bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorocarbon and Hydrocarbon Benzodioxocycloalkane (C8–C10) End Groups: Effects on Mesomorphism
Authors: Cao Wanwan , Liu Peilian , Chen Hongren , Zhu Yaohang , Chen Rihao , Zhou Qifang , Zeng Zhuo
Published: July 2013

A new class of benzodioxocycloalkane‐based (C8–C10) liquid crystals were prepared. The impact of ring (C8–C10) as end group was investigated. The 8–9 membered ring derivatives, 3a–3b, exhibited the nematic phases (N). The mesomorphic behaviors were weakened with increasing the size of the ring. For the ?uorinated medium ring (C8–C10) 3d–3f, it was found only the fluorinated ten membered ring 3f showed the LC phases behaviours. Modification of the ring size with different length alkyl groups and variation of the alkyl to polyfluoroalkyl markedly influenced the properties of these compounds.
Radical Addition of Perfluoroalkyl Iodides to Alkenes and Alkynes Initiated by Sodium Dithionite in an Aqueous Solution in the Presence of a Novel Fluorosurfactant
Authors: Xiao Zhiwei , Hu Huawei , Ma Jiaoli , Chen Qingyun , Guo Yong
Published: July 2013

A new fluorinated anionic surfactant Cl(CF2)6O(CF2)2SO3N(C2H5)4 was prepared and characterized. The application of the fluorosurfactant allowed the fluoroalkylation to occur in the water without adding organic solvent. The addition of perfluoroalkyl iodides with olefins and alkynes under the initiation of Na2S2O4 in water in the presence of the fluorosurfactant gave the corresponding adducts in good to excellent yields. The fluorosurfactant was suitable for a radical addition process.
Triazole and Benzotriazole Derivatives as Novel Inhibitors for p90 Ribosomal S6 Protein Kinase 2: Synthesis, Molecular Docking and SAR Analysis
Authors: Yuan Jun , Zhong Ye , Li Shiliang , Zhao Xue , Luan Guoqin , Zhao Zhenjiang , Huang Jin , Li Honglin , Xu Yufang
Published: July 2013

A series of triazole and benzotriazole derivatives as novel p90 ribosomal S6 protein kinase 2 (RSK2) inhibitors were designed and synthesized. The in vitro activities against RSK2 were evaluated, and among 14 compounds, compounds 5, 6, 11, 12, 13 and 14 exhibited enzyme IC50 values of 8.91, 2.86, 3.19, 3.05, 4.49 and 2.09 µmol/L respectively. The proposed binding modes were simulated using molecular docking method, and the docking results coupled with the structure‐activity relationship (SAR) analysis indicated that all these active compounds bound to the RSK2 ATP binding site at NTKD, and the electron‐donating groups on the 4‐position of phenyl were the determinant point for the inhibitory activity.
A new replicate variance estimator for unequal probability sampling without replacement
Authors: Escobar Emilio L. , Berger Yves G.
Published: July 2013

We propose a new replicate variance estimator suitable for differentiable functions of estimated totals. The proposed variance estimator is defined for any unequal‐probability without‐replacement sampling design, it naturally includes finite population corrections and it allows two‐stage sampling. We show its design‐consistency and its close relationship with linearization variance estimators. When estimating a total, the proposed estimator reduces to the Horvitz–Thompson variance estimator. Simulations suggest that the proposed variance estimator is more stable than its replicate competitors.The Canadian Journal of Statistics41: 508–524; 2013 © 2013 Statistical Society of Canada
Triple Oral Antithrombotic Therapy in Atrial Fibrillation and Coronary Artery Stenting
Authors: Reed Grant W. , Cannon Christopher P.
Published: July 2013

Patients with atrial fibrillation affected by an acute coronary syndrome have indications for oral anticoagulation and dual antiplatelet therapy with aspirin and a P2Y12 adenosine diphosphate receptor inhibitor after coronary artery stenting. The concurrent use of all 3 agents, termed triple oral antithrombotic therapy, significantly increases the risk of bleeding. To date, there is a lack of evidence on the proper combination and duration of anticoagulant and antiplatelet agents in patients with indications for both therapies. As such, care has been guided by expert opinion, and there is wide variation in clinician practice. In this review, the latest evidence on the risks and benefits of triple oral antithrombotic therapy in patients with atrial fibrillation after coronary artery stenting is summarized. We discuss the clinical risk scores useful in guiding the prediction of stroke, bleeding, and stent thrombosis. Additionally, we highlight where additional evidence is needed to determine the proper balance of anticoagulant and antiplatelet agents in this patient population.
Baseflow and Runoff Event Metal Concentrations, Partition and Its Relation with Physicochemical Variables in an Agroforestry Catchment
Authors: Palleiro Laura , Rodríguez‐Blanco María Luz , Taboada‐Castro María Mercedes , Taboada‐Castro María Teresa
Published: July 2013

Partitioning to suspended sediments plays an important role in controlling metal speciation in natural waters. In order to model both dissolved and particulate forms of metals, it is essential to determine possible relationships between partition coefficient (KD) and various water quality variables. This paper examines temporal variability in particulate and dissolved metals (Al, Fe, Mn, Cu, and Zn) collected from a rural stream (NW Spain) during three years under baseflow and runoff events conditions, and investigates the role of pH, suspended sediments (SS) and dissolved organic carbon (DOC) on KD of these metals. The mean concentrations of metals during events were much higher than those in baseflow (except MnD and CuD), but particulate metals were always predominant. Metal concentrations did not exhibit a seasonal pattern. Generally, a similar pattern of metals to discharge was seen for both hydrological conditions, although different metal‐discharge relationships were observed depending on the type and form of the metal: negative for FeD and MnD, no relation for AlD, CuD, and ZnD, and positive correlation for all particulate metals (except for CuP and ZnP in baseflow). Partitioning results showed that SS and DOC were the main factors in controlling KD of all metals during events (except for Fe) as well as KD of Al under baseflow. SS play the most important role on KD of Cu and Zn in baseflow, and DOC on KD of Fe (regardless of the discharge regime). For all the above‐mentioned findings, this study demonstrates the need to consider hydrological changes when we analyze geochemical factors affecting metal concentrations, even in relatively unpolluted environments.
Stability and Removal of Naproxen and Its Metabolite by Advanced Membrane Wastewater Treatment Plant and Micelle–Clay Complex
Authors: Qurie Mohannad , Khamis Mustafa , Malek Fida , Nir Shlomo , Bufo Sabino A. , Abbadi Jihad , Scrano Laura , Karaman Rafik
Published: July 2013

Naproxen, a non‐steroidal anti‐inflammatory drug, commonly used for fever, inflammation and for different health problems, as found for many pharmaceuticals has been recently detected in sewage effluents, surface, and ground water, and sometimes even in drinking water. An advanced wastewater treatment plant (WWTP), utilizing ultra‐filtration, activated charcoal (AC), and reverse osmosis (RO) after the primary biological treatment, showed that both nano‐ and micro‐ultrafiltration were not sufficient for removing spiked naproxen to a safe level, whereas RO membrane was quite efficient. No naproxen degradation was detected in pure water whereas it underwent biodegradation within three days in activated sludge giving O‐desmethyl‐naproxen. Adsorption performed on micelle–clay complex and AC under steady state conditions, showed that the former adsorbent is highly effective in removing naproxen with fast kinetics. Laboratory micelle–clay complex filters under continuous naproxen‐spiked water flowing were found to be efficient in removing this drug, suggesting that the efficiency of existing advanced WWTP could be improved by including filtration columns filled with suitable sand/micelle–clay mixtures.
Synthesis and in vitro Evaluation of West Nile Virus Protease Inhibitors Based on the 1,3,4,5‐Tetrasubstituted 1H‐Pyrrol‐2(5H)‐one Scaffold
Authors: Gao Yaojun , Samanta Sanjay , Cui Taian , Lam Yulin
Published: July 2013

West Nile virus (WNV), a member of the Flaviviridae family, is a mosquito‐borne pathogen that causes a large number of human infections each year. There are currently no vaccines or antiviral therapies available for human use against WNV. Therefore, efforts to develop new chemotherapeutics against this virus are highly desired. In this study, a WNV NS2B–NS3 protease inhibitor with a 1,3,4,5‐tetrasubstituted 1H‐pyrrol‐2(5H)‐one scaffold was identified by screening a small library of nonpeptidic compounds. Optimization of this initial hit by the synthesis and screening of a focused library of compounds with this scaffold led to the identification of a novel uncompetitive inhibitor ((−)‐1a16, IC50=2.2±0.7 μM) of the WNV NS2B–NS3 protease. Molecular docking of the chiral compound onto the WNV protease indicates that the R enantiomer of 1a16 interferes with the productive interactions between the NS2B cofactor and the NS3 protease domain and is thus the preferred isomer for inhibition of the WNV NS2B–NS3 protease.
Thalamic Input to Representations of the Teeth, Tongue, and Face in Somatosensory Area 3b of Macaque Monkeys
Authors: Cerkevich Christina M. , Qi Hui‐Xin , Kaas Jon H.
Published: July 2013

Representations of the parts of the oral cavity and face in somatosensory area 3b of macaque monkeys were identified with microelectrode recordings and injected with different neuroanatomical tracers to reveal patterns of thalamic projections to tongue, teeth, and other representations in primary somatosensory cortex. The locations of injection sites and resulting labeled neurons were further determined by relating sections processed to reveal tracers to those processed for myeloarchitecture in the cortex and multiple architectural stains in the thalamus. The ventroposterior medial subnucleus (VPM) for touch was identified as separate from the ventroposterior medial parvicellular nucleus (VPMpc) for taste by differential expression of several types of proteins. Our results revealed somatotopically matched projections from VPM to the part of 3b representing intra‐oral structures and the face. Retrogradely labeled cells resulting from injections in area 3b were also found in other thalamic nuclei including: anterior pulvinar (Pa), ventroposterior inferior (VPI), ventroposterior superior (VPS), ventroposterior lateral (VPL), ventral lateral (VL), center median (CM), central lateral (CL), and medial dorsal (MD). None of our injections, including those into the representation of the tongue, labeled neurons in VPMpc, the thalamic taste nucleus. Thus, area 3b does not appear to be involved in processing taste information from the thalamus. This result stands in contrast to those reported for New World monkeys. J. Comp. Neurol. 521:3954–3971, 2013. © 2013 Wiley Periodicals, Inc.
Numerical simulation of dental bone remodeling induced by implant‐supported fixed partial denture with or without cantilever extension
Authors: Wang Chao , Li Qing , McClean Colin , Fan Yubo
Published: July 2013

The current study aims to evaluate and compare the bony biomechanical response and possible long‐term restorative consequences stemming from the use of two‐unit fixed partial dentures (FPDs) with or without cantilever configuration. The numerical simulations of bone remodeling were performed using an adaptive strain energy density algorithm, which incorporates an overloading bone resorption process. A patient specific 3D finite element model of a maxillary bone with two absent central incisors was constructed on the basis of clinical computed tomography data. Two different implant‐supported two‐unit FPD models were developed. The simulated remodeling results were visualized by examining the variation of apparent bone density. Different bone responses under normal and overload conditions were compared quantitatively and qualitatively between the cantilever and non‐cantilever models. The mechanical stress/strain distributions were also examined. Furthermore, the simulation results were compared with a similar clinical X‐ray image of the implant site. This study revealed that bone resorption due to overloading was more severe in the cortical neck around the implant‐supported cantilever FPD, as compared with the non‐cantilever configuration, which is better for maintaining the overall health of bone tissue. It is expected that such simulation methodology can be helpful in improving longevity and reliability of future dental implants. Copyright © 2013 John Wiley & Sons, Ltd.
Analysis of power‐saving techniques over a large multi‐use cluster with variable workload
Authors: McGough Andrew Stephen , Forshaw Matthew , Gerrard Clive , Robinson Paul , Wheater Stuart
Published: July 2013

Reduction of power consumption for any computer system is now an important issue, although this should be carried out in a manner that is not detrimental to the users of that computer system. We present a number of policies that can be applied to multi‐use clusters where computers are shared between interactive users and high‐throughput computing. We evaluate policies by trace‐driven simulations to determine the effects on power consumed by the high‐throughput workload and impact on high‐throughput users. We further evaluate these policies for higher workloads by synthetically generating workloads based around the profiled workload observed through our system. We demonstrate that these policies could save 55% of the currently used energy for our high‐throughput jobs over our current cluster policies without affecting the high‐throughput users’ experience. Copyright © 2013 John Wiley & Sons, Ltd.
Efficient support for in‐place metadata in Java software transactional memory
Authors: Dias Ricardo J. , Vale Tiago M. , Lourenço João M.
Published: July 2013

Software transactional memory (STM) algorithms associate metadata with the memory locations accessed during a transaction's lifetime. This metadata may be stored in an external table by resorting to a mapping function that associates the address of a memory cell with the table entry containing the corresponding metadata (out‐place or external strategy). Alternatively, the metadata may be stored adjacent to the associated memory cell by wrapping the cell and metadata together (in‐place strategy). The implementation techniques to support these two approaches are very different and each STM framework is usually biased towards one of them, only allowing the efficient implementation of STM algorithms which suit one of the approaches and inhibiting a fair comparison with STM algorithms suiting the other. In this paper, we introduce a technique to implement in‐place metadata that does not wrap memory cells, thus overcoming the bias and allowing STM algorithms to directly access the transactional metadata. The proposed technique is available as an extension to Deuce and enables the efficient implementation of a wide range of STM algorithms and their fair (unbiased) comparison in a common STM framework. We illustrate the benefits of our approach by analyzing its impact in two popular transactional memory algorithms with several transactional workloads, TL2 and multiversioning, each befitting out‐place and in‐place, respectively. Copyright © 2013 John Wiley & Sons, Ltd.
Temperature‐Independent Hole Mobility of a Smectic Liquid‐Crystalline Semiconductor based on Band‐Like Conduction
Authors: Funahashi Masahiro , Ishii Tomohiko , Sonoda Akinari
Published: July 2013

A liquid‐crystalline (LC) phenylterthiophene derivative, which exhibited an ordered smectic phase at room temperature, was purified by vacuum sublimation under a flow of nitrogen. During the sublimation process, thin plates with sizes of 1 mm grew on the surface of the vacuum tube. The crystals exhibited the same X‐ray diffraction patterns as the ordered smectic phase of the LC state that was formed through a conventional recrystallization process by using organic solvents. Because of the removal of chemical impurities, the hole mobility in the ordered smectic phase of the vacuum‐grown thin plates increased to 1.2×10−1 cm2 V−1 s−1 at room temperature, whereas that of the LC precipitates was 7×10−2 cm2 V−1 s−1. The hole mobility in the ordered smectic phase of the vacuum‐sublimated sample was temperature‐independent between 400 and 220 K. The electric‐field dependence of the hole mobility was also very small within this temperature range. The temperature dependence of hole mobility was well‐described by the Hoesterey–Letson model. The hole‐transport characteristics indicate that band‐like conduction affected by the localized states, rather than a charge‐carrier‐hopping mechanism, is a valid mechanism for hole transport in an ordered smectic phase.
Highly Efficient Singlet–Singlet Energy Transfer in Light‐Harvesting [60,70]Fullerene–4‐Amino‐1,8‐naphthalimide Dyads
Authors: Remón Patricia , Parente Carvalho Cátia , Baleizão Carlos , Berberan‐Santos Mario Nuno , Pischel Uwe
Published: July 2013

New C60 and C70 fullerene dyads formed with 4‐amino‐1,8‐naphthalimide chromophores have been prepared by the Bingel cyclopropanation reaction. The resulting monoadducts were investigated with respect to their fluorescence properties (quantum yields and lifetimes) to unravel the role of the charge‐transfer naphthalimide chromophore as a light‐absorbing antenna and excited‐singlet‐state sensitizer of fullerenes. The underlying intramolecular singlet–singlet energy transfer (EnT) process was fully characterized and found to proceed quantitatively (ΦEnT≈1) for all dyads. Thus, these conjugates are of considerable interest for applications in which fullerene excited states have to be created and photonic energy loss should be minimized. In polar solvents (tetrahydrofuran and benzonitrile), fluorescence quenching of the fullerene by electron transfer from the ground‐state aminonaphthalimide was postulated as an additional path.
Teaching Conflict Resolution: A Model for Student Research in Cyprus
Authors: Reilly David
Published: July 2013

Field‐based experiential learning is an effective way to introduce alternative dispute resolution concepts. This article presents a model of field‐based learning in Cyprus that integrates concepts of conflict resolution with real‐world experiences. Through this process, students learn to assess the effectiveness of conflict resolution strategies and to research, analyze, and report on conflict processes and their resolution. Although the model is based on a course in Cyprus, the example and course model are applicable to other locations and other conflicts.
A cost‐effective PWM dimming method for LED lighting applications
Authors: Chiu Huang‐Jen , Lo Yu‐Kang , Lin Yu‐Liang , Jane Gwan‐Chi
Published: July 2013

This paper presents a novel cost‐effective pulse‐width‐modulation (PWM) dimming method for light‐emitting diode (LED) lighting applications. High efficiency, high power factor, circuit simplicity, and low cost can be achieved by a Flyback power factor correction converter with the studied adaptive PWM dimming method. The operation principles and design considerations of the proposed LED dimming method are analyzed and discussed. A 45 W laboratory prototype has been built and tested to verify the feasibility of the proposed scheme. Copyright © 2013 John Wiley & Sons, Ltd.
Salivary cytokines in healthy adolescent girls: Intercorrelations, stability, and associations with serum cytokines, age, and pubertal stage
Authors: Riis Jenna L. , Out Dorothee , Dorn Lorah D. , Beal Sarah J. , Denson Lee A. , Pabst Stephanie , Jaedicke Katrin , Granger Douglas A.
Published: July 2013

Theoretically, the measurement of cytokines in saliva may have utility for studies of brain, behavior, and immunity in youth. Cytokines in saliva and serum were analyzed across three annual assessments in healthy adolescent girls (N = 114, 11–17 years at enrollment). Samples were assayed for GM‐CSF, IFNγ, IL‐1β, IL‐2, IL‐6, IL‐8, IL‐10, IL‐12p70, TNFα, adiponectin, and cotinine. Results revealed: (1) cytokine levels, except IFNγ and IL‐10, were detectable in saliva, and salivary levels, except IL‐8 and IL‐1β, were lower than serum levels; (2) salivary cytokine levels were lower in older girls and positively associated with adiponectin; (3) compared to serum levels, the correlations between salivary cytokines were higher, but salivary cytokines were less stable across years; and (4) except for IL‐1β, there were no significant serum–saliva associations. Variation in basal salivary cytokine levels in healthy adolescent girls reflect compartmentalized activity of the oral mucosal immune system, rather than systemic cytokine activity. © 2013 Wiley Periodicals, Inc. Dev Psychobiol 56: 797–811, 2014.
An unusual case of risperidone instability in a fatality presenting an analytical and interpretative challenge
Authors: Taylor Kerry , Elliott Simon
Published: July 2013

This paper describes the detection and characterization of unusual metabolite/breakdown products of the anti‐psychotic drug risperidone in post‐mortem blood and urine as part of a toxicological investigation into an unexpected death of a male suffering from paranoid schizophrenia prescribed risperidone and previously paroxetine. Compounds detected in the post‐mortem blood and urine specimens were shown to be benzisoxazole ring scission products of risperidone and a hydroxy metabolite. These compounds are never routinely detected in blood and urine but can be present in mammalian faeces indicating that gut bacteria could be responsible for their formation. In this case, evidence for this process was demonstrated by the controlled in vitro stability study of risperidone spiked into the case blood and urine leading to the hypothesis that the post‐mortem blood and urine samples analyzed could have contained bacteria with the ability to breakdown risperidone and its metabolite in this way. This finding is very unusual and has not been encountered before in any previous risperidone cases investigated by the authors, or widely reported in the post‐mortem toxicological literature. However, a recently published paper has supported these findings in blood. As a result of this work, it was shown that the deceased had taken risperidone prior to death, even in the absence of any risperidone or its hydroxy metabolite(s) in the blood and urine. Given that risperidone has been reported to interact with paroxetine, the ingestion of risperidone could have been a factor that contributed to the death. Copyright © 2013 John Wiley & Sons, Ltd.
Laser‐mediated cell ablation during post‐implantation mouse development
Authors: Angelo Jesse R. , Tremblay Kimberly D.
Published: July 2013

BACKGROUND: Laser‐mediated cell ablation is a powerful tool that has been used to understand cell fate in a variety of externally developing organisms but has not been used during mammalian post‐implantation development. RESULTS: We describe a method pairing laser ablation with murine embryo culture and establish parameters that can be used to precisely ablate cells in the selected field with minimal disruption to adjacent cells or the underlying cell matrix. Ablation of a large domain of endoderm, followed by ∼1 day of culture results in a phenotypically normal embryo and gut tube, indicating that laser ablation is compatible with normal development. We next focused on one of the three precursor populations that have been shown to produce the liver bud. Ablations of a single progenitor domain result in a unilateral delay in the liver bud while the contralateral side is unaffected. CONCLUSIONS: We demonstrate that laser ablation is a specific and useful technique for studying cell fate in the mouse embryo. This method represents a powerful advance in developmental studies in the mouse and can be used to provide information on the specification of organs, differentiation, cell migration, and vital tissue interactions during development. Developmental Dynamics, 242:1202–1209, 2013. © 2013 Wiley Periodicals, Inc.
Advanced Open‐Chain Nitramines as Energetic Materials: Heterocyclic‐Substituted 1,3‐Dichloro‐2‐nitrazapropane
Authors: Klapötke Thomas M. , Penger Alexander , Pflüger Carolin , Stierstorfer Jörg , Sućeska Muhamed
Published: July 2013

There are great demands to develop explosives with higher performance accompanied by reduced sensitivities towards external stimuli, higher thermal stability and improved environmental acceptability. This contribution presents modified nitramines, which were investigated by nucleophilic substitution reactions of potassium salts of 5‐amino‐3‐nitro‐1,2,4‐triazole, 3,5‐dinitro‐1,2,4‐triazole, 3,5‐dinitroimidazole, 2,4‐dinitroimidazole, 4‐amino‐3,5‐dinitropyrazole, 3,5‐dinitropyrazole, 3,4‐dinitropyrazole and 3,4,5‐trinitropyrazole on 1,3‐dichloro‐2‐nitrazapropane. The energetic compounds were comprehensively characterized and their detonation parameters were calculated by the EXPLO5 code. Heats of formation were calculated by the atomization method using CBS‐4M electronic enthalpies. The presented compounds show detonation performances comparable to pentaerythritol tetranitrate (PETN). In addition, they possess high thermal stabilities and low sensitivities, which make them interesting for further investigations and possible applications as insensitive, high‐energy dense materials.
Synthesis and Coordination of the Cagelike Siloxane Compounds E2{(SiMe2)2O}3 (E = As, Sb, Bi)
Authors: Bimbös Christian , Jost Maximilian , von Hänisch Carsten , Harms Klaus
Published: July 2013

The cage compounds [E2{(SiMe2)2O}3] for E = P, As, Sb, and Bi (1, 4, 5, and 6, respectively) are readily accessible in moderate yields by the reaction of Na3E (for E = P, As, Sb, Bi) or [Li(dme)EH2] (for E = P, As; dme = dimethoxyethane) with 1,3‐dichloro‐1,1,3,3‐tetramethyldisiloxane. These compounds were isolated and characterized by X‐ray crystallographic analysis. The major structural parameters such as the E–Si bond length and the Si–E–Si angles are discussed and compared with those of similar compounds. The small Si–E–Si angles in these compounds are attributable to steric and electronic reasons. Further, the R3M–E[(SiMe2)2O]3E–MR3 (M = Al, E = As, Sb; M = Ga, E = Sb) Lewis acid–base adducts were formed as well as the W(CO)5 adduct of compound 1 and a heteroleptic Na[Al(ORF)4] (RF = C(CF3)3) adduct with 4 to investigate the coordination properties of the cage compounds. The structural changes caused by coordination follow the Haaland model, which gives qualitative information on the adduct stability. The assumptions made by the Haaland model are valid for a versatile set of Lewis acids. To investigate coordination on the inside of the cage, a reaction of 4 with Li[Al(ORF)4] was performed to yield a new dimeric ligand of the constitution As4[(SiMe2)2O]6.
Mechanistic Aspects of Water Oxidation Catalyzed by Organometallic Iridium Complexes
Authors: Savini Arianna , Bucci Alberto , Bellachioma Gianfranco , Rocchigiani Luca , Zuccaccia Cristiano , Llobet Antoni , Macchioni Alceo
Published: July 2013

The reactions of three iridium water‐oxidation catalysts {[Cp*IrL1L2L3]Xn; 1: L1, L2 = 2,2‐bipyridine (bpy), L3 = Cl, n = 1, X = Cl; 2: L1, L2 = 2‐benzoylpyridine (bzpy), L3 = NO3; 3: L1 = L2 = L3 = H2O, n = 2, X = NO3; Cp* = pentamethylcyclopentadienyl} with cerium ammonium nitrate (CAN) and NaIO4 (sacrificial oxidants, SOs) have been studied by Clark electrode measurements (both in solution and in the gas phase), on‐line mass spectrometry, manometry and UV/Vis spectroscopy. Furthermore, cyclic voltammetry has been applied to evaluate the relative tendency of 1 and 2 to be oxidized. The turnover frequency (TOF) increases as the ratio (R) between the concentration of the SO and that of the catalyst increases. O2 production with CAN is observed in experiments with R = 20 for 1 and 3, whereas O2 becomes detectable with 2 only when R = 40. Catalyst 2 has the highest tendency to be oxidized to IrIV and forms a blue intermediate I characterized by a UV/Vis band at 574 nm. The formation of I occurs with the same velocity as that of the production of O2, which indicates that I is a species directly involved in the catalytic cycle. The disappearance of I, when O2 evolution is finished, is a second‐order process more than one order of magnitude slower than O2 production and is strongly accelerated by the presence of benzyl alcohol. This suggests that I is a molecular species that slowly undergoes disproportion when catalysis is over. Experiments in which multiple aliquots of SO (CAN) were added (R = 20 and 40) indicate that catalysts 1–3 can reinitiate the catalytic cycle once they have been kept in a dormant state for 0–9 min; the TOFs of the second and third additions are approximately equal and higher than that of the first addition. By combining manometry and on‐line mass spectrometry measurements, it was found that O2 evolution is parallel to the production of a small amount of CO2 owing to catalyst degradation. The TOFs of the experiments performed with NaIO4 as the SO are about 2–3 times lower than those with CAN, but the same reactivity order is found 3 > 2 > 1. The activation parameters were evaluated with NaIO4 for all catalysts and with CAN for 2 at 10–45 °C. ΔG# is practically the same in all situations (25–26 kcal mol–1), whereas ΔH# is appreciably lower for 2 (13.1 kcal mol–1 with CAN and 13.3 kcal mol–1 with NaIO4) than for 1 (16 kcal mol–1) and 3 (16.9 kcal mol–1). The lowest enthalpic cost with 2 is balanced by the highest entropic cost (–41 cal mol–1 K–1) that approaches that typical for an associative bimolecular process.
Copper(II) Complexes of N,N‐Diisopropylpicolinamide – Solvatochromic and Thermochromic Phase Change of a Monomeric Complex to a Ferromagnetically Coupled Dimeric Complex
Authors: Lumb Isha , Hundal Maninder Singh , Corbella Montserrat , Gómez Verónica , Hundal Geeta
Published: July 2013

The synthesis and characterization of mononuclear [Cu(L)2(Cl)2] (1), dinuclear [{CuCl(L)}2(μ‐Cl)2] (2), and another mononuclear complex [Cu(L)2(ClO4)2] (3) with a bidentate N,N‐diisopropylpicolinamide ligand (abbreviated L) are described. Complexes 1 and 2 were obtained from the same reaction mixture and show thermo‐ and solvatochromic behavior. Complex 1 shows irreversible thermochromism by changing into 2 upon heating at 160 °C. These two complexes also show solvatochromism in various solvents. The coordination geometry of the metal ions in 1 and 3 is distorted octahedral, whereas 2 has CuII ions in a distorted square‐pyramidal geometry. Variable‐temperature magnetic susceptibility measurements for the dinuclear copper complex show a ferromagnetic interaction between the CuII ions. The chromotropism has been attributed to a change in geometry from octahedral with terminal chloride ligands to a distorted square‐pyramidal coordination with bridging chloride ions.
Phosphorescent Square‐Planar Platinum(II) Complexes of 1,3‐Bis(2‐pyridylimino)isoindoline with a Monodentate Strong‐Field Ligand
Authors: Wen Hu‐Min , Wang Jin‐Yun , Li Bin , Zhang Li‐Yi , Chen Chang‐Neng , Chen Zhong‐Ning
Published: July 2013

A series of platinum(II) complexes bearing 1,3‐bis(2‐pyridylimino)isoindoline (BPI) derivatives as ligand have been prepared by substitution of the coordinated Cl in precursors [Pt(L)Cl] [L = L1 (1), L2 (2), L3 (3)] by a monodentate strong‐field ligand such as CN–, CN‐cyclohexyl, PPh3, NCS–, PhS–, or N(CN)2–. Most of these compounds display orange‐to‐red luminescence in both the solid state and solution at ambient temperature. Compared with precursors 1–3, both low‐energy absorption and emission bands in ligand‐substituted platinum(II) complexes 4–13 exhibit distinct blueshifts. The emission of platinum(II) complexes with CN‐containing monodentate ligands shows progressive blueshifts with increasing ligand field strength: 609 (10, NCS–) → 603 [12, N(CN)2–] → 590 (4, CN–) → 581 nm (7, C≡N‐cyclohexyl). The emission of complexes 4–9 originates mainly from the 3[π → π*(BPI)] 3IL triplet excited state, mixed with some 3[dπ(Pt) → π*(BPI)] 3MLCT character. In contrast, the emission of 10–13 arises from a clearly increased 3[π(L) → π*(BPI)] 3LLCT state with reduced 3[π → π*(BPI)] 3IL and 3[5d(Pt) → π*(BPI)] 3MLCT character. Noticeably, dicyanamido‐linked dinuclear complex 13 displays a significant ligand–ligand electronic interaction between the two BPI across the Pt–N≡C–N–C≡N–Pt bridge with remarkable LLCT character from one BPI to the other.
One‐Pot Enol Silane Formation/Mukaiyama–Mannich Addition of Ketones, Amides, and Thioesters to Nitrones in the Presence of Trialkylsilyl Trifluoromethanesulfonates
Authors: Downey C. Wade , Dombrowski Carolyn M. , Maxwell Erin N. , Safran Chelsea L. , Akomah Odamea A.
Published: July 2013

Ketones, amides, and thioesters form enol silanes and add to N‐phenylnitrones in one pot in the presence of trimethylsilyl trifluoromethanesulfonate and trialkylamine. The reaction is general to a range of silyl trifluoromethanesulfonates and N‐phenylnitrones. The β‐(silyloxy)amino carbonyl products are stable to chromatography and can be isolated in 63–99 % yield.
Zinc/Iron‐Mediated Ring Opening of Dibromocyclopropanes for In Situ Diels–Alder Reactions with Electron‐Deficient Aldehydes and Imines
Authors: Pünner Florian , Hilt Gerhard
Published: July 2013

Dibromocyclopropanes can be ring‐opened by utilizing zinc dibromide in catalytic amounts and iron powder in substoichiometric amounts. The presence of the carbonyl group of aldehydes, ketones, glyoxylic esters, or imines is necessary for the ring‐opening reaction. The ring opening leads to a bromo‐functionalized 1,3‐diene, which then reacts in situ with the carbonyl group in a hetero‐Diels–Alder reaction. The products are formed with high control of the regiochemistry and in good yields for electron‐deficient aldehydes and imines, such as carbamates. The application of (E)‐ethyl 2‐(methoxycarbonylimino)acetate led to a cyclic α‐amino acid derivative. The use of unsymmetrical dibromo‐ and dihalocyclopropanes is also reported.
Chemometric Strategies to Develop a Nanocomposite Electrode for Simultaneous Determination of Ascorbic Acid, Dopamine, and Uric Acid
Authors: de Pieri Troiani Estela , Rodrigues Pereira‐Filho Edenir , Censi Faria Ronaldo
Published: July 2013

A simple and sensitive method for simultaneously measuring dopamine (DA), ascorbic acid (AA), and uric acid (UA) using a poly(1‐aminoanthracene) and carbon nanotubes nanocomposite electrode is presented. The experimental parameters for composite film synthesis as well as the variables related to simultaneous determination of DA, AA, and UA were optimized at the same time using fractional factorial and Doehlert designs. The use of carbon nanotubes and poly(1‐aminoanthracene) in association with a cathodic pretreatment led to three well‐defined oxidation peaks at potentials around −0.039, 0.180 and 0.351 V (vs. Ag/AgCl) for AA, DA, and UA, respectively. Using differential pulse voltammetry, calibration curves for AA, DA, and UA were obtained over the range of 0.16–3.12×10−3 mol L−1, 3.54–136×10−6 mol L−1, and 0.76–2.92×10−3 mol L−1, with detection limits of 3.95×10−5 mol L−1, 2.90×10−7 mol L−1, and 4.22×10−5 mol L−1, respectively. The proposed method was successfully applied to determine DA, AA, and UA in biological samples with good results.
Bayesian stable isotope mixing models
Authors: Parnell Andrew C. , Phillips Donald L. , Bearhop Stuart , Semmens Brice X. , Ward Eric J. , Moore Jonathan W. , Jackson Andrew L. , Grey Jonathan , Kelly David J. , Inger Richard
Published: July 2013

In this paper, we review recent advances in stable isotope mixing models (SIMMs) and place them into an overarching Bayesian statistical framework, which allows for several useful extensions. SIMMs are used to quantify the proportional contributions of various sources to a mixture. The most widely used application is quantifying the diet of organisms based on the food sources they have been observed to consume. At the centre of the multivariate statistical model we propose is a compositional mixture of the food sources corrected for various metabolic factors. The compositional component of our model is based on the isometric log‐ratio transform. Through this transform, we can apply a range of time series and non‐parametric smoothing relationships. We illustrate our models with three case studies based on real animal dietary behaviour. Copyright © 2013 John Wiley & Sons, Ltd.
Comparison of fundamental properties of new types of fiber‐mesh‐reinforced seismic isolators with conventional isolators
Authors: Karimzadeh Naghshineh Ali , Akyüz Uğurhan , Caner Alp
Published: July 2013

New types of fiber‐reinforced rubber‐based seismic isolators have been a research interest for a number of engineers in the past decade. These new types of isolators can have similar seismic performances compared with the conventional ones. In most of the previous researches, the fiber‐reinforced rubber‐based isolators is usually manufactured with placing fiber sheets between precut rubber layers with the use of a bonding agent. This research differs from the previous researches in terms of manufacturing process, use of fiber mesh instead of fiber sheets, and use of lead in the core for some of the bearings. The aim of this research is to provide comparisons in fundamental seismic response properties of the new type of fiber mesh reinforced isolators and conventional isolators. In this scope, four pairs of fiber mesh reinforced elastomeric bearings and four pairs of steel‐reinforced elastomeric bearings are subjected to various levels of compression stresses and cyclic shear strains under constant vertical pressure. The tested types of isolators are fiber mesh reinforced elastomeric bearing, fiber mesh reinforced elastomeric bearing with lead core, steel‐reinforced elastomeric bearings, and steel‐reinforced elastomeric bearings with lead core. In this research, steel‐reinforced bearings are called conventional isolators. The major advantage for fiber mesh reinforced bearings observed during the tests is that these isolators can develop a considerable low horizontal stiffness compared with the conventional isolators. The damping characteristics of the new and conventional types are similar to each other. Copyright © 2013 John Wiley & Sons, Ltd.
Experimental study of the response of a gravel streambed to increased sediment supply
Authors: Podolak Charles Joseph Pena , Wilcock Peter R.
Published: July 2013

If increased sediment supply to a river channel exceeds its transport capacity, deposition necessarily occurs as the bed adjusts to accommodate the increased supply. Both the mean and spatial patterns in bed elevation and grain size may change and an ability to understand their relative importance is needed to predict bed response. We report on an experiment in a field‐scale flume in which sediment supply is increased to a gravel bed with alternate bars. Sediment was recirculated in the experiments, but augmented in two steps, after which the bed was allowed to reach a new steady state. The transport rate at the end of the experiment was three times larger than at the start. High‐resolution sediment flux and topographic measurements, grain size derived from photographs, and hydrodynamic modeling allow us to document the topographic and textural response of the bed to increased sediment supply. The spatial patterns of bed topography and texture were forced by the flume setup and the initial and final steady states included long stationary alternate bars with associated grain size sorting. The transient bed contained several scales of shorter wavelength migrating bedforms superimposed on, and temporarily replacing the stationary alternate bars. Bed topography and textural patterns adjusted to increased sediment supply over different timescales. Bed slope and mean stress increased directly with sediment supply rate to produce a new transport steady state in a time about 2.5 times the minimum needed to deposit the required sediment wedge, indicating a trap efficiency of about 40% for the aggrading wedge. Adjustments in local topography and sorting, primarily in the form of smaller, migrating bars, continued for a period approximately equal to that required to initially reach transport steady state. Copyright © 2013 John Wiley & Sons, Ltd.
Forecasting Simultaneously High‐Dimensional Time Series: A Robust Model‐Based Clustering Approach
Authors: Wang Yongning , Tsay Ruey S. , Ledolter Johannes , Shrestha Keshab M.
Published: July 2013

This paper considers the problem of forecasting high‐dimensional time series. It employs a robust clustering approach to perform classification of the component series. Each series within a cluster is assumed to follow the same model and the data are then pooled for estimation. The classification is model‐based and robust to outlier contamination. The robustness is achieved by using the intrinsic mode functions of the Hilbert–Huang transform at lower frequencies. These functions are found to be robust to outlier contamination. The paper also compares out‐of‐sample forecast performance of the proposed method with several methods available in the literature. The other forecasting methods considered include vector autoregressive models with ∕ without LASSO, group LASSO, principal component regression, and partial least squares. The proposed method is found to perform well in out‐of‐sample forecasting of the monthly unemployment rates of 50 US states. Copyright © 2013 John Wiley & Sons, Ltd.
Forecasting Volatility with Many Predictors
Authors: Ke Tsung‐Han , Hu Yu‐Pin
Published: July 2013

This study investigates the forecasting performance of the GARCH(1,1) model by adding an effective covariate. Based on the assumption that many volatility predictors are available to help forecast the volatility of a target variable, this study shows how to construct a covariate from these predictors and plug it into the GARCH(1,1) model. This study presents a method of building a covariate such that the covariate contains the maximum possible amount of predictor information of the predictors for forecasting volatility. The loading of the covariate constructed by the proposed method is simply the eigenvector of a matrix. The proposed method enjoys the advantages of easy implementation and interpretation. Simulations and empirical analysis verify that the proposed method performs better than other methods for forecasting the volatility, and the results are quite robust to model misspecification. Specifically, the proposed method reduces the mean square error of the GARCH(1,1) model by 30% for forecasting the volatility of S&P 500 Index. The proposed method is also useful in improving the volatility forecasting of several GARCH‐family models and for forecasting the value‐at‐risk. Copyright © 2013 John Wiley & Sons, Ltd.
Advances in Metal Supported Cells in the METSOFC EU Consortium
Authors: McKenna B. J. , Christiansen N. , Schauperl R. , Prenninger P. , Nielsen J. , Blennow P. , Klemensø T. , Ramousse S. , Kromp A. , Weber A.
Published: July 2013

The EU‐sponsored project “METSOFC”, completed at the end of 2011, resulted in a number of advancements toward implementing a mechanically robust metal support as the structural element in SOFC. Technical University of Denmark (DTU) Energy Conversion's research into planar metal supported cells (MSCs) has produced an advanced cell design with high performance and mechanical robustness. At low operation temperatures (650 °C), these cells have shown low Area‐specific resistances (ASRs): 0.35 Ω cm2 in cell tests (16 cm2 active area) and under 0.3 Ω cm2 in button cells (0.5 cm2 active area). Further success was attained with even larger cell areas of 12 × 12 cm2 squares, which facilitated integration into small stacks at Topsoe Fuel Cell having powers approaching 1/2 kW. Development of MSC stacks showed that the MSCs could achieve similar or better performance, compared to most standard industrial anode supported ceramic cells. The best stacked MSCs had power densities approaching 275 mW cm–2 (at 680 °C and 0.8 V). Furthermore, extended testing at AVL determined extra stack performance and reliability characteristics, including behavior toward sulfur and simulated diesel reformate, and tolerance to thermal cycles and load cycles. These and other key outcomes of the METSOFC consortium are covered, along with associated work supported by the Danish National Advanced Technology Foundation.
SOFC System Design Using Ideal Efficiency Modeling – Model and Experimental Implementation
Authors: Heddrich M. P. , Jahn M. , Michaelis A. , Näke R. , Weder A.
Published: July 2013

A simple thermodynamic system model for the analysis and evaluation of possible SOFC system concepts with regard to reachable electric efficiency is presented. All reforming concepts, various available fuels and anode off‐gas recirculation are included in the model. Furthermore, the model allows the characterization of the reforming conditions necessary to reach the calculated and desired electric efficiencies by the use of two dimensionless energy flow ratios, which are introduced. It is presented how to quickly assess system concepts and identify system concepts that are particularly interesting due to a simple process, high electric efficiency, or preferably a combination of those. Within the experimental section, the model is used to support the system design process of a biogas‐driven SOFC system with partial oxidation as reforming concept, without anode off‐gas recirculation. Since adjustable operating parameters are input into the model, the parameters' influence on efficiency and reforming conditions can be analyzed. With the model real system effects are investigated making it possible to reach a maximum gross electric efficiency of 0.55 with the real designed system.
Degradation Mechanism of Anode‐Supported Solid Oxide Fuel Cell In Planar‐Cell Channel‐Type Setup
Authors: Lim H.‐T. , Hwang S. C. , Jung M. G. , Park H. W. , Park M. Y. , Lee S.‐S. , Jung Y.‐G.
Published: July 2013

The degradation mechanism of anode‐supported planar solid oxide fuel cells is investigated in the present work. We fabricate a large‐area (10 cm × 10 cm) cell and carry out a long‐term test with the assembly components. A constant current of ∼0.4 A cm–2 is applied to the cell for ∼3,100 h, and the furnace temperature is controlled in the sequence 750–800–750 °C to investigate the effect of operating temperature and thermal cycling on the degradation rate. Impedance spectra and current–voltage characteristics are measured during the operation in order to trace any increase in Ohmic and non‐Ohmic resistance as a function of time. The degradation rate is rapid during the operation at the higher temperature of ∼800 °C compared to that during the operation at ∼750 °C. Even after cooling down to ∼750 °C, that rate is still accelerated. The main contribution to the cell degradation is from an increase in the Ohmic resistance. Postmaterial analyses indicate that the cathode is delaminated at the electrolyte/cathode interface, which is attributed to the difference in thermal expansion coefficient (TEC). Thus, the present results emphasize the importance of matching the TEC between cell layers, especially under severe operating conditions such as long duration and complex thermal cycling.