bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of craters on the lunar neutron flux
Authors: Eke V. R. , Bower K. E. , Diserens S. , Ryder M. , Yeomans P. E. L. , Teodoro L. F. A. , Elphic R. C. , Feldman W. C. , Hermalyn B. , Lavelle C. M. , Lawrence D. J. 
Published: July 2015

AbstractThe variation of remotely sensed neutron count rates is measured as a function of cratercentric distance using data from the Lunar Prospector Neutron Spectrometer. The count rate, stacked over many craters, peaks over the crater center, has a minimum near the crater rim, and at larger distances, it increases to a mean value that is up to 1% lower than the mean count rate observed over the crater. A simple model is presented, based upon an analytical topographical profile for the stacked craters fitted to data from the Lunar Orbiter Laser Altimeter. The effect of topography coupled with neutron beaming from the surface largely reproduces the observed count rate profiles. However, a model that better fits the observations can be found by including the additional freedom to increase the neutron emissivity of the crater area by ∼0.35% relative to the unperturbed surface. It is unclear what might give rise to this effect, but it may relate to additional surface roughness in the vicinities of craters. The amplitude of the crater‐related signal in the neutron count rate is small, but not too small to demand consideration when inferring water‐equivalent hydrogen (WEH) weight percentages in polar permanently shaded regions (PSRs). If the small crater‐wide count rate excess is concentrated into a much smaller PSR, then it can lead to a large bias in the inferred WEH weight percentage. For instance, it may increase the inferred WEH for Cabeus crater at the Moon's south pole from ∼1% to ∼4%.
Analysis of geomagnetic hourly ranges
Authors: Danskin D. W. , Lotz S. I. 
Published: July 2015

AbstractIn an attempt to develop better forecasts of geomagnetic activity, hourly ranges of geomagnetic data are analyzed with a focus on how the data are distributed. A lognormal distribution is found to be able to characterize the magnetic data for all observatories up to moderate disturbances with each distribution controlled by the mean of the logarithm of the hourly range. In the subauroral zone, the distribution deviates from the lognormal, which is interpreted as motion of the auroral electrojet toward the equator. For most observatories, a substantial deviation from the lognormal distribution was noted at the higher values and is best modeled with a power law extrapolation, which gives estimates of the extreme values that may occur at observatories which contribute to the disturbance storm time (Dst) index and in Canada.
Automatic CME front edge detection from STEREO white‐light coronagraph images
Authors: Kirnosov Vladimir , Chang Lin‐Ching , Pulkkinen Antti 
Published: July 2015

AbstractThe coronagraph images captured by a Solar Terrestrial Relations Observatory (STEREO) Ahead/Behind (A/B) spacecraft allow tracking of a coronal mass ejection (CME) from two different viewpoints and reconstructing its propagation in three‐dimensional space. The reconstruction can be done using a triangulation technique that requires a CME front edge location. There are currently no robust automatic CME front edge detection methods that can be integrated with the triangulation technique. In this paper, we propose a novel automatic method to detect the front edge of the CME using STEREO coronagraph 2 red‐colored Red, Green, Blue color model images. Our method consists of two modules: preprocessing and classification. The preprocessing module decomposes each coronagraph image into its three channels and uses only the red channel image for CME segmentation. The output of the preprocessing module is a set of segmented running‐difference binary images which is fed into the classification module. These images are then transformed into polar coordinates followed by CME front edge detection based on the distance that CME travels in the field of view. The proposed method was validated against a manual method using total 56 CME events, 28 from STEREO A and 28 from STEREO B, captured in the period from 1 January 2008 to 16 August 2009. The results show that the proposed method is effective for CME front edge detection. The proposed method is useful in quantitative CME processing and analysis and will be immediately applicable to assist automatic triangulation method for real‐time space weather forecasting.
Palladium‐Catalyzed Synthesis of 2,3‐Disubstituted Benzofurans: An Approach Towards the Synthesis of Deuterium Labeled Compounds
Authors: Agasti Soumitra , Maity Soham , Szabo Kalman J. , Maiti Debabrata 
Published: July 2015

AbstractPalladium‐catalyzed oxidative annulations between phenols and alkenylcarboxylic acids produced a library of benzofuran compounds. Depending on the nature of the substitution of the phenol precursor, either 2,3‐dialkylbenzofurans or 2‐alkyl‐3‐methylene‐2,3‐dihydrobenzofurans can be synthesized with excellent regioselectivity. Reactions between conjugated 5‐phenylpenta‐2,4‐dienoic acids and phenol gave 3‐alkylidenedihydrobenzofuran alkaloid motifs while biologically active 7‐arylbenzofuran derivatives were prepared by starting from 2‐phenylphenols. More interestingly, selective incorporation of deuterium from D2O has been discovered, which offers an attractive one‐step method to access deuterated compounds.magnified image
Biochemical and molecular predictors for prognosis in nonketotic hyperglycinemia
Authors: Swanson Michael A. , Coughlin Curtis R. , Scharer Gunter H. , Szerlong Heather J. , Bjoraker Kendra J. , Spector Elaine B. , Creadon‐Swindell Geralyn , Mahieu Vincent , Matthijs Gert , Hennermann Julia B. , Applegarth Derek A. , Toone Jennifer R. , Tong Suhong , Williams Kristina , Van Hove Johan L. K. 
Published: July 2015

ObjectiveNonketotic hyperglycinemia is a neurometabolic disorder characterized by intellectual disability, seizures, and spasticity. Patients with attenuated nonketotic hyperglycinemia make variable developmental progress. Predictive factors have not been systematically assessed.MethodsWe reviewed 124 patients stratified by developmental outcome for biochemical and molecular predictive factors. Missense mutations were expressed to quantify residual activity using a new assay.ResultsPatients with severe nonketotic hyperglycinemia required multiple anticonvulsants, whereas patients with developmental quotient (DQ) > 30 did not require anticonvulsants. Brain malformations occurred mainly in patients with severe nonketotic hyperglycinemia (71%) but rarely in patients with attenuated nonketotic hyperglycinemia (7.5%). Neonatal presentation did not correlate with outcome, but age at onset ≥ 4 months was associated with attenuated nonketotic hyperglycinemia. Cerebrospinal fluid (CSF) glycine levels and CSF:plasma glycine ratio correlated inversely with DQ; CSF glycine > 230 μM indicated severe outcome and CSF:plasma glycine ratio ≤ 0.08 predicted attenuated outcome. The glycine index correlated strongly with outcome. Molecular analysis identified 99% of mutant alleles, including 96 novel mutations. Mutations near the active cleft of the P‐protein maintained stable protein levels. Presence of 1 mutation with residual activity was necessary but not sufficient for attenuated outcome; 2 such mutations conferred best outcome. Divergent outcomes for the same genotype indicate a contribution of other genetic or nongenetic factors.InterpretationAccurate prediction of outcome is possible in most patients. A combination of 4 factors available neonatally predicted 78% of severe and 49% of attenuated patients, and a score based on mutation severity predicted outcome with 70% sensitivity and 97% specificity. Ann Neurol 2015;78:606–618
Homodecoupled 1,1‐ and 1,n‐ADEQUATE: Pivotal NMR Experiments for the Structure Revision of Cryptospirolepine
Authors: Saurí Josep , Bermel Wolfgang , Buevich Alexei V. , Sherer Edward C. , Joyce Leo A. , Sharaf Maged H. M. , Schiff Paul L. , Parella Teodor , Williamson R. Thomas , Martin Gary E. 
Published: July 2015

AbstractCryptospirolepine is the most structurally complex alkaloid discovered and characterized thus far from any Cryptolepis specie. Characterization of several degradants of the original, sealed NMR sample a decade after the initial report called the validity of the originally proposed structure in question. We now report the development of improved, homodecoupled variants of the 1,1‐ and 1,n‐ADEQUATE (HD‐ADEQUATE) NMR experiments; utilization of these techniques was critical to successfully resolving long‐standing structural questions associated with crytospirolepine.
Ein [Fe19]‐“Super‐Lindqvist”‐Aggregat und ein großes, sich durchdringendes, dreidimensionales Koordinationspolymer aus Solvothermalreaktionen von [Fe2(OtBu)6] mit Ethanol
Authors: Nachtigall Olaf , Kusserow Matthias , Clérac Rodolphe , Wernsdorfer Wolfgang , Menzel Michael , Renz Franz , Mrozinski Jerzy , Spandl Johann 
Published: July 2015

AbstractWir berichten über die Synthesen, Kristallstrukturen und physikalischen Eigenschaften von [HFe19O14(OEt)30] und [{Fe11(OEt)24}∞]. Das oktaederförmige Molekül [HFe19O14(OEt)30] kann als dreidimensionaler Ausschnitt aus dem Natriumchloridgitter aufgefasst werden, wobei das zentrale Eisenion von sechs μ6‐Oxo‐Gruppen koordiniert ist. [{Fe11(OEt)24}∞] ist ein gemischtvalentes Koordinationspolymer, in dem die FeIII‐Ionen ein dreidimensionales (10,3)‐b‐Netz bilden. Die Anordnung der FeIII‐Ionen ist mit der von Siliciumionen in α‐ThSi2 vergleichbar. Die beschriebenen Strukturen zeigen eine Schnittstelle zwischen Molekül‐ und Festkörperchemie auf.
Translating Molecular Recognition into a Pressure Signal to enable Rapid, Sensitive, and Portable Biomedical Analysis
Authors: Zhu Zhi , Guan Zhichao , Liu Dan , Jia Shasha , Li Jiuxing , Lei Zhichao , Lin Shuichao , Ji Tianhai , Tian Zhongqun , Yang Chaoyong James 
Published: July 2015

AbstractHerein, we demonstrate that a very familiar, yet underutilized, physical parameter—gas pressure—can serve as signal readout for highly sensitive bioanalysis. Integration of a catalyzed gas‐generation reaction with a molecular recognition component leads to significant pressure changes, which can be measured with high sensitivity using a low‐cost and portable pressure meter. This new signaling strategy opens up a new way for simple, portable, yet highly sensitive biomedical analysis in a variety of settings.
Kupfer‐ und Silber‐Carbenkomplexe ohne Heteroatom‐Stabilisierung: Struktur, Spektroskopie und relativistische Effekte
Authors: Hussong Matthias W. , Hoffmeister Wilhelm T. , Rominger Frank , Straub Bernd F. 
Published: July 2015

AbstractSalze eines Kupfercarben‐ und eines Silbercarben‐Komplexes wurden aus Dimesityldiazomethan hergestellt, ermöglicht durch die sterische Abschirmung des N‐heterocyclischen Steuerliganden IPr**. Der minzgrüne Komplex [IPr**AgCMes2]+[NTf2]− ist der erste isolierte Silbercarben‐Komplex ohne Heteroatom‐Donorsubstituenten. Seine durch Einkristall‐Röntgenstrukturanalyse erhaltene Festkörperstruktur erbringt den Nachweis für einen vorherrschenden Carbenoid‐Charakter und stützt die Annahme solch reaktiver Spezies als Intermediate in Silber‐katalysierten CH‐Aktivierungsreaktionen. Die spektroskopischen Eigenschaften des grünlich‐currygelben Kupfercarben‐Komplexes [IPr**CuCMes2]+[NTf2]− liegen zwischen denen des isostrukturellen Silberkomplexes und denen des schon beschriebenen smaragdgrünen Goldcarben‐Komplexes. Ein Vergleich der Elemente der Kupfertriade weist darauf hin, dass relativistische Effekte für die starke σ‐Bindung und die signifikante π‐Rückbindung in der Goldcarben‐Einheit verantwortlich sind.
Towards Clathrates: Frozen States of Hydration of tert‐Butylamine
Authors: Dobrzycki Łukasz , Taraszewska Paulina , Boese Roland , Cyrański Michał K. , Cirkel Sebastian A. 
Published: July 2015

AbstractThe dilution of tert‐butylamine (tBA) with water and subsequent cooling leads to a large series of different crystalline hydrates by an in situ IR laser melting‐zone procedure. The crystal structures were determined for tBA⋅n H2O, with n=0, ${{ 1/4 }}$, 1, 7 ${{ 1/4 }}$, 7 ${{ 3/4 }}$, 9 ${{ 3/4 }}$, 11, and 17. For the two lower hydrates (n=${{ 1/4 }}$, 1), one‐ and two‐dimensional hydrogen‐bonded networks are formed, respectively. The higher hydrates (n>1) exhibit a clathrate‐like three‐dimensional water framework with the tBA molecules as part of, or sitting inside, the cages. In all cases, tBA is hydrogen‐bonded to the H2O framework. In the intermediate range (1<n<7 ${{ 1/4 }}$), crystallization is hindered, and no crystalline phases could be observed. The crystal structures that are achieved from the dilution of tBA with water are considered to be frozen stages of hydration, describing the genesis of such clathrate‐like structures, finally ending at ice as an example of an infinitely diluted hydrate.
Bioinduced Room‐Temperature Methanol Reforming
Authors: Heim Leo E. , Thiel Daniel , Gedig Christian , Deska Jan , Prechtl Martin H. G. 
Published: July 2015

AbstractImitating nature′s approach in nucleophile‐activated formaldehyde dehydrogenation, air‐stable ruthenium complexes proved to be exquisite catalysts for the dehydrogenation of formaldehyde hydrate as well as for the transfer hydrogenation to unsaturated organic substrates at loadings as low as 0.5 mol %. Concatenation of the chemical hydrogen‐fixation route with an oxidase‐mediated activation of methanol gives an artificial methylotrophic in vitro metabolism providing methanol‐derived reduction equivalents for synthetic hydrogenation purposes. Moreover, for the first time methanol reforming at room temperature was achieved on the basis of this bioinduced dehydrogenation path delivering hydrogen gas from aqueous methanol.
Unconventional Magnetic and Resistive Hysteresis in an Iodine‐Bonded Molecular Conductor
Authors: Kawaguchi Genta , Maesato Mitsuhiko , Komatsu Tokutaro , Kitagawa Hiroshi , Imakubo Tatsuro , Kiswandhi Andhika , Graf David , Brooks James S. 
Published: July 2015

AbstractSimultaneous manipulation of both spin and charge is a crucial issue in magnetic conductors. We report on a strong correlation between magnetism and conductivity in the iodine‐bonded molecular conductor (DIETSe)2FeBr2Cl2 [DIETSe=diiodo(ethylenedithio)tetraselenafulvalene], which is the first molecular conductor showing a large hysteresis in both magnetic moment and magnetoresistance associated with a spin‐flop transition. Utilizing a mixed‐anion approach and iodine bonding interactions, we tailored a molecular conductor with random exchange interactions exhibiting unforeseen physical properties.
Enantioselective Synthesis of Quaternary Carbon Stereocenters: Addition of 3‐Substituted Oxindoles to Vinyl Sulfone Catalyzed by Pentanidiums
Authors: Zong Lili , Du Shubo , Chin Kek Foo , Wang Chao , Tan Choon‐Hong 
Published: July 2015

AbstractA pentanidium‐catalyzed highly enantioselective conjugate addition of 3‐alkyloxindoles to phenyl vinyl sulfone has been demonstrated. This approach allows the construction of 3,3‐dialkyl‐substituted oxindole frameworks with high yield and excellent enantioselectivity (up to 99 %) under simple phase‐transfer conditions. A variety of oxindoles bearing all‐carbon quaternary stereogenic centers were obtained in the presence of 0.25 mol % pentanidium. Meanwhile, practicality was illustrated by a gram‐scale asymmetric synthesis of two 3,3‐dialkyl‐substituted oxindoles. The resulting adduct can be smoothly transformed to the natural product analogue in a short synthetic route.
A Catalytic SEAr Approach to Dibenzosiloles Functionalized at Both Benzene Cores
Authors: Omann Lukas , Oestreich Martin 
Published: July 2015

AbstractA general procedure for the catalytic preparation of dibenzosiloles functionalized at one or both benzene rings starting from readily available ortho‐silylated biphenyls is reported. This method provides rapid access to silole building blocks substituted with chlorine atoms at both phenylene groups, thereby allowing catalytic access to directly polymerizable dibenzosiloles. Moreover, it is shown that, despite the involvement of highly electrophilic intermediates, a considerable range of Lewis‐basic, for example, oxygen‐ and nitrogen‐containing, functional groups is tolerated. The mechanism of this intramolecular electrophilic aromatic substitution (SEAr) proceeds through a sulfur‐stabilized silicon cation, generated catalytically from the hydrosilane precursor.
Electrophilic Fluorophosphonium Cations in Frustrated Lewis Pair Hydrogen Activation and Catalytic Hydrogenation of Olefins
Authors: vom Stein Thorsten , Peréz Manuel , Dobrovetsky Roman , Winkelhaus Daniel , Caputo Christopher B. , Stephan Douglas W. 
Published: July 2015

AbstractThe combination of phosphorus(V)‐based Lewis acids with diaryl amines and diaryl silylamines promotes reversible activation of dihydrogen and can be further exploited in metal‐free catalytic olefin hydrogenation. Combined experimental and density functional theory (DFT) studies suggest a frustrated Lewis pair type activation mechanism.
A Kinetic Model for Exfoliation Kinetics of Layered Materials
Authors: Texter John 
Published: July 2015

AbstractExfoliation of two‐dimensional materials is key to obtaining high‐performance properties. We present a simple kinetic model for exfoliation that is readily solved analytically. Random and irreversible sheet separation is postulated in the presence of highly effective stabilizers. This model appears to quantitatively fit graphene exfoliation data, and it illuminates mechanistic aspects of exfoliation. Thicker sheets exfoliate much faster than trilayer and bilayer sheets. Exfoliation follows highly activated diffusion‐controlled intercalation of stabilizer into inter‐sheet galleries. Application to the most concentrated graphene exfoliation data available supports these assumptions and provides insight for practical treatment regimens.
Aging of polyamide 11. Part 2: General multiscale model of the hydrolytic degradation applied to predict the morphology evolution
Authors: Mazan Tobiasz , Jørgensen Jens Kjær , Echtermeyer Andreas 
Published: July 2015

ABSTRACTAccelerated aging tests are the conventional way to evaluate long‐term degradation of polymers, in particular for offshore flexible risers. In this article, a multiscale model has been developed combining diffusion, chemical kinetic reactions, structure–property relationships, and composite models to provide faster and less labor extensive property predictions. A general methodology is presented and applied to predict the density and crystallinity evolution. Results are compared with experimental ageing of polyamide 11 in deoxygenated water at 120 °C. For both density and degree of crystallinity the modeled trend is close to the experimental test results. Accurate prediction of the morphological parameters during degradation allows extension of the multiscale model for the prediction of mechanical properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42630.
Thermoplastic polyurethane synthesis with modified montmorillonite prepared by torque rheometry: Investigation of morphological, thermal, chemical, and physical properties
Authors: Ornaghi Felipe Gustavo , Pistor Vinicios , de Oliveira Ricardo Vinícius Boff 
Published: July 2015

ABSTRACTIn this study, samples of thermoplastic polyurethane (TPU) were synthesized by reactive processing in an instrumented batch mixer with 0, 1, 2, 5, and 10 wt % of organophilic montmorillonite (OMMT) clay. Fourier transform infrared spectroscopy confirmed the obtainment of TPU. Transmission electron microscopy showed several types of clay dispersion. Analysis by X‐ray diffraction revealed modifications in the TPU microstructure, a reduction in the degree of crystallinity, and an increase in the crystal size. Dynamic mechanical properties showed that the incorporation of OMMT has a strong influence on the storage and loss moduli obtained for the TPU matrix. The incorporation of OMMT also altered the crystallization and thermal stability of the TPU. With the use of the Flynn–Wall–Ozawa method it was observed that the nanoclay had a higher apparent activation energy. The results obtained applying the Criado method indicated that the solid state reaction is essentially controlled by geometric contraction, random nucleation with one nucleus for each individual particle and diffusion. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42640.
Design and Comparison Base Analysis of Adaptive Estimator for Completely Unknown Linear Systems in the Presence of OE Noise and Constant Input Time Delay
Authors: Tutsoy Onder 
Published: July 2015

AbstractIn this paper, an adaptive estimator (AE) is introduced to learn the approximate Q‐function and control policy by only using the noisy states and control signals of the unknown linear, discrete time systems having constant input time delay. The system measurements are uncertain owing to output error (OE)‐type noise acting randomly on the system measurements. Therefore, this research differs from the designed AE in the literature since previous research ignores the role of the external random disturbances on AE‐based learning. In order to compare the AE‐based learning results with traditional system identification (SI) approaches, a modified version of the OE model structure for unstable systems is reviewed and parameters of a second‐order unstable system with constant input time delay are identified. The simulation results demonstrate that the designed AE efficiently minimizes the stochastic cost function and the temporal difference error by learning the approximate solution for the Hamilton‐Jacobi‐Bellman (HJB) equation. It is noted that the error in the Q‐function obtained with the AE is slightly larger than the Q‐function attained with the identified OE parameters. However, as the noise standard deviation increases, the error in the AE‐based learning results reduces whereas the error in the OE‐based learning increases. This indicates that even though the added random noise deteriorates the performance of the OE predictor, it improves the learning efficiency of the AE since it acts like exploration noise.