Small residential courtyards big problems : the density ideal's effects on the maintenance work and long-term sustainability

Av FN:s 17 globala mål för hållbar utveckling finns två mål av särskilt intresse för landskapsarkitekturen i kontexten hållbar stadsplanering, mål 11: Hållbara städer och samhällen samt mål 15: Ekosystemtjänster och biologisk mångfald. För att uppnå dessa mål krävs att stadsplanerare hittar långsiktigt hållbara lösningar. Den samtida stadsplaneringens vision om ett hållbart samhälle stavas förtätning, ett stadsbyggnadsideal som präglat den svenska stadsplaneringen i över 40 år. Med förtätade städer följer kompakta bostadsgårdar. I många kommuner tillämpas verktyget grönytefaktor, en räknemodell som hjälper planeringssektorn att tillgodose tillräckligt med ändamålsenliga grönytor på kompakta bostadsgårdar. Men i dagsläget saknas uppföljning, tillika utvärdering, av de bostadsgårdar som gestaltats utifrån denna princip. Å andra sidan finns kunskap att hämta från förvaltningssektorn, vars uppgift är att sköta om och utveckla dessa bostadsgårdar, som en del i ledet av en hållbar stadsutveckling. Genom kvalitativa djupgående intervjuer med representanter från förvaltningssektorn i Uppsala får man ett nytt perspektiv av täthetsidealets och grönytefaktorns effekter. Slutsatsen är att till följd av förtätning och tillämpande av grönytefaktor skapas mångfunktionella bostadsgårdar, vilket leder till en småskalig utformning. Det leder i sin tur till en komplex förvaltning. Detta äventyrar den hållbara stadsutvecklingen. Vidare forskning inom detta område blir viktigt för att finna lösningar på hur samspelet kan stärkas.Of the UN's 17 global goals for sustainable development, there are two goals of particular interest to landscape architecture in the context of sustainable urban planning, goal 11: Sustainable cities and communities and goal 15: Ecosystem services and biodiversity. To achieve these goals, urban planners must find long-term sustainable solutions. Contemporary urban planning's vision of a sustainable society is called densification, an urban planning ideal that has characterized Swedish urban planning for over 40 years. With denser cities comes denser residential courtyards. In many municipalities, the green area factor tool is applied, a model that helps the planning sector to accommodate sufficient, and appropriate, green areas on densified residential courtyards. However, there is currently a lack of follow-up, as well as evaluation, of the residential courtyards designed based on this principle. On the other hand, there is knowledge to be gained from the maintenance sector, whose task is to look after and develop these residential courtyards, as part of the process of sustainable urban development. Through qualitative in-depth interviews with representatives from the maintenance sector in Uppsala, a new perspective is obtained on the effects of the densification ideal and the green space factor. The conclusion is that as a result of densification and application of the green space factor, multifunctional residential courtyards are created, which leads to a small-scale design. This in turn leads to complex management. This endangers sustainable urban development. Further research in this area will be important to find solutions for how the interaction can be strengthened

Lipid phase behaviour under steady state conditions

At the interface between two regions, for example the air–liquid interface of a lipid solution, there can arise non-equilibrium situations. The water chemical potential corresponding to the ambient RH will, in general, not match the water chemical potential of the solution, and the gradients in chemical potential cause diffusional flows. If the bulk water chemical potential is close to a phase transition, there is the possibility of forming an interfacial phase with structures qualitatively different from those found in the bulk. Based on a previous analysis of this phenomenon in two component systems (C. Åberg, E. Sparr, K. J. Edler and H. Wennerström, Langmuir, 2009, 25, 12177), we here analyse the phenomenon for three-component systems. The relevant transport equations are derived, and explicit results are given for some limiting cases. Then the formalism is applied conceptually to four different aqueous lipid systems, which in addition to water and a phospholipid contain (i) octyl glucoside, (ii) urea, (iii) heavy water, and (iv) sodium cholate as the third component. These four cases are chosen to illustrate (i) a method to use a micelle former to transport lipid to the interface where a multi-lamellar structure can form; (ii) to use a co-solvent to inhibit the formation of a gel phase at the interface; (iii) a method to form pure phospholipid multi-lamellar structures at the interface; (iv) a method to form a sequence of phases in the interfacial region. These four cases all have the character of theoretically based conjectures and it remains to investigate experimentally whether or not the conditions can be realized in practice.TS 11.09.1