bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting Critical Micelle Concentrations with Molecular Dynamics Simulations and COSMOmic
Authors: Jakobtorweihen Sven , Yordanova Denitsa , Smirnova Irina 
Published: September 2017

AbstractSurfactants 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

AbstractWird 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

AbstractIm 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

AbstractMakromoleküle 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

AbstractThe 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.
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 SummaryWe 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 SummaryIn 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

AbstractBACKGROUNDMembrane 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.RESULTSIn 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.CONCLUSIONThe 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

AbstractBACKGROUNDNowadays 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.RESULTSFindings 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.CONCLUSIONUHT 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

AbstractBACKGROUNDTemperature 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.RESULTSIn 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).CONCLUSIONConsidering 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
Empirical evidence for declines in muskrat populations across the United States
Authors: Ahlers Adam A. , Heske Edward J. 
Published: September 2017

ABSTRACTMuskrats (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

AbstractIn 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.
Influence of bias voltage and sputter mode on the coating properties of TiAlSiN
Authors: Tillmann W. , Dildrop M. 
Published: September 2017

AbstractSilicon offers promising opportunities to improve the characteristics of thin coatings. By adding silicon to TiAlN, the oxidation resistance as well as the tribological properties can be increased and improved. To analyze the influence of the silicon content on the coating properties of TiAlSiN, it is necessary to keep the ratio of the other coating elements constant by using the right target configuration. Within this study, TiAlSiN coatings were deposited on hot work steel AISI H11 by using magnetron sputtering (Cemecon CC800/9 sinox ML). This steel was previously plasma nitrided to increase the hardness and hence the carrying load of the substrate, avoiding shell egg effect during the analysis. Different sputter modes were used to analyze the possibility to produce TiAlSiN by utilizing a pure low conductive silicon target. The bias voltages were systematically varied to see their influence on the structure and chemical compositions of the coating which were investigated by means of scanning electron microscopy and energy dispersive X‐ray spectroscopy (EDX). Furthermore, the roughness of the surface of the coatings was measured by an optical three‐dimensional surface analyzer. The results of this study serve as a basis for further investigations regarding the variation of the silicon content of TiAlSiN coatings.
In‐situ heated stage scanning electron microscope analysis and characterisation of recrystallization behaviour of a 7000 series alloy with nickel additions
Authors: Taylor S. , Janik V. , Grimes R. , Dashwood R. 
Published: September 2017

AbstractObservation of microstructural evolution and processes are typically observed by means of “snap shots” where a sample is removed from a thermal cycle and then analysed using varying microscopy techniques. Advanced techniques such as hot stage electron back scattered diffraction (EBSD) and fore scattered detection (FSD) allow for direct in‐situ observation of these processes to give better and more accurate analysis. This paper investigates two 7000 series alloys with a 1.6 wt% nickel addition and compares the recrystallization behaviours of both. Recrystallization was observed to occur at a higher rate and at a lower initiation temperature of 277 °C in sheet rolled from the original smaller 10 kg cast of material compared to the higher temperature of 285 °C in sheet from a second larger 60 kg cast. In‐situ back scattered scans of both alloys microstructures were observed to be near identical to bulk back scattered scans taken from samples recrystallized externally, validating the accuracy of the observed results.
Tautomerism of amidoximes and other oxime species
Authors: Novikov Alexander S. , Bolotin Dmitrii S. 
Published: September 2017

AbstractThe tautomerism of the aliphatic MeC(NH2)═NOH and the aromatic PhC(NH2)═NOH amidoximes in protic (H2O, MeOH) and aprotic (Me2CO, Me2SO, and CHCl3) solvents was studied by density functional theory calculations at the M06‐2X/6‐311+G(d,p) level of theory. In both types of solutions, these species exist in 3 tautomeric forms, viz, (Z)‐ or (E)‐amidoximes, and (Z)‐aminonitrone. The (Z)‐form is the dominant, and energy gap between the (Z)‐ and (E)‐tautomers of the amidoximes slightly depends on the nature of a solvent and significantly higher than that for other oxime species. For the amidoximes, the zwitterionic (Z)‐aminonitrone form is stabilized by protic solvents. The oxime‐nitrone energy gap is reduced by electron‐donor substituents at the oxime moiety at different types of oxime species.
Thickness dependence of structural relaxation in spin‐cast polynorbornene films with high glass transition temperatures (>613 K)
Authors: Lewis Elizabeth A. , Vogt Bryan D. 
Published: September 2017

ABSTRACTThe isothermal structural relaxation (densification) of a family of glassy polynorbornene films with high glass transition temperatures (Tg > 613 K) is assessed via spectroscopic ellipsometry. Three polymers were examined: poly(butylnorbornene) (BuNB), poly(hydroxyhexafluoroisopropyl norbornene) (HFANB), and their random copolymer, BuNB‐r‐HFANB. The effective aging rate, β(T), of thick (∼1.2 μm) spun cast films of BuNB‐r‐HFANB is approximately 10−3 over a wide temperature window (0.49 < T/Tg < 0.68). At higher temperatures, these polymers undergo reactions that more dramatically decrease the film thickness, which prohibits erasing the process history by annealing above Tg. The aging rate for thick BuNB‐r‐HFANB films is independent of the casting solvent, which infers that rapid aging is not associated with residual solvent. β (at 373 K) decreases for films thinner than ∼500 nm. However, the isothermal structural relaxation of thin films of BuNB‐r‐HFANB exhibits nonmonotonic temporal evolution in thickness for films thinner than 115 nm film. The thickness after 18 h of aging at 373 K can be greater than the initial thickness. The rapid aging of these polynorbornene films is attributed to the unusual rapid local dynamics of this class of polymers and demonstrates the potential for unexpected structural relaxations in membranes and thin films of high‐Tg polymers that could impact their performance. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 53–61
Patterns of unmet supportive needs and relationship to quality of life in Chinese cancer patients
Authors: Zhu Lei , Yao Juntao , Schroevers Maya J. , Zhang Hongmei , Xie Juan , Liu Ailan , Fleer Joke , Ranchor Adelita V. , Song Zhangjun 
Published: September 2017

AbstractObjectiveThis study aimed to (1) identify distinct patterns of unmet needs in Chinese cancer patients; (2) examine whether sociodemographic and medical characteristics distinguished these patterns; and (3) examine whether people with distinct patterns reported differential quality of life (QoL).MethodsThis cross‐sectional study recruited 301 cancer patients from 2 hospitals in China. The 34‐item Supportive Care Needs Survey Short‐Form was used to measure unmet needs across 5 domains: physical and daily living, psychological, patient care and support, health systems and information, and sexuality. Latent class analysis was performed to identify patterns of unmet needs across these domains.ResultsFour patterns of unmet needs were identified, differing in levels and nature of unmet needs. Participants in class 1 (47%) reported few unmet needs. Patients in class 2 (15%) had moderate levels of unmet needs, displaying similar levels across 5 domains. People in class 3 (25%) and class 4 (13%) reported similarly high levels on “psychological,” “health care system and information,” “physical and daily living,” and “patient care,” but differing in “sexuality,” with class 3 reporting low levels while class 4 high on “sexuality.” None of sociodemographic and medical characteristics distinguished these patterns significantly. Compared to other classes, people in class 1 reported highest levels of QoL.ConclusionsThis study demonstrates the existence of 4 patterns of unmet supportive needs in Chinese cancer patients. Patients with few unmet needs reported the best QoL.