bluuebunny/crossref_metadata_2025_split huggingface dataset:
Substance P analogs containing α,α‐dialkylated amino acids with potent anticancer activity
Authors: Prasad Sudhanand , Mathur Archna , Jaggi Manu , Singh Anu T. , Mukherjee Rama 
Published: July 2007

AbstractSix analogs (peptides 1–6) of the potent substance P (SP) derivative known as ‘Antagonist D’ were synthesized by substituting constrained amino acids Aib or Acp (cycloleucine, 1‐amino cyclopentane carboxylic acid) at different positions in the Antagonist D sequence: D‐Arg1‐Pro2‐Lys3‐Pro4‐D‐Phe5‐Gln6‐D‐Trp7‐Phe8‐D‐Trp9‐Leu10‐Leu11‐NH2. In the preliminary in vitro antiproliferative screening of the analogs on different human cancer cell lines by 3–(4,5–dimethylthiazol–2–yl)–2,5–diphenyltetrazolium bromide (MTT) assay, peptide 1 was found to be the most active. Further, peptide 1 was butanoylated (analog 5) or octanoylated (analog 6) at the N‐terminus. SP analogs 1, 5, and 6 were evaluated in vivo in a xenograft model of human primary colon tumor (PTC) cell line in athymic nude mice and were found to cause tumor regression. This study investigates if the use of the constrained amino acids Aib and Acp in the designed SP analogs can retain the in vitro and in vivo anticancer activities, which could be useful in cancer therapy and drug targeting. Further, the strategy of incorporation of Aib or Acp in biologically active peptides can be exploited in determining the receptor‐bound conformation and in transforming these bioactive peptides into pharmacologically useful drugs. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
First‐ and second order Raman scattering in Sb and Bi at high pressure
Authors: Olijnyk H. , Nakano S. , Takemura K. 
Published: July 2007

AbstractSb and Bi were investigated by high‐pressure Raman spectroscopy in their low pressure phases. One‐ and two‐phonon spectra were measured in the stability field of the A7 structure. The optical zone‐centre modes of monoclinic Bi‐II were obtained for the first time and have been monitored over an extended pressure range. The pressure response of the observed phonon modes, which is qualitatively similar for both substances, is discussed within the context of the anisotropic bonding properties and their gradual lowering under compression. At ambient conditions in both substances the contributions to the temperature shift of both Raman modes due to thermal expansion are much smaller than the explicit contributions. In contrast to Bi‐I, there is evidence that in Sb‐I both phonon–phonon‐ and electron–phonon interactions significantly increase with the application of pressure. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Area selective growth of GaAs by migration‐enhanced epitaxy
Authors: Horikoshi Y. , Uehara T. , Iwai T. , Yoshiba I. 
Published: July 2007

AbstractApplication of migration‐enhanced deposition sequence to area selective growth of GaAs and other III–V compound semiconductors makes it possible to achieve well‐defined area selective growth even using solid source molecular beam epitaxy. Successful growth of small disks and other structures has been performed on SiO2 masked (111)A and (111)B substrates at temperatures around 590 °C. General rule for facets formation suggests that the facet angle is quite sensitive to the V/III flax ratio as well as the substrate orientation. To create vertical $ \bar 1 $ facets around the structures at relatively low V/III flux ratios, (111)A substrates is much more preferable to (111)B substrate. However, high density of hillocks emerges on the structures grown on (111)A substrate. It is found that the hillocks are caused by the stacking faults. The density of hillocks has been dramatically reduced by depositing As in the Ga deposition period. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Boson Green's functions treatment of three‐layer ferrimagnetic superlattice [Comment on “Magnon energy gap and the magnetically structural symmetry in a three‐layer ferrimagnetic superlattice”, phys. stat. sol. (b) 243, No. 8, 1983–1995 (2006)]
Authors: Kapor D. , Pantić M. , Škrinjar M. , Pavkov M. , Radošević S. , Rutonjski M. 
Published: July 2007

AbstractA magnetic superlattice with three‐layer (plane) unit cell was treated within the boson formalism. The energies were derived using Green's functions formalism, and it is shown that previous calculations did not take into account the principal demand that excitation energies should be positive, so many previous conclusions should be re‐examined. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bonded semiconductor interfaces with twist and tilt rotation: TEM analysis supported by molecular dynamics structure modelling
Authors: Wilhelm T. , Kuhlmann V. , Scheerschmidt K. 
Published: July 2007

AbstractRegular dislocation networks have been created by hydrophobic wafer direct bonding of (001) oriented Si wafers. The dislocation densities depend on the (arbitrary) rotational misorientation of the wafers in [001] (twist) and the miscut (tilt). The interfaces have been studied by transmission electron microscopy. Additionally, molecular dynamics simulations have been used to study the system. The simulation of arbitrary angles and multiple misorientations prevents the use of periodic boundary conditions and necessitates the calculation of large cells with up to 500 000 atoms. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preface: phys. stat. sol. (c) 4/8
Authors: Leipner Hartmut S. , Kittler Martin 
Published: July 2007

AbstractThis issue of physica status solidi – Proceedings contains papers presented as oral and poster contribu‐tions at the International Conference on Extended Defects in Semiconductors (EDS 2006) held in Halle, Germany, on 17–22 September 2006. The event was organized by the Martin‐Luther‐Universität Halle–Wittenberg, the Max‐Planck‐Institut für Mikrostrukturphysik Halle, and the Fraunhofer‐Institut für Werkstoffmechanik Halle. The EDS conference series was inaugurated in Hünfeld (Germany) and followed by conferences in Poland, France, Great Britain, Germany, and Russia. The EDS 2006 is the direct follower of the conferences of 2002 held in Bologna (Italy) and 2004 in Chernogolovka (Russia). Although there were some difficulties in numbering the EDS conferences, we followed the scheme in‐troduced at the conference in Brighton 2000 and define our meeting as EDS13. In order to appreciate the 1200th anniversary of the city of Halle in 2006, we selected the famous five towers of the market square as the conference logo. The dislocation expert, however, will recognize a dislocation line, pinned by glide obstacles.The aim of the conference was to provide a forum on the current state of art of investigation and modeling of extended defects in semiconductors in order to achieve a deeper understanding of lattice imperfections, their interaction, and their role in the development of semiconductor technology. The following main topics were covered: Structure of defects, defect imaging, structure modelling, electronic structure of extended defects, mechanical properties and dislocation dynamics, interaction between different kinds of defects, structure of strained layers, compliant substrates, wafer bonding, defects in thin films and interfaces, interface structures, role of extended defects in devices, utilizing of defects for devices, wide band gap materials (SiC, diamond, ZnO, III–V nitrides), defects in solar cell materials and photovoltaic devices, embedded semiconductor nanoparticles, and quantum‐dot‐like “extended defects”.As a new topic, we introduced a crossover between extended defects and nanostructures in semiconductors. We think that the comparison of experiments and the theoretical description of extended defects and nanostructures in semiconductors may give exciting new insights into the understanding of dimensionally confined systems in general. This approach will certainly be extended in the next EDS conference to be held in Poitiers, France, in 2008.We dedicate this proceedings volume to our friend and colleague Jürgen Schreiber, who suddenly passed away during the preparation of this conference. His cathodoluminescence studies on dislocations in semiconductors will be a lasting contribution to the defect community.Halle, January 2007
Graphical weibull analysis of repairable systems
Authors: Hurtler Gisela 
Published: July 2007

AbstractA graphical method is given for the analysis of repairable systems failing according to a Weilbull process. The integrated hazard rate is plotted in a logarithmic co‐ordinate system. If the process is of Weibull type the observed data will be located around a straight line. The plot provides estimates of the parameters. The graphical procedure is completed by confidence bands and variation bands built either around the observed failure numbers at fixed time or vice versa.
Reliability analysis techniques for mechanical systems
Authors: Bernstein N. 
Published: July 2007

AbstractThis paper discusses the application of known system reliability analysis techniques and identifies problems encountered in the practical implementation of these methods, revealing that no single technique is sufficient or even feasible in the case of complex mechanical systems. A new functional analysis method as well as a (new) criticality quantitative approach and failure mechanism analysis are presented and used to analyse an aircraft fuel system. A rigorous and detailed FMECA is still required. Besides its main function it will supply much of the valuable information for many other techniques.
How pulsed operation affects aluminium bond wires
Authors: Fredriksson Gunnel 
Published: July 2007

AbstractAluminium bond wires are exposed to pulsed current with varying duty cycles, pulse widths and current amplitudes. How these parameters influence the temperature rise in the wire and what it takes to damage or break it are studied. There are two possible failure modes. One is burn‐out due to high current amplitude, the other is metallurgical flexure fatigue at the bond heel. Both failure modes are described. The thermal time constant of the wire is determined for different wire lengths. SEM studies of wires during pulsing are made to see structural changes in the wire when it heats. The bond wire may suffer from damage, which affects the reliability, but it may still function electrically.
Production reliability in flexible manufacturing systems
Authors: Khodabandehloo K. , Sayles R. S. 
Published: July 2007

AbstractA typical flexible manufacturing system, Westland Helicopters' sheet metal detail manufacturing complex, has been analysed for reliability. The techniques of fault tree analysis and event tree analysis are presented and their applicability to this study investigated. Event tree analysis has been found to be a more effective method for analysing manufacturing systems. The failure states of the system have been identified from the construction of an event tree which considers random hardware faults that influence production. Failure rate data have been used to quantify the critical production failure states in terms of machine failures. Estimates are made of the system's MTTF and percentage availability using typical MTTR figures. The probability that a selected production route fails to complete the manufacture of a set of parts is also evaluated. A dependency of systems reliability on the production demand has been discovered, and a possible method for modelling and assessing the reliability of systems capable of producing several products is proposed.
Optimization of product and process design for quality and cost
Authors: Phadke M. S. , Dehnad K. 
Published: July 2007

AbstractRobust product and process design is an important technique for achieving high quality at low cost. It involves making the product's function much less sensitive to various sources of noise such as manufacturing variation, environmental variation and deterioration. This is a problem in optimization involving minimization of the mean square loss resulting from the deviation of the product's function from its target. Here we show that the optimization can be carried out in two steps: first maximize a quantity called signal‐to‐noise ratio (S/N) and then bring the performance on target by special adjustment parameters. The two‐step procedure works for a wide variety of product functions and makes the optimization process more efficient and practical compared to the direct minimization of the quadratic loss function.
High‐performance, low‐cost analog data processing and control using a 16‐bit single‐board microcomputer
Authors: Huang M. , Driels M. 
Published: July 2007

AbstractIn this article, the implementation of a microcomputer‐based control system using a low‐cost 16‐bit single‐board microcomputer combined with a general‐purpose data acquisition board is described. It is intended that this combination forms a suitable basis of a control system for the type of complex sensor systems currently associated with modern industrial robots. The technique of interfacing a 16‐bit microcomputer to a peripheral environment which has essentially an 8‐bit architecture is presented. The result is a high‐performance, low‐cost analog data processing and control system. A novel timing device with both software‐ and hardware‐configurable features has been developed so that an accurate interval timer for use with sample data systems is also available. To demonstrate the potential use of the system, an illustrative example of real‐time adaptive process control is described.
Nonadaptive dynamic control for manipulation robots: Centralized or decentralized control
Authors: Vukobratović Miomir , Stokić Dragan 
Published: July 2007

AbstractDifferent concepts for dynamic control of manipulation robots are presented. Principles for the synthesis of optimal control, optimal regulator, “inverse problem” technique, force feedback, decoupled control, and decentralized control are considered. An attempt is made to provide a comparative analysis of all the stated control algorithms and to point out the advantage of decentralized control concept.
Generalized algorithm for computing the 4‐3‐4 N‐axis robotic trajectory
Authors: Shahinpoor M. , Abdel‐Rahman S. Z. 
Published: July 2007

AbstractA generalized inversion technique and algorithm is presented for the purpose of computing the 9n coefficients pertaining to the three segments—i.e., liftoff, transitory, and setdown—of a motion trajectory of an n‐axis robot manipulator. The technique and the computer program presented is general enough to be immediately applicable to an n‐axis robot manipulator if only the desired initial and final position, velocity, acceleration, as well as the intermediate “via” positions are given. A number of examples are presented for a wide spectrum of these constraint conditions on the desired motion trajectories.
A generic multirobot control experimental system
Authors: Maimon Oded Z. 
Published: July 2007

AbstractThis article describes a generic experimental system that implemented the activity controller theory. The controller has the ability to coordinate any number of robots (and other automated machines) and to respond to the random arrival of components, so as to efficiently assemble various mixes of products. The work also briefly presents the structure of the coordination system, and a solution frame to the dynamic collision avoidance problem. The computer‐controlled experimental system is used to simultaneously operate two robots sharing tasks and auxiliary devices in an assembly cell.
Movement coordination for single‐track robot systems
Authors: Kim Chul E. , Langston Michael A. 
Published: July 2007

AbstractWe consider problems associated with the coordination of movement within a multiple‐robot system in which all motion is restricted to a single track. Our objective is to minimize the reconfiguration time, that is, the total time required to move a collection of robots from an initial to a goal configuration. We show that various models give rise to a wide range of problem complexities. For these problems we design and analyze optimization and approximation strategies.
Nonlinear repetitive control with application to trajectory control of manipulators
Authors: Omata Tohru , Hara Shinji , Nakano Michio 
Published: July 2007

AbstractIn this article, a new control scheme named repetitive control is proposed for a class of nonlinear systems described by x(t) = Ax(t) + Bu(t) + n(x(t)) and y(t) = Cx(t), in which the controlled variables follow periodic reference commands. The stability condition is derived by applying the passivity theorem. We show how to apply the repetitive control scheme to the trajectory control of a manipulator. A simple repetitive control scheme is developed for the trajectory control of a manipulator by using nonlinear compensation and feedbacks of position and velocity signals. Experimental results for a three link manipulator verify that the proposed repetitive control reduces the tracking error to a very low level.
Hypersurfaces of special configurations of serial manipulators and related concepts. part II: Passive joints, configurations, component manifolds and some applications
Authors: Soylu Resit , Duffy Joseph 
Published: July 2007

AbstractIn this article the novel concepts of passive/active joints, component/subcomponent manifolds of the HSC, configurations/subconfigurations and their applications are presented. The article also contains a theorem which predicts the existence of passive joints and a synthesis procedure for passive joints. The concepts introduced here and in Part I are illustrated by way of examples which include three existing industrial manipulators.
Interaction dynamics of multiple mobile robots with simple navigation strategies
Authors: Wang P. K. C. 
Published: July 2007

AbstractThe global dynamic behavior of multiple interacting autonomous mobile robots with simple navigation strategies is studied. Here, the effective spatial domain of each robot is taken to be a closed ball about its mass center. It is assumed that each robot has a specified cone of visibility such that interaction with other robots takes place only when they enter its visibility cone. Based on a particle model for the robots, various simple homing and collision‐avoidance navigation strategies are derived first. Then, an analysis of the dynamical behavior of the interacting robots in unbounded spatial domains is made. The article concludes with the results of computer simulation studies of two or more interacting robots.
A computationally efficient method for manipulator dynamic analysis
Authors: Song Shin‐Min , Lin Yueh‐Jaw 
Published: July 2007

AbstractA computationally efficient method for manipulator dynamic analysis is presented. This method adopts two schemes to improve the computational efficiency. First, it takes the advantage of the following geometric feature of most manipulators: For the first three‐degree‐of‐freedom (DOF) mechanism (positioning mechanism), all the links are moving in a principal plane that is rotating about the base axis with respect to the ground. With this geometry, only three equations of motion per link, two equations for the forces in the principal plane and one equation for the moments which are perpendicular to the principal plane, are needed for the inverse dynamic analysis of the first three‐DOF motion. Thus, the number of equations can be reduced to half. Second, this method adopts longitudinal and transverse force components at certain joints in the formulation of equations of motion. This eliminates the need of a simultaneous solution of many equations, which is necessary in conventional Newton‐Euler method. Hence, this method is more computationally efficient than the many existing dynamic analysis methods. Two examples, one is closed‐chain type and the other is open‐chain type, are used as illustrations.
A simple and efficient computational approach for the forward dynamics of elastic robots
Authors: Serna Miguel Angel , Bayo Eduardo 
Published: July 2007

AbstractA simple and efficient Lagrangian formulation is presented for the forward dynamic analysis of elastic robots. The proposed method formulates the equations of motion with respect to a floating frame that follows the rigid motion of the links. By virtue of the proposed formulation the constraint conditions are inserted in the Hamilton's principle by means of a penalty formulation rather than by the classical Lagrange's multiplier technique. As a consequence, the number of equations that define the behavior of the robot does not increase. The numerical implementation of the new method is very simple and always leads to the solution of positive definite matrices. A series of elastic robots are analyzed and the results demonstrate the capabilities of the new formulation for the forward dynamics.
Integrated distributed sensing and active vibration suppression of flexible manipulators using distributed piezoelectrics
Authors: Tzou H. S. 
Published: July 2007

AbstractStructural oscillation of flexible robot manipulators would severely hamper their operation accuracy and precision. This article presents an integrated distributed sensor and active distributed vibration actuator design for elastic or flexible robot structures. The proposed distributed sensor and actuator is a layer, or multilayer of piezoelectric material directly attached on the flexible component needed to be monitored and controlled. The integrated piezoelectric sensor/actuator can monitor the oscillation as well as actively and directly constrain the undesirable oscillation of the flexible robot manipulators by direct/converse piezoelectric effects, respectively. A general theory on the distributed sensing and active vibration control using the piezoelectric elements is first proposed. An equivalent finite element formulation is also developed. A physical model with distributed sensor/actuator is tested in laboratory; and a finite element model with the piezoelectric actuator is simulated. The distributed sensing and control effectiveness are studied.
Kinematics of robot manipulators via line transformations
Authors: Kim Jung‐Ha , Kumar Vijay R. 
Published: July 2007

AbstractRobot kinematics is an extensively researched subject and several well developed techniques for the analysis of robot manipulators and spatial mechanisms exist. Most of these methods are based on point transformations. However, far less research is in evidence for line transformations. Lines and screws are more fundamental to velocity analysis and hence line transformations are believed to be better suited for the kinematic and static analysis of manipulators. In this article, the kinematics for serial chain manipulators using line transformations is investigated. Dual number quaternions are used as spatial transformation operators since they allow compact representation of both rotations and translations. Further, the symbolic computation of the direct and inverse kinematics equations using dual number quaternions is described.
Nuclear sample management using a plutonium dissolution robotic system
Authors: Hollen Robert M. 
Published: July 2007

AbstractAt Los Alamos National Laboratory, a unique sample management robotic system has been developed that automates plutonium metal acid dissolutions, the aliquoting of resulting solutions to be analyzed using several analytical chemistry methods, and automates the barcode labeling of the solution containment vial providing positive solution identification. This system is based upon a commercial laboratory robot from Zymark, Inc. that has been enhanced by the addition of custom robotic workstations engineered and fabricated at our facility. This system will significantly reduce personnel radiation exposure and eliminate the redundancy of each analytical area producing separate dissolved plutonium solutions, which are used in chemical analyses.