Local Percolation Probabilities for a Natural Sandstone

Local percolation probabilities are used to characterize the connectivity in porous and heterogeneous media. Together with local porosity distributions they allow to predict transport properties \cite{hil91d}. While local porosity distributions are readily obtained, measurements of the local percolation probabilities are more difficult and have not been attempted previously. First measurements of three dimensional local porosity distributions and percolation probabilities from a pore space reconstruction for a natural sandstone show that theoretical expectations and experimental results are consistent.Comment: 9 pages, see also http://www.ica1.uni-stuttgart.de , Physica

Terahertz conductivity of the heavy-fermion compound UNi2Al3

We have studied the optical properties of the heavy-fermion compound UNi2Al3 at frequencies between 100 GHz and 1 THz (3 cm^-1 and 35 cm^-1), temperatures between 2 K and 300 K, and magnetic fields up to 7 T. From the measured transmission and phaseshift of radiation passing through a thin film of UNi2Al3, we have directly determined the frequency dependence of the real and imaginary parts of the optical conductivity (or permittivity, respectively). At low temperatures the anisotropy of the optical conductivity along the a- and c-axes is about 1.5. The frequency dependence of the real part of the optical conductivity shows a maximum at low temperatures, around 3 cm^-1 for the a-axis and around 4.5 cm^-1 for the c-axis. This feature is visible already at 30 K, much higher than the Neel temperature of 4.6 K, and it does not depend on external magnetic fields as high as 7 T. We conclude that this feature is independent of the antiferromagnetic order for UNi2Al3, and this might also be the case for UPd2Al3 and UPt3, where a similar maximum in the optical conductivity was observed previously.Comment: 7 pages, 9 figure

Does text structure/summarization instruction facilitate learning from expository text?

The work upon which this publication is based was performed pursuant to Contract no. NIE-400-81-0030 of the National Institute of Educatio

Consumption trends of steel and aluminium in the context of decarbonization

In order to be able to analyze future ecological as well as economic aspects of the climate protection potential through decarbonisation of German industries, the aluminium and steel industry must be investigated in detail. The construction and mechanical sectors are among the biggest consumers of aluminium and steel in Germany. Consequently this paper examines the future consumption trends of steel and aluminium for these sectors. To project the consumption trends for a long-term perspective (2050), a simple regression model is developed. The model consists of four steps. First, the future German GDP is projected. Secondly, overall aluminium and steel consumption is calculated based on a linear regression function with GDP as the explanatory variable. Third, the future sector shares of each material are calculated with the help of a trend analysis. Finally, the results of steps two and three are combined to derive the future material consumption of each sector by multiplication. According to the simple regression model developed in the paper the consumption of both analyzed materials will increase until 2050 - in case of steel by 41 % and of aluminium by 95 %. The construction sector will increase its absolute amount of steel consumption, but reduce its aluminium consumption. These consumption patterns are the exact opposite for the mechanical engineering sector, albeit on a different scale. The presented results show their plausibility when compared to those in the literature. Although a high uncertainty implies the results due to the lack of data, especially in the case of the projected steel consumption trends

Magnetrecycling bei Pedelecs: Rahmenbedingungen und Akteure - Status Quo und Perspektiven

Dieses Arbeitspapier untersucht die Möglichkeiten der Etablierung eines Recyclingsystems für NdFeB-Magnete aus Elektromotoren am Beispiel von Pedelecs. Die Ergebnisse basieren neben Literaturrecherchen auf Interviews mit Akteuren, die in den Pedelec Life-Cycle direkt oder indirekt involviert sind. In diesem Papier werden zunächst sowohl die Marktentwicklung wie auch die rechtlichen Rahmenbedingungen eingeführt. In diesem Zusammenhang werden auch Einflussfaktoren auf die Lebensdauer von Pedelecs diskutiert. Anschließend werden zunächst die im Pedelec Life-Cycle involvierten Akteure sowie ihre Beziehungen dargestellt. Anschließend wird der aktuelle Status-Quo der Kreislaufführung zusammengefasst und erwartete Entwicklungen diskutiert. Es stellt sich heraus, dass die Akteure aktuell relativ unvorbereitet bzgl. des Recyclings von Pedelecs bzw. der entsprechenden Motoren sind. Weiter stellen Fragen der korrekten Akku-Entsorgung oder -Revitalisierung aktuell noch ein dringenderes Problem im Vergleich zur Pedelec-Entsorgung dar. Es ist aber zu erwarten, dass Fragen zur Rücknahme mit steigender Anzahl von Alt-Pedelecs erhöht auftreten werden. Bzgl. der Rücknahme-Verpflichtung wurde festgestellt, dass nur ein sehr kleiner Anteil der Fahrradhändler tatsächlich einer Rücknahme-Verpflichtung unterliegt. Dies begründet sich in der Branchenstruktur des Fahrradhandels, die weiterhin durch verhältnismäßig kleine Händler geprägt ist

Iron-enriched diet contributes to early onset of osteoporotic phenotype in a mouse model of hereditary hemochromatosis

Osteoporosis is associated with chronic iron overload secondary to hereditary hemochromatosis (HH), but the causative mechanisms are incompletely understood. The main objective of this study was to investigate the role of dietary iron on osteoporosis, using as biological model the Hfe-KO mice, which have a systemic iron overload. We showed that these mice show an increased susceptibility for developing a bone loss phenotype compared to WT mice, which can be exacerbated by an iron rich diet. The dietary iron overload caused an increase in inflammation and iron incorporation within the trabecular bone in both WT and Hfe-KO mice. However, the osteoporotic phenotype was only evident in Hfe-KO mice fed the iron-enriched diet. This appeared to result from an imbalance between bone formation and bone resorption driven by iron toxicity associated to Hfe-KO and confirmed by a decrease in bone microarchitecture parameters (identified by micro-CT) and osteoblast number. These findings were supported by the observed downregulation of bone metabolism markers and upregulation of ferritin heavy polypeptide 1 (Fth1) and transferrin receptor-1 (Tfrc), which are associated with iron toxicity and bone loss phenotype. In WT mice the iron rich diet was not enough to promote a bone loss phenotype, essentially due to the concomitant depression of bone resorption observed in those animals. In conclusion the dietary challenge influences the development of osteoporosis in the HH mice model thus suggesting that the iron content in the diet may influence the osteoporotic phenotype in systemic iron overload conditions.National Funds through Foundation for Science and Technology (FCT) Norte-01-0145-FEDER-000012 Portuguese Foundation for Science and Technology (FCT) SFRH/BD/77056/2011 European Regional Development Fund (FEDER) Norte-01-0145-FEDER-000012info:eu-repo/semantics/publishedVersio

Observing the anisotropic optical response of the heavy-fermion compound UNi2Al3

The optical conductivity of heavy fermions can reveal fundamental properties of the charge carrier dynamics in these strongly correlated electron systems. Here we extend the conventional techniques of infrared optics on heavy fermions by measuring the transmission and phase shift of THz radiation that passes through a thin film of UNi2Al3, a material with hexagonal crystal structure. We deduce the optical conductivity in a previously not accessible frequency range, and furthermore we resolve the anisotropy of the optical response (parallel and perpendicular to the hexagonal planes). At frequencies around 7cm^-1, we find a strongly temperature-dependent and anisotropic optical conductivity that - surprisingly - roughly follows the dc behavior.Comment: 3 pages, 2 figures, accepted for proceedings of QCnP 200

Sociability is decreased following deletion of the _trpc4_ gene

Shyness and social anxiety are predominant features of some psychiatric disorders including autism, schizophrenia, anxiety and depression. Understanding the cellular and molecular determinants of sociability may reveal therapeutic approaches to treat individuals with these disorders and improve their quality of life. Previous experiments from our laboratory have identified selective mRNA and protein expression of a nonselective cation channel known as the canonical transient receptor potential channel 4 (TRPC4s) in brain regions implicated in emotional regulation and anxiety. TRPC4 is highly expressed in the corticolimbic regions of the mammalian brain. We hypothesized that robust corticolimbic expression of TRPC4 may regulate the brain’s response to emotion and anxiety resulting in changes in social interaction. Here we test trpc4 gene knockout rats in a model of social anxiety/interaction. We found that the Trpc4 knockout animals spent significantly less time exploring a juvenile intruder rat compared to their wild-type counterparts and Sprague-Dawley (SD) rats. Furthermore, Trpc4 wild-type (Fisher 344) rats explored the juvenile significantly less than the SD rats. These findings indicate that the _trpc4_ gene plays a role in modulating cellular excitability in specific regions of the brain associated sociality and/or anxiety

Hypertrophic scars after therapy with CO2 laser for treatment of multiple cutaneous neurofibromas

BACKGROUND. CO2 laser surgery is a treatment modality for cutaneous neurofibromas. OBJECTIVE. Hypertrophic and atrophic scars can result from treatment with CO2 laser surgery. We present a case of cutaneous neurofibromatosis that developed hypertrophic scars postoperatively. METHODS. Continuous wave CO2 laser surgery therapy was applied to the patient. RESULTS. Hypertrophic scars developed 2 months after therapy. CONCLUSION. With a preliminary test treatment the patient is able to see the expected result

Verfahren zur Bewertung des Statistischen Multiplex bei der Videocodierung

Dieser Beitrag beschreibt ein Verfahren zur objektiven Bewertung von Systemen mit statistischem Multiplex, das für den Vergleich verschiedener Systeme und zur Abschätzung des Gewinns an Datenrate eingesetzt werden kann. Für die Auswertung wurde zunächst eine Mittelwertbildung für objektive PSNR-Messungen begutachtet und zusätzlich mit den Verfahren DMOS und JND, als zwei Repräsentanten mit Modellierung subjektiver Eigenschaften, verglichen. In der Konsequenz wurde ein Verfahren entwickelt, das auf einer einfachen PSNR-Berechnung für jedes Einzelbild mit einer anschließenden Auswertung eines PSNR-Histogramms beruht. Dabei wird letztlich die Auftrittshäufigkeit niedriger PSNR-Werte als Maß für die Bildqualität eines Kanals im Statistischen Multiplex genutzt