bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of spatial heterogeneity of local surface albedo on the area-averaged surface albedo retrieved from airborne irradiance measurements
Authors: Jäkel E. , Wendisch M. , Mayer B.
Published: March 2013

Abstract. Spectral airborne upward and downward irradiance measurements are used to derive the area-averaged surface albedo. Real surfaces are not homogeneous in their reflectivity. Therefore, this work studies the effects of the heterogeneity of surface reflectivity on the area-averaged surface albedo to quantify how well aircraft measurements can resolve the small-scale variability of the local surface albedo. For that purpose spatially heterogeneous surface albedo maps were input into a 3-dimensional (3-D) Monte Carlo radiative transfer model to simulate 3-D irradiance fields. The calculated up- and downward irradiances in altitudes between 0.1 and 5 km are used to derive the area-averaged surface albedo using an iterative retrieval method that removes the effects due to atmospheric scattering and absorption within the layer beneath the considered level. For the case of adjacent land and sea surfaces, parametrizations are presented which quantify the horizontal distance from the coastline that is required to reduce surface heterogeneity effects on the area-averaged surface albedo to a given limit. The parametrization which is a function of altitude, aerosol optical depth, single scattering albedo, and the ratio of local land and sea albedo was applied for airborne spectral measurements. In addition, the deviation between area-averaged and local surface albedo is determined for more complex surface albedo maps. For moderate aerosol conditions (optical depth less than 0.4) and a wavelength range between 400 and 1000 nm, the altitude and the heterogeneity of the surface albedo are the dominant factors determining the mean deviation between local and area-averaged surface albedo. A parametrization of the mean deviation is applied to an albedo map that was derived from a Landsat image of an area in East Anglia (UK). Parametrization and direct comparison of local and area-averaged surface albedo show similar mean deviations (20% vs. 25%) over land.
Occurrence of benthic microbial nitrogen fixation coupled to sulfate reduction in the seasonally hypoxic Eckernförde Bay, Baltic Sea
Authors: Bertics V. J. , Löscher C. R. , Salonen I. , Dale A. W. , Gier J. , Schmitz R. A. , Treude T.
Published: March 2013

Abstract. Despite the worldwide occurrence of marine hypoxic regions, benthic nitrogen (N) cycling within these areas is poorly understood and it is generally assumed that these areas represent zones of intense fixed N loss from the marine system. Sulfate reduction can be an important process for organic matter degradation in sediments beneath hypoxic waters and many sulfate-reducing bacteria (SRB) have the genetic potential to fix molecular N (N2). Therefore, SRB may supply fixed N to these systems, countering some of the N lost via microbial processes, such as denitrification and anaerobic ammonium oxidation. The objective of this study was to evaluate if N2 fixation, possibly by SRB, plays a role in N cycling within the seasonally hypoxic sediments from the Eckernförde Bay, Baltic Sea. Monthly samplings were performed over the course of one year to measure nitrogenase activity (NA) and sulfate reduction rates, to determine the seasonal variations in bioturbation (bioirrigation) activity and important benthic geochemical profiles, such as sulfur and N compounds, and to monitor changes in water column temperature and oxygen concentrations. Additionally, at several time points, the active N-fixing community was examined via molecular tools. Integrated rates of N2 fixation (approximated from NA) and sulfate reduction showed a similar seasonality pattern, with highest rates occurring in August (approx. 22 and 880 nmol cm−3 d−1 of N and SO42−, respectively) and October (approx. 22 and 1300 nmol cm−3 d−1 of N and SO42− respectively), and lowest rates occurring in February (approx. 8 and 32 nmol cm−3 d−1 of N and SO42−, respectively). These rate changes were positively correlated with bottom water temperatures and previous reported plankton bloom activities, and negatively correlated with bottom water oxygen concentrations. Other variables that also appeared to play a role in rate determination were bioturbation, bubble irrigation and winter storm events. Molecular analysis demonstrated the presence of nifH sequences related to two known N2 fixing SRB, namely Desulfovibrio vulgaris and Desulfonema limicola, supporting the hypothesis that some of the nitrogenase activity detected may be attributed to SRB. Overall, our data show that Eckernförde Bay represents a complex ecosystem where numerous environmental variables combine to influence benthic microbial activities involving N and sulfur cycling.
Formation and maintenance of high-nitrate, low pH layers in the Eastern Indian Ocean and the role of nitrogen fixation
Authors: Waite A. M. , Rossi V. , Roughan M. , Tilbrook B. , Akl J. , Thompson P. A. , Feng M. , Wyatt A. S. J. , Raes E. J.
Published: March 2013

Abstract. We investigate the biogeochemistry of Low Dissolved Oxygen High Nitrate layers forming against the backdrop of several interleaving regional water masses in the Eastern Indian Ocean, off northwest Australia adjacent to Ningaloo Reef. These water masses, including the forming Leeuwin Current, have been shown directly to impact the ecological function of Ningaloo Reef and other iconic coastal habitats downstream. Our results indicate that LODHN layers are formed from multiple subduction events of the Eastern Gyral Current beneath the Leeuwin Current (LC); the LC originates from both the Indonesian Throughflow and tropical Indian Ocean. Density differences of up to 0.025 kg m−3 between the Eastern Gyral Current and the Leeuwin Current produce sharp gradients that can trap high concentrations of particles (measured as low transmission) along the density interfaces. The oxidation of the trapped particulate matter results in local depletion of dissolved oxygen and regeneration of dissolved nitrate (nitrification). We document an associated increase in total dissolved carbon dioxide, which lowers the seawater pH by 0.04 units. Based on isotopic measurements (δ15N and δ18O) of dissolved nitrate, we determine that ∼40–100% of the nitrate found in LODHN layers is likely to originate from nitrogen fixation, and that regionally, the importance of N fixation in contributing to LODHN layers is likely be highest at the surface and offshore.
Development of a parameterization of black carbon aging for use in general circulation models
Authors: Oshima N. , Koike M.
Published: March 2013

Abstract. A parameterization of black carbon (BC) aging in the atmosphere is developed for use in general circulation models (GCMs) that separately treat hydrophobic BC and hydrophilic BC modes but do not explicitly calculate the aging processes of BC. The rate of BC aging is expressed as the conversion rate from hydrophobic BC to hydrophilic BC modes (i.e., inverse of the e-folding time of the conversion, 1/τBC). In this study, the conversion rates are estimated using results of detailed calculations by a size and mixing state resolved aerosol box model with numerous initial conditions. We introduce a new concept, the hydrophobic-BC-mass-normalized coating rate (VBC), defined as the rate of increase of the mass concentration of condensed materials on hydrophobic BC normalized by the hydrophobic BC mass concentration. Although the conversion rate largely varies depending on the atmospheric conditions and the concentrations of chemical species, we find that the variations of the conversion rate are generally expressed well by a unique function of VBC for given lognormal size distributions of hydrophobic BC. The parameterized conversion rate is expressed as a function of VBC, which enables the representation of diurnal and seasonal variations of the BC aging rate and its spatial differences in polluted and clean air, while other widely used constant conversion rates cannot. Application of our newly developed parameterization to GCMs will provide more reliable estimates of the spatial distribution of BC and its radiative effects at regional and global scales.
Modelling the Caspian Sea and its catchment area using a coupled regional atmosphere-ocean model (RegCM4-ROMS): model design and preliminary results
Authors: Turuncoglu U. U. , Giuliani G. , Elguindi N. , Giorgi F.
Published: March 2013

Abstract. We describe the development of a coupled regional atmosphere-ocean model (RegCM4-ROMS) and its implementation over the Caspian Sea basin. The coupled model is run for the period 1999–2008 (after a spin up of 4 yr) and it is compared to corresponding stand alone model simulations and a simulation in which a distributed 1d lake model is run for the Caspian Sea. All model versions show a good performance in reproducing the climatology of the Caspian Sea basin, with relatively minor differences across them. The coupled ROMS produces realistic, although somewhat overestimated, Caspian Sea Surface Temperature (SST), with a considerable improvement compared to the use of the simpler coupled lake model. Simulated near surface salinity and sea currents are also realistic, although the upwelling over the eastern coastal regions is underestimated. The sea ice extent over the shallow northern shelf of the Caspian Sea and its seasonal evolution are well reproduced, however, a significant negative bias in sea-ice fraction exists due to the relatively poor representation of the bathymetry. ROMS also calculates the Caspian Sea Level (CSL), showing that for the present experiment excessive evaporation over the lake area leads to a drift in estimated CSL. Despite this problem, which requires further analysis due to many uncertainties in the estimation of CSL, overall the coupled RegCM4-ROMS system shows encouraging results in reproducing both the climatology of the region and the basic characteristics of the Caspian Sea.
Preparation of Naturally Textured Aluminum-Doped Zinc Oxide Films on Flexible Poly(ether sulfone) Substrate by Radio Frequency Magnetron Sputtering
Authors: An Jae Seok , Shin Jin Koog , Lee Jong Ho , Choi Bum Ho
Published: March 2013

Transparent conducting oxide (TCO) layers of naturally textured aluminum-doped zinc oxide (AZO) were prepared on flexible poly(ether sulfone) (PES) substrates by controlling the radio frequency (RF) magnetron sputtering power without chemical wet etching, and their morphological, optical, and electrical properties were characterized. Layers with crater structures were formed at a single RF power; whereas at high RF power (2000 W), their surfaces resembled that of chemically wet-etched AZO. Layers were also formed by dual RF sputtering powers: sputtering a 0.15-µm-thick layer at high power and a subsequent 0.45-µm-thick layer at low power produced flakes with larger grains or crater-like structures. The measured visible transmittance of all the layers was >85% – sufficient for use in amorphous silicon (a-Si) thin-film solar cells. The measured optical and electrical properties of the naturally textured AZO layers are comparable to those of chemically wet-etched AZO layers, suggesting a possible method for fabricating inexpensive flexible a-Si thin-film solar cells in fewer steps.
Chemical Structure of Interfacial Transition Layer Formed on Si(100) and Its Dependence on Oxidation Temperature, Annealing in Forming Gas, and Difference in Oxidizing Species
Authors: Suwa Tomoyuki , Teramoto Akinobu , Kumagai Yuki , Abe Kenichi , Li Xiang , Nakao Yukihisa , Yamamoto Masashi , Nohira Hiroshi , Muro Takayuki , Kinoshita Toyohiko , Sugawa Shigetoshi , Ohmi Tadahiro , Hattori Takeo
Published: March 2013

The angle-resolved Si 2p photoelectron spectra arising from a interfacial transition layer formed on a Si(100) were measured with a probing depth of nearly 2 nm. The novel analytical procedure of these spectra was developed by considering that one SiO2monolayer, two compositional transition layers (CTLs), and one Si monolayer constituting the Si substrate surface are continuously connected with each other to maintain the areal density of Si atoms. It was found for thermally grown transition layers that two CTLs are formed on the oxide side of the CTL/Si interface and the chemical structures correlated with the residual stress appear on the Si substrate side of the interface. The effects of oxidation temperature in the range from 900 to 1050 °C, annealing in the forming gas, and oxidation using oxygen radicals on the chemical structures of transition layers formed on both sides of the interface were also clarified.
Flat Band Slow Light Performance in Dual-Slot Silicon-on-Insulator Based Photonic Crystal Waveguide
Authors: Tian Huiping , Zhou Jian , Zhai Yi , Ji Yuefeng
Published: March 2013

The photonic band structure and slow light performance in dual-slot photonic crystal waveguide based on silicon-on-insulator (SOI) substrate are studied by using three-dimensional (3D) plane wave expansion method. The numerical results show that both the position and the width of the slots have significant effect on photonic band structure. The guided mode edge and the photonic band gap increases with the increasing of the two slots' widths. When slots move close to the boundary of the waveguide, a flat band of slow light appears. The slow light property has also been discussed by modifying the radius of the two rows of air holes nearest to the dual-slot waveguide. The negligible dispersion bandwidths ranging from 6.70 to 25.70 nm for group indices from 62 to 20 are obtained, respectively. The numerical results show that the proposal structure has potential application in optical buffer.
A Fabry–Pérot Etalon with an Ultralow Expansion Ceramic Spacer
Authors: Hosaka Kazumoto , Inaba Hajime , Akamatsu Daisuke , Yasuda Masami , Sugawara Jun , Onae Atsushi , Hong Feng-Lei
Published: March 2013

We have developed a Fabry–Pérot etalon with an ultralow expansion ceramic spacer and investigated the thermal properties of the ceramic. We found that the ceramic cavity has a “zero crossing temperature” at room temperature where the thermal expansion coefficient crosses zero. The sensitivity of the thermal expansion coefficient of the ceramic to temperature change is about five times greater than that of ultralow expansion (ULE) glass at around the zero cross temperature. Nevertheless, owing to the high specific rigidity and relatively low thermal expansion at room temperature, the ceramic should be an attractive material for long optical cavities that can reduce the effect of the thermal noise relatively.
Effects of Tilt Angle, DNA Concentration, and Surface Potential on Directed Alignment of DNA Molecule for the Application to Nanodevices
Authors: Kim Hyung Jin , Hong Byungyou
Published: March 2013

This paper reports an efficient approach to control both the density and direction of highly aligned DNA molecules and thus DNA-templated gold nanowires (AuNWs) on Si chips. We utilized tilting method to prepare stretched DNA structures on SiO2/Si substrate and found important parameters in the alignment process that tilt angle, DNA concentration, and surface potential are controlled the density and structure of DNA aligned on the surface. In additional, we also can be directly connected DNA-templated AuNWs between two terminal electrodes on Si chips. This method also describes a simple way to form singled, bundled and networked DNA arrays on Si substrates.
Rashba Effect on the Structure of the Bi One-Bilayer Film: Fully Relativistic First-Principles Calculation
Authors: Kotaka Hiroki , Ishii Fumiyuki , Saito Mineo
Published: March 2013

Using first-principles calculations, we study the spin–orbit interactions and spin textures of a Bi one-bilayer film, which attracts scientific interest because of the topological insulator and so on. The substrate effect is successfully mimicked by applying on electric field in the perpendicular direction of the film, which breaks the inversion symmetry. We study the highest occupied band around the Γ point. Although the vortex of the in-plane spin component is well explained on the basis of the conventional Rashba effect, we find a substantial out-of-plane component which cannot be explained by the conventional Rashba model. This spin texture is similar to that of a multi-bilayer Bi film, which has recently been observed using a spin-resolved angle-resolved photoemission spectroscopy experiment. We also find a spin vortex around the K point although this point has no time-reversal symmetry. We expect that a similar vortex appears in materials having the p3m1 symmetry, whose spin–orbit interactions have recently attracted scientific interest.
Moisture Barrier Properties of Al2O3 Films deposited by Remote Plasma Atomic Layer Deposition at Low Temperatures
Authors: Choi Hagyoung , Lee Sanghun , Jung Hyunsoo , Shin Seokyoon , Ham Giyul , Seo Hyungtak , Jeon Hyeongtag
Published: March 2013

We report the effect of process temperature on moisture permeation barrier properties of Al2O3 films deposited by remote plasma atomic layer deposition (RPALD) at various low temperatures from 50 to 200 °C. XPS analysis of O 1s peak reveals that the O–H ratio decreases with process temperature from 38.1% at 50 °C to 25.8% at 200 °C. The water transmission rates using electrical Ca degradation test indicates that the 100 nm Al2O3 film enhances the moisture barrier performance from 2.0×10-2 to 5.0×10-4 g m-2 day-1 with increasing the process temperature. This result indicates that increasing the process temperature improves the moisture permeation barrier properties significantly even in RPALD process. It is attributed to the increase in the Al2O3 mass density due to the decrease of relatively O–H ratio with increase in temperature as revealed by XPS O 1s peak deconvolution and FTIR analysis in the Al2O3 films.
Investigation of Positive and Negative Bias Temperature Instability of High-κ Dielectric Metal Gate Metal–Oxide–Semiconductor-Field-Effect-Transistors by Random Telegraph Signal
Authors: Huang Da-Cheng , Gong Jeng , Huang Chih-Fang
Published: March 2013

We investigate the impact of positive and negative bias temperature instability (P/NBTI) on the current degradation by using the drain current random telegraph signal (I
dRTS) in high-κ gate dielectric and metal-gate MOSFETs. The samples were stressed at typical BTI oxide electric field (∼7 MV/cm) and I
dRTS amplitude (ΔI
dRTS) distributions were measured before and after P/NBTI stress. It is shown that I
dRTS degradation (ΔI
dRTS/I
dRTS) in NBTI devices exhibits a wider amplitude distribution than the PBTI one. In addition, we trace trapped charge-induced saturation current I
Dsat degradation in P/NBTI stress. As a result, the statistical analysis indicates that ΔI
Dsat/I
Dsat of the p-MOSFET is larger than ΔI
Dsat/I
Dsat of the n-MOSFET. Moreover, the lifetime of the device is numerically estimated based on current degradation with or without RTS. We consequently found that P/NBTI lifetime comes worse by considering the effect of RTS.
Bias-Assisted Photochemical Planarization of GaN(0001) Substrate with Damage Layer
Authors: Sadakuni Shun , Murata Junji , Sano Yasuhisa , Yagi Keita , Matsuyama Satoshi , Yamauchi Kazuto
Published: March 2013

An electrochemical polishing process for an n-GaN(0001) surface with a subsurface damage layer has been developed that involves irradiating with ultraviolet (UV) light and applying a voltage. In this method, a positively biased GaN substrate is exposed to UV light to oxidize its surface. The oxide layer does not dissolve in solution; rather it is chemically removed from the protruding region by a solid acid catalyst, which functions as a polishing pad. The wafer was prepared by mechanical polishing with diamond particles. Without a bias, the removal rate is quite low because photoinduced carriers are rapidly depleted through recombination at crystallographic defects. In contrast, when a bias is applied, photoinduced electrons and holes are forcibly separated so that they contribute to surface oxidation. Consequently, the damaged surface was effectively planarized when a bias was applied.
Electron Optical Properties of Microcolumn with Field Emitter
Authors: Neo Yoichiro , Koike Akifumi , Fujino Takahiro , Mimura Hidenori , Murata Hidekazu , Yoshida Tomoya , Nishi Takashi , Nagao Masayoshi
Published: March 2013

We present the electron optical properties of a newly designed microcolumn. The microcolumn consists of an objective lens and an electron gun, which is composed of a microscale field emitter and a condenser lens. An acceleration lens was used as the objective lens. Each component was optimized to maximize its own function while minimizing its impact on the functions of the other components. The current–voltage characteristics of each electrode were evaluated. The current variation characteristics of each electrode indicated that each optimized structure could be used to control the electron beam. The objective lens could also focus the electron beam to a diameter of approximately 40 µm at a working distance of 2 mm and 400× magnification when no acceleration electric field was applied between the microcolumn and the anode.
A novel approach for ultra‐deep adsorptive desulfurization of diesel fuel over TiO2–CeO2/MCM‐48 under ambient conditions
Authors: Xiao Jing , Wang Xiaoxing , Fujii Mamoru , Yang Qiujing , Song Chunshan
Published: March 2013

Significance

A novel approach for ultra‐deep desulfurization of diesel fuel was proposed, in which the original fuel was treated by light irradiation before adsorptive desulfurization (ADS) over the TiO2–CeO2/MCM‐48 adsorbent under ambient conditions. A superior capacity of 95 cm3‐fuel/g‐adsorbent (32 times higher than that of the original fuel) was achieved. The promoting effect of light irradiation was likely through in situ peroxides generation in fuel under visible light/sunlight, which may oxidize organosulfur to form strongly adsorbed sulfones over the adsorbent.
The Origin of the Emission Properties of π‐Conjugated Molecules that have an Acid‐responsive Benzimidazole Unit
Authors: Inouchi Toshifumi , Nakashima Takuya , Kawai Tsuyoshi
Published: March 2013

The photophysical properties, especially the emission properties, of π‐conjugated molecules with an acid‐responsive N‐methylbenzimidazole unit have been characterized and compared between T‐shaped cross‐conjugated and linear conjugated molecules. X‐ray crystal structures and optimized structures based on DFT calculations suggest a planar conformation of the 2‐thienyl‐N‐benzimidazole structure even after protonation where intramolecular S–N and NH–S interactions, respectively, are responsible for the stabilization of planar structures. Despite the planarity in the ground state, the T‐shaped cross‐conjugated molecules exhibit the twisted intramolecular charge‐transfer (TICT) emission in response to protonation, whereas the corresponding linear conjugated molecule without a horizontal π‐system does not have a charge‐transfer state. The difference in the separation of frontier molecular orbitals of the HOMO and LUMO and the energy barrier of the rotation about the thienyl ring predicted by the DFT calculations accounts for the difference in the emission decay process between the linear and cross‐conjugated molecules with a protonated benzimidazole unit. An orthogonally allocated π‐conjugated system appears to be essential for the emergence of TICT characteristics upon protonation in terms of the separation of molecular orbitals of the HOMOs and LUMOs, as well as the ease of rotation.
Parameters characterizing the kinetics of the nonisothermal crystallization of thermoplastic starch/poly(lactic acid) composites as determined by differential scanning calorimetry
Authors: Li Sha , Xiong Zhouyi , Fei Peng , Cai Jie , Xiong Hanguo , Tan Jun , Yu Yan
Published: March 2013

To guide the use of thermoplastic starch (TPS)/poly(lactic acid) (PLA) composites, the nonisothermal crystallization kinetics of pure PLA and TPS/PLA composites were investigated with differential scanning calorimetry (DSC) at three different cooling rates. The results indicate that the TPS/PLA composites showed different crystallizations because of their different contents and different cooling rates. TPS, as a nucleating agent, improved the crystallinity of the PLA and constrained the mobility of the PLA chains. Three theoretical models, namely, the Avrami, Ozawa, and Mo models, were used to describe the process of nonisothermal crystallization. The Avrami analysis modified by Jeziorny and the Mo method was successful in describing the nonisothermal crystallization process of the pure PLA and the TPS/PLA composites. However, the Ozawa analysis could not give an adequate description. Kinetic parameters such as the Avrami exponent, kinetic crystallization rate constant, relative degree of crystallinity, and crystallization enthalpy, among others, were determined at various scanning rates. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
High flux and rejection with chiral chitosan composite nanofiltration membranes: Preparation and characterization
Authors: Mu Tao , Cong Yuehua , Zhang Baoyan
Published: March 2013

Two series of novel composite nanofiltration (NF) membranes were prepared by the overcoating of polysulfone ultrafiltration membranes with a mixture of chitosan and chitosan derivatives modified with two different chiral compounds. The two chiral compounds and their chitosan derivatives were characterized by IR spectroscopy, differential scanning calorimetry, and polarimetry. The structure of the membrane was characterized by scanning electron microscopy (SEM). The rejection and flux of the composite NF membranes were strictly related to the chiral compound grafted to chitosan and its composition in the mixture. An extremely high rejection, 98.23%, was observed with P2–3 of the polymer (P2) composite NF membrane, and the flux remained as high as 351 L m−2 h−1 at 0.4 MPa with 1000 mg/L NaCl. These results, together with SEM and IR images of the composite NF membrane, indicated that the chiral compound structure was crucial for the structure and function of the composite membrane. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synergistic effects of β‐modification and impact polypropylene copolymer on brittle‐ductile transition of polypropylene random copolymer
Authors: Zhu Yanling , Luo Feng , Bai Hongwei , Wang Ke , Deng Hua , Chen Feng , Zhang Qin , Fu Qiang
Published: March 2013

In this work, the synergistic effects of β‐modification and impact polypropylene copolymer (IPC) on brittle–ductile (B–D) transition behavior of polypropylene random copolymer (PPR) have been investigated. It is interesting to find that adding both IPC and β‐nucleating agent into PPR has three effects: (i) leading to a significant enhancement in β‐crystallization capability of PPR, (ii) contributing to the shift of B–D transition to lower temperatures, (iii) increasing the B–D transition rate. The reason for these changes can be interpreted from the following two aspects. On one hand, the transition of crystalline structure from α‐form to β‐form reduces the plastic resistance of PPR matrix, thus causing the initiation of matrix shear yielding much easier during the impact process. On the other hand, the well dispersed rubbery phase in IPC with high molecular mobility at relatively low temperatures is beneficial to the shear yielding of PPR matrix and, subsequently, the great improvement in impact toughness of the ternary blends. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Dispersion control of immiscible polymer blend using selective heating by infrared laser irradiation
Authors: Saito Takushi , Kawaguchi Tatsuya , Satoh Isao
Published: March 2013

In this study, a selective heating technique by irradiating an infrared laser to an immiscible polymer blend was proposed to actively control the distribution of the dispersed phase in the blend. In the technique, the viscosity ratio between the matrix and dispersed phases was not changed by the molecular weight or shear rate but was changed by the controlled temperature distribution due to selective heating. The feasibility of the proposed technique was investigated through a numerical simulation of the temperature field and an experimental study using a test blend. The results showed that the technique successfully caused the deformation of relatively large droplets and enhanced the micro‐scale dispersion. It was also confirmed that the droplet size of the dispersed phase could be estimated by a simple method similar to the conventional technique: the chart of capillary number change with respect to the viscosity ratio. From the obtained results, it was concluded that the technique proposed in this study is a promising candidate for the development of a new blend process. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Properties of crosslinked polyurethanes obtained by acrylic side‐group polymerization and of their blends with various plant oils
Authors: Oprea Stefan
Published: March 2013

Novel polyurethane elastomers have been developed to incorporate plant oil into their matrix. Bisphenol A glycerolate diacrylate was used as a chain extender for the polyurethane prepolymer obtained from poly(tetramethylene oxide) glycol and 1,6‐hexane diisocyanate. The curing of the polyurethane acrylate matrix in the presence of the plant oil results in a network matrix which includes renewable resources in their structure. The effects of the inclusion of different vegetable oil (such as soybean oil, rapeseed oil, cotton oil, or sunflower oil) into the crosslinked polyurethane acrylates matrix were studied by evaluating various properties of the films such as the thermal behavior, the tensile properties, and the surface properties. The increases in chain extender content determine an increase of the thermal stability (the 10% weight loss decomposition temperatures increase from 325 to 375°C) and mechanical strength (from 3 to 9 MPa). Contact angle measurements have shown that the hydrophobic property of the films surface slightly increased with the incorporation of plant oil into the crosslinked polyurethane matrix. In addition, polyurethane/plant oil blends exhibit enhanced mechanical strength (from 3 to 9.8 MPa), as well as an increased roughness reaching a maximum average (113 nm) in the case of cotton oil. All polyurethane/plant oil blend present higher values for glass transition temperature and slightly enhanced values for thermal stability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation of hairy particles by grafting PEG onto the poly(styrene‐co‐maleic anhydride) surface and PEG effect on SiO2 nanoparticles adsorption
Authors: Song LinYong , Nie WangYan , Zhou YiFeng
Published: March 2013

Hairy particles were prepared by immobilization of poly(ethylene glycol) (PEG) on the surface of poly(styrene‐co‐maleic anhydride) (poly(S‐co‐MA)) spheres. It was found that the carbonyl groups on the poly(S‐co‐MA) surface can be conveniently esterified with the hydroxyl groups of PEG. Chemical and morphological changes were analyzed by FT‐IR, TEM, and water contact angle. Results revealed that, with the immobilization of PEG, the morphology of poly(S‐co‐MA) turned from a smooth surface to a hairy‐like structure and the hydrophilicity of the polymer particles improved. In addition, berry‐like polymer/silica particles can be obtained by using the hairy particles as template. The PEG hairy chains show steric repulsion during the deposition of silica nanoparticles by in situ sol‐gel process. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Journal impact and proximity: An assessment using bibliographic features
Authors: Ni Chaoqun , Shaw Debora , Lind Sean M. , Ding Ying
Published: March 2013

Journals in the Information Science & Library Science category of Journal Citation Reports (JCR) were compared using both bibliometric and bibliographic features. Data collected covered journal impact factor (JIF), number of issues per year, number of authors per article, longevity, editorial board membership, frequency of publication, number of databases indexing the journal, number of aggregators providing full‐text access, country of publication, JCR categories, Dewey decimal classification, and journal statement of scope. Three features significantly correlated with JIF: number of editorial board members and number of JCR categories in which a journal is listed correlated positively; journal longevity correlated negatively with JIF. Coword analysis of journal descriptions provided a proximity clustering of journals, which differed considerably from the clusters based on editorial board membership. Finally, a multiple linear regression model was built to predict the JIF based on all the collected bibliographic features.
Inducing terminologies from text: A case study for the consumer health domain
Authors: Muresan Smaranda , Klavans Judith L.
Published: March 2013

Specialized medical ontologies and terminologies, such as SNOMED CT and the Unified Medical Language System (UMLS), have been successfully leveraged in medical information systems to provide a standard web‐accessible medium for interoperability, access, and reuse. However, these clinically oriented terminologies and ontologies cannot provide sufficient support when integrated into consumer‐oriented applications, because these applications must “understand” both technical and lay vocabulary. The latter is not part of these specialized terminologies and ontologies. In this article, we propose a two‐step approach for building consumer health terminologies from text: 1) automatic extraction of definitions from consumer‐oriented articles and web documents, which reflects language in use, rather than relying solely on dictionaries, and 2) learning to map definitions expressed in natural language to terminological knowledge by inducing a syntactic‐semantic grammar rather than using hand‐written patterns or grammars. We present quantitative and qualitative evaluations of our two‐step approach, which show that our framework could be used to induce consumer health terminologies from text.
Bauzustandsanalyse und Instandsetzung von Nagelbindern
Authors: Rug Wolfgang , Paarmann Volker , Toppel Jörg
Published: March 2013

Seit 1930 werden in Deutschland Fachwerkbinder aus Brettern oder Bohlen und Nagelverbindungen mit Spannweiten bis 30 m hergestellt. Wegen ihrer Wirtschaftlichkeit wurden sie gerade häufig in den Zeiten verwendet, in denen eine sparsame Baustoffverwendung ökonomisch wichtig war. Bestehende Hallenkonstruktionen mit Nagelbindern können heute auch weiterhin ohne Einschränkung genutzt werden, wenn sie vor ihrer Um‐ und Weiternutzung einer fachkundigen Bauzustandsanalyse unterzogen werden. Der Beitrag befasst sich mit den Fragen der Analyse des Bauzustandes und der Beseitigung von typischen Baumängeln und Bauschäden. Vorgefundene Schäden und Baumängel können, wie die Beispiele zeigen, in aller Regel mit einfachen handwerklichen Methoden beseitigt werden.

Investigationstage of construction and maintenance of nail trusses

Since 1930 in Germany are manufactured trusses made of boards or planks and nail joints in lengths up to 30 m. Due to their efficiency, they were very often used in the days when an economical use of building materials was economically important. Existing indoor structures with nail trusses can now continue to be used without restriction if they are subjected to prior to implementation and continued use of a specialized construction stage analysis. The article deals with the issues of analysis of building condition and the elimination of typical construction defects and structural damages. Corpus of damage and construction defects can, as the examples show, are usually eliminated with simple craft methods.
Nord/Süd‐Metrolinie Amsterdam – Schild Transfer System (STS)
Authors: Friedemann Wolf , Fennker Jens‐Rüdiger , Schwitte Marion , Otten Frank
Published: March 2013

Der Bau der Nord/Süd‐Metrolinie Amsterdam in den Niederlanden ist ein herausforderndes Tunnelbauprojekt in innerstädtischer Umgebung. Aufgrund des vorhandenen Baugrunds, enger und abgetreppter Stationsbauwerke sowie dichter übertägiger Bebauung sind innovative Lösungen notwendig, um den maschinellen Tunnelvortrieb im Hydroschildmodus zu ermöglichen. Bei herkömmlichen Start‐ und Zielvorgängen für Hydroschildvortriebe im drückenden Grundwasser kommen gewöhnlich ein Dichtblock vor der Station und eine Brillendichtung bzw. ein kurzer Dichttopf in der Station zum Einsatz. Sie stellen ein redundantes System für Start‐/Zieldichtungen dar. Aus geometrischen Gründen ist dies beim Bau der Metrolinie in Amsterdam nicht immer möglich. Deshalb wurde das so genannte innovative Schild Transfer System (STS) entwickelt, mit dem alle erforderlichen Start‐ und Zieldichtebenen in die Station verlegt werden können. Ein wesentliches Merkmal des STS stellt die Möglichkeit des Transports der TBM durch die Stationen inklusive dem Überwinden von bis zu 1,65 m hohen Stufen dar. Der nachfolgende Artikel beschreibt die Konstruktion des STS aus statischer und baubetrieblicher Sicht und erläutert die Unterschiede zu herkömmlichen Start‐ und Zielvorgängen.

North/South Metro Line Amsterdam – Shield Transfer System (STS) – a technical innovation for the construction of a metro tunnel in urban environment

The construction of the North/South metro line in Amsterdam, the Netherlands, is a challenging tunnelling project in an urban environment. Innovation and creativity are needed to enable tunnelling with a mixed shield TBM, which considers the existing ground conditions, the narrow station structures and the densely built‐up areas on the surface. A sealing block in front of the station and lip sealing or a short sealing pot within the station are usually used for conventional launch and arrival situations of mixed shield tunnelling in pressurized groundwater conditions. They represent a redundant system for launch and arrival situations. Due to geometric reasons, these sealing systems cannot always be used in the construction of the Metro Line in Amsterdam. Therefore, the innovative Shield Transfer System (STS) was developed. The big advantage of which is that all the required launch and arrival sealing systems can be installed inside the stations. The transfer of the TBM through the stations, including the lifting over the steps (heights of up to 1.65 m), is an essential feature of the STS. The following article describes the construction of the STS from a static and constructional point of view and is explaining the differences with respect to conventional launch and arrival situations.
Begehbare Achterbahn in Duisburg
Authors: Staffa Michael , Kemme Carola
Published: March 2013

Eine begehbare Großskulptur wurde 2011 auf einem Abraumhügel in Duisburg erbaut. Auf ein doppelt gekrümmtes Hauptrohr wurde die Gehbahn als unregelmäßige Treppe mit einem Belag aus Gitterrosten aufgebracht. Die Konstruktion wurde mit Hilfe eines parametrischen Geometriemodells geplant. Dieses Modell ermöglichte die Planung des geometrisch extrem schwierigen Projekts. Auf Grund der schlechten Bodenverhältnisse und der daher sehr geringen zulässigen Bodenpresssung musste die Gründung ungewöhnlich stark dimensioniert werden. Wegen der Schwingungsanfälligkeit der Konstruktion wurden an signifikanten Stellen Horizontal‐Dämpfer eingebaut.

An accessible rollercoaster in Duisburg

An accessible oversize sculpture was built in 2011 on an excavation heap in Duisburg. On a double curved tube a footway was applied with unregular stairs of steel gratings. The structure was planned with aid of a parametric model. This model enabled the design of the geometrically extreme difficult project. Due to the bad soil conditions and for this reason the low soil strength, the foundations had to be dimensioned exceptionally huge. Vibration absobers were assembled on significant places in order to insulate horizontal oscillation.
Brückenertüchtigung – eine notwendige Voraussetzung für ein zuverlässiges Fernstraßennetz
Authors: Colditz Brit
Published: March 2013

Das prognostizierte Verkehrsaufkommen geht von einer starken Zunahme des Güterverkehrs auf den Straßen aus. Dies wird zukünftig zu einer noch stärkeren Auslastung und damit zu einer noch größeren Beanspruchung der Brücken führen. Viele ältere Brücken können den stetig wachsenden Anforderungen nicht mehr uneingeschränkt standhalten. Bei diesen Bauwerken, darunter auch zahlreiche große Tal‐ und Strombrücken, treten zunehmend Abnutzungserscheinungen und Schäden auf. Sie befinden sich fast ausschließlich in den alten Bundesländern. Es stellt sich die Frage, wie diese Brücken weiter genutzt oder auch ertüchtigt werden können. Mit der vom Bundesministerium für Verkehr, Bau und Stadtentwicklung entwickelten Strategie zur Nachrechnung und Ertüchtigung des Brückenbestandes wurde gemeinsam mit der Bundesanstalt für Straßenwesen und den Straßenbauverwaltungen der Länder ein bundeseinheitliches Vorgehen erarbeitet. Dieses Konzept sieht vor, bei jeder einzelnen der betroffenen Brücken zu prüfen, ob sie den Anforderungen des heutigen und zukünftigen Schwerverkehrs noch genügt. Die eigens dafür erarbeitete so genannte Nachrechnungsrichtlinie bildet das Kernstück dieser Aufgabe. Es gilt, sowohl den Bauwerkszustand der Straßenbrücken zu verbessern als auch Defizite bei der Tragfähigkeit zu beseitigen. Ziel aller Anstrengungen muss es sein, umfangreiche Verkehrseinschränkungen bis hin zur Sperrung einer Brücke zu verhindern.

Bridge strengthening – a necessary prerequisite for a reliable highway network

The traffic forecast assumes a sharp increase in goods transport by road. In the future, this will result in an even higher traffic load and thus to an even higher degree of wear of the bridges. Many older bridges can no longer fully meet the continually increasing requirements. These structures, including many large valley and river bridges, are affected more and more by wear and tear and damages. They are located almost exclusively in the old federal states. The question arises as to how these bridges can be used or even strengthened in the future. With the strategy for post‐test calculations and strengthening of the bridge stock developed by the Federal Ministry of Transport, Building and Urban Development a nationally uniform approach was elaborated together with the Federal Highway Institute and the road construction administration of the federal states. This concept aims at examining for everyone of the individual bridges concerned whether it still meets the requirements of heavy‐goods transport today and in the future. The so‐called post‐test calculation guideline specially developed for this purpose forms the core of this task. What needs to be done is to improve the structural condition of the road bridges as well as to eliminate deficits of the load‐bearing capacity. The objective of all efforts has to be the prevention of extensive traffic restrictions up to the closure of a bridge.
Überwerfungsbauwerke VleuGel, Utrecht
Authors: Breuer Klaus
Published: March 2013

Die Eisenbahnstrecken in den Niederlanden gehören zu den am stärksten belasteten Strecken der Welt. Mit dem Projekt “VleuGel” bei Utrecht wird durch die Gleiserweiterung deutlich mehr Streckenkapazität geschaffen. Technisch anspruchsvoll sind insbesondere drei Bauwerke: “Diveunders”, “Viadukt A27” und “Unterführung Fortweg”. Für die “Diveunders” benötigt man 31650 m2 dauerhafte Schlitzwände für ein neues Überwerfungsbauwerk. Die Herstellung erfolgte bei laufendem Gleisbetrieb zwischen den Bahngleisen und der angrenzenden Bebauung. An die sichtbaren Schlitzwände wurden hohe Anforderungen hinsichtlich Betonqualität, Wasserdichtigkeit und Maßgenauigkeit gestellt. Heijmans Civiel (Rosmalen, NL) erhielt den Auftrag von ProRail für die komplette Baumaßnahme und beauftragte die Franki Grundbau mit der Ausführung der Schlitzwandarbeiten.

Crossing construction, VleuGel, Utrecht

The railway lines in the Netherlands are among the busiest in the world. The “VleuGel” project near Utrecht will create significantly more rail capacity by providing more track. Three structures are particularly technically demanding: “Dive unders”, “Viaduct A27” and “Fortweg Underpass”. For the “Dive unders” 31650 m2 of permanent diaphragm wall were needed for the construction of the crossing. The construction was carried out between the rail tracks and the adjoining developments under continuing rail traffic. High demands were made on the visible diaphragm walls in regard to quality of the concrete, watertightness and dimensional accuracy. ProRail awarded the contract for the complete building construction to Heijmans Civiel (Rosmalen, NL), who contracted Franki Grundbau with the construction of the diaphragm walls.
Zur Planung und Ausführung von Ziegeldecken nach neuer DIN 1045‐100 mit Eurocode 2
Authors: Fingerloos Frank , Jedamzik Heinz‐Werner , Kranzler Thomas
Published: March 2013

Ziegeldecken (früher auch als “Stahlsteindecken” bezeichnet) bestehen aus Deckenziegeln, Betonrippen und Betonstahl, deren Zusammenwirken im Verbund zur Aufnahme der Schnittgrößen erforderlich ist. Ziegeldecken weisen gegenüber vergleichbaren Vollplatten aus Ortbeton geringere Eigenlasten und teilweise günstigere bauphysikalische Eigenschaften auf. Sie sind relativ einfach auf der Baustelle zu verlegen, zu bewehren und auszubetonieren. Sie eignen sich daher auch besonders gut beim Bauen im Bestand. In der Regel werden Ziegeldecken heutzutage jedoch als vorgefertigte Deckenelemente im Neubau verlegt. Ende 2011 wurde eine überarbeitete Ausgabe DIN 1045‐100: “Bemessung und Konstruktion von Stahlbeton‐ und Spannbetontragwerken – Teil 100: Ziegeldecken” herausgegeben. Diese wurde zusammen mit dem Eurocode 2 im Juli 2012 bauaufsichtlich in Deutschland eingeführt. Im folgenden Beitrag wird auf die Überarbeitung der normativen Regeln für Ziegeldecken und auf ihre Bemessung und Ausführung eingegangen.

Design and construction of clay block floor plates in accordance with new DIN 1045‐100 and Eurocode 2

Floor plates made with clay blocks (formerly also referred to as “reinforced block slabs”) consist of special clay blocks for floors, concrete ribs and reinforcing steel. These three components form a bond that is necessary to take up the internal forces. Compared to solid cast‐in‐place slabs, clay block floor plates have a lower self weight and, to a certain extent, more favorable thermal characteristics. It is relatively easy to lay the clay blocks on a formwork, to reinforce and to concrete the ribs. They are thus particularly suitable for modernizing and upgrading existing buildings. Nowadays in general brick clay block floor plates are installed as precast floor elements in new construction projects.

At the end of 2011 a revised standard DIN 1045‐100: Design and construction of reinforced concrete and prestressed concrete structures – Part 100: Brick floors has been published in order to be introduced in Germany together with Eurocode 2 in July 2012. The following paper gives an overview about the overwork of the standard rules for clay block floor plates and about their design and construction.