Three-Omega Thermal-Conductivity Measurements with Curved Heater Geometries

The three-omega method, a powerful technique to measure the thermal conductivity of nanometer-thick films and the interfaces between them, has historically employed straight conductive wires to act as both heaters and thermometers. When investigating stochastically prepared samples such as two-dimensional materials and nanomembranes, residue and excess material can make it difficult to fit the required millimeter-long straight wire on the sample surface. There are currently no available criteria for how diverting three-omega heater wires around obstacles affects the validity of the thermal measurement. In this Letter, we quantify the effect of wire curvature by performing three-omega experiments with a wide range of frequencies using both curved and straight heater geometries on SiO$_2$/Si samples. When the heating wire is curved, we find that the measured Si substrate thermal conductivity changes by only 0.2%. Similarly, we find that wire curvature has no significant effect on the determination of the thermal resistance of a $\sim$65 nm SiO$_2$ layer, even for the sharpest corners considered here, for which the largest measured ratio of the thermal penetration depth of the applied thermal wave to radius of curvature of the heating wire is 4.3. This result provides useful design criteria for three-omega experiments by setting a lower bound for the maximum ratio of thermal penetration depth to wire radius of curvature.Comment: 4 pages, 3 figure

Involvement that makes an impact on healthcare:Perceptions of the Swedish public

Aim: ‘Participation and influence in society’ is the first of 11 objective domains in Swedish public health policy. The aim of this article is to investigate the views of the Swedish general population on the impact of a range of health participation activities, and whether these views were associated with sociodemographic characteristics. Methods: The study utilizes a national representative survey of the Swedish population, aged 15 years and over (n = 1500). Results: Apart from voting in regional elections – which most of the respondents believed to be an influential way to make improvements in healthcare (74%) – respondents believed more in individual patient activities than activities associated with adopting a citizen role and acting collectively. A majority of respondents believed in the impact of replying to patient surveys (67%), making a complaint (61%), talking directly to staff (58%) or changing their healthcare provider (54%). Fewer believed in the impact of joining a patient organization (46%), taking part in a citizen council (35%) or joining a political party (34%). Beliefs in impact increased with educational attainment and decreased with age. Conclusions: The results suggest people have more confidence in the impact of participating as individual patients rather than collectively and as citizens. To ensure that activities enable ‘participation and influence in society’, complementary opportunities for collective involvement that also take into account under-represented voices such as those with a low level of education need to be developed

Vegetation as a heat reducing tool in the urban landscape : green infrastructure and heat reducing effects of vegetation

En av de svåraste utmaningarna dagens samhälle står inför idag är den globala uppvärmningen och de globala klimatförändringarna. Den globala uppvärmningen bidrar till stora temperaturförändringar i våra städer och Norden är den del av Europa som kommer att påverkas i störst utsträckning av denna klimatförändring. Den urbana miljön är i ständig utveckling. Städer förtätas och tätorter expanderas vilket innebär en ökad andel hårdgjorda ytor och en reducering av vegetativa ytor. I dagens läge består stadsmiljön framförallt av hårdgjorda ytor vilket innebär att de har en låg kylningseffekt och en låg infiltrationskapacitet. Detta bidrar till att det uppstår värmeöar i både städer och tätorter. Stadskärnor är där värmeön är som mest intensiv och på dagen kan lufttemperaturen ligga mellan 3-5°C högre än rurala områden. På natten kan denna temperaturskillnad stiga upp emot 12°C. Samhällets och ekosystemens förmåga att återhämta sig måste därför förstärkas. Grön infrastruktur har enligt flera studier visat sig vara en effektiv och socialt accepterad lösning för att förmildra värmeö-effekten, genom att reducera lufttemperaturen i den urbana miljön och på så sätt förstärka ekosystemtjänster i samhällen. Att integrera grön infrastruktur inom olika politiska områden erbjuder attraktiva lösningar på ekonomiska, sociala och miljömässiga problem i våra samhällen. Syftet med detta examensarbete är att undersöka hur olika system av grön infrastruktur påverkar temperaturen i urbana miljöer samt vilka faktorer som bidrar till en temperaturförändring. Litteraturstudien har därmed inriktat sig på vegetativa faktorer som albedo, evapotranspiration, modifiering av vindförhållande och skugga för att studera hur dessa påverkar temperaturen i staden. Litteraturstudien innefattar även hur olika typer av grön infrastruktur såsom träd, gröna tak, vertikala grön system och grönområden bidrar till värmereducering i sin omgivning. Målet är att bilda en uppfattning om hur stor inverkan grön infrastruktur har på klimatet i den urbana miljön och på så sätt bidra till ökad förståelse för olika aktörer inom grönyteplanering. Slutsatsen redovisar att faktorer som evapotranspiration, albedo, modifiering av vindförhållanden och skugga har en påverkan på hur vegetationen bidrar med en reducering av temperaturen i den urbana miljön. Vatten visade sig vara en avgörande faktor till hur mycket kylningseffekt vegetationen avger, då alla temperaturreducerande faktorer hos vegetationen är direkt beroende av tillgängligt vatten. De olika typerna av grön infrastruktur som studerades i litteraturstudien har alla en påverkan på det urbana klimatet avseende temperaturen på ytor och i luften. Däremot bidrar de olika typerna av gröna system på olika sätt med temperaturreduceringar i staden. Träd bidrar i större omfattning på kylning av omgivningstemperaturen genom evapotranspiration jämfört med gröna tak. Gröna tak bidrar däremot med isolering och beskuggning av takytan på byggnader. Alla typer av gröna system bidrar till en ökad värmereducering och en minskad energiförbrukning i staden, därmed är det kanske en fråga om utrymme istället för total värmereducerande effekt som städer bör ta fasta på

Numerical Simulations and Empirical Data for the Evaluation of Daylight Factors in Existing Buildings in Sweden

Point Daylight Factor (DFP) has been used for daylighting design in Sweden for more than 40 years. Progressive densification of urban environments, in combination with stricter regulations on energy performance and indoor environmental quality of buildings, creates complex daylight design challenges that cannot be adequately solved with DFP. To support a development of the current and future daylight indicators in the Swedish context, the authors have developed a comprehensive methodology for the evaluation of daylight levels in existing buildings. The methodology comprises sample buildings of various use and their digital replicas in 3D, detailed numerical simulations and correlations of diverse DF metrics in existing buildings, a field investigation on residents\u27 satisfaction with available daylight levels in their homes, and a comparison between the numerical and experimental data. The study was deliberately limited to the evaluation of DF metrics for their intuitive understanding and easy evaluation in real design projects. The sample buildings represent typical architectural styles and building technologies between 1887 and 2013 in Gothenburg and include eight residential buildings, two office buildings, two schools, two student apartment buildings, and two hospitals. Although the simulated DFP is 1.4% on average, i.e., above the required 1%, large variations have been found between the studied 1200 rooms. The empirical data generally support the findings from the numerical simulations, but also bring unique insights in the residences\u27 preferences for rooms with good daylight. The most remarkable result is related to kitchens, typically the spaces with the lowest DF values, based on simulations, while the residents wish them to be the spaces with the most daylight. Finally, the work introduces a new DF metric, denoted DFW, which allows daylighting design in early stages when only limited data on the building shape and windows\u27 arrangement are available

An economic and logistical analysis of increased storage capacity and structuring of storage at Domsjö Fiber AB : a design of Domsjö Fibers bearing surfaces

Skogsbrukets industrier kräver ofta en stor lagerhållningskapacitet. Kostnaderna för dessa lager är ofta höga och inte sällan är lagringsplatserna för virket inte genomtänkta, vilket leder till att allt fler företag börjar se över sin internlogistik. Domsjö Fibers huvudsakliga uppgift är att försörja ägarbolagen med råvara. Företaget har uppmärksammat att inlåsningseffekter förekommer på lagerytorna och vill undersöka hur dessa effekter kan minimeras utan att minska lagerkapacitet. Syftet med studien var att ta fram ett antal handlingsalternativ för en ny lagerstruktur åt Domsjö Fiber AB och även göra en ekonomisk redovisning för upprustningskostnader av nya lagerytor för att kompensera för omstruktureringen av deras befintligt lager. I studien utformades med hjälp av inmätningar i ArcMap tre handlingsalternativ för att tillgodose Domsjö Fiber ABs behov med varierande prioriteringar. Det första alternativet prioriterade att lösa de inlåsningseffekter som Domsjö Fiber AB hade, det andra alternativet fokuserade på att lagra så stora virkesarealer som möjligt på virkesplanen. Det tredje alternativet hade samma fokus som alternativ ett, bortsett från att man inte skulle ta bort den tågräls som finns på virkesplan idag. Alternativen medförde kostnadsförändringar för truckarna. Studien visar då att de största besparingarna i transportkostnader för timmertruckarna resulterade i 99788kr/år p.g.a. minskade transportsträckor. Det alternativ som ansågs som det val som ger bäst resultat är efter undersökning alternativ ett, med den lilla verkstaden som finns på virkesplanen borttagen. Detta för att man då utan lagerförluster kan lagra virket utan inlåsningseffekter och minska sina transportkostnader. Efter upprättande av en ekonomisk kalkyl bedöms kostnaden för att upprusta de idag delvis obrukbara lagerytorna till 5,7 milj.kr, förutsatt att detta görs internt av Domsjö Fiber AB.De osäkerheter som bör klargöras i praktiken av Domsjö Fiber AB är hur mycket en saneringsutredning kan komma att påverka priset för upprustningen.Forestry industries often require a large storage capacity. The cost of these stocks are often high and the wood yard surfaces are often not very well planned, and because of this more companies start to review their internal logistics. Domsjö Fiber AB is owned by Övik Energi AB and Domsjö Fabriker AB and their main purpose is to support the holding companies with raw material. The company has noted that lock-in effects occur on the bearing surfaces and would like to examine how these effects can be minimized without reducing storage capacity. The purpose of the study was to develop a number of options for a new stock structure to Domsjö Fiber AB, and also to make a financial report for the renovation costs of new storage surfaces to compensate for the restructuring of the existing stock surfaces. Three different options was designed with the tool ArcMap, to meet Domsjö Fiber AB’s needs with varying priorities. The first option prioritized solving the lock-in effects Domsjö Fiber AB was having, the second option focused on storing as much timber as possible in the timber field, without lock-in effects taken into account. The third option had the same focus as the first option, except that it would not remove the railroad available on the wood yard today. The different options entailed changes in costs for the log-handlers, the study will show that the largest savings in transportation costs for log-handlers resulted in 99788kr/year due to reduced transportation distances. The option that’s considered as the choice that gives the best results are after studying the different alternatives option one, with the small workshop located in the timber field deleted. This because you can store the timber without the lock-in effects and reduce their transportation costs without any losses of inventory. After establishing an economic analysis the cost to renovate the now partly unusable bearing surfaces ended up at a cost of 5700 000 kr , provided that this is done internally by Domsjö Fiber AB. The uncertainties that should be made clear in the practice of Domsjö Fiber AB is to do a clean-up inquiry, which may come to affect the price of rearmament

Disambiguating the Similar: Investigating Pattern Separation in Medial Temporal Lobe Structures Using Rodent Models

This dissertation investigates the mechanisms underlying pattern separation, using rodent models and behavioural tasks that assess the use of representations for similar stimuli. Pattern separation is a theoretical mechanism involving the transformation of inputs into output representations that are less correlated to each other. Because of this orthogonalizing process, similar experiences are stored as discrete non-overlapping representations. Studying pattern separation emphasizes the important but often overlooked fact that successful memory involves more than just remembering events over a period of time, but also differentiating between similar memories. Through a series of experiments this dissertation adds support to the literature that the dentate gyrus (DG) subregion of the hippocampus is important for pattern separation when encoding spatial and contextual inputs. Using the Spontaneous Location Recognition (SLR) task it is shown the brain-derived neurotrophic factor (BDNF) can improve performance by acting via N-methyl-D-aspartate (NMDA) glutamate receptors in the DG and adult-born hippocampal neurons. Manipulating the level of neurogenesis by inhibiting Wnt signalling or by administering acyl-ghrelin systemically is shown to impair and enhance performance on SLR, respectively. Using a novel exposure paradigm in combination with SLR, it is demonstrated for the first time that the relationship between pattern separation and neurogenesis may be reciprocal, such that inhibiting neurogenesis impairs pattern separation, enhancing neurogenesis improves pattern separation, and performing pattern separation enhances the production or survival of adult-born hippocampal neurons. Finally, it is shown that the $TgTau^{P301L}$ mouse model of dementia exhibits spatial and object recognition memory impairments once aged, recapitulating a dementia-like phenotype. Understanding the mechanisms that contribute to effective pattern separation may help elucidate the processes underlying the memory impairment experienced by AD patients. This dissertation concludes with a critical discussion about whether pattern separation can be studied using behavioural paradigms.Gates Cambridge; NSERC; St. John’s Colleg

MASQOT: a method for cDNA microarray spot quality control

BACKGROUND: cDNA microarray technology has emerged as a major player in the parallel detection of biomolecules, but still suffers from fundamental technical problems. Identifying and removing unreliable data is crucial to prevent the risk of receiving illusive analysis results. Visual assessment of spot quality is still a common procedure, despite the time-consuming work of manually inspecting spots in the range of hundreds of thousands or more. RESULTS: A novel methodology for cDNA microarray spot quality control is outlined. Multivariate discriminant analysis was used to assess spot quality based on existing and novel descriptors. The presented methodology displays high reproducibility and was found superior in identifying unreliable data compared to other evaluated methodologies. CONCLUSION: The proposed methodology for cDNA microarray spot quality control generates non-discrete values of spot quality which can be utilized as weights in subsequent analysis procedures as well as to discard spots of undesired quality using the suggested threshold values. The MASQOT approach provides a consistent assessment of spot quality and can be considered an alternative to the labor-intensive manual quality assessment process

Glucose regulation and pain in older people-The Helsinki Birth Cohort Study

Aims: To assess if individuals with diabetes or prediabetes report more pain or have increased use of pain medication compared to normoglycaemic individuals. Methods: Using cross-sectional data, we studied 928 men and 1075 women from the Helsinki Birth Cohort Study in 2001-2004 at a mean age of 61.5 years. Glucose regulation was assessed with a 2-h 75 g oral glucose tolerance test, and applying World Health Organization criteria, participants were defined as having normoglycaemia, prediabetes (impaired fasting glucose or impaired glucose tolerance), newly diagnosed diabetes or previously diagnosed diabetes. Self-reported pain intensity and interference during the previous 4 weeks was estimated using the RAND 36-Item Health Survey 1.0. Information on use of pain medication during the past 12 months was obtained from the Social Insurance Institution of Finland. Results: There was no difference in pain intensity or interference between glucose regulation groups for neither men nor women after adjusting for covariates (age, body mass index, education years, Beck Depression Inventory and physical activity). In addition, use of pain medication was similar between glucose regulation groups. Conclusions: Although pain is a common symptom in the general population, impairments in glucose regulation alone does not seem to increase pain among older individuals. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of Primary Care Diabetes Europe. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe