bluuebunny/crossref_metadata_2025 huggingface dataset:
Continuous Polymerization of Caprolactam-Polyether Sulfone Solutions in a Twin Screw Extruder to Form Reactive Polyamide–6/Polyether Sulfone Blends and Their Melt Spun Fibers
Authors: Kye H. , White J. L.
Published: December 2013

The continuous anionic polymerization of caprolactam solutions of polyether sulfone in a modular intermeshing co-rotating twin screw extruder has been investigated. The polyether sulfone appears to react with the polymerizing monomer. The polyamide-6/polyether sulfone reactive blends formed have been characterized. Studies were also made of melt spinning reactive blends into oriented filaments. The structure and mechanical properties of the blend melt spun filaments were characterized.
Gear Pump Performance in Polypropylene Filament Yarn Uniformity
Authors: Shumpert B. B. , Padsalgikar A. D. , Ellison M. S. , Hosangadi G. S. , Henshaw Ian
Published: December 2013

We report the development of a high resolution computerized monitoring system for fiber melt spinning and the results of its application to polypropylene fiber production. Variation in pack pressure caused by the melt pump was found to significantly affect the uniformity of the filament linear density. In this study, the variation in the pack, or gear pump outlet, pressure during polypropylene fiber melt spinning is correlated with various process parameters and the resulting fiber characteristics. We found the coefficient of variation in pump discharge pressure to decrease with increasing pump capacity and pump speed. The coefficient of variation in pack pressure was directly correlated with the coefficient of variation in filament yarn uniformity. Pump wear was found to have a marked impact on the variance in pack pressure.
Effect of Pressure and Shear Stress on Crystallization Behaviors in Injection Molding
Authors: Ito H. , Minagawa K. , Takimoto J. , Tada K. , Koyama K.
Published: December 2013

We studied in detail the effects of pressure and shear stress on the crystallization behaviors during injection molding process. Crystallization of isotactic-polypropylene (iPP) was simulated for various injection flow rates. The crystallization started during the filling stage under long filling condition. Moreover, the crystallization in some layers showed two -step growth behavior, while in other layers the crystallization does not progress during the packing -cooling stage. Since pressure becomes very high during molding process under long filling time condition, the change of pressure is the most important factor governing the crystallization.
Influence of Processing Temperature on the Morphological and Mechanical Properties of a PC/TLCP Blend
Authors: Wang H. , Hinrichsen G.
Published: December 2013

The influence of processing temperature on the morphological and mechanical properties of polycarbonate (PC) blended with a thermotropic liquid crystalline polymer (TLCP) has been studied. At a barrel temperature of 310°C, the TLCP of the blends exhibits the high orientation level and fiber alignment which correspond to maximum tensile strength. This indicates that the processing temperature might result in the change of the viscosity ratios of the dispersed and continuous phase and is one of the main processing parameters.
A New Approach to Simulation of Die Flow which Incorporates the Extruder and Rotating Screw Tips in the Analysis
Authors: Lawal A. , Railkar S. , Kalyon D. M.
Published: December 2013

The traditional method of mathematical modeling of the die flows treats the die as a stand alone tool which is independent of the extrusion conditions which feed the polymer melt into the die. Here, we demonstrate that especially under the conditions where a breaker plate is not used the flow and the deformation which occur in the die are dependent on the prevailing velocity and the stress conditions of the fluid at the extruder which feeds the die. A finite element method based technique is used to solve the conservation equations using a mesh which covers both the die and the rotating conical screw tips of the extruder. The presented methodologies provide a more realistic representation of the thermo-mechanical history experienced by the polymer melt or structured fluids including emulsions or suspensions in the die and thus provide better tools for die design and process optimization. The results also suggest that significant improvements in die design and hence die performance could ensue by using the geometry of the screw tips, the distance between the screw tips and the die and the rotational screw speed as additional parameters for design and optimization.
Numerical Simulation of the Multi-Component Injection Moulding Process
Authors: Zoetelief W. F. , Peters G. W. M. , Meijer H. E. H.
Published: December 2013

The versatility of the injection moulding process can be increased by combining multiple polymers in one product. The multi-component injection moulding process (MCIM) offers the possibility to inject two or three materials sequentially or simultaneously into a mould to make products that consist of e.g. a layered structure. For a successful application of this technique for geometrically complex products or multiple materials, the material distribution in the product has to be predicted. In this paper numerical tools are described for calculating the positions of material particles during the flow in the mould cavity. These tools make it possible to solve the inverse problem of predicting the injection sequence in MCIM given a required material distribution in the product. The simulations are validated using experimental results of a co-injected strip with stiffener ribs. Furthermore the effect of a bifurcation of the midsurface on the material distribution is investigated numerically using a simplified model based on the local mass balance.
Modelling the PVT Behavior of Isotactic Polypropylene
Authors: Hieber C. A.
Published: December 2013

Making use of available data from the literature, a master correlation based upon a two-domain-Tait representation is developed which describes the asymptotic high-temperature and low-temperature PVT behavior of isotactic polypropylene. The transition between these two asymptotes in the cooling mode is then handled based upon the quiescent-crystallization-kinetics equation of Nakamura, employing model constants for the temperature- and pressure-dependent crystallization rate based upon earlier work by the present investigator. As a further step, it is shown that a rule-of-mixtures approach can describe the low-temperature and high-temperature asymptotic PVT behavior equally as well as the 2-domain-Tait model while requiring two less free parameters. In turn, since the rule-of-mixtures representation contains the absolute crystallinity as an explicit parameter, it is proposed that this model might also be used under flow-induced conditions once the corresponding crystallization kinetics become established.
Extension of 2½ D Control Volume Methods for Transverse Flow at Sprues, Gates and Junctions
Authors: Batch G.
Published: December 2013

Commercial injection mold filling simulations use the lubrication approximation to model pressure and temperature during flow. This approximation is valid when flow streamlines are parallel to a cavity surface, such as when the cavity thickness is much smaller than the flow length. Yet this approximation may not be valid in complex cavities where the streamlines are not parallel. Flow through junctions, gates and sprues are always accompanied by a velocity component transverse to the mold surface which is not included in the model. Neglecting transverse flow through use of the lubrication approximation can result in anomalous changes in bulk mean temperature, filling patterns, and molecular and fiber orientation. This paper presents a mass balance algorithm for approximating transverse flow through gates, sprues and junctions. This new algorithm is presently suitable for only relatively simple geometries. Future work will attempt to make a similar algorithm for transverse flow through complex mold shapes with negligible penalty in additional computational run time.
Modular Tangential Counter-Rotating Twin Screw Extrusion: Non-Newtonian and Non-Isothermal Simulation
Authors: Bang D.-S. , White J. L.
Published: December 2013

A non-Newtonian flow model for individual elements of a modular tangential counter-rotating twin screw extruder is developed. A non-Newtonian non-isothermal flow model for a composite modular machine is then described. Fill factor, pressure and temperature profiles along the axis of the twin screw machines were predicted for various modular screw configurations. Finally, experiments were carried out on the modular machine to verify the predictions. Generally, good agreement with the flow analysis was found.
A Parametric Study of Sink Marks in Injection-Molded Plastic Parts using the Finite Element Method
Authors: Battey D. J. , Gupta M.
Published: December 2013

A numerical procedure to simulate the formation of a sink mark near the base of a rib in an injection-molded plastic part has been developed. This method uses two commercially available software packages, C-Mold and Abaqus, to model the injection molding process. The C-Mold software uses a generalized Hele-Shaw formulation to simulate the mold filling, packing and cooling stages of injection molding. From this analysis, pressure and temperature histories in the rib area are derived. These are used to determine the initial conditions and boundary conditions for a sequentially-coupled thermal / structural finite element analysis of a cross-section of the rib, using the Abaqus software. An elastic-plastic material model with temperature-dependent material properties is employed. The thermal/structural finite element analysis provides an accurate model of the two-dimensional cooling and shrinkage behavior of the part during molding. To verify the accuracy of the method, the dependence of sink mark depth on various geometric and molding parameters has been analyzed. The predicted sink mark depth is found to be in good agreement with experimental results from the literature.
Processing of Sheath-Core and Matrix-Fibril Fibers Composed of PP and a TLCP
Authors: Robertson C. G. , Baird D. G.
Published: December 2013

Isotactic polypropylene (PP) was reinforced with Vectra B950 (VB), a thermotropic liquid crystalline polymer (TLCP), in two novel fiber spinning processes which both employ two extruders to allow separate thermal histories to be applied to PP and VB prior to their combination. In one process, a single VB melt stream was surrounded by a sheath of PP, in a manner comparable to a wire coating process, just prior to melt spinning to generate fibers possessing a sheath-core structure. The other process involved the distribution of continuous VB melt streams within a separately plasticated PP melt to form a composite melt which was drawn to create matrix-fibril fibers consisting of a PP matrix reinforced with VB fibrils. Both processes allow polymers with non-overlapping processing temperatures to be combined and melt spun to form composite fibers. The effect of fiber draw ratio on the tensile mechanical properties was assessed for composite fibers reinforced with 50 wt.-% (39 vol.-%) VB. Numerical simulations of the non-isothermal fiber drawing processes and an investigation of fiber morphology were undertaken in order to explain the mechanical properties. The composite fibers were compression molded at a temperature 80°C below the melting temperature of VB to form unidirectionally reinforced plaques. For both fiber types, the plaques exhibited excellent retention of fiber properties, illustrating the potential for using the fibers to form reinforced composite parts.
Application of Neural Networks to Analyze the Drawing Process of PET Films
Authors: Kim H. D. , Kim S. Y.
Published: December 2013

Multilayer feedforward neural networks with error backpropagation algorithm have been applied to analyze the drawing process of PET films. Six kinds of process conditions, four kinds of material structures and six kinds of material properties were used as inputs and outputs chosen to analyze the relationships between process conditions, material structures and properties. It was shown that the trained neural networks represent a small error between the target and the corresponding estimated values. It has been shown quantitatively that material studies play an intermediate role in the relationship between process conditions, material structures and properties. It was also shown that model-free simulator predictions by neural networks are more reliable than the corresponding conventional non-linear regression analysis in the complex polymer processing.
Stabilising the Structure of HDPE by the Use of Highly-dispersed Mixture of Fe/FeO
Authors: Ozden S. , Hhatsukova M. A. , Mashukov H. I. , Kozlov G. V.
Published: December 2013

An oxygen acceptive catalyser Fe/FeO mixture was added to the high density polyethylene (HDPE) at different amounts and the stabilisation effects of this additive on the structure of HDPE was investigated. It was shown that the mechanical behaviour and the temperature stability of HDPE was significantly improved with the application of the additive. The experimental results were found to be in accordance with analytical approaches.
Rheological Behaviour of HDPE/PA 11 Blends
Authors: Dospíšil D. , Kubát J. , Sáha P. , Pavlínek V. , Becker J.
Published: December 2013

This paper presents the results of an experimental study of the unstable capillary flow of HDPE/PA 11 blends with special emphasis on the pressure oscillation region. The main result is the finding that addition of only 1 % by weight of the PA 11 component to HDPE completely suppresses the oscillation phenomenon normally found with the latter polymer when the measurement is carried out in a rheometer with a plane capillary entrance. In comparative experiments with a capillary rheometer with a conical (120°) entrance, the pressure oscillation effect disappeared at a PA 11 content of 5%. In compounds containing 1, 3 and 7 % PA 11, distinct pressure oscillations were recorded in the latter case.

The stress and elongation at break of the extrudates change in a monotonic fashion with the composition. SEM photographs and DSC measurements show that the two components are basically immiscible.
On the Charge State of Melt-Blown Polymer Materials
Authors: Pinchuk L. S. , Kravtsov A. G. , Voronezhtsev Yu. I. , Gromyko Yu. V.
Published: December 2013

Fibrous polymer materials formed by LDPE melt spraying with a gas flow during extrusion were exposed to thermally stimulated depolarization. The analysis of thermally stimulated current spectra and the sample charge state has shown that the fibers possess the spontaneous polarizing charge. IR-spectroscopy has proved the material production to be accompanied by vinylene, vinyl, transvinylene and other nonsaturated groups formation. The latters are, probably, behaving as neutral trapping centers during their interaction with charge carriers formed at melt dispersion by the compressed gas flow and its contact with metal parts of equipment. The kinetics of these processes can be monitored by regulating technological regimes of fibrous material formation. Intensified action on the polymer melt might rise the spontaneous polarizing charge whose density can reach 10−10 to 10−12 C/cm2. Charge of the materials under study is rather stable. It does not fall below 40% upon a 160-days storage in humid atmosphere. It appears thus that the technique of fibrous material production by polymer melt spraying is an electret method.
Melt Flow Instabilities of Filled HDPE
Authors: Dospíšil D. , Kubát J. , Sáha P. , Trlica J. , Becker J.
Published: December 2013

Data relating to the influence of several fillers on flow instabilities in capillary extrusion of two grades of high density polyethylene (HDPE) are presented. Special attention is paid to the pressure oscillation region of the flow curve. First we show that a certain level of flow stabilisation can be achieved with carbon fibres, while carbon black and CaCO3 have a minor influence only on the oscillation effect when varying the filling between 5% and 10%. The temperature used was 200° C and the capillary entrance was plane (180°). We also show that a complete disappearance of pressure oscillations is obtained when using a different HDPE grade filled with 7% fumed silica or carbon black (also different grade). Compounds containing 7% talc did not stabilise the flow. The same was true when the filling was reduced to 3%. In the latter experiments a capillary rheometer with a conical entrance (120°) was used. The temperature was 160°C. Data obtained by frequency analysis of the fluctuating pressure transducer signal mounted on the rheometric equipment, operating in both cases at constant piston speed, are also presented.
Generation of Partially Crosslinked Expanded PP-films and -sheets
Authors: Fritz H. G. , Bölz U. , Lü R.
Published: December 2013

A modified concept for the generation of partially crosslinked expanded PP-films and -sheets, useable in automotive industry, is presented. The paper describes in detail an optimized formulation window for the organosilane crosslinking of the selected PP-copolymers, an adequate plant design for the realization of this innovative processing concept as well as approved process parameters. As derived from experimental studies, gel content and the amount of blowing agent seem to be the most essential parameters with regard to foam structure, foam density and cell size homogeneity.
Continuous Polymerization and Copolymerization of Lauryl Lactam in a Modular Corotating Twin Screw Extruder
Authors: Ha S. K. , White J. L.
Published: December 2013

A study is presented of the polymerization of lauryl lactam and the copolymerization of lauryl lactam and caprolactam in a modular co-rotating twin screw extruder. Lauryl lactam had not been previously polymerized in a twin screw extruder. It was found possible to do this to high molecular weights. Generally, lower screw speeds result in longer residence times and higher conversions and molecular weights. The copolymers produced have broad melting transitions and their melting temperatures and heats of fusion exhibit minima as a function of comonomer composition.
Thermal Polymerization of Methyl Methacrylate at High Temperature
Authors: Fenouillot F. , Terrisse J. , Rimlinger T.
Published: December 2013

Kinetic studies of the bulk polymerization of methyl methacrylate at high temperature have been carried out first without any additives and then in the presence of 1-Butanethiol as a chain transfer agent. A pressurised dilatometric reactor operating at high temperature is used to determine the time-conversion curves at temperatures between 150 and 180°C. A two-stage polymerization is observed. The high polymerization rate obtained initially is attributed to traces of an initiating impurity, while the second, slower polymerization stage could be considered as the actual thermal polymerization. The chain transfer agent or an impurity it may contain also initiates the reaction. Therefore, the rates of both the initial polymerization and of the second stage are increased when the thiol is added.

Experimental data on the degree of conversion versus time and on the final average molecular weight are used to determine the chain transfer constants to the monomer and to the mercaptan as well as the initiation rate constants. These constants are used to model the thermal polymerization of MMA at high temperatures where these initiation reactions can no longer be neglected, especially when an industrial polymerization process has to be optimized and controlled.
Modeling Flow and Fusion of Mixtures/Blends of Polymer Pellets and a Low Viscosity Phase in a Modular Co-rotating Twin Screw Extruder
Authors: Lee S-H. , White J. L.
Published: December 2013

A method of modeling the two phase flow and fusion process for a blend of low viscosity and high viscosity polymers in a modular intermeshing co-rotating twin screw extruder is presented. The delayed melting/fusing process in a large viscosity ratio system is simulated mathematically. Calculations were made for specific modular screw configurations. The screw configurations included both screw elements and kneading disk blocks. The temperature rise in a suspension of low viscosity melted and unmelted solid pellets was calculated along the screw axis. The suspension-blend transition temperature to a blend system was then determined. Furthermore, we tested the usefulness of this model by comparing the simulation with experimental results.
Morphology of Injection Molded Polyacetal during Filling
Authors: Mizuno W. , Tomari K. , Hamada H. , Maekawa Z.
Published: December 2013

The morphology of injection molded polyacetal was investigated using spiral-flow test mold and shear effect on crystallization phenomena is discussed. Morphology differed for skin, shear and core layers. The thickness of the shear layer was proportional to flow time.
Warpage of Injection Moulded Plates and Corner Products
Authors: Jansen K.M.B. , van Dijk D.J. , Keizer K.P.
Published: December 2013

This paper contains a systematic study on warpage of injection moulded plates and corner products as a function of mould temperature difference and holding pressure. The study is restricted to unfilled amorphous materials. As expected, experiments showed that warpage increased linearly with the applied temperature difference between mould halves. Not expected was that at low holding pressures the plates curved towards the hot side, whereas at high holding pressures they warped towards the cold side. A simple thermoelastic theory is proposed which could explain all observations qualitatively and quantitatively. Standard simulation software, on the other hand, was seen to predict warpage behaviour at the higher holding pressures which was completely opposite to the experimental observations.
Thyroid Hormones and Antioxidant Systems: Focus on Oxidative Stress in Cardiovascular and Pulmonary Diseases
Authors: Mancini Antonio , Raimondo Sebastiano , Di Segni Chantal , Persano Mariasara , Gadotti Giovanni , Silvestrini Andrea , Festa Roberto , Tiano Luca , Pontecorvi Alfredo , Meucci Elisabetta
Published: December 2013

In previous works we demonstrated an inverse correlation between plasma Coenzyme Q10 (CoQ10) and thyroid hormones; in fact, CoQ10 levels in hyperthyroid patients were found among the lowest detected in human diseases. On the contrary, CoQ10 is elevated in hypothyroid subjects, also in subclinical conditions, suggesting the usefulness of this index in assessing metabolic status in thyroid disorders. A Low-T3 syndrome is a condition observed in several chronic diseases: it is considered an adaptation mechanism, where there is a reduction in pro-hormone T4 conversion. Low T3-Syndrome is not usually considered to be corrected with replacement therapy. We review the role of thyroid hormones in regulation of antioxidant systems, also presenting data on total antioxidant capacity and Coenzyme Q10. Published studies suggest that oxidative stress could be involved in the clinical course of different heart diseases; our data could support the rationale of replacement therapy in low-T3 conditions.
Rheumatoid Arthritis-Associated MicroRNA-155 Targets SOCS1 and Upregulates TNF-α and IL-1β in PBMCs
Authors: Li Xiaochuan , Tian Feng , Wang Fei
Published: December 2013

miR-155 plays a crucial role in proinflammatory activation. This study was carried out to assess the association of abnormal expression of miR-155 in peripheral blood of patients with Rheumatoid arthritis with the expression of TNF-α and IL-1β. Release of TNF-α and IL-1β, and expression of miR-155 were determined in RA peripheral blood or peripheral blood macrophages, followed by correlation analysis of the cytokines release and miR-155 expression. Furthermore, in vitro studies indicate that miR-155 inhibited the expression of SOCS1. Our results suggest that there is a correlation between the high-level expression of miR-155 and the enhanced expression of TNF-α and IL-1β. miR-155 targets and suppresses the expression of SOCS1, and the decrease of SOCS1 may lead to the upregulation of TNF-α and IL-1β.
One Step Synthesis of NiO Nanoparticles via Solid-State Thermal Decomposition at Low-Temperature of Novel Aqua(2,9-dimethyl-1,10-phenanthroline)NiCl2 Complex
Authors: Barakat Assem , Al-Noaimi Mousa , Suleiman Mohammed , Aldwayyan Abdullah , Hammouti Belkheir , Hadda Taibi , Haddad Salim , Boshaala Ahmed , Warad Ismail
Published: December 2013

[NiCl2(C14H12N2)(H2O)] complex has been synthesized from nickel chloride hexahydrate (NiCl2·6H2O) and 2,9-dimethyl-1,10-phenanthroline (dmphen) as N,N-bidentate ligand. The synthesized complex was characterized by elemental analysis, infrared (IR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy and differential thermal/thermogravimetric analysis (TG/DTA). The complex was further confirmed by single crystal X-ray diffraction (XRD) as triclinic with space group P-1. The desired complex, subjected to thermal decomposition at low temperature of 400 °C in an open atmosphere, revealed a novel and facile synthesis of pure NiO nanoparticles with uniform spherical particle; the structure of the NiO nanoparticles product was elucidated on the basis of Fourier transform infrared (FT-IR), UV-vis spectroscopy, TG/DTA, XRD, scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDXS) and transmission electron microscopy (TEM).
Facile and Selective Synthetic Approach for Ruthenium Complexes Utilizing a Molecular Sieve Effect in the Supporting Ligand
Authors: Oyama Dai , Fukuda Ayumi , Yamanaka Takashi , Takase Tsugiko
Published: December 2013

It is extremely important for synthetic chemists to control the structure of new compounds. We have constructed ruthenium-based mononuclear complexes with the tridentate 2,6-di(1,8-naphthyridin-2-yl)pyridine (dnp) ligand to investigate a new synthetic approach using a specific coordination space. The synthesis of a family of new ruthenium complexes containing both the dnp and triphenylphosphine (PPh3) ligands, [Ru(dnp)(PPh3)(X)(L)]n+ (X = PPh3, NO2−, Cl−, Br−; L = OH2, CH3CN, C6H5CN, SCN−), has been described. All complexes have been spectroscopically characterized in solution, and the nitrile complexes have also been characterized in the solid state through single-crystal X-ray diffraction analysis. Dnp in the present complex system behaves like a “molecular sieve” in ligand replacement reactions. Both experimental data and density functional theory (DFT) calculations suggest that dnp plays a crucial role in the selectivity observed in this study. The results provide useful information toward elucidating this facile and selective synthetic approach to new transition metal complexes.
Semiconductor Nanomaterials-Based Fluorescence Spectroscopic and Matrix-Assisted Laser Desorption/Ionization (MALDI) Mass Spectrometric Approaches to Proteome Analysis
Authors: Kailasa Suresh , Cheng Kuang-Hung , Wu Hui-Fen
Published: December 2013

Semiconductor quantum dots (QDs) or nanoparticles (NPs) exhibit very unusual physico-chemcial and optical properties. This review article introduces the applications of semiconductor nanomaterials (NMs) in fluorescence spectroscopy and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for biomolecule analysis. Due to their unique physico-chemical and optical properties, semiconductors NMs have created many new platforms for investigating biomolecular structures and information in modern biology. These semiconductor NMs served as effective fluorescent probes for sensing proteins and cells and acted as affinity or concentrating probes for enriching peptides, proteins and bacteria proteins prior to MALDI-MS analysis.
Integrating Solar Induced Fluorescence and the Photochemical Reflectance Index for Estimating Gross Primary Production in a Cornfield
Authors: Cheng Yen-Ben , Middleton Elizabeth , Zhang Qingyuan , Huemmrich Karl , Campbell Petya , Corp Lawrence , Cook Bruce , Kustas William , Daughtry Craig
Published: December 2013

The utilization of remotely sensed observations for light use efficiency (LUE) and tower-based gross primary production (GPP) estimates was studied in a USDA cornfield. Nadir hyperspectral reflectance measurements were acquired at canopy level during a collaborative field campaign conducted in four growing seasons. The Photochemical Reflectance Index (PRI) and solar induced chlorophyll fluorescence (SIF), were derived. SIF retrievals were accomplished in the two telluric atmospheric oxygen absorption features centered at 688 nm (O2-B) and 760 nm (O2-A). The PRI and SIF were examined in conjunction with GPP and LUE determined by flux tower-based measurements. All of these fluxes, environmental variables, and the PRI and SIF exhibited diurnal as well as day-to-day dynamics across the four growing seasons. Consistent with previous studies, the PRI was shown to be related to LUE (r2 = 0.54 with a logarithm fit), but the relationship varied each year. By combining the PRI and SIF in a linear regression model, stronger performances for GPP estimation were obtained. The strongest relationship (r2 = 0.80, RMSE = 0.186 mg CO2/m2/s) was achieved when using the PRI and SIF retrievals at 688 nm. Cross-validation approaches were utilized to demonstrate the robustness and consistency of the performance. This study highlights a GPP retrieval method based entirely on hyperspectral remote sensing observations.
“Festivalisation” of Urban Governance in South African Cities: Framing the Urban Social Sustainability of Mega-Event Driven Development from Below
Authors: Fleischer Matthias , Fuhrmann Maximilian , Haferburg Christoph , Krüger Fred
Published: December 2013

This article is based on field research in two South African host cities of the Men’s Football World Cup 2010 (eThekwini and Johannesburg). The discussed work is part of the research project “Festivalisation” of Urban Governance: The Production of Socio-Spatial Control in the Context of the FIFA World Cup 2010 in South Africa. In the context of mega-events, impacts and changes on urban development can vary on a spectrum of festivalisation between opposing poles, either “driven by the event”, or on the other hand where existing configurations of actors and established policies are “driving the event”. By drawing on a theoretical framework which is inspired by an analytical understanding of urban governance, our assumptions are that (a) different configurations of governance promote different ways of handling the challenges associated to the hosting and (b) that different types of “festivalisation” have different consequences and effects for the lived realities of the residents at a local level. The latter is an arena in which urban governance policies are translated, adapted, renegotiated or rejected. We argue that the bringing together of both spheres (local and metropolitan) provides a profound understanding of the process of mega-event implementation and its relation to urban social sustainability.
Supporting Urban Planning of Low-Carbon Precincts: Integrated Demand Forecasting
Authors: Lehmann Steffen , Zaman Atiq , Devlin John , Holyoak Nicholas
Published: December 2013

Waste is a symbol of inefficiency in modern society and represents misallocated resources. This paper outlines an on-going interdisciplinary research project entitled “Integrated ETWW demand forecasting and scenario planning for low-carbon precincts” and reports on first findings and a literature review. This large multi-stakeholder research project develops a shared platform for integrated ETWW (energy, transport, waste and water) planning in a low-carbon urban future, focusing on synergies and alternative approaches to urban planning. The aim of the project is to develop a holistic integrated software tool for demand forecasting and scenario evaluation for residential precincts, covering the four domains, ETWW, using identified commonalities in data requirements and model formulation. The authors of this paper are overseeing the waste domain. A major component of the project will be developing a method for including the impacts of household behavior change in demand forecasting, as well as assessing the overall carbon impacts of urban developments or redevelopments of existing precincts. The resulting tool will allow urban planners, municipalities and developers to assess the future total demands for energy, transport, waste and water whilst in the planning phase. The tool will also help to assess waste management performance and materials flow in relation to energy and water consumption and travel behavior, supporting the design and management of urban systems in different city contexts.
Vector-Virus Interactions and Transmission Dynamics of West Nile Virus
Authors: Ciota Alexander , Kramer Laura
Published: December 2013

West Nile virus (WNV; Flavivirus; Flaviviridae) is the cause of the most widespread arthropod-borne viral disease in the world and the largest outbreak of neuroinvasive disease ever observed. Mosquito-borne outbreaks are influenced by intrinsic (e.g., vector and viral genetics, vector and host competence, vector life-history traits) and extrinsic (e.g., temperature, rainfall, human land use) factors that affect virus activity and mosquito biology in complex ways. The concept of vectorial capacity integrates these factors to address interactions of the virus with the arthropod host, leading to a clearer understanding of their complex interrelationships, how they affect transmission of vector-borne disease, and how they impact human health. Vertebrate factors including host competence, population dynamics, and immune status also affect transmission dynamics. The complexity of these interactions are further exacerbated by the fact that not only can divergent hosts differentially alter the virus, but the virus also can affect both vertebrate and invertebrate hosts in ways that significantly alter patterns of virus transmission. This chapter concentrates on selected components of the virus-vector-vertebrate interrelationship, focusing specifically on how interactions between vector, virus, and environment shape the patterns and intensity of WNV transmission.
Development of an Open Metadata Schema for Prospective Clinical Research (openPCR) in China
Authors: Guan Z. , Sun J. , Wang Z. , Geng Y. , Xu W.
Published: December 2013

Objectives: In China, deployment of electronic data capture (EDC) and clinical data management system (CDMS) for clinical research (CR) is in its very early stage, and about 90% of clinical studies collected and submitted clinical data manually. This work aims to build an open metadata schema for Prospective Clinical Research (openPCR) in China based on openEHR archetypes, in order to help Chinese researchers easily create specific data entry templates for registration, study design and clinical data collection.

Methods: Singapore Framework for Dublin Core Application Profiles (DCAP) is used to develop openPCR and four steps such as defining the core functional requirements and deducing the core metadata items, developing archetype models, defining metadata terms and creating archetype records, and finally developing implementation syntax are followed.

Results: The core functional requirements are divided into three categories: requirements for research registration, requirements for trial design, and requirements for case report form (CRF). 74 metadata items are identified and their Chinese authority names are created. The minimum metadata set of openPCR includes 3 documents, 6 sections, 26 top level data groups, 32 lower data groups and 74 data elements. The top level container in openPCR is composed of public document, internal document and clinical document archetypes. A hierarchical structure of openPCR is established according to Data Structure of Electronic Health Record Architecture and Data Stand -ard of China (Chinese EHR Standard). Meta-data attributes are grouped into six parts: identification, definition, representation, relation, usage guides, and administration.

Discussions and Conclusion: OpenPCR is an open metadata schema based on research registration standards, standards of the Clinical Data Interchange Standards Consortium (CDISC) and Chinese healthcare related stand -ards, and is to be publicly available throughout China. It considers future integration of EHR and CR by adopting data structure and data terms in Chinese EHR Standard. Archetypes in openPCR are modularity models and can be separated, recombined, and reused. The authors recommend that the method to develop openPCR can be referenced by other countries when designing metadata schema of clinical research. In the next steps, openPCR should be used in a number of CR projects to test its applicability and to continuously improve its coverage. Besides, metadata schema for research protocol can be developed to structurize and standardize protocol, and syntactical interoperability of openPCR with other related standards can be considered.
An Electronic Specimen Collection Protocol Schema (eSCPS)
Authors: Semjonow A. , Oezguer E. , Herden J. , Akbarov I. , Tok A. , Engelmann U. , Wille S. , Eminaga O.
Published: December 2013

Background: The integrity of collection protocols in biobanking is essential for a high-quality sample preparation process. However, there is not currently a well-defined universal method for integrating collection protocols in the biobanking information system (BIMS). Therefore, an electronic schema of the collection protocol that is based on Extensible Markup Language (XML) is required to maintain the integrity and enable the exchange of collection protocols.

Materials and Methods: The development and implementation of an electronic specimen collection protocol schema (eSCPS) was performed at two institutions (Muenster and Cologne) in three stages. First, we analyzed the infrastructure that was already established at both the biorepository and the hospital information systems of these institutions and determined the requirements for the sufficient preparation of specimens and documentation. Second, we designed an eSCPS according to these requirements. Fi -nally, a prospective study was conducted to implement and evaluate the novel schema in the current BIMS.

Results: We designed an eSCPS that provides all of the relevant information about collection protocols. Ten electronic collection protocols were generated using the supplementary Protocol Editor tool, and these protocols were successfully implemented in the existing BIMS. Moreover, an electronic list of collection protocols for the current studies being performed at each institution was included, new collection protocols were added, and the existing protocols were redesigned to be modifiable. The documentation time was significantly reduced after implementing the eSCPS (5 ± 2 min vs. 7 ± 3 min; p = 0.0002).

Conclusion: The eSCPS improves the integrity and facilitates the exchange of specimen collection protocols in the existing open-source BIMS.
A Simplification and Implementation of Random-effects Meta-analyses Based on the Exact Distribution of Cochran’s Q
Authors: Preuß M. , Ziegler A.
Published: December 2013

Background: The random-effects (RE) model is the standard choice for meta-analysis in the presence of heterogeneity, and the stand ard RE method is the DerSimonian and Laird (DSL) approach, where the degree of heterogeneity is estimated using a moment-estimator. The DSL approach does not take into account the variability of the estimated heterogeneity variance in the estimation of Cochran’s Q. Biggerstaff and Jackson derived the exact cumulative distribution function (CDF) of Q to account for the variability of Ť 2.

Objectives: The first objective is to show that the explicit numerical computation of the density function of Cochran’s Q is not required. The second objective is to develop an R package with the possibility to easily calculate the classical RE method and the new exact RE method.

Methods: The novel approach was validated in extensive simulation studies. The different approaches used in the simulation studies, including the exact weights RE meta-analysis, the I 2 and T 2 estimates together with their confidence intervals were implemented in the R package metaxa.

Results: The comparison with the classical DSL method showed that the exact weights RE meta-analysis kept the nominal type I error level better and that it had greater power in case of many small studies and a single large study. The Hedges RE approach had inflated type I error levels. Another advantage of the exact weights RE meta-analysis is that an exact confidence interval for T 2is readily available. The exact weights RE approach had greater power in case of few studies, while the restricted maximum likelihood (REML) approach was superior in case of a large number of studies. Differences between the exact weights RE meta-analysis and the DSL approach were observed in the re-analysis of real data sets. Application of the exact weights RE meta-analysis, REML, and the DSL approach to real data sets showed that conclusions between these methods differed.

Conclusions: The simplification does not require the calculation of the density of Cochran’s Q, but only the calculation of the cumulative distribution function, while the previous approach required the computation of both the density and the cumulative distribution function. It thus reduces computation time, improves numerical stability, and reduces the approximation error in meta-analysis. The different approaches, including the exact weights RE meta-analysis, the I 2 and T 2estimates together with their confidence intervals are available in the R package metaxa, which can be used in applications.
Synthesis and electrochemical performance of Li2Co1−xMxPO4F (M = Fe, Mn) cathode materials
Authors: Khasanova Nellie R , Drozhzhin Oleg A , Fedotov Stanislav S , Storozhilova Darya A , Panin Rodion V , Antipov Evgeny V
Published: December 2013

In the search for high-energy materials, novel 3D-fluorophosphates, Li2Co1−xFexPO4F and Li2Co1−xMnxPO4F, have been synthesized. X-ray diffraction and scanning electron microscopy have been applied to analyze the structural and morphological features of the prepared materials. Both systems, Li2Co1−xFexPO4F and Li2Co1−xMnxPO4F, exhibited narrow ranges of solid solutions: x ≤ 0.3 and x ≤ 0.1, respectively. The Li2Co0.9Mn0.1PO4F material demonstrated a reversible electrochemical performance with an initial discharge capacity of 75 mA·h·g−1 (current rate of C/5) upon cycling between 2.5 and 5.5 V in 1 M LiBF4/TMS electrolyte. Galvanostatic measurements along with cyclic voltammetry supported a single-phase de/intercalation mechanism in the Li2Co0.9Mn0.1PO4F material.
Novel supramolecular affinity materials based on (−)-isosteviol as molecular templates
Authors: Lohoelter Christina , Brutschy Malte , Lubczyk Daniel , Waldvogel Siegfried R
Published: December 2013

The readily available ex-chiral-pool building block (−)-isosteviol was combined with the C3-symmetric platforms hexahydroxytriphenylene and hexaaminotriptycene providing large and rigid molecular architectures. Because of the persistent cavities these scaffolds are very potent supramolecular affinity materials for head space analysis by quartz crystal microbalances. The scaffolds serve in particular as templates for tracing air-borne arenes at low concentration. The affinities of the synthesized materials towards different air-borne arenes were determined by 200 MHz quartz crystal microbalances.
Voedingpraktyke en behoeftes van hulpbron-arm gemeenskappe deur die oë van laerskoolonderwysers
Authors: Ferreira Ronel , Fraser William J. , Botha Karien , Cook Elzaan , Du Toit Peet J. , Gericke Gerda
Published: December 2013

In this article we discuss the perceptions teachers (n = 45) have regarding the nutritional practices of a sample of primary school learners and their families in a resource-constrained community. We specifically focus on the needs, practices and expectations related to food consumption, which implies food production, food choice and food preparation. Our study forms the first part of a more comprehensive institutional research project. For the purpose of our study we utilised participatory reflection and action-based workshops with the participants in order to generate data, and employed interpretivism to interpret the findings. This study emphasises the need of resource-constrained and unemployed community members, who are often forced to purchase food as a reduced cost of which the quality is not optimal. An attenuated breakfast, lunch or dinner where choices are often limited to black tea, porridge and one or two slices of stale bread, confirms the manifestations of poverty in resource-constrained communities. Meals are often limited to large quantities of carbohydrates, few vegetables, canned fish, porridge with inkomazi and marog. Chicken feet and tripe may supplement the menu. Teachers emphasise the fact that community members typically rely on donations from employers, churches and grocery stores in order to supplement their food budget. Teachers furthermore focus on the needs of community members to be educated. In their view community members need to be informed in respect of food production, vegetable gardens, techniques of determining the quality of soil, irrigation and the application of sustainable crop rotation. The article concludes with achievable and informative ideas for educating rural communities. Based on these research findings an intervention programme is currently being developed, with the purpose of implementing the intervention in the various participating schools in support of healthy nutrition-related behaviour and well-being.
Association between Pituitary Langerhans Cell Histiocytosis and Papillary Thyroid Carcinoma
Authors: Guarino Salvatore , Giusti Deborah Maria , Rubini Antonello , Favoriti Pasqualino , Fioravanti Cristina , Di Matteo Filippo Maria , D'Andrea Vito , De Antoni Enrico , Catania Antonio
Published: December 2013

Here we report a case of panhypopituitarism caused by pituitary Langerhans cell hystocitosis (LCH) in a 22-year-old woman affected by papillary thyroid carcinoma (PTC). Although several cases of the coexistence of PTC and LCH within thyroid tissue have been described in relative literature, in this case, the patient presented a unique suprasellar retrochiasmatic histocytosis localization which, to the best of our knowledge, had never been described before in association with PTC. Even if this aspect is not addressed in the present case report, it is worth noting that about 50% of the patients affected either by LCH or PTC are characterized by activating mutations of the proto-oncogene BRAF. This, along with other clinical studies, may warrant further biomolecular large-scale case study investigations in order to evaluate a possible connection between the 2 conditions and shed light on the etiology of these diseases, which are still largely unknown.
Reply to the Commentary on "Graphite and its hidden superconductivity"
Authors: Esquinazi P.
Published: December 2013

A Reply to the Commentary by E. M. Forgan [Pap. Phys. 5, 050008 (20013)].Received: 30 October 2013, Accepted: 4 November 2013; Edited by: S. A. Grigera; DOI: http://dx.doi.org/10.4279/10.4279/PIP.050009Cite as: P. Esquinazi, Papers in Physics 5, 050009 (2013)