Abstract Eine Berechnung von Wärmeübergangskoeffizienten aus den Eigenschaften binärer Flüssigkeitsgemische ist bisher nicht möglich. Um diese Lücke zu schließen, wurde versucht, ausgehend Messungen, Gleichungen zur aufzustellen, in welche die Konzentrationsdifferenz zwischen gasförmiger und flüssiger Phase als Einflußgröße eingeht. Meßergebnisse an 17 verschiedenen binären Gemischen im Druckbereich 1 bis 10 bar ließen sich mit einer mittleren quadratischen Abweichung ß 8,6% durch...

This paper presents a novel approach to synchronizing the phases of several oscillators for coherent power combining either in conventional power-combining circuit or free space as each oscillator drives an antenna element phased array. A set nonlinear differential equations is derived predict system's behavior. These are used computer-aided design and construction demonstration three-oscillator inter-injection-locked system at VHF. Good qualitative agreement between initial experimental...

Based on available experimental data, the thermal conductivity of fluid air has been critically evaluated. A new set recommended values is presented covering a pressure range from 1 to 1000 bar and temperature 70 K. Using concept residual are described by 13-parameter equation state in terms density which may be applied up 900 kg/m3. From comparisons all data sources, uncertainty was estimated below ±4%. Additional experiments needed, especially subcritical region liquid air.

A low-cost radiometric temperature sensor system is described, with emphasis on the use of a 12.5 GHz near-field focused microstrip array to provide low-profile compact product suitable for commercial and industrial applications. An overview given, followed by design details array, including patterns antenna efficiency measurements. Temperature measurements made in food-processing plant field test show that can resolve individual hamburger patties at practical measurement distance

Abstract Die bekannte Graetz‐Nußelt‐Lösung für den Wärmeübergang laminarer Rohrströmungen setzt ausgebildete Geschwindigkeitsprofile voraus. Sofern jedoch bei Beginn einer Beheizung oder Abkühlung das Geschwindigkeitsprofil noch nicht ausgebildet ist, überlagern sich die hydrodynamische und thermische Einlaufströmung. Dieses Problem wird unter Annahme konstanter Stoffwerte untersucht.

The viscosity and the thermal conductivity of fluid nitrogen were critically evaluated correlated on basis a comprehensive literature survey. Recommended values generated in temperature range from 70 to 1100 K pressures up 100 MPa using residual concept. To retain consistency with IUPAC Thermodynamic Tables, same thermodynamic key data used. Additionally, so-called transport equation state was established that makes it possible achieve unified representation terms pressure temperature.

The behavior of a system coupled oscillators is shown to have potential applications in the generation power for integrated phased antenna arrays. Nonlinear differential equations are derived describe by an arbitrary frequency-dependent network. State-variable analysis linearized leads closed-form solutions one- and two-dimensional array systems. Experimental data VHF prototype presented, practical considerations design discussed.

An integrated planar antenna-mixer structure for use at millimeterwave frequencies is described. A simple but accurate theory of the slot-ring antenna applied to several experimental devices. Mixer conversion loss about 6.5 dB was obtained from an X-band model. Measured radiation patterns structures designed 65 GHz agree reasonably well with theory.

Alkohol Geraniol isomer,

Supplementing the recently completed IUPAC tables for thermodynamic properties of oxygen, this paper presents a data evaluation transport properties, viscosity, and thermal conductivity. From comprehensive literature survey available have been complied, their quality was assessed. Selected measurements were correlated to generate skeleton most reliable along vapor-liquid coexistence curve fluid region at pressures from 0.1 100 MPa temperatures 70 1400 K. The set correlations which developed...

The social implications of a wide variety technologies are the subject matter IEEE Society on Social Implications Technology (SSIT). This paper reviews SSIT's contributions since Society's founding in 1982, and surveys outlook for certain key that may have significant impacts future. Military security technologies, always interest to SSIT, become more autonomous with less human intervention, this both good bad consequences. We examine some current trends such as mobile, wearable, pervasive...

Abstract Bei turbulenter und bei laminarer Strömung in Ringspalten kann die Wärme entweder nur am Innenrohr, oder Außenrohr, schließlich an beiden Rohren übertragen werden. Der Wärmeübergang läßt sich durch modifizierte Formen der für Rohrströmung gültigen Gleichungen von Hausen beschreiben. Die abgeleiteten eignen zur Berechnung Wärmeübergangszahl erzwungener Ringspalten; sie gelten alle Bereiche des Durchmesserverhältnisses.

Abstract Es wird ein Modellbild vom Mechanismus der Wärmeübertragung an siedende Flüssigkeiten entwickelt. Dazu zunächst die Bildung von Dampfblasen festen Wänden studiert. Mit Hilfe dabei gewonnenen Ergebnisse läßt sich Einfluß Blasenbildung auf den Wärmeübergang untersuchen. Damit ist es möglich, dimensionslose Kenngrößen anzugeben. Zur Aufstellung eines Modellgestzes werden Experimente durchgeführt, um auch Oberflächenrauhigkeit Heizfläche zu erfassen.