Preparation and characterization of ciprofloxacin‐loaded alginate/chitosan sponge as a wound dressing material

The aim of this study is preparation and characterization of alginate/chitosan sponges including a model antibiotic (i.e., ciprofloxacin) to use in wound and/or burn treatment. Sponges were prepared firstly by the gelation of sodium alginate followed by lyophilization, crosslinking with calcium chloride, and finally coating with chitosan. Sponges were characterized with respect to morphology, water uptake, in vitro drug release behavior, and antimicrobial activity. Investigated and evaluated parameters in all of these studies were selected as the concentration of calcium chloride, alginate viscosity, drug content, and molecular weight of chitosan. Drug release and water uptake were found to be greatly influenced by these parameters. Water uptake and drug release rate were decreased by increasing the crosslinking density, chitosan molecular weight, and alginate viscosity. In the antimicrobial tests, it was obtained that the antimicrobial activity is directly proportional with the release rates and water uptake. Morphological studies showed a highly porous structure with interconnected pores. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1602–1609, 2006     

时光机器：对话卡斯·卡恩教授

"致密化"是现代城市发展不可回避的趋势。城市新插件与历史环境交融并置将是下一个时代浪潮的重要特征,这将进一步引发关于历史价值与当代性的讨论和思辨。荷兰作为高密度国家典型代表,近十年在建成环境的适应性转型中表现突出。文章通过与荷兰卡恩建筑事务所主持建筑师卡斯·卡恩教授的访谈,深度辨析荷兰建筑师面向复杂历史环境的立场与方法。对话重点聚焦于改造策略、遗产价值与实践经验,以期获得设计介入保护与更新议题的可描摹的研究线索。     

重振城市景观的的“乌托邦” 阿尔斯特图书馆和表演艺术学院

<正>阿尔斯特图书馆和表演艺术学院坐落在比利时阿尔斯特,由一栋8000m~2的砖结构建筑和一栋引人注目的 19世纪后期的历史建筑组成。项目的名称为"乌托邦",与托马斯莫尔的著作《乌托邦》同名,这本书是由阿尔斯特市民德克马滕斯首先出版。     

Structure–Activity Relationships and Molecular Docking of Novel Dihydropyrimidine‐Based Mitotic Eg5 Inhibitors

Dihydropyrimidine‐based compounds belong to the first discovered inhibitors of the human mitotic kinesin Eg5. Although they are used by many research groups as model compounds for chemical genetics, considerably less emphasis has been placed on the improvement of this type of inhibitor, with the exception of two recent studies. Dihydropyrimidines can be divided into class I (analogues that bind in the S configuration) and class II type inhibitors, which bind in the R configuration. Herein we report the synthesis and optimization of novel class II type dihydropyrimidines using a combination of in vitro and docking techniques.     

Control of ball screw drives based on disturbance response optimization

This paper presents a new method for designing control laws for ball screw drives by directly optimizing the load side disturbance response against cutting forces. The design applies, concurrently, the principles of pole placement and loop shaping, and is easy to implement in practice. In addition to good low frequency disturbance rejection, the control law provides active vibration damping, which reduces the magnification of tracking errors near the drive's mechanical resonance. Effectiveness of the proposed strategy is demonstrated in machining and high speed tracking experiments, where its performance is compared to the industry standard P-PI cascade control law.     

Virtual CNC system. Part I. System architecture

The paper presents a comprehensive virtual simulation model of a realistic and modular CNC system. The Virtual CNC architecture represents an actual CNC, but with modular feed drives, sensors, motors, and amplifiers. The CNC software library includes a variety of trajectory interpolation and axis control laws. Constant, trapezoidal and cubic acceleration profiles can be selected as a trajectory generation module. The control laws can be selected ranging from a simple PID to complex Pole Placement, Generalized Predictive Control or Sliding Mode Controller with friction compensation. When the Virtual CNC is assembled, its performance can be tested using frequency and time domain response analyses, which are automated. The Virtual CNC includes both analytical tuning methods for linear controllers, as well as Fuzzy Logic based expert auto-tuning system for Adaptive Sliding Mode Control. The paper includes detailed experimental verification of the Virtual CNC.     

High speed CNC system design. Part I: jerk limited trajectory generation and quintic spline interpolation

Reference trajectory generation plays a key role in the computer control of machine tools. Generated trajectories must not only describe the desired tool path accurately, but must also have smooth kinematic profiles in order to maintain high tracking accuracy, and avoid exciting the natural modes of the mechanical structure or servo control system. Spline trajectory generation techniques have become widely adopted in machining aerospace parts, dies, and molds for this reason; they provide a more continuous feed motion compared to multiple linear or circular segments and result in shorter machining time, as well as better surface geometry. This paper presents a quintic spline trajectory generation algorithm that produces continuous position, velocity, and acceleration profiles. The spline interpolation is realized with a novel approach that eliminates feedrate fluctuations due to parametrization errors. Smooth accelerations and decelerations are obtained by imposing limits on the first and second time derivatives of feedrate, resulting in trapezoidal acceleration profiles along the toolpath. Finally, the reference trajectory generated with varying interpolation period is re-sampled at the servo loop closure period using fifth order polynomials, which enable the original kinematic profiles to be preserved. The proposed trajectory generation algorithm has been tested in machining a wing surface on a three axis milling machine, controlled with an in house developed open architecture CNC.     

Ein KI-Verfahren für das Kartenspiel Magic: The Gathering

Zusammenfassung  Das Projekt LOSER entwickelt eine künstliche Intelligenz für das Sammelkartenspiel ,,Magic: The Gathering“. Da dies viele verschiedene Teilprobleme aufweist, findet eine Vielzahl von Algorithmen Verwendung, die variabel umgesetzt werden, um Ver?nderungen der Spielregeln angemessen zu begegnen.     

Determination of the Minimum Scan Size to Obtain Representative Textures by Electron Backscatter Diffraction

A new method for analyzing microstructure is proposed to evaluate the long-range dependence of texture. The proposed method calculates the average disorientation as a function of distance between data points as measured by electron backscatter diffraction patterns. This method gives a measure of clustering of texture and is used to evaluate accurately the effective grain size. This procedure in conjunction with Information theory is used to estimate a representative scan size for various materials. Analyses show that the optimal scan size depends on grain morphology and crystallographic texture. The results also indicate that on an average the optimal scan size needs to be 10 times the effective grain size.