bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kationische, zweifach koordinierte Gold‐π‐Komplexe
Authors: Brooner Rachel E. M. , Widenhoefer Ross A. 
Published: October 2013

AbstractKationische zweifach koordinierte Gold‐π‐Komplexe, die einen Phosphan‐ oder N‐heterocyclischen Hilfsliganden enthalten, fanden kürzlich große Beachtung angesichts der möglichen Bedeutung dieser Spezies als Intermediate in der goldkatalysierten Funktionalisierung von C‐C‐Mehrfachbindungen. Obwohl neutrale zweifach koordinierte Gold‐π‐Komplexe seit mehr als 40 Jahren bekannt sind, war bis 2006 kein katalytisch bedeutsames Beispiel kationischer zweifach koordinierter Gold(I)‐π‐Komplexe bekannt. Diese Situation änderte sich in den letzten Jahren dramatisch, und inzwischen sind zahlreiche wohldefinierte Gold‐Komplexe mit zweifach koordinierten, kationischen Alken‐, Alkin‐, Dien‐, Allen‐ und Enoletherliganden beschrieben. Dieser Kurzaufsatz fasst diese neuesten Arbeiten zusammen, mit einem Hauptaugenmerk auf der Struktur, den Bindungsverhältnissen und dem Ligandenaustauschverhalten der Komplexe.
Extracting kinetic parameters of aniline polymerization from thermal data of a batch reactor. simulation of the thermal behavior of a reactor
Authors: Cavallo Pablo Cesar , Muñoz Diego Jose , Miras Maria Cristina , Barbero Cesar , Acevedo Diego Fernando 
Published: October 2013

ABSTRACTA simulation model of the thermal behavior of a reactor during aniline polymerization is proposed. The model takes into account the polymerization mechanism together with heat production and dissipation. The temperature–time profiles can be simulated with different kinetic parameters. The model is used for two purposes: to extract kinetic parameters by fitting experimental temperature–time profiles of a cooled agitated batch reactor; and to estimate the temperatures changes occurring in a reactor under different experimental conditions to find the best conditions for industrial production of polyaniline. The rate equation used includes two rate constants: one in the absence of polymer (k1) and another in the presence of polymer (k2). The thermal factors, such as the heat transfer coefficient and the reaction enthalpy, are experimentally measured. A computer program is written that fits the experimental data using different kinetic parameters. The data analysis shows a temperature peak (Tmax) whose magnitude decreases when k2 decreases, whereas it is not affected by k1. The time to reach the Tmax is inversely proportional to k1 and k2. The model allows obtaining the kinetic parameters in different reaction media, e.g. varying the concentration of acid. The model is used to simulate the thermal behavior, to polymerize 1M of aniline: in one step the temperature of the reactor will increase till 82ºC, such thermal runaway will cause polymer degradation, successive additions of portions of the total oxidant amount, paced at defined time intervals, is devised to maintain low temperatures while producing the same amount of polymer. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39409.
Antiscaling properties of novel maleic‐anhydride copolymers prepared via iron (II) – chloride mediated ATRP
Authors: Al‐Roomi Yousef M. , Hussain Kaneez F. 
Published: October 2013

ABSTRACTA class of maleic anhydride copolymers (YMR‐A series) with a narrow molecular weight distribution between 500–1500 and a polydispersity of 1.0–1.11 was obtained from n‐alkylacrylamide and maleic anhydride monomers via atom transfer radical polymerization. The monomer conversion reached about 71% corresponding to 1:4 [FeCl2] to [SA] molar ratios for (AAH/MA) copolymer initiated by CPN whereas for the polymerization initiated by MCPN the conversion reached 51.9% under similar condition showing better performance of CPN initiator. Resultant polymers were characterized by means of 1H‐NMR and 13C‐NMR. The inhibition behavior of these YMR‐A polymers against CaCO3 and CaSO4 was evaluated using static scale inhibition method. The inhibition efficiency on the calcium carbonate scale is much higher and even with 5 ppm dosage level the efficiency is around 99.33 % at pH 10.45 and temperature 70°C, where as for calcium sulfate scales the inhibition efficiency, is lower and 99.9% inhibition is observed at 7–9 ppm level. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39827.
Flammability and thermal properties of epoxy/glass/MWNT Composites
Authors: Hesami Mahdis , Bagheri Rouhollah , Masoomi Mahmood 
Published: October 2013

ABSTRACTThe aim f this work is to study the effect of nanotubes on flammability properties of epoxy/glass composites. Multiwalled carbon nanotubes (MWNT) and its functionalized derivative (amino functionalized nanotubes) were incorporated into epoxy resin. To disperse MWNTs in the epoxy resin, different ways were employed. Microscopic observations showed that, the best dispersion state was gained by using ultrasonication method and high shear flow simultaneously. Thermal resistance of cured epoxy resins containing various amounts of nanotubes (0.25–0.7 wt %), was investigated by thermo gravimetric analysis (TGA). Introducing MWNTs and amino‐MWNTs to samples increased the initial thermal decomposition temperature for about 32 and 37°C, respectively. LOI measurements of composite samples showed an increase up to 32. Cone calorimetry test was carried out on epoxy/glass and epoxy/glass containing 0.5% MWNT. The results showed that, introducing 0.5% MWNTs decreases maximum average rate of heat emission for about 26%. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39849.
Main‐chain smectic liquid crystalline polymer exhibiting unusually high thermal conductivity in an isotropic composite
Authors: Yoshihara Shusuke , Tokita Masatoshi , Ezaki Toshiaki , Nakamura Mitsuru , Sakaguchi Masashi , Matsumoto Kazuaki , Watanabe Junji 
Published: October 2013

ABSTRACTThe thermal conductivity (TC) of an isotropic composite comprising of a main‐chain smectic liquid crystalline PB‐10 polyester and 50‐μm‐sized roughly spherical magnesium oxide (MgO) particles is investigated. The increase in the composite TC with higher MgO fractions is steeper than that expected by Bruggeman's theory for the TC of a polydomain PB‐10 polyester (0.52 W m−1 K−1). When the filler content is larger than 30 vol %, the composite TC approaches a value that can be explained only if the polyester functions as a matrix with 1.0 W m−1 K−1, which is five times as high as those of isotropic common polymers (0.2 W m−1 K−1). Such an unusually high TC for a polymer matrix is attributed to some polymer lamellae that lie parallel to the particle surface and are stacked toward neighboring particles, thus creating effective heat paths between the particles and a continuous thermal network in a composite. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39896.
Synthesis and characterization of poly(ester carbonate)s by melt‐phase interchange reactions of dihydroxy compounds with alkylene and arylene diphenyl dicarbonates containing ester groups
Authors: Sweileh Bassam A. , Al‐Qalawi Hussam R. , Mohammad Hani A. 
Published: October 2013

ABSTRACTA new method of synthesis of poly(ester carbonate)s, based on the reaction of dihydroxy compounds with diphenyl dicarbonates containing ester groups was presented. The monomers utilized were diphenyl dicarbonates of cis/trans‐1,4‐cyclohexane dicarboxylate and of terephthalate units with butanediol or bisphenol A. The process consisted of a precondensation step under a stream of dry argon at atmospheric pressure with the elimination of phenol, followed by a melt polycondensation step at 225 or 250°C under vacuum. The prepared polymers consisted of linear chains containing partial random sequence distribution of monomer residues in the backbone. The inherent viscosities of polymers were from 0.23 to 0.48 dL/g and their Tg values were in the range −9 to 134°C. This method may open door to novel polycarbonates containing other organic functional groups. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39904.
Modification of polyurethane‐coated fabrics by sol–gel thin films
Authors: Škoc Maja Somogyi , Macan Jelena , Pezelj Emira 
Published: October 2013

AbstractSol–gel derived silica and hybrid films from tetraethoxysilane (TEOS) and 3‐glycidyloxypropyltrimethoxysilane (GLYMO) were deposited by dip‐coating, in order to find the best treatment. GLYMO‐based treatments preserved textile feel of the material. The coatings were characterized by infrared spectroscopy (IR), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and water contact angle measurement. IR spectra confirmed the existence of silicate network and successfully conducted modification for both precursors. DSC and TGA showed that the conditions of hydrolysis had greater influence on TEOS than GLYMO‐based treatments. Both treatments shifted the degradation onset to higher temperatures. SEM images showed that polyurethane surface and pores were completely covered and filled by silica or hybrid thin films forming a composite organic–inorganic coating. Hydrophobic effect was preserved for all the samples, except for a single treatment of the GLYMO, due to its polar epoxy group. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2014,131, 39914.
Preparation and characterization of supported ordered nanoporous carbon membranes for gas separation
Authors: Zhang Bing , Shi Yi , Wu Yonghong , Wang Tonghua , Qiu Jieshan 
Published: October 2013

ABSTRACTSupported ordered nanoporous carbon membranes (ONCM) were prepared by coating a membrane‐forming solution of resorcinol‐formaldehyde (RF) resin on plate support through solvent evaporation and pyrolysis. The membrane solution was formed by the organic‐organic assembly of RF resin with Pluronic F127 in the presence of triethyl orthoacetate and catalyst hydrochloric acid. The thermal stability of precursor, the microstructure, functional groups, and morphology and porous structure of resultant support and ONCM were investigated by the techniques of thermogravimetry, X‐ray diffraction, Fourier transformed infrared spectroscopy, scanning electron microscopy/transmission electron microscopy and nitrogen adsorption‐desorption, respectively. Results have shown that the as‐obtained ONCM has well‐developed porous regularity with bi‐modal narrow pore size distribution. ONCM is tightly adhered to the adopted phenolic resin‐based carbon support. Gases permeating through the ONCM are dominated by molecular sieving mechanism. The ideal gas separation factor of the supported ONCM can be reached to 46.4, 4.7 and 3.3 for H2/N2, CO2/N2 and O2/N2, respectively. The supported ONCM obtained in this work exhibits most promising application for permanent gas separation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39925.
Prediction Error Based Performance Monitoring, Degradation Diagnosis and Remedies in Offset‐Free MPC: Theory and Applications
Authors: Pannocchia G. , De Luca A. , Bottai M. 
Published: October 2013

AbstractWe present in this paper a control performance monitoring method for linear offset‐free model predictive control (MPC) algorithms, in which the prediction error sequence is used to detect whether the internal model and the observer are correct or not. When the prediction error is a white noise signal, revealed by the Ljung‐Box test, optimal performance is detected. Otherwise, we use a closed‐loop subspace identification approach to reveal the order of a minimal realization of the system from the deterministic input to the prediction error. When such order is zero, we prove that the model is correct and the source of suboptimal performance is an incorrect observer. In such cases, we suggest an optimization method to recalculate the correct augmented state estimator. If, instead, such order is greater than zero we prove that the model is incorrect, and re‐identification is suggested. A variant for (large‐scale) block‐structured systems is presented, in which diagnosis and corrections are performed separately in each block. Two examples of different complexity are presented to highlight effectiveness and scalability of the method.
A methodological framework for the economic evaluation of CO2 emissions from transport
Authors: Nocera Silvio , Cavallaro Federico 
Published: October 2013

SUMMARYAs the main cause of the global warming, CO2 emissions are a relevant externality in the transport sector. However, feasibility assessments do not always take these effects into adequate account, because a number of scientific and economic uncertainties make it difficult to determine a reliable estimate for a unitary CO2 cost.This paper first analyses the methods generally used to determine the cost of CO2 emissions, showing that market‐based prices are not always suitable for this aim. Avoidance and damage cost methods are then thoroughly discussed, evaluating their pros and cons, including an extensive review of previous studies of methods for comparing costs. To determine the most reliable values, a method based on both avoidance and damage costs is proposed here.This method is then applied to the case study of the Brenner Base Tunnel, comparing the outcomes of three different scenarios: ‘minimum’ suggests the maintenance of the ‘do‐nothing’ option (no tunnel realisation), whereas ‘trend’ and ‘consensus’ both imply the construction of the tunnel with different political choices, namely, a complete market liberalisation in trend and sustainable interventions in consensus. Results up to 2035 reveal that, in comparison with the do‐nothing option, the enlightened transport policy shown in consensus could bring about a CO2 economic saving of up to around €331m for the community, whereas a simple liberalisation (trend) increases the costs derived from global warming by about €228m. Copyright © 2013 John Wiley & Sons, Ltd.
Hochfester Beton in Gleitschalung.
Authors: Maliha R. , Hilsdorf H. K. 
Published: October 2013

AbstractIn einem Forschungsvorhaben werden die Möglichkeiten der Herstellung von hochfestem Beton in Gleitschalbauweise untersucht. Es werden Schalungsreibung, Verschleißwiderstand und Mikrorißbildung an der Oberfläche in Gleitversuchen bestimmt.
Durchstanzbemessung von Doppelkopfankern nach Europäischen Technischen Zulassungen
Authors: Lindorf Alexander 
Published: October 2013

AbstractDie Einführung des EC2 im Stahlbetonhochbau führte zu einer umfangreichen Umstellung der bisherigen Regeln zur Bemessung gegen Durchstanzen. Betroffen sind davon vor allem auch die Bewehrungsformen mit Doppelkopfankern. Die Verwendung dieser speziellen Durchstanzbewehrungen wurde in Deutschland bislang über allgemeine bauaufsichtliche Zulassungen geregelt. Die Nachweisführung erfolgte in Anlehnung an DIN 1045‐1. Um nunmehr dem Bemessungskonzept des EC2 gerecht zu werden, waren neue Zulassungsdokumente erforderlich, welche mittlerweile in Form von Europäischen Technischen Zulassungen erteilt wurden. Allerdings weicht die darin festgeschriebene Bemessung von Doppelkopfankern in einigen wichtigen Punkten vom EC2 ab. In diesem Beitrag wird ein Überblick über die einzelnen Regelungen und deren Hintergründe gegeben. Ein Bemessungsbeispiel demonstriert den allgemeinen Bemessungsablauf.Punching shear design of double‐headed anchors according to European Technical ApprovalsThe introduction of EC2 in structural engineering led to an extensive transformation of the existing guidelines for the design against punching shear failure. Especially reinforcement types consisting of double‐headed anchors are affected. In Germany, the use of these special punching shear reinforcements was previously regulated by national approvals. The verification procedure was carried out according to DIN 1045‐1. In order to satisfy the design concept according to EC2, new approval documents were required. Meanwhile European Technical Approvals were issued. However, in some important aspects the specified design method of double‐headed anchors differs from EC2. The paper gives an overview of the various rules and their backgrounds. A design example demonstrates the general design process.
Spider silks from plants – a challenge to create native‐sized spidroins
Authors: Hauptmann Valeska , Weichert Nicola , Rakhimova Marziya , Conrad Udo 
Published: October 2013

AbstractSilk threads from spiders exhibit extraordinary mechanical properties, such as superior toughness and elasticity. Spider silks consist of several different large repetitive proteins that act as the basic materials responsible for these outstanding features. The production of spider silk protein variants in plants opens up new horizons in the production and functional investigation that enable the use of spider silks in innovative material development, nanotechnology and biomedicine in the future. This review summarizes and discusses production of spider silk protein variants in plants, especially with regards to plant expression systems, purification strategies, and characteristics of spider silk variants. Furthermore, the challenge of producing native‐sized recombinant spidroins in planta is outlined, presenting three different strategies for achieving these high repetitive proteins with the help of non‐repetitive C‐terminal domains, crosslinking transglutaminase, and self‐linking inteins. The potential of these fascinating proteins in medicine is also highlighted.
Fluorogenic small molecules requiring reaction with a specific protein to create a fluorescent conjugate for biological imaging–what we know and what we need to learn
Authors: Baranczak Aleksandra , Connelly Stephen , Liu Yu , Choi Sungwook , Grimster Neil P. , Powers Evan T. , Wilson Ian A. , Kelly Jeffery W. 
Published: October 2013

ABSTRACTWe seek fluorogenic small molecules that generate a fluorescent conjugate signal if and only if they react with a given protein‐of‐interest (i.e., small molecules for which noncovalent binding to the protein‐of‐interest is insufficient to generate fluorescence). Consequently, it is the new chemical entity afforded by the generally irreversible reaction between the small molecule and the protein‐of‐interest that enables the energy of an electron occupying the lowest unoccupied molecular orbital (LUMO) of the chromophore to be given off as a photon instead of being dissipated by nonradiative mechanisms in complex biological environments. This category of fluorogenic small molecules is created by starting with environmentally sensitive fluorophores that are modified by an essential functional group that efficiently quenches the fluorescence until a chemoselective reaction between that functional group and the protein‐of‐interest occurs, yielding the fluorescent conjugate. Fluorogenic small molecules are envisioned to be useful for a wide variety of applications, including live cell imaging without the requirement for washing steps and pulse‐chase kinetic analyses of protein synthesis, trafficking, degradation, etc. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 484–495, 2014.
Cycloartanes from the Gum Resin of Gardenia gummifera L.f.
Authors: Gandhe Sreekanth , Lakavath Suryanarayana , Palatheeya Sujatha , Schuehly Wolfgang , Amancha Kalpana , Kiran Reddy Nallamaddi Ravi , Palepu Anupama , Thakur Yogita , Rao Adavi Rao Belvotagi Venkat , Kumar Bobbala Ravi , Narasimha Appa Rao Achanta Venkata , Kunert Olaf 
Published: October 2013

AbstractThe gum resin exuding from the leaf buds of Gardenia gummifera was investigated. Eight new cycloartane triterpenes, 1–6, 8, and 10, together with two known triterpenes, 25‐hydroxycycloart‐23‐en‐3‐one (7) and cycloartenone (9), were isolated and identified by extensive NMR spectroscopy. For cycloartenone (9), full NMR assignments are given as these data were not available in the literature. Eight compounds possess a C(3)O group, two are 3,4‐secocycloartanes bearing a free C(3)OOH group; in one of the cycloartanes, gummiferartane‐9 (10), ring A occurs as a seven‐membered lactone.
The Volatile Profiles of a Rare Apple (Malus domesticaBorkh.) Honey: Shikimic Acid‐Pathway Derivatives, Terpenes, and Others
Authors: Kuś Piotr Marek , Jerković Igor , Tuberoso Carlo Ignazio Giovanni , Šarolić Mladenka 
Published: October 2013

AbstractThe volatile profiles of rare Malus domestica Borkh. honey were investigated for the first time. Two representative samples from Poland (sample I) and Spain (sample II) were selected by pollen analysis (44–45% of Malus spp. pollen) and investigated by GC/FID/MS after headspace solid‐phase microextraction (HS‐SPME) and ultrasonic solvent extraction (USE). The apple honey is characterized by high percentage of shikimic acid‐pathway derivatives, as well as terpenes, norisoprenoids, and some other compounds such as coumaran and methyl 1H‐indole‐3‐acetate. The main compounds of the honey headspace were (sample I; sample II): benzaldehyde (9.4%; 32.1%), benzyl alcohol (0.3%; 14.4%), hotrienol (26.0%, 6.2%), and lilac aldehyde isomers (26.3%; 1.7%), but only Spanish sample contained car‐2‐en‐4‐one (10.2%). CH2Cl2 and pentane/Et2O 1 : 2 (v/v) were used for USE. The most relevant compounds identified in the extracts were: benzaldehyde (0.9–3.9%), benzoic acid (2.0–11.2%), terpendiol I (0.3–7.4%), coumaran (0.0–2.8%), 2‐phenylacetic acid (2.0–26.4%), methyl syringate (3.9–13.1%), vomifoliol (5.0–31.8%), and methyl 1H‐indole‐3‐acetate (1.9–10.2%). Apple honey contained also benzyl alcohol, 2‐phenylethanol, (E)‐cinnamaldehyde, (E)‐cinnamyl alcohol, eugenol, vanillin, and linalool that have been found previously in apple flowers, thus disclosing similarity of both volatile profiles.
Chemical Composition of Essential Oils and Aromatic Waters from Different Italian Anthemis maritima Populations
Authors: Ciccarelli Daniela , Noccioli Cecilia , Pistelli Luisa 
Published: October 2013

AbstractThe chemical composition of the essential oils and aromatic waters isolated from six Italian Anthemis maritima populations was determined by GC‐FID and GC/MS analyses. In total, 122 and 100 chemical compounds were identified in the essential oils and the aromatic waters, respectively. The main compound classes represented in the oils were monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpene hydrocarbons, oxygenated sesquiterpenes, and terpene esters. Multivariate chemometric techniques such as cluster analysis (CA) and principal coordinate analysis (PCO) were used to classify the samples according to the geographical origin. Statistical analysis allowed the attribution of the analyzed populations to different chemotype groups.
The effects of artemisinin on the proliferation and apoptosis of vascular smooth muscle cells of rats
Authors: Wang Hai‐yang , Huang Ren‐ping , Han Peng , Xue Dong‐bo , Li Hai‐bin , Liu Bing , Shan Peng , Wang Qing‐shan , Li Ke‐shen , Li Ha‐li 
Published: October 2013

ObjectiveThe aim of this study was to evaluate the effect of artemisinin on the proliferation and apoptosis of rat vascular smooth muscle cells (VSMCs).MethodPrimary rat VSMCs were treated with various doses of artemisinin. Cell proliferation was evaluated by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay, and the messenger RNA and protein expressions of proliferating cell nuclear antigen were determined by reverse‐transcription polymerase chain reaction and immunohistochemistry. Apoptosis was measured using annexin V and propidium iodide double staining evaluated by flow cytometry. Protein expression of Bax, Bcl2, and cyclin‐dependent kinase 4 was determined by Western blot.ResultsAfter 72 h of treatment, artemisinin significantly inhibited VSMC proliferation in a dose‐dependent manner. Treatment with 1 mM artemisinin for 72 h significantly reduced the expression of proliferating cell nuclear antigen messenger RNA. On the other hand, the same treatment increased the apoptosis of VSMCs, the activation of caspase‐3, the Bax protein expression, and the Bax/Bcl2 ratio.ConclusionThe results suggest that artemisinin can effectively inhibit VSMC proliferation and induce VSMC apoptosis. Copyright © 2013 John Wiley & Sons, Ltd.