Unified Treatment of Asymptotic van der Waals Forces

In a framework for long-range density-functional theory we present a unified full-field treatment of the asymptotic van der Waals interaction for atoms, molecules, surfaces, and other objects. The only input needed consists of the electron densities of the interacting fragments and the static polarizability or the static image plane, which can be easily evaluated in a ground-state density-functional calculation for each fragment. Results for separated atoms, molecules, and for atoms/molecules outside surfaces are in agreement with those of other, more elaborate, calculations.Comment: 6 pages, 5 figure

Matrix Metalloproteinases-8 and-9 and Tissue Inhibitor of Metalloproteinase-1 in Burn Patients. A Prospective Observational Study

Introduction Matrix metalloproteinases (MMPs) -8 and -9 are released from neutrophils in acute inflammation and may contribute to permeability changes in burn injury. In retrospective studies on sepsis, levels of MMP-8, MMP-9, and tissue inhibitor of metalloproteinase-1 (TIMP-1) differed from those of healthy controls, and TIMP-1 showed an association with outcome. Our objective was to investigate the relationship between these proteins and disease severity and outcome in burn patients. Methods In this prospective, observational, two-center study, we collected plasma samples from admission to day 21 post-burn, and burn blister fluid samples on admission. We compared MMP-8, -9, and TIMP-1 levels between TBSA20% (N = 30) injured patients and healthy controls, and between 90-day survivors and non-survivors. MMP-8, -9, and TIMP-1 levels at 24-48 hours from injury, their maximal levels, and their time-adjusted means were compared between groups. Correlations with clinical parameters and the extent of burn were analyzed. MMP-8, -9, and TIMP-1 levels in burn blister fluids were also studied. Results Plasma MMP-8 and -9 were higher in patients than in healthy controls (P20% groups. MMP-8 and -9 were not associated with clinical severity or outcome measures. TIMP-1 differed significantly between patients and controls (P20% groups (PPeer reviewe

Van der Waals Interactions in Density Functional Theory

Density functional theory is a very important method for calculating ground-state properties for atoms, molecules and solids. Albeit exact in principle, its implementation requires an approximation for the so-called exchange-correlation energy. The most popular of these approximations, the local-density and generalized-gradient approximations, are local or semi-local and do not include the highly non-local van der Waals interaction.<p /> In this thesis a density functional for calculating the asymptotic van der Waals interaction energy for objects of different sizes and geometries is proposed. It is based on the adiabatic-connection formula for the exchange-correlation energy, where two basic approximations are made. First, the density response function is calculated at the level of the random phase approximation. Second, a local approximation is made for the screened response.<p /> In practice a doubly local approximation for the dielectric function is used when evaluating the interactions, together with a cutoff of each interacting object. This real-space cutoff prevents spurious overestimates of the response in the density tails otherwise caused by the local approximation. Explicit forms of the functional are derived for three model systems --- interacting atoms or molecules, an atom or molecule outside a surface and finally two interacting surfaces. Also the derivation of a correction to the 1 / z²-dependence for the asymptotic interaction between two surfaces is accounted for.<p /> The functional is applied to and found very reasonable for a number of different objects, such as atoms, fullerenes, and other molecules. Surfaces at different levels of approximation are treated successfully, from jellium surfaces to low-indexed Al surfaces calculated within a plane-wave pseudopotential code, with both surface structure and relaxation of the outermost atomic layers. Anisotropic effects for interacting molecules and molecules outside a surface are also considered.<p /> In summary, this thesis demonstrates that it is indeed possible to restore van der Waals interactions in density functional theory. An explicit van der Waals density functional that is proposed for long-ranged interactions is successfully applied to a range of test cases with mutual interactions of atoms, molecules, and surfaces. The prospects for a working van der Waals functional, applicable to problems within solid state physics, chemistry, and biology look very good

Individualism meets altruism : A qualitative study on board members interplay with the non-profit organization

Research in volunteer work commonly either focuses on underlying motives and reasons why people volunteer or a macro-perspective on the non-profit sector as an organizational field. The purpose of this study is to investigate the link between the volunteers and the humanitarian non-profit organization they participate in. We conducted interviews with 12 board members from Amnesty International Sweden and the Swedish Red Cross Youth Organization to investigate how volunteers experience the formal and informal structures within the organizational context. The data is analyzed with Thornton and Ocasio’s theory of institutional logics and organizational theory with focus on the definition of formal structures. Blau’s social exchange theory is also used throughout the study to identify the interaction and mutual exchange between the volunteers and the organization. The results show that these volunteers value informal structures such as flexibility, the internal communication, group dynamics and autonomy within the organization to a greater extent than the formal structures the organizations provide. However, some volunteers have expressed feelings of confusion and lack of directives in relation to the responsibilities of their role and say they would benefit from more formal guidelines. On the other hand, a more formal structure within the organizations could clash with their ability to see the organization as adaptable. To further complicate the issue, many non-profit organizations portray themselves to prospective volunteers as flexible and emphasize on individualistic motives when recruiting for volunteers, such as future career and employability. As a result of this, many volunteers enter the organization with the expectation that they’ll have the freedom to do work which aligns with their personal motives. This in turn means they may be unprepared or run into issues with executing the work and responsibilities the organization expects from them. The most significant conclusion we reached is how the interplay between the volunteer and the organization is dependent on the individualistic volunteer’s ability to identify with the organization and by extent the purpose of the organization. This to balance out working solely off of personal motives which does not automatically get the organization to reach their mission

Spänning i vardagen : Konstruktion av miniverk i byggsatsform

Denna rapport sammanfattar det examensarbete som utförts 2012 på kandidatnivå av Erika Dahlström och Josefin Hult på Mälardalens Högskola i Eskilstuna. Examensarbetet har utförts i samarbete med ÅF Technology AB i Västerås. Projektets idé uppstod i ett tidigare fiktivt högskoleprojekt där tanken om ett vindkraftverk skulle vara intressant för privatpersoner kom till. Detta projekt har vidareutvecklat denna tanke och projektet har då utvecklats till att syfta till att undersöka om det finns en marknad för miniverk i byggsatsform avsett för privatpersoner, vad marknaden efterfrågar samt utveckla och konstruera en miniverksmast. Ett miniverk är ett vindkraftverk som vanligtvis inte behöver bygglov. För att kunna besvara hur marknaden ser ut har omfattande research utförts samt en marknadsundersökning. Från researchen sågs att det finns liknande befintliga produkter vilket innebar att projektets syfte gick från att konceptutveckla ett helt miniverk till att differentiera vår produkt från konkurrenternas. Detta gjordes genom att utveckla en mast som ger brukaren större valmöjligheter genom bland annat underlätta montering samt underhåll av sitt miniverk. Vid konstruktion har fokus lagts på knäckningsberäkningar då knäckning måste tas på största allvar för att undvika potentiellt allvarliga olyckor. Beräkningar har jämförts med simuleringar utförda i Solid Works vilket visar på att beräkningarna bör vara korrekta. Resultatet blev en 15,4 meter hög mast uppdelad i fem sektioner. Masten höjs och sänks genom en vev, block och vajrar. För att säkra att masten står stabilt finns åtta stycken stabiliserande vajrar fästa på två mastsektioner. Denna mast uppfyller majoriteten av de krav som ställts upp i en kravspecifikation. Att alla krav inte kunde uppfyllas beror på projektets begränsade tid. Dock har tydliga rekommendationer getts för att möjliggöra en vidareutveckling av detta resultat så att alla krav kan uppfyllas. Under hela produktutvecklingsprocessen har ett flertal olika produktutvecklingsverktyg använts som stöd och kvalitetssäkring i arbetet. Arbetet med projektet har fungerat väl, dock var en del frågor inom projektet mycket komplexa vilket innebar en del förseningar

Individualism meets altruism : A qualitative study on board members interplay with the non-profit organization

Research in volunteer work commonly either focuses on underlying motives and reasons why people volunteer or a macro-perspective on the non-profit sector as an organizational field. The purpose of this study is to investigate the link between the volunteers and the humanitarian non-profit organization they participate in. We conducted interviews with 12 board members from Amnesty International Sweden and the Swedish Red Cross Youth Organization to investigate how volunteers experience the formal and informal structures within the organizational context. The data is analyzed with Thornton and Ocasio’s theory of institutional logics and organizational theory with focus on the definition of formal structures. Blau’s social exchange theory is also used throughout the study to identify the interaction and mutual exchange between the volunteers and the organization. The results show that these volunteers value informal structures such as flexibility, the internal communication, group dynamics and autonomy within the organization to a greater extent than the formal structures the organizations provide. However, some volunteers have expressed feelings of confusion and lack of directives in relation to the responsibilities of their role and say they would benefit from more formal guidelines. On the other hand, a more formal structure within the organizations could clash with their ability to see the organization as adaptable. To further complicate the issue, many non-profit organizations portray themselves to prospective volunteers as flexible and emphasize on individualistic motives when recruiting for volunteers, such as future career and employability. As a result of this, many volunteers enter the organization with the expectation that they’ll have the freedom to do work which aligns with their personal motives. This in turn means they may be unprepared or run into issues with executing the work and responsibilities the organization expects from them. The most significant conclusion we reached is how the interplay between the volunteer and the organization is dependent on the individualistic volunteer’s ability to identify with the organization and by extent the purpose of the organization. This to balance out working solely off of personal motives which does not automatically get the organization to reach their mission

Spänning i vardagen : Konstruktion av miniverk i byggsatsform

Denna rapport sammanfattar det examensarbete som utförts 2012 på kandidatnivå av Erika Dahlström och Josefin Hult på Mälardalens Högskola i Eskilstuna. Examensarbetet har utförts i samarbete med ÅF Technology AB i Västerås. Projektets idé uppstod i ett tidigare fiktivt högskoleprojekt där tanken om ett vindkraftverk skulle vara intressant för privatpersoner kom till. Detta projekt har vidareutvecklat denna tanke och projektet har då utvecklats till att syfta till att undersöka om det finns en marknad för miniverk i byggsatsform avsett för privatpersoner, vad marknaden efterfrågar samt utveckla och konstruera en miniverksmast. Ett miniverk är ett vindkraftverk som vanligtvis inte behöver bygglov. För att kunna besvara hur marknaden ser ut har omfattande research utförts samt en marknadsundersökning. Från researchen sågs att det finns liknande befintliga produkter vilket innebar att projektets syfte gick från att konceptutveckla ett helt miniverk till att differentiera vår produkt från konkurrenternas. Detta gjordes genom att utveckla en mast som ger brukaren större valmöjligheter genom bland annat underlätta montering samt underhåll av sitt miniverk. Vid konstruktion har fokus lagts på knäckningsberäkningar då knäckning måste tas på största allvar för att undvika potentiellt allvarliga olyckor. Beräkningar har jämförts med simuleringar utförda i Solid Works vilket visar på att beräkningarna bör vara korrekta. Resultatet blev en 15,4 meter hög mast uppdelad i fem sektioner. Masten höjs och sänks genom en vev, block och vajrar. För att säkra att masten står stabilt finns åtta stycken stabiliserande vajrar fästa på två mastsektioner. Denna mast uppfyller majoriteten av de krav som ställts upp i en kravspecifikation. Att alla krav inte kunde uppfyllas beror på projektets begränsade tid. Dock har tydliga rekommendationer getts för att möjliggöra en vidareutveckling av detta resultat så att alla krav kan uppfyllas. Under hela produktutvecklingsprocessen har ett flertal olika produktutvecklingsverktyg använts som stöd och kvalitetssäkring i arbetet. Arbetet med projektet har fungerat väl, dock var en del frågor inom projektet mycket komplexa vilket innebar en del förseningar

Supporting Software Decision Meetings: Heatmaps for Visualising Test and Code Measurements

To achieve software quality it is critical to quickly understand the current test status, its changes over time as well as its relation to source code changes. However, even if this information is available in test logs and code repositories it is seldomly put to good use in supporting decision processes in software development. The amount of information is often large, is time consuming to extract and hard to monitor. This case study shows how visualisation and correlation between software measurements can support improvement discussions. In particular, simple heat maps were found to be effective to visualize and monitor changes and identify recurring patterns in the development of a space-bourn, embedded control system. Statistical analysis quantified the correlation between different sources of development data and heat maps then effectively focused the attention of stakeholders to importants parts of the system. Here the visual analysis was focused on post-project, historical data but we discuss how early identification based on dynamic data analysis could support more effective analysis, planning and execution of quality assurance. Based on our findings we state requirements on such an online, visual analysis system and present a prototype implementation that can help software measurements better support value-based decisions in software development