Sökning: "Strain gradient"

Visar resultat 1 - 5 av 76 avhandlingar innehållade orden Strain gradient.

1. 1. Gradient-based optimization of non-linear structures and materials

   Författare :Anna Dalklint; Hållfasthetslära; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Topology optimization; Shape optimization; Finite strain; Eigenvalue problems; Soft robotics;

   Sammanfattning : Gradient-based optimization is a potent tool in many design processes today. It is particularly useful in industries where weight considerations are crucial, such as aerospace, but can also be exploited in for example civil engineering applications to reduce the material use and thereby the environmental impact. LÄS MER

3. 2. Strain Gradient Plasticity Modelling of Precipitation Strengthening

   Författare :Mohammadali Asgharzadeh; Jonas Faleskog; Samuel Forest; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The introduction of particles and precipitates into a matrix material results in strengthening effects. The two main mechanisms involved in this matter are referred to as Orowan and shearing. To numerically study this phenomenon is the motivation to the research done, which is presented here in this thesis. LÄS MER

4. 3. Survival and functional recovery following valve replacement in patients with severe aortic stenosis

   Författare :Wenhong Ding; Michael Y Henein; Eugenio Picano; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Aortic stenosis; surgical aortic valve replacement; transcatheter aortic valve implantation; survival; predictor; echocardiography; speckle tracking; ventricular function; twist; strain; Cardiology; kardiologi;

   Sammanfattning : Background: Aortic stenosis (AS) is the most common heart valve disease in Europe and North America. Age-related calcification of the valve is the commonest cause of acquired AS, especially in patients older than 70 years. LÄS MER

5. 4. SOD1 prions transmit templated aggregation and fatal ALS-like disease

   Författare :Elaheh Ekhtiari Bidhendi; Thomas Brännström; Stefan L. Marklund; Peter M. Andersen; Inger Nennesmo; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; ALS; amyotrophic lateral sclerosis; SOD1; prion; neurodegeneration; strain; seeding; protein misfolding; protein aggregation; propagation; transgenic mice; Pathology; patologi; Neurology; neurologi;

   Sammanfattning : Amyotrophic lateral sclerosis (ALS) is an adult-onset fatal neurodegenerative disease characterized by a progressive degeneration of the upper and lower motor neurons. The resulting paresis begins focally, usually in one muscle, and spreads contiguously, leading to muscle wasting, progressive paralysis and eventually death. LÄS MER

7. 5. Micro-mechanical mechanisms for deformation in polymer-material structures

   Författare :Jessica Strömbro; Peter Gudmundson; Per Gradin; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Length-scale effects; Strain gradient; Moisture change; Humidity change; Network model; Fibre model; Mathematical model; Polymer; Micro-indentation; Particle composite; Interfacial debonding; Matrix cracking; Paper; Mechano-sorptive creep; Accelerated creep; Other materials science; Övrig teknisk materialvetenskap;

   Sammanfattning : In this thesis, the focus has been on micro-mechanical mechanisms in polymer-based materials and structures. The first part of the thesis treats length-scale effects on polymer materials. Experiments have showed that the smaller the specimen, the stronger is the material. LÄS MER