bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of 2008 Kasatochi volcanic sulfate direct radiative forcing: assimilation of OMI SO2 plume height data and comparison with MODIS and CALIOP observations
Authors: Wang J. , Park S. , Zeng J. , Ge C. , Yang K. , Carn S. , Krotkov N. , Omar A. H.
Published: February 2013

Abstract. Volcanic SO2 column amount and injection height retrieved from the Ozone Monitoring Instrument (OMI) with the Extended Iterative Spectral Fitting (EISF) technique are used to initialize a global chemistry transport model (GEOS-Chem) to simulate the atmospheric transport and lifecycle of volcanic SO2 and sulfate aerosol from the 2008 Kasatochi eruption, and to subsequently estimate the direct shortwave, top-of-the-atmosphere radiative forcing of the volcanic sulfate aerosol. Analysis shows that the integrated use of OMI SO2 plume height in GEOS-Chem yields: (a) good agreement of the temporal evolution of 3-D volcanic sulfate distributions between model simulations and satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar with Orthogonal Polarisation (CALIOP), and (b) an e-folding time for volcanic SO2 that is consistent with OMI measurements, reflecting SO2 oxidation in the upper troposphere and stratosphere is reliably represented in the model. However, a consistent (~25%) low bias is found in the GEOS-Chem simulated SO2 burden, and is likely due to a high (~20%) bias of cloud liquid water amount (as compared to the MODIS cloud product) and the resultant stronger SO2 oxidation in the GEOS meteorological data during the first week after eruption when part of SO2 underwent aqueous-phase oxidation in clouds. Radiative transfer calculations show that the forcing by Kasatochi volcanic sulfate aerosol becomes negligible 6 months after the eruption, but its global average over the first month is −1.3 Wm−2, with the majority of the forcing-influenced region located north of 20° N, and with daily peak values up to −2 Wm−2 on days 16–17. Sensitivity experiments show that every 2 km decrease of SO2 injection height in the GEOS-Chem simulations will result in a ~25 % decrease in volcanic sulfate forcing; similar sensitivity but opposite sign also holds for a 0.03 μm increase of geometric radius of the volcanic aerosol particles. Both sensitivities highlight the need to characterize the SO2 plume height and aerosol particle size from space. While more research efforts are warranted, this study is among the first to assimilate both satellite-based SO2 plume height and amount into a chemical transport model for an improved simulation of volcanic SO2 and sulfate transport.
Factors determining the formation of secondary inorganic aerosol: a case study in the Po Valley (Italy)
Authors: Squizzato S. , Masiol M. , Brunelli A. , Pistollato S. , Tarabotti E. , Rampazzo G. , Pavoni B.
Published: February 2013

Abstract. Physicochemical properties of aerosol were investigated by analyzing the inorganic water soluble content in PM2.5 samples collected in the eastern part of the Po Valley (Italy). In this area the EU limits for many air pollutants are frequently exceeded as a consequence of local sources and regional-scale transport of secondary inorganic aerosol precursors. Nine PM2.5-bound major inorganic ions (F−, Cl−, NO3−, SO42−, Na+, NH4+, K+, Mg2+, Ca2+) were monitored over one year in three sites categorized as semi-rural background, urban background and industrial. The acidic properties of the PM2.5 were studied by applying the recently developed E-AIM thermodynamic model 4 (Extended Aerosol Thermodynamics Model). The experimental data were also examined in relation to the levels of gaseous precursors of secondary inorganic aerosol (SO2, NOx, NO, NO2) and on the basis of some environmental conditions having an effect on the secondary aerosols generation processes. A chemometric procedure using cluster analysis on experimental [NH4+]/[SO42−] molar ratio and NO3− concentration has been applied to determine the conditions needed for ammonium nitrate formation in different chemical environments. Finally, some considerations on the secondary inorganic aerosol formation and the most relevant weather conditions concerning the sulfate-nitrate-ammonium system were also discussed. The obtained results and discussion can help in understanding the secondary aerosol formation dynamics in the Po Valley, which is one of the most critical regions for air pollution in southern Europe.
Global CO2 fluxes estimated from GOSAT retrievals of total column CO2
Authors: Basu S. , Guerlet S. , Butz A. , Houweling S. , Hasekamp O. , Aben I. , Krummel P. , Steele P. , Langenfelds R. , Torn M. , Biraud S. , Stephens B. , Andrews A. , Worthy D.
Published: February 2013

Abstract. We present one of the first estimates of the global distribution of CO2 surface fluxes using total column CO2 measurements retrieved from the Greenhouse gases Observing SATellite (GOSAT). We derive optimized fluxes from June 2009 to December 2010. We estimate fluxes from surface CO2 measurements to use as baselines for comparing GOSAT data-derived fluxes. Assimilating only GOSAT data, we can reproduce the observed CO2 time series at surface and TCCON sites in the tropics and the northern extra-tropics. In contrast, in the southern extra-tropics GOSAT XCO2 leads to enhanced seasonal cycle amplitudes compared to independent measurements, and we identify it as the result of a land-sea bias in our GOSAT XCO2 retrievals. A bias correction in the form of a global offset between GOSAT land and sea pixels in a joint inversion of satellite and surface measurements of CO2 yields plausible global flux estimates which are more tightly constrained than in an inversion using surface CO2 data alone. We show that assimilating the bias-corrected GOSAT data on top of surface CO2 data (a) reduces the estimated global land sink of CO2, and (b) shifts the terrestrial net uptake of carbon from the tropics to the extra-tropics. It is concluded that while GOSAT total column CO2 provide useful constraints for source-sink inversions, small spatiotemporal biases – beyond what can be detected using current validation techniques – have serious consequences for optimized fluxes, even aggregated over continental scales.
The diurnal and semidiurnal tides over Ascension Island (8° S, 14° W) and their interaction with the stratospheric QBO: studies with meteor radar, eCMAM and WACCM
Authors: Davis R. N. , Du J. , Smith A. K. , Ward W. E. , Mitchell N. J.
Published: February 2013

Abstract. Horizontal winds in the mesosphere have been measured over Ascension Island (8° S, 14° W) in the tropical mid-Atlantic region throughout the years 2002–2011. The observations were made by a VHF meteor radar. The results reveal the presence of atmospheric tides of large amplitude. The results are analysed to characterise the seasonal and interannual variability of the diurnal and semidiurnal tides. Monthly-mean diurnal tidal amplitudes are found to reach values as large as 48 m s−1 in the meridional component and 41 m s−1 in the zonal. A semiannual seasonal variation is found in diurnal-tidal amplitudes with amplitude maxima at the equinoxes and amplitude minima at the solstices. Diurnal tidal meridional vertical wavelengths are generally in the range 24–30 km. The diurnal zonal vertical wavelengths are similar to the meridional, except for the winter months when the zonal vertical wavelengths are much longer, occasionally exceeding 100 km. Semidiurnal amplitudes are observed to be significantly smaller than diurnal amplitudes. Semidiurnal vertical wavelengths range from 20 to more than 100 km. Our observations of tidal amplitudes and phases are compared with the predictions of the extended Canadian Middle Atmosphere Model (eCMAM) and the Whole Atmosphere Community Climate Model (WACCM). Both eCMAM and WACCM reproduce the trend for greater diurnal amplitudes in the meridional component than the zonal. However, in winter eCMAM tends to over-estimate meridional amplitudes, while WACCM under-estimates zonal and meridional amplitudes. Semidiurnal amplitude predictions are generally good for both models. Vertical wavelength predictions are also generally good for both models, however eCMAM predicts shorter zonal vertical wavelengths than observed for the diurnal tide in winter, while WACCM predicts longer zonal semidiurnal vertical wavelengths than observed for most months. It is found that larger-than-average diurnal and semidiurnal tidal amplitudes occur when the stratospheric QBO at 10 hPa is eastwards, and smaller-than-average amplitudes occur when it is westwards. However, the precise mechanism for this modulation of tidal amplitudes by the stratospheric QBO remains unclear.
Subsurface low pH and carbonate saturation state of aragonite on China side of the North Yellow Sea: combined effects of global atmospheric CO2 increase, regional environmental changes, and local biogeochemical processes
Authors: Zhai W.-D. , Zheng N. , Huo C. , Xu Y. , Zhao H.-D. , Li Y.-W. , Zang K.-P. , Wang J.-Y. , Xu X.-M.
Published: February 2013

Abstract. Based upon seven field surveys conducted between May 2011 and January 2012, we investigated pH, carbonate saturation state of aragonite (Ωarag), and ancillary parameters on the Chinese side of the North Yellow Sea, a western North Pacific continental margin of major economic importance. Subsurface waters were nearly in equilibrium with air in May and June. From July to October, the fugacity of CO2 (fCO2) of bottom water gradually increased to 697 ± 103 μatm and pH decreased to 7.83 ± 0.07 due to respiration/remineralization processes of primary production induced biogenic particles. In November and January, bottom water fCO2 decreased and pH gradually returned to an air-equilibrated level due to cooling enhanced vertical mixing. The corresponding bottom water Ωarag was 1.74 ± 0.17 (May), 1.77 ± 0.26 (June), 1.70 ± 0.26 (July), 1.72 ± 0.33 (August), 1.32 ± 0.31 (October), 1.50 ± 0.28 (November), and 1.41 ± 0.12 (January). Critically low Ωarag values of 1.0 to 1.2 were mainly observed in subsurface waters in a salinity range of 31.5–32.5 psu in October and November, accounting for ~ 10% of the North Yellow Sea area. Water mass derived from the adjacent Bohai Sea had a typical water salinity of 30.5–31.5 psu, and bottom water Ωarag values ranged mostly between 1.6 and 2.4. This study showed that the carbonate system in the North Yellow Sea was substantially influenced by global atmospheric CO2 increase. The community respiration/remineralization rates in typical North Yellow Sea bottom water mass were estimated at 0.55–1.0 μmol O2 kg−1 d−1 in warm seasons, leading to seasonal drops in subsurface pH and Ωarag. Outflow of the Bohai Sea water mass counteracted the subsurface Ωarag reduction in the North Yellow Sea.
A new permanent multi-parameter monitoring network in Central Asian high mountains – from measurements to data bases
Authors: Schöne T. , Zech C. , Unger-Shayesteh K. , Rudenko V. , Thoss H. , Wetzel H.-U. , Gafurov A. , Illigner J. , Zubovich A.
Published: February 2013

Abstract. Long-term monitoring of water resources and climate parameters at the scale of river basins requires networks of continuously operated in-situ stations. Since 2009, GFZ and CAIAG, in cooperation with the National Hydrometeorological Services (NHMS) of Central Asia, are establishing such a regional monitoring network in Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan, and lately Afghanistan to collect observations of meteorological and hydrological parameters and to deliver them to the end-users for operational tasks and scientific studies. The newly developed and installed remotely operated multi-parameter stations (ROMPS) do not only monitor standard meteorological and hydrological parameters, but also deliver Global Navigation Satellite System (GNSS) data for atmospheric sounding as well as tectonic studies. Additionally, three stations integrate seismic sensors for earthquake monitoring. The observational data from the ROMPS is transmitted nominally in near-real time, but at least once a day to a centralized geo-database infrastructure for long-term storage and data redistribution. Users can access the data manually using a web-interface or automatically using SOS requests; in addition, data is planed to be distributed to the NHMS through standard communication and data exchange channels.
Benefits from using combined dynamical-statistical downscaling approaches – lessons from a case study in the Mediterranean region
Authors: Guyennon N. , Romano E. , Portoghese I. , Salerno F. , Calmanti S. , Petrangeli A. B. , Tartari G. , Copetti D.
Published: February 2013

Abstract. Various downscaling techniques have been developed to bridge the scale gap between global climate models (GCMs) and finer scales required to assess hydrological impacts of climate change. Such techniques may be grouped into two downscaling approaches: the deterministic dynamical downscaling (DD) and the statistical downscaling (SD). Although SD has been traditionally seen as an alternative to DD, recent works on statistical downscaling have aimed to combine the benefits of these two approaches. The overall objective of this study is to assess whether a DD processing performed before the SD permits to obtain more suitable climate scenarios for basin scale hydrological applications starting from GCM simulations. The case study presented here focuses on the Apulia region (South East of Italy, surface area about 20 000 km2), characterised by a typical Mediterranean climate; the monthly cumulated precipitation and monthly mean of daily minimum and maximum temperature distribution were examined for the period 1953–2000. The fifth-generation ECHAM model from the Max-Planck-Institute for Meteorology was adopted as GCM. The DD was carried out with the Protheus system (ENEA), while the SD was performed through a monthly quantile-quantile correction. The SD resulted efficient in reducing the mean bias in the spatial distribution at both annual and seasonal scales, but it was not able to correct the miss-modelled non-stationary components of the GCM dynamics. The DD provided a partial correction by enhancing the spatial heterogeneity of trends and the long-term time evolution predicted by the GCM. The best results were obtained through the combination of both DD and SD approaches.
Dynamic decision making for dam-break emergency management – Part 1: Theoretical framework
Authors: Peng M. , Zhang L. M.
Published: February 2013

Abstract. An evacuation decision for dam breaks is a very serious issue. A late decision may lead to loss of lives and properties, but a very early evacuation will incur unnecessary expenses. This paper presents a risk-based framework of dynamic decision making for dam-break emergency management (DYDEM). The dam-break emergency management in both time scale and space scale is introduced first to define the dynamic decision problem. The probability of dam failure is taken as a stochastic process and estimated using a time-series analysis method. The flood consequences are taken as functions of warning time and evaluated with a human risk analysis model (HURAM) based on Bayesian networks. A decision criterion is suggested to decide whether to evacuate the population at risk (PAR) or to delay the decision. The optimum time for evacuating the PAR is obtained by minimizing the expected total loss, which integrates the time-related probabilities and flood consequences. When a delayed decision is chosen, the decision making can be updated with available new information. A specific dam-break case study is presented in a companion paper to illustrate the application of this framework to complex dam-breaching problems.
Near-surface measurements of sea spray aerosol production over whitecaps in the open ocean
Authors: Norris S. J. , Brooks I. M. , Moat B. I. , Yelland M. J. , de Leeuw G. , Pascal R. W. , Brooks B.
Published: February 2013

Abstract. Simultaneous measurements of near-surface aerosol (0.12 < R < 9.25 μm) and bubble spectra (13 < R < 620 μm) were made during five buoy deployments in the open ocean of the North Atlantic and used to estimate aerosol fluxes per unit area of whitecap. The measurements were made during two cruises as part of the Sea Spray, Gas Flux, and Whitecaps (SEASAW) project, a UK contribution to the international Surface Ocean Lower Atmosphere Study (SOLAS) program. The mean bubble number concentrations for each deployment are in broad agreement with other open ocean spectra and are consistently one to two orders of magnitude lower than surf zone studies. Production fluxes per unit area of whitecap are estimated from the mean aerosol concentration for each buoy deployment. They are found to increase with wind speed, and span the range of values found by previous laboratory and surf-zone studies for particles with radius at 80% relative humidity, R80 < 1 μm, but to drop off more rapidly with increasing particle size for larger particles. Estimates of the mean sea spray flux were made by scaling the whitecap production fluxes with in situ estimates of whitecap fraction. The sea spray fluxes are also compared with simultaneous individual eddy covariance flux estimates, and with a sea spray source function derived from them.
Impact of the Indonesian throughflow on Agulhas leakage
Authors: Le Bars D. , Dijkstra H. A. , De Ruijter W. P. M.
Published: February 2013

Abstract. Using ocean models of different complexity we show that opening the Indonesian Passage between the Pacific and the Indian Ocean increases the input of Indian Ocean water into the South Atlantic via the Agulhas leakage. In a strongly eddying global ocean model this response results from an increased Agulhas Current transport and a constant proportion of Agulhas retroflection south of Africa. The leakage increases through an increased frequency of ring shedding events. In an idealized two-layer and flat-bottom eddy resolving model, the proportion of the Agulhas Current transport that retroflects is (for a wide range of wind stress forcing) not affected by an opening of the Indonesian Passage. A linear ocean model is not able to explain this behavior which reveals the importance of mixed barotropic/baroclinic instabilities in controlling the Agulhas leakage.
High sensitivity of tidewater outlet glacier dynamics to shape
Authors: Enderlin E. M. , Howat I. M. , Vieli A.
Published: February 2013

Abstract. Variability in tidewater outlet glacier behavior under similar external forcing has been attributed to differences in outlet shape (i.e. bed elevation and width), but this dependence has not been investigated in detail. Here we use a numerical ice flow model to show that the dynamics of tidewater outlet glaciers under external forcing are highly sensitive to width and bed topography. Our sensitivity tests indicate that for glaciers with similar discharge, the trunks of wider glaciers and those grounded over deeper basal depressions tend to be closer to flotation, so that less dynamically induced thinning results in rapid, unstable retreat following a perturbation. The lag time between the onset of the perturbation and unstable retreat varies with outlet shape, which may help explain intra-regional variability in tidewater outlet glacier behavior. Further, because the perturbation response is dependent on the thickness relative to flotation, varying the bed topography within the range of observational uncertainty can result in either stable or unstable retreat due to the same perturbation. Thus, extreme care must be taken when interpreting the future behavior of actual glacier systems using numerical ice flow models that are not accompanied by comprehensive sensitivity analyses.
The Public Affairs Party: The Political Enterprise of a Business Firm Party
Authors: Hloušek Vít
Published: February 2013

The paper is devoted to the analysis of the Public Affairs Party, which entered the Czech House of Deputies after the 2010 parliamentary elections. The aim of the paper is to cover organizational matters and certain peculiarities of the party. As the most appropriate tool of analysis, the concept of a business firm party is used. The author shows how the political and economic interests of the party’s most influential member, Vít Bárta, overlapped significantly and that Bárta could be depicted as a kind of “political entrepreneur” misusing political activity for his business purposes. The analysis of the functioning of the Public Affairs Party and especially the distribution of power inside the party shows, in comparison to classical examples of business firm parties, that Public Affairs embodies a new way of intersecting politics and business practices: the already existing party was taken over (in a hostile way, to use the language of business) by a business company.
Zpráva z konference výzkumné skupiny IPSA pro politickou komunikaci
Authors: Hrbková Lenka , Zagrapan Jozef
Published: February 2013

Ve dnech 8. a 9. listopadu 2012 se v Brně konala konference Political Communication Sessions výzkumné skupiny IPSA pro politickou komunikaci (neboli RC 22). Jednalo se o první akci tohoto typu v České republice, kterou spolu s RC 22 organizovala katedra politologie a Mezinárodní politologický ústav FSS.
UNC93B1 mediates differential trafficking of endosomal TLRs
Authors: Lee Bettina L , Moon Joanne E , Shu Jeffrey H , Yuan Lin , Newman Zachary R , Schekman Randy , Barton Gregory M
Published: February 2013

UNC93B1, a multipass transmembrane protein required for TLR3, TLR7, TLR9, TLR11, TLR12, and TLR13 function, controls trafficking of TLRs from the endoplasmic reticulum (ER) to endolysosomes. The mechanisms by which UNC93B1 mediates these regulatory effects remain unclear. Here, we demonstrate that UNC93B1 enters the secretory pathway and directly controls the packaging of TLRs into COPII vesicles that bud from the ER. Unlike other COPII loading factors, UNC93B1 remains associated with the TLRs through post-Golgi sorting steps. Unexpectedly, these steps are different among endosomal TLRs. TLR9 requires UNC93B1-mediated recruitment of adaptor protein complex 2 (AP-2) for delivery to endolysosomes while TLR7, TLR11, TLR12, and TLR13 utilize alternative trafficking pathways. Thus, our study describes a mechanism for differential sorting of endosomal TLRs by UNC93B1, which may explain the distinct roles played by these receptors in certain autoimmune diseases.
Different routes to the same destination
Authors: Hayashi Kachiko , Iwasaki Akiko
Published: February 2013

The toll-like receptors that detect viral DNA and viral RNA in cells take different paths from the endoplasmic reticulum to the endosome.
Direct detection pays off for electron cryo-microscopy
Authors: Grigorieff Nikolaus
Published: February 2013

Improved electron detectors and image-processing techniques will allow the structures of macromolecules to be determined from tens of thousands of single-particle cryo-EM images, rather than the hundreds of thousands needed previously.
Phytoplankton Diversity in Offshore, Port and Ballast Water of a Foreign Vessel in Negros Occidental, Philippines
Authors: Sarinas Brian Gil S. , Gellada Lorna D. , Teruňez Marlon R. , Flores June Raymund Peter V. , Hisanan Aaron C. , Garzon Jomar Rey B. , Tiangao Erviwynn M. , Morato Kier Nicole , Envidiado Dennis Albert
Published: February 2013

Introduction of harmful aquatic organisms and pathogens in our ocean is one of the greatest threats according to the IMO (International Maritime Organization). Alien or invasive species travel from one ocean to the other through ballast water from the international shipping industry which is very inevitable. In the Philippines, few existing studies were established on phytoplankton composition in ballast tanks of a foreign vessel; thus this study is conducted. This study aimed to identify the phytoplankton diversity of offshore, port and ballast water from a foreign vessel docking in Negros Occidental, Philippines. Furthermore, this study aimed to determine the cell density, generic diversity and evenness and physicochemical characteristics such as pH, temperature and salinity. A total of 39 liters were taken from the middle column of the offshore, port and ballast tanks through sounding pipe and siphon technique. Temperature, pH and salinity were measured, in situ. All water samples were preserved with Lugol’s solution and transported in the Phycology laboratory at Southeast Asian Fisheries Development Center-AQD. This study provides baseline information on phytoplankton diversity present in offshore, port and ballast water from a foreign-going vessel in the Philippines.   Keywords - ecology and conservation, ballast water, phytoplankton, generic diversity, ballast water sampling, generic evenness, Negros Occidental, Philippines
Understanding the Reduced Efficiencies of Organic Solar Cells Employing Fullerene Multiadducts as Acceptors
Authors: Faist Mark A. , Shoaee Safa , Tuladhar Sachetan , Dibb George F. A. , Foster Samuel , Gong Wei , Kirchartz Thomas , Bradley Donal D. C. , Durrant James R. , Nelson Jenny
Published: February 2013

The use of fullerenes with two or more adducts as acceptors has been recently shown to enhance the performance of bulk‐heterojunction solar cells using poly(3‐hexylthiophene) (P3HT) as the donor. The enhancement is caused by a substantial increase in the open‐circuit voltage due to a rise in the fullerene lowest unoccupied molecular orbital (LUMO) level when going from monoadducts to multiadducts. While the increase in the open‐circuit voltage is obtained with many different polymers, most polymers other than P3HT show a substantially reduced photocurrent when blended with fullerene multiadducts like bis‐PCBM (bis adduct of Phenyl‐C61‐butyric acid methyl ester) or the indene C60 bis‐adduct ICBA. Here we investigate the reasons for this decrease in photocurrent. We find that it can be attributed partly to a loss in charge generation efficiency that may be related to the LUMO‐LUMO and HOMO‐HOMO (highest occupied molecular orbital) offsets at the donor‐acceptor heterojunction, and partly to reduced charge carrier collection efficiencies. We show that the P3HT exhibits efficient collection due to high hole and electron mobilities with mono‐ and multiadduct fullerenes. In contrast the less crystalline polymer Poly[[9‐(1‐octylnonyl)‐9H‐carbazole‐2,7‐diyl]‐2,5‐thiophenediyl‐2,1,3‐benzothiadiazole‐4,7‐diyl‐2,5‐thiophenediyl (PCDTBT) shows inefficient charge carrier collection, assigned to low hole mobility in the polymer and low electron mobility when blended with multiadduct fullerenes.
Von Ein‐ zu Zwei‐Photonen‐Sonden: photoaktivierbare Reagentien, Aktuatoren und Photoschalter
Authors: Bort Guillaume , Gallavardin Thibault , Ogden David , Dalko Peter I.
Published: February 2013

Molekulare Systeme, die mit Licht “ferngesteuert” werden können, sind von wachsender Bedeutung in der Zellbiologie, der Physiologie und den Neurowissenschaften. Der entscheidende Aspekt hierbei ist die hohe räumliche und zeitliche Präzision, die mit Methoden der Lasermikroskopie erreicht werden kann. Das Verfahren der Zwei‐Photonen‐Anregung hat signifikante Vorzüge bei der Visualisierung biologischer Gewebe, allerdings ist der gezielte Entwurf intelligenter Sonden, die mit der Zellphysiologie kompatibel sind, nicht trivial. Dieser Aufsatz diskutiert die “chemischen” Herausforderungen bei der Entwicklung von Zwei‐Photonen‐Sonden.
Grafting polymerization of polylactic acid on the surface of nano‐SiO2 and properties of PLA/PLA‐grafted‐SiO2 nanocomposites
Authors: Wu Feng , Lan Xiaorong , Ji Deyun , Liu Zhengying , Yang Wei , Yang Mingbo
Published: February 2013

Poly(lactic acid) (PLA) chains are directly grafted onto a silicon surface by in situ amidation and PLA/PLA‐grafted SiO2 nanocomposites are compounded using a Haake torque rheometer. To have a better understanding of the interaction between grafted polymer chains and PLA matrix, thermal, and rheological properties of PLA/PLA‐grafted SiO2 nanocomposites are explored. DSC analysis shows that PLA‐grafted‐SiO2 can accelerate the cold crystallization rate and increase the degree of crystallinity of PLA. Shear rheology testing indicates that PLA/PLA‐grafted‐SiO2 nanocomposites still exhibits the typical homopolymer‐like terminal behavior at low frequency range even at a content of PLA‐grafted‐SiO2 of 5 wt %, compared to PLA/SiO2, it is also found that the nanocomposites show stronger shear‐thinning behaviors in the high frequency region after grafting. In addition, elongation viscosity testing shows the entanglement between grafted chains and matrix that is needed to improve the melt strength of PLA. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Plastic waste minimization: Compatibilization of polypropylene/polyamide 6 blends by polyalkenyl‐poly‐maleic‐anhydride‐based agents
Authors: Miskolczi Norbert , Kucharczyk Pavel , Sedlarik Vladimir , Szakacs Hajnalka
Published: February 2013

The present article discloses the properties improvement in PP/PA 6 blends by new type experimental coupling additives. By the experimental agents especially the tensile properties could be improved. For example, the tensile strength and the elongation were 16.5 MPa and 4.4% without additive, which increased to 25.5, 20.1, 46.8 MPa and 8.1, 6.4, 8.6% in specimens containing polyalkenyl‐poly‐maleic‐anhydride‐amide, polyalkenyl‐poly‐maleic‐anhydride‐ester, and MA‐grafted‐low‐polymer additives, respectively. DSC curves shows that compatibilizers influenced thermal properties of the polymer blends and reveal affecting of crystalline phase formation process in the blends due to the compatibilization step. Additives A and B rather leads to influencing of PA crystallinities. According to the SEM and FTIR analysis well separated polypropylene and polyamide phases was observed in case of specimens absence of additives but only one well distributed phase by the applying of the synthetized coupling agents. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Configurational effects on the crystalline morphology and amorphous phase behavior in poly(3‐hydroxybutyrate) blends with tactic poly(methyl methacrylate)
Authors: Ni'mah Hikmatun , Woo Eamor M.
Published: February 2013

Poly(3‐hydroxybutyrate) (PHB) blends with two tactic poly(methyl methacrylate)s [PMMAs; isotactic poly(methyl methacrylate) (iPMMA) and syndiotactic poly(methyl methacrylate) (sPMMA)], being chiral/tactic polymer pairs, were investigated with regard to their crystalline spherulite patterns, optical birefringence, and amorphous phase behavior with polarized optical microscopy and differential scanning calorimetry. The PHB/sPMMA and PHB/iPMMA blends exhibited upper critical solution temperatures of about 225 and 240°C, respectively, on the basis of the results of thermal analysis and phase morphology. The interactions of two constituents in the blends (PHB/iPMMA or PHB/sPMMA) were measured to be insignificantly different for the PHB/sPMMA and PHB/iPMMA blends. However, syndiotacticity in PMMA exerted a prominent effect on the alteration of the PHB spherulite morphology, whereas, by contrast, isotacticity in PMMA had almost no effect at all. At high sPMMA contents (e.g., 30 wt %) in the PHB/sPMMA blend, the spherulites were all negatively birefringent and ringless when they were crystallized at any crystallization temperature between 50 and 90°C. That is, not only was the original ring‐banded pattern in the neat PHB spherulites completely disrupted, but the optical sign was also reverted completely from positively to negatively birefringent in the sPMMA/PHB blend; this was not observed in the iPMMA/PHB one. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Empirical evidence for the relevance of fractional scoring in the calculation of percentile rank scores
Authors: Schreiber Michael
Published: February 2013

Fractional scoring has been proposed to avoid inconsistencies in the attribution of publications to percentile rank classes. Uncertainties and ambiguities in the evaluation of percentile ranks can be demonstrated most easily with small data sets. But for larger data sets, an often large number of papers with the same citation count leads to the same uncertainties and ambiguities, which can be avoided by fractional scoring, demonstrated by four different empirical data sets with several thousand publications each, which are assigned to six percentile rank classes. Only by utilizing fractional scoring does, the total score of all papers exactly reproduce the theoretical value in each case.
Practical and Efficient Organocatalytic Enantioselective α‐Hydroxyamination Reactions of β‐Ketoamides
Authors: Mailhol Damien , Castillo Juan‐Carlos , Mohanan Kishor , Abonia Rodrigo , Coquerel Yoann , Rodriguez Jean
Published: February 2013

The first organocatalytic general, efficient and highly enantioselective α‐hydroxyamination reactions of β‐ketoamides with nitrosobenzene are described using a thiourea/tertiary amine bifunctional catalyst. Significantly, the products were obtained in high enantiomeric purity using a low catalyst loading, and in the context of sustainable development, the full reaction mixture, including solvent, catalyst and excess substrate, can be recycled without significant erosion in the efficiency and enantioselectivity of the reaction. The described catalytic transformations secure a practical synthetic access to stereodefined and conformationally constrained α‐amino acid derivatives exhibiting a quaternary chiral center at the α position.
Hydrothermal Carbonization of Carbohydrates: A Kinetic and Mechanistic Study
Authors: Liebeck Miriam , Pfeifer Christian , Drochner Alfons , Vogel G. Herbert
Published: February 2013

Die hydrothermale Carbonisierung (HTC) ist in Hinblick auf die energetische Verwertung von Biomasse eine vielversprechende Methode. Trotz der langen Historie dieses Verfahrens sind Mechanismus und Kinetik nur unzureichend verstanden. In den hier vorgestellten Experimenten wurde mithilfe der Kombination von Analysenmethoden die Umsetzung von Kohlenhydraten mit sauren und basischen Zusätzen untersucht. Dabei konnte vor allem der Einfluss von Säure auf die Hydrolyse von Cellulose beobachtet werden. Die HTC von Glucose hingegen bleibt weitestgehend von den Zusätzen wie Säure oder Base unbeeinflusst. Durch Veränderung der Reaktionsbedingungen wie der Heizrate können die Biokohle‐Eigenschaften wie z. B. die Acidität der Kohle variiert werden.
Structural and Bonding Analyses on a Homologous Metal–Metal Bond Guest–Host Series M2@C50X10(M = Zn, Cd, Hg; X = CH, N, B)
Authors: Liu Yan‐Chun , Wu Shui‐Xing , Kan Yu‐He , Zhang Hou‐Yu , Su Zhong‐Min
Published: February 2013

A systematic density functional study was performed on the structures and bonding features in a homologous metal–metal (M–M) host–guest series M2@C50X10(M = Zn, Cd, Hg; X = CH, N, B). Calculations indicated thatD5dconformers are energy minima for Zn2@C50X10(X = CH, N) and Cd2@C50X10(X = CH, N, B), whereas Zn2@C50B10has no imaginary frequency with the loweredC2hsymmetry. Among these hybrid fullerene–metal complexes, those with dizinc and dicadmium guests adopt η5/η5coordination, except for an η2/η2case inC2h‐Zn2@C50B10, to meet appropriate interactions between the metal atom and cage; and the η1/η1coordination mode can only be satisfied in just one (Hg2@C50N10) of the complexes with Hg–Hg guests, regardless of the enforced coordination surroundings. The nature of metal–cage interactions between M22+and C50X102–moieties and M–M bonds have been analyzed by means of the topological properties of electron densities and energy‐partitioning methods, and results suggest that the two types of interactions are almost similar to those in their M2(C5H5)2counterparts.
A Novel Method for Corrosion Reaction Analysis by Fourier Transform Electrochemical Impedance Spectroscopy: Corrosion of 9Cr‐1 Mo Ferritic Steel in 0.050 M H2SO4
Authors: Ko Younghoon , Singh Indra B. , Park Su‐Moon
Published: February 2013

We hereby report a novel method of analyzing corrosion reactions by real‐time Fourier transform electrochemical impedance (FTEIS) spectroscopy and applied it to the corrosion study of 9Cr‐1 Mo ferritic steel in 0.050 M sulfuric acid. The real‐time monitoring was achieved by running small signal staircase linear sweep voltammetric experiments, in which each voltage step and the chronoamperometric current obtained thereupon were converted to impedance data by first converting them into frequency domain employing Fourier transformation followed by acquisition of impedance spectra. The technique provided real‐time potentiodynamic impedance data in real time while the potential was being swept. A large body of impedance data thus obtained as a function of swept potential allowed not only corrosion potentials and currents but also a full set of kinetic parameters of reactions involved in corrosion to be evaluated. The quantitative data obtained for corrosion also help better elucidate the corrosion mechanism at the steel electrode/electrolyte interface.
New solution IEF device for micropreparative separation of peptides and proteins
Authors: Duša Filip , Šlais Karel
Published: February 2013

The article presents a new concept of preparative solution IEF where time requirements and efficiency are similar to gel‐based IEF whereas simple fraction handling as well as quick and complete protein recovery typical for solution‐based IEF methods are maintained. The presented method is based on the IEF in separation medium soaked in a segmented strip of nonwoven fabric. The strip is positioned in an open horizontal V‐shaped trough. Suggested focusing method combines free solution IEF under continuous evaporation and whole channel dispensing. Separation medium based on ethylene glycol/water mixture enhances viscosity enough to reduce electroosmosis and prevents the medium from completely drying out. Generation of pH gradient and final local pH is visually traced by colored low‐molecular pI markers added to input mixture, which enables an optimization of focusing process and collection of individual fractions at desired pH range. The proposed method was tested by fractionation of the proteins and bioactive peptides originating from raw whey. Moreover, subsequent HPLC analysis of the individually collected solution IEF fractions was used for identification of whey components. We confirmed that the method is capable to process directly few tenths of milliliters of raw samples including the salty ones.
Regulation—Rates: Improving regulatory outcomes: Reengineering the rate case
Authors: Starkweather Richard D.
Published: February 2013

The number of rate cases filed each year by electric and gas utilities has consistently increased over the past 10 years.
Natural gas—Legal issues: Federal court: Fracking disputes are not a force majeure
Authors: Sabino Anthony Michael , Abatemarco Michael J.
Published: February 2013

A federal court sitting in New York's “natural gas patch” recently answered the question of whether the Empire State's pending moratorium against “fracking” constituted a force majeure event that would forestall the expiration of drillers' leasehold rights. While deciding that the current ban against fracking was not such an event and thus did not extend the drillers' rights, the decision provides a crucial lesson in the workings of this ancient legal doctrine, as it collides with a more modern controversy that we have recently dealt with in these pages.
Natural gas & electricity pricing: Price impacts of regulating the worldwide fracking frenzy
Authors: Bodell Tanya
Published: February 2013

On August 8, 2005, at Sandia National Laboratories in New Mexico, President George W. Bush signed into law the Energy Policy Act of 2005.1 The act included an exemption that prohibited regulation under the Safe Drinking Water Act of any hydraulic fracturing used for the purpose of oil, natural gas, and geothermal production.2 This regulatory relief, combined with technological advances in shale extraction, led to significant increases in shale gas production and dramatic reductions in natural gas prices.
Complex Adaptable Systems based on Self‐Assembling Dendrimers and Dendrons: Toward Dynamic Materials
Authors: Roche Cécile , Percec Virgil
Published: February 2013

Self‐assembling dendrons are biologically inspired complex systems that can form self‐organized periodic arrays in the bulk state. Here we adopt the point of view of Constitutional Dynamic Chemistry (CDC) to discuss the design and properties of self‐assembling dendrimers and dendronized structures. Among other objectives, CDC seeks to generate chemical diversity through constitutional dynamics, and to improve the design of dynamic materials using adaptive systems. Can we address these issues with dendrimer chemistry? We will show that generational and co‐assembly approaches in the synthesis of self‐assembling dendritic systems lead to a remarkable collection of periodic lattices and quasi‐periodic arrays. Moreover, in some cases the morphological properties of the resulting supramolecular structures can be tuned by external signals. These dendron‐based adaptive systems find applications in various fields such as nano‐machines and switches or porous protein mimics.
Therapeutic apheresis in the elderly: An update
Authors: Abdel‐Rahman Emaad M. , Balogun Rasheed A.
Published: February 2013

Therapeutic apheresis medicine comprises many procedures, the most common being therapeutic plasma exchange (TPE). There is wide acceptance and use of TPE in the treatment of disease conditions that cut across several organ systems in the body and affect patients of various age groups. Patients that are 65 years or older form a significant cohort with increasing need for TPE. This brief report addresses special considerations in this cohort with useful comparisons made with younger cohorts as presented in the Therapeutic Apheresis Academy at the University of Virginia in September 2012. J. Clin. Apheresis 28:84–86, 2013. © 2013 Wiley Periodicals, Inc.
Therapeutic apheresis in kidney transplantation: A review of renal transplant immunobiology and current interventions with apheresis medicine
Authors: Nishio-Lucar Angie , Balogun Rasheed A. , Sanoff Scott
Published: February 2013

Transplantation is the treatment of choice for end stage renal disease. Kidney transplants convey both a significant survival advantage to the individual recipient as well as cost savings to the medical system. Circulating alloantibodies directed against donor human leukocyte antigens and blood group antigens are fairly common among potential recipients. They are known to injure allografts, shorten allograft survival, and limit access to kidney transplantation. Hence, screening for pretransplant alloantibodies using complement dependent cytotoxic cross‐matching and more sensitive techniques such as the solid phase assays, have become routine in an attempt to avoid incompatible donor–recipient pairs and risk stratify those with donor specific antibodies (DSA). By removing harmful antibodies, therapeutic apheresis (TA) has become a critical tool for improving access to transplantation in cases where the immunologic risk had previously been considered unacceptable. It has also allowed us to transplant across the barrier of ABO blood group incompatibility and expand the pool of donors with reasonable success. Furthermore, it is an important tool in the treatment of antibody‐mediated rejection. Advanced apheresis technologies, such as immunoadsorption, and the use of TA in combination with innovative paired‐donor exchange programs, offer the potential to further improve access and outcomes, minimizing the short comings of one single form of therapy alone. J. Clin. Apheresis 28:56–63, 2013. © 2013 Wiley Periodicals, Inc.
Protein‐specific force field derived from the fragment molecular orbital method can improve protein–ligand binding interactions
Authors: Chang Le , Ishikawa Takeshi , Kuwata Kazuo , Takada Shoji
Published: February 2013

Accurate computational estimate of the protein–ligand binding affinity is of central importance in rational drug design. To improve accuracy of the molecular mechanics (MM) force field (FF) for protein–ligand simulations, we use a protein‐specific FF derived by the fragment molecular orbital (FMO) method and by the restrained electrostatic potential (RESP) method. Applying this FMO‐RESP method to two proteins, dodecin, and lysozyme, we found that protein‐specific partial charges tend to differ more significantly from the standard AMBER charges for isolated charged atoms. We did not see the dependence of partial charges on the secondary structure. Computing the binding affinities of dodecin with five ligands by MM PBSA protocol with the FMO‐RESP charge set as well as with the standard AMBER charges, we found that the former gives better correlation with experimental affinities than the latter. While, for lysozyme with five ligands, both charge sets gave similar and relatively accurate estimates of binding affinities. © 2013 Wiley Periodicals, Inc.
Effects of Mentoring on the Development of Leadership Self‐Efficacy and Political Skill
Authors: Chopin Suzzette M. , Danish Steven J. , Seers Anson , Hook Joshua N.
Published: February 2013

This study of 260 business graduate students considered the relationship between mentoring and leadership self‐efficacy, and mentoring and political skill. Comparisons between nonmentored and mentored individuals showed that having a mentor was associated with increased political skill but not with increased leadership self‐efficacy. Among mentees, higher quality mentoring relationships were associated with significantly higher leadership self‐efficacy but not with significantly higher political skill. Results suggest that the presence of a mentor affects protégé development of political skill, but the quality of the relationship is important for protégé development of leadership self‐efficacy.
Shape‐Memory Natural Rubber: An Exceptional Material for Strain and Energy Storage
Authors: Heuwers Benjamin , Beckel Anna , Krieger Andreas , Katzenberg Frank , Tiller Joerg C.
Published: February 2013

Shape‐memory polymers (SMPs) are smart, responsive materials with numerous potential applications. Based on previously introduced shape‐memory natural rubber (SMNR), which shows exceptional properties such as strain storage of 1000%, cold storage, cold programmability, and mechanical and thermal triggers tunable both during and after programming, different SMNRs regarding their shape‐memory parameters are investigated. Furthermore, their energy‐storage capability and their mechanical properties are explored. SMNRs show fixity ratios of up to 94% and excellent recovery ratios of up to 100% whereas strains even above 1000% can be stored. Energies of up to 4.88 J g−1 can be stored with efficiencies of up to 53.30%. Further, the Young's modulus of SMNR can be switched by two orders of magnitude upon triggering or programming.

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