Rate Of Upward Movement Research Articles

Upward surface movement above deep coal mines after closure and flooding of underground workings

After the mass closures of entire coal mine districts in Europe at the end of the last century, a new phenomenon of surface movement was observed—an upward movement. Although most surface movement (i.e., subsidence) occurs in the months and years after mining by the longwall method, surface movement still occurs many decades after mining is terminated. After the closure and flooding of underground excavations and surrounding rock, this movement was reversed. This paper focuses on quantifying the upward movement in two neighboring coal mines (Winterslag and Zwartberg, Belgium). The study is based on data from a remote sensing technique: interferometry with synthetic aperture radar (INSAR). The results of the study show that the rate of upward movement in the decade after closure is about 10 mm/year on average. The upward movements are not linked directly to the past exploitation directly underneath a location. The amounts of subsidence at specific locations are linked mainly to their positions relative to an inverse trough shape situated over the entire mined-out areas and their immediate surroundings. Local features, such as geological faults, can have a secondary effect on the local variation of the uplift. The processes of subsidence and uplift are based on completely different mechanisms. Subsidence is initiated by a caving process, while the process of uplift is clearly linked to flooding.

Performance of a Pier Group Foundation in Swelling Rock

Foundations on claystone with swell potential may experience upward movement and failure. In this case study, the cause of 58 mm upward movement of drilled-in piers is analyzed using survey data, extensometer readings, and moisture content monitoring of claystone at the site. Laboratory swell tests were conducted to characterize the swelling characteristics of the weathered rock. A swell potential analysis for the pier group foundations is presented. The interaction of the pier group with the swelling rock is considered in analyzing the initiation of the upward movement. Furthermore, a novel inverse analysis method is presented to integrate the laboratory swell test results and numerical modeling to identify the representative swell pressures acting on the pier group as well as upward movement of the pier system. The numerical analysis indicates that the studied pier system is expected to have 135 mm heave and its rate of upward movement is compared with field observations. The behavior of the pier group foundation in swelling rock under various pier spacings and superstructure pressures shows that the uplift is considerably less for piers with smaller center-to-center spacing. The results of pier group numerical modeling provide the correlation of upward deformation changes due to center-to-center spacing of the piers, pier diameters and superstructure pressures.

Quantification of the forces driving self-assembly of three-dimensional microtissues

In a nonadhesive environment, cells will self-assemble into microtissues, a process relevant to tissue engineering. Although this has been recognized for some time, there is no basis for quantitative characterization of this complex process. Here we describe a recently developed assay designed to quantify aspects of the process and discuss its application in comparing behaviors between cell types. Cells were seeded in nonadhesive micromolded wells, each well with a circular trough at its base formed by the cylindrical sidewalls and by a central peg in the form of a right circular cone. Cells settled into the trough and coalesced into a toroid, which was then driven up the conical peg by the forces of self-assembly. The mass of the toroid and its rate of upward movement were used to calculate the cell power expended in the process against gravity. The power of the toroid was found to be 0.31 ± 0.01 pJ/h and 4.3 ± 1.7 pJ/h for hepatocyte cells and fibroblasts, respectively. Blocking Rho kinase by means of Y-27632 resulted in a 50% and greater reduction in power expended by each type of toroid, indicating that cytoskeletal-mediated contraction plays a significant role in the self-assembly of both cell types. Whereas the driving force for self-assembly has often been viewed as the binding of surface proteins, these data show that cellular contraction is important for cell-cell adhesion. The power measurement quantifies the contribution of cell contraction, and will be useful for understanding the concerted action of the mechanisms that drive self-assembly.

Numerical Simulation of Deep‐Well Injection in Geismar, Louisiana

AbstractIndustrial waste water has been injected into a permeable part of the Upper Miocene injection reservoirs near Geismar, Louisiana since 1971. The injection zone is a series of alternating extremely permeable sands and impermeable clays, hydraulically isolated from the surficial aquifer system by a thick layer of clay, which acts as a confining layer. The study area encompasses four industrial facilities and 12 active injection wells. Numerical simulations were performed to evaluate injection‐well design and potential for movement of injected waste water within the hydrogeologic system. Numerical modeling was conducted in both cylindrical coordinates and Cartesian coordinates. A convection cell developed around a single prototype injection well in cylindrical‐coordinate system with a buoyant injection rising to form a lens within the injection zone. Around an ideal, fully penetrating well cased into the injection sand and open from a depth of 5,056 feet to 5,456 feet, simulations show the injectant moves upward to a depth of 4,866 feet, forms a lens about 400 feet thick, and spreads radially outward to a distance of 1,670 feet after 10 years. Comparison simulations of injection through wells having open depth intervals of 5,056 to 5,256 feet and 5,256 to 5,456 feet demonstrate that such changes in well design have little effect on the areal spread of the injectant lens or the rate of upward movement. Multiple injection well simulations in Cartesian coordinates indicate that about 5,10, and 80 percent of the study area would be underlain by injected waste water after 10,20, and 100 years of injection, respectively. Outward movement of waste water proceeds even after injection stops. The rate of outward movement under the post‐operational period (after injection ceases) is much smaller than under the operational period (injection period).

Influence of Environment and Stage of Growth on Honey Mesquite (Prosopis glandulosa) Response to Herbicides

Honey mesquite (Prosopis glandulosaTorr. # PRCJG) was treated with four herbicides at 1.1 kg ae/ha at 14 dates from April 30 through September 23 over a 2-yr period. Overall, clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) was the most effective herbicide, killing 80% or more of the honey mesquite at most dates. Picloram (4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid), triclopyr {[(3,5,6-trichloro-2-pyridinyl)oxy] acetic acid}, and 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid] were less effective than clopyralid. Honey mesquite control was correlated with Julian day of year sprayed, 15 plant, 11 environmental, and 8 herbicide concentration variables. Most effective control was negatively correlated with Julian day of year sprayed and new xylem ring thickness. Control was positively correlated with total daily apparent photosynthesis, upward methylene blue dye movement in the xylem, and herbicide concentration in the xylem 3 days after spraying. The only environmental variable of 11 measured that was significantly correlated with honey mesquite control was soil water and that was only with picloram. The concentration of herbicide in the stem was highest for clopyralid, followed by picloram, and then by 2,4,5-T and triclopyr, which were about equal. Variables most useful in regression equations for predicting control with herbicides were total daily apparent photosynthesis and rate of upward movement of methylene blue dye. Variables most incorporated into regression equations relating honey mesquite control with herbicide content were herbicide concentrations in the xylem 3 or 30 days after treatment.

Water Movement Factors Important to the Design and Operation of Subirrigation Systems

ABSTRACT THE factors affecting water movement in sub-irrigation-drainage systems are identified and discussed as they relate to the design of such systems. Methods for quantifying steady, upward water move-ment from the water table are reviewed. The effect on design of the functional relationships between rate of up-ward movement and water table depth is analyzed. Ap-proximate methods for calculating the position and shape of the water table during steady state and transient subirrigation are reviewed. Methods are presented for predicting, in terms of certain design parameters, the time required to raise the water table for certain initial and boundary conditions. The use of the water manage-ment model, DRAINMOD, for analyzing the operation of a subirrigation system under changing weather condi-tions is discussed. The methods presented and discussed for the design and analysis of a subirrigation system are demonstrated by a case study for a site near Farmville, NC. Results of analyses for steady state, transient and continuous operation of several alternative designs for both conven-tional drainage and subirrigation-drainage systems are presented. The results show that both subirrigation and drainage requirements can be satisfied with an 18 m drain spacing, while a 25 m spacing will be required for conventional drainage alone.

Behavioral Responses to Changes in Hydrostatic Pressure and Light During Larval Development of the Lobster Homarus gammarus

Larvae of the lobster Homarus gammarus hatched and reared under laboratory conditions in shallow water responded to changes in hydrostatic pressure in a depth-regulatory manner. Responsiveness to instantaneous pressure increments ranging from 1 to 20 psi increased linearly and there was no threshold of sensitivity within the range tested. Pressure sensitivity was retained throughout larval life up to and including stage IV (megalopa) but responsiveness weakened with age at least up to stage III. Stage IV larvae were highly responsive to pressure changes but stage V (1st juvenile) lobsters were nonresponsive. Older larvae accommodated to sustained pressure more rapidly than younger larvae and larvae quickly became nonresponsive to repeated pressure changes. After being held at high pressure, larvae responded to slight pressure decreases by downward movement even though still held at pressures to which they would initially respond by vigorous upward movement. Larvae were more responsive to pressure in overhead light than in darkness but light intensity had no apparent effect on the initial response nor on the rate of accommodation to sustained pressure, but in darkness the initial response was slower. Responsiveness to sudden changes in light intensity was much less marked than to pressure changes and it also weakened with age. In the sea older larvae showed a stronger tendency for downward movement when released at the surface and a decreasing tendency for upward movement when released at depths of 25 ft (7.61 m) or more. The average rate of upward movement decreased over a 5-min period and there was no consistent difference in this rate or in the rate at which it decreased when larvae were released at different depths. The average rate of upward movement tended to decrease with age.

Zonal melting as mechanism in evolution of the Earth's crust

The paper treats the problem of upward movement of a molten zone in the Earth's crust. Due to the melting temperature gradient of 3°C/sm, such a zone is in an unstable state: melting occurs at the upper boundary, where crystallization takes place at the base. During this process, the net thickness of the molten zone decreases, since additional heat is required to raise the temperature of the overlying rock to the melting point. The process continues until the thickness of the molten zone is reduced to zero or until it reaches a level above which open fractures exist. Based on thermodynamic considerations, estimates are given for the rate of upward movement and thinning: lifting the upper boundary of the molten zone from a depth of 100 km to 20 km requires a reduction in thickness by about 60 km or 30 km, in the continental or oceanic crust, respectively. The lifting time is estimated as 10–100 m. y. --H. Jahns.

MOVEMENT OF RADIOACTIVE ISOTOPES IN YELLOW BIRCH AND WHITE PINE AS DETECTED WITH A PORTABLE SCINTILLATION COUNTER

Movement of rubidium86 and calcium45 injected into the trunks of yellow birch and white pine was followed with a newly-developed portable scintillation counter. Maximum rate of upward movement of the rubidium86 in the xylem of yellow birch approximates one foot per minute along a narrow channel spiralling upward (usually dextrally) from the point where the isotope was first introduced. Movement in decadent yellow birch was very slow with an apparent increase of permeability of the bark tissue as indicated by lateral diffusion of the isotope. In October no upward movement was discerned in healthy trees but rather an active downward translocation in the phloem.

GEOTROPIC CREEPING OF YOUNG RATS

The rate of upward creeping in negatively geotropic rats aged 13 to 14 days is a function of the gravitational stimulus. The rate of upward movement on the creeping plane, like the angle of orientation, is directly proportional to the logarithm of the gravity component. The variability in the speed of creeping decreases in proportion to the logarithm of the gravitational effect. When weights are attached to the animals' tails the rate of upward creeping varies almost directly as the logarithm of the attached weight, and the speed of creeping is still proportional to the angle of upward orientation.

GEOTROPISM AND MUSCLE TENSION IN HELIX

1. The snail Helix aspersa Müller, is negatively geotropic during the daytime, but positive or indifferent at night. 2. The precision of geotropic orientation is a function of the gravity component acting on the body. 3. The rate of geotropic locomotion is also determined by the gravity component (sine of the angle of inclination). 4. The rate of upward movement is increased 1.51 times at 45 degrees inclination by loading the snail with one-half its weight. No such increase is seen in loaded snails creeping on a horizontal surface. 5. Moderate centrifugation results in orientation and locomotion towards the center of rotation. 6. A response analogous to the homostrophic reflex occurs when a backward pull to right or to left is exerted on the shell. Bilaterally equal tension applied to the shell causes locomotion along a path parallel and opposite to the direction of the pull. 7. All the observations go to show that the stimulus for geotropic orientation and locomotion is tension of the body muscles produced by the downward pull of gravity, and that the stimulus is received by the proprioreceptors of these muscles. Otolith apparatus and analogous organs, when present, may assist in the response, but they do not seem to be requisite in all cases. Since the precision of orientation and the rate of locomotion are functions of the gravity component acting on the body, the muscle tension theory of the geotropic reactions accords fully with Loeb's tropism doctrine for animals.