bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetics of the simultaneous oxidation of nickel(II) and sulfur(IV) by oxygen in alkaline medium in Ni(II)–sulfur(IV)–O2 system
Authors: Sharma Anil Kumar , Mudgal Punit Kumar , Bansal S. P. , Gupta K. S.
Published: June 2010

In the Ni(II)–S(IV)–O2 system in the region of pH > 8.4, both Ni(II) and S(IV) are simultaneously autoxidized, and when sulfur is consumed fully NiOOH precipitates. At pH > 8.4, ethanol has no effect on the rate, whereas ammonia strongly inhibits the reaction when pH > 7.0. The kinetics of the reaction, in both the presence and the absence of ethanol, is defined by the rate law

equation image

where k is the rate constant, KO is the equilibrium constant for the adsorption of O2 on Ni(OH)2 particle surface. In ammonia buffer, the factor F is defined by

equation image

where K, KOH, K1, K2, K3, and K4 are the stability constants of NiSO3, NiOH+, Ni(NH3)2+, Ni(NH3), Ni(NH3), and Ni(NH3), respectively. In unbuffered medium, the factor F reduces to

equation image

The values of k and Ksp were found to be (1.3 ± 0.08) × 10−1 s−1 and (4.2 ± 3.5) × 10−16, respectively, at 30°C. A nonradical mechanism that assumes the adsorption of both SO32− and O2 on the Ni(OH)2 particle surface has been proposed. At pH ≤ 8.2, Ni(II) displays no catalytic activity for sulfur(IV)‐autoxidation and it is also not oxidized to NiOOH. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 464–478, 2010
A comparison of management approaches to control muddy floods in central Belgium, northern France and southern England
Authors: Evrard O. , Heitz C. , Liégeois M. , Boardman J. , Vandaele K. , Auzet A.‐V. , van Wesemael B.
Published: June 2010

Muddy floods, i.e. water flowing from agricultural fields and carrying large quantities of soil, affect routinely numerous municipalities of central Belgium, northern France and southern England. A comparison of flood frequency between different European regions is difficult, because of the lack of a uniform and official database as well as the landscape heterogeneity of administrative entities. Agri‐environmental measures [AEMs; e.g. grass buffer strips (GBS)] can contribute to the control of muddy floods but their installation is voluntary and depends therefore on farmers' willingness. Actions to increase awareness and to inform the farmers proved to increase drastically their participation rate in AEM programmes. In all the studied regions, flood prone areas are increasingly taken into account to define land approved for development. Moreover, several schemes for the control of muddy floods have also been proposed at the regional scale. However, there is a spatial mismatch between the scale at which muddy floods are triggered (small catchment scale) and the scale at which public authorities can operate (municipality, grouping of municipalities, delineated flood prone areas, river basin). In future, beside curative measures (e.g. retention ponds and dams), farming techniques preventing runoff and erosion in the field (e.g. conservation tillage) should be encouraged. This could be achieved by the creation of a new AEM. Moreover, guidelines for the location of AEMs could usefully be introduced. Existing flood control schemes should also be systematically carried out by catchment agencies including legal, environmental and financial expertise. These agencies should be set up for local groupings of municipalities and provide them technical assistance to equip the flood prone areas and carry out maintenance of the implemented control measures. Copyright © 2010 John Wiley & Sons, Ltd.
Molecular dynamics simulations of elastohydrodynamic lubrication oil film
Authors: Washizu Hitoshi , Ohmori Toshihide
Published: June 2010

This paper reviews recent research in molecular dynamics studies of the traction properties of hydrocarbon fluids under elastohydrodynamic lubrication, focusing on the technical problems that arise on making predictions of the traction properties of an oil film with a submicron thickness at the actual sliding contacts of the machine elements by at a nanoscale molecular simulation. The effect of the oil film thickness and shear rate are examined including the result of a submicron thickness simulation of the oil film using a tera‐flops computer. The mechanism of the phase transition of the fluids under high pressure, the boundary slip, and the momentum transfer related to the molecular structure of the fluids are also presented. Copyright © 2010 John Wiley & Sons, Ltd.
Application of Mhaskar‐Prestin operators to the convergence of orthonormal expansions
Authors: Mashele H. P.
Published: June 2010

Let I be either R or (–1, 1), and let W: I → (0, ∞). Assume that W2 is a weight. We study the quasi‐interpolatory polynomial operators τl,n,m introduced by Mhaskar and Prestin, for Freud weights, Erdös weights, and the exponential weights on (–1, 1). We investigate boundedness of τl,n,m in weighted Lp spaces. We then use this result to show that

equation image

for even exponetial weights (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the stable rank and reducibility in algebras of real symmetric functions
Authors: Rupp R. , Sasane A.
Published: June 2010

Let Aℝ(𝔻) denote the set of functions belonging to the disc algebra having real Fourier coefficients. We show that Aℝ(𝔻) has Bass and topological stable ranks equal to 2, which settles the conjecture made by Brett Wick in [18]. We also give a necessary and sufficient condition for reducibility in some real algebras of functions on symmetric domains with holes, which is a generalization of the main theorem in [18]. A sufficient topological condition on the symmetric open set 𝔻 is given for the corresponding real algebra Aℝ(𝔻) to have Bass stable rank equal to 1 (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modular Approaches to Star and Miktoarm Star Polymers by ATRP of Cross‐Linkers
Authors: Gao Haifeng , Matyjaszewski Krzysztof
Published: June 2010

The topologies and site‐specific functionalities of a variety of star and miktoarm star copolymers can be easily manipulated by copolymerization of monomers and cross‐linkers using the ATRP technique. The polymerization of monomer prior to addition of cross‐linker produced core cross‐linked star polymers with initiating sites in the core, while polymerization of cross‐linker before monomer led to the core cross‐linked star polymers with initiating sites on the star periphery. When a mixture of linear macroinitiator and/or macromonomer was cross‐linked in a one‐pot reaction, miktoarm star copolymers with freely‐varied arm compositions and ratios were obtained.
HyperMacs – Highly Branched Network Precursors or Semi‐Interpenetrating Networks?
Authors: Dodds Jonathan M. , Hutchings Lian R.
Published: June 2010

We describe here a strategy for the synthesis of HyperMacs – long‐chain branched analogues of hyperbranched polymers. The building blocks for HyperMacs, AB2 macromonomers, are synthesized by living anionic polymerization and, as such, are well‐defined in terms of molecular weight (MW) and polydispersity. Size exclusion chromatography (SEC) studies show that the nature of the coupling reaction used to generate the highly branched HyperMacs results in branched polymers with a distribution of MWs and architectures. Solubility studies show that, in certain cases, a significant weight fraction of the resulting HyperMacs forms insoluble, swollen gels when added to a good solvent, and SEC analysis shows that a modest weight fraction of the soluble polymer has a “very high MW”, in excess of 10,000,000 g mol−1. Although an AB2 coupling reaction should, in theory, not lead to a “crosslinked” network, such is the efficiency of this reaction that the resulting polymers appear to behave as semi‐interpenetrating networks.
Multi‐Functional Conetworks Based on Cross‐Linked Star Polymers
Authors: Georgiou Theoni K. , Achilleos Demetra S. , Patrickios Costas S.
Published: June 2010

Three series of conetworks based on cross‐linked star polymers of different architectures were prepared using group transfer polymerization. The first series of conetworks were amphiphilic, based on the hydrophobic monomer benzyl methacrylate and the ionizable hydrophilic 2‐(dimethylamino)ethyl methacrylate (DMAEMA); the second series were double‐hydrophobic, based on methyl methacrylate and n‐butyl methacrylate; the third series were ampholytic, based on the negatively ionizable methacrylic acid (MAA) and the positively ionizable DMAEMA. The MAA units were introduced into the conetworks via the polymerization of tetrahydropyranyl methacrylate followed by its acid hydrolysis after network formation. All the precursors to the conetworks were characterized in terms of their molecular weights using gel permeation chromatography. The degrees of swelling (DSs) of all the conetworks were measured as a function of pH or in a mixture of solvents. Moreover, the effect of the architecture of the conetworks on the DS was investigated. The DS was found to be influenced more by the charge density of the conetwork than by the compatibility with the solvent, and more by the solvent compatibility than by the architecture of the conetwork.
Segmental Order Parameters and Swelling in Polymer Networks
Authors: Sommer Jens‐Uwe , Saalwächter Kay
Published: June 2010

We study segmental order parameters in polymer networks in good solvent. In particular we consider the tensor order parameter which characterizes the degree of orientational order of segments and which is directly related to the residual coupling constant obtained in NMR‐experiments. Using a simple relation between the order parameter and the force acting on the chain end at a given extension we derive an universal relation for the order parameter for concentrations above the overlap threshold. Considering polymer gels at the equilibrium state of swelling we predict a unique relation between the tensor order parameter and the correlation length (blob size) of the gel. Experiments applying multi‐quantum NMR‐methods to both end‐linked and randomly cross‐linked polymer networks are in excellent agreement with this prediction. We critically discuss the widely used Flory‐Rehner model of network swelling and show that initial decay of the tensor order parameter as observed in experiments at low degrees of swelling can be explained as a solvent effect without making additional assumptions about constraint release processes during swelling.
Amphiphilic Polymer Conetworks as Matrices for Phase Transfer Reactions
Authors: Bruns Nico , Hanko Michael , Dech Stephan , Ladisch Reinhild , Tobis Jan , Tiller Joerg C.
Published: June 2010

Amphiphilic polymer conetworks were prepared, characterized and used as highly activating matrices for phase transfer reactions. Several applications such as biocatalysis in organic solvents, metathesis reactions in water, biosensor designs for detecting metabolites in organic solvents, as well as gas sensor designs are discussed.
Study of the use of metallic foam in a vehicle for an energy‐economy racing circuit
Authors: Cardoso E. , Oliveira B. F.
Published: June 2010

The emphasis of this work is on the use of metal foams in automotive design for weight reduction with the purpose of studying the mechanical behaviour and possible project alternatives, through the modelling and subsequent computer simulation according to the case study – chassis of the “Sabiá 5”. The “Sabiás” are hyper‐economic vehicles created to compete in an energy‐economy racing circuit (Shell Eco‐marathon). For the structural analysis, the finite element software Abaqus/CAE is used. The tests performed are static and dynamic tests simulating the vehicle passing across a rough track and crash test. According to the results of the computational tests, metal foams demonstrated to be a good choice for the studied application, presenting the necessary weight reduction with the expected structural performance.
Effect of thickening agent and foaming agent on the micro‐architecture and deformation response of closed cell aluminum foam
Authors: Mondal D. P. , Das S.
Published: June 2010

Closed cell aluminum foam was synthesized using different types of thickening agents. The effect of temperature,%foaming agent,%thickening agent and the type of thickening agent were varied in order to examine the influence of these parameters on the foam architecture and deformation behaviour. Attempts were also made to make a foam without using any thickening agent and the characteristics of these foams have been compared with the other foams which are made with the use of the thickening agent. It was observed that 0.6 wt.% calcium hydride was sufficient for foaming of aluminum and the relative density of aluminum foam did affected only marginally with an increase in calcium hydride beyond 0.6 wt.%. The increase in melt temperature decreases the relative density of aluminum foam. The relative density of aluminum foam, however, remained invariant to the % thickening agent. On the other hand the relative density of aluminum foam was found to be varied with the type of thickening agent. It was further observed that 10wt% silicon carbide could be the optimum amount as thickening agent considering the relative density and deformation response. Deformation response was found to be varying with the type of thickening agent. It was further noted that aluminum foam could be made without using any thickening agent.
Research into the influence of ground tire rubber (GTR) in the mechanical and thermal properties of recycled thermoplastic materials
Authors: Crespo J. E. , Nadal A. , Parres F.
Published: June 2010

In this work, we investigate the influence and interaction of the elastomeric material known as ground tire rubber (GTR), obtained from shredded tires, in the compound obtained by mixing this material with a thermoplastic matrix of high density recycled polyethylene (HDPE). The mixing process is carried out using a mill with heated rollers and the mixture is then sintered. We analyzed the influence of GTR on the thermal and mechanical properties of the mixture, as well as its influence on environmental degradation taking place in the mixture. The study was concluded with an analysis of fracture in the material using a scanning electron microscope (SEM), with the objective of observing the deformation and fracture that takes place, analysing the interaction between the elastomeric waste and the thermoplastic matrix.
Water absorption in unsaturated polyester composites reinforced with caroá fiber fabrics: modeling and simulation
Authors: Nóbrega M. M. S. , Cavalcanti W. S. , Carvalho L. H. , de Lima A. G. B.
Published: June 2010

Studies on composites reinforced with natural fibers show that they are sensitive to influences from environmental agents such as water. The moisture causes degradation of the mechanical properties of natural fiber reinforced composites to a larger extent when compared to synthetic fiber reinforced composites. This is a consequence of the higher moisture absorption, and the organic nature of the natural fibers. In this sense, the purpose of this work was to study theoretically and experimentally water absorption in unsaturated polyester composites reinforced with caroá fiber at 25, 50 and 70°C. The composites had a weight composition of 30% caroá and 70% unsaturated polyester with dimensions of 20×20×3 mm3 and 20×20×6 mm3. Water absorption tests were conducted by immersing samples in a distilled water bath and the water uptake was followed gravimetrically for different elapsed time. A three‐dimensional mathematical model was developed to predict the mass transfer during the water absorption in parallelepiped solids. Results of water absorption kinetic and moisture content distribution inside these composites are shown and analyzed. The knowledge of this moisture distribution allows verifying more favorable areas which presents delamination problems due to the weakness of the fiber‐matrix interface and consequently reduction in the mechanical properties. It was verified that moisture induced degradation of composite samples was significant at elevated temperature.
Fabrication of smart structure using shape memory alloy wire embedded hybrid composite
Authors: Jung B.‐S. , Kim M.‐S. , Kim Y.‐M. , Ahn S.‐H.
Published: June 2010

Shape Memory Alloys (SMA) have been actively studied in many fields utilizing their high energy density, and SMA wire embedded composite, in particular, can be used as a smart material for a load carrying structure and actuator. Composite materials such as Glass Fiber Reinforced Plastics (GFRP) can sustain large loads, but at the same time the high stiffness of the material limits the displacement range of the SMA wire embedded composite. In this research, a SMA wire embedded hybrid composite was designed and fabricated to have a larger displacement than a SMA wire embedded single composite. The hybrid composite is designed with a n‐shape and it is comprised of three parts with different stiffness materials, GFRP with higher stiffness at both ends and silicone rubber with lower stiffness in the middle to increase the displacement range of the structure. The SMA wire embedded hybrid composite can be actuated by applying an electric current through the embedded SMA wire. The fabricated composite was mechanically fastened to prevent separation between the wire and the composite laminae induced by temperature rise of the wire. The displacement of SMA wire embedded hybrid composite was examined by measuring the radius of curvature.
Fatigue behaviour of bonded anchors subjected to tensile loads
Authors: Lazzarin P. , Grün J. , Mutignani F. , Ronchi R.
Published: June 2010

Following recent studies on the fatigue behaviour of noise barriers for high speed railways for train transits, threaded rods bonded with epoxy resin for column base plate anchorage had to be qualified. A fatigue test campaign was carried out at Fischer Laboratories in Denzlingen (Germany) on M20 and M30 (8.8 Grade) threaded rod samples embedded in concrete by means of FIS EM epoxy resin. The tests considered also threaded rods (M16 and M30, 8.8 Grade) not directly embedded in concrete, but in pre‐cast corrugated pipes having a diameter constant and equal to 40 mm. The results were found to be very satisfactory as far as the resin performance was concerned. In fact, under tensile loads carried out under a nominal load ratio R ≈ 0, all fatigue failures took place in the threaded rods, under the nut, notwithstanding the embedment length was that suggested by technical manuals for static loading. Some typical fracture surfaces relating to medium and high cycle fatigue regime are documented. A statistical re‐analysis has been carried out considering also other data, either obtained at Fischer laboratories from analogous threaded applications or taken from the literature. A new scatterband is provided for threaded rods with diameter equal to or less than 20 mm.
A study on the behavior of a cylindrical type Li‐Ion secondary battery under abnormal conditions
Authors: Kim S. , Lee Y. S. , Lee H. S. , Jin H. L.
Published: June 2010

Li‐ion (lithium ion) secondary batteries are rechargeable batteries in which lithium ions move between the cathode and the anode. Lithium is not as safe as nickel cadmium (NiCd), and the Li‐ion battery can under some conditions increase in temperature and ignite abnormal conditions which includes overcharging, being subjected to an impact, or being hit by a projectile. Before studying causes of Li‐ion battery explosions, the term “abnormal condition” was defined. Next, to check the mechanical conditions, an impact test by a free falling object of 9.1 kg weight made of steel was carried out. After the impact test, the damage of the separator around the hollow of the jelly roll in the cell was observed. Following this, the same cell's electrochemical conditions were assessed through a heating test to determine the potential thermal runaway. Finally, to analyze the mechanical damage to the Li‐ion batteries during the charging and the impact test, a finite element analysis was performed using LS‐DYNA and ABAQUS software. A cylindrical type Li‐ion secondary battery was selected for the impact test, heating test, and simulation. The test and simulation results provided insights into the extent to which cylindrical cells can endure abnormal conditions.
Increasing access to specialty care: A pilot, randomized controlled trial of telemedicine for Parkinson's disease
Authors: Dorsey E. Ray , Deuel Lisa M. , Voss Tiffini S. , Finnigan Kara , George Benjamin P. , Eason Sheelah , Miller David , Reminick Jason I. , Appler Anna , Polanowicz Joyce , Viti Lucy , Smith Sandy , Joseph Anthony , Biglan Kevin M.
Published: June 2010

We conducted a randomized, controlled pilot trial to evaluate the feasibility of providing subspecialty care via telemedicine for patients with Parkinson's disease residing in a remote community located ∼130 miles from an academic movement disorders clinic. Study participants were randomized to receive telemedicine care with a movement disorder specialist at the University of Rochester or to receive their usual care. Participants in the telemedicine group received three telemedicine visits over six months. Feasibility, as measured by the completion of telemedicine visits, was the primary outcome measure. Secondary measures were quality of life, patient satisfaction, and clinical outcomes. Ten participants residing in the community were randomized to receive telemedicine care (n = 6) or their usual care (n = 4). Four nursing home patients were assigned to telemedicine. Those receiving telemedicine completed 97% (29 of 30) of their telemedicine visits as scheduled. At the study's conclusion, 13 of 14 study participants opted to receive specialty care via telemedicine. Compared with usual care, those randomized to telemedicine had significant improvements in quality of life (3.4 point improvement vs. 10.3 point worsening on the Parkinson's Disease Questionnaire 39; P = 0.04) and motor performance (0.3 point improvement vs. 6.5 point worsening on the Unified Parkinson's Disease Rating Scale, motor subscale; P = 0.03). Relative to baseline, nursing home patients experienced trends toward improvement in quality of life and patient satisfaction. Providing subspecialty care via telemedicine for individuals with Parkinson's disease living remotely is feasible. © 2010 Movement Disorder Society
Topotecan dynamics, tautomerism and reactivity—1H/13C NMR and ESI MS study
Authors: Hyz Karolina , Kawȩcki Robert , Bednarek Elżbieta , Bocian Wojciech , Sitkowski Jerzy , Kozerski Lech
Published: June 2010

Topotecan (TPT) is in clinical use as an antitumor agent, hycamtin™. Because of this, it requires both biologically and chemically useful information to be available. TPT acts by binding to the covalent complex formed by nicked DNA and topoisomerase I. This has a poisonous effect since inserted into the single‐strand nick and TPT inhibits its religation. We used NMR to trace TPT dynamics, tautomerism and solvolysis products in various solvents and conditions. Chemical stability was assessed in methanol and DMSO as compared to water, and the regioselectivity of the N‐ and O‐methylation was studied using various alkylating agents. The reaction products of quaternization of the nitrogen atom and methylation of the oxygen atom were characterized by means of ESI MS, 1H/13C‐HMBC and ‐HSQCAD NMR. We have focused on the NMR characterization of TPT with an anticipation that its aggregation, tumbling properties and the intramolecular dipolar interactions will be a common feature for other compounds described in this article. These features can also be useful in tracing the interactions of this class of topoisomerase I (TopoI) poisons with DNA. Moreover, the results explained shed light on the recently disclosed problem of lack of stability of TPT in the heart tissue homogenate samples using the analytical assays developed for this class of compounds carried out in the presence of methanol. Copyright © 2010 John Wiley & Sons, Ltd.
Ethical infrastructure: A new requirement of the state's industrial policy
Authors: Choi Chong Ju , Digol Diana
Published: June 2010

Ethics of business leadership has witnessed a renewed interest in recent years provoked perhaps by a number of cases of business leadership failure. Unlike the critics of the industrial policy and direct market intervention by the state, in this paper we argue for an increased role of the state in imposing the ethical standards and the need to integrate the ethical infrastructure into the state's industrial policy. We believe that overall national economic success is dependent on four essential elements: financial infrastructure, physical infrastructure, knowledge infrastructure and ethical infrastructure. We further believe that proper integration and correct functioning of these elements within the state's industrial policy is fundamental to economic development and growth in any country in 21st century. We consider that the ethical infrastructure might provide an important element of a possible riposte in the future to the serious financial scandals of the kind that recently affected global business. We foresee that ethical infrastructure fosters best practice. In this paper, we argue that the integration of the ethical infrastructure is a new requirement of the state's industrial policy.

Copyright © 2010 John Wiley & Sons, Ltd.
Health information systems, decentralisation and democratic accountability
Authors: Madon Shirin , Krishna S. , Michael Edwin
Published: June 2010

While decentralisation is a much‐used term in development discourse, there is lack of clarity about how much autonomy should be granted to local agencies in programme implementation. This is particularly the case in the health sector in developing countries where decentralisation has resulted in the primary health centre (PHC) being identified as the focal point for the delivery of basic health services to rural citizens. An important element of primary healthcare reform has been the implementation of health information systems (HIS). These systems primarily account for monies spent to higher levels of administration and funding bodies rather than account for primary healthcare provision to citizens. In this article, we focus on various emergent processes of change that are occurring under the auspices of the National Rural Health Mission (NRHM) in India to strengthen the interface between the PHC and the community. We present a case study of Gumballi PHC in Karnataka, South India. Our findings reveal ways in which these new processes can be supported by conceptualising the HIS as more than a mere reporting tool. Copyright © 2010 John Wiley & Sons, Ltd.
Anaphylactoid reaction to high‐dose methotrexate and successful desensitization
Authors: Oulego‐Erroz Ignacio , Maneiro‐Freire Mercedes , Bouzón‐Alejandro Marta , Vázquez‐Donsión Manuel , Couselo José Miguel
Published: June 2010

Anaphylactic/anaphylactoid reaction to methotrexate (MTX) is uncommon. It may occur with the first dose (non‐allergic reactions) or after a previous exposure to the drug (allergic or specific reactions). Desensitization has been shown effective in children with allergic‐type reactions permitting the continuation of high‐dose methotrexate (HDMTX) therapy. We report the case of a child with localized osteosarcoma who developed an anaphylactoid reaction after a first HDMTX course. A desensitization protocol was successfully applied allowing the administration of four additional courses. In our experience, desensitization can be a safe and effective procedure in children with anaphylactoid reactions to HDMTX. Pediatr Blood Cancer. 2010;55:557–559. © 2010 Wiley‐Liss, Inc.
Cattell–Horn–Carroll abilities and cognitive tests: What we've learned from 20 years of research
Authors: Keith Timothy Z. , Reynolds Matthew R.
Published: June 2010

This article reviews factor‐analytic research on individually administered intelligence tests from a Cattell–Horn–Carroll (CHC) perspective. Although most new and revised tests of intelligence are based, at least in part, on CHC theory, earlier versions generally were not. Our review suggests that whether or not they were based on CHC theory, the factors derived from both new and previous versions of most tests are well explained by the theory. Especially useful for understanding the theory and tests are cross‐battery analyses using multiple measures from multiple instruments. There are issues that need further explanation, of course, about CHC theory and tests derived from that theory. We address a few of these issues including those related to comprehension–knowledge (Gc) and memory factors, as well as issues related to factor retention in factor analysis. © 2010 Wiley Periodicals, Inc.
Thermal state of permafrost and active layer in Central Asia during the international polar year
Authors: Zhao Lin , Wu Qingbai , Marchenko S.S. , Sharkhuu N.
Published: June 2010

Permafrost in Central Asian is present in the Qinghai–Tibet Plateau in China, the Tien Shan Mountain regions in China, Kazakhstan and Kyrgyzstan, the Pamirs in Tajikistan, and in Mongolia. Monitoring of the ground thermal regime in these regions over the past several decades has shown that the permafrost has been undergoing significant changes caused by climate warming and increasing human activities. During the International Polar Year, measured mean annual ground temperature (MAGT) at a depth of 6 m ranged from −3.2°C to 0.2°C on the Qinghai–Tibet Plateau and the active‐layer thickness (ALT) varied between 105 and 322 cm at different sites. Ground temperatures at the bottom of the active layer (TTOP) warmed on average by 0.06°C yr−1 over the past decade. In Mongolia, MAGT at 10–15 m depth increased by up to 0.02–0.03°C yr−1 in the Hovsgol Mountain region, but by 0.01–0.02°C yr−1 in the Hangai and Hentei Mountain regions. The increase in permafrost temperatures in the northern Tien Shan from 1974 to 2009 ranged from 0.3°C to 0.6°C. At present measured permafrost temperatures vary from −0.5°C to −0.1°C. The ALT increased from 3.2 to 4 m in the 1970s to a maximum of 5.2 m between 1995 and 2009. Copyright © 2010 John Wiley & Sons, Ltd.
Thermal state of permafrost in North America: a contribution to the international polar year
Authors: Smith S.L. , Romanovsky V.E. , Lewkowicz A.G. , Burn C.R. , Allard M. , Clow G.D. , Yoshikawa K. , Throop J.
Published: June 2010

A snapshot of the thermal state of permafrost in northern North America during the International Polar Year (IPY) was developed using ground temperature data collected from 350 boreholes. More than half these were established during IPY to enhance the network in sparsely monitored regions. The measurement sites span a diverse range of ecoclimatic and geological conditions across the continent and are at various elevations within the Cordillera. The ground temperatures within the discontinuous permafrost zone are generally above −3°C, and range down to −15°C in the continuous zone. Ground temperature envelopes vary according to substrate, with shallow depths of zero annual amplitude for peat and mineral soils, and much greater depths for bedrock. New monitoring sites in the mountains of southern and central Yukon suggest that permafrost may be limited in extent. In concert with regional air temperatures, permafrost has generally been warming across North America for the past several decades, as indicated by measurements from the western Arctic since the 1970s and from parts of eastern Canada since the early 1990s. The rates of ground warming have been variable, but are generally greater north of the treeline. Latent heat effects in the southern discontinuous zone dominate the permafrost thermal regime close to 0°C and allow permafrost to persist under a warming climate. Consequently, the spatial diversity of permafrost thermal conditions is decreasing over time. Copyright © 2010 Crown in the right of Canada and John Wiley & Sons, Ltd.
Resolution of extensive severe bronchiectasis in an infant
Authors: Crowley Suzanne , Matthews Iren
Published: June 2010

Bronchiectasis is, by definition, an irreversible condition. Following recent reports of reversible bronchiectasis in children, it has been suggested that the definition be broadened to include pre‐bronchiectasis and transitional reversible states. We describe the case of a young infant who had extensive, severe bronchiectasis of unknown etiology that resolved following prolonged treatment with antibiotics and a tapering course of oral steroids. We suggest that the prolonged treatment may have played a role, perhaps by eradicating infection and thus enabling regeneration of bronchial anatomy. Pediatr Pulmonol. 2010; 45:717–720. © 2010 Wiley‐Liss, Inc.
Theoretical Prediction of Physicochemical Properties, Performances and Sensitivities of some New Derivatives of Dinitro Triazolyl Triazine
Authors: Keshavarz Mohammad Hossein , Esmailpoor Karim , Tehrani Masoud Kavosh
Published: June 2010

In this paper, important properties of some new derivatives of dinitro triazolyl triazine as novel heterocyclic energetic compounds are evaluated and discussed by using some reliable models. The predicted properties are also compared with octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) as a benchmark compound and 2,4,6‐trinitro‐1,3,5‐triazine (TNTA) as a theoretically new high performance energetic compound. It is shown that some of these compounds can be seen as interesting high‐nitrogen organic explosives with relatively low sensitivity which could be introduced for some important industrial applications. Since some of the new compounds have good oxygen balance, calculated specific impulses confirm that these compounds can be considered as suitable oxidizers in solid propellants.
Molecular orientation studied by reflection anisotropy spectroscopy
Authors: Lane P. D. , Isted G. E. , Cole R. J.
Published: June 2010

A description of the reflection anisotropy spectroscopy (RAS) results from oriented thin films is presented. The RAS signals of a 1 nm thick film are simulated to investigate the effect of molecular tilt on the RAS response of the system. Whilst the spectroscopic measurements themselves appear to be relatively insensitive to the effects of the tilt, the variation of the RAS signal with rotation of the sample azimuthal angle sees sensitivity to out of surface plane anisotropy, characterized by a sin θs effect.
Nonradiative resonance energy transfer directed from colloidal CdSe/ZnS quantum dots to epitaxial InGaN/GaN quantum wells for solar cells
Authors: Nizamoglu Sedat , Sari Emre , Baek Jong‐Hyeob , Lee In‐Hwan , Demir Hilmi Volkan
Published: June 2010

We report on Förster‐type nonradiative resonance energy transfer (NRET) directed from colloidal quantum dots (QDs) to epitaxial quantum wells (QWs) with an efficiency of 69.6% at a rate of 1.527 ns–1 for potential application in III‐nitride based photovoltaics. This hybrid exciton generation–collection system consists of chemically‐synthesized cyan CdSe/ZnS core/shell QDs (λPL = 490 nm) intimately integrated on epitaxially‐grown green InGaN/GaN QWs (λPL = 512 nm). To demonstrate directional NRET from donor QDs to acceptor QWs, we simultaneously show the decreased photoluminescence decay lifetime of dots and increased lifetime of wells in the hybrid dipole–dipole coupled system. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The development of artemisinin resistance in malaria: reasons and solutions
Authors: Chrubasik Cosima , Jacobson Raymond L.
Published: June 2010

Despite world‐wide efforts in fighting malaria, this mosquito‐borne infectious disease is a huge burden for the population, especially in tropical and subtropical areas. The WHO recommends artemisinin‐based combination therapy for the treatment of uncomplicated Plasmodium falciparum malaria. However, artemisinin resistance cannot now be ignored. Factors affecting the development of artemisinin resistance include uncontrolled use of artemisinin‐based combination therapy (ACT), mobile populations and migrants, artemisinin monotherapy, the use of subtherapeutic levels of artesiminin, substandard and counterfeit drugs, high treatment cost, and co‐use of artemisinin derivates as prophylactic agents. Promising herbal alternatives are already in the pipeline, but the only long‐term solution for eradicating malaria would be the development of a successful vaccination. Copyright © 2010 John Wiley & Sons, Ltd.
Antiinflammatory activity of coumarins from Ligusticum lucidum Mill. subsp. cuneifolium (Guss.) Tammaro (Apiaceae)
Authors: Menghini Luigi , Epifano Francesco , Genovese Salvatore , Marcotullio Maria C. , Sosa Silvio , Tubaro Aurelia
Published: June 2010

Four coumarin derivatives [selidinin 1, (+)‐praeruptorin A 2, visnadin 3 and (R)‐(+)‐7‐(2′,3′‐epoxy‐3′‐methylbutoxy)‐coumarin 4] were isolated from the aerial parts of Ligusticum lucidum Mill. subsp. cuneifolium (Guss.) Tammaro (Apiaceae). This is the first report on the identification of these compounds in the Ligusticum genus. Their topical antiinflammatory activity was evaluated as the inhibition of croton oil‐induced ear dermatitis in mice. Each compound (0.3 μmol/cm2) induced a significant oedema reduction and compound 4 exerted an effect similar to that of the equimolar dose of the reference drug indomethacin. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of damming a large lowland river on chironomids and fish assessed with the (multiplicative partitioning of) true/Hill biodiversity measure
Authors: Głowacki Ł. , Grzybkowska M. , Dukowska M. , Penczak T.
Published: June 2010

The impact of a large lowland temperate zone reservoir on chironomid and fish biodiversity was investigated in the same upstream (U) and downstream (D) sites on the same sampling occasions in spring and autumn of several post‐impoundment years. The true/Hill N1 diversity measure was used to construct diversity models of the impact, and partitioning of N1 to reveal the importance of ecological gradients. N1 is unique in being decomposable among multiple levels and easily comparable across ecosystems and animal groups.

Chironomids were more diverse than fish in all community sets owing to their probably lower mobility, lower interspecific competition, opportunistic character and much shorter life spans than those of fish. Fish exerted consumption pressure on chironomids upstream by foraging mostly on benthic insects, but not downstream where they fed on microcrustaceans of reservoir origin or on epiphytic fauna (mainly Chironomidae).

The reservoir impact on chironomids decreased their diversity in U and increased in D, while much the opposite was true in fish. In D in macroinvertebrates, the impact consisted in advancing over time intensification of seasonal development of submersed macrophytes, while in D in fish in a few species escaping from the reservoir after their populational explosions each year.

Partitioning of diversity revealed that the spatial (upstream–downstream) gradient was the strongest factor of diversity change in chironomids as compared with season, and age of the impoundment. No gradient was dominant in fish. Comparisons of observed data with a null model testified to very strong intraspecific aggregation in both chironomids and fish. Copyright © 2010 John Wiley & Sons, Ltd.
Versatile two‐state land mobile satellite channel model with first application to DVB‐SH analysis
Authors: Prieto‐Cerdeira R. , Perez‐Fontan F. , Burzigotti P. , Bolea‐Alamañac A. , Sanchez‐Lago I.
Published: June 2010

Standardization activities on Digital Video Broadcasting–Satellite services to Handheld Devices (DVB‐SH) have driven the need for a consolidated Land Mobile Satellite (LMS) narrowband channel model. In the DVB‐SH system, the satellite broadcasts a signal carrying multimedia services aimed directly to a variety of mobile (handheld or vehicular) and fixed terminals.

A three‐state LMS channel model that describes the narrowband propagation channel in three possible shadowing states—line‐of‐sight conditions, moderate shadowing and deep shadowing—had been selected as a baseline for physical layer simulation of the DVB‐SH waveform. This type of model, capable of generating complex time series, was originally selected, because it is the simplest model that allows the simulation of first‐ and second‐order effects of the LMS channel in a realistic manner. The main limitations of such model are, first of all, that a classification in three states does not necessarily correspond with reality and, secondly, that the statistical parameters for each state were fixed for a given scenario and elevation angle. Those limitations may impact the selection of Physical Layer parameters of the DVB‐SH standard.

A new channel model is proposed based on the original three‐state model including two major modifications: a reduction in the number of states and the introduction of a versatile selection of statistical parameters describing each state. Furthermore, the state machine is governed either by Markov or by semi‐Markov chains. The new‐state classification does not necessarily correspond to intuitive physical definitions of the states as before (line‐of‐sight, shadowing) but instead to channel variations that share similar statistical characteristics. The two‐states are termed for convenience,GoodandBadstates, representing a range of LOS‐to‐moderate shadowing and moderate‐to‐deep shadowing, respectively. For the model parameters selection, datasets at L‐ and S‐band have been analysed using an iterative algorithm that includes automatic data classification and parameter extraction. The proposed model is considered more suitable for the analysis of DVB‐SH test cases.

This study starts with an overview of the main DVB‐SH system parameters and assumptions. The original three‐state model is briefly introduced; the new model is presented in detail, including simulator implementation. Finally, both models and experimental data sets are compared on a statistical basis. The performance of both models are discussed to show how effective the model is for the representation of shadowed conditions and therefore, its suitability for the analysis and optimal configuration of the physical and link layer parameters (namely physical layer interleaver size, link layer protection time, overall redundancy, etc.). Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis of polypyrrole coatings on surface of iron particles
Authors: Oriňáková Renáta , Kupková Miriam , Oriňák Andrej , Fedorková Andrea , Dudrová Eva
Published: June 2010

A simple oxidative polymerization of pyrrole (Py) directly onto the surface of Fe microparticles was applied to enhance its mechanical properties and to increase the content of carbon in resulting material. The study is focused on investigation of the chemical synthesis of polypyrrole (PPy) coatings on the surface of iron particles, and their effect on the internal and surface structure. Moreover, the effect of PPy coating on the compressibility of coated Fe powder is analyzed. Namely, a set of specimens was uniaxially pressed in a steel die. Compaction pressures ranged from 100 up to 600 MPa. To quantify the compressibility of powders, the compressibility equation proposed by Panelli and Ambrosio Filho has been. It was found that PPy coating has a positive effect on the compaction behavior of iron powders.

Detection and quantification of the PPy coatings obtained were performed by means of pyrolysis gas chromatography (Py‐GC). Both the light optical and scanning electron microscopy (LOM, SEM) were used to characterize the morphology and surface appearance of samples coated with PPy. It was found that the content of PPy in final powder material can be controlled by conditions of chemical oxidative polymerization process. The surface morphology of powder particles coated with PPy layers was changed in compliance with PPy content. Copyright © 2010 John Wiley & Sons, Ltd.
Ion, sputter and useful ion yields for accurate quantification of Si1−xGex(0 < x < 1) using ultra low energy O2+ SIMS
Authors: Morris R. J. H. , Dowsett M. G.
Published: June 2010

It has been previously demonstrated that accurate measurement of x in the Si1−xGex (x ≤ 0.3) alloy can be achieved using a variety of O2+ SIMS conditions. With SiGe device technology still developing to exploit its full potential, the useful matrices now extend from 0 ≤ x ≤ 1. Using the previously established conditions, we have found that roughening of the material occurs when x approaches 1. To overcome this limitation we have developed a set of conditions that enables the whole Si1−xGex (0 ≤ x ≤ 1) range to be quantified. This is achieved by using an O2+ primary beam energy of ≤ 500 eV at near‐normal incidence. Here, we present a comprehensive study of the measured (Si and Ge) ion, useful ion and sputter yield behavior as a function of matrix composition and incident beam energy (250 eV–1 keV), from which these new conditions have been established. For the extended Si1−xGex (0 ≤ x ≤ 1) range and primary beam energies used here, the measured Si and Ge ion yields were found to be well described by quartic, cubic or quadratic dependences as a function of x. The useful ion yields and sputter yields all showed moderate matrix effects, with the former decreasing monotonically for increasing x except in the case of Ge at 250 eV. Here, the useful Ge ion yield was found to be invariant with x while its measured ion yield (for all x) was observed to be proportional to its sputter yield. Copyright © 2010 John Wiley & Sons, Ltd.
New neutral cesium evaporation chamber and UHV suitcase
Authors: Bendler B. , Barrahma R. , Philipp P. , Wirtz T.
Published: June 2010

It is well known that the use of Cs+ primary ions results in an important increase of the negative ionization probability during SIMS analyses. Moreover, Cs+ bombardment allows working in the MCsx+ mode, which is a widely used technique to reduce the matrix effect. A major drawback of Cs+ primary ion bombardment is that the Cs+ beam serves both for the incorporation of Cs and for the sputtering of the surface. Therefore, the sputtering yield, and consequently the cesium surface concentration, are constricted by the primary bombardment conditions.

To overcome this problem, the Cation Mass Spectrometer (CMS), equipped with an evaporator delivering a collimated and adjustable stream of neutral Cs onto the sample, has been developed at the SAM department. By continuous Cs0 deposition during the SIMS analysis, optimal Cs surface concentrations, and thus optimal ionization probabilities are obtained.1

In order to make the Cs0 deposition technique available for other analysis instruments, a standalone UHV instrument for Cs evaporation prior to SIMS analyses has been developed. Furthermore, a suitcase for the transfer under UHV conditions of the samples in‐between the Cs0 evaporation chamber and the analysis instruments has been designed, to avoid any contaminations. In this work, we present this new Cs0 evaporation chamber, as well as our new UHV suitcase in terms of their characteristics and handling. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis and fragmentation of organic samples by (low‐energy) dynamic SIMS
Authors: Ngo K. Q. , Philipp P. , Jin Y. , Morris S. E. , Shtein M. , Kieffer J. , Wirtz T.
Published: June 2010

Up to now, the analysis of organic or biological samples was mainly investigated using static SIMS, while dynamic SIMS was generally limited to the analysis of inorganic samples. The increasing sophistication of organic optoelectronic devices (e.g. organic light emitting diodes and organic photovoltaic cells, etc.) requires molecular‐level dimensional control in the fabrication of multilayered structures with specifically engineered interfaces. However, analytical tools for monitoring such fabrication precision are scarce. In a current project, we address this challenge by advancing the development of low‐energy Secondary Ion Mass Spectrometry (LE‐SIMS) for the analysis of organic‐based optoelectronic materials systems.

In the present work, we investigate the fragmentation as well as the ionization mechanisms for several molecules used in such devices: fullerene, copper phthalocyanine and tris(8‐hydroxyquinolinato) aluminium have been deposited onto silicon wafers. The study has been carried out on a Cameca SC‐Ultra instrument under Cs+ bombardment for various impact energies in the M− mode. Constant M− secondary ion intensities have been observed throughout the organic layers for some characteristic fragments of the organic molecules. Copyright © 2010 John Wiley & Sons, Ltd.