Search results for "NGS"
showing 10 items of 6306 documents
Aurophilicity as a cofactor in crystal engineering. Dicyanoaurate(I) anion as a building block in a novel Co(II)–Au(I) bimetallic assembly
2002
A 2D grid-shaped cyanide-bridged Co(II)–Au(I) bimetallic coordination polymer, [Co(DMF)2{Au(CN)2}2], has been prepared from the [Au(CN)2]2 building block; sheets associate pair-wise by aurophilic interactions and the compound exhibits zeolite-like properties. Lloret Pastor, Francisco, Francisco.Lloret@uv.es
Orationes tres
1594
Mollīna tipogrāfijā nodrukātas Orationes tres: trīs runas, ko turēja sholarhi (Rīgas rātes prokonsuls Nikolajs Eke; 1541-1623 un sindiks Dāvids Hilhens; 1561-1610) un Domskolas rektors Johans Rīvijs (Rivius, 1528-1596, Domskolas rektors (1589) un inspektors (1594)) reorganizētās Domskolas atjaunošanai veltītajā svinīgajā pasākumā 1589. gada 15. jūlijā. Vairāki grāmatas eksemplāri bija domāti dāvināšanai ievērojamām Rīgas personām, tāpēc iesieti grezni: brūnā ādā, ar Rīgas ģerboni zelta iespiedumā uz vāka. Runu tekstus papildina tabulas, kur fiksēts visu triju skolas klašu stundu plāni. Runu izdošana un iespiešana ilga četrus gadus. Izdevums kavējās dēļ burtstabiņu trūkuma grieķu teksta iesp…
An integrated approach to evaluating the tribo-contact for coated cutting inserts
2000
Abstract The orthogonal machining process when end turning medium carbon and austenitic stainless steels with cemented WC-Co tools coated with single-layer (TiC), two-layer (TiC/TiN), and three-layer (TiC/Al2O3/TiN) hard thin films was investigated. Extensive experimental investigations including the thermal, mechanical and tribological responses of the tribo-contact between the coating–substrate system and the chip, under different cutting conditions, were carried out. The study sheds light on the cutting forces, the interface temperatures and the tribo-contact conditions, including the friction energy dissipated at the tool–chip interface, the frictional heat flux conducting into either t…
The influence of thin hard coatings on frictional behaviour in the orthogonal cutting process
2000
New knowledge about the tribological response deriving from the interaction of the substrate/coating-chip system, with special attention to the orthogonal cutting process when chatter-free end turning using natural contact tools, is developed. In order to evaluate the frictional behaviour of this process under modified contact conditions, experimental investigations including the contact temperature, the contact loads, friction and the frictional heat flux per unit area were carried out. In contrast to the most obvious approach, the coefficient of sliding friction versus the cutting speed, the contact temperature, the normal pressure and the interface control factor is considered. A number …
Microstructural evolution of wear-resistant FeCrB and FeCrNiCoB coating alloys during high-energy mechanical attrition
2008
Mechanical milling/attrition provides a convenient scope of simulating the microstructural changes encountered by wear-resistant coating alloys subjected to deformation under high frequency and high-intensity impact loading or accelerated wear condition. In the present study, the microstructural evolution of two commercial coating materials, FeCrB (Armacor M) and FeCrNiCoB (Armacor C), in the course of low- and high-intensity mechanical attrition, was monitored by X-ray diffraction and high-resolution transmission electron microscopy. While low-intensity milling leads to marginal grain refinement but no change in phase-aggregate in FeCrB, similar mechanical attrition causes boride precipita…
Influence of friction on the local mechanical and electrochemical behaviour of duplex stainless steels.
2006
International audience; The electrochemical behaviour of ferritic and austenitic phases in duplex stainless steel (UNS S32304) and the modifications induced by straining during sliding were studied by potentiodynamic polarisation curves determined at the microscale in a 1MNaCl (pH 3) solution, using an electrochemical microcell. The mechanical properties and stress state of each phase were determined by microhardness and X-ray microdiffraction measurements, before and after straining. The results show that sliding generates elastic straining of the ferrite and plastic deformation of the austenite. The electrochemical behaviour of these phases is dramatically altered, inducing a reduction of…
Zu interkulturellen Begegnungen in der gymnasialen Oberstufe : Erfahrungen finnischer Schüler mit finnisch-deutschen Schulpartnerschaften
2011
Nykyinen käsitys vieraiden kielten opettamisesta Suomessa painottaa kielen lisäksi myös kohdekulttuurin tuntemusta. Kielen opetuksessa tulisi huomioida sen kulttuurinen konteksti. Tämän tutkimuksen tavoitteena oli kartoittaa suomalaisten lukiolaisten kokemuksia ulkomaisesta ystävyyskoulutoiminnasta. Erityisen kiinnostuksen kohteena olivat lukiolaisten motiivit osallistua projektiin, heidän näkemyksensä projektin suunnittelusta ja toteutuksesta, sekä heidän kokemuksensa projektin vaikutuksista kulttuurienväliseen oppimiseen ja kielitaitoon. Työn teoreettisessa osassa tarkastellaan kulttuurienvälistä kompetenssia kansainvälisyyskasvatuksen tavoitteena Suomen lukio-opetussuunnitelmassa ja sen …
REDESIGN OF AN AUTO-LEVELLING BASE FOR SUBMARINE SEISMIC SENSOR
2011
The OBS (acronym of Ocean Bottom Seismometer) is a system to monitor the submarine seismic activity. To properly work, an OBS system needs a suitable auto-levelling base to maintain a fixed (horizontal) position during the measurement phases. In this work a new auto-levelling base for submarine seismic sensors has been designed. During the redesign process a preliminary phase of analysis of the state of art has been made. Afterwards, the technological solutions chosen by different manufactures have been critically analysed, and a full description of their functionalities, working principles and system performances has been carried out. Later, some innovative concepts have been proposed. Amo…
Inhibitoren der Korrosion 21 (1) - Autoxidationsstudien an Fe2+-Salzen der Tetramethylen-1,4-bis-phosphonsäure, der Hexamethylen-1,6-bis-phosphonsäur…
1978
Die Wirksamkeit der organischen Bisphosphonsauren als Inhibitoren der Korrosion von Eisen ist dadurch bedingt, das die aus der Eisenoberflache auftretenden Fe2+-Ionen direkt am Austrittsort mit den Sauren reagieren und an Ort und Stelle dreidimensional vernetzte Deckschichten aufbauen. Je dichter die Struktur dieser Schichten, je bestandiger das Netzwerk gegen Sauerstoff und je hydrolysebestandiger die FeOP-Bindungen, desto besser ist die Schutzwirkung: Dadurch wird sowohl dem Sauerstoff als auch dem Chloridion der Zugang zur Metalloberflache verwehrt. Die Modellversuche ermoglichen aufgrund der Verteilung des Phosphors in den Niederschlagen Ruckschlusse auf den Vernetzungsgrad. Corrosion I…
Inhibitoren der Korrosion 19 (1). Autoxidationsstudien an Fe2+-Trimethylen-1,3-bis-phosphonat als Modell einer die Korrosion inhibierenden Deckschicht
1976
Die Autoxidationsgeschwindigkeit der Fe2+. Salze ist stark abhangig vom pH und ist bei pH 2 praktisch gleich Null, bei pH 5–7 sehr hoch. Durch Zusatz von Trimethylen-1,3-bis-phosphonsaure wird die Autoxidation etwas verlangsamt und der Sauerstoffverbrauch starker erhoht als es der Stochiometrie der Fe2+-Oxidation entspricht. Dieser Umstand erklart sich durch den oxidativen Abbau der Trimethylen-1,3-bis-phosphonsaure zu Phosphorsaure, wobei Salze des dreiwertigen Eisens als Niederschlag ausfallen. Diese Fe3+-bis-phosphonate sind dreidimensional vernetzt; das Fe:P-Verhaltnis liegt zwischen 0.5 und 0.9 und wird mit abnehmendem pH-Wert geringer. Inhibitors of corrosion 19 (1). Autoxidation stud…