Argon-Geochemie von Mineralen hydrothermaler Bildung (Zeolithe; Serizite in Plagioklas)

Untersucht wurde die Argon-Geochemie von Mineralen die unter hydrothermalen Bedingungen entstanden oder alteriert sind. Hierbei wurde die Veränderung der Argon-Isotopie und die zeitliche Einordnung solcher Aktivitäten betrachtet. Dies sollte anhand von Zeolithen und Seriziten (in Plagioklasen) bestimmt werden. Bei den Zeolithen konnte festgestellt werden, daß viele Proben ungewöhnliche Argon-Isotopien aufwiesen, insbesondere niedrige 40Ar/36Ar-Verhältnisse, deren Ursprung in der Entstehung der Minerale unter Beteiligung von Fluiden zu suchen ist. Es konnte eine Argon-Isotopenfraktionierung bei einigen Zeolithen nachgewiesen werden, was zeigt, daß sie geeignet sind solche Prozesse bei der Mineralentstehung und Veränderung zu untersuchen. Die Daten der Serizit-Plagioklas-Mischungen zeigen, daß die verwendeten und neu entwickelten Verfahren geeignet sind, Prozesse bzw. Auswirkungen einer Serizitisierung zu beschreiben und das Aussagen über die Zeiträume der Bildung der beiden Minerale möglich sind. Gezeigt wurde dies an Proben des Odenwaldes (Gabbro) und der Vogesen (Andesit). Bei den Gabbros konnte eine Hauptserizitisierungsphase auf einen Zeitraum von 130 -150 Ma festgelegt werden. Eine sysnintrusive Serizitisierung ist wahrscheinlich, trägt aber nur einen minimalen Anteil an der Serizit-Menge bei. Das Intrusionsalter des Gabbros, bzw. das Abkühlalter des Ploagioklases konnte mit ca. 360 Ma bestimmt werden. Im Falle des Andesits konnten mindestens zwei Serizitisierungsphasen ausgemacht werden. Mittels geologischer Randparametern und vergleichenden Überlegungen konnten die Serizitisierungsphasen auf eine mesozoische (zeitgleiche hydrothermale Alteration in vielen Gegenden Europas) und eine synintrusive Serizi! tisierung (bei der Intrusion der den Andesit umgebenden karbonischen Granitoide) festgelegt werden. Das Abkühlalter der Plagioklase konnte nicht bestimmt werden, da sie im Verdacht stehen Exzeß-Argon zu tragen, welches den Alterswert von ca. 450 Ma erhöht h

Petrology, geochemistry and tectono-magmatic affinity of gabbroic olistoliths from the ophiolite mélange in the NW Dinaric-Vardar ophiolite zone (Mts. Kalnik and Ivanščica, North Croatia)

Mafic intrusive rocks are subordinately represented fragments of the oceanic crust in the ophiolite mélange exposedat Mts. Kalnik and Ivanščica located in the NW Dinaric-Vardar ophiolite zone. This ophiolite mélange occurs in thenorthern area of the Kalnik Unit and represents the SW surface boundary of the Zagorje-Mid-Transdanubian ShearZone. The mélange, except for mafic intrusive rocks, consists of a chaotic mixture of various extrusive rocks formedin different tectonic settings of the Repno Oceanic Domain (ROD). The ROD was the segment of Neo-Tethys thatconnects the Meliata-Maliak and Dinaric-Vardar oceanic systems. Previous study of mafic extrusive sequences suggestedan 80 Ma period of tectono-magmatic evolution of the ROD from intra-continental rifting during the Anisian,to the formation of proto-arc crust during the Callovian-Oxfordian. The domain exposes ophiolitic rocks in four mélangeareas. Isotropic gabbroic rocks that are abundant in two northern areas (Mts. Kalnik and Ivanščica), can be discriminatedinto three distinct geochemical groups: (A) N-MORB-type gabbro [(Th/Nb)n = 0.99–1.10; (Nb/La)n =0.95–0.99], (B) IAT-type amphibole gabbro with clear supra-subduction characteristics [(Th/Nb)n = 6.04–8.16; (Nb/La)n = 0.32–0.42] and (C) BABB-type amphibole-bearing gabbro [(Th/Nb)n = 2.88–4.02; (Nb/La)n = 0.58–0.69].Representative gabbro samples of each geochemical group were dated by the Ar-Ar and/or the K-Ar dating method.The Early Jurassic N-MORB-type gabbros (geochemical group A), ~185 Ma old, signifies a peculiar stage of Palaeo-Tethyan slab break-off. The Late Jurassic IAT-type gabbros (geochemical group B), ~147 Ma old, is the vestige of anascent intra-oceanic arc, whilst the Early Cretaceous BABB-type gabbros (geochemical group C), ~100 Ma old,provides evidence of magmatism in the back-arc marginal basin. The analyzed gabbroic rocks enable refinement andcompletion of the geodynamic evolution of the ROD, from the opening of an ensialic back-arc basin during the Ladinianand a continuous spreading event until the Bajocian. Intra-oceanic convergence was initiated in the Bathonian,with the formation of a nascent island-arc during the Tithonian, leading to formation of a Cretaceous ensimatic backarcmarginal basin. There are many lines of evidence that correlate the geodynamic evolution of the ROD with theAlbanide-Hellenide Neo-Tethyan oceanic segment.</p

Результаты теоретических и опытных работ по изучению механизма работы буровых компоновок со смещенным центром масс поперечного сечения

Актуальность работы: необходимость повышения эффективности бурения геологоразведочных скважин в сложных горно-геологических условиях, в том числе связанных с естественным искривлением скважин. Цель исследования: разработка методики использования и конструкций буровых компоновок со смещенным центром масс (тяжести) поперечного сечения, позволяющих повысить эффективность бурения геологоразведочных скважин. Методы исследования: аналитические исследования, опытно-конструкторские работы и экспериментальные опытные работы. Результаты. Разработаны теоретические положения, методика применения и конструкции буровых компоновок со смещенным центром тяжести поперечного сечения; проведены производственные испытания различных конструкций буровых компоновок со смещенным центром тяжести поперечного сечения при различных способах бурения. Выводы. На основе разработанной модели движения буровых компоновок со смещенным центром тяжести поперечного сечения получены аналитические зависимости для расчета величин эксцентриситета поперечного сечения буровых компоновок, обеспечивающие их вращение вокруг оси скважины (вид Ф1), а также длину вовлекаемого в режим вращения Ф1 участка колонны, что позволяет создавать компоновки бурильной колонны, способные работать в более благоприятном режиме и обеспечивать повышение эффективности бурового процесса. На основе стандартных снарядов со съемным керноприемником типоразмера HQ разработаны и изготовлены трубы со смещенным центром тяжести, которые испытаны на производственных скважинах в составе компоновки, в которой размещено три трубы со смещенным центром тяжести поперечного сечения. Результаты испытаний показали, что в составе высокосбалансированных бурильных колонн снаряда со съемным керноприемником эффективно применение труб со смещенным центром тяжести: достигается снижение интенсивности естественного искривления скважин, снижается вибрация и затраты мощности на работу бурильной колонны.Relevance of the research is the necessity to increase the efficiency of drilling prospecting wells in difficult mining-and-geological conditions, including those connected with a natural curvature of wells. The aim of the research is to develop a technique of using and designs of boring configurations with the displaced cross section mass center which allow increasing the efficiency of drilling the prospecting wells. Research methods: analytical researches, developmental works and experimental skilled works. Results. The authors have developed the theoretical regulations, a technique of application and a design of boring configurations with the displaced cross section mass center and carried out the production tests of various designs of boring configurations of with the displaced cross section mass center when drilling. Conclusions. Based on the developed model of movement of boring configurations with the displaced center of gravity of cross section the authors obtained the analytical dependences for calculating the sizes of eccentricity of boring configuration cross section providing their rotation round a well axis (Ф1 type), as well as the length of the column part involved in the rotation mode Ф1 that allows developing the configurations of a boring column capable of operating in more favorable mode and providing the increase of boring efficiency. Based on standard shells with the removable core receiver of a standard size of HQ the pipes with the displaced cross section mass center were developed and produced. They were tested on production wells as a part of configuration in which three pipes with the displaced cross section mass center were placed. The results of the tests showed that it is efficient to apply the pipes with the displaced cross section mass center as a part of the high-balanced boring columns as the decrease in intensity of natural curvature of wells is reached, vibration and costs of power for boring column operation decrease

Beam dynamics for the sc cw heavy ion linac at GSI

For future experiments with heavy ions near the coulomb barrier within the SHE (super-heavy elements) research project a multi-stage R&D program of GSI, HIM and IAP is currently in progress. It aims at developing a superconducting (sc) continuous wave (cw) LINAC with multiple CH cavities as key components downstream the High Charge Injector (HLI) at GSI. The beam dynamics concept is based on EQUUS (equidistant multigap structure) constant-beta cavities. Advantages of its periodicity are a high simulation accuracy, easy manufacturing and tuning with minimized costs as well as a straightforward energy variation. The next milestone will be a full performance beam test of the first LINAC section, comprising two solenoids and a 15-gap CH cavity inside a cryostat (Demonstrator)

Curvature force and dark energy

A curvature self-interaction of the cosmic gas is shown to mimic a cosmological constant or other forms of dark energy, such as a rolling tachyon condensate or a Chaplygin gas. Any given Hubble rate and deceleration parameter can be traced back to the action of an effective curvature force on the gas particles. This force self-consistently reacts back on the cosmological dynamics. The links between an imperfect fluid description, a kinetic description with effective antifriction forces, and curvature forces, which represent a non-minimal coupling of gravity to matter, are established.Comment: 14 pages; references added, to appear in New Journal of Physics (v3

Cosmic anti-friction and accelerated expansion

We explain an accelerated expansion of the present universe, suggested from observations of supernovae of type Ia at high redshift, by introducing an anti-frictional force that is self-consistently exerted on the particles of the cosmic substratum. Cosmic anti-friction, which is intimately related to ``particle production'', is shown to give rise to an effective negative pressure of the cosmic medium. While other explanations for an accelerated expansion (cosmological constant, quintessence) introduce a component of dark energy besides ``standard'' cold dark matter (CDM) we resort to a phenomenological one-component model of CDM with internal self-interactions. We demonstrate how the dynamics of the LambdaCDM model may be recovered as a special case of cosmic anti-friction. We discuss the connection with two-component models and obtain an attractor behavior for the ratio of the energy densities of both components which provides a possible phenomenological solution to the coincidence problem.Comment: 19 pages, 7 (3 new) figures, new derivation of kinetic equation with force term, accepted by Physical Review

Systematic review with meta-analysis: cytokines in fibromyalgia syndrome

<p>Abstract</p> <p>Background</p> <p>To perform a systematic review and meta-analysis on cytokine levels in patients with fibromyalgia syndrome (FMS).</p> <p>Methods</p> <p>Through December 2010 we systematically reviewed the databases PubMed, MEDLINE, and PsycINFO and screened the reference lists of 22 review articles for suitable original articles. Original articles investigating cytokines in patients with FMS were included. Data were extracted by two independent authors. Differences of the cytokine levels of FMS patients and controls were summarized by standardized mean differences (SMD) using a random effects model. Study quality was assessed applying methodological scores: modified Center of Evidence Based Medicine, Newcastle-Ottawa-Scale, and Würzburg Methodological Quality Score.</p> <p>Results</p> <p>Twenty-five articles were included investigating 1255 FMS patients and 800 healthy controls. Data of 13/25 studies entered meta-analysis. The overall methodological quality of studies was low. The results of the majority of studies were not comparable because methods, investigated material, and investigated target cytokines differed. Systematic review of the selected 25 articles revealed that FMS patients had higher serum levels of interleukin (IL)-1 receptor antagonist, IL-6, and IL-8, and higher plasma levels of IL-8. Meta-analysis of eligible studies showed that FMS patients had higher plasma IL-6 levels compared to controls (SMD = -0.34 [-0.64, -0.03] 95% CI; p = 0.03). The majority of investigated cytokines were not different between patients and controls.</p> <p>Conclusions</p> <p>The pathophysiological role of cytokines in FMS is still unclear. Studies of higher quality and with higher numbers of subjects are needed.</p

Genome-Wide Association Study and Functional Characterization Identifies Candidate Genes for Insulin-Stimulated Glucose Uptake

Distinct tissue-specific mechanisms mediate insulin action in fasting and postprandial states. Previous genetic studies have largely focused on insulin resistance in the fasting state, where hepatic insulin action dominates. Here we studied genetic variants influencing insulin levels measured 2 h after a glucose challenge in \u3e55,000 participants from three ancestry groups. We identified ten new loci (P \u3c 5 × 10-8) not previously associated with postchallenge insulin resistance, eight of which were shown to share their genetic architecture with type 2 diabetes in colocalization analyses. We investigated candidate genes at a subset of associated loci in cultured cells and identified nine candidate genes newly implicated in the expression or trafficking of GLUT4, the key glucose transporter in postprandial glucose uptake in muscle and fat. By focusing on postprandial insulin resistance, we highlighted the mechanisms of action at type 2 diabetes loci that are not adequately captured by studies of fasting glycemic traits

The genetics of blood pressure regulation and its target organs from association studies in 342,415 individuals

To dissect the genetic architecture of blood pressure and assess effects on target-organ damage, we analyzed 128,272 SNPs from targeted and genome-wide arrays in 201,529 individuals of European ancestry and genotypes from an additional 140,886 individuals were used for validation. We identified 66 blood pressure loci, of which 17 were novel and 15 harbored multiple distinct association signals. The 66 index SNPs were enriched for cis-regulatory elements, particularly in vascular endothelial cells, consistent with a primary role in blood pressure control through modulation of vascular tone across multiple tissues. The 66 index SNPs combined in a risk score showed comparable effects in 64,421 individuals of non-European descent. The 66-SNP blood pressure risk score was significantly associated with target-organ damage in multiple tissues, with minor effects in the kidney. Our findings expand current knowledge of blood pressure pathways and highlight tissues beyond the classic renal system in blood pressure regulation