Sökning: "spaceflight"

Visar resultat 1 - 5 av 9 avhandlingar innehållade ordet spaceflight.

  1. 1. Wafer Bonding for Spaceflight Applications : Processing and Characterisation

    Författare :Kerstin Jonsson; Maaike Visser-Taklo; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; wafer bonding; oxygen plasma; wet chemical; anodic bonding; gamma irradiation; proton irradiation; temperature cycling; vibration; shock; Weibull; adhesion quantification; double cantilever beam; tensile; chevron; blister; Teknisk fysik; Engineering physics; Teknisk fysik;

    Sammanfattning : Bonding techniques intended for assembling space microsystems are studied in this work. One of the largest problems in bonding pre-processed semiconductor wafers are the severe process restrictions imposed by material compatibility issues. LÄS MER

  3. 2. Nitric oxide and the lung : effects of spaceflight and hypergravity

    Författare :Lars Karlsson; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Nitric oxide (NO) is an important signal molecule in the body, in particular in the cardiovascular system. This highly reactive molecule is difficult to detect in tissues, but in gas-filled cavities such as the airways it can be detected in part per billion amounts. LÄS MER

  4. 3. Fluid dynamic principles for analysis of intracranial pressure control : application towards space medicine and hydrocephalus

    Författare :Petter Holmlund; Anders Eklund; Sara Qvarlander; Jan Malm; Marek Czosnyka; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Intracranial pressure; posture; cerebrospinal fluid; microgravity; venous collapse; internal jugular vein; fluid dynamics; venous pressure; spaceflight-associated neuro-ocular syndrome; hydrocephalus; mathematical modeling; ultrasound; magnetic resonance imaging;

    Sammanfattning : Intracranial pressure (ICP) is an important component of the fluid dynamic environment of the brain and plays a central role with regards to the maintenance of normal cerebral blood flow and neuronal function. However, many regulatory mechanisms controlling the ICP are still poorly understood. LÄS MER

  5. 4. Effects of unloading and resistance exercise on skeletal muscle function, size and composition in man

    Författare :Björn Alkner; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Atrophy; bed rest; confinement; countermeasure; electromyography; human; knee extensors; magnetic resonance imaging; microgravity; muscle function; myosin heavy chains; plantar flexors; resistance exercise; skeletal muscle; spaceflight; strength; training specificity; unloading;

    Sammanfattning : Exposure to microgravity, i.e., spaceflight, causes muscle unloading leading to muscle atrophy and dysfunction. Thus, there is a need for effective countermeasures to combat these effects. LÄS MER

  7. 5. Cardiovascular function after long-term bed rest

    Författare :Jonas Spaak; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Microgravity; simulated weightlessness; carotid baroreflex; static exercise; muscle chemoreflex; orthostasis; tilting; leg exercise; blood pressure; heart rate; stroke volume;

    Sammanfattning : On earth, daily activities involve standing, changes of posture and various types of muscle action, all of which challenge the cardiovascular regulation. Removal of the orthostatic stress for a longer period, as during spaceflight or head-down tilt bed rest, consistently results in cardiovascular deconditioning. LÄS MER