bluuebunny/crossref_metadata_2025 huggingface dataset:
Peroxide Induced Crosslinking and Degradation of PA
Authors: Yu Q. , Zhu S.
Published: December 2013

Peroxide induced crosslinking and degradation of nylon-12 were experimentally investigated using an on-line electron spin resonance (ESR) spectrometer. It was found that different types of polymer radicals were involved in various peroxide modification processes. Five-line ESR spectra were observed in the DCP/nylon-12 and TBPB/nylon-12 systems, while the L130/nylon-12 system gave a three-line spectrum initially, followed by a transition to a single line. Based on the radical information, as well as gelation and viscosity measurements, various reaction mechanisms were proposed depending on the type of peroxide. TBPB is in favor of the degradation of nylon-12, while DCP and L130 promote crosslinking of the polymer. The gel formation was followed to facilitate the study of crosslinking kinetics. The initial gelation rate increased linearly with the peroxide concentration and/or temperature. The formation of crosslinked network impeded the crystallization of nylon-12 and reduced the degree of crystallinity. The high crosslinking extent resulted in low melting temperature and heat.
Squalane as Model for Free Radical Reactivity of PP
Authors: Drillières S. , Mestanza R. , Graebling D.
Published: December 2013

The degradation, grafting and crosslinking of polypropylene have been studied with a free modelling system: the squalane. This study used conditions similar to reactive extrusion in terms of temperature and concentration of actives species. The products of reactions were characterized by mass spectrometry and IR spectroscopy. The reaction between peroxide and squalane confirms the importance of the half-life of the peroxide in limiting the degradation of the squalane chain. In presence of monomer, we observed simultaneously grafting and β-scission of squalane. Comparison between methacrylates and acrylates shows that acrylates are much more effective for grafting than methacrylates. With trifunctional monomers, the main reaction is the crosslinking of squalane (or recombination of macroradicals via the monomer). In this case, triacrylates were also more effective.
Using Mold Pressure Rise Data to Obtain Viscosity of Fast Polymerizing Systems
Authors: Kim D. S. , Garcia M. A. , Macosko C. W.
Published: December 2013

Typical reaction injection molding oligomers gel in less than 5 s, making it very difficult to measure their viscosity rise in a rheometer. The parameters of the viscosity function for two thermoset polyurethane (PU) systems made from modified 4,4'-diphenylmethane diisocyanates and polyether polyols were obtained through nonlinear regression of a mold filling simulation model using pressure rise data. The pressure rises were measured at the inlet point of an end gated rectangular mold. Adiabatic temperature rise experiments were carried out to obtain reaction kinetic equations of the PU systems. A second order Arrhenius type reaction kinetic equation described the adiabatic temperature data well. Viscosity change of a low catalyst PU system during isothermal polymerization was measured using a parallel plate rheometer, and a viscosity function was estimated from these data and the kinetic data. The viscosity function determined through regression of pressure rise data using the mold filling simulation model compared reasonably well to the viscosity function obtained from the rheometer data.
Effect of Temperature and Compatibilizer on Interfacial Tension of PE/PA-6 and PP/EVOH
Authors: Garmabi H. , Demarquette N. R. , Kamal M. R.
Published: December 2013

Interfacial tension measurements for polyethylene/polyamide-6 (PE/PA-6) and polypropylene/ethylene-vinyl alcohol copolymer (PP/EVOH) pairs were performed using the spinning drop method. The effects of the temperature and maleation content of the polyolefin on the interfacial tension were evaluated. The temperature coefficients of interfacial tension were found to be 0.036 and 0.087 dyne/cm/°C for the PE/PA-6 and maleated PP/EVOH systems, respectively. The interfacial tension of PE/PA-6 system showed exponential dependence on the maleation content of PE. The accuracy of the spinning drop method was evaluated against the pendant drop technique. It was found that the spinning drop technique tends to yield lower interfacial tension values than the pendant drop method. The harmonicmean equation was found to provide a fair estimate for the interfacial tension of PE/PA-6 pair.
Pseudoplasticity and Dilatancy in Shallow Channel Flows
Authors: Lindt J. T.
Published: December 2013

A novel formulation is presented applicable to flows of inelastic, shear-thinning and shear-thickening, fluids between parallel plates. The solution is documented by comprehensive contour maps allowing flow descriptions to be reconstructed for the Ostwald-deWaele and the Cross-/Carreau fluid model fluids within an exhaustive range of rheological and flow parameters, 0 < n ≤ 2 and 0 ≤ q ≤ 2. The description of pseudoplastic behavior is extended to values approaching zero, numerical stability permitting (0.01 ≤ n < 1). The paper highlights the dilatant behavior, 1 ≤ n ≤ 2, reported previously to arise in certain heterogeneous systems, and shown to affect significantly other types of non-Newtonian flows. It is suggested that in thermally and compositionally developing flows, typical of reactive processing, where dilatancy may arise, the present formulation can facilitate solutions to the coupled rheological and heat/mass transfer problems encountered. The newly generated data on dilatant liquids suggest a dramatic increase in energy dissipation with the increasing degree of dilatancy.
Development of High Quality LLDPE and Optimised Processing for Film Blowing
Authors: Debbaut B. , Goublomme A. , Homerin O. , Koopmans R. , Liebman D. , Meissner J. , Schroeter B. , Reckmann B. , Daponte T. , Verschaeren P. , Agassant J.-F. , Vergnes B. , Venet C.
Published: December 2013

The majority of LLDPE resins is processed via blown film extrusion techniques for various applications in the industrial and consumer packaging business. These LLDPE resins all have, independent of the molecular structure differences, the same intrinsic limitation in blown film extrusion processing. These limitations are: low output, high sensitivity to surface defects (stripes, sharkskin), high machine power requirement, need for large die gaps, lower bubble stability, and low melt strength. As a consequence, the more versatile—manufacturing and property wise—LLDPE resins are not used to their full potential. The industrial objective is therefore threefold:

•

develop a new LLDPE resin overcoming the above limitations,

•

develop a new flexible blown film extrusion line tailored to the new generation of LLDPE resins,

•

develop an efficient 3-D finite element simulation code to assist in the resin and blown film extrusion line development.
Structure and Properties of Injection Moldings of β-Crystal Nucleator-added PP
Authors: Fujiyama M.
Published: December 2013

A homo isotactic polypropylene (PP) and random and block PP copolymers with ethylene were added with 0 to 10 ppm of γ-quinacridone which is a β-crystal nucleator of PP. Flexural and Izod impact test specimens were injection-molded from the PPs at cylinder temperatures of 200 to 320°C and the structure and properties have been studied. 1) Although the β-crystal content of the block PP is nearly the same as that of the homo PP, the β-crystal content of the random PP is largely lower than that of the homo PP. 2) The Izod impact strength is increased by the addition of γ-quinacridone. The increase is high for the homo and block PPs and very low for the random PP. There are cases where the Izod impact strength is increased by more than four folds for the block PP. 3) The flexural modulus and strength are decreased by the addition of γ-quinacridone and the decreases of the random PP are lower than those of the homo and block PPs. From above, it may be said that the modification effect of PP by the addition of γ-quinacridone is prominent for the homo and block PPs in which the β-crystal is ease to form and the effect is weak for the random PP in which the β-crystal is difficult to form.
Thermal Effects in the Numerical Simulation of the Thermoforming of Multilayered Polymer Sheets
Authors: Bellet M. , Vantal M.-H. , Monasse B.
Published: December 2013

This paper mainly treats the thermal effects during the thermoforming process while most of the previous analyses consider an isothermal deformation. A non isothermal three dimensional finite element model of the thermoforming process is proposed. It couples the thermal equations in the thickness and mechanical equations on the mean surface of the sheet. The mechanical resolution is done by a finite element method using a membrane approximation. The deformation is driven by a pressure difference through the sheet. The thermal resolution uses a one dimension finite element method in the thickness with convection or conduction at the surface and dissipation of mechanical energy. The polymer cooling is very efficient during the contact with the tools. The coupling is done by the thermal dependent rheology. The respective contributions of friction and thermal effects in the thickness of the part during the process are discussed. The model also considers a possible multilayered material, with specific rheological parameters inside each layer. The rheology of a polystyrene was measured under elongation as a function of temperature, strain and strain-rate and described by a viscoplastic law. The predictions of the model were compared with measurements on an instrumented thermoforming machine and with the local thickness of axisymmetrical parts and with 3-D parts thermoformed with the same polystyrene.
Measurement and Prediction of Anisotropy in Injection Moulded PP Products
Authors: Jansen K. M. B.
Published: December 2013

Exact knowledge of anisotropy in thermal and mechanical properties of moulded articles is important since it is directly related to undesired phenomena like warpage. In this study careful measurements of the coefficients of thermal expansion, elastic moduli, Poisson constants and linear compressibilities showed that the anisotropy of these properties was about 10%, for injection moulded polypropylene plates. A simple composite model was proposed which could predict all thermal and mechanical properties mentioned above from data of the amorphous and crystalline phases. The degree of crystallization, skin thickness and average orientation of the fibrillar precursors are the main input parameters. It turned out that although individual values were slightly over or underpredicted, the amount of anisotropy was usually predicted correctly. The only prediction which disagreed with the measurements was that of the coefficient of thermal expansion, which was measured to be larger in flow direction than in width direction.

The changes of shrinkage and shrinkage anisotropy along the flowpath were studied experimentally for different processing conditions. The most remarkable observations were that variations in injection velocity only affected width shrinkage, while melt and mould temperatures specifically acted on length shrinkage. Holding pressure, on the other hand, affected both length and width shrinkage with the same amount.
Gas Penetrations in Symmetrical Tapping Ribs during Gas-Assisted Injection Molding
Authors: Parng S. H. , Yang S. Y.
Published: December 2013

The system of gas penetrations through melt at symmetrical rib channels is found unstable. By varying cross-sectional area of gas channel along the flow length, this research is devoted to observing the effect of the gas penetrations system in tapering symmetrical ribs during gas-assisted injection molding. With decreasing the cross section along the flow length and decelerate the penetration of gas-tip fronts, the degree of uneven gas penetrations can be reduced and stability is improved.
Flow Analysis in Screw Extruders-Effect of Kinematic Conditions
Authors: Rauwendaal C. , Osswald T. A. , Tellez G. , Gramann P.J.
Published: December 2013

Recently, several investigators have challenged the simplifying assumption of using a stationary screw with a rotating barrel when analyzing the flow in single screw extruders. The investigators claim that there are significant differences between the realistic and simplified cases, such as a 12 percent difference in throughput [1]. This paper presents an analytical derivation for the flow in a laid out system and one which includes the curvature of the screw. An experimental set-up was built which allows the rotation of the barrel with a stationary screw and the rotation of the screw with a stationary barrel, and a three dimensional flow simulation program was used to model the flow in the extruder using the two conditions. The analytical, experimental and numerical analyses show that it is justified to use the stationary screw assumption when modeling the flow in single screw extruders.
Distributive Mixing in an Axial Discharge Continous Mixer
Authors: Yao C.-H. , Manas-Zloczower I.
Published: December 2013

The axial discharge continuous mixer-LCMAX 40, which combines the features of a continuous mixer and the co-rotating twin screw extruder, was analyzed in this work for its distributive mixing efficiency. We analyzed the distributive mixing performance for various rotor configurations. Four designs with either alternating or block arrangements of pushing and counter-pushing units were investigated. A fluid dynamics analysis package-FIDAP, based on the finite element method was used to model the flow behavior of a power law model fluid. Distributive mixing was quantified using particle distributions along the axial distance. Residence time distribution (RTD) functions were calculated and found to reveal interesting information related to design features. The influence of design on the evolution of the particle path length and shear strain distribution was also discussed. The counter-pushing units and their arrangements were found to play an important role in distributive mixing.
Manufacture-Induced Inaccuracies of Spinning Dies1
Authors: Beyreuther R. , Brünig H. , Hofmann H.
Published: December 2013

The die in the melt spinning process distributes the whole melt stream into individual small melt streams that pass the die parallel to each other. The number of holes in the die determines the number of filaments in the spun fiber bundle. As the whole melt stream (i. e. the total throughput) is enforced by a precise gear pump (the spinning pump) the sharing out into the single hole throughputs is dependent on the pressure and the flow resistances of the single holes. Only for constant pressure and equal resistances the single hole throughputs are equal, too. The present paper deals with the influence of geometrical inaccuracies of the holes in the spinning die on the fineness and structural variations across the spun fiber bundle.
Numerical Calculation of the Velocity and Temperature Field in the Reverse Roll Coating
Authors: Klostermann R. , Mewes D.
Published: December 2013

Rotating rolls are used to distribute liquids onto papers or other materials in order to coat their surfaces with thin films for further technical applications of the composed materials. In this contribution a numerical method is applied which solves the momentum balance in the liquid phase with the support of the Finite Element Method (FEM), taking free surfaces into consideration. The coupled equations of momentum and energy are solved on the basis of the Boundary Element Method (BEM). The process parameters are summarized in the friction number, the capillary number, the Reynolds number, the Stokes number and several ratios of the linear dimensions. Their influence on the fields of pressure, velocity, tension, and temperature is investigated and displayed graphically. A temperature gradient superimposed to the flow through the gap between the roll surfaces results in an additional influence on the velocity field and the coating thickness. The results of the numerical calculations are approximated by rather simple empirical equations.
Structure and Properties of Injection Moldings of β-Crystal Nucleator-added PP
Authors: Fujiyama M.
Published: December 2013

In this paper, we aim at a synergism of improvements of impact strength of polypropylene by the addition of β-crystal nucleator and of its rigidity by the addition of α-crystal nucleator. Co-addition of both the nucleators has been studied. 30 ppm of γ-quinacridone which is a β-crystal nucleator and 0 to 10000 ppm of talc (FC), aluminum salt of benzoic acid (BA), or dibenzylidene sorbitol (GA) which are α-crystal nucleators were added to a homo isotactic polypropylene (PP). Flexural and lzod impact test specimens were injection-molded from the PPs under constant molding conditions and the structure and properties have been investigated. Although the α-crystal nucleators scarcely affect the β-crystal content (K value) at nucleator contents below 100 ppm, the K value decreases with increasing nucleator content at contents above 100 ppm. The decrease is in the order of BA > GA > TC Although the lzod impact strength scarcely changes at α-crystal nucleator contents below 100 ppm, it decreases with increasing nucleator content at contents above 100 ppm. The decrease is the larger as the decrease of K value is the larger. The flexural modulus shows a reverse tendency of the lzod impact strength. From above, it may be said that the properties of injection molding of β- and α-crystal nucleator-added PP are unitarily determined by the β-crystal content and thus the expected synergism could not be obtained.
Design and Experimental Approach to the Construction of a Human Signal-Molecule-Profiling Database
Authors: Zhao Xinyan , Dong Tao
Published: December 2013

The human signal-molecule-profiling database (HSMPD) is designed as a prospective medical database for translational bioinformatics (TBI). To explore the feasibility of low-cost database construction, we studied the roadmap of HSMPD. A HSMPD-oriented tool, called “signal-molecule-profiling (SMP) chip” was developed for data acquisition, which can be employed in the routine blood tests in hospitals; the results will be stored in the HSMPD system automatically. HSMPD system can provide data services for the TBI community, which generates a stable income to support the data acquisition. The small-scale experimental test was performed in the hospital to verify SMP chips and the demo HSMPD software. One hundred and eighty nine complete SMP records were collected, and the demo HSMPD system was also evaluated in the survey study on patients and doctors. The function of SMP chip was verified, whereas the demo HSMPD software needed to be improved. The survey study showed that patients would only accept free tests of SMP chips when they originally needed blood examinations. The study indicated that the construction of HSMPD relies on the self-motivated cooperation of the TBI community and the traditional healthcare system. The proposed roadmap potentially provides an executable solution to build the HSMPD without high costs.
Visual Detection and Evaluation of Latent and Lytic Gene Expression during Epstein-Barr Virus Infection Using One-Step Reverse Transcription Loop-Mediated Isothermal Amplification
Authors: Liu Xiaoying , Tang Jingfeng , Wang Man , Ma Qiang , Wang Yefu
Published: December 2013

Epstein-Barr virus (EBV)-associated disease exhibits distinct gene expression patterns characterized by the transcription of EBV nuclear antigen (EBNA) 1, EBNA2, latent membrane protein (LMP) 1, LMP2A, and BZLF1 (Zebra). A series of visual reverse transcript loop-mediated isothermal amplification (RT-LAMP) assays were performed to examine the expression of EBNA1, EBNA2, LMP1, LMP2A and BZLF1. The sensitivity of RT-LAMP for these transcripts was approximately equivalent to real-time RT-PCR (RT-qPCR), which was developed to quantify relative levels of EBV transcripts, and 10 to 100-fold more sensitive than conventional RT-PCR. Cross-reactions to other viruses were not observed upon examination of cell lines infected with herpes simplex viruses-1 and -2 (HSV-1 and -2), varicella zoster virus (VZV), human cytomegalovirus (HCMV) or Kaposi’s sarcoma-associated herpesvirus. When applied to 146 specimens, RT-LAMP exhibited high clinical sensitivity and specificity, with an excellent agreement (κ > 0.92) compared to RT-qPCR. These assays are convenient for rapid early diagnosis and for surveillance of EBV-infected individuals by evaluating the EBV transcriptional profile, because the results can be visualized with the naked eye. These assays may be employed in further investigations because they can aid the design of improved therapeutic regimens and can be used specifically in resource-poor settings.
Antimicrobial, Mechanical and Thermal Studies of Silver Particle-Loaded Polyurethane
Authors: Paul Deepen , Paul Sharmistha , Roohpour Nima , Wilks Mark , Vadgama Pankaj
Published: December 2013

Silver-particle-incorporated polyurethane films were evaluated for antimicrobial activity towards two different bacteria: Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Distributed silver particles sourced from silver nitrate, silver lactate and preformed silver nanoparticles were mixed with polyurethane (PU) and variously characterized by field emission scanning electron microscopy (FESEM), fourier transform infra-red (FTIR) spectroscopy, X-ray diffraction (XRD) and contact angle measurement. Antibacterial activity against E.coli was confirmed for films loaded with 10% (w/w) AgNO3, 1% and 10% (w/w) Ag lactate and preformed Ag nanoparticles. All were active against S. aureus, but Ag nanoparticles loaded with PU had a minor effect. The apparent antibacterial performance of Ag lactate-loaded PU is better than other Ag ion-loaded films, revealed from the zone of inhibition study. The better performance of silver lactate-loaded PU was the likely result of a porous PU structure. FESEM and FTIR indicated direct interaction of silver with the PU backbone, and XRD patterns confirmed that face-centred cubic-type silver, representative of Ag metal, was present. Young’s modulus, tensile strength and the hardness of silver containing PU films were not adversely affected and possibly marginally increased with silver incorporation. Dynamic mechanical analysis (DMA) indicated greater thermal stability.
Automatic and Objective Assessment of Alternating Tapping Performance in Parkinson’s Disease
Authors: Memedi Mevludin , Khan Taha , Grenholm Peter , Nyholm Dag , Westin Jerker
Published: December 2013

This paper presents the development and evaluation of a method for enabling quantitative and automatic scoring of alternating tapping performance of patients with Parkinson’s disease (PD). Ten healthy elderly subjects and 95 patients in different clinical stages of PD have utilized a touch-pad handheld computer to perform alternate tapping tests in their home environments. First, a neurologist used a web-based system to visually assess impairments in four tapping dimensions (‘speed’, ‘accuracy’, ‘fatigue’ and ‘arrhythmia’) and a global tapping severity (GTS). Second, tapping signals were processed with time series analysis and statistical methods to derive 24 quantitative parameters. Third, principal component analysis was used to reduce the dimensions of these parameters and to obtain scores for the four dimensions. Finally, a logistic regression classifier was trained using a 10-fold stratified cross-validation to map the reduced parameters to the corresponding visually assessed GTS scores. Results showed that the computed scores correlated well to visually assessed scores and were significantly different across Unified Parkinson’s Disease Rating Scale scores of upper limb motor performance. In addition, they had good internal consistency, had good ability to discriminate between healthy elderly and patients in different disease stages, had good sensitivity to treatment interventions and could reflect the natural disease progression over time. In conclusion, the automatic method can be useful to objectively assess the tapping performance of PD patients and can be included in telemedicine tools for remote monitoring of tapping.
Sustainability Standards and the Reorganization of Private Label Supply Chains: A Transaction Cost Perspective
Authors: Banterle Alessandro , Stranieri Stefanella
Published: December 2013

Private standards are among the main measures that can be implemented to differentiate food production. Retailers have been particularly active in setting food safety and quality systems for the development of their private labels. The purpose of this paper is to identify the effects of introducing measures that guarantee the environmental sustainability of food production on vertical dyadic relations. We focus our attention on the adoption of integrated pest management (IPM) systems that are designed by retailers to support private label products, with the aim of studying how these systems affect the governance structure of transactions between retailer and farmer/processor. Transaction cost analysis is used as theoretical framework to assess changes in vertical coordination after the adoption of an IPM system. Four case studies related to food retailers in Italy were analyzed to identify changes in transaction characteristics, costs, and governance that are related to the adoption of this system. The results show that the introduction of an IPM system leads to an increase of transaction asset specificity (i.e., especially of human and material asset specificity) among the agents of the supply chain, and a decrease of the degree of transaction uncertainty. The variations in transaction characteristics determine changes in transaction costs. These changes lead to new hybrid forms of transaction governance, namely dyadic contracts, and a centralized organization of vertical relationships.
Measuring Carbon Emissions Performance in 123 Countries: Application of Minimum Distance to the Strong Efficiency Frontier Analysis
Authors: Wang Ling , Chen Zhongchang , Ma Dalai , Zhao Pei
Published: December 2013

In this paper, we have proposed a general approach to obtain a projection of the nearest targets and minimum distance for a given unit. The method takes undesirable output into account. The idea behind it is that nearest targets and minimum distance lead to less variation in inputs and outputs of the inefficient decision making units (DMUs) being evaluated to reach the production possibility set (PPS) frontier. Our results have shown that the carbon emissions comprehensive performance indexes (CECPIs) of developing countries are lower than those of developed countries, and that the inefficiency shares of energy consumption, capital stock and desirable output are declining while those of labor force and undesirable output are climbing. Further, using cluster analysis, we have shown that nine countries, including Ukraine, Kazakhstan, Uzbekistan and Iraq, should take severe measures to save energy and reduce carbon emissions. Moreover, the gap in CECPIs among the 123 countries is narrowing by kernel density estimation.
In vitro biomechanical comparison of the effects of cerclage wires, an intramedullary pin and the combination there of on an oblique osteotomy of the canine tibia
Authors: van der Zee J.
Published: December 2013

To compare the in vitro biomechanical effects of single loop cerclage wires, an intramedullary pin and the combination thereof as applied to an oblique mid-diaphyseal osteotomy of canine tibiae.

Three groups of nine bones with long oblique osteotomies were repaired with the following methods: 1) Three single loop cerclage wires and a transcortical skewer pin, 2) intramedullary pinning with a smooth Steinmann pin, and 3) a combination of both methods. The repaired constructs were tested in a single cycle four-point-bending test to failure. Load displacement curves were drawn and the following parameters were calculated or extrapolated: Stiffness, load at yield, and force resisted at 2 mm actuator displacement. The latter was determined to demonstrate the difference in the amount of energy absorbed between the different groups.

The stiffness and force resisted at 2 mm displacement of the groups with cerclage wires were significantly higher than the group with an intramedullary pin alone (p ≤ 0.05). The differences in stiffness (p = 0.15) and force required at 2 mm displacement (p = 0.56) between cerclage wires and the combination of cerclage wires and intramedullary pins were not significant.

Cerclage wire repair results in higher stiffness than repair with an intramedullary pin. When cerclage wires are combined with an intramedullary pin, the intramedullary pin does not provide protection to the cerclage wire repair and the wires or the bone under the wires has to fail before the pin resists significant load.
Sterilization by gamma radiation of antibiotic impregnated polymethylmethacrylate and plaster of Paris beads
Authors: Trencart P. , Batista E. Rodriguez , Michaud G. , Elce Y. A.
Published: December 2013

Ethylene oxide is currently recommended for sterilization of antibiotic impregnated beads; however this method carries health risks to personnel and is becoming less available.

To perform a pilot study of the effect of radiation for sterilization of polymethylmethacrylate (PMMA) and plaster of Paris (POP) beads impregnated with amikacin, enrofloxacin, and ceftiofur.

Radiation would effectively sterilize the beads without affecting the efficacy of the antibiotic.

Beads of PMMA and POP were prepared in a clean but nonsterile manner with one of the three antibiotics (amikacin, enrofloxacin, ceftiofur) or no antibiotic. Beads were then exposed to radiation for a total dose of 0 kiloGray (kGy), 10 kGy and 25 kGy. Beads were incubated on Mueller-Hinton agar plates seeded with Escherichia coli, Staphylococcus aureus or Pseudomonas aeruginosa for 24 hours or cultured in brain-heart infusion broth for 48 hours. Zones of inhibition were measured on the agar plates and statistics were performed on the diameters of the zones of inhibition using an analysis of variance.

There were no differences in the diameters of inhibition for all levels of radiation for all PMMA beads. The same was true with POP beads with the exception of enrofloxacin which had a significantly decreased zone of inhibition with increased levels of radiation, though the clinical significance of this finding was not assessed. Only beads without antibiotics and not exposed to radiation had bacterial growth.

Radiation may be an effective method of sterilization for antibiotic impregnated beads.
Development and characterization of 11 polymorphic microsatellite markers in Tapiscia sinensis (Staphyleaceae)
Authors: Zhang Pengfei , Wang Zhiguang , Liu Yaling , Tian Hua , Yao Xiaohong , Zhang Jinju
Published: December 2013

• Premise of the study: We developed and characterized five polymorphic microsatellite loci from an AC‐enriched genomic library of a rare tree, Tapiscia sinensis, and six compound microsatellite primers using a dual‐suppression‐PCR–based approach, to investigate geographical genetic structure.

• Methods and Results: The polymorphism of these loci was assessed in 102 samples collected from three populations. The number of alleles per locus ranged from one to nine. Expected heterozygosity per locus ranged from 0.000 to 0.709 and observed heterozygosity ranged from 0.000 to 0.750. Five loci deviated from Hardy–Weinberg equilibrium after Bonferroni correction.

• Conclusions: This set of microsatellites may be useful for investigating broad‐scale genetic variation in the extant populations of the endangered tree species T. sinensis.
Geology, Norman Wells (southwest), Northwest Territories
Authors: Fallas K M , MacNaughton R B , MacLean B
C , Hadlari T
Published: December 2013

The southwest quadrant of Norman Wells map area (NTS 96-E) covers parts of the Franklin Mountains, Mackenzie Plain, and Mackenzie Mountains, Northwest Territories. The area varies from low-lying forested plain to alpine mountainous terrain, with bedrock exposures
concentrated in the mountains on either side of the Mackenzie River. The geological interpretation in poorly exposed portions of the Mackenzie Plain has been enhanced by examination of public-domain seismic-reflection lines, archived with the National Energy Board. Cordilleran deformation from the
southwest has uplifted Proterozoic and/or Paleozoic strata along reverse or thrust faults, and anticlinal folds in both the Mackenzie and Franklin mountains. The intervening Mackenzie Plain is dominated by folded and faulted Devonian and Cretaceous siliciclastic strata that have largely been planed
off by glacial activity. The lack of surface exposure of Proterozoic strata in the Norman Range indicates this interval is not involved in Franklin Mountain structures, in contrast to the Mackenzie Mountains. An unconformity at the base of Upper Cretaceous strata cuts more deeply into underlying
strata to the northeast, a reflection of uplift along the Keele Arch before deposition of the Slater River Formation. Exploration by petroleum companies in the area has typically targeted potential reservoirs in buried Devonian strata.
An Evaluation of the Cumulative Surface Water Pollution on Selected Areas within the Consolidated Main Reef Area, Roodepoort, South Africa
Authors: Muruven D.N. , Tekere M.
Published: December 2013

Mining has long been at the center of the South African economy and has contributed to significant developments within the country. However, despite the large economic impact, surface water pollution due to mining is prevalent in most of the country's water catchments. Surface water in many areas of the central Roodepoort area in Johannesburg, South Africa, has also been impacted primarily by mining activities. The surface water quality for the Bosmontspruit, Russell's Stream, and the New Canada Dam was assessed in this study from October 2010 to March 2011. Physicochemical and biological characteristics of the water were determined for eight monitoring points, and the results obtained were compared with the in-stream water quality guidelines for the Klip River catchment and the South African Water Quality Guidelines. A trend noticed throughout the sampling period was the noncompliance to the set target water quality ranges (TWQRs) in the levels of total dissolved solids (TDS) and dissolved oxygen (DO). The results indicate that concentrations of iron, aluminum, nickel, manganese, and potassium were above the permissible limits across the Bosmontspruit and Russell's Stream. Excessive fecal coliforms and ammonium pollution were also detected in the Bosmontspruit. Additionally, during the monitoring period, it was noted that the water was being utilized for domestic purposes, and may pose health hazards due to poor water quality.
Quantifying black carbon from biomass burning by means of levoglucosan – a one year time series at the Arctic observatory Zeppelin
Authors: Yttri K. E. , Lund Myhre C. , Eckhardt S. , Fiebig M. , Dye C. , Hirdman D. , Ström J. , Klimont Z. , Stohl A.
Published: December 2013

Abstract. Levoglucosan, a highly specific tracer of particulate matter from biomass burning, has been used to study the influence of residential wood burning, agricultural waste burning and boreal forest fire emissions on the Arctic atmosphere black carbon (BC) concentration. A one year time series from March 2008 to March 2009 of levoglucosan has been established at the Zeppelin Observatory in the European Arctic. Elevated concentrations of levoglucosan in winter (Mean: 1.02 ng m−3) compared to summer (Mean: 0.13 ng m−3) were observed, resembling the seasonal variation seen for e.g. sulphate and BC. The mean concentration in the winter period was two to three orders of magnitude lower than typical values reported for European urban areas in winter, and one to two orders of magnitude lower than European rural background concentrations. Episodes of elevated levoglucosan concentration were more frequent in winter than in summer and peak values were higher, exceeding 10 ng m−3 at the most. Concentrations of elemental carbon from biomass burning (ECbb) were obtained by combining measured concentrations of levoglucosan and emission ratios of levoglucosan and EC for wild/agricultural fires and for residential wood burning. Neglecting chemical degradation by OH provides minimum levoglucosan concentrations, corresponding to a mean ECbb concentration of 3.7±1.2 ng m−3 in winter (October–April) and 0.8±0.3 ng m−3 in summer (May–September) or 8.8±4.5% of the measured equivalent black carbon (EBC) concentration in winter and 6.1±3.4% in summer. When accounting for chemical degradation of levoglucosan by OH, an upper estimate of 31–45% of EBC could be attributed to ECbb* (ECbb adjusted for chemical degradation) in winter and <65% in summer. Hence, fossil fuel sources appear to dominate the European Arctic BC concentrations in winter, whereas the very wide range obtained for summer does not allow us to conclude upon this for the warm season. Calculations using the Lagrangian particle dispersion model FLEXPART show that the seasonal variation of the modelled ECbb (ECbb,m) concentration compared relatively well with observationally derived ECbb from agricultural/wild fires during summer, and residential wood burning in winter. The model overestimates by a factor of 2.2 in winter and 4.4 in summer when compared to the observationally derived mean ECbb concentration, which provides the minimum estimate, whereas it underestimates by a factor of 2.3–3.3 in winter and a factor of 4.5 in summer when compared to ECbb*, which provides the upper estimate. There are indications of too low emissions of residential wood burning in Northern Russia, a region of great importance with respect to observed concentrations of BC in the European Arctic.
Trajectory matching of ozonesondes and MOZAIC measurements in the UTLS – Part 1: Method description and application at Payerne, Switzerland
Authors: Staufer J. , Staehelin J. , Stübi R. , Peter T. , Tummon F. , Thouret V.
Published: December 2013

Abstract. With the aim of improving ozonesonde observations in the upper troposphere/lower stratosphere (UTLS), we use three-dimensional forward and backward trajectories, driven by ERA-Interim wind fields to match and compare ozonesonde measurements at Payerne (Switzerland) with observations from the MOZAIC aircraft program from 1994–2009. The uncertainties associated with the sonde–MOZAIC match technique were assessed using "self-matches", i.e. matches of instruments of the same type, such as MOZAIC–MOZAIC. Despite strong vertical gradients of ozone at the tropopause, which render the match approach difficult, the method provides excellent results, showing mean differences between different MOZAIC aircraft of ±2% (typically with a few hours between the up- and downstream match points). Matches between MOZAIC aircraft and Payerne ozonesondes show an agreement of ±5% for sondes equipped with electrochemical concentration cells (ECC) and between < 5% (not scaled to total ozone) and < 10% (scaled) for the Brewer–Mast (BM) sondes after 1998. Prior to 1998, BM sondes show an offset of around 20% (scaled). No break can be identified through the change from the BM to ECC sonde types in September 2002. A comparison of BM sondes with ozone measurements from the NOXAR B747 project for the period 1995–1996 show a smaller offset of around 15% (scaled), which may indicate a small drift in the MOZAIC calibration.
Comparison between experimental and numerical stratigraphy emplaced by prograding bedforms with a downstream slip face
Authors: Viparelli E. , Blom A. , Ferrer-Boix C. , Kuprenas R.
Published: December 2013

Abstract. A one-dimensional model that is able to store the stratigraphy emplaced by prograding bedforms with a downstream slip face is validated against experimental results. The laboratory experiment describes the migration of a Gilbert delta on a sloping basement into standing water, i.e. a condition in which the stratigraphy emplaced by the delta front (the lee face) is entirely stored in the deposit. The migration of the delta front and the deposition on the delta top are modeled with a total and a grain size based mass conservation models. The vertical sorting on the delta front is modeled with a lee face sorting model, as a function of the grain size distribution of the sediment deposited at the brinkpoint, i.e. at the downstream end of the delta top. Notwithstanding the errors associated with the grain size specific bedload transport formulation, the comparison between numerical and experimental results shows that the model is able to reasonably describe the progradation of the delta front, the frictional resistances on the delta top, and the overall grain size distribution of the delta top and delta front deposits. Further validation of the model under the case of variable base level is currently in progress to allow for future studies on Gilbert delta progradation at field scale.
Sea cliff instability susceptibility at regional scale: a statistically based assessment in the southern Algarve, Portugal
Authors: Marques F. M. S. F. , Matildes R. , Redweik P.
Published: December 2013

Abstract. Sea cliff evolution is dominated by the occurrence of slope mass movements of different types and sizes, which are a considerable source of natural hazard, making their assessment a relevant issue in terms of human loss prevention and land use regulations. To address the assessment of the spatial component of sea cliff hazards, i.e. the susceptibility, a statistically based study was made to assess the capacity of a set of conditioning factors to express the occurrence of sea cliff failures affecting areas located along their top. The study was based on the application of the bivariate information value and multivariate logistic regression statistical methods, using a set of predisposing factors for cliff failures, mainly related to geology (lithology, bedding dip, faults) and geomorphology (maximum and mean slope, height, aspect, plan curvature, toe protection), which were correlated with a photogrammetry-based inventory of cliff failures that occurred in a 60 yr period (1947–2007). The susceptibility models were validated against the inventory data using standard success rate and ROC curves, and provided encouraging results, indicating that the proposed approaches are effective for susceptibility assessment. The results obtained also stress the need for improvement of the predisposing factors to be used in this type of study and the need for detailed and systematic cliff failure inventories.
Collisions of two breathers at the surface of deep water
Authors: Dyachenko A. I. , Kachulin D. I. , Zakharov V. E.
Published: December 2013

Abstract. We present results of numerical experiments on long-term evolution and collisions of breathers (which correspond to envelope solitons in the NLSE approximation) at the surface of deep ideal fluid. The collisions happen to be nonelastic. In the numerical experiment it can be observed only after many acts of interactions. This supports the hypothesis of "deep water nonintegrability". The experiments were performed in the framework of the new and refined version of the Zakharov equation free of nonessential terms in the quartic Hamiltonian. Simplification is possible due to exact cancellation of nonelastic four-wave interaction.
Taxonomic revision and phylogeny of the Ophiocoma brevipes group (Echinodermata, Ophiuroidea), with description of a new subgenus (Breviturma) and a new species
Authors: Stöhr Sabine , Boissin Emilie , Hoareau Thierry B.
Published: December 2013

The taxonomy of the genus Ophiocoma was last revised by Devaney in 1970. Recent discoveries of new species and re-instatement of previously synonymized names suggest that we still do not fully understand the species limits in this genus. A recent biodiversity survey of the SW Indian Ocean shallow reefs strongly suggested an unrecognised species in the genus, closely related to O. brevipes/O. dentata. This study examined both the molecular phylogenetic relationships and the morphological characteristics of several species in the genus in order to characterise the unrecognised species. The focal species clusters with O. brevipes, O. dentata, O. doederleini within a monophyletic clade supported by molecular data for the first time. The name Breviturma subgen. nov. is proposed for this clade, previously known as brevipes group. Type material of nominal species that have been synonymized with O. dentata was examined and re-assessed. Ophiocoma marmorata proved not conspecific with O. dentata. A rarely used character, dorsal disc granule density, was tested and showed differences between the examined species at similar sizes. In combination with colour pattern, disc granule density, arm spine sequence and maximum disc size, the new species was delimited morphologically and described as Ophiocoma krohi sp. nov.
Electric car with solar and wind energy may change the environment and economy: A tool for utilizing the renewable energy resource
Authors: Liu Quanhua
Published: December 2013

Energy and environmental issues are among the most important problems of public concern. Wind and solar energy may be one of the alternative solutions to overcome energy shortage and to reduce greenhouse gaseous emission. Using electric cars in cities can significantly improve the air quality there. Through our analyses and modeling on the basis of the National Centers for Environment Prediction data we confirm that the amount of usable solar and wind energy far exceeds the world's total energy demand, considering the feasibility of the technology being used. Storing the surplus solar and wind energy and then releasing this surplus on demand is an important approach to maintaining uninterrupted solar‐ and wind‐generated electricity. This approach requires us to be aware of the available solar and wind energy in advance in order to manage their storage. Solar and wind energy depends on weather conditions and we know weather forecasting. This implies that solar and wind energy is predictable. In this article, we demonstrate how solar and wind energy can be forecasted. We provide a web tool that can be used by all to arrive at solar and wind energy amount at any location in the world. The tool is available at www.renewableenergyst.org. The website also provides additional information on renewable energy, which is useful to a wide range of audiences, including students, educators, and the general public.
Single‐crystal equation of state of phase D to lower mantle pressures and the effect of hydration on the buoyancy of deep subducted slabs
Authors: Rosa A. D. , Mezouar M. , Garbarino G. , Bouvier P. , Ghosh S. , Rohrbach A. , Sanchez‐Valle C.
Published: December 2013

An understanding of the physical properties of the hydrous magnesium silicate phase D is important for the interpretation of the seismic anomalies observed in subducted slabs and to evaluate the effect of hydration on slab dynamics. Here we report the equation of state of phase D (Mg1.1Si1.8H2.5O6) up to 65 GPa obtained from high‐precision single‐crystal X‐ray diffraction. A single‐crystal of phase D was loaded in a diamond anvil cell using helium as pressure transmitting medium to ensure quasi‐hydrostatic conditions during the entire data collection. The volume of phase D decreases smoothly over the entire pressure range, without the anomalies in the compressibility reported at 40 GPa in previous powder diffraction studies. If existing in phase D, a hydrogen bond symmetrization transition as predicted by first‐principles calculation is therefore not associated with anomalies in the volume compression behavior. The isothermal bulk modulus KT and its pressure derivative K′T obtained from the fitting of the unit cell volumes using a third‐order Birch‐Murnaghan equation of state are KT = 151.4 ± 1.2 GPa and K′T = 4.89 ±0.08, respectively. This bulk modulus is in good agreement with a recent single‐crystal Brillouin scattering experiment. The presence of 16 vol. % of phase D in hydrous peridotite lithologies reduces the density by up to 2.6% at upper most lower mantle pressure‐temperature conditions (1273 K and 30 GPa), phase D is thus a potential candidate to influence the buoyancy of hydrated stagnant slabs below the transition zone.