Showing papers on "Water environment published in 1981"

The Water Environment

Abstract: IAEA Sub-programme on water resources IHS plans for 1999-2000 In memoriam Measuring climate change Hydrology, isotopes and the IAEA 1997 IAEA group fellowship training Isotopes in arid-zone hydrology Stream gauging with tracers in Graz, Austria. See page 6

Micromechanics of Flaw Growth in Static Fatigue: Influence of Residual Contact Stresses

Abstract: Residual contact stresses about indentation flaws are demonstrated to have a strong deleterious effect on specimen lifetime in static fatigue. The underlying basis of conventional fatigue analysis is first examined critically and is argued to be deficient in the way the stress intensity factor for the flaws is related to the characteristic parameters of crack geometry and applied loading. In general, it is necessary to incorporate a residual term into the stress intensity formulation. A modified theory of static fatigue is accordingly developed, in which the residual contact stresses play a far from secondary role in the micromechanics of flaw evolution to failure. Strength tests on Vickers-indented soda-lime glass disks in water environment provide clear experimental confirmation of the major theoretical predictions. Implications of the residual stress effect concerning fracture mechanics predictions of lifetimes for “real” ceramic components under service conditions are discussed.

Virus Survival in Receiving Waters

Abstract: Large numbers of potentially dangerous enteric viruses are regularly discharged into the water environment where they are known to survive better than fecal indicator bacteria. The use of such waters can, therefore, pose a threat to human and animal health. A number of laboratory and field studies have been conducted to determine how long enteric viruses can survive in various types of receiving waters. However, the inherent differences in viruses used and the variations in experimental design and method of reporting the results make it very difficult to draw any general conclusions from the data available. Among the factors that may affect virus survival in receiving waters are: (a) hydrological, seasonal and climatic (temperature, rate of flow, volume, turbulence, average depth and the nature and extent of suspended particulates and sediment of the receiving waters, rain, snow fall and sunlight), (b) chemical (pH; organic and inorganic components), (c) biological and biochemical (bacteria, fungi, protozoa, shellfish and other species of aquatic plants and animals), (d) pollutants (domestic, industrial, agricultural and farm). Our understanding of virus survival in receiving waters is still very rudimentary. Substantial progress in this regard cannot be expected unless better virus “anchors” are developed to permit a closer simulation of field conditions. There is also a pressing need for the standardization of materials and methodology to be used in such investigations.

Construction of hydration shells for the tautomeric forms of heterocycles based on electrostatic potentials

Abstract: A formalism for the determination of the most favored sites of monohydration and the orientation of water molecules around a solute by means of electrostatic potentials is suggested. The results of this method may serve as starting point for explicit supermolecule calculations. The hydration schemes determined in this way for the tautomeric forms of 2- and 4-hydroxypyridine can be used as a basis for the evaluation of the displacement of the lactam–lactim equilibrium under the influence of the water environment.

Low Cycle Fatigue of Commercial Piping Steels in a BWR Primary Water Environment

Abstract: This report summarizes results of a comprehensive experimental program on the low cycle fatigue behavior of commercial grade piping steels in a high-pressure, high-temperature, oxygenated water environment. A total of 110 specimens of special design were tested in a boiling water reactor (BWR) primary water environment (500°F, 1040 psig (or 260° C, ∼ 7 MPa). Four piping steels, in several different metallurgical conditions, were involved (Types-304 and –304L stainless steels, Inconel-600 and A-516 carbon steel). Companion tests, employing the same types of specimens, were conducted in 500° F (260° C) air. The results of this work confirm the adequacy of the current ASME Section III fatigue design curves to account for the effect of a BWR primary water environment on the low cycle fatigue behavior of the four materials tested.

System for holding and transporting lobsters

Abstract: A specially adapted container for transporting lobsters or other marine organisms in an aerated water environment is in the basic configuration of a drum housing with removeable cover and vent hole. A low pressure air diffuser is positioned in the drum housing at the base for releasing diffuse low pressure air into sea water contained in the drum. Air coupling for delivering low pressure air to the diffuser is provided along with inlet and outlet openings for circulating fresh sea water in lieu of diffuser aeration. Different covers for the container may be provided for loading by the fisherman and for subsequent transport. The invention further includes a complete system for containerized transport of lobsters by truck or other vehicle in the aerated water environment provided by the containers. The method of the invention provides for handling and transporting lobsters in aerated sea water from a boat at the dock to a lobster pound or similar destination. The method may be completely automated as disclosed. Injury to the lobsters and consequent shrinkage of pounded lobsters live stored for long periods of time is effectively eliminated.

Detecting acoustic emission during cyclic crack growth in simulated BWR environment

Abstract: An attempt is made to detect and analyze acoustic emissions from cyclic crack growth in SA 533 Grade B steel in the simulated boiling-water reactor (BWR) water environment. Significant levels of signals caused by the environment-enhanced crack growth were obtained through appropriate noise reduction techniques. By reducing the frictional noises between the loading pins and the specimen, and by characterizing the spectrum of signals emitted from various sources, discrete signal identification was made possible. From an empirical relationship between the energy of emission and the crack growth rate, the possibility of utilizing this type of acoustic emission technique was discussed in relation to future continuous monitoring of operating nuclear plants. 10 refs.

Detecting acoustic emission during cyclic crack growth in simulated BWR environment. Discussion

Abstract: An attempt is made to detect and analyze acoustic emissions from cyclic crack growth in SA 533 Grade B steel in the simulated boiling-water reactor (BWR) water environment. Significant levels of signals caused by the environment-enhanced crack growth were obtained through appropriate noise reduction techniques. By reducing the frictional noises between the loading pins and the specimen, and by characterizing the spectrum of signals emitted from various sources, discrete signal identification was made possible. From an empirical relationship between the energy of emission and the crack growth rate, the possibility of utilizing this type of acoustic emission technique was discussed in relation to future continuous monitoring of operating nuclear plants.

Development of In-Reactor Fuel Behavior Observation System

Abstract: A great effort has been made to develop an optical apparatus for direct observation of transient fuel behavior in a water environment in actual in-reactor experiments. There are many difficulties to be overcome, such as high radiation fluence, limited space, shock pressure generation, fission products release. Through the extensive irradiation tests of various kinds of glasses, optical fibers and film and ex-reactor simulation tests, an in-reactor fuel behavior observation system was designed and fabricated for NSRR (Nuclear Safety Research Reactor) experiments. The system consists of a test capsule and connected upper containments. As an image guide is installed inside the containment a periscope with non-browning lenses whose lower part is covered by a stainless steel pipe with anti-shock window made of quartz in the test capsule, and the top of the periscope is connected with a high speed camera. A high intense lamp is immersed directly into water in the capsule as a light source. The motion pictures t...

Water-armed/air-safed release apparatus

Abstract: An improved release apparatus, including an actuator device, a release dee and a firing device, releases the firing device in a water environment and not in an air environment when the actuator device is remotely actuated. When in a water environment, a predetermined gas pressure from the actuator device drives forward a pusher piston and valve sleeve arrangement, disposed in a water chamber of the release device, initially to close off lower entry/exit orifices in the water chamber by action of the valve sleeve, and then to compress an entrapped column of water to a predetermined water pressure sufficiently to cause shearing off of an annular lip of a ball lock piston thereby separating the firing device from the release device. When in an air environment, the pressure from a compressed entrapped air column is not sufficient to cause shearing off or folding down of the annular lip of the ball lock piston, and, accordingly, the release apparatus is safed.

Countercurrent steam/water flow above a perforated plate-vertical injection of water. Topical report, August 1980-July 1981

Abstract: Countercurrent flow limiting phenomenon above a perforated plate has been studied in a steam/water environment. Water was injected as a vertical jet and the injection height above the perforated plate was changed from 0 cm to 35.6 cm. The 15 hole perforated plate has a rectangular cross section with a perforation ratio of 0.423. The weep-points and total dumping points have been determined for low and high water injection heights above the perforated plate and the results have been compared to those of the horizontal water spray experiments. The data corresponding to high water injection heights were similar to those of the horizontal water spray experiments. However, a different behavior was observed for the weep-point data with low water inlet heights. The dumping point was little affected by the water inlet position above the perforated plate. The dimensionless effective steam flow rate defined for the experiments with horizontal water spray was used to correlate the data corresponding to both the onset of weeping and the total dumping points. The correlation was successful for the weep-point data with high water injection heights. However the dimensionless parameter was redefined for the weeping-point data with low water injection heights.

Rapid Detection of Enteroviruses in Water by a Quantitative Fluorescent Antibody Technique

Abstract: An indirect fluorescent antibody technique has been developed to rapidly detect and identify selected enteroviruses in the water environment. This method has been applied to poliovirus types 1, 2 and 3 and Coxsackievirus B5. These enteroviruses formed plaques in monolayers of BGM cells which were quantifiable within a 24 hour period. The efficiency of recovery of Coxsackievirus B5 after concentration from 40 liters of water was determined by this technique.

Resedimented volcaniclastics in the Carmanville area, northeastern Newfoundland—depositional remnants of Early Palaeozoic oceanic islands

Abstract: The olistostromal Carmanville ophiolitic mClange of northeastern Newfoundland contains two extensive mafic volcanic and volcaniclastic rafts (4 km x 1 km, 11 km X 7 krn), which were previously interpreted as an assemblage of lavas and pyroclastics. These rafts are ? Upper Cambrian - Arenigian in age and, prior to tectonic transport and subsequent resedimentation and incorporation into the submarine slides (olistostromes) of the Carmanville ophiolitic mClange, were originally deposited on the slopes of a volcanic edifice (volcanic islands). The primary sedimentation history and depositional environment of the volcanic and volcaniclastic rocks are examined in detail. Four volcaniclastic facies are now recognized (facies 14), each differentiated on the basis of megascopic descriptive and genetic criteria. The essential characteristics of each facies are described in detail. These facies essentially represent shallow-water mafic volcanic material resedimented into a deeper water submarine slope or fan valley system by mass-emplacement depositional mechanisms, which included debris, turbidity, and possibly fluidized sediment flows. Normal contour-following bottom currents could possibly have been responsible for depositing or at least reworking some of the volcaniclastic siltstones of facies 3. Facies 1-4 were introduced into a deeper water environment itself characterized by the formation of massive and pillowed lavas and their hyaloclastic equivalents (facies 5) envisaged as the end product of deposition from submarine seamounts and guyots.

The Directory to Toxic Blue-Green Algae (Cyanobacteria) Literature

Abstract: This literature search was conducted in order to provide a comprehensive list of the publications concerning toxic blue-green algae Although originally intended for distribution to participants at the 1980 conference on The Water Environment: Algal Toxins and Health, it is hoped that this directory will be of use to all researchers interested in the subject Our sources for this directory were several review papers, computer searches, and personal communications from conference participants and others around the world Many important articles are published in journals which may not be widely distributed We hope this directory will help lead researchers to literature they might otherwise have missed Interesting developments are taking place in toxic blue-green algae research Good communication between researchers all over the world is needed now more than ever

The effect of water and hydrogen gas environments on subcritical crack growth in generator rotor steels

Abstract: Long-time (approximately WOO days) static and cyclic loading subcritical crack growth tests were conducted with 4 in (1016 cm) thick WOL-type compact toughness specimens of NiMoV and NiCrMoV rotor steels exposed to both distilled water and dry hydrogen gas environments Results show that neither steel is susceptible to environment induced cracking under static loading conditions in the test environments However, environment did have a significant detrimental effect on the fatigue crack growth performance of both steels The hydrogen gas environment increased the rate of fatigue crack growth by factors of about 5 and 10 (over that encountered in laboratory air) for the NiCrMoV and NiMoV steels, respectively A t a low frequency (00017 Hz), the water environment increased the rate of fatigue crack growth by a factor of about 25 to 3 for both steels It was also shown that loading frequency has a significant effect on the fatigue crack growth behavior observed in water (increasing growth rate with decreasing frequency) but no effect on the behavior observed in hydrogen gas The results of these long-time tests were compared to results generated with more conventional short-time tests and recommendations made for predicting long-time subcritical crack growth behavior from short-time tests

The Study of Nitrogen Transformation in Fresh Water: Experiments and Mathematical Modeling

Abstract: Two main transformations occur in water environments -- one due to the effect of microorganisms and the other due to chemical reactions. Both transformations are very closely interwoven. Of the transformation processes in the water environment, nitrogen transformation is perhaps the most interesting because nitrogen and its compounds (both organic and mineral), affect the development of practically all aquatic microorganisms and therefore determine the trophic state and the quality of a water environment. Nitrogen compounds are present in sewage and other waste water discharged into water bodies. Therefore, it is quite understandable why during the last few years nitrogen transformation is the subject of study at descriptive and experimental levels, as well as by mathematical modeling techniques. This paper reports on the results of a collaborative study between IIASA and the Institute of Experimental Biology and Ecology of the Slovak Academy of Sciences in Bratislava, on nitrogen transformations. The data of twelve experiments covering a broad set of initial conditions in nitrogen concentrations and at two temperatures (180 degrees Celsius and 120 degrees Celsius) are presented in this report. These experimental data were analyzed with the help of the mathematical model developed at IIASA (WP-80-86) and intended for understanding processes of nitrogen transformation in water environments. The results of model description of nitrogen compound dynamics are evaluated by statistics to find a quantitative criteria in model assessment. In the discussion of simulation results, attention was focused on the analysis of bacterial activities in the conversion of organic as well as mineral nitrogen forms. The results reported here are considered to be the basis for the simulation of nitrogen dynamics in water bodies and for studying various aspects of ecology and aquatic ecosystem behavior.