Resonance de-enhancement in the 2<SUP>1</SUP>A<SUB>g</SUB> state of trans-azobenzene

We analyze the origin of de-enhancement for a number of vibrational modes in the 21 A g excited state of trans-azobenzene. We have used the time-dependent wave packet analysis of the RR intensities by including the multimode damping effects in the calculation. This avoids the use of unrealistically large values for the damping parameter. It is concluded that the de-enhancement is caused by the interference between the two uncoupled electronic states, and that the intensities observed under the so-called symmetry forbidden 21 A g ← 11 A g transition are purely due to resonance excitation. It is also observed that the use of the time-dependent approach to study the de-enhancement effects caused by multiple electronic states on the RR intensities is not necessarily useful if one is interested in the structural dynamics

Structure of the triplet excited state of bromanil from time-resolved resonance Raman spectra and simulation

Time-resolved resonance Raman (TR3) spectroscopy has been used to study the structure of the triplet excited state of bromanil. These experimental results were then simulated using parameters from density functional theoretical (DFT) calculations and wave packet dynamics, in order to understand the structure and mode-specific displacements of the resonant excited state. The transition dipole moments and the energy separation of the T1 and Tn states were obtained from time-dependent DFT calculations. We have demonstrated application of the technique to tetrabromo-p-benzoquinone. From our calculations, the observed T1->Tn absorption spectrum has been assigned to the 3Bg&#8594;3Bu transition. The geometry has been optimized for the resonant higher triplet state, Tn, and is found to be in good agreement with the predictions of the wave packet dynamical simulations. Mode-specific displacements of the triplet state geometry have been obtained from simulations and these have been rationalized with respect to the molecular orbital involved. Thus, we have demonstrated that from the simulations of the experimental TR3 spectral data, valuable additional information can be derived on the structure of the transient states that may then be used for elucidation of structure-reactivity correlation in the future

TILLBLIVELSER : En trasslig berättelse om design som normkritisk praktik

The increasing awareness of norm-critical perspectives (in society, academia and industry) brings with it the need to develop methods to ensure they can be implemented in practice. This thesis discusses how the role of design contributes to and maintains norms, and shows how design as a norm critical practice has great potential to bridge the gap between theory and practice in norm-critical work. This potential lies in using design as a peda-gogic tool that can concretize and make understandable what would otherwise be perceived as complex, unclear or remote. The thesis pays special attention to the role of artefacts in the creation of the stories of the world. The discursive design thing is introduced as a tool to visualize norms and to create discussion. The three-dimensional, physical thing exposes us to a more diverse experience of norms than when we just address them in words or pictures.The empirical work in this thesis stems from five research projects that differ from each other and were carried out under varied conditions. The projects have tackled a range of problems and power relationships. However, together they draw a complex picture of how norms arise, overlap and constantly change over time, place and space – and how design can be used to support or disrupt this process.By revisiting the projects, it becomes clear how the researcher’s position and actions (or non-actions) shape the norm development process. This results in an insight that meaning can not be construc-ted from an outside perspective, but is a constant ”becoming” that occurs in an entanglement of relationships arising between different bodies, both human and non-human. As a norm critical perspective implies paying attention to power relationships, it also assumes a power critical approach to the production of meaning extracted from the norm-critical work, and that we – as researchers and designers – take responsibility for our prevail by highlighting our own bodies and gaze.The thesis therefore proposes the concept of diffraction as an approach to the production of meaning in norm critical design practices. A diffractive approach enables an understanding of how the production of meaning occurs in various coincidences, but also how our own interventions shape the story. It opens up to the realization that parallel narratives are possible and thus becomes a tool to break away from the linear understanding framework and offer an exploration of alternative thought patterns. A diffractive approach to the production of meaning is thus also a tool to pro-mote increased creativity.QC 20170222</p

TRÅDLÖSA SENSORNÄTVERK I JORDBRUKET

År 2050 väntas jorden nå en befolkningsmängd på nio miljarder. För att kunna livnära den växande befolkningen måste produktionen av mat öka med 60% fram till dess, vilket ställer höga krav på världens jordbruk. Samtidigt är världens mark- och vattenresurser begränsade och det ställs allt högre krav på hållbar tillväxt och miljömedvetenhet. Produktionsökningen av mat måste ske utan att jordens resurser sätts på spel, vilket betyder att jordbruket måste minska bevattningsmängden, minimera användningen av miljöförstörande tillsatsmedel och bättre utnyttja knappa resurser. En lösning är att ta hjälp av trådlösa sensornätverk i jordbruket. Trådlösa sensornätverk handlar om att styckvis placera ett fåtal till flera tusen sensorer över jordbruksfälten. Sensorerna övervakar och mäter mark- och miljö egenskaperöver fältets olika delar i syfte att hjälpa en jordbrukare att fatta mer effektiva och underbyggda beslut. Genom att förstå fältets olika variationer kan en jordbrukare välja att rikta åtgärder, som bevattning eller besprutning, på specifika delar inom en större skörd istället för att behandla hela fältet som en enda enhet. Tanken är att jordbrukare till följd kan behandla sina skördar optimalt och därmed ökar produktionen av mat samtidigt som de minskar användningen av olika tillsatsmedel vilket resulterar i hållbar tillväxt. Följande rapport undersöker om och hur trådlösa sensornätverk kan öka jordbrukarnas avkastning i skörden och samtidigt optimera användningen av vatten och tillsatsmedel. Eftersom implementering av trådlösa sensornätverk i jordbruket ännu befinner sig på konceptstadiet undersöker rapporten även drivkrafter och hinder för implementering. Rapporten identifierar mer effektiv användning av resurser som bevattning, gödning och skadedjursbekämpning som de allra tydligaste fördelarna med trådlösa sensornätverk. Riktade åtgärder som minskar resursslöseri antas minska kostnader och samtidigt minska avtrycken på miljön. Det finns däremot flera utmaningar med att erhålla adekvata mått på avkastningsökningen till följd av trådlösa sensornätverk. En svårighet är att isolera effekten av trådlösa sensornätverk i jordbruket då jordbruksmiljön och skörden varierar, till skillnad från andra produktionsmiljöer. Rapporten undersöker vidare utmaningar och drivkrafter för implementering av trådlösa sensornätverk både ur ett tekniskt perspektiv men även ur ett användarperspektiv. De tekniska utmaningarna skiljer sig beroende på användningsområde men innefattar bland annat sensorernas robusthet, storlek och energiförbrukning. Drivkrafter, utöver ökad avkastning och resurseffektivisering, som identifierades var bland annat jämnare och säkrare skörd, tillgång till rådgivning och support samt samhällets krav på miljömedvetenhet. Implementering av trådlösa sensornätverk kräver tvärvetenskaplig förståelse och broar mellan forskare, ingenjörer och jordbrukare behöver upprättas innan trådlösa sensornätverk kan implementeras för kommersiellt bruk.By 2050 the world population is estimated to reach nine billion. In order to feed the growing population the food production must increase by 60% until 2050, which puts high pressure on agriculture production. Land and water resources are, at the same time, limited and sustainable growth and environmental awareness is in the limelight. Agriculture must increase the production of food without putting earth’s resources at risk, which means that agriculture must reduce irrigation, minimize the use of polluting additives and make the most of scarce resources. One solution is to use wireless sensor networks in agriculture. By placing a few, up to several thousand, sensors over agricultural fields the sensors can collect information about environmental and physical attributes on a field to improve monitoring and decision-making. By understanding how the field varies, farmers can irrigate or add pesticides on specific parts in a field instead of processing the field as a single unit. The idea is to help farmers to treat their crops optimally and by that increases food production while at the same time reducing the use of various additives, which in the end generates sustainable growth. The following report examines whether and how wireless sensor networks can increase farm yields in the harvest while at the same time optimizing the use of water and additives. Since the implementation of wireless sensor networks in agriculture is still in an initial stage, the report also identifies drivers and barriers for implementation. The report identifies more efficient use of resources such as irrigation, fertilization and pest control as the most obvious benefits of wireless sensor networks. Targeted measures to reduce waste of resources assumed save costs while reducing the footprint on the environment. However, there are several challenges in obtaining adequate measure of the yield increase due to wireless sensor networks. One difficulty is to isolate the effect of wireless sensor networks in agriculture since the environment and harvest varies, unlike other production environments. The report also identifies challenges and drivers for implementing wireless sensor networks, both from a technical perspective but also from a user perspective. The technical challenges differ depending on the application, but include sensor robustness, size and power consumption. Driving forces, beyond increased yields and resource efficiency, include reliable harvest, support access and societal demands on environmental awareness. Implementation of wireless sensor networks requires inter disciplinary understanding. Bridges between scientists, engineers and farmers need to be established before the wireless sensor networks can be implemented for commercial use