Displacement experiments

Displacement experiments yield an inverse sigmoidal curve for nearly all modes of antagonism. 

Effect of excess receptor in binding experiments displacement experiments (4.6.10)... 

Effect of Excess Receptor in Binding Experiments Displacement Experiments... 

A novel nondestructive method for the determination of total charges and hence of EQ=Qy that is based on the CO displacement experiments has been worked out.795,796 This method has been applied to Pt(lll) and Pt(l 10) electrodes in contact with solutions at different pHs. For both Pt faces, the potential-of-zero total charge lies in a potential region similar to that forpc-Pt.8,10,11 It was found that thepztc depends on pH in different ways for Pt(l 11) and Pt(l 10), which demonstrates that not only is the pztc structure sensitive, but also that it varies with pH.795 The value of pztc for Pt(l 11) is more positive than that for Pt(l 10), and df j/dpHis higher for Pt( 111) than for Pt( 110). 

Chalk reservoirs encounter some specific problems during secondary recovery of oil by waterflooding. Displacement experiments in several formations... 

We present a general approach for estimating relative permeability and capillary pressure functions from displacement experiments. The accuracy with which these functions are estimated will depend on the information content of the measurements, and hence on the experimental design. We determine measures of the accuracy with which the functions are estimated, and use these measures to evaluate different experimental designs. In addition to data measured during conventional displacement experiments, we show that the use of multiple injection rates and saturation distributions measured with MRI can substantially increase the accuracy of estimates of multiphase flow functions. 

Displacement experiments can be relatively complex and time-consuming, so the experimental design can be a critical issue. Using suitable system and parameter identification methods, we obtain the best estimates of properties from the available data. It is most desirable to have some measures of the accuracy with which the properties are estimated. If that level of accuracy is less than desired, one can consider other ways of conducting the experiments so that additional information about the properties may be obtained. 

Our approach was demonstrated by determining multiphase flow functions from displacement experiments. Spatially resolved porosity and permeability distributions can be incorporated to mitigate errors encountered by assuming that the properties are uniform. We developed measures of the accuracy of the estimates and demonstrated improved experimental designs for obtaining more accurate estimates of the flow functions. One of the candidate experimental designs incorporated MRI measurements of saturation distributions conducted during the dynamic experiments. 

P. C. Richmond 1988, (Estimating Multiphase Flow Functions From Displacement Experiment), Ph.D. Thesis, Texas A M University. 

These displacement experiments can be utilized to evaluate different base properties of ligands which are attached to the tin atom as illustrated by Eqs. (13) u2) and (14)94). 

Of specific interest here are the analyses by Cortis and Berkowitz (2004) of transport in partially saturated, laboratory columns. Three typical breakthrough curves from a series of miscible displacement experiments in partially saturated... 

Van Genuchten, M. Th., and Parker, T. C. (1984). Boundary Conditions for Displacement Experiments through Short Laboratory Soil Columns. Soil Sci. Soc. Am. J., 48, 703-708. 

This chapter describes recent work in our laboratories examining density modification of DNAPLs through a combination of batch non-equilibrium rate measurements and DNAPL displacement experiments in 2D aquifer cells. The objective of this work was to evaluate the applicability of nonionic surfactants as a delivery mechanism for introducing hydrophobic alcohols to convert the DNAPL to an LNAPL prior to mobilizing the NAPL. Three different nonionic surfactants were examined in combination with n-butanol and a range of DNAPLs. Overall, it was found that different surfactants can produce dramatically different rates of alcohol partitioning and density modification. However, for some systems interfacial tension reduction was found to be a problem, leading to unwanted downward... 

Here one makes an effort to describe simultaneously transport-controlled and chemical kinetics processes (Skopp, 1986). Thus, an attempt is made to describe both the chemistry and physics accurately. For example, outflow curves from miscible displacement experiments on soil columns are matched to solutions of the conservation of mass equation. The matching process introduces a potential ambiquity such that experimental uncertainties are translated into model uncertainties. Often, an error in the description of the physical process is compensated for by an error in the chemical process and vice-versa (i.e., Nkedi-Kizza etal, 1984). 

Koelling et al. (70) conducted nonisothermal, pressurized gas-bubble Newtonian fluid-displacement experiments. The fluid used was PB H-300. It was injected into a capillary tube maintained at 60°C. The tube was then transferred in a different temperature bath at 0°C. The penetrating gas was then injected after different delay times, t. The longer the delay time, the deeper the cooling penetration thickness will be, since it is dependent on the Fourier number,... 

Casey FXM, Ong SK, Horton R. Degradation and transformation of trichloroethylene in miscible displacement experiments through zerovalent metals. Environ Sci Technol 2000 34 5023-5029. 

Thomson NR, Graham DN, Farquhar GJ (1992) One-dimensional immiscible displacement experiments. J Contam Hydrol 10 197-223... 

A dynamic affinity plot is presented in Fig. 10 for the proteins bovine and horse heart cytochrome c on a cation-exchange column. As one moves in a counterclockwise direction, the dynamic affinity of the molecule increases. The dynamic affinity plot provides an easy method of determining the order of elution in a displacement experiment as is shown in Fig. 4B. 

It is worthy of special interest to study directly the displacement of a herbicide by plastoquinone or its analogues. In normal thy-lakoids, almost no displacement of DCMU even by a million-fold excess of the short-chain plastoquinone analogue plastoquinone-1 can be observed (28). This may be due to the high endogenous plastoquinone content of the thylakoid membrane. If the thylakoids are depleted of plastoquinone by means of n-hexane extraction, a competitive displacement of DCMU by plastoquinone-1 is observed (28). This result establishes a direct interaction between herbicide and plastoquinone, though not necessarily at an identical binding site. From the displacement experiments, a binding constant for plastoquinone-1 of 51 19 jiM in plastoquinone-depleted thylakoids can be calculated (28). ... 

As compared to DCMU (binding constant 34 nM (24)) the affinity of plastoquinone-1 is more than three orders of magnitude less. In a similar displacement experiment of bromoxynil by plastoquinone-1 in triazine-resistant thylakoids, Vermaas et al. (29) found a plastoquinone-1 binding constant of 20 pM which is in the same order of magnitude as our value (28). 

Totsche, K.U., Danzer, J., and Kogel-Knabner, I., Dissolved organic matter-enhanced retention of polycyclic aromatic hydrocarbons in soil miscible displacement experiments, J. Environ. Qual., 26, 1090, 1997. 

Nearly all the experiments described were performed in an ultra high vacuum chamber at pressures of about 10 10 torr. The specific equipment and experimental procedures used have been described elsewhere (7-9). Experimental protocol for the thermal desorption experiments and for the chemical displacement reactions is presented below. All these experiments were repeated with a control, blank experiment with a metal crystal that had the front and exposed face covered with gold the sides and back of the crystal were exposed (8,9). These blank experiments were performed to ensure that all thermal desorption and chemical displacement experiments monitored only the surface chemistry of the front exposed face of the metal crystal under study. 

Relevant to the conflicting reports of copper versns nickel reqnirements for enzyme activity,biochemical stndies demonstrated the existence of a labile nickel associated with the a snbnnit of ACS/CODH. Very recently, model stndies on a metal-ion captnre of a peptide-backbone, nonlabile [MN2S2] (26) nnit have established the capability of snch a nickel dithiolate to bind exogeneons metals. A qualitative ranking of the binding ability of complex (26) with Zn +, Cn+, and Ni + was established by a metal-ion displacement experiment (Zn + < < Cn+), as shown in Scheme 9. ... 

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