bluuebunny/crossref_metadata_2025 huggingface dataset:
MUTUALISM SYMBIOSIS BETWEEN PEDESTRIANS AND STREET VENDORS (Case Study: Pedestrian Ways in Dr Radjiman Street Surakarta)
Authors: Karmilah Mila , Surosohadi Tjoek , Puspitasari Ardiana Yuli
Published: September 2017

The spatial development of Surakarta is characterized as a transition city between residential and commercial activities. Within the area, the city center develops around the Kasunanan and the Mangkunegaran palaces; here in these two regions the study was conducted. The study conducted in Dr Radjiman Street Solo aims to analyze the characteristics and service facilities for pedestrians on this road segment. Generally speaking, this study is an analytical, descriptive study using qualitative rationalistic approach that focuses on the behavioral approach with behavioral mapping technique. Behavioral mapping approach is used because it is considered as the most suitable and supporting method to identify problems related to the relationship between human and its environment (its spatial system), as well as to make improvements on the design, especially in the commercial area of Dr Radjiman Street. According to this study, the perceptions of street vendors (PKL) are as follows: 1. Street vendors consider that the sidewalk is a space that they can use as a place for trading; 2. This is due to the trade location and their residential area is just as far as 1-2 km; 3. In addition, the merchants also consider that they (and their family) had used the location for more than >15 years, thus they unwilling to move away from that location. On the other hand, some factors which become visitor perceptions related to the existence of sidewalks in the Corridor of Dr. Radjiman Street are: 1. The visitors consider that the existence of street vendors make the pavement becomes such an uncomfort place (53.3%), this is because the space for pedestrians become narrowed for <3 meters.
The Impact of Satellite‐Derived Land Surface Temperatures on Numerical Weather Prediction Analyses and Forecasts
Authors: Candy B. , Saunders R. W. , Ghent D. , Bulgin C. E.
Published: September 2017

Land surface temperature (LST) observations from a variety of satellite instruments operating in the infrared have been compared to estimates of surface temperature from the Met Office operational numerical weather prediction (NWP) model. The comparisons show that during the day the NWP model can underpredict the surface temperature by up to 10 K in certain regions such as the Sahel and southern Africa. By contrast at night the differences are generally smaller. Matchups have also been performed between satellite LSTs and observations from an in situ radiometer located in Southern England within a region of mixed land use. These matchups demonstrate good agreement at night and suggest that the satellite uncertainties in LST are less than 2 K. The Met Office surface analysis scheme has been adapted to utilize nighttime LST observations. Experiments using these analyses in an NWP model have shown a benefit to the resulting forecasts of near‐surface air temperature, particularly over Africa.
Emissions embodied in global trade have plateaued due to structural changes in China
Authors: Pan Chen , Peters Glen P. , Andrew Robbie M. , Korsbakken Jan Ivar , Li Shantong , Zhou Dequn , Zhou Peng
Published: September 2017

In the 2000s, the rapid growth of CO2 emitted in the production of exports from developing to developed countries, in which China accounted for the dominant share, led to concerns that climate polices had been undermined by international trade. Arguments on “carbon leakage” and “competitiveness”—which led to the refusal of the U.S. to ratify the Kyoto Protocol—put pressure on developing countries, especially China, to limit their emissions with Border Carbon Adjustments used as one threat. After strong growth in the early 2000s, emissions exported from developing to developed countries plateaued and could have even decreased since 2007. These changes were mainly due to China: In 2002–2007, China's exported emissions grew by 827 MtCO2, amounting to almost all the 892 MtCO2 total increase in emissions exported from developing to developed countries, while in 2007–2012, emissions exported from China decreased by 229 MtCO2, contributing to the total decrease of 172 MtCO2 exported from developing to developed countries. We apply Structural Decomposition Analysis to find that, in addition to the diminishing effects of the global financial crisis, the slowdown and eventual plateau was largely explained by several potentially permanent changes in China: Decline in export volume growth, improvements in CO2 intensity, and changes in production structure and the mix of exported products. We argue that growth in China's exported emissions will not return to the high levels during the 2000s, therefore the arguments for climate polices focused on embodied emissions such as Border Carbon Adjustments are now weakened.

Plain Language Summary

In the 2000s, CO2 emissions from production in developed countries flattened while emissions from their consumption grew. The rapid growth of exported emissions from developing countries to developed countries, with the largest contribution from China, played a significant role. This led to concerns that climate polices had been undermined by rapid growth in international trade. Since around 2007, growth in these exported emissions has plateaued, predominantly due to changes in China. Our study investigates China's changes, demonstrating that in addition to the effects of global financial crisis, China implemented potentially permanent structural changes. We argue that China's exported emissions are unlikely to return to the growth levels from the 2000s, and therefore trade‐related climate polices will be much less relevant.
Global Structure and Sodium Ion Dynamics in Mercury's Magnetosphere With the Offset Dipole
Authors: Yagi M. , Seki K. , Matsumoto Y. , Delcourt D. C. , Leblanc F.
Published: September 2017

We conducted global magnetohydrodynamics (MHD) simulation of Mercury's magnetosphere with the dipole offset, which was revealed by MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) observations, in order to investigate its global structure under northward interplanetary magnetic field conditions. Sodium ion dynamics originating from the Mercury's exosphere is also investigated based on statistical trajectory tracing in the electric and magnetic fields obtained from the MHD simulations. The results reveal a north‐south asymmetry characterized by open field lines around the southern polar region and northward deflection of the plasma sheet in the far tail. The asymmetry of magnetic field structure near the planet drastically affects trajectories of sodium ion and thus their pressure distributions and precipitation pattern onto the planet. Weaker magnetic field strength in the southern hemisphere than in the north increases ion loss by precipitation onto the planetary surface in the southern hemisphere. The “sodium ring,” which is formed by high‐energy sodium ions drifting around the planet, is also found in the vicinity of the planet. The sodium ring is almost circular under nominal solar wind conditions. The ring becomes partial under high solar wind density, because dayside magnetosphere is so compressed that there is no space for the sodium ions to drift around. In both cases, the sodium ring is formed by sodium ions that are picked up, accelerated in the magnetosheath just outside the magnetopause, and reentered into the magnetosphere due to combined effects of finite Larmor radius and convection electric field in the dawnside magnetosphere.
Magnetosheath High‐Speed Jets: Internal Structure and Interaction With Ambient Plasma
Authors: Plaschke F. , Karlsson T. , Hietala H. , Archer M. , Vörös Z. , Nakamura R. , Magnes W. , Baumjohann W. , Torbert R. B. , Russell C. T. , Giles B. L.
Published: September 2017

For the first time, we have studied the rich internal structure of a magnetosheath high‐speed jet. Measurements by the Magnetospheric Multiscale (MMS) spacecraft reveal large‐amplitude density, temperature, and magnetic field variations inside the jet. The propagation velocity and normal direction of planar magnetic field structures (i.e., current sheets and waves) are investigated via four‐spacecraft timing. We find structures to mainly convect with the jet plasma. There are indications of the presence of a tangential discontinuity. At other times, there are small cross‐structure flows. Where this is the case, current sheets and waves overtake the plasma in the jet's core region; ahead and behind that core region, along the jet's path, current sheets are overtaken by the plasma; that is, they move in opposite direction to the jet in the plasma rest frame. Jet structures are found to be mainly thermal and magnetic pressure balance structures, notwithstanding that the dynamic pressure dominates by far. Although the jet is supermagnetosonic in the Earth's frame of reference, it is submagnetosonic with respect to the plasma ahead. Consequently, we find no fast shock. Instead, we find some evidence for (a series of) jets pushing ambient plasma out of their way, thereby stirring the magnetosheath and causing anomalous sunward flows in the subsolar magnetosheath. Furthermore, we find that jets modify the magnetic field in the magnetosheath, aligning it with their propagation direction.
Deducing Climatic Elasticity to Assess Projected Climate Change Impacts on Streamflow Change across China
Authors: Liu Jianyu , Zhang Qiang , Zhang Yongqiang , Chen Xi , Li Jianfeng , Aryal Santosh K.
Published: September 2017

Climatic elasticity has been widely applied to assess streamflow responses to climate changes. To fully assess impacts of climate under global warming on streamflow and reduce the error and uncertainty from various control variables, we develop a four‐parameter (precipitation, catchment characteristics n, and maximum and minimum temperatures) climatic elasticity method named PnT, based on the widely used Budyko framework and simplified Makkink equation. We use this method to carry out the first comprehensive evaluation of the streamflow response to potential climate change for 372 widely spread catchments in China. The PnT climatic elasticity was first evaluated for a period 1980–2000, and then used to evaluate streamflow change response to climate change based on 12 global climate models under Representative Concentration Pathway 2.6 (RCP2.6) and RCP 8.5 emission scenarios. The results show that (1) the PnT climatic elasticity method is reliable; (2) projected increasing streamflow takes place in more than 60% of the selected catchments, with mean increments of 9% and 15.4% under RCP2.6 and RCP8.5 respectively; and (3) uncertainties in the projected streamflow are considerable in several regions, such as the Pearl River and Yellow River, with more than 40% of the selected catchments showing inconsistent change directions. Our results can help Chinese policy makers to manage and plan water resources more effectively, and the PnT climatic elasticity should be applied to other parts of the world.
Three‐Dimensional Modeling of Two Interacting Streamers
Authors: Shi Feng , Liu Ningyu , Dwyer Joseph R.
Published: September 2017

Interacting streamers are commonly found in natural plasma discharges, such as lightning, jets and sprites, but are poorly understood at present. In this paper, we report a three‐dimensional modeling study of two interacting streamers simultaneously initiated from identical plasma columns in a uniform ambient field. Simulation results show that the streamers no longer propagate in the direction of the ambient field due to strong repulsion between them. The results also show that the peak field in the streamer head determines the direction of streamer propagation, and that the two streamers propagate in separate directions. We further conjecture that they will be unlikely to merge later on. Finally, the interacting streamers still grow exponentially, with a growth rate similar to an isolated streamer under the same condition.
Observation‐Based Study on Aerosol Optical Depth and Particle Size in Partly Cloudy Regions
Authors: Várnai T. , Marshak A. , Eck T. F.
Published: September 2017

This study seeks to help better understand aerosol‐cloud interactions by examining statistical relationships between aerosol properties and nearby low‐altitude cloudiness using satellite data. The analysis of a global data set of Moderate Resolution Imaging Spectroradiometer observations reveals that the positive correlation between cloudiness and aerosol optical depth (AOD) reported in earlier studies is strong throughout the globe and during both winter and summer. Typically, AOD is 30–50% higher on cloudier‐than‐average days than on less cloudy days. A combination of satellite observations and Modern‐Era Retrospective analysis for Research and Applications, Version 2 global reanalysis data reveals that the correlation between cloud cover and AOD is strong for all aerosol types considered: sulfate, dust, carbon, and sea salt. The observations also indicate that in the presence of nearby clouds, aerosol size distributions tend to shift toward smaller particles over large regions of the Earth. This is consistent with a greater cloud‐related increase in the AOD of fine‐mode than of coarse‐mode particles. The greater increase in fine‐mode AOD implies that the cloudiness‐AOD correlation does not come predominantly from cloud detection uncertainties. Additionally, the results show that aerosol particle size increases near clouds even in regions where it decreases with increasing cloudiness. This suggests that the decrease with cloudiness comes mainly from changes in large‐scale environment, rather than from clouds increasing the number or the size of fine‐mode aerosols. Finally, combining different aerosol retrieval algorithms demonstrated that quality assessment flags based on local variability can help identifying when the observed aerosol populations are affected by surrounding clouds.
Hollow‐Structured Graphene–Silicone‐Composite‐Based Piezoresistive Sensors: Decoupled Property Tuning and Bending Reliability
Authors: Luo Ningqi , Huang Yan , Liu Jing , Chen Shih‐Chi , Wong Ching Ping , Zhao Ni
Published: September 2017

A versatile flexible piezoresistive sensor should maintain high sensitivity in a wide linear range, and provide a stable and repeatable pressure reading under bending. These properties are often difficult to achieve simultaneously with conventional filler–matrix composite active materials, as tuning of one material component often results in change of multiple sensor properties. Here, a material strategy is developed to realize a 3D graphene–poly(dimethylsiloxane) hollow structure, where the electrical conductivity and mechanical elasticity of the composite can be tuned separately by varying the graphene layer number and the poly(dimethylsiloxane) composition ratio, respectively. As a result, the sensor sensitivity and linear range can be easily improved through a decoupled tuning process, reaching a sensitivity of 15.9 kPa−1 in a 60 kPa linear region, and the sensor also exhibits fast response (1.2 ms rising time) and high stability. Furthermore, by optimizing the density of the graphene percolation network and thickness of the composite, the stability and repeatability of the sensor output under bending are improved, achieving a measurement error below 6% under bending radius variations from −25 to +25 mm. Finally, the potential applications of these sensors in wearable medical devices and robotic vision are explored.
Specific and Direct Amplified Detection of MicroRNA with MicroRNA:Argonaute‐2 Cleavage (miRACle) Beacons
Authors: Luby Benjamin M. , Zheng Gang
Published: September 2017

MicroRNA detection is a valuable method for determining cell identity. Molecular beacons are elegant sensors that can transform intracellular microRNA concentration into a fluorescence intensity. While target binding enhances beacon fluorescence, the degree of enhancement is insufficient for demanding applications. The addition of specialty nucleases can enable target recycling and signal amplification, but this process complicates the assay. We have developed and characterized a class of beacons that are susceptible to the endogenous nuclease Argonaute‐2 (Ago2). After purification of the complex by co‐immunoprecipitation, microRNA:Ago2 cleavage (miRACle) beacons undergo site‐ and sequence‐specific cleavage, and show a 13‐fold fluorescence enhancement over traditional beacons. The system can be adapted to any microRNA sequence, and can cleave nuclease‐resistant, non‐RNA bases, potentially allowing miRACle beacons to be designed for cells without interference from non‐specific nucleases.
Branched Hydrosilane Oligomers as Ideal Precursors for Liquid‐Based Silicon‐Film Deposition
Authors: Haas Michael , Christopoulos Viktor , Radebner Judith , Holthausen Michael , Lainer Thomas , Schuh Lukas , Fitzek Harald , Kothleitner Gerald , Torvisco Ana , Fischer Roland , Wunnicke Odo , Stueger Harald
Published: September 2017

Herein a convenient synthetic method to obtain 2,2,3,3‐tetrasilyltetrasilane 3 and 2,2,3,3,4,4‐hexasilylpentasilane 4 on a multigram scale is presented. Proton‐coupled 29Si NMR spectroscopy and single‐crystal X‐ray crystallography enabled unequivocal structural assignment. Owing to their unique properties, which are reflected in their nonpyrophoric character on contact with air and their enhanced light absorption above 250 nm, 3 and 4 are valuable precursors for liquid‐phase deposition (LPD) and the processing of thin silicon films. Amorphous silicon (a‐Si:H) films of excellent quality were deposited starting from 3 and characterized by conductivity measurements, ellipsometry, optical microscopy, and Raman spectroscopy.
Practical Chemical Synthesis of Atypical Ubiquitin Chains by Using an Isopeptide‐Linked Ub Isomer
Authors: Tang Shan , Liang Lu‐Jun , Si Yan‐Yan , Gao Shuai , Wang Jia‐Xing , Liang Jun , Mei Ziqing , Zheng Ji‐Shen , Liu Lei
Published: September 2017

Chemical ubiquitination is an effective approach for accessing structurally defined, atypical ubiquitin (Ub) chains that are difficult to prepare by other techniques. Herein, we describe a strategy that uses a readily accessible premade isopeptide‐linked 76‐mer (isoUb), which has an N‐terminal Cys and a C‐terminal hydrazide, as the key building block to assemble atypical Ub chains in a modular fashion. This method avoids the use of auxiliary‐modified Lys and instead employs the canonical and therefore more robust Cys‐based native chemical ligation technique. The efficiency and capacity of this isoUb‐based strategy is exemplified by the cost‐effective synthesis of several linkage‐ and length‐defined atypical Ub chains, including K27‐linked tetra‐Ub and K11/K48‐branched tri‐, tetra‐, penta‐, and hexa‐Ubs.
Evaluation of β‐Aminocarboxylic Acid Derivatives in Hippocampal Excitatory Synaptic Transmission
Authors: Oliveira Daniela R. , Luchez Cibele V. , Bortolotto Zuner A. , Fernandes João P. S.
Published: September 2017

β‐Aminocarboxylic acid derivatives (LINS04 series) were screened with the aim to explore their potential functional role in excitatory synaptic transmission in the central nervous system. We used field recordings in rat hippocampal slices to investigate the effects of the LINS04 series on the synaptic transmission at hippocampal CA1 synapses. We found that LINS04008 and LINS04009 increase the size of the evoked field excitatory postsynaptic potential (EPSP) in a dose‐dependent manner. The concentration–response curve shows that the efficacy of LINS04008 is highest in the series (EC50 = 91.32 µM; maximum fEPSP 44.97%). The esters LINS04006 and LINS04005 did not affect the synaptic evoked activity. These data provide the first evidence of synaptic activity enhancement by these compounds and the importance of the acidic group to the activity. This set of data may provide direction for a strategic procedure to restore the glutamate synaptic transmission; however, further studies are needed to establish a more complete picture of how these molecules act on the glutamate transmission, which are in our mind for the next steps.
Multi‐criteria analysis of a biorefinery for co‐production of lactic acid and ethanol from sugarcane lignocellulose
Authors: Mandegari Mohsen Ali , Farzad Somayeh , van Rensburg Eugéne , Görgens Johann F.
Published: September 2017

Biorefineries are regarded as a key enabler to facilitate the transition toward a sustainable and low carbon bioeconomy. In this study, alternative lignocellulose biorefineries annexed to a typical sugar mill were investigated to co‐produce ethanol (EtOH), lactic acid (LA), and/or electricity, utilizing bagasse and a component of harvesting residues (brown leaves) as feedstock. Studied scenarios included EtOH as the sole product from glucose and xylose (Scenario 1), LA as the sole product from these two sugars (Scenario 2), EtOH from glucose and LA from xylose (Scenario 3), and EtOH from xylose and LA from glucose (Scenario 4), all of which were associated with some level of export electricity production. Aspen Plus® simulations of the scenarios were developed considering all supplementary units, such as evaporation, water treatment, boiler, and steam/power generation in addition to the process units required for the main product streams. Economic evaluation, energy assessment, and environmental life cycle assessment (LCA) were carried out on the developed simulations, in a multi‐criteria analysis of the desirability of each scenario. To service the combined energy demands of a sugar mill and annexed biorefinery, a 35 to 40% bypass of lignocellulose directly to the boiler section was required to achieve integrated scenarios that were energy self‐sufficient, i.e., not dependent on external (fossil) energy sources. Scenario 2 was economically most attractive with the highest internal rate of return (IRR) of 31.1%, whereas Scenario 1 had the lowest IRR of 10.0%. Scenarios 2 and 4 were economically the most robust, with the least sensitivity to variations in the key economic drivers, i.e., EtOH, LA and enzymes. The LCA suggested that LA producing scenarios introduced environmental burdens that were marginally higher than Scenario 1, due to higher consumption of processing chemicals. Overall, Scenario 4 was found to be the most desirable biorefinery scenario, by balancing financial and environmental considerations. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd
Dilemma during ultrasound‐guided internal jugular venous catheterization
Authors: Dwarakanath Sanjay , Cheriyan Monica , Rebel Annette
Published: September 2017

Key Clinical Message

The presence of Internal Jugular Valves can pose a diagnostic and procedural challenge during ultrasound‐guided cannulation. After ruling out dissection, thrombus, or ultrasound artifacts, it can still be accessed and successfully cannulated with appropriate precautions including use of Live ultrasound, positioning, use of soft‐tipped catheters, and minimizing duration of catheter placement.
Maxillary molar healing after treatment of an uninstrumented canal with a novel root canal procedure: a case report
Authors: DiVito Enrico E. , Le Khang T.
Published: September 2017

Key Clinical Message

A major cause for endodontic failure is the inability to treat all anatomy. Studies report endodontic retreatments contain 42% missed canals. This case illustrates dentin preservation of a molar with an uninstrumented mesiobuccal‐3 canal revealed post‐GentleWave Procedure. Efficient cleaning and disinfection with maintained healing to 18 months is demonstrated.
Nasopharyngeal carcinoma presenting as an inconspicuous primary lesion with extensive cavernous sinus involvement and temporal lobe extension: a case report and review of literature
Authors: Pollard Courtney , Mesko Shane M. , Ginsberg Lawrence E. , Kies Merrill S. , Raza Shaan M. , Su Shirley Y. , Tung Sam , Phan Jack
Published: September 2017

Key Clinical Message

Detection of nodal metastasis in the neck or adjacent structures is common in nasopharyngeal carcinoma (NPC) when there is frank primary disease. Intracranial extension without obvious nasopharyngeal disease is not common. Here, we discuss a patient with NPC that presented with extensive intracranial disease with subtle findings in the nasopharynx.
Rate and Selectivity Control in Thioether and Alkene Oxidation with H2O2 over Phosphonate‐Modified Niobium(V)–Silica Catalysts
Authors: Thornburg Nicholas E. , Notestein Justin M.
Published: September 2017

Supported metal oxide catalysts are versatile materials for liquid‐phase oxidations, including alkene epoxidation and thioether sulfoxidation with H2O2. Periodic trends in H2O2 activation was recently demonstrated for alkene epoxidation, highlighting Nb‐SiO2 as a more active and selective catalyst than Ti‐SiO2. Three representative catalysts are studied consisting of NbV, TiIV, and ZrIV on silica, each made through a molecular precursor approach that yields highly dispersed oxide sites, for thioanisole oxidation by H2O2. Initial rates trend Nb>Ti≫Zr, as for epoxidation, and Nb outperforms Ti for a number of other thioethers. In contrast, selectivity to sulfoxide vs. sulfone trends Ti>Nb≫Zr at all conversions. Modifying the Nb‐SiO2 catalyst with phenylphosphonic acid does not completely remove sulfoxidation reactivity, as it did for photooxidation and epoxidation, and results in an unusual material active for sulfoxidation but neither epoxidation nor overoxidation to the sulfone.
Accessing d‐Valine Synthesis by Improved Variants of Bacterial Cyclohexylamine Oxidase
Authors: Gong Rui , Yao Peiyuan , Chen Xi , Feng Jinhui , Wu Qiaqing , Lau Peter C. K. , Zhu Dunming
Published: September 2017

Chemoenzymatic deracemization was applied to prepare d‐valine from racemic valine ethyl ester or l‐valine ethyl ester in high yield (up to 95 %) with excellent optical purity (>99 % ee) by employing a newly evolved cyclohexylamine oxidase (CHAO) variant Y321I/M226T exhibiting catalytic efficiency that was 30 times higher than that of the wildtype CHAO. Interestingly, CHAO and its variants showed opposite enantioselectivity for valine ethyl ester and phenylalanine ethyl ester.
Stereoselective Arene‐Forming Aldol Condensation: Catalyst‐Controlled Synthesis of Axially Chiral Compounds
Authors: Witzig Reto M. , Lotter Dominik , Fäseke Vincent C. , Sparr Christof
Published: September 2017

The fundamental role that aldol chemistry adopts in various disciplines, such as stereoselective catalysis or the biosynthesis of aromatic polyketides, illustrates its exceptional versatility. On the one hand, numerous aldol addition reactions reliably transfer the stereochemical information from catalysts into various valuable products. On the other hand, countless aromatic polyketide natural products are produced by an ingenious biosynthetic machinery based on arene‐forming aldol condensations. With the aim of complementing aldol methodology that controls stereocenter configuration, we recently combined these two tenets by investigating small‐molecule‐catalyzed aldol condensation reactions that stereoselectively form diverse axially chiral compounds through the construction of a new aromatic ring.
Role of the Bridging Group in Bis‐Pyridyl Ligands: Enhancing Both the Photo‐ and Electroluminescent Features of Cationic (IPr)CuI Complexes
Authors: Elie Margaux , Weber Michael D. , Di Meo Florent , Sguerra Fabien , Lohier Jean‐François , Pansu Robert B. , Renaud Jean‐Luc , Hamel Matthieu , Linares Mathieu , Costa Rubén D. , Gaillard Sylvain
Published: September 2017

We report on the benefits of changing the bridging group X of bis‐pyridyl ligands, that is, Py‐X‐Py where X is NH, CH2, C(CH3)2, or PPh, on the photo‐ and electroluminescent properties of a new family of luminescent cationic H‐heterocyclic carbene (NHC) copper(I) complexes. A joint experimental and theoretical study demonstrates that the bridging group affects the molecular conformation from a planar‐like structure (X is NH and CH2) to a boat‐like structure (X is C(CH3)2 and PPh), leading to i) four‐fold enhancement of the photoluminescence quantum yield (ϕem) without affecting the thermally activated delayed fluorescence mechanism, and ii) one order of magnitude reduction of the ionic conductivity (σ) of thin films. This leads to an overall enhancement of the device efficacy and luminance owing to the increased ϕem and the use of low applied driving currents.
Predicting Critical Micelle Concentrations with Molecular Dynamics Simulations and COSMOmic
Authors: Jakobtorweihen Sven , Yordanova Denitsa , Smirnova Irina
Published: September 2017

Surfactants are amphiphilic molecules which are capable of forming micelles. Therefore, they are used in many applications. The critical micelle concentration (CMC), the surfactant concentration at which micelles start to form, is an important property of these systems. Here, the applicability of COSMOmic (an extension of COSMO‐RS) to predict CMCs is reported for the first time. Molecular dynamics simulations were used as second method to calculate transfer free energies needed for the calculation of CMCs. In particular, CMCs for poly(oxyethylene) monoalkyl ether surfactants are determined.
Nachhaltige Nanochemie – Zwei einfache Green Chemistry‐Synthesen für den Chemieunterricht
Authors: Wilke Timm , Abdelaziz Ramzy , Elbahri Mady , Schwarzer Stefan
Published: September 2017

Wird im Unterricht das Thema „Nanotechnologie“ vermittelt, steht das fokussierte Nanomaterial oftmals in dessen Zentrum – als Dreh‐ und Angelpunkt der Einheit bieten dessen besondere Eigenschaften die Grundlage für experimentelle Untersuchungen und die sich daraus ableitenden Lerngelegenheiten und (Alltags‐)Anwendungen. Nicht nur aus diesem Grund kommen Synthese und Synthesekonzepten von Nanomaterialien eine besondere Bedeutung zu. In diesem Artikel werden je ein Synthesekonzept für Nanopartikel sowie nanostrukturierte Materialien beschrieben. Einerseits soll gezeigt werden, wie die besonderen Reaktionsbedingungen des sogenannten Leidenfrost‐Reaktors für einfache Synthesen diverser Nanopartikel im wässrigen Milieu verwendet werden. Andererseits können mit dem einfach verständlichen Konzept der Templatchemie Silica‐Materialien mit Strukturen im Nanometerbereich und entsprechend großen Oberflächen erhalten werden. In beiden Fällen handelt es sich um Green Chemistry‐Synthesen, da hierbei nur sehr geringe Mengen an Chemikalien benötigt werden bzw. diese einfach recycelt werden können.
Struktur‐Eigenschafts‐Beziehungen an aktuellen Beispielen aus der Forschung weitergedacht: „Mikro‐“ und „nano‐“Schichten sowie Oberflächen für Schule und Schülerlabor
Authors: Schwarzer Stefan , Stamer Insa , Baum Michael , Bethke Christine , Ingwersen Daniela , Liedtke Patrick , Adelung Rainer , Herges Rainer , Parchmann Ilka
Published: September 2017

Im Sonderforschungsbereich „Funktion durch Schalten“ an der Universität zu Kiel stehen kleinste, molekulare Maschinen im Mittelpunkt der Forschung im Bereich der Nanowissenschaften. Die technisch und präparativ anspruchsvollen Forschungsaufgaben werden in einem Teilprojekt zur Öffentlichkeitsarbeit für verschiedene Lernanlässe didaktisch aufbereitet. Dies geschieht in enger Kooperation von Chemiedidaktik und Fachwissenschaften. Ein Hauptaugenmerk liegt dabei auf dem Erfahrbarmachen von mikro‐ und nanodimensionierten (schaltbaren) Strukturen und Schichten für Schülerinnen sowie Schüler. Zwei Beispiele, die Schichtdickenbestimmung einer Seifenblasenhaut und die Generierung einer mikro‐ und nanostrukturierten Oberfläche mit Lotos‐Effekt, werden im Arbeitsmaterial behandelt. Beide Themen bieten damit die Möglichkeit, der Betrachtung von Oberflächen einen höheren Stellenwert im Chemieunterricht einzuräumen und damit das Basiskonzept Struktur‐Eigenschafts‐Beziehungen gewinnbringend zu ergänzen.
Makromoleküle – Strukturbildner mit besonderen Eigenschaften
Authors: Deusing‐Gottschalk Ilka , Mischnick Petra
Published: September 2017

Makromoleküle sind sehr große, aus einzelnen Bausteinen zu langen Ketten verknüpfte Moleküle. Die Architektur der entstehenden Gebilde ist vielfältig und bestimmt ganz wesentlich die Eigenschaften. Viele dieser Eigenschaften lassen sich mit bloßem Auge erkennen. Dies ist für das Experimentieren im Schülerlabor ideal, da ohne besondere Hilfsmittel ein Zusammenhang zwischen Struktur und Eigenschaften herstellbar ist. Das Projekt „Von Groß zu Klein“ im Agnes‐Pockels‐SchülerInnen‐Labor hatte das Ziel, Aufbau und Eigenschaften von Makromolekülen experimentell zu erschließen und anhand von Modellen zu erklären. Daraus werden beispielhaft Alginat als natürliches und Polyacrylat als synthetisches Polymer vorgestellt. An diesen beiden Polyelektrolyten lassen sich Gelierungsverhalten und Einflussgrößen darauf systematisch untersuchen. Auch anwendungsorientierte Experimente werden beschrieben. Die Versuche sind für die Sek. I konzipiert und können für Grundschule und Sek. II angepasst werden.
Anion Layering and Steric Hydration Repulsion on Positively Charged Surfaces in Aqueous Electrolytes
Authors: Hu Qingyun , Weber Christian , Cheng Hsiu‐Wei , Renner Frank Uwe , Valtiner Markus
Published: September 2017

The molecular structure at charged solid/liquid interfaces is vital for many chemical or electrochemical processes, such as adhesion, catalysis, or the stability of colloidal dispersions. How cations influence structural hydration forces and interactions across negatively charged surfaces has been studied in great detail. However, how anions influence structural hydration forces on positively charged surfaces is much less understood. Herein we report force versus distance profiles on freshly cleaved mica using atomic force microscopy with silicon tips. We characterize steric anion hydration forces for a set of common anions (Cl−, ClO4−, NO3−, SO42− and PO43−) in pure acids at pH ≈1, where protons are the co‐ions. Solutions containing anions with low hydration energies exhibit repulsive structural hydration forces, indicating significant ion and/or water structuring within the first 1–2 nm on a positively charged surface. We attribute this to specific adsorption effects within the Stern layer. In contrast, ions with high hydration energies show exponentially repulsive hydration forces, indicating a lower degree of structuring within the Stern layer. The presented data demonstrates that anion hydration forces in the inner double layer are comparable to cation hydration forces, and that they qualitatively correlate with hydration free energies. This work contributes to understanding interaction processes in which positive charge is screened by anions within an electrolyte.
Synthesis and Optical Properties of Push–Push–Pull Chromophores Based on Imidazo[5,1,2‐cd]indolizines and Naphtho[1′,2′:4,5]imidazo[1,2‐a]pyridines
Authors: Maitra Ratnava , Chen Jie‐Hong , Hu Ching‐Han , Lee Hon Man
Published: September 2017

Four series of new push–push–pull chromophores based on two types of heterocyclic cores, namely imidazo[5,1,2‐cd]indolizines and naphtho[1′,2′:4,5]imidazo[1,2‐a]pyridines, and two types of linear π spacers, namely diphenylacetylene and biphenyl, were prepared. The two isomeric heterocyclic compounds were prepared by palladium‐catalyzed double C–H functionalization reactions. Further palladium‐catalyzed C–C coupling reactions allow the construction of diphenylacetylene and biphenyl spacers on the chromophores. Different electron‐donors including NMe2, NPh2, and OMe and CN acceptors were incorporated into the chromophores. The corresponding donor‐ and acceptor‐free compounds were also prepared for comparative studies. In the case of chromophores with strong NMe2 or NPh2 donors, a strong intramolecular charge‐transfer (ICT) process occurs leading to fluorescence emission quenching in polar solvents. The use of a slightly weaker OMe donor together with the naphtho[1′,2′:4,5]imidazo[1,2‐a]pyridine core allows to obtain an intense blue fluorescence with high quantum yield of up to 0.825. DFT and TD‐DFT calculations offer satisfactory explanations to the observed photophysical data.
Synthesis ofcis‐ andtrans‐Configured Octahydroperylenes
Authors: Pfaff Dominik , Bestgen Sebastian , Podlech Joachim
Published: September 2017

Lewis acid catalysed dimerization of 5‐methoxy‐1,2,3,4‐tetrahydronaphthalen‐1‐ol yields 4,10‐dimethoxy‐1,2,3,6b,7,8,9,12b‐octahydroperylene, in which the hydrogen atoms at the 6b‐ and 12b‐positions aretrans‐arranged. This isomer is less stable than the correspondingcisisomer. Conversion of thetrans‐configuredmesocompound into the racemiccisisomer is possible by heating with a radical initiator to give an anthracene derivative, which is then reduced under Birch conditions. The energetic course of these reactions was investigated with DFT calculations.
Co‐parenting through subsidiaries: A model of value creation in the multinational firm
Authors: Pla‐Barber José , Villar Cristina , Madhok Anoop
Published: September 2017

Research Summary

We analyze a novel way to configure and manage multinational networks and propose a model of “co‐parenting,” characterized by the sharing of parenting roles and distribution of responsibilities between two units. We develop our argument around the notion of the springboard subsidiary, an operating subsidiary that assumes headquarters’ functions since it shares greater institutional closeness with both the headquarters’ country as well as with the host region. Based upon qualitative data, our inductive model revolves around three stages: establishment, consolidation, and maturity, each of which reflects distinct roles and loci of decision making among the three actors involved: headquarters, springboard subsidiary, and local subsidiary. Overall, our study sheds distinct light on when and how headquarters add value by matching parenting to context.

Managerial Summary

In expanding across regions, multinational firms often face a situation where neither the local unit nor the corporate headquarters possesses the competencies to be at the competitive forefront. This article analyzes a model of interregional expansion of multinational firms by using springboard subsidiaries—operating subsidiaries that can serve as a bridge between headquarters and local subsidiaries since they share institutional and business ties with both. We develop a model in which some parenting functions—coordination, control, and knowledge creation—are distributed between headquarters and the springboard subsidiary along an accumulative process of capabilities. By demonstrating how a springboard subsidiary can help align control to context, the model offers a tool for strategic analysis that helps avoid potential value destruction by headquarters.
A novel photocatalytic membrane decorated with RGO‐Ag‐TiO2 for dye degradation and oil–water emulsion separation
Authors: Chen Qi , Yu Zongxue , Li Fei , Yang Yang , Pan Yang , Peng Yixin , Yang Xi , Zeng Guangyong
Published: September 2017

BACKGROUND

Membrane separation is a promising process for treatment of dye and oily wastewater if the antifouling capacity and recyclability can be improved. In recent years, the development of photocatalytic materials has provided new methods for research into membrane technology.

RESULTS

In this study, a novel photocatalytic membrane decorated with RGO‐Ag‐TiO2 nanomaterial was fabricated by simple vacuum filtration for degradation of dye and separation of oil–water. First, TiO2 nanowires were prepared for more effective photocatalysis, reduced graphene oxide (RGO)‐Ag‐TiO2 was fabricated by a facile hydrothermal reaction, then it was directly decorated on cellulose acetate (CA) membrane using polyethylene glycol and glutaraldehyde.

CONCLUSION

The as‐prepared photocatalytic membrane can simultaneously degrade dye and separate oil–water emulsions under visible‐light irradiation in a short time. The membrane has extremely high water flux (191 L m‐2 h‐1) and rejection rates (almost 100%) of dye–oil–water emulsion. More importantly, the photocatalytic membrane shows excellent antifouling capacity and recyclability, and retains relatively stable dye–oil–water permeation flux (about 27.5 L m‐2 h‐1) and high rejection rates (up to 99%) after six cycles of experiments under visible‐light irradiation. Overall, the photocatalytic membrane opens up new avenues for the treatment of wastewater. © 2017 Society of Chemical Industry
Molecular interactions of milk protein with phenolic components in oat‐based liquid formulations following UHT treatment and prolonged storage
Authors: Kaur Jasmeet , Katopo Lita , Ashton John , Whitson Andrew , Kasapis Stefan
Published: September 2017

BACKGROUND

Nowadays there is a growing demand for nutritionally balanced breakfast beverages enriched with functional ingredients including wholegrain oat, which is rich in phenolic acids. Such beverages typically contain added food ingredients (e.g. milk protein, sugar and lipids) and undergo thermal processing that initiates many molecular processes. Therefore, this work aims to investigate the molecular interactions between milk protein and phenolic acids that govern bioactivity in model oat‐based beverages.

RESULTS

Findings showed the susceptibility of ferulic and p‐coumaric acids, in model oat beverages, to ultra‐high temperature (UHT) processing at 145 °C for 8 s. Among model beverages, those with added milk protein demonstrated a considerable loss of phenolic acids following UHT processing due to the interaction between these micronutrients and the protein. The nature of molecular interactions was mainly categorized as covalent with hydrogen bonds playing a supportive role.

CONCLUSION

UHT processing of oat‐based beverage formulations facilitates the formation of protein–phenolic acid complexes, which are largely covalent and static in nature. This finding underlines the ability of UHT treatment to induce chemical modifications of food ingredients. © 2017 Society of Chemical Industry
Effect of seasonal climate fluctuations on the evolution of glycoconjugates during the ripening period of grapevine cv. Muscat à petits grains blancs berries
Authors: Crespo Julia , Rigou Peggy , Romero Valeria , García Margarita , Arroyo Teresa , Cabellos Juan M
Published: September 2017

BACKGROUND

Temperature changes and rainfall fluctuations affect the winemaking industry by altering vine phenology, crop yield, must composition and wine quality. Here, the evolution of the varietal aroma potential during ripening over three consecutive seasons has been analyzed considering climate conditions. The effect of season, ripening date and climatic conditions on aroma precursor accumulation in grapes was studied by multivariate analysis and discussed in regard to the potential aromatic quality of the wine.

RESULTS

In contrast to musts obtained from grapes harvested in warm and dry seasons (2014 and 2015), musts obtained from grapes harvested in the coolest and most humid year (2013) showed a lower pH, higher total acidity, higher varietal aroma potential index (IPAv), and higher aromatic potential of linalool, geraniol and nerol (typical of the Muscat flavor).

CONCLUSION

Considering the three seasons, grapes synthesized and accumulated more precursors when milder temperatures and late rains throughout veraison were recorded. However, we observed a high fluctuation of aroma precursors during the ripening period, so choosing the correct harvesting date (according to grape aroma potential) may overcome some of the negative effects linked to climate conditions. © 2017 Society of Chemical Industry
ERAS—Value based surgery
Authors: Ljungqvist Olle , Thanh Nguyen X. , Nelson Gregg
Published: September 2017

This paper reviews implementation of ERAS and its financial implications. Literature on clinical outcomes and financial implications were reviewed. Reports from many different surgery types shows that implementation of ERAS reduces complications and shortens hospital stay. These improvements have major impacts on reducing the cost of care even when costs for implementation, and investment in time for personnel and training is accounted for. The conclusion is that ERAS is an excellent example of value based surgery.
Empirical evidence for declines in muskrat populations across the United States
Authors: Ahlers Adam A. , Heske Edward J.
Published: September 2017

Muskrats (Ondatra zibethicus) are native to North America and widely distributed across the continent. Recent evidence and anecdotal reports suggest that muskrat populations may be declining; however, this assumption has not been rigorously evaluated. We used 42 years of muskrat harvest data (1970–2012) from 37 states to examine trends in muskrat populations across the United States. Annual harvest data are highly correlated with annual pelt prices, which must be controlled for prior to analysis. After adjusting harvest data for the effects of current‐year and 1‐year‐lagged pelt prices, we found strong support that muskrat populations have declined during this period. The slope of decline appeared stronger in the southeastern states and less pronounced in the midwestern states. Our results suggest that wildlife managers should consider active management programs for muskrat populations in regions where declines are observed. Along with recording annual muskrat harvest data, managers should also use rigorous surveys to identify changes in muskrat population abundances. Additionally, our study highlights the need for future research directed at revealing mechanistic explanations for synchronous muskrat declines across this large spatiotemporal scale. © 2017 The Wildlife Society.
Damage mechanism of composite cemented backfill based on complex defects influence
Authors: Gao R. , Zhou K. , Yang C.
Published: September 2017

In order to reduce mining waste discharge and realize efficient application of tailing material in underground backfilling, the characteristics and mechanism of backfill damage is analyzed, and also the composed behavior and failure characteristic of cemented backfill. Five types of backfills were tested under uniaxial compression loading in SHT4206 electro‐hydraulic servo testing system. Based on the experimental results, the damage constitutive equations of cemented backfills with five cement−tailing ratios were proposed on the basis of damage mechanics and then validated. Research shows that the damage growth rate of backfills with lower cement−tailing is lower before peak value of stress, but it grows more rapidly after that. In addition, four backfill combination schemes were designed for mechanical test. Combining with research results on fracture characteristic of different backfills, a defects coupled constitutive model based on continuum damage mechanics was established. Research shows that the piecewise nonlinear model can well embodies effect of complex defects in backfills on the stress‐strain curve. Accuracy of the model is well verified by measured curve of backfill composite members. The results of this work provide a scientific basis for failure process prediction of backfills and reasonable matching design of framed filling.