence of a food intake failures, the attitude of the society and parents. It deals with different attitudes to slenderness, self-esteem, eating habits of girls and how present-day girls are informed about food intake failures. The diploma thesis main aim within a practical part is the illustration of a theoretical part and the description of subjectively sensed possible causes from women who suffered from food intake failures. There are 6 casuistries described here which are subsequently summarized in the results. Possible comments and ideas are mentioned in the discussion.

This diploma thesis deals with the subject of slenderness bars’ stability assessment, especially in the steel structures. Before the assessment of bars in the frame constructions, we search for the influence of the computational model’s settings on the final result. The initial geometrical imperfections are examined on the model of Euler’s bar. The influence of the rigidity of girders on the poles’ buckling length is examined on the basic frame construction. The buckling lengths are assessed in the comparison with the figures we got from the statistical tables and the computational software. The influence of construction’s initial tilt and its replacement by the system of outer forces is examined on the frame structure. Three-hinged frame structure with variable cross-section member is designed then and the influence of non-linear calculations on the inner forces is studied. In the complex frame assessment, the influence of the number of parts of variable cross-section member on the bars’ buckling length is examined.