THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

Review of Charged Particle Dynamics. Beam Optics and Focusing Systems Without Space Charge. Linear Beam Optics with Space Charge. Self-Consistent Theory of Beams. Emittance Variation. Beam Physics Research from 1993 to 2007. Appendices. List of Frequently Used Symbols. Bibliography. Index.

Theory and Design of Charged Particle Beams

A review is presented of the present status of the theory, the developed technology and the current applications of dielectrophoresis (DEP). Over the past 10 years around 2000 publications have addressed these three aspects, and current trends suggest that the theory and technology have matured sufficiently for most effort to now be directed towards applying DEP to unmet needs in such areas as biosensors, cell therapeutics, drug discovery, medical diagnostics, microfluidics, nanoassembly, and particle filtration. The dipole approximation to describe the DEP force acting on a particle subjected to a nonuniform electric field has evolved to include multipole contributions, the perturbing effects arising from interactions with other cells and boundary surfaces, and the influence of electrical double-layer polarizations that must be considered for nanoparticles. Theoretical modelling of the electric field gradients generated by different electrode designs has also reached an advanced state. Advances in the technology include the development of sophisticated electrode designs, along with the introduction of new materials (e.g., silicone polymers, dry film resist) and methods for fabricating the electrodes and microfluidics of DEP devices (photo and electron beam lithography, laser ablation, thin film techniques, CMOS technology). Around three-quarters of the 300 or so scientific publications now being published each year on DEP are directed towards practical applications, and this is matched with an increasing number of patent applications. A summary of the US patents granted since January 2005 is given, along with an outline of the small number of perceived industrial applications (e.g., mineral separation, micropolishing, manipulation and dispensing of fluid droplets, manipulation and assembly of micro components). The technology has also advanced sufficiently for DEP to be used as a tool to manipulate nanoparticles (e.g., carbon nanotubes, nano wires, gold and metal oxide nanoparticles) for the fabrication of devices and sensors. Most efforts are now being directed towards biomedical applications, such as the spatial manipulation and selective separation/enrichment of target cells or bacteria, high-throughput molecular screening, biosensors, immunoassays, and the artificial engineering of three-dimensional cell constructs. DEP is able to manipulate and sort cells without the need for biochemical labels or other bioengineered tags, and without contact to any surfaces. This opens up potentially important applications of DEP as a tool to address an unmet need in stem cell research and therapy.

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Review Article—Dielectrophoresis: Status of the theory, technology, and applications

This review addresses the recent developments of the, processing of cellulose nanocomposites, focusing on the most used techniques, including solution casting, melt-processing of thermoplastic cell ...

/pdf/review-of-the-recent-developments-in-cellulose-nanocomposite-6fx85zish5.pdf

Review of the recent developments in cellulose nanocomposite processing

Many machining monitoring systems based on artificial intelligence (AI) process models have been successfully developed in the past for optimising, predicting or controlling machining processes. In general, these monitoring systems present important differences among them, and there are no clear guidelines for their implementation. In order to present a generic view of machining monitoring systems and facilitate their implementation, this paper reviews six key issues involved in the development of intelligent machining systems: (1) the different sensor systems applied to monitor machining processes, (2) the most effective signal processing techniques, (3) the most frequent sensory features applied in modelling machining processes, (4) the sensory feature selection and extraction methods for using relevant sensory information, (5) the design of experiments required to model a machining operation with the minimum amount of experimental data and (6) the main characteristics of several artificial intelligence techniques to facilitate their application/selection.

A review of machining monitoring systems based on artificial intelligence process models

Improvement of surface integrity of electro-chemical discharge machining process using powder-mixed electrolyte

Electrochemical discharge machining (ECDM) is a spark-based micromachining method especially suitable for the fabrication of various microstructures on nonconductive materials, such as glass and some engineering ceramics. However, since the spark discharge frequency is drastically reduced as the machining depth increases ECDM microhole drilling has confronted difficulty in achieving uniform geometry for machined holes. One of the primary reasons for this is the difficulty of sustaining an adequate electrolyte flow in the narrow gap between the tool and the workpiece, which results in a widened taper at the hole entrance, as well as a significant reduction of the machining depth. In this paper, ultrasonic electrolyte vibration was used to enhance the machining depth of the ECDM drilling process by assuring an adequate electrolyte flow, thus helping to maintain consistent spark generation. Moreover, the stability of the gas film formation, as well as the surface quality of the hole entrance, was improved with the aid of a side-insulated electrode and a pulse-power generator. The side-insulated electrode prevented stray electrolysis and concentrated the spark discharge at the tool tip, while the pulse voltage reduced thermal damage to the workpiece surface by introducing a periodic pulse-off time. Microholes were fabricated in order to investigate the effects of ultrasonic assistance on the overcut and machining depth of the holes. The experimental results demonstrated that the possibility of consistent spark generation and the machinability of microholes were simultaneously enhanced.

https://iopscience.iop.org/article/10.1088/0960-1317/19/6/065004/pdf

Geometric improvement of electrochemical discharge micro-drilling using an ultrasonic-vibrated electrolyte

A fabrication method of curved surfaces on silicon-based micro-structures using magnetorheological finishing is studied. Thorough explanations are made on the procedures for the evaluation and analysis of surface characteristics of a workpiece and on the fabrication method of the curved surface profile associated with the experiments using magnetorheological finishing. The effect of magnetic field around tool assembly on finished surface profiles is investigated using a finite element method (FEM). The analysis on the magnetic field is performed separately from that of the fluid flow field with the assumption that the field is weakly coupled to the working fluid at steady state with a certain geometric configuration adopted in this work. Several experiments were performed under controlled conditions and the results are demonstrated along with the physical interpretations thereof. The edge effect is turned out to be very important as the target workpiece gets smaller, which can be actively used for the fabrication of curved surfaces on millimeter-scale structures. Response surface methodology (RSM) is applied to predict the profile and roughness of the curved surface of the workpiece to be proceeded with a set of known experimental conditions. In order to use the RSM method, two control input and two response variables are chosen deliberately. Among the multi-regression models generally used in the modeling area, a second-order regression model is employed. The predicted results are verified through additional experiments performed independently.

A study on the fabrication of curved surfaces using magnetorheological fluid finishing

The use of magnetorheological fluids for finishing is one of the most promising smart processes for the fabrication of ultra-fine surfaces, particularly three-dimensional millimeter or micrometer structures. This process is not readily applicable to hard-surface materials, like an Al 2 O 3 –TiC hard disk slider, if a conventional rotating tool is used. This is due to the rotational speed and the resulting actual impressed abrasion energy limits, and the consequent low efficiency of the material removal rate. In this study, the main mechanism responsible for the decrease of the material removal rate on hard materials for a wheel-type magnetorheological finishing process is examined, both theoretically and experimentally, and a solution to this problem is devised via two approaches. The first uses a rectilinear alternating motion to improve processing conditions, and the second focuses on the use of more effective abrasives, namely magnetizable abrasives made of iron powders sintered with carbon nanotubes, which are new abrasives that have not yet been introduced in the field of surface finishing. Furthermore, it is shown that these abrasives increase the lifetime of consumables (magnetorheological fluid and abrasives) and the material removal rate.

Magnetorheological finishing process for hard materials using sintered iron-CNT compound abrasives

Electrochemical discharge machining (ECDM) is an effective spark-based machining method for nonconductive materials such as glass. The spark generation in ECDM processes is closely related to the electrode effects phenomenon, which has been explained as an immediate breakdown of electrolysis due to the gas film formation at the electrode surface. The initiation of the electrode effects is mainly influenced by the critical current density, which is dependent on several parameters such as the wettability of the gas bubble, surface conditions of the electrode and hydrodynamic characteristics of the bubbles. In ECDM processes, precise control of the spark generation is difficult due to the random formation of the dielectric gas film. In this study, a partially side-insulated electrode that maintained a constant contact surface area with the electrolyte was used for the ECDM process to ensure that a uniform gas film was formed. Visual inspections indicated that the side-insulated tool provides new possibilities for describing the exact geometry of a gas film by inducing single bubble formations. Experiment results demonstrated that ECDM with a side-insulated electrode immersed in the electrolyte generated more stable spark discharges compared to non-insulated electrodes. Microchannels were fabricated to investigate the effects of the side insulation on the geometric accuracy and the surface integrity of the machined part.

http://iopscience.iop.org/article/10.1088/0960-1317/18/4/045019/pdf

Sang Jo Lee

Papers

Improvement of surface integrity of electro-chemical discharge machining process using powder-mixed electrolyte

Geometric improvement of electrochemical discharge micro-drilling using an ultrasonic-vibrated electrolyte

A study on the fabrication of curved surfaces using magnetorheological fluid finishing

Magnetorheological finishing process for hard materials using sintered iron-CNT compound abrasives

Modeling gas film formation in electrochemical discharge machining processes using a side-insulated electrode