Direct Vapor Pressure Measurement of Heatset Inks

Several types of ink are used in web offset printing. However, heatset inks predominate in general commercial work. In these inks, the vehicle consists of resin dissolved in a solvent, and drying takes place mainly by evaporation. In heatset web offset printing, the printed web is passed through dryers, which raise the temperature of the web enough to cause evaporation of the solvent. leaving only the resin to bind the pigment into a film and to the paper.

Since the solvents used in the heatset inks vary in boiling range from approximately 232° C to 316° C, and the solvent selected depends on the printing conditions, it is necessary to determine the vapor pressure values of heatset inks versus web temperatures for drying calculations. The isoteniscope method is limited to only the vapor pressure measurement of liquids. It cannot be used for materials such as heatset inks. To overcome this difficulty, an apparatus was designed and con- structed by TEC Systems for directly measuring the vapor pressure versus temperature of heatset inks from approximately 21°C to 316°C. In this paper, TEC's apparatus, test procedure developed, and typical test results for pure solvents and heatset inks will be described.     

A simplified method for calculating the substation grounding gridresistance

A simple and accurate formula for calculating the grounding grid resistance is proposed in this paper. This method is based on a theoretical manipulation of the numerical moment method and of the current image. The formula is dependent on the substation grounding grid design, such as grid depth, grid size, number of meshes, grid-conductor diameter, etc. A comparison study is performed to check the accuracy of the proposed formula with respect to six different formulas and methods in the literature. An excellent agreement was found between the results of this formula and the results of a sophisticated computerized method     

On the design of multiple key hashing files for concurrent orthogonal range retrieval between two disks

This paper concerns the following problem: given a set of multi-attribute records, a fixed number of buckets and a two-disk system, arrange the records into the buckets and then store the buckets between the disks in such a way that, over all possible orthogonal range queries (ORQs), the disk access concurrency is maximized. We shall adopt the multiple key hashing (MKH) method for arranging records into buckets and use the disk modulo (DM) allocation method for storing buckets onto disks. Since the DM allocation method has been shown to be superior to any other allocation methods for allocating an MKH file onto a two-disk system for answering ORQs, the real issue is knowing how to determine an optimal way for organizing the records into buckets based upon the MKH concept.

A performance formula that can be used to evaluate the average response time, over all possible ORQs, of an MKH file in a two-disk system using the DM allocation method is first presented. Based upon this formula, it is shown that our design problem is related to a notoriously difficult problem, namely the Prime Number Problem. Then a performance lower bound and an efficient algorithm for designing optimal MKH files in certain cases are presented. It is pointed out that in some cases the optimal MKH file for ORQs in a two-disk system using the DM allocation method is identical to the optimal MKH file for ORQs in a single-disk system and the optimal average response time in a two-disk system is slightly greater than one half of that in a single-disk system.     

Semiconductor optical amplifier for CWDM operating over 1540-1620 nm

A semiconductor optical amplifier was developed for coarse wavelength-division-multiplexing (CWDM) operating over 1540-1620 nm (C-L band). A unique quantum-well structure was designed to meet the requirements for the CWDM operation such as wide bandwidth, low polarization-dependent gain, and high-saturation power at the short wavelength end of the band (1540 nm). Over the band, 24-dB maximum chip gain was obtained with less than 4.3-dB gain flatness and more than 14.6-dBm saturation power.     

Use of 3D modelling and several ultrasound sensors to assess overflow rate.

A new instrumentation mode has been put in place in order to determine the overflow rate of five complex CSOs of the system in Sélestat (French), which are subject to self monitoring. 3D and 1D models have made it possible to predict the shapes of the water lines and suggest a location for the ultrasound sensors. In order to validate the instrumentation principle, three overhead sensors were placed on a weir. The overflow laws suggested are of the type Q(overflow) = a1h1b1 + a2h2b2 + a3h3b3. Early results of the overflow rate that have been obtained by applying the law are close to 10 % of the flow measured in the physical test bench. On the actual site, the ultrasound sensors were assembled on a rail covering the entire weir in order to be able to change their position in future after models calibration.     

Electroluminescence spectroscopy for reliability investigations of 1.55 μm bulk semiconductor optical amplifier

This paper demonstrates the complementary relation between functional parameters and electroluminescence spectroscopy for reliability investigations of 1550 nm Semiconductor Optical Amplifiers of 700 μm length active region. Ageing tests have been set to 270 mA-100 °C-1500 h and realized on two different wafers showing more impact on wafer 1 than on wafer 2. Our investigations are particularly focused on interpretation of electroluminescence spectra, from reference and aged SOAs of wafer 1, leading to an improvement of degradation mechanisms understanding. The shift rate to lower energies of the recombination energy peak at 1550 nm, as reported by electroluminescence spectra between reference and aged SOAs in relation with the decrease of optical power measured at 200 mA for the degraded SOA and completed by I(V) characterizations, suggest occurrence of non radiative deep centers near the buried ridge structure in relation with the cleaning process uniformity of interfaces before epitaxial overgrowth. These defects mainly trap majority injected carriers instead of minority carriers reducing the luminescence in the active zone. By monitoring the most sensitive failure indicator (pseudo-threshold current), lifetime distributions are also calculated to determine failure rate, between 150 and 200 FITs over 15 years for operating conditions (25 °C-200 mA) using experimental degradation laws and statistic computations, demonstrating the overall robustness of this technology.     

Precision winding of fiber optic filament. II. Winding control

For pt.I see ibid., vol.39, no.3, p.258-67 (1992). The winding of fiber optic filament in the hoop, or precision, pattern is considered. Various automatic control options that have been designed and tested are described. The controllers are designed to regulate the fiber lag angle, which is the angle at which the feed filament approaches the take-up spool. Successful, flawless winding is directly related to accurate lag regulation. The contributions are distinguished by the fact that the automatic winding rate is 10 to 30 times greater than that achieved before by operator-assisted winding     

Effects of measurement errors on microwave antenna holography

The effects of measurement errors appearing during the implementation of the microwave holographic technique are investigated in detail, and many representative results are presented based on computer simulations. The numerical results are tailored for cases applicable to the utilization of the holographic technique for the NASA's Deep Space Network antennas, although the methodology of analysis is applicable to any antenna. Many system measurement topics are presented and summarized