Load and Season Adapted Solar Collectors

In Sweden solar irradiation and space heating loads are unevenly distributed over the year. Domestic hot water loads may be nearly constant. Test results on solar collector performance are often reported as yearly output of a certain collector at fixed temperatures, e g 25, 50 and 75 C. These data are not suitable for dimensioning of solar systems, because the actual performance of the collector depends heavily on solar fraction and load distribution over the year.At higher latitudes it is difficult to attain high solar fractions for buildings, due to overheating in summer and small marginal output for added collector area. Solar collectors with internal reflectors offer possibilities to evade overheating problems and deliver more energy at seasons when the load is higher. There are methods for estimating the yearly angular irradiation distribution, but there is a lack of methods for describing the load and the storage in such a way as to enable optical design of season and load adapted collectors.This report describes two methods for estimation of solar system performance with relevance for season and load adaption. Results regarding attainable solar fractions as a function of collector features, load profiles, load levels and storage characteristics are reported. The first method uses monthly collector output data at fixed temperatures from the simulation program MINSUN for estimating solar fractions for different load profiles and load levels. The load level is defined as estimated yearly collector output at constant collector temperature divided be yearly load. This table may examplify the results:CollectorLoadLoadSolar Improvementtypeprofile levelfractionover flat plateFlat plateDHW 75 %59 %Load adaptedDHW 75 %66 %12 %Flat plateSpace heating 50 %22 %Load adaptedSpace heating 50 %28 %29 %The second method utilises simulations with one-hour timesteps for collectors connected to a simplified storage and a variable load. Collector output, optical and thermal losses, heat overproduction, load level and storage temperature are presented as functions of solar incidence angles. These data are suitable for optical design of load adapted solar collectors. Results for a Stockholm location indicate that a solar combisystem with a solar fraction around 30 % should have collectors that reduce heat production at solar heights above 30 degrees and have optimum efficiency for solar heights between 8 and 30 degrees.

Softproof och färghantering i designprocessen : Från skärm till tryck

Målet med detta examensarbete har varit att ge en överblick över de parametrar som påverkar möjligheten att upprätta ett färghanterat arbetsflöde. Ett färghanterat arbetsflöde ger möjlighet att förutsäga färgåtergivningen i trycksaker via softproof – skärmkorrektur. Examensarbetet belyser de problem och fallgropar som finns i arbetsflödet och hur de kan påverka relevansen för en bedömning av tryckresultat via softproof. Examensarbetet behandlar hur färgåtergivningen påverkas av betraktningsljus och omgivningsljus samt vikten av att arbeta med en kalibrerad bildskärm – en förutsättning för att kunna utföra en färgriktig softproof. Som utgångspunkt för examensarbetet har arbetsflödet på fyra företag i branschen använts och hur väl de uppfyller gällande standarder, ISO 3664 och ISO 12646. Genom ett visuellt test som utarbetats inom examensarbetet har arbetsmiljöns påverkan på färgseendet kunnat påvisas. Testet kan ge en vägledning om hur avvikelser från ISO 3664 och ISO 12646 i arbetsmiljön påverkar bedömningen av färger vid softproof och provtryck.

A fuzzy rule-based decision support system for Duodopa treatment in Parkinson

A decision support system (DSS) was implemented based on a fuzzy logic inference system (FIS) to provide assistance in dose alteration of Duodopa infusion in patients with advanced Parkinson’s disease, using data from motor state assessments and dosage. Three-tier architecture with an object oriented approach was used. The DSS has a web enabled graphical user interface that presents alerts indicating non optimal dosage and states, new recommendations, namely typical advice with typical dose and statistical measurements. One data set was used for design and tuning of the FIS and another data set was used for evaluating performance compared with actual given dose. Overall goodness-of-fit for the new patients (design data) was 0.65 and for the ongoing patients (evaluation data) 0.98. User evaluation is now ongoing. The system could work as an assistant to clinical staff for Duodopa treatment in advanced Parkinson’s disease.