Sökning: "Radiation Effects"

Visar resultat 31 - 35 av 584 avhandlingar innehållade orden Radiation Effects.

  1. 31. Mechanisms for the Influence from Ice Nucleus Aerosols on Clouds and their Indirect Effects: Cloud Modelling

    Författare :Deepak Waman; MERGE: ModElling the Regional and Global Earth system; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; clouds; Radiation; Ice Nuclei; Primary Biological Aerosol Particles; Ice particles; Secondary ice; primary ice; Aerosol particles; thunderstorm;

    Sammanfattning : The role of multiple groups of primary biological aerosol particles (PBAPs) as ice nucleating particles (INPs), and of ice formation processes such as time-dependent freezing of various INPs, and various secondary ice production(SIP) mechanisms in overall ice concentration has been evaluated in a range of cloud systems by simulating them numerically with the state-of-the-art ‘Aerosol-Cloud’ (AC) model in a 3D mesoscale domain. Also, the mechanismsof aerosol indirect effects (AIEs) arising from anthropogenic INPs, and the responses to these AIEs from time-dependent INP freezing and SIP processes are investigated in the simulated clouds. LÄS MER

  2. 32. An investigation of the radiation chemistry of a hydrocarbon system and simulation of ESR spectra of triplet state molecules

    Författare :Ola Claesson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Radiation chemistry; isotope effects; energy transfer; selective straction; spectrum simulation;

    Sammanfattning : This thesis can be divided into two parts.The aim of the studies described in the first part of the thesis isto make clear the dominating processes in the selective decorrpositionof certain solutes that follow low-terrperature radiolysis of crystalline hydrocarbons.1. LÄS MER

  3. 33. Adjuvant treatments to prevent local reurrence after breast-conserving surgery for early breast cancer : radiation, endocrine- or brachytherapy

    Författare :Åsa Wickberg; Göran Liljegren; Johan Ahlgren; Roger Olofsson Bagge; Örebro universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Breast-conserving surgery; radiotherapy; endocrine therapy; intraoperative brachytherapy;

    Sammanfattning : Radiotherapy after breast-conserving surgery due to breast cancer is an established treatment, known to reduce the incidence of recurrence and even death from the disease. However some women are over-treated with sometimes serious adverse effects. De-escalating the treatment and find alternative adjuvant methods are becoming an important issue. LÄS MER

  4. 34. Biomarkers of ionising radiation relevant to carcinogenesis : Dose, dose rate and LET dependency of the responses

    Författare :Milagrosa López Riego; Andrzej Wojcik; Lovisa Lundholm; Alexandros G. Georgakilas; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Ionising radiation; low dose; low dose rate; linear energy transfer LET ; mixed beams; dose and dose rate effectiveness factor DDREF ; cancer; DNA damage response; biomarkers; molekylär biovetenskap; Molecular Bioscience;

    Sammanfattning : A better understanding of the relationship between ionising radiation (IR) dose, dose rate and radiation quality, and the risk of stochastic effects would improve risk extrapolation from atomic bomb survivors’ data. Owing to insufficient statistical power of epidemiological studies to detect excess incidence of cancer following low doses of IR delivered at low dose rates (LDLDR), as typically encountered in most common human exposure scenarios, radiobiological experiments are fundamental to describe the biological effectiveness of LDLDR and to define the underlying molecular mechanisms. LÄS MER

  5. 35. Dosimetric effects of breathing motion in radiotherapy

    Författare :Anneli Edvardsson; Lund Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; radiotherapy; breathing motion; DIBH; interplay effects; VMAT; proton therapy; breast cancer; Hodgkin’s lymphoma; liver; dosimetry; treatment planning; medical physics;

    Sammanfattning : The goal of radiotherapy is to deliver a homogeneous high dose of radiation to a tumour while minimising the dose to the surrounding healthy tissue. To achieve this, increasingly advanced treatment techniques, such as volumetric modulated arc therapy (VMAT) and proton therapy, have been developed. LÄS MER