Performance implications of the thermal-induced frequency drift infast wavelength switched systems with heterodyne detection

The frequency modulation response and tuning dynamics of a two-section DFB laser are determined by carrier and thermal modulation of the active layer refractive index. In response to a step change in the injection current for switching between channels in a wavelength division multiplexed system, the optical frequency changes rapidly due to the carrier effect, and then slowly drifts toward a steady state value due to the thermal effect. For wavelength switched applications with heterodyne detection, the drifting of the optical frequency broadens the spectrum of the IF signal and may impose a limit on the time that the signal remains within the IF passband (residency time). The IF spectral broadening and residency time are investigated theoretically and experimentally. Based upon a minimum mean square error fit between experimental and theoretical FM responses, the dependence of the spectral broadening and residency time on the bias condition of the laser and the optical frequency switching interval is characterized     

A new technology for preparation of saturating powder mixtures for diffusion galvanizing

The powder mixtures used for diffusion galvanizing (Zn + inert filler + activator) have the following deficiencies: susceptibility to sintering and fusing under elevated CTT temperatures, complexity of correcting the set of components in repeated use of the mixtures and the related instability of the results obtained, complexity of regeneration of worked-out mixtures, elevated ecological hazard of their use, etc. This explains the need for the present work, which shows that most of the mentioned deficiencies can be eliminated by an appropriate choice of the mixture components and (or) preliminary treatment of them.     

Dynamic thermal methods and microprocessing units for measuring the rates and properties of material flows

A multifunctional measurement system utilizing a noncontacting, thermal-tracer primary detector is described. It provides for the automatic acquisition of information on volumetric and mass flow rates and the properties of fluid flows.Translated from Izmeritel'naya Tekhnika, No. 8, pp. 10–11, August, 1994.     

Thick film NO2 Sensor

 Thick film technology was used to manufacture a solid-state electrochemical nitrogen dioxide sensor. The prepared sensor has a linear dependence of electromotive force that is based in the NO₂ concentration level. This paper presents discussion on a thick-film sensor that has a much smaller dimension and shorter response time as compared to typical ceramic solid-state electrochemical devices. Received: 26 February 1996/Accepted: 27 June 1996     

Elderly hospitalized patients'' perceptions of the interaction with the social worker during discharge planning

During parasitization of Heliothis virescens, Campoletis sonorensis deposits an egg along with venom, polydnavirus particles (CsPDV), and ovarian proteins (OPs). Oviposited eggs are not encapsulated, while washed eggs are encapsulated rapidly by H. virescens. Early protection from encapsulation is afforded by a group of 29-36 kD OP glycoforms. These glycoforms are endocytosed by host hemocytes within 30 min post-parasitization (pp) and disrupt hemocyte spreading behavior and egg encapsulation through at least 24 h p.i. Purified CsPDV does not protect eggs from encapsulation early, but disrupts hemocyte spreading and egg encapsulation from 24 h through at least 5 days p.i. Functional activity of CsPDV appears to be correlated with time-dependent accumulation of virus-specific proteins in parasitized insects. We propose that the fast-acting 29-36 kD OP protects Campoletis eggs from encapsulation until accumulation of CsPDV proteins which sustain immunosuppression.     

Predicting the dynamic behavior of axial-field actuators

A method is presented for predicting the dynamic behavior of axial-field actuators. This method entails the numerical solution of a system of nonlinear differential equations that govern the dynamics. The theory is applied to a specific actuator geometry, and the predicted results are compared with empirical data