bluuebunny/crossref_metadata_2025 huggingface dataset:
Input Data Influence on FEM Simulation of Steam Turbine Blades Materials Hot Forming
Authors: Džugan Jan , Zemko Michal
Published: November 2013

Computer simulation/optimization is widely applied to hot forming processes nowadays. A crucial point of any kind of computer simulation is the input data. There are implemented in all FEM codes some basic material database, but usually for limited materials and material states. As the input data decide about the output results quality, it is always necessary to pay attention, what are the simulation inputs. The best solution, but not always possible, is direct measurement of materials parameters for considered material and state. As this is in some cases not possible, materials data are searched in alternative ways. One possibility is survey of published data in literature. A reliability of published data is difficult to assess, as there are usually not available sufficient information about the material investigated in publications. Other possibility how to obtain material data nowadays is utilization of programs predicting material behavior on the basis of chemical composition.
One of currently available software for material properties prediction is JMatPro. The program is able to calculate a broad range of properties and behavior with the use of established thermodynamics models on the basis of chemical composition and the initial state of the considered material state. There can be for example determined thermophysical and physical properties (from room temperature to the liquid state), time-temperature-transformation/ continuous-cooling transformation diagrams, stress/strain diagrams, proof and tensile stress, hardness, coarsening of γ and γ , and creep.
The current paper is dealing with the simulation of hot forming of steam blade made of Ti-based alloy. As an input material data used for FEM simulation are conventionally measured data and data obtained from JMatPro. With the use of both material data sets, a sample component forming is simulated. The results obtained from both simulations are subsequently compared with the results obtained from physical forming of the sample component. Performance of both simulations is discussed here, taking into account results of physical forming results.
Bondability of Dissimilar Metal Sheets by Shot Peening
Authors: Harada Yasunori , Nunobiki Masayuki
Published: November 2013

In shot peening, bombarding the surface with steel shot propelled at high velocity causes plastic deformation of surface. The process with the characteristic deformation was applied to joining process. Our approach has been applied to the butt joining of the dissimilar metal sheets. In this method, however, the joint strength was lower than the flow stress of base metal. The modified joining processing was being carried out to improve the bondability. In the present study, the joining of dissimilar metal sheets using a shot peening process was investigated to improve the bondability. In the joined section, the edge of the joint area of the sheets were slit using a laser. In this method, the edges of the sheet are overlapped the other sheet. When the connection is peened, the material undergoes large plastic deformation near the surface due to the collision of shots. In this process, particularly noteworthy is the plastic flow near surface layer. The edges of the sheet are joined to the other sheet, thus two sheets can be joined each other. In the experiment, the shot peening treatment was performed by using an air-type peening machine. The shots used were made of high carbon cast steel. Air pressure was 0.6 MPa and peening time was in the range of 30-240s. The metal sheets were commercial low-carbon steel, stainless steel, pure aluminium, aluminium alloy, and pure copper. The effects of processing conditions on the bondability were mainly examined. It was found that the present method was effective for joining of dissimilar metal sheets.
Thermal Parameter Affects on the Part Built Using 3D Printer Projet SD 3000
Authors: Ahmad Mohd Syahrir , Baharudin B.T.H.T. , Leman Zulkiflle , Ismail N. , Sulaiman Shamsuddin
Published: November 2013

The implementation of Rapid Prototyping technology in industrial and manufacturing processes has revolutionized new product development process. However, there are some restrictions of RP parts, primarily in the geometrical accuracy, shrinkage and distortion after the typical post processing method. This paper presents the experimental study using specially designed specimen to determine the effect of thermal parameter used on the RP part built using 3D printer ProJet SD 3000. The parameters of concern are geometrical dimension, shrinkage and flatness. The mechanical properties of the specimen have been determined using the tensile testing machine in order to indentify the effect of post processing temperature on the strength of the specimens. It is expected that the post processing temperature will play the major role in maintaining the geometrical accuracy of the RP products since heating used will lead to increase the shrinkage, warpage and reduce the accuracy. The effects of the heating used during post processing on the geometrical accuracy, shrinkage, strength and warpage on the specimens are discussed in this paper.
A Method to Optimize Aluminum Alloy Door Impact Beam Stamping Process Using NSGA-II
Authors: Zhou Jing , Wang Bao Yu , Fu Lei , Meng Qing Lei
Published: November 2013

The process parameters of aluminium alloy hot stamping produce an importantly effect on production forming quality. In the case of a door impact beam inside the car doors, the fi-nite-element model of aluminium alloy hot stamping is set up. Based on the model, the forming quality is investigated under usual process condition. Using the Latin hypercube method, we sampled the data points from design space of process parameters. Data points are imported into finite-element model to calculate the forming quality indices. According to their responding values, the quadratic response surfaces between process parameter inputs and forming quality indices are initialized. By optimized the response of the process parameters exercising multi-objective genetic algorithm—NSGA-II (non-dominated sorting genetic algorithm), the Pareto combinations of blank hold force and stamping velocity are obtained. Finally, by comparison with the results of stamping trial and numerical simula-tion, it is concluded that the finite-element model can be used to predict forming defects and is consistent with actual condition. Thus the optimization method is feasible.
Effect of Material Properties on the Mechanical Performance of Nitinol Esophageal Stent: Finite Element Analysis
Authors: Nematzadeh Fardin , Sadrnezhaad Sayed Khatiboleslam , Kokabi A.H. , Razani M. , Mohagheghi A.H.
Published: November 2013

Stent placement has been a main approach to treat gastrointestinal diseases during past decade. Nitinol superelastic stents have been considered as a solution to such difficulties as restenosis after implantation, low twisting ability, inadequate radial mechanical strength and inappropriate dynamic behaviors associated with the ducts. In this paper, effects of Af temperatures on mechanical performance of z-shaped Nitinol wire stent under crimping test for clinical applications are investigated by finite element simulation. Having 60% crimping and high radial resistive strength, favorable superelastic behaviors are attained at Af temperature of 22°C. The performance of the stent is seen to be drastically different with a mere change of 1° in the segments angle.
Anharmonicity Dependent Heat Conduction in One-Dimensional Lattices
Authors: Shah Shreya , Shah Tejal N. , Gajjar P.N.
Published: November 2013

The temperature profile, heat flux and thermal conductivity are investigated for the chain length of 67 one-dimensional (1-D) oscillators. FPU-β and FK models are used for interparticle interactions and substrate interactions, respectively. As harmonic chain does not produce temperature gradient along the chain, it is required to introduce anharmonicity in the numerical simulation. The anharmonicity dependent temperature profile, thermal conductivity and heat flux are simulated for different strength of anharmonicity β = 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1. It is concluded that heat flux obeys J = 0.3947 e0.553β with R2 = 0.9319 and thermal conductivity obeys κ = 0.0276 e0.5559β with R2 = 0.9319.
Study of Ac Conductivity and Dielectric Properties of PMMA with Fe2O3+ Al2O3 Composite Films
Authors: Sannakki Basavaraja , Gandhe Anita , Doddamani V.H.
Published: November 2013

Abstract. The PMMA with Fe2O3+ Al2O3 films at different weight percent have been used for measurement of dielectric properties such as dielectric constant, dielectric loss and a. c. conductivity as a function of frequency over the range 50 Hz – 5 MHz at room temperature. The dielectric constant and the dielectric loss (tan δ) of the polymer composite films decreases exponentially at lower frequencies over the range 100 Hz-1 kHz, where as above 1 kHz the values of dielectric constant remains same. But, it has been observed that the value of dielectric constant of PMMA composite films with Fe2O3+ Al2O3 increases as weight percent of Fe2O3+ Al2O3 increases. The a c conductivity of the polymer composite films remains constant over the frequency range 50 Hz to 300 K Hz and afterwards it increases exponentially. Further, PMMA with Fe2O3+ Al2O3 have been characterized using X-Ray diffractometer for the crystallinity. The morphological studies have been made using the FESEM.
Atomic Transport Properties of 3D Liquid Transition Metals Using Different Reference Systems
Authors: Thakor Pankajsinh B. , Sonvane Yogeshkumar A. , Jani Ashvin R.
Published: November 2013

Atomic transport properties like self diffusion coefficient (D), viscosity coefficient (η) of 3d liquid transition metals are studied. Here we have applied our own model potential to describe electron ion interaction with different reference system like Percus - Yevick Hard Sphere (PYHS), One Component Plasma (OCP) and Charge Hard Sphere (CHS) systems. We have investigated the effect of different correction function like Hartree (H), Vashishta-Singwi (VS), Hubbard-Sham (HS), Sarkar et al (S), Ichimaru-Utsumi(IU), Taylor (T) and Farid et al (F) on atomic transport properties. The proper choice of the model potential alongwith the local field correction function and reference system plays a vital role in the study of the atomic transport properties of 3d liquid transition metals.
Single Crystal Growth of Bi:Sb Alloys
Authors: Patel Piyush , Patel Manisha , Vyas Sandip M. , Jani Maunik P. , Pandya Girish R.
Published: November 2013

The solid-liquid interface of Bi (1-x) Sb(x) crystal growth is most favorable for investigation of electron and phonon phenomena. Bismuth is a semimetal with high electron and hole mobility. Interest in Bi-Sb material system has recently been stimulated by promise of a new generation of thermoelectric materials based on these alloy. The crystals were grown using zone melting method with 1.0 and 1.5 cm/hour growth velocity and temperature gradient 650C/cm. The surface was determinal on the basis of growth feature profiles under optical microscope. The features observed on the top-free surface of as-grown crystals have also been discussed. The crystals have been characterized by using the powder XRD technique. The optical absorption was measured in the wave number range 510 cm-1 to 4000 cm-1. From the optical absorption through direct inter band transition.The results are reported and discussed in detailed.
Effect of 100 MeV Ag+7 Ion Irradiation on Electrical Properties of Ag/La0.7Sr0.3MnO3/Ag Planar Structures
Authors: Bhavsar Komal H. , Joshi Utpal S. , Mistry Bhaumik V. , Chhaya U.V. , Khan S.A. , Avasthi D.K.
Published: November 2013

Swift heavy ion (SHI) irradiation of materials induces variety of functionalities and tenability in advance materials. Recent observations of electrical switching in perovskite oxides have triggered a lot of interest for its potential use as non volatile random access memory (NVRAM). We report on the resistance switching induced by swift heavy ion SHI irradiation in La0.7Sr0.3MnO3 (LSMO) thin films grown on SiO2 substrates by chemical solution deposition technique. Well defined hysteresis loops with sharp on-off transition in the I-V curves were observed for the sample irradiated with 100 MeV Ag+7 ions at 1x1012 ions/cm2, indicating that the sample possess low resistance state (LRS) and high resistance state (HRS). Symmetrical resistance ratio (Rhigh/Rlow) of ~ 330% at -1.7 V has been achieved whereas the pristine samples showed only linear I-V characteristics. The RS is bipolar and may be attributed to SHI induced defects in the device. Such defect induced resistive switching has recently been proposed theoretically and our results are direct evidence of the phenomenon.
Dielectric and Electrical Properties of Binary Mixtures of Anisole and 1-Heptanol in the Frequency Range 20 Hz to 2 MHz
Authors: Chaube Hemantkumar A. , Rana Vipinchandra A.
Published: November 2013

The complex relative dielectric function ε*(ω) = ε’- jε” of anisole (AN), 1-heptanol (1-HeOH) and their binary mixtures of varying concentration have been measured using Precision LCR meter in the frequency range 20 Hz to 2 MHz at 303 K. The electrical/dielectric properties of the liquid samples are represented in terms of intensive quantities namely, complex relative dielectric function ε*(ω), electrical modulus M*(ω), electrical conductivity σ*(ω) and extensive quantities, i.e. complex admittance Y*(ω) and complex impedance Z*(ω). All of these presentations are used to explore various processes contributed in the electrical/dielectric properties of the mixtures of two polar liquids.
Structural and Vibrational Properties of Manganese Sulfide
Authors: Thakore Brijmohan Y. , Vahora A.Y. , Khambholja S.G. , Jani A.R.
Published: November 2013

Structural properties of MnS have been studied using plane wave pseudopotential density functional theory as implemented in Quantum Espresso code. Local density approximation (LDA) along with ultrasoft pseudopotential has been used for total energy calculations. The calculated total energies are fitted to Murnaghan equation of state to calculate equilibrium lattice constant, isothermal bulk modulus and pressure derivative of isothermal bulk modulus for NaCl-type structure of MnS and compared with previous experimental and theoretical calculations and good agreement is achieved with those results. Phonon frequencies have also been derived for B1 phase of MnS along high symmetry directions using the density functional perturbation theory at ambient condition.
Thermal Properties of Divalent Metal Oxides: CaO as a Prototype
Authors: Bhatt Nisarg K. , Thakore Brijmohan Y. , Vyas P.R. , Vahora A.Y. , Jani Asvin R.
Published: November 2013

Commonly employed quasiharmonic approximation (QHA) is inadequate to account for intrinsic anharmonism such as phonon-phonon interaction, vacancy contribution, etc. Though anharmonic contributions are important at high temperatures and low pressure, complete ab initio calculations are scanty due largely to laborious computational requirements. Nevertheless, some simple semi-empirical schemes can be used effectively to incorporate the anharmonism. In this regards, in the present study we have proposed a simple computational scheme to include the effect of vacancy directly into the description within the mean-field potential approach, which calculates vibrational free energy of ions. Validity of the scheme is verified by taking calcium oxide as a test case. Equilibrium properties at (T,P) = (0,0) condition is obtained within the tight-binding second-moment approximation (TB-SMA), whose parameters were determined through first principles density functional theory. Kohn-Sham equations for core electrons were solved using ultrasoft plane-wave pseudopotential employing the generalized gradient approximation for exchange and correlation. Present findings for thermal expansion and high-T EOS clearly show perceptible improvement over the case when vacancy contribution was not included. Some related thermodynamic properties are also calculated and compared with the available experimental and theoretical data.
Nano Crystallite ZrO2, La2O3 and CeO2: Synthesis, Characterization and their Properties
Authors: Patel A.K. , Umatt A.R. , Chakrabarty B.S.
Published: November 2013

It is well known that a minor addition of rare earth oxides can provide a beneficial effect towards various catalytic reactions. Use of rare earth oxide in different applications could improve commercial productivity in an affordable way. Among the rare earth oxides, ZrO2, La2O3 and CeO2 are very interesting due to their various characteristics showing a large range of applications in organic reactions. The changes in the molecular properties of materials at the nano scale level greatly enhance their physical properties as well as chemical properties and activity. Due to the extremely small size of the particles, an increased surface area is provided to the reactant enabling more molecules to react at the same time, thereby speeding up the process. In this work, the enhancement in the catalytic activity of these nano structured rare earth oxides has been studied under different reaction conditions. Nano crystalline ZrO2, La2O3 and CeO2 samples were synthesized using precipitation method and optimum reaction conditions have been established; whereas the corresponding bulk samples were synthesized by combustion method. The identification of phase and crystalline size of synthesized oxides have been done by X-ray diffraction, the band gape of these three oxides in both the forms has been analyzed by UV absorbance and surface area has been determined by gas adsorption analysis (BET). Moreover their different properties and the activity of nano crystallite oxides have also been compared with their bulk counterparts. Even the activity of ZrO2 is also compared with the rare earth oxides La2O3 and CeO2.
Dielectric Spectroscopy of Dry and Wet Soils in Frequency Region from 20 Hz to 20 GHz
Authors: Gadani Deepak H. , Vyas Amar Datta , Rana V.A. , Bhatnagar S.P. , Prajapati A.N.
Published: November 2013

The complex permittivity of a soil is a very much useful parameter in remote sensing applications. The measurement of complex permittivity of soil at various microwave frequencies can be related with the moisture content in the soil, which is useful in Agriculture, Hydrology and Meteorology. The complex dielectric spectra of dry and wet soil samples were measured in the frequency range from 20 Hz to 20 GHz. For this, various instruments and different methods were used. The complex permittivity of the soils, in the frequency range from 20 Hz to 2 MHz, was measured using a precision LCR meter, and a newly designed and developed coaxial capacitor probe. The complex permittivity of the soils, in the frequency range from 75 MHz to 1.5 GHz, was measured using a Vector Network Analyzer. The complex permittivity of the soils at 5.65 GHz, 9.5 GHz and 19.3 GHz was measured using microwave bench set up. The results are presented in the paper.
Synthesis and Electrical Properties of 1-x(Na0.5K0.5NbO3)-x(CoFe2O4)
Authors: Varma Ramesh R. , Sengunthar Purnima S. , Joshi Nikhil G. , Gadhvi M.R. , Chhaya U.V. , Joshi Utpal S.
Published: November 2013

Magnetoelectric (ME) effect is a coupled two-field effect in which application of an electric field induces magnetization and a magnetic field induces electrical polarization. However, it is difficult for a single material to have this combination of the ferromagnetic and ferroelectric properties. Thus, ferromagnetic–ferroelectric/dielectric composite materials become an attractive subject. Na1−xKxNbO3(NKN) is a combination of ferroelectric KNbO3and antiferroelectric NaNbO3, and forms a morphotropic phase boundary (MPB) near 50/50 composition (x=0.50) separating two orthorhombic phases. NKN has high electromechanical coupling coefficient (k2) and high phase transition temperature (Tc = 425 °C), especially near the morphotropic phase boundary (MPB). CoFe2O4(CFO), on the other hand, is well known spinel ferrite with high Curie temperature. We have synthesized ceramic composites, 1-x(Na0.5K0.5NbO3)-x(CoFe2O4) with x = 0.0 to 1.0 (in step of 0.2) by standard solid state reaction route. Powder XRD show a mixed cubic phase without impurity peaks for the samples under study. In low frequency range the dielectric properties of the NKN/CFO composites show Maxwell–Wagner relaxation. Systematic change in the electrical polarization with increasing x was observed at various applied fields at room temperature.
Large Magnetoviscous Effect in Magnetic and Non Magnetic Ferrodispersion
Authors: Parmar Mayur , Virpura Hiral , Patel Rajesh
Published: November 2013

Under the application of magnetic field, magnetic fluids exhibits magnetoviscous effect. We have observed large magneto viscous effects by dispersing magnetic and non-magnetic anisotropic micron size magnetic particles in a ferrofluid , the mixture is known as ferrodispersion. For both the samples density and volume concentrations of large particles are kept identical i.e. 25, 50 and 75 vol %. It is observed that for 25% and 50% vol. concentration the magnetoviscous effect for both the samples is comparable, however for 75% concentration the field dependent viscosity of non-magnetic bentonite anisotropic particles are much larger than its counterpart. This shows even non magnetic particle can also enhance the magneto viscous effect. Results can be useful to develop a novel kind of bidispersed magnetorheological fluids to increase its commercial applicability.
Electronic and Optical Properties of MoS2
Authors: Ahuja Ushma , Dashora Alpa
Published: November 2013

Electronic properties along with the absorption coefficients and dielectric tensors of MoS2 thin films in (0001) direction and the bulk state have been computed using density functional theory within full potential linearized augmented plane wave method. Surface energies and work functions are also deduced for different number of layers to check the quantum size effects and thereby the stability of thin films. The dielectric tensors and absorption coefficients (optical properties) of these materials are discussed to explore the utility of MoS2 in photovoltaic applications.
The permanent struggle for hope: Three suburban pieces
Authors: Ullyatt Tony
Published: November 2013

No abstract available.
Beach Morphological Dynamics at Cocos Bay (Manzanilla), Trinidad
Authors: Darsan Junior
Published: November 2013

The Manzanillabeach in Cocos Bay, Trinidad is a barrier beach that protects the freshwaterNariva Swamp from the marine environment of the Atlantic. The Manzanilla beachis a very dynamic system owing to the open bay morphology, and its exposure tothe Atlantic Ocean. This study evaluated thespatial and temporal morphological and sedimentological characteristics,alongside hydrodynamic conditions operating on the beach. This studyinvestigates the beach’s response to tidal cycles diurnally, from spring toneap tide, and seasonally. Data from nine sites during the period December 2005to September 2007 are analyzed. Coastal parameters such as beach profiles,littoral data and sediment samples were obtained using standardgeomorphological techniques. The beach volumetric changes that occurred overthe tidal cycles are also quantified. Results indicate that wave height andwave energy were good predictors of beach change. The study showed that erosionwas linked to rising tide and accretion to falling tide diurnally. Erosionoccurred during spring tide conditions and accretion dominated during neaptides. Seasonally more erosion occurred in the winter period (dry season) andbeach changes in the summer period (wet season) were controlled by theformation and migration of bars.
New proofs of certain finite filling results results via Khovanov homology
Authors: Watson Liam
Published: November 2013

We give a Khovanov homology proof that hyperbolic twist knots do not admit non-trivial Dehn surgeries with finite fundamental group.
Cables of thin knots and bordered Heegaard Floer homology
Authors: Petkova Ina
Published: November 2013

We use bordered Floer homology to give a formula for

\widehat{\rm HFK} (K_{p, pn+1})

of any

(p, pn+1)

-cable of a thin knot

K

in terms of

\Delta_K(t)

,

\tau(K)

,

p

, and

n

. We also give a formula for the Ozsváth–Szabó concordance invariant

\tau(K_{p, q})

in terms of

\tau(K)

,

p

, and

q

, for all relatively prime

p

and

q

.
$|Z_{\mathrm{Kup}}|=|Z_{\mathrm{Henn}}|^2$ for lens spaces
Authors: Chang Liang , Wang Zhenghan
Published: November 2013

M. Hennings and G. Kuperberg defined quantum invariants

Z_{\rm Henn}

and

Z_{\rm Kup}

of closed oriented 3-manifolds based on certain Hopf algebras, respectively. We prove that

|Z_{\rm Kup}|=|Z_{\rm Henn}|^2

for lens spaces when both invariants are based on factorizable finite dimensional ribbon Hopf algebras.
A duality formalism in the spirit of Grothendieck and Verdier
Authors: Boyarchenko Mitya , Drinfeld Vladimir
Published: November 2013

We study monoidal categories that enjoy a certain weakening of the rigidity property, namely, the existence of a dualizing object in the sense of Grothendieck and Verdier. We call them
Grothendieck–Verdier categories
. (They have also been studied in the literature under the name

*

-
autonomous categories
.) Notable examples include the derived category of constructible sheaves on a scheme (with respect to tensor product) as well as the derived and equivariant derived categories of constructible sheaves on an algebraic group (with respect to convolution).

We show that the notions of pivotal category and ribbon category, which are well known in the setting of rigid monoidal categories, as well as certain standard results associated with these notions, have natural analogues in the world of Grothendieck–Verdier categories.
Effect of chemical structure on secondary organic aerosol formation from C12 alkanes
Authors: Yee L. D. , Craven J. S. , Loza C. L. , Schilling K. A. , Ng N. L. , Canagaratna M. R. , Ziemann P. J. , Flagan R. C. , Seinfeld J. H.
Published: November 2013

Abstract. The secondary organic aerosol (SOA) formation from four C12 alkanes (n-dodecane, 2-methylundecane, hexylcyclohexane, and cyclododecane) is studied in the Caltech Environmental Chamber under low-NOx conditions, in which the principal fate of the peroxy radical formed in the initial OH reaction is reaction with HO2. Simultaneous gas- and particle-phase measurements elucidate the effect of alkane structure on the chemical mechanisms underlying SOA growth. Reaction of branched structures leads to fragmentation and more volatile products, while cyclic structures are subject to faster oxidation and lead to less volatile products. Product identifications reveal that particle-phase reactions involving peroxyhemiacetal formation from several multifunctional hydroperoxide species are key components of initial SOA growth in all four systems. The continued chemical evolution of the particle-phase is structure-dependent, with 2-methylundecane SOA formation exhibiting the least extent of chemical processing and cyclododecane SOA achieving sustained growth with the greatest variety of chemical pathways. The extent of chemical development is not necessarily reflected in the oxygen to carbon (O : C) ratio of the aerosol as cyclododecane achieves the lowest O : C, just above 0.2, by the end of the experiment and hexylcyclohexane the highest, approaching 0.35.
The simulations of sulfuric acid concentration and new particle formation in an urban atmosphere in China
Authors: Wang Z. B. , Hu M. , Mogensen D. , Yue D. L. , Zheng J. , Zhang R. Y. , Liu Y. , Yuan B. , Li X. , Shao M. , Zhou L. , Wu Z. J. , Wiedensohler A. , Boy M.
Published: November 2013

Abstract. Simulations of sulfuric acid concentration and new particle formation are performed by using the zero-dimensional version of the model MALTE (Model to predict new Aerosol formation in the Lower TropospherE) and measurements from the Campaign of Air Quality Research in Beijing and Surrounding areas (CAREBeijing) in 2008. Chemical reactions from the Master Chemical Mechanism version 3.2 (MCM v3.2) are used in the model. High correlation (slope = 0.72, R = 0.74) between the modelled and observed sulfuric acid concentrations is found during daytime (06:00–18:00). The aerosol dynamics are simulated by the University of Helsinki Multicomponent Aerosol (UHMA) model including several nucleation mechanisms. The results indicate that the model is able to predict the on- and offset of new particle formation in an urban atmosphere in China. In addition, the number concentrations of newly formed particles in kinetic-type nucleation including homogenous homomolecular (J=K[H2SO4]2) and homogenous heteromolecular nucleation involving organic vapours (J=Khet[H2SO4][Org]) are in satisfactory agreement with the observations. However, the specific organic compounds that possibly participate in the nucleation process should be investigated in further studies. For the particle growth, only a small fraction of the oxidized total organics condense onto the particles in polluted environments. Meanwhile, the OH and O3 oxidation mechanism contribute 5.5% and 94.5% to the volume concentration of small particles, indicating the particle growth is more controlled by the precursor gases and their oxidation by O3.
Very short-lived bromomethanes measured by the CARIBIC observatory over the North Atlantic, Africa and South-East Asia during 2009–2013
Authors: Wisher A. , Oram D. E. , Laube J. C. , Mills G. P. , van Velthoven P. , Zahn A. , Brenninkmeijer C. A. M.
Published: November 2013

Abstract. Short-lived organic brominated compounds make up a significant part (~20%) of the organic bromine budget in the atmosphere. Emissions of these compounds are highly variable and there are limited measurements, particularly in the extra-tropical upper troposphere/lower stratosphere and tropical troposphere. Measurements of five short-lived bromomethanes (VSLB) were made in air samples collected on the CARIBIC project aircraft over three flight routes; Germany to Venezuela/Columbia during 2009–2011, Germany to South Africa during 2010 and 2011 and Germany to Thailand/Kuala Lumpur, Malaysia during 2012 and 2013. In the tropical troposphere, as the most important entrance region to the stratosphere, we observe a total mean organic bromine derived from these compounds across all flights at 10–12 km altitude of 3.4 ± 1.5 ppt. Individual mean tropical tropospheric mixing ratios across all flights were 0.43, 0.74, 0.14, 0.23 and 0.11 ppt for CHBr3, CH2Br2, CHBr2Cl, CHBrCl2 and CH2BrCl respectively. The highest levels of VSLS-derived bromine (4.20 ± 0.56 ppt) were observed in flights between Bangkok and Kuala Lumpur indicating that the South China Sea is an important source region for these compounds. Across all routes, CHBr3 and CH2Br2 accounted for 34% (4.7–71) and 48% (14–73) respectively of total bromine derived from the analysed VSLB in the tropical mid-upper troposphere totalling 82% (54–89). In samples collected between Germany and Venezuela/Columbia, we find decreasing mean mixing ratios with increasing potential temperature in the extra-tropics. Tropical mean mixing ratios are higher than extra-tropical values between 340–350 K indicating that rapid uplift is important in determining mixing ratios in the lower tropical tropopause layer in the West Atlantic tropics. O3 was used as a tracer for stratospherically influenced air and we detect rapidly decreasing mixing ratios for all VSLB above ~100 ppb O3 corresponding to the extra-tropical tropopause layer.
A novel method for estimating shortwave direct radiative effect of above-cloud aerosols using CALIOP and MODIS data
Authors: Zhang Z. , Meyer K. , Platnick S. , Oreopoulos L. , Lee D. , Yu H.
Published: November 2013

Abstract. This paper describes an efficient and unique method for computing the shortwave direct radiative effect (DRE) of aerosol residing above low-level liquid-phase clouds using CALIOP and MODIS data. It accounts for the overlapping of aerosol and cloud rigorously by utilizing the joint histogram of cloud optical depth and cloud top pressure. Effects of sub-grid scale cloud and aerosol variations on DRE are accounted for. It is computationally efficient through using grid-level cloud and aerosol statistics, instead of pixel-level products, and a pre-computed look-up table in radiative transfer calculations. We verified that for smoke over the southeast Atlantic Ocean the method yields a seasonal mean instantaneous shortwave DRE that generally agrees with more rigorous pixel-level computation within 4%. We have also computed the annual mean instantaneous shortwave DRE of light-absorbing aerosols (i.e., smoke and polluted dust) over global ocean based on 4 yr of CALIOP and MODIS data. We found that the variability of the annual mean shortwave DRE of above-cloud light-absorbing aerosol is mainly driven by the optical depth of the underlying clouds.
Dispersion relation analysis of turbulent magnetic field fluctuations in fast solar wind
Authors: Perschke C. , Narita Y. , Gary S. P. , Motschmann U. , Glassmeier K.-H.
Published: November 2013

Abstract. Physical processes of the energy transport in solar wind turbulence are a subject of intense studies, and different ideas exist to explain them. This manuscript describes the investigation of dispersion properties in short-wavelength magnetic turbulence during a rare high-speed solar wind event with a flow velocity of about 700 km s−1 using magnetic field and ion data from the Cluster spacecraft. Using the multi-point resonator technique, the dispersion relations (i.e., frequency versus wave-number values in the solar wind frame) of turbulent magnetic fluctuations with wave numbers near the inverse ion inertial length are determined. Three major results are shown: (1) the wave vectors are uniformly quasi-perpendicular to the mean magnetic field; (2) the fluctuations show a broad range of frequencies at wavelengths around the ion inertial length; and (3) the direction of propagation at the observed wavelengths is predominantly in the sunward direction. These results suggest the existence of high-frequency dispersion relations partly associated with normal modes on small scales. Therefore nonlinear energy cascade processes seem to be acting that are not described by wave–wave interactions.
Solute-specific scaling of inorganic nitrogen and phosphorus uptake in streams
Authors: Hall R. O. , Baker M. A. , Rosi-Marshall E. J. , Tank J. L. , Newbold J. D.
Published: November 2013

Abstract. Stream ecosystem processes such as nutrient cycling may vary with stream position in the network. Using a scaling approach, we examined the relationship between stream size and nutrient uptake length, which represents the mean distance that a dissolved solute travels prior to removal from the water column. Ammonium (NH4+) uptake length increased proportionally with stream size measured as specific discharge (discharge/stream width) with a scaling exponent = 1.01. In contrast, uptake lengths for nitrate (NO3−) and soluble reactive phosphorus (SRP) increased more rapidly than increases in specific discharge (scaling exponents = 1.19 for NO3− and 1.35 for SRP). Additionally, the ratio of inorganic nitrogen (N) uptake length to SRP uptake length declined with stream size; there was relatively lower demand for SRP compared to N as stream size increased. Finally, we related the scaling of uptake length with specific discharge to that of stream length using Hack's law and downstream hydraulic geometry. Ammonium uptake length increased less than proportionally with distance from the headwaters, suggesting a strong role for larger streams and rivers in regulating nutrient transport.
Strong stimulation of N2 fixation in oligotrophic Mediterranean Sea: results from dust addition in large in situ mesocosms
Authors: Ridame C. , Guieu C. , L'Helguen S.
Published: November 2013

Abstract. The response of N2 (dinitrogen) fixation to contrasted (wet and dry) Saharan dust deposition was studied in the framework of the DUNE project (a DUst experiment in a low-Nutrient, low-chlorophyll Ecosystem) during which realistic simulations of dust deposition (10 g m−2) into large mesocosms (52 m3) were performed. Three distinct experimental dust additions were conducted in June 2008 (DUNE-1-P: simulation of a wet deposition, DUNE-1-Q: simulation of a dry deposition) and 2010 (DUNE-2-R: simulation of 2 successive wet depositions) in the northwestern oligotrophic Mediterranean Sea. Here we show that wet and dry dust deposition induced a rapid (24 h or 48 h after dust additions), strong (from 2- to 5.3-fold) and long (at least 4–6 days duration) increase in N2 fixation, indicating that both wet and dry Saharan dust deposition was able to relieve efficiently the nutrient limitation(s) of N2 fixation. This means in particular that N2 fixation activity was not inhibited by the significant input of nitrate associated with the simulated wet deposition (~ 9 mmol NO3− m−2). The input of new nitrogen associated with N2 fixation was negligible relative to the atmospheric NO3− input associated with the dust. The contribution of N2 fixation to primary production was negligible (≤ 1%) before and after dust addition in all experiments, indicating that N2 fixation was a poor contributor to the nitrogen demand for primary production. Despite the stimulation of N2 fixation by dust addition, the rates remained low, and did not significantly change the contribution of N2 fixation to new production since only a maximum contribution of 10% was observed. The response of N2 fixation by diazotrophs and CO2 fixation by the whole phytoplankton community suggests that these metabolic processes were limited or co-limited by different nutrients. With this novel approach, which allows us to study processes as a function of time while atmospheric particles are sinking, we show that new atmospheric nutrients associated with Saharan dust pulses do significantly stimulate N2 fixation in the Mediterranean Sea and that N2 fixation is not a key process in the carbon cycle in such oligotrophic environments.
Juneau Icefield Mass Balance Program 1946–2011
Authors: Pelto M. , Kavanaugh J. , McNeil C.
Published: November 2013

Abstract. The annual surface mass balance records of the Lemon Creek Glacier and Taku Glacier observed by the Juneau Icefield Research Program are the longest continuous glacier annual mass balance data sets in North America. Annual surface mass balance (Ba) measured on Taku Glacier averaged +0.40 m a−1 from 1946–1985, and −0.08 m a−1 from 1986–2011. The recent annual mass balance decline has resulted in the cessation of the long-term thickening of the glacier. Mean Ba on Lemon Creek Glacier has declined from −0.30 m a−1 for the 1953–1985 period to −0.60 m a−1 during the 1986–2011 period. The cumulative change in annual surface mass balance is −26.6 m water equivalent, a 29 m of ice thinning over the 55 yr. Snow-pit measurements spanning the accumulation zone, and probing transects above the transient snow line (TSL) on Taku Glacier, indicate a consistent surface mass balance gradient from year to year. Observations of the rate of TSL rise on Lemon Creek Glacier and Taku Glacier indicate a comparatively consistent migration rate of 3.8 to 4.1 m d−1. The relationship between TSL on Lemon Creek Glacier and Taku Glacier to other Juneau Icefield glaciers (Norris, Mendenhall, Herbert, and Eagle) is strong, with correlations exceeding 0.82 in all cases. doi:10.5065/D6NZ85N3
Morphodynamic regime change induced by riparian vegetation in a restored lowland stream
Authors: Eekhout J. P. C. , Hoitink A. J. F.
Published: November 2013

Abstract. With the aim to establish and understand morphological changes in response to stream restoration measures, a detailed monitoring plan was implemented in a lowland stream called Lunterse Beek, located in the Netherlands. Over a period of 1.5 yr, the monitoring included serial morphological surveys, continuous discharge and water level measurements and riparian vegetation mapping. Morphological processes occurred mainly in the initial period, before riparian vegetation development. In the subsequent period, riparian vegetation started to emerge, with a maximum coverage halfway the survey period, which coincides with the end of the summer period. Detailed morphological and hydrological data show a marked difference in behaviour between the unvegetated initial stage and the vegetated final period. The riparian vegetation cover, obtained from an aerial photo, shows a strong correlation with inundation frequency. We applied linear regression to relate morphological activity to time-averaged bed shear stress. In the initial stage after construction, with negligible riparian vegetation, channel morphology adjusted without a clear response to the discharge hydrograph. In the subsequent period, morphological activity in the channel bed and bank zones showed a clear response to discharge variation. The two stages of morphological response to the restoration measures reveal the role of riparian vegetation, which acts to focus the morphodynamic developments in the main channel.
Quantification of the volatile organic compounds in the smoke from prescribed burning and comparison with the occupational exposure limits
Authors: Barboni T. , Santoni P.-A.
Published: November 2013

Abstract. Prescribed burning represents a serious threat to the personnel fighting fires because of smoke inhalation. This study aims to increase the knowledge about foresters exposure to the prescribed burning smoke by focusing on exposure to volatile organic compounds (VOCs). We initially assessed the methodology for smoke sampling. Then, we identified potentially dangerous molecules among the VOCs identified at 4 prescribed burning sites located around Corsica. The values measured were very high, exceeding the exposure limits, particularly for benzene, phenol, and furfural, whose concentrations were above short-term exposure limit (STEL) values. In conclusion, obvious but necessary recommendations were made for the protection of the personnel involved in fighting fires on a professional basis.
Further summer speedup of Jakobshavn Isbræ
Authors: Joughin I. , Smith B. E.
Published: November 2013

Abstract. We have extended the record of flow speed on Jakobshavn Isbræ through the summer of 2013. These new data reveal large seasonal speedups, 30 to 50% larger than previous summers. At a point a few kilometres inland from the terminus, the mean annual speed for 2012 is nearly three times as large as that in the mid 1990s, while the peak summer speeds are more than a factor of 4 greater. These speeds were achieved as the glacier terminus retreated to the bottom of an overdeepened basin with a depth of ~ 1300 m below sea level. While retreat may slow slightly as the terminus retreats farther – to a moderate rise in the bed – it is likely to reach the deepest section of the trough within a few decades, at which point it should rapidly retreat to the shallower regions ~ 50 km farther upstream, potentially by the end of this century.
Who is Teaching Us about Sustainable Happiness and Well-Being?
Authors: O'Brien C
Published: November 2013

The growing recognition that happiness and well-being are intertwined with sustainability is leading to new opportunities for enhancing happiness and well-being, sustainably. The education sector has a critical role in advancing this work but has been slow to incorporate sustainability education and applications of positive psychology. The concept of sustainable happiness (happiness that contributes to individual, community and/or global well-being without exploiting other people, the environment or future generations) (O’Brien, 2010a) offers an innovative perspective to re-invigorate sustainability education and shape priorities for 21st century learning – contributing to resilient, sustainable happiness and well-being for all.
Staying Positive: Women's illness narratives and the stigmatized vernacular
Authors: Bock S.
Published: November 2013

This article uses the stigmatized vernacular (Goldstein & Shuman, 2012) as a conceptual framework for examining the public construction and reception of women’s illness narratives. I begin by making the case that personal illness narratives – a genre that works to translate the subjective illness experience to a public audience – are rich sites for exploring how discourses of veneration and repudiation can become inextricably intertwined.  Discussing illustrative examples of the construction and reception of women’s illness narratives shared in contexts of breast cancer and fibromyalgia, I show how popular understandings of emotions, particularly positive emotions like happiness, play a major role in the regimes of value shaping how women’s illness experiences become tellable or untellable, and thereby valued or devalued.  Integrating scholarship on illness narratives, stigma, and happiness, I aim to contribute to a richer and more multifaceted view of the illness narrative genre and the discursive contagion of stigma.
As If You Have a Choice: Autism mothers and the remaking of the human
Authors: Douglas P. N.
Published: November 2013

This paper utilizes feminist phenomenology to explore how contemporary representations of autism, and autism mothers, are integrally caught up in western (and now globalizing) understandings of health, happiness and the “normative” human.  I examine the historical emergence of “autism mothers” as a new category of identity, and track this alongside a global autism mother recruitment campaign to get at what’s “behind” this phenomenon.  I argue that emerging autism mother figures like the feminine warrior are new and contradictory neoliberal subjectivities that contain a most “hateful” unethical and increasingly global duty: the reinscription and intensification of the “normal” human as bourgeois, nondisabled, white and western, and the “new” femininity as “naturally” nurturing and necessarily instrumental.  Even more, these new subjectivities are governmental, operating as western colonialist translations of happiness, compelling compulsory participation in increasingly limited, violent, and globalizing frames of normative humanity for us all.
Chronic Illness as a Source of Happiness: Paradox or perfectly normal?
Authors: Hoppe S.
Published: November 2013

In this paper I analyse the relation between happiness and chronic illness from the perspective of medical anthropology and disability studies. By looking at the disability paradox I deconstruct society’s view of people with a disability. I argue that the disability paradox is problematic as it ignores the views of people with a disability. Moreover, such a paradox reinforces the idea that living with a chronic illness or disability is a devastating experience and that happiness and disability are mutally exclusive realities. Based on empiric examples of people who suffer from Multiple Sclerosis I demonstrate that people with a chronic illness can experience happiness in spite of illness, but also as a consequence of it.
Understanding Well-Being in Multi-Levels: A review
Authors: Ng E. C. W. , Fisher A. T.
Published: November 2013

Well-being is not only an emerging research agenda, but also a critical issue concerning the individual as well as the societal development, because how the issue is viewed has a huge theoretical as well as practical, even policy, implication. In academic, while some argue that well-being is in the subjective perception of one’s life or psychological functioning, others argue that well-being is in the objective conditions and the broader environment. This paper, drawing on psychology tradition, tries to go beyond the dichotomy of well-being as either an individual attribute or external conditions. Instead, this article acknowledges the multi-levels of well-being are closely tied and should be taken into accounts when well-being is concerned. We will provide a brief review of the two major approaches – subjective well-being and quality of life – of well-being before the multi-level approach is introduced. The strength and challenges of the multilevel approach will be discussed.