bluuebunny/crossref_metadata_2025 huggingface dataset:
On‐site characterisation and energy efficiency of grid‐connected PV inverters
Authors: Muñoz J. , Martínez‐Moreno F. , Lorenzo E.
Published: July 2010

The size of inverters in large grid‐connected photovoltaic (PV) systems is increasing. At present, the largest installed inverters have nominal powers of several hundreds of kW, which makes their characterisation in the laboratory difficult. As an alternative, on‐site characterisation requires only measurement equipment and has the advantage that the inverter is tested in its own PV system under real operating conditions. This paper describes an on‐site testing procedure for assessing the power efficiency of an inverter and the results obtained for 13 inverters with nominal powers between 3.3 and 350 kW. The inverters were tested in PV grid‐connected systems whose aggregate power capacity is nearly 150 MW. The energy efficiency of the inverters tested was also calculated yearly, and the results were compared with both European and Californian energy efficiency parameters, which are widely used in the current PV market. Copyright © 2010 John Wiley & Sons, Ltd.
Solvolyses of 4‐methylbenzenediazonium ions in trifluoroethanol/water mixtures: Effects of [TFE], acidity and temperature on the kinetics and mechanism of the reaction
Authors: Fernández‐Alonso Alejandra , Bravo‐Díaz Carlos
Published: July 2010

We studied the solvolyses of 4‐methylbenzenediazonium (4MBD) ions in 2,2,2‐trifluoroethanol (TFE) – water mixtures by employing a combination of spectrometric (UV–VIS) and chromatographic (high performance liquid chromatography (HPLC)) techniques. HPLC analyses of the reaction mixtures show that very small amounts (<8%) of the reduction product toluene, ArH, are obtained, suggesting that the reaction occurs primarily through a heterolytic mechanism. Kinetic results show that kobs values do not change significantly on changing solvent composition, which means that nucleophilic attack by solvent is not involved in the rate‐limiting step of the reaction. On lowering the acidity, both kobs values and product distributions remained basically unchanged, suggesting that diazo ethers do not form in TFE, in contrast with the behaviour found in alcohols such as MeOH, EtOH or BuOH. In these reactions, the results support the formation of diazo ethers, ArNNOR. To obtain additional evidence for the ionic mechanism, we determined the effect of temperature on kobs at different acidities and calculated the corresponding activation parameters. ΔH‡ values are high compared to those of bimolecular and radical reactions, and ΔS‡ values are small, but positive. The results are consistent with the traditional heterolytic DN + AN dediazoniation with a rate‐determining formation of a highly reactive aryl cation that traps any nucleophile available in its solvation shell. Copyright © 2010 John Wiley & Sons, Ltd.
CH bond activation of ethylene by bare neutral palladium and platinum atoms: a theoretical investigation
Authors: Li Tao Hong , Wang Chuan Ming , Xie Xiao Guang
Published: July 2010

The reactions of bare neutral palladium (Pd) and platinum (Pt) atoms with ethylene on both singlet and triplet surfaces were investigated at B3LYP and CCSD (T) levels of theory. The calculated potential energy profiles clearly show that Pt has higher reactivity than Pd toward ethylene. For both Pd and Pt, the reactions on singlet surfaces are energetically more favorable than those on triplet surfaces. However, notable barriers lie on the singlet and triplet surfaces for Pd +ethylene. This result rationalizes the experimental observation that Pd mainly forms π‐complex with ethylene. But under high‐energy condition, the reaction can proceed to yield dehydrogenation products, Pd‐CCH. and Pd (HCCH). For Pt, triplet‐singlet surface crossing was suggested to occur in the region where Pt forms π‐complex with ethylene to lead the reactions to the energetically more favorable singlet surfaces. For both the two metals, π‐complex and CH bond insertion species are the reaction intermediates and the H.‐elimination products are the final products. Copyright © 2010 John Wiley & Sons, Ltd.
A wide mechanistic spectrum observed in three different reactions with organometallic reagents
Authors: Rodríguez Cristian , Vázquez Alvaro Joaquin , Nudelman y Norma Sbarbati
Published: July 2010

The halogen–lithium exchange reaction is of one of the most powerful method for the preparation of organolithium compounds, but its mechanism is still controversial. To afford some new elements, we synthesized a new suitable fast radical clock, bearing a phenyl group at the alkene C‐terminal. The examination of some mechanistic clues, as well as the identification of the unexpected by‐products allowed the conclusion that the reaction proceeds by a polar mechanism and no evidence for radicals were found. The second reaction discussed is the insertion of NO in the NLi bond of lithium amides. Evidence for the involving of paramagnetic and nitrosonium intermediates, as well as equilibria between different reactive species were essential for the proposal of a whole complex mechanism, which was confirmed by theoretical calculations. Finally, results on the addition of heteroaromatic organocuprates to α,β‐unsaturated substrates are presented. Several reaction conditions were looked for to lead the reaction toward the more interesting 1,4‐conjugated addition. Thus, addition of up to 6 equivalents of TMSCl to the reaction with arylcuprates leads to a clean addition yielding more than 95% of the 1,4‐addition product. A further objective of the paper is to show how the search of unexpected routes of reaction allowed developing original pathways to lead them toward the formation of appealing functionalized compounds. Copyright © 2010 John Wiley & Sons, Ltd.
Controlled cationic polymerization of styrene using AlCl3OBu2 as a coinitiator: Toward high molecular weight polystyrenes at elevated temperatures
Authors: Frolov Alexander N. , Kostjuk Sergei V. , Vasilenko Irina V. , Kaputsky Fyodor N.
Published: July 2010

The controlled cationic polymerization of styrene using CumOH/AlCl3OBu2/Py initiating system in a mixture CH2Cl2/n‐hexane 60/40 v/v at −40 and −60 °C is reported. The number‐average molecular weights of the obtained polystyrenes increased with increasing monomer conversion (up to Mn = 85,000 g mol−1) although experimental values of Mn were higher than the theoretical ones at the beginning of the reaction that was ascribed to slow exchange between reversible‐terminated and propagating species. The molecular weight distribution became narrower through the reaction and leveled of at the value of Mw/Mn = 1.8–2.0. A kinetic investigation revealed that the rate of polymerization was first‐order in AlCl3OBu2 concentration meaning that monomeric counteranion (AlCl3OH− or AlCl) involved in the initiation and propagation steps of the reaction. It was also found that the rate of polymerization decreased with lowering temperature, which could be attributed to a decrease in concentration of free Lewis acid (AlCl3), the true coinitiator of polymerization, because of an increase in the tightness of its complex with dibutyl ether. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3736–3743, 2010
Development of reactive methacrylates based on glycidyl methacrylate
Authors: Karahan Ozlem , Aydin Kinyas , Edizer Seda , Odabasi Nihan , Avci Duygu
Published: July 2010

Six methacrylate monomers have been synthesized for use as reactive diluents in dental composites and evaluated to investigate the relationship between molecular structure and monomer reactivity. Four were synthesized by reactions of glycidyl methacrylate (GMA) with various acids, 2‐(2‐methoxyethoxy)acetic acid (1), 2‐(2‐(2‐methoxyethoxy)ethoxy)acetic acid (2), cyanoacetic acid (3), and benzoic acid (4); others were synthesized by reactions of GMA with diethyl hydrogen phosphate (5) or methanol (6). Monomers 1 and 2 are novel, 3 seems to be novel, 4 and 6 were synthesized via a novel method, and the synthesis of 5 was described in the literature. The monomers showed high crosslinking tendencies during thermal bulk polymerizations. The photo‐, homo‐, and copolymerization behavior of the monomers with 2,2‐bis[4‐(2‐hydroxy‐3‐methacryloyloxy)phenyl]propane (Bis‐GMA) were investigated. The maximum rate of polymerizations of monomers 2–6 was found to be greater than triethyleneglycol dimethacrylate, Bis‐GMA, 2‐hydroxyethyl methacrylate, and glycerol dimethacrylate. For the more reactive monomers (2, 3, and 4), the oxygen sensitivity of polymerization was found to be low due to a hydrogen abstraction/chain transfer reaction. The computationally calculated dipole moment and lowest unoccupied molecular orbital energies indicated that there seems to be a correlation between these quantities and reactivity for ester linked monomers (1–5), which was also supported by 13C NMR data. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3787–3796, 2010
Investigation of thiol‐ene addition reaction on poly(isoprene) under UV irradiation: Synthesis of graft copolymers with “V”‐shaped side chains
Authors: Wang Guowei , Fan Xiaoshan , Huang Junlian
Published: July 2010

Poly(isoprene) (PI) with pendant functional groups was successfully synthesized by thiol‐ene addition reaction under 365 nm UV irradiation, and the functionalized PI was further modified and used to prepare graft copolymers with “V”‐shaped side chains. First, the pendant SCH2CH(OH)CH2OH groups were introduced to PI by thiol‐ene addition reaction between 1‐thioglycerol and double bonds, and the results showed that the addition reaction carried out only on double bonds of 1,2‐addition isoprene units. After the esterification of hydroxyl groups by 2‐bromoisobutyryl bromide, the forming macroinitiator was used to initiate the atom transfer radical polymerization (ATRP) of styrene (St) and tert‐butyl acrylate (tBA), and the graft copolymers PI‐g‐PS2 and PI‐g‐PtBA2 or PI‐g‐PAA2 (by hydrolysis of PI‐g‐PtBA2) were obtained, respectively. It was confirmed that the graft density of side chains on PI main chains could be easily controlled by variation of the contents of modified 1,2‐addition isoprene units on PI. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3797–3806, 2010
Cleavage of polystyrene‐b‐poly(ethylene oxide) block copolymers with a trithiocarbonate linkage in solutions
Authors: Cao Min , Wang Jian‐Qi , Chen Peng‐Cheng , Xu Jun‐Ting , Fan Zhi‐Qiang
Published: July 2010

In this work, the polystyrene‐b‐poly(ethylene oxide) (PS‐b‐PEO) block copolymers with a trithiocarbonate group between the blocks were prepared by polymerization of styrene in the presence of a trithiocarbonate reversible addition fragmentation chain transfer (RAFT) agent connected with PEO. Decomposition of the trithiocarbonate group by UV irradiation was investigated in three different types of solvent: tetrahydrofuran (THF, common solvent for both blocks), cyclohexane/dioxane mixture (selective solvent for the PS block) and N,N‐dimethylformamide (DMF)/ethanol mixture (selective solvent for the PEO block). It is found that cleavage of the block copolymers can take place in all these three solvents and the cleavage ratio ranges from 76 to 86%. The micellar morphologies in selective solvents before and after cleavage were examined. It is observed that the size of the micelles is reduced after cleavage and sometimes aggregation of the micelles occurs due to removal of the corona of micelles. It shows that this work provides a facile and general method for synthesis of cleavable block copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3834–3840, 2010
Magnetic particle‐loaded polymer brushes induced by external magnetic field: A Monte Carlo simulation
Authors: ye Yisheng , Pan Zhengquan , Zhang Linxi , He Linli , Xia Agen , Liang Haojun
Published: July 2010

The effects of applied magnetic field on the system composed of polymer brushes and magnetic particles are studied by means of Monte Carlo simulation. The direction of the applied magnetic field is chosen to be perpendicular to the substrate plane. Polymer brushes and magnetic particles are attracted to each other. The average heights of polymer brushes depend not only on the strength of applied magnetic field (H) but also on the brush grafting density (σ) and the chain length (N). The applied magnetic field influences the arrangement of magnetic particles, and in turn, the arrangement of magnetic particles affects the spatial distribution of polymer brush monomers. When the strength of the magnetic field is increased, the average height of polymer brushes will be increased accordingly. The reason is that the orientations of the magnetic moments of particles must be along the magnetic field direction, and this leads polymer brushes to rearrange along the magnetic field direction. At the same time, the chain length and the grafting density of polymer brushes have also effects on the properties of the magnetic particles, such as the magnetic particles distribution, magnetic susceptibility, and pair correlation functions. Comparisons with the experimental ones are also made, and this investigation can provide some insights into statistical properties of magnetic particle‐loaded brushes induced by external magnetic field. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1873–1881, 2010
Selective distribution, reinforcement, and toughening roles of MWCNTs in immiscible polypropylene/ethylene‐co‐vinyl acetate blends
Authors: Liu Li , Wu Haiyan , Wang Yong , Wu Jun , Peng Ya , Xiang Fangming , Zhang Jihong
Published: July 2010

Polypropylene/ethylene‐co‐vinyl acetate (PP/EVA) nanocomposites with functionalized multiwalled carbon nanotubes (FMWCNTs) have been prepared. The dissolution experiment, transmission electronic microscope, and scanning electronic microscope characterizations prove that, in the nanocomposites with sea–island morphology, although some FMWCNTs are observed in both PP and EVA phases, most of FMWCNTs distribute at the interface; however, in the nanocomposites with cocontinuous morphology, FMWCNTs mainly distribute in EVA phase. Further results based on (differential scanning calorimetry) measurements show that the different dispersion states of FMWCNTs, which are resulted by the different melt blending sequences, result in the different crystallization behaviors of PP matrix. The mechanical measurements show that FMWCNTs exhibit apparent reinforcement and toughening effects for immiscible PP/EVA blends, and such effects are greatly dependent upon the blending sequences. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1882–1892, 2010
Pressure–volume–temperature data and surface tension of blends of poly(ethylene oxide) and poly(methyl acrylate) in the melt
Authors: Pfefferkorn Dirk , Sonntag Sven , Kyeremateng Samuel O. , Funke Zofia , Kammer Hans‐Werner , Kressler Jörg
Published: July 2010

The pressure–volume–temperature behavior of miscible blends of poly(ethylene oxide) (PEO) and poly(methyl acrylate) (PMA) was studied over extended ranges of temperature and pressure. From pressure–volume–temperature data, the reduction parameters for the Flory‐Orwoll‐Vrij equation‐of‐state were determined. It was found that reduction parameters as well as density, thermal expansion coefficient, and isothermal compressibility vary with composition in a nonlinear manner. The surface tension of the blends in the molten state was measured over the whole composition range using the sessile drop method. The surface tension was found to display negative deviation from additivity pointing toward a remarkable surface excess of PMA. Moreover, surface tension displays a minimum in the range of low PEO content at weight fraction of ∼0.19. In addition, the temperature coefficient of surface tension shows negative deviation from linearity. It stays constant when PMA is in excess. Results are discussed in terms of equation‐of‐state thermodynamics. The minimum of surface tension can be well explained by weak self‐association of PEO in the bulk. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1893–1900, 2010
Efficiency droop in nitride‐based light‐emitting diodes
Authors: Piprek Joachim
Published: July 2010

Nitride‐based light‐emitting diodes (LEDs) suffer from a reduction (droop) of the internal quantum efficiency with increasing injection current. This droop phenomenon is currently the subject of intense research worldwide, as it delays general lighting applications of GaN‐based LEDs. Several explanations of the efficiency droop have been proposed in recent years, but none is widely accepted. This feature article provides a snapshot of the present state of droop research, reviews currently discussed droop mechanisms, contextualizes them, and proposes a simple yet unified model for the LED efficiency droop.

magnified image

Illustration of LED efficiency droop (details in Fig. 13).
Stability of ferromagnetism within the time‐dependent Gutzwiller approximation for the Hubbard model
Authors: Günther F. , Seibold G. , Lorenzana J.
Published: July 2010

We study the problem of itinerant ferromagnetism (FM) in one‐, two‐ and infinite‐dimensional Hubbard models. Our investigations are based on the time‐dependent Gutzwiller approximation (TDGA) which allows for the derivation of a generalized ‘GA Stoner criterion’ for the instability towards ferromagnetic, but also antiferromagnetic and incommensurate magnetic order. After having established magnetic phase boundaries we investigate the stability of FM by including the effect of transverse fluctuations.We also compute the spin‐wave velocity in the ferromagnetic phase and compare our results with other approaches like HF + RPA Stoner theory. Our investigations reveal that even in the fully polarized ferromagnetic phase the TDGA yields a renormalized excitation spectrum with respect to Stoner theory although the double occupancy vanishes in this case.
An assessment of the kernel‐distance‐based multivariate control chart through an industrial application
Authors: Gani Walid , Taleb Hassen , Limam Mohamed
Published: July 2010

Traditional multivariate quality control charts assume that quality characteristics follow a multivariate normal distribution. However, in many industrial applications the process distribution is not known, implying the need to construct a flexible control chart appropriate for real applications. A promising approach is to use support vector machines in statistical process control. This paper focuses on the application of the ‘kernel‐distance‐based multivariate control chart’, also known as the ‘k‐chart’, to a real industrial process, and its assessment by comparing it to Hotelling's T2 control chart, based on the number of out‐of‐control observations and on the Average Run Length. The industrial application showed that the k‐chart is sensitive to small shifts in mean vector and outperforms the T2 control chart in terms of Average Run Length. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis of horizontal machining center field failure data based on generalized linear mixed model—a case study
Authors: Liu Fanmao , Zhu Haiping , Shao Xinyu , Gao Guibing
Published: July 2010

In order to assess the operational reliability of the horizontal machining center (HMC), field failure data for 14 HMCs over one year are collected from an engine plant of a large automobile manufacturing company in China. In contrast with the usual approach, which just pools the data from all copies under the assumption that each copy is modeled by the same power law processes (PLP), a new model based on the generalized linear mixed model (GLMM) is proposed for analyzing the failure data from all copies of HMC. A basic idea of this method is to assume heterogeneity among all copies of HMC; it is also found that the underlying model for each individual copy is a PLP model with different shape parameters and scale parameters in the GLMM model. This method can make inferences about both the population and each individual copy. Meanwhile, the modified Anderson–Darling test is adapted to the goodness‐of‐fit test of the model. The results of the analysis suggest that this method is effective to analyze reliability of HMC. Copyright © 2010 John Wiley & Sons, Ltd.
Shewhart and EWMA t control charts for short production runs
Authors: Celano Giovanni , Castagliola Philippe , Trovato Enrico , Fichera Sergio
Published: July 2010

Short‐run productions are common in manufacturing environments like job shops, which are characterized by a high degree of flexibility and production variety. Owing to the limited number of possible inspections during a short run, often the Phase I control chart cannot be performed and correct estimates for the population mean and standard deviation are not available. Thus, the hypothesis of known in‐control population parameters cannot be assumed and the usual control chart statistics to monitor the sample mean are not applicable. t‐charts have been recently proposed in the literature to protect against errors in population standard deviation estimation due to the limitation of available sampling measures. In this paper the t‐charts are tested for implementation in short production runs to monitor the process mean and their statistical properties are evaluated. Statistical performance measures properly designed to test the chart sensitivity during short runs have been considered to compare the performance of Shewhart and EWMA t‐charts. Two initial setup conditions for the short run fixing the population mean exactly equal to the process target or, alternatively, introducing an initial setup error influencing the statistic distribution have been modelled. The numerical study considers several out‐of‐control process operating conditions including one‐step shifts for the population mean and/or standard deviation. The obtained results show that the t‐charts can be successfully implemented to monitor a short run. Finally, an illustrative example is presented to show the use of the investigated t charts. Copyright © 2010 John Wiley & Sons, Ltd.
Improving the performance of CUSUM charts
Authors: Riaz Muhammad , Abbas Nasir , Does Ronald J. M. M.
Published: July 2010

The control chart is an important statistical technique that is used to monitor the quality of a process. Shewhart control charts are used to detect larger disturbances in the process parameters, whereas CUSUM and EWMA charts are meant for smaller and moderate changes. Runs rules schemes are generally used to enhance the performance of Shewhart control charts. In this study, we propose two runs rules schemes for the CUSUM charts. The performance of these two schemes is compared with the usual CUSUM, the weighted CUSUM, the fast initial response CUSUM and the usual EWMA schemes. The comparisons revealed that the proposed schemes perform better for small and moderate shifts, whereas they reasonably maintain their efficiency for large shifts as well. Copyright © 2010 John Wiley & Sons, Ltd.
A theoretical study of semiclassic models: Toward a quantum mechanical representation of chemical processes
Authors: Crespo R. , Piqueras M.‐C. , Aulló J. M. , Tapia O.
Published: July 2010

CASPT2 level of theory and aug‐cc‐pV6Z atomic basis set for hydrogen and 6 base states is sufficient to accurately reproduce the historical calculations of Kolos‐Wolniewicz for H21Σ potential energy curve. We found that for H + H process experimental and adiabatic theory results are contradictory. By analyzing different levels of semiclassic theory, we identify the nature of the failure. We propose an approximate scheme that may bridge semiclassic to QM model. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Source—destination obfuscation in wireless ad hocnetworks
Authors: Hayajneh Thaier , Doomun Razvi , Krishnamurthy Prashant , Tipper David
Published: July 2010

The identity and/or location of communicating entities in wireless ad hocnetworks is extremely important due to the potential of their being identified and subsequently subjected to cyber or physical attacks. In this paper, we show that a global attacker who can eavesdrop on the overall data transmissions and count them can simply visualize the transmissions and infer contextual information. Current approaches to obfuscate the locations of source and destinations do not provide protection against such attacks. We propose two novel techniques (1) SECLOUD: Source and Destination Seclusion using Clouds to obfuscate the true source/destination nodes and make them indistinguishable among a group of neighbor nodes, and (2) ANONYRING: Anonymous Ring which hides the source/destination nodes within a group of nodes that form a ring. Both proposed techniques work well even under network‐wide traffic visualization by a global attacker. Furthermore the proposed techniques are shown viasimulation to be superior to existing schemes in the literature. Copyright © 2010 John Wiley & Sons, Ltd.
Impact of wind power in autonomous power systems—power fluctuations—modelling and control issues
Authors: Margaris Ioannis D. , Hansen Anca D. , Cutululis Nicolaos A. , Sørensen Poul , Hatziargyriou Nikos D.
Published: July 2010

This paper describes a detailed modelling approach to study the impact of wind power fluctuations on the frequency control in a non‐interconnected system with large‐scale wind power. The approach includes models for wind speed fluctuations, wind farm technologies, conventional generation technologies, power system protection and load. Analytical models for wind farms with three different wind turbine technologies, namely Doubly Fed Induction Generator, Permanent Magnet Synchronous Generator and Active Stall Induction Generator‐based wind turbines, are included. Likewise, analytical models for diesel and steam generation plants are applied. The power grid, including speed governors, automatic voltage regulators, protection system and loads is modelled in the same platform. Results for different load and wind profile cases are being presented for the case study of the island Rhodes, in Greece. The scenarios studied correspond to reference year of study 2012. The effect of wind fluctuations in the system frequency is studied for the different load cases, and comments on the penetration limits are being made based on the results. Copyright © 2010 John Wiley & Sons, Ltd.
Computer security
Authors: Gollmann Dieter
Published: July 2010

Computer security encompasses concepts and methods for protecting sensitive resources in computer systems. Computer security starts from the policies that regulate access to protected resources. In technology, the focus is on mechanisms for enforcing these policies. We will put various enforcement mechanisms into context with the policies and the IT architectures they were originally designed for. We will also briefly touch on network security and conclude with remarks on security evaluation. Copyright © 2010 John Wiley & Sons, Inc.

This article is categorized under:

Algorithms and Computational Methods > Networks and Security
Thiosemicarbazone Derivatives of Copper(I): Influence of Substituents (R) at N1 Atom of [(C5H4N)HC2=N3N2H‐C1(=S)N1HR] in the Formation of 1D or 2D Networks of Copper(I) Complexes
Authors: Lobana Tarlok S. , Sharma Rekha , Castiñeiras Alfonso , Butcher Ray Jay
Published: July 2010

Copper(I) halides with N1‐substituted pyridine‐2‐carbaldehyde thiosemicarbazones [(C5H4N)HC2=N3N2H‐C1(=S)N1HR] in the presence of Ph3P have formed complexes of stoichiometry, [CuX(Hpytsc‐N1HR)(Ph3P)2] [X, R; Br, Me (1); Br, Et (2), Cl, Ph (3·CH3CN)]. All these complexes are characterised by elemental analysis, IR and NMR (1H, 31P) spectroscopy and X‐ray crystallography. The role of substituents at N1 atom of pyridine‐2‐carbaldehyde thiosemicarbazones in intermolecular interactions in copper(I) complexes is described. A 1D polymer of compound 1 is formed by intermolecular CH(methyl)···π(py) interactions. The hydrogen atoms of EtN1H and ethyl group interact with the phenyl ring of PPh3 {via EtN1H···π(Ph), H2CH(Et)···π(Ph)} to form a 1D polymer of 2. A 2D sheet arrangement of compound 3 is formed by pyridyl–phenyl (CH(py)···π(Ph)) interactions along the a axis and phenyl–phenyl [CH(Ph)···π(Ph)] interactions (phenyl at N1 with phenyl of PPh3) along the b axis.
Differences in distribution patterns around river confluences among hydrophilic vegetation groups
Authors: Osawa Takeshi , Mitsuhashi Hiromune , Niwa Hideyuki , Ushimaru Atushi
Published: July 2010

In riparian areas, the distribution patterns of plant species are generally considered to depend on their flooding tolerance. Areas around river confluences are known to experience frequent and/or strong flooding events and provide diverse habitats for plants in riparian areas. However, the degree to which hydrophilic vegetation types increase their distribution around confluences may depend on their flooding tolerance. To test this hypothesis, we compared patch numbers and total areas of ten vegetation groups between confluences and single‐flow areas. The vegetation groups were classified on the basis of life form and morphology of dominant species. Additionally, we compared total area of natural bare ground (an index of flooding disturbance) between confluences and single‐flow areas. We found that patch numbers of annual grass, forb, and vine, perennial grass and forb, and riparian forest vegetation, as well as total areas of annual forb and vine, perennial grass and forb, bamboo and riparian forest vegetation, and natural bare ground, were greater around river confluences than in single‐flow areas. On the other hand, patch numbers of shrub vegetation and total areas of annual grass, perennial vine, willow, and shrub vegetation decreased around confluences. These results suggest that confluences enhance diverse, but not all, types of habitat for hydrophilic vegetation. Thus, river confluences are a key element in maintaining diverse riparian vegetation.
1 oder 2 oder 3? Zur Konstituierung möglicher Metropolregionen an Rhein und Ruhr
Authors: H. Blotevogel Hans , Schulze Kati
Published: July 2010

The article discusses an advancement of the planning concept of “Metropolitan Region Rhine Ruhr”, which has been established in the year 1995, but never realised in practice. Based on a measuring concept that quantifies the metropolitan functions, the potential separate Metropolitan Regions Cologne-Bonn and Düsseldorf as well as the constitution of a comprehensive Metropolitan Region Rhineland are put in a direct comparison to the big German Metropolitan Regions. In addition, inter- and intraregional linkage patterns of the metropolitan area are analysed by means of commuter relations. Based on these empirical results, promotive and aggravating factors for the formation of alternative Metropolitan Regions are finally identified and the demarcation variations are compared.
Diabetes, cardiovascular disease, and health care use in people with and without schizophrenia
Authors: Bresee L.C. , Majumdar S.R. , Patten S.B. , Johnson J.A.
Published: July 2010

Purpose

To compare the prevalence of cardiovascular risk factors (CV-RF) and disease (CV-D) and health care use in people with and without schizophrenia.

Subjects/materials and methods

Data from the Canadian Community Health Survey (CCHS), cycle 3.1, were used. Prevalence of CV-RF, CV-D, and health care use were compared in those with and without schizophrenia using logistic regression analysis. Sampling weights and bootstrap variance estimates were used to account for survey design.

Results

A total of 399 (0.3%) people with schizophrenia were identified and compared to 120,044 (97.7%) people without. Individuals with schizophrenia were significantly more likely to be obese (34.8% vs. 15.6%) and report diabetes (11.9% vs. 5.3%). After accounting for sociodemographic variables, schizophrenia was not independently associated with diabetes (adjusted odds ratio [aOR]: 0.86; 0.49–1.51). Individuals with schizophrenia were more likely to be hospitalized (21.9% vs. 8.0%; aOR: 2.37; 95% CI: 1.51–3.74) but no more likely to visit their physician (86.7% vs. 85.7%; aOR: 1.23; 95% CI: 0.65–2.35).

Discussion/conclusion

Our findings suggest that people with schizophrenia access the primary health care system at least as frequently as someone without schizophrenia, and the opportunity for management of modifiable CV-RF exists in this vulnerable population.
Telomeres: Structures in need of unwinding
Authors: Paeschke Katrin , McDonald Karin R. , Zakian Virginia A.
Published: July 2010

Telomeres protect the ends of eukaryotic chromosomes from being recognized and processed as double strand breaks. In most organisms, telomeric DNA is highly repetitive with a high GC‐content. Moreover, the G residues are concentrated in the strand running 3′–5′ from the end of the chromosome towards its center. This G‐rich strand is extended to form a 3′ single‐stranded tail that can form unusual secondary structures such as T‐loops and G‐quadruplex DNA. Both the duplex repeats and the single‐stranded G‐tail are assembled into stable protein–DNA complexes. The unique architecture, high GC content, and multi‐protein association create particularly stable protein–DNA complexes that are a challenge for replication, recombination, and transcription. Helicases utilize the energy of nucleotide hydrolysis to unwind base paired nucleic acids and, in some cases, to displace proteins from them. The telomeric functions of helicases from the RecQ, Pifl, FANCJ, and DNA2 families are reviewed in this article. We summarize data showing that perturbation of their telomere activities can lead to telomere dysfunction and genome instability and in some cases human disease.
THE CONSTRUCTION OFSALAFIYYA: RECONSIDERING SALAFISM FROM THE PERSPECTIVE OF CONCEPTUAL HISTORY
Authors: Lauzière Henri
Published: July 2010

For nearly a century of scholarship, uncertainties and paradoxes have beleaguered interpretations of the origins and meaning of Salafism (al-salafiyya). Although academics and journalists alike are well aware of the various definitions and conflicting narratives of Salafism, relieving some of the confusion that beclouds the term continues to prove difficult. Given that concepts are fluid and relational, this state of affairs may seem inevitable. Yet there are reasons to believe that the current confusion surrounding Salafism is in part attributable to faulty scholarship and that consequently the substance and history of this religious orientation will remain unnecessarily puzzling so long as the production of knowledge about Salafism goes unexamined. In that sense, recent scholarly efforts to remedy the situation by providing deeper insights into the intellectual, geographical, and political diversity of Salafism have produced mixed results, for they have largely overlooked two of the most persistent epistemological problems that are at the root of much of the present-day ambiguity.
PRESENTING THE “TRUE FACE OF SYRIA” TO THE WORLD: URBAN DISORDER AND CIVILIZATIONAL ANXIETIES AT THE FIRST DAMASCUS INTERNATIONAL EXPOSITION
Authors: Martin Kevin W.
Published: July 2010

International fairs—the “folk-festivals of capitalism”—have long been a favorite topic of historians studying quintessential phenomena of modernity such as the celebration of industrial productivity, the construction of national identities, and the valorization of bourgeois leisure and consumption in the late 19th and early 20th centuries in Europe, the United States, and Latin America. To date, however, such spectacles occurring in the modern Middle East remain largely unexamined. This article, an analysis of the discourse surrounding the first Damascus International Exposition in 1954, is conceived in part as a preliminary effort to redress this historiographic imbalance.
THE LOCATION OF PALESTINE IN GLOBAL COUNTERINSURGENCIES
Authors: Khalili Laleh
Published: July 2010

I begin with a pair of narratives:

[Jenin] itself showed signs of the Government's wrath. It was in a shocking state, having the appearance of a front-line town in a modern war. Huge gaps were visible between the blocks of buildings and houses, while piles of rubble lay across the streets. . . . Many men had been arrested and detained, while many buildings, including shops and offices, had been demolished as a punitive measure by the military.

On the fourth day, they managed to enter [the Jenin camp] because . . . this giant tank could simply run over booby traps, especially since they were very primitive booby traps. Once the army took over our street, they started shooting missiles from the air. On the fifth day they started shelling homes. A large number of people were killed or wounded. My neighbour's home was blown up by missiles . . . Close to us was a group of [detained] young men. They were handcuffed, naked, and lying on their stomachs . . . They would take each one of us and force us onto the ground, stomping on our backs and heads. One soldier would put his machine gun right on your head, and the other would tie you up.

The first narrative dates from 1939, when the British finally suppressed the Arab Revolt; the second is from the Israeli counterinsurgency against Palestinians during the second intifada in 2002. What is striking about the two narratives is not only the similarity of “control” measures and the targeting of politically mobilized towns and villages across time but also the persistence of these techniques across different administrative/colonial systems. Further, these practices—house demolitions, detention of all men of a certain age, and the targeting of civilian spaces and populations—are familiar from other counterinsurgency contexts, whether British and French colonial wars in the 20th century or the 21st-century wars of the United States in Iraq and Afghanistan.
Approaches to Coptic History after 641
Authors: Armanios Febe
Published: July 2010

The study of Coptic history usually brings to mind gnostic texts, remote monastic enclaves, archeological ruins, conflicts with Byzantium, or a long-forgotten language. Until recently, a disproportionate focus on early Christianity has bound Copts to an ancient and seemingly timeless heritage, which explains the dearth of critical examinations on Coptic life from the Islamic conquests to the early modern period. In general, Coptic experiences after 641 have been overshadowed by other themes in Egyptian history writing, in particular political and military changes. Although the latter are as relevant for a better understanding of the Coptic past, they have been predominately examined from the perspective of the Muslim majority, exclusive of Coptic concerns, perspectives, and beliefs. Only in recent years has scholarship on Copts begun to expand. Scholars have drawn from fields such as papyrology, gender studies, art history, and law in pursuit of a more comprehensive historical narrative. We are increasingly encouraged to evaluate the Coptic experience not only as a missing cog in Egyptian historiography but also as one that complicates canonical studies of postconquest Egypt and enriches our understanding of Middle Eastern history in general.
PRESENTING THE “TRUE FACE OF SYRIA” TO THE WORLD: URBAN DISORDER AND CIVILIZATIONAL ANXIETIES AT THE FIRST DAMASCUS INTERNATIONAL EXPOSITION
Authors: Martin Kevin W.
Published: July 2010

The postwar period of 1945 to 1963 witnessed dramatic political and economic transformations in Syria. To date, however, the cultural manifestations of these transformations remain largely unexamined. This article seeks to begin the process of redressing that historiographic imbalance and recovering the meaning of these transformations for those who experienced them through a close reading of the discourse surrounding the first Damascus International Exposition of 1954. This event constituted the stage upon which the recently independent, and still fragile, Syrian state conducted an exercise in autoethnography, the attempt to define and represent itself to its citizenry and to the outside world, as well as the screen upon which Syrians' collective longings were focused and projected. Thus, I treat this body of discourse as a unique opportunity to apprehend an emergent elite's anxieties about foreigners' perceptions of their country, as expressed in this stratum's homiletic discourse about street begging and other forms of urban disorder that threatened to disrupt the exposition's staging.
Women's Perceptions of Consequences of Career Interruptions due to Childcare in Central and Eastern Europe
Authors: VALENTOVA MARIE , ZHELYAZKOVA NEVENA
Published: July 2010

The present paper aims to examine the effect of the transition from a state socialist regime to democracy and a liberal economy on women's perceptions of the consequences of employment breaks due to childcare on their further careers in seven post-socialist Eastern and Central European countries. The paper uses data from the 2004 European Social Survey to explore whether women who interrupted their careers to look after young children were more likely to suffer negative consequences for their careers after the transition from socialism to a market-based economy than before the lifting of the Iron Curtain. The paper does this by comparing the consequences perceived by women whose children were born before 1987 with those of women with at least one child born later. It begins by grouping together women from across the region, and then looks at the differences by country of the consequences as perceived by these women. It concludes that women across the region were more likely to experience negative consequences after the transition than before. However, the effect of transition is not found to differ across countries using the ESS data.
Can conflict-generated diasporas be moderate actors during episodes of contested sovereignty? Lebanese and Albanian diasporas compared
Authors: KOINOVA MARIA
Published: July 2010

Conflict-generated diasporas are considered likely to maintain radical behaviours. This article seeks to explain why and how they nevertheless adopt moderate claims, especially when advocating highly sensitive issues such as state sovereignty. Focusing on groups in the US I investigate the Lebanese diaspora linked to the pro-sovereignty movement in Lebanon (2000–2005) and the Albanian diaspora linked to Kosovo's independence movement (1999–2008). The contentious episodes take place during the original homeland's post-conflict reconstruction. Embedded in the literatures on diasporas, conflicts, and transnational social movements, this article argues that instrumental approach towards the achievement of sovereignty explains why conflict-generated diasporas adopt moderate behaviours. Diasporas hope that by linking their claims to a global political opportunity structure of ‘liberalism’ they ‘play the game’ of the international community interested in promoting the liberal paradigm, and thus expect to obtain its support for the legitimisation of their pro-sovereignty goals. Diaspora entrepreneurs advance their claims in a two-step process. Initially they use frame bridging and frame extension to formulate their existing grievances. Then, an increased responsiveness from their host-state emerges to sustain their initial moderation. While individuals or groups in diaspora circles occasionally issue threats during the contentious episodes, the majority in the diaspora consider moderate politics as their dominant behaviour.
The Utrecht-Management of Identity Commitments Scale (U-MICS)
Authors: Crocetti Elisabetta , Schwartz Seth J. , Fermani Alessandra , Meeus Wim
Published: July 2010

The present study examined the psychometric properties of the Dutch and Italian versions of the Utrecht-Management of Identity Commitments Scale (U-MICS) in large community samples of adolescents from Italy (N = 1,975) and The Netherlands (N = 1,521). Confirmatory factor analyses indicated that the three-factor model, consisting of commitment, in-depth exploration, and reconsideration of commitment, provided a better fit to the data than alternative one- and two-factor models. The three-factor model fit equivalently across sex and across age groups (early and middle adolescents). Furthermore, we demonstrated cross-national equivalence of the factor structure of the U-MICS. Additionally, results indicated that the latent means for commitment were higher in the Dutch sample, while latent means for both in-depth exploration and reconsideration of commitment were substantially higher in the Italian sample. The three identity processes were found to be meaningfully related to measures of self-concept, psychosocial problems, and parent-adolescent relations in both countries. These findings suggest that the U-MICS is a reliable tool for assessing identity processes in Italian and Dutch adolescents.
The Development and Initial Validation of a Brief Daily Hassles Scale Suitable for Use with Adolescents
Authors: Wright Michalle , Creed Peter , Zimmer-Gembeck Melanie J.
Published: July 2010

Daily hassles are defined as “irritating, frustrating demands that occur during everyday transactions with the environment” ( Holm & Holroyd, 1992, p. 465 ). They need to be differentiated from significant life events, which refer to “environmental circumstance[s] that [have] an identifiable onset and ending and may carry the potential for altering an individual’s present state of mental and physical well-being” ( Goodyer, 2001, p. 204 ). Significant life events, such as the death of a family member or having a parent move out of home, typically occur infrequently and have readily identifiable onsets and endings. Daily hassles, on the other hand, such as those that come when interacting with family or friends, occur with regular frequency, and have less readily identifiable beginnings and endings. Previous research has suggested that the stress from ongoing daily hassles is detrimental to the wellbeing of adolescents ( Sim, 2000 ), and may be more important than significant life events for psychological adjustment in this population ( Goodyer, 2001 ). Three studies led to the development and initial validation of a brief daily hassles scale that could be used with adolescents. Study 1 drew on hassles identified in existing scales, hassles from the literature, a focus group with adolescents, and expert feedback to generate and finalize 69 daily hassle items. In Study 2, the items were administered to a sample of 212 adolescents. We then used item and exploratory factor analysis to reduce the number of items to 14, which represented two homogeneous and internally reliable subscales of family and peer/other hassles. In Study 3, the brief daily hassles scale was administered to a second sample of 236 adolescents. Here we tested the initial structure using confirmatory factor analysis and examined construct validity by testing the scale’s relationship with measures of depression, anxiety, and life satisfaction.
Ways to Happiness in German-Speaking Countries
Authors: Ruch Willibald , Harzer Claudia , Proyer René T. , Park Nansook , Peterson Christopher
Published: July 2010

Peterson, Park, and Seligman (2005 ) developed the Orientations to Happiness (OTH) questionnaire to measure three routes to happiness: life of pleasure (hedonism), life of engagement (flow) and life of meaning (eudemonia). The questionnaire was translated into German in several steps (independent translations by five experts, creation of the initial version by committee approach, retranslation, modification, and final version). Data were collected in paper-pencil (N = 1,152) and Internet samples (N = 4,174). The OTH scales showed satisfactory internal consistencies (.63 ≤ α ≤ .76) and stability across 6 months (all ≥ .63). The factorial structure of the German OTH was analyzed (RMSEA ≤ .074 and SRMR ≤ .043 for the 3-factor solution) in both samples. Tucker’s Phi coefficients for factorial congruence between the two samples were .99. The three scales were positively intercorrelated. The endorsement of the life of pleasure was higher in younger, unmarried, and nonreligious participants. The life of meaning was more pronounced among the religious participants. There was a good convergence (all > .49) between homologous scale of the self- and peer-form, and the OTH predicted behavior in prototypical pleasure, engagement, and meaning situations. Most importantly, high scores in each of the orientations to happiness corresponded to higher degrees of overall satisfaction with life.