Varmepumper og Lavtemperatur-fjernvarme - Rapportering fra to workshops

Denne rapport udgør et delbidrag af rapporteringen fra projektet ” Effektiv fjernvarme i fremtidens energisystem”, som under Energistyrelsens Energiforskningsprogram (EFP) udføres af et konsortium af EA-energianalyse, Systemanalyseafdelingen på Risø DTU, RAM-løse edb samt Fjernvarmens visionsudvalg nedsat under Dansk Fjernvarmeforening.Formålet med projektet er at belyse, hvordan fjernvarmens rolle i energiforsyningen kan udvikles på langt sigt gennem effektiv drift, anvendelse af ny teknologi samt dynamisk samspil med elmarkedet. En fremtidig udvikling mod et bæredygtigt energisystem vil kræve betydelige energibesparelser, herunder i rumopvarmningen. Dette vil alt andet lige mange steder føre til, at grundlaget for fjernvarmen vil ændre sig. Det er således centralt i projektet, at opstille en række scenarier for fjernvarmens fremtidige rolle i energisystemet, herunder at belyse hvad reducerede varmetab i fjernvarmenet og dynamisk anvendelse af kendte og nye energiteknologier kan betyde. Disse teknologier omfatter bl.a. varmepumper, geotermi, fjernkøling og varmelagring. Endvidere er formålet at belyse hvordan samspillet mellem elmarkedet og fjernvarmen kan effektiviseres, samt at pege på hvilke rammebetingelser der især er kritiske for fjernvarmens fortsatte udvikling og effektivisering.Som et led i analyserne i projektet er der afholdt to workshops om henholdsvis anvendelsen af varmepumper og lavtemperatur-fjernvarmenet. Denne rapport er en dokumentation af de to workshops, idet den indeholder program, deltagerliste, præsentationer og korte resumeer. I begge workshops deltog eksterne indledere parallelt med projektgruppens egne deltagere. Vi takker deltagerne for præsentationer og engageret deltagelse i diskussionerne

Six Weeks of Low-Load Blood Flow Restricted and High-Load Resistance Exercise Training Produce Similar Increases in Cumulative Myofibrillar Protein Synthesis and Ribosomal Biogenesis in Healthy Males

Purpose: High-load resistance exercise contributes to maintenance of muscle mass, muscle protein quality, and contractile function by stimulation of muscle protein synthesis (MPS), hypertrophy, and strength gains. However, high loading may not be feasible in several clinical populations. Low-load blood flow restricted resistance exercise (BFRRE) may provide an alternative approach. However, the long-term protein synthetic response to BFRRE is unknown and the myocellular adaptations to prolonged BFRRE are not well described.Methods: To investigate this, 34 healthy young subjects were randomized to 6 weeks of low-load BFRRE, HLRE, or non-exercise control (CON). Deuterium oxide (D2O) was orally administered throughout the intervention period. Muscle biopsies from m. vastus lateralis were collected before and after the 6-week intervention period to assess long-term myofibrillar MPS and RNA synthesis as well as muscle fiber-type-specific cross-sectional area (CSA), satellite cell content, and myonuclei content. Muscle biopsies were also collected in the immediate hours following single-bout exercise to assess signaling for muscle protein degradation. Isometric and dynamic quadriceps muscle strength was evaluated before and after the intervention.Results: Myofibrillar MPS was higher in BFRRE (1.34%/day, p < 0.01) and HLRE (1.12%/day, p < 0.05) compared to CON (0.96%/day) with no significant differences between exercise groups. Muscle RNA synthesis was higher in BFRRE (0.65%/day, p < 0.001) and HLRE (0.55%/day, p < 0.01) compared to CON (0.38%/day) and both training groups increased RNA content, indicating ribosomal biogenesis in response to exercise. BFRRE and HLRE both activated muscle degradation signaling. Muscle strength increased 6–10% in BFRRE (p < 0.05) and 13–23% in HLRE (p < 0.01). Dynamic muscle strength increased to a greater extent in HLRE (p < 0.05). No changes in type I and type II muscle fiber-type-specific CSA, satellite cell content, or myonuclei content were observed.Conclusions: These results demonstrate that BFRRE increases long-term muscle protein turnover, ribosomal biogenesis, and muscle strength to a similar degree as HLRE. These findings emphasize the potential application of low-load BFRRE to stimulate muscle protein turnover and increase muscle function in clinical populations where high loading is untenable

Density functional theory based screening of ternary alkali-transition metal borohydrides: A computational material design project

The dissociation of molecules, even the most simple hydrogen molecule, cannot be described accurately within density functional theory because none of the currently available functionals accounts for strong on-site correlation. This problem led to a discussion of properties that the local Kohn-Sham potential has to satisfy in order to correctly describe strongly correlated systems. We derive an analytic expression for the nontrivial form of the Kohn-Sham potential in between the two fragments for the dissociation of a single bond. We show that the numerical calculations for a one-dimensional two-electron model system indeed approach and reach this limit. It is shown that the functional form of the potential is universal, i.e., independent of the details of the two fragments.We acknowledge funding by the Spanish MEC (Grant No. FIS2007-65702-C02-01), “Grupos Consolidados UPV/EHU del Gobierno Vasco” (Grant No. IT-319-07), and the European Community through e-I3 ETSF project (Grant Agreement No. 211956).Peer reviewe