bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of local ionization on ionospheric densities in Titan's upper atmosphere
Authors: Sagnières Luc B. M. , Galand Marina , Cui Jun , Lavvas Panayotis P. , Vigren Erik , Vuitton Véronique , Yelle Roger V. , Wellbrock Anne , Coates Andrew J.
Published: July 2015

Titan has the most chemically complex ionosphere of the solar system. The main sources of ions on the dayside are ionization by EUV solar radiation and on the nightside include ionization by precipitated electrons from Saturn's magnetosphere and transport of ions from the dayside, but many questions remain open. How well do models predict local ionization rates? How strongly do the ionization processes drive the ionospheric densities locally? To address these questions, we have carried out an analysis of ion densities from the Ion and Neutral Mass Spectrometer (INMS) from 16 close flybys of Titan's upper atmosphere. Using a simple chemical model applied to the INMS data set, we have calculated the ion production rates and local ionization frequencies associated with primary ions
and
. We find that on the dayside the solar energy deposition model overestimates the INMS‐derived
production rates by a factor of 2. On the nightside, however, the model driven by suprathermal electron intensities from the Cassini Plasma Spectrometer Electron Spectrometer sometimes agrees and other times underestimates the INMS‐derived
production rates by a factor of up to 2–3. We find that below 1200 km, all ion number densities correlate with the local ionization frequency, although the correlation is significantly stronger for short‐lived ions than long‐lived ions. Furthermore, we find that, for a given N2 local ionization frequency,
has higher densities on the dayside than on the nightside. We explain that this is due to CH4 being more efficiently ionized by solar photons than by magnetospheric electrons for a given amount of N2 ionization.
From products to processes: Academic events to foster interdisciplinary and iterative dialogue in a changing climate
Authors: Addor Nans , Ewen Tracy , Johnson Leigh , Çöltekin Arzu , Derungs Curdin , Muccione Veruska
Published: July 2015

In the context of climate change, both climate researchers and decision makers deal with uncertainties, but these uncertainties differ in fundamental ways. They stem from different sources, cover different temporal and spatial scales, might or might not be reducible or quantifiable, and are generally difficult to characterize and communicate. Hence, a mutual understanding between current and future climate researchers and decision makers must evolve for adaptation strategies and planning to progress. Iterative two‐way dialogue can help to improve the decision making process by bridging current top‐down and bottom‐up approaches. One way to cultivate such interactions is by providing venues for these actors to interact and exchange on the uncertainties they face. We use a workshop‐seminar series involving academic researchers, students, and decision makers as an opportunity to put this idea into practice and evaluate it. Seminars, case studies, and a round table allowed participants to reflect upon and experiment with uncertainties. An opinion survey conducted before and after the workshop‐seminar series allowed us to qualitatively evaluate its influence on the participants. We find that the event stimulated new perspectives on research products and communication processes, and we suggest that similar events may ultimately contribute to the midterm goal of improving support for decision making in a changing climate. Therefore, we recommend integrating bridging events into university curriculum to foster interdisciplinary and iterative dialogue among researchers, decision makers, and students.
Appreciation of peer reviewers for 2014
Authors: Becker Thorsten W. , Bass Jay , Blichert‐Toft Janne , Derry Lou , Lee Cin‐Ty , Tyburczy James , Vance Derek , Yokoyama Yusuke
Published: July 2015

The editorial and scientific publishing process relies on the sustained work of volunteer reviewers, and evaluating the interdisciplinary and broad interest papers published in G‐Cubed can be a particular challenge. As Editors and Associated Editors, we are therefore hugely appreciative of the efforts of our reviewers, and would like to thank and acknowledge them in this editorial. G‐Cubed published 257 manuscripts out of 431 submissions in 2014, and for this, we were able to rely on the efforts of 710 dedicated reviewers. Their names are listed below; in italics are those 27 who provided three or more reviews. A big thank you from the G‐Cubed team!
Space geodetic observation of the deformation cycle across the Ballenas Transform, Gulf of California
Authors: Plattner Christina , Malservisi Rocco , Amelung Falk , Dixon Timothy H. , Hackl Matthias , Verdecchia Alessandro , Lonsdale Peter , Suarez‐Vidal Francisco , Gonzalez‐Garcia Javier
Published: July 2015

The Gulf of California, Mexico, accommodates ~90% of North America‐Pacific plate relative motion. While most of this motion occurs on marine transform faults and spreading centers, several fault segments in the central Gulf come close to peninsular Baja California. Here we present Global Positioning System and interferometric synthetic aperture radar data near the Ballenas transform fault, separating the peninsula from Angel de la Guarda Island. We observe interseismic motion between June 2004 and May 2009 and displacements associated with the 3 August 2009Mw6.9 earthquake. From the interseismic data we estimate a locking depth of 9–12.5 km and a slip rate of 44.9–48.1 mm/yr, indicating that faults east of Angel de la Guarda deform at negligible rates and that the Ballenas Transform accommodates virtually all of the relative motion between the North American plate and the Baja California microplate. Our preferred model for coseismic slip on a finite rectangular fault plane suggests 1.3 m of strike‐slip displacement along a vertical rupture plane that is 60 km long and extends from the surface to a depth of 13 km in the eastern Ballenas Channel, striking parallel to Baja California‐North America relative plate motion. These estimates agree with the seismic moment tensor and the location of the major foreshock and aftershocks and are compatible with the fault location identified from high‐resolution bathymetric mapping. The geodetic moment is 33% higher than the seismic moment in part because some afterslip and viscous flow in the first month after the earthquake are included in the geodetic estimate. Coulomb stress changes for adjacent faults in the Gulf are consistent with the location of smaller aftershocks following the 2009 main shock and suggest potential triggering of the 12 April 2012Mw6.9 Guaymas earthquake.
Retrieving of atmospheric parameters from multi‐GNSS in real time: Validation with water vapor radiometer and numerical weather model
Authors: Li Xingxing , Zus Florian , Lu Cuixian , Dick Galina , Ning Tong , Ge Maorong , Wickert Jens , Schuh Harald
Published: July 2015

The multiconstellation Global Navigation Satellite Systems (GNSS) (e.g., GPS, GLObal NAvigation Satellite System (GLONASS), Galileo, and BeiDou) offers great opportunities for real‐time retrieval of atmospheric parameters for supporting numerical weather prediction nowcasting or severe weather event monitoring. In this study, the observations from different GNSS are combined to retrieve atmospheric parameters based on the real‐time precise point positioning technique. The atmospheric parameters, retrieved from multi‐GNSS observations of a 180 day period from about 100 globally distributed stations, including zenith total delay, integrated water vapor, horizontal gradient, and slant total delay (STD), are analyzed and evaluated. The water vapor radiometer data and a numerical weather model, the operational analysis of the European Centre for Medium‐Range Weather Forecasts (ECMWF), are used to independently validate the performance of individual GNSS and also demonstrate the benefits of multiconstellation GNSS for real‐time atmospheric monitoring. Our results show that the GLONASS and BeiDou have the potential capability for real‐time atmospheric parameter retrieval for time‐critical meteorological applications as GPS does, and the combination of multi‐GNSS observations can improve the performance of a single‐system solution in meteorological applications with higher accuracy and robustness. The multi‐GNSS processing greatly increases the number of STDs. The mean and standard deviation of STDs between each GNSS and ECMWF exhibit a good stability as function of the elevation angle, the azimuth angle, and time, in general. An obvious latitude dependence is confirmed by a map of station specific mean and standard deviations. Such real‐time atmospheric products, provided by multi‐GNSS processing with higher accuracy, stronger reliability, and better distribution, might be highly valuable for atmospheric sounding systems, especially for nowcasting of extreme weather.
A new ice cloud parameterization for infrared radiative transfer simulation of cloudy radiances: Evaluation and optimization with IIR observations and ice cloud profile retrieval products
Authors: Vidot Jérôme , Baran Anthony J. , Brunel Pascal
Published: July 2015

A new ice cloud optical property database in the thermal infrared has been parameterized for the RTTOV radiative transfer model. The Self‐Consistent Scattering Model (SCSM) database is based on an ensemble model of ice crystals and a parameterization of the particle size distribution. This convolution can predict the radiative properties of cirrus without the need of a priori information on the ice particle shape and an estimate of the ice crystal effective dimension. The ice cloud optical properties are estimated through linear parameterizations of ambient temperature and ice water content. We evaluate the new parameterization against existing parameterizations used in RTTOV. We compare infrared observations from Imaging Infrared Radiometer, on board CALIPSO, against RTTOV simulations of the observations. The simulations are performed using two different products of ice cloud profiles, retrieved from the synergy between space‐based radar and lidar observations. These are the 2C‐ICE and DARDAR products. We optimized the parameterization by testing different SCSM databases, derived from different shapes of the particle size distribution, and weighting the volume extinction coefficient of the ensemble model. By selecting a large global data set of ice cloud profiles of visible optical depths between 0.03 and 4, we found that the simulations, based on the optimized SCSM database parameterization, reproduces the observations with a mean bias of only 0.43 K and a standard deviation of 6.85 K. The optimized SCSM database parameterization can also be applied to any other radiative transfer model.
Identifying robust transport features of the upper tropical troposphere
Authors: Bergman J. W. , Pfister L. , Yang Q.
Published: July 2015

Multimodel ensembles of back trajectories calculated from four different analysis data sets and two different trajectory formulations (“diabatic” and “kinematic”) are analyzed to investigate seasonal mean boundary layer‐to‐“tropopause” (100 hPa) transport in the tropics. Transport paths are separated into two legs: “convective uplift” (boundary layer to detrainment) and “radiative ascent” (detrainment to tropopause). The following three diagnostic measures are used: source location, source‐to‐tropopause transport time, and the source “influence” (i.e., the fraction of air with short transport times) at 100 hPa. Ensemble means and standard deviations identify “robust features” (i.e., common to all ensemble members) while experimental hybrid calculations explain model‐to‐model discrepancies. Convective uplift is a major contributor to uncertainties in boundary layer‐to‐tropopause transport times and source locations. Spatial patterns of boundary layer influence at 100 hPa are nevertheless robust. Detrainment‐to‐tropopause transport times are robust despite substantial model‐to‐model variations of convective detrainment height because ascent rates are faster at low altitudes than at high altitudes. Detrainment‐to‐tropopause transport also has robust horizontal spatial patterns for both convective sources and convective influence, particularly during boreal winter. Most model‐to‐model discrepancies occur at small spatial scales and are associated with differing distributions of convection. The location of maximum convective influence associated with the Asian summer monsoon is a notable exception. This exceptionally large discrepancy is associated primarily with radiative ascent. The fact that the observed maxima of important tropospheric constituents are collocated with the maximum convective influence for the diabatic calculations but not for the kinematic calculations suggests that diabatic trajectories could be more reliable in this region.
A Flexible Quasi‐Solid‐State Asymmetric Electrochemical Capacitor Based on Hierarchical Porous V2O5 Nanosheets on Carbon Nanofibers
Authors: Li Linlin , Peng Shengjie , Wu Hao Bin , Yu Le , Madhavi Srinivasan , Lou Xiong Wen (David)
Published: July 2015

The development of 3D nanoarchitectures on flexible current collectors has emerged as an effective strategy for preparing advanced portable and wearable power sources. Herein, a flexible and efficient electrode is demonstrated based on electrospun carbon fibers (ECF) substrate with elaborately designed hierarchical porous V2O5 nanosheets (V2O5–ECF). The unique configuration of V2O5–ECF composite film fully enables utilization of the synergistic effects from both high electrochemical performance of V2O5 and excellent conductivity of ECF, endowing the films to be an excellent electrode for flexible and lightweight electrochemical capacitors (ECs). Benefiting from their intriguing structural features, V2O5–ECF and ECF films, directly used as electrodes for flexible asymmetric quasi‐solid‐state electrochemical capacitors, achieve superior flexibility and reliability, enhanced energy/power density, and outstanding cycling stability. Moreover, the ability to power light‐emitting diodes (LED) also indicates the feasibility for practical use. Therefore, it is believed that this novel design may find promising application in flexible devices in future.
Ni‐Al2O3/Ni‐foam catalyst with enhanced heat transfer for hydrogenation of CO2 to methane
Authors: Li Yakun , Zhang Qiaofei , Chai Ruijuan , Zhao Guofeng , Liu Ye , Lu Yong , Cao Fahai
Published: July 2015

Monolithic Ni‐Al2O3/Ni‐foam catalyst is developed by modified wet chemical etching of Ni‐foam, being highly active/selective and stable in strongly exothermic CO2 methanation process. The as‐prepared catalysts are characterized by x‐ray diffraction scanning electron microscopy, inductively coupled plasma atomic emission spectrometry, and H2‐temperature programmed reduction‐mass spectrometry. The results indicate that modified wet chemical etching method is working efficiently for one‐step creating and firmly embedding NiO‐Al2O3 composite catalyst layer (∼2 μm) into the Ni‐foam struts. High CO2 conversion of 90% and high CH4 selectivity of >99.9% can be obtained and maintained for a feed of H2/CO2 (molar ratio of 4/1) at 320°C and 0.1 MPa with a gas hourly space velocity of 5000 h−1, throughout entire 1200 h test over 10.2 mL such monolithic catalysts. Computational fluid dynamics calculation and experimental measurement consistently confirm a dramatic reduction of “hotspot” temperature due to enhanced heat transfer. © 2015 American Institute of Chemical Engineers AIChE J, 61: 4323–4331, 2015
Hybrid mixture theory based modeling of transport mechanisms and expansion‐thermomechanics of starch during extrusion
Authors: Ditudompo Srivikorn , Takhar Pawan S.
Published: July 2015

Water, vapor, and heat transport mechanisms and thermomechanical changes occurring inside the expanding extrudate were described using hybrid mixture theory‐based unsaturated transport equations. Transport equations were transformed from the Eulerian coordinates to the Lagrangian coordinates. Good agreements between the predicted and experimental values of surface temperature, moisture content, and expansion ratio of the extrudates were obtained. The model was also used to calculate temperature, moisture content, pore‐pressure, and viscoelastic‐stress distribution in the extrudate. Matrix collapse and glassy crust formation under the surface was calculated as a function of extrusion conditions. Expansion behavior of the extrudate was described using the difference between stress due to pore pressure and viscoelastic stress. The modeling results can serve as a guide for predictably modifying the extrusion parameters for obtaining specific textural attributes of expanded starch for various food, feed, and biomedical applications. © 2015 American Institute of Chemical Engineers AIChE J, 61: 4517–4532, 2015
Trajectory modeling of gas–liquid flow in microchannels with stochastic differential equation and optical measurement
Authors: Zhang Lexiang , Xin Feng , Peng Dongyue , Zhang Weihua , Wang Yuexing , Chen Xiaodong , Wang Yi
Published: July 2015

The numbering‐up of microchannel reactors definitely faces great challenge in uniformly distributing fluid flow in every channel, especially for multiphase systems. A model of stochastic differential equations (SDEs) is proposed based on the experimental data recorded by a long‐term optical measurement to well quantify the stochastic trajectories of gas bubbles and liquid slugs in parallel microchannels interconnected with two dichotomic distributors. The expectation and variance of each subflow rate are derived explicitly from the SDEs associated with the Fokker–Planck equation and solved numerically. A bifurcation in the trajectory is found using the original model, then a modification on interactions of feedback and crosstalk is introduced, the evolutions of subflow rates calculated by the modified model match well with experimental results. The established methodology is helpful for characterizing the flow uniformity and numbering‐up the microchannel reactors of multiphase system. © 2015 American Institute of Chemical EngineersAIChE J, 61: 4028–4034, 2015
Multivariate statistical process monitoring of batch‐to‐batch startups
Authors: Yan Zhengbing , Huang Bi‐Ling , Yao Yuan
Published: July 2015

In batch processes, multivariate statistical process monitoring (MSPM) plays an important role for ensuring process safety. However, despite many methods proposed, few of them can be applied to batch‐to‐batch startups. The reason is that, during the startup stage, process data are usually nonstationary and nonidentically distributed from batch to batch. In this article, the trajectory signal of each process variable is decomposed into a series of components corresponding to different frequencies, by adopting a nonparametric signal decomposition technique named ensemble empirical mode decomposition. Then, through instantaneous frequency calculation, these components can be divided into two groups. The first group reflects the long‐term trend between batches, which extracts the batch‐wise nonstationary drift information. The second group corresponds to the short‐term intrabatch variations. The variable trajectory signals reconstructed from the latter fulfills the requirements of conventional MSPM. The feasibility of the proposed method is illustrated using an injection molding process. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3719–3727, 2015
Schaltung und Fixierung der Konformation von Amiden durch nahegelegene positive Ladungen
Authors: Bartuschat Amelie L. , Wicht Karina , Heinrich Markus R.
Published: July 2015

Tertiäre Amide, die üblicherweise als cis‐trans‐Gemische auftreten, können wirkungsvoll in die cis‐Konformation überführt werden, indem man eine positive Ladung in der Nähe der Amidcarbonylgruppe platziert. Dieser Effekt ermöglichte die Herstellung eines cis‐Prolylamids und die Verbesserung einer stark Rotamer‐abhängigen radikalischen Cyclisierung.
Anellierte Thiophen‐Pyrrol‐haltige Ringsysteme bis zu einem Heterodecacen
Authors: Wetzel Christoph , Brier Eduard , Vogt Astrid , Mishra Amaresh , Mena‐Osteritz Elena , Bäuerle Peter
Published: July 2015

Eine neue Klasse von π‐konjugierten polycyclischen Kohlenwasserstoffen, die interessante elektronische Eigenschaften verspricht, wird vorgestellt. Die Synthese und Erweiterung der nur aus Fünfring‐Heterocyclen bestehenden S,N‐Heteroacenreihe bis zu einem sehr langen, stabilen und noch gut löslichen Decacen SN10 gelingt über mehrfache Pd‐katalysierte Aminierungen von halogenierten Thiophenvorstufen als zentrale Reaktionen. Die neuartigen Heteroacene wurden über optische Spektroskopie und Elektrochemie charakterisiert und liefern interessante Struktur‐Eigenschafts‐Beziehungen. Ein fast vollständiger Bindungslängenausgleich im “Inneren” des konjugierten π‐Systems und eine ungewöhnliche Fischgräten‐Packung im Festkörper sind strukturelle Besonderheiten der neuen Systeme.
Post‐Assembly Stabilization of Rationally Designed DNA Crystals
Authors: Zhao Jiemin , Chandrasekaran Arun Richard , Li Qian , Li Xiang , Sha Ruojie , Seeman Nadrian C. , Mao Chengde
Published: July 2015

This manuscript reports an effort to stabilize self‐assembled DNA crystals. Owing to their weak inter‐unit cohesion, self‐assembled DNA crystals are fragile, which limits the potential applications of such crystals. To overcome this problem, another molecule was introduced, which binds to the cohesive sites and stabilizes the inter‐unit interactions. The extra interactions greatly improve the stability of the DNA crystals. The original DNA crystals are only stable in solutions of high ionic strength (e.g., ≥1.2 M (NH4)2SO4); in contrast, the stabilized crystals can be stable at ionic strengths as low as that of a 0.02 M solution of (NH4)2SO4. The current strategy is expected to represent a general approach for increasing the stability of self‐assembled DNA nanostructures for potential applications, for example, as structural scaffolds and molecular sieves.
Chemical Evolution of a Bacterial Proteome
Authors: Hoesl Michael Georg , Oehm Stefan , Durkin Patrick , Darmon Elise , Peil Lauri , Aerni Hans‐Rudolf , Rappsilber Juri , Rinehart Jesse , Leach David , Söll Dieter , Budisa Nediljko
Published: July 2015

We have changed the amino acid set of the genetic code of Escherichia coli by evolving cultures capable of growing on the synthetic noncanonical amino acid L‐β‐(thieno[3,2‐b]pyrrolyl)alanine ([3,2]Tpa) as a sole surrogate for the canonical amino acid L‐tryptophan (Trp). A long‐term cultivation experiment in defined synthetic media resulted in the evolution of cells capable of surviving Trp→[3,2]Tpa substitutions in their proteomes in response to the 20 899 TGG codons of the E. coli W3110 genome. These evolved bacteria with new‐to‐nature amino acid composition showed robust growth in the complete absence of Trp. Our experimental results illustrate an approach for the evolution of synthetic cells with alternative biochemical building blocks.
Self‐Healing Materials from V‐ and H‐Shaped Supramolecular Architectures
Authors: Chen Senbin , Mahmood Nasir , Beiner Mario , Binder Wolfgang H.
Published: July 2015

Integrating self‐healing capability into supramolecular architectures is an interesting strategy, and can considerably enhance the performance and broaden the scope of applications for this important class of polymers. Herein we report the rational design of novel V‐shaped barbiturate (Ba) functionalized soft–hard–soft triblock copolymers with a reversible supramolecular healing motif (Ba) in the central part of the hard block, which undergoes autonomic repair at 30 °C. The designed synthesis also offers a suitable macromolecular building block to further self‐assemble with heterocomplementary α,ω‐Hamilton wedge (HW) functionalized polyisoprene (PI; HW‐PI‐HW), resulting in an H‐shaped supramolecular architecture with efficient self‐healing capabilities that can recover up to around 95 % of the original mechanical performance at 30 °C within 24 h.
1,3‐Butadienyl Dianions as Non‐Innocent Ligands: Synthesis and Characterization of Aromatic Dilithio Rhodacycles
Authors: Wei Junnian , Zhang Yongliang , Zhang Wen‐Xiong , Xi Zhenfeng
Published: July 2015

Herein we report that 1,4‐dilithio‐1,3‐butadienes, a type of 1,3‐butadienyl dianion, can act as non‐innocent ligands, taking electrons from low‐valent transition metals. Dilithio reagents reacted with [{RhCl(cod)}2] to give dilithio rhodacycle 3 a. Single‐crystal X‐ray structural analysis revealed the structure of 3 a with averaged bond lengths. XPS data suggested that the oxidation state of Rh in 3 a was more likely to be Rh3+. CDA/ECDA confirmed the electron‐transfer process. 7Li NMR spectra of 3 a and theoretical calculations revealed a considerable aromatic character. In this process, the dilithio compounds behaved as non‐innocent ligands and formal oxidants. These results demonstrated that organolithium compounds with suitable π‐conjugation could be used as electron acceptor.
A Native Ternary Complex Trapped in a Crystal Reveals the Catalytic Mechanism of a Retaining Glycosyltransferase
Authors: Albesa‐Jové David , Mendoza Fernanda , Rodrigo‐Unzueta Ane , Gomollón‐Bel Fernando , Cifuente Javier O. , Urresti Saioa , Comino Natalia , Gómez Hansel , Romero‐García Javier , Lluch José M. , Sancho‐Vaello Enea , Biarnés Xevi , Planas Antoni , Merino Pedro , Masgrau Laura , Guerin Marcelo E.
Published: July 2015

Glycosyltransferases (GTs) comprise a prominent family of enzymes that play critical roles in a variety of cellular processes, including cell signaling, cell development, and host–pathogen interactions. Glycosyl transfer can proceed with either inversion or retention of the anomeric configuration with respect to the reaction substrates and products. The elucidation of the catalytic mechanism of retaining GTs remains a major challenge. A native ternary complex of a GT in a productive mode for catalysis is reported, that of the retaining glucosyl‐3‐phosphoglycerate synthase GpgS from M. tuberculosis in the presence of the sugar donor UDP‐Glc, the acceptor substrate phosphoglycerate, and the divalent cation cofactor. Through a combination of structural, chemical, enzymatic, molecular dynamics, and quantum‐mechanics/molecular‐mechanics (QM/MM) calculations, the catalytic mechanism was unraveled, thereby providing a strong experimental support for a front–side substrate‐assisted SNi‐type reaction.
A fuzzy logic‐based variable speed limit controller
Authors: Li Duo , Ranjitkar Prakash
Published: July 2015

Variable speed limit (VSL) is an emerging intelligent transportation system (ITS) measure to improve operational and safety performance of motorway systems. Rule‐based algorithms have been widely used in VSL applications because of their comprehensibility and ease of application. However, most of the algorithms proposed in the literature under this category are rather rough for the speed control. Pre‐specified rules show some difficulties in appropriately activating/deactivating control actions in real time because of non‐stationary and nonlinear nature of the traffic system. This paper proposes a fuzzy logic‐based VSL control algorithm as an alternative to the existing VSL control algorithms. The proposed algorithm uses fuzzy sets instead of crisp sets to allow the separation of attribute domains into several overlapping intervals. The discretization using fuzzy sets can help to overcome the sensitivity problem caused by crisp discretization used in the existing VSL algorithms. The proposed algorithm is assessed for a test bed in Auckland using AIMSUN micro‐simulator and verified against a well‐known VSL algorithm. The simulation results show that the proposed algorithm outperforms the existing one to improve the efficiency performance of the motorway system with the critical bottleneck capacity increased by 6.42% and total travel time reduced by 12.39% when compared to a no‐control scenario. Copyright © 2015 John Wiley & Sons, Ltd.
Towards plant protein refinery: Review on protein extraction using alkali and potential enzymatic assistance
Authors: Sari Yessie W. , Mulder Wilhelmus J. , Sanders Johan P. M. , Bruins Marieke E.
Published: July 2015

The globally increasing protein demands require additional resources to those currently available. Furthermore, the optimal usage of protein fractions from both traditional and new protein resources, such as algae and leaves, is essential. Here, we present an overview on alkaline plant protein extraction including the potentials of enzyme addition in the form of proteases and/or carbohydrolases. Strategic biomass selection, combined with the appropriate process conditions can increase protein yields after extraction. Enzyme addition, especially of proteases, can be useful when alkaline protein extraction yields are low. These additions can also be used to enable processing at a pH closer to 7 to avoid the otherwise severe conditions that denature proteins. Finally, a protein biorefinery concept is presented that aims to upcycle residual biomass by separating essential amino acids to be used for food and feed, and non‐essential amino acids for production of bulk chemicals.
In Situ Photocatalytically Heterostructured ZnOAg Nanoparticle Composites as Effective Cathode‐Modifying Layers for Air‐Processed Polymer Solar Cells
Authors: Yuan Kai , Chen Lie , Chen Yiwang
Published: July 2015

A heterostructured semiconductor–metal ZnOAg nanoparticle (NP) composite was constructed through a straightforward photocatalytic strategy by using UV irradiation of ZnO NPs and an aqueous solution of Ag precursor. The ZnOAg NP composites serve as an effective cathode‐modifying layer in polymer solar cells (PSCs) with increased short‐circuit current density owing to the light‐trapping effect, and improved optical and electrical conductivity properties compared with pure ZnO NPs. The Ag NPs, which are photodeposited in situ on ZnO NPs, can act as effective antennas for incident light to maximize light harvesting and minimize radiative decay or nonradiative losses, consequently resulting in the enhanced photogeneration of excitons in PSCs. Systematic photoelectron and ‐physical investigations confirm that heterostructured ZnOAg NPs can significantly improve charge separation, transport, and collection, as well as lower charge recombination at the cathode interface, leading to a 14.0 % improvement in air‐processed device power conversion efficiency. In addition, this processable, cost‐effective, and scalable approach is compatible with roll‐to‐roll manufacturing of large‐scale PSCs.
Supramolecular Fluorescent Nanoparticles Constructed via Multiple Non‐Covalent Interactions for the Detection of Hydrogen Peroxide in Cancer Cells
Authors: Wei Xuan , Dong Ruijiao , Wang Dali , Zhao Tianyu , Gao Yongsheng , Duffy Patrick , Zhu Xinyuan , Wang Wenxin
Published: July 2015

Overabundance of hydrogen peroxide originating from environmental stress and/or genetic mutation can lead to pathological conditions. Thus, the highly sensitive detection of H2O2 is important. Herein, supramolecular fluorescent nanoparticles self‐assembled from fluorescein isothiocyanate modified β‐cyclodextrin (FITC‐β‐CD)/rhodamine B modified ferrocene (Fc‐RB) amphiphile were prepared through host–guest interaction between FITC‐β‐CD host and Fc‐RB guest for H2O2 detection in cancer cells. The self‐assembled nanoparticles based on a combination of multiple non‐covalent interactions in aqueous medium showed high sensitivity to H2O2 while maintaining stability under physiological condition. Owing to the fluorescence resonance energy transfer (FRET) effect, addition of H2O2 led to obvious fluorescence change of nanoparticles from red (RB) to green (FITC) in fluorescent experiments. In vitro study showed the fluorescent nanoparticles could be efficiently internalized by cancer cells and then disrupted by endogenous H2O2, accompanying with FRET from “on” to “off”. These supramolecular fluorescent nanoparticles constructed via multiple non‐covalent interactions are expected to have potential applications in diagnosis and imaging of diseases caused by oxidative stresses.
Acylation of (Hetero)Arenes through CH Activation with Aroyl Surrogates
Authors: Wu Xiao‐Feng
Published: July 2015

In this Minireview, the major achievements in the acylation of arenes and heteroarenes by CH activation with aroyl groups are summarized and discussed. As the products are carbonyl‐containing compounds that are typical products from carbonylation chemistry, the possible inspirations for these reactions are also discussed, as are mechanistic issues and possible problems for carbonylative diaryl ketone synthesis by CH activation.
A Geomimetic Approach to the Formation and Identification of Fossil Sterane Biomarkers in Crude Oil: 18‐nor‐D‐homo‐Androstane and 5α,14β‐Androstane
Authors: Bender Matthias , Schmidtmann Marc , Summons Roger E. , Rullkötter Jürgen , Christoffers Jens
Published: July 2015

A diazonium ion derived from 18‐aminoandrostane rearranged upon decomposition by a carbonium and a carbenium ion to furnish a mixture of a cyclopropanated compound and two D‐homo‐androstenes. Hydrogenation of this mixture gave the saturated hydrocarbons, 18‐nor‐D‐homo‐androstane and 5α,14β‐androstane, which are both fossil sterane biomarkers in Neoproterozoic crude oil. The so far unknown constitution and configuration as well as the geochemical genesis were established by this experiment. The starting material for this investigation, 18‐aminoandrostane, was prepared in twelve steps from androstan‐17‐one (12.5 % overall yield) with a Barton reaction as the key step.
Formation and Reactivity of a Molecular Magnesium Hydride with a Terminal MgH Bond
Authors: Schnitzler Silvia , Spaniol Thomas P. , Maron Laurent , Okuda Jun
Published: July 2015

A complex featuring a terminal magnesium hydride bond supported by an NNNN macrocyclic ligand, [Mg{Me3TACD⋅Al(iBu)3}H] (3), was formed from its labile Al(iBu)3 adduct. Use of Al(iBu)3 to block the amido nitrogen of the NNNN macrocyclic ligand was essential to prevent aggregation. The structurally characterized compound 3 reacted with BH3 to give the BH4 derivative, whereas Me3SiCCH and PhSiH3 led to the corresponding acetylide and silyl derivative under H2 elimination. Pyridine is inserted into the MgH bond to give selectively the 1,4‐dihydropyridinate.
High‐throughput RNA sequencing reveals structural differences of orthologous brain‐expressed genes between western lowland gorillas and humans
Authors: Lipovich Leonard , Hou Zhuo‐Cheng , Jia Hui , Sinkler Christopher , McGowen Michael , Sterner Kirstin N. , Weckle Amy , Sugalski Amara B. , Pipes Lenore , Gatti Domenico L. , Mason Christopher E. , Sherwood Chet C. , Hof Patrick R. , Kuzawa Christopher W. , Grossman Lawrence I. , Goodman Morris , Wildman Derek E.
Published: July 2015

The human brain and human cognitive abilities are strikingly different from those of other great apes despite relatively modest genome sequence divergence. However, little is presently known about the interspecies divergence in gene structure and transcription that might contribute to these phenotypic differences. To date, most comparative studies of gene structure in the brain have examined humans, chimpanzees, and macaque monkeys. To add to this body of knowledge, we analyze here the brain transcriptome of the western lowland gorilla (Gorilla gorilla gorilla), an African great ape species that is phylogenetically closely related to humans, but with a brain that is approximately one‐third the size. Manual transcriptome curation from a sample of the planum temporale region of the neocortex revealed 12 protein‐coding genes and one noncoding‐RNA gene with exons in the gorilla unmatched by public transcriptome data from the orthologous human loci. These interspecies gene structure differences accounted for a total of 134 amino acids in proteins found in the gorilla that were absent from protein products of the orthologous human genes. Proteins varying in structure between human and gorilla were involved in immunity and energy metabolism, suggesting their relevance to phenotypic differences. This gorilla neocortical transcriptome comprises an empirical, not homology‐ or prediction‐driven, resource for orthologous gene comparisons between human and gorilla. These findings provide a unique repository of the sequences and structures of thousands of genes transcribed in the gorilla brain, pointing to candidate genes that may contribute to the traits distinguishing humans from other closely related great apes. J. Comp. Neurol. 524:288–308, 2016. © 2015 Wiley Periodicals, Inc.
Optimal Fine‐Scale Structures in Compliance Minimization for a Shear Load
Authors: Kohn Robert V. , Wirth Benedikt
Published: July 2015

We return to a classic problem of structural optimization whose solution requires microstructure. It is well‐known that perimeter penalization assures the existence of an optimal design. We are interested in the regime where the perimeter penalization is weak; i.e., in the effect of perimeter as a selection mechanism in structural optimization. To explore this topic in a simple yet challenging example, we focus on a two‐dimensional elastic shape optimization problem involving the optimal removal of material from a rectangular region loaded in shear. We consider the minimization of a weighted sum of volume, perimeter, and compliance (i.e., the work done by the load), focusing on the behavior as the weight ɛ of the perimeter term tends to 0. Our main result concerns the scaling of the optimal value with respect to ɛ. Our analysis combines an upper bound and a lower bound. The upper bound is proved by finding a near‐optimal structure, which resembles a rank‐2 laminate except that the approximate interfaces are replaced by branching constructions. The lower bound, which shows that no other microstructure can be much better, uses arguments based on the Hashin‐Shtrikman variational principle. The regime being considered here is particularly difficult to explore numerically due to the intrinsic nonconvexity of structural optimization and the spatial complexity of the optimal structures. While perimeter has been considered as a selection mechanism in other problems involving microstructure, the example considered here is novel because optimality seems to require the use of two well‐separated length scales.© 2016 Wiley Periodicals, Inc.
Stability of Regression‐Based Monte Carlo Methods for Solving Nonlinear PDEs
Authors: Alanko Samu
Published: July 2015

The regression‐based Monte Carlo methods for backward stochastic differential equations (BSDEs) have been the object of considerable research, particularly for solving nonlinear partial differential equations (PDEs). Unfortunately, such methods often become unstable when implemented with small time steps because the variance of gradient estimates is inversely proportional to the time step (σ2∼ 1/Δ t). Recently new variance reduction techniques were introduced to address this problem in~a paper by the author and Avellaneda. The purpose of this paper is to provide a rigorous justification for these techniques in the context of the discrete‐time BSDE scheme of Bouchard and Touzi. We also suggest a new higher‐order scheme that makes the variance proportional to the time step (σ2∼Δ t). These techniques are easy to implement. Numerical examples strongly indicate that they render the regression‐based Monte Carlo methods stable for small time steps and thus viable for numerical solution of nonlinear PDEs.© 2016 Wiley Periodicals, Inc.
Platinum(II) Schiff Base Complexes as Photocatalysts for Visible‐Light‐Induced Cross‐Dehydrogenative Coupling Reactions
Authors: Shelar Deepak Prakash , Li Ting‐Ting , Chen Yong , Fu Wen‐Fu
Published: July 2015

Four phosphorescent platinum(II) Schiff base complexes are screened for application in visible‐light‐induced cross‐dehydrogenative coupling (CDC) reactions. Preliminary studies show that, among the four platinum(II) complexes, Pt3 is an efficient catalyst for CDC reactions with oxygen as an oxidant. Light irradiation (λ>420 nm) on a mixture of the PtII complex, tertiary amine, and a variety of nucleophiles (nitroalkanes, ketones, or indoles) under aerobic conditions gives α‐functionalized tertiary amines in good to excellent yields. The photoluminescence quenching experiment reveals that the CDC reaction is initiated by photoinduced electron transfer from N‐phenyltetrahydroisoquinoline to the PtII complex. Further, electron spin resonance (ESR) measurements clearly indicate the formation of superoxide radical anions (O2.−) rather than singlet oxygen (1O2) during the photocatalytic reaction.
Improving the Performance of Microbial Fuel Cells through Anode Manipulation
Authors: Lu Min , Qian Yijun , Huang Ling , Xie Xiaoji , Huang Wei
Published: July 2015

The continued focus on microbial fuel cells (MFCs) is due to their applications in power generation and simultaneous wastewater treatment. In the past decade, MFCs have been developed as a new class of energy devices and hold promise for broad applications in bioremediation, bioproduction, and biosensing. Despite the advances, the overall performance of MFCs is still limited, and particularly the energy loss at anode, where electrons are generated, is a restriction. Recent progress on MFC anodes has led to several effective approaches to improve MFC performance. In this Minireview, we discuss the performance losses in MFC anodes from the electrochemical point of view and then focus on the main strategies developed to overcome the anode performance losses. We also discuss the potential directions of future research on MFC anodes.
Three‐step process improves crystal quality of Cu2ZnSnS4 absorber layer and efficiency of solar cell
Authors: Fan Donghua , Zhang Junzhi , Wang Xianghu , Xu Manqin , Xu Shuai
Published: July 2015

Cu2ZnSnS4 (CZTS) films are fabricated using the three‐step process, including deposition, preheating and sulfurization of Cu–Zn–Sn (CZT) precursors. The effect of preheating temperature on structures, morphologies, and optical properties of CZTS films is investigated detailedly by X‐ray diffraction, Raman spectra, scanning electron microscopy, and UV spectrophotometer. It is found that the proper preheating temperature can improve the crystal quality of CZTS films. The prepared CZTS film by sulfurizing the preheated precursor at 300 °C presents high crystallinity, uniform surface morphology, and suitable optical properties. Compared with two‐step process, three‐step method can not only improve crystal quality of CZTS films but also decline sulfurization temperature. We also discuss the mechanism of improving the properties of CZTS absorber layer by the preheating route in detail. In addition, the experimental results also indicate that solar cell prepared by three‐step method displays higher conversion efficiency.
Effect of CuCl2 on hydrothermal crystallization of calcium sulfate whiskers prepared from FGD gypsum
Authors: Wang Xiao , Jin Biao , Yang Liushuan , Zhu Xinfeng
Published: July 2015

Using purified flue‐gas desulfurization (FGD) gypsum as raw material, effects of CuCl2 on crystal morphology, phase structure, aspect ratio and crystallization of hydrothermal products prepared via hydrothermal crystallization in H2SO4‐H2O solutions were investigated. The results show that dosage of CuCl2 has a significant effect on the morphology, aspect ratio and crystallization of calcium sulfate whiskers (CSWs), but no effect on their phase transformation. At a dosage of 15 g CuCl2/kg FGD gypsum, the produced calcium sulfate whiskers had diameters ranging from 1 to 3 μm with average aspect ratio greater than 200. Transmission electron diffraction patterns and highly magnified surface morphology of CSWs were found different from those of self‐assembly crystals. Compared to self‐assembly crystals, the produced CSWs showed a single crystal structure and their surface was very smooth.
Influence of GaN substrate crystallographic quality on the intensity of AlGaN epitaxial layer X‐ray diffraction peaks
Authors: Krysko M. , Grzanka E. , Domagala J. , Leszczynski M.
Published: July 2015

In the case of nearly perfect semiconductor layers (as AlGaAs on GaAs), the experimental data of X‐ray Diffraction are well simulated using the Dynamical Theory of X‐ray Diffraction. In the case of AlGaN and InGaN layers, intensity of their XRD peaks depend very strongly on the crystallographic quality of not only the layers, but also the substrates. In the paper, we show differences in XRD peak intensities for the AlGaN layers on GaN of the same thickness and Al‐content, but of different dislocation density.
What is a protein crystal? Can we apply the terminology of classical industrial crystallization to them?
Authors: Ulrich Joachim , Pietzsch Markus
Published: July 2015

The nature of protein crystals is discussed. Since protein crystals contain not only proteins but also other substances the usage of conventional terms (of industrial crystallization) of naming such crystals is questioned. The proof that there are other components than the protein itself in a protein crystal is given. It is suggested to use a procedure like in biotechnology to guarantee the production of the right protein crystals according to the PAT concept. It is suggested not to use other established names like “hydrates”, “solvates”, “but crystals for proteins since the definitions do not fit the nature of the protein crystals.
Effect of alcohols additives on hydrothermal formation of magnesium hydroxide sulfate hydrate whiskers
Authors: Zhao Wenpeng , Gao Chuanhui , Wang Ting , Wu Yumin
Published: July 2015

Two different organic alcohols, ethylene glycol and 1, 2‐propanediol, were used in hydrothermal formation of MgSO4·5Mg(OH)2·2H2O (MHSH) whiskers. Compared with the MHSH whiskers without alcohols, the crystallinity and defect of products were improved. It could also be observed that not only aspect ratio but also crystallinity and purity of the products were improved when 1, 2‐propanediol was used. A reasonable model was proposed to explain the growth process derived from the organic alcohol. In addition, the room temperature photoluminescence (PL) indicated that the spectrum intensity of MHSH whiskers used 1, 2‐propanediol was also significantly improved.
Structural properties of bulk GaN substrates: Impact of structural anisotropy on non‐polar and semi‐polar crystals
Authors: Serafińczuk Jarosław , Kucharski Robert , Zając Marcin , Gotszalk Teodor Paweł , Kudrawiec Robert
Published: July 2015

In this paper we show the structural parameters and structural anisotropy of the bulk GaN substrates of various crystallographic orientations (00.1), (10.0), (11.0) and (20.1) obtained by ammonothermal method. The structural parameters were investigated using high resolution X‐Ray Diffraction. Perfect crystalline structure manifests in very narrow peaks in X‐ray rocking curves. The full width at half maximum (FWHM) values of 16 and 18 arcsec for the symmetrical and asymmetrical peaks, respectively, have been observed. In addition, we observed structural anisotropy in the non‐polar and semi‐polar crystals, depending on the orientation of the sample relative to the X‐ray beam. It is conducted that this anisotropy is a intrinsic property of non‐polar and semi‐polar GaN substrates.