Active cooling of low-concentrating hybrid PV/Thermal collectors

A series of measurements on the performance of solar cell string modules with low-concentrating CPC reflectors with a concentration factor C ˜ 4X have been carried out. To minimise the reduction in efficiency due to high cell temperatures, the modules were cooled. Four different way of cooling were tested:1) The thermal mass of the module was increased, 2) passive air cooling was used by introducing a small air gap between the module and the reflector, 3) the PV cells were cooled by a large cooling fin, 4) the module was actively cooled by circulating cold water on the back. The best performance was given with the actively cooled PV module which gave 2,2 times the output from a reference module while for the output from the module with a cooling fin the value was 1,8.Active cooling is also interesting due to the possibility of co-generation of thermal and electrical energy which is discussed in the paper. Simulations, based on climate data from Stockholm, latitude 59.4°N, show that there are good prospects for producing useful temperatures of the cooling fluid with only a slightly reduced performance of the electrical fraction of the PV thermal hybrid system.

Experimental performance of a string module in a CPC reflector cavity

The purpose of the work is to develop a cost effective semistationary CPC concentrator for a string PV-module. A novel method of using annual irradiation distribution diagram projected in a north-south vertical plane is developed. This method allows us easily to determine the optimum acceptance angle of the concentrator and the required number of annual tilts. Concentration ranges of 2-5x are investigated with corresponding acceptance angles between 5 and 15°. The concentrator should be tilted 2-6 times per year. Experiments has been performed on a string module of 10 cells connected in a series and equipped with a compound parabolic concentrator with C = 3.3X. Measurement show that the output will increase with a factor of 2-2.5 for the concentrator module, compared to a reference module without concentrator. If very cheap aluminium reflectors are used the costs for the PV-module can be decreased nearly by a factor of two.

Historiografisk metafiktion och faktion : Romantikens berättelse om den förstenade gruvdrängen Fet-Mats i två postmoderna versioner

Fet-Mats är den gruvdräng som omkom och försvann i en rasolycka i Falu koppargruva under 1670-talet och vars kropp upptäcktes välbevarad, med fortfarande ungdomligt utseende, mer än fyra årtionden senare 1719. Han igenkändes då av sin trolovade - nu en gammal gumma. På grund av den märkligt bibehållna kroppen och det hisnande ögonblick då den åldrade kvinnan återsåg sin ungdoms kärlek, blev Fet-Mats och hans historia snabbt känd, även internationellt. Den spreds under 1800- och 1900-talen i Europa som novell och poesi, dramatik och opera. Även idag berättas historien om Fet-Mats både utomlands och i Sverige. Intresset för historien är rentav i växande. Orsaken härtill är omdaningen under senare år av Falu gruva från storindustri till musealt världsarv, från malmbrytning till turistorienterad upplevelseindustri. Fet-Mats-berättelsen bildar centrum i denna upplevelseindustri. I mitt paper diskuteras detta förhållande samt den nutida Fet-Mats-epikens karakteristika i ett semiotiskt, narratologiskt och tematiskt perspektiv. Jag finner bl.a. att Fet-Mats-berättandet idag, på ett annat sätt än tidigare, äger en flermedial karaktär och formulerar det postmoderna tillståndets centrala tematik: representationens kris. Jag fokuserar särskilt på två berättelser med anknytning till Fet-Mats-motivet: Julian Barnes historiografiska metafiktion The Story of Mats Israelson (2004) och det dramadokumentära seriealbumet Fet-Mats: en gruvdrängs hemska öde (2005).

Health system context and implementation of evidence-based practices-development and validation of the Context Assessment for Community Health (COACH) tool for low- and middle-income settings

Background: The gap between what is known and what is practiced results in health service users not benefitting from advances in healthcare, and in unnecessary costs. A supportive context is considered a key element for successful implementation of evidence-based practices (EBP). There were no tools available for the systematic mapping of aspects of organizational context influencing the implementation of EBPs in low- and middle-income countries (LMICs). Thus, this project aimed to develop and psychometrically validate a tool for this purpose. Methods: The development of the Context Assessment for Community Health (COACH) tool was premised on the context dimension in the Promoting Action on Research Implementation in Health Services framework, and is a derivative product of the Alberta Context Tool. Its development was undertaken in Bangladesh, Vietnam, Uganda, South Africa and Nicaragua in six phases: (1) defining dimensions and draft tool development, (2) content validity amongst in-country expert panels, (3) content validity amongst international experts, (4) response process validity, (5) translation and (6) evaluation of psychometric properties amongst 690 health workers in the five countries. Results: The tool was validated for use amongst physicians, nurse/midwives and community health workers. The six phases of development resulted in a good fit between the theoretical dimensions of the COACH tool and its psychometric properties. The tool has 49 items measuring eight aspects of context: Resources, Community engagement, Commitment to work, Informal payment, Leadership, Work culture, Monitoring services for action and Sources of knowledge. Conclusions: Aspects of organizational context that were identified as influencing the implementation of EBPs in high-income settings were also found to be relevant in LMICs. However, there were additional aspects of context of relevance in LMICs specifically Resources, Community engagement, Commitment to work and Informal payment. Use of the COACH tool will allow for systematic description of the local healthcare context prior implementing healthcare interventions to allow for tailoring implementation strategies or as part of the evaluation of implementing healthcare interventions and thus allow for deeper insights into the process of implementing EBPs in LMICs.