Förgasning-Gasmotor för småskalig kraft-värme

In a joint project, Linnaeus University in Växjö (LNU) and the Faculty of Engineering at Lund University (LTH) were commissioned by the Swedish Energy Agency to make an inventory of the techniques and systems for small scale gasifier-gas engine combined heat and power (CHP) production and to evaluate the technology. Small scale is defined here as plants up to 10 MWth, and the fuel used in the gasifier is some kind of biofuel, usually woody biofuel in the form of chips, pellets, or sawdust. The study is presented in this report. The report has been compiled by searching the literature, participating in seminars, visiting plants, interviewing contact people, and following up contacts by e-mail and phone. The first, descriptive part of the report, examines the state-of-the-art technology for gasification, gas cleaning, and gas engines. The second part presents case studies of the selected plants: Meva Innovation’s VIPP-VORTEX CHP plant DTU’s VIKING CHP plant Güssing bio-power station Harboøre CHP plant Skive CHP plant The case studies examine the features of the plants and the included unit operations, the kinds of fuels used and the net electricity and overall efficiencies obtained. The investment and operating costs are presented when available as are figures on plant availability. In addition we survey the international situation, mainly covering developing countries. Generally, the technology is sufficiently mature for commercialization, though some unit operations, for example catalytic tar reforming, still needs further development. Further development and optimization will probably streamline the performance of the various plants so that their biofuel-to-electricity efficiency reaches 30-40 % and overall performance efficiency in the range of 90 %. The Harboøre, Skive, and Güssing plant types are considered appropriate for municipal CHP systems, while the Viking and VIPP-VORTEX plants are smaller and considered appropriate for replacing hot water plants in district heating network. The Danish Technical University (DTU) Biomass Gasification Group and Meva International have identified a potentially large market in the developing countries of Asia. Areas for suggested further research and development include: Gas      cleaning/upgrading Utilization      of produced heat System      integration/optimization Small scale      oxygen production Gas engine      developmentsI ett gemensamt projekt har Linnéuniversitetet i Växjö och Lunds Tekniska Högskola, på uppdrag av Energimyndigheten, genomfört en inventering av teknik och system för småskalig kombinerad värme och kraft produktion via förgasare-gasmotor teknik. Definitionen för småskalighet i denna studie, är anläggningar med en termisk effekt upp till 10 MW(3 MWel) och där bränslet är någon form av biomassa, vanligtvis träbaserad (trä eller skogsavfall) i form av flis, pellets eller spån. Projektrapporten innehåller först en deskriptiv del över teknikens ståndpunkt inom småskalig förgasning, gasrening och gasmotorer. Den andra delen utgörs av en fallbeskrivning för de olika anläggningarna som ingår i studien. MEVA Innovations VIPP-VORTEX CHP anläggning DTU:s VIKING CHP anläggning Bio-kraftverket i Güssing Harboøre CHP anläggning Skive CHP anläggning I fallbeskrivningarna gås anläggningarnas särdrag, funktioner samt enhetsoperationer igenom, samt vilken typ av bränsle som används och vilka verkningsgrader som uppnås. Investerings- och driftskostnaderna, där sådana är tillgängliga, presenteras tillsammans med uppgifter på anläggningarnas tillgänglighet. Även en internationell utblick, huvudsakligen fokuserad på utvecklingsländer, har genomförts.    Generellt sett är tekniken tillräckligt mogen för kommersialisering. Det finns dock en del enhetsoperationer, t.ex. tjärkrackning och tjärreformering, som behöver fortsatt forskning och utveckling. Fortsatt utveckling av systemen kommer förmodligen att göra prestandan för anläggningarna än mera lika och öka elverkningsgraden till 30-40 % med en total verkningsgrad runt 90 %. Harboøre-, Güssing- och Skiveanläggningarna är avsedda som kommunala kraft-värmeanläggningar medan Viking och VIPP-VORTEX är avsedda att ersätta mindre varmvattencentraler i fjärrvärmenätet. Bimass Gasification Group DTU och MEVA Innovation har också identifierat en potentiellt stor marknad i utvecklingsländer i Asien.      Förslag till områden för fortsatt forsknings och utvecklingsarbete: Gasrening/Gasuppgradering Användning av producerat värme System integration/optimering Småskalig syre-produktion Vidareutveckling av gasmotore

June AJP

The optimal dose range was derived from successful laboratory trials prior to the literature search. In the first step of the reviewing procedure, an optimal dose range was We investigated if low level laser therapy (LLLT) of the joint capsule can reduce pain in chronic joint disorders. A literature search identified 88 randomised controlled trials, of which 20 trials included patients with chronic joint disorders. Six trials were excluded for not irradiating the joint capsule. Three trials used doses lower than a dose range nominated a priori for reducing inflammation in the joint capsule. These trials found no significant difference between active and placebo treatments. The remaining 11 trials including 565 patients were of acceptable methodological quality with an average PEDro score of 6.9 (range 5-9). In these trials, LLLT within the suggested dose range was administered to the knee, temporomandibular or zygapophyseal joints. The results showed a mean weighted difference in change of pain on VAS of 29.8 mm (95% CI, 18.9 to 40.7) in favour of the active LLLT groups. Global health status improved for more patients in the active LLLT groups ( relative risk of 0.52; 95% CI 0.36 to 0.76). Low level laser therapy with the suggested dose range significantly reduces pain and improves health status in chronic joint disorders, but the heterogeneity in patient samples, treatment procedures and trial design calls for cautious interpretation of the results

Evaluation of the effects of Er:YAG laser, Nd:YAG laser, and two different desensitizers on dentin permeability: in vitro study

Yilmaz, Nasibe Aycan/0000-0001-5939-8170; KURT, Sevda/0000-0002-3711-6520WOS: 000450033200006PubMed: 29850962The purpose of this in vitro study was to evaluate and compare the efficacy of erbium-doped yttrium aluminum garnet (Er:YAG) laser, neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, PrevDent nano-hydroxyapatite toothpaste plus Repairing Serum Kit (PNH), and NUPRO Sensodyne Prophylaxis Paste with NovaMin (NPP) on dentin permeability reduction. Forty dentin discs obtained from bovine incisors were divided into four study groups: Er:YAG laser-treated (2940nm; 0.2W, 80mJ/pulse, 3Hz); Nd:YAG laser-treated (1064nm; 1W, 10Hz); PNH-treated; and NPP-treated groups. the quantitative changes in permeability of each dentin disc were measured using a computerized fluid filtration method (CFFM) before and after desensitizer treatments. the data were analyzed using the Wilcoxon, paired-samples t, Kruskal-Wallis, and Mann-Whitney U tests. the dentin surfaces and tubules were also morphologically detected by scanning electron microscopy (SEM). in all groups, dentin permeability was significantly reduced after the desensitizer and laser treatments (p<0.05). Among the groups, we detected a significant difference in only when comparing the Er:YAG laser- and NPP-treated groups (p=0.034). SEM analysis revealed physical changes in the dentin surface in all groups. This in vitro study shows that all tested desensitizers and laser treatments reduced dentin permeability. Also, surface changes, such as complete or partial occlusion or shrinkage of dentin tubules, were observed in all groups. Although the laser groups performed best, the PNH protocol can be considered as an alternative therapeutic product. in addition, clinical and laboratory studies should be performed for this product, and their efficacy should be assessed by combined therapy with lasers