bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Structural Inheritance Phenomenon at Producing the Al-Mg System Alloys
Authors: Nikitin Konstantin V. , Nikitin Vladimir I. , Chernikov Dmitrij
Published: February 2016

The prototype flat section ingots have been obtained by means of immersion casting from aluminum alloys of Al-Mg system. It is established that magnalium modification by ligature additives AlS 2.4 on the basis of introduction amount of 0.02% Sc in mass contributes to the strain degree increase at cold rolling without intermediate annealing.
Influence of Temperature, Strain Rate, and Sheet Thickness on the Deformation Behaviour of Twin-Roll Cast, Rolled and Heat-Treated AZ31 under Uniaxial Loading
Authors: Berge Franz , Wollschläger Markus , Krbetschek Christina , Ullmann Madlen
Published: February 2016

The influence of temperature, strain rate, and sheet thickness on the mechanical properties of twin-roll cast, rolled and heat-treated AZ31 was investigated under tensile loading from different directions (0°, 90°). To assess the forming behaviour of different sheet thicknesses (0.6 mm, 1 mm), tensile tests were performed with an electromechanical testing device between 20 °C and 300 °C at strain rates of 10−4 s−1 and 10−2 s−1. With rising temperature, the flow stress decreased while the elongation to failure (A80) increased, which may be related to the enhanced dislocation motion and the activation of additional nonbasal slip systems at T > 200 °C. It can be seen that the anisotropy of flow stress and elongation to failure was influenced by the temperature, the strain rate, and the sheet thickness.
Stress-Corrosion Defects Fatigue Development in Compressor Station Output Gas Pipeline
Authors: Scherbo I.V. , Kholodkov S.A. , Afanasyev A.V. , Vaskov M.I.
Published: February 2016

This article examines the influence of operational factors on the development of stress-corrosion defects in accordance with the statistics of its detection on different parts of the gas transportation industry equipment. Results of the operational mode analysis and research samples of stress corrosion cracking of the compressor stations output pipeline are given. Results of X-ray microanalysis of the products of corrosion and cracking of the metal in the zone are shown.
Fabrication of Al-AlN Nanocomposites
Authors: Amosov Aleksandr P. , Titova Y.V. , Timoshkin I.Y. , Kuzina Antonina A.
Published: February 2016

A review of the methods of obtaining and properties of aluminum matrix composites, discretely reinforced with ceramic particles and nanoparticles of aluminum nitride AlN, is given. The survey shows that at low weight, nanocomposites Al-AlN possess improved physical and mechanical properties, including at high temperatures up to 400-550°C, which makes them very attractive for applications in automotive, aerospace and semiconductor technology. However, due to the long duration and energy consumption, expensive and complicated equipment, low productivity of existing solid-phase methods of powder metallurgy and liquid-phase metallurgical processes of fabrication of nanocomposites of Al-AlN, there are not yet the mastered technologies of industrial production of these composites. Azide technology of self-propagating high-temperature synthesis (SHS-AZ) using sodium azide NaN3 as a solid nitriding reagent allows you to get relatively inexpensive nanopowder of aluminum nitride in the form of nanofibers along with side salt of cryolite Na3AlF6, which can play the role of flux when working with molten aluminum. A new simple ex-situ method of introduction of AlN particles in the molten aluminum alloy in the form of a composite master alloy obtained by fusing together a flux carnallite KCl·MgCl2 with AlN nanopowder mixed with cryolite Na3AlF6 was proposed. Results of experiments on the application of the proposed method for obtaining nanocomposite with matrix made of aluminum-magnesium alloy AlMg6 containing up to 1 % of the reinforcing phase AlN are presented.
Obtaining Nanopowder Pseudo-Ligatures Al-(SiC+Si3N4) for Modification of Aluminum Alloys
Authors: Kuzina Antonina A. , Kuts Anna V.
Published: February 2016

It was investigated the mechanical mixing and compacting briquettes of aluminum powder (particle size 75...250 μm) and nanopowder modifier SiC+Si3N4 (particle size 70...100 nanometers), obtained by the azide technology SHS. The mixtures containing 2.5%, 5%, 10%, 15% of the modifier were investigated. Mechanical mixing was carried out during 60 minutes in planetary mill «Pulverizette-5». Some physic-technological properties of the obtained powder mixtures, such as, particle size distribution, density, bulk weight and flowability, are determined. The powder compositions pressing was carried out on hydraulic press PSU-50 with pressure 25...90 MPa. Nanopowder pseudo-ligatures of 18 mm diameter, height to 4.6 mm, weighing 2.5 grams, with relative density 77...93%, intended for subsequent input in aluminum melt with the aim of modification are obtained.
Recovery Technology Features of Aerospace Parts by Layering Synthesis
Authors: Smelov V.G. , Sotov A.V. , Agapovichev A.V.
Published: February 2016

In this article, the method of the recovery process of aerospace parts developed. The methodology consists in selecting of multivariate iterative process parameters. Using this methodology can significantly reduce the technological preparation time of production and the proportion of experimental research. Researches of repair annular surfaces pins of gas turbine engine were conducted in order to confirm the developed technique. Appearance reconstructed surfaces studied macro-and microstructural analysis was carried out, as the microhardness of the cross-section thin section cladding measured.
Metal-Polymer-Metal Laminates for Lightweight Application
Authors: Palkowski Heinz , Carradò Adele
Published: February 2016

In the last decade, wide research was carried out on developing light-weight materials with improved mechanical properties, for instance comparable specific stiffness and strength, improved isolation, superior vibration and sound damping properties. To satisfy the increasing demands, Metal-Polymer-Metal Laminates have been numerously developed. Here, a short background of composites structures is presented.
Study of Stress Relaxation for 5056 Alloy in Vacuum Conditions
Authors: Yushin Valentin Dmitrievich , Tregub Valery Ivanovich , Voronin Sergey V.
Published: February 2016

The aim of the presented work is to establish relationship of behavior of stress relaxation process in 5056 alloy in vacuum conditions for stress levels of 116 MPa, 83 MPa and 50 MPa and temperatures of 293 K and 353 K. Method of circular specimens with equal flexural strength was used as the main method for stress relaxation testing. Results of the studies allowed to develop the advanced methodology for evaluation of stress relaxation, which increases measurement accuracy up to 0.04 MPa. Increase of accuracy was achieved using the proposed new shape of a specimen of equal flexural strength, its manufacturing technology and developed design of accessories for precision marking. It was established that for studied temperatures stress relaxation in vacuum is occurring more intensively independently from level of initial stress. That fact can be explained by increase of influence of dislocation mechanism on stress relaxation. The results of the presented studies serve as a basis for increase of reliability and consistency of dimensions of elements of aircraft's structure and their parts and components, which are operating in vacuum conditions.
A New Method of Metallic Alloys Producing with Interphases, which are Formed Coherent Coupling of Compounds’ Atoms
Authors: Mikheev V.A. , Doroshko G.P.
Published: February 2016

A new method of producing metallic alloys with interfacial boundaries formed by the coherent superposition of atoms is based on the internal temperatures of the chemical combination in which substances form a single material. It is based on the theory of thermal analysis through the formation of the Association of the two alternative methods of DTA+IDS studies of the properties of the material.
Study of Possibility of Obtaining Nanopowder Composition of "Aluminum Nitride – Boron Nitride" by Azide SHS Technology
Authors: Shiganova Ljudmila , Bichurov George , Kerson Irina , Novikov Vladislav A. , Amosov Aleksandr P.
Published: February 2016

Processes and products of combustion of systems of "sodium azide – aluminum and boron halides " are studied. Halide salts AlF3, Na3AlF6, KBF4 and NH4BF4 are used as precursors of Al and B elements. The measured combustion temperature is in the range from 900 to 1800°C. It is established that the end product of combustion synthesis consists of several phases, not only the target phases (AlN and BN), but also the by-products (Na3AlF6, К2NaAlF6, NaF, KF), part of which is removed by water washing. The composite powder of AlN-BN is formed only in the case of AlF3 as precursor of Al; in doing so, it is formed with side, impurity product К2NaAlF6 or Na3AlF6. In the case of precursor Na3AlF6, the washed product of SHS may only be a by-product К2NaAlF6 or Na3AlF6 or along with the by-product, it may contain AlN or BN, but not their composition. That is explained by different combustion temperature.The structure formation of the composite powder is investigated. The obtained agglomerated nitride nano- and micropowders have an irregular and predominantly acicular shape with an average particle size of 50-170 nm in the agglomerates.
Characterization Analytic Method Specifying the Steel X10CRNITI18-10 Cylinder Surface Layer Quality Hardened by a Traveling Sphere
Authors: Abulkhanov Stanislav Rafaelevich , Skuratov Dmitrii Leonidovich , Shvetcov Aleksei Nicolaevich
Published: February 2016

A traveling sphere by an elastic cylinder surface boundary problem is considered. At a contact zone the friction force and adhesive bond areas are supposed. The received solution enabled to estimate a plastic deformation area. The experimental and calculation data comparison found the acceptable accuracy of plastic deformation depth estimation. The devised methodology makes it possible to estimate the radius joining points depth of the plastic deformation by sphere.
Influence of 3104 Alloy Microstructure on Sheet Performance in Ironing Aluminum Beverage Cans
Authors: Andrianov A.V. , Kandalova E.G. , Aryshensky E.V. , Grechnikova A.F.
Published: February 2016

This paper studied sizes and distribution of Fe-containing constituents in 3104 ingots, their breakage during subsequent rolling and the resultant influence on the final gauge sheet performance in ironing beverage cans. It was observed that coarse Fe-containing constituents had retained on the sheet surface from the ingot scalped by 7 mm per rolling face. They broke up during rolling by 7.5 times and mostly in reversing mill, but they still were coarse on the final gauge sheet that caused pitting formation on can side walls during ironing at body makers. The microstructure of the sheet rolled from 20 mm scalped ingot was fine and did not contain constituents over 20 μm in size that resulted in its robust performance at body makers. It was shown that Fe-containing constituents were extremely critical for the sheet microstructure and its subsequent ironing performance at body makers. The ingot scalping depth should be determined based on their sizes and distribution below the rolling faces to avoid coarse constituent remains on the sheet surface.
An Industrial and Sociological Research of Consumers Requirements to a Lathing Tool
Authors: Ostapenko M.S. , Vasilega D.S.
Published: February 2016

Within the frameworks of the development of the methodology of a lathing tool quality evaluation and rating of consumers requirements to the lathing tool they have conducted an analysis of a lathing tool market. They developed and realized procedures “An analysis of risks in case of disestablishment of a lathing tool from a market” and “Formation of consumers requirements list to the lathing tool. As a result of this they established basic consumer requirements and evaluated a level of their necessity.
Development of FMEA Method with the Purpose of Quality Assessment of Can Stock Production
Authors: Klochkov Yurij , Its Alena , Vasilieva Irina
Published: February 2016

Existing methods of quality assessment of flat products are not sufficiently effective: they can be used for technological process management with certain limitations. Our research suggests an improved approach to the calculations of priority number of risks. The new suggested approach will allow risk assessment of dependent undesired events.
Testing of Thin-Walled Tubular Workpieces
Authors: Simagina S.G.
Published: February 2016

In accordance with the Russian Federation State program called “Industrial growth and improving competitiveness” it becomes more wide-spread to use thin-walled makes for pieces, modern materials with new treating methods in mechanical engineering, in automobile production and modern aviation industry. As well as requirements for quality and mechanical characteristics of finished products constantly grow. In relation to these standards, methods of intensive irreversible deformation under conditions of complex stressed state are used with increasing frequency. Study of the following parameters has a great practical importance: loaded capability of the makes during exploitation and work material strength performance under complex production process. Such strain tasks are frequently counted as most complex and demand experimental verification because of geometric and physical task nonlinearity.The current study proposes testing method for thin-walled tubular workpieces which combines implementation simplicity with a wide range of strain-stressed state charts.
Pulse-Magnetic Processing of Materials - Development - Problems and Solution Techniques
Authors: Glushchenkov Vladimir
Published: February 2016

The paper describes main directions of application of pulse magnetic fields in the technological purposes which (directions) are developed at Samara State Aerospace University. In addition to the traditional application of pulse-magnetic processing in blank-stamping production, the paper presents new directions of action of the pulse-magnetic field on the melt, hybrid and combined technologies, changes in properties of metals, special technologies of space, deep-sea, metallurgical and oil purpose. The paper is illustrated with examples of technological application of the pulse-magnetic field in these areas.
The Parameters of the Stress State in the Operations of Plastic Deformation
Authors: Sosenushkin Evgeny N. , Kadymov Vagid A. , Yanovskaya Elena A. , Tatarencev Andrey A. , Sosenushkin Aleksandr E.
Published: February 2016

The invariant characteristics of stress state arising on the sheet metal forming operations are considered. Using the trigonometric presentation of stresses, the stress state is constructed. In this case the trajectories of principal stresses are presented by the help of the arcs of circles, that confirms the nonmonotonicity of the processes of deformation.
Influence of Temperature and Loading Rate on the Forming Limit Behaviour of Twin-Roll Cast, Rolled and Heat-Treated AZ31 as a Function of the Stress State
Authors: Berge Franz , Henseler Thorsten , Krbetschek Christina , Ullmann Madlen , Kawalla Rudolf
Published: February 2016

Magnesium and its alloys have high potential for lightweight applications in the automotive and aerospace industries. In order to design parts for new applications with optimized mechanical properties and higher, more economic production rates, the forming limit behaviour of thin sheets (t < 1.0 mm) has to be known for different temperatures and loading rates. In this study, forming limit curves of 0.8 mm thick AZ31 sheet were measured for deformation at 200 °C and 250 °C and at loading rates of 1 mm/s and 10 mm/s with the Nakajima test. The investigations showed that an increase in temperature from 200 °C to 250 °C tends toward higher forming limit values for all stress states. In contrast, an increase in the loading rate from 1 mm/s to 10 mm/s induces a reduction in formability. It can be seen that the temperature, loading rate, and stress state influence the force-distance curves, the distribution of the local major strains, and the sheet thickness reduction.
The Study of Plastic Deformation at High Strain Rates in Upset Forging of Cylinders
Authors: Grechnikov Fedor V. , Khaimovich Alexander I.
Published: February 2016

This paper presents a method for acquiring true stress–strain curves using engineering strain curves obtained from upset forging of cylindrical specimens. The main problem deals with determination the true strain in upset hot forging on hummers when the values of strain rates are differ in the range from 0 to 10-3s. At such strain rates due to wave processes strain distribution in cylindrical specimen will be uneven. The purpose of this publication is to analytically determine the strain distribution in compressed cylindrical specimen.
Influence of Deformation Conditions on the Microstructure and Formability of Sintered Mg-PSZ Reinforced TRIP-Matrix-Composites
Authors: Guk Sergey , Milisova Diana , Pranke Katja
Published: February 2016

The present technical work reports on the formability and related behaviour of components during hot rolling of metal matrix composites (MMC) produced from powder. A new metal matrix composite based on TRIP (Transformation Induced Plasticity) austenitic steel AISI304 with varying amounts (10% and 20%) of homogeneously embedded zirconium dioxide (partially stabilized with Mg (Mg-PSZ)) was investigated by means of compression tests and rolling of wedge shaped samples at temperature of 900°C and 1100°C. Two different particle size distributions of Mg-PSZ powder were investigated: fine and coarse. Based on the experimental results, the deformation behaviour (arc of contact length, roll gap ratio, strain, strain rate), the microstructure evaluation (pore amount and their cross sectional area) and the formability (equivalent fracture strain) under different stress state conditions had been analyzed.
Biomedical Implants and Tissues: Status and Prospects
Authors: Husain Hadiya , Ahmad Riaz
Published: February 2016

Treatments in healthcare utilizing implants, grafts, carriers and scaffolds divulge conspicuous and dire need of perfectly complementary materials which opens new vistas for research and other exploration in this field. The vast array and assemblage of various combinations of biomaterials have evinced immaculate promising applications in healthcare sector without excluding the fact that suitability and intricacy of the constructs is equally significant. This manuscript is an attempt to sort out the agglomeration of biomaterials as well as to provide a more explicit manifestation of the eminent giant leaps in the biomedical applications. Shortage of human organs essential for liver transplantation has led to the explorations in the tissue engineering arena. This manuscript specifically highlights most of the pertinent developments in the vicinity of liver tissue engineering utilizing polymers and composites. Tissue engineered products having live cells are less susceptible to immune rejection. Hence, this potent phenomenon which utilizes scaffolds of biomaterials has been discussed here thoroughly.
Green Analytical Methods in Analysis of Aflatoxins
Authors: Ali Sana
Published: February 2016

The detection and determination of aflatoxins at nanogram level is important from human health point of view. Aflatoxins exhibit acute toxicity demonstrating teratogenic, mutagenic and carcinogenic effects. Amongst the available aflatoxins, B1, B2, G1, G2, M1 and M2 have been the more frequently analysed aflatoxins by chromatographic, spectroscopic and immuochemical methods. Because of the presence of aflatoxins at trace level in food and feedstuff used for human and animal consumption, new analytical methods have been designed for sensitive and selective detection and quantification of aflatoxins. Each of the employed analytical methods, described herein, such as thin layer chromatography, high performance liquid chromatography, gas chromatography and immunochemical methods, among others, has inherent merits and demerits in aflatoxins analysis. This chapter critically examines each of the analytical methods currently in use in the analysis of aflatoxins. Deviating from the earlier approaches, this chapter focuses on the need of methodologies that have negligible environmental impact. Though most of the existing methods are highly sensitive and reasonably safer to use but still there is the need of development of new green methodologies focusing on the reduction of solvent consumption, replacement of environmentally hazardous solvents with more benign alternatives, miniaturization of instrumentation and solvent-free sample preparation.
Lead Poisoning – The Roman Scenario and Today’s World
Authors: Sharma S.D. , Sharma Charu
Published: February 2016

Lead Poisoning is unfamiliar to most of the people although it is still a potent industrial disease. A new explanation for the fall of Rome, based on evidences such as the study of old bones, old Roman recipes and Lead lined pots for brewing poisons esteemed as delicious by the ancient Roman aristocrats, is given. It is concluded that decline and eventual fall of the Roman Empire was a net result of many causes and not the Lead Poisoning alone, as generally believed. It is also a mistaken belief that Lead Poisoning was an occupational hazard. Lead alkyls used in Gasoline are environmental poisons subtly poisoning human populations globally. Inspite of strict regulations for removing most of the lead in gasoline, food cans, glazes, paints and medicines, it will continue to poison the mankind and earth’s biosphere to a significant extent for a long time.
Electrical Conductivity, Dielectric, Modulus and Optical Studies of Ag2SO4 and TiO2 Composite Solid Electrolytes
Authors: Iqbal Mohd Zafar , Rafiuddin
Published: February 2016

Composite solid electrolytes of the molecular formula (1-x) Ag2SO4 and x TiO2 have been prepared by solid state reaction method. The prepared materials were characterized by various techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric-diffrential thermal analysis (TG-DTA) and scanning electron microscopy (SEM). A sharp increase of conductivity was found in the Arrhenius plot at 693 K due to the β →α phase transition, which is slowed down with the addition of TiO2 particles. The composition x=0.3 shows the maximum conductivity σ = 12.31 S cm-1 at 500 °C. The temperature dependent modulus values involve single type of conduction mechanism over the entire range of temperatures. The optical band gap energy for the pure Ag2SO4 is found to be 4.79 eV, which has decreased with the amount of TiO2 contents because of the defects and changes in local lattice symmetry of the composites.
Fabrication, Characterization and Cytotoxicity of Guar Gum/Copper Oxide Nanocomposite: Efficient Removal of Organic Pollutant
Authors: Sharma Gaurav , Katwal Rishu , Sharma Gaurav
Published: February 2016

Gaur gum/copper oxide (GG/CuO) nanocomposite was synthesized using sol-gel method. GG/CuO nanocomposite was characterized by techniques such as ultraviolet-visible (UV-visible) spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermo gravimetric analysis (TGA/DTA), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). TEM analysis revealed the size of the GG/CuO nanocomposite particles in the range of 20-50 nm. GG/CuO nanocomposite was used for degradation of malachite green dye under different conditions.The degradation of MG dye was recorded 89% under irradiationtime of 180 min. The antimicrobial activity of GG/CuO was also ascertained against S. aureus. The GG/CuO nanocomposite was non-toxic for the CHO-K1 cells, oral cancer cells KB and rat glioma C6 cells.
Isolation and Identification of a Flavone Apigenin from Marine Red Alga Acanthophora spicifera with Antinociceptive and Anti-Inflammatory Activities
Authors: Shoubaky Gihan A. El , Abdel-Daim Mohamed M. , Mansour Mohamed H. , Salem Essam A.
Published: February 2016

Physicochemical investigation of the red alga Acanthophora spicifera (Vahl) Borgesen, collected from Al-Shoaiba coast, Red Sea, Saudi Arabia, led to the isolation of a flavone from the algal tissue with acetone. Preparative chromatography on silica gel thin-layer chromatography was used for the separation of the flavone and eluted with the methanol:chloroform:ethyl acetate (1:7:2) solvent system. The physicochemical analyses infrared, mass spectra, and ultraviolet spectra in addition to shift reagents (NaOMe, NaOAc, NaOAc + H3BO3, AlCl3, and AlCl3 + HCl) were used for the identification and elucidation of the structure of the flavone compound (4,5,7-trihydroxy flavonoids). The flavone compound was identified as apigenin bycomparing its physicochemical data with those in the literature. Analgesic and anti-inflammatory activities of apigenin were evaluated. Apigenin showed promising analgesic and anti-inflammatory activities in the hot plate test and writhing test in mice as well as tail-immersion tests and carrageenan-induced paw edema and cotton pellet-induced granuloma formation in rats. It is concluded that apigenin possesses potent analgesic, anti-inflammatory, and antiproliferative activities, which might be due to the inhibition of PGE2 as well as proinflammatory cytokines such as interleukin-1β, interleukin-6, and tumor necrosis factor- α.
The Effect of Research Compensation in the Form of Cheques on Gamblers' Cash-in Behaviour
Authors: Cantinotti Michael , Leclerc Bernard-Simon , Brochu Priscilla , Jacques Christian , Sévigny Serge , Giroux Isabelle
Published: February 2016

A view that is commonly held by Research Ethics Board members is that offering money as research compensation has the potential to unduly influence or even coerce subjects into participating in studies. Because money is the core resource of gambling activity, gamblers with financial needs might show an increased propensity to take part in research that offers financial compensation. We hypothesized that pathological gamblers at electronic gambling machines in venues outside of casinos would tend to cash in their compensation cheque faster than non-pathological gamblers would. The current results support this hypothesis. It is therefore necessary to understand gamblers' motivations related to research activities and the ways in which the research context can sustain rational decision making when gamblers consider taking part in scientific studies.
Four-year long-path monitoring of ambient aerosol extinction at a central European urban site: dependence on relative humidity
Authors: Skupin A. , Ansmann A. , Engelmann R. , Seifert P. , Müller T.
Published: February 2016

Abstract. The ambient aerosol particle extinction coefficient is measured with the Spectral Aerosol Extinction Monitoring System (SÆMS) along a 2.84 km horizontal path at 30–50 m height above ground in the urban environment of Leipzig (51.3° N, 12.4° E), Germany, since 2009. The dependence of the particle extinction coefficient (wavelength range from 300 to 1000 nm) on relative humidity up to almost 100 % was investigated. The main results are presented. For the wavelength of 550 nm, the mean extinction enhancement factor was found to be 1.75 ± 0.4 for an increase of relative humidity from 40 to 80 %. The respective 4-year mean extinction enhancement factor is 2.8 ± 0.6 for a relative-humidity increase from 40 to 95 %. A parameterization of the dependency of the urban particle extinction coefficient on relative humidity is presented. A mean hygroscopic exponent of 0.46 for the 2009–2012 period was determined. Based on a backward trajectory cluster analysis, the dependence of several aerosol optical properties for eight air flow regimes was investigated. Large differences were not found, indicating that local pollution sources widely control the aerosol conditions over the urban site. The comparison of the SÆMS extinction coefficient statistics with respective statistics from ambient AERONET sun photometer observations yields good agreement. Also, time series of the particle extinction coefficient computed from in situ-measured dry particle size distributions and humidity-corrected SÆMS extinction values (for 40 % relative humidity) were found in good overall consistency, which verifies the applicability of the developed humidity parameterization scheme. The analysis of the spectral dependence of particle extinction (Ångström exponent) revealed an increase of the 390–881 nm Ångström exponent from, on average, 0.3 (at 30 % relative humidity) to 1.3 (at 95 % relative humidity) for the 4-year period.
Contribution of ship emissions to the concentration and deposition of air pollutants in Europe
Authors: Aksoyoglu Sebnem , Baltensperger Urs , Prévôt André S. H.
Published: February 2016

Abstract. Emissions from the marine transport sector are one of the least-regulated anthropogenic emission sources and contribute significantly to air pollution. Although strict limits were introduced recently for the maximum sulfur content in marine fuels in the SECAs (sulfur emission control areas) and in EU ports, sulfur emissions outside the SECAs and emissions of other components in all European maritime areas have continued to increase in the last two decades. We have used the air quality model CAMx (Comprehensive Air Quality Model with Extensions) with and without ship emissions for the year 2006 to determine the effects of international shipping on the annual as well as seasonal concentrations of ozone, primary and secondary components of PM2.5, and the dry and wet deposition of nitrogen and sulfur compounds in Europe. The largest changes in pollutant concentrations due to ship emissions were predicted for summer. Concentrations of particulate sulfate increased due to ship emissions in the Mediterranean (up to 60 %), the English Channel and the North Sea (30–35 %), while increases in particulate nitrate levels were found especially in the north, around the Benelux area (20 %), where there were high NH3 land-based emissions. Our model results showed that not only are the atmospheric concentrations of pollutants affected by ship emissions, but also depositions of nitrogen and sulfur compounds increase significantly along the shipping routes. NOx emissions from the ships, especially in the English Channel and the North Sea, cause a decrease in the dry deposition of reduced nitrogen at source regions by moving it from the gas phase to the particle phase which then contributes to an increase in the wet deposition at coastal areas with higher precipitation. In the western Mediterranean region, on the other hand, model results show an increase in the deposition of oxidized nitrogen (mostly HNO3) due to the ship traffic. Dry deposition of SO2 seems to be significant along the shipping routes, whereas sulfate wet deposition occurs mainly along the Scandinavian and Adriatic coasts. The results presented in this paper suggest that evolution of NOx emissions from ships and land-based NH3 emissions will play a significant role in future European air quality.
An empirical method to correct for temperature dependent variations in the overlap function of CHM15k ceilometers
Authors: Hervo Maxime , Poltera Yann , Haefele Alexander
Published: February 2016

Abstract. Imperfections in a lidar's overlap function lead to artefacts in the background, range and overlap corrected lidar signals. These artefacts can erroneously be interpreted as an aerosol gradient or, in extreme cases, as a cloud base leading to false cloud detection. A correct specification of the overlap function is hence crucial to use automatic elastic lidars (ceilometers) for the detection of the planetary boundary layer or low clouds. In this study an algorithm is presented to correct such artefacts. It is based on the assumption of a homogeneous boundary layer and a correct specification of the overlap function down to a minimum range, which must be situated within the boundary layer. The strength of the algorithm lies in a sophisticated quality check scheme which allows to reliably identify favorable atmospheric conditions. The algorithm has been applied to 2 years of data from a CHM15k ceilometer from the company Lufft. Backscatter signals corrected for background, range and overlap have been compared using the overlap function provided by the manufacturer and the one corrected with the presented algorithm. Differences between corrected and uncorrected signals reach up to 45 % in the first 300 m above ground. The amplitude of the correction turned out to be temperature dependent being larger for higher temperatures. A linear model of the correction as a function of the instrument's internal temperature has been derived from the experimental data. Case studies and a statistical analysis of the strongest gradient derived from corrected signals reveal that the temperature model is capable to correct overlap artefacts with high quality, in particular such due to diurnal variations. The presented correction method has the potential to significantly improve the detection of the boundary layer with gradient based methods because it removes false candidates and hence simplifies the attribution of the detected gradients to the planetary boundary layer. A particularly high benefit can be expected for the detection of shallow stable layers typical for nighttime situations. The algorithm is completely automatic and does not require any intervention on site but requires the definition of an adequate instrument specific configuration. It is therefore suited for the use in large ceilometer networks.
Interpretation of deformed ionograms induced by vertical ground motion of seismic Rayleigh waves and infrasound in the thermosphere
Authors: Maruyama Takashi , Yusupov Kamil , Akchurin Adel
Published: February 2016

Abstract. The vertical ground motion of seismic surface waves launches acoustic waves into the atmosphere and induces ionospheric disturbances. Disturbances due to Rayleigh waves near the short-period Airy phase appear as wavy fluctuations in the virtual height of an ionogram and have a multiple-cusp signature (MCS) when the fluctuation amplitude is increased. An extremely developed MCS was observed at Kazan, Russia, after the 2010 M 8.8 Chile earthquake. The ionogram exhibited steep satellite traces for which the virtual heights increased rapidly with frequency starting near the top of cusps and continuing for 0.1–0.2 MHz. This complicated ionogram was analyzed by applying a ray tracing technique to the radio wave propagation in the ionosphere that was perturbed by acoustic waves. Acoustic wavefronts were inclined by the effects of finite Rayleigh wave velocity and sound speed in the thermosphere. The satellite echo traces were reproduced by oblique returns from the inclined wavefronts, in addition to the nearly vertical returns that are responsible for the main trace.
Atmospheric CO2 source and sink patterns over the Indian region
Authors: Fadnavis Suvarna , Ravi Kumar K. , Tiwari Yogesh K. , Pozzoli Luca
Published: February 2016

Abstract. In this paper we examine CO2 emission hot spots and sink regions over India as identified from global model simulations during the period 2000–2009. CO2 emission hot spots overlap with locations of densely clustered thermal power plants, coal mines and other industrial and urban centres; CO2 sink regions coincide with the locations of dense forest. Fossil fuel CO2 emissions are compared with two bottom-up inventories: the Regional Emission inventories in ASia (REAS v1.11; 2000–2009) and the Emission Database for Global Atmospheric Research (EDGAR v4.2) (2000–2009). Estimated fossil fuel emissions over the hot spot region are  ∼  500–950 gC m−2 yr−1 as obtained from the global model simulation, EDGAR v4.2 and REAS v1.11 emission inventory. Simulated total fluxes show increasing trends, from 1.39 ± 1.01 % yr−1 (19.8 ± 1.9 TgC yr−1) to 6.7 ± 0.54 % yr−1 (97 ± 12 TgC yr−1) over the hot spot regions and decreasing trends of −0.95 ± 1.51 % yr−1 (−1 ± 2 TgC yr−1) to −5.7 ± 2.89 % yr−1 (−2.3 ± 2 TgC yr−1) over the sink regions. Model-simulated terrestrial ecosystem fluxes show decreasing trends (increasing CO2 uptake) over the sink regions. Decreasing trends in terrestrial ecosystem fluxes imply that forest cover is increasing, which is consistent with India State of Forest Report (2009). Fossil fuel emissions show statistically significant increasing trends in all the data sets considered in this study. Estimated trend in simulated total fluxes over the Indian region is  ∼  4.72 ± 2.25 % yr−1 (25.6 TgC yr−1) which is slightly higher than global growth rate  ∼  3.1 % yr−1 during 2000–2010.
Effects of eustatic sea-level change, ocean dynamics, and nutrient utilization on atmospheric pCO2 and seawater composition over the last 130 000 years: a model study
Authors: Wallmann K. , Schneider B. , Sarnthein M.
Published: February 2016

Abstract. We have developed and employed an Earth system model to explore the forcings of atmospheric pCO2 change and the chemical and isotopic evolution of seawater over the last glacial cycle. Concentrations of dissolved phosphorus (DP), reactive nitrogen, molecular oxygen, dissolved inorganic carbon (DIC), total alkalinity (TA), 13C-DIC, and 14C-DIC were calculated for 24 ocean boxes. The bi-directional water fluxes between these model boxes were derived from a 3-D circulation field of the modern ocean (Opa 8.2, NEMO) and tuned such that tracer distributions calculated by the box model were consistent with observational data from the modern ocean. To model the last 130 kyr, we employed records of past changes in sea-level, ocean circulation, and dust deposition. According to the model, about half of the glacial pCO2 drawdown may be attributed to marine regressions. The glacial sea-level low-stands implied steepened ocean margins, a reduced burial of particulate organic carbon, phosphorus, and neritic carbonate at the margin seafloor, a decline in benthic denitrification, and enhanced weathering of emerged shelf sediments. In turn, low-stands led to a distinct rise in the standing stocks of DIC, TA, and nutrients in the global ocean, promoted the glacial sequestration of atmospheric CO2 in the ocean, and added 13C- and 14C-depleted DIC to the ocean as recorded in benthic foraminifera signals. The other half of the glacial drop in pCO2 was linked to inferred shoaling of Atlantic meridional overturning circulation and more efficient utilization of nutrients in the Southern Ocean. The diminished ventilation of deep water in the glacial Atlantic and Southern Ocean led to significant 14C depletions with respect to the atmosphere. According to our model, the deglacial rapid and stepwise rise in atmospheric pCO2 was induced by upwelling both in the Southern Ocean and subarctic North Pacific and promoted by a drop in nutrient utilization in the Southern Ocean. The deglacial sea-level rise led to a gradual decline in nutrient, DIC, and TA stocks, a slow change due to the large size and extended residence times of dissolved chemical species in the ocean. Thus, the rapid deglacial rise in pCO2 can be explained by fast changes in ocean dynamics and nutrient utilization whereas the gradual pCO2 rise over the Holocene may be linked to the slow drop in nutrient and TA stocks that continued to promote an ongoing CO2 transfer from the ocean into the atmosphere.
Decadal evaluation of regional climate, air quality, and their interactions over the continental US and their interactions using WRF/Chem version 3.6.1
Authors: Yahya Khairunnisa , Wang Kai , Campbell Patrick , Glotfelty Timothy , He Jian , Zhang Yang
Published: February 2016

Abstract. The Weather Research and Forecasting model with Chemistry (WRF/Chem) v3.6.1 with the Carbon Bond 2005 (CB05) gas-phase mechanism is evaluated for its first decadal application during 2001–2010 using the Representative Concentration Pathway 8.5 (RCP 8.5) emissions to assess its capability and appropriateness for long-term climatological simulations. The initial and boundary conditions are downscaled from the modified Community Earth System Model/Community Atmosphere Model (CESM/CAM5) v1.2.2. The meteorological initial and boundary conditions are bias-corrected using the National Center for Environmental Protection's Final (FNL) Operational Global Analysis data. Climatological evaluations are carried out for meteorological, chemical, and aerosol–cloud–radiation variables against data from surface networks and satellite retrievals. The model performs very well for the 2 m temperature (T2) for the 10-year period, with only a small cold bias of −0.3 °C. Biases in other meteorological variables including relative humidity at 2 m, wind speed at 10 m, and precipitation tend to be site- and season-specific; however, with the exception of T2, consistent annual biases exist for most of the years from 2001 to 2010. Ozone mixing ratios are slightly overpredicted at both urban and rural locations with a normalized mean bias (NMB) of 9.7 % but underpredicted at rural locations with an NMB of −8.8 %. PM2.5 concentrations are moderately overpredicted with an NMB of 23.3 % at rural sites but slightly underpredicted with an NMB of −10.8 % at urban/suburban sites. In general, the model performs relatively well for chemical and meteorological variables, and not as well for aerosol–cloud–radiation variables. Cloud-aerosol variables including aerosol optical depth, cloud water path, cloud optical thickness, and cloud droplet number concentration are generally underpredicted on average across the continental US. Overpredictions of several cloud variables over the eastern US result in underpredictions of radiation variables (such as net shortwave radiation – GSW – with a mean bias – MB – of −5.7 W m−2) and overpredictions of shortwave and longwave cloud forcing (MBs of  ∼  7 to 8 W m−2), which are important climate variables. While the current performance is deemed to be acceptable, improvements to the bias-correction method for CESM downscaling and the model parameterizations of cloud dynamics and thermodynamics, as well as aerosol–cloud interactions, can potentially improve model performance for long-term climate simulations.
An analytical model for simulating two-dimensional multispecies plume migration
Authors: Chen Jui-Sheng , Liang Ching-Ping , Liu Chen-Wuing , Li Loretta Y.
Published: February 2016

Abstract. The two-dimensional advection-dispersion equations coupled with sequential first-order decay reactions involving arbitrary number of species in groundwater system is considered to predict the two-dimensional plume behavior of decaying contaminant such as radionuclide and dissolved chlorinated solvent. Generalized analytical solutions in compact format are derived through the sequential application of the Laplace, finite Fourier cosine, and generalized integral transform to reduce the coupled partial differential equation system to a set of linear algebraic equations. The system of algebraic equations is next solved for each species in the transformed domain, and the solutions in the original domain are then obtained through consecutive integral transform inversions. Explicit form solutions for a special case are derived using the generalized analytical solutions and are compared with the numerical solutions. The analytical results indicate that the analytical solutions are robust, accurate and useful for simulation or screening tools to assess plume behaviors of decaying contaminants.
Risk for Disability and Poverty Among Central Asians in the United States
Authors: Siordia Carlos , Ramos Athena K.
Published: February 2016

Understanding the disability-poverty relationship among minority groups within the United States (US) populations may help inform interventions aimed at reducing health disparities. Limited information exists on risk factors for disability and poverty among “Central Asians” (immigrants born in Kazakhstan, Uzbekistan, and other Central Asian regions of the former Soviet Union) in the US. The current cross-sectional analysis used information on 6,820 Central Asians to identify risk factors for disability and poverty. Data from the 2009-2013 Public Use Microdata Sample (PUMS) file from the American Community Survey (ACS) indicate that being married, non-Latino-white, and having higher levels of educational attainment are protective against disability and poverty. In contrast, older age, residing in the Middle Atlantic geographic division, and having limited English language ability are risk factors for both disability and poverty. Research should continue to develop risk profiles for understudied immigrant populations. Expanding knowledge on the well-being of Central Asians in the US may help impact public health interventions and inform health policies.
Students’ Perceptions of Life Skill Development in Project-Based Learning Schools
Authors: Meyer Kimberly , Wurdinger Scott
Published: February 2016

This research aimed to examine students’ perceptions of their life skills while attending project-based learning (PBL) schools. The study focused on three questions including: 1) What are students’ perceptions of their development of life skills in project-based learning schools? 2) In what ways, if any, do students perceive an increase in their life skill development over a one-year period of time? 3) What relationship, if any, is there between grade level and students’ perceptions of their life skills? The subjects were 275 6-12 students from two project-based learning charter schools in Minnesota. One school was located in a rural location; the other in an urban location. The triangulating data collection methods included a Likert-scale survey, semi-structured interviews, and focus groups. Quantitative analysis using SPSS were used to analyze the survey data. Qualitative analysis methods used were coding and identification of emergent themes. Qualitative results showed perceptions of most improved skills as time management, collaboration, communication, and self-directedness. Quantitative data results showed most improved skills within an academic year as responsibility, problem-solving, self-directedness, and work ethic. Self-directedness was the single skill that was evident in all data results. The results showed students’ perceptions of their life skills were positive and that project-based learning helped them develop multiple life skills including, but not limited to communication, collaboration, problem-solving, responsibility, and time management. Implications of this research suggest that project-based learning has a positive influence on students’ life skills development across 6-12 grade levels and helps prepare them to be successful in the 21st century global community and economy.
What Is Modern Periodical Studies?
Authors: Collier Patrick
Published: February 2016

It has been a decade since the launch of the of the Modernist Journals Project heralded the arrival of what might be called “modern periodical studies.” This essay ponders the degree to which work in this new field has broadened or changed our sense of early twentieth-century print culture and literary history. It focuses on the first five years of the Journal of Modern Periodical Studies as a way of gauging whether modern periodical studies has lived up to its promise of uncovering “largely unexplored ways” in which periodical publishing “shaped modernity,” to quote the journal's opening editorial. I reach a number of provisional conclusions, including that the field of periodicals under scrutiny has expanded dramatically; the imprimatur of literary modernism remains very strong in the field, limiting the degree to which modern periodical studies has expanded or provided fresh views of the literary field; and a tacit disagreement exists as to the object of knowledge in modern periodical studies, with some scholars using early twentieth-century periodicals as a means toward a fuller understanding of modernism, others using them to gain insights about modernity and culture more broadly, and a relative few using them to gain insights into how literature and print culture functioned outside the rubric of modernism. I conclude with a renewed call to make periodicals the primary object of study in ways that are not beholden to preexisting critical categories.