Mechanisms of active folding of the landscape (Southern Tianshan, China)

We explore the kinematic mechanisms of active large-scale folding, based on analysis of two adjacent major anticlines in Tian Shan (central Asia) that share an acceleration of shortening rate leading to topographic emergence and folded geomorphic surfaces. Their folding mechanisms are fundamentally different. Yakeng anticline is a gentle pure shear detachment fold with 1200 m of shortening and a well-constrained history of growth beginning at 5.5 Ma with an order-of-magnitude increase in shortening rate from 0.16 to 1.2–1.6 mm/yr at 0.16–0.21 Ma. The shape of the deformed topographic surface and of subsurface horizons deposited during deformation is a linearly proportional image at reduced amplitude of the deeper structure, which shows that instantaneous uplift rates have been pointwise linearly proportional to the current finite fold amplitude. In contrast, Quilitak anticline is a complex fault bend fold with uplift rates proportional to the sine of the fault dip, showing discontinuities in uplift rate across active axial surfaces. The 10- to 20-km-wide anticline is topographically emergent only in a central 5- to 7-km-wide mountainous uplift, the abrupt southern edge of which is marked by 600- to 700-m-high triangular facets that result from active folding of a pediment across an active axial surface. The giant facets are shown to form by kink band migration and record postemergence deformation since an order-of-magnitude acceleration in shortening rate from 0.6 t 4–5 mm/yr, apparently contemporaneous with Yakeng. Sections logged across the active 115-m-wide hinge zone show that recent strata provide a bed- by-bed record of fold scarp growth, which is quantitatively deciphered by fitting bed shapes to a finite width kink band migration model

Switching the Spin State of Pentafluorophenylnitrene: Isolation of a Singlet Arylnitrene Complex

The chemistry of arylnitrenes is dominated by their triplet ground states and excited open-shell singlet states. This results in radical-type reactions and unwanted rearrangements, which diminish the use of arylnitrenes as intermediates in organic synthesis. While the closed-shell singlet states of arylnitrenes are expected to undergo useful chemical transformations (comparable to the closed-shell singlet states of carbenes), these states are too high in energy to be chemically accessible. When triplet pentafluorophenylnitrene is interacting with the Lewis acid BF₃ under the conditions of matrix isolation, a Lewis acid–base complex consisting of the closed-shell singlet state of the nitrene and two molecules of BF₃ is formed. Although the closed-shell singlet state of pentafluorophenylnitrene is calculated (CCSD­(T)) to lie more than 25 kcal/mol above its triplet ground state, the reaction with BF₃ results in switching the spin state from triplet to singlet. The formation of the singlet complex was monitored by IR, UV–vis, and EPR spectroscopy. DFT, CCSD­(T), and CASPT2 calculations confirm the experimental findings

Experimental study on AR fiberglass connectors for bridges made of composite materials

6 páginas, 11 figuras, 1 tabla.[ES] Un aspecto relevante dentro del proyecto de un puenterealizado en materiales compuestos es el estudio de losconectores. El caso mas frecuente de puente en materialescompuestos es aquel que presenta un tablero de materialescompuestos soportado por vigas metalicas o de hormigonarmado. En este trabajo se analizaran los tipos deconectores mas utilizados en este tipo de puentes Se analizaran tambien los conectores utilizados en elKing Stormwater Channel Bridge, donde ademas deltablero en fibra de vidrio, se fabricaron las vigas en fibrasde carbono rellenas de hormigon. En este articulo se propondran varios tipos de conectoresy se presentaran los resultados experimentales correspondientesal ensayo de “push-out” de varios prototipos condiferentes geometrias. Tras evaluar los resultados, se determinara el mas idoneopara su implantacion en el Paso Superior de la Autovia delCantabrico, de 46 metros de luz y que presenta las vigasen fibra de carbono y los conectores de vidrio AR.[EN] One highly relevant aspect in composite material bridge desing is the study of the shear connectors to be used. Composite material bridges most commonly comprise a composite deck resting on steel or reinforced concrete girders. This article analyzes the connectors most frequently used in such bridges. It also reviews the connectors used in the King Stormwater Channel Bridge, whose fibreglass deck is supported by girders made of concrete-filled carbon fibre girders. The paper advances proposals for several types of connectors and discusses the results of push-out test run on a number of prototypes with different geometries. The results are analyzed to identify the optimum model for the “Autovía del Cantábrico” Overpass, with its 46-m span, carbon fibre girders and AR glass shear connectors.Peer reviewe

A Wind Turbine Tower Design Based on the Use of Fibre-Reinforced Composites.

Abstract not availableJRC.G-Institute for the Protection and the Security of the Citizen (Ispra

Noninvasive Assessment of Coronary Artery Disease in Women: What’s Next?

Significant progress in research has been made in the areas of sex-specific aspects of cardiovascular disease. Despite these advances, coronary artery disease (CAD) is the leading cause of death of women in the Western world. Over the past decade, the focused research on women at risk for ischemic heart disease has helped to clarify our understanding of some of the sex-specific factors, which are important in detecting CAD. In women, the detection and evaluation of physiologically significant CAD is challenging, especially given that traditional tests designed to detect focal areas of coronary artery stenosis are less sensitive and specific in female patients who have a lower prevalence of obstructive coronary disease, greater burden of symptoms, and a high atherosclerotic burden. In this article, we review the available evidence on the role of contemporary cardiovascular imaging techniques in evaluating ischemic heart disease in women

Design and Construction Methods of Caisson-Type Maritime Infrastructures Using GFRP

Glass-fiber-reinforced polymers (GFRPs) are commonly used in various applications in civil-engineering projects. However, they are not common in the construction of civil-marine structures. The GFRP caisson technology was developed for the construction of two mooring dolphins in Puerto el Rosario (Fuerteventura, Spain). Ultraviolet-protected glass-fiber and epoxy resin coats were used to build a 12-m diameter, 13.3-m high cylindrical structure. A finite-element model was used to verify the sandwich composite configuration using the Tsai?Hill criteria?the shear strength of the skins and honeycomb core and the buckling and local failure modes with respect to the composite configuration. This is the first time that the two caissons were designed and built of polymeric materials and installed in a seaport. Accordingly, the construction technique marks a milestone in civil engineering because of its highly innovative nature in addition to significantly reducing the time associated with and the complexity of construction operations

Comparative Definitions for Moderate-Severe Ischemia in Stress Nuclear, Echocardiography, and Magnetic Resonance Imaging

The lack of standardized reporting of the magnitude of ischemia on noninvasive imaging contributes to variability in translating the severity of ischemia across stress imaging modalities. We identified the risk of coronary artery disease (CAD) death or myocardial infarction (MI) associated with \u3e= 10% ischemic myocardium on stress nuclear imaging as the risk threshold for stress echocardiography and cardiac magnetic resonance. A narrative review revealed that \u3e= 10% ischemic myocardium on stress nuclear imaging was associated with a median rate of CAD death or MI of 4.9%/year (interquartile range: 3.75% to 5.3%). For stress echocardiography, \u3e= 3 newly dysfunctional segments portend a median rate of CAD death or MI of 4.5%/year (interquartile range: 3.8% to 5.9%). Although imprecisely delineated, moderate-severe ischemia on cardiac magnetic resonance may be indicated by \u3e= 4 of 32 stress perfusion defects or \u3e= 3 dobutamine-induced dysfunctional segments. Risk-based thresholds can define equivalent amounts of ischemia across the stress imaging modalities, which will help to translate a common understanding of patient risk on which to guide subsequent management decisions. (C) 2014 by the American College of Cardiology Foundatio