Synthesis and electrical studies of modified PbTiO3 ceramics: (Pb1−x Ca x ) (Mn0·05W0·05Ti0·90) O3

Modified ceramics (Pb_1−x Ca _x )[(Mn_0·5W_0·5)_0·10Ti_0·90]O₃ have been fabricated forx=0, 0·05, 0·10 and 0·15 by high temperature solid state reaction technique. XRD, SEM, DTA and electrical studies of the sample withx=0·10 have been performed. These studies show that the sample is homogeneous single phase perovskite type with tetragonal structure. The phase transition occurs at 330°C. Electrical behaviour of other samples have also been investigated as a function of frequency (1 kHz to 1 MHz) and temperature (26°C to 300°C). The samples withx=0·05 and 0·10 have low loss, low dielectric constant, and show negligible pyroelectric effect. The sample withx=0·15 has minimum values ofɛ and loss which are temperature independent up to about 200°C. It also shows good pyroelectric behaviour. Hence it may be of use in pyroelectric infrared sensors.     

Phenidone blocks the increases of proenkephalin and prodynorphin gene expression induced by kainic acid in rat hippocampus: involvement of Fos-related antigene protein

To determine the possible role of cyclooxygenase/lipoxygenase pathway in the regulation of proenkephalin (proENK) and prodynorphin (proDYN) gene expression induced by kainic acid (KA) in rat hippocampus, the effects of esculetin, aspirin, or phenidone on the seizure activity, proENK and proDYN mRNA levels, and the level of fos-related antigene (Fra) protein induced by KA in rat hippocampus were studied. Esculetin (5 mg/kg), aspirin (15 mg/kg), or phenidone (50 mg/kg) was administered orally five times every 12 h before the injection of KA (10 mg/kg, i.p.). Seizure activity induced by KA was significantly attenuated by phenidone. However, neither esculetin nor aspirin affected KA-induced seizure activity. The proENK and proDYN mRNA levels were markedly increased 4 and 24 h after KA administration. The elevations of both proENK and proDYN mRNA levels induced by KA were inhibited by pre-administration with phenidone, but not with esculetin and aspirin. ProENK-like protein level increased by KA administration was also inhibited by pre-administration with phenidone, but not with esculetin and aspirin. The increases of proENK and proDYN mRNA levels induced by KA were well correlated with the increases of Fra protein level. Additionally, the induction of Fra protein was inhibited by pre-administration with phenidone, but not with esculetin and aspirin. The results suggest that blockade of both cyclooxygenase and lipoxygenase pathways appears to be responsible for increases of proENK and proDYN mRNA levels induced by KA via inhibiting the induction of Fra protein in rat hippocampus.     

High-speed recursive digital filter realization

Pipeline techniques have been successfully applied to speeding up processing in both general- and special-purpose digital computers. Application of these techniques to nonrecursive (FIR) filters has been suggested and is quite straightforward. Application to recursive (IIR) filters has not previously been shown. In this paper, the technique for applying pipeline techniques to recursive filters is shown and the advantages and disadvantages of the technique are discussed. Using these techniques, recursive digital filters operating at hitherto impossibly high rates can be designed.The basic research for this idea was supported by the Department of Electrical and Computer Engineering, University of California, Davis, California 95616. The basic idea is the subject of a pending patent application. Subsequent research was supported by the U.S. Naval Electronic Systems Command.On leave from the Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA.     

Interval Global Optimization in Solvent Design

This paper discusses the use of an interval analysis based global optimization approach for the systematic design of ink cleaning solvent (commonly referred to as blanket washes) for lithographic printing. Very often the end-user (for example the printing press operator) has available to them blanket washes from different manufacturers. These blanket washes have to be mixed in different proportions (often by trial and error) until a blend is obtained that is suited to a particular cleaning operation. The trial and error approaches are costly, time-consuming and may not necessarily yield the solvent blend with the desired performance attributes. For example, the solvent blend may have a drying time that is too slow for the intended use. Another major performance objective is minimizing the effect of the solvent blend on the surface characteristics of the blanket. Surface characteristics of the blanket are affected through the swelling of the rubber blanket, which supports the printing paper. It should be noted that depending on the performance criteria and process constraints, a different solvent blend would be obtained. These criteria may vary according to the printer, the blanket wash sources, and whether or not the blanket wash blend would be dispensed by an automated process or by a manual process. Another thing to note is that in newspaper printing, the ink residue on the blanket has to be removed (using blanket wash) after the morning newspaper edition, in time for the afternoon or evening edition.The simultaneous consideration of associated process constraints, property requirements, and environmental restrictions makes the blanket wash design a rather difficult problem. To address this, we present a framework for designing cleaning solvent blends that meet thermo-physical property requirements and environmental restrictions. The resulting mathematical program is a mixed-integer optimization problem involving (a) the selection of solvents from a set of pure component solvents (the discrete problem) and (b) finding the blend composition (the continuous problem).The framework has been used to solve an industrially relevant problem of designing optimal blends for blanket wash applications in the printing industry taking into account solvent power, viscosity and surface tension.     

Pulp reconstruction of fingers with very small sensate medial plantar free flap

The essence in dealing with the pulp deficit accompanying fingertip injuries lies in functional restitution of the inherent skin texture and characteristics unique to that area and sufficient preservation of digital length, along with successful restoration of fine tactile sensation indispensable to delicate and skillful maneuvers. Among various techniques used to meet such demands, the very small sensate medial plantar free flap can be considered an excellent method in view of the skin texture that allows firm grasping, durability to friction rub, a cushion effect, and adequate sensation. Six cases of finger pulp reconstruction with the very small sensate medial plantar free flap are presented. At follow-up examination (an average follow-up of 24.3 months), the patients were evaluated clinically and neurologically. The operative procedures, advantages, and results in clinical cases are presented. Satisfactory results were obtained with sufficient preservation of digital length and good sensory recovery. No functional deficit was found at the donor site.