bluuebunny/crossref_metadata_2025_split huggingface dataset:
Capillary flow of low‐density polyethylene
Authors: Ansari Mahmoud , Zisis Thanasis , Hatzikiriakos Savvas G. , Mitsoulis Evan 
Published: February 2012

AbstractThe capillary flow of a commercial low‐density polyethylene (LDPE) melt was studied both experimentally and numerically. The excess pressure drop due to entry (Bagley correction), the compressibility, the effect of pressure on viscosity, and the possible slip effects on the capillary data analysis have been examined. Using a series of capillary dies having different diameters,D, and length‐to‐diameterL/Dratios, a full rheological characterization has been carried out, and the experimental data have been fitted both with a viscous model (Carreau‐Yasuda) and a viscoelastic one (the Kaye—Bernstein, Kearsley, Zapas/Papanastasiou, Scriven, Macosko, or K‐BKZ/PSM model). Particular emphasis has been given on the pressure‐dependence of viscosity, with a pressure‐dependent coefficient βp. For the viscous model, the viscosity is a function of both temperature and pressure. For the viscoelastic K‐BKZ model, the time‐temperature shifting concept has been used for the non‐isothermal calculations, while the time–pressure shifting concept has been used to shift the relaxation moduli for the pressure‐dependence effect. It was found that only the viscoelastic simulations were capable of reproducing the experimental data well, while any viscous modeling always underestimates the pressures, especially at the higher apparent shear rates andL/Dratios. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
From poly(N‐isopropylacrylamide)‐block‐poly(ethylene oxide)‐block‐poly(N‐isopropylacrylamide) triblock copolymer to poly(N‐isopropylacrylamide)‐block‐poly(ethylene oxide) hydrogels: Synthesis and rapid deswelling and reswelling behavior of hydrogels
Authors: Zheng Qinqin , Zheng Sixun 
Published: February 2012

AbstractPoly(N‐isopropylacrylamide)‐block‐poly(ethylene oxide)‐block‐poly(N‐isopropylacrylamide) (PNIPAAm‐b‐PEO‐b‐PNIPAAm) triblock copolymer was synthesized via the reversible addition‐fragmentation chain transfer/macromolecular design via the interchange of xanthate (RAFT/MADIX) process with xanthate‐terminated poly(ethylene oxide) (PEO) as the macromolecular chain transfer agent. The successful synthesis of the ABA triblock copolymer inspired the preparation of poly(N‐isopropylacrylamide)‐block‐poly(ethylene oxide) (PNIPAAm‐b‐PEO) copolymer networks with N,N′‐methylenebisacrylamide as the crosslinking agent with the similar approach. With the RAFT/MADIX process, PEO chains were successfully blocked into poly(N‐isopropylacrylamide) (PNIPAAm) networks. The unique architecture of PNIPAAm‐b‐PEO networks allows investigating the effect of the blocked PEO chains on the deswelling and reswelling behavior of PNIPAAm hydrogels. It was found that with the inclusion of PEO chains into the PNIPAAm networks as midblocks, the swelling ratios of the hydrogels were significantly enhanced. Furthermore, the PNIPAAm‐b‐PEO hydrogels displayed faster response to the external temperature changes than the control PNIPAAm hydrogel. The accelerated deswelling and reswelling behaviors have been interpreted based on the formation of PEO microdomains in the PNIPAAm networks, which could act as the hydrophilic tunnels to facilitate the diffusion of water molecules in the PNIPAAm networks. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Development of near‐isogenic lines and identification of markers linked to auxinic herbicide resistance in wild mustard (Sinapis arvensis L.)
Authors: Mithila Jugulam , McLean Michael D , Chen Shu , Christopher Hall John 
Published: February 2012

AbstractBACKGROUND: Auxinic herbicides are widely used for selective control of many broadleaf weeds, e.g. wild mustard. An auxinic‐herbicide‐resistant wild mustard biotype may offer an excellent model system to elucidate the mechanism of action of these herbicides. Classical genetic analyses demonstrate that the wild mustard auxinic herbicide resistance is determined by a single dominant gene. Availability of near‐isogenic lines (NILs) of wild mustard with auxinic herbicide resistance (R) and herbicide susceptibility (S) will help to study the fitness penalty as well as the precise characterization of this gene.RESULTS: Eight generations of backcrosses were performed, and homozygous auxinic‐herbicide‐resistant and auxinic‐herbicide‐susceptible NILs were identified from BC8F3 families. S plants produced significantly more biomass and seed compared with R plants, suggesting that wild mustard auxinic herbicide resistance may result in fitness reduction. It was also found that the serrated margin of the first true leaf was closely linked to auxinic herbicide resistance. Using the introgressed progeny, molecular markers linked to auxinic herbicide resistance were identified, and a genetic map was constructed.CONCLUSION: The fitness penalty associated with the auxinic herbicide resistance gene may explain the relatively slow occurrence and spread of auxinic‐herbicide‐resistant weeds. The detection of the closely linked markers should hasten the identification and characterization of this gene. Copyright © 2012 Society of Chemical Industry
Photoluminescence properties of selectively grown InN microcrystals
Authors: Kamimura Jumpei , Kishino Katsumi , Kikuchi Akihiko 
Published: February 2012

AbstractWe investigated the photoluminescence (PL) properties of regularly arranged N‐polar InN microcrystals with m ‐plane sidewall facets. We observed narrow PL emission at 0.678 eV with a linewidth of ∼14 meV at 4 K and a clear band‐filling effect with increasing excitation power. We also observed a normal red shift of the PL peak energy as large as 51 meV (∼150 nm) with increasing temperature from 4 to 300 K, similar to that observed for non‐degenerated semiconductors. The integrated PL intensity ratio I300K/I4K was measured to be 6.1%. These results indicate that InN microcrystals have a low residual carrier density and excellent optical properties without being adversely affected by surface electron accumulation, despite their relatively high surface area. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tunneling magnetoresistance and electroresistance properties of composite‐barrier ferroelectric tunnel junctions
Authors: Petraru A. , Soni R. , Kohlstedt H. 
Published: February 2012

AbstractThe multiferroic properties of ferroelectric tunnel junctions with a composite barrier comprising a fully epitaxial La0.7Sr0.3MnO3/BaTiO3/SrTiO3/La0.7Sr0.3MnO3 heterostructure are reported in this study. The patterned junctions having extended top electrodes show tunnel magnetoresistance ratios ranging from 20% to 110% at 77 K. Furthermore, tunneling electroresistance – induced by ferroelectric polarization switching and showing two‐state memory effect in the dynamic resistance – has also been observed in these junctions. Thus, with the concurrence of tunneling electroresistance and magnetoresistance, these tunnel junctions serve as memory devices with four resistance states. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Axel and DuAxel rovers for the sustainable exploration of extreme terrains
Authors: Nesnas Issa A.D. , Matthews Jaret B. , Abad‐Manterola Pablo , Burdick Joel W. , Edlund Jeffrey A. , Morrison Jack C. , Peters Robert D. , Tanner Melissa M. , Miyake Robert N. , Solish Benjamin S. , Anderson Robert C. 
Published: February 2012

AbstractSome of the most appealing science targets for future exploration missions in our solar system lie in terrains that are inaccessible to state‐of‐the‐art rover technology. This paper discusses the challenges and constraints of designing a robotic explorer for these “extreme'' terrains and then examines the trade‐offs among different mobility architectures. To address many of these challenges, we have developed the Axel family of rovers. The Axel rover is a two‐wheeled tethered robot capable of rappelling down steep slopes and traversing rocky terrain. The DuAxel rover, which is a four‐wheeled vehicle formed from two Axel rovers, provides untethered mobility to get to extreme terrains. We describe the basic design principles of these rovers and review our efforts to implement the key features of the Axel concept. Limitations found during experiments with prior Axel rover prototypes led to the design of a third‐generation Axel rover. We describe the features of this new rover and then present a thermal analysis conducted to assess the feasibility of exploring lunar cold traps, which are expected to have a temperature range of 40 to 70 K. We conclude the paper with results showcasing Axel and DuAxel's extreme‐terrain performance as evaluated during two recent field tests in a steeply sloped Southern California rock quarry and at a location in Arizona that closely resembles rugged Martian terrain. We also summarize lessons learned during the Axel development program. © 2012 Wiley Periodicals, Inc.
Die mehrfeldrige Spannbandbrücke Slinky Springs to Fame in Oberhausen
Authors: Schlaich Mike , Goldack Arndt , Nier Mathias 
Published: February 2012

AbstractEssen wurde im Jahr 2010 Europäische Kulturhauptstadt, und zu diesem Anlass wurde der Künstler Tobias Rehberger eingeladen, eine Skulptur über den Rhein‐Herne‐Kanal zu gestalten, die gleichzeitig Brückenfunktion übernehmen sollte. Für die früh ins Planungsteam gerufenen Bauingenieure ergab sich so die Möglichkeit, in der eher seltenen Konstellation Künstler‐Bauingenieur das Brücken‐Gesamtkunstwerk anzugehen: gute Kunst und gutes Tragwerk. Das Resultat, die Brückenskulptur Slinky Springs to Fame, ist eine leichte, mehrfeldrige und sehr farbenfrohe Spannbandbrücke, die, von einer Spirale umwickelt, den Rhein‐Herne‐Kanal in Oberhausen überspannt. In diesem Beitrag werden Entwurf, Konstruktion und Bau dieser Brücke sowie ihre dynamischen Besonderheiten beschrieben.The multi‐span stress ribbon bridge called Slinky Springs to Fame in Oberhausen, Germany. The city of Essen became European Capital of Culture in 2010. For this reason, the artist Tobias Rehberger was invited to design a sculpture across the Rhein‐Herne‐Canal, which also should enable people to cross the canal. The structural engineers, who could join the team at an early design stage, had the opportunity to strive within the relation artist – structural engineer for a synthesis: good art and good structure. The result, the bridge sculpture Slinky Springs to Fame, is a lightweight and very colourful stress ribbon bridge crossing the Rhein‐Herne‐Canal, which is wrapped by a spiral. This paper describes in detail the conceptual and structural design as well as dynamic aspects and the construction of the bridge.
Physical–chemical, thermal, and functional properties of achira (Canna indica L.) flour and starch from different geographical origin
Authors: Andrade‐Mahecha Margarita M. , Tapia‐Blácido Delia R. , Menegalli Florencia C. 
Published: February 2012

AbstractAchira (Canna indica L.) is a plant native to the Andes in South America, a starchy source, and its cultivation has expanded to different tropical countries, like Brazil. In order to evaluate the potential of this species, starch and flours with different particle size were obtained from Brazilian achira rhizomes. Proximal analyses, size distribution, SEM, swelling power, solubility, DSC, XRD analysis, and FTIR were performed for characterization of these materials. Flours showed high dietary fiber content (16.5–32.2% db) and high concentration of starch in the case of the smaller particle size fraction. Significant differences in protein and starch content, swelling power, solubility, and thermal properties were observed between the Brazilian and the Colombian starch. All the studied materials displayed the B‐type XRD pattern with relative crystallinity of 20.1% for the flour and between 27.0 and 28.0% for the starches. Results showed that the starch and flour produced from achira rhizomes have great technological potential for use as functional ingredient in the food industry.
Seismic performance evaluation of staggered wall system structures with middle corridors
Authors: Lee Joonho , Kang Hyungoo , Kim Jinkoo 
Published: February 2012

SUMMARYIn this paper, the seismic performance of reinforced concrete (RC) staggered wall structures with middle corridor was evaluated. To this end, 6‐, 12‐ and 18‐storey structural models were designed and were analyzed to investigate the seismic load‐resisting capacity. The response modification factors were computed based on the overstrength and the ductility capacities obtained from pushover curves. The effect of a few retrofit schemes on the enhancement of strength and ductility was also investigated. The pushover analysis results showed that the response modification factors ranged between about 4.0 and 6.0 with the average value around 5.0. When the bending rigidity of the link beams increased up to 100%, the overall overstrength increased by only about 25%. When the rebar ratio of the link beams was increased by 50%, the overstrength increased by about 40%. The replacement of the RC link beams with steel box beams resulted in superior performance of the structures with reduced beam depth. The displacement time histories of the model structures subjected to the earthquake ground motions scaled to the design seismic load showed that the maximum interstorey drifts were well below the limit state specified in the design code. Based on the analysis results, it was concluded that the staggered wall systems with a middle corridor had enough capacity to resist the design seismic load. Copyright © 2012 John Wiley & Sons, Ltd.
High‐intensity focused ultrasound treatment for twin reversed arterial perfusion sequence
Authors: Ichizuka K. , Hasegawa J. , Nakamura M. , Matsuoka R. , Sekizawa A. , Okai T. , Umemura S. 
Published: February 2012

AbstractTwin reversed arterial perfusion (TRAP) sequence is a serious complication of monochorionic twin pregnancies, in which arterioarterial anastomoses allow blood flow from a ‘pump’ fetus to an acardiac fetus via reversed flow in the latter's umbilical artery. Several trial treatments for TRAP sequence have been reported, but all of these have been invasive. We present a case of TRAP sequence in which high‐intensity focused ultrasound (HIFU) was applied to the umbilical artery of the anomalous twin at 26 weeks as a non‐invasive fetal therapy. The HIFU intensity was set at approximately 2300 W/cm2 with exposure periods of 10 s. Color Doppler ultrasound showed a decrease in blood supply to the anomalous twin, although complete occlusion of the targeted vessel was not achieved. Delivery was by Cesarean section at 29 weeks' gestation and the pump twin survived, without severe clinical complications at 6 months. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Prefrontal space ratio: comparison between trisomy 21 and euploid fetuses in the second trimester
Authors: Sonek J. , Molina F. , Hiett A. K. , Glover M. , McKenna D. , Nicolaides K. H. 
Published: February 2012

AbstractObjectiveTo evaluate a novel ultrasound measurement, the prefrontal space ratio (PFSR), in second‐trimester trisomy 21 and euploid fetuses.MethodsStored three‐dimensional volumes of fetal profiles from 26 trisomy 21 fetuses and 90 euploid fetuses at 15–25 weeks' gestation were examined. A line was drawn between the leading edge of the mandible and the maxilla (MM line) and extended in front of the forehead. The ratio of the distance between the leading edge of the skull and that of the skin (d1) to the distance between the skin and the point where the MM line was intercepted (d2) was calculated (d2/d1). The distributions of PFSR in trisomy 21 and euploid fetuses were compared, and the relationship with gestational age in each group was evaluated by Spearman's rank correlation coefficient (rs).ResultsThe PFSR in trisomy 21 fetuses (mean, 0.36; range, 0–0.81) was significantly lower than in euploid fetuses (mean, 1.48; range, 0.85–2.95; P < 0.001 (Mann–Whitney U‐test)). There was no significant association between PFSR and gestational age in either trisomy 21 (rs = 0.25; 95% CI, − 0.15 to 0.58) or euploid (rs = 0.06; 95% CI, − 0.15 to 0.27) fetuses.ConclusionThe PFSR appears to be a highly sensitive and specific marker of trisomy 21 in the second trimester of pregnancy. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Radiofrequency ablation vs bipolar umbilical cord coagulation in the management of complicated monochorionic pregnancies
Authors: Bebbington M. W. , Danzer E. , Moldenhauer J. , Khalek N. , Johnson M. P. 
Published: February 2012

AbstractObjectiveThe application of radiofrequency ablation (RFA) termination procedures to complicated cases involving monochorionic twins offers the potential of a less invasive option when compared to endoscopic techniques. The purpose of this study was to compare outcomes between these two techniques.MethodsA retrospective review was undertaken of all cases of complicated monochorionic twin gestations treated at the Children's Hospital of Philadelphia from July 1996 to December 2010. Cases were identified from the fetal treatment database and data extracted in a uniform fashion from the patients' charts.ResultsA total of 149 cases were identified with procedures performed on 146. Indications for selective termination of one fetus were twin reversed arterial perfusion sequence in 53, severe twin‐to‐twin transfusion syndrome in 43, discordance for fetal anomalies in 26 and selective intrauterine growth restriction in 24. Eighty‐eight cases were managed with bipolar cord coagulation (BCC) and 58 with RFA. The procedures in all cases were technically successful in achieving selective termination. The mean gestational age at the time of the procedure was 20.9 ± 2.7 weeks in the BCC group vs 20.2 ± 2.2 weeks in the RFA group (P = 0.1). The median gestational age at delivery was 34.7 (interquartile range (IQR), 29.2–38.6) weeks for the BCC group vs 33.0 (IQR, 23.4–38.9) weeks in the RFA group (P = 0.073). Mean birth weight did not differ between the two groups. The procedure‐to‐delivery time was 87.1 ± 42.1 days for the BCC group vs 73.8 ± 47.2 days for the RFA group (P = 0.1). Overall survival was 85.2% in the BCC group vs 70.7% in the RFA group (P = 0.014). This was attributed primarily to a survival rate of 10.5% in the RFA group compared with 31.6% in the BCC group for cases where delivery occurred before 28 weeks' gestation (P = 0.01). Premature rupture of the membranes occurred in 27.3% in the BCC group vs 13.7% in the RFA group (P = 0.05). Preterm labor was more common in the BCC group than in the RFA group (22.4 vs 7%, respectively; P = 0.009).ConclusionDespite the smaller caliber of the instrument, RFA is not associated with a decrease in the overall complication rate for selective termination procedures. The technique used for selective termination should still be determined by technical considerations but patients should be informed of the survival rate associated with each technique. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Kinetics of the Transesterification of Castor Oil with Maleic Anhydride Using Conventional and Microwave Heating
Authors: Mazo Paula , Estenoz Diana , Sponton Marisa , Rios Luis 
Published: February 2012

AbstractThe transesterification of castor oil with maleic anhydride was studied using conventional and microwave heating. Reactions were followed by measuring the acid value and the reaction products were characterized by FTIR and 1H NMR. A kinetic model that fit the experimental data was derived. The transesterification was non‐catalytic and first‐order with respect to each reactant. Non‐thermal effects of microwaves were not observed. Activation energy, enthalpy of activation, entropy of activation and free energy of activation were similar regardless of the heating method. Rate constants and the pre‐exponential factor were lower with the use of microwave heating, which could be a consequence of the decrease in the dielectric constant of the reaction liquid as the reaction progresses.
Increasing Stearidonic Acid (SDA) in Modified Soybean Oil by Lipase‐Mediated Acidolysis
Authors: Kleiner Leslie , Vázquez Luis , Akoh Casimir C. 
Published: February 2012

AbstractThe objective of this work was to synthesize a structured lipid (SL) enriched in stearidonic acid (SDA, C18:4 ω‐3), from modified soybean oil (MSO) originally containing ~25% SDA. Low temperature crystallization (LTC) of MSO triacylglycerols (TAG) and free fatty acids (FFA) was performed. The TAG and FFA crystallization products (LTC‐TAG and LTC‐FFA, respectively) had SDA contents of 48.72 and 60.78%, respectively. Enzymatic acidolysis between MSO and LTC‐FFA was studied utilizing Novozym 435 and Lipozyme TL IM as biocatalysts. Substrate molar ratio, incubation time, solvent, and enzyme load were explored. Equilibrium was reached at 96 and 48 h for Novozym 435 and Lipozyme TL IM‐catalyzed reactions, respectively. The best conditions from these studies were also applied to the acidolysis of LTC‐TAG and LTC‐FFA. Utilizing Lipozyme TL IM and solvent free conditions, SLs with SDA contents of 37.61 ± 1.00% (20.86 ± 6.48% at sn‐2 position) and 53.46 ± 1.85% SDA (36.37 ± 3.14% at sn‐2 position) were obtained from the acidolysis reaction between MSO and LTC‐FFA, and LTC‐TAG and LTC‐FFA, respectively. Compared to the original SDA content of MSO, this process leads to a 52 and 116% increase in SDA content, respectively.
Timing analysis of leader-based and decentralized Byzantine consensus algorithms
Authors: Borran Fatemeh , Hutle Martin , Schiper André 
Published: February 2012

Abstract
We consider the Byzantine consensus problem in a partially synchronous system with strong validity. For this problem, two main algorithms—with different resilience—are described in the literature. These two algorithms assume a leader process. A decentralized variant (variant without leader) of these two algorithms has also been given in a previous paper. Here, we compare analytically, in a round-based model, the leader-based variant of these algorithms with the decentralized variant. We show that, in most cases, the decentralized variant of the algorithm has a better worst-case execution time. Moreover, for the practically relevant case t≤2 (where t is the maximum number of Byzantine processes), this worst-case execution time is even at least as good as the execution time of the leader-based algorithms in fault-free runs.
An exception handling system for service component architectures
Authors: Castor Fernando , Leite Douglas Siqueira , Rubira Cecília Mary F. 
Published: February 2012

AbstractThe Service Component Architecture (SCA) makes it possible to combine existing and new services based on a variety of technologies with components built using a component-based development approach. However, when asynchronous service compositions are executed, one or more errors can occur, possibly at the same time, affecting the dependability of the composition. To guarantee that the composition succeeds or at least fails in a controlled manner, fault tolerance mechanisms must be employed. In this paper, we propose a novel exception handling model that targets the needs of dependable SCA applications. The model is applicable to service-oriented systems and allows the creation of fault-tolerant asynchronous service compositions. The EH-SCA framework instantiates the proposed model as an extension of the Apache Tuscany SCA infrastructure. Developers can apply this instantiation of the model to both new and existing applications by using a simple and flexible aspect-oriented programming model. Finally, a case study of the EH-SCA framework shows how it can be used to build dependable distributed applications.