OA&M framework for multiwavelength photonic transport networks

Photonic networks based on wavelength division multiplexing (WDM) and optical path technologies are expected to realize flexible, transparent, and cost-effective transport networks with a large transmission capacity. This paper explores the design framework of photonic transport networks taking into consideration the operation administration and maintenance (OA&M) functions required for the successful introduction of WDM systems based on the optical path concept. From the view point of network maintenance, clear distinction is made between the optical path layer and the optical section layer to facilitate accurate and smooth failure localization. The digital multiplexing span between physical multiplexing interfaces at the end-to-end digital nodes should have the same maintenance span as the corresponding optical path. We argue that cooperative maintenance by OA&M functions at both the digital and optical layers can be a practical way of network supervision. A supervisory (SV) signal transfer method and a configuration that is suitable for the terrestrial trunk network are also indicated. As an example, a practical SV system design methodology and an actual procedure developed for a single channel optical transmission system based on optical in-line amplifiers are introduced. Furthermore, application of the developed SV system and network restoration schemes is discussed for future WDM-based photonic networks. The OA&M aspects introduced will be valuable for creating future photonic network systems     

Air entrainment in fresh concrete with PFA

The results of a study into the influence of PFA on air entrainment in fresh concrete are discussed It is shown that the required dosage of AEA to produce an air content of 5.5 ± 0.5% in a PFA modified concrete mix is two-six times that required in the corresponding neat OPC concrete mix. The dosage of a vinsol based air entraining agent (AEA) required appears to be directly related to the PFA content of the mix. Similar direct relationships were obtained with a range of different PFAs. The dosage of an AEA based on the salt of a fatty acid appears to be sensitive to both PFA and OPC contents. For the type of PFA used, the variability of measured air content or the amount of air retained after continued agitation both indicated that vinsol based AEAs show the highest variability whilst fatty acid based AEAs show low variability. The between batch variability of air content was significantly improved by the addition of PFA regardless of the AEA used.     

Use of a transparent rabbit ear chamber in the study of biomaterials

Tests of biocompatibility are obligatory in the development of implants. Use of a polycarbonate transparent rabbit ear is a practical and relatively economical way of observing and documenting progressive interaction between potential prosthetic materials and granulation tissue. Fabrication of the chambers is technically straightforward and the surgical procedure involved in their insertion is simple and minimally invasive.     

Fluorimetric methods for the measurement of intermediate metabolites (lactate,pyruvate, alanine, β-hydroxybutyrate,glycerol) using a COBAS FARA centrifugal analyser

Intermediate products of the metabolism of glucose, fat and amino-acid are important in the evaluation of such metabolic disorders as diabetes mellitus, liver disease and metabolic acidosis. In the present study, methods for the measurement of intermediate metabolites (lactate, pyruvate, alanine, β-hydroxybutyrate and glycerol) have been adapted to a fast centrifugal analyzer: the COBAS FARA. Correlation coeffcients rangedfrom 0.90 to 0.99, compared to established manual spectrophotometric methods. Within-run coeffcients of variation (CVs) ranged between 2.9 and 8.8% at low levels, between 1.5 and 5.7% at medium levels and between 1.2 and 5.6% at high levels. Between-run CVs were between 4.0 and 15.0% at low levels, between 1.7 and 7.0% at medium levels and between 1.3 and 2.7% at high levels. These fluorimetric assays for the determination of intermediate metabolites on COBAS FARA (Roche) have a good sensitivity and precision, are less costly than manual methods and can be used on a routine basis.     

Microparticle separation on a perforated electrode in a nonuniform electric field

We solve the problem of passage of microparticles through a perforated electrode under conditions of their electrodynamic fluidization (EDF) in a nonuniform electric field. It is shown that when the particle size is considerably smaller than the perforated hole size, microparticle sizing takes place in the region under the electrode. We report the experimental data.Intrabranch Institute of Advanced Training at the Ural State Technical University, Ekaterinburg, Russia. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 66, No. 1, pp. 46–49, January, 1994.     

Effects of high fat diets on the activity of palmitoyl-CoA hydrolase in rat liver

Palmitoyl-CoA hydrolase [EC 3.1.2.2.] activity in rat liver was found to be enhanced by high fat diets. Partially hydrogenated marine oil and high-erucic acid rapeseed oil diets produced a greater increase than a diet containing soybean oil. With diets containing from 5 to 30% (w/w) of partially hydrogenated marine oil the increase in palmitoyl-CoA hydrolase activity was similar to the increase observed in peroxisomal β-oxidation activity (correlation coefficient r=0.94). A positive correlation (r=0.86) also was observed between the activity of palmitoyl-CoA hydrolase and previously determined levels of long-chain acyl-CoA. The results presented may suggest a common “induction” mechanism for palmitoyl-CoA hydrolase and peroxisomal β-oxidation enzymes, possibly exerted through an increased cellular level of long-chain acyl-CoA.