Search results

Den främsta orsaken till en ökad växthuseffekt anses idag bero på en högre koncentrationav koldioxid i atmosfären. Sedan den industriella revolutionen harmänniskan påverkat mängden koldioxid i atmosfären genom aktiviteter så somförbränning av fossila bränslen, avskogning, förändringar i markanvändning, samtcementproduktion. För att kunna motverka framtida klimatförändringar krävs enfördjupad kunskThis thesis focuses on the development and application of efficient mathematicaltools for estimating and modelling the exchange of carbon dioxide (CO2) between the Earth and its atmosphere; here referred to as the global CO2 surface flux.There are two main approaches for estimating the CO2 flux: Processed based(bottom-up) modelling and atmospheric inversion (top-down) modelling. Thefirst part of t

Alloys and bimetallic systems have shown many advantages in heterogeneous catalysis, but the details of their catalytic functions are not always known. For instance, the atomic details about surface reconstructions under catalytic reaction conditions, or which phases that are high-active or low-active. Furthermore, the model catalysts studied in laboratories often differ a lot from the industrial

Background: A hip fracture is a common cause of morbidity, functional disability, and decreased health-related quality of life (HRQOL). With demographic changes showing a growing proportion of older people, hip fractures will be an increasing challenge for healthcare services in the future. Hip fractures threaten the independence of individuals in their everyday lives. In Sweden, more than one thiBackground: A hip fracture is a common cause of morbidity, functional disability, and decreased health-related quality of life (HRQOL). With demographic changes showing a growing proportion of older people, hip fractures will be an increasing challenge for healthcare services in the future. Hip fractures threaten the independence of individuals in their everyday lives. In Sweden, more than one thi

Whole blood is rich in information about the physical state of an individual and is routinely used in a variety of clinical and research applications. In this thesis, the use of a microfluidic technique called acoustophoresis for separation of different blood components is explored. Acoustophoresis uses an ultrasonic standing wave field to manipulate cells in a microfluidic device. Cells within th

Popular ScienceThe growing need for green processes in industry makes scientists design and develop processes that are more energy efficient than current processes. Naturally, some reactions require a high energy and long time to occur. This will cause high energy consumption and, typically, even more waste production. Therefore, many efforts have been done to design materials that can help to chaThe research work that I describe in my thesis deals with three different heterogenisation approaches for synthesising a heterogeneous transition metal catalyst used for direct C-H activation reactions. The three heterogenisation approaches considered in my research are: (1) heterogenisation of a molecular catalyst on a polymer support using covalent bonds, (2) heterogenisation of a catalyst on a

In laser-wakefield acceleration (LWFA), a femtosecond laser pulse is tightly focused in a gas to intensities exceeding 1018 W/cm2 . The laser radiation ionizes the medium and excites a plasma wave that travels behind the laser pulse. Electrons can be trapped in the oscillations in the plasma density, where electric fields of the order of several hundreds of GV/m accelerate them to relativistic ene

Autoignition in SI engines is an abnormal combustion mode and may lead to engine knock which is an undesired phenomenon in SI engines. It may cause damage and it is a source of noise in engines. Knock limits the compression ratio of the engine and a low compression ratio means low fuel conversion efficiency of the engine. This thesis presents a theoretical investigation about the modeling of the e

The global society is dependent on transportation to function and a big part of these transports are driven by an internal combustion engine. Heavy-duty vehicles utilizes conventional diesel combustion is a combustion concept where the fuel is often ignited during the injection event and while it gives a high combustion efficiency, the combustion mode is also characterized by high emission of NOx

The importance of the ability to use bipedal stance and gait in everyday life cannot be underestimated. Bipedal stance is learned during childhood and constantly adapted to changing circumstances throughout life. Failure to attain and maintain the control of upright posture can have catastrophic consequences. Postural competence needs to be recovered in a multitude of illness, in developmental dis

Background: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by tau and amyloid brain pathology. With the gradual degeneration of neurons, cognitive symptoms will arise and the affected individual will eventually develop AD dementia. The neuropathologic hallmarks of AD have been observed also in cognitively healthy individuals, which has led to the assumption that the disorde

Soda lakes represent the most stable naturally-occurring alkaline environments on Earth and harbour a diverse population of alkaliphiles. Alkaliphilic microorganisms have attracted a great interest due to their ability to produce extracellular enzymes that are active and stable at high pH values. Screening for alkaliphilic starch-hydrolyzing bacteria from samples of soda lakes at the Ethiopian Rif

Popular Abstract in Swedish Bakgrund Hjärntumör hos barn är en relativt ovanlig sjukdom som drabbar cirka 70 barn i Sverige årligen. Under de senaste 40 åren har överlevnaden i barnhjärntumör ökat avsevärt från under 40 % till över 70 %. Överlevnaden har inte varit utan pris och många barn får kognitiva svårigheter efter behandlingen, t.ex. problem med långsamhet, dåligt minne, bristande uppmärksaBackground: Pediatric Brain Tumor (PBT) survivors suffer from cognitive sequelae, especially within the areas of cognitive tempo, attention, executive function and memory. The cognitive difficulties are often accentuated over the years, but knowledge about the long term trajectory is still scarce. Aim: The aim of this thesis was to examine cognitive sequelae after Pediatric Brain Tumor (PBT); ris

Popular Abstract in Swedish Immunsystemet skyddar kroppen mot infektion. För att kunna skydda mot infektion krävs att immunsystemet är utrustat med kraftfulla biokemiska motmedel. Ett sådant motmedel är antikroppar. Antikroppar är proteiner som känner igen och specifikt binder till andra molekyler via en s k molekylbindande klyfta. När antikropparna har bundit in till en molekyl på t ex en bakteriPrimary infections and vaccination stimulates the immunesystem to produce memory cells that rapidly respond to reexposure of the same antigen. These memory responses are dependent on an adaptive type of immunity that sustains the reactivity of the immune system by long-lived memory immune cells. From an evolutionary perspective adaptive immunity as such appears to be restricted to jawed vertebrate

Popular Abstract in Swedish Den svenska grundskolan har under de senaste åren genomgått och genomgår fortfarande en stark utveckling inom ramen för den allmänna decentraliseringen i samhället. Beslut och ansvar läggs allt längre ner i organisationen. De krav som ställdes på en skolledare tillbaka i tiden var i första hand att han skulle vara administratör och den som bevakade att skolans verk-samThe issues of the study are: How do the assistant principals face the work as school leaders? Which demands of competence do the new school leaders face? Which needs of competence development exist for new school leaders? In the school studied the organization of the management was changed from one principal and one director of studies to one principal and six assistant principals. All of these we

Typical for Western classical music is the process of interpreting and conveying a written score into sounding music. However, sometimes the communication of musical issues between musicians may be experienced as aggravating. In educational contexts in a broad sense, it might be advantageous if this communication could be facilitated, for example, by using visual illustrations as a complement to t

It is generally acknowledged that wetlands and barrier islands can reduce surge and waves. However, while a general qualitative understanding of these interactions is available in the scientific literature, quantification of these interactions is lacking and has previously been based on limited data of relatively poor quality. The overall aim of this study was to improve the understanding of the i

The main purpose of the present work is to increase knowledge of in-plane tension behav-iour of masonry and develop a model able to describe the impact of parameters influencing cracking caused by restrained shrinkage. In the process the mechanism of load transfer between units and mortar joints is described. The influence of cohesion between units and mortar joints, unit and joint geometry and ex

At the end of the eighteenth century, Edward Gibbon described the antiquarian scholars of previous generations as men of “profound learning and easy faith.” His exemplar was the Swedish polymath Olof Rudbeck, who in a series of frantic and combative tomes sought to portray Sweden as the model for Plato’s Atlantis and the seething cultural cauldron from which Western civilization had emerged. A Pil

Popular Abstract in Swedish Tidigare trodde man att den vuxna hjärnan inte hade någon förmåga att nybilda nervceller. Detta skulle innebära att nervceller aldrig blev ersatta om de skadades eller dog. Nu vet man däremot att den vuxna hjärnan fortfarande producerar nya nervceller från särskilda moderceller, s.k. stamceller, belägna i åtminstone två områden i hjärnan: subgranulära zonen i hippocamThe adult brain constantly produces new neurons from endogenous neural progenitor cells located in at least two regions, the subgranular zone (SGZ) in dentate gyrus of the hippocampus, and the subventricular zone (SVZ). Major efforts are underway to discover the functional significance of new neurons in the adult brain. Several studies have indicated a relationship exists between newborn hippoca