bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of maleic acid polymer for use as scale deposits inhibitors
Authors: Benbakhti A. , Bachir‐Bey T. 
Published: July 2010

AbstractThe problem of scale formation in oil field production facilities is encountered as a result of mixing of injection water (Lias) rich in sulfate with formation water (Ordovicien) rich in barium.1 A large number of methods have been developed for the prevention of these deposits. In this work, poly(maleic acid) was studied to ascertain its suitability as an inhibitor of barium sulfate scale deposits. It was synthesized by a free radical solution polymerization. Two different initiators were used namely a potassium persulfate and a redox system composed of potassium persulfate/sodium‐hypophosphite monohydrate. Their concentrations were varied to obtain low‐molecular weight polymers. Physical and chemical properties of the polymers obtained were measured by infrared and UV/VIS spectrometry, solubility test, viscosimetry, refractometry, and liquid chromatography. The effectiveness of poly (maleic acid) formulations as scale inhibitor was studied by turbidimetric tests. The most effective inhibitor formulation was found to be that based on poly(maleic acid) prepared via a redox initiating system. This polymer, used at a concentration of 3 ppm, presented the highest effectiveness namely 96% and 88% at room and oil well temperature, respectively, when compared with two commercial inhibitors. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Positron Lifetime Spectroscopy and Differential Scanning Calorimetric study of polystyrene‐based composites with fly ash, cenospheres, and calcium aluminosilicate as fillers
Authors: Altaweel Abdullah M.A. Mohamad , Ranganathaiah C. , Siddramaiah B. 
Published: July 2010

AbstractPolystyrene‐based composites with Fly ash, Cenospheres, and Calcium aluminosilicate as fillers have been examined for their mechanical and microstructure properties. Free volume measurements have been carried out using Positron Lifetime Spectroscopy to probe the microstructural features of the composites. Incorporation of fly ash, cenospheres, and calcium aluminosilicate improved the thermal properties of the composites due to increased Tg of the composites as revealed by the DSC data. Also, it was observed that the mechanical properties of calcium aluminosilicate filled composites improved more compared to fly ash and cenospheres filled composites. We attribute these favorable changes to the higher silica content of calcium aluminosilicate on account of possible interactions between the polymer matrix and silica and to some extent from particulate size. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Comparison of polyimide/multiwalled carbon nanotube (MWNT) nanocomposites by in situ polymerization and blending
Authors: Wu Kuan‐Lung , Chou Shang‐Chih , Cheng Yao‐Yi 
Published: July 2010

AbstractIn this research, multiwalled carbon nanotube (MWNT) was oxidized and then modified to form carboxylic groups (COOH) on the surface and the end of the tube. After that, the MWNT was added to polyimide matrix to enhance its mechanical and electrical properties by in situ polymerization and blending. The PI/MWNT composites were obtained by spin coating and multistep thermal curing process. The comparison of in situ polymerization and blending as well as the effect of unmodified and modified MWNT were discussed in this study. The results indicate that in situ polymerization is able to make a perfect dispersion by adding modified MWNT into polyimide matrix. Thermal and mechanical properties of the composites can be improved by hydrogen bonding interaction between the modified MWNT and polyimide matrix. Electrical resistance of the composites can be decreased to meet the criterion of electrostatic charge (ESC) mitigation as the surface resistance is reduced into the range of 106–1010 Ω/cm2 by adding modified MWNT. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Constrained multivariable stable predictive control based on Toeplitz equation
Authors: Liu Bin , Su Hongye , Jiang Zheng , Fang Kangling 
Published: July 2010

AbstractA stable constrained multivariable predictive control algorithm based on the Toeplitz predictive equation is presented. An analytical method for transformation between left and right coprime factorization of multivariable system is put forward, and then an unconstrained control law and its stable condition are given. Furthermore, for the constrained multivariable controlled system, a predictive controller and its asymptotically stable condition are presented and proved. Finally, the constrained receding horizon optimization is transformed into a typical linear matrix inequality (LMI) problem and solved. The detailed control algorithm is depicted in a numerical example, and the simulation results reveal the effectiveness and practicability of the presented algorithm.Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Assessing the on‐road route efficiency for an air‐express courier
Authors: Lin Erwin T. J. , Lan Lawrence W. , Hsu Cathy S.T. 
Published: July 2010

AbstractThis paper proposes an EXO‐CAT data envelopment analysis (DEA) model to evaluate the efficiency of on‐road activities (pickup and delivery) for an air‐express courier on a route‐by‐route basis. The proposed model combines the constraints of exogenously fixed inputs DEA and categorical DEA to account for the continuous and discrete external environmental factors affecting the courier route efficiency. We select labor, route length (a proxy of fuel consumption), and vehicle capacity as the inputs; number of documents delivered, number of boxes delivered, number of documents picked‐up, and number of boxes picked‐up as the outputs. A case study with 248 on‐road routes currently operated by an air‐express courier in Taiwan is undertaken. It is found that stop density, travel speed, and service area type have significant influences on the couriers' route efficiency. Based on the detailed DEA results, the managers do not need to perform check‐rides for all routes; instead, they need only to focus on the most inefficient ones. Such DEA results can also be applied to develop new projects or make judgments on investing any new on‐road routes. Copyright © 2010 John Wiley & Sons, Ltd.
Zur Auswahl eines geeigneten Verfahrens für die Berücksichtigung der Mitwirkung des Betons auf Zug
Authors: Quast Ulrich 
Published: July 2010

AbstractDie Auswahl eines geeigneten Verfahrens zur Berücksichtigung der Mitwirkung des Betons auf Zug sollte nach DIN 1045‐1:2001‐07, 8.5.1 (9), in Abhängigkeit von der jeweiligen Bemessungsaufgabe getroffen werden. In den Erläuterungen zu DIN 1045‐1 wird im Heft 525 des DAfStb als einziges Verfahren nur die Verringerung der Betonstahldehnung mit einer modifizierten Spannungs‐Dehnungslinie für Betonstahl erläutert. Verfahren, die mittlere wirksame Betonzugspannungen in der Betonzugzone berücksichtigen, werden erwähnt aber nicht erläutert. Mit den Ergebnissen nachgerechneter Moment‐Verkrümmungs‐Werte von Stahlbetonröhren aus drei Versuchen mit unterschiedlichen Längskräften wird gezeigt, dass die Mitwirkung des Betons auf Zug mit dem Verfahren nach Heft 525 DAfStb nur bei reiner Biegung befriedigend erfasst wird. Bei Biegung mit Längskraft werden besser mittlere wirksame Betonzugspannungen berücksichtigt. Es werden vier unterschiedliche Ansätze für die Betonzugspannungen besprochen.On the selection of an adequate method for considering the contribution of concrete in tension. The selection of an adequate method for considering the contribution of concrete in tension should according to DIN 1045‐1:2001‐07, 8.5.1 (9), be chosen with respect to the particular design problem. The explanations to DIN 1045‐1 in book 525 from DAfStb describe only one method, the method which reduces the steel strain taking a modified stress‐strain relationship into account. Methods that consider mean effective concrete stresses in tension are mentioned but not explained. The results of recomputed moment‐curvature values from three tests with different longitudinal forces show that the method in book 525 DAfStb covers the contribution of concrete in tension only for reinforced concrete members without longitudinal forces. For members with longitudinal forces methods with mean effective concrete stresses give better agreements. Four different assumptions for the concrete stresses in tension are discussed.
Static and dynamic light scattering from dilute insulin solutions
Authors: Bohidar Himadri B. , Geissler Erik 
Published: July 2010

AbstractStatic and dynamic light‐scattering measurements are reported on zinc‐insulin at room temperature (21 ± l°C) and pH = 6.88 in 0.1M NaCl aqueous solution. The experiments were performed at very low concentration, in the range 0.12 × 10−4 to 0.90 × 10−4 g cm−3. Within experimental error, we find no evidence for a critical micellar concentration in this system. The aggregation phenomenon starts immediately after preparation of the solutions, and takes several days to come to stable equilibrium. The concentration dependence of the diffusion coefficients, Dz, = Do (1 — kDC), is negative, and kD was observed to decrease as a function of time, while the aggregate size was found to increase. The equivalent concentration coefficient, −2BMW, obtained from static light scattering, showed a similar behavior, and, within experimental error, was found to be numerically equal to kD. From the relation found between the diffusion coefficient at infinite dilution and the molecular weight of the aggregates, log D0 = −0.240 log Mw − 5.077, we deduce that the insulin aggregates are compact structures with a characteristic radius of 0.71 Å/(dalton)1/3, surrounded by a hydration layer of a thickness of 8.0 Å. The equilibrium aggregation number is approximately 10.
Potential‐Energy surface for double‐helical DNA with Watson‐Crick Pairs. I. Complete scanning in the space of torsion angles
Authors: Neyfack Yu. A. , Tumanyan V. G. 
Published: July 2010

AbstractComplete scanning of correct double‐helical DNA structures was performed in the space of torsion angles using rapid analytical procedures for generation of regular double helices with Watson‐Crick base pairs. Potential energy of structures was calculated by pair‐wise potential functions and used as necessary condition to single out physically meaningful forms. We found 12 discrete potential wells containing these physically meaningful forms, with only one well containing all classical forms (A, B, etc.). On the basis of the new structures listed, alternative models for DNA and DNA‐like polymers and appropriate conformations for fluctuations leading to DNA bending and kink formation are suggested.
Characterization of the transition state of lysozyme unfolding. II. Effects of the intrachain crosslinking and the inhibitor binding on the transition state
Authors: Segawa Shin‐Ichi , Sugihara Mitsuru 
Published: July 2010

AbstractThe reversible refolding of a lysozyme derivative containing an extra crosslink between Glu 35 and Trp 108 was observed at pH 3.7 in solutions of 4.5M LiBr and 4.SM 1‐PrOH. The rate constants of unfolding and folding for crosslinked lysozyme were compared with those for intact lysozyme. In LiBr solutions, the crosslinking greatly increases kf but only slightly decreases kuf. This means that the crosslinking restricts possible conformations of the U state to some conformations on the folding pathway, whereas the possible conformations of the transition state are little restricted. Although the crosslinking produces an apparently different effect on the rate constants in a PrOH solution, this could be explained by assuming that the crosslinking counteracts the effect of PrOH on the transition state. These observations suggest that the Glu 35 and Trp 108 of intact lysozyme already come into contact with each other in the course of refolding to the transition state. Kinetics of the unfolding and folding reactions of intact lysozyme were measured in the presence of 8mAf (NAG)3. The apparent folding rate (k) was nearly equal to kf, while the apparent unfolding rate (k) decreased sixfold. This means that the inhibitor binding stabilizes the native conformation but makes no contribution to the stabilization of the transition state. Specific interactions between (NAG)3 and the cleft of lysozyme become available only at the last stage of folding.
Conformational flexibilities in malformin A
Authors: Mitra Alok K. , Chandrasekaran R. 
Published: July 2010

AbstractThe linked‐atom‐least‐squares (LALS) technique has been applied to generate exactly cyclized and stereochemically satisfactory conformations of the cyclic pentapeptide, malformin A, which contains an intramolecular disulfide bridge across a D‐Cys—D‐Cys linkage. Consistent with theoretical, ir, and x‐ray evidence from studies on analogs of the LKiysteinyl—L‐cysteine disulfide, it is shown that the peptide bond across the SS bridge in malformin A can retain a cis configuration. The two all‐trans structures proposed earlier by A.E. Tonelli [(1978) Biopolymers 17, 1175–1179] from solution nmr data have also been analyzed. Both P‐(χs ∼ 90°) and M‐(χs ∼ −90°)‐type helicity of the SS bridge are found to be accessible in both the trans and the cis models in which the respective conformations of the homodetic rings are essentially preserved. The details of six different conformational states and their relative energies have been evaluated and compared. Our findings, which suggest that a variety of conformational states are accessible to malformin A, are compatible with other published results from solution studies. On the basis of hydrogen‐bonding interactions, a model is proposed to explain how malformin A might be inactivated specifically by L‐Hyp, and not by L‐Pro or other amino acids, as has been observed from in vivo investigations [Buckhout, T.J. & Curtis, R.W. (1976) Nature 260, 435–436]
Characterization of the fluorescence of the protamine thynnine and studies of binding to double‐stranded DNA
Authors: Ausio Juan , Greulich Karl Otto , Haas Elisha , Ellenwachtel  
Published: July 2010

AbstractThe protamine thynnine is an arginine‐rich protein approximately 30 amino acids long with a tyrosine in the middle of its sequence. Its fluorescence decay kinetics can be described by a biexponential function with lifetimes of 0.52 and 2.1 ns, with almost equal preexponential factors. The fluorescence quencher CsCl does not affect the short lifetime but shifts the equilibrium between the long and short lifetime toward the short one and reduces the long lifetime. In nature, thynnine is found complexed with chromosomal DNA. In vitro complexes of thynnine with double‐stranded (ds) DNA are stable at physiologic ionic strength but dissociate at high NaCl concentration. This dissociation can be monitored by steady‐state fluorescence. From the salt concentration dependence of the dissociation of the complex of thynnine with ds‐DNA 145 bp long, it can be concluded that only 4 of 21 possible full electrostatic bonds are involved in thynnine‐DNA binding. In addition, the binding constant at 1M NaCl is of the order of 106, indicating a strong nonelectrostatic component in arginine‐DNA binding.
Tritium exchange of spectrin versus temperature
Authors: Bonnet D. , Begard Marden, E. , Hoa G. Hui Bon , Douzou P. 
Published: July 2010

AbstractTritium‐exchange experiments were performed to assess the dynamics of the spectrin molecule. From the kinetics presented, spectrin appears as a fast‐exchanging protein compared to globular proteins. This is easily explained by its known elongated structure. Spectrin tritium exchange is also shown to be highly temperature sensitive, even in buffer conditions that greatly reduce the temperature dependence of hydroxyl catalyst concentration. At high ionic strength, the exchange rates of specific hydrogens deduced from a power‐law simulation are shown to exhibit an Arrhenius behavior, with enthalpies ranging from 70 to 140 kjmol−1. These results are discussed in relation to the known high α‐helix content of spectrin. Finally, a molecular model of α‐helix opening is proposed that provides satisfactory agreement with the totality of the spectrin behavior in tritium‐exchange experiments.
Binding modules alter the activity of chimeric cellulases: Effects of biomass pretreatment and enzyme source
Authors: Kim Tae‐Wan , Chokhawala Harshal A. , Nadler Dana , Blanch Harvey W. , Clark Douglas S. 
Published: July 2010

AbstractImproving the catalytic activity of cellulases requires screening variants against solid substrates. Expressing cellulases in microbial hosts is time‐consuming, can be cellulase specific, and often leads to inactive forms and/or low yields. These limitations have been obstacles for improving cellulases in a high‐throughput manner. We have developed a cell‐free expression system and used it to express 54 chimeric bacterial and archaeal endoglucanases (EGs), with and without cellulose binding modules (CBMs) at either the N‐ or C‐terminus, in active enzyme yields of 100–350 µg/mL. The platform was employed to systematically study the role of CBMs in cellulose hydrolysis toward a variety of natural and pretreated solid substrates, including ionic‐liquid pretreated Miscanthus and AFEX‐pretreated corn stover. Adding a CBM generally increased activity against crystalline Avicel, whereas for pretreated substrates the effect of CBM addition depended on the source of cellulase. The cell‐free expression platform can thus provide insights into cellulase structure‐function relationships for any substrate, and constitutes a powerful discovery tool for evaluating or engineering cellulolytic enzymes for biofuels production. Biotechnol. Bioeng. 2010;107:601–611. © 2010 Wiley Periodicals, Inc.
“Molded” rods of macroporous polymer for preparative separations of biological products
Authors: Svec Frantisek , Fréchet Jean M. J. 
Published: July 2010

AbstractA continuous rod of porous poly(glycidy1 methacrylate‐co‐ethylene dimethacrylate) has been prepared by a free radical polymerization within the confines of a 16‐mm‐i.d. glass column. The epoxide groups of the rod have been modified in situ by their reaction with diethylamine to afford the ionizable weak base 1‐N,N‐diethylamino‐2‐hydroxypropyl functionalities that are required for the ion‐exchange chromatographic mode. The bimodal pore size distribution curve typical for other molded separation media also prevail for the preparative‐size rod. The column has been used successfully for the chromatographic separation of a mixture of standard proteins and yeast enzymes. The column exhibits a dynamic capacity that exceeds 420 mg of bovine serum albumin at a flow velocity of 60 cm/h. © 1995 John Wiley & Sons, Inc.
Interviewing children in custody cases: Implications of research and policy for practice
Authors: Saywitz Karen , Camparo Lorinda B. , Romanoff Anna 
Published: July 2010

AbstractResearch on child interviewing has burgeoned over the past 25 years as expectations about children's agency, competence, and participation in society have changed. This article identifies recent trends in research, policy, and theory with implications for the practice of interviewing children in cases of contested divorce and for the weight to be given the information children provide. A number of fields of relevant research are identified, including studies of families who have participated in the family law system, studies of child witnesses in the field, experimental studies of the effects of interview techniques on children's memory and suggestibility, and ethnographic methods that elicit children's views of their own experiences. Finally, a set of 10 principles for practice are delineated based on the best available science. Copyright © 2010 John Wiley & Sons, Ltd.
A morphometric study of the inferior orbital fissure using three‐dimensional anatomical landmarks: Application to orbital surgery
Authors: Ozer Mehmet Asim , Celik Servet , Govsa Figen 
Published: July 2010

AbstractThe inferior orbital fissure (IOF) is an important structure during orbital surgery, however, neither its anatomical features nor the procedures necessary to expose the IOF have been examined in detail. A morphometric analysis of the IOF was performed on 232 orbits using computer software. The longest and shortest borders of the IOF were 18.2 ± 4.9 and 1.9 ± 1.3 mm, respectively. The outer and the inner angles were 138.9 ± 32.7° and 38.4 ± 24.7°, respectively. The perimeter of the IOF was 50.6 ± 13.5 mm and its area was 61.3 ± 39.1 mm2. Eight types of IOF were observed. Type 1 IOF was observed in 42.2% and the Type 2 IOF was identified in 15.9%. A statistically significant relation was found between the longest edge and area and the widest edge and area of the IOF. The findings of our study suggest that the removal of the lateral wall should begin inferiorly, just lateral to the IOF and extended superolaterally. These data may be useful during surgical approaches to the orbit. Clin. Anat. 22:649–654, 2009. © 2009 Wiley‐Liss, Inc.
An interactive simulation tool for image registration education
Authors: Gharaibeh Khaled M. , Malkawi Mohammed J. , Hamza A. Ben 
Published: July 2010

AbstractA medical image registration simulation toolkit built using MATLAB graphical user interface (GUI) is presented. The developed Matlab GUI's provide an effective tool for exploring different image registration techniques including a new feature‐based image registration technique proposed by the authors. The toolkit is useful for biomedical engineering students and can be used as a web‐based learning tool. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 225–237, 2010; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20179
Problem of computer programming education for technical engineers
Authors: Trontl Kresimir 
Published: July 2010

AbstractWhen discussing the computer programming education at university level, one is usually focused on education of future computer science experts, while the computer education of technical engineers is put aside. Technical engineers are mostly trained in using commercial software specific for their area of expertise. However, due to somewhat extreme specialization and lack of commercial software, technical engineers are often encountered with the necessity of creating their own computer codes, whether by some basic “programming” in existing software like Excell or Access, or by hardcore programming in programming language of their choice. As a result of truly altruistic ideas, such software can usually be downloaded from World Wide Web (WWW), or obtained freely, directly from the creators. At that moment, the problems of computer programming education for technical engineers come to surface. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 200–202, 2010; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20187
Effect of instructional software on achievement of undergraduate students in Digital Signal Processing
Authors: Al‐Ajlouni Ahmad F. , Yamin H.Y. , Harb B. 
Published: July 2010

AbstractTraditional tools used in education, are increasingly more complemented with computer based Instructional software. This paper presents an interactive approach for teaching the Digital Signal Processing (DSP) course. The effect of the Instructional Software on the achievement of students in the subject of DSP is compared to the conventional teaching method. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 703–708, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20275