bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphology and rheological properties of blends of chemically modified thermoplastic starch and polycaprolactone
Authors: Shin Boo Young , Narayan Ramani , Lee Sang Il , Lee Tae Jin
Published: September 2008

Polycaprolactone (PCL) was blended in a twin‐screw extruder with chemically modified thermoplastic starch (CMPS) to provide biobased and biodegradable resin composition. Reacting starch with maleic anhydride (MA) in the presence of a plasticizer and a free radical initiator provided the CMPS. The starch modification improved interfacial adhesion and processability in blending with other thermoplastic polyesters. The rheological, mechanical, thermal, and morphological properties of the blends were examined. Differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) studies revealed that the PCL/CMPS blends are thermodynamically immiscible. However, they formed compatible blends due to the reaction of the carboxyl groups on starch backbone with hydroxyl groups of the PCL chain ends. The tensile strength and elongation decreased with increasing CMPS content, whereas the modulus increased. Dynamic viscoelastic measurements showed that the flow behavior of PCL was that of Newtonian fluid within the tested frequencies, whereas the CMPS exhibited strong shear thinning characteristics. The flow behavior of the blends varied with the CMPS content. The complex viscosity, storage, and loss moduli of the blends containing more than 40% of CMPS were higher than those of pure CMPS and PCL. In addition, the properties of CMPS to those of chemically unmodified thermoplastic starch (TPS) were compared. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Injection molding of a diffractive optical element
Authors: Tofteberg Terje , Amédro Hélène , Andreassen Erik
Published: September 2008

The injection molding of a microfeatured component, a diffractive optical element, was studied. The component has a wave‐like pattern on the surface, with amplitude 0.5 μm and wavelength 3 μm. Two different polymers were used: a polymethylmethacrylate and an ethylene‐norbornene copolymer (cyclic olefin copolymer). The topography was investigated using white light interferometry (WLI), atomic force microscopy (AFM), and scanning electron microscopy (SEM). A new WLI‐based technique is proposed for rapid quantification of the replication of periodic surface patterns. This technique gives almost the same information regarding the degree of replication as AFM but can be performed much faster. Quantitative data on the degree of replication as function of processing conditions are presented. At optimal conditions, almost perfect replication is obtained using both materials. At suboptimal conditions, it is observed that the degree of replication increases with increasing injection velocity and increasing mold temperature, with similar characteristics for both materials. The difference in replication quality between the two materials seems to be related to the different temperature dependencies of the viscosities. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Film insert molding as a novel weld‐line inhibition and strengthening technique
Authors: Leong Yew Wei , Umemura Toshikazu , Hamada Hiroyuki
Published: September 2008

Specimens with weld lines were produced via conventional and film insert molding techniques using two types of materials as the substrate resin, i.e. a polycarbonate/acrylonitrile‐butadiene‐styrene (PC/ABS) blend and glass fiber‐filled polycarbonate (PC‐gf). The formation and morphology of the weld line region was assessed with and without the presence of 0.5‐mm‐thick PC film inserts. The weld line formation and characteristics were found to be dependent on the extent of interaction between the injected resin and the mold surface or the film insert. Better interfacial interaction between the substrate and film led to the distortion of the weld line orientation, which significantly enhanced the mechanical properties of the weld line. The incorporation of glass fibers into the substrate resin would usually reduce the resistance of the weld line towards tensile, flexural and impact loadings. However, with the attachment of film inserts, the mechanical properties of the weld line region have significantly improved, even with the presence of rigid fibers. Upon examination of tensile and impact fracture surfaces of film insert specimens, a unique orientation of fibers across the weld line (parallel to the flow direction and perpendicular to the weld line) could be observed at regions directly under the film. The combination of favorable properties from the unique fiber orientation and distortion of the weld line, as well as the ability of the film to effectively dissipate forces towards a larger area, have synergistically contributed towards the mechanical property enhancement of the weld line region in film insert moldings. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Analysis of electrical, dielectric, and electromagnetic interference shielding behavior of graphite filled high density polyethylene composites
Authors: Panwar Varij , Mehra R.M.
Published: September 2008

Conducting polymer composites were prepared by hot compression molding of high‐density polyethylene (HDPE) prelocalized with graphite (Gr). The variation of room temperature electrical conductivity, dielectric constant, and Shore‐D hardness as a function of graphite content were studied below and above percolation threshold. The percolation threshold at which insulator‐conductor transition takes place is estimated to be 0.029 volume fraction of graphite. The observed increase in dielectric constant with addition of graphite also found to be percolative in nature. Above percolation threshold, the dielectric constant is found to decrease sharply with increase in frequency. Electromagnetic shielding effectiveness of HDPE/Gr composites was evaluated in the X‐band frequency range. The composites were found to possess both positive and negative temperature coefficient of resistance. Reproducibility of electrical resistivity with temperature was observed only below the processing temperature. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Multiobjective optimization of an industrial nylon‐6 semi batch reactor using the a‐jumping gene adaptations of genetic algorithm and simulated annealing
Authors: Ramteke Manojkumar , Gupta Santosh K.
Published: September 2008

The elitist nondominated sorting genetic algorithm (NSGA‐II) and multiobjective simulated annealing (MOSA) with the robust fixed‐length jumping gene adaptation (aJG) are used to solve three computationally intensive multiobjective optimization problems for an industrial semi batch nylon‐6 reactor. In Problems 1 and 2, the batch time and the final concentration of the undesirable side‐product (cyclic dimer) are minimized while maintaining desired values of the degree of polymerization of the product and the monomer conversion (monomer conversion is maximized as a third objective in Problem 3). The histories of two decision variables, pressure [or vapor release rate] and jacket fluid temperature, are used to obtain the Pareto optimal fronts. The study predicts considerable improvement over earlier results when (i) a single‐stage steam jet ejector is used to create subatmospheric pressures in the reactor, (ii) when the jacket fluid temperature is taken as a function of time, and (iii) when some amino caproic acid (from the depolymerization of scrap nylon‐6) is added to the feed. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Challenges of shape memory polymers: A review of the progress toward overcoming SMP's limitations
Authors: Rousseau Ingrid A.
Published: September 2008

Many applications ranging from biomedical to aerospace have been proposed for the use of shape memory polymers (SMPs). To optimize SMPs properties for appropriately targeting such wide‐spreading application requirements, it becomes necessary to understand the structure/property relationships in SMPs. The literature was reviewed and the recent advances made in the development of SMPs were determined to establish guidelines for composition and structure considerations for designing SMPs with targeted chemical, physical, and shape memory (SM) properties. It was concluded that covalently crosslinked glassy thermosets appear to be better SMP candidates because of their intrinsically higher modulus, greater thermal and chemical stability, higher shape fixity and recovery, and possibly their longer cycle life. However, material design allows for reaching comparable or better properties for all classes of SMPs. This emphasizes that optimization of SMPs requires application‐specific molecular, structural, and geometrical design. Current techniques for improving stress recovery and cycle time, which compared to shape memory alloys are the two main limitations of SMPs, are extensively discussed. Understanding the relationships between the composition and structure of an SMP and its SM properties as well as its limitations enables one to better define the development areas for high performance SMPs. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Advances in the assessment of social competence: Findings from a preliminary investigation of a general outcome measure for social behavior
Authors: Cummings Kelli D. , Kaminski Ruth A. , Merrell Kenneth W.
Published: September 2008

This study describes the initial validation of an innovative social‐‐behavioral observational assessment tool that is designed to be used on a repeated basis to assess growth and development of social competence over time to: (a) identify the social functioning of all students, (b) assist in planning support for students at risk, and (c) evaluate the effectiveness of individual and system‐wide interventions. Eighteen first‐grade students were monitored over an 8‐week period using the Initiation‐Response Assessment (IRA) Code. The School Social Behavior Scales, a published teacher rating scale, was included as a criterion measure. Estimates of reliability and criterion‐related validity were calculated for the IRA. The measure's sensitivity to growth over time and between‐group variability were also assessed using hierarchical linear modeling procedures. Results indicate that scores on this measure are stable, and tap constructs similar to those assessed via teacher rating. © 2008 Wiley Periodicals, Inc.
Impact of videotaped instruction in dialogic reading strategies: An investigation of caregiver implementation integrity
Authors: Briesch Amy M. , Chafouleas Sandra M. , Lebel Teresa J. , Blom‐Hoffman Jessica A.
Published: September 2008

Research during the past 15 years has repeatedly demonstrated the beneficial effects of dialogic reading (DR), a form of shared storybook reading, on the development of language in preschool children. Although much is known about the effects of DR on children, little attention has been paid to the role that adult caregivers play in the DR experience. Specifically, we do not yet have an understanding of the frequency and consistency with which caregivers use DR strategies in daily practice, prior to and following training. In the current study, the integrity with which six caregivers used DR strategies with their preschool‐aged children subsequent to viewing a commercially available training videotape was investigated. Results indicate that caregivers can learn to use several DR strategies through videotaped training; however, supplemental training may be necessary to teach caregivers certain strategies if they are to use them with integrity. © 2008 Wiley Periodicals, Inc.
The MS Society
Authors: Bentley Chris
Published: September 2008

The MS Society is the UK's largest charity dedicated to supporting everyone whose life is touched by MS. It provides respite care, a freephone MS helpline, grants for home adaptations and mobility aids, education and training, specialist MS nurses and a wide range of information. The MS Society also funds over 40 vital MS research projects in the UK. Chris Bentley, press officer for the MS Society, provides more detail. Copyright © 2008 Wiley Interface Ltd
British Association for Psychopharmacology 2008 Summer Meeting
Authors: Donoghue John
Published: September 2008

The British Association for Psychopharmacology (BAP) held its summer meeting in Harrogate in July. Medical writer, John Donoghue, reports on the highlights of some of the sessions, covering cognitive dysfunction in mood disorders, early intervention in schizophrenia and management of bipolar disorder. Copyright © 2008 Wiley Interface Ltd
Cambridge Behavioural Inventory for the diagnosis of dementia
Authors: Hancock Paula , Larner Andrew J
Published: September 2008

The Cambridge Behavioural Inventory (CBI) is a short, self‐administered informant questionnaire developed to distinguish between the behavioural and psychiatric symptoms of Alzheimer's dementia and fronto‐temporal dementia. Here, Dr Hancock and Dr Larner present the results of their study to investigate the diagnostic utility of the Cambridge Behavioural Inventory in a cohort of patients attending their memory clinic. Copyright © 2008 Wiley Interface Ltd
Study of the Desensitizing Effect of Different [60]Fullerene Crystals on Cyclotetramethylenetetranitramine (HMX)
Authors: Jin Bo , Peng Rufang , Chu Shijin , Huang Yiming , Wang Rong
Published: September 2008

Three types of [60]fullerene crystals were obtained. The first one was the direct commercial [60]fullerene, and the other two were recrystallized from the first one in carbon bisulfide and in carbon bisulfide/petroleum ether, respectively. Scanning electron microscopy (SEM), X‐ray powder diffractometry (XRD), and FT‐IR spectrometry were used to study the physical characteristics of the crystals. The thermal stability of the three [60]fullerene crystals was studied by differential thermal analysis (DTA), and the effects of the three [60]fullerenes on the mechanical sensitivity and friction sensitivity of HMX were tested and analyzed. It was found that the three types of [60]fullerenes have different thermal stabilities, and the friction and impact sensitivities of HMX are reduced from 100% to 70% and to 60%, respectively when 1% [60]fullerene 3 was added in HMX.
Pyrotechnic Countermeasures: IV. Radiometric Performance of a Sulphur‐based Flare Composition
Authors: Koch Ernst‐Christian
Published: September 2008

Radiometric performance of a sulphur‐based flare composition has been investigated. Composition comprising sulphur, potassium perchlorate and antimony sulphide has acceptable band ratio but an order of magnitude weaker spectral efficiency than typical carbon‐based compositions. The use of other sulphur compounds with potential for increased performance is discussed. For part III see Ref. [1].
Influence of Mg doping on the behaviour of polaronic light‐induced absorption in LiNbO3
Authors: Conradi D. , Merschjann C. , Schoke B. , Imlau M. , Corradi G. , Polgár K.
Published: September 2008

Transient light‐induced absorption changes αli(t), caused by optically generated small polarons, are investigated in LiNbO3:Mg below and above the optical‐damage‐resistance threshold (ODRT). The lifetime of αli(t) is reduced by three orders of magnitude above the ODRT while a significantly enhanced amplitude $ \alpha ^{\rm max} _{\rm li} $ is observed in the infrared. Our observations are in full accordance with the predictions of microscopic models for the ODRT, namely the removal of NbLi antisite defects upon incorporation of Mg ions, and an enhanced dark conductivity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Maintaining quality of fresh strawberries through various modified atmosphere packaging
Authors: Caner Cengiz , Aday Mehmet Seckin
Published: September 2008

The influence of various modified atmosphere packaging (MAP) (21/0.05, 4/8 and 60/20% O2/% CO2) on fresh strawberry qualities [pH, acidity, °Brix, colour (L, a) and texture profile analyses] was investigated and compared during storage.

Among the gas combinations used, pH of fresh strawberry was 3.281 at 1 day, and increased to 3.561 for air [21/0.05% (O2/CO2)], 3.53 for low (4/8) and 3.538 high (60/20) at 12 days. At the end of the storage, °Brix had evolved from the initial 7.07 to 5.47, 5.65 and 5.62 for 21% O2; 4% O2 and 60% O2, respectively. Storage in 60% O2 or 4% O2 delayed the decrease of °Brix, titratable acidity and increased pH compared with 21% O2. At the end of the storage, the strawberry L values had slightly decreased.

Initial values of the firmness were 1067 gf and reduced to 501 gf (21% O2); 613 gf (4% O2) and 575 gf (60% O2) at 12 days storage. Higher O2 resulted in better springiness and chewiness than those treated with 4% O2 and 21% CO2, but did not significantly affect resilience.

These results show that the use of various MAP gas compositions, including high oxygen, could be a good alternative to maintain fresh strawberry qualities for at least 12 days. Copyright © 2008 John Wiley & Sons, Ltd.
The impact of satellite retrievals in a global sea‐surface‐temperature analysis
Authors: Brasnett Bruce
Published: September 2008

An analysis of sea surface temperature (SST) is described. It incorporates in situ observations and retrievals from one microwave and three infrared sensors. Statistical interpolation is used to update the analysis daily on a global grid with a resolution of 1/3°. The background or first‐guess field is essentially the analysis from the previous day. Satellite retrievals and buoy observations undergo a thinning and all data is subjected to a careful quality control. A scheme to remove large‐scale biases from the satellite data is included, and its impact is assessed.

Analysis error is estimated using two sources of independent data with similar results. The global average r.m.s. error is less than 0.4 K. Zonally averaged errors were computed over 15°‐wide latitude bands giving errors in the range 0.25 K to 0.5 K. The contributions from infrared and microwave data are found to be roughly of equal importance. The two data types are shown to be complementary, producing a significant improvement in analysis error when used together compared with the error obtained when only one is used. The analysis also compares favourably with SST analyses produced by three other centres. Copyright © 2008 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.
Characteristics and comparison of different radiofrequency‐only multipole cooling cells
Authors: He Jian , Yu Quan , Li Lingfeng , Hang Wei , Huang Benli
Published: September 2008

Various multipole cooling cells are widely used in mass spectrometry for their outstanding performance with regard to transmission and cooling effects. Among these, radiofrequency (RF)‐only quadrupoles, hexapoles, and octopoles are routinely used in practical instrumentation. A study of their performance has been carried out using a house‐built electrospray time‐of‐flight mass spectrometer equipped with three different multipole devices. In addition, a user‐written program was developed using SIMION 7.0 to simulate ion transmission characteristics for the different devices utilized. Systematic experiments and simulations were performed with an RF‐only quadrupole, hexapole, and octopole to study their theoretical and practical characteristics. Copyright © 2008 John Wiley & Sons, Ltd.
Selective isolation of N‐terminal peptides from proteins and their de novo sequencing by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry without regard to unblocking or blocking of N‐terminal amino acids
Authors: Yamaguchi Minoru , Nakayama Daisuke , Shima Keisuke , Kuyama Hiroki , Ando Eiji , Okamura Taka‐aki , Ueyama Norikazu , Nakazawa Takashi , Norioka Shigemi , Nishimura Osamu , Tsunasawa Susumu
Published: September 2008

We have developed a new method to determine the N‐terminal amino acid sequences of proteins, regardless of whether their N‐termini are modified. This method consists of the following five steps: (1) reduction, S‐alkylation and guanidination for targeted proteins; (2) coupling of sulfo‐NHS‐SS‐biotin to Nα‐amino groups of proteins; (3) digestion of the modified proteins by an appropriate protease followed by oxidation with performic acid; (4) specific isolation of N‐terminal peptides from digests using DITC resins; (5) de novo sequence analysis of the N‐terminal peptides by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) using the CAF (chemically assisted fragmentation) method or tandem mass spectrometric (MS/MS) analysis according to unblocked or blocked peptides, respectively. By employing DITC resins instead of avidin resins used in our previous method (Yamaguchi et al., Rapid Commun. Mass Spectrom. 2007; 21: 3329), it has been possible to isolate selectively N‐terminal peptides from proteins regardless of modification of N‐terminal amino acids. Here we propose a universal method for N‐terminal sequence analysis of proteins. Copyright © 2008 John Wiley & Sons, Ltd.
Characteristic negative ion fragmentations of deprotonated peptides containing post‐translational modifications: mono‐phosphorylated Ser, Thr and Tyr. A joint experimental and theoretical study
Authors: Andreazza Hayley J. , Fitzgerald Mark , Bilusich Daniel , Hoffmann Ralf , Hoffmann Peter , Eichinger Peter C. H. , Bowie John H.
Published: September 2008

Peptides and proteins may contain post‐translationally modified phosphorylated amino acid residues, in particular phosphorylated serine (pSer), threonine (pThr) and tyrosine (pTyr). Following earlier work by Lehmann et al., the [M–H]− anions of peptides containing pSer and pThr functionality show loss of the elements of H3PO4. This process, illustrated for Ser (and using a model system), is CH3CONH−C(CH2OPO3H2)CONHCH3 → [CH3CONHC(CH2)CONHCH3 (−OPO3H2)] (a) → [CH3CONHC(CH2)CONHCH3–H]− + H3PO4, a process endothermic by 83 kJ mol−1 at the MP2/6‐31++G(d,p)//HF/6‐31++G(d,p) level of theory. In addition, intermediate (a) may decompose to yield CH3CONHC(CH2)CONHCH3 + H2PO in a process exothermic by 3 kJ mol−1. The barrier to the transition state for these two processes is 49 kJ mol−1. Characteristic cleavages of pSer and pThr are more energetically favourable than the negative ion backbone cleavages of peptides described previously. In contrast, loss of HPO3 from [M–H]− is characteristic of pTyr. The cleavage [NH2CH(CH2‐C6H4‐OPO3H−)CO2H] → [NH2C(CH2‐C6H4‐O−)CO2H (HPO3)] (b) → NH2CH(CH2‐C6H4‐O−)CO2H + HPO3 is endothermic by 318 kJ mol−1 at the HF/6‐31+G(d)//AM1 level of theory. In addition, intermediate (b) also yields NH2CH(CH2‐C6H4‐OH)CO2H + PO (reaction endothermic by 137 kJ mol−1). The two negative ion cleavages of pTyr have a barrier to the transition state of 198 kJ mol−1 (at the HF/6‐31+G(d)//AM1 level of theory) comparable with those already reported for negative ion backbone cleavages. Copyright © 2008 John Wiley & Sons, Ltd.
Joint modelling of longitudinal and competing risks data
Authors: Williamson P. R. , Kolamunnage‐Dona R. , Philipson P. , Marson A. G.
Published: September 2008

Available methods for joint modelling of longitudinal and survival data typically have only one failure type for the time to event outcome. We extend the methodology to allow for competing risks data. We fit a cause‐specific hazards sub‐model to allow for competing risks, with a separate latent association between longitudinal measurements and each cause of failure.

The method is applied to data from the SANAD trial of anti‐epileptic drugs (AEDs), as a means of investigating the effect of drug titration on the relative effects of lamotrigine (LTG) and carbamazepine (CBZ) on treatment failure. Concern had been expressed that differential titration rates may have been to the disadvantage of CBZ. The beneficial effect of LTG on unacceptable adverse events leading to drug withdrawal did not lessen and indeed increased slightly when a calibrated dose was accounted for in the joint model. Adjustment for the titration rate of LTG relative to CBZ resulted in an unchanged effect of the former on drug withdrawals due to inadequate seizure control. LTG remains the AED of choice from this analysis. Copyright © 2008 John Wiley & Sons, Ltd.
A bivariate autoregressive linear mixed effects model for the analysis of longitudinal data
Authors: Funatogawa Ikuko , Funatogawa Takashi , Ohashi Yasuo
Published: September 2008

In clinical studies, dependent bivariate continuous responses may approach equilibrium over time. We propose an autoregressive linear mixed effects model for bivariate longitudinal data in which the current responses are regressed on the previous responses of both variables, fixed effects, and random effects. The equilibria are modeled using fixed and random effects. This model is a bivariate extension of the model for univariate longitudinal data given by Funatogawaet al. (Statist. Med.2007;26:2113–2130). As an illustration of the approach we analyze parathyroid hormone and serum calcium measurements in the treatment of secondary hyperparathyroidism in chronic hemodialysis patients. Copyright © 2008 John Wiley & Sons, Ltd.
Connecting organizations: Developing the idea of network learning in inter‐organizational settings
Authors: White Leroy
Published: September 2008

The purpose of this paper is to introduce a form of analysis that is important in the development of inter‐agency working and partnerships. Social network analysis is being seen as increasingly important in understanding inter‐organizational life. The paper will introduce the idea of network learning, which is in principle a way of making social networks explicit and using an understanding of them as a part of a learning process for partnership development. The paper will also argue for a practice of network learning which integrates social network analysis with Soft Operational Research. This combination, it will be shown, provides further insights into understanding collaboration (a systems‐level phenomena) in inter‐agency networks or partnerships. These ideas will be described and reviewed in detail via a case study. Copyright © 2008 John Wiley & Sons, Ltd.
Earthquake proof efficacy of Velocity and Displacement Dependent Hydraulic Damper (VDHD) for R.C. structures
Authors: Shih Ming‐Hsiang , Sung Wen‐Pei , Chen Chang‐Liang
Published: September 2008

The objective of this research is to study whether a Velocity and Displacement Dependent Hydraulic Damper (VDHD) will provide effective damping without increasing the acceleration response of a reinforced concrete structure during an earthquake before the yield strength is reached. The study also includes whether this device will provide hysteretic energy after the yield strength is reached to effectively lower the structural displacement reaction. The efficiency of VDHD is confirmed using a nonlinear numerical model developed by the authors for carrying out numerical analyses of three dampers, i.e. Viscous Damper (VD), Bulking Resistant Bracing (BRB) and VDHD, to study the response of structures excited by earthquake and to compare model parameters based on their seismic performance. The results indicate that when a reinforced concrete structure is subject to near‐fault earthquake for various durations, VDHD has a better structural displacement response capability than either VD or BRB with a medium efficiency to suppress the acceleration response between VD and BRB. These observations conform to the theoretical predications thus verifying the capability of VDHD to lower the displacement and acceleration responses of a reinforced concrete structure during earthquake. The results presented in this paper illustrate the earthquake resistant capacity of VDHD to protect reinforced concrete structures. Copyright © 2008 John Wiley & Sons, Ltd.
First occurrence of cylindrospermopsin in freshwater in France
Authors: Brient Luc , Lengronne Marion , Bormans Myriam , Fastner Jutta
Published: September 2008

Eleven waterbodies in Western France dominated by cyanobacteria of the genera Aphanizomenon and Anabaena were analyzed in September 2006 for microcystins (MC) and cylindrospermopsin (CYN). CYN was detected for the first time in France in four of them in the presence of Aphanizomenon flos‐aquae and in the presence of Anabaena planctonica in the other. The intracellular concentrations of CYN measured by LC‐MS/MS ranged between 1.55 and 1.95 μg/L. The occurrence of CYN represents an additional health hazard to MC especially because Aphanizomenon flos‐aquae is the third most common species in freshwaters in France. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009.
In vitro cytotoxicities of ionic liquids: Effect of cation rings, functional groups, and anions
Authors: Kumar R. Anand , Papaïconomou Nicolas , Lee Jong‐Min , Salminen Justin , Clark Douglas S. , Prausnitz John M.
Published: September 2008

In vitro cytotoxicities were measured for ionic liquids (ILs) containing various cations and anions using the MCF7 human breast cancer cell line. We measured the cytotoxicities of ionic liquids containing the cations pyridinium, pyrrolidinium, piperidinium, or imidazolium with various alkyl chain lengths, and the anions bromide, bis(trifluoromethanesulfone)imide (Tf2N), trifluoromethylsulfonate (TfO), or nonafluoromethylsulfonate (NfO). Three new hydrophobic, task‐specific ionic liquids (TSILs), namely, [MBCNPip]+[Tf2N]−, [MPS2Pip]+[Tf2N]−, and [MPS2Pyrro]+[Tf2N]− designed for metal‐ion extraction were also evaluated. IC50 values of the ionic liquids toward the MCF7 cells ranged from 8 μM to 44 mM. The toxicity depended significantly on the nature of the cations and anions, especially when the cations contained a long side chain. TSILs studied in this work were less toxic than the classical ILs. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009.
Towards adaptive security for convergent wireless sensor networks in beyond 3G environments
Authors: Mitseva Anelia , Aivaloglou Efthimia , Marchitti Maria , Prasad Neeli Rashmi , Skianis Charalabos , Gritzalis Stefanos , Waller Adrian , Baugé Tim , Pennington Sarah
Published: September 2008

The integration of wireless sensor networks with different network systems gives rise to many research challenges to ensure security, privacy and trust in the overall architecture. The main contribution of this paper is a generic security, privacy and trust framework providing context‐aware adaptability, flexibility and scalability which allows customisation of wireless sensor networks to a diverse set of application spaces. Suitable protocols and mechanisms are identified, which when combined according to the framework form a complete toolbox solution which fits the architecture of Beyond 3G environments. Performance evaluation results demonstrate the feasibility and estimate the benefits of the security framework for a variety of scenarios. Copyright © 2008 John Wiley & Sons, Ltd.
Impact of wind power forecasting error bias on the economic operation of autonomous power systems
Authors: Tsikalakis Antonis G. , Hatziargyriou Nikos D. , Katsigiannis Yiannis A. , Georgilakis Pavlos S.
Published: September 2008

Many efforts have been presented in the literature for wind power forecasting in power systems and few of them have been used for autonomous power systems. In addition, some recent studies have evaluated the impact on the operation of power systems and energy markets that the improvement of wind power forecasting can have. In this paper, the value of the information provided to the operators of autonomous power systems about forecasting errors is studied. This information may vary significantly, e.g. it can be only the normalized mean absolute error of the forecast, or a probability density function of the errors for various levels of forecasted wind power, which can be provided either during the evaluation phase of the wind power forecasting tool or by online uncertainty estimators. This paper studies the impact of the level of detail provided about wind power forecasting accuracy for various levels of load and wind power production. The proposed analysis, when applied to the autonomous power system of Crete, shows significant changes among the various levels of information provided, not only in the operating cost but also in the wind power curtailment. Copyright © 2008 John Wiley & Sons, Ltd.
Delegated dispatching of wind farms: an optimal approach considering continuous control and interruption capabilities
Authors: Castronuovo Edgardo , Usaola Julio , Jaramillo Álvaro
Published: September 2008

In grids with high wind power penetration, the System Operator may curtail the power injected at critical moments for security reasons. An intermediate operator can optimize this power reduction for a group of wind farms under its control, attending to their controllability. In this way, resources may be used efficiently, and in cooperation with the system operation. In this paper, an optimization‐based procedure is proposed to allocate the power reductions among the wind farms of a region. Application examples based on the Spanish situation are shown, because in that country, these intermediate entities (called Delegated Dispatches) are about to begin their full operation. Copyright © 2008 John Wiley & Sons, Ltd.
Von N,N′‐Bis(1,1,3‐trisila‐2‐aza)‐ethylen‐diaminen zu N,N′‐Bis(1,3‐disila‐2‐lithiumamido)‐ethylensilylaminen – Synthesen, Kristallstrukturen, Reaktionen
Authors: Matthes Christoph , Klingebiel Uwe , Deuerlein Stephan , Ott Holger , Stalke Dietmar
Published: September 2008

From N,N′‐Bis(1,1,3‐trisila‐2‐aza)‐ethylene‐diamines to N,N′‐Bis(1,3‐disila‐2‐lithiumamido)‐ethylenesilylamines – Syntheses, Crystal Structures, Reactions

Ethylenediamine reacts with the chloro‐functional tris(silyl)amines ClSiMe2N(SiMe3)SiMe2R in a molar ratio of 1:2 to give the N,N′‐bis(1,1,3‐trisila‐2‐aza)‐ethylenediamines, [CH2‐NH‐SiMe2‐N(SiMe3)SiMe2R]2, R = Me (1) and CMe3 (2). A structural isomer of 2 (CH2‐NSiMe2CMe3‐SiMe2‐NHSiMe3 = 3) is formed thermally, via 1,3‐silyl group migration from the Me3CSiMe2‐N‐SiMe3 group, at 200 °C. 1 reacts with butyllithium at 0 °C in a molar ratio of 1:2, forming the diamide 4, which was characterized as the monomer [CH2–NSiMe3–SiMe2–N(SiMe3)Li]2. Again two silyl groups migrate from the N(SiMe3)2 groups to the ethyleneamine nitrogen atoms. The lithium ions are coordinated by both amido groups forming a planar four‐membered ring. With THF as a solvent, each lithium ion of 4 coordinates one THF molecule. [CH2–NSiMe3–SiMe2–N–(SiMe3)Li–THF]2 (5) is obtained. With TMEDA as the donor base the cage structures of 4 and 5 are broken up to give an open‐chain dilithium salt [CH2–NSiMe3–SiMe2–N(SiMe3)Li–TMEDA]2 (6) with each lithium ion coordinated by one TMEDA molecule. Halosilanes and haloboranes react with 4, 5, and 6 to give an N,N′‐bis(1,1,3‐trisila‐2‐aza)‐ethylenesilylamine [CH2–NSiMe3–SiMe2–N(SiMe3)R]2, R = SiF2CMe3 (7), and N,N′‐bis(1‐bora‐1,3‐disila‐2‐aza)‐ethylenesilylamines, R = B(F)N(SiMe3)2 (8), B(F)[N(CMe2CH2)2CH2] (9).
The Structure of Silverpentafluorobenzoate Monohydrate, AgCO2C6F5·H2O
Authors: Weigand Holger , Tyrra Wieland , Naumann Dieter
Published: September 2008

Silverpentafluorobenzoate monohydrate, AgCO2C6F5·H2O, was prepared from the reaction of AgNO3 and NaCO2C6F5 in aqueous solution. Crystallization of the raw material from water at 20 °C gave single crystals suitable for X‐ray diffraction. The title compound crystallizes in the monoclinic space group P21/c (Z = 4).
Benzannulated Bisgermylenes – Aggregation Behavior and Coordination Chemistry
Authors: Hahn F. Ekkehardt , Zabula Alexander V. , Pape Tania , Hepp Alexander
Published: September 2008

The N‐heterocyclic benzannulated bisgermylene 3 with a 1,3‐(CH2)2C6H4 linker between the germylene moieties and sterically non‐demanding N‐CH2CH3 groups has been prepared. An X‐ray diffraction study shows intermolecular Ge···N interactions in the solid state. This interaction leads to a polymeric arrangement of the bisgermylene molecules in the crystal lattice. The bisgermylene 4 with a long and flexible –(CH2)5– linking unit between the germylene moieties reacts with [Mo(ndb)(CO)4] to yield complex [Mo(4)(CO)4] (5). The X‐ray analysis of 5 shows two rotamers co‐existing in a unit cell. Both conformers significantly differ from each other by the orientation of the coordinated germylene moieties to each other. Two conformers were also observed in the Raman spectrum of crystalline 5.
The Solid Solutions M19Q6X7 with M = Ag, Cu; Q = S, Se, Te and X = S, Se, Te
Authors: Nilges Tom
Published: September 2008

X‐ray powder diffraction, EDX‐ and DSC measurements were performed in order to determine the structural and thermal properties of the solid solutions Ag19Te6Br7−xClx, Ag19Te6Br7−yIy, Ag19Te6−aSaBr7, Ag19Te6−bSebBr7 and Ag19−zCuzTe6Br7. Three different structure types, the Ag19Te6Br7, the Ag19Te5SeBr7 and the Ag19Te6Br5.4I1.6 type are realized, dependent on the type and grade of substitution. The Ag19Te6Br7 structure type is present for the solid solutions Ag19Te6Br7−xClx, Ag19Te6−aSaBr7 and Ag19−zCuzTe6Br7. For b ≥1 in case of Ag19Te6−bSebBr7 and for y ≥1.25 in Ag19Te6Br7−yIy the Ag19Te6Br7 structure type is replaced by the Ag19Te5SeBr7 and the Ag19Te6Br5.4I1.6 structure type. All compounds show peritectic decomposition to the binary compounds Ag23Te12Br and Ag5Te2Cl, respectively.
Monomere versus dimere Dialkylaluminiumalkinide R2Al‐C≡C‐R′ – dreifach koordinierte Aluminiumatome gebunden an C≡C‐Dreifachbindungen
Authors: Uhl Werner , Er Elif , Hübner Olaf , Himmel Hans‐Jörg
Published: September 2008

Monomeric versus Dimeric Dialkylaluminum Alkynides R2Al‐C≡C‐R′ – Tricoordinated Aluminum Atoms Attached to C≡C Triple Bonds

Addition of lithium ethynides, Li‐C≡C‐R (R = C6H5, CMe3), to cooled solutions of the chloroalane Cl‐Al[CH(SiMe3)2]2 (1) afforded the corresponding dialkylaluminum alkynides. Caused by the effective steric shielding the products (2 and 3) are monomeric in solution and in the solid state. They possess coordinatively unsaturated, tricoordinated aluminum atoms attached to C≡C triple bonds and relatively short bonds between aluminum and the alkinyl carbon atoms (<191.4 pm). Owing to quantum‐chemical calculations an interaction between the empty p‐orbital at aluminum with the π‐system of the triple bond can clearly be excluded. The sterically less shielded di(tert‐butyl)aluminum chloride yielded the dimeric aluminumalkynide 4 upon treatment with lithium tert‐butylalkynide. Lithium‐trimethylsilylethynide, Li‐C≡C‐SiMe3, and 1 gave always the alanate Li[(Me3Si‐C≡C)2Al{CH(SiMe3)2}2] (5) independently of the stoichiometric ratio of the starting compounds.
Magnetic and Electronic Properties of RENiBi (RE = Pr, Sm, Gd–Tm, Lu) Compounds
Authors: Casper Frederick , Felser Claudia
Published: September 2008

Resistivity and magnetic measurements were used to examine the ternary rare earth compounds RENiBi (RE = Pr, Sm, Gd‐Tm, Lu). These compounds order antiferromagnetically with TN below 16 K (RE = Pr, Sm, Gd‐Tm) or are paramagnetic (LuNiBi). For some of these compounds a metal–insulator transition was found. The metal–insulator transition temperature depends strongly on the preparation conditions. Both the magnetic ground states and the resistance behavior are in good agreement with electronic band structure calculations.
Organometallic Compounds of the Lanthanides. 183 Lanthanide Benzyl Complexes of the Type [Li(tmeda)2][Ln(CHRSiMe2R′)3Cl] (Ln = Pr, Nd, Sm, Er, Lu; R = Ph, 3,5‐Me2C6H3; R′ = Me,tBu, Ph) and [Li(tmeda)]2(μ‐Cl)3Ln(CHPhSiMe2tBu)2(Ln = Er, Lu)
Authors: Schumann Herbert , Freckmann Dominique M. M. , Dechert Sebastian
Published: September 2008

PrCl3, NdCl3, SmCl3, ErCl3, and LuCl3react with three mole equivalents of [Li(tmeda)][CHPhSiMe3] (1), [Li(tmeda)][CHPhSiMe2tBu] (2), [Li(tmeda)][CHPhSiMe2Ph] (3), and [Li(tmeda)][CH(C6H3Me2‐3,5)SiMe2tBu] (4) forming theatecomplexes [Li(tmeda)2][Ln(CHPhSiMe3)3Cl] (Ln = Pr (5a), Nd (6a), Sm (7a)), [Li(tmeda)2][Ln(CHPhSiMe2tBu)3Cl] (Ln = Pr (5b), Nd (6b), Sm (7b)), [Li(tmeda)2][Pr(CHPhSiMe2Ph)3Cl] (5c), and [Li(tmeda)2][Ln(CH(C6H3Me2‐3,5)SiMe2tBu)3Cl] (Ln = Er (8d), Lu (9d)). {[Li(tmeda)]2[Nd(CHPhSiMe3)Cl4]}2(10) and {[Li(tmeda)][Nd(CHPhSiMe3)Cl3(THF)]}2(11) crystallize from concentrated ethereal solutions of6aafter addition of pentane.4reacts with two equivalents of ErCl3and LuCl3yielding [Li(tmeda)]2(μ‐Cl)3Ln(CHPhSiMe2tBu)2(Ln = Er (12), Lu (13)). Compounds7a,b,9d, and13have been characterized by1H and9dand13also by13C NMR spectroscopy, compounds6b,7a,8d,9d,10,11,12, and13by X‐ray structure analysis.
Reactions of Carbodiimides with ZnEt2 and MeZnCl
Authors: Schulz Stephan , Münch Marlene , Flörke Ulrich
Published: September 2008

The reaction of ZnEt2 and i‐PrN=C=Ni‐Pr in toluene at elevated temperature yields the zinc amidinate complex [{EtC(Ni‐Pr)2}ZnEt]2 1. In contrast, the reaction of stronger Lewis acidic MeZnCl with t‐BuN=C=Nt‐Bu resulted in the formation of the Lewis acid‐base adduct Me(Cl)Zn‐N(t‐Bu)CNt‐Bu 2, which adopts a dimeric, Cl‐bridged structure in the solid state. 1 and 2 were characterized by elemental analyses, mass and multinuclear (1H, 13C{1H}) NMR spectroscopy (1H, 13C), and single crystal X‐ray analysis.
Carbid‐verbrückte Komplexe [HB(pz)3(OC)2Mo≡C‐Pt(PPh3)2Br], [(TPP)Fe≡C‐M(CO)4‐M(CO)5] (M = Mn, Re), [(TPP)Fe=C=Cr(CO)5] und (TPP)Fe=C=Fe(CO)4] (pz = 3,5‐dimethylpyrazol‐1‐yl; TPP = Tetra‐phenylporphyrinat) aus Halogeno‐Carbin und ‐Carben‐Komplexen
Authors: Knauer Wolfgang , Beck Wolfgang
Published: September 2008

Carbide Bridged Complexes [HB(pz)3(OC)2Mo≡C‐Pt(PPh3)2Br], [(TPP)Fe≡C‐M(CO)4‐M(CO)5] (M = Mn, Re), [(TPP)Fe=C=Cr(CO)5], (TPP)Fe=C=Fe(CO)4] (pz = 3,5‐dimethylpyrazol‐1‐yl; TPP = Tetraphenylporphyrinate) from Halogeno‐Carbyne and ‐Carbene Complexes

The reaction of the bromocarbyne complex [HB(pz)3(OC)2Mo≡C‐Br] with [(Ph3P)2Pt(η2‐C2H4)] at room temperature affords the dimetallapropene $\rm [HB(pz)_{3}(OC)_{2}-M\overline{o=C(Br)-P}t(PPh_{3})_{2}]$ complex. At higher temperature the isomeric carbide bridged complex [HB(pz)3(OC)2Mo≡C‐Pt(PPh3)2Br] is formed. From the tetraphenylporphyrinato‐dichlorocarbene–iron complexes [(TPP)Fe=CCl2] with the carbonyl metallates Na[Re(CO)5], Na[Mn(CO)5], Na2[Cr(CO)5] and Na2[Fe(CO)4] the carbide bridged complexes [(TPP)Fe≡C‐M(CO)4‐M(CO)5] (M = Mn, Re), [(TPP)Fe=C=Cr(CO)5] and [(TPP)Fe=C=Fe(CO)4] have been obtained. Instead of TPP also tetrakis(p‐methoxyphenyl)porphyrinate and tetrakis(p‐cyanophenyl)porphyrinate have been used.
Structural and Catalytic Aspects of Dioxomolybdenum(VI) Complexes with ω‐Hydroxy Functionalized N‐Salicylidene Hydrazides
Authors: Debel Robert , Buchholz Axel , Plass Winfried
Published: September 2008

The new cis‐dioxomolybdenum(VI) complexes [MoO2(salhyhb)]2 (1), [MoO2(salhyhp)] (2), and [MoO2(salhyhh)(MeOH)] (3) with the hydrazone ligands H2salhyhb, Hsalhyhp, and H2salhyhh derived from salicylaldehyde and ω‐hydroxy carbonic acid hydrazides with different chain lengths, have been synthesized and spectroscopically characterized. The crystal structures of all three complexes reveal an octahedral environment for the molybdenum atoms with the same basic structural motif. In addition to the two oxo groups an [NO3] donor set is observed which is given by the tridentate Schiff‐base ligand and an oxygen atom of a coordinating alcohol. Depending on the side chain length different modes of association are observed. For complex 1 a dimeric structure is obtained, which is linked by coordination of the side chain hydroxy group at the molybdenum atom of the other monomer. The extension of the side chain by one methylene group in complex 2 leads to a polymeric structure, which is based on a similar intermolecular coordination of the side chain hydroxy group. The further increase of the side‐chain length in complex 3 results in the coordination of a methanol molecule at the molybdenum atom. For compounds 2 and 3 the additional hydrogen‐bonding network leads to the formation of layered structures in the solid state. The synthesized cis‐dioxomolybdenum(VI) complexes were tested for their catalytic ability towards the oxidation of sulfides. Although no significant influence of the side chain lengths could be detected, these complexes are efficient catalysts for sulfoxidation.
A Rare Example of a Cationic Niobium Cluster Complex with Octahedral Core of Metal Atoms: Synthesis, Structure, and Properties of [Nb6Cl12(C2H5CN)6][SbCl6]3·2C2H5CN
Authors: Flemming Anke , Köckerling Martin
Published: September 2008

Treatment of K4[Nb6Cl18] with antimony(V) chloride in propionitrile gives [Nb6Cl12(C2H5CN)6][SbCl6]3·2C2H5CN (1), which crystallizes in the orthorhombic space group Pccn (No. 56). The structure was determined by single crystal X‐ray diffraction: a = 21.1022(5), b = 22.7785(6), c = 15.4561(4) Å, Z = 4, R1(F)/wR2(F2) = 0.0435/0.0959. The compound contains isolated, molecular [Nb6Cl12(C2H5CN)6]3+ cluster cations with an octahedral core of metal atoms, edge bridged by chlorido ligands, and propionitrile ligands on all the six exo positions. The IR and FIR spectra of the compound are reported.
Synthesis, Structural Characterization and Properties of the Palladium(II) and Platinum(II) Complexes of 2‐{2‐[(pyridin‐2‐yl)aminomethylene]hydrazono}‐thiazolidin‐4‐one and the 3‐methyl Derivative
Authors: Castiñeiras Alfonso , García‐Santos Isabel , Saa Manuel
Published: September 2008

Reactions of N′‐(4‐oxothiazolidin‐2‐ylidene)picolinohydrazonamide (HAm4DHotaz, 1) and N′‐(3‐methyl‐4‐oxothiazolidin‐2‐ylidene)picolinohydrazonamide (Am4Motaz, 2) with K2[PdCl4] or K2[PtCl4] afforded good yields of the complexes [Pd(Am4DHotaz)Cl]·2H2O (3), [Pd(Am4DHotaz)Cl]·1/2DMF (3a), [Pt(Am4DHotaz)Cl]·3H2O (4), [Pd(Am4Motaz)Cl2]·0.5H2O (5), [Pt(Am4Motaz)Cl2]·5H2O (6), and [Pt(Am4Motaz)2]Cl2 (6a). The crystal structures of the ligands 1 and 2, and of two of the complexes, 3a and 6a, have been studied by X‐ray diffractometry. All of the new compounds were characterized by elemental analysis, mass spectrometry, IR, and 1H and 13C NMR spectroscopy and, when pertinent and allowed by the solubility of the compounds, by 195Pt NMR spectroscopy. In the square planar complexes of HAm4DHotaz, the ligand is bound to the metal atoms in an N,N,N‐terdentate deprotonated coordination mode, whereas in the dicationic complexes of Am4Motaz, the metal atom is four‐coordinated in a planar fashion by N,N atoms from two symmetry related ligands. Interesting intermolecular interactions were observed in the solid state in the ligands and complexes and these were based on hydrogen‐bonding. In particular, complex 3a formed a pseudo‐dimer, although the Pd–Pd distance between the two molecules is 3.360(1) Å, i.e. greater than the sum of van der Waal' radii.
Ethylene Addition to Group‐9 Transition Metal Dioxo Compounds – A Quantum Chemical Study
Authors: Haunschild Robin , Frenking Gernot
Published: September 2008

Quantum chemical calculations employing density functional theory (B3LYP) have been carried out to elucidate the reaction pathways for ethylene addition to iridium [IrO2CH3CH2], rhodium [RhO2CH3CH2] and cobalt [CoO2CH3CH2] complexes. The comparison of the results shows that all three complexes prefer a [3+2] cycloaddition pathway rather than a [2+2] addition. For the iridium and rhodium species, the [3+2]C,O pathway where the transition metal‐carbon and transition metal‐oxygen double bonds are involved is favoured, whereas the cobalt compound prefers the [3+2]O,O addition where both transition metal‐oxygen double bonds are participating with concomitant hydrogen migration. For all three metal compounds, the reaction energies are highly exothermic and only small barriers are necessary to overcome.