In‐plane photocurrent spectroscopy in GaAs-AlAs superlattices

The in‐plane photoconductivity of GaAs‐AlAs superlattices on GaAs substrates is experimentally studied as a function of the incident photon energy at different temperatures and light intensities. Superlattice and substrate are electrically isolated by a thick  Al0.3Ga0.7As barrier but connected through penetrating contacts. Depending on the transport properties of the two subsystems pseudo‐negative photoconductivity can be observed, i.e., at the absorption maximum of the superlattice the photocurrent exhibits a minimum

Gestaltningsförslag av utemiljö vid Villa Roos Park

I det här examensarbetet undersöks hur en avgränsad del av utemiljön vid Vardaga Villa Roos Park (i regi av omsorgsföretaget Vardaga, fortsättnings vis benämnt Villa Roos Park), ett särskilt boende för personer med demenssjukdom, kan utvecklas med stöd av EBD, evidensbaserad design av utemiljöer i vårdsammanhang (Bengtsson et al., 2018). Frågeställningarna som besvaras är hur en avgränsad del av utemiljön vid Villa Roos Park kan utvecklas med stöd av evidens baserad design och vilka växter som är lämpliga utifrån målgruppens särskilda behov. Syftet har varit att utarbeta en övergripande designlösning för att visa hur utemiljön i högre utsträckning kan användas och integreras i aktiviteter med fokus på växtlighetens positiva betydelse för upplevelsen av trädgården. Utgångspunkten för kandidatarbetet har varit kursen Hälsoträdgårdar, inom pro grammet Trädgårdsingenjör design, SLU. Där gav en fördjupningsdel möjlighet att lära mer om personer med demenssjukdom och deras behov i kontakt med utemiljön. Arbetet inleds med en kort beskrivning av begreppet hälsoträdgård. Fakta om demenssjukdomar och hur personer påverkas av demenssjukdom har också sammanställts, för förståelse av målgruppens behov. En teoretisk bakgrund beskriver de analysmodeller som använts (se sidan 3). Arbetets resultatdel fokuserar kring designprocessen med stöd av EBD (Bengtsson et al., 2018). Processen har genomförts i tre steg där steg ett inbegrep undersökning av miljön med platsbesök, platsdokumentation och samtal med verksamhetschef om önskemål för utveckling av den avgränsade delen av trädgården. Resultat av undersökningar och information sammanställdes. Ett antal brister i den nuvarande utemiljön identifierades och ett antal önskemål om trädgårdens användning framkom. Utifrån indelning under rubrikerna Brister i utemiljön och Önskemål för trädgårdens utveckling gavs i steg två förslag till åtgärder. Dessa samlades under tre teman med utgångspunkt i QET, Quality evulation tool (Bengtsson & Grahn, 2014). QET-verktyget behandlar platsens möjlighet att anpassas utifrån evidensbaserade designteorier i vårdsammanhang. I det tredje steget och som resultat av designprocessen presenteras ett gestaltningsförslag i form av en övergripande illustrationsplan med tillhörande växtförslag. Gestaltningen bygger på de tre temana, utifrån vilka fem trädgårdsrum skapats: Gångstråk, Innergård, Stilla trädgård, Köksträdgård och Regnträdgård. Trädgårdsrum har skapats för sociala aktiviteter, sinnesstimulans och möjlighet till motion såväl som för lugn och ro i en mer kravlös miljö. Genomgående läggs fokus på orienterbarhet och säkerhet (ibid). Flera faktorer har beaktats gällande växtvalen: Trädgården har försetts med en vintergrön struktur och växter har valts som tydliggör årstidsväxlingar och skapar skönhetsvärden året om. Växter har valts för att vara välbekanta (Grönt kulturarv 2020) och för färg, doft och smak. Växter som gynnar pollinatörer och bidrar till en upplevelserik och varierad miljö är också betydelsefulla. I köksträdgården kan en mängd aktiviteter ske knutna till odling, skötsel och skörd. Frukt, bär, grönsaker och örter är därför viktiga inslag i trädgården. Växters behov utifrån ståndort, skötsel och särskilda växtval för översvämningsytan har varit andra faktorer att beakta, liksom att undvika giftiga växter (Giftinformationscentralen 2014) och alltför pollenspridande växter (Astma- & allergilinjen u. å.). Resultatet av arbetet tydliggjorde att en mängd faktorer behöver beaktas gällande utformning av miljöer för personer med demens. Växtlighetens positiva betydelse för utemiljöer i vård sammanhang kan inte nog understrykas. Om rätt förutsättningar ges vid utformandet av utemiljön, så att den kan samspela med såväl omgivning som arkitektur på bästa sätt, ges den även möjlighet att stödja varje brukare utifrån individuella behov.This thesis examines how a limited part of the outdoor environment at Vardaga Villa Roos Park (under the auspices of the care company Vardaga, hereafter referred to as Villa Roos Park), a nursery home for people suffering from dementia, can be developed with the support of EBD, evidence-based design of outdoor environments in care context (Bengtsson et al., 2018). The questions that are answered are how a limited part of the outdoor environment at Villa Roos Park can be developed with the support of evidence-based design and which plants that are suitable based on the target group’s special needs. The purpose has been to prepare an overall design solution to show how the outdoor environment can be used and integrated to a greater extent in activities with a focus on the positive significance of vegetation for the experience of the garden. The starting point for the bachelor’s thesis has been the course Health Gardens, within the program Garden Engineer Design, SLU. There, an in-depth section provided the opportunity to learn more about people with dementia and their needs in contact with the outdoor environment. The introdction of the thesis is a brief description of the concept of health gardens. Facts about dementia and how people are affected by dementia have also been compiled, to understand the needs of the target group. A theoretical background describes the analysis models used (see page 3). The results part of the work focuses on the design process with the support of EBD (Bengtsson et al., 2018). The process has been implemented in three steps, where step one included an investigation of the environment with site visits, site documentation and conversations with the operations manager about wishes for the development of the delimited part of the garden. The result of surveys and information were compiled. A number of deficiencies in the current outdoor environment were identified and a number of requests for the use of the garden emerged. Based on the division under the headings Deficiencies in the outdoor environment and Requests for garden development, proposals for souloutions were given in step two. These were assembled under three themes based on QET, Quality evulation tool (Bengtsson & Grahn, 2014). The QET tool processes the site’s ability to adapt based on evidence-based design theories in healthcare contexts. In the third step and as a result of the design process, a design proposal is presented in the form of an overall illustration plan with associated plant proposals. The design is based on the three themes, from which five garden rooms have been created: Walkway, Courtyard, Quiet garden, Kitchen garden and Rain garden. Garden rooms have been created for social activities, sensory stimulation and the opportunity for exercise as well as for peace and quiet in a more unpretentious environment. Throughout, the focus is on orientability and security (ibid). Several factors have been taken into account regarding the plant choices: The garden has been provided with an evergreen structure and plants have been chosen that clarify seasonal changes and create beauty values all year round. Plants have been chosen to be familiar (Grönt kulturarv 2020) and for color, aroma and taste. Plants that benefit pollinators and contribute to an experiential and varied environment are also important. In the kitchen garden, a variety of activities can take place related to cultivation, care and harvesting. Fruits, berries, vegetables and herbs are therefore important elements in the garden. The needs of plants based on location, care and special plant choices for the rain garden have been other factors to consider, as well as avoiding poisonous plants (Giftinformationscentralen 2014) and overly pollen-spreading plants (Astma- & allergilinjen u. å.). The results of the work made it clear that a number of factors need to be taken into account regarding the design of environments for people with dementia. The positive significance of vegetation for outdoor environments in care contexts cannot be overemphasized. If the right conditions are given for designing a health-care garden, so that it can interact with both the environment and architecture in the best way, it can also support each user based on individual needs

Den sista vilan : vad kännetecknar en rofylld begravningsplats?

This essay examines the criteria for a peaceful cemetery. First there is a short history of the Swedish funeral place. After that follows the definitions of a peaceful place according to environmental psychology. From these definitions an analysis method is constructed for identifying a peaceful cemetery. The analysis method contains six criteria, shape of the entrances, existence of sound, vegetation character, the cemetery’s demarcation, the cemetery’s management and what feeling the cemetery mediates. The analysis method is put into practice on three cemeteries, Överklinten cemetery, Stockholm forest cemetery and the old cemetery in Malmö. The results are then put together and show that the two most important criteria for a peaceful place are vegetation and sound. Are these two criteria not fulfilled the cemetery is not a peaceful place. The simplest step to take is to change the vegetation since it has with the actual area to do. Most of the cemeteries have grounds which are not used for burying. These places can be of use for planting shrubs and trees to increase the quality of the vegetation. It is much more difficult to change the sound because the noise often has its origin outside the cemetery. The only way to change the sound is to shut of the cemetery with some kind of shield

Tiedepolitiikan myyttejä ja tosiasioita

acceptedVersionNon peer reviewe

Estimation of the Dose and Dose Rate Effectiveness Factor

Current models to estimate radiation risk use the Life Span Study (LSS) cohort that received high doses and high dose rates of radiation. Transferring risks from these high dose rates to the low doses and dose rates received by astronauts in space is a source of uncertainty in our risk calculations. The solid cancer models recommended by BEIR VII [1], UNSCEAR [2], and Preston et al [3] is fitted adequately by a linear dose response model, which implies that low doses and dose rates would be estimated the same as high doses and dose rates. However animal and cell experiments imply there should be curvature in the dose response curve for tumor induction. Furthermore animal experiments that directly compare acute to chronic exposures show lower increases in tumor induction than acute exposures. A dose and dose rate effectiveness factor (DDREF) has been estimated and applied to transfer risks from the high doses and dose rates of the LSS cohort to low doses and dose rates such as from missions in space. The BEIR VII committee [1] combined DDREF estimates using the LSS cohort and animal experiments using Bayesian methods for their recommendation for a DDREF value of 1.5 with uncertainty. We reexamined the animal data considered by BEIR VII and included more animal data and human chromosome aberration data to improve the estimate for DDREF. Several experiments chosen by BEIR VII were deemed inappropriate for application to human risk models of solid cancer risk. Animal tumor experiments performed by Ullrich et al [4], Alpen et al [5], and Grahn et al [6] were analyzed to estimate the DDREF. Human chromosome aberration experiments performed on a sample of astronauts within NASA were also available to estimate the DDREF. The LSS cohort results reported by BEIR VII were combined with the new radiobiology results using Bayesian methods

Daily Eastern News: April 10, 2014

https://thekeep.eiu.edu/den_2014_apr/1007/thumbnail.jp