Managing run-time interactions between call-processing features[intelligent networks]

Network service providers continue to require new and different call processing features for their switching systems. Open call processing addresses the limitations of the current feature procurement process by being vendor-independent; i.e. the same call processing model is used for all switching systems and it is required that features be independently installable on a running system. A structure for call processing software that supports open call processing is described. Different approaches to managing call processing features are discussed. The implementation of a simulation model of a feature manager that ties 17 interacting features together into a single feature package is presented     

Chain-configurational properties of novolac phenol–formaldehyde resins

Rotational isomeric-state chain-configurational calculations have been applied to the novolac phenol–formaldehyde structure. Steric interference allows the chain to be considered with a twofold potential energy barrier model. Computations that fit the observed dipole-moment data over a range of molecular weights indicate that the conformational angle is near ±80°, with the g^±g⁼ states on the average being 155 cal/mole below the g^±g^± states. The limiting dipole-moment ratio is computed to be 1.47, compared to the experimental value of 1.48. A negative temperature coefficient agrees in sign with the experimental value, and the characteristic ratio of the end-to-end molecular dimensions is calculated to be 3.27, as compared to the experimental value of 4.76.     

Optically Active Binary Liquid Crystal Thermometry

Research on the biological effects and medical applications of non-ionizing electromagnetic fields often requires the use of nonmetallic non-perturbing temperature sensors. The highly temperature dependent optical activity observed in certain types of liquid crystals makes possible the construction of very sensitive non-perturbing fiberoptic thermometers. A knowledge of the effect of various parameters on the optical rotatory power of the chosen liquid crystal is essential for the construction of such a device. The dependence of the optical rotatory power on temperature, composition, and sample thickness in a binary mixture of a nematic (MBBA) and a cholesteric (Cholesteryl Oleate) liquid crystal was studied. The dependence of effective pitch on composition was determined. Application of the data on rotatory power and effective pitch to the construction of devices is discussed. Illinois under Grant USPHSCA 09067.     

A experimental investigation of turbulent flow and heat transfer in elliptical duets

Fully developed turbulent flow and heat transfer to air and water in ducts of elliptical cross section have been investigated experimentally. For the ducts of aspect ratio 2.5 1 and larger, a reduction in the overall heat transfer rate was found in the lower turbulent Reynold's number range (Re<25,000). Similar effects have been noted by investigators of narrow triangular cross sections where flow measurements indicated the possible co-existence of laminar and turbulent flow resulting in localised increases in thermal resistance. It was found that the analogy between momentum and heat transfer could not be applied directly to the larger aspect ratio ducts where significant circumferential variations of wall temperature occurred.

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Zusammenfassung Voll entwickelte turbulente Strömung und Wärmeübertragung an Luft und Wasser in elliptischen Kanälen wurden experimentell untersucht. Für Kanäle mit Achsenverhältnissen von 2,5 1 und größer fand man eine Verringerung des Wärmedurchgangs im Bereich geringer Reynolds-Zahlen (Re < 25 000). Ähnliche Effekte waren von anderen Autoren in engen Dreieckskanälen gefunden worden, wobei man aus Strömungsmessungen das gleichzeitige Auftreten von laminarer und turbulenter Strömung mit örtlicher Zunahme des thermischen Widerstandes folgern konnte. Die Analogie zwischen Impuls- und Wärmeübertragung konnte nicht unmittelbar auf Kanäle mit großem Achsenverhältnis, bei denen die Umfangstemperatur beträchtlich variierte, angewendet werden.

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Nomenclature A cross-sectional area - b duct wall thickness - C_p specific heat at constant pressure - d_e equivalent diameter of noncircular cross-section (=4A/p) - f Fanning friction coefficient - h local heat transfer coefficient (=q_w/(T_w-T_b)) - ¯h average circumferential heat transfer coefficient - k thermal conductivity of fluid - k_w thermal conductivity of wall material - K^* wall conductivity parameter (= k_wb/kd_e) - p wetted perimeter - q_w wall heat flux - T_b bulk fluid temperature - T_w local wall temperature - absolute viscosity - kinematic viscosity (=/) - mass density - Nu Nusselt number (= h d_e/k) - Nu average circumferential Nusselt number (= ¯h d_e/k) - Pr Prandtl number (= C_p/k) - Re Reynolds number (= d_e/) - St Stanton number (= Nu/Re · Pr)     

The second-order elastic constants of an AgBr-(56.6%) AgCl mixed crystal from 20°C to 400°C

Abstract

Initial measurements of the second-order elastic constants of an AgBr-(56.6%) AgCl mixed crystal have been made from 20—400°C. Over this temperature range, C'₁₁ decreased by 44%, C' by 71%, C₄₄ by 22%, C₁₁ by 53%, C₁₂ by 40%, and B _s by 46%. The decreases in the elastic constants are linear until approximately 280°C, whereupon all but C' begin to decrease more rapidly than linearly with variations from linearity of 4—20% at 400°C and C' remains linear at all temperatures. This anomalous behavior is similar to other silver halide physical properties and may be attributed to the unusually high defect concentration at high temperatures. Similar elastic constant changes are seen in superionic conductors near the superionic transition, indicating that the silver halides may be starting the transition to a superionic state when the halide sublattice melts and the transition is frustrated.     

Aspartate‐Based CXCR4 Chemokine Receptor Binding of Cross‐Bridged Tetraazamacrocyclic Copper(II) and Zinc(II) Complexes

The CXCR4 chemokine receptor is implicated in a number of diseases including HIV infection and cancer development and metastasis. Previous studies have demonstrated that configurationally restricted bis‐tetraazamacrocyclic metal complexes are high‐affinity CXCR4 antagonists. Here, we present the synthesis of Cu²⁺ and Zn²⁺ acetate complexes of six cross‐bridged tetraazamacrocycles to mimic their coordination interaction with the aspartate side chains known to bind them to CXCR4. X‐ray crystal structures for three new Cu²⁺ acetate complexes and two new Zn²⁺ acetate complexes demonstrate metal‐ion‐dependent differences in the mode of binding the acetate ligand concomitantly with the requisite cis‐V‐configured cross‐bridged tetraazamacrocyle. Concurrent density functional theory molecular modelling studies produced an energetic rationale for the unexpected [Zn(OAc)(H₂O)]⁺ coordination motif present in all of the Zn²⁺ cross‐bridged tetraazamacrocycle crystal structures, which differs from the chelating acetate [Zn(OAc)]⁺ structures of known unbridged and side‐bridged tetraazamacrocyclic Zn²⁺‐containing CXCR4 antagonists.