bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of process parameters on properties of wet‐spun poly(L,D‐lactide) copolymer multifilament fibers
Authors: Rissanen Marja , Puolakka Arja , Hukka Terttu , Ellä Ville , Nousiainen Pertti , Kellomäki Minna 
Published: April 2009

AbstractPoly(L,D‐lactide) [P(L,D)LA], LL/D ratio 96/4, and poly(L,DL‐lactide) [P(L,DL)LA], L/DL ratio 70/30, multifilament fibers were prepared by wet‐spinning and the effects of the spin draw ratio and the coagulant on the morphological, thermal, and mechanical properties of the filaments were studied. The hydrolytic degradation of filaments was studied in vitro. The filament diameter and the mechanical properties of filaments were highly dependent on the spin draw ratio, whereas the coagulant had no or minor effect. The filament diameters were in the range of 11–36 μm and the maximum tenacity of 150 MPa was obtained at the spin draw ratio of 7.0 for both copolymers. The copolymer had the main importance on the crystallinity of filaments, but it was also affected by the duration of the coagulation process. The crystallinities of P(L,D)LA 96/4 filaments were in the range of 5–16%, whereas P(L,DL)LA 70/30 filaments were totally amorphous. The degree of crystallinity had effect on the hydrolytic degradation of filaments. The tenacity loss of P(L,D)LA 96/4 filaments was about 10% and that of P(L,DL)LA 70/30 filaments was as high as 50% after 24 weeks in vitro. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Functional Correlates of Fiber Architecture of the Lateral Caudal Musculature in Prehensile and Nonprehensile Tails of the Platyrrhini (Primates) and Procyonidae (Carnivora)
Authors: Organ Jason M. , Teaford Mark F. , Taylor Andrea B. 
Published: April 2009

AbstractPrehensile‐tailed platyrrhines (atelines and Cebus) and procyonids (Potos) display bony tail features that have been functionally and adaptively linked to their prehensile behaviors, particularly the need to resist relatively greater bending and torsional stresses associated with supporting their body weight during suspensory postures. We compared fiber architecture of the mm. intertransversarii caudae (ITC), the prime tail lateral flexors/rotators, in 40 individuals distributed across 8 platyrrhine and 2 procyonid genera, divided into one of two groups: prehensile or nonprehensile. We tested the hypothesis that prehensile‐tailed taxa exhibit relatively greater physiologic cross‐sectional areas (PCSAs) to maintain tail suspensory postures for extended periods. As an architectural trade‐off of maximizing force, we also predicted prehensile‐tailed taxa would exhibit relatively shorter, more pinnate fibers, and a lower mass to tetanic tension ratio (Mass/PO). Prehensile‐tailed taxa have relatively higher PCSAs in all tail regions, indicating their capacity to generate relatively greater maximum muscle forces compared to nonprehensile‐tailed taxa. Contrary to our predictions, there are no group differences in pinnation angles, fiber lengths or M/PO ratios. Therefore, the relatively greater prehensile PCSAs are driven largely by relative increase in muscle mass. These findings suggest that relatively greater ITC PCSAs can be functionally linked to the need for prehensile‐tailed taxa to suspend and support their body weight during arboreal behaviors. Moreover, maximizing ITC force production may not come at the expense of muscle excursion/contraction velocity. One advantage of this architectural configuration is it facilitates suspension of the body while simultaneously maximizing tail contact with the substrate. Anat Rec, 292:827–841, 2009. © 2009 Wiley‐Liss, Inc.
Cover Picture: Monitoring the Formation of Coordination Complexes Using Electrospray Mass Spectrometry (Chem. Asian J. 5/2009)
Authors: Mathieson Jennifer S. , Cooper Geoffrey J. T. , Pickering Alexandra L. , Keller Marco , Long De‐Liang , Newton Graham N. , Cronin Leroy 
Published: April 2009

AbstractThe rigid Schiff‐base ligand cis,trans‐1,3,5‐tris(pyridine‐2‐carboxaldimino) cyclohexane is synthesized, and its complexation to copper(II) salts at a range of stoichiometries is investigated. L. Cronin et al. show that the complexation reaction leads to the crystallization of transition‐metal complexes with nuclearities of 1, 2, and 4, and the formation of the complexes can be followed stepwise, in real time, using electrospray mass spectrometry. For more information, see their Full Paper on page 681 ff.magnified image
Industrial perspectives of AFM control
Authors: Su Chanmin 
Published: April 2009

AbstractThe controllers delivered by atomic force microscope (AFM) manufacturers to AFM users are several decades behind various advanced control technology. This paper is trying to analyze factors that created this gap to reach certain specifications, either quantitatively or qualitatively, of an ideal controller viewing from AFM industries. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Identification, control and hysteresis compensation of a 3 DOF metrological AFM
Authors: Merry Roel , Uyanik Mustafa , van de Molengraft René , Koops Richard , van Veghel Marijn , Steinbuch Maarten 
Published: April 2009

AbstractAtomic Force Microscopes (AFMs) are widely used for the investigation of samples at the nanometer scale. The metrological AFM used in this work uses a 3 degrees‐of‐freedom (DOFs) stage, driven by piezo‐stack actuators, for sample manipulation in combination with a fixed cantilever. The piezo‐stack actuators suffer from hysteresis, which acts as a nonlinear disturbance on the system and/or can change the system dynamics. The contributions of this paper are the application of feedback control to all 3 DOFs of the metrological AFM and the design and application of a hysteresis feedforward for the asymmetric hysteresis present in the system. The amount of coupling between the DOFs is assessed by a non‐parametric multiple‐input‐multiple‐output (MIMO) identification. Since the dynamics appear to be decoupled in the frequency range of interest, feedback controllers are designed for each DOF separately. For the modeling of the asymmetric hysteresis an extended Coleman‐Hodgdon model is proposed. This model is used for feedforward compensation of the hysteresis. The combination of feedback control for all DOFs and the asymmetric hysteresis feedforward enables the AFM to track scanning profiles within the sensor bound of 5 nm. Real‐time imaging of the sample is possible with an accuracy of 2 nm. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
High‐speed serial‐kinematic SPM scanner: design and drive considerations
Authors: Leang Kam K. , Fleming Andrew J. 
Published: April 2009

AbstractThis paper describes the design of a flexure‐guided, two‐axis nanopositioner (scanner) driven by piezoelectric stack actuators. The scanner is specifically designed for high‐speed scanning probe microscopy (SPM) applications, such as atomic force microscopy (AFM). A high‐speed AFM scanner is an essential component for acquiring high‐resolution, three‐dimensional, time‐lapse images of fast processes such as the rapid movement of cells and the diffusion of DNA molecules. A two‐axis SPM scanner is proposed, where the slow and fast scanning axes are serially connected and flexure guided to minimize runout. The scanner's achievable scan range is approximately 10µm × 10µm. Finite element analysis is utilized to optimize the mechanical resonance frequencies of the scanner. Experimental results show a first major resonance in the slow and fast axis at 1.5 and 29 kHz, respectively. This paper also discusses the various tradeoffs between speed, range, electrical requirements, and scan trajectory design for high‐speed nanopositioning. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Creep and hysteresis compensation for nanomanipulation using atomic force microscope
Authors: Yang Qinmin , Jagannathan S. 
Published: April 2009

AbstractIn this paper, a novel scheme is presented to simultaneously compensate the inherent creep and hysteresis nonlinearities of a piezoelectric actuator while positioning the Atomic Force Microscope (AFM) tip. In order to mitigate these nonlinearities, creep and hysteresis phenomenon are first modeled separately by using the classical Prandtl‐Ishlinskii (PI) operator. Then, a linear time‐invariant (LTI) representation is obtained to identify the creep uncertainty and subsequently an adaptive control scheme is devised for the piezoelectric actuator to track a desired path in the presence of creep. An additional dynamic inversion loop is utilized by using an online approximator to offset the hysteresis effects without the need of identifying the parameters within the hysteresis model. Rigorous performance analysis is conducted using standard Lyapunov stability approach along with simulation results. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
A new potential field method for mobile robot path planning in the dynamic environments
Authors: Yin Lu , Yin Yixin , Lin Cheng‐Jian 
Published: April 2009

AbstractA new potential field method for mobile robot path planning is proposed in this paper. At present, most potential field methods are designed to be applied in the stationary environment, and several improved potential functions have brought in the velocity factors in the dynamic circumstances. Based on the consideration that the moving trend of the robot in the dynamic environments is also necessary to produce more reasonable path, this paper defines new attractive potential function with respect to the relative position, velocity, and acceleration between the robot and the goal, as well as the repulsive potential function with respect to the relative positions, velocities, and accelerations between the robot and the obstacles. The virtual forces are calculated to make the robot plan its motion, not only with right positions, but also with suitable velocities. Furthermore, the robot will keep a similar moving trend with the goal and contrary trends with the obstacles. Finally, some methodic simulations are carried out to validate and demonstrate the effectiveness of the new potential field method. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
On stability and stabilizability of positive delay systems
Authors: Wu Ligang , Lam James , Shu Zhan , Du Baozhu 
Published: April 2009

AbstractThe stabilization problem with positivity is investigated in this note for discrete‐time linear systems with time delay. A delay‐independent necessary and sufficient condition is proposed in terms of linear matrix inequalities (LMIs) for the existence of desired controllers that guarantee the closed‐loop system to be asymptotically stable and positive. In addition, the obtained result is further extended to more general case when the system matrices contain uncertain parameters, where a sufficient condition is obtained. The frequently used polytopic parameter uncertainty is taken into consideration. Since the conditions obtained are expressed as LMIs, which can be easily verified by using standard numerical software. A numerical example is provided to illustrate the proposed results. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Shrinkage drift parameter estimation for multi‐factor Ornstein–Uhlenbeck processes
Authors: Nkurunziza Sévérien , Ahmed S. Ejaz 
Published: April 2009

AbstractWe consider some inference problems concerning the drift parameters of multi‐factors Vasicek model (or multivariate Ornstein–Uhlebeck process). For example, in modeling for interest rates, the Vasicek model asserts that the term structure of interest rate is not just a single process, but rather a superposition of several analogous processes. This motivates us to develop an improved estimation theory for the drift parameters when homogeneity of several parameters may hold. However, the information regarding the equality of these parameters may be imprecise. In this context, we consider Stein‐rule (or shrinkage) estimators that allow us to improve on the performance of the classical maximum likelihood estimator (MLE). Under an asymptotic distributional quadratic risk criterion, their relative dominance is explored and assessed. We illustrate the suggested methods by analyzing interbank interest rates of three European countries. Further, a simulation study illustrates the behavior of the suggested method for observation periods of small and moderate lengths of time. Our analytical and simulation results demonstrate that shrinkage estimators (SEs) provide excellent estimation accuracy and outperform the MLE uniformly. An over‐ridding theme of this paper is that the SEs provide powerful extensions of their classical counterparts. Copyright © 2009 John Wiley & Sons, Ltd.
Pension funding problem with regime‐switching geometric Brownian motion assets and liabilities
Authors: Chen Ping , Yang Hailiang 
Published: April 2009

AbstractThis paper extends the pension funding model in (N. Am. Actuarial J.2003;7:37–51) to a regime‐switching case. The market mode is modeled by a continuous‐time stationary Markov chain. The asset value process and liability value process are modeled by Markov‐modulated geometric Brownian motions. We consider a pension funding plan in which the asset value is to be within a band that is proportional to the liability value. The pension plan sponsor is asked to provide sufficient funds to guarantee the asset value stays above the lower barrier of the band. The amount by which the asset value exceeds the upper barrier will be paid back to the sponsor. By applying differential equation approach, this paper calculates the expected present value of the payments to be made by the sponsor as well as that of the refunds to the sponsor. In addition, we study the effects of different barriers and regime switching on the results using some numerical examples. The optimal dividend problem is studied in our examples as an application of our theory. Copyright © 2009 John Wiley & Sons, Ltd.
Solvent‐dependent conformation of amylose tris(phenylcarbamate) as deduced from scattering and viscosity data
Authors: Fujii Taichi , Terao Ken , Tsuda Maiko , Kitamura Shinichi , Norisuye Takashi 
Published: April 2009

AbstractThe z‐average mean‐square radius of gyration 〈S2〉z, the particle scattering function P(k), the second virial coefficient, and the intrinsic viscosity [η] have been determined for amylose tris(phenylcarbamate) (ATPC) in methyl acetate (MEA) at 25°C, in ethyl acetate (EA) at 33°C, and in 4‐methyl‐2‐pentanone (MIBK) at 25°C by light and small‐angle X‐ray scattering and viscometry as functions of the weight‐average molecular weight in a range from 2 × 104 to 3 × 106. The first two solvents attain the theta state, whereas the last one is a good solvent for the amylose derivative. Analysis of the 〈S2〉z, P(k), and [η] data based on the wormlike chain yields h (the contour length or helix pitch per repeating unit) = 0.37 ± 0.02 and λ−1 (the Kuhn segment length) = 15 ± 2 nm in MEA, h = 0.39 ± 0.02 and λ−1 = 17 ± 2 nm in EA, and h = 0.42 ± 0.02 nm and λ−1 = 24 ± 2 nm in MIBK. These h values, comparable with the helix pitches (0.37–0.40 nm) per residue of amylose triesters in the crystalline state, are somewhat larger than the previously determined h of 0.33 ± 0.02 nm for ATPC in 1,4‐dioxane and 2‐ethoxyethanol, in which intramolecular hydrogen bonds are formed between the CO and NH groups of the neighbor repeating units. The slightly extended helices of ATPC in the ketone and ester solvents are most likely due to the replacement of those hydrogen bonds by intermolecular hydrogen bonds between the NH groups of the polymer and the carbonyl groups of the solvent. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 729–736, 2009.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
A spectroscopic investigation into the interactions of 3′‐O‐carboxy esters of thymidine with bovine serum albumin
Authors: Ghosh Kalyan Sundar , Sen Shiladitya , Sahoo Bijaya Ketan , Dasgupta Swagata 
Published: April 2009

AbstractBinding studies of 3′‐O‐carboxy esters of thymidine, reported inhibitors of ribonucleases, with bovine serum albumin (BSA) have been explored in this report. Fluorescence spectroscopy in combination with Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopy have been used to determine the nature and mode of binding. The binding and quenching parameters were determined from tryptophan fluorescence quenching by Scatchard plots and modified Stern–Volmer plots. The association constants are of the order of 104M−1for both the ligands. Thermodynamic parameters suggest that apart from an initial hydrophobic association, hydrogen bonding and van der Waals interactions play a decisive role during protein‐ligand complex formation. Minor changes were observed in the secondary structures of human serum albumin (HSA) as revealed by FTIR and CD. Docking studies suggest that the ligands are close to Trp 213, which causes fluorescence quenching. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 737–744, 2009.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Cultural consequences of miscarriages of justice
Authors: Cole Simon A. 
Published: April 2009

AbstractSocial science scholarship has tended to focus more on the causes than the consequences of miscarriages of justice. Within the literature on consequences, the overwhelming emphasis has been on individual consequences: psychological and material impacts on the wrongly convicted individual and, in some cases, other indirectly impacted individuals such as family members of the wrongly convicted and victims of the true perpetrator's future crimes. Some attention has been devoted to social harms, the impact of miscarriages of justice on the broader society within which they are situated, such as the undermining of the legitimacy of the criminal justice system. This paper focuses on what are called here cultural consequences of miscarriages of justice: the way in which some high‐profile miscarriages of justice can shape the public's beliefs about some of the most basic “facts” about crime, such as the nature, prevalence, or even existence of certain categories of crime and the types of individual who tend to perpetrate particular types of crime. In this way, the paper argues, miscarriages of justice may have hitherto underexplored consequences: reshaping, based on false premises, the public's belief about the very nature of crime itself. This paper discusses three cases studies of miscarriages of justice that for varying periods of time created widespread false beliefs about the nature of crime in large segments of the public. The paper concludes by noting that the “righting” of these false beliefs was in most cases fortuitous. This suggests that unexposed miscarriages of justice may still be shaping popular beliefs about the nature of crime, and aspects of the public's current conception of crime may yet be based on false premises. Copyright © 2009 John Wiley & Sons, Ltd.
Preparation of Enantiopure Chiral Amino‐[D1]methyllithium Compounds and Determination of Their Micro‐ and Macroscopic Configurational Stabilities
Authors: Kapeller Dagmar C. , Hammerschmidt Friedrich 
Published: April 2009

AbstractThe smaller the better: Enantiopure aminomethyllithiums, such as depicted, the smallest of their kind, have been prepared and tested for their micro‐ and macroscopic configurational stabilities, which are delicately influenced by R1 and R2. The species with R1=R2=Bn is macroscopically configurationally stable below −95 °C.magnified imageChiral amino‐[D1]methyllithiums have been tested with regard to their microscopic and macroscopic configurational stabilities. The N‐Boc‐N‐diethoxyphosphinyl‐substituted analogue immediately rearranged, showing complete retention of configuration at up to 0 °C. The N‐Boc‐N‐PMB‐protected analogue enantiomerized at −78 °C, but displayed an ee value of 65 % at −95 °C under macroscopic conditions when quenched with benzaldehyde seconds after its generation. Isocyanomethyllithium proved to be configurationally labile at this temperature and racemized completely, even on the microscopic timescale. Only the non‐stabilized N,N‐dibenzylaminomethyllithium was found to be virtually macroscopically configurationally stable below −95 °C.
Metathesis‐like Splitting Reactions of Metallated [36]Octaphyrins(1.1.1.1.1.1.1.1): Experimental and Computational Investigations
Authors: Tanaka Yasuo , Shinokubo Hiroshi , Yoshimura Yosuke , Osuka Atsuhiro 
Published: April 2009

AbstractDo the splits! Metalation of [36]octaphyrin (1) and the metathesis‐like splitting behavior of 1–metal complexes were examined both experimentally and theoretically. Complexes 1–CuCu and 1–CoCu underwent quantitative splitting reactions into two metalloporphyrins, whereas 1–Cu, 1–Co, and 1–ZnZn did not show such reactivity.magnified imagemeso‐Octakis(pentafluorophenyl)‐substituted [36]octaphyrin(1.1.1.1.1.1.1.1) (1) is a figure‐of‐eight nonaromatic macrocycle that serves as a unique platform to induce a metathesis‐like splitting reaction upon bis‐CuII metalation. To get a better understanding of this splitting reaction, we examined the metalation of 1 with several metal ions. In contrast with the smooth and quantitative splitting reaction of bis‐CuII complex 1–CuCu, free‐base 1, mono‐CuII complex 1–Cu, and bis‐ZnII complex 1–ZnZn do not undergo the splitting reaction. Mono‐CoII complex 1–Co was selectively produced from metalation with the CoII ion, from which hybrid complex 1–CoCu was synthesized. The hybrid complex 1–CoCu undergoes the splitting reaction to give 2–Co and 2–Cu quantitatively. Activation parameters of the splitting reactions were determined: Ea=104 kJ mol−1, ΔH≠=101 kJ mol−1, ΔS≠=−25.0 J mol−1 K−1, and ΔV≠=18 cm3 mol−1 for 1–CuCu and Ea=105 kJ mol−1, ΔH≠=102 kJ mol−1, and ΔS≠=−29.9 J mol−1 K−1 for 1–CoCu. A marked difference between the splitting reaction reactivity of 1–CuCu and 1–ZnZn has been examined by DFT calculations at the B3LYP/631SDD//B3LYP/LANL2DZ level, which revealed that the reaction proceeds through a stepwise route involving initial C1C20 bond formation to give INT1 as the rate‐determining step and subsequent C21C40 bond formation to give a spirocyclobutane intermediate (INT2), followed by a radical reverse cycloaddition reaction to give two metalloporphyrins. Inherent instability of 1–CuCu, which may arise from its strongly distorted structure, was indicated to be a main factor in the smooth splitting reaction. Finally, a new bis‐PdII complex (5–PdPd) was isolated in the metalation of 1 with Pd(OAc)2 in a 9:1 mixture of 2,2,2‐trifluoroethanol and methanol as a manifestation of the transannular electronic interaction in metalated octaphyrin complexes. Collectively, these results underscore the importance of the transannular electronic interactions that are enhanced by metalation, depending upon the coordinated metal ions.
Cover Picture: Palladium‐Catalyzed Carbon–Carbon Bond Formation and Cleavage of Organo(hydro)fullerenes (Chem. Eur. J. 19/2009)
Authors: Nambo Masakazu , Itami Kenichiro 
Published: April 2009

AbstractAn unexpected CH bond dimerization reaction and CC bond‐cleavage reaction in organo(hydro)fullerenes have been discovered. In their Communication on page 4760 ff., K. Itami and M. Nambo describe the use of Pd catalysts for a number of interesting reactions of such fullerenes.magnified image