bluuebunny/crossref_metadata_2025 huggingface dataset:
Ozone trends derived from the total column and vertical profiles at a northern mid-latitude station
Authors: Nair P. J. , Godin-Beekmann S. , Kuttippurath J. , Ancellet G. , Goutail F. , Pazmiño A. , Froidevaux L. , Zawodny J. M. , Evans R. D. , Wang H. J. , Anderson J. , Pastel M.
Published: October 2013

Abstract. The trends and variability of ozone are assessed over a northern mid-latitude station, Haute-Provence Observatory (OHP: 43.93° N, 5.71° E), using total column ozone observations from the Dobson and Système d'Analyse par Observation Zénithale spectrometers, and stratospheric ozone profile measurements from light detection and ranging (lidar), ozonesondes, Stratospheric Aerosol and Gas Experiment (SAGE) II, Halogen Occultation Experiment (HALOE) and Aura Microwave Limb Sounder (MLS). A multivariate regression model with quasi-biennial oscillation (QBO), solar flux, aerosol optical thickness, heat flux, North Atlantic Oscillation (NAO) and a piecewise linear trend (PWLT) or equivalent effective stratospheric chlorine (EESC) functions is applied to the ozone anomalies. The maximum variability of ozone in winter/spring is explained by QBO and heat flux in the ranges 15–45 km and 15–24 km, respectively. The NAO shows maximum influence in the lower stratosphere during winter, while the solar flux influence is largest in the lower and middle stratosphere in summer. The total column ozone trends estimated from the PWLT and EESC functions are of −1.47 ± 0.27 and −1.40 ± 0.25 DU yr−1, respectively, over the period 1984–1996 and about 0.55 ± 0.30 and 0.42 ± 0.08 DU yr−1, respectively, over the period 1997–2010. The ozone profiles yield similar and significant EESC-based and PWLT trends for 1984–1996, and are about −0.5 and −0.8% yr−1 in the lower and upper stratosphere, respectively. For 1997–2010, the EESC-based and PWLT estimates are of the order of 0.3 and 0.1% yr−1, respectively, in the 18–28 km range, and at 40–45 km, EESC provides significant ozone trends larger than the insignificant PWLT results. Furthermore, very similar vertical trends for the respective time periods are also deduced from another long-term satellite-based data set (GOZCARDS–Global OZone Chemistry And Related trace gas Data records for the Stratosphere) sampled at northern mid-latitudes. Therefore, this analysis unveils ozone recovery signals from total column ozone and profile measurements at OHP, and hence in the northern mid-latitudes.
Mass spectrometry of refractory black carbon particles from six sources: carbon-cluster and oxygenated ions
Authors: Corbin J. C. , Sierau B. , Gysel M. , Laborde M. , Keller A. , Kim J. , Petzold A. , Onasch T. B. , Lohmann U. , Mensah A. A.
Published: October 2013

Abstract. We discuss the major mass spectral features of different types of refractory carbonaceous particles, ionized after laser vapourization with an Aerodyne High-Resolution Soot-Particle Aerosol Mass Spectrometer (SP-AMS). The SP-AMS was operated with a switchable 1064 nm laser and a 600 °C thermal vapourizer, yielding respective measurements of the refractory and non-refractory particle components. Six samples were investigated, all of which were composed primarily of refractory material: fuel-rich and fuel-lean propane/air diffusion-flame combustion particles; graphite-spark-generated particles; a commercial Fullerene-enriched Soot; Regal Black, a commercial carbon black; and nascent aircraft-turbine combustion particles. All samples exhibited a spectrum of carbon-cluster ions Cxn+ in their refractory mass spectrum. Smaller clusters (x<6) were found to dominate the Cxn+ distribution. For Fullerene Soot, fuel-rich-flame particles and spark-generated particles, significant Cxn+ clusters at x≫6 were present, with significant contributions from multiply-charged ions (n>1). In all six cases, the ions C1+ and C3+ contributed over 60% to the total C15 were present. When such signals were present, C1+/C3+ was close to 1. When absent, C1+/C3+ was <0.8. This ratio may therefore serve as a proxy to distinguish between the two types of spectra in atmospheric SP-AMS measurements. Significant refractory oxygenated ions such as CO+ and CO2+ were also observed for all samples. We discuss these signals in detail for Regal Black, and describe their formation via decomposition of oxygenated moieties incorporated into the refractory carbon structure. These species may be of importance in atmospheric processes such as water uptake, aging and heterogeneous chemistry.
Role of coarse and fine mode aerosols in MODIS AOD retrieval: a case study
Authors: Sai Suman M. N. , Gadhavi H. , Ravi Kiran V. , Jayaraman A. , Rao S. V. B.
Published: October 2013

Abstract. In the present study we have compared the MODIS (Moderate Resolution Imaging Spectroradiometer) derived aerosol optical depth (AOD) data with that obtained from operating sky-radiometer at a remote rural location in South India (Gadanki, 13.45° N, 79.18° E). While the comparison between total (coarse mode + fine mode) AOD shows R2 value of about 0.71 with a negligible bias of 0.01, if one separates the AOD into fine and coarse mode, the comparison becomes very poor, particularly for fine mode with an R2 value of 0.44. The coarse mode AOD derived from MODIS and sky-radiometer compare better with an R2 value of 0.74 and also the seasonal variation is well captured by both measurements. It is shown that the fine mode fraction derived from MODIS data is more than a factor of two smaller than that derived from the sky-radiometer data. Based on these observations we argue that the selection of aerosol types used in the MODIS retrieval algorithm are not appropriate particularly in the case of South India. Instead of selecting a moderately absorbing aerosol type (as being done currently in the MODIS retrieval) a more absorbing type aerosol is better suited for fine mode aerosols, while reverse is true for the coarse mode aerosols, where instead of using "dust aerosols" which is relatively more absorbing, usage of coarse sea-salt particles which is less absorbing is more appropriate.
Exploring the response of West Siberian wetland methane emissions to future changes in climate, vegetation, and soil microbial communities
Authors: Bohn T. J. , Lettenmaier D. P.
Published: October 2013

Abstract. We ran the VIC land surface model over the West Siberian Lowland (WSL), forced with outputs from 32 CMIP5 models for the RCP4.5 scenario, and compared the effects of changes in climate and vegetation (leaf area index in particular) on predicted wetland CH4 emissions and other fluxes for the period 2071–2100, relative to the period 1981–2010. We also explored possible responses of soil microbial communities to these changes. Our results suggest that, if soil microbial communities acclimatize to elevated temperatures without changes in species abundances, end-of-century CH4 emissions from the WSL will only rise to 3.6 Tg CH4 yr−1 (6% above historical emissions). In contrast, if microbial species abundances in the north additionally shift to resemble those in the south, CH4 emissions will more than double, to 7.3 Tg CH4 yr−1. Crucially, while historical emissions were concentrated in the southern half of the domain, acclimatization plus microbial population shifts concentrate almost 3/4 of future emissions in the northern half of the domain, where the possible release of carbon with permafrost thaw is a concern. In addition, microbial population shifts disproportionately increase microbial activity in the period during and immediately following snowmelt, when highly labile carbon is first thought to be released from the soil. This work indicates the importance of better constraining the responses of soil microbial communities to changes in climate and vegetation as they are critical determinants of the region's future methane emissions.
Mixed layer variability and chlorophyll a biomass in the Bay of Bengal
Authors: Narvekar J. , Prasanna Kumar S.
Published: October 2013

Abstract. Mixed layer is the most variable and dynamically active part of the marine environment that couples the underlying ocean to the atmosphere and plays an important role in determining the chlorophyll concentration. In this paper we examined the seasonal variability of the mixed layer depth in the Bay of Bengal, the factors responsible for it and the coupling of mixed layer processes to the chlorophyll biomass using a suite of in situ as well as remote sensing data. The basin-wide mixed layer depth was the shallowest during spring intermonsoon, which was associated with strong themohaline stratification of the upper water column. The prevailing winds which were the weakest of all the seasons were unable to break the stratification leading to the observed shallow mixed layer. Consistent with the warm oligotrophic upper ocean, the surface chlorophyll concentrations were the least and the vertical profile of chlorophyll was characterized by a subsurface chlorophyll maximum. Similarly, during summer though the monsoon winds were the strongest they were unable to break the upper ocean haline-stratification in the northern Bay brought about by a combination of excess precipitation over evaporation and fresh water influx from rivers adjoining the Bay of Bengal. Consistent with this though the nitrate concentrations were high in the northern part of the Bay, the chlorophyll concentrations were low indicating the light limitation. In contrast, in the south, advection of high salinity waters from the Arabian Sea coupled with the westward propagating Rossby waves of annual periodicity were able to decrease stability of the upper water column and the prevailing monsoon winds were able to initiate deep mixing leading to the observed deep mixed layer. The high chlorophyll concentration observed in the south resulted from the positive wind stress curl which pumped nutrient rich subsurface waters to the euphotic zone. The southward extension of the shallow mixed layer in fall intermonsoon resulted from the advection of low salinity waters from the northern Bay combined with the secondary heating by the incoming short wave radiation. The satellite-derived chlorophyll pigment concentration during fall intermonsoon was similar to that of summer but with reduced values. The basin-wide deep mixed layer during winter resulted from a combination of reduced short wave radiation, increase in salinity and comparatively stronger winds. The mismatch between the low nitrate and comparatively higher chlorophyll biomass during winter indicated the efficacy of the limited nitrate data to adequately resolve the coupling between the mixed layer processes and the chlorophyll biomass.
On the magnitude and frequency of Karakoram Glacier surges
Authors: Quincey D. J. , Luckman A.
Published: October 2013

Abstract. The return periods of Karakoram glacier surges are almost entirely unknown. Here, we present evidence of an historic surge of the Khurdopin Glacier that began in the mid-1970s and peaked in 1979. Measured surface displacements reached > 5 km yr–1, two orders of magnitude faster than during quiescence and twice as large as any previously recorded velocity in the region. The Khurdopin Glacier next surged in the late-1990s, equating to a return period of 20 yr. Surge activity in the region needs to be better understood if accurate mass balance assessments of Hindu-Kush–Karakoram–Himalaya glaciers are to be made.
George Lippard's Fragile Utopian Future and 1840s American Economic Turmoil
Authors: Williams Nathaniel
Published: October 2013

Nineteenth-century U.S. novelist and social activist George Lippard wrote his 1845 best seller, The Quaker City; or, The Monks of Monk Hall, in the wake of economic chaos following the Banking Panic of 1837. While most of the novel portrays sensationalized acts of violence and sexual aggression used to call attention to the dire social circumstances of his era, Lippard includes two contrasting prophecies of America's future: one, a dystopian nightmare set in A.D. 1950, and the other, a brief, utopian vision set in approximately A.D. 2040. Lippard's inclusion of this utopian revelation, which portrays a United States free of violence, provides insights into the fate of utopia in America during troubled economic times. This article examines Lippard's early brand of urban socialism and his role as a sensation novelist, noting his narrative method for articulating utopian ideas. By selecting a precariously stationed female character as his visionary, Lippard underscores the fragility of utopian potentiality amid 1840s U.S. economic chaos. Because of Lippard's allegorical structure, as his heroine is threatened, so too is the utopian future she foresees.
Beyond Triton: Samuel R. Delany's Critical Utopianism and the Colliding Worlds in “We, in Some Strange Power's Employ, Move on a Rigorous Line”
Authors: Tabone Mark A.
Published: October 2013

Samuel R. Delany is among a group of authors who revivified the utopian imagination in science fiction during the late 1960s and early 1970s. This article discusses Delany's novella “We, in Some Strange Power's Employ, Move on a Rigorous Line” (1968). It revisits scholarship on Delany and on utopia to offer theoretical and historical perspectives concerning how this text, which has been lauded by reviewers but overlooked by scholars, represents an early contribution to the then-nascent genre of the “critical utopia,” one that bears many of the genre's hallmarks and prefigures later works. “We, in Some Strange Power's Employ” narrates a mid-twenty-first-century clash between two fully articulated utopian visions. This article details how the tension between these diametrically opposed “worlds” foments critical scrutiny of both in order to gesture toward a utopian horizon beyond them. It also demonstrates how Delany's novella performs a critical utopian intervention in the cultural politics of its present. Through the “play of worlds” in the narrative's “possible future” Delany advances evenhanded critiques of both sides of the 1960s “culture war” while retaining the decade's utopian zeitgeist, a desire for an impossible “something else” beyond the culture/counterculture dichotomy.
Hippies and the Mystic Way: Dropping Out, Unitive Experiences, and Communal Utopianism
Authors: Shipley Morgan
Published: October 2013

This article hopes to uncover the relationship among psychedelics, mystic interpretations, and hippie projects of communal utopianism. Specifically, it traces the evolution of dropping out as an ahistorical, mystical orientation dialectically emerging within the framework of liberal-capitalist modernity. This orientation results from a fissure within the constructs of modernity itself, unsettling the progressive pulse of modern practices, revealing spaces to simultaneously challenge institutional hierarchy or materialist consumerism while experimenting with alternative moments of unitive togetherness. To construct an investigation into hippie mysticism and communal utopianism, this article (1) engages the dystopic problem of modernity through the lens of 1960s social, political, and cultural theorists, specifically Herbert Marcuse, who influenced the intellectual landscape of countercultural responses and situates the utopic implications of dropping out; and (2) uncovers the mystical vision of a key hippie philosopher, Stephen Gaskin, whose communal utopianism continues to challenge the homogeneity of modern culture, offering a vision of absolute love, responsibility, and community. I argue that dropping out offered a distinct antimodern impulse derived from mystical prophecies and experiences of absolute togetherness that, potentially, presents a lens through which to critically engage the challenges of “modern” society, rescuing the intuitive sense “of all of us being one.”
Margaret Murray (1863–1963): Pioneer Egyptologist, Feminist and
First Female Archaeology Lecturer
Authors: Whitehouse Ruth
Published: October 2013

Margaret Murray, who was born 150 years ago, was one of the first archaeologists
to be employed at UCL and one of the most distinguished, although her role in
the history of archaeology is often underestimated. This article provides a
brief outline of the career and contribution of a highly productive and
innovative, if sometimes controversial, scholar, who also participated in the
wider social movements of her time, particularly the campaign for women’s
suffrage.
Rapa Nui (Easter Island)’s Stone Worlds
Authors: Hamilton Sue
Published: October 2013

This article explores the spatial, architectural and conceptual relationships between
landscape places, stone quarrying, and stone moving and building during Rapa Nui’s
statue-building period. These are central themes of the ‘Rapa Nui Landscapes of
Construction Project’ and are discussed using aspects of the findings of our recent
fieldwork. The different scales of expression, from the detail of the domestic sphere to
the monumental working of quarries, are considered. It is suggested that the
impressiveness of Rapa Nui’s stone architecture is its conceptual coherence at the
small scale as much as at the large scale.
Las industrias extractivas y sus implicaciones políticas y económicas
Authors: Kahhat Kahatt Farid
Published: October 2013

El artículo revisa la literatura académica sobre la relación entre dependencia de industrias extractivas de exportación y desempeño económico y político en Estados en desarrollo, elaborando un estado de la cuestión. Revisa primero la relación entre dependencia de industrias extractivas de exportación y violencia política y discute por qué hay más guerras civiles en países que dependen de esas industrias. Revisa luego la relación entre dependencia de industrias extractivas de exportación y régimen político y examina la influencia que puede tener esa dependencia en las perspectivas de democratización. Revisa finalmente la relación entre dependencia de industrias extractivas de exportación y desempeño económico e institucional (es decir, la denominada «maldición de los recursos»).
Internal and External Forces Measurement of Planar 3-DOF Redundantly Actuated Parallel Mechanism by Axial Force Sensors
Authors: Harada Takashi , Liu Podi
Published: October 2013

This paper proposes a method for measuring the internal and external forces of a planar 3-DOF (degree of freedom) redundantly actuated parallel mechanism. The internal forces, force acts inside the endplate and mechanism constraint force, and the external forces, forces act on the endplate and thrusts by actuators, were measured simultaneously using the axial forces of the rods. Kinetostatic equations of the parallel mechanism were used to derive algorithms for measuring the internal and external forces. A link axis force sensor was developed using a strain gauge sensor. To verify the actual internal force of the endplate, a force sensor was also installed on the endplate. A real-time system for measuring the forces of the parallel mechanism was developed using RT-Linux. The external and internal forces were measured accurately.
Validita a reliabilita výskumných nástrojov: princípy a reálna prax
Authors: Gavora P.
Published: October 2013

Článok odpovedá na otázku, ako sa uplatňujú v praxi princípy zisťovania validity a reliability, ktoré udávajú renomované učebnice metodológie. Prvé dve časti príspevku načrtávajú teoretický rámec a opisujú koncept validity a reliability. Nasledujúce časti vysvetľujú proces analýzy a uvádzajú jej výsledky. Z časopisu The Journal of Educational Research bolo náhodným spôsobom vybratých 56 štúdií. Veľká väčšina (91 %) výskumných nástrojov v nich boli posudzovacie škály a testy, zvyšok boli dotazníky, pozorovacie schémy a interview. Na prekvapenie bola validita zdokumentovaná len u 26 % nástrojov, zvyšok nástrojov boli štandardizované testy, alebo sa autori spoliehali na zrejmú (face) validitu. U posudzovacích škál sa použila konštruktová validita zistená pomocou faktorovej analýzy. Obsahová validita a face validita sa použili pri testoch, dotazníkoch a interview. Kombinované zdroje validity (napr. konštruktová spolu so súbežnou alebo diskriminačnou) sa použili veľmi málo, čo považujeme za nedostatok vo validizačnom procese. Reliabilita bola uvedená pri 80 % nástrojoch. Najfrekventovanejší spôsob bola Cronbachova alfa u posudzovacích škál. Zhoda medzi posudzovateľmi sa použila pri pozorovaní a testoch. Test-retest sa použil pri overovaní, či je merací nástroj na pretest-posttest stabilný v priebehu času. Koeficienty reliability väčšinou presahovali 0,80. Pri analýze štúdií sa potvrdilo, že pri posudzovaní adekvátnosti validizácie a reliabilizácie je potrebné silne prihliadať k špecifickým podmienkam konkrétneho výskumu.
Standardy závěrečných prací pedagogických oborů
Authors: Němec J.
Published: October 2013

Téma kvality závěrečných prací obhajovaných na vysokých školách je v kontextu občasných plagiátorských kauz stále živé. Studie zkoumá dokumenty fakult (standardy), které se svým tématem a obsahem váží k závěrečným pracím. Analyzovanou jednotkou jsou dokumenty z prostředí fakult, ústavů (kateder), které v ČR garantují a zajišťují pedagogické obory. Výchozí pozicí pro studii je popis proměny současného kontextu, především přechod na dvoustupňové studium, vzrůstající počet studentů v terciárním vzdělávání v uplynulém desetiletí, důraz na kvalitu a learning outcomes v kontextu konceptu přístupu zaměřeného na studenta a celostátního projektu Q-RAM. Celkem bylo analyzováno 24 dokumentů prostřednictvím strukturní obsahové analýzy s využitím formálních, obsahových, typizujících a stupnicových forem analýzy. Výsledkem je rozkrytí struktury dokumentů, které nám následně umožnilo popis jejich hlavních charakteristik. Jedno ze zjištění dokládá převahu procedurálních charakteristik těchto dokumentů na úkor zdůraznění obsahových náležitostí a oborových standardů, které by studentům jasnou a srozumitelnou formou sdělovaly, co od nich daná instituce očekává. Závěr studie konstatuje, že se jedná o téma, které garantům pedagogických oborů otevírá prostor pro koncepční a tvůrčí práci při vytváření relace mezi kompetencemi absolventů, výstupů učení jednotlivých disciplín a potřebou formulovat smysluplný standard závěrečné práce daného oboru.
Etika vědecké práce a publikování pro mírně pokročilé
Authors: Knecht P. , Dvořák D.
Published: October 2013

Metodická studie informuje o nejčastěji uváděných projevech porušování publikační etiky s cílem zvýšit citlivost výzkumníků k porušování pravidel publikační etiky a přispět ke kultivaci publikačního prostředí v české pedagogické vědě a výzkumu. V první části příspěvku autoři analyzují důvody, které výzkumníky zpravidla vedou k porušování publikační etiky, a upozorňují, že jednou z možných příčin může být mimo jiné aktuálně platný systém financování a hodnocení vědy a výzkumu. Následně jsou na základě analýzy dostupné literatury rozebírány nejčastěji uváděné projevy publikačně závadného jednání, přičemž autoři využívají analogii s biblickým Desaterem. Jedná se o: 1. vymýšlení a zkreslování/falšování výzkumných zjištění, 2. plagiátorství, 3. připisování spoluautorů, 4. duplicitní/simultánní publikování, 5. dělení publikací do více článků, 6. recyklování textů, 7. vzájemné (reciproční) citování spřízněných kolegů, 8. zkreslené citování, 9. nepřiznaný konflikt zájmů, 10. porušování majetkových autorských práv. Autoři v závěru navrhují opatření, která by podporovala důslednější dodržování etických pravidel v praxi.
Finite frequency whole mantle P wave tomography: Improvement of subducted slab images
Authors: Obayashi Masayuki , Yoshimitsu Junko , Nolet Guust , Fukao Yoshio , Shiobara Hajime , Sugioka Hiroko , Miyamachi Hiroki , Gao Yuan
Published: October 2013

We present a new whole mantle P wave tomographic model GAP_P4. We used two data groups; short‐period data of more than 10 million picked‐up onset times and long‐period data of more than 20 thousand differential travel times measured by waveform cross correlation. Finite frequency kernels were calculated at the corresponding frequency bands for both long‐ and short‐period data. With respect to an earlier model GAP_P2, we find important improvements especially in the transition zone and uppermost lower mantle beneath the South China Sea and the southern Philippine Sea owing to broadband ocean bottom seismometers (BBOBSs) deployed in the western Pacific Ocean where station coverage is poor. This new model is different from a model in which the full data set is interpreted with classical ray theory. BBOBS observations should be more useful to sharpen images of subducted slabs than expected from simple raypath coverage arguments.
Efficient gas exchange between a boreal river and the atmosphere
Authors: Huotari Jussi , Haapanala Sami , Pumpanen Jukka , Vesala Timo , Ojala Anne
Published: October 2013

Key Points

First gas exchange measurements with eddy covariance technique over river

Measured gas transfer velocity was clearly higher than modeled

Results suggest that gas emissions from large rivers are likely underestimated
Observations of Doppler and delay spreads on HF signals received over polar cap and trough paths at various stages of the solar cycle
Authors: Stocker A. J. , Warrington E. M. , Siddle D. R.
Published: October 2013

Information on delay and Doppler spreading is of importance to designers and operators of digital communication systems within the HF band since modem performance rapidly deteriorates when delay and Doppler spreads exceed system dependent thresholds. The northerly ionosphere is a particularly challenging region in this regard as delay and Doppler spreads often significantly exceed those for similar length paths at midlatitudes. This paper presents results from an extensive set of measurements undertaken over three northerly paths: two subauroral paths aligned along the midlatitude trough (Uppsala to Bruntingthorpe and Nurmijärvi to Bruntingthorpe) and one path (Qaanaaq to Ny‐Ålesund) contained entirely within the polar cap. Measurements span the period from the 2009 solar minimum to July 2012, close to solar maximum and 2001, close to the previous solar maximum.
Homogeneous Optical and Electronic Properties of Graphene Due to the Suppression of Multilayer Patches During CVD on Copper Foils
Authors: Han Zheng , Kimouche Amina , Kalita Dipankar , Allain Adrien , Arjmandi‐Tash Hadi , Reserbat‐Plantey Antoine , Marty Laëtitia , Pairis Sébastien , Reita Valérie , Bendiab Nedjma , Coraux Johann , Bouchiat Vincent
Published: October 2013

A synthesis method of strictly monolayer and fully homogeneous graphene across tens of centimeter squares, by chemical vapour deposition onto standard copper foils, is presented. The growth technique involves cyclic injection of a carbon precursor separated by idle times with constant hydrogen exposure. The formation of spurious multilayer patches, which accompanies the standard growth techniques based on continuous exposure to methane, is inhibited here, in a broad range of pressure and gas composition, including in two pressure regimes which are known to yield distinctive grain morphologies (dendritic versus hexagonal). Raman spectra confirm the absence of defects within the graphene films. A mechanism for growth/suppression of the multilayer patches based on the carbon storage at defective regions is proposed. The importance of multilayer suppression is highlighted in a comparative study showing the detrimental effect of patches on the performances of graphene transistors and on the optical transparency of stacked layers. The full‐layer graphene sheets are superiorly homogeneous in terms of their optical and electronic properties, and are thus suited for applications for high‐density integration as well as transparent electrodes with spatially continuous optical absorbance. Graphene transistors fabricated by the pulsed CVD method exhibit room‐temperature mobilities with a mean value of 5000 cm2 V−1 s−1.
Aerosol‐Synthesis of Mesoporous Organosilica Nanoparticles with Highly Reactive, Superacidic Surfaces Comprising Sulfonic Acid Entities
Authors: Gehring Julia , Schleheck David , Luka Martin , Polarz Sebastian
Published: October 2013

Combining high internal surface area with tailor‐made surface properties is pivotal for granting advanced functional properties in many areas like heterogeneous catalysis, electrode materials, membranes, or also biomimetics. In this respect, organic‐inorganic hybrid nanostructures and in particular mesoporous organosilica materials are ideal systems. Here, the preparation of mesoporous solids via a new sol–gel building block comprising sulfonic acid (R‐SO3H) is described. The degree of organic modification is not only maximal (100%), it is also proven that the novel material exhibits superacid properties. Furthermore, an aerosol assisted method is applied for generating this material in the form of mesoporous, spherical nanoparticles with substantial colloidal stability. Highly acidic, high surface area materials, like prepared here, are promising candidates for numerous future applications like in heterogeneous catalysis or for proton conducting membranes. However, first experiments addressing the antibacterial effect of the sulfonic‐acid, mesoporous organosilica materials are shown. It is demonstrated that the superacid character is required for exhibiting sufficient antifouling activity.
Photoreduction of Graphene Oxides: Methods, Properties, and Applications
Authors: Zhang Yong‐Lai , Guo Li , Xia Hong , Chen Qi‐Dai , Feng Jing , Sun Hong‐Bo
Published: October 2013

In view of mass‐production and solution‐processing capabilities, graphene oxides (GOs), generally prepared by chemical oxidation of graphite and subsequent exfoliation in aqueous solution, are widely used as an effective route to graphene‐like materials. However, the oxygen‐containing groups (OCGs) on the graphene sheets make GO insulating, which significantly restricts its applications, especially for electronics. Therefore, reduction methods that are used to remove OCGs become critical. In recent years, in addition to thermal and chemical reduction, photoreduction has emerged as an appealing alternative because photoreduction does not rely on either high temperature or toxic chemicals. In this progress report, the recent development of the photoreduction of GOs and their unique properties are highlighted, as well as their related applications. Photoreduction strategies including photothermal reduction, catalytic/catalyst‐free photochemical reduction, and solid state/in‐solution laser reduction are summarized. Moreover, photoreduction of GO permits exquisite control over film conductivities, residual oxygen contents, porosity, and surface wettability, which lead to various functionalities towards a wide range of applications, such as field‐effect‐transistors (FETs), flexible electrodes, sensors, supercapacitors, Li‐ion batteries, photovoltaic devices, and photocatalysis. It is anticipated that, with the rapid progress of photoreduction methodology, GOs would be more competitive in the graphene‐oriented applications.
Linking Vertical Bulk‐Heterojunction Composition and Transient Photocurrent Dynamics in Organic Solar Cells with Solution‐Processed MoOx Contact Layers
Authors: Tremolet de Villers Bertrand J. , MacKenzie Roderick C. I. , Jasieniak Jacek J. , Treat Neil D. , Chabinyc Michael L.
Published: October 2013

It is demonstrated that a combination of microsecond transient photocurrent measurements and film morphology characterization can be used to identify a charge‐carrier blocking layer within polymer:fullerene bulk‐heterojunction solar cells. Solution‐processed molybdenum oxide (s‐MoOx) interlayers are used to control the morphology of the bulk‐heterojunction. By selecting either a low‐ or high‐temperature annealing (70 °C or 150 °C) for the s‐MoOx layer, a well‐performing device is fabricated with an ideally interconnected, high‐efficiency morphology, or a device is fabricated in which the fullerene phase segregates near the hole extracting contact preventing efficient charge extraction. By probing the photocurrent dynamics of these two contrasting model systems as a function of excitation voltage and light intensity, the optoelectronic responses of the solar cells are correlated with the vertical phase composition of the polymer:fullerene active layer, which is known from dynamic secondary‐ion mass spectroscopy (DSIMS). Numerical simulations are used to verify and understand the experimental results. The result is a method to detect poor morphologies in operating organic solar cells.
Methode der kontinuierlichen Variation: Verwendung von Job‐Plots zur Untersuchung molekularer Assoziationen in der metallorganischen Chemie
Authors: Renny Joseph S. , Tomasevich Laura L. , Tallmadge Evan H. , Collum David B.
Published: October 2013

Dieser Aufsatz beschreibt Anwendungen der Methode der kontinuierlichen Variation (MCV oder Job‐Plots) auf Fragen der metallorganischen Chemie. Die MCV bietet qualitative und quantitative Einblicke in die Stöchiometrien, die der Assoziation von m Molekülen A und n Molekülen B zur Bildung von AmBn zugrunde liegen. Auch komplexere Fälle von Metallclustern und Aggregaten sind beschreibbar. Job‐Plots, in denen Reaktionsgeschwindigkeiten verfolgt werden, liefern relative Stöchiometrien geschwindigkeitsbestimmender Übergangsstrukturen. In einer speziellen Variante werden von den Liganden oder dem Lösungsmittel abhängige Reaktionsgeschwindigkeiten in Grundzustands‐ und Übergangszustandsbeiträge aufgegliedert, was einen Einblick in die vollständige Reaktionskoordinate mithilfe eines einzigen Job‐Plots ermöglicht. Die Lücken in der Literatur werden aufgezeigt und besprochen.
Self‐assembled nanoblends of functional polystyrene and a reactive aramid: Morphological and thermomechanical profile
Authors: Kausar Ayesha , Zulfiqar Sonia , Sarwar Muhammad Ilyas
Published: October 2013

Various blends composed of pure polystyrene (PS) and modified PS [amino‐functionalized polystyrene (PS–NH2)] were prepared with a new aromatic polyamide obtained through the polycondensation of 1,5‐diaminonaphthalene and 1,4‐phenylenediamine with isophthaloyl chloride. The variation in the morphological and thermophysical profiles in the two blend systems with aramid loading were investigated. The amine functionality introduced to PS enhanced its compatibility with the polyamide because of the formation of an aramid‐graft‐PS copolymer. The grafting, hydrogen bonding, and phenylene‐ring (π–π) stacking between the chains of the two components finally nurtured self‐assembled nanostructured blends. A strong compatibilizing effect was observed for the 50, 60, and 70 wt % aramid blends, where an exceptionally inimitable cocontinuous self‐assembled morphology was formed by PS–NH2/aramid. Significant developments in the morphology along with thermal and mechanical stability were observed for the reactive PS/aramid system. The most favorable mechanical and thermal data supported by the finest nanostructure were observed with 70 wt % polyamide addition. Future prospects may involve the formation of nanotemplates and nanostructured membranes. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2014,131, 39954.
Default risk analysis via a discrete‐time cure rate model
Authors: De Leonardis Daniele , Rocci Roberto
Published: October 2013

Cure models represent an appealing tool when analyzing default time data where two groups of companies are supposed to coexist: those which could eventually experience a default (uncured) and those which could not develop an endpoint (cured). One of their most interesting properties is the possibility to distinguish among covariates exerting their influence on the probability of belonging to the populations’ uncured fraction, from those affecting the default time distribution. This feature allows a separate analysis of the two dimensions of the default risk: whether the default can occur and when it will occur, given that it can occur. Basing our analysis on a large sample of Italian firms, the probability of being uncured is here estimated with a binary logit regression, whereas a discrete time version of a Cox's proportional hazards approach is used to model the time distribution of defaults. The extension of the cure model as a forecasting framework is then accomplished by replacing the discrete time baseline function with an appropriate time‐varying system level covariate, able to capture the underlying macroeconomic cycle. We propose a holdout sample procedure to test the classification power of the cure model. When compared with a single‐period logit regression and a standard duration analysis approach, the cure model has proven to be more reliable in terms of the overall predictive performance. Copyright © 2013 John Wiley & Sons, Ltd.
Pricing a stochastic car value depreciation deal
Authors: Alshamary Bader , Calin Ovidiu
Published: October 2013

This paper deals with pricing a contract under which a dealer buys back a car from a client, for a cash amount contained in a given depreciation table. The value of the car is supposed to depreciate according to a stochastic model with random repairs modeled by a Poisson process. Copyright © 2013 John Wiley & Sons, Ltd.
Determination of chromium(III) in aqueous solution using CePO4:Tb3+ nanocrystals in a fluorescence resonance energy transfer system
Authors: Chen Hong‐Qi , Wu Yong , Zhang Yi‐Yan , Guan Ying‐Ying , Wang Lun
Published: October 2013

Trivalent chromium is an essential element required for normal carbohydrate, lipid and protein metabolism in humans and animals. This article describes an efficient fluorescence resonance energy transfer (FRET) system between CePO4:Tb3+ nanocrystals as the donor and chromium(III) as the acceptor. CePO4:Tb3+ nanocrystals were synthesized in aqueous solution, and characterized by transmission electron microscopy. Under optimum conditions, a linear calibration graph was obtained (R2 = 0.996). The linear range and detection limit of chromium(III) were 0.01–2.2 μM, and 9.1 nM, respectively. The proposed method had a wide linear range and proved to be very sensitive, rapid and simple. Moreover, the method was applied successfully to the determination of chromium(III) in synthetic samples and tap water. Copyright © 2013 John Wiley & Sons, Ltd.
Mushroom Hunting by Using Bioinformatics: Application of a Predictive Framework Facilitates the Selective Identification of Sesquiterpene Synthases in Basidiomycota
Authors: Quin Maureen B. , Flynn Christopher M. , Wawrzyn Grayson T. , Choudhary Swati , Schmidt‐Dannert Claudia
Published: October 2013

The Basidiomycota fungi represent a diverse source of natural products, particularly the sesquiterpenoids. Recently, genome sequencing, genome mining, and the subsequent discovery of a suite of sesquiterpene synthases in Omphalotus olearius was described. A predictive framework was developed to facilitate the discovery of sesquiterpene synthases in Basidiomycota. Phylogenetic analyses indicated a conservation of both sequence and initial cyclization mechanisms used. Here, the first robust application of this predictive framework is reported. It was used to selectively identify sesquiterpene synthases that follow 1,6‐, 1,10‐, and 1,11‐cyclization mechanisms in the crust fungus Stereum hirsutum. The successful identification and characterization of a 1,6‐ and a 1,10‐cyclizing sesquiterpene synthase, as well as three 1,11‐cyclizing Δ6‐protoilludene synthases, is described. This study verifies the accuracy and utility of the predictive framework as a roadmap for the discovery of specific sesquiterpene synthases from Basidiomycota, and thus represents an important step forward in natural product discovery.
Optical coherence tomography derived differences of plaque characteristics in coronary culprit lesions between type 2 diabetic patients with and without acute coronary syndrome
Authors: Reith Sebastian , Battermann Simone , Hoffmann Rainer , Marx Nikolaus , Burgmaier Mathias
Published: October 2013

Objective

To compare optical coherence tomography (OCT)‐derived plaque characteristics of coronary target lesions between diabetic patients with acute coronary syndrome (ACS) versus stable angina pectoris (SAP).

Background

In vivo assessment of plaque composition of coronary culprit lesions in a cardiovascular high‐risk population with diabetes mellitus is incompletely elucidated.

Methods

102 diabetic patients with coronary de novo lesions were enrolled and categorized into an ACS‐group (40 patients) and a SAP‐group (62 patients) according to their clinical presentation. Assessment of clinical data, angiographic, and OCT imaging including the analysis of plaque composition and lipid content of the target lesions were performed prior to percutaneous coronary intervention and compared between the two groups.

Results

Plaque characteristics of patients in the ACS‐group compared with the SAP‐group showed a higher incidence of lipid‐rich plaque [33 (82.5%) vs. 25 (40.3%)], thin‐capped fibroatheroma [29 (72.5%) vs. 10 (16.1%)], macrophage infiltration [32 (80.0%) vs. 21 (33.9%)], thrombus [23 (57.5%) vs. 2 (3.2%)], and plaque rupture [27 (67.5%) vs. 2 (3.2%)] (all P < 0.001). Moreover, there was a wider lipid arc (174.5 ± 33.8° vs. 122.9 ± 43.9°), a longer lipid plaque length (6.52 ± 2.04 mm vs. 3.73 ± 2.16 mm), a greater lipid volume index (1117.2 ± 349.9 vs. 504.8 ± 379.3), and a smaller minimal fibrous cap thickness (51.52 ± 9.14 µm vs. 80.33 ± 26.71 µm) within lipid‐rich lesions of ACS patients (all P < 0.001).

Conclusion

Diabetic patients with ACS exhibit more vulnerable plaque features in coronary culprit lesions compared with diabetic patients with SAP. This may provide rationale for a specific therapeutic strategy either by pharmacological plaque stabilization or coronary intervention in any lesion with vulnerable plaque morphology in patients with diabetes. © 2013 Wiley Periodicals, Inc.
Endovascular management of splenic artery aneurysms: Case series using telescoping guide and cage/coil technique
Authors: Darki Amir , Goswami Nilesh J. , Mishkel Gregory J.
Published: October 2013

Splenic artery aneurysms are rare, but still the third most common abdominal aneurysm. Rupture is associated with significant morbidity and mortality. Traditionally, cardiologists have rarely been involved in the management of this entity. We present a series of four patients managed percutaneously by interventional cardiology using a combined telescoping guide and cage/coil technique. © 2013 Wiley Periodicals, Inc.
Renal artery duplex ultrasound criteria for the detection of significant in‐stent restenosis
Authors: del Conde Ian , Galin Ira D. , Trost Biana , Kang Jeanwan , Lookstein Robert , Woodward Mark , Gustavson Susan , Cambria Richard P. , Jaff Michael R. , Olin Jeffrey W.
Published: October 2013

Objectives

To define velocity criteria by ultrasonography for the detection of hemodynamically significant (>60%) renal artery in‐stent restenosis (ISR).

Background

The restenosis rate after renal artery stenting ranges between 10% and 20%. While duplex ultrasound criteria have been validated for native renal artery stenosis, there are no uniformly accepted validated criteria for stented renal arteries.

Methods

Vascular laboratory databases from two academic medical centers were retrospectively reviewed for patients who underwent renal artery stenting followed by duplex ultrasound evaluation and angiography (CT angiography or catheter angiography) as the gold standard.

Results

A cohort of 132 stented renal arteries that had angiographic comparisons was analyzed. Eighty‐eight renal arteries demonstrated 0–59% stenosis while 44 renal arteries revealed 60–99% stenosis by angiography. Both the mean peak systolic velocity (PSV) and the renal artery‐to‐aortic ratio (RAR) were significantly higher in renal arteries with 60–99% restenosis compared with those with 0–59% restenosis (PSV: 382 cm/sec ± 128 vs. 129 cm/sec ± 62, P<0.001; RAR: 5.3 ± 2.4 vs. 2.1 ± 1.0, P <0.001). The optimal PSV and RAR cutoffs for detecting 60–99% ISR were calculated by receiver operator characteristics curve analysis. The velocity criteria that are associated with these results will be discussed.

Conclusion

Duplex ultrasonography is an accurate technique to identify significant restenosis in stented renal arteries. The PSV and RAR cutoffs for detecting renal artery ISR are higher than those in native, unstented renal arteries. A normal duplex ultrasound after renal artery stenting virtually excludes significant restenosis. © 2013 Wiley Periodicals, Inc.
A Dinuclear Ruthenium(II) Complex as a One‐ and Two‐Photon Luminescent Probe for Biological Cu2+ Detection
Authors: Zhang Pingyu , Pei Lingmin , Chen Yu , Xu Wenchao , Lin Qitian , Wang Jinquan , Wu Jingheng , Shen Yong , Ji Liangnian , Chao Hui
Published: October 2013

A new dinuclear RuII polypyridyl complex, [(bpy)2Ru(H2bpip)Ru(bpy)2]4+ (RuH2bpip, bpy=2,2‐bipyridine, H2bpip=2,6‐pyridyl(imidazo[4,5‐f][1,10]phenanthroline), was developed to act as a one‐ and two‐photon luminescent probe for biological Cu2+ detection. This RuII complex shows a significant two‐photon absorption cross section (400 GM) and displays a remarkable one‐ and two‐photon luminescence switch in the presence of Cu2+ ions. Importantly, RuH2bpip can selectively recognise Cu2+ in aqueous media in the presence of other abundant cellular cations (such as Na+, K+, Mg2+, and Ca2+), trace metal ions in organisms (such as Zn2+, Ag+, Fe3+, Fe2+, Ni2+, Mn2+, and Co2+), prevalent toxic metal ions in the environment (such as Cd2+, Hg2+, and Cr3+), and amino acids, with high sensitivity (detection limit≤3.33×10−8 M) and a rapid response time (≤15 s). The biological applications of RuH2bpip were also evaluated and it was found to exhibit low cytotoxicity, good water solubility, and membrane permeability; RuH2bpip was, therefore, employed as a sensing probe for the detection of Cu2+ in living cells and zebrafish.
ChemInform Abstract: Hexagonal‐Diamond‐Like Gold Lattices, Ba and (Au,T)3 Interstitials, and Delocalized Bonding in a Family of Intermetallic Phases Ba2Au6(Au,T)3 (T: Zn, Cd, Ga, In, or Sn).
Authors: Lin Qisheng , Mishra Trinath , Corbett John D.
Published: October 2013

The title intermetallic phases are prepared from the elements at 700—800 °C for 6—10 h followed by annealing at 400—500 °C for 7—14 d.
ChemInform Abstract: Synthesis of Highly Luminescent Silica‐Coated CdSe/CdS Nanorods.
Authors: Pietra Francesca , van Dijk‐Moes Relinde J. A. , Ke Xiaoxing , Bals Sara , Van Tendeloo Gustaaf , de Mello Donega Celso , Vanmaekelbergh Daniel
Published: October 2013

The highly luminescent title nanorods are synthesized using the reverse micelle method.
ChemInform Abstract: Tunable Blue‐Green‐Emitting Ba3LaNa (PO4)3F:Eu2+,Tb3+ Phosphor with Energy Transfer for Near‐UV White LEDs.
Authors: Jiao Mengmeng , Guo Ning , Lue Wei , Jia Yongchao , Lv Wenzhen , Zhao Qi , Shao Baiqi , You Hongpeng
Published: October 2013

A series of (Ba1‐mEum) 3La1‐nTbnNa(PO4)3F (m = 0—0.07; n = 0—0.60) phosphors are prepared by solid state reaction of BaCO3, BaF2, La2O3, Na2CO3, NH4H2PO4, Eu2O3, and Tb4O7 (20% H2/80% N2, 1050 °C, 3 h).
ChemInform Abstract: An FeF3·0.5H2O Polytype: A Microporous Framework Compound with Intersecting Tunnels for Li and Na Batteries.
Authors: Li Chilin , Yin Congling , Gu Lin , Dinnebier Robert E. , Mu Xiaoke , van Aken Peter A. , Maier Joachim
Published: October 2013

A new open‐framework fluoride pyrochlore phase, FeF3·0.5H2O, is prepared from a mixture of Fe(NO3)3·9H2O and single‐wall carbon nanotubes suspended in [bmim]BF4 or 1‐decyl‐3‐methylimidazolium tetrafluoroborate (100 °C, 12 h).
ChemInform Abstract: Layered Molybdenum (Oxy)pyrophosphate a Cathode for Lithium‐Ion Batteries.
Authors: Wen Bohua , Chernova Natasha A. , Zhang Ruibo , Wang Qi , Omenya Fredrick , Fang Jin , Whittingham M. Stanley
Published: October 2013

The layered compound δ‐(MoO2)2P2O7 is synthesized by heating MoO2HPO4·H2O (560 °C, 6 min).
ChemInform Abstract: A Rational Approach Towards a New Ferrocenyl Pyrrolidine for Stereoselective Enamine Catalysis.
Authors: Petruzziello Diego , Stenta Marco , Mazzanti Andrea , Cozzi Pier Giorgio
Published: October 2013

A new ferrocene‐based catalyst is designed in which the ferrocenyl group in connection with the geminal dialkylmethyl‐linker impose the preferred conformation of the pyrrolidine moiety for intermediary enamine formation.