On the birational section conjecture with local conditions

A birationally liftable Galois section s of a hyperbolic curve X/k over a number field k yields an adelic point x(s) in the smooth completion of X. We show that x(s) is X-integral outside a set of places of Dirichlet density 0, or s is cuspidal. The proof relies on $GL_2(F_\ell)$-quotients of $\pi_1(U)$ for some open U of X. If k is totally real or imaginary quadratic, we prove that all birationally adelic, non-cuspidal Galois sections come from rational points as predicted by the section conjecture of anabelian geometry. As an aside we also obtain a strong approximation result for rational points on hyperbolic curves over Q or imaginary quadratic fields.Comment: Theorem C (and Section 7) of the original version have been deleted due to a gap in the proof. This is the journal versio

Results of special mechanical analyses of Luna 16 material

The studies carried out on the Luna 16 regolith have confirmed the data that were already published internationally. By means of activation analysis under irradiation in the reactor, activation analysis with a 14 MeV U-generator, and mass spectroscopy on samples of 10 or 20 mg, six main and 63 trace elements were quantitatively determined and compared with known data

Wind turbine generator interaction with conventional diesel generators on Block Island, Rhode Island. Volume 2: Data analysis

Assessing the performance of a MOD-OA horizontal axis wind turbine connected to an isolated diesel utility, a comprehensive data measurement program was conducted on the Block Island Power Company installation on Block Island, Rhode Island. The detailed results of that program focusing on three principal areas of (1) fuel displacement (savings), (2) dynamic interaction between the diesel utility and the wind turbine, (3) effects of three models of wind turbine reactive power control are presented. The approximate two month duration of the data acquisition program conducted in the winter months (February into April 1982) revealed performance during periods of highest wind energy penetration and hence severity of operation. Even under such conditions fuel savings were significant resulting in a fuel reduction of 6.7% while the MOD-OA was generating 10.7% of the total electrical energy. Also, electrical disturbance and interactive effects were of an acceptable level

Wind turbine generator interaction with conventional diesel generators on Block Island, Rhode Island. Volume 1: Executive summary

Primary results are summarized for a three-part study involving the effects of connecting a MOD-OA wind turbine generator to an isolated diesel power system. The MOD-OA installation considered was the third of four experimental nominal 200 kW wind turbines connected to various utilities under the Federal Wind Energy Program and was characterized by the highest wind energy penetration levels of four sites. The study analyses address: fuel displacement, dynamic interaction, and three modes of reactive power control. These analyses all have as their basis the results of the data acquisition program conducted on Block Island, Rhode Island

Crack Growth Studies in a welded Ni-base superalloy

It is well known that the introduction of sustained tensile loads during high-temperature fatigue (dwell-fatigue) significantly increases the crack propagation rates in many superalloys. One such superalloy is the Ni-Fe based Alloy 718, which is a high-strength corrosion resistant alloy used in gas turbines and jet engines. As the problem is typically more pronounced in fine-grained materials, the main body of existing literature is devoted to the characterization of sheets or forgings of Alloy 718. However, as welded components are being used in increasingly demanding applications, there is a need to understand the behavior. The present study is focused on the interaction of the propagating crack with the complex microstructure in Alloy 718 weld metal during cyclic and dwell-fatigue loading at 550 °C and 650 °C

Room temperature plasticity in sub-micrometer thermally grown oxide scales

Thermally grown oxides (TGOs) are generally considered to be brittle, capable of sustaining very limited plastic deformation before fracture. As they are prone to exhibit different forms of defects, the fracture toughness, typically measured to be some 1–2 MPa m1/2 [1], is typically reached well before sufficiently high stresses to induce plasticity can be applied [2]. This is particularly true at room temperature, where possible low-stress thermally activated creep mechanisms are suppressed. However, the occurrence of plasticity in e.g. Al2O3 single crystals at room temperature can occur for samples in the micrometer range [3]. Most measurements of the deformation of TGOs have been made on relatively thick scales, (\u3e1 micrometer), which are limited by the fracture originating from inherent defects. Furthermore, the studies have been limited in resolution and sensitivity, as the scales were adherent to the substrates and tested as a composite. Recently, micro-mechanical testing has been introduced as a method to evaluate mechanical behavior of TGOs on a ferritic/martensitic steel [4], where micro-cantilever bending was used to test specimen extracted from different layers in a 5–10 micrometers thick oxide. Still, the cantilever cross-section was typically several micrometers, and the very similar fracture stresses for notched and un-notched cantilevers seems to indicate that the deformation is still limited by inherent defects. Please click Additional Files below to see the full abstract

Resolution and Efficiency of the ATLAS Muon Drift-Tube Chambers at High Background Rates

The resolution and efficiency of a precision drift-tube chamber for the ATLAS muon spectrometer with final read-out electronics was tested at the Gamma Irradiation Facility at CERN in a 100 GeV muon beam and at photon irradiation rates of up to 990 Hz/square cm which corresponds to twice the highest background rate expected in ATLAS. A silicon strip detector telescope was used as external reference in the beam. The pulse-height measurement of the read-out electronics was used to perform time-slewing corrections which lead to an improvement of the average drift-tube resolution from 104 microns to 82 microns without irradiation and from 128 microns to 108 microns at the maximum expected rate. The measured drift-tube efficiency agrees with the expectation from the dead time of the read-out electronics up to the maximum expected rate

Reaction behavior of iron and copper complexes towards dioxygen

To provide a better understanding of the reactions of iron and copper proteins with dioxygen, the corresponding reactions of small molecule model complexes with dioxygen were analysed using spectroscopic and kinetic methods. Special attention focused upon the binding and activation of dioxygen by iron proteins such as hemerythrin (Hr) and protocatechuat-3,4-dioxygenase (3,4-PCD) and by copper proteins like hemocyanin (Hc) and tyrosinase. Iron complexes of the ligand tmpa (tmpa = tris[(2-pyridyl)methyl]amine, also known as tpa in literature) were synthesised and modifications of the tmpa ligand were made. Increasing as well as decreasing chelate ring sizes in the highly active complex [Fe(tmpa)(dbc)]B(C6H5)4 (dbc = 3,5-di-tert-butylcatecholate dianion), only resulted in decreased reactivity of the investigated compounds. A detailed low-temperature stopped-flow investigation of the reaction of dioxygen with [Fe(tmpa)(dbc)]B(C6H5)4 was performed and activation parameters of Delta H# = 23 +- 1 kJ mol-1 and Delta S# = -199 +- 4 J mol-1 K-1 were obtained. Crystal structures of bromo-(tetrachlorocatecholato-O,O\u27)(bis((2-pyridyl)methyl)-2-pyridylamine-N,N\u27,N\u27\u27)-iron(III) (2), (mu-oxo)-bis(bromo)(bis((2-pyridyl)methyl)-2-pyridylamine-N,N\u27,N\u27\u27,N\u27\u27\u27)-diiron(III) (3), dichloro-((2-(2-pyridyl)ethyl)bis((2-pyridyl)methyl)amine-N,N\u27,N\u27\u27,N\u27\u27\u27)-iron(III) (4) and (tetrabromocatecholato-O,O\u27)((2-(2-pyridyl)ethyl)bis((2-pyridyl)methyl)amine-N,N\u27,N\u27\u27,N\u27\u27\u27)-iron(III) (5) are reported (Chapter 2). Besides altering the chelate ring size the influence of the donor atoms of the ligand on catechol dioxygenase reactivity was investigated. Two derivatives of the tmpa ligand (uns-penp and acetyl-uns-penp) were synthesised, where one aromatic nitrogen donor was replaced by an aliphatic nitrogen donor. The iron(III) complexes of the tripodal ligands N\u27,N\u27-bis[(2-pyridyl)methyl]ethylenediamine (uns-penp), [Fe(uns-penp)Cl2]ClO4 x CH3CN, [{Fe(uns-penp)Cl}2O](ClO4)2 x 2CH3CN and the amide derivative N-Acetyl-N\u27,N\u27-bis[(2-pyridyl)methyl]ethylenediamine (acetyl-uns-penp), [Fe2(acetyl-uns-penp)2O](ClO4)2 x H2O, [Fe(acetyl-uns-penp)(tcc)Br] x (C2H5)2O and [{Fe(acetyl-uns-penp)(tcc)}2O] x (C2H5)2O x CH3OH were synthesised and characterised. Catechol dioxygenase reactivity of in situ prepared complex solutions only showed slower reactions in comparison with the iron tmpa system (Chapter 3). Corresponding ligand system variations in the small molecule model complexes of copper proteins were made and analysed with respect to dioxygen reactivity. Intramolecular ligand hydroxylation was observed during the reactions of dioxygen with the dicopper(I) complexes of the ligands L3 (L3 = alpha,alpha\u27-bis[(2-pyridylethyl)amino]-m-xylene) and L5 (L5 = alpha,alpha\u27-bis[N-(2-pyridylethyl)-N-(2-pyridylmethyl)-amino]-m-xylene). The dinuclear copper(I) complex [Cu2L5](ClO4)2 and the dicopper(II) complex [Cu2(L3-O)(OH)(ClO4)]ClO4 were characterised by single-crystal X-ray structure analysis. Furthermore, phenolate-bridged complexes were synthesised with the ligand L4-OH and Me-L5-OH (structurally characterised: [Cu2(L4-O)Cl3] with L4 = alpha,alpha\u27-bis[N-methyl-N-(2-pyridylethyl)amino]-m-xylene and [Cu2(Me-L5-O)(mu-X)](ClO4)2 x nH2O with Me-L5-OH = 2,6-bis[N-(2-pyridylethyl)-N-(2-pyridylmethyl)amino]-4-methylphenol and X = C3H3N2- (prz), MeCO2- and N3-). Temperature-dependent magnetic studies revealed the antiferromagnetic coupling of the copper ions of these complexes (Chapter 4). The reactions of dioxygen with copper(I) complexes of the tridentate ligands 1,1,4,7,7-pentamethyldiethylethylenetriamine (Me5dien), 1,1,4,7,7-pentaethyldiethylethylenetriamine (Et5dien), N-methyl-[bis(2-pyridyl)methyl]amine (Me-bpa) and N-methyl-[(2-pyridyl)ethyl(2-pyridyl)methyl]amine (MeL) have been investigated using low-temperature stopped-flow techniques. The formation of a bis(mu-oxo) copper complex as a reactive intermediate could only be detected spectroscopically at low temperatures for [Cu(Me5dien)(CH3CN)]ClO4 and allowed a quantitative kinetic analysis to be performed. Crystal structures of the copper(II) complexes [(Me-bpa)Cu(Cl)2], [{(Me-bpa)Cu(Cl)(ClO4)}2], [{(MeL)Cu(Cl)(ClO4)}2] and [(MeL)Cu(NCS)2] are reported. (Chapter 5)Zum besseren Verständnis der Reaktionen von Eisen- und Kupferproteinen mit elementarem Sauerstoff wurden im Rahmen dieser Arbeit für Eisen- und Kupferproteine Modellkomplexe mit geringer Molekularmasse mit spektroskopischen oder kinetischen Methoden untersucht. Besondere Aufmerksamkeit wurde hierbei der Bindung und der Aktivierung von elementarem Sauerstoff durch die Eisenproteine, wie z. B. Hämerythrin (Hr) und Protocatechuat-3,4-dioxygenase (3,4-PCD), und die Kupferproteine, wie z. B. Hämocyanin (Hc) und Tyrosinase, gewidmet. Bezüglich der Modelle für Eisenenzyme wurde der Ligand tmpa (tmpa = tris[(2-pyridyl)methyl]amin; in der Literatur auch mit tpa abgekürzt) untersucht und systematisch variiert. Die Vergrößerung und Verkleinerung der Chelatringgröße im hochreaktiven Komplex [Fe(tmpa)(dbc)]B(C6H5)4 (dbc = 3,5-Di-tert-butylcatecholat Dianion) führte nur zu einer verringerten Reaktivität der untersuchten Verbindungen. Die Reaktion von elementaren Sauerstoff mit [Fe(tmpa)(dbc)]B(C6H5)4 wurde mittels der Tieftemperatur-\u27stopped-flow\u27-Technik untersucht und ergab die Aktivierungsparameter Delta H# = 23 +- 1 kJ mol-1 und Delta S# = -199 +- 4 J mol-1 K-1. Weiterhin wurden die Kristallstrukturanalysen der Verbindungen bromo-(tetra-chlorocatecholato-O,O\u27)(bis((2-pyridyl)methyl)-2-pyridylamine-N,N\u27,N\u27\u27)-eisen(III) (2), (mü-oxo)-bis(bromo)(bis((2-pyridyl)methyl)-2-pyridylamine-N,N\u27,N\u27\u27,N\u27\u27\u27)-dieisen (III) (3), dichloro-((2-(2-pyridyl)ethyl)bis((2-pyridyl)methyl)amine-N,N\u27,N\u27\u27,N\u27\u27\u27)-eisen (III) (4) und (tetrabromocatecholato-O,O\u27)((2-(2-pyridyl)ethyl)bis((2-pyridyl)methyl) amine-N,N\u27,N\u27\u27,N\u27\u27\u27)-eisen (III) (5) beschrieben (Kapitel 2). Neben der Änderung der Chelatringgröße wurde auch der Einfluss der Donoratome des Liganden untersucht. Dazu wurden abgeleitet vom tmpa zwei Liganden (uns-penp und acteyl-uns-penp) synthetisiert, bei denen ein aromatischer Stickstoff durch einen aliphatischen Stickstoff ersetzt wurde. Die Eisen(III)-Komplexe mit den tripodalen Liganden N\u27,N\u27-bis[(2-pyridyl)methyl]ethylenediamin (uns-penp), [Fe(uns-penp)Cl2]ClO4 x CH3CN, [{Fe(uns-penp)Cl}2O](ClO4)2 x 2CH3CN und dem Amidderivat N-Acetyl-N\u27,N\u27-bis[(2-pyridyl)methyl]ethylenediamin (acetyl-uns-penp), [Fe2(acetyl-uns-penp)2O](ClO4)2 x H2O, [Fe(acetyl-uns-penp)(tcc)Br] x (C2H5)2O und [{Fe(acetyl-uns-penp)(tcc)}2O] x (C2H5)2O x CH3OH wurden synthetisiert und charakterisiert. Untersuchungen zur Catecholdioxygenasereaktivität der in situ dargestellten Komplexlösungen zeigten nur langsamere Reaktionen im Vergleich zu dem Eisen-tmpa-System (Kapitel 3) Die Ligandensysteme für Modelle von Kupferproteinen wurden nach denselben Gesichtspunkten verändert wie bei den Modellen für die Eisenproteine. Intramolekulare Hydroxylierung des Liganden war bei der Reaktion von elementaren Sauerstoff mit Dikupfer(I)-Komplexen der Liganden L3 (L3 = alpha,alpha\u27-bis[(2-pyridylethyl)amino]-m-xylol) und L5 (L5 = alpha,alpha\u27-bis[N-(2-pyridylethyl)-N-(2-pyridylmethyl)-amino]-m-xylol) zu beobachten. Der dinukleare Kupfer(I)-Komplex [Cu2L5](ClO4)2 und der Dikupfer(II)-Komplex [Cu2(L3-O)(OH)(ClO4)]ClO4 konnten durch Einkristallröntgenstrukturanalyse charakterisiert werden. Zusätzlich wurden Phenolatverbrückte Komplexe mit den Liganden L4-OH und Me-L5-OH synthetisiert (Strukturlösungen für [Cu2(L4-O)Cl3] mit L4 = alpha,alpha\u27-bis[N-methyl-N-(2-pyridylethyl)amino]-m-xylol und [Cu2(Me-L5-O)(mü-X)](ClO4)2 x nH2O (Me-L5-OH = 2,6-bis[N-(2-pyridylethyl)-N-(2-pyridylmethyl)amino]-4-methylphenol und X = C3H3N2- (prz), MeCO2- und N3-). Temperaturabhängige magnetische Untersuchungen zeigten antiferromagnetische Kopplung der Kupferionen in diesen Komplexen (Kapitel 4). Die Reaktionen von elementaren Sauerstoff mit Kupfer(I)-Komplexen der dreizähnigen Liganden 1,1,4,7,7-pentamethyldiethylethylenetriamin (Me5dien), 1,1,4,7,7-pentaethyldiethylethylenetriamin (Et5dien), N-methyl-[bis(2-pyridyl) methyl]amin (Me-bpa) und N-methyl-[(2-pyridyl)ethyl(2-pyridyl)methyl]amin (MeL) mit Hilfe der Tieftemperatur-\u27stopped-flow\u27-Technik untersucht. Die Bildung eines bis(mü-oxo)-Kupferkomplexes konnte dabei bei tiefen Temperaturen nur für den Komplex [Cu(Me5dien)(CH3CN)]ClO4 spektroskopisch beobachtet und quantitativ kinetisch analysiert werden. Die Komplexe [(Me-bpa)Cu(Cl)2], [{(Me-bpa)Cu(Cl)(ClO4)}2], [{(MeL)Cu(Cl)(ClO4)}2] und [(MeL)Cu(NCS)2] konnten kristallographisch charakterisiert werden. (Kapitel 5