Showing papers on "Water environment published in 1978"

The effect of training on the swimming muscles of the goldfish (carassius auratus)

Abstract: Goldfish (Carassius auratus) were exercised continuously for periods of 28 days at swimming speeds of 1.5, 3.0 and 4.5 body lengths per second and their rates of growth were determined. Changes in muscle fibre size were examined, as were changes which occurred in the concentrations of the major chemical constituents of these cells. These fish, typical of the carp family in that they are found only in still or slowly moving water, did not adapt well to the flowing water environment at any swimming speed. They often grew less than the controls, although consuming much more food. Changes in the composition of the muscle fibres indicated that excess food was not being stored, and also indicated that the major fuel for swimming at all speeds was glycogen. The fish survived well at high speeds and it was suggested that this was due to the ability of the species to metabolize glycogen anaerobically without the production of lactic acid.

Washer/separator system for drilling cuttings in water environment oil wells

Abstract: A washer separator system for drilling cuttings for use in drilling mud washing systems for water environment oil wells filled with washing solution is described using a receiving tank with an agitation subchamber which causes thorough scrubbing of the deposited drilling cuttings. The washed cuttings settle to the bottom of the tank causing the solution level to rise. When a predetermined solution level is reached, an auger, situated at the bottom of the tank, is activated and the collected cuttings are removed. When the solution level drops a sufficient amount for removal of the cuttings, the auger is shut off and the cycle begins anew. Fresh water washing solutions may be used, so that the oil saturated depleted solution may be added to the drilling mud. Collected cuttings may be deposited in the water environment without a slick forming. A pump delivers solution to the top of the cuttings trough. Intake for the pump is above the collected cuttings.

Viral Pollution of Surface Waters Due to Chlorinated Primary Effluents

Abstract: The role of chlorinated primary effluents in viral pollution of the Ottawa River (Ontario) was assessed by examining 282 field samples of wastewaters from two different sewage treatment plants over a 2-year period. The talc-Celite technique was used for sample concentration, and BS-C-1 cells were employed for virus detection. Viruses were detected in 80% (75/94) of raw sewage, 72% (68/94) of primary effluent, and 56% (53/94) of chlorinated effluent samples. Both raw sewage and primary effluent samples contained about 100 viral infective units (VIU) per 100 ml. Chlorination produced a 10- to 50-fold reduction in VIU and gave nearly 2.7 VIU/100 ml of chlorinated primary effluent. With a combined daily chlorinated primary effluent output of approximately 3.7 × 108 liters, these two plants were discharging 1.0 × 1010 VIU per day. Because the river has a mean annual flow of 8.0 × 1010 liters per day, these two sources alone produced a virus loading of 1.0 VIU/8 liters of the river water. This river also receives at least 9.0 × 107 liters of raw sewage per day and undetermined but substantial amounts of storm waters and agricultural wastes. It is used for recreation and acts as a source of potable water for some 6.0 × 105 people. In view of the potential of water for disease transmission, discharge of such wastes into the water environment needs to be minimized.

Pulse radiolysis of deuterated aqueous LiCl glasses. Dependence of the yields and rates of reaction of visible and infrared absorbing trapped electrons on LiCl concentration

Abstract: The yields and reactions of trapped electrons which absorb in the visible (evis−) and infrared (eir−) have been studied by pulse radiolysis in deuterated aqueous 6–15 M LiCl glasses at low temperatures. At 76 K G(evis−) increases and G(eir−) decreases as the concentration of LiCl is increased, but over the whole concentration range. Because the hydration number of Li+ is 4, G(eir−)/G(evis−) was plotted against [free D2O]/[LiCl•4D2O] and found to give a straight line passing through the origin, for [D2O]/[LiCl] > 4. From this proportionality it is concluded that eir− is an electron trapped in a purely amorphous water environment and evis− is mainly associated with water bound to Li+.The reactions of eir− and evis− with Cu(II) and SeO42− have been investigated. At 138 K the rate of reaction of evis− with SeO42− increases with decreasing [LiCl] whereas its rate of reaction with Cu(Il) is slower and independent of [LiCl]. At 76 K, where the rates of reaction of eir− with the scavengers can also be measured, i...

Protein folding and heterogeneity inside globular proteins.

Abstract: THE compact globular structure of enzymes and other proteins is the result of a struggle between two major forces. One is the entropy of the protein backbone, which strives towards an open, more random configuration, and the other is the entropy of the water environment, which drives the water-ordering nonpolar sidechains into tightly packed, water-excluding clusters. However, the protein globule would still be relatively flexible were it not for the fact that some polar groups, including those of the backbone are also found in the interior of proteins and make up a skeletal network of hydrogen bonds. The net result is that the interior of a globular protein has continuous clusters of nonpolar sidechains separated by relatively polar regions in which nonpolar sidechains are comparatively infrequent. We have undertaken a study to quantify this structural heterogeneity and to illuminate the folding and packing of sidechains in globular proteins. This study not only uses a simple procedure for analysing protein structure, but provides a method, demonstrated here, for predicting which residues occur in the nonpolar clusters and conversely, the polar or partially polar regions of globular proteins.

Fuel Failure Behavior of Unirradiated Fuel Rods under Reactivity Initiated Accident Conditions

Abstract: An in-reactor experimental research on fuel behavior under reactivity initiated accident conditions has been performed in the Nuclear Safety Research Reactor (NSRR). Unirradiated test fuel rods were exposed to pulse-power at the energy depositions of 39-433 cal/g·UO2 in water environment with ambient pressure and temperature.Oxidation and deformation of the cladding commence at the energy deposition of about 140 cal/g·UO2, and increase almost in proportion to the energy deposition.There are two types of fuel failure which are characterized by the circumferential cracks in the cladding or guillotine type break, and by the accompaniment of fuel fragmentation. The threshold energy depositions for them are about 260 and 380 cal/g·UO2, respectively.The former is the brittle fracture of the cladding. The cladding material becomes thinner because of melting of the cladding inner surface, and becomes brittle by oxidation. The failure is caused by the prevention of cladding contraction at or after the time of quenching of the brittle cladding due to strong binding between the pellets and cladding.The latter is the failure caused by the melting of the pellet accompanied with the considerable loss of mechanical strength in the cladding, resulting in the generation of mechanical energy.

Contact‐Induced Static Fatigue of Annealed and Tempered Glass

Abstract: The role of environmentally assisted crack growth in the contact-induced strength degradation of brittle surfaces was studied. Indentation fracture mechanics, incorporating a standard crack-velocity function, are used to predict remaining strength as a function of contact load and duration. Strength tests on annealed and tempered glass disks, indented with a diamond pyramid or tungsten carbide sphere in a water environment, are in accord with the predicted degradation characteristics. The results indicate that fatigue effects are likely to be of only secondary importance in designing for maximum resistance to in-service contact damage.

Damping in saturated soil

Abstract: A mathematical model is described which predicts damping and wave velocity in water-saturated soils. Two mechanisms for energy loss are included in the model; one accounts for inelasticity of the soil skeleton in a water environment and the other for viscous losses in the pore-water as it moves relative to the skeleton. The result is damping which is frequency dependent and which depends on such parameters as porosity, grain size, permeability and effective stress. The model predicts that losses in the soil skeleton dominate at low frequencies while viscous losses due to motion of the interstitial water become predominant at higher frequencies. The terms high and low are relative, with their actual values depending on the physical properties of the particular soil being modeled. Because of the importance of pore fluid motion, results of vibration tests such as the resonant column must be carefully interpreted in order for these tests to yield results which can be used to predict attenuation in propagating waves. Since viscous losses affect both shearing and extensional motion, all the various types of test are subject to their influence. Curves are presented showing the effect on damping of various parameters such as frequency and permeability. The input for generating the curves is based on well established data already in the literature and the results suggest an explanation for some of the early test results for saturated soils that were published but never fully interpreted.

Development of the Ornithine-Urea Cycle

Abstract: One of the fundamental facts about mammals is that they are intolerant to even modest concentrations of ammonium ion in the cellular environment. Simpler organisms living in a water environment have little problem with nitrogen disposal, since ammonia diffuses freely and is thereby diluted to a very low concentration. During evolution, when a movement from marine to terrestrial environment occurred, a more efficient detoxication mechanism for ammonia was needed, and the formation of urea developed.

Reliability of Dynamic Fatigue Data for Plastic Coated Fused Silica Optical Waveguide Fibers

Abstract: The reduction in strength of glass fibers under stress and in the presence of moisture or water follows a log stress vs. log time to failure dependence theoretically and experimentally. Errors in the acquisition of fatigue data for plastic coated fibers are minimized when the time dependent parameter in the dynamic case is actual time to failure and not strain rate. Also for those fibers tested in humid or water environments, the transport time of water through the fiber coating must be considered for those systems demonstrating a time and/or temperature dependence of transport. The time dependent reduction in strength by slow crack growth is fatigue and its rate is given by the slope of the log stress vs. log time to failure curve. The intercept of this curve is the "instantaneous" strength. For plastic coated fibers this intercept shows marked reduction in a water environment as compared to drier ambient conditions. This reduction is attributed to surface energy decrease, but this concept has not been rigorously researched. Slope and intercept data given for a variety of plastic coatings on fused silica fiber and compared statistically in ambient and water environments, enable engineering worst case predictions of lifetime to be made. These predictions, however, are for fibers having high instantaneous strengths in > 20 Km lengths and are therefore not representative of fibers exhibiting low proof-test strength levels. Also, the possibility of interfacial coating-glass interactions occuring and having adverse effects on these predicted fiber lifetimes is not considered.

Fatigue growth in piping and rpv steels in simulated BWR water environment

Abstract: This report summarizes results of an experimental testing program focused on establishing the fatigue crack growth behavior of several commercial pressure vessel and piping steels typically used in light water reactors. Testing was done in a simulated boiling water reactor (BWR) primary water environment (1230 psig, 550/sup 0/F demineralized water). The data obtained were analyzed using linear elastic fracture mechanics principles and, in the case of the reactor pressure vessel alloy steel, compared to existing ASME design codes. The results show that crack growth rates are increased in this BWR water environment by decreasing the frequency of cyclic loading or increasing the mean load present during the load cycle. However, in the case of the pressure vessel alloy steel, these effects are moderated by transverse secondary microcracking, which is a manifestation of a crack tip chemistry interaction for this environment/material pair. This behavior is consistent with previous GE experience with in-service cracking in pressure vessel components, wherein analytic projections of cracking rates always tend to overpredict crack depths when compared to actual field observations. The results for the Type-304 stainless steel and the Inconel 600 establish threshold values on cyclic loading frequency for intergranular stress corrosion cracking behavior in thesemore » two material/environment pairs.« less