Johnson principle

Foam can also be broken with a rotating perforated basket [Lem-lich, Principles of Foam Fractionation, in Periy (ed.), Progre.ss in Separation and Purification, vol. 1, Interscience, New York, 1968, chap. 1]. If the foamate is aqueous (as it usually is), the operation can be improved by discharging onto Teflon instead of glass [Haas and Johnson, Am. In.st. Chem. Fng. J., II, 319 (1965)]. A turbine can be used to break foam [Ng, Mueller, and Walden, Can. J. Chem. Fng., 55, 439 (1977)]. Foam which is not overly stable has been broken by running foamate onto it [Brunner and Stephan, Ind. Fng. Chem., 57(5), 40 (1965)]. Foam can also be broken by sound or ultrasound, a rotating disk, and other means [Ohkawa, Sakagama, Sakai, Futai, and Takahara,y. Ferment. Technol, 56,428, 532 (1978)]. 

Dutrowski [5] in 1969, and Johnson and coworkers [6] in 1971, independently, observed that relatively small particles, when in contact with each other or with a flat surface, deform, and these deformations are larger than those predicted by the Hertz theory. Johnson and coworkers [6] recognized that the excess deformation was due to the interfacial attractive forces, and modified the original Hertz theory to account for these interfacial forces. This led to the development of a new theory of contact mechanics, widely referred to as the JKR theory. Over the past two decades or so, the contact mechanics principles and the JKR theory have been employed extensively to study the adhesion and friction behavior of a variety of materials. 

By definition a minor element in seawater is one has a concentration less than Ippm(m). It is experimentally challenging to determine the total concentrations, much less their major chemical forms. Development of new analytical techniques has greatly extended our knowledge (Johnson et al, 1992). Because early data (prior to about 1975) was so erratic, the principle of oceanographic consistency was proposed as a test for the data (Boyle and Edmond, 1975). According to this principle the analyses of minor elements should ... 

In media selective for enterobacteria a surface-active agent is the main selector, whereas in staphylococcal medium sodium and lithium chlorides are the selectors staphylococci are tolerant of salt concentrations to around 7.5%. Mannitol salt, Baird-Parker (BP) and Vogel-Johnson (VJ) media are three examples of selective staphyloccocal media. Beside salt concentration the other principles are the use of a selective carbon source, mannitol or sodium pyruvate together with a buffer plus acid-base indicator for visualizing metabolic activity and, by inference, growth. BP medium also contains egg yolk the lecithin (phospholipid) in this is hydrolysed by staphylococcal (esterase) activity so that organisms are surrounded by a cleared zone in the otherwise opaque medium. The United States Pharmacopeia (1990) includes a test for staphylococci in pharmaceutical products, whereas the British Pharmacopoeia (1993) does not. 

Vibrational spectroscopy is of utmost importance in many areas of chemical research and the application of electronic structure methods for the calculation of harmonic frequencies has been of great value for the interpretation of complex experimental spectra. Numerous unusual molecules have been identified by comparison of computed and observed frequencies. Another standard use of harmonic frequencies in first principles computations is the derivation of thermochemical and kinetic data by statistical thermodynamics for which the frequencies are an important ingredient (see, e. g., Hehre et al. 1986). The theoretical evaluation of harmonic vibrational frequencies is efficiently done in modem programs by evaluation of analytic second derivatives of the total energy with respect to cartesian coordinates (see, e. g., Johnson and Frisch, 1994, for the corresponding DFT implementation and Stratman etal., 1997, for further developments). Alternatively, if the second derivatives are not available analytically, they are obtained by numerical differentiation of analytic first derivatives (i. e., by evaluating gradient differences obtained after finite displacements of atomic coordinates). In the past two decades, most of these calculations have been carried... 

Sudhakar, A.V., J. Karl Johnson, and S. David, Sholl identification of destabilized metal hydrides for hydrogen storage using first principles calculations, /. Phys. Chem. B, 110,8769-8776,2006. 

Criss RE (1999) Principles of stable isotope distribution. Oxford Univ Press, New York Croal LR, Johnson CM, Beard BL, Newman DK (2004) Iron isotope fractionation by anoxygenic Fe(II)-phototrophic bacteria. Geochim Cosmochim Acta in press Duce RA, Tindale NW (1991) Atmospheric transport of iron and its deposition in the ocean. Limnol... 

The disodium salt of diphenylacetylene dianion is stable in THE solution at -78°C. Methanol acts as a proton source toward the salt and causes the formation of a mixture of 1,2-diphenylethane with diphenylacetylene and small amounts of tran -stilbene (Chang and Johnson 1965, 1966). It seems logical that the reaction between (PhC=CPh) , 2Na and MeOH leads at first to PhCH=CHPh. The second step is supposed to consist of the further reduction of PhCH=CHPh at the expense of electrons from the nonreactedpartof the initial dianion. In principle, the electron transfer may proceed faster than the reaction of the initial dianion with protons. As a result, the diphenylacetylene dianion has to discharge into diphenylacetylene, whereas stilbene dianion has to form diphenylethane as follows ... 

The basis for all of the evaluation techniques to be discussed here is what is commonly referred to as the similar-property principle, which was first stated explicitly by Johnson and Maggiora in their seminal 1990 book (1). The principle states that structurally similar molecules are expected to exhibit similar properties. It is clear that there are many exceptions to the principle as stated... 

P. Diep and J. K. Johnson, An Accurate H2 H2 Interaction Potential from First Principles, J. Chem. Phys. 112 (2000), 4465. 

S. V. Alapati, J. K. Johnson, and D. S. Sholl, Using First Principles Calculations to Identify New Destabilized Metal Hydride Reactions for Reversible Hydrogen Storage, Phys. Chem. Chem. Phys. 9 (2007), 1438. 

Amersham Biosciences (2002) Affinity chromatography principles and methods, www.chromatography.amershamhiosciences.com Dean PDG, Johnson WS, Middle FA (eds.) (1985) Affinity chromatography a practical approach, IRL Press, Oxford Jack GW (1994) Molec Biotechnol 1 59... 

Tukey RH, Johnson EF. Molecular aspects of regulation and structure of the drug-metabolizing enzymes. In Pratt WB, Taylor P, eds. Principles of Drug Action. New York Churchill Livingstone, 1990. 

Johnson proposed a more general set of linear dynamic equations taking into account a mass coupling in the inertia terms [73]. This theory is based on a general phenomenological scheme originally proposed by Biot to describe dynamics in porous media [74,75], Johnson claimed that the inertia terms, the left hand sides of Eqs. (6.1) and (6.2), should in principle be replaced by... 

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