Emerging Energy Storage Solutions for Transportation Electrification – A Review

Energy storages have caught the attention of transportation community for the past several years. Recent developments in hybrid and plug-in electric vehicles together with novel concepts in transportation such as electric highways are the reasons for raising the role of energy storages in transportation to such a significant level. Performance demands for energy storage solutions vary significantly from one transportation application to the other, making it difficult for the scientific community to converge to a single energy storage solution that caters all. This paper reviews the key performance demands of the major transportation applications. It also investigates the characteristics of emerging energy storage solutions and assess their suitability for those reviewed transportation applications

Trender i surhetstillstånd i skogs-, myr- och fjällbäckar i Dalarna

Försurningen av sjöar och vattendrag har generellt minskat i Sverige och det är följaktligen intressant att följa upp och söka förklara utvecklingen i Dalarnas vattendrag. Länsstyrelsen har därför initierat en vattenkemisk utvärdering av de regionalt övervakade vattendragen. Syftet med utvärderingen är att utvärdera surhetstillståndets utveckling med tiden samt att söka förklara orsakerna till eventuella trender i Hyttingsån, Acktjärnsbäcken, Göljån och Skidbågsbäcken (SK1 och SK2). Utvärderingen omfattar hela mätperioden t.o.m. 2012. Om man undantar den kalkade Skidbågsbäcken SK2, var samtliga bäckar jonsvaga med en medelkonduktivitet i intervallet 1,2-2,5 mS/m. I samtliga bäckar förutom Skidbågsbäcken SK1 var Ca2+ den dominerande baskatjonen (BC) följt av Na+, Mg2+ och K+. I Skidbågsbäcken SK1 dominerade Na+. BC-halterna balanserades primärt av RCOO- och HCO3-. Båda dessa anjoner bildas vid nedbrytning av organiskt material respektive vid koldioxidvittring av olika silikatmineral och utgjorde mellan 57-84% av anjonerna i de okalkade bäckarna. Andelen SO42- varierade mellan 8-25% med de högsta värdena i Hyttingsån och Göljån. Det är därför troligt att mänskligt betingad försurning bidrog med maximalt 8-25% i de studerade vattendragen och att denna påverkan var som störst i Hyttingsån och Göljån. I den kalkade Skidbågsbäcken SK2 var Ca2+ extremt dominerande och balanserat av HCO3-, båda med ursprung i den kalk som spridits. Buffertsystemet i Skidbågsbäcken SK1 dominerades helt av svaga organiska syror, vilket gav ett lågt medel-pH (4,5), medan buffertsystemen i Acktjärnsbäcken och Göljån dominerades av kolsyrasystemet och därför hade betydligt högre pH (6,1 respektive 6,4 i medeltal). Hyttingsån uppvisade en mix av de båda buffertsystemen och hade därför ett något lägre medel-pH (5,8) betingat av högre halter organiska syror. Den kalkade Skidbågsbäcken SK2 hade pH≈6,5. Med undantag av Hyttingsån, som inte uppvisar någon statistiskt signifikant trend (p>0,05), har pH ökat med ca 0,15, 0,3 och 0,45 pH-enheter under de ca 15 år som övervakningen pågått i Skidbågsbäcken SK1, Göljån respektive Acktjärnsbäcken. pH-ökningen sammanfaller med minskande SO42- -halter, vilket indikerar minskande påverkan från svavelnedfall. Hyttingsån uppvisar den största minskningen i SO42- -halter (2,8 µekv/l, år), men pH har inte förändrats. En förklaring är att de minskade SO42- -halterna i hög grad kompenserats av att baskatjonen Ca2+ minskat samtidigt som halterna organiska syror ökat. För samtliga bäckar förutom Hyttingsån indikerar BDM-resultaten att försurningstrycket var som högst i början på tidsserierna och endast Göljån uppvisade 1995 ett pH-värde som indikerar försurning. I Hyttingsån indikerar resultaten försurat tillstånd under vårarna 1996, 1999, 2001 och 2008. Någon generell trend går inte att spåra i Hyttingsån, vilket gör det angeläget att fortsätta mätningarna där. Efter 2008 bedöms samtliga vattendrag som icke-försurade med BDM-modellen

Thermodynamic limit of the density matrix renormalization for the spin-1 Heisenberg chain

The density matrix renormalization group (``DMRG'') discovered by White has shown to be a powerful method to understand the properties of many one dimensional quantum systems. In the case where renormalization eventually converges to a fixed point we show that quantum states in the thermodynamic limit with periodic boundary conditions can be simply represented by a special type of product ground state with a natural description of Bloch states of elementary excitations that are spin-1 solitons. We then observe that these states can be rederived through a simple variational ansatz making no reference to a renormalization construction. The method is tested on the spin-1 Heisenberg model.Comment: 13 pages uuencoded compressed postscript including figure

A class of ansatz wave functions for 1D spin systems and their relation to DMRG

We investigate the density matrix renormalization group (DMRG) discovered by White and show that in the case where the renormalization eventually converges to a fixed point the DMRG ground state can be simply written as a ``matrix product'' form. This ground state can also be rederived through a simple variational ansatz making no reference to the DMRG construction. We also show how to construct the ``matrix product'' states and how to calculate their properties, including the excitation spectrum. This paper provides details of many results announced in an earlier letter.Comment: RevTeX, 49 pages including 4 figures (macro included). Uuencoded with uufiles. A complete postscript file is available at http://fy.chalmers.se/~tfksr/prb.dmrg.p

Overall asthma control achieved with budesonide/formoterol maintenance and reliever therapy for patients on different treatment steps

<p>Abstract</p> <p>Background</p> <p>Adjusting medication for uncontrolled asthma involves selecting one of several options from the same or a higher treatment step outlined in asthma guidelines. We examined the relative benefit of introducing budesonide/formoterol (BUD/FORM) maintenance and reliever therapy (Symbicort SMART^®Turbuhaler^®) in patients previously prescribed treatments from Global Initiative for Asthma (GINA) Steps 2, 3 or 4.</p> <p>Methods</p> <p>This is a <it>post hoc </it>analysis of the results of five large clinical trials (>12000 patients) comparing BUD/FORM maintenance and reliever therapy with other treatments categorised by treatment step at study entry. Both current clinical asthma control during the last week of treatment and exacerbations during the study were examined.</p> <p>Results</p> <p>At each GINA treatment step, the proportion of patients achieving target levels of current clinical control were similar or higher with BUD/FORM maintenance and reliever therapy compared with the same or a higher fixed maintenance dose of inhaled corticosteroid/long-acting β₂-agonist (ICS/LABA) (plus short-acting β₂-agonist [SABA] as reliever), and rates of exacerbations were lower at all treatment steps in BUD/FORM maintenance and reliever therapy versus same maintenance dose ICS/LABA (P < 0.01) and at treatment Step 4 versus higher maintenance dose ICS/LABA (P < 0.001). BUD/FORM maintenance and reliever therapy also achieved significantly higher rates of current clinical control and significantly lower exacerbation rates at most treatment steps compared with a higher maintenance dose ICS + SABA (Steps 2-4 for control and Steps 3 and 4 for exacerbations). With all treatments, the proportion of patients achieving current clinical control was lower with increasing treatment steps.</p> <p>Conclusions</p> <p>BUD/FORM maintenance and reliever therapy may be a preferable option for patients on Steps 2 to 4 of asthma guidelines requiring a more effective treatment and, compared with other fixed dose alternatives, is most effective in the higher treatment steps.</p

Lipoprotein‐Associated Phospholipase A2 Activity Is a Marker of Risk But Not a Useful Target for Treatment in Patients With Stable Coronary Heart Disease

Background: We evaluated lipoprotein‐associated phospholipase A2 (Lp‐PLA2) activity in patients with stable coronary heart disease before and during treatment with darapladib, a selective Lp‐PLA2 inhibitor, in relation to outcomes and the effects of darapladib in the STABILITY trial. Methods and Results: Plasma Lp‐PLA2 activity was determined at baseline (n=14 500); at 1 month (n=13 709); serially (n=100) at 3, 6, and 18 months; and at the end of treatment. Adjusted Cox regression models evaluated associations between Lp‐PLA2 activity levels and outcomes. At baseline, the median Lp‐PLA2 level was 172.4 μmol/min per liter (interquartile range 143.1–204.2 μmol/min per liter). Comparing the highest and lowest Lp‐PLA2 quartile groups, the hazard ratios were 1.50 (95% CI 1.23–1.82) for the primary composite end point (cardiovascular death, myocardial infarction, or stroke), 1.95 (95% CI 1.29–2.93) for hospitalization for heart failure, 1.42 (1.07–1.89) for cardiovascular death, and 1.37 (1.03–1.81) for myocardial infarction after adjustment for baseline characteristics, standard laboratory variables, and other prognostic biomarkers. Treatment with darapladib led to a ≈65% persistent reduction in median Lp‐PLA2 activity. There were no associations between on‐treatment Lp‐PLA2 activity or changes of Lp‐PLA2 activity and outcomes, and there were no significant interactions between baseline and on‐treatment Lp‐PLA2 activity or changes in Lp‐PLA2 activity levels and the effects of darapladib on outcomes. Conclusions: Although high Lp‐PLA2 activity was associated with increased risk of cardiovascular events, pharmacological lowering of Lp‐PLA2 activity by ≈65% did not significantly reduce cardiovascular events in patients with stable coronary heart disease, regardless of the baseline level or the magnitude of change of Lp‐PLA2 activity