Excess Water Content Research Articles

Model for Heave and Settlement Predictions in Discontinuous Permafrost

Heave and settlement of soils in discontinuous permafrost regions may be predicted using a model based on capillary stress theory. A one-dimensional numerical method has been developed which couples temperature and ground water migration to or from a freeze/thaw front and predicts the resultant ground heave/settlement. This model is among the first to predict both heave and settlement based on seasonal natural ground surface thermal disturbances. The results of the model are presented as graphs of time-dependent temperatures, excess pore water pressures, water contents, heave and settlement, and frost and thaw penetrations versus depth. The heave/settlement predictions follow closely experimental results presented elsewhere and indicate that an accurate model has been constructed within the limitations of the chosen data and the numerical technique.

British Food Journal Volume 84 Issue 4 1982

The volume and range of food law enforcement in the field of purity and quality control has grown dramatically in recent times. Only those able to recall the subject from upwards of half a century ago can really appreciate the changes. Compositional control now appears as more of a closely knit field of its own, keeping pace with the advances of food processing, new methods and raw materials. It has its problems but enforcement agencies appear well able to cope with them, e.g. the restructuring of meat, excess water content, fat content, the application of compositional standards to new products, especially meat products, but the most difficult of all areas is that of securing and maintaining acceptable standards of food hygiene. This is one of the most important duties of environmental health officers, with a considerable impact on health and public concern; and one of the most intractible problems, comparable in its results with the insidious onslaught of the ever‐growing problem of noise, another area dependent on the reactions of people; to use an oft repeated cliche — “the human element”.

Model Studies on Immediate Settlement Behavior of Submarine Pipelines

Currently immediate settlement of submarine pipelines can be assessed by using a method proposed by Small, et al. [3]. Concepts advanced by Reid [2] and Ghazzaly and Lim [4] have been extended herein to enable evaluation of immediate settlement. The immediate settlements of model pipelines measured in an apparatus devised for this purpose, in two cohesive soils at water contents in excess of liquid limits, have been used to assess the validity of the three methods. For immediate settlement to diameter ratio (Df/D) ≤ 0.4, experimentally observed values agree with prediction based on concepts of Ghazzaly and Lim as extended herein. For Df/D ≥ 0.5, Small, et al.’s theory compares well with observed data.

Relative roles of edema versus contracture in the myocardial postischemic “no-reflow” phenomenon

Failure to reestablish blood flow to the subendocardium of the left ventricle may occur after prolonged myocardial ischemia and it has been suggested that edema may be responsible for this “noreflow” phenomenon. However, the process of ischemic contracture is also associated with prolonged myocardial ischemia and an inability to reperfuse the subendocardium. This study was designed to clarify the relative roles of edema and contracture in the pathogenesis of subendocardial “no-reflow.” This objective was achieved by determining the transmural distribution of tissue blood flow and water content across the wall of the left ventricle, in both the presence and absence of contracture, during the reperfusion phase after global myocardial ischemia of sufficient duration to exhaust myocardial anerobic metabolism. We made use of the fact that ischemic contracture can be inhibited in the intact canine heart by decreasing the temperature to a level of moderate hypothermia (28°C) in order to separate the variables of contracture and edema. We found that the subendocardial “no-reflow” phenomenon was present when contracture was present, but absent when contracture was absent. While edema, assessed by tissue water contents in excess of control values, was much greater in the deeper layers of the left ventricular wall in the absence of contracture than in its presence, there was no evidence that it impeded myocardial blood flow. Edema was indeed found to be greater in regions of greater flow. These findings challenge the concept that myocardial edema following ischemic arrest in cardiac surgery is directly responsible for inadequate reperfusion leading to necrosis.

Effect of moisture on process of diesel fuel dewaxing with crystalline urea

In the course of mastering the urea dewaxing process, the following points were established: 1. The moisture content of the suspension is the most important technological index governing the operability of the G-64 units; these units operate normally with a solid-phase moisture content of 0.7–1.5% in the adduct formation stage, 0.1% (trace) in the adduct decomposition stage, and 0.2–0.5% in the washing. 2. Moisturizing of the suspension as a result of using naphtha or feedstock with excessive water content cannot be tolerated; it leads to a gradual precipitation and sticking or lumping of the solid phase and plugging of the lines, pumps, and other equipment, and a shutdown of production. 3. The removal of moisture in an electroseparator and by settling in the regenerated-naphtha tank will serve as a reliable means for maintaining the required moisture content of the system.

Urban growth effects on low-temperature fog in Edmonton

Visibility observations at rural and urban airports in the Edmonton area during the severe winter of 1968–69 are compared with similar observations described in 1955 by G. W. Robertson for the winter of 1949–50. The new observations tend to confirm Robertson's finding that low-temperature fog in Edmonton is due mainly to saturation of the air by water vapour produced in burning natural gas. Visibilities in such fog are strongly temperature-dependent. The urban population more than doubled between 1950 and 1969, and new large sources of water vapour were added to the city. The effects of both changes are apparent in the visibility data. Computations of excess water content and temperature increases are made assuming that an isothermal layer develops as rural air passes over the city and is modified by the combustion of natural gas and motor vehicle fuel. The results are consistent with local measurements of surface temperature and vertical temperature gradients in the lowest 100 m over the city. Computations of excess water content are presented for fuel consumption rates corresponding to populations of 150000 to 800000. Measurements of the thickness of the fog layer over the city and of the frozen water content of ice fog for various visibilities are needed for additional verification of the calculations.

Composition and structure of boehmite films

Studies were made of the composition and structure of boehmite films formed on aluminum sheets in boiling aqueous solutions by electron microscopy, electron diffractiometry, and X-ray diffractiometry; and also made of the effects of kind and concentration of additives on the film.The following results were obtained:(1) The results of tests of sheet metals showed that the boehmite film formed on an aluminum sheet consisted of a continuous thin film tightly adhering to the aluminum surface and numerous fine needle crystals, independent of the presence and kind of additives.(2) Both of the continous thin film and fine needle crystals were composed of boehmite, and the latter were preferentially oriented in (001) planes parallel to the surface.(3) The results of tests of aluminum powder showed that only boehmite was formed in water after boiled for 15min., and bayerite was also formed together with boehmits after boiled for 1hr. or more. The addition of triethanolamine to deionized water accellrated the growth of boehmite but inhibited the growth of bayerite. Whereas, the addition of ammonia accelerated the growths of both boehmite and bayerite.(4) The results of X-ray diffractiometry showed that the boehmite formed on aluminum powder was not a standard boehmite, but was judged to be a quasi-boehmite having an excessive water content.

On the Theory of Convective Currents

A theory of steady state, saturated, convective currents is presented which includes the transfer of heat and momentum by lateral diffusion as well as the systematic entrainment of environmental air. The system of equations governing the behavior of such convective currents is derived and numerically integrated for a variety of initial and environmental conditions. In agreement with basic physical principles, it is found that the cloud height, mass, vertical velocity, temperature excess over the environment, and liquid water content all increase with increasing (a) initial temperature, (b) environmental relative humidity, and (c) environmental lapse rate; but all decrease as the diffusion coefficient increases. Also the cloud height, vertical velocity, temperature excess, and liquid water content increase with increasing initial velocity: however, the total mass of air decreases with increasing initial velocity, reflecting a lower rate of entrainment. Even with frictional drag in the form of momentum loss by diffusion, the updraft overshoots the level of zero buoyancy in the upper part of the cloud, giving rise to cloud temperatures at the cloud top which may be several degrees colder than the environment. When applied to an upper-air sounding taken near the time and location of a thunderstorm, the model gives the right order of magnitude for the cloud height, vertical velocity, and temperature excess over environment for a diffusion coefficient of k 1 = .001 sec −1 . While the life cycle of a convective cloud is certainly not a steady-state phenomenom, the theory probably affords a fair approximation of the convective cloud during the updraft stage. DOI: 10.1111/j.2153-3490.1959.tb00002.x

On the Theory of Convective Currents

A theory of steady state, saturated, convective currents is presented which includes the transfer of heat and momentum by lateral diffusion as well as the systematic entrainment of environmental air. The system of equations governing the behavior of such convective currents is derived and numerically integrated for a variety of initial and environmental conditions. In agreement with basic physical principles, it is found that the cloud height, mass, vertical velocity, temperature excess over the environment, and liquid water content all increase with increasing (a) initial temperature, (b) environmental relative humidity, and (c) environmental lapse rate; but all decrease as the diffusion coefficient increases. Also the cloud height, vertical velocity, temperature excess, and liquid water content increase with increasing initial velocity: however, the total mass of air decreases with increasing initial velocity, reflecting a lower rate of entrainment.
 Even with frictional drag in the form of momentum loss by diffusion, the updraft overshoots the level of zero buoyancy in the upper part of the cloud, giving rise to cloud temperatures at the cloud top which may be several degrees colder than the environment.
 When applied to an upper-air sounding taken near the time and location of a thunderstorm, the model gives the right order of magnitude for the cloud height, vertical velocity, and temperature excess over environment for a diffusion coefficient of k1 = .001 sec–1. While the life cycle of a convective cloud is certainly not a steady-state phenomenon, the theory probably affords a fair approximation of the convective cloud during the updraft stage.

Dielectric Properties of Wool-Water Systems at 3000 and 9300 Megacycles

The dielectric constant ε′ and dielectric loss ε″ for wool-water systems have been determined at frequencies of 3000 and 9300 Mc by a cavity resonator method. The water content of the wool fibers was varied between 0 and 14 percent of the weight of the dry wool. The upper limit of 14 percent is approximately one-half the amount of water wool will absorb in a saturated atmosphere at 25°C. The increased dielectric loss in the systems studied and the resultant attenuation of microwave power prevented measurements from being made at water contents in excess of approximately 14 percent. The results of the measurements show that both ε′ and ε″ increase with increasing water content. The results have been analyzed in terms of a sorption theory proposed by Cassie which shows that the water sorbed by wool consists of localized water which is intimately bound to polar sites in the wool and mobile water which constitutes the remainder sorbed. The dielectric constant of the localized water is found to be 5.8 at both frequencies. This result compares favorably with the microwave dielectric constant of irrotationally bound water obtained by Buchanan et al. from studies of protein hydration. It has been found that ε′ and ε″ of the mobile water are less than for liquid water if the dielectric properties of the wool are assumed to be unaffected by water sorption. The alternate assumption (in which ε′ and ε″ for the mobile water are set equal to those of liquid water) is discussed.

Water content of the myocardium in hypertrophy and chronic congestive failure

Abstract 1.1. The water content of the myocardium from persons with cardiac hypertrophy and with cardiac hypertrophy with congestive heart failure was determined and compared with normals used as controls. 2.2. The hearts from patients with wasting diseases and the aged showed relatively low water contents. Children, on the other hand, showed relatively high myocardial water contents normally and in congestive heart failure. 3.3. In cardiac hypertrophy without failure the water content was not increased. The increase in heart weight in cardiac hypertrophy is due to an intrinsic increase in muscle mass and not to an increased amount of water. 4.4. In congestive heart failure the water content of the myocardium was increased due to anasarca which involved also the myocardium. The greatest increase of water was observed in childhood, reaching 82.1 per cent in one instance. Normal figures in the aged patients with wasting diseases may represent actual water retention. 5.5. The beneficial effects of diuresis in congestive heart failure may in part be due to reduction of excessive myocardial water content, thereby improving cardiac contractility.