bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative Study of Photochromic Ferrocene‐Conjugated Dimethyldihydropyrene Derivatives
Authors: Muratsugu Satoshi , Kishida Masa‐aki , Sakamoto Ryota , Nishihara Hiroshi 
Published: November 2013

AbstractThe photochemical properties and the mixed‐valence state of bis(ferrocenylethynyl)benzodimethyldihydropyrene (1) and other benzodimethyldihydropyrene (BzDHP) derivatives were investigated to understand the reversible photoswitching in the electronic communication of 1. Absorption spectra of 1 were characterized by UV/Vis spectroscopy and calculated by using time‐dependent density functional theory (TD‐DFT), and the d orbitals of the ferrocene (Fc) moieties were shown to contribute to the occupied valence orbitals that were responsible for the photochromic behavior. 1 exhibited reversible photoisomerization in THF; however, photochromic behavior was not observed in dichloromethane. Analysis of redox potentials showed that the mixed‐valence state of 1 was more stable in dichloromethane than in THF. This is consistent with the observation that chemical oxidation led to an intervalence charge‐transfer (IVCT) band between the Fc moieties in the mixed‐valence state of 1 in dichloromethane, whereas such a band was not observed for one‐electron‐oxidized 1 in THF. Bis(pentamethylferrocenylethynyl)benzodimethyldihydropyrene (2) did not show photochromic behavior even in THF. The mixed‐valence state of 2 was much less stable than that of 1 in dichloromethane, and no obvious IVCT band was observed for one‐electron‐oxidized 2 in dichloromethane. The difference in the redox contribution of Fc and pentamethylferrocene (Me5Fc) to BzDHP played an important role for these redox and photochromic behaviors; this was supported by analysis of valence orbital energies from DFT calculations. Designing molecules that connect redox centers through the use of a photochromic linker with a redox potential close to that of the redox centers could constitute a useful approach for the production of photochromic redox‐active metal complexes with strong electronic communication.
The Beginning of High Pressure Chemistry and the Leuna Factory – A Chapter of History of Technical Chemistry Part 1
Authors: Becker Karl 
Published: November 2013

AbstractDie Anfänge der Hochdruckchemie haben ihren Ursprung zu Beginn des 20. Jahrhunderts. Nachdem eine Fülle technisch völlig neuer Probleme in unglaublich kurzer Zeit gelöst worden war, einschließlich der Entwicklung eines geeigneten Katalysators, konnte vor 100 Jahren durch die BASF in Ludwigshafen, mit der Synthese von Ammoniak aus Stickstoff und Wasserstoff, die erste Hochdrucksynthese großtechnisch realisiert werden. Ab 1916 war an diesem Erfolg die BASF‐Tochter am Standort Leuna, das Ammoniakwerk Merseburg, beteiligt. Sehr schnell folgten weitere Hochdrucksynthesen – die Methanol‐ und die Isobutylölsynthese sowie die Hydrierung von Kohle zu flüssigen Kohlenwasserstoffen. An diese Entwicklungen, die die Welt der technischen Chemie revolutionierten, wird in diesem Beitrag erinnert.
Stigmatizing attitudes and beliefs about bulimia nervosa: Gender, age, education and income variability in a community sample
Authors: McLean Siân A. , Paxton Susan J. , Massey Robin , Hay Phillipa J. , Mond Jonathan M. , Rodgers Bryan 
Published: November 2013

ABSTRACTObjectiveStigmatizing attitudes towards eating disorders negatively impacts treatment seeking. To determine the effect of interventions to reduce stigma, a measure of stigma that is simple to implement is required. This study aimed to develop a measure of stigmatizing attitudes and beliefs towards bulimia nervosa (SAB‐BN) and evaluate the distribution of beliefs across gender, age, education, and income groups.MethodParticipants were 1828 community adults (890 men; 938 women) aged 18–65 sampled from the Australian Electoral Roll responded to a mailed questionnaire. Participants provided demographic information and completed the SAB‐BN questionnaire.ResultsFive components of stigmatizing attitudes and beliefs were identified; advantages of BN, minimization/low seriousness, unreliability, social distance, and personal responsibility. Stigma was low except on social distance and personal responsibility sub‐scales, which indicated negative attitudes toward people with bulimia. Men compared with women and lower compared with higher education and income groups held significantly higher stigmatizing attitudes and beliefs. There were few differences between age groups in stigma. Differences between demographic groups provides evidence for known‐groups validity.DiscussionThe SAB‐BN questionnaire provides a potentially useful tool for evaluating stigma in relation to BN. Results provide insight into components of stigma and the demographic groups to whom interventions should be targeted. © 2013 Wiley Periodicals, Inc.
Steric Factors in the Single‐Electron Transfer Carbolithiation and Transannular Reduction of 6,12‐Diphenyldibenzo[b,f]­[1,5]­diazocine by Organolithium Reagents
Authors: Eisch John J. , Yu Kun , Rheingold Arnold L. 
Published: November 2013

AbstractThe puckered tricyclic heterocycle 6,12‐diphenyldibenzo[b,f][1,5]diazocine, a novel probe for revealing single‐electron transfer (SET) reactions, is here employed as a model substrate for investigating the carbolithiation of imines and the stereochemistry, the regiochemistry, and the electronic nature (polar or SET) of such R–Li additions. The chemical behavior of the following organolithium reagents (mainly in THF) toward the diazocine was studied: benzyl‐, methyl‐, phenyl‐, n‐butyl‐, and phenylethynyllithiums, as well as the reactive allylmagnesium chloride and the typical tert‐butylmagnesium chloride. The only reagent that failed to carbometalate or to reduce the diazocine transannularly was phenylethynyllithium. The tert‐butyl Grignard reagent could not carbometalate but did reduce the diazocine with photocatalysis. The other five organometallics yielded both carbometalation of the diazocine and, upon hydrolysis, transannular SET reduction to 4b,9b‐diphenyl‐4b,5,9b,10‐tetrahydroindolo[3,2‐b]indole (“indoloindole”) in varying proportions. Three types of carbometalation products were observed in such hydrolyzed reactions: (1) exo‐1,2‐addition to a C=N bond by C6H5CH2Li, H2C=CHCH2MgCl, and CH3Li, as established by spectral and XRD data; (2) 1,4‐addition to the ortho‐phenyl carbon Co=C‐C=N linkage by phenyllithium with the subsequent elimination of LiH; and (3) 1,4‐addition, as in type 2, by n‐butyllithium but without the elimination of LiH. The foregoing modes of reactivity, the concomitant formation of the telltale SET reduction product, “indoloindole”, and the failure of PhC≡CLi to react at all with the diazocine are marshaled to support the conclusion that the organometallics reacting with the diazocine, by carbometalation and by transannular reduction, do so by SET processes and not by straightforward nucleophilic attack. The relative stabilities of sp3‐, sp2‐, and sp‐hybridized carbon radicals possibly involved were assessed in concluding that PhC≡CLi is incapable of reacting through any SET pathway.
Driving the Morita–Baylis–Hillman Reaction to a Multicomponent Organic Transformation
Authors: Guillouzic Anne‐Françoise , Montel Sonia , Laborde Coralie , Volle Jean‐Noël , Pirat Jean‐Luc , Virieux David 
Published: November 2013

AbstractThe combination of a trivalent phosphorus reagent with an aldehyde and a Michael olefin in the presence of water led to the formation of functionalized phosphine oxides. This approach turned the Lewis base organocatalyzed Morita–Baylis–Hillman reaction into a multicomponent organic transformation to provide rapid access to polyfunctionalized molecules.
An Experimental Evaluation of using Waste Cooking Oil Biodiesel in a Diesel Engine
Authors: El‐Adawy M. , Ibrahim Amr , El‐Kassaby M. M. 
Published: November 2013

AbstractWaste‐cooking‐oil biodiesel has a great potential to be widely used as an alternative, renewable fuel for diesel engines in the near future. The aim of this investigation was to experimentally study the effect of using different blends of waste‐cooking‐oil biodiesel and diesel fuel on the diesel‐engine performance, combustion characteristics, and emissions. It was found that increasing the percentage of biodiesel in the fuel blend from 0 to 50 % decreased engine torque and thermal efficiency by 9 and 11 %, respectively, for an engine speed of 1500 rpm. On the other hand, the engine fuel consumption increased by 17 %. In addition, the CO and HC emissions decreased by 31 and 40 %, respectively, whereas CO2 and NOx emissions increased by 17 and 40 %, respectively. It was also found that the ignition delay period decreased and the total combustion duration increased with increasing percentage of biodiesel in the fuel blend.
ASSESSING THE PERFORMANCE OF SMALLHOLDER IRRIGATION AND DERIVING BEST MANAGEMENT PRACTICES IN SOUTH AFRICA
Authors: Gomo T. , Senzanje A. , Mudhara M. , Dhavu K. 
Published: November 2013

ABSTRACTThe performance of smallholder irrigation schemes is multidimensional and can be looked at from different perspectives. This study assessed the technical performance of the Mooi River irrigation scheme (MRIS) to derive a comprehensive set of best management practices (BMPs). This was done acknowledging that the farmer is now the water manager, in line with participatory irrigation management (PIM) and irrigation management transfer (IMT) concepts. Five performance indicators related to water supply and delivery and agricultural performance were assessed through the field measurement method during spring and summer of the 2010/2011 season. Farmers were interviewed through a questionnaire to gather suggestions on ways to improve the performance of their scheme. Their responses helped in the selection of the BMPs for the scheme which were then ranked using the analytic hierarchy process (AHP). The results show a scheme average conveyance efficiency of 86.4%, maximum dependability of irrigation interval between water applications of 2.57 in spring and the scheme relative irrigation supply of 1.48. Agricultural performance indicators—output per unit irrigation supply and water productivity (ET)—were found to be 0.64 and 5.37 kg m‐3, respectively. Irrigation scheduling was the most preferred BMP by the farmers, while volumetric measurement of irrigation water used by each block was the least preferred. This study concludes that water management in smallholder schemes is poor, thus affecting performance of these schemes, and that farmers are aware of the problems and possible solutions to perennial problems hindering performance in smallholder schemes. The study recommends deepening farmers' participation in policy formulation and derivation of BMPs. Copyright © 2013 John Wiley & Sons, Ltd.
Patient‐centered blood management
Authors: Hohmuth Benjamin , Ozawa Sherri , Ashton Maria , Melseth Richard L. 
Published: November 2013

BACKGROUNDTransfusions are common in hospitalized patients but carry significant risk, with associated morbidity and mortality that increases with each unit of blood received. Clinical trials consistently support a conservative over a liberal approach to transfusion. Yet there remains wide variation in practice, and more than half of red cell transfusions may be inappropriate. Adopting a more comprehensive approach to the bleeding, coagulopathic, or anemic patient has the potential to improve patient care.METHODSWe present a patient‐centered blood management (PBM) paradigm. The 4 guiding principles of effective PBM that we present include anemia management, coagulation optimization, blood conservation, and patient‐centered decision making.RESULTSPBM has the potential to decrease transfusion rates, decrease practice variation, and improve patient outcomes.CONCLUSIONPBM's value proposition is highly aligned with that of hospital medicine. Hospitalists' dual role as front‐line care providers and quality improvement leaders make them the ideal candidates to develop, implement, and practice PBM. Journal of Hospital Medicine 2014;9:60–65. © 2013 Society of Hospital Medicine
Synthesis of Amphiphilic Polymers Based on Fatty Acids and Glycerol‐Derived Monomers – A Study of Their Self‐Assembly in Water
Authors: Rotta Jefferson , Pham Phuoc Dien , Lapinte Vincent , Borsali Rédouane , Minatti Edson , Robin Jean‐Jacques 
Published: November 2013

Amphiphilic polymers are synthesized from various biobased compounds involving telomerization of glycerin‐derived acrylate monomers with mercaptan‐modified fatty acids. The effects of the chemical structure of the saturated or unsaturated hydrophobic block are investigated. Dynamic and static light scattering measurements, transmission electronic microscopy, and atomic force microscopy observations show that these copolymers are capable of self‐assembling into nanosized spherical particles in aqueous solution, made from compound micelles. The critical micellar concentration of these polymers is in the range of 10–60 mg L−1 determined by fluorescence. These biobased polymers could have applications in various industrial fields, such as cosmetics and agrochemicals.
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Multiplexed and data‐independent tandem mass spectrometry for global proteome profiling
Authors: Chapman John D. , Goodlett David R. , Masselon Christophe D. 
Published: November 2013

AbstractOne of the most important early developments in the field of proteomics was the advent of automated data acquisition routines that allowed high‐throughput unattended data acquisition during HPLC introduction of peptide mixtures to a tandem mass spectrometer. Prior to this, data acquisition was orders of magnitude less efficient being based entirely on lists of predetermined ions generated in a prior HPLC‐MS experiment. This process, known generically as data‐dependent analysis, empowered the development of shotgun proteomics where hundreds to thousands of peptide sequences are matched per experiment. In their most popular implementation, the most abundant ionized species from every precursor ion scan at each moment in chromatographic time are successively selected for isolation, activation and tandem mass analysis. While extremely powerful, this strategy has one primary limitation in that detectable dynamic range is restricted (in a top‐down manner) to the peptides that ionize the best. To circumvent the serial nature of the data‐dependent process and increase detectable dynamic range, the concepts of multiplexed and data‐independent acquisition (DIA) have emerged. Multiplexed‐data acquisition is based on more efficient co‐selection and co‐dissociation of multiple precursor ions in parallel, the data from which is subsequently de‐convoluted to provide polypeptide sequences for each individual precursor ion. DIA has similar goals, but there is no real‐time ion selection based on prior precursor ion scans. Instead, predefined m/z ranges are interrogated either by fragmenting all ions entering the mass spectrometer at every single point in chromatographic time; or by dividing the m/z range into smaller m/z ranges for isolation and fragmentation. These approaches aim to fully utilize the capabilities of mass spectrometers to maximize tandem MS acquisition time and to address the need to expand the detectable dynamic range, lower the limit of detection, and improve the overall confidence of peptide identifications and relative protein quantification measurements. This review covers all aspects of multiplexed‐ and data‐independent tandem mass spectrometry in proteomics, from experimental implementations to advances in software for data interpretation. © 2013 Wiley Periodicals, Inc. Mass Spec Rev 33: 452–470, 2014.
Routing optimization for underwater optical networks in swarm configuration
Authors: Tabacchiera Marco , Persia Samuela , Cidronelli Paolo , Betti Silvello 
Published: November 2013

AbstractUnderwater wireless networks have been deeply studied in the last few years. Particular attention has been recently devoted to swarm networks, which can operate and take decision in collaborative manner. In swarm networks, the limited distance between nodes can be exploited by implementing optical links when the characteristics of the communication channel make it possible. With respect to acoustic communications, that solution can lead to an increase in data rate, to the absence of signal latency and to significant energy saving. A performance analysis is presented for an underwater swarm network in case of optical link among mobile nodes, considering LED optical transmitter and typical parameters for the communication channel. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:34–38, 2014
X‐band voltage‐controlled oscillator with built‐in envelope detection
Authors: Chen Cheng‐Yu , Li Hsiao‐Yun , Fu Jia‐Shiang 
Published: November 2013

ABSTRACTA wide‐tuning‐range X‐band voltage‐control oscillator (VCO) with built‐in envelope detectors is designed and measured. The VCO is implemented using a 0.18‐μm CMOS technology. The VCO core is composed of a cross‐coupled pair and a parallel‐LC resonator. The variable capacitance is implemented using MOS varactors. Large varactor capacitance and small transistor size are used to reduce the tuning‐range degradation due to the parasitic capacitance of the cross‐coupled pair and buffer amplifier. Each single‐ended output of the differential buffer amplifier is connected to a Greinacher voltage doubler, which serves as an envelope detector that senses the output power of the VCO and translates it into a dc voltage. The chip area of the VCO is 1.25 × 0.6 mm2. The measured frequency tuning range and FoMT (at 1‐MHz offset) are 31.7% and −192.5 dBc/Hz, respectively. The relation between the VCO output power and detector output voltage is characterized. Using the relation, the envelope detectors can be used for real‐time monitoring of the power level at any location in a chip, providing built‐in self‐test capability. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:11–14, 2014
Broadband and miniaturization of tilted beam antenna using CSRR splits and flower‐spiral structure
Authors: Li Si‐jia , Cao Xiang‐yu , Gao Jun , Zheng Qiu‐rong , Yang Huan‐huan 
Published: November 2013

ABSTRACTA miniaturized broadband circularly polarized antenna with tilted beam is designed and fabricated using the complementary split ring resonator (CSRR) splits and flower‐spiral (FS) structure. This antenna is composed of a FS structure, helix feed line, and ground plane loaded five CSRR splits. The voltage standing wave ratio is improved through the FS structure based on the Archimedean spiral arm. And the axial ratio is improved due to the five CSRR splits and FS structure. Simulated and measured results both confirm that the ground plane is reduced about 75.2% and the bandwidth significantly broadened from about 10.5% to about 27.6%. Experimental data show a reasonably good agreement between the simulation and measured results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:27–31, 2014
High reference impedance reflectometer for nonresonant matching of near‐field microwave microscope tip probe
Authors: Glay David , Fellahi Abdelhatif El , Lasri Tuami 
Published: November 2013

ABSTRACTIn this letter, we present a nonresonant high impedance reflectometer integrating a tip probe dedicated to near‐field microwave microscopy. A 1‐kohms reflectometer is fabricated by using lumped elements to validate the approach proposed to solve the problem of impedance mismatch between the probe and the measurement system. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:64–69, 2014
A compact wideband planar microstrip‐fed quasi‐yagi antenna with a C‐shape reflector
Authors: Wang Hao , Li Ping , Wu Ting , Wei Shi Xiao 
Published: November 2013

ABSTRACTA compact wideband planar microstrip‐fed quasi‐Yagi antenna is presented. Through optimizing the structure of the C‐shape reflector, a broadband impedance bandwidth of 75.3% (1.83 ∼ 4.04 GHz) for return loss less than −10 dB and a gain of 3.83 ∼ 8.48 dBi are obtained. Simulation based on HFSS and measurement results are provided and discussed. The agreements between the simulation and measurement results indicate that the antenna is suitable for wireless communication applications and phased arrays. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:241–244, 2014
High‐performance wide stop band low‐pass filter using a vertically coupled DGS‐DMS‐resonators and interdigital capacitor
Authors: Boutejdar Ahmed , Omar Abbas , Burte Edmund 
Published: November 2013

ABSTRACTUsing the simple multilayer technique and defected ground structure‐defected microstrip structure (DGS‐DMS) methods, a novel wide stop band low‐pass filter is proposed and implemented using coupled DMS and DGS resonators. The filter consists of two cascaded λ/2‐DMS‐resonators, which are etched on a 50 Ω microstrip feed line and vertically coupled with two cascaded DGS resonators. They are etched, opposed to the DMS‐Elements, on the ground plane. The proposed miniaturized low‐pass filters using DMS and DGS have been simulated and fabricated on a substrate with dimensions of 3.3 cm × 1.5 cm. The substrate has a relative dielectric constant of 3.38 and a thickness of 0.813 mm. The interdigital‐DGS‐DMS LPF achieved insertion loss less than 0.5 dB and a wide rejection in the stop band with overall 20 dB attenuation up to 8 GHz. The simulated and measured results show good agreement and validate the proposed approach. Such filter structures are expected to be applied widely for microwave integrated circuit and in modern communication systems. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:87–91, 2014
Broadband radar absorbing material based on orthogonal arrangement of CSRR etched artificial magnetic conductor
Authors: Zhao Yi , Cao Xiang‐yu , Gao Jun , Li Wen‐qiang 
Published: November 2013

ABSTRACTIn this article, a novel design method of broadband radar absorbing material is proposed. This method is based on orthogonal arrangement of complementary split‐ring resonator etched artificial magnetic conductors, which exhibit polarization‐dependent features. Owing to phase cancellation, scattering energy along the boresight is reduced over a wide frequency range. Measured results demonstrate that the frequency range of −10 dB RCS reduction spans from 7.38 to 10.47 GHz with the bandwidth up to 34.6%, validating the effectiveness of the method. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:158–161, 2014
Single‐, dual‐, and triple‐band metamaterial‐inspired electrically small planar magnetic dipole antennas
Authors: Turkmen Oznur , Turhan‐Sayan Gonul , Ziolkowski Richard W. 
Published: November 2013

ABSTRACTThe design and performance characteristics of metamaterial‐inspired electrically small, single, dual and triple band antennas at the GSM (1.93–1.99 GHz), ISM (2.43–2.4835 GHz), and WiMAX (3.3–3.6 GHz) frequencies are reported. These antennas are based on a coaxially fed printed dipole integrated in a planar configuration with capacitively loaded loops (CLLs) as its near‐field resonant parasitic radiators. In the proposed topology, the number of operating frequencies is determined by the number of CLLs. These antennas are geometrically simple, operate as magnetic dipoles (directivities ∼1.6−2.0 dB), and have high (≥80%) radiation efficiencies at all of their operating frequencies. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:83–87, 2014