bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Long-Term Annealing at Elevated Temperature on Microstructure and Hardness of Heat-Resistant Steel
Authors: Kosec Ladislav , Gojić Mirko , Kožuh Stjepan , Kosec Borut , Dražič Goran , Šavli Štefan
Published: April 2014

The stainless steel group AISI 310 is very often used for application in high-temperature conditions. This study investigated the effect of long-term annealing on microstructure and hardness of AISI 310S (24.3% Cr-19.3% Ni 1.8% Mn 0.21% Mo 0.67% Si, wt.%) heat-resistant steel. Microstructural changes and hardness distribution were analyzed after isothermal annealing at 800 °C in long-term exposure (from 1 to 1740 hours). Microstructure and fracture surface mode were analyzed using scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). It was found that after annealing the sigma phase particles were precipitated at grain boundaries and within austenite grains. The chromium content in the sigma phase increased with the prolongation of annealing time. The morphology of sigma phase was changed from fine precipitates at lower annealing times to coarser particles at higher annealing times. Also, presence of sigma phase was confirmed by transmission electron microscopy (TEM). At annealing temperature of 800 °C the hardness began to increase after 16 hours. With longer times of annealing the fracture surfaces were changed. This change is associated with a change of content and the morphology of sigma phase.
Metallographic Examination of Fracture Splitting 44SMn28 Steel Used in the Manufacture of Rotor Shaft
Authors: Jurasz Zbigniew , Kochel Ryszard , Adamaszek Krzysztof
Published: April 2014

In this work a failed rotor shaft of φ 7.2 mm diameter manufactured from constructional steel 44SMn28 (1.0762) was examined. Fracture splitting into 2 pieces in the threaded part of the shaft in a direction parallel to the longitudinal axis occurred. The failure was induced by mechanical forces in the threading process. The failed shaft was examined on a metallographic and scanning microscope. It was found that the failure was caused by excessive accumulation of MnS inclusions in an unfavourable banded formation.
Failure Analysis of Spherical Roller Bearing
Authors: Juliš Martin , Čelko Ladislav , Spotz Zdeněk , Doležal Pavel , Pavloušková Zina , Švejcar Jiří
Published: April 2014

The failure of a spherical-roller bearing consisting of spherical rollers, outer and inner rings made of 100CrMn6 steel was studied. After a trial test, in which several spherical rollers were completely destroyed and a long continuous radial crack appeared in the outer ring, pitting degradation was observed on all bearing parts. The bearing components were studied (separately) by means of light and electron microscopy. The chemical composition was estimated by means of glow discharge optical emission spectroscopy. X-ray diffraction was utilized for qualitative and quantitative phase analyses. As a representative of mechanical properties, the hardness was also measured.
Cavitation Erosion Behavior of the Antifriction Alloy YSn83
Authors: Potoceanu Nadia , Nedeloni Marian Dumitru , Chirus Daniel , Florea Danut
Published: April 2014

This paper presents the cavitation erosion research of the antifriction alloy YSn83 regarding on its behavior in laboratory. The antifriction alloy YSn83 is not subject to cavitation erosion in its practical applications, as is happening in reality at the materials used in hydraulic turbines, valves, piping; but the experimental tests for this material, highlight the laboratory research on its behavior by means of images and graphs in this paper. The laboratory tests were performed in accordance with the standards G32-92 (Standard Method of Vibratory Cavitation Erosion Test) and G32-10 (Standard Test Method for Cavitation Erosion Using Vibratory Apparatus).
Microstructural Stability of P23/P91 Dissimilar Welds during Creep at 500°C
Authors: Střílková Lucie , Holešinský Jan , Maslova Anastasia , Kuboň Zdeněk , Vodárek Vlastimil
Published: April 2014

This paper deals with microstructural stability of P23/P91 dissimilar welds during long-term creep exposure at 500°C. Detailed TEM investigations on minor phase evolution were performed on specimens after long-term creep exposure. Microstructural changes in the decarburized layer of the P23 steel were studied using EBSD and TEM. Experimental data on minor phase evolution were compared to the results of thermodynamic (Thermocalc) and kinetic (Dictra) simulations. Evolution of minor phases in the P23/P91 welds during creep at 500°C was in a good agreement with results of microstructural modelling. Partial decarburization of the P23 occurred at the expense of dissolving M7C3 phase. Microstructure of the partly decarburized zone in the P23 steel remained bainitic in all specimens investigated. In spite of the partial decarburization in the P23 steel during longterm creep exposure at 500°C, creep failures occurred in the ICHAZ of the P23 steel.
Evaluation of Materials Degradation Extent after their Long Term Exposition in Power Plants Equipments
Authors: Kraus Martin , Mareš Vratislav , Bystrianský Jaroslav
Published: April 2014

Load processes and their interaction over long-term service exposition influence on degradation of construction materials in the equipment of conventional power plants. A wide range of destructive testing methods and number of test for each of them were used to clarify of the extent and mechanism of the damage steel components of the power plants pressure circuit. Changes of material properties were by those methods evaluated in state after operational exposition - till 190 000 hours and after heat treatment reprocessing, for all observed components in the entire profile of the wall thickness. Great attention was paid to metallographic evaluation of the creep damage also. The results of test were compared with the supposed properties of the undegraded material in origin state.
Creep of Cast Steel P91 with Weld Joint
Authors: Vlasák Tomás , Hakl Jan , Novák Pavel , Sochor Jiří , Čech Jan
Published: April 2014

High-temperature martensitic steel P91, internationally marked GX12CrMoVNbN91, is the material used in the energy industry. Creep and high-temperature corrosion resistances are important properties that affect the application of this material at higher temperatures. Weldment reduces creep properties. This work deals with the quantification of this decrease in the case of material P91. The main focus is except the evaluation of creep test results given to the mathematical description of the weld creep strength reduction. Further metallographic analyses of weld joint after creep exposures were performed.
Highly Thermally Stable Light-Weight Al Based Alloys Prepared by Centrifugal Atomization and Powder Compaction
Authors: Vojtěch Dalibor , Dám Karel , Průša Filip
Published: April 2014

Combination of centrifugal melt spraying and hot die-forging of a rapidly solidified semi-product was presented as a promising and inexpensive method for processing of aluminium based alloys of unconventional chemical compositions, e.g., those containing high concentrations of thermally stabilizing transition metals. In our study, the use of this processing method is illustrated for the Al–23Si–8Fe–5Mn (wt. %) alloy. Structure was examined by LM, SEM, EDS and XRD. Mechanical properties were determined by hardness and compressive tests. Thermal stability was assessed by measuring the hardness development during long-term annealing, elevated temperature compressive tests and creep tests. The research showed that the investigated alloy exhibits excellent thermal stability as compared with commercial thermally stable aluminium alloys currently used in automotive and aerospace industry.
Microstructure Evolution of Fe-Al-Si and Ti-Al-Si Alloys during High-Temperature Oxidation
Authors: Novák Pavel , Kříž Jan , Michalcová Alena , Vojtěch Dalibor
Published: April 2014

Alloys based on TiAl and FeAl aluminides are modern materials for high-temperature applications in automotive or aerospace industry due to low density combined with good high-temperature mechanical properties and oxidation resistance. Previous works proved that the addition of silicon to these alloys improves the oxidation resistance as well as the thermal stability. In this work, the mechanism of the silicon effect was investigated by observing the microstructure of the oxide layer and the near-surface area of the Ti-Al-Si and Fe-Al-Si alloys prepared by reactive sintering powder metallurgy. It was found that silicon improves the compactness of the oxide layers. The oxide layers on Fe-Al-Si alloys are formed by Al2O3 and small amount of iron oxide (Fe2O3) while Ti-Al-Si alloys cover by TiO2 and Al2O3 during the oxidation. Due to aluminium depletion of the alloy, a layer of silicides is formed under the oxide layer, thus acting as the additional protection against high-temperature oxidation.
The Study of Iron Intermetallic Phases Morphology with Applying Deep Etching in Secondary Al-Si Alloys
Authors: Hurtalová Lenka , Tillová Eva , Chalupová Mária
Published: April 2014

The morphology control of intermetallic phases is very important in secondary aluminium cast alloy, because these alloys contain more of additional elements, which forms various intermetallic phases in the structure. Improvement of the mechanical properties is strongly depending upon the morphology, type and distribution of the second phases, which are in turn a function of the alloy composition and cooling rate. The iron intermetallic phase has the greatest influence on mechanical properties. It is necessary to study microstructure of Al-Si alloys, because the metallographic evaluation of aluminium alloys is not simple and these alloys are used for production many mechanical components, especially for cars, aerospace and rail vehicles. The study of iron intermetallic phases was performed using light microscope Neophot 32 and SEM observation with EDX analysis. For study the morphology of these phases were samples deep-etched for 30 s in HCl solution, in order to reveal the three-dimensional morphology of the iron phases.
Microstructure Analysis of AlSi10MgMn Aluminium Cast Alloy
Authors: Chalupová Mária , Tillová Eva , Farkašová Mária
Published: April 2014

The present study was performed on primary AlSi10MgMn cast alloy to analyze the morphology and composition of complex microstructure of the intermetallic phases. AlSi10MgMn cast alloy is a typical casting alloy used for parts with thin walls and complex geometry. It offers good strength, hardness and dynamic properties and is therefore also used for parts subject to high loading. In this study, several methods were used such as: optical light microscopy (LM) and scanning (SEM) electron microscopy in combination with EDX analysis using standard etched or deep etched sample to identify intermetallic. Alloy was analyzed in as-cast state (rapidly cooled right after casting) and after T6 heat treatment. T6 treatment (solution annealing, quenching and age hardening) improves mechanical properties. The results show that the microstructure of AlSi10MgMn alloy consisted of several phases: α-matrix, eutectic, Fe-rich intermetallic phases (Al15(FeMn)3Si2, Al5FeSi), Mg2Si, Al8FeMg3Si6 and of other phases in formation. Iron-rich intermetallic phases are well known to be strongly influential on mechanical properties in Al-Si alloys. The most common morphology was the long platelets of Al5FeSi phase. After heat treatment were observed spheroidisation of eutectic Si, dissolution and fragmentation of Fe-phases.
The Influence of Thermo-Plastic Processes on Materials Recovery
Authors: Kvačkaj Tibor , Kočiško Robert , Bidulský Robert , Bidulská Jana , Bella Peter , Lupták Miloslav , Kováčová Andrea , Bacsó Július
Published: April 2014

The influence of thermo-plastic processes through methods of severe plastic deformations (SPD) and rolling carried out at ambient and cryogenic temperatures on recovery of two materials was investigated. The aim of this study was to insert strains to materials having middle and high stacking fault energy (SFE) in ambient and cryogenic temperature conditions, respectively and subsequently, through DSC method, to observe an influence of the storage energy on structural recovery of materials. As experimental materials were used oxygen free high conductivity copper (OFHC Cu) and C-Si steel which represent materials with middle and high stacking fault energy (SFE), respectively. The OFHC Cu was subjected to equal channel angular rolling (ECAR) by seven passes. ECAR is a method belonging to a SPD group. It was shown, five ECAR passes have a significant effect on material properties. The rolling performed at cryogenic temperatures using a laboratory duo rolling mill was carried out only once. This study implies that a recovery process (characterized by the mobility of structural defects) starts as follows: for OFHC Cu without ECAR and processed by 5thECAR passes: 0.31·Tmeltand 0.19·Tmelt, respectively, for C-Si steel processed by cryorolling: 0.095·Tmelt.
Effect of Technologies Processing on Material Properties of Selected Aluminium Alloys
Authors: Lacková Petra , Žabecká Daniela , Milkovič Ondrej , Škrobian Milan , Bajcura Matúš
Published: April 2014

The paper is concerned with an analysis of utility properties of selected aluminium alloys, namely EN AW 6082 (AlSi1MgMn), EN AW 6061 (AlMg1SiCu) and EN AW 7075 (AlZn5.5MgCu) with different technology of hot processing. The alloys were hot processed to reach T3 condition (solution annealing, cold forming and natural aging) and to reach T4 condition (solution annealing and natural aging). The following parameters were subject to evaluation: microstructure and sub-structure, mechanical properties (strength and plastic characteristics stated in Table. 1) as well as fatigue properties of these alloys assessed during alternative symmetrical stress in torsion. The paper was aimed to study the affect of processing technology of three aluminium alloys on their utility properties in the conditions of tensile stress and cyclic stress in torsion.
Shear Strength of Joints Fabricated by Solders with High Indium Content
Authors: Koleňák Roman , Martinkovič Maroš
Published: April 2014

Feasibility of pure indium and solders containing high amount of indium as 70In30Sn to wet the different types of metallic and ceramic materials at application of power ultrasound was studied. The shear strength of soldered joints fabricated on metallic (Cu, Ni, Al, Ti, AISI 316 steel) and ceramic substrates was assessed. The shear strength of In solders on Al2O3 and SiC ceramic materials varied from 3.5 to 7 MPa. The shear strength on metallic materials attained from 12.5 to 71 MPa. Joint fracture in most cases occurred in the solder and was of ductile character. Failure took place by shear mechanism.
Oxide Reduction Processes, Microstructure and Properties of Sintered Chromium Pre-Alloyed Steel
Authors: Hrubovčáková Monika , Dudrová Eva , Kabátová Margita
Published: April 2014

The reduction processes during the sintering of Fe-3Cr-0.5Mo+0.5C pre-alloyed powder using continuous monitoring of exhaust gas composition (CO, CO2, H2O) have been identified and interpreted in relation to the density (6.5-7.4 g/cm3), sintering temperature (1120 and 1200°C), heating and cooling rates (10 and 50°C/min) and type of sintering atmosphere (10%H2-N2, N2), respectively. The progress in reduction processes was evaluated by the change in C and O contents, and fracture strength values as well. The results were compared with metallographic study of microstructure and fractographic observations of fracture surfaces. Higher sintering temperature (1200°C) and low density (<7.0 g/cm3) resulted in a relative decrease in oxygen content by more than 80%. Higher cooling rate (50°C/min) eliminates re-oxidation during cooling. High density of 7.4 g/cm3,achievedby double pressing, indicated to have a negative effect on reduction processes due to restricted replenishment of the “microclimate” atmosphere with the processing gas. Higher O2 content causes weakening of interfaces with residual oxides.
Thermal Cycling of Copper Based Composite Reinforced with High Modulus Carbon Fibres
Authors: Štefánik Pavol , Iždinský Karol , Simančík František , Beronská Naďa
Published: April 2014

The thermal expansion behaviour of Cu-1Cr/C composite subjected to 5 thermal cycles in the temperature range 30 - 1000 °C was investigated. The coefficients of thermal expansions (CTEs) as low as 0.7 x 10-6 K-1 in longitudinal and as large as 24.0 x 10-6 K-1 in transversal direction were obtained. Electron microscopy observations confirmed the high structural stability of the thermally cycled composite as no signs of disintegration were observed within the applied thermal cycling conditions.
The Influence of Y211 Milling Conditions on the Microstructure of Y123/Y211 Bulk Superconductors
Authors: Šefčíková Martina , Piovarči Samuel , Radusovska Monika , Antal Vitaliy , Diko Pavel
Published: April 2014

The YBCO bulk single-grain superconductors were prepared by Top-Seeded Melt-Growth (TSMG) process. Y2BaCuO5 (Y211) fine powder was added to YBa2Cu3O7-δ (Y123) nominal composition. Powder refinement was characterized by X-ray powder difractometry, laser granulometry and scanning electron microscopy. The system behaviour was characterized by thermal analysis. Microstructure of prepared samples was studied by polarized light microscopy. The influence of Y211 addition the sample microstructures are shown.
Quantitative Evaluation of Alitize Coating on ŽS6K Ni-Base Superalloy
Authors: Belan Juraj
Published: April 2014

The aerospace industry is one of the biggest consumers of advanced materials because of its unique combination of mechanical and physical properties and chemical stability. Highly alloyed stainless steel, titanium alloys and nickel based superalloys are mostly used for aerospace applications. The aim of the work is to evaluate protective Al Si coating applied by diffusion annealing on substrate, Ni base superalloy ZS6K. This superalloy is used for turbine blade production in aero jet engine DV 2. Using of protective alitize coating provides an increasing of heat resistance of superalloy surface and increases working temperature up to 800°C. However, overcrossing of working temperature range (for ZS6K turbine blades it is from 705°C to 750°C) sometimes happen and that is the reason for detailed study of protective coating degradation. The alitize coating were evaluated in starting stage and after various time of regular loading in real aero jet engines DV 2. Coating and its degradation was evaluated with help of quantitative metallography methods (metallography software NIS Elements) and colour contrast as well.
Microstructural Characterization of Slurry Aluminide Diffusion Coatings
Authors: Čelko Ladislav , Hutařová Simona , Petrenec Martin , Obrtlík Karel , Hrčková Martina , Podrábský Tomáš
Published: April 2014

Commercially pure aluminium powder and a mixture of aluminium and silicon powders, both in a liquid amyl acetate-based organic binder, were sprayed onto the surface of Inconel 713LC nickel base superalloy. A two-stage heat treatment process in an argon atmosphere flow was designed and applied to produce nickel aluminide diffusion coatings. Two coating systems composed of different layers with gradual changes in chemical composition and phase quantities were formed. Scanning electron microscope, scanning electron microscope/focused ion beam, both equipped with energy dispersive microanalyzers, were utilized to characterize the microstructure and chemical composition of the coatings.
Aluminide Protective Coatings Obtained by Slurry Method
Authors: Kochmańska Agnieszka , Kochmański Paweł
Published: April 2014

The slurry aluminide coatings are produced on the three kind of substrates: hightemperature creep resistant cast steel, titanium alloy and nickel alloy. The slurry as active mixture containing aluminium and silicon powders, an activator and an inorganic binder. The coating were obtained by annealed in air atmosphere. The structure of these coatings is two zonal and depend on the type of substrate and technological parameters of producing.
Comparative Analysis of Hard Anodized Layer on Aluminium Alloy
Authors: Klakurková Lenka , Hégr Eduard , Čelko Ladislav , Podrábský Tomáš , Juliš Martin , Remešová Michaela , Švejcar Jiří
Published: April 2014

Hard anodized layers were produced by two different manufacturers on the same type of aluminium alloy on a vacuum pump part of complex shape. The sulphuric acid/water solution was used to produce alumina layers, which were subsequently sealed in demineralized water. A comparative analysis based on metallographic methodology, with the aim to control the stability of alumina formation process and to identify its defects, was performed by means of light and scanning electron microscopy, surface profilometry and microhardness measurements. To determine the thickness of alumina layers, the image analysis was also used.
Structural Properties of Zinc and ZnMgAl Coatings on Steel Sheets
Authors: Kollárová Mária , Hrabčáková Lucia , Graban Juraj , Šohajová Marta
Published: April 2014

In the paper mutual comparison of zinc coatings enriched with small additions of Mg and Al (up to 1 wt.% Mg and 1 wt.% Al) and traditional zinc coatings produced by hot dip galvanizing, concerning some important properties of coatings like coating structure, cracks formation after deformation and corrosion resistance of deformed samples was studied. It was shown, that while traditional hot-dip zinc coatings are formed by homogenous zinc layer, exhibiting only low amount of soluble aluminium, coatings enriched by small amounts of Mg and Al, namely 0.6% Mg and 0.8% Al are formed by dendritic zinc matrix and interdendritic phase containing Zn-Mg-Al eutectics. Development of cracks was investigated in the area of maximal deformation of the samples subjected to stretching. It was found, that while traditional zinc coatings showed sporadic long fine cracks, zinc coatings enriched with Mg and Al exhibited aggregation of short thick cracks in the deformed area. Samples of both materials after stretching were also exposed in neutral salt spray atmosphere in corrosion chamber. It can be concluded, that material with coatings enriched with Mg and Al showed better results in corrosion tests contrary to the presence of massive cracks in the coating. This significantly increased corrosion resistance is possible due to excellent adhesion of zinc coatings, containing Mg and Al on drawing steels.
Microstructural Features of Bronze-Coated Iron Coins from the Roman Empire
Authors: Strobl Susanne , Haubner Roland
Published: April 2014

At the late second and early third century coin copies, termed subferrata, were produced in the provinces Noricum and Pannonia of the Roman Empire. Subferrata consist of an iron core, which was plated with a copper alloy. To get information about the manufacturing process and the materials used, coins were cut and investigated after metallographic preparation by light optical microscope (LOM). Scanning electron microscopy (SEM) and energy disperse X-ray analysis (EDX) were used to get information about the local chemical compositions. The general composition was determined by X-ray fluorescence analysis (RFA). The Cu alloy coatings consist of Cu, Pb, Sn, Zn and small amounts of Ag. This alloy is a variant of gunmetal, known as leaded red brass. The coatings show mainly differences in the Pb and Sn content and moreover the intermetallic phase Cu41Sn11was found. Inside the red brass coating droplet-shaped iron inclusions were observed. Near the interface, between coating and iron core, Cu and Pb were detected at the grain boundaries (liquid metal embrittlement). Probably, the iron flan was plated by immersing in a molten copper alloy. In the ferritic-pearlitic iron core, slag inclusions and regions with various carbon contents were observed. Furthermore, deformation twins (Neumann lines) were found in the Fe core ́s microstructure, leading to the suggestion that coining was performed after cooling the flan.
Kinetics of Austenite Recrystallization of Selected Steels Used for Heavy Forgings
Authors: Horník Jakub , Zuna Petr , Malek Jaroslav , Jandoš František
Published: April 2014

The kinetics of austenite recrystallization was evaluated in range of typical forging temperatures (850 - 1250) °C. The steels SA-508 and 3.5Ni-1.5Cr were compared. The laboratory one step deformation was applied. The effect of selected chemical elements in evaluated steels on grain growth and recrystallization kinetics of austenite and precipitation was monitored using metallographic methods. The retarding of static recrystallization was proved and no abnormal grain coarsening at defined condition was observed.
Impact of Microstructure Modification on Deformation Behaviour of Bulk TRIP Steel
Authors: Zrník Jozef , Muránsky Ondrej , Šittner Petr
Published: April 2014

The paper presents results ofin-situneutron diffraction experiments aimed on monitoring the phase evolution and load distribution in TRIP steel when subjected to tensile loading. Tensile deformation behaviour of TRIP steel with different initial microstructures showed that the applied tensile load is redistributed at the yield point and the harder retained austenite (Feγ) bears larger load then ferrite (Feα) matrix. After load partioning is finished, macroscopic yielding comes through simultaneous activity of the martensite transformation (in the austenite) and plastic deformation process in ferrite. The steel with higher volume fraction of retained austenite and less stronger ferrite appears to be a better TRIP steel having efficient structure for better plasticity purpose.
Cutting Edge: The Transcription Factor Bob1 Counteracts B Cell Activation and Regulates miR-146a in B Cells
Authors: Lindner John M. , Kayo Hiroyuki , Hedlund Sebastian , Fukuda Yoko , Fukao Taro , Nielsen Peter J.
Published: April 2014

Mice lacking the lymphocyte-specific transcription factor Bob1 (also called OBF-1 or OCA-B) fail to generate germinal centers and a robust Ig response. We show that peripheral B cells in Bob1−/− mice bear characteristics of chronically activated or anergic-like B cells and identify the immunosuppressive microRNA-146a, together with other microRNAs, as novel transcriptional targets of Bob1. The inability to restrict B cell signaling could contribute to the immunodeficient phenotype of these mice and is consistent with an important role for Bob1 in suppressing B cell activation in vivo.
Disease Association and Arthritogenic Potential of Circulating Antibodies against the α1,4-Polygalacturonic Acid Moiety
Authors: Dai Hui , Dong Hong-Liang , Gong Fang-Yuan , Sun Shu-Liang , Liu Xiang-Yuan , Li Zhan-Guo , Xiong Si-Dong , Gao Xiao-Ming
Published: April 2014

Much progress has been made in recent years on the diagnostic value, Ag specificity, and pathogenic roles of autoantibodies correlated to the development of rheumatoid arthritis (RA) in humans. However, carbohydrate Ag-specific autoantibodies that may also play important roles in RA have largely been ignored. In this article, we report that serum levels of Abs capable of recognizing α1,4-polygalacturonic acid [(PGA); major structural component of pectin] strongly correlate with RA in humans. The measurements of PGA-specific Abs (PGA-Abs) in sera are comparable to rheumatoid factors and anti–cyclic citrullinated peptide Abs as serological diagnostic markers for RA in terms of sensitivity and specificity. Immunohistochemical staining results indicate that the PGA-Abs selectively bound synovial membrane cells and chondrocytes in the joints of both humans and rabbits (but not rodents). Induction of PGA-Abs by s.c. immunization of rabbits with carrier protein–conjugated synthetic PGA led to severe inflammatory reactions (synovial hyperplasia, small vessel proliferation, and inflammatory cell infiltration) in the joints. Injection of affinity purified anti-PGA IgG into the synovial cavity of rabbits resulted in accumulation of proinflammatory cytokines such as TNF-α, IL-8, and IL-1β in synovial fluid, as well as local pathological damage. We conclude that the PGA–cross-reactive moiety represents a major autoantigen in the joints and can be targeted by autoantibodies capable of triggering arthritogenic responses in vivo.
Geology of McBride map-area, British Columbia (93H)
Authors: Campbell R B , Mountjoy E W , Young F G
Published: April 2014

McBride map-area, about 5, 800 square miles in east-central British Columbia, includes parts of the Interior Plateau, Cariboo Mountains, Rocky Mountain Trench, Rocky Mountains, and F oothills. About 25, 000 feet of Prote rozoic (Windermere) and Lower Cambrian
strata can be correlated in some detail from Rocky to Cari boo Mountains. The precision of the correl ation, based partly on lithologic similarities , depends primarily on the obvious equivalence of the fossiliferous Lower Cambrian carbonate (Mural Formation) in each sequence. The stratigraphy above
the Lower Cambrian diffe rs sharply from one side of the Trench t o the other. In Rocky Mountains a carbonate-shale Cambra-Ordovician sequence, much like that at Mount Robson, becomes shaly near the Trench where overlying Silurian strata include volcanic rocks. The Upper Devonian to Permian and
Mesozoic sedimentary rocks of the Front Range and Foothills are similar to those of the well-known Jasper-Banff region. West of the Trench, Lower Cambrian beds pass upward t o a Middle (?) and Upper Cambrian shale sequence that is unconforrnably overlain by Lower Devonian and(?) younger sedimentary
rocks w hich in turn lie dis co rdantly below conglomerate and basaltic pillow lava at l eas t partly of Lower Mississippian age. These are followed by unconforrnably overlying Uppe r Triassic (?) phy llite and shale. The Uppe r Triassic and Lowe r Jurassic volcanic rocks of the Inte rior Plateau
are just west of the map-area. Minor dykes and sills and a small body of serpentinite are the only known intrusive rocks in the map-area. Typical Rocky Mountain thrust faults are confined to the eastern Main Ranges, Front Ranges, and Foothills. Farther we st in Rocky Mountains and also west of the
Trench fold ing is prominent and r ecognizable fau lts are steeply dipping. In Cari boo Mountains folds in structurally deep levels apparently grade upward to a highly faulted and little folded terrane. To date the only significant mineral production was from the gold placer and l ode d e posits
near Barkerville. The Bowron River coal d epos its have been extensively expl o r e d. Small copper showings are known near Dorne Creek.
Indicator mineral signatures of the Sisson W-Mo deposit, New Brunswick: part 2 till
Authors: McClenaghan M B , Parkhill M A , Seaman A A , Pronk A G , Averill S
A , Rice J M , Pyne M
Published: April 2014

An indicator mineral case study was carried out around the Sisson W-Mo deposit, one of the largest W deposits in the world. The work was carried out as part of the Geological Survey of Canada's (GSC) Targeted Geoscience Initiative 4 (TGI-4), a collaborative
federal geoscience program with a mandate to provide industry with the next generation of geoscience knowledge and innovative techniques that will result in more effective targeting of buried mineral deposits. This indicator mineral study is the first case study around a major W-Mo deposit in
glaciated terrain. It is also the first indicator mineral case study in any terrain to identify a broad range of indicator minerals for this deposit type, in addition to the commonly known minerals scheelite and molybdenite.
Indicator minerals for the Sisson W-Mo deposit include the primary ore minerals scheelite, wolframite, and molybdenite, as well as secondary ore minerals chalcopyrite, joseite, native Bi, bismutite, bismuthinite, galena, sphalerite, arsenopyrite, pyrrhotite, and pyrite. Indicator minerals in 10 kg
till samples clearly define glacial dispersal at least 10 km down-ice (southeast) of the deposit. The presence of coarse (0.5-2.0 mm) indicator minerals indicates proximity (<1 km) to the source. Thus, the use of heavy mineral sampling in regional exploration programs for W-Mo deposits is
recommended. A 2 km spacing of surface till samples is likely sufficiently dense to detect the glacial dispersal train from the Sisson deposit, as well as its polymetallic nature.
Geochemical and mineralogical dispersal in till from the Mount Polley Cu-Au porphyry deposit, central British Columbia, Canada
Authors: Hashmi S , Ward B , Plouffe A , Ferbey T , Leybourne M
Published: April 2014

Mount Polley Mine is an alkaline, silica-under saturated Cu-Au porphyry deposit owned by Imperial Metals Ltd. It is located 8 km southwest of Likely, within the Interior Plateau of British Columbia. This region was glaciated several times during the Quaternary
and is predominantly covered by till. This makes it an ideal site to develop drift prospecting exploration methods for detecting buried mineralization. Glaciers are dynamic, eroding bedrock, and transporting and depositing the resulting debris as till in the direction of ice movement. If a glacier
erodes mineralized bedrock, the resulting till will be enriched in elements and minerals derived from the mineralization. Porphyry mineralization and the associated alteration zones are spatially extensive, which may result in large dispersal trains in till. The objective of this research is to
characterize the geochemical and mineralogical composition of till in the Mount Polley region in order to identify key indicators of porphyry mineralization in till, benefiting future exploration for porphyry deposits in areas of thick drift cover. This research is funded by the Geological Survey of
Canada's Targeted Geoscience Initiative (TGI-4) program. Dominant ice flow in the Mount Polley region is to the northwest with an earlier west-southwestward flow. During the 2012 and 2013 field seasons, 87 till samples were collected up-ice, overlying and down-ice from the deposit based on these
flow measurements. Elements and minerals associated with the mineralization show elevated content near the deposit, which progressively decreases towards the northwest (or down-ice direction). These include copper, silver (in the 2 ?m fraction) and gold (in the 63 ?m fraction), up to 1548 ppm, 503
ppb and 90.2 ppb, respectively. Gold grain content of up to 87 grains per 10 kg is observed in the silt-fine sand fraction. In the heavy mineral concentrates (s.g > 3.2), apatite (up to 0.5%), chalcopyrite (up to 98 grains per 10 kg), and epidote (up to 90%), observed in the 0.25
- 0.5 mm fraction. Gold grain, chalcopyrite, and epidote are excellant indicators of Mount Polley mineralization. However, apatite may not be a suitable indicator of Mount Polley mineralization in till.
From virtue ethics to rights ethics: Did the Reformation pave the way for secular ethics?
Authors: Vorster Nico
Published: April 2014

In chapter four of his book, The unintended Reformation, Brad Gregory argues that ethical thinking since the 1500’s experienced a major shift in emphasis from the teleological concept of a ‘substantive morality of the good’ to liberalism’s ‘formal morality of rights’. He attributes it to the religious upheavals and ‘sociopolitical disruptions’ during the Reformation era. This article probes three elements of Gregory’s argument. Firstly, the article offers a critical assessment of Gregory’s depiction of the Reformation’s stance towards reason. It pays particular attention to the Reformation’s understanding of the effects of sin on the human being’s image of God, reason and the possibility for a shared social ethics. Secondly, this study scrutinises Gregory’s argument that the Reformation created an individualist notion of selfhood in contrast to the Roman Catholic communal notion of selfhood and thereby paved the way for modernism. Lastly, the discussion probes into Gregory’s claim that the Reformation’s ethical paradigm diverged radically from the Latin Christendom paradigm and that this contributed to the subjectivisation of ethics, by replacing a virtue ethics with a rights ethics.
Revisiting intra-arterial drug delivery for treating brain diseases or is it “déjà-vu, all over again”?
Authors: Joshi Shailendra , Ellis Jason , Emala Charles
Published: April 2014

For over six decades intra-arterial (IA) drugs have been sporadically used for the treatment of lethal brain diseases. In recent years considerable advance has been made in the IA treatment of retinoblastomas, liver and locally invasive breast cancers, but relatively little progress has been made in the treatment of brain cancers. High resting blood flow and the presence of the blood-brain barrier (BBB), makes IA delivery to the brain tissue far more challenging, compared to other organs. The lack of advance in the field is also partly due to the inability to understand the complex pharmacokinetics of IA drugs as it is difficult to track drug concentrations in sub-second time frame by conventional chemical methods. The advances in optical imaging now provide unprecedented insights into the pharmacokinetics of IA drug and optical tracer delivery. Novel delivery methods, improved IA drug formulations, and optical pharmacokinetics, present us with untested paradigms in pharmacology that could lead to new therapeutic interventions for brain cancers and stroke. The object of this review is to bring into focus the current practice, problems, and the potential of IA drug delivery for treating brain diseases. A concerted effort is needed at basic sciences (pharmacology and drug imaging), and translational (drug delivery techniques and protocol development) levels by the interventional neuroradiology community to advance the field.
Rate and reasons for elective ventilation in patients undergoing intracranial tumour surgery
Authors: Mahajan Charu , Rath Girija , Sharma Manish , Dube Surya , Rajagopalan Vanitha , Bithal Parmod
Published: April 2014

Background: Mechanical ventilation (MV) after neurosurgery is often decided by the preoperative neurological status of the patient. However, there is paucity of information regarding factors responsible for continuation of MV in these patients. This study was carried out to identify the indications and risk factors for elective ventilation after intracranial tumour surgery. Materials and Methods: A prospective observational study was carried out on consecutive adult patients who underwent elective craniotomy for tumour excision, and postoperatively required MV. Data on anaesthesia technique, duration of anaesthesia and surgery, blood loss and transfusion and volume of fluids infused were noted. Intraoperative complications like tight brain, massive blood loss, brainstem handling, cranial nerve handling, haemodynamic instability, cardiac arrhythmias, venous air embolism, electrolyte abnormality and hypothermia were also recorded. Statistical analysis was done using Strata 9.0 software. Categorical data was analysed using Chi-square test or Fisher's exact test and continuous data by Student's t-test. Results: A total of 709 patients enrolled for the study over a period of one year out of which 347 patients (48.9%) required continuation of MV during the postoperative period. The mean duration of MV was 29.7 ± 39.7 hrs. The most common causes for postoperative MV were ‘not responding to commands’ (43.2%), and neurosurgeon's advice (41.8%). The mean ICU and hospital stays were 92.2 ± 134.0 hrs and 13.8 ± 16.5 days, respectively. 47.6% of patients who required postoperative MV on neurosurgeon's advice developed complications whereas it was 33.2% for those ventilated other reasons (P < 0.05). Glasgow outcome scale (GOS) at discharge was poor in 12.4%. On multivariate analysis, intraoperative blood transfusion, tracheostomy and duration of ventilation more than 48 hrs were the independent risk factors associated with poor outcome. Conclusions: Although the neurosurgeon's advice for elective ventilation should not be ignored, but prolonged and avoidable MV may exacerbate the postoperative morbidities apart from increasing the cost of treatment. Hence, a complete understanding of intraoperative events, cerebral physiology and various factors influencing it during the perioperative period may not be overemphasised.
Anaesthetic management of patients undergoing surgery for Moyamoya disease – our institutional experience
Authors: Sharma Vivek , Prabhakar Hemanshu , Rath Girija , Bithal Parmod
Published: April 2014

Background: Moyamoya disease (MMD) is a chronic cerebrovascular disorder, defined as the progressive stenosis or occlusion of the intracranial vessels. Because of the insecure cerebral circulation, these patients represent an anaesthetic challenge. Literature is scarce on the anaesthetic management of MMD, especially from the Indian subcontinent. The main objective of our study was to evaluate the peri-operative course and outcome of patients undergoing surgery for MMD. Materials and Methods: We analysed available medical records of all patients who underwent revascularisation surgeries for MMD over a period of 10 years (January 2002 to June 2012). Various intra- and post-operative data related to anaesthesia were recorded. The patients for the analysis were divided into two groups: Group 1, paediatrics (<18 years) and group 2, adults (≥18 years). Data are presented as number (%) or mean ± SD or median (range). Results: There were 36 patients (12 adults and 24 children). Normotension, normovolaemia, normo- or mild-hypercapnia and normothermia were maintained in all patients. No patient developed complications or new neurological deficit in the post-operative period. All patients were discharged with a full Glasgow coma scale (GCS) and no new neurologic deficit. Conclusion: Although the incidence of MMD is not high in India, it is an important cause of cerebral stroke in children and adults. Proper pre-operative evaluation is the most effective method to achieve good results. Anaesthetic management of MMD should focus on the maintenance of adequate cerebral blood flow and cerebral perfusion pressure ensuring adequate cerebral oxygenation to avoid ischaemic complications.
An attempt at estimating Paris area CO2 emissions from atmospheric concentration measurements
Authors: Bréon F. M. , Broquet G. , Puygrenier V. , Chevallier F. , Xueref-Rémy I. , Ramonet M. , Dieudonné E. , Lopez M. , Schmidt M. , Perrussel O. , Ciais P.
Published: April 2014

Abstract. Atmospheric concentration measurements are used to adjust the daily to monthly budget of CO2 emissions from the AirParif inventory of the Paris agglomeration. We use 5 atmospheric monitoring sites including one at the top of the Eiffel tower. The atmospheric inversion is based on a Bayesian approach, and relies on an atmospheric transport model with a spatial resolution of 2 km with boundary conditions from a global coarse grid transport model. The inversion tool adjusts the CO2 fluxes (anthropogenic and biogenic) with a temporal resolution of 6 h, assuming temporal correlation of emissions uncertainties within the daily cycle and from day to day, while keeping the a priori spatial distribution from the emission inventory. The inversion significantly improves the agreement between measured and modelled concentrations. However, the amplitude of the atmospheric transport errors is often large compared to the CO2 gradients between the sites that are used to estimate the fluxes, in particular for the Eiffel tower station. In addition, we sometime observe large model-measurement differences upwind from the Paris agglomeration, which confirms the large and poorly constrained contribution from distant sources and sinks included in the prescribed CO2 boundary conditions These results suggest that (i) the Eiffel measurements at 300 m above ground cannot be used with the current system and (ii) the inversion shall rely on the measured upwind-downwind gradients rather than the raw mole fraction measurements. With such setup, realistic emissions are retrieved for two 30 day periods. Similar inversions over longer periods are necessary for a proper evaluation of the results.
Uptake of phytodetritus by benthic foraminifera under oxygen depletion at the Indian margin (Arabian Sea)
Authors: Enge A. J. , Witte U. , Kucera M. , Heinz P.
Published: April 2014

Abstract. Benthic foraminifera in sediments on the Indian margin of the Arabian Sea, where the oxygen minimum zone (OMZ) impinges on the continental slope, are exposed to particularly severe levels of oxygen depletion. Food supply for the benthic community is high but delivered in distinct pulses during upwelling and water mixing events associated with summer and winter monsoon periods. In order to investigate the response by benthic foraminifera to such pulsed food delivery under oxygen concentrations of less than 0.1 mL L−1 (4.5 μmol L−1), an in situ isotope labeling experiment (13C, 15N) was performed on the western continental slope of India at 540 m water depth (OMZ core region). The assemblage of living foraminifera (>125 μm) in the uppermost centimeter at this depth is characterized by an unexpectedly high population density of 3982 individuals 10 cm−2 and a strong dominance by few calcareous species. For the experiment, we concentrated on the nine most abundant taxa, which constitute 93% of the entire foraminiferal population at 0–1 cm sediment depth. Increased concentrations of 13C and 15N in the cytoplasm indicate that all investigated taxa took up labeled phytodetritus during the 4 day experimental phase. In total, these nine species had assimilated 113.8 mg C m−2 (17.5% of the total added carbon). Uptake of nitrogen by the three most abundant taxa (Bolivina aff. B. dilatata, Cassidulina sp., Bulimina gibba) was 2.7 mg N m−2 (2% of the total added nitrogen). The response to the offered phytodetritus varied largely among foraminiferal species with Uvigerina schwageri being by far the most important species in short-term processing, whereas the most abundant taxa Bolivina aff. B. dilatata and Cassidulina sp. showed comparably low uptake of the offered food. We suggest the observed species-specific differences are related to species biomass and specific feeding preferences. In summary, the experiment in the OMZ core region shows rapid processing of fresh phytodetritus by foraminifera under almost anoxic conditions. The uptake of large amounts of organic matter by few species within four days suggests that foraminifera may play an important role in short-term carbon cycling in the OMZ core region on the Indian margin.
Implications of incorporating N cycling and N limitations on primary production in an individual-based dynamic vegetation model
Authors: Smith B. , Wårlind D. , Arneth A. , Hickler T. , Leadley P. , Siltberg J. , Zaehle S.
Published: April 2014

Abstract. The LPJ-GUESS dynamic vegetation model uniquely combines an individual- and patch-based representation of vegetation dynamics with ecosystem biogeochemical cycling from regional to global scales. We present an updated version that includes plant and soil N dynamics, analysing the implications of accounting for C–N interactions on predictions and performance of the model. Stand structural dynamics and allometric scaling of tree growth suggested by global databases of forest stand structure and development were well reproduced by the model in comparison to an earlier multi-model study. Accounting for N cycle dynamics improved the goodness of fit for broadleaved forests. N limitation associated with low N-mineralisation rates reduces productivity of cold-climate and dry-climate ecosystems relative to mesic temperate and tropical ecosystems. In a model experiment emulating free-air CO2 enrichment (FACE) treatment for forests globally, N limitation associated with low N-mineralisation rates of colder soils reduces CO2 enhancement of net primary production (NPP) for boreal forests, while some temperate and tropical forests exhibit increased NPP enhancement. Under a business-as-usual future climate and emissions scenario, ecosystem C storage globally was projected to increase by ca. 10%; additional N requirements to match this increasing ecosystem C were within the high N supply limit estimated on stoichiometric grounds in an earlier study. Our results highlight the importance of accounting for C–N interactions in studies of global terrestrial N cycling, and as a basis for understanding mechanisms on local scales and in different regional contexts.