Thermal diffusion by Brownian motion induced fluid stress

The Ludwig-Soret effect, the migration of a species due to a temperature gradient, has been extensively studied without a complete picture of its cause emerging. Here we investigate the dynamics of DNA and spherical particles sub jected to a thermal gradient using a combination of Brownian dynamics and the lattice Boltzmann method. We observe that the DNA molecules will migrate to colder regions of the channel, an observation also made in the experiments of Duhr, et al[1]. In fact, the thermal diffusion coefficient found agrees quantitatively with the experimental value. We also observe that the thermal diffusion coefficient decreases as the radius of the studied spherical particles increases. Furthermore, we observe that the thermal fluctuations-fluid momentum flux coupling induces a gradient in the stress which leads to thermal migration in both systems.Comment: 6 pages, 5 figue

Iatrogenic Neurovascular Entrapment InjuriesCaused by Reduction and IntramedullaryFixation of Fractures of the Lower Limb

Background:: Damage to the main neurovascular trunk in the lower limb due to trauma has also been described in the literature. Little attention, however, has been directed toward the quantitative assessment of iatrogenic injury to peripheral neurovascular structures caused by the treatment of open fractures in the lower limb. Obtaining an angiography of the lower limb early in the course of treatment of such injuries is necessary. Methods:: We performed a retrospective analysis of 253 patients with open fractures. We divided into them into two groups, treated either with an intramedullary (A) or an extramedullary (B) approach. We furthermore noted whether a free tissue transfer was necessary in either group. Particular attention was directed to iatrogenic neurovascular injuries caused by reduction and intramedullary fixation. Results:: In group A, we found two cases of entrapment of the anterior tibial artery and its concomitant veins, and the deep peroneal nerve. In group B, we recorded four cases of iatrogenic injuries to the common peroneal nerve. Free tissue transfer was performed in 102 cases, 4 of which were emergency free flaps. Conclusion:: We wish to stress that ascertaining the anatomy and patency of the vascular anatomy of the injured limb early during the primary assessment of the patient, either by palpation, portable Doppler flowmeter, duplex sonography, or angiography before, and preferably also after, reduction and intramedullary nailing of the fracture is in our view mandatory, before any treatment of the fracture is envisione

Impedance analysis of automotive high voltage networks for EMC measurements

This paper deals with a method of determining the high-frequency impedances of automotive HV power networks. A Vector Network Analyzer (VNA) is used to measure Scattering parameters of different HV power cables and an automotive Li-Ion accumulator battery. Matrix conversions allow calculating an impedance network, which is able to represent an automotive HV networks

Analyse von Kopplungseigenschaften verschiedener KFZ-Bordnetzspannungsebenen auf System- und Komponentenebene

Zur genaueren Untersuchung von Ausbreitungspfaden für elektromagnetische Störungen wurde eine Messmethode vorgestellt, mit der das Kopplungsverhalten zwischen der HV- und der LV-Ebene charakterisiert werden kann. Dazu wird HV-seitig ein HF-Störsignal im Common- bzw. Differential-Mode eingespeist und die Überkopplung in den LV-Teil gemessen. Die Signalauskopplung kann dabei kapazitiv, induktiv oder mit fahrzeugeigenen Antennen vorgenommen werden. Das Verfahren wurde für die Untersuchung eines Gesamtfahrzeugs angewendet, im Beitrag wird die Untersuchung eines Systemaufbaus vorgestellt, der alle HVKomponenten eines rein elektrisch angetriebenen Fahrzeuges enthält. Mit Hilfe der gemessenen Transferfunktionen können kritische Komponenten und Betriebszustände ermittelt werden und entsprechende Entstörungsmaßnahmen ergriffen bzw. bewertet werden. Bei der Untersuchung von Fahrzeuggesamtsystemen ist sichergestellt, dass reale Bedingungen betrachtet werden. Dazu zählen vor allem die Verlegung der Kabelsätze und reale Eingangsimpedanzen der Komponenten. Außerdem kann das HF-Kopplungsverhalten verschiedener Fahrzeuge miteinander verglichen werden. Für die Prüfung von Komponenten müssen außerdem die bestehenden CISPR 25 Messverfahren erweitert bzw. angepasst werden. Dabei muss beachtet werden, dass durch den Wechsel der Untersuchungsebene die Betriebsbedingungen entscheidend geändert werden. Die durchgeführte Analyse der HV-/LV-Kopplungseigenschaften an verschiedenen Untersuchungsebenen ist ein Beitrag zur Festlegung neuer Komponentenmessverfahren

Die IAB-Regionalstichprobe 1975-2001: IABS-R01

'Die Arbeit stellt die neue regionalisierte Stichprobe aus der Beschäftigten- und Leistungshistorik des Instituts für Arbeitsmarkt- und Berufsforschung vor. Ausgehend von der Datengrundlage und den Arbeiten der Datenaufbereitung und Anonymisierung werden vor allem die Neuerungen gegenüber früheren Regionalstichproben vorgestellt, so der größere Stichprobenumfang, die Möglichkeit, die Stichprobe zukünftig wesentlich schneller und einfacher zu aktualisieren, oder die Einbeziehung geringfügiger Beschäftigungsverhältnisse ab dem Jahr 1999. Auch ein Online-Informationsangebot für die Arbeit mit der Stichprobe steht zur Verfügung. Ein kurzes Beispiel verdeutlicht abschließend das Analysepotenzial der Daten.' (Autorenreferat)'The latest version of the IAB employment sample contains information on the course of employment and unemployment of more than 1 million individuals as well as information on the region where the respective employer is located. Together with basic information on the data from which the sample is drawn and details about data processing and anonymisation, we describe major innovations in the current sample, e.g. the larger sample size, better possibilities for future updates of the sample and the inclusion of 'petty jobs' ('geringfügige Beschäftigung') starting from 1999. The new release will be accompanied by an online information service. A short example demonstrates the potential for analysis offered by the data' (author's abstract)

Photoswitching of azobenzene multilayers on a layered semiconductor

In situ photoelectron spectroscopy is used to study the adsorption and photoisomerization of azobenzene multilayers on the layered semiconductor HfS 2 at liquid nitrogen temperatures. The measured valence band spectra indicate weak molecule–substrate coupling and provide evidence for reversible switching of azobenzene multilayers by light with different wavelengths. The photoswitching manifests itself in spectral shifts due to changes in the electrical surface conductance and in modifications of the electronic structure consistent with the results of outer valence Green’s function calculations. The photoemission results appear to establish azobenzene as an optoelectrical molecular switch

Children's tooth decay in a public health program to encourage low-income pregnant women to utilize dental care

<p>Abstract</p> <p>Background</p> <p>A community-based public health program to provide a dental home for women covered by the Oregon Health Plan (Medicaid) in Klamath County, Oregon USA was instituted with the long-term goal to promote preventive oral care for both mothers and their new infants provided by dental managed care companies.</p> <p>Methods</p> <p>As part of the evaluation of the program, children in Klamath and comparable non-program counties were examined in their 2^ndyear of life to begin to determine if benefits accrued to the offspring of the mothers in Klamath County.</p> <p>Results</p> <p>Eighty-five and 58.9% of the children were caries free in the Klamath and comparison county samples, respectively (RR = 1.48, 95% CI 1.13, 1.93). The mean (SD) number of teeth with any decay was .75 (2.5) in the test population and 1.6 (2.5) in the comparison population (t = 2.08, p = .04).</p> <p>Conclusions</p> <p>The assessment showed that children of mothers in the Klamath County program were about one and a half times more likely to be caries free than children in the comparison counties. Additional controlled studies are being undertaken.</p