Showing papers on "Water environment published in 1980"

Confirmation of Biot’s theory

Abstract: Plona’s recent measurements of elastic‐wave speeds in a water‐saturated porous structure of sintered glass beads are compared quantitatively to the predictions of Biot’s theory. The theoretical predictions lie within the bounds of experimental error (3%) for the fast compressional wave and for the shear wave in all cases. For the slow compressional wave, the theoretically predicted speeds lie within about 10% of the experimental values and increase with increase in porosity as observed. Our model achieves this agreement with no significant free parameters. The frame moduli are estimated using a recently developed self‐consistent theory of composite materials. The induced mass of the frame in a water environment is also estimated theoretically.

Clinical and laboratory characteristics of Achromobacter xylosoxidans infection.

Abstract: Achromobacter xylosoxidans was isolated from six patients. The organism causes opportunistic infections in patients who are compromised. A. xylosoxidans is a catalase- and oxidase-positive, motile, gram-negative rod that oxidizes xylose and glucose. The organism exists in a water environment and may be confused with Pseudomonas species. Unlike pseudomonas, achromobacter has peritrichous flagella. The clinical and laboratory characteristics of A. xylosoxidans are presented.

Flaw Characteristics in Dynamic Fatigue: The Influence of Residual Contact Stresses

Abstract: The effect of residual contact stresses on the dynamic fatigue response of surfaces containing indentation-induced flaws is studied. Indentation fracture mechanics is used to analyze the growth of well-defined “median/radial” cracks in combined residual (elastic/plastic) contact and applied (uniform) tensile fields, and thence to determine strength characteristics. In this way a general formulation is obtained for the fatigue strength at constant stress rate. Experimental confirmation of the essential predictions of the theory is obtained from strength tests on Vickers-indented soda-lime glass disks in water environment. It is thereby implied that residual stresses can have a significant deleterious influence on the fatigue behavior of any brittle solid whose controlling flaws have a contact history. Such effects need to be considered in the design of structural ceramics, most notably where fracture-mechanics calibrations of crack-velocity parameters are used for lifetime predictions.

Survival, growth and production of Penaeus monodon Fabricius at different stocking densities in earthen ponds with flow-through system and supplemental feeding.

Abstract: The survival, growth and production of Penaeus monodon in earthen ponds were observed. A significant effect of stocking density on the survival rate of prawns was observed. The final average weight obtained varied inversly with the stocking density and the production varied directly with stocking density and survival rates. The maintenance of a clear water environment is recommended as a preventive measure against Vorticella attack.

Statistical approach to delayed failure of brittle materials

Abstract: Delayed failure tests or static fatigue tests were performed on soda-lime glass in water environment. Testing consisted of four-point bend and three-point bend with constant load. The time-to-failure and fracture location of specimens were measured. The theory of stochastic process is combined with the extreme value distribution in stress and the time dependent probability distribution function is obtained to predict the time-to-failure of specimens as well as the location of fracture. It is shown that the theoretical prediction is in good agreement with the experimental data.

A Review of Fatigue Crack Growth of Pressure Vessel and Piping Steels in High-Temperature, Pressurized Reactor-Grade Water.

Abstract: : Fatigue crack growth data sets, for pressure vessel and piping steels, in reactor-grade water environment have appeared in various reports and publications since about 1972. All of the results which have been published from 1972 through 1979 have been plotted and are presented in this report. Beginning with a discussion of the need for these data, and an explanation of the laboratory facilities which are required for this research, this report goes on to describe the overall trends which have evolved through consideration of the data sets and the conditions under which they were generated. A model for hydrogen assisted fatigue crack growth is described and applied to the pressurized water reactor type of environment. A complete listing of references is included in the report. (Author)

Taxonomy and distribution of chasmopine trilobites

Abstract: The Ordovician pterygometopid subfamily Chasmopinae is considered to include not only Chasmops McCoy, 1849, and Uralops Ancigin, 1970, but also a number of other genera which encompass species previously referred to Chasmops. These are: Toxochasmops McNamara, 1979; Scopelochasmops gen.nov.; Bolbochasmops gen.nov.; and Rollmops gen.nov. A close correlation is shown to exist between distribution of chasmopines and lithofacies, which indicates habitation in ashallow water environment. A westerly spread of chasmopine species at various times from eastern Baltoscandia is considered to correspond with a similar spread of the shallow water environment. This is shown by the periodic appearance of members of the subfamily in the Oslo region and Britain. Thereis a general reduction in number of chasmopine species and genera away fromthe eastern Baltic.

Electron spin resonance studies of silver atom solvation in ethanol-water mixtures

Abstract: Frozen solutions of silver perchlorate exposed to /sup 60/Co ..gamma.. irradiation at 4 K form silver atoms by reaction of radiation-produced electrons with the silver ion. At 4 K the silver atoms are initially produced in a nonequilibrium or presolvated state, and upon brief warming to 77 K the first solvation shell geometry changes to produce an equilibrium or solvated silver atom. The presolvated and solvated silver atoms in water and ethanol matrices are characterized by different isotropic hyperfine couplings and line widths measured by electron spin resonance. We have investigated silver atoms in water-ethanol mixtures to search for preferential solvation effects. From 0 to 13 mol % ethanol the presolvated silver atom formed at 4 K exhibits parameters characteristic of a water environment. At 13 mol % the parameters suddenly change to those characteristic of an ethanol environment. This suggests that the original silver ion undergoes a drastic change in its first solvation shell at 13 mol % ethanol. This dramatic change appears to corrleate with the minimum in the excess enthalpy of mixing of ethanol and water vs ethanol mole percent. Further solvation changes occur on thermal annealing the silver atoms at 77 K.

A review of fatigue crack growth of pressure vessel and piping steels in high-temperature, pressurized reactor-grade water. Interim report

Abstract: Fatigue crack growth data sets, for pressure vessel and piping steels, in reactor-grade water environment have appeared in various reports and publications since about 1972. All of the results which have been published from 1972 through 1979 have been plotted and are presented in this report. Beginning with a discussion of the need for these data, and an explanation of the laboratory facilities which are required for this research, this report goes on to describe the overall trends which have envolved through consideration of the data sets and the conditions under which they were generated. A model for hydrogen assisted fatigue crack growth is described and applied to the pressurized water reactor type of environment. A complete listing of references is included in the report.

Electrochemical oxidation of “rokaphenol n-6”

Abstract: The commonly known and applied methods of purification of waste waters prove useless for neutralization of concentrated solutions of nonionic surface-active substances (NSAS). Because of their high resistance to biochemical decomposition the substances are very dangerous for water environment and their neutralization in the available waste water treatment plants is a very difficult task. Experiments have shown that an electrochemical method is one of the most effective methods of decomposition of the substances. Investigations of electrochemical oxidation of Rokaphenol N-6 basic component of a commonly used detergent Roksol IT allowed to establish a dependence of the degree of oxidation of the investigated compound on the below mentioned parameters: current value 0,01 - 0,3A, current density 0,01 - 0,1 A/cm2, temperature 293 - 333 K, initial concentration of NSAS 100 - 800 mg/dm3, concentration of NaCl 2,5 - 35 g/dm3. It has been found that with the determined parameters of the process: current density 0,025 A/cm2, temperature 333 K, concentration of NaCl 20 g/dm3 and initial concentration of the solutions of surface-active substances 500 mg/dm3 a high degree of oxidation of “Rokaphenol N-6” about 90 % can be obtained. Consumption of electric energy for the above mentioned parameters has been relatively low of the order of 10 KWh/kg of oxidized Rokaphenol N-6. It has been found that the amount of oxidized Rokaphenol N-6 is proportional to its initial concentration in an electrolyte, whereas consumption of electric energy decreases with the growth of initial concentration of NSAS and the increase in NaCl concentration.

Simulation of Nuclear Underwater Shock Waves Using Planar Sources: An Investigation of Feasibility.

Abstract: : Various high explosive and/or propellant sources were assessed for use in the Shock Block nuclear simulation development program. The purpose of this program is to design and engineer a planar source that can develop a fast risetime (approximately 0.1 millisecond), long pulse width (approximately 5 milliseconds) pressure pulse at a constant amplitude of approximately 20 MPa (3000 psi) in water. Assessment techniques included: (1) a survey of the properties of fast-burning propellants; (2) one- and two-dimensional finite-difference calculations of candidate charge designs in a water environment; and (3) small-scale experiments investigating the feasibility of developing an HE/propellant charge. Recommendations are made concerning the design of future charges to be tested in the continuing program. These designs rely on: (1) decoupling the high explosive source from the water by means of an air gap; (2) forcing the explosive gases to push a steel plate; and (3) sealing the charge edges as means to ensure a more constant pressure source for the simulation technique. The computed results are made credible by their close agreement with data from a previous Shock Block test. (Author)

External Attachment of Titanium Sheathed Thermocouples to Zirconium Nuclear Fuel Rods For The Loss-Of-Fluid-Test (LOFT) Reactor

Abstract: The Exxon Nuclear Company, Inc. acting as a Subcontractor to EG&G Idaho Inc.3 Idaho National Engineering Laboratory, Idaho Falls, Idaho, has developed a welding process to attach titanium sheathed thermocouples to the outside of the zircaloy clad fuel rods. The fuel rods and thermocouples are used to test simulated loss-of-coolant-accident (LOCA) conditions in a pressurized water reactor (LOFT Reactor, Idaho National Laboratory). The design goals were to (1) reliably attach thermocouples to the zircaloy fuel rods, (2) achieve or exceed a life expectancy of 6,000 hours of reactor operation in a borated water environment of 316°C at 2260 psi, (3) provide and sustain repeatable physical and metallurgical properties in the instrumented rods subjected to transient temperatures up to 1538°C with blowdown, shock, loading, and fast quench. A laser beam was selected as the optimum welding process because of the extremely high energy input per unit volume that can be achieved allowing local fusion of a small area irrespective of the difference in material thickness to be joined. A commercial pulsed laser and energy control system was installed along with specialized welding fixtures. Laser room facility requirements and tolerances were established. Performance qualifications and detailed welding procedures were also developed. Product performance tests were conducted to assure that engineering design requirements could be met on a production basis. Irradiation tests showed no degradation of thermocouples or weld structure. Fast thermal cycle and heater rod blowdown reflood tests were made to subject the weldments to high temperatures, high pressure steam, and fast water quench cycles. From the behavior of these tests, it was concluded that the attachment welds would survive a series of reactor safety tests.

Observations on the use of the Radio-Isotope 32P in the Study of Food Uptake by some Mayflies and other Benthic Macro-Invertebrates in a Laboratory Stream Ecosystem

Abstract: A laboratory model stream ecosystem was used to study the transfer of the radio-isotope 32P in a food chain, from the water environment through the benthic algae and submerged vegetation to the primary and secondary consumer levels. This type of investigation, in which the nymphs of the mayflies Baetis harrisoni, Neurocaenis discolor, Caenis sp and Euthraulus bugandensis were used, revealed the value of 32P (and possibly other isotopes) in the study of not only the rates and quantities of food taken up by mayfly nymphs but also the diurnal activities in feeding by these organisms.

DEVELOPMENT OF A NOVEL HYDROCARBON-IN-WATER MONITOR: I. Concept Feasibility Demonstration

Abstract: Publisher Summary Oil, at present, is one of the main sources of energy necessary to power the industries, to provide lubricants, and to yield many petroleum products that have innumerable uses in the everyday living. All of these are essential for the national well-being and security. However, accidents, negligence, and mechanical failures result in wasteful and harmful discharges of oil to the water environment. The largest source of oil pollution is associated with spill incidents involving transportation by tankers, river barges, pipelines, trucks, and rail tank cars. As the huge volumes of crude and refined oil products transported by sea far exceed the combined tonnage of all other commodities, a fractional-percent spill of the total volume can be sizeable in cost, energy loss, and damage to the environment. As the discharge of oils into surface waters remains one of the serious and continuing water problems, the monitoring of discharged petroleum products is an important necessity for energy and resource conservation and for environmental improvement.