bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion density and temperature profiles along (XGSM) and across (ZGSM) the magnetotail as observed by THEMIS, Geotail, and ARTEMIS
Authors: Artemyev A. V. , Angelopoulos V. , Hietala H. , Runov A. , Shinohara I. 
Published: January 2017

AbstractCharacteristics of the two‐dimensional configuration of the magnetotail current sheet are important for modeling magnetotail motion/evolution and charged particle energization. Because of the magnetotail current sheet's dynamical nature, however, simultaneous plasma and magnetic field measurements at different radial distances are required to reveal this configuration. Simultaneous observations of the magnetotail current sheet from Time History of Events and Macroscale Interactions during Substorms (THEMIS) D (around 10RE downtail), Geotail (around 30RE downtail), and Acceleration, Reconnection, Turbulence and Electrodynamics of the Moons Interaction with the Sun (ARTEMIS) P1 (around 55RE downtail) are used to study distributions of plasma (ion) density and temperature along (Earth‐Sun direction) and across (north‐south direction) the magnetotail. Fourteen events (each including several current sheet crossings at different downtail distances) are studied. We demonstrate that the plasma temperature along and across the magnetotail varies more significantly than plasma density does. The temperature decrease from equatorial plane to current sheet boundaries is a major contributor to the cross‐tail pressure balance. The Alfven velocity VA,B calculated at the current sheet boundaries increases significantly toward the Earth from 700 km/s at lunar orbit ∼55RE to 2200 km/s around ∼10RE downtail. The corresponding energy
(mp is the proton mass) is 4 times larger than the plasma temperature T0 in the magnetotail's equatorial plane, whereas the ratio EA/T0 is constant along the magnetotail. The plasma temperature T0 measured around lunar orbit in the magnetotail agrees well with the simultaneously measured energy of solar wind protons
(VSW is the solar wind speed).
Post‐emplacement cooling and contraction of lava flows: InSAR observations and a thermal model for lava fields at Hekla volcano, Iceland
Authors: Wittmann Werner , Sigmundsson Freysteinn , Dumont Stéphanie , Lavallée Yan 
Published: January 2017

AbstractLava flows contract as they cool, causing progressive subsidence of the flow surface. Here we study this process by measuring and modeling the deformation of emplaced lava flows and the surrounding substrate. The temporal trend of vertical lava movements was investigated using interferometric analysis of synthetic aperture radar (InSAR) images from the 1991 and 2000 Hekla eruptions, covering periods of 23 and 12 years, respectively. Data from six tracks from three satellites, including both ascending and descending passes, were used to create 99 interferograms, from which trends of accumulated subsidence and subsidence velocities were derived. Subsidence rates are similar for both lava flows and decay approximately exponentially from about 20 mm/yr 5 years after emplacement to about 2 mm/yr 15 years after emplacement. A one‐dimensional, semi‐analytical model was fitted to the observed subsidence rates, with subsidence due to phase change calculated analytically and subsidence due to thermal contraction calculated numerically using dilatometric constraints obtained experimentally. The initial thicknesses of the 1991 and 2000 lava fields, D1991 and D2000, scaled thermal expansivity, γα, and thermal diffusivity, κ, are the crucial parameters influencing lava subsidence and subsidence rate. Inversion for these parameters reveal linear correlations between them. Best fitting results of inversions for D1991 range from 10 m to 27 m, for D2000 from 10 m to 30 m, γα= 9–24 ×10−6 K−1, and κ= 1–7 ×10−7 m2 s−1.
Improving Global Forecast System of extreme precipitation events with regional statistical model: Application of quantile‐based probabilistic forecasts
Authors: Shastri Hiteshri , Ghosh Subimal , Karmakar Subhankar 
Published: January 2017

AbstractForecasting of extreme precipitation events at a regional scale is of high importance due to their severe impacts on society. The impacts are stronger in urban regions due to high flood potential as well high population density leading to high vulnerability. Although significant scientific improvements took place in the global models for weather forecasting, they are still not adequate at a regional scale (e.g., for an urban region) with high false alarms and low detection. There has been a need to improve the weather forecast skill at a local scale with probabilistic outcome. Here we develop a methodology with quantile regression, where the reliably simulated variables from Global Forecast System are used as predictors and different quantiles of rainfall are generated corresponding to that set of predictors. We apply this method to a flood‐prone coastal city of India, Mumbai, which has experienced severe floods in recent years. We find significant improvements in the forecast with high detection and skill scores. We apply the methodology to 10 ensemble members of Global Ensemble Forecast System and find a reduction in ensemble uncertainty of precipitation across realizations with respect to that of original precipitation forecasts. We validate our model for the monsoon season of 2006 and 2007, which are independent of the training/calibration data set used in the study. We find promising results and emphasize to implement such data‐driven methods for a better probabilistic forecast at an urban scale primarily for an early flood warning.
Breakup modes of the drops suspended in a vertical wind tunnel in presence of the horizontal electric field
Authors: Bhalwankar Rohini , Deshpande C. G. , Kamra A. K. 
Published: January 2017

AbstractThe influence of strong horizontal electric field (EH) on different stages of deformation and eventual breakup of the large water drops of 6.6, 7.0, and 7.25 mm diameter has been observed in a vertical wind tunnel using high‐speed photography. Dumbbell, filament, and bag modes of drop breakup are observed when EH = 0. However, drops elongate in horizontal direction, mostly develop sharp curvature at their ends, eject a fine jet spray of tiny droplets, and ultimately break up into several droplets in EH = 500 kV m−1. Extreme elongation up to 29 mm is observed for a 7.0 mm diameter drop. Results show that the breakup time, i.e., the time from the drop's extreme prolate shape to its breakup in its final oscillation, ranges from 13 to 41 ms when EH = 0 and 57–105 ms when EH = 500 kV m−1. So although the lifetime of the drop since its suspension to breakup is reduced, its elongation and breakup time increase in EH. It suggests that the effect of EH in final oscillation before breakup overcomes the effect of hydrodynamic and aerodynamic forces in elongating the drop. Also, no breakup of bag type is observed in EH = 500 kV m−1. Moreover, the fragments formed after the drop breakup and tiny droplets ejected by their fragments carry electrical charges of polarity determined by the induced charge on the parent drop in EH. The significance of the results is discussed in modifying the drop growth and the radar echo‐precipitation relationships in thunderclouds.
Calibration [Air Monitoring Methods, 2016]
Authors: Hebisch R. , Ball M. , Breuer D. , Heckmann P. , Krämer W. , Maschmeier C.‐P. , Nitz G. , Riepe W. , Schuh C. , Brock T.H. , Hartwig A. ,   MAK Commission
Published: January 2017

Workplace measurements are intended to give information about kind and extent of workers' exposure during their activities with hazardous substances. For this purpose calibration is necessary to establish the relationship between a known concentration and the corresponding measuring signal resulting in reliable measuring results at a high level of quality. Therefore, calibration strongly influences accuracy and precision of the whole measuring procedure. Calibration is required for different tasks. During development of a measurement procedure the calibration range has to be determined, for which there must be a linear relationship between the concentration of the analyte and the response of the analytical procedure. Important analytical parameters such as limit of detection (LOD) and limit of quantification (LOQ) may also be determined using calibration procedures. Normally, calibration is needed for the quantification of hazardous substances from workplace measurements. In this case the composition of calibration solutions should be as near as possible to that of the collected samples. The calibrated concentration range should yield unambiguous analytical results. Traceability of the complete calibration procedure from the measuring result back to the typically used (certified) reference material must be ensured. This chapter describes how to perform calibration for different purposes and the possible sources of errors which have to be considered. Requirements for reference materials are also specified.
Joint Publication of the Analytical Subcommittee of the Chemistry Board of Experts of the Expert Committee Raw Materials and Chemical Industry of the German Social Accident Insurance and the Working Group “Air Monitoring Methods” of the Permanent Senate Commission of the DFG for the Investigation of Health Hazards of Chemical Compounds in the Work Area.
Adipinsäure [MAK Value Documentation in German language, 2017]
Authors: Hartwig Andrea ,   MAK‐Kommission
Published: January 2017

Adipic acid [hexanedioic acid]
The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated adipic acid to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints.
The critical effect is moderate local irritation as shown with the Draize test in the rabbit eye. Available inhalation studies are limited and not suitable to derive a MAK value. Systemic toxicity only occurs at high doses. In a limited oral 2‐year study the body weight of rats was reduced at 2250 mg/kg body weight/day. The resulting systemic NOAEL is 750 mg/kg body weight/day.

After comparing adipic acid with other solid acids, a MAK value of 2 mg adipic acid/m
3
I has been set in analogy to phosphoric acid, which is considered to be the worst‐case.

As the critical effect is local, adipic acid is assigned to Peak Limitation Category I. In analogy to phosphoric acid, a default excursion factor of 2 is set.
There is no reason to fear damage to the embryo or foetus when the MAK value is observed; thus, the substance is classified in Pregnancy Risk Group C.
Adipic acid is not genotoxic and not carcinogenic. No contact sensitizing effects have been observed. Skin contact is not expected to contribute significantly to systemic toxicity.
Laurinsäure [MAK Value Documentation in German language, 2017]
Authors: Hartwig Andrea ,   MAK‐Kommission
Published: January 2017

Lauric acid [dodecanoic acid]
The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated lauric acid, considering all toxicity endpoints.

In an oral 18‐week study no substance‐related effects were observed in rats up to 9000 mg/kg body weight and day. As lauric acid is an organic acid, the respiratory tract might be a target organ; however, inhalation studies are not available. A maximum concentration at the workplace (MAK value) was derived by read across to other solid acids. Lauric acid is irritating to the rabbit eye but less so than succinic and adipic acid. Also the acidity of saturated solutions of lauric acid is less than that of succinic and adipic acid. For the latter acids, a MAK value of 2 mg/m
3
for the inhalable fraction was set like that for phosphoric acid. Phosphoric acid is a stronger acid that is corrosive to the eyes of rabbits. Therefore, in analogy to phosphoric acid as a worst‐case, a MAK value of 2 mg/m
3
for the inhalable fraction is set for lauric acid.

As the MAK value has been derived in analogy to phosphoric acid, lauric acid is also classified in Peak Limitation Category I with an excursion factor of 2.
Lauric acid does not have genotoxic potential. There are no carcinogenicity studies available with lauric acid. Results of a dermal initiation‐promotion study with lauric acid alone were negative; promoting activity was seen only after application of an initiator. Lauric acid is no longer classified as carcinogenic to humans, based on the Commission's evaluation of this type of study.
No significant contribution to systemic toxicity was demonstrated in calculations of dermal absorption. Limited data in animals do not indicate a sensitizing potential for lauric acid.
Developmental toxicity studies are lacking; therefore, lauric acid is assigned to Pregnancy Risk Group D.
Terpentinöl [MAK Value Documentation in German language, 2017]
Authors: Hartwig Andrea ,   MAK‐Kommission
Published: January 2017

Turpentine OilThe German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated turpentine oil, considering all toxicity endpoints.Turpentine oil is a mixture of different terpenes, terpenoids and terpene hydrocarbons, mostly mono and bicyclic monoterpenes like pinene, camphene, dihydropinene, carene or dipentene (limonene) with the main component being alpha‐pinene with 60 to 86%. In 14‐week studies with alpha‐pinene in rats and mice, the critical effect was hyperplasia of the epithelium of the urinary bladder in mice at 100 ml/m3with a no observed adverse effect concentration (NOAEC) of 50 ml/m3. No irritation was observed up to the highest concentration of 400 ml/m3in rats and mice. Taking into account that the systemic NOAEC might be lower after chronic exposure and with the increased breathing volume of workers, a maximum concentration at the workplace (MAK value) of 5 ml/m3was derived for turpentine oil. This concentration is far below 80 ml/m3, at which changes in bronchoalveolar lavage fluid were observed in volunteers after short‐term exposure to a mixture of alpha and beta‐pinene and delta‐carene and which is below the NOAEC for alpha‐pinene of 40 ml/m3for sensory irritation in humans.The MAK value was derived from a systemic effect; therefore, turpentine oil is classified in Peak Limitation Category II with an excursion factor of 2.Turpentine oil and its major constituents do not have genotoxic potential. There are no carcinogenicity studies available with turpentine oil or its major components. Results of a dermal initiation‐promotion study with turpentine oil alone were negative; promoting activity was seen only after application of an initiator. Turpentine oil is no longer classified as carcinogenic to humans, based on the Commission's evaluation of this type of study.A significant contribution to systemic toxicity was demonstrated in a model calculation of dermal absorption and turpentine oil is designated with an “H”. Due to the data described in the evaluation of 1996, turpentine oil continues to be designated with an “Sh”.Valid developmental toxicity studies are lacking; therefore, turpentine oil is assigned to Pregnancy Risk Group D.
Chiral Titanium Coordination Assemblies: Robust Cooperative Self‐Supported Catalysts for Asymmetric Ring Opening of meso‐Epoxides with Aliphatic Amines
Authors: Sun Zheming , Chen Jiangbo , Liu Yaoqi , Tu Tao 
Published: January 2017

AbstractBy utilizing the oxygen bridge in dimeric μ‐oxo‐titanium‐salen complexes as an efficient cross‐linkage, a series of robust chiral titanium coordination assemblies has been successfully fabricated with the ditopic bridging ligands derived from BINOL and salen derivatives via coordination polymerization, which are fully characterized by IR, elemental analysis, XRD and microscopic studies. Because of their insolubility in most organic solvents and water, these metal‐organic assemblies can successfully function as robust self‐supported chiral catalysts, allowing an asymmetric ring opening (ARO) of meso‐epoxides with aliphatic amines. Remarkably, owing to the linkage effects and the cooperation of two kinds of chiral titanium moieties in the metal‐organic assemblies, the self‐supported chiral catalysts demonstrate extremely high stability. They not only show high tolerance towards various meso‐epoxides and nucleophilic aliphatic amines, but also can be reused in more than 20 runs without obvious metal leaching and loss in yields and enantioselectivities. Furthermore, the self‐supported catalyst accomplished a one‐pot tandem olefin epoxidation and ARO of an epoxide sequence starting from the olefin, 30% hydrogen peroxide and benzylamine. In marked contrast, the reaction failed to work when using the two corresponding homogeneous catalysts under identical reaction conditions. Good yields and enantioselectivities were obtained by the robust self‐supported catalyst, which clearly indicates the cooperative effects between two chiral moieties within the metal‐organic assemblies. The two catalytic centers can perform their own duties without interference and this further supports our strategy for the self‐supported catalyst design.magnified image
One‐Pot Palladium‐Catalyzed Cross‐Coupling Treble of Borylation, the Suzuki Reaction and Amination
Authors: Jong Howard , Eey Stanley T.‐C. , Lim Yee Hwee , Pandey Sangeeta , Iqbal Nurul Azmah Bte , Yong Fui Fong , Robins Edward G. , Johannes Charles W. 
Published: January 2017

AbstractA methodology for a sequential palladium‐catalyzed cross‐coupling procedure consisting of borylation, the Suzuki reaction and amination has been developed for the assembly of molecules with multi‐aryl backbones. The linchpin of this development is the meta‐terarylphosphine ligand, Cy*Phine, which has been employed as an air‐ and moisture‐stable precatalyst, Pd(Cy*Phine)2Cl2, to improve the efficiency of one‐pot borylation–Suzuki reactions. Additionally, the reactivity of the Pd‐Cy*Phine system could be tuned to furnish a one‐pot, borylation–Suzuki reaction–amination (BSA) cross‐coupling treble. The methodology successfully integrated complementary conditions for three distinctly different and modular reactions. Average yields of 74–94% could be achieved for each segment that cumulatively afforded 50–84% yield over the entire three‐step sequence in a single pot.magnified image
Cooperative Electrocatalytic and Chemoselective Alcohol Oxidation by Shvo's Catalyst
Authors: Lybaert Jeroen , Trashin Stanislav , Maes Bert U. W. , De Wael Karolien , Abbaspour Tehrani Kourosch 
Published: January 2017

AbstractA new electrocatalytic conversion of alcohols to ketones and aldehydes was developed based on an electrochemical study of Shvo's complex. The oxidation of secondary alcohols was efficiently performed under mild conditions using a catalytic amount of Shvo's catalyst, in combination with a sub‐stoichiometric amount of 2,6‐dimethoxy‐1,4‐benzoquinone in N,N‐dimethylformamide at 80 °C. The hydroquinone thus formed is continuously reoxidized with the aid of an electrochemical device. Excellent yields for different ketones, aromatic as well as aliphatic and α,β‐unsaturated ketones, are obtained. In addition, chemoselectivity towards oxidation of the secondary alcohol is achieved when converting vicinal diols such as 1,2‐octanediol and 1,2‐decanediol.magnified image
Silver‐Catalyzed Carbon‐Phosphorus Functionalization for Polyheterocycle Formation
Authors: Liu Jianming , Zhao Shanshan , Song Weiwei , Li Rong , Guo Xinyu , Zhuo Kelei , Yue Yuanyuan 
Published: January 2017

AbstractPolyheterocycle construction with high diastereoselectivity by utilizing a radical process is still problematic. In this communication, a silver‐catalyzed carbon‐phosphorus functionalization for polyheterocycle formation is described that furnishes good diastereoselectivity. Various substituted 1‐(1H‐indol‐1‐yl)‐3‐phenylprop‐2‐en‐1‐ones and phosphine oxides were suitable for this transformation. This work avoids the installation of direct functional groups and thus makes full use of shorter and more efficient synthetic processes. Preliminary mechanistic investigations indicate that phosphorus radicals are involved by attacking the α‐position of α,β‐unsaturated carbonyl compounds to generate the desired products.magnified image
Rhodium‐Catalyzed Decarbonylative Borylation of Aromatic Thioesters for Facile Diversification of Aromatic Carboxylic Acids
Authors: Ochiai Hidenori , Uetake Yuta , Niwa Takashi , Hosoya Takamitsu 
Published: January 2017

AbstractTransformation of aromatic thioesters into arylboronic esters was achieved efficiently using a rhodium catalyst. The broad functional‐group tolerance and mild conditions of the method have allowed for the two‐step decarboxylative borylation of a wide range of aromatic carboxylic acids, including commercially available drugs.
General Enantioselective C−H Activation with Efficiently Tunable Cyclopentadienyl Ligands
Authors: Jia Zhi‐Jun , Merten Christian , Gontla Rajesh , Daniliuc Constantin G. , Antonchick Andrey P. , Waldmann Herbert 
Published: January 2017

AbstractCyclopentadienyl (Cp) ligands enable efficient steering of various transition‐metal‐catalyzed transformations, in particular enantioselective C−H activation. Currently only few chiral Cp ligands are available. Therefore, a conceptually general approach to chiral Cp ligand discovery would be invaluable as it would enable the discovery of applicable Cp ligands and to efficiently and rapidly vary and tune their structures. Herein, we describe the three‐step gram‐scale synthesis of a structurally diverse and widely applicable chiral Cp ligand collection (JasCp ligands) with highly variable and adjustable structures. Their modular nature and their amenability to rapid structure variation enabled the efficient discovery of ligands for three enantioselective RhIII‐catalyzed C−H activation reactions, including one unprecedented transformation. This novel approach should enable the discovery of efficient chiral Cp ligands for various further enantioselective transformations.
Photoproduction of Hydrogen by Decamethylruthenocene Combined with Electrochemical Recycling
Authors: Rivier Lucie , Peljo Pekka , Vannay Laurent A. C. , Gschwend Grégoire C. , Méndez Manuel A. , Corminboeuf Clémence , Scanlon Micheál D. , Girault Hubert H. 
Published: January 2017

AbstractThe photoinduced hydrogen evolution reaction (HER) by decamethylruthenocene, Cp2*RuII (Cp*=C5Me5), is reported. The use of a metallocene to photoproduce hydrogen is presented as an alternative strategy to reduce protons without involving an additional photosensitizer. The mechanism was investigated by (spectro)electrochemical and spectroscopic (UV/Vis and 1H NMR) measurements. The photoactivated hydride involved was characterized spectroscopically and the resulting [Cp2*RuIII]+ species was electrochemically regenerated in situ on a fluorinated tin oxide electrode surface. A promising internal quantum yield of 25 % was obtained. Optimal experimental conditions— especially the use of weakly coordinating solvent and counterions—are discussed.
Dual Fluorescent‐ and Isotopic‐Labelled Self‐Assembling Vancomycin for in vivo Imaging of Bacterial Infections
Authors: Yang Cuihong , Ren Chunhua , Zhou Jie , Liu Jinjian , Zhang Yumin , Huang Fan , Ding Dan , Xu Bing , Liu Jianfeng 
Published: January 2017

AbstractThe increase of bacterial resistance demands rapid and accurate diagnosis of bacterial infections. Biosurface‐induced supramolecular assembly for diagnosis and therapy has received little attention in detecting bacterial infections. Herein we present a dual fluorescent‐nuclear probe based on self‐assembly of vancomycin (Van) on Gram‐positive bacteria for imaging bacterial infection. A Van‐ and rhodamine‐modified peptide derivative (Rho‐FF‐Van), as the imaging agent, binds to the terminal peptide of the methicillin‐resistant staphylococcus aureus (MRSA) and self‐assembles to form nanoaggregates on the surface of MRSA. In an in vivo myositis model, Rho‐FF‐Van results in a significant increased fluorescence signal at the MRSA infected site. Radiolabeled with iodine‐125, Rho‐FF‐Van shows strong radioactive signal in the MRSA‐infected lungs in a murine model. This novel dual fluorescent and nuclear probe promises a new way for in vivo imaging of bacterial infections.