bluuebunny/crossref_metadata_2025 huggingface dataset:
The Sweep Efficiency of Viscoelastic Polymer Solution
Authors: Jiang Hai Mei , Zhang Jin Qing , Zhang Shu Xu , Sun Xiao Kang
Published: April 2013

A finite volume method for the numerical solution of viscoelastic flows is presented in this paper. The flow of a differential upper-convected Maxwell (UCM) model fluid through an abrupt expansion has been chosen as a prototype example. The equations are solved using the finite volume method (FVM) in a staggered grid. Stable solutions are found for high Weissenberg number (We), further extending the range of simulations with the FVM. Numerical results show the viscoelasticity of polymer solutions is the main factor influencing sweep efficiency.
Temperature Dependence of Reaction Rate in the Oxidation of Dafosi Coal
Authors: Zhong Xiao Xing , Dou Guo Lan , Chen Yun , Wang De Ming
Published: April 2013

Adiabatic self-heating tests had been conducted on Dafosi coal. Analysis of the relationship of temperature and reaction rate revealed that the dependence of coal sample temperature on reaction rate can be described by a third order polynomial from 40°C up to 155°C. But at a small interval of temperature, the reaction rate still conforms to the Arrhenius kinetic model. When Arrhenius equation is used to solve the kinetic parameters of the coal spontaneous combustion, the coal temperature should be processed in segment.
Advances in Chemical-Looping Combustion for Solid Fuels
Authors: Luo Ming , Wang Shu Zhong , Wang Long Fei
Published: April 2013

Chemical-looping combustion (CLC) is a new method for the combustion of fuels with inherent separation of carbon dioxide, which can simultaneously improve combustion efficiency and reduce environmental pollution. Since solid coal is considerably more abundant than natural gas, it would be highly advantageous if the CLC process could be adapted for solid fuels. The present review introduces the technical approaches for the solid fuels CLC process, and the existing technical problems in solid fuels CLC are discussed. The demands in oxygen carriers of chemical looping combustion for solid fuels are analyzed, and the recent advances in metal oxides oxygen carriers (Cu-, Ni- and Fe-based) and calcium based oxygen carrier are summarized. The recent advances in reactor design are outlined. The main problems in reactor deign are mentioned and the relative measures are pointed.
Estimation of Crystalline Size of Deformed 5251 Al Alloy Using PALT and XRD Techniques
Authors: Abdel-Rahman M. , Attallah Ahmed G. , El-Sayed M. , Ibrahim A.A. , Akel A.A. , Ali Atef E. , Badawi Emad A.
Published: April 2013

Certain radioactive isotopes decay by emitting positrons, and the positrons can be used to probe the structure of solid materials. For example, one can investigate the grain size due to deformation in a metal. XRD is also a powerful technique for detection the defects introduced into a metal and for investigating the microstructure of a deformed metal. In this paper we shall investigate the plastic deformation effect on the grain size of 5251 Al alloys using two different techniques, PALT and XRD. The study shows a significant effect of the plastic deformation on the grain size which decreases as the deformation increases.
Studies of Knight Shifts and Hyperfine Structure Constants of Tl2Ba2CuO6+y
Authors: Kuang Min Quan , Wu Shao Yi , Hu Xian Fen , Song Bo Tao
Published: April 2013

The Knight shifts and hyperfine structure constants of Tl2Ba2CuO6+yare theoretically studied from the high order perturbation formulas of these quantities for a tetragonally elongated octahedral 3d9cluster. The calculation results reveal good agreement with the observed values. The obvious anisotropies of the Knight shifts can be ascribed to the local tetragonal elongation of the Cu2+site. The results and the local structure of the system are discussed.
Tube Hydroforming (THF): Process Optimization of an Automotive Component
Authors: Attanasio Aldo , Ceretti Elisabetta , Maccarini Giancarlo
Published: April 2013

This paper reports the results obtained during a research project funded by the Italian Government and involving several Italian Universities (PRIN INTEMA). The activities have been focused on side impact bar manufacturing by means of Tube Hydroforming process (THF). Punch movement paths and fluid pressure curve were optimized by means of FEM software (LS-DYNA) to guarantee tube sealing and material feeding during the tube deformation. The side impact bar geometry was optimized till reaching the shape guaranteeing the obtainment of safe parts with the best compromise in terms of final part geometry and thickness reduction. Different fluid pressure and punch movement paths were investigated. Once accomplished all the simulations and identified the best working solution, experimental tests were performed setting the process parameters according to the values defined during the simulation phase. Good agreement between FEM and experimental results were highlighted.
Numerical Modeling of Tube Hydropiercing Using Phenomenological and Micro-Mechanical Damage Criteria
Authors: Hassannejadasl Amir , Green Daniel E.
Published: April 2013

Hydropiercing is an efficient way of piercing holes in mass produced hydroformed parts with complex geometries. By driving piercing punches radially into a hydroformed and fully pressurized tube, holes will be pierced and extruded into the tube-wall. Recent experimental studies have shown that the formability of advanced high strength steel (AHSS) tubes can be increased with the application of internal pressure. In this study, three-dimensional finite element simulations of a tube hydropiercing process of a dual phase steel (DP600) were performed in LS-DYNA, using phenomenological, micromechanical and combined damage criteria. Damage was included in the numerical analysis by applying constant equivalent plastic strain (CEPS), the Gurson-Tvergaard-Needleman (GTN), and the Extended GTN (GTN+JC) model. In order to calibrate the parameters in each model, a specialized hole-piercing fixture was designed and piercing tests were carried out on non-pressurized tube specimens. Of the various ductile fracture criteria, the results predicted with the GTN+JC model, such as the punch load-displacement, the roll-over depth, and the quality of the clearance zone correlated the best with the experimental data.
Formability Characteristics of AA5083 Sheets under Hot Forming Conditions
Authors: Bruschi Stefania , Ghiotti Andrea , Michieletto Francesco
Published: April 2013

The production of aluminum alloy components through sheet forming processes conducted at elevated temperatures is gaining more and more interest as it gives raise to the possibility of a significant enhancement of the metal formability characteristics, compared to room temperature forming. Aluminum alloy AA5083 blanks, which present a limited formability at room temperature, are usually formed through superplastic forming at elevated temperature: however, this processing route is too slow to be applicable for large batch production, typical for instance of the automotive industry. The paper is aimed at exploring the formability characteristics of the AA5083 when deformed at elevated temperature, but in a range of strain rates higher than those usually applicable in superplastic forming. To this aim, uni-axial tensile tests were carried out, in order to record the material formability characteristics as a function of temperature and strain rate, and to correlate them with the developed microstructural features. It is shown that it is possible to work at higher strain rates, still preserving a significant formability, even without using a conventional fine-grained superplastic alloy.
Numerical Simulation of Welding Thin Titanium Sheets
Authors: Lacki Piotr , Adamus Konrad
Published: April 2013

Different titanium grades are used in aircraft construction because of titaniums unique properties. These materials are mostly joined by different welding methods. Electron beam welding technology is often used in the aircraft industry to join structural elements made of titanium alloys. The goal of the work is a numerical analysis of the electron beam welding process applied to joining thin titanium sheets. The analysis was performed using finite element method, FEM. Temperature distribution, size of heat affected zone (HAZ), depth and width of fusion zone were determined for the assumed heat source model. Thermo-mechanical (TMC) simulation of the electron beam welding process using FEM is presented in the paper. The joining of two sheets, one made of commercially pure titanium Grade 2 and the other made of titanium alloy Grade 5 (Ti6Al4V), is analysed in the work. For the sheet welding process distributions of temperature, effective stress, and sheet deformation were calculated.
Determination of Friction in Sheet Metal Forming by Means of Simulative Tribo-Tests
Authors: Ceron Ermanno , Bay Nils
Published: April 2013

Numerical modeling of complex sheet stamping operations is well developed and implemented in industry. The weakest link now seems to be appropriate modeling of friction and to some extent also material properties especially when it comes to new lubricants and materials. In modeling of 3-D stamping operations a coefficient of friction μ is often determined by calibration of the simulation results with experimental observations of material flow and/or measured load. In case of modeling of new stamping operations μ is typically selected based on former experience. These procedures are, however, not appropriate when introducing new tribo-systems (lubricant, workpiece material, tool material or tool coating). In order to determine friction under the very varied conditions in sheet stamping simulative testing may be applied, e.g., Plane-Strip-Testing (PST), Draw-Bead-Testing (DBT) and Bending-Under-Tension testing (BUT) but these tests should be analyzed and carefully tuned with the production process in question to ensure useful results. The present paper illustrates how the BUT test combined with classical analytical modeling may lead to very large errors in estimation of the coefficient of friction, whereas detailed numerical simulation of the test can give useful friction values as demonstrated in comparative analysis of an industrial, multistage deep drawing.
The THF Compression Test for Friction Estimation: Study on the Influence of the Tube Material
Authors: Fiorentino Antonio , Ceretti Elisabetta , Giardini Claudio
Published: April 2013

In the Tube Hydroforming (THF) process, a tube, placed in closed dies, is expanded by a high pressure liquid and two punches push its edges in order to feed the material into the expansion zones. Because of the high pressure and the contact area involved in the process, high friction stresses act on the tube walls restricting the material flow so reducing the amount of fed material, the part formability and affecting the soundness of the final part and its geometry. In fact, previous studies showed that the lower the friction coefficient at the tube-die interface, the more uniform the friction distribution and, therefore, the more uniform the stresses acting on the tube walls. The tube deformation being dependent on the stresses, its final thickness is influenced by friction. Starting from this premise, the authors proposed a reference test which is able to highlight the effect of friction on the final tube thickness. In this test, namely the THF Compression Test, a tube is placed in a cylindrical die having the same diameter as the outside of the tube, it is pressurized and then compressed by the punches. In this way, the tube has no expansion and its final thickness depends on the process parameters (tube material, pressure, punch stroke, tube material and geometry). Using FE simulations, it is possible to express the friction coefficient as a function of the process conditions and to use it in combination with experimental results. In the present paper, the previously validated FE model is used to investigate the influence of the tube material on the compression test results. Therefore, a simulation study was performed using different values of strength and hardening coefficients showing how the method is affected by the tested material thereby giving further indication of the test sensitivity.
FEM Analysis of Mecano-Welding Process for Manufacturing Cylinders
Authors: Feng Zheng Kun , Champliaud Henri
Published: April 2013

Cylindrical components produced by mecano-welding process are widely used in industries. The mecano-welding process consists of a roll bending sub-process which can produce non-closed cylinders and a welding process which can seam gaps. This paper proposes a numerical model to simulate the process and to get better understanding of the process mechanism. Explicit and implicit solvers are applied to the numerical modeling by using LS-DYNA and ANSYS software. The numerical model can provide a useful tool for design and optimization of the mecano-welding process.
Modelling Aspects in Accumulative Roll Bonding Process by Explicit Finite Element Analysis
Authors: Fratini Livan , Merklein Marion , Böhm Wolfgang , Campanella Davide
Published: April 2013

Accumulative Roll-Bonding (ARB) process is a severe plastic deformation (SPD) process, capable of developing grains below 1 μm in diameter and improving mechanical properties of the material. In this study, the authors compared two different FE-codes with respect of its applicability for numerical analysis of the ARB process. Modelling this process was achieved using the explicit code for Abaqus/CAE both in 2D and 3D. The proposed model was used to assess the impact of ARB cycles on the final material properties. The numerical results in 2D and 3D were compared and contrasted. The research work presented in this paper is focused on the simulation optimization based on CPU time minimization. The numerical simulations were also validated through a comparison with the experimental results.
Quality Assurance of Laser Welded Axisymmetric Sandwich Structure
Authors: Illikainen Kimmo , Holappa Kalle , Mäntyjärvi Kari
Published: April 2013

This study focuses on quality assurance in a laser welded axisymmetric sandwich structure that functions as the body of an electric machine. The manufacturing quality of the structure was measured using destructive testing and visual inspection. The destructive tests included both fatigue and static tests in addition to a macrographic examination. The visual inspection comprised ocular estimates of the laser welded seams as well as their requirements. Compared with the real working conditions of the machine, the experimental tests were exhaustive. Nevertheless, in the tests, the bodies held up very well which shows the great strength of the structure.
State of the Art: Prototyping of the Roll Bending Machine
Authors: Mäkikangas Jarmo , Kutuniva Kari , Mäntyjärvi Kari
Published: April 2013

This paper focuses on the development of a new type of roll bending machine. Our primary aim was to build a machine that could form ultra-high-strength steels (UHS) with smaller inner radii than those achieved by traditional bending methods. One of the main planning principles was modular construction, so a length of a bending line could be easily selected or changed later by the user without major changes to the basic construction of the machine. In contrast, in traditional roll forming, the blank does not move during the forming process, so the accuracy of the profile can be better controlled. Different kinds of cut to size-open profiles can be produced by this machine, which utilizes and combines bending and rolling techniques. In the initial stages of the project, the needs of smaller companies that do short-run productions are taken into account. First, the prototype is designed mainly for research use; moreover, it is important that the properties of the machine are multifunctional. In addition, forming can be done in several ways by this machine. In this paper, there is shown creation of a machine, designing of construction and manufacturing steps of the whole machine including assembling. Also detailed description of the various functional components and the operating principle is presented. The results of the forming tests are also presented.
Surface Topography from Single Point Incremental Forming Using an Acetal Tool
Authors: Ham M. , Powers B.M. , Loiselle J.
Published: April 2013

This paper investigates a new tool, where the forming tip is constructed from acetal. The acetal tip is investigated because it is self-lubricating and more compliant than traditional SPIF tools. This work characterizes the topography of surfaces created by forming aluminum with both the acetal-tipped tool and a carbide tool. When the parts are compared visually, the parts formed with the acetal tool maintain the appearance of the unformed sheet metal. The surfaces of the parts are measured using an Olympus LEXT OLS4000, a vertical scanning laser confocal microscope. Surface height as a function of lateral position on both sides of the parts (contact and free surface) is measured. These measurements are analyzed quantitatively using areal surface texture parameters and qualitatively compared with micrographs of the surfaces. Comparisons of the surfaces that are in contact with the tool reveal that the surfaces produced with the acetal tool are rougher but more isotropic than those produced using the carbide tool. The surfaces produced by the carbide tool have a more anisotropic appearance, which is created by the tool as it steps down to form the part. The benefit of using the acetal tool rather than the carbide tool is the absence of the anisotropy caused by tool step down. The free surfaces produced by both tools are much rougher than the surfaces that contact the forming tools, since the tool does not affect roughness of the free surfaces.
Mechanical Behavior of Laminated Composites with Circular Holes
Authors: Achache Habib , Boutabout Benali , Ouinas Djamel
Published: April 2013

This paper presents a numerical method for the evaluation of the stress concentration factor (SCF) in three dimensional laminated composites under mechanical loads. The proposed method uses the finite element formulation. The composites materials based on the epoxy matrix and reinforcing fibers are extensively used in aircraft structures due to their high specific characteristics. However, the withstanding of composite structures can be significantly reduced by the addition of geometric singularities, such as perforations or notches. To Analyses the stress concentration around geometrical notches, several studies as analytical, numerical and experimental techniques are available. The stress distribution in a laminated composite plate with the presence of a circular hole was investigated using the finite element method. In order, the results obtained by this study are compared with those reported in literature. The aim of this analysis is to evaluate numerically the factor of stress concentration under the influence of several parameters such as fibers orientation, the mechanical characteristics of composites and the distance between notches of cross-laminated.
Validation of Mechanical Damage Monitoring on Aluminium Freestanding Thin Films Using Electrical Measurements
Authors: Fourcade Thibaut , Broue Adrien , Dhenni Jeremie , Desmarres Jean Michel , Seguineau Cedric , Dalverny Olivier , Alexis Joël , Masri Talal
Published: April 2013

This paper describes a new technique allowing the monitoring of damage in metallic freestanding thin films during micro-tensile test by using electrical characterization. After a presentation of the set-up, results obtained on Aluminium thin coatings by using two calculation methods for damage variable are presented and commented.
Experimental Study for the Choice of a Matrix Epoxy Resin for the Elaboration of Laminates
Authors: Aribi C. , Bezzazi B. , Mir A.
Published: April 2013

The performances of composite materials are influenced by the properties of the matrix used. The latter ensures the desired form and the protection of the reinforcements against the external attacks.
This work comprises a comparative study between laminates developed with different matrices in epoxy resin. Their characterization has to choose the best matrix able to give best results in static and dynamic tests. The resins used are provided by Granitex Algéria and which are primary Médapoxy STR resins, Médapoxy inject 812 and Médapoxy Al resin. Hence, the results of tensile tests prove a fragility of the AL resin which influences the maximal constraint of traction compared to the STR primary resin. Furthermore, Inject 812 resin shows very limited mechanical properties due to the changes of the epoxy network with the addition of diluents which has significantly decreased its viscosity.
Mechanical Behaviour of Butt Jointsunder Traction Using the Image Stereocorrelation Technique
Authors: Karama Moussa , Mistou Sébastien , Brault Romain
Published: April 2013

This study presents the measurement of fields of displacement and deformations on butt joints in hydrostatic depression. The aim of this paper is to observe the general behaviour of the rubber. Various definitions of butt joints were tested in traction. We are interested on the types of fracture and the phenomenon of vacuolization, which occurs in the rubber.
A Dugdale Crack at the Interface of Two Different Materials under Antiplane Shear Loading
Authors: Ferdjani Hichème
Published: April 2013

The elastostatic antiplane problem of a Dugdale crack at the interface of two different materials is considered. Using integral transform, the problem is reduced to a single integral equation. The integral equation is solved numerically. The evolution of the crack for different values of the physical and geometrical parameters of the problem is studied. A comparison between the results obtained with the Griffith and Dugdale models is presented.
Eddy Current Characterization of (Fe65Co35)xAl1-x Nanocrystalline Alloy Synthesized by Mechanical Alloying Process
Authors: Haddad Ahmed , Azzaz Mohammed
Published: April 2013

An investigation was conducted to explore the applicability of Eddy Current (EC) and magnetic techniques to characterize the formation and grains size variation during Mechanical Alloying (MA) and the formation of a new mixture due to the variation of crystallography parameters. The change in apparent density was attributable to the irregular particles of the metal powders. A series of Nanocrystalline (Fe65Co35)xAl1-x samples have been prepared using M.A based on planetary ball mill under several milling conditions. M.A is a non-equilibrium process for materials synthesis. The structural effects of MA of powders were investigated by X-Ray diffraction analysis, SEM, microwaves, hysteresis magnetic and Eddy Current technique.
Consequently, a nanostructure alloy was obtained with an average grain size of 8 nm. Experimental results show that fine nanocrystalline alloy powders prepared by mechanical milling are very promising for microwave applications and it is suggested that Eddy current measurement technique is a useful tool for the characterization of nanocrystalline materials.
Valorization of Asphalt Rubber Fine Powder in Road Field
Authors: Kebaïli Nabil , Belabdelouahab Farid , Zerzour Ali
Published: April 2013

In the framework of valorization of the worn tires and environment preservation, several techniques exist in many fields. In Algeria, and since 2005, about 19 facilities are carried out using the so-called `Pneusol' technique. Currently, researches are interested in the use of rubber fine powder (RFP) that results from worn tires crushing. The letters constitute a cumbersome waste.[1,2]
The present work presents, beginning from an experimental investigation, the possible using of tire scrap in road coating. The main purpose of such mixture is to improve certain mechanical properties, and also to reduce waste materials in the urban or agricultural zones leading to environmental and human damage. The mean study approach refers to the behavior of asphaltic concrete containing fine powders. The latter is produced by crushing of rubbery products and worn-out tires through dry and wet processes. Changes in rheological laws and in mechanical properties of the bituminous powder mixture are checked by means of experiments.
The present study highlights the influence of fine powder content, size distribution and mixing conditions on some product properties such as deformation modulus, compactness and creep.
The experimental results of the whole survey lead to interesting correlations. In addition, the rubber fine powder (RFP) is recognized taking into account road and environment interests. This appears to be, economically, interesting.
Canine spirocercosis-associated extraskeletal osteosarcoma with central nervous system metastasis
Authors: Pazzi Paolo , Tompkins Samantha , Kirberger Robert M.
Published: April 2013

A five-year-old male Boerboel presented for examination, collapsed for an unknown period of time. On clinical examination, multifocal subcutaneous masses and enlarged prescapular lymph nodes as well as neurological deficits that suggested a multifocal neurological syndrome were found. Fine needle aspirates of the prescapular lymph nodes revealed cells suggestive of osteosarcoma. Radiographs showed foci of mineralisation within the soft tissue masses as well as diffuse pulmonary metastasis and a caudodorsal mediastinal mass believed to be a Spirocerca lupi nodule. Computed tomography imaging, necropsy and histopathology confirmed S. lupi oesophageal neoplastic transformation (extraskeletal osteosarcoma), believed to be the primary lesion, and the majority of secondary metastasis to the brain, spine, heart, multiple muscular groups and abdominal organs. This is the first known report of extraskeletal osteosarcoma metastasis to the brain and spinal cord in a dog.
A comparison between tick species collected in a controlled and control free area on a game ranch in South Africa
Authors: Schroder Bradley , Reilly Brian K.
Published: April 2013

Despite the large number of collection records, there are no recent collections of ixodid ticks of this magnitude in the Waterberg area, Limpopo Province, South Africa. Free-living ticks on a commercial game farm were obtained by a total of 432 drag-samples in eight sample sites from September 2003 to August 2008. The ticks were collected to establish the difference between tick species and densities associated with acaricide-controlled (semi-intensive) and control-free areas on a game farm in the Thabazimbi District, Limpopo Province, South Africa. A total of eight tick species were collected, namely Amblyomma hebraeum, Rhipicephalus (Boophilus) decoloratus, Haemaphysalis elliptica, Hyalomma rufipes, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi, Rhipicephalus zambeziensis and Rhipicephalus spp. The most abundant tick species collected was Rhipicephalus (Boophilus) decoloratus. The difference in species and numbers reflects the effectiveness of acaricide treatment against ticks and its relevance to tick numbers on a game farm.
Historical changes in grain yield and quality of spring wheat varieties cultivated in Siberia from 1900 to 2010
Authors: Morgounov Alexey I. , Belan Igor , Zelenskiy Yuriy , Roseeva Lyudmila , Tömösközi Sandor , Békés Ferenc , Abugalieva Aygul , Cakmak Ismail , Vargas Mateo , Crossa Jose
Published: April 2013

Morgounov, A. I., Belan, I., Zelenskiy, Y., Roseeva, L., Tömösközi, S., Békés, F., Abugalieva, A., Cakmak, I., Vargas, M. and Crossa, J. 2013. Historical changes in grain yield and quality of spring wheat varieties cultivated in Siberia from 1900 to 2010. Can. J. Plant Sci. 93: 425–433. This study focusses on changes in yield, protein content, micronutrient composition and bread-making quality of 32 historical bread wheat varieties. The germplasm was divided into four groups: viz. 1: bred before 1935; 2: bred 1955–1975; 3: bred 1976–1985; 4: bred after 1985. Yield genetic gain was 0.59% per year. The last three periods scored significantly higher for protein, gluten content and alveograph W values, compared with the first group, but did not differ significantly from each other. The physical dough properties of varieties developed between 1976 and 1985 were superior, as reflected by the W value, farinograph mixing time and degree of softening. Loaf volume was highest for the 1950–1975 group, representing a 15.6% superiority. There were significant and gradual reductions between the earliest and latest groups for protein (7.6%) and wet gluten (7.7%) contents. No changes in zinc and iron contents, important in determining grain nutritional value, were detected. Generally, modern germplasm had superior physical dough quality and stability. This improvement was not clearly associated with changes in the frequencies of high- and low-molecular weight glutenin alleles. Sustaining the genetic gains for yield and quality will require investigation of the effects and interactions of genes controlling adaptation and end-use quality of spring wheat in Siberia.
Genetic and phenotypic variation inLotus japonicus(Regel) K. Larsen, a model legume species
Authors: Mimura Makiko
Published: April 2013

Mimura, M. 2013. Genetic and phenotypic variation in Lotus japonicus (Regel) K. Larsen, a model legume species. Can. J. Plant Sci. 93: 435–444. Lotus japonicus is a model legume species with more than 90% of its gene space determined; however, its ecological and evolutionary background is little known. The genetic and phenotypic variation of this model species was investigated within the Japanese Archipelago, where it exists in various climates and has experienced repeated vegetative shifts in conjunction with historical climate changes, using nuclear microsatellite loci and common garden experiments. The partial Mantel test was performed to detect the influence of phylogeographic effects on phenotypic variation among accessions along environmental gradients. Western Japan showed more complex genetic population structures than northern Japan, which may reflect past population dynamics. The total biomass demonstrated clinal variation with a climatic variable (ClimatePC). The trend was significant in a partial Mantel test when controlling for genetic distance, which is independent of the environmental distance. This suggests adaptive divergence within the Japanese Archipelago. With highly accessible genome information, L. japonicus appears to be a promising species for future ecological and evolutionary studies.
NRG010 General Purpose spring wheat
Authors: Depauw R. M. , Knox R. E. , Singh A. K. , Mccaig T. N. , Clarke J. M. , Cuthbert R. D.
Published: April 2013

DePauw, R. M., Knox, R. E., Singh, A. K., McCaig, T. N., Clarke, J. M. and Cuthbert, R. D. 2013. NRG010 General Purpose spring wheat. Can. J. Plant Sci. 93: 549–555. Based on 26 trials over 2 yr, the cultivar NRG010 yielded similar to the General Purpose checks Hoffman and AC Andrew. NRG010 had significantly shorter stature than Hoffman. NRG010 had a large white kernel intermediate in size to AC Andrew and Hoffman. NRG010 expressed resistance to prevalent races of leaf rust, stem rust and common bunt, and moderate susceptibility to prevalent races of loose smut and fusarium head blight. NRG010 is eligible for the Canada General Purpose wheat class.
Observation and a numerical study of gravity waves during tropical cyclone Ivan~(2008)
Authors: Chane Ming F. , Ibrahim C. , Jolivet S. , Keckhut P. , Liou Y.-A. , Kuleshov Y.
Published: April 2013

Abstract. Activity and spectral characteristics of gravity-waves (GWs) are analyzed during tropical cyclone (TC) Ivan (2008) in the troposphere and lower stratosphere using radiosonde and GPS radio occultation data, ECMWF outputs and simulations of French numerical model Meso-NH with vertical resolution varying between 150 m near the surface and 500 m in the lower stratosphere. Conventional methods for GW analysis and signal and image processing tools provide information on a wide spectrum of GWs with horizontal wavelengths of 40–1800 km and short vertical wavelengths of 0.6–10 km respectively and periods of 20 min–2 days. MesoNH model, initialized with Aladin-Réunion analyses, produces realistic and detailed description of TC dynamics, GWs, variability of the tropospheric and stratospheric background wind and TC rainband characteristics at different stages of TC Ivan. In particular a dominant eastward propagating TC-related quasi-inertia GW is present during intensification of TC Ivan with horizontal and vertical wavelengths of 400–600 km and 1.5–3.5 km respectively during intensification. A wavenumber-1 vortex Rossby wave is identified as a source of this medium-scale mode while short-scale modes located at north-east and south-east of the TC could be attributed to strong localized convection in spiral bands resulting from wavenumber-2 vortex Rossby waves. Meso-NH simulations also reveal high-frequency GWs with horizontal wavelengths of 20–80 km near the TC eye and high-frequency GWs-related clouds behind TC Ivan. In addition, GWs produced during landfall are likely to strongly contribute to background wind in the middle and upper troposphere as well as the stratospheric quasi-biennial oscillation.
Dynamic modelling of a 3-CPU parallel robot via screw theory
Authors: Carbonari L. , Battistelli M. , Callegari M. , Palpacelli M.-C.
Published: April 2013

Abstract. The article describes the dynamic modelling of I.Ca.Ro., a novel Cartesian parallel robot recently designed and prototyped by the robotics research group of the Polytechnic University of Marche. By means of screw theory and virtual work principle, a computationally efficient model has been built, with the final aim of realising advanced model based controllers. Then a dynamic analysis has been performed in order to point out possible model simplifications that could lead to a more efficient run time implementation.
Renal Transplantation Is Associated with Improved Clinical Outcomes in Nephrogenic Systemic Fibrosis
Authors: Yacoub Rabi , Kandukurti Kiran , Panesar Mandip
Published: April 2013

Nephrogenic systemic fibrosis is a debilitating disorder seen in chronic kidney disease patients and is characterized by stiffening of the joints and thickening of the skin. Treatment options are limited, but some patients have had an improvement of their clinical symptoms after renal transplantation and the use of immunosuppression. Although there is a variable response to renal transplantation, it is currently unknown what factors promote a favorable outcome. Our objective was to evaluate if the response to renal transplantation was superior to other treatment modalities and to determine which characteristics allowed for a positive response to occur. We retrieved the data from the literature of 298 reported patients, compared the response to renal transplantation and to other treatments, and analyzed their characteristics. We found that more patients had a higher response to renal transplantation, as determined by softening of the skin and improved joint mobility, and among those that did respond, they had a shorter dialysis vintage. We suggest that if renal transplantation is to be considered as a treatment modality, it should be initiated at the earliest possible in the course of the disease to achieve maximum clinical benefit.
Recovering from Hurricane Sandy Coordination, Planing Bolster Storm Response
Authors: Reed Douglas , Stephenson Roger , Hyland Steven
Published: April 2013

With proper preparations, swift response, steady leadership, and a ready support team, the Rockaway (N.Y.) Wastewater Treatment Plant weathered Hurricane Sandy to restore critical services in a timely manner. Others can learn from the experience to protect their utilities.
Hydraulic Model Improves Contamination Response
Authors: Specht David
Published: April 2013

With the Revised Total Coliform Rule set to go into effect in 2016, engineers in Philadelphia Water Department's water quality group decided it was a good time to see if the utility's repeat‐sampling plan needed to be updated.
How Can We Obtain Emergency Funding?
Authors: Baker Dan
Published: April 2013

Emergencies such as floods, drought, fire, or chemical spills can quickly overwhelm a water system financially. Although utilities usually have some reserve funds and insurance, many water systems facing emergencies need additional funding to return to normal operations.
Assessments Are Coming—Are You Prepared?
Authors: Roberson Alan
Published: April 2013

Published in the Feb. 13, 2013, Federal Register (78 FR 10270), the final Revised Total Coliform Rule (RTCR) represents the culmination of more than a decade of work by a variety of stakeholders in the drinking water community, including the US Environmental Protection Agency (USEPA), state regulators, drinking water utilities, technical assistance providers, public health officials, environmental advocates, and consumer advocates.
Acrylic copolymers crosslinked by click chemistry: Some aspects of synthesis, curing, and crosslinking
Authors: Sukumaran Smitha C. , Sunitha K. , Mathew Dona , Reghunadhan Nair C. P.
Published: April 2013

Acrylic polymers bearing pendant azide and propargyl groups were synthesized by chemical transformation of epoxy‐ and carboxylic functional acrylic precursor polymers and were characterized. These copolymers were crosslinked by reacting them in the presence of Cu(I) catalyst via the azide–alkyne click reaction leading to triazole networks. Influence of catalyst concentration on the crosslinking cure kinetics was investigated, and the activation parameters were evaluated. The activation energy decreased from 90 kJ mol−1 to 25 kJ mol−1 on catalyzing the cure reaction as estimated by Ozawa method. Differential scanning calorimetric analysis indicated thermal decomposition of the residual azide groups at around 200–220°C, which was catalyzed by Cu(I) with associated activation energy of 130–94 kJ mol−1. Isothermal cure reaction and decomposition of the azide groups were predicted using these parameters. Estimation of crosslink density by solvent swelling and dynamic mechanical analyses showed a normal crosslinking behavior. While the solvent swelling rate and the equilibrium swelling decreased, the front factor and diffusion coefficient of swelling showed a transition from non‐Fickian to Fickian as the triazole concentration increased in the network. The click reaction offered an alternate means to crosslink acrylate polymers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1289‐1300, 2013
Preparation and characterization of lignin‐layered double hydroxide/styrene‐butadiene rubber composites
Authors: Xiao Suo , Feng Jianxiang , Zhu Jin , Wang Xi , Yi Chunwang , Su Shengpei
Published: April 2013

Lignin‐layered double hydroxide (lignin‐LDH) complex was synthesized by in situ method, and then styrene‐butadiene rubber (SBR)/lignin‐LDH composites were prepared by the melt compounding method. X‐ray diffraction analysis showed that crystal lignin‐LDH was successfully obtained and transmission electron microscopy analysis showed well dispersion of lignin‐LDH in SBR matrix. The tensile strength, elongation at break, 300% modulus and hardness of lignin‐LDH/SBR were significantly improved compared to LDH/SBR composites. Thermogravimetric analysis indicated that the thermal degradation temperature of the lignin‐LDH/SBR at 10% weight loss (T10) decreased whereas 50% weight loss (T50) was much higher than that of pristine LDH/SBR due to barrier property of the well dispersed Lignin‐LDH in SBR matrix. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1308‐1312, 2013
Preparation, characterization and properties of a halogen‐free phosphorous flame‐retarded poly(butylene terephthalate) composite based on a DOPO derivative
Authors: Liu Peng , Liu Mingming , Gao Chong , Wang Feng , Ding Yanfen , Wen Bin , Zhang Shimin , Yang Mingshu
Published: April 2013

A phosphorous flame retardant (DOPO‐MAH) was synthesized through the reaction between of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) and maleic anhydride (MAH) and confirmed by FT‐IR, 1H NMR, and 31P NMR techniques. The obtained flame retardant was then melt blended with poly(butylene terephthalate) (PBT) to prepare flame retardant PBT/DOPO‐MAH composites. The composites were characterized by LOI, UL‐94, and mechanical tests as well as scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry analysis. On adding 20 wt % DOPO‐MAH, LOI increased from 20.9 to 25.7 and the UL‐94 V‐0 rating was achieved, whereas the tensile and flexural properties were notably improved. Torque‐time profile during the melt blending and intrinsic viscosity of the composite indicated that DOPO‐MAH acted as both flame retardant and chain extender for the PBT matrix. The results showed that PBT/DOPO‐MAH composite is a promising material for its good comprehensive properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1301‐1307, 2013
Synthesis and optical properties of cholesteric liquid‐crystalline oligomers displaying reversible thermochromism
Authors: Wang Ji‐Wei , Zhang Bao‐Yan
Published: April 2013

A series of side‐chain liquid crystalline oligomers (P1–P7) have been synthesized with cyclo(methylhydrogeno)siloxane and two cholesteric liquid crystalline monomers cholesteryl 4‐(10‐undecylen‐1‐yloxy)benzoate (M1) and cholesterol 4‐{6‐[(4‐(allyloxyl)‐benzoyl]‐hexanoxocarbonyl}‐benzoate (M2). The chemical structures and liquid crystalline properties of the synthesized oligomers were investigated using various experimental techniques such as FTIR,1H‐NMR, DSC, POM, and XRD. All monomers and chiral oligomers show a cholesteric mesophase with very wide mesophase temperature ranges. They appear highly thermally stable with decomposition temperatures (Td) at 5% weight loss greater than 300°C. The optical properties of the oligmers have been characterized by reflection spectra and optical rotation analysis. All synthesized oligomers display colors at room temperature, and show reversible thermochromism within a wide temperature range (>120°C). The λmaxvalues of the oligomers also nearly coincide during the first, second, and third heating cycles. The specific rotation of each oligomer is very sensitive to temperature, and the specific rotation value of P3smoothly changes from −21.7° to −0.7° when it is heated. The optical properties of the oligomers offer tremendous potential for various optical applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1321‐1327, 2013
Click To Bind: Metal Sensors
Authors: Bryant Jonathan J. , Bunz Uwe H. F.
Published: April 2013

The copper‐catalyzed azide–alkyne “click” cycloaddition reaction is an efficient coupling reaction that results in the formation of a triazole ring. The wide range of applicable substrates for this reaction allows the construction of a variety of conjugated systems. The additional function of triazoles as metal‐ion ligands has led to the click reaction being used for the construction of optical sensors for metal ions. The triazoles are integral binding elements, which are formed in an efficient modular synthesis. Herein, we review recent examples of triazoles as a metal‐binding element in conjugated metal‐ion sensors.
A human embryonic stem cell line adapted for high throughput screening
Authors: Caron Nicolas J. , Gage Blair K. , O'Connor Michael D. , Eaves Connie J. , Kieffer Timothy J. , Piret James M.
Published: April 2013

Human embryonic stem cells (hESCs) can be differentiated into multiple cell types with great therapeutic potential. However, optimizing the often multi‐week cultures to obtain sufficient differentiated cell yields has been in part limited by the high variability of even parallel hESC differentiation cultures. We describe the isolation and features of a subline of CA1 hESCs (CA1S) that display a very high 25% cloning efficiency while retaining many properties of the parental hESCs, including being karyotypically normal and their ability to generate teratomas containing all three germ layers. Although more detailed analysis revealed that CA1S cells have a 3.8 Mb genomic duplication on chromosome 20, they remain highly useful. In particular, CA1S cells are readily expanded at high yields in culture and possess greatly reduced well‐to‐well variation even when seeded at 100 cells/well. Thus, 108 CA1S cells can be generated within one week from 106 cells to seed 106 wells. We determined that CA1S cells have the capacity to follow established in vitro differentiation protocols to pancreatic progenitors and subsequent hormone‐positive cell types and used CA1S cells to explore definitive endoderm induction in a high performance screen (Z‐factor = 0.97). This system revealed that CA1S cells do not require WNT3A to efficiently form definitive endoderm, a finding that was confirmed with H1 hESCs, although H1 cells did show modest benefits of high WNT3A doses. Proliferative index measurements of CA1S cells were shown to rapidly reflect their differentiation status in a high throughput system. Though results obtained with CA1S cells will need to be confirmed using conventional hESC lines, these cells should ease the development of optimized hESC growth and differentiation protocols. In particular, they should limit the more arduous secondary screens using hESCs to a smaller number of variables and doses. Biotechnol. Bioeng. 2013;110: 2706–2716. © 2013 Wiley Periodicals, Inc.
Evolutionary engineering of Saccharomyces cerevisiae for enhanced tolerance to hydrolysates of lignocellulosic biomass
Authors: Almario María P. , Reyes Luis H. , Kao Katy C.
Published: April 2013

Lignocellulosic biomass has become an important feedstock to mitigate current ethical and economical concerns related to the bio‐based production of fuels and chemicals. During the pre‐treatment and hydrolysis of the lignocellulosic biomass, a complex mixture of sugars and inhibitors are formed. The inhibitors interfere with microbial growth and product yields. This study uses an adaptive laboratory evolution method called visualizing evolution in real‐time (VERT) to uncover the molecular mechanisms associated with tolerance to hydrolysates of lignocellulosic biomass in Saccharomyces cerevisiae. VERT enables a more rational scheme for isolating adaptive mutants for characterization and molecular analyses. Subsequent growth kinetic analyses of the mutants in individual and combinations of common inhibitors present in hydrolysates (acetic acid, furfural, and hydroxymethylfurfural) showed differential levels of resistance to different inhibitors, with enhanced growth rates up to 57%, 12%, 22%, and 24% in hydrolysates, acetic acid, HMF and furfural, respectively. Interestingly, some of the adaptive mutants exhibited reduced fitness in the presence of individual inhibitors, but showed enhanced fitness in the presence of combinations of inhibitors compared to the parental strains. Transcriptomic analysis revealed different mechanisms for resistance to hydrolysates and a potential cross adaptation between oxidative stress and hydrolysates tolerance in several of the mutants. Biotechnol. Bioeng. 2013;110: 2616–2623. © 2013 Wiley Periodicals, Inc.