Massless Spectra and Gauge Couplings at One-Loop on Non-Factorisable Toroidal Orientifolds

So-called `non-factorisable' toroidal orbifolds can be rewritten in a factorised form as a product of three two-tori by imposing an additional shift symmetry. This finding of Blaszczyk et al., arXiv:1111.5852, provides a new avenue to Conformal Field Theory methods, by which the vector-like massless matter spectrum - and thereby the type of gauge group enhancement on orientifold invariant fractional D6-branes - and the one-loop corrections to the gauge couplings in Type IIA orientifold theories can be computed in addition to the well-established chiral matter spectrum derived from topological intersection numbers among three-cycles. We demonstrate this framework for the $\mathbb{Z}_4 \times \Omega\mathcal{R}$ orientifolds on the $A_3 \times A_1 \times B_2$-type torus. As observed before for factorisable backgrounds, also here the one-loop correction can drive the gauge groups to stronger coupling as demonstrated by means of a four-generation Pati-Salam example.Comment: 65 pages, 10 figures; v3: matches published version (ref + explanatory remarks added

Help From and Help to Neighbors Among Older Adults in Europe

Neighborhoods can be a valuable source of social support particularly for older adults. Such support can be mutual; however, the influential factors in giving and receiving are unclear. This study investigated neighborhood help among the older European population using representative data for 17 countries from the Survey of Health, Ageing and Retirement in Europe (SHARE). The analyses were based on 104,059 observations of 39,113 respondents aged 50 years and older. In general, ~6% of all respondents provided recently neighborhood help, and 4% received help. Moreover, the results indicate a high degree of reciprocity in giving and receiving neighborhood help. However, the situation varied widely among age groups and countries. Our multilevel results suggest that the provision and receipt of help are driven by personal characteristics (age, sex, education, income, and retirement), health resources (subjective health, activities of daily living, and instrumental activities of daily living), living situation (homeownership, location, and length of time in a residence), social factors (marital status, partner, parents, and children), and contextual factors (gross domestic product, social expenditures, poverty rate, Gini index, population density, country-centered satisfaction with life, living, and relationships)

Deutsches "Beschäftigungswunder" und flexible Arbeitszeiten

In der schärfsten Nachkriegskrise erweist sich der Arbeitsmarkt in Deutschland als wesentlich robuster als in anderen von der weltweiten Krise betroffenen Ländern. Neben dem offensiven Einsatz öffentlich geförderter Kurzarbeit fangen flexible Arbeitszeiten stärker als in früheren konjunkturellen Abschwüngen den ansonsten kaum vermeidbaren Beschäftigungseinbruch auf. Das vorliegende Diskussionspapier zeichnet zunächst das bisherige Entwicklungsmuster der Arbeitszeitflexibilisierung nach und beschreibt die veränderte Rolle der Arbeitszeit in der aktuellen Wirtschaftskrise im Vergleich zu früheren Abschwungphasen. So erfolgreich dieser Weg auch ist, so stoesst er doch an Grenzen. Die Instrumentenpalette wurde gegenüber früheren Konjunkturabschwüngen zwar deutlich erweitert, die beschäftigungsstabilisierende Wirkung einiger Instrumente ist aber zeitlich begrenzt. Was aber kommt, wenn diese Instrumente stumpf werden und der konjunkturelle Aufschwung nicht ausreicht, die vorhandenen Arbeitskräfte zu beschäftigen? Es könnte die Stunde weiterer Arbeitszeitverkürzungen werden. Der vorliegende Beitrag greift diese Überlegung auf und trägt einige Anregungen zu dieser Debatte bei. --

Charakterizace paliv z biomasy v IPFR reaktoru

Combustion of fossil fuels is one of the most important source of energy. However low carbon politics and environmental commitments, affects developing combustion and co – combustion technologies. Utilization of biomass fuels can be answer for new challenges, although more research on effective utilization of these fuels are needed. Nowadays, combustion of biomass fuels, especially straw, causes many technical problems, mainly slagging formation, fouling of heat exchangers inside combustion chamber and insufficient fuel burnout. This paper focuses on analysis of biomass combustion. Better knowledge of behavior during biomass combustion may help to optimization of PF (Pulverized Fuel) boiler of and avoid some technical problems. The results of investigation shows that temperature and oxygen concentration in reactor play significant role in process of devolatilization and char burnout. For instance during char burnout experiments at temperature 850⁰C at 14% oxygen concentration after 200 ms more than 80% of mass loss were achieved. Compared to 700⁰C at 14% oxygen concentration this same level of mass loss were completed after 500 ms. Experiments performed on Isothermal Plug Flow Reactor (IPFR) at Institute of Energy Process Engineering and Fuel Technology (IEVB) at TU Clausthal were a part of project between IEVB and the Karlsruhe Institute of Technology (KIT) in Germany.Spalování fosilních paliv je jedním z nejdůležitějších zdrojů energie. Nicméně nízkouhlíková politika a environmentální závazky ovlivňují vývoj spalovacích a spolu-spalovacích technologií. Využívání paliv z biomasy může být odpovědí na nové výzvy, i když je zapotřebí více výzkumu o efektivním využití těchto paliv. V současné době spalování paliv z biomasy, zejména slámy, způsobuje řadu technických problémů, zejména tvorbu strusky, zanášení výměníků tepla uvnitř spalovací komory a nedostatečné vyhoření paliva. Tento příspěvek se zaměřuje na analýzu spalováníbiomasy. Lepší znalost chování procesů při spalování biomasy může přispět k optimalizaci návrhu práškového kotle a vyhnout se tím technickým problémům. Výsledky výzkumu ukazují, že teplota a koncentrace kyslíku v reaktoru hrají významnou roli v procesu tvorby prchavé hořlaviny a vyhoření tuhého zbytku. Například během experimentů s vyhořelým tuhým zbytkem při teplotě 850 ° C při 14% koncentraci kyslíku po 200 ms bylo dosaženo více než 80% úbytku hmotnosti. Ve srovnání se 700 ° C při 14% koncentraci kyslíku byla stejná úroveň úbytku hmotnosti dosažena po 500 ms. Experimenty provedené na izotermickém reaktoru (IPFR) v Institutu energetických procesů a technologií paliv (IEVB) na TU Clausthal byly součástí projektu mezi IEVB a „Karlsruhe Institute of Technology (KIT)“ v Německu

Complex THz and DC inverse spin Hall effect in YIG/Cu1−x_{1-x}Irx_{x} bilayers across a wide concentration range

We measure the inverse spin Hall effect of Cu$_{1-x}$Ir$_{x}$ thin films on yttrium iron garnet over a wide range of Ir concentrations ($0.05 \leqslant x \leqslant 0.7$). Spin currents are triggered through the spin Seebeck effect, either by a DC temperature gradient or by ultrafast optical heating of the metal layer. The spin Hall current is detected by, respectively, electrical contacts or measurement of the emitted THz radiation. With both approaches, we reveal the same Ir concentration dependence that follows a novel complex, non-monotonous behavior as compared to previous studies. For small Ir concentrations a signal minimum is observed, while a pronounced maximum appears near the equiatomic composition. We identify this behavior as originating from the interplay of different spin Hall mechanisms as well as a concentration-dependent variation of the integrated spin current density in Cu$_{1-x}$Ir$_{x}$. The coinciding results obtained for DC and ultrafast stimuli show that the studied material allows for efficient spin-to-charge conversion even on ultrafast timescales, thus enabling a transfer of established spintronic measurement schemes into the terahertz regime.Comment: 12 pages, 4 figure