Photographic Image Intensification and Reduction: A Unified Optical Approach

A simple, non-destructive method of image intensification and reduction is described which can be applied to continuous-tone negative materials. The method employs a commercially available direct copy (reversal) film whose contrast (γ) can be continuously varied by pre-exposure from 0.8 to ~ 10.0. This film is then used with a difTuse-light contact printer to extract images from negatives which have been severely under- or over-exposed. Examples of images extracted from Plus-X negatives which have received from eight SlOps over- to seven stops underexposure are shown. This same process can be used to retrieve usable images from exposures where the chemical or image fog levels approach developed densities of 5.0. The technique compares favourably with the complicated autoradiographic procedures recently introduced for thin negative enhancement but is not affected by high levels of chemical fog. It appears that the process is versatile enough to replace traditional chemical methods of photographic intcnsification and reduction.     

Functional modeling with goal-oriented activities for analysis of effects of failures on functions and operations

Current qualitative device and process models represent only the structure and behavior of physical systems. However, systems in the real world include goal-oriented activities that generally cannot be represented easily using current modeling techniques. We propose an extension of a qualitative modeling system, known as functional modeling, which captures goaloriented activities explicitly, and we show how they may be used to support intelligent automation and fault management.     

Impaired aerobic glycolysis in muscle phosphofructokinase deficiency results in biphasic post-exercise phosphocreatine recovery in 31P magnetic resonance spectroscopy

Using 31P magnetic resonance spectroscopy, energy metabolism in calf muscles of two patients with biochemically and genetically proven muscular phosphofructokinase deficiency, and an asymptomatic heterozygote was monitored during isometric foot plantarflexion performed under aerobic and anaerobic conditions and in the aerobic recovery phases. In the heterozygote only a moderate alteration from normal was found in terms of an elevated ATP demand during exercise. In the homozygote, hexose phosphates, indicated as phosphomonoesters, increased dramatically during contraction. Phosphomonoester accumulation resulted in consumption of free inorganic phosphate (P(i)). During ischemic exercise the absence of glycolytic ATP formation resulted in a linear time course of phosphocreatine breakdown and a moderate alkalinization. During the recovery, phosphocreatine resynthesis showed a biphasic time course, indicating that mitochondrial function itself was not directly affected. At first glance, the early depletion of P(i) below initial resting levels and the rate of phosphate splitting from sugar phosphates seemed to become the limiting factor for the rate of the oxidative phosphorylation and creatine kinase reaction. However, the actual concentrations of P(i) and ADP estimated at the onset of delay were too high to exclusively explain the dramatic delay in PCr resynthesis. For this reason, a reduced turnover of the citric acid cycle was assumed, which was caused by the complete absence of glycolysis in PFK deficiency patients. Furthermore, results from PFK deficiency patients were compared with previous findings from myophosphorylase deficiency patients in the literature.     

A longitudinal study of circulating lymphocyte subsets in the peripheral blood during the acute stage of Guillain-Barré syndrome

We investigated sequential changes in bile flow, serum and biliary biochemical parameters in phalloidin-induced cholestasis in rats. Intrahepatic cholestasis was induced by administration with phalloidin (500 microg/kg) for 7 days, and then the animals were allowed to survive for 1, 2, 4, 7, 14 and 28 days after the last treatment. In phalloidin-treated rats, bile flow significantly decreased up to 4 days of recovery, compared with the control animals. In contrast, serum ALP activity, LAP activity, cholesterol concentration and phospholipid concentration exhibited a marked elevation throughout the recovery periods. For biliary parameters, bilirubin excretion rate was unchanged but, cholesterol excretion rate showed a marked decrease throughout the recovery periods. These results demonstrate that some parameters, particularly important indexes of cholestasis (serum ALP, cholesterol, bile flow and so on), continued significant changes at least 4 days after the last administration of phalloidin. These results demonstrate that successive treatment with phalloidin can cause damage in most of serum and biliary parameters at a chronic stage of cholestasis. Thus, our findings may provide useful information for diagnosis of drug-induced cholestasis and help to further elucidate the biochemical mechanisms of drug-induced cholestasis in humans.     

Thermodynamic investigations of the C-Cr-Fe system by galvanic cell technique

In view of the applications of intermetallic carbides in the hard materials industries, the thermodynamic properties of the C-Cr-Fe system have been measured by the use of the solid-state galvanic cell technique with CaF₂ as the solid electrolyte. The thermodynamic activities of chromium have been calculated from the results of the electromotive force (EMF) measurements. For the calculations, pure bcc-Cr was used as the standard state. X-ray diffraction (XRD) and scanning electron microscopy were used to identify the stable phases present in each investigated sample, as well as for establishing the phase compositions. The experimental results obtained were compared with data calculated by the use of the TCFE3 database available with the Thermo-Calc software.     

Towards integrated catchment management: opening the paradigm locks between hydrology,ecology and policy‐making

A recently launched international initiative on “Hydrology for the Environment, Life and Policy” (HELP) aims at a science‐based approach to integrated catchment management, and in particular to facilitating the dialogue needed between scientists, stakeholders and policy makers. The ultimate challenge of a sustainability‐oriented environmental management is to find the proper balance between humans and the impacts that their activities cause to ecosystems. This makes the catchment a useful landscape unit for an integrated approach where a balancing between humans and nature can be carried out. The catchment can be seen as containing two mosaics, one of human water‐related activities and the other of water‐dependent ecosystems, terrestrial as well as aquatic. These two mosaics are internally linked by water flows but partly incompatible. Therefore, a management task is to orchestrate the catchment for compatibility, which will demand intentional trade‐offs. Past water management policy has often been based on outdated knowledge and technology, for instance by a ‘paradigm lock’ between scientists and stakeholders, isolating them from each other: scientists by the lack of proven utility of their findings, and stakeholders by legal and professional precedence and disaggregated institutions. The HELP initiative encourages the water policy, water resources management and scientific communities to work together within a field‐oriented context so that science may be closely integrated with policy and management needs.     

The physical metallurgy of high strength zirconium alloys

The requirements of materials for use in the core section of unenriched uranium type nuclear reactors are, to a large extent, fulfilled by zirconium alloys. However, the operating temperature of such reactors is circumscribed by the inability of the presently available alloys to maintain their properties at temperatures exceeding 350–400° C. This paper is concerned with the selection of alloying elements for the improvement of the high temperature strength of zirconium alloys and reports the results obtained from a study of the phase transformations in dilute Zr-Cr alloys.     

Effect of orientation on electrical properties of polymers

This article deals with the effect of orientation on the electrical properties (tangent of the angle of dielectric losses tan δ, electric strength E, and lifetime τ) of polymer films. It is shown that the orientational stretching of PVC and PC films leads to the change of the temperature position of dipole segmental losses and reduces the value of tan δ in the maximum of this region. Under the orientation the electric strength of PE and PVC films increases considerably, and the lifetime τ increases under the high strengths of the field, and reduces under the low ones. The mechanical loads causing no orientation only reduce the lifetime of the polymer films.