bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zum Problem radialer Trennzugspannungen beim Tübbingschacht
Authors: Klein Joachim 
Published: March 2013

AbstractGut 150 Jahre ist es nun her, dass im Bergbau erstmals mit eisernen englischen Tübbingen als Schachtausbau größere Teufen erfolgreich erreicht werden konnten. Die Wandstärken wurden in jener Zeit nach der Fassformel oder anderen empirischen Faustformeln festgelegt, erst seit etwa 100 Jahren wird der zum “Deutscher Tübbing” entwickelte Ausbau mit unterschiedlichen baustatischen Berechnungsverfahren dimensioniert. Vor genau 50 Jahren begann ein Arbeitskreis des Steinkohlenbergbauvereins in Essen damit, einheitliche Richtlinien zur Berechnung von Schachtauskleidungen in nicht standfestem Gebirge aufzustellen, die späteren Schachtbaurichtlinien. In diesem Beitrag werden noch einmal in kompakter Form das viel diskutierte Problem des Lastangriffs des Wasserdrucks und seine Bedeutung bei der Ausbaubemessung dargestellt.Problem of separating radial tension stresses in a tubbing shaftIn water‐bearing strata the watertight shaft lining can be constructed as non‐rock‐connected sliding shaft or as bedded tubbing shaft consisting of adequate material. Concerning cylindrical shafts the widest advance to a watertight wall, i.e. the minimum radius of the water loads has a decisive influence on the design. Not only the greater tangential stresses but also the corresponding radial stresses are of importance. The problem of separating radial tension stresses and the consequences for the construction are recalled by an example of a classical cast iron tubbing shaft. From statics point of view, those impacts acting within a composite cross section form a special load case, which is not limited to tubbing shafts but does hold true for all watertight shaft‐lining systems.
Informations‐ und Dialogprozess zur Sicherheit und Umweltverträglichkeit der Fracking‐Technologie: Ergebnisse der Risikostudie
Authors: Borchardt Dietrich , Ewen Christoph , Richter Sandra , Hammerbacher Ruth 
Published: March 2013

AbstractUnternehmen der Erdgasindustrie planen in Deutschland die Förderung von Erdgas aus unkonventionellen Lagerstätten (Schiefergas, Kohleflözgas) mit der Fracking‐Technologie (Hydraulic Fracturing). Dabei wird ein Wasser‐Chemikalien‐Sand Gemisch unter hohem Druck in das Gas führende Gestein gepresst und gezielt Risse erzeugt, um das fest eingeschlossene Gas zu mobilisieren. Um die teilweise massiven Bedenken aus der Öffentlichkeit zu adressieren, wurde ein “Informations‐ und Dialogprozess über die Sicherheit und Umweltverträglichkeit der Fracking‐Technologie” initiiert. Eine dabei erarbeitete Risikostudie gibt Empfehlungen für eine in der Sache fundierte, sorgfältige und realistische Diskussion über die Vertretbarkeit des “Frackings” aus umweltbezogener Sicht.Dialogue and information dissemination process concerning the health and environmental aspects of hydrofrackingIn Germany, several gas companies are currently prospecting for so‐called unconventional natural gas reservoirs (shale gas and coal bed methane) in many parts of the country using the fracking technology (hydraulic fracturing). Therefore, a mixture of water, chemicals and sand is forced in the reservoir rock under high pressure in order to mobilize the enclosed gas. To address the sometimes massive public concerns about the safety and the environmental compatibility of the fracking technology the “Dialogue and information dissemination process concerning the health and environmental aspects of hydrofracking” has been initiated. During the process recommendations have been developed by a panel of experts to promote a thoughtful, realistic and fact‐based debate on the vices and virtues of hydrofracking.
Bohren auf der oberen Ebene – eine wirtschaftliche Alternative im Streckenvortrieb im Bergbau und im Tunnelbau
Authors: Saelhoff Günther 
Published: March 2013

AbstractWenn sich der Geräteeinsatz im Strecken‐ und Tunnelvortrieb auf die untere Querschnittsebene beschränkt, müssen die einzelnen Arbeitsgänge für Ausbruch und Sicherung nacheinander ausgeführt werden, sodass die Vortriebsgeschwindigkeit durch die Zeitdauer der einzelnen Arbeitsgänge und die Rüstzeiten für das Umsetzen der Geräte bestimmt wird. In nahezu allen Strecken‐ und Tunnelvortrieben können die Bohrarbeiten aber auch von im Firstbereich verfahrbar aufgehängten Bohrgeräten bewältigt werden. Durch die Trennung der Arbeitsebenen ergeben sich vielfältige Möglichkeiten zur Parallelisierung von Arbeitsvorgängen als Voraussetzung für höhere Vortriebsleistungen. Der Beitrag fasst den Entwicklungsstand der verfügbaren Maschinensysteme für Streckenvortriebe mit Teilschnittmaschinen und mit Bohr‐ und Sprengarbeit im Bergbau sowie im konventionellen Tunnelbau zusammen.Drilling works on the upper gateroad – an alternative in gateroad and tunnel excavationIf the use of machinery to drive gateroads and tunnels is restricted to the floor of the cross‐section, the individual working steps of excavation and support have to be performed successively, so the advance rate will be determined by the duration of the individual working steps and the setting‐up times for moving machines. For nearly all roadway and tunnel drives, however, it is also possible to carry out drilling works using mobile drill rigs suspended from the crown. The separation of working levels opens up many opportunities for performing working steps in parallel as a precondition for faster advance rates. The article summarises the state of development of the machinery available for driving roadways and galleries using roadheaders and drill and blast in mining as well as in conventional tunnel construction.
Meta‐analytic approaches to determine gender differences in the age‐incidence characteristics of schizophrenia and related psychoses
Authors: Jackson Dan , Kirkbride James , Croudace Tim , Morgan Craig , Boydell Jane , Errazuriz Antonia , Murray Robin M. , Jones Peter B. 
Published: March 2013

AbstractA recent systematic review and meta‐analysis of the incidence and prevalence of schizophrenia and other psychoses in England investigated the variation in the rates of psychotic disorders. However, some of the questions of interest, and the data collected to answer these, could not be adequately addressed using established meta‐analysis techniques. We developed a novel statistical method, which makes combined use of fractional polynomials and meta‐regression. This was used to quantify the evidence of gender differences and a secondary peak onset in women, where the outcome of interest is the incidence of schizophrenia. Statistically significant and epidemiologically important effects were obtained using our methods. Our analysis is based on data from four studies that provide 50 incidence rates, stratified by age and gender. We describe several variations of our method, in particular those that might be used where more data is available, and provide guidance for assessing the model fit. Copyright © 2013 John Wiley & Sons, Ltd.
Association of pre‐operative brain pathology with post‐operative delirium in a cohort of non‐small cell lung cancer patients undergoing surgical resection
Authors: Root James C. , Pryor Kane O. , Downey Robert , Alici Yesne , Davis Marcus L. , Holodny Andrei , Korc‐Grodzicki Beatriz , Ahles Tim 
Published: March 2013

AbstractObjectivePost‐operative delirium is associated with pre‐operative cognitive difficulties and diminished functional independence, both of which suggest that brain pathology may be present in affected individuals prior to surgery. Currently, there are few studies that have examined imaging correlates of post‐operative delirium. To our knowledge, none have examined the association of delirium with existing structural pathology in pre‐operative cancer patients. Here, we present a novel, retrospective strategy to assess pre‐operative structural brain pathology and its association with post‐operative delirium. Standard of care structural magnetic resonance imaging (MRIs) from a cohort of surgical candidates prior to surgery were analyzed for white matter hyperintensities and cerebral atrophy.MethodsWe identified 23 non‐small cell lung cancer patients with no evidence of metastases in the brain pre‐operatively, through retrospective chart review, who met criteria for post‐operative delirium within 4 days of surgery. 24 age‐ and gender‐matched control subjects were identified for comparison to the delirium sample. T1 and fluid‐attenuated inversion recovery sequences were collected from standard of care pre‐operative MRI screening and assessed for white matter pathology and atrophy.ResultsWe found significant differences in white matter pathology between groups with the delirium group exhibiting significantly greater white matter pathology than the non‐delirium group. Measure of cerebral atrophy demonstrated no significant difference between the delirium and non‐delirium group.ConclusionsIn this preliminary study utilizing standard of care pre‐operative brain MRIs for assessment of structural risk factors to delirium, we found white matter pathology to be a significant risk factor in post‐operative delirium. Limitations and implications for further investigation are discussed. Copyright © 2013 John Wiley & Sons, Ltd.
Obliterative lower airway lesions in childhood: Bronchoscopic diagnosis and clinical spectrum
Authors: Quizon Annabelle , Minic Pedrag , Pohunek Petr , Tal Asher , Colin Andrew A. 
Published: March 2013

AbstractPrevious reports have described structural airway abnormalities in children with non‐cystic fibrosis chronic supportive lung disease as well as obliterative membranes in the major bronchi of cystic fibrosis patients. The putative paradigm proposed in the evolution of these membranes invokes intense inflammation resulting in granulation tissue and neovascularization with the formation of pyogenic granuloma and eventually fibrosis.Our series of four cases widens the spectrum of conditions that may be conducive to large airway obliteration to include non‐suppurative chronic infections and possibly immunosuppression. Obliteration of lumina in proximal and distal airways was visualized on bronchoscopy, the latter by the use of the ultrathin bronchoscopes. An attempt at invasive intervention by transbronchial breaching of the obstruction was unsuccessful in three cases, and in one case, the obliterative process resolved spontaneously and without any radiologic trace, presumably by resorption or rupture or through development of collateral ventilation.This series highlights the use of bronchoscopy for diagnosis and occasionally for therapeutic intervention in hitherto little recognized obliterative airway lesions. These acquired obliterative lesions should be considered in the evaluation of patients with isolated non‐resolving pulmonary infiltrates or other conditions in which bronchial and bronchiolar patency may be impaired. Pediatr Pulmonol. 2014; 49:E27–E34. © 2013 Wiley Periodicals, Inc.
Preparation and characterization of superhard AlB2‐type WB2 nanocomposite coatings
Authors: Jiang Chunlei , Pei Zhiliang , Liu Yanming , Xiao Jinquan , Gong Jun , Sun Chao 
Published: March 2013

AbstractWB2 nanocomposite coatings were synthesized by dc magnetron sputtering. The morphology, chemical composition, chemical bonding state, microstructure, hardness, and tribological properties were investigated. The columnar‐structured coatings are dense and uniform. The as‐deposited coatings were found to have a metastable AlB2‐type structure as characterized by X‐ray diffraction and further confirmed by high‐resolution transmission electron microscopy. Coatings exhibit superhardness about 43.2 ± 5 GPa (taken from the plateau region) obtained by nanoindentation. In addition, the steady‐state friction coefficient µ = 0.23 and wear rate K = 6.5 × 10−6 mm3 N−1 m−1 were obtained under dry sliding condition in ambient environments. These characteristics indicate AlB2‐type WB2 coatings have high potential application as superhard and low wear coatings. Moreover, the AlB2‐type WB2 can hardly be prepared using the conventional powder metallurgy technology without high pressure, and this study proposes a new practical approach to prepare it.
Unique Role of Self‐Assembled Monolayers in Carbon Nanomaterial‐Based Field‐Effect Transistors
Authors: Chen Hongliang , Guo Xuefeng 
Published: March 2013

AbstractMolecular self‐assembly is a promising technology for creating reliable functional films in optoelectronic devices with full control of thickness and even spatial resolution. In particular, rationally designed self‐assembled monolayers (SAMs) play an important role in modifying the electrode/semiconductor and semiconductor/dielectric interfaces in field‐effect transistors. Carbon nanomaterials, especially single‐walled carbon nanotubes and graphene, have attracted intense interest in recent years due to their remarkable physicochemical properties. The combination of the advantages of both SAMs and carbon nanomaterials has been opening up a thriving research field. In this Review article, the unique role of SAMs acting as either active or auxiliary layers in carbon nanomaterials‐based field‐effect transistors is highlighted for tuning the substrate effect, controlling the carrier type and density in the conducting channel, and even installing new functionalities. The combination of molecular self‐assembly and molecular engineering with materials fabrication could incorporate diverse molecular functionalities into electrical nanocircuits, thus speeding the development of nanometer/molecular electronics in the future.
Effect of horizontal members on column shortening of reinforced concrete building structures
Authors: Kim Han‐Soo 
Published: March 2013

SUMMARYAn improved analysis method for column shortening of tall buildings has been proposed. The analysis method considers the restraining effects of steel bars and horizontal members. A step‐by‐step method was applied for the exact displacement and internal forces for any elapsed time. The sectional properties of the asymmetrically reinforced and cracked section were also taken into account. Column shortenings of an 80‐story reinforced concrete frame–shear wall building were investigated as numerical examples. The horizontal members reduce the differential shortening between the adjacent vertical members and transfer the axial forces of more shortened vertical members to less shortened members.
Pedotransfer functions for permeability: A computational study at pore scales
Authors: Hyman Jeffrey D. , Smolarkiewicz Piotr K. , Larrabee Winter C. 
Published: March 2013

Key Points
Computational experiments are used to develop generalized pedotransfer functions
Kozeny eqn gives good estimates of permeability for porosities in a normal range
Power laws give better estimates of permeability across wider ranges of porosity
Modeling fine‐scale soil surface structure using geostatistics
Authors: Croft H. , Anderson K. , Brazier R. E. , Kuhn N. J. 
Published: March 2013

Key Points
Aggregate breakdown and crust formation represented by decrease in sill variance
Soil cracks quantifiable by local semi‐variance maxima at a given length‐scale
Directional semi‐variograms modelled the spatial orientation of erosional areas
Synthese und Deprotonierung des verzweigten Triphosphanyltetrasilans PhSi(SiMe2PH2)3
Authors: von Hänisch Carsten , Feierabend Michael 
Published: March 2013

AbstractThe branched triphosphanyltetrasilane PhSi(SiMe2PH2)3 (1) could be obtained in a three‐stage synthesis. It was characterised by multi‐nuclear NMR spectroscopy, mass spectrometry and IR spectroscopy. Deprotonation of 1 with GaiPr3 or [M{N(SiMe3)2}2(thf)2] (M = Ca, Sr, Ba) yields new phosphorus bridged polynuclear complexes of these metals with phosphorus atoms connected through tetrasilane fragments. While trinuclear complexes with single deprotonated phosphanyl groups could be obtained from the reactions of 1 with GaiPr3, calcium or barium silazanide (compounds 2, 3 and 5), the tetranuclear complex [Sr4{PhSi(SiMe2PH)2(SiMe2P)}2(dme)6] (4) was formed in the reaction of 1 with strontium silazanide. In this compound, two of six phosphorus atoms are deprotonated twice. Compounds 2–5 were characterised by single‐crystal X‐ray diffraction, elemental analysis as well as IR spectroscopy and as far as possible by NMR spectroscopic techniques.
Wolfphos in Sheep's Clothing: The First Trinuclear Triboryl‐ and Other Boryl Platinum Complexes Featuring a Flexible Phosphine Ligand
Authors: Braunschweig Holger , Brenner Peter , Radacki Krzysztof 
Published: March 2013

AbstractStudies on the reactivity of the novel bis(phosphine) platinum complex [Pt{P(CH2Cy)3}2] towards haloboranes are presented. The resulting complexes of the general formula trans‐[Pt{B(R)R′}X{P(CH2Cy)3}2] were isolated in good to excellent yields (82–91 %) and the molecular structure of trans‐[Pt{B(Br)Fc}Br{P(CH2Cy)3}2] is reported. The reactions of 1,4‐(Br2B)2C6H4 and 1,3,5‐(Br2B)3C6H3 with two and three equivalents of the platinum precursor yield the corresponding di‐ and trinuclear boryl platinum complexes, respectively. The structural characterization of the first trinuclear triboryl complex 1,3,5‐trans‐[Pt(BBr)Br{P(CH2Cy)3}2]3C6H3 extends the number of possible structural motifs in boryl platinum chemistry by a noteworthy example and confirms that P(CH2Cy)3 has flexible steric bulk.
Perchlorate‐Free Pyrotechnic Formulations Utilizing Energetic Chlorine Donors: 1‐CDN, 11‐CDN, 13‐CDN
Authors: Naud Darren L. , Hiskey Michael A. , Chavez David E. 
Published: March 2013

AbstractSeveral novel materials were investigated as energetic chlorine donors, specifically for the preparation of perchlorate‐free pyrotechnic formulations with low‐smoke output. The novel compounds, 2‐chloromethyl‐2‐methyl‐5,5‐dinitro‐1,3‐dioxane (1‐CDN), 2,2‐bis(chloromethyl)‐5,5‐dinitro‐1,3‐dioxane (13‐CDN), and 2‐(dichloromethyl)‐2‐methyl‐5,5‐dinitro‐1,3‐dioxane (11‐CDN), were formulated with a variety of fuels and oxidizers and their resulting colored flames analyzed for color quality. The preparation and preliminary characterization of these energetic chlorine donors are described.
Katol Meteorite Shower, Maharashtra: A Preliminary Study
Authors: Suresh G. , Wankhade S. H. , Shareef Mohamed , Malviya Vivek P. , Kumar Binod , Mohan M. 
Published: March 2013

Abstract:
A meteorite shower occurred in Katol (21° 15' 30" N ; 78° 35' 00" E ; at an elevation of 415 m above msl), Nagpur district of Maharashtra state, India on May 22, 2012 between 14:00 to 14:30 hrs (Indian Standard Time) with a presently observed strewn field of ~5.0 sq km area. The event was experienced by the hundreds of inhabitants with a loud noise and fire ball between Akola in the west to Nagpur in the east. The Geological Survey of India has so far collected 27 meteorite pieces with a total weight of 3500 gm. The locations, size, shape and surface features of the individual meteorite pieces have been recorded. Based on their physical properties, mineralogy, mineral chemical mapping and REE chemistry, the Katol meteorites have been classified as olivine-rich H5 type differentiated stony meteorite with reconstituted chondrules. The preliminary evidence suggests the presence of pre-solar grains in Katol meteorite.
Proterozoic Granite Magmatism along the Terrane Boundary Tectonic Zone to the East of Cuddapah Basin, Andhra Pradesh – Petrotectonic Implications for Precambrian Crustal Growth in Nellore Schist Belt of Eastern Dharwar Craton
Authors: Sai V. V. Sesha 
Published: March 2013

Abstract:
The area adjoining the western part of Archaean Nellore schist belt and the eastern margin of the Proterozoic Cuddapah basin in south Peninsular India is marked by emplacement of a number of granite plutons of Proterozoic age, intermittently extending over a stretch of 350 km from Vinukonda in the north to Sri Kalahasti in the south. Vinukonda, Darsi, Podili and Anumalakonda plutons are intensely deformed particularly along the margins, while development of crude deformational fabric is noticed in Kanigiri, Rapur and Kayyuru-Vendodu plutons. Petrographically majority of these granites vary from alkali feldspar granite to granite with the exception of Rapur granite which varies from granite to granodiorite. Geochemically they exhibit calc-alkaline trend and in A/NK-A/CNK plot they are positioned at the juncture of peraluminous-metaluminous-peralkaline field. Characteristically, majority of these granites are fluorite bearing. Biotite mineral chemistry suggests high FeOT contents (31.68 to 34.69 %) and very low MgO contents (0.49 to 2.41 %). Geochemically, these are charecterised by high SiO2 (69 to 74.5 %), Na2O+K2O (8.19 to 10.11%), Zr (280-660ppm), Y (70-340 ppm), Rb content (180-370 ppm) and high REE contents (except Eu); and low CaO (0.01 to 1.99), MgO (0.01 to 0.92%) and Sr (10 ppm to 85 ppm) contents. Rare earth element studies reveal a general enrichment of LREE, pronounced negative Eu anomaly; flat and depleted HREE. Enriched LILE and HFSE contents; presence of fluorite and interstitial biotite indicate that these granites are crystallized from a fluorine saturated magma derived from enriched crustal source. The field setup, distinct mineralogy and chemical characteristics suggest that these granite plutons are emplaced along a major tectonic zone i.e. terrane boundary shear zone (TBSZ) in a late-orogenic to anorogenic tectonic setup, close to the vicinity of a collision boundary zone; western margin of NSB and eastern margin of Nallamalai Fold Belt (NFB). The Proterozoic granite magmatism reported in the present studies represents a significant event of Precambrian crustal growth at the juncture of two tectonically contrasting terranes i.e. the Archaean Nellore schist belt and the Proterozoic Cuddapah basin in eastern Dharwar craton.
Disposition of Aquifer System, Geo-electric Characteristics and Gamma-log Anomaly in the Kuttanad Alluvium of Kerala
Authors: Vinayachandran N. , Narayana A. C. , Najeeb K. MD. , Narendra P. 
Published: March 2013

Abstract:
Kuttanad near the western coast of Kerala is a low lying area below mean sea level. The hydrogeological scenario in this wet land dominated tract, known as kole lands, was investigated by using the lithological and geophysical data generated under the R&D exploration programme of Central Ground Water Board (CGWB) during the year 2000, as also other related data generated till the year 2009. The hydrogeology of the tract is complex, and the presence of carbonaceous and organic matter in the soil and sub-soil influences the geochemical and geo-electric characteristics of the sub-surface geological formations as reflected by SP and resistivity logs. The lithologs and geophysical logs of bore wells were used to define the aquifer geometry. While the lateral and vertical variations of the aquifer systems identified were high, the bottom aquifer was relatively brackish over a large area. The gamma log behavior in these granular zones is anomalous and misguiding in nature. The radioactivities recorded against clay horizons were in the range of 130 to 200cps and in the granular zones 150 to 350 cps. The presence of monazite bearing sands at certain depths was responsible for anomalously high gamma counts against granular zones. The water quality in the granular zones was inferred from the electrical logs. The depth of occurrence of high radiation sand beds was also demarcated.