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The Interplay Between the Notch Signaling Pathway and Cellular Metabolism
SLANINOVÁ, Věra
We identified four metabolic genes as direct targets of Notch signaling pathway both in vitro and in vivo and investigated the hypothesis that Notch directed metabolic changes support the growth of the imaginal wing dics. Vice versa, we observed the influence of metabolic changes on the activity of Notch signaling pathway and we identified Sirt1 as a metabolic sensor for the Notch pathway that helps to elicit an efficient response to Notch signal, in a metabolism sensitive manner.
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Stress concentrators in aircraft structures
Černota, Jiří ; Pejchar, Jan (referee) ; Augustin, Petr (advisor)
This bachelor´s thesis deals with significant stress concentrators in compossed plane constructions made of metal materials. It generates summary of the most significant notches and their effect on fatigue life. It further states opportunities of description of constructional solution leading to reduction of stress concentration.
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Use of \kur{Notch} gene for the production of genetic "sexing" lines of codling moth.
ŠVELLEROVÁ, Hana
The codling moth, Cydia pomonella, is the key pest of pome fruit and walnut orchards in the temperate regions of the world. The extensive use of insecticides for a control of this pest has resulted in the development of resistance to these chemicals, and there is an increasing demand on the use of environment-friendly control tactics, such as the Sterile Insect Technique (SIT). Codling moth SIT relies on the mass rearing and release of genetically sterile both males and females into a wild population. However, male-only releases could significantly reduce costs of the mass rearing and increase SIT efficiency. In this thesis I focused on the use of a temperature-sensitive mutant allele of the Notch gene for production of genetic "sexing" lines of codling moth.
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Růst krátkých trhlin z vrubů ve dvoufázové austenitcko-feritické oceli
Kotecký, Ondřej ; Degallaix, S. ; Polák, Jaroslav
The effect of microstructure and stress gradient in a two-phase austenitic-ferritic steel in specimens with confined plasticity is studied. Direct optical observations and potential drop technique calibrated via the finite element method are used to measure the surface crack size and its depth and to determine the surface crack growth. The effect of stress and strain gradients on the crack propagation kinetics and crack shape is evaluated and dicussed.
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Kinetics of fatigue crack growth under notches in duplex steel
Kotecký, Ondřej ; Degallaix, S. ; Polák, Jaroslav
While under elastic fatigue loading of structural components with a stress concentration the material response is quite well known and the predictions are accurate, under elastic-plastic fatigue loading the predictions are poor and result in over-dimensioning the structure. The present work studies the effect of the stress gradient and the microstructure in an austenitic-ferritic (or duplex) 2507 stainless steel. Fatigue tests were performed on double edge notched specimens. Direct optical observations and potential drop technique calibrated via the finite element method are used to measure the surface crack size and its depth and to determine the in-depth and surface crack growth. The effect of stress and strain gradients on the crack propagation kinetics is evaluated and discussed.
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Comparison of fracture behaviour of cracks and sharp notches
Klusák, Jan ; Knésl, Zdeněk
The theoretical background of linear elastic fracture mechanics of V-notches is presented. A crack is considered as a special case of the V-notch with zero open angle. Conditions for stability of a general singular stress concentrator are formulated. Based on results obtained a fracture behaviour of notches and cracks is compared.
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Application of contour integrals to assessment of notch stability in linear elasticity
Gröger, Roman ; Knésl, Zdeněk
The article yields a teoretical background of a well- sophisticated numerical method for calculation of GSIF and T stress, especially for case when the integration across the nonhomogeneous material interface is unavoidable. The main advantage of the integral approach over the well-known direct methods is its accuracy induced by monotonous convergence of the solution. This work contributes to more accurate description of the instability state of V-notches in composite structures.
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Calculation of the fracture parameters for a crack growing from the tip of a V-notch
Gröger, Roman ; Hutař, Pavel
This article yields a comparison of two principles for caculation of the fracture parameters - the direct finite element method and hybrid element method. The stress intensity factor and the T stress for a crack growing from the tip of a nonsingular stress concentrator for a large variety of notch angles is obtained. It is discussed the sensitivity of each parameter on the ratio of crack length to the width of the specimen. The obtained results can contribute to more precise characterisation of the crack instability state in a case of the combination V-notch + crack.
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Comparison of fracture behaviour of notches and cracks
Klusák, Jan ; Knésl, Zdeněk
The theoretical background of linear elastic fracture mechanics of V-notches is presented. A crack is considered as a special case of the V-notch with zero open angle. Conditions for stability of a general singular stress concentrator are formulated. Based on results obtained a fracture behaviour of notches and cracks is compared.
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