Vemmenhögsprojektet

Det är mycket viktigt att förhindra att bekämpningsmedelsubstanser läcker ut i miljön och orsakar skada. Lagstiftningen kräver därför att läckaget av bekämpningsmedel från odlad mark minskas. Olika myndigheter och organisationer har olika ansvarsområden beträffande bekämpningsmedel. Bekämpningsmedelssubstanser kan, om de inte hanteras rätt, vara skadliga och därför finns det tydliga bestämmelser om hur dessa substanser ska hanteras. Många oberoende undersökningar visar tydligt på att det förekommer läckage av bekämpningsmedel i samband med att de används i behandlingar av odlad mark. Undersökningar har pågått under lång tid både i Sverige och i andra länder. Ett flertal åtgärder och metoder mot läckage av bekämpningsmedel från odlad mark har framtagits och utvecklats som radikalt kan minska läckaget av bekämpningsmedel. I mitt examensarbete sammanställer och redogör jag för dessa metoder och hoppas på så sätt medverka till att sprida denna information till aktiva lantbrukare. Det världsberömda Vemmenhögsprojektet som pågår i ett odlingsområde i södra Skåne sedan 1990, har redovisat framgångsrika resultat där man minskat läckaget av bekämpningsmedel med över 90 %. It is important that we prevent that pesticides leak into the environment and cause damage. Legislation claims today that leakage by pesticides from cultivated fields should be reduced. Different government authorities and organisations have different areas of responsibility concerning pesticides. Pesticides can, if they are not handled correctly, be very harmful and therefore there are rules and regulations about how these substance should be used and handled. Research show clearly that leakage by pesticides occurs in connection with pesticide application on cultivated fields. Investigations about leakage of pesticides from cultivated fields have be going on under a long time in Sweden as well as in other countries. The majority of measures and methods against leakage of pesticides from cultivated fields are designed and developed and can radically reduce leakage of pesticides. The methods to reduce leakage by pesticides are descibed in my work and may contribute to spread this information to active farmers. The world-famous Vemmenhögprojekt has been going on since 1990 in agricultural land in southern Sweden. This project shows that leakage by pesticides can be reduced by over 90%

The Immunophilin-Like Protein XAP2 Is a Negative Regulator of Estrogen Signaling through Interaction with Estrogen Receptor α

XAP2 (also known as aryl hydrocarbon receptor interacting protein, AIP) is originally identified as a negative regulator of the hepatitis B virus X-associated protein. Recent studies have expanded the range of XAP2 client proteins to include the nuclear receptor family of transcription factors. In this study, we show that XAP2 is recruited to the promoter of ERα regulated genes like the breast cancer marker gene pS2 or GREB1 and negatively regulate the expression of these genes in MCF-7 cells. Interestingly, we show that XAP2 downregulates the E2-dependent transcriptional activation in an estrogen receptor (ER) isoform-specific manner: XAP2 inhibits ERα but not ERβ-mediated transcription. Thus, knockdown of intracellular XAP2 levels leads to increased ERα activity. XAP2 proteins, carrying mutations in their primary structures, loose the ability of interacting with ERα and can no longer regulate ER target gene transcription. Taken together, this study shows that XAP2 exerts a negative effect on ERα transcriptional activity and may thus prevent ERα-dependent events

Slöjdsalen : det pedagogiska rummet

Intervjustudien i detta examensarbete omfattar sex kvalitativa intervjuer med behöriga slöjdpedagoger yrkesverksamma inom den kommunala grundskolan. Syftet med detta examensarbete är att undersöka hur slöjdlärare inom trä- och metallslöjd organiserar sina slöjdsalar utifrån ett pedagogiskt perspektiv. En genomgång av litteratur och forskningsresultat inom området fysiska miljöer och slöjd, syftar till att ge en bild av dessa två områden och hur de samverkar. Resultatet av undersökningen visar på olika förhållningssätt till organiserandet av slöjdsalen ur ett pedagogiskt perspektiv. Hur intentioner och traditioner påverkar ambitionen hos de intervjuade lärarna. I analysen framkom att lärarna inte hade någon medveten och/eller långsiktig strategi för att organisera slöjdsalen utifrån ett pedagogiskt perspektiv. De framför också olika faktorer som hinder för genomförandet, och om dessa inte fanns, skulle ett organiserande vara lättare att genomföra

Förstudie: Felmoder hos spår och fordon

För att kunna detektera fel i fordon, bana och/eller en kombination av fordon mot bana. Förhoppningen är att accelerometerar i korg och boggier, skall kunna användas för att underlätta felsökning när åkkomforten för en vagn är dålig. I denna analys har vagnen varit bestyckad med fyra accelerometrar: en accelerometer mitt i varje boggi och två accelerometrar i korgen mitt över varje boggi.Etablera systematiskt arbetssätt för att förbättra gångkomfort för passagerartåg -dålig gån

Surface characterization of 2D transition metal carbides (MXenes)

Research on two-dimensional (2D) materials is a rapidly growing field owing to the wide range of new interesting properties found in 2D structures that are vastly different from their three-dimensional (3D) analogues. In addition, 2D materials embodies a significant surface area that facilitates a high degree of surface reactions per unit volume or mass, that is imperative in many applications such as catalysis, energy storage, energy conversion, filtration, and single molecule sensing. MXenes constitute a family of 2D materials consisting of transition metal carbides and/or nitrides, which are typically formed after selective etching of their 3D parent MAX phases. The latter, are a family of nanolaminated compounds that typically follow the formula Mn+1AXn (n=1-3), where M is a transition metal, A is a group 13 or 14 element, and X is C and or N. Selective etching by aqueous F- containing acids removes the A layer leaving 2D Mn+1Xn slabs instantly terminated by a mix of O-, OH- and F-groups. The first and most investigated MXene is Ti3C2TX, where TX stands for surface termination, which has shown record properties in a range of applications (eg. electrode in Li-batteries, supercapacitors, sieving membrane, electromagnetic interference shielding, and carbon capture). Adding to that, over 30 different MXenes have been discovered since 2011, exhibiting alternative or superior properties. Most importantly, elegant routes for property design in the MXene family has been demonstrated, by means of either varying the chemistry in the Mn+1Xn compound, by alloying two M elements, or by changing the structure of the MXene by introducing vacancies. The present work has a led to an additional route for post synthesis property tuning in MXenes by manipulation of surface termination elements. This enables a unique toolbox for property tuning which is not available to other 2D materials and is highly beneficial for applications that is dependent on surface reactions. Furthermore, chemical and structural characterization of terminations on single sheets is essential to rule out the influence of intercalants or contamination that is typically present in multilayer MXene samples or thin films. For that purpose, a method for preparing isolated contamination free single sheets of MXene samples for transmission electron microscopy (TEM) characterization was established. In order to determine vacancy and termination sites, atomically resolved scanning (S)TEM imaging and image simulations was carried out. Two main processes were employed to substitute the termination elements. 1) An initial thermal treatment in vacuum facilitates F desorption and it was shown that O-terminations rearranges on the evacuated sites. H2 gas exposure in a controlled environment demonstrated a removal of the remaining O-terminations. As a result, termination-free MXene is possible to realize under vacuum conditions. 2) CO2 was introduced as a first non-inherent termination on MXene by in situ CO2 gas exposure at low temperatures. That was a first demonstration of Ti3C2TX as promising material for carbon capture. Additionally, O-saturated surfaces were demonstrated after introduction of O2 gas on the F-depleted Ti3C2TX MXene, which is highly relevant for hydrogen evolution reactions where fully O-terminated Ti3C2TX are predicted to improve efficiency. A Lewis acid melt synthesis method was used to realize the first MXene exclusively terminated with Cl. Moreover, this was the first report of a MXene directly synthesised with terminations other than O, OH, and F. Furthermore, we have expanded the space of property tuning by introduction of chemical ordering, by selective etching of Y in an alloyed (Mo2/3Y1/3)2CTX MXene. This either produced chemical ordering with one M (Mo) element and vacancies, or ordering between two M (Mo and Y) elements. This was further reported to significantly increase volumetric capacitance because of the increased number of active sites around vacancies, leading to an increasing charge density. As a final note, the stability of Nb2CTX MXene under ambient conditions was investigated. It was found that the surface Nb adatoms, present after etching, got oxidized over time which resulted in local clustering and effectively degraded the MXene. This work has demonstrated reproducible surface characterization methods for determining termination elements and sites in 2D MXenes, that is ultimately governing MXene properties. Most importantly, we report on a new approach for MXene property tuning as well as contributing to several existing property tuning approaches.

Performance analysis of a CFD-code on the IBM-SP2

The results presented in this report treats the performance of the the AVBP (ver.2.0) CFDcode on the IBM-SP2 parallel supercomputer. AVBP is a cell-vertex finite volume code designed to solve the partial differential equations that govern the motion of compressible fluid flow, e.g. the Navier-Stokes equations or the simplified set of equations known as the Euler equations. AVBP is able to handle structured and unstructured meshes in both 2D and 3D. As test cases we have used the three dimensional geometries known as the ONERA M6 wing (simple wing geometry) and the Dassault Falcon aircraft (full aircraft geometry). Both these grids are unstructured with tetrahedral elements. The report will emphasize the importance of choosing an appropriate grouping of the elements since non-appropriate chosen the computation time might be more than 50 % longer than necessary. On the other hand, the report shows that the choice between the RCB (Recursive Coordinate Bisection) and the RIB (Recursive Ine..