bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Nickel(II) Azacorroles by Pd‐Catalyzed Amination of α,α′‐Dichlorodipyrrin NiII Complex and Their Properties
Authors: Horie Miki , Hayashi Yosuke , Yamaguchi Shigeru , Shinokubo Hiroshi
Published: March 2012

Synthesis of nickel(II) complexes of meso‐aryl‐substituted azacorroles was performed by Buchwald–Hartwig amination of a dipyrrin NiII complex with benzylamine through CN and CC coupling. The highly planar structure of NiII azacorroles was elucidated by X‐ray diffraction analysis. 1H NMR analysis and nucleus independent chemical shift (NICS) calculation on NiII azacorrole revealed its distinct aromaticity with [17]triaza‐annulene 18π conjugation. In addition, acylation of azacorrole selectively afforded N‐ and C‐acylated azacorroles depending on the reaction conditions, showing the dual reactivity of azacorroles.
Numerical Methods for Dimensioning of Stirring Systems
Authors: Rohn Nicole , Stadtaus Marc , Himmelsbach Werner
Published: March 2012

Numerische Methoden nehmen einen festen Platz in der Auslegung von Rührsystemen ein. CFD beschreibt Strömungszustände im Rührbehälter und liefert Aussagen zum Prozessergebnis. Dynamische Belastungen von Bauteilen aufgrund der Rührerströmung lassen sich damit zuverlässig vorhersagen. Diese dienen als Eingangsgröße für die Berechnung von Spannungen oder Verformungen mittels FEM. Insbesondere turbulente Strömungen stellen dynamische Beanspruchungen dar, die Einbauten anregen und zur Resonanz bringen können. Solche Zustände lassen sich mit der Modalanalyse vorhersagen. Die beschriebenen Werkzeuge leisten damit einen wichtigen Beitrag zur betriebssicheren Auslegung und Effizienz der Produktionsanlagen.
Concept of correlation time, autocorrelation functions, and spectral densities of the tunneling jumps through the potential barrier
Authors: Latanowicz Lidia
Published: March 2012

The concept of the tunneling correlation time according to Schrödinger is presented. This tunneling jumps and the over the barrier jumps (Arrhenius type) correlation times are applied to calculate the autocorrelation functions and spectral densities of a complex motion. Complex motion means that the relaxation vector performs more than one motion. Two examples of temperature dependencies of a complex motion in a wide temperature regime are given. One example concerns the complex motion consisting of the fast hindered rotation of the methyl group which participates additionally in a slower isotropic motion. The other example concerns the complex motion consisting of the jumps of the proton–proton vector between the two sites in a double hydrogen bond as well as the jumps between other two equilibrium sites (librations of the whole molecule). The latter motion is assumed as slower than the concerted motion of two protons in a double hydrogen bond. In both examples the tunneling jumps are considered as a component of a complex motion. However, only the tunneling jumps of the faster motion are taken into account. Why the tunneling jumps of the slower motion are neglected is explained. The tunneling spectral density dominates only at low temperatures and contributes to the spectral density of the complex motion at intermediate temperatures up to Ttun temperature. The sense of Ttun temperature is explained. A comparison is made with the other theories of tunneling correlation time. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part A 40A: 66–79, 2012.
Relative intensities of components of quadrupolar‐split multiplets in NMR spectra: Rationale for a simple rule
Authors: Philp David J. , Naumann Christoph , Kuchel Philip W.
Published: March 2012

Nuclear magnetic resonance (NMR) spectra of quadrupolar nuclei in a uniformly anisotropic environment like a stretched gel usually display multiplets of resonances whose components have particular relative intensities. We present the multiplicities and relative integrals of the components of the quadrupolar‐split resonances in experimental NMR spectra of a series of quadrupolar nuclei in stretched gels. We give an intuitive explanation of the physical basis of the multiplicity and a simple mathematical formula that enables one to calculate the values of their relative intensities given the spin quantum number of the nuclei. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part A 40A: 90–99, 2012.
Fault‐tolerant programmable logic array for nanoelectronics
Authors: Flak Jacek , Laiho Mika
Published: March 2012

This paper presents the architecture for a nanoelectronic logic system in which a regular array of logic gates with programmable interconnections is accompanied by a data transmitter and receiver as well as program registers and a controller. Binary programmable interconnections assure system versatility by providing the means of computing different logic operations. They also allow setting the redundancy level via the number of columns clustered to compute a certain function. A system operation is explained and visualized with a number of examples. The embedded scheme of fault tolerance can effectively mitigate permanent, as well as transient, faults. Some implementation and performance aspects are approached through simulations of single‐electron tunneling structures. However, the proposed architectural concept is generic and can be applied to systems implemented with alternative nanotechnologies. Copyright © 2012 John Wiley & Sons, Ltd.
Distributed mapping management of identifiers and locators in mobile‐oriented Internet environment
Authors: Gohar Moneeb , Jung Heeyoung , Koh Seok‐Joo
Published: March 2012

Many schemes have recently been proposed for the separation of identifier (ID) and locator (LOC), which include the Host Identity Protocol, the Identifier‐Locator Network Protocol, and the Locator Identifier Separation Protocol. However, all of these schemes were originally designed in fixed network environment, rather than mobile network environment. In particular, these schemes are based on a centralized map server that is used as an anchor point for mobile nodes, and thus intrinsically subject to some limitations in a mobile environment. In this paper, we propose a distributed ID‐LOC mapping management scheme in a mobile‐oriented Internet environment. In the proposed scheme, we assume that a host has a globally unique and hierarchical Host ID (HID) that contains the information of its home network domain. Each network domain has a distributed map server for distributed management of ID‐LOC mappings. For roaming support, each distributed map server maintains its own home HID register and visiting HID register, which are used to keep the mappings of HID and LOCs for mobile nodes in the distributed manner. By performance analysis, it is shown that the proposed distributed scheme can give better performance than the existing centralized schemes in terms of ID‐LOC binding update and data delivery costs. Copyright © 2012 John Wiley & Sons, Ltd.
Comparison of hydraulic behaviour of unvegetated and vegetation‐stabilized sand dunes in arid desert ecosystems
Authors: Wang Xin‐ping , Quan Gui‐jing , Pan Yan‐xia , Hu Rui , Zhang Ya‐feng , Tedeschi Anna , Basile Angelo , Comegna Alessandro , Coppola Antonio , de Mascellis Roberto
Published: March 2012

Revegetation was one of most successful measures to restore desert sand dunes and to improve regional eco‐environments in the Tengger Desert, Northwest China. The potential for soil moisture replenishment by precipitation in the revegetation restored desert ecosystems is influenced strongly by the hydraulic properties of the surface soils. Steady‐state infiltration rates from tension disc infiltrometer were measured at revegetation restored desert soils (VS) and unvegetated sand dunes (SD), respectively. Results indicated that the site specific VS and SD hydraulic properties differed significantly. Compared with SD, the long term VS has the effect of decreasing the hydraulic conductivity of the surface soil, while increasing the capillary effect on the infiltration rate. Averagely, the hydraulic conductivity of VS was 0·43 times of SD at the near saturation conditions. At VS, tension infiltration were dominated by capillarity effect more than that of SD, which were ascribed to the differences in soil properties where the former has a higher amount of finer particles, organic matters content and lower bulk densities. Accordingly, the hydraulically functioning mean pore sizes were larger at SD, where the gravity effect dominated the tension infiltration process. Therefore, in the study area under the pulse precipitation events in the growing seasons, VS contains more soil water by capillarity effect than SD does, which would contribute to shallow rooted herbage and cryptogam water consumption. Nevertheless, looking at the whole soil profile, for the actual rainfall water regimes, VS has insignificant effects on the soil profile water regime, with unchanged deep fluxes. Copyright © 2012 John Wiley & Sons, Ltd.
Thermodynamic Discrimination in the Formation of Tetranuclear Lanthanide Helicates
Authors: Zebret Soumaila , Besnard Céline , Bernardinelli Gérald , Hamacek Josef
Published: March 2012

The complexation of lanthanide cations with a tripodal ligand bearing terminal ester functions was investigated. Thermodynamic speciation was achieved by a combination of different physicochemical methods, and the stability constants of the related complexes were determined spectrophotometrically. The formation of tetranuclear 3D edifices occurs preferentially with heavier lanthanides. Their molecular structure was confirmed by X‐ray crystallography. Solid‐state luminescence properties of the EuIII and TbIII compounds were also examined.
In Situ Dearomatisation/Alkylation of Arylphosphane Derivatives
Authors: Stankevič Marek , Wójcik Karolina , Jaklińska Magdalena , Pietrusiewicz K. Michał
Published: March 2012

The dearomatisation of aryldialkylphosphane–boranes and aryldialkylphosphane oxides under Birch reduction conditions, followed by treatment with reactive alkyl halides, provides the corresponding α‐functionalised (cyclohexa‐1,4‐dien‐3‐yl)phosphane derivatives. This reaction offers a method of choice for the synthesis of bulky (cyclohexadienyl)phosphanes.
Intramolecular Iodine‐Mediated Oxygen Transfer from Nitro Groups to C≡C Bonds
Authors: Cikotiene Inga
Published: March 2012

Highly regioselective oxygen transfer from nitro groups to C≡C bonds has been achieved by employment of iodine monochloride or molecular iodine. The precursors are heterocyclic, aromatic or acyclic compounds, each bearing a nitro group ortho to an internal alkyne. The developed methodology is general for the preparation of a wide range of fused isoxazoles, each bearing a carbonyl function in the fifth position in the isoxazole ring. It is very important to note that the outcomes of the cycloisomerizations are not dictated by the natures of the heterocycle or alkyne substituents. Moreover, this is a unique example of iodine‐mediated ring closure of internal alkynes without introduction of halogen into the newly formed rings.
Enantioselective β‐Vinylation of α,β‐Unsaturated Aldehydes Using a β‐Nitroethyl Sulfone as Vinyl Anion Equivalent
Authors: Gianelli Chiara , Lopez Rosa , Puente Ángel , Zalacain Maitane , Palomo Claudio
Published: March 2012

A concise method for the asymmetric β‐vinylation of enals is presented. The success of the reaction lies in the stereoselective organocatalyzed addition of β‐nitroethyl sulfone 1 to enals and in the ability of Mg to promote the concomitant elimination of the sulfone moiety and the nitrous acid. The method performed in a three‐step one‐pot operation allows the synthesis of enantioenriched β‐vinyl aldehydes and derivatives thereof.
Sensitive and fast determination of Sudan dyes in chilli powder by partial‐filling micellar electrokinetic chromatography–tandem mass spectrometry
Authors: Fukuji Tatiana S. , Castro‐Puyana María , Tavares Marina F. M. , Cifuentes Alejandro
Published: March 2012

A fast and sensitive method for the simultaneous determination of Sudan dyes (I, II, III, and IV) in food samples was developed for the first time using partial filling micellar electrokinectic chromatography‐mass spectrometry (MEKC‐MS). The use of MEKC was essential to achieve the separation of these neutral analytes, while the partial filling technique was necessary to avoid the contamination of the ion source with non‐volatile micelles. MEKC separation and MS detection conditions were optimized in order to achieve a fast, efficient, and sensitive separation of the four dyes. Filling 25% of the capillary with an MEKC solution containing 40 mM ammonium bicarbonate, 25 mM SDS, and 32.5% (v/v) acetonitrile, a baseline separation of the four azo‐dyes was obtained in 10 min. Tandem MS was investigated in order to improve the sensitivity and selectivity of the analysis. Limits of detection (LOD) values 5, 8, 15, and 29 times better were obtained for Sudan III, I, II, and IV, respectively, using partial filling MEKC‐MS/MS instead of partial filling MEKC‐MS. Under optimized conditions, LOD from 0.05 to 0.2 μg/mL were obtained. The suitability of the developed method was demonstrated through the fast and sensitive determination of Sudan I, II, III, and IV in spiked chilli powder samples. This determination could not be achieved by MEKC‐UV due to the existence of several interfering compounds from the matrix.
Comparative proteomic profiling of human lung adenocarcinoma cells (CL 1–0) expressing miR‐372
Authors: Lai Juo‐Hsin , She Tzu‐Fang , Juang Yu‐Min , Tsay Yeou‐Guang , Huang Ay‐Huey , Yu Sung‐Liang , Chen Jeremy J. W. , Lai Chien‐Chen
Published: March 2012

Lung cancer is a common malignancy and has a poor overall prognosis. Widespread metastasis is a common phenomenon in non‐small cell lung cancer (NSCLC). It has been demonstrated that cancer relapse and survival can be predicted by the presence of a five‐microRNA (miRNA) signature independent of stage or histologic type in NSCLC patients. Among the five miRNAs in the signature, miR‐372 has been shown to play a significant role in metastasis and in the development of human testicular germ cell tumors. In addition, there is evidence that miR‐372 posttranscriptionally downregulates large tumor suppressor, homolog 2 (Lats2), resulting in tumorigenesis and proliferation. To further investigate the cellular mechanisms involved in miR‐372‐induced silencing, we conducted a comparative proteomic analysis of NSCLC CL 1–0 cells expressing miRNA‐372 and/or vector only by using two‐dimensional gel electrophoresis (2DE), two‐dimensional difference gel electrophoresis (2D‐DIGE), and LC/MS/MS. Proteins identified as being up‐ or downregulated were further classified according to their biological functions. Many of the proteins identified in our study may be potential diagnostic biomarkers of NSCLC, particularly phosphorylated eIF4A‐I.
In‐depth performance investigation of a nano‐LC gradient generator
Authors: Siviero Antonella , Bergna Manuela , Famiglini Giorgio , Mantegazza Alessandra , Palma Pierangela , Cappiello Achille
Published: March 2012

An innovative approach for nano‐liquid chromatography (LC) gradient generation is presented. This system represents an optimized and refined version of a prototype proposed by the authors a few years ago: the current version is characterized by a new configuration that guarantees complete automation and easier operation. The core of the system is an electronically controlled, multiposition valve that hosts six loops, filled with different mobile phase compositions of increasing strength. A conventional flow rate of water is reduced at nano‐scale through a split device to push the content of the on‐line loop into the column. No mixing occurs between solvents inside the loops, due to the low flow rate and the reduced loop diameter. Valve actuation allows the selection of the on‐line loop to obtain the solvent gradient. The evaluation of the system performance takes into account gradient accuracy, precision, delay time, shape (linear, convex, or concave), and organic solvent consumption. Results highlight the reliability and the competitiveness of the system, especially in terms of accuracy and precision. A comparison between the described system and a conventional split‐based one demonstrates that the new approach reduces the solvent consumption by about 40 times, improving green chromatography and cutting laboratory costs.
Alignment of laser‐induced fluorescence and mass spectrometric detection traces using electrophoretic mobility scaling in CE‐LIF‐MS of labeled N‐glycans
Authors: Huhn Carolin , Ruhaak L. Renee , Mannhardt Joachim , Wuhrer Manfred , Neusüß Christian , Deelder André M. , Meyer Hans
Published: March 2012

The combination of optical detection techniques like photometry (UV) or laser‐induced fluorescence (LIF) with mass spectrometry for capillary electrophoresis offers advantages, both for later use of stand‐alone CE‐UV or CE‐LIF systems and for combined CE‐UV‐MS or CE‐LIF‐MS analysis. Faster method development is enabled, the identification of analytes is facilitated, and it allows christian the optical detection scheme to be used for more precise quantification. However, shortcomings of current methodology and equipment hindered the broader use of such detection combinations mainly due to the long distance between the detection points (at least 20 cm). Large shifts in migration times and changes in resolution are visible between the detection traces hindering their straightforward comparison. We present here novel equipment for a robust coupling of CE‐LIF‐MS with the shortest possible distance between detection points (12 cm) determined by the length of the electrospray needle. In addition, we encourage the use of a normalization of detection traces using a scale of effective electrophoretic mobility to obtain the same x‐scale for both detection traces. As an example, the proposed methodology is applied to a mixture of labeled as well as non‐labeled N‐glycans.
Microfluidic chip‐based liquid chromatography coupled to mass spectrometry for determination of small molecules in bioanalytical applications
Authors: Lin Shu‐Ling , Bai Hsin‐Yu , Lin Tzuen‐Yeuan , Fuh Ming‐Ren
Published: March 2012

The development and integration of microfabricated liquid chromatography (LC) microchips have increased dramatically in the last decade due to the needs of enhanced sensitivity and rapid analysis as well as the rising concern on reducing environmental impacts of chemicals used in various types of chemical and biochemical analyses. Recent development of microfluidic chip‐based LC mass spectrometry (chip‐based LC‐MS) has played an important role in proteomic research for high throughput analysis. To date, the use of chip‐based LC‐MS for determination of small molecules, such as biomarkers, active pharmaceutical ingredients (APIs), and drugs of abuse and their metabolites, in clinical and pharmaceutical applications has not been thoroughly investigated. This mini‐review summarizes the utilization of commercial chip‐based LC‐MS systems for determination of small molecules in bioanalytical applications, including drug metabolites and disease/tumor‐associated biomarkers in clinical samples as well as adsorption, distribution, metabolism, and excretion studies of APIs in drug discovery and development. The different types of commercial chip‐based interfaces for LC‐MS analysis are discussed first and followed by applications of chip‐based LC‐MS on biological samples as well as the comparison with other LC‐MS techniques.
Analysis of drugs of forensic interest with capillary zone electrophoresis/time‐of‐flight mass spectrometry based on the use of non‐volatile buffers
Authors: Gottardo Rossella , Mikšík Ivan , Aturki Zeineb , Sorio Daniela , Seri Catia , Fanali Salvatore , Tagliaro Franco
Published: March 2012

he present work is aimed at investigating the influence of the background electrolyte composition and concentration on the separation efficiency and resolution and mass spectrometric detection of illicit drugs in a capillary zone electrophoresis‐electrospray ionization‐time of flight mass spectrometry (CZE‐ESI‐TOF MS) system. The effect of phosphate, borate and Tris buffers on the separation and mass spectrometry response of a mixture of 3,4‐methylenedioxyamphetamine, 3,4‐methylenedioxymethamphetamine, methadone, cocaine, morphine, codeine and 6‐monoacetylmorphine was studied, in comparison with a reference ammonium formate separation buffer. Inorganic non‐volatile borate and Tris buffers proved hardly suitable for capillary electrophoresis‐mass spectrometry (CE‐MS) analysis, but quite unexpectedly ammonium phosphate buffers showed good separation and ionization performances for all the analytes tested. Applications of this method to real samples of hair from drug addicts are also provided.
CE‐ESI‐MS separation of divalent organic and inorganic anions using a tricationic complexing reagent
Authors: Gerardi Anthony R. , Lin Xiuli , Breitbach Zachary S. , Armstrong Daniel W. , Colyer Christa L.
Published: March 2012

A tricationic ion‐pairing reagent, 1,3,5‐1‐butyl‐3‐methyl‐1H‐imidazol‐3‐ium‐2,4,6‐trimethylbenzene, was used to form complexes with doubly charged anions for their subsequent analysis by capillary electrophoresis‐electrospray ionization‐mass spectrometry (CE‐ESI‐MS) in the positive‐ion mode. This methodology offers the advantages of greater versatility and sensitivity relative to direct detection of the anions in negative‐ion mode, and it can be realized by a number of possible complexation strategies, including pre‐column, on‐column, and post‐column modes. Three model anions, sulfate [SO42−], thiosulfate [TSFA, S2O32−], and benzenedisulfonate [BZDS, C6H4(SO3)22−], were amenable to complexation with the tricationic reagent, yielding singly charged cations with greater mass‐to‐charge (m/z) ratios than the native analytes. By utilizing optimized parameters obtained through previous work with dicationic reagents and singly charged anions, including the CE separation buffer composition and pH, the concentration of the dicationic reagent, the mode of complexation, the nebulizing gas pressure, and the sheath liquid composition, it was possible to develop a robust CE‐ESI‐MS method appropriate for the analysis of divalent anions in a mixture.
An optimized electrochemistry‐liquid chromatography‐mass spectrometry method for studying guanosine oxidation
Authors: Erb Robert , Plattner Sabine , Pitterl Florian , Brouwer Hendrik‐Jan , Oberacher Herbert
Published: March 2012

Oxidative stress can disrupt the integrity of genetic material. Due to its importance in the pathogenesis of different kinds of disease, including neurodegenerative disease, cardiovascular disease and cancer, major efforts are put into the elucidation of mechanisms involved. Herein, the combination of electrochemistry/liquid chromatography/mass spectrometry (EC/LC/MS) is presented as convenient, fast and simple method to study nucleic acids oxidation. Guanosine was selected as test compound. 8‐Hydroxyguanosine and (guanosine‐H)2 were identified as primary oxidation products. Oxidation was accomplished in an electrochemical thin‐layer cell integrated in the flow path of the autosampler of the chromatographic system. The reaction mixture was separated and mass analyzed by LC/MS. The use of LC was found to be particularly beneficial to resolve isobaric oxidation products. Another advantage of the setup used was the ability to decouple the electrochemical cell and the electrospray ionization source from each other eliminating any kind of cell potential interaction. Separation of EC from LC/MS, furthermore, facilitates method optimization. Experimental parameters were optimized for both techniques independently. Highest yields and best detectability of oxidation products were obtained with 10 mM ammonium formate at physiological pH delivered at a flow rate of 2.5‐5 μL/min through the electrochemical cell.
A neurosteroid analogue photolabeling reagent labels the colchicine‐binding site on tubulin: A mass spectrometric analysis
Authors: Chen Zi‐Wei , Chen Li‐Hai , Akentieva Natalia , Lichti Cheryl F. , Darbandi Ramin , Hastings Randy , Covey Douglas F. , Reichert David E. , Townsend R. Reid , Evers Alex S.
Published: March 2012

Previous studies have shown that the neurosteroid analogue, 6‐Azi‐pregnanolone (6‐AziP), photolabels voltage‐dependent anion channels and proteins of approximately 55 kDa in rat brain membranes. The present study used two‐dimensional electrophoresis and nanoelectrospray ionization ion‐trap mass spectrometry (nano‐ESI‐MS) to identify the 55 kDa proteins (isoelectric point 4.8) as isoforms of β‐tubulin. This identification was confirmed by immunoblot and immunoprecipitation of photolabeled protein with anti‐β‐tubulin antibody and by the demonstration that 6‐AziP photolabels purified bovine brain tubulin in a concentration‐dependent pattern. To identify the photolabeling sites, purified bovine brain tubulin was photolabeled with 6‐AziP, digested with trypsin, and analyzed by matrix‐assisted laser desorption/ionization MS (MALDI). A 6‐AziP adduct of TAVCDIPPR(m/z = 1287.77), a β‐tubulin specific peptide, was detected by MALDI. High‐resolution liquid chromatography‐MS/MS analysis identified that 6‐AziP was covalently bound to cysteine 354 (Cys‐354), previously identified as a colchicine‐binding site. 6‐AziP photolabeling was inhibited by 2‐methoxyestradiol, an endogenous derivative of estradiol thought to bind to the colchicine site. Structural modeling predicted that neurosteroids could dock in this colchicine site at the interface between α‐ and β‐tubulin with the photolabeling group of 6‐AziP positioned proximate to Cys‐354.
Poly(glycidyl methacrylate‐divinylbenzene) based immobilized pH gradient capillary isoelectric focusing coupling with MALDI mass spectrometry for enhanced neuropeptide analysis
Authors: Zhang Zichuan , Wang Junhua , Hui Limei , Li Lingjun
Published: March 2012

Herein, we report an immobilized pH gradient (IPG) capillary isoelectric focusing‐matrix‐assisted laser desorption/ionization mass spectrometry (CIEF‐MALDI MS) platform designed for the separation of complex neuropeptides. This platform features a poly(glycidyl methacrylate‐divinylbenzene) (GMA‐DVB)‐based monolithic column for CIEF separation. Different from regular CIEF, carrier ampholytes are preimmobilized on the monolithic surface instead of being added to the sample. An off‐line coupling of IPG‐CIEF to MALDI MS has been established. Comparison with regular CIEF and optimizations are performed with bovine serum albumin tryptic peptides and extracted neuropeptide mixtures from crustacean Callinectes sapidus. It has been demonstrated that the separation of complex peptide mixtures in neutral and basic pH ranges can be achieved in less than 10 min with comparable separation efficiency with regular CIEF, while the MS signal is significantly enhanced when employing IPG‐CIEF. Enhanced neuropeptide detection is also observed after coupling IPG‐CIEF with MALDI MS.
Estimating return levels from serially dependent extremes
Authors: Fawcett Lee , Walshaw David
Published: March 2012

In this paper, we investigate the relationship betweenreturn levelsof a process and the strength of serial correlation present in the extremes of that process. Estimates of long period return levels are often used as design requirements, andpeaks over thresholdsanalyses have, in the past, been used to obtain such estimates. However, analyses based on such declustering schemes are extremely wasteful of data, often resulting in great estimation uncertainty represented by very wide confidence intervals. Using simulated data, we show that—provided theextremal indexis estimated appropriately—usingallthreshold excesses can give more accurate and precise estimates of return levels, allowing us to avoid altogether the sometimes arbitrary process of cluster identification. We then apply our method to two data examples concerning sea‐surge and wind‐speed extremes. Copyright © 2012 John Wiley & Sons, Ltd.
Degradation of aniline catalyzed by heterogeneous Fenton‐like reaction using iron oxide/SiO2
Authors: Huang Yao‐Hui , Su Chia‐Chi , Yang Yun‐Pei , Lu Ming‐Chun
Published: March 2012

The immobilized iron oxides on quartz granules (SG) were withdrawn from the fluidized bed reactors and then used to catalyze hydrogen peroxide (H2O2) from heterogeneous generating hydroxyl radical (•OH). The effects of the reaction conditions including the initial pH, SG loading, and concentrations of aniline on aniline degradation were examined. The experimental result showed that the decomposition of H2O2 decreased with increased concentrations of H2O2 once the concentration of H2O2 increased to more than 0.05 M. The rate constant of aniline degradation (kobs) increased when increasing amounts of SG were added. The evidence proved the initial pH = 4–6 in the solution is an optimum condition for the degradation of aniline using SG as a heterogeneous catalyst. The aniline degradation suggested that •OH initially attacked the aromatic ring‐NH2 bonding of aniline, and the ring opening of aniline was then formed. Results demonstrate that the iron oxides are recyclable, cheaper, and more active. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 187‐192, 2013
Biosorption and bioaccumulation studies of acid Orange 7 dye by Ceratophylum demersum
Authors: Daneshvar Ehsan , Kousha Masoud , Koutahzadeh Negin , Sohrabi Mohammad Salar , Bhatnagar Amit
Published: March 2012

Biosorption and bioaccumulation studies of acid orange 7 (AO7) dye by an aquatic plant, C. demersum, were investigated in the present work. The effects of different parameters such as, initial solution pH (2–11), initial dye concentration (30–90 mg/L), contact time (5–150 min), biomass dosage (1.8–23.4 g/L for living and 0.2–2.6 g/L for nonliving or dried plant) and salt concentration (0.5–20 g/L) on the decolorization of AO7 dye were investigated by batch method. The efficiency of both leaf and stem of the living plant was also assessed for the dye removal. Living plant of C. demersum exhibited higher decolorization potential as compared with the dried plant which might be attributed to the active metabolism of the former. The sorption kinetic data were successfully described with pseudo‐second order model for living and dried plant. Thermodynamic studies revealed that the sorption process is endothermic in nature at studied temperature range of 283–313 K. These findings revealed that aquatic plant, C. demersum, can be a suitable alternative for decolorization of AO7 dye from aqueous solution. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 285‐293, 2013
Rapid screening of catalytic pyrolysis reactions of Organosolv lignins with the vTI‐mini fast pyrolyzer
Authors: Choi Hang Seok , Meier Dietrich , Windt Michael
Published: March 2012

The vTI‐mini fast pyrolyzer was applied for screening fast pyrolysis reactions of different Organosolv lignins, such as Alcell (Repap Technologies) and lignin from a German biorefinery project. To investigate the catalytic effects on the pyrolysis of the technical lignins, three catalysts such as zeolite HZSM‐5, FCC, and Olivine were used. The catalytic pyrolysis characteristics and decomposition products of the Organosolv lignins were scrutinized by varying pyrolysis temperature and catalyst type. From the pyrolysis experiments, obtained pyrolyzed products were generally categorized into three parts such as coke, noncondensable gas, and biocrude oil. To evaluate the yield of biocrude oil, mass balances of products and reactants were established and the collected biocrude oil was analyzed by GC/MS. From the results, the increase or decrease patterns of certain chemical compounds were found according to the different pyrolysis temperatures as well as various catalysts. In particular, size exclusion chromatography (SEC) was performed for extracts of the solid residue to get information on the catalytic effect and severity of lignin degradation. © 2012 American Institute of Chemical Engineers Environ Prog, 2012
Optimal source–sink matching in carbon capture and storage systems with time, injection rate, and capacity constraints
Authors: Tan Raymond R. , Aviso Kathleen B. , Bandyopadhyay Santanu , Ng Denny K. S.
Published: March 2012

Carbon capture and storage (CCS) involves capturing relatively pure carbon dioxide (CO2) from gaseous combustion products and storing it in various reservoirs. In this work, a multiperiod mixed integer linear programming model focusing primarily on physical and temporal considerations of CO2 source–sink matching is proposed. CO2 sources are assumed to be characterized by variable flow rates and fixed operating lives; on the other hand, CO2 sinks are characterized by finite injection rate and storage capacity limits, as well as earliest time of availability. The proposed approach takes into account important temporal issues that may be encountered in planning the CCS system, particularly when the operating lives of sources and sinks do not completely overlap. Two illustrative case studies are then solved to illustrate the use of the model to realistic CCS planning problems. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 411‐416, 2013
Mineral nutrient recovery from pyrolysis systems
Authors: Wise Jatara , Vietor Donald , Provin Tony , Capareda Sergio , Munster Clyde , Boateng Akwasi
Published: March 2012

Bioenergy plants such as sorghum, bioenergy rice, corn stover, and switchgrass can be thermochemically converted by pyrolysis to produce bio‐oil, synthesis gas from noncondensable gases, and biochar. The biochar fraction can be recycled back to the production field to improve soil physical qualities and nutrient status. Although previous publications have described the beneficial effects of pyrolysis biochar on soil physical properties; relatively little has been published on the recovery of mineral nutrients from pyrolysis co‐products. This work quantified the recovery of nutrients (P, K, Ca, and Mg) from pyrolysis coproducts from various feedstocks using two distinct reactors. Nutrient mass balances, on a feedstock basis, were calculated for comparison of the two reactors' efficiency in the recovery of the nutrients. The results revealed the recovery of nutrients varied by (1) species, (2) reactor design, and (3) correlated highly with nutrient mass loss in biochar. Computations also revealed P recoveries of 93% (fixed‐bed reactor) and 58% and 55% (fluidized‐bed reactor) for pyrolyzed sorghum. The recovery of key mineral nutrients in pyrolysis coproducts (primarily biochar) is directly related to the feasibility of nutrient recycling through biochar. © 2012 American Institute of Chemical Engineers Environ Prog, 2012
Adsorption of Pb(II) ions onto surface modified Guazuma ulmifolia seeds and batch adsorber design
Authors: Rajkumar P. , Senthil Kumar P. , Dinesh Kirupha S. , Vidhyadevi T. , Nandagopal J. , Sivanesan S.
Published: March 2012

This article reports the removal of Pb(II) ions from aqueous solution by the surface modified Guazuma ulmifolia (SMGU) seeds as an adsorbent and this material was prepared by treating the Guazuma ulmifolia seeds with sulphuric acid. The effectiveness of the SMGU has been investigated as a function of solution pH, adsorbent dose, contact time, and initial Pb(II) ion concentration. The Pb(II) adsorption was favored with maximum adsorption at pH 6.0. The Pb(II) adsorption equilibrium was attained within 60 min. The experimental data were analyzed using the Langmuir and Freundlich isotherm equations. The equilibrium data fit wellthe Freundlich isotherm. The experimental data were analyzed using four adsorption kinetic models: the pseudo‐first‐order and pseudo‐second‐order equations, the Elovich equation, and intraparticle diffusion equation to determine the best fit equation for the adsorption of Pb(II) ions onto SMGU. The characteristic parameters for each kinetic model have been determined and the coefficient of determination have been calculated to assess which model provides the best fit predicted data with experimental results. The kinetic results show that the pseudo‐second‐order equation provides the best correlation for the adsorption process. The nature of the possible adsorbent and metal ion interactions was examined by the FTIR technique. Surface morphological study was also done using BET and scanning electron microcopy analysis. The equilibrium data were applied for a single‐stage batch adsorber design. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 307‐316, 2013
Secondary reactions of levoglucosan and char in the fast pyrolysis of cellulose
Authors: Ronsse Frederik , Bai Xianglan , Prins Wolter , Brown Robert C.
Published: March 2012

In fast pyrolysis of cellulose, levoglucosan is often reported as the most abundant primary decomposition product. Char, the solid residue of pyrolysis is thought to catalyze secondary reactions that decompose levoglucosan into water and additional, secondary char. A CDS Analytical Pyroprobe 5200 was used to pyrolyze pure cellulose to levoglucosan and the generated vapors were passed through a temperature‐controlled tubular reactor filled with material to be tested for catalytic activity and then to a GC‐FID for analysis. Carbonaceous materials included as‐received and acid‐washed char derived from pyrolysis of red oak and, pure graphite. Acid‐washed red oak char and pure graphite had little effect on levoglucosan decomposition compared with the empty tubular reactor for the range of tubular reactor temperatures studied (200–400°C). In contrast, unwashed red oak char significantly reduced the amount of levoglucosan when the tubular reactor was operated above 300°C. These results suggest that metals—which are removed through the procedure of acid washing—rather than the fixed carbon in the char, catalyze the decomposition of levoglucosan in the vapor phase. © 2012 American Institute of Chemical Engineers Environ Prog, 2012
Application of atomic force microscopy for characterizing membrane biofouling in the micrometer and nanometer scales
Authors: Zaky Amr M. , Escobar Isabel C. , Gruden Cyndee L.
Published: March 2012

Despite the availability of new detection and monitoring methods, a complete understanding of biofouling is still lacking. Therefore, this study employed a combination of biofilm characterization protocols macro, micro, and nano (meter) scales to provide insight into the early stages of biofilm formation using cellulose acetate ultrafiltration membranes. Membranes were fouled during 53 hours of crossflow filtration using two distinct feed waters. Biofilm characterization techniques included flux decline, image analysis, and atomic force microscopy (AFM). The flux decline and image analysis (bulk biofilm surface area coverage) data could not be correlated with feed water characteristics. Using AFM, it was possible to provide feature height analyses on the nano‐ scale to verify distinct biofilm distribution and formation as function of feed water characteristics. These findings suggest that AFM‐based biofilm characterization may provide the details needed to distinguish variations in cell deposition on a single membrane surface and/or between varied feed waters. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 449–457, 2013
Lactones 38: Synthesis and odoriferous properties of p‐menthane lactones
Authors: Dams Iwona , Białońska Agata , Ciunik Zbigniew , Wawrzeńczyk Czesław
Published: March 2012

An enantiomeric pair of bicyclic δ‐lactones with the p‐menthane system was obtained from enantiomerically pure isomers of (1R,2S,5R)‐(–) and (1S,2R,5S)‐(+)‐isopulegol. The Horner–Wadsworth–Emmons olefination of isopulegones followed by hydrolysis of esters and lactonization of acids were the key steps of the syntheses presented. The structures of the compounds were determined by both spectroscopic and crystallographic methods. Enantiomeric p‐menthane esters and δ‐lactones are characterized by interesting odoriferous properties. Copyright © 2012 John Wiley & Sons, Ltd.
Application of the Jacobi–Davidson method to accurate analysis of singular linear hydrodynamic stability problems
Authors: Gheorghiu C.I. , Rommes J.
Published: March 2012

The aim of this paper is to show that the Jacobi–Davidson (JD) method is an accurate and robust method for solving large generalized algebraic eigenvalue problems with a singular second matrix. Such problems are routinely encountered in linear hydrodynamic stability analysis of flows that arise in various areas of continuum mechanics. As we use the Chebyshev collocation as a discretization method, the first matrix in the pencil is nonsymmetric, full rank, and ill‐conditioned. Because of the singularity of the second matrix, QZ and Arnoldi‐type algorithms may produce spurious eigenvalues. As a systematic remedy of this situation, we use two JD methods, corresponding to real and complex situations, to compute specific parts of the spectrum of the eigenvalue problems. Both methods overcome potentially severe problems associated with spurious unstable eigenvalues and are fairly stable with respect to the order of discretization. The real JD outperforms the shift‐and‐invert Arnoldi method with respect to the CPU time for large discretizations. Three specific flows are analyzed to advocate our statements, namely a multicomponent convection–diffusion in a porous medium, a thermal convection in a variable gravity field, and the so‐called Hadley flow. Copyright © 2012 John Wiley & Sons, Ltd.
Quantile Regression Analysis of the Asymmetric Return‐Volatility Relation
Authors: Badshah Ihsan Ullah
Published: March 2012

We use quantile regression to investigate the short‐term return‐volatility relation between stock index returns and changes in implied volatility index. Neither the leverage hypothesis nor the volatility feedback hypothesis effectively explains the asymmetric return‐volatility relation. Instead, behavioral explanations, such as the affect and representativeness heuristics, are supported by our results, particularly in the short‐term; the affect heuristic plays an important role. Moreover, in the context of an extreme volatility change distribution, the affect heuristic and time‐pressure dominate. Thus, we observe strong negative and asymmetric relations between each volatility index and its corresponding stock market index. The asymmetry increases monotonically from the median quantile to the uppermost quantile (i.e., 95%); therefore, ordinary least squares (OLS) regression underestimates this relation at upper quantiles. Additionally, the VIX presents the highest asymmetric return‐volatility relation, followed by the VSTOXX, VDAX, and VXN. Finally, the observed asymmetry is more pronounced with the new volatility index measure than with the old, at‐the‐money volatility index measure. © 2012 Wiley Periodicals, Inc. Jrl Fut Mark 33:235–265, 2013
Neuroplasticity‐based computerized cognitive remediation for geriatric depression
Authors: Morimoto Sarah Shizuko , Wexler Bruce E. , Alexopoulos George S.
Published: March 2012

Objective

This article describes a novel treatment model designed to target specific neurocognitive deficits in geriatric depression with neuroplasticity‐based computerized cognitive remediation (NBCCR).

Method

The recent National Institute of Mental Health (NIMH) report “From Discovery to Cure” calls for studies focusing on mechanisms of treatment response with the goal of arriving at new interventions for those who do not respond to existing treatments. We describe the process that led to the identification of specific executive deficits and their underlying neurobiology, as well as the rationale for targeting these symptoms as a part of a strategy intended to improve both executive dysfunction and depression. We then propose a strategy for further research in this emerging area

Results and Conclusions

Despite significant developments, conventional antidepressant treatments leave many older adults still depressed and suffering. Psychotherapy may be effective in some depressed elders, although a recent review concluded that none of the available treatment studies meets stringent criteria for efficacy in the acute treatment of geriatric depression. Appropriately developed and targeted NBCCR, has the potential to serve as a novel treatment intervention for geriatric depression. Pathophysiological changes associated with executive dysfunction may be an appropriate target for NBCCR. Examining both behavioral changes and indices of structural integrity and functional change of networks related to cognitive and emotional regulation may lead to a novel treatment and elucidate the role of specific cerebral networks in geriatric depression. Copyright © 2012 John Wiley & Sons, Ltd.
Neurocognitive functioning in early‐onset and late‐onset older patients with euthymic bipolar disorder
Authors: Martino Diego J. , Strejilevich Sergio A. , Manes Facundo
Published: March 2012

Objective

Most neurocognitive studies have not taken into account the fact that older patients with bipolar disorder (BD) are a heterogeneous population. The main goal of this study was to compare neurocognitive performance and extrapyramidal symptoms in older patients with early‐onset BD (EO‐BD) and late‐onset BD (LO‐BD).

Methods

Euthymic older patients with EO‐BD (n = 20), LO‐BD (n = 20), and healthy controls (n = 20) were evaluated with traditional clinical instruments and measures of exposure to psychotropic drugs, as well as extrapyramidal symptoms. All subjects completed an extensive neuropsychological battery.

Results

Patients with EO‐BD showed poorer performance than healthy controls in two measures of verbal memory and two measures of executive functions, whereas patients with LO‐BD exhibited lower performance scores than healthy controls in almost all of the measures assessed. Impairments in the LO‐BD group included even neurocognitive domains typically spared in mixed‐age patients. Additionally, there was a trend toward displaying higher extrapyramidal symptoms in the LO‐BD group compared with both EO‐BD and healthy control groups. In both patient groups, psychosocial functioning was related with executive dysfunction and extrapyramidal symptoms.

Conclusions

Patients with LO‐BD may have more extensive and severe cognitive impairments, as well as higher vulnerability to extrapyramidal symptoms, compared with patients with EO‐BD. Cognitive–motor disturbances may help to explain impairments in daily functioning among older patients with EO‐BD and LO‐BD during remission. Copyright © 2012 John Wiley & Sons, Ltd.
Estimates of changes in design rainfall values for Canada
Authors: Burn Donald H. , Taleghani Amir
Published: March 2012

Annual maximum rainfall data from 51 stations in Canada were analyzed for trends and changes by using the Mann–Kendall trend test and a bootstrap resampling approach, respectively. Rainfall data were analyzed for nine durations ranging from 5 min to 24 h. The data analyzed are typically used in the development of intensity‐duration‐frequency (IDF) curves, which are used for estimating design rainfall values that form an input for the design of critical water infrastructure. The results reveal more increasing than decreasing trends and changes in the data with more increasing changes and larger changes, noted for the longer rainfall durations. The results also indicate that a traditional trend test may not be sufficient when the interest is in identifying changes in design rainfall quantiles. Copyright © 2012 John Wiley & Sons, Ltd.