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2 from Perseus Tools and Information

1. Poly Branch: Arkansas, United States [Atlas site] (4.19)

2. Poly Top Butte: Oregon, United States [Atlas site] (3.75)

28 from Greek and Roman Materials

1. Susan Matheson; Polygnotos and His Group: (in English) [Text] (8.74)

2. The Niobid Painter and the Group of Polygnotos [Section in Susan Matheson, Polygnotos and His Group] (4.86)

3. POLY CLES [Reference article in A dictionary of Greek and Roman biography and mythology (ed. William Smith)] (4.68)

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2 from AIM25 - Archives in London

1. Hanover Bicycle Club<BR>Polytechnic Cycling Club; Polytechnic Cycling Club: Records of the Polytechnic Cycling Club and its predecessor, 1883-1989, including accounts, 1883-1981 (incomplete series); handbooks, 1889-1956 (incomplete series); photographs, 1891-1964 and undated; various championship boards, 1891-1914, 1920-1939, 1945-1958, and trophies, 1893-1959; <I>Polytechnic Cycling Club Gazette</I>, 1896-1968 (incomplete series); photocopy of a brief history of the Club, 1899; scrapbook of A E 'Jenny' Walters, 1899-1902; annual dinner menu cards, some with tickets enclosed, 1899-1978 (incomplete series); minutes, including committees, 1899-1989 (incomplete series); Club badges, 19th century; medal, 1902; letter head, 1905; papers, 1910s-1920s; AGM attendance book, 1922-1981; speech given at the jubilee dinner (1928), 1929; membership records and prize books, 1920s-1930s; programme of race meeting, 1938; photographs, medals and memorabilia of David Edward Ricketts, including Olympic diploma, 1948; correspondence files, 1940s-1960s; papers, 1950s-1960s, including meeting records, programmes and notices; Dick Swann, <I>Bert Harris of the Poly</I>, 1964; papers relating to the Polytechnic Institute's relationship with the Polytechnic of Central London and the loss of club room in no 309 Regent Street, 1988-1989; other memorabilia. [Text] [View with Perseus links] (0.74)

2. PCL | Polytechnic of Central London; Polytechnic of Central London: Records, 1968-1992, of the Polytechnic of Central London: <BR>Minutes and committee papers comprise Court of Governors minutes, 1970-1992, and Annual Reports and Statements of Accounts, 1978-1988; Standing Committee of Council minutes, 1972-1983; Finance and General Purposes Committee minutes, 1970-1989, Finance and Property Committee minutes, 1989-1992, and Audit Committee minutes, 1989-1992; Higher Degree Committee papers, 1973-1974, 1985-1987, Research Degree Committee papers, 1974-1983, Research Committee papers, 1976-1992, and other research papers; Staff Development Committee papers, 1976-1981; nursery management committee minutes and papers, 1978-1990; Committees of PCL Health and Safety, 1980-1988; Resource Consultative Committee papers, 1985-1987, and Resources Committee papers, 1987-1989; Committees of Directors of London Polytechnics, 1972-1986; and other committee papers. <BR>Other administrative papers comprise Memorandum and Articles of Association, 1970; certificate of incorporation, 1970; Instrument recording designation as a Polytechnic, 1970; correspondence and papers concerning the Instrument and Articles, 1968-1988; Structure Commission Report on Poly/Holborn amalgamation, 1970; file on designation ceremony and Holborn foundation stone, 1960-1970; papers and reports of J Eric Richardson, including 'The development of the Polytechnic 1957-1970' [1970]; programme of designation and opening of new buildings, 1971; report of the Working Party on Examinations and Assessment, 1971; accommodation strategy report, 1971; papers on organisation of the academic administration, 1972; proposals for the London Regional Management Centre, 1973; annual maintenance grant applications to ILEA (block grant), 1974-1989; papers relating to the CNAA, including its Institutional Review, 1978-1992; specimen certificates for award on successful completion of courses [1970s]; consultants' report on efficiency review, 1986; papers relating to the merger with Harrow College of Higher Education, 1987-1989; papers on the change to University status, 1989-1991; Charity Commissioners' scheme for the Quintin Hogg Memorial Fund, 1991; correspondence with the Privy Council concerning adoption of the title University, coat of arms and letters patent, 1991-1992; PCL Accommodation Strategy report by Touche Ross & Co, 1991. <BR>Financial records include balance sheet and accounts, 1969-1970, report and statement of accounts, 1971-1981, 1983-1985, 1988, and Enterprise in Higher Education Annual Report, 1990. <BR>Departmental records include file of the Library Development Officer, 1972-1973; Library handbooks, 1971-1972, and guide to services [1978]; Library Development Plan, 1980-1985; Department of Surveying proposals for submission of BSc in Quantity Surveying to the CNAA, 1974; American Studies Resource Centre teaching materials, including videos and maps [1980]; photograph album and booklet on the School of Management. <BR>Other records include Teaching Staff Association papers, 1970-1977. <BR>Material, including ephemera, relating to events includes telegram of thanks for the Polytechnic's message on the silver wedding of the Queen and Duke of Edinburgh, 1973; programmes of annual dinner at the Cafe Royal, 1974, 1976; programme of supper and concert for the silver jubilee, 1977; publicity material relating to the 150th anniversary, 1988. <BR>Publications, 1970-1992, include PCL prospectuses (general and departmental), leaflets, brochures and posters for courses and events, guides for applicants, student handbooks, and other information for students; programmes of presentation ceremonies, 1972-1974; Polytechnic Institute <i>Members' Magazine</i> [1971]-1974; typescript Polytechnic Sports and Social Club monthly newsletter, 1974-1975, succeeded by the <i>Newsletter of Polytechnic Members</i>, 1976-1988; typescript Institute of Polytechnic Sports and Social Clubs newsletter, 1991-1992; publications for staff, comprising miscellaneous PCL staff information bulletins and magazines, 1970-1977, and <i>Central Issue</I>, the staff newspaper, 1977-1985, succeeded by <I>Clarion</i>, 1987-1992; <i>McGarel</i>, 1968/69-1992/93 (incomplete series), described as Polytechnic Students' Newspaper and later as Polytechnic Students' Union Newspaper; printed articles on Polytechnic buildings in Marylebone Road and New Cavendish Street, 1970-1971, and other publications relating to the Polytechnic, 1981, 1983. <BR>Photographs and slides, 1970-1992, including buildings, students, activities and events, among them the designation ceremony, 1971. [Text] [View with Perseus links] (0.44)

510 from Beazley Archive

1. Altenburg, Staatliches Lindenau-Museum, 291: HYDRIA; HECTOR PAINTER, PELEUS PAINTER, POLYGNOTOS, GROUP OF; DRAPED MAN WITH STAFF, WARRIOR WITH SPEAR AND PHIALE, WOMAN WITH OINOCHOE, ROCK [Beazley Archive Vase] (10.33)

2. Athens, Agora Museum, P10355: BELL-KRATER FRAGMENT; POLYGNOTOS, POLYGNOTOS, GROUP OF; YOUTHS [Beazley Archive Vase] (6.95)

3. New York (NY), Metropolitan Museum, 56.171.48: CALYX-KRATER; POLYGNOTOS, POLYGNOTOS, GROUP OF; DRAPED YOUTHS, ONE WITH STAFF, HALTERES SUSPENDED, OLD MAN WITH STAFF, THESEUS, WITH CLUB AND SWORD, AND THE BULL, WOMAN WITH OINOCHOE AND PHIALE [Beazley Archive Vase] (6.57)

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8 from BioMed Central

1. Claire Gaillard, Francois Strauss; DNA loops and semicatenated DNA junctions: (in English) AbstractBackgroundAlternative DNA conformations are of particular interest as potential signals to mark important sites on the genome. The structural variability of CA microsatellites is particularly pronounced; these are repetitive poly(CA) · poly(TG) DNA sequences spread in all eukaryotic genomes as tracts of up to 60 base pairs long. Many in vitro studies have shown that the structure of poly(CA) · poly(TG) can vary markedly from the classical right handed DNA double helix and adopt diverse alternative conformations. Here we have studied the mechanism of formation and the structure of an alternative DNA structure, named Form X, which was observed previously by polyacrylamide gel electrophoresis of DNA fragments containing a tract of the CA microsatellite poly(CA) · poly(TG) but had not yet been characterized.ResultsFormation of Form X was found to occur upon reassociation of the strands of a DNA fragment containing a tract of poly(CA) · poly(TG), in a process strongly stimulated by the nuclear proteins HMG1 and HMG2. By inserting Form X into DNA minicircles, we show that the DNA strands do not run fully side by side but instead form a DNA knot. When present in a closed DNA molecule, Form X becomes resistant to heating to 100°C and to alkaline pH.ConclusionsOur data strongly support a model of Form X consisting in a DNA loop at the base of which the two DNA duplexes cross, with one of the strands of one duplex passing between the strands of the other duplex, and reciprocally, to form a semicatenated DNA junction also called a DNA hemicatenane. [Text] [View with Perseus links] (2.23)

2. ... ; Assessing the contribution of the herpes simplex virus DNA polymerase to spontaneous mutations: (in English) AbstractBackgroundThe thymidine kinase (tk) mutagenesis assay is often utilized to determine the frequency of herpes simplex virus (HSV) replication-mediated mutations. Using this assay, clinical and laboratory HSV-2 isolates were shown to have a 10- to 80-fold higher frequency of spontaneous mutations compared to HSV-1.MethodsA panel of HSV-1 and HSV-2, along with polymerase-recombinant viruses expressing type 2 polymerase (Pol) within a type 1 genome, were evaluated using the tk and non-HSV DNA mutagenesis assays to measure HSV replication-dependent errors and determine whether the higher mutation frequency of HSV-2 is a distinct property of type 2 polymerases.ResultsAlthough HSV-2 have mutation frequencies higher than HSV-1 in the tk assay, these errors are assay-specific. In fact, wild type HSV-1 and the antimutator HSV-1 PAAr5 exhibited a 2-4 fold higher frequency than HSV-2 in the non-HSV DNA mutatagenesis assay. Furthermore, regardless of assay, HSV-1 recombinants expressing HSV-2 Pol had error rates similar to HSV-1, whereas the high mutator virus, HSV-2 6757, consistently showed signficant errors. Additionally, plasmid DNA containing the HSV-2 tk gene, but not type 1 tk or LacZ DNA, was shown to form an anisomorphic DNA stucture.ConclusionsThis study suggests that the Pol is not solely responsible for the virus-type specific differences in mutation frequency. Accordingly, it is possible that (a) mutations may be modulated by other viral polypeptides cooperating with Pol, and (b) the localized secondary structure of the viral genome may partially account for the apparently enhanced error frequency of HSV-2. [Text] [View with Perseus links] (1.18)

3. Amit Maiti, Samir Brahmachari; Poly purine.pyrimidine sequences upstream of the beta-galactosidase gene affect gene expression in Saccharomyces cerevisiae: (in English) AbstractBackgroundPoly purine.pyrimidine sequences have the potential to adopt intramolecular triplex structures and are overrepresented upstream of genes in eukaryotes. These sequences may regulate gene expression by modulating the interaction of transcription factors with DNA sequences upstream of genes.ResultsA poly purine.pyrimidine sequence with the potential to adopt an intramolecular triplex DNA structure was designed. The sequence was inserted within a nucleosome positioned upstream of the β-galactosidase gene in yeast, Saccharomyces cerevisiae, between the cycl promoter and gal 10Upstream Activating Sequences (UASg). Upon derepression with galactose, β-galactosidase gene expression is reduced 12-fold in cells carrying single copy poly purine.pyrimidine sequences. This reduction in expression is correlated with reduced transcription. Furthermore, we show that plasmids carrying a poly purine.pyrimidine sequence are not specifically lost from yeast cells.ConclusionWe propose that a poly purine.pyrimidine sequence upstream of a gene affects transcription. Plasmids carrying this sequence are not specifically lost from cells and thus no additional effort is needed for the replication of these sequences in eukaryotic cells. [Text] [View with Perseus links] (1.08)

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90 from CIMI Metadata Harvesting Working Group Demonstration Repository

1. The Poly's: SPLIT ENZ (Band), Noel CROMBIE (Costume designer), Noel CROMBIE (Musician); Trousers - Lemon,tan and black cotton print. Large square pattern with inner geometric designs. Based on Polynesian motifs. Elastic waist. Waist:750mm. Worn with Jacket (1984.004.087) Part of The Poly's set of costumes worn by Split Enz, 1978. [Text] (3.11)

2. The Poly's: SPLIT ENZ (Band), Noel CROMBIE (Costume designer), Noel CROMBIE (Musician); Trousers - Pink,black and white cotton print - patterned vertical bands alternate with white. Based on Polynesian motifs. Elastic waste. Waist:690mm. Worn with Jacket (1984.004.079) Part of The Poly's set of costumes worn by Split Enz, 1978. [Text] (3.02)

3. Melontroppo Suit: Sue BROADWAY (Circus Performer), Tim COLDWELL (Circus performer); Pink & green poly-satin stretch bodysuit with green poly-satin appliqued stars at neck and pink poly-satin stars down left hip [Text] (2.86)

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3 from Chemistry Preprint Server

1. Watson Loh, M Spitzer, E Sabadini; Poly(ethylene glycol) or poly(ethylene oxide)? Magnitude of end-group contribution to the partitioning of ethylene oxide oligomers and polymers between water and organic phases.: PEO partitioning from water to CH₂Cl₂ and CHCl₃ increases with its molar mass, leveling off at ca. 3 000 g mol^-1. Such a behaviour is related to PEO end-group contributions, suggesting a polyglycol to polyether transition at ca. 3 000 g mol^-1. [Text] [View with Perseus links] (1.06)

2. ASSOULI Badr, Z. A. Ait Chikh, H. Idrissi and A. Srhiri; Electrochemical Properties of Poly (2-Mercaptobenzimidazole) Films Prepared in Methanol Alkaline Solvent on Copper-Zinc Alloy: The kinetic of electropolymerization of the 2-mercaptobenzimidazole (2-MBI) on Brass substrate in methanol alkaline solution was investigated using cyclic polarization, chronoamperometry and electrochemical impedance techniques. The polymeric film was prepared by successive cycling potential of Cu-Zn electrode between 0.2V and 2.4V. At the second cycling, the oxidation peak of monomer disappears indicating the formation of insulating film. We have also shown that monomer oxidation reaction is essentially irreversible and controlled by a diffusion process. The protective effect of the film formed on brass, has been studied in 3% NaCl solution. The results showed an important inhibition efficiency was very high in the order of 96% for 4h of testing time.Key words : 2-mercaptobenzimidazole, electropolymerization, isolating film, inhibition of corrosion, NaCl 3%. [Text] [View with Perseus links] (0.74)

3. Michael J. Bucknum; Calculating Topological Indexes of Networks from the Corresponding Wells Point Symbol: This paper begins with a review of the Euler relation for the convex polyhedra. The Schlafli relation is derived from this by introducing the secondary topological indexes of polygonality and connectivity. A topology map of the polyhedra and extended structures, in a Schlafli space, is illustrated and is discussed from the point of view of its organizational value for defining the topological relationship of structures from their Schl䦬i indexes. A comment is then made with respect to the definition of the various vertex connectivities in structures, from knowledge of the circuit number of the vertex. It is shown here that vertices containing polar connections have a reduced circuit number from that calculated according to the prescription p(p-1)/2. Next a review is made of the Wells point symbols and corresponding Schlafli indexes; first of the regular diamond and graphene nets; second of the semi-regular nets, including the Archimedean fullerene polyhedron and the Cooperite structure-type, and the Catalan fluorite and Waserite structure-types; and third of the irregular nets to include the Wellsean glitter and phenacite structure-types. The direct translation of the Wells point symbol to a weighted average polygonality, n, and a weighted average connectivity, p, is demonstrated in these examples. [Text] [View with Perseus links] (0.34)

2 from DUETT - Dissertations and other Documents of the Gerhard-Mercator-University Duisburg

1. Seidel, Renate Magdalene; Molekulare Mangan-,Eisen- und Cobalt-Komplexe mit neuartigen Metall-Chalcogen-Gerusten - Molecular manganese-, iron- and cobalt-complexes with novell metal-chalcogenides frameworks: Prof. Dr. P. Sartori, Prof. Dr. G. Henkel; (in German) The possibility of synthesis of (poly-)chalcogenide and chalcogenolate ions to manganese, iron and cobalt was expanded with the introduction of the donor ligand carbon monoxide. The metal atoms get than greater coordination numbers. So it was possible to synthesise new metal frameworks, p. e. Co11E7 in the complexes [Ph4P]2[Co11Se7(CO)10] and [Ph4P]2[Co11Te7(CO)10], in which the cobalt atoms built a inner centred pentagonal prism. In the examined reaction systems Mn2(CO)10/Na2Sex/Kat, Fe(CO)5/Na2Ex/Kat and Co2(CO)8/Na2Ex/Kat (E = Se or Te; x = 1 or 2; Kat = Ph4PCl or PPNCl) succeeded the synthesis of [Co6Se8(CO)6]-/2-anions as first anionic clusters of the M6E8L6 class. The difference between the new [Co6Se8(CO)4]- anion and the M6E8L6-complex class is the extraordinary compressed Co6-oktaeder and considerable shorter Co-Co-distances. In addition to the higher mentioned compounds it was possible to synthesise and characterize unambiguous with the aid of single crystal x-ray crystallography the following complexes: [Ph4P]2[Fe3Te(CO)9]; [Ph4P][Fe3EH(CO)9] fur E=Se,Te; [Ph4P]2 [Fe4Te2(CO)14]; [Ph4P]2 [Fe6Se6(CO)12]; [Ph4P]2 [Mn3Se2(CO)9]. Worth mentioning is also the unusual square pyramidal coordination of the manganese atom in the [Ph4P][Mn(CO)5] crystal. Until now were only penta carbonyl complexes known with a trigonal bipyramidal coordination. [Text] [View with Perseus links] (1.26)

2. Hoffmann, Dirk; NMR-Untersuchungen an Nanokapsel-Dispersionen - NMR investigations on nanocapsule dispersions: Prof. Dr. Wiebren S. Veeman; (in German) Nanocapsules are generally considered as spherical, hollow structures. Important potential applications are pharmaceutically related such as drug targeting and controlled release. Typically, the capsules consist of a polymeric wall, filled with an oil which can dissolve lipophilic agents. To enable a stable aqueous dispersion, the capsule surface is covered by an amphiphilic surfactant. Nanocapsule-dispersions were investigated by means of solid-state nmr. Cross polarization experiments revealed the morphology of the polymeric wall. Further, the spin-lattice relaxation times for the proton magnetization in the rotating frame were studied under direct excitation as well as under cross polarization conditions. Based on the results, a special mechanism of cross polarization is proposed, initiated by a temporary adsorption of mobile oil- and surfactant-molecules to the more rigid capsule surface. - Nanokapseln sind spharische, hohle Objekte, die in der Medizin als gewebespzifische Wirkstoff-Trager-Systeme eingesetzt werden sollen. Vereinfacht bestehen die Kapseln aus einem Oltropfen, der von einem Polymergerust umgeben ist. In die innere Olphase konnen lipophile Wirkstoffe eingeschlossen werden. Die Nanokapselwand ist mit einer Tensidschicht umgeben, die stabilisierend wirkt und ermoglicht, dass die Kapseln in einer wasserigen Phase dispergiert werden konnen. Als analytische Methode wurde die Festkorper-NMR-Spektroskopie gewahlt. Die Morphologie der Polymerwand wurde mit Kreuzpolarisationsexperimenten aufgeklart. Zusatzlich wurden die Relaxationszeiten im rotierenden Koordinatensystem der Protonen unter Direktanregungs- und Kreuzpolarisationsbedingungen untersucht. Die Ergebnisse dieser Untersuchungen konnten mit einer temporaren Adsorption der Ol- und Tensidmolekule an der Nanokapseloberflache interpretiert werden. [Text] [View with Perseus links] (0.69)

1 from Digital Library of the Commons

1. Allen, Barbara; Heterogeneity and Federal Systems: Group Rights, Individual Rights, and Multicultural Citizenship: (in English) "In society, the term heterogeneity may be used to describe an asymmetrical distribution of political resources. When applied to the physical environment, 'heterogeneity' can signify important differences in resource characteristics and, as a consequence, the need to look at resource boundaries as well as political boundaries to understand the relationship between natural and social worlds. Political institutions can advance or retard cultural heterogeneity and diversity in the physical environment. Federal systems explicitly embrace complexity, heterogeneity, and complimentarity as basic principles of institutional development. As a form of polycentric authority, federalism facilitates cultural heterogeneity by enabling diverse, interdependent peoples who occupy a single geographical space to exercise shared prerogatives of rule. Federalism relies on commonly held principles of collective decision making and shared values. This paper considers the origins of common value and political practice in the example of American federalism, taking Alexis de Tocqueville's observations of American democracy as a point of departure. In America, the "federal principle" developed during the colonial period as individuals and peoples united through the act of covenanting. Covenants can unite independent polities without destroying their existing governments, suggesting that federalism provides one method of political integration that preserves cultural diversity." [Text] [View with Perseus links] (0.36)

1 from Hong Kong University Theses Online

1. Ho Chung-fong, Jonathan; Poly(methylmethacrylate) dentures reinforced with highly drawn polyethylene fibres : dimensional changes during processing and in service / : y Jonathan Ho Chung Fong [Text] [View with Perseus links] (1.92)

8 from Humboldt University of Berlin, GERMANY, Document Server

1. Mbakop, Guy Merlin; Effiziente Losung reeller Polynomialer Gleichungssysteme: (in German) This dissertation deals with {\em geometric algorithms} for solving real multivariate polynomial equation systems, that define a reduced regular sequence (cf. subsection $\ref{abschgeo}$). Real solving means that one has to find at least one real point in each connected component of a real compact and smooth variety $V := W \cap \R^n$. \\ The main point of this thesis is the use of a complex symbolic geometric algorithm, which is designed for an algebraically closed field and was published in the papers \cite{gh2} and \cite{gh3}. The models of computation are {\em straight--line programms} and {\em arithmetic Networks} with parameters in $\; \Q$. Let the polynomials be given by a division--free straight--line programm of size $L$. A geometric solution for the system of equations given by the regular sequence consists in a {\em primitiv element} of the ring extension associated with the system, a minimal polynomial of this primitive element and a parametrization of the coordinates. This representation has a long history going back to {\em Leopold Kronecker} \cite{kron}. The time--complexity of our algorithms turns out to be linear in $L$ and polynomial with respect to $n, d, \delta$ or $\delta '$, respectively. Here $n$ denotes the number of variables, $d$ is an upper bound of the degrees of the polynomials involved in the system, $\delta$ and $\delta '$ are geometric invariants representing the maximum of the {\em affine (geometric) degree} of the system under consideration and the affine (geometric) degree of suitable {\em polar varieties} (cf. \cite{he} for the ({\em geometric}) degree). The application of an algorithm running in the complex numbers to solve polynomial equations in the real case becomes possible by the introduction of polar varieties (cf. \cite{bank}). The polar varieties introduced for this purpose prove to be the corner--stone and the preliminary tool for the efficient use of the geometric algorithm mentioned above. An incremental algorithm is designed to find at least one real point on each connected component of the zero set defined by the input under the assumption that the given semialgebraic set $V = W \cap \R^n$ is a bounded, smooth (local) complete intersection manifold in $\R^n$. The increment of the new algorithm is the codimension of the polar varieties under consideration. The main theorems are Theorem $\ref{theorem12}$ on page $\pageref{theorem12}$ for the hypersurface case, and Theorem $\ref{theoresult}$ on page $\pageref{theoresult}$ for the complete intersection as well as the statement in the introduction of this thesis on page $\pageref{vollres}$. [Text] [View with Perseus links] (3.13)

2. Muller-Hilke, Brigitte; Die differentielle Expression von MHC II-Genen als Mechanismus bei der Entstehung von Autoimmunerkrankungen: (in German) Protective/suppressive MHC class II alleles have been identified in man and mouse where they exert a disease-protective and immunosuppressive effect. As a mode of action we here investigate differential expression of MHC class II genes in different types of antigen-presenting cells impacting on the Type 1-Type 2 balance. We found that the murine I-Ab and I-Ek molecules, both well characterized as protective/suppressive, are expressed at a high level on almost all bone marrow derived macrophages for five to eight days after which expression slowly declines. In contrast, the collagen-induced arthritis (CIA) associated I-Aq-expression is lower, peaks over a shorter period and declines more rapidly. No differential expression could be detected on B cells or dendritic cells (DC). In addition, the differential MHC class II expression found on macrophages skews the cytokine response of T cells as shown by an in vitro restimulation assay. The results indicate that macrophages of the protective/ suppressive haplotypes express MHC class II molecules at a high level and exert Type 1 bias whereas low level expression favors a Type 2 response. We suggest that the extent of expression of the class II gene gates the back-signal from T cells and in this way controls the activity of macrophages. This effect mediated by polymorphic non-exon segments of MHC class II genes may play a role in determining disease susceptibility in mouse and man. Indeed, we also found differential expression of HLA II genes on human antigen presenting cells. However, in humans, differential expression affects both, B cells and monocytes and seems to be restricted to the non-polymorphic DRB4 gene coexpressed with the rheumatoid arthritis (RA) associated DR4 and the neutral DR7. We finally aimed at reverting the Type 1 bias characteristic of RA and CIA. A murine system was developed where polarized Type 2 cells were used to manipulate collagen II-specific type 1 T cells responsible for the development of collagen induced arthritis. The polarized inducer cells indeed exerted their maximum effect when the two T-cell populations were activated within the same cluster, implemented by allowing a single DC to present both their epitopes. [Text] [View with Perseus links] (0.62)

3. Mundry, Tobias; Einbrennsilikonisierung bei pharmazeutischen Glaspackmitteln - Analytische Studien eines Produktionsprozesses: (in German) [Text] [View with Perseus links] (0.58)

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14 from Institut National de Physique Nucleaire et de Physique des Particules

1. ... ; Pulsed laser crystallization of hydrogen-free a-Si thin films for high-mobility poly-Si tft fabrication [Text] (1.76)

2. ... ; ATLAS [Text] (1.71)

3. ... ; Charged particle multiplicity distributions in Z$^0$ hadronic decays [Text] (1.37)

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2 from LSU Electronic Thesis and Dissertation Archive

1. Calderon, Gina Marie; The Radiation Induced Degradation of Poly(Diene Sulfones) as X-ray Resists: (in English) The microlithographic process, essential in the fabrication of silicon chip integrated circuits, uses high-energy radiation to transfer a pattern onto a thin film of polymer resist. Pattern transfer occurs by modifying the properties (solubility or volatility) of the polymer film exposed to radiation. Poly(olefin sulfones) exhibit a high sensitivity to x-rays, which is a desirable property for polymer resists, but typically undergo a glass transition around room temperature and a thermal degradation at moderate temperatures. The thermal properties of the poly(olefin sulfones) reduce the processing latitude for industrial microelectronics applications. Poly(unsaturated olefin sulfones) containing a carbon-carbon double bond in the polymer backbone exhibit good thermal stability and film forming properties comparable to those observed with poly(methyl methacrylate), PMMA. The potential utility of these new resins prompted a study of the mechanism of degradation promoted by x-ray radiation. In this study, the effect of x-ray radiation on polysulfones with varied chemical structures was analyzed using x-ray absorption near-edge structure (XANES) spectroscopy. The volatile by-products formed upon irradiation of each polysulfone were characterized by in-situ mass spectroscopy. Distinct differences between the mode of degradation of poly(olefin sulfones) such as poly(butane-1 sulfone), PBS,and that of poly(hexadiene sulfone), PHS, were observed. The energy positions of the sulfur K-edge in irradiated PBS are approximately 2473 eV, (sulfide) and 2479 eV (sulfone). Decomposition is accompanied by sulfide formation and the evolution of butene-1 in the gaseous by-products. In contrast, the sulfur K edge spectra of PHS exhibits the following energy positions, 2473 eV (sulfide), 2475 eV (sulfoxide), 2478 eV (sulfone) and 2482 eV (sulfonate). Only sulfur oxide by-products were observed in the mass spectra indicating that the predominant mode of degradation is oxidative. Further studies will be required to elucidate the mechanism of this new mode of degradation. [Text] [View with Perseus links] (1.60)

2. Ford, Sean M.; Fabricating Microfluidic Devices in Polymers for Bioanalytical Applications: (in English) The research presented in this document focuses on the fabrication, characterization and application of microfluidic systems fabricated in poly(methyl methacrylate) (PMMA) with the emphasis focused on the fabrication processing steps. Microfluidic devices were produced in PMMA using X-ray lithography. The fabrication methods investigated were sacrificial mask, polyimide membrane mask and embossing techniques. PMMA microfluidic devices fabricated using X-ray lithography were characterized using scanning electron microscopy (SEM) and optical microscopy, while analytical techniques such as electroosmotic flow determination, separations, and fluorescent microscopy were used to characterize fluid transport in these devices. A novel method for the heat annealing of PMMA to PMMA to create a closed system is described. Characterization of this technique was carried out by optical microscopy and scanning electron microscopy. The manufacturing techniques utilized in producing mold inserts for hot embossing and injection molding is discussed as well. Both the mold insert and devices produced from the inserts were characterized using scanning electron microscopy. Devices produced can be used to perform a number of analytical techniques including single molecule detection and fluorescence lifetime monitoring. The primary goal of this research was to develop molding tools consisting of high-aspect-ratio microstructures using robust and reproducible processing steps. [Text] [View with Perseus links] (0.26)

46 from NCSTRL Historical Collection

1. Agarwal, K Pankaj, Aronov, Boris, O'Rourke, Joseph, Schevon, A Catherine; Star Unfolding of a Polytope with Applications: \def\poly{{\cal P}} We define the notion of a {\em star unfolding} of the surface $\poly$ of a convex polytope with $n$ vertices, and use it to solve several problems related to shortest paths on $\poly$. The first algorithm computes the edge sequences traversed by shortest paths on $\poly$ in time $O(n^6 \beta (n) \log n)$, where $\beta (n)$ is an extremely slowly-growing function. A much simpler $O(n^6)$ time algorithm that finds a small superset of all such edge sequences is also sketched. Second, we describe an $O(n^{8}\log n)$ time procedure for computing the {\em geodesic diameter} of $\poly$: the maximum possible separation of two points on $\poly$, with the distance measured along~$\poly$. Finally, we describe an algorithm that preprocesses $P$ into a data structure that can efficiently answer the queries of the form: Given two points, what is the length of the shortest path connecting them?'' Given a parameter $n^2 \le s \le n^4$, it can preprocess $\poly$, in time $O(n^4 s^{1+\delta})$ for any $\delta > 0$, into a data structure of size $O(n^4s^{1+\delta})$, so that a query can be answered in time $O(\frac{n}{s^{1/4}} \log^2 n)$. If one query point always lies on an edge of $\poly$, the algorithm can be improved to use $O(n^3 s^{1+\delta})$ preprocessing time and storage and guarantee $O(\frac{n}{s^{1/3}} \log^2 n)$ query time for $n^2 \le s \le n^3$. [Text] (6.14)

2. ... ; Polarization stability of amorphous piezoelectric polyimides: Amorphous polyimides containing polar functional groups have been synthesized and investigated for potential use as high temperature piezoelectric sensors. The thermal stability of the piezoelectric effect of one polyimide was evaluated as a function of various curing and poling conditions under dynamic and static thermal stimuli. First, the polymer samples were thermally cycled under strain by systematically increasing the maximum temperature from 50C to 200C while the piezoelectric strain coefficient was being measured. Second, the samples were isothermally aged at an elevated temperature in air, and the isothermal decay of the remanent polarization was measured at room temperature as a function of time. Both conventional and corona poling methods were evaluated. This material exhibited good thermal stability of the piezoelectric properties up to 100C. [Text] (4.51)

3. Beimel, Amos, Kushilevitz, Eyal; Learning Boxes in High Dimension: We present exact learning algorithms that learn several classes of (discrete) boxes in $\{0,\ldots,\ell-1\}^n$. In particular we learn: (1) The class of unions of $O(\log n)$ boxes in time $\poly(n,\log\ell)$ (solving an open problem of \cite{GGM94,BGGM94}; in~\cite{BBBKV97} this class is shown to be learnable in time $\poly(n,\ell)$). (2) The class of unions of disjoint boxes in time $\poly(n,t,\log\ell)$, where $t$ is the number of boxes. (Previously this was known only in the case where all boxes are disjoint in one of the dimensions; in~\cite{BBBKV97} this class is shown to be learnable in time $\poly(n,t,\ell)$). In particular our algorithm learns the class of decision trees over $n$ variables, that take values in $\{0,\ldots,\ell-1\}$, with comparison nodes in time $\poly(n,t,\log\ell)$, where $t$ is the number of leaves (this was an open problem in \cite{Bsh93} which was shown in \cite{BBBKV96} to be learnable in time $\poly(n,t,\ell)$). (3) The class of unions of $O(1)$-degenerate boxes (that is, boxes that depend only on $O(1)$ variables) in time $\poly(n,t,\log\ell)$ (generalizing the learnability of $O(1)$-DNF and of boxes in $O(1)$ dimensions). The algorithm for this class uses only equivalence queries and it can also be used to learn the class of unions of $O(1)$ boxes (from equivalence queries only). [Text] (3.14)

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36 from OCLC Online Computer Library Center Theses and Dissertations Repository

1. Umrigar, Pesi Polly,--1951-; Synthesis of some potentially biologically active derivatives of the divinyl ether/maleic anhydride copolymer /--by Pesi Polly Umrigar.: Typescript., Vita., Thesis (M. S.)--University of Florida., Bibliography: leaves 34-37. [Text] (2.82)

2. Mozes, Lee Wolfe,--1947-; Distinguishing characteristics of interferon induction with poly IA?·poly C and Newcastle disease virus in cultured cells. /--Lee Wolfe Mozes.: Also on film., Thesis (Ph. D.)--New York University, Graduate School. [Text] (2.74)

3. Moore, Robert Earl,--1947-; The turnover of cytoplasmic free and membrane-bound poly(A)RNAs in hepatic tissues of the rat /--by Robert E. Moore.: Vita., Thesis - Wisconsin., Bibliographical references. [Text] (2.32)

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1 from Objects under development

1. Kreyssig, Andreas; Einfluss der magnetischen Ordnung auf Supraleitung und Kristallstruktur in Seltenerd-Nickel-Borkarbid-Verbindungen, alternative/translated: Influence of the magnetic order on superconductivity and crystal structure in rare earth nickel borocarbides: TU Dresden, Mathematik und Naturwissenschaften, Physik, Institut fur Angewandte Physik und Didaktik der Physik; (in German) Seltenerd-Nickel-Borkarbid-Verbindungen RNi2B2C sind bestens zur Untersuchung eines der interessantesten Probleme der modernen Festkorperphysik geeignet: Diese Substanzen weisen Konkurrenz und Koexistenz von Supraleitung und Magnetismus auf, wobei die vom R3+-Ion abhangigen Ubergangstemperaturen in einem experimentell gut zuganglichen Bereich von 1 K bis 25 K liegen. Die vorliegende Dissertation stellt experimentelle Arbeiten zum Wechselspiel der beiden Ordnungsphanomene vor. Fur poly- und einkristalline Proben werden die magnetischen Ordnungen und resultierende Veranderungen der Kristallstruktur mittels Neutronendiffraktion in Abhangigkeit von der Temperatur und vom ausseren Magnetfeld bestimmt und mit den makroskopischen magnetischen und elektrischen Eigenschaften verglichen. Hierbei werden die tetragonalen RNi2B2C-Verbindungen gezielt in ihrer Ni-B-Stochiometrie variiert sowie die magnetischen R3+-Ionen partiell durch andere magnetische als auch unmagnetische R?3+-Ionen substituiert. Fur HoNi2B2C werden in einem engen Temperaturbereich drei verschiedene magnetische Strukturen nachgewiesen. Wahrend in zwei magnetischen Ordnungen die Ho3+-Momente entlang der c-Achse moduliert sind, wird fur die dritte magnetische Ordnung eine Modulation in a-Richtung beobachtet. Sowohl durch die partielle Substitution der Ho3+-Ionen als auch durch die Ni-B-Stochiometrievariation wird die Auspragung der magnetischen Strukturen stark modifiziert. Der Vergleich mit den ebenfalls veranderten supraleitenden Eigenschaften ergibt das folgende Bild fur die HoNi2B2C-Verbindungen: Die Supraleitung koexistiert mit den beiden c-Achsen-modulierten magnetischen Strukturen, das Einsetzen der magnetischen Ordnung fuhrt jedoch zu einer Schwachung der Supraleitung. Die a-Achsen-modulierte magnetische Struktur weist Momentkomponenten in c-Richtung auf, die auf Grund der resultierenden lokalen Magnetfelder an den Ni-Platzen eine starke Unterdruckung der Supraleitung bewirken. Die beobachtete Konkurrenz zwischen der Supraleitung und der a-Achsen-modulierten magnetischen Struktur gibt andererseits einen starken Hinweis darauf, dass die Modifizierung der elektronischen Struktur im supraleitenden Zustand auf das magnetische System ruckwirkt. Als weitere Auswirkung des Magnetismus kommt es in RNi2B2C-Verbindungen mit R = Ho, Dy, Tb und Er zu Veranderungen der Kristallstruktur. Mittels hochauflosender Neutronendiffraktion werden magnetisch induzierte, tetragonal-zu-orthorhombische Gitterverzerrungen fur diejenigen magnetischen Ordnungen nachgewiesen, bei denen die magnetischen Momente der R3+-Ionen parallel bzw. antiparallel ausgerichtet sind. Die Richtung der Gitterverzerrung, die Abhangigkeit ihrer Grosse vom Quadrat des geordneten magnetischen Momentes als auch von der Art der R3+-Ionen deuten darauf hin, dass die magneto-elastischen Wechselwirkungen durch Kristallfeldeffekte bestimmt werden. Diese Einsicht unterstutzt auch die Aufklarung der magnetischen Phasendiagramme mittels magnetfeldabhangiger Neutronenbeugungsexperimente. Fur eine magnetische Phase schrankt das Auftreten bzw. Fehlen der magneto-elastischen Effekte die Vielfalt der moglichen magnetischen Strukturen ein. Die aus der Literatur bekannten magnetischen Phasen von HoNi2B2C werden bestatigt. Fur DyNi2B2C werden die experimentellen Ergebnisse unter Nutzung eines einfachen Modelles interpretiert und die magnetischen Strukturen bestimmt. Anhand von Molekularfeldrechnungen konnen die Unterschiede in den magnetischen Strukturen fur ansteigendes und fur abnehmendes Magnetfeld als sehr starke Hystereseeffekte in Zusammenhang mit Phasenubergangen erster Ordnung gedeutet werden., Rare-earth nickel borocarbids RNi2B2C are particularly suitable for investigations on one of the most interesting problems in modern solid-state physics: these compounds display competition and coexistence of superconductivity and magnetism. Depending on the R3+ ion, the transition temperatures are in an experimentally easy accessible range of 1 K to 25 K. This thesis presents experimental studies on the interplay of both ordering phenomena. Neutron diffraction is used to determine the magnetic order and the resulting changes of the crystal structure. Experiments are performed on polycrystalline and single crystal samples in dependence on temperature and external magnetic fields. The Ni-B stoichiometry of the tetragonal RNi2B2C compounds is systematically varied and the magnetic R3+ ions are partially substituted by other magnetic or nonmagnetic R?3+ ions. The experimental results are compared with macroscopic magnetic and electrical properties. For HoNi2B2C three different magnetic structures are found in a narrow temperature range. While for two magnetic structures the Ho3+ moments are modulated along the c axis, a third magnetic structure with a modulation in a direction is observed. Both, partial substitution of Ho3+ ions and variation of the Ni-B stoichiometry, strongly modify the formation of these different types of magnetic order. The comparison with the concomitant changes of the superconducting properties yields the following scenario for HoNi2B2C-based compounds: superconductivity coexists with both magnetic structures with modulations in c direction. However, the onset of magnetic order weakens the superconductivity. For the magnetic structure with modulation along the a axis, components of the magnetic moments arise in c direction. The resulting local magnetic fields on Ni sites yield a strong suppression of the superconductivity. The observed competition between superconductivity and the magnetic structure with modulation along the a axis strongly suggests that the modification of the electronic structure due to the superconducting state influences the magnetic ordering. As a further impact of the magnetism in RNi2B2C compounds with R = Ho, Dy, Tb and Er changes of the crystal structure are investigated. Using high-resolution neutron diffraction, tetragonal-to-orthorhombic lattice distortions are found. They are induced by those magnetic structures with either parallel or anti-parallel alignement of R3+ magnetic moments. The direction of the lattice distortions, the dependence of their size on the square of the effective ordered magnetic moment and on the type of the R3+ ions indicate that the magneto-elastic interactions are determined by crystal-field effects. This fact also facilitates the elucidation of the magnetic phase diagrams by neutron diffraction experiments in external magnetic fields. For a given phase, absence or presence of magneto-elastic lattice distortions restrict the set of possible magnetic structures. For HoNi2B2C the magnetic phases reported in literature are confirmed. The experimental results for DyNi2B2C are interpreted using a simple model to determine the magnetic structures. Based on mean field calculations, the differences in the magnetic structures for increasing and decreasing magnetic fields can be understood as very strong hysteresis effects in connection with first-order phase transitions. [Text] (0.15)

2 from State and University Library Bremen

1. Garbrecht, Thomas; Impuls- und Waermeaustausch zwischen der Atmosphaere und dem eisbedeckten Ozean: (in German) Polarstern (PS) cruise ARK XII led into the Laptev Sea and into the Kara Sea. Measurements of atmospheric processes within the polar surface layer were performed by a turbulence probe mounted at the bow crane of the ship.The meteorological conditions during the cruise were characterised by moderate winds and low temperature differences between the atmosphere and the underlying surface.Detailed information about the variation of meteorological parameters and of the surface fluxes were achieved as a function of the surface characteristics. The measurements are used to analyse small scale processes such as the atmospheric flow over polynjas and over pressure ice ridges. The studies allow a general insight into the physics of boundary layer flow over the ice covered ocean and they provide helpful data to initialize and to verify model calculations of small scale processes in the polar boundary layer.The form drag concept is used to calculate the total vertical turbulent flux over the ice covered oceanas the sum of a skin drag effect and of a form drag effect. In polar regions, the latter results from the aerodynamic resistance of obstacles such as ice ridges and floes edges while the skin drag is given by the surface drag of a rather smooth ice field. Improved formulations for the coefficient of resistance of single ice ridges and for the shadowing effect leeward of a ridge are derived by the PS measurements and are implemented to the form drag concept. Shipborne and airborne measurements are used to validate the concept and a good agreement between measured and calculated values of the transfer coefficient of momentum is achieved. Sensitivity studies show, that the shadowing of the wind field due to densely distributed ice ridges does not significantly reduce the form drag of an ice field under realistic sea ice conditions and that the effect of densitystratification on the exchange of momentum is neglectable for typical atmospheric conditions during summertime. [Text] (0.88)

2. Michaelis, Sven; Entwicklung von mikromechanischen Schaltern fuer neuartige MEMS-Produkte unter Aspekten industrieller Fertigungsprozesse: (in German) The subject of this thesis is the development of new micromechanical switches as MEMS (Micro Electro Mechanical Systems) products for use in a variety of communication-applications.The research work performed within the frame of this thesis on the tch o-frequency switch) is used to demonstrate the importance of an ated design and development approach product-development. The successful realization, not only from a technological but also from an economic perspective, can only be achieved by considering all aspects of production for the entire end-to-end process, starting with the definition of the initial device-concept. Therefore an optimized integration of the front-end of line (FE-) processing and the back-end of line (BE-) processing together with the device packaging at the very end of the fabrication sequence has to be realized.The RF-switches are produced using a newly developed semiconductor process combination. First a poly-Si surface micromachining (SMM) process is used to create the mechanical switch-structure. Afterwards the special metal contacts are formed using additive electroplating technology (AET) in order to establish the electrically functional switch. The switch-element is then protected from the environment with a waferlevel-packaging scheme, before the individual device can be mounted into an SMD-package.The scientific focus of this thesis is marked by the device-concept for the RF-switch and the development of the end-to-end production process within the fab. The development of newly designed processing steps was required for this, which also included the challenging task of integrating these individual processing clusters and steps with each other within the production line. An analysis and characterization of the fabricated devices demonstrates the successful production capability. A discussion of the promising growth-potential for MEMS-products and RF-switches in particular is included in the appendix. [Text] (0.28)

5 from Technical University of Chemnitz - MONARCH

1. Ina Voigt; Synthese und Oberflachencharakterisierung von Poly(vinylamin)-co-Poly(vinylformamid)-Kieselgel-Hybrid-Materialien: (in German) In der vorliegenden Arbeit wird der Einfluss der Ladungsdichte des Polyelektrolyts sowie der Molmasse und der Ionenkonzentration der Losung bei der Adsorption von Poly(vinylformamid) und Poly(vinylamin) an Kieselgel 60 und an Titandioxid unter-sucht. Die Charakterisierung der Polyelektrolyteigenschaften der modifizierten anorganischen Partikel erfolgt mit elektrokinetischen und potentiometrischen Mes-sungen. Es konnte gezeigt werden, dass Poly(vinylamine) mit geringen Ladungs-dichte ein Screening-enhanced-Verhalten zeigen, wahrend bei hoher Ladungsdichte am Polyelektrolyt ein Screening-reduced-Verhalten vorliegt. Der Einfluss der Polymerfunktionalisierung auf die Oberflachenpolaritat der Hybridpartikel wurde durch UV-VIS-spektroskopische Bestimmung der ET(30)-Werte nach Reichardt nachgewiesen. Ausgehend von den Ergebnissen der Adsorption von Poly(vinylaminen) wird die Synthese von geladenen Netzwerken auf der Oberflache der anorganischen Partikel vorgestellt. Die aus wassriger Losung adsorbierte Polyelektrolytschicht wird dabei in einem zweiten Schritt in einem organischen Losungsmittel mit bifunktionellen Vernetzermolekulen (4,4-Diisocyanato)diphenylmethan, Fulleren C60] umgesetzt. Der erfolgreiche Ablauf der Reaktion konnte im Fall des Isocyanats mit Festkorper-NMR-, ESCA- und ATR-FTIR-Messungen nachgewiesen werden. Um die Umsetzung mit Fullerenen nachzuweisen, wurde die EPR-Spektroskopie eingesetzt. [Text] [View with Perseus links] (2.64)

2. Annett Graser; Kationische Wirt-Gast-Polymerisation in Y-Zeolithen und MCM-41: Synthese und Charakterisierung neuartiger organisch-anorganischer Polymer-Zeolith-Hybride: (in German) Die Synthese von neuartigen organisch-anorganischen Polymer-Zeolith-Hybriden wird in der vorliegenden Arbeit vorgestellt. Die Hybride wurden durch kationische Polymerisation elek-tronenreicher Monomere direkt in den Poren der Zeolithe und zeolithanalogen Materialien hergestellt. Die Vinylether Ethyl-, Isobutyl-, Cyclohexyl- und 2-Chlor-ethylvinylether, 2,3-Dihydrofuran, 2-Methoxypropen sowie N-Vinylcarbazol wurden zur Herstellung der orga-nischen Komponente der Hybride genutzt. Die Polymerisation wurde dabei einerseits durch die Protonen der Zeolithgitter und andererseits durch separate Oberflacheninitiatoren gestar-tet. Die anorganische Basis der Hybride bildeten vorrangig mikroporoser HY-Zeolith und mesoporoses MCM-41. Bei der Synthese entstand neben dem eingeschlossenen Polymer im Zeolith eine vom Hybrid extrahier-bare Polymerfraktion. Beide Fraktionen wurden mittels GPC und einer speziellen Kopplung von GPC und UV/Vis-Spektrometer analysiert. DSC und dielektrische Spektro-skopie wurden zur Glasubergangstemperaturbestimmung herangezogen. Die Strukturuntersuchung der neuartigen Hybridmaterialien erfolgte mit Festkorper-NMR-Spektroskopie, Rontgendiffraktometrie XRD, Transmissionselektronenmikroskopie TEM, Sekun-darelektro-nenmikroskopie SEM, Elektronenstrahlmikroanalyse ESMA, UV/Vis-Spektroskopie und Infrarotspektroskopie FT-IR. Die Porentopologie wurde mit Stick-stoff-sorp-tionsmessungen bestimmt. [Text] [View with Perseus links] (1.57)

3. Torsten Meyer; Synthesewege zu neuen Hybridmaterialien aus stickstoffhaltigen Monomeren und silikatischen Partikeln: (in German) Die vorliegende Arbeit beschreibt verschiedene Synthesewege zur Oberflachenmodifizierung silikatischer Partikel mit 1,3-Divinylimidazolidin-2-on (Bisvinylethylenharnstoff, BVH) und Vinylformamid (VFA), z. B. radikalische Pfropfpolymerisationen (IJgrafting from/toN) und radikalisch vernetzende Copolymerisation von VFA mit BVH. Es werden Versuche zur sauren Verseifung der Formamidgruppen und zur Charakterisierung der gebildeten Polyvinylamin (PVAm)/Kieselgel Hybridmaterialien vorgestellt. Die Eigenschaften der PVAm/Kieselgel Hybridmaterialien sind je nach zugrundeliegendem Polymerisationsprozess verschieden und werden mittels 13 C{1 H}-CP-MAS-NMR-Spektroskopie, Zetapotentialmessungen, SANS, Quelltests und rheologischen Methoden untersucht. Die kationische Oberflachenpolymerisation von BVH unter Verwendung des Initiatorsystems Triphenylmethylchlorid/Kieselgel wird ausfuhrlich erlautert. Die Struktur der resultierenden Hybridmaterialien wird mittels quantitativer Elementaranalyse, 13 C{1 H}-CP-MAS-NMR-, DRIFT- und ESCA- Spektroskopie, sowie TGA und Zetapotentialmessungen untersucht. Die Anwendung der Poly-BVH/KG Hybridmaterialien zur Adsorption von Schwermetallsalzen wird am Beispiel der Adsorption von CuCl2, CoCl2, CoI2 und FeCl3 beschrieben. Dabei werden der Einfluss des Polymergehaltes der Hybride und des Metallanions auf die adsorbierte Sattigungsstoffmenge diskutiert. Eine quantitative Beschreibung der Adsorption nach dem LANGMUIR-Modell wird gegeben, welche in einem Vorschlag fur die Wechselwirkung zwischen Hybridmaterial und Metallsalz mundet. Mit der Adsorption von Goldnanoclustern an Poly-BVH/Kieselgel Hybriden wird eine weitere Moglichkeit der Modifizierung und des Aufbaus von funktionellen Multischichtsystemen vorgestellt. [Text] [View with Perseus links] (0.53)

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2 from The Eberhard Karls University of Tuebingen

1. Hanack, Michael, Hafelinger, Gunter; ... : Chemie an der Schwelle des 21. Jahrhunderts, Studium Generale, WiSe 1999/2000, 27.10.1999: Prof. Dr. Dr.h.c. Michael Hanack referiert uber das Thema: "Materialwissenschaften: Ein neues Feld der Organischen Chemie"., Begrussung; Hafelinger, Gunter, Professor fur theoretische organische Chemie; Forschungsspektrum der Tubinger Chemie; Chemie im nachsten Jahrhundert; Kombinatorische Chemie; Computermodulation komplexerer Systeme; Materialwissenschaften; Hanack, Professor, Referat; Materialwissenschaft, ein neues Feld der organischen Chemie; Referent, Vorstellung von Prof. Hanack; Elektrolumineszenz organischer Verbindungen; Vorlesung, Inhalt; Forschungsergebnisse der Tubinger Fakultat fur Chemie, Pharmazie und Biochemie; Versuche durch Mitarbeiter; Materialwissenschaft, Erklarung; Organische Chemie, spezielle Wissenschaft; Anorganische Chemie, Chemie der Metalle und ihrer Salze; Organische Chemie; Formelsprache in der Chemie; Aspirin, wichtiges Arzeneimittel; Organische Synthese von Aspirin (Acetylsalicylsaure); Organische Materialwissenschaft; Materialwissenschaftliche Forschungsgebiete; Polymerchemie; Polymere; Polyethylen; Styropor; Polyurethan; Polymerisationsreaktion, experimentelle Darstellung von Schaumstoff; Nylon, Strumpfhosen; Nylonfaden, experimentelle Darstellung; Leitfahigkeit der Polymere; Isolator; Elektrische Leitfahigkeit organischer und anorganischer Materialien; Spezifische Wiederstande, Vergleich der verschiedenen Werkstoffe; Polyethylenbildung; Polyacetylen; Polymere, elektrisch leitfahig; Polypyrrol, Herstellung; Supraleitung; Tetrathiafulvalen; Tetracyano-p-chinodinmethan; Leuchtdiode; Licht, Erzeugung; Fluoreszenz, Bildung durch Bestrahlen von organischen Verbindungen mit UV-Licht; Elektrolumineszenz; Chemolumineszenz; Polymer, Poly-para-phenylenvinylen; Organische LED; Chemolumineszenz; Diskussion [Image] [View with Perseus links] (0.41)

2. Nei, Masatoshi; ... : Evolution by a birth-and-death process in the MHC and other multigene families: Evolutionary Aspects of Antigen Presentation, MHC loci, Polymorphism; Multigene families, Evolution; Key restriction enzyme sites; HLA polymorphism; Gene conversion, Ohta; T-Cell Receptor; Antigens; HLA; Birth and death model, Evolution; Class I loci in primates; MHC loci, Conclusions; Immunoglobulin (Ig) genes; TCR; Poly-u loci, Scenarios; Conclusions; Discussion [Image] [View with Perseus links] (0.33)

3 from The University of Michigan. University Library. Digital Library Production Service.

1. Serret, Paul Joseph, 1827-1898.; G&#x0e9;om&#x0e9;trie de direction. Application des coordonn&#x0e9;es poly&#x0e9;driques. Propri&#x0e9;t&#x0e9; de dix points de l'ellipso&#x0ef;de, de neuf points d'une courbe gauche du quatri&#x0e8;me ordre, de huit points d'une cubique gauche, par Paul Serret. [Text] [View with Perseus links] (2.98)

2. Pillet, Jules, 1842-1912.; Trait&#x0e9; de g&#x0e9;ometrie descriptive, ligne droite et plan-poly&#x0e8;dres-surfaces, texte et dessins par Jules Pillet. [Text] [View with Perseus links] (1.16)

3. Serment, Vinicio.; Polar effects in the raditation chemistry of p-substituted polystyrenes / / Vinicio Serment.: "February 1961"--T.p., Also submitted as the author's dissertation (Ph.D.)--University of Michigan, 1961., At head of title: The University of Michigan, Industry Program of the College of Engineering., University of Michigan. College of Engineering. Industry Program. [Text] [View with Perseus links] (1.07)

2 from University of Illinois Library

1. Lewis, A.; Roly Poly San [Text] (3.17)

2. Sloane, A.; My roly poly oly tulip maiden [Text] (2.53)

69 from Virginia Tech Electronic Thesis and Dissertation Collection

1. Mecham, Jeffrey Brent; Synthesis and Characterization of Cycloaliphatic and Aromatic Polyester/Poly(dimethylsiloxane) Segmented Copolymers: James F. Wolfe, Thomas C. Ward, James E. McGrath; (in English) Linear thermoplastic polyesters are commonly used in high volume applications such as food containers, films and textile fibers. The physical and mechanical properties of these materials are well documented and are a function of chemical structure and morphology (e.g. semi-crystalline, amorphous, etc.). Polyesters, as are many organic polymers, are quite flammable. Polydimethylsiloxane homopolymer exhibits low mechanical strength and, even at high molecular weight, exists as a viscous fluid rubbery gum due to its low glass transition temperature of approximately -123°C. However, one of the many attractive properties of this polymer is its relatively low flammability and if properly designed, organic sand-like silicates are produced in oxidizing atmospheres at elevated temperatures (e.g. 500-700°C). This thesis discusses the synthesis and characterization of novel, high molecular weight cycloaliphatic and aromatic polyester/ poly(dimethylsiloxane) segmented copolymers. The cycloaliphatic copolymers were synthesized via a melt process using a high trans content 1,4 dimethylcyclohexanedicarboxylate, and 1,4 butanediol or cyclohexanedimethanol, while the partially aromatic systems were synthesized using dimethyl terephthalate and butanediol. Primary and secondary aminopropyl terminated poly(dimethylsiloxane) oligomers of controlled molecular weight were endcapped with excess diester to form an amide linked diester terminated oligomer. The latter was then incorporated into the copolymer via melt transesterification to afford a multiphase segmented copolymer. Selected compositions showed enhanced ductility and hydrophobic surface modification. The polysiloxane segment was effeciently incorporated into the copolymers and was unaffected by the transesterification catalyst under typical reaction conditions. The homopolymers and copolymers were characterized by solution, thermal, and mechanical, and surface techniques. The segmented copolymers were demonstrated to be microphase separated as determined by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and transmission electron microscopy. The surface of the copolymers was enriched with the polysiloxane segment as evidenced by contact angle analysis. Thermal gravimetric analysis of the segmented copolymers containing identical amounts of PDMS, but varying in the primary or secondary nature of their amide linkages, exhibited quantitatively identical char yields and weight loss behavior. The segmented copolymers exhibited char yields in air superior to those of their respective homopolymers. Additionally, aromatic poly(tetramethyleneoxide) (PTMO) based polyether/polyester segmented copolymers were modified with poly(dimethylsiloxane). DMA revealed an apparent shift (higher Tg) of the PTMO segment reflecting an increase in phase mixing with the hard polyester segment, possibly induced by the hydrophobic PDMS phase. [Text] [View with Perseus links] (2.73)

2. Laot, Christelle Marie III; SPECTROSCOPIC CHARACTERIZATION OF MOLECULAR INTERDIFFUSION AT A POLY(VINYL PYRROLIDONE) / VINYL ESTER INTERFACE: Dr. Eva Marand, Dr. Richey M. Davis, Dr. Hideko T. Oyama, Dr. Thomas C. Ward; (in English) Mechanical properties of (woven carbon fiber / vinyl ester matrix) composites can be greatly improved if the interphase between the reinforcing high-strength low-weight fiber and the thermoset resin is made more compliant. In order to improve the adhesion of the vinyl ester matrix to the carbon fiber, a thermoplastic coating such as poly(vinyl pyrrolidone) (PVP) can be used as an intermediate between the matrix and the fiber. The extent of mutual diffusion at the (sizing material / polymer matrix) interphase plays a critical role in determining the mechanical properties of the composite. <p> <p> In this research, the molecular interdiffusion across a poly(vinyl pyrrolidone))/vinyl ester monomer (PVP/VE) interface is being investigated by Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR) spectroscopy. The ATR method which can be used to characterize the transport phenomena, offers several advantages, such as the ability to monitor the diffusion <I>in situ</I> or to observe chemical reactions. In order to separate the effects of the vinyl ester monomer diffusion and the crosslinking reaction, ATR experiments were carried out at temperatures below the normal curing temperature. Diffusion coefficients were determined by following variations in infrared bands as a function of time, and fitting this data to a Fickian model. The values of the diffusion coefficients calculated were consistent with values found in the literature for diffusion of small molecules in polymers. The dependence of diffusion coefficients on temperature followed the Arrhenius equation. Hydrogen bonding interactions were also characterized. The diffusion model used in this study, however, does not seem to be appropriate for the particular (PVP/VE) system. Because the glass transition temperature of the PVP changed as diffusion proceeded, one would expect that the mutual diffusion coefficient did not stay constant. In fact, it was shown that the Tg can drop by 140oC during the diffusion process. A more suitable model of the (PVP/VE) system should take into account plasticization, hydrogen bonding, and especially a concentration dependent diffusion coefficient. Further analysis is therefore needed. [Text] [View with Perseus links] (2.70)

3. Stadelmann, Iris Patricia; Extraction of alcohols from gasoline using solid phase microextraction (SPME): Dr. Harold M. McNair, Dr. Herve Marand, Dr. Larry T. Taylor; (in English) It is common practice to add oxygenates, such as ethers or alcohols, to gasoline in areas suffering from ozone or smog problems in order to reduce pollution. The most commonly used oxygenates are ethanol (EtOH) and methyl tert-butyl ether (MTBE). However, MTBE is now forbidden by the environmental protection agency (EPA) because of the possibility of ground water contamination. The current trend is to use EtOH, therefore this work focuses on the analysis and quantification of EtOH in gasoline by solid phase microextraction (SPME). The major problem in quantifying EtOH in gasoline is the coelution of hydrocarbons with EtOH. There have been several approaches to solve this problem; among the chromatographic ones, three major types have been proposed: (1) the first one uses a detector selective for oxygen containing compounds; (2) the second one uses two or more columns; (3) and the third one uses an extraction step prior to GC analysis. In this work an extraction step with water is used prior to a solid phase microextraction (SPME) sample preparation coupled to a gas chromatographic (GC) analysis. <p>Solid phase microextraction is a recent technique, invented by Pawliszyn in 1989, and available commercially since 1994. A fiber is used to extract small amounts (ppm, ppb, ppt) of analytes from a solution, usually water. The fiber is beneficial in concentrating analytes. Most work using SPME has been done with hydrophobic (non polar) analytes, extracted using a polydimethylsiloxane (PDMS; non polar) coating on a fused silica fiber. Since very little work has been done with polar analytes, the novel approach of this work is the extraction of EtOH. <p>Since EtOH is the analyte of interest, a polar fiber, carboxen/polydimethyl siloxane (Car/PDMS) is used. Two methods are used for quantification of EtOH in gasoline: the method of a standard calibration curve, and the method of standard addition. They are both successful in quantifying the amount of EtOH in gasoline. The relative errors, with the method of standard addition, vary from 5.3% to 14%, while the ones with the method of calibration curve vary from 1.6% to 7.2%. Moreover, some extraction time studies for both direct and headspace sampling are performed. Direct sampling shows the presence of an equilibrium condition for the carboxen/PDMS fiber, for which no extraction theory is available. Conversely, headspace sampling shows no equilibrium state; after a sampling time of one hour, the amount of EtOH extracted decreases with sampling time. This is probably due to displacement of EtOH by other compounds in the fiber. [Text] [View with Perseus links] (2.65)

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13 from arXiv

1. Wu, M. W., Conwell, E. M.; Effect of interchain coupling on conducting polymer luminescence: excimers in derivatives of poly(phenylene vinylene): Optical excitation of a chain in a polymer film may result in formation of an excimer, a superposition of on-chain excitons and charge-transfer excitons on the originally excited chain and a neighboring chain. The excimer emission is red-shifted compared to that of an on-chain exciton by an amount depending on the interchain coupling $t_\perp$. Setting up the excimer wavefunction and calculating the red shift, we determine average $t_\perp$ values, referred to a monomer, of 0.52 eV and 0.16 eV for poly(2,5-hexyloxy $p$-phenylene cyanovinylene), CN-PPV, and poly[2-methoxy, 5-(2'-ethyl-hexyloxy)-1, 4 p-phenylene vinylene], MEH-PPV, respectively, and use them to determine the effect of interchain distance on the emission., Comment: 10 pages, RevTeX, 1 PS figure, replaced version of cond-mat/9707095, accepted for publication in Phys. Rev. B, Rapid Communication [Text] [View with Perseus links] (2.56)

2. Wu, M. W., Conwell, E. M.; Theory of photoinduced charge transfer in weakly coupled donor-acceptor conjugated polymers: application to an MEH-PPV:CN-PPV pair: In a pair of coupled donor-acceptor conjugated polymer chains, it is possible for an exciton photoexcited on either polymer to decay into a hole in the donor polymer's valence band and an electron in the conduction band of the acceptor polymer. We calculate the corresponding exciton decay rate and its dependence on inter-polymer distance. For a pair of derivatives of poly(phenylene vinylene), PPV, specifically poly[2-methoxy, 5-(2$^\prime$-ethyl-hexyloxy)-1, 4 PPV], MEH-PPV, and poly(2,5-hexyloxy $p$-phenylene cyanovinylene), CN-PPV, at a separation of 6 \AA ~the characteristic decay time is 2.2 ps, whereas at 4 \AA ~it is $\sim 50$ fs., Comment: 9 pages, RevTeX, 4 PS files, to be published in a special issue of Chem. Phys [Text] [View with Perseus links] (1.50)

3. Diakonov, D. I., Petrov, V. Yu., Pobylitsa, P. V., Polyakov, M. V., Weiss, C.; Unpolarized and polarized quark distributions in the large-Nc limit: The isosinglet unpolarized and isovector polarized twist-2 quark distributions of the nucleon at low normalization point are calculated in the large-Nc limit. The nucleon is described as a soliton of the effective chiral theory. We derive the expressions for the distribution functions in the large-Nc limit starting from their definition as numbers of partons carrying momentum fraction x in the infinite momentum frame. We develop a numerical method for computation of the quark and antiquark distributions as sums over the quark single-particle levels in the pion field of the soliton. The contributions of the discrete bound-state level as well as the Dirac continuum are taken into account. The quark- and antiquark distributions obtained explicitly satisfy all general requirements. Results are in reasonable agreement with parametrizations of the data at low normalization point., Comment: 32 p., LaTeX, 6 figures included using epsf [Text] [View with Perseus links] (0.95)

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