162,261 research outputs found
An experimental and theoretical study of oligo- and polyelectrolyte adsorption
No full textThe purpose of this study is the description of the behaviour of a model polyelectrolyte near a model interface.Chapter 1 gives a general background and the outline of the investigations.The chapters 2 and 3 comprise the theoretical parts. Chapter 2 considers the applicability of equilibrium thermodynamics to polymer adsorption, an important prerequisite. We focus our attention on the applicability of Gibbs' law to polymer adsorption. In many cases results from surface tension measurements do not obey the classically formulated Gibbs' law, which is based on equilibrium thermodynamics. Thus, the use of equilibrium thermodynamics was questioned. We show that it is important to take the heterodispersity of the polymers used in adsorption studies into account when Gibbs' law is applied. Although not all problems could be solved completely, this result encourages the use of equilibrium thermodynamics in the polyelectrolyte adsorption theory.Chapter 3 describes the polyelectrolyte adsorption theory. Expressions are derived for the potential distribution in and the free energy of a double layer containing polyelectrolyte charge. In the case of the Debye-Hückel approximation of the Poisson-Boltzmann equation analytical expressions are obtained. When the full Poisson-Boltzmann equation is used, we have to rely on numerical procedures. The electrostatic interactions are incorporated in the phase equilibria theory of Flory and the Roe theory and the Scheutjens-Fleer theory of polymer adsorption. Electrostatic interactions strongly influence the conformation of the adsorbed polyelectrolyte. Because of the mutual repulsion of the charged segments the formation of loops and tails is strongly suppressed. Thus very flat adsorbed layers are predicted. For uncharged polymers the increase of the adsorption with chain length and polymer concentration mainly takes place in the loops and tails. As for polyelectrolytes, these are all but absent, their adsorption is nearly chain length-independent and the plateau value of the adsorption isotherms is much more constant than with uncharged polymers. Polyelectrolyte solutions are resilient against phase separation in much poorer solvents than uncharged polymers, depending on chain charge density and indifferent electrolyte concentration.The chapters 4 and 5 make up the experimental part. As the polyelectrolyte adsorption theory does not only apply to long polymer chains, but also to the adsorption of oligomers, it is important to test the theory for short chains, too.Chapter 4 describes the synthesis of these oligomers. Repeated coupling of chains of equal length yields a series of two, four, eight, sixteen and thirty-two segments long. For this kind of coupling reactions peptides are suitable compounds, since standard methods of synthesis have been developed for the benefit of protein research. Using only one type of amino acid, L-lysine, we obtained poly-L-lysine type oligomers.Chapter 5 presents characteristics for the adsorption of the model-polyelectrolyte poly-L-lysine on the model-colloid silver iodide. Several colloid chemical techniques can be applied to in vestigate this system both in the absence and in the presence of poly-L-lysine. We investigated adsorption isotherms, charge potential curves, coagulation kinetics and electrophoretic mobil ities. From the results the following picture of polyelectrolyte adsorption emerges:(i) At low ionic strength only a thin layer of adsorbed poly-electrolyte is formed.(ii) Under these conditions the adsorption is chain length in dependent, provided the chains are not too short.(iii) Because of the shielding of indifferent electrolyte some loops and tails are formed at high salt concentrations.(iv) Oligomer adsorption increases with chain length.This picture is in agreement with the theoretical predictions of chapter 3.Chapter 6 gives a quantitative comparison of the experimental and theoretical data. The quantitative agreement between theory and experiment is also satisfactory. This chapter also gives some, suggestions for further improvement of the theory and for additional experimental tests
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
Onderzoek naar veldwerk bij aardrijkskunde in het vmbo
No full textDeze bijdrage geeft een korte tussenstand van een promotieonderzoek naar veldwerk aardrijkskunde in het vmbo. Na een beknopte bespreking van belangrijke literatuur over veldwerk worden enkele resultaten van een vragenlijst over veldwerk onder aardrijkskundedocenten gepresenteerd. De focus ligt echter op een van de eerste stappen van een ontwerponderzoek waarbij samen met vmbo docenten aardrijkskunde getracht is veldwerk zo op te zetten dat er meer diepgang in het leren van leerlingen plaats vindt
Murder on the mountain: author talk with Peter J. Wosh
No full textAuthor talk by Peter J. Wosh on May 5th, 2022, on his book, "Murder on the Mountain: crime, passion, and punishment in gilded age New Jersey.
Geospatial Technology in Geography Education
No full textThe book is presented as an important starting point for new research in Geography Education (GE) related to the use and application of geospatial technologies (GSTs). For this purpose, the selection of topics was based on central ideas to GE in its relationship with GSTs. The process of geospatial practices (GPs) as the way to learn about GST and with GST marks the central ideas. The sequential presentation of chapters starts with a theoretical approach, followed by the use of GST at different levels in formal education. Teacher education represents an important third topic that analyzes professional development when learning about GST and using GST. The fourth topic focuses on the effectiveness of GST as a tool for teaching and learning in order to assess geospatial thinking in different educational settings. The exploration of trends and recommendations for future development are the final topic of this book. In one sentence, the book touches upon the most important issues on the use of GST in education and includes the most up to date information and discussions related to GST. Although GE is not in the front line of the Information and Communication Technology (ICT) revolution it cannot stay behind as modern education uses technology to prepare better citizens. The importance of this book relies on this basic and fundamental fact
Circular Geodesics Of Naked Singularities In The Kehagias-sfetsos Metric Of Hořava's Gravity
No full textWe discuss photon and test-particle orbits in the Kehagias-Sfetsos (KS) metric of Hořava's gravity. For any value of the Hořava parameter ω, there are values of the gravitational mass M for which the metric describes a naked singularity, and this is always accompanied by a vacuum "antigravity sphere" on whose surface a test particle can remain at rest (in a zero angular momentum geodesic), and inside which no circular geodesics exist. The observational appearance of an accreting KS naked singularity in a binary system would be that of a quasistatic spherical fluid shell surrounded by an accretion disk, whose properties depend on the value of M, but are always very different from accretion disks familiar from the Kerr-metric solutions. The properties of the corresponding circular orbits are qualitatively similar to those of the Reissner-Nordström naked singularities. When event horizons are present, the orbits outside the Kehagias-Sfetsos black hole are qualitatively similar to those of the Schwarzschild metric. © 2014 American Physical Society.90214-37086G; GACR; Czech Science FoundationHořava, P., (2009) Phys. Rev. D, 79, p. 084008. , PRVDAQ 1550-7998 10.1103/PhysRevD.79.084008Hořava, P., (2009) Phys. Rev. Lett., 102, p. 161301. , PRLTAO 0031-9007 10.1103/PhysRevLett.102.161301Hořava, P., Melby-Thompson, Ch.M., (2010) Phys. Rev. D, 82, p. 064027. , PRVDAQ 1550-7998 10.1103/PhysRevD.82.064027Griffin, T., Hořava, P., Melby-Thompson, Ch.M., (2013) Phys. Rev. Lett., 110, p. 081602. , PRLTAO 0031-9007 10.1103/PhysRevLett.110.081602Kehagias, A., Sfetsos, K., (2009) Phys. Lett. B, 678, p. 123. , PYLBAJ 0370-2693 10.1016/j.physletb.2009.06.019Enolskii, V., Hartmann, B., Kagramanova, V., Kunz, J., Lämmerzahl, C., Sirimachan, P., (2011) Phys. Rev. D, 84, p. 084011. , PRVDAQ 1550-7998 10.1103/PhysRevD.84.084011Harko, T., Kovács, Z., Lobo, F.S.N., (2011) Classical Quantum Gravity, 28, p. 165001. , CQGRDG 0264-9381 10.1088/0264-9381/28/16/165001Yagi, K., Blas, D., Barausse, E., Yunes, N., (2014) Phys. Rev. D, 89, p. 084067. , PRVDAQ 1550-7998 10.1103/PhysRevD.89.084067Iorio, L., Ruggiero, M.L., (2010) Int. J. Mod. Phys. A, 25, p. 5399. , IMPAEF 0217-751X 10.1142/S0217751X10050780Liu, M., Lu, J., Yu, B., Lu, J., (2011) Gen. Relativ. Gravit., 43, p. 1401. , GRGVA8 0001-7701 10.1007/s10714-010-1123-0Harko, T., Kovács, Z., Lobo, F.S.N., (2011) Proc. R. Soc. A, 467, p. 1390. , PRLAAZ 1364-5021 10.1098/rspa.2010.0477Iorio, L., Ruggiero, M.L., (2011) Int. J. Mod. Phys. D, 20, p. 1079. , IMPDEO 0218-2718 10.1142/S0218271811019281Shakura, N.I., Sunyaev, R.A., (1973) Astron. Astrophys., 24, p. 337. , AAEJAF 0004-6361Novikov, I.D., Thorne, K.S., (1973) Black Holes, p. 345. , in, edited by C. DeWitt and B.S. DeWitt (Gordon & Breach, New York), p.Kluźniak, W., Michelson, P., Wagoner, R.V., (1990) Astrophys. J., 358, p. 538. , ASJOAB 0004-637X 10.1086/169006Abramowicz, M.A., Kluzniak, W., Epicyclic frequencies derived from the effective potential: Simple and practical formulae (2005) Astrophysics and Space Science, 300 (1-3), pp. 127-136. , DOI 10.1007/s10509-005-1173-zSadowski, A., Abramowicz, M., Bursa, M., Kluźniak, W., Lasota, J.-P., Rózańska, A., (2011) Astron. Astrophys., 527, pp. A17. , AAEJAF 0004-6361 10.1051/0004-6361/201015256Bursa, M., Abramowicz, M.A., Karas, V., Kluźniak, W., Schwarzenberg-Czerny, A., (2007) RAGtime 8/9: Workshops on Black Holes and Neutron Stars, , edited by S. Hledík and Z. Stuchlík (Silesian University, Opava)Fukumura, K., Kazanas, D., Stephenson, G., (2009) Astrophys. J., 695, p. 1199. , ASJOAB 0004-637X 10.1088/0004-637X/695/2/1199Chen, J., Wang, Y., (2010) Int. J. Mod. Phys. A, 25, p. 1439. , IMPAEF 0217-751X 10.1142/S0217751X10048962Abdujabbarov, A., Ahmedov, B., Hakimov, A., (2011) Phys. Rev. D, 83, p. 044053. , PRVDAQ 1550-7998 10.1103/PhysRevD.83.044053Dwornik, M., Horváth, Zs., Gergely, L.A., (2013) Astron. Nachr., 334, p. 1039. , ASNAAN 0004-6337Kovács, Z., Harko, T., (2010) Phys. Rev. D, 82, p. 124047. , PRVDAQ 1550-7998 10.1103/PhysRevD.82.124047Stuchlík, Z., Hledík, S., (2002) Acta Phys. Slovaca, 52, p. 363. , APSVCO 0323-0465Pugliese, D., Quevedo, H., Ruffini, R., (2011) Phys. Rev. D, 83, p. 024021. , PRVDAQ 1550-7998 10.1103/PhysRevD.83.024021Goluchová, K., Kulczycki, K., Vieira, R.S.S., Stuchlík, Z., Kluźniak, W., Abramowicz, M., (unpublished)Zhou, S., Liu, W., (2011) Int. J. Theor. Phys., 50, p. 1776. , IJTPBM 0020-7748 10.1007/s10773-011-0686-1Phillips, N.G., Hu, B.L., Noise kernel and the stress energy bitensor of quantum fields in hot flat space and the Schwarzschild black hole under the Gaussian approximation (2003) Physical Review D, 68 (10), p. 104002. , DOI 10.1103/PhysRevD.68.104002García, A., Hackmann, E., Kunz, J., Lämmerzahl, C., Macias, A., arXiv:1306.2549v3Balbus, S.A., Hawley, J.F., Instability, turbulence, and enhanced transport in accretion disks (1998) Reviews of Modern Physics, 70 (1), pp. 1-54. , DOI 10.1103/RevModPhys.70.1Stuchlík, Z., Schee, J., arXiv:1402.2891Matt, G., Fabian, A.C., Ross, R.R., (1996) Mon. Not. R. Astron. Soc., 278, p. 1111. , MNRAA4 0035-8711 10.1093/mnras/278.4.1111Schee, J., Stuchlík, Z., J. Cosmol. Astropart. Phys., 2013 (4), p. 005. , JCAPBP 1475-7516 10.1088/1475-7516/2013/04/005Schee, J., Stuchlík, Z., (2009) Gen. Relativ. Gravit., 41, p. 1795. , GRGVA8 0001-7701 10.1007/s10714-008-0753-yStuchlík, Z., Schee, J., (2010) Classical Quantum Gravity, 27, p. 215017. , CQGRDG 0264-9381 10.1088/0264-9381/27/21/215017Stuchlík, Z., Schee, J., (2013) Classical Quantum Gravity, 30, p. 075012. , CQGRDG 0264-9381 10.1088/0264-9381/30/7/075012Stuchlík, Z., Schee, J., Abdujabbarov, A., (2014) Phys. Rev. D, 89, p. 104048. , PRVDAQ 1550-7998 10.1103/PhysRevD.89.104048Stuchlík, Z., (1980) Bull. Astron. Inst. Czech., 31, p. 129. , BAICAP 0004-624
Mr. Melvin J. Collier, RWWL AUC, June 2011
No full textThis video is a conversation with Mr. Melvin J. Collier. Mr. Collier talks about his book, "From Mississippi to Africa: A Journey of Discovery". Daniel Le, AUC Woodruff Library, is the interviewer
The international challenge of more thinking through geography
No full textGeography is a brilliant, exciting subject but you would not say that when you look in some classrooms. Often pupils are bored and demotivated. The question is how to make geography lessons more interesting. In the 1990s the Thinking Through Geography (TTG) group, comprising teachers and lecturers in geographical education and based in north-east England, developed some successful strategies to stimulate pupils to think through geography. Some years later the ideas reached the Netherlands. A survey showed that geography teachers in the Netherlands like the innovation - a liking that grows with familiarity. Although there may be a discussion about the usability of specific strategies, more Thinking Through Geography should be an international challenge. \ua9 2003 J. van der Schee et al
A Tripartite Post-Recession Rebalancing
No full textIn this latest Advance & Rutgers Report, entitled “A Tripartite Post-Recession Rebalancing,” Dean James W. Hughes and Professor Joseph J. Seneca deliver an incisive assessment of the current market conditions and obstacles in the path of our economic recovery. They offer a statistical cautionary tale that the private and public sector need to hear and acknowledge in order for the economy to make continued progress.This report was published as Issue Paper Number 7, November 2011, in Advance & Rutgers Report
- …
