Ceramic coatings on smooth surfaces

A metallic coating is plasma sprayed onto a smooth surface of a metal alloy substitute or on a bond coating. An initial thin ceramic layer is low pressure sprayed onto the smooth surface of the substrate or bond coating. Another ceramic layer is atmospheric plasma sprayed onto the initial ceramic layer

Champion Networks in Federated Interorganizational Systems: Case Studies in Telemedicine

Champions are critical to the success of an information system implementation. Research shows that success in implementing a large information system may hinge on there being more than one type of champion. This study investigates the types of champions used in federated inter-organizational systems (FIOS) in a state telemedicine context. Case studies were conducted in Georgia, Pennsylvania, Ohio, and Wisconsin to identify the network of champions in state telemedicine systems. We found that FIOS that relied on a network of champions, including a sponsorship champion at the state level, as well as a technical champion and user champion at site locations, were more successful than those that lacked such a network. We suggest that our model of champions in FIOS applies not only to state telemedicine, but also to any large-scale system implementation spanning a federation of loosely coupled organizations

Kinetic modeling of free radical polymerization of styrene initiated by the bifunctional initiator 2,5-dimethyl-2,5-bis(2-ethyl hexanoyl peroxy) hexane

This paper deals with the kinetic study of bulk free radical polymerization of styrene initiated with the commercial bifunctional initiator 2,5-dimethyl-2,5-bis(2-ethyl hexanoyl peroxy)hexane (Lupersol 256). The polymerization kinetics is investigated by DSC measurement for temperatures between 80 and 110°C and for initiator initial concentration from 0.115 up to 0.46 mol%. The experimental conversion and reaction rate are compared and discussed with the calculated values. For modeling the polymerization rate, a reaction scheme similar to the one given by Yoon and Choi (Polymer 1992;33(21):4582–4591) has been used and adapted. A detailed diffusional and semi-empirical model proposed by Chiu et al. (Macromolecules 1983;16(3):348–357) has been modified by Rouge (Etude de la polymérisation radicalaire du styrène initiée par un amorceur bifonctionnel dans un réacteur tubulaire à recyclage, Diploma work, DC, EPF, Lausanne, 1997) in order to describe these results. The model allows the description of the number molecular weight, but the polydispersity is underestimated for conversion higher than 70%. For temperature higher than 100°C, thermal initiation must be taken into account. The efficiency factor is found close to 1, but seems to decrease for temperatures above 100°C

Behavior of thiosemicarbazones derived from some terpenones under acetylation conditions. Part II

Preparation of chiral heterocyclic compounds of the thiadiazoline types, starting from natural α,β-unsaturated and bicyclic terpenones is described. Stereochemical assignment of the compounds synthesized was performed by NMR spectroscopy and X-ray analysis. ©ARKAT.Fil:D'Accorso, N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Moltrasio, G.Y. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Interoperability applications of TELEMAC-MASCARET System

Water Qualit

Microchannel reactors for fast periodic operation: the catalytic dehydrogenation of isopropanol

A microchannel reactor specially designed for periodic operation and a process to deposit a catalyst, g-alumina, inside the reactor channels were developed. The hydrodynamics of the reactor was characterised. Although the flow in the microchannels is laminar, a uniform radial concentration profile and consequently a narrow residence time distribution were obtained. Depending on the manufacturing method the Bodenstein number was found to be Bo=ud/Dm=~70. The catalytic coating had no influence on this distribution indicating a uniform deposition of the catalyst within the microchannels. As the inlet function was only slightly modified in the reactors, frequencies of up to 1 Hz could be imposed for periodic operation. The dehydration of isopropanol to propene was chosen as model reaction to study the dynamic behaviour of a microreactor under periodic concentration variations. The kinetics was firstly studied in a conventional fixed-bed reactor with the catalyst developed for the microreactor. Experimental results confirmed the theoretically predicted increase of the reactor performance under periodic operation exceeding the maximum obtainable performance under steady-state conditions

Double-Lepton Polarization Asymmetries in B_s \rar \phi \ell^+ \ell^- Decay in the Fourth-Generation Standard Model

In this paper, we investigate the effects of the fourth generation of quarks on the double-lepton polarization asymmetries in the B_s \rar \phi \ell^+ \ell^- decay. It is shown that these asymmetries in B_s \rar \phi \ell^+ \ell^- decay compared with those of B \rar K \ell^+ \ell^- decay are more sensitive to the fourth-generation parameters. We conclude that an efficient way to establish the existence of the fourth generation of quarks could be the study of these asymmetries in the B_s \rar \phi \ell^+ \ell^- decay.Comment: 25 pages and 7 figure