Two-fold efficiency increase by selective excitation of ions for consecutive activation by ion-electron reactions and vibrational excitation in tandem fourier transform ion cyclotron resonance mass spectrometry

A new technique called selective excitation of ions for consecutive activation (SEICA) is proposed for obtaining complementary fragmentation mass spectra from the same precursor ion population. SEICA utilizes precursor ions remaining intact after electron capture dissociation or another ion-electron reaction for efficient MS/MS based on a vibrational excitation (VE) technique, such as infrared multiphoton dissociation. SEICA uses the ability of ion-trapping instruments to detect product ions while retaining inside the trap intact precursor ions, making the latter available for consecutive activation by a VE technique. The possibility of practical implementation of SEICA by software-only modification of a commercial instrument is demonstrated. A 2-fold increase in the efficiency is achieved for both "single-scan" and "multiple-scan" experiments. This improvement can be particularly important for high-sensitivity applications in, for example, proteomics, where limited ECD efficiency poses an obstacle for broad implementation of this technique.     

Liquid PMMA: A High Resolution Polymethylmethacrylate Negative Photoresist as Enabling Material for Direct Printing of Microfluidic Chips

Polymethymethacrylate (PMMA) is one of the most important thermoplasts and a commonly used material in microsystem fabrication, for example, microfluidics owning mainly to its optical transparency, biocompatibility, low autofluorescence, and low cost. However, being a thermoplastic material PMMA is typically structured using industrial replication techniques making PMMA unsuitable for rapid prototyping. The fact that neither material nor processing technique can be directly transferred from laboratory to industrial state makes the research‐to‐business conversion often extremely difficult in microfluidics since material properties have a major impact on the final system behavior. This paper presents “Liquid PMMA,” a fast curing viscous PMMA prepolymer which can be used as a negative photoresist and directly structured using ultraviolet or visible light with tens of micron resolution and smooth surfaces. Using this technique microfluidic chips in PMMA can be fabricated within minutes. The cured Liquid PMMA parts show the same high optical transparency, low autofluorescence, and surface properties like commercial PMMA. In this way, microfluidic chips can be rapidly developed and optimized on the laboratory scale in the same material which is later on used on the industrial scale.

     

陶瓷燃料电池电解质流延膜的烧结工艺及其性能研究

本文采用“三明治式多孔夹板”烧结方法制得了均匀致密的、用于燃料电池的固体电解质膜材,用SEM方法观察了膜材的微观形貌,还用复数阻抗频谱仪对烧结膜材的电导性能进行了测定,实验结果表明,所采用的烧结工艺能有效解决单层厚膜烧结中易出现的起翘与开裂问题,所制得的膜材的电性能亦能满足陶瓷燃料电池的要求．     

Electroformed composite materials

Electroforming has been used as a method of incorporating fibres in a metal matrix. Studies on both conducting and non-conducting fibres formed the basis of a critical assessment of the potentialities of this technique for making composite materials. Examples of the application of the method to the forming of various materials are given.originally submitted to Applied Materials Research 7 November 1966     

An improved adaptive wavelet shrinkage for ultrasound despeckling

Ultrasound imaging is the most widely used medical diagnostic technique for clinical decision making, due to its ability to make real time imaging for moving structures, low cost and safety. However, its usefulness is degraded by the presence of signal dependent speckle noise. Several wavelet-based denoising schemes have been reported in the literature for the removal of speckle noise. This study proposes a new and improved adaptive wavelet shrinkage in the translational invariant domain. It exploits the knowledge of the correlation of the wavelet coefficients within and across the resolution scales. A preliminary coefficient classification representing useful image information and noise is performed with a novel inter-scale dependency measure. The spatial context adaptation of the wavelet coefficients within a subband is achieved by a local spatial adaptivity indicator, determined by using a truncation threshold. A weighted signal variance is estimated based on this measure and used in the determination of a subband adaptive threshold. The proposed thresholding function aims to reduce the fixed bias of the soft thresholding approach. Experiments conducted with the proposed filter are compared with the existing filtering algorithms in terms of Peak-Signal to Noise Ratio (PSNR), Mean Square Error (MSE), Structural Similarity Index Measure (SSIM), Equivalent Number of Looks (ENL) and Edge Preservation Index (EPI). A comparison of the results shows that the proposed filter achieves an improvement in terms of quantitative measures and in terms of visual quality of the images.     

A design for low-flow sheathless electrospray emitters

An extremely simple design has been developed for producing durable sheathless electrospray emitters that give highly stable electrospray for unlimited lifetimes. The emitters can be fashioned from any style fused-silica capillary and are ideally suited for generating "all-in-one" microcolumn-emitter systems thus eliminating unwanted void volumes. The emitters give stable electrospray at low (30 nL/min) as well as high (1 mL/min) flow rates without the aid of nebulizing gas. Fabrication of these emitters (aka the "fairy dust" technique) does not involve the use of a metallized coating but rather the adherance of 2-μm gold particles to the capillary tip resulting in a robust approach to the problem of making an electrical contact with the electrospray solvent.     

Crystal growth of organic materials in glass capillaries

Three potentially useful electro-optic organic materials have been grown as good optical quality single crystals of up to 30 mm length inside hollow glass fibres of 35 to 50m i.d. Capillary attraction was used to fill the fibres and a furnace with small cross-sectional area was designed for the recrystallization of the material inside. The crystallization process is fast and only 0.5 g purified material is needed, thus making the technique attractive for the rapid assessment of the electro-optic properties of many organic materials.     

Atomic-precision multilayer coating of the first set of optics for an extreme-ultraviolet lithography prototype system

We present our results of coating a first set of optical elements for an extreme-ultraviolet (EUV) lithography system. The optics were coated with Mo-Si multilayer mirrors by dc magnetron sputtering and characterized by synchrotron radiation. Near-normal incidence reflectances above 65% were achieved at 13.35 nm. The run-to-run reproducibility of the reflectance peak wavelength was maintained to within 0.4%, and the thickness uniformity (or gradient) was controlled to within +/-0.05% peak to valley, exceeding the prescribed specification. The deposition technique used for this study is an enabling technology for EUV lithography, making it possible to fabricate multilayer-coated optics to accuracies commensurate with atomic dimensions.     

Sound speed in liquid lead at high temperatures

A dynamic technique, the isobaric expansion experiment (IEX), is used to reach high-temperature and pressure states in liquid lead. A unique technique is described for making sound-speed measurements once a final equilibrium end state is obtained. Data over an extended density range are presented. The sound speed in liquid lead over this range appears to vary linearly with density and has no dependence on temperature within our experimental precision (±7 %).Paper presented at the Ninth Symposium on Thermophysical Properties, June 24–27, 1985, Boulder, Colorado, U.S.A.     

Process integration design methods for water conservation and wastewater reduction in industry

This paper is part 2 of a three-part series of papers addressing operational techniques for applying mass integration design in industry with special focus on water conservation and wastewater reduction. This paper presents a design technique for any number of wastewater streams containing multiple contaminants. The technique comprises a single non-linear optimization program to minimize the wastewater discharged (or maximize the amount of recycled wastewater). This program is developed based on general water allocation principles and uses the transshipment model theory to allow the "shipment" of wastewater (referred to as "sources" or "warehouses") to process water users (referred to as "sinks", "demands" or "customers"). A detailed case study of industrial significance, highlighting land treatment technology, is included to illustrate the proposed methodology and various process scenarios are evaluated within this case study to demonstrate the general applicability of the proposed optimization program.     

A novel X-ray technique for inspection of steel pipes

The corrosion-induced material loss in crude oil carrying steel pipelines was originally studied by making use of the backscatter X-ray technique. The steel thickness can be determined by studying the density profile of the backscatter intensity vs. the depth location of a voxel. There are, however, some practical limitations to the above method, and a new method for evaluating steel thickness, namely, the transcatter technique is described. This technique uses the intensity of the beam which is transmitted by the pipe wall and subsequently scattered by the hydrocarbon inside the pipeline. The thickness is evaluated using three techniques, namely, the sequential technique, the dual angle technique, and the reference technique. Of the three techniques, the sequential technique has been studied in detail. The mathematical equations and experimental results related to the transcatter technique show that the thickness can be measured with an accuracy of better than 10% for a nominal steel thickness of 8 mm with a measurement time of several minutes.     

Directed self-assembly of epitaxial CoFe2O(4)-BiFeO3 multiferroic nanocomposites

CoFe(2)O(4) (CFO)-BiFeO(3) (BFO) nanocomposites are an intriguing option for future memory and logic technologies due to the magnetoelectric properties of the system. However, these nanocomposites form with CFO pillars randomly located within a BFO matrix, making implementation in devices difficult. To overcome this, we present a technique to produce patterned nanocomposites through self-assembly. CFO islands are patterned on Nb-doped SrTiO(3) to direct the self-assembly of epitaxial CFO-BFO nanocomposites, producing square arrays of CFO pillars.     

Calculation of Magnetic Remanence

This paper outlines a technique for predicting the residual field in magnetizable media after the source is removed. Ship builders are considering the use of dc cables, and many land-based power systems have dc links as a power feed. What will the neighboring steel's remanent field be if the cables are excited with a large current, e.g., under short circuit conditions? This paper presents a procedure for replacing the steel with a continuum of nonlinear permanent magnets. The technique consists of discretizing the magnetizable medium into subregions, as defined by a contour plot of $vertvec{B}vert$. Each subregion is assigned a magnetization curve according to the characteristic $B$ in that region. The source field is used to assign local magnetization within these regions. The technique is novel, but the real contribution is a technique that can be implemented by any user of a commercial code, and not isolated to developers.      

Application of a liquid-crystal spatial light modulator for brightness adaptation in microscopic topometry

Three-dimensional optical topometry of technical surfaces becomes increasingly important for the control of industrial processes. However, the local reflectance of the surface of the investigated sample often varies within a wide range, making accurate measurements by fringe projection difficult. We demonstrate the use of a liquid-crystal spatial light modulator as the fringe-generating element in a standard stereo microscope. With this device the brightness of the projected patterns can be adapted pixelwise. This technique leads to a significant improvement of the results of our measurements with a phase-shifting algorithm.     

雅安社会创新设计中的锔瓷造器

目的研究社会创新背景下"锔瓷造器"的新方法和对传统手工艺的发展途径。方法雅安社会创新项目中"锔瓷造器"是进行不可复制、独一无二的器型再造,重新创造出一件新的器物,让它以另一种面貌获得"重生",这与传统锔瓷工艺在创意构思、设计理念上都有所不同。结论在社会创新大背景下,研究如何将传统工艺与当代设计相结合,将其参与到社会创新设计支持的公益实践中,使锔瓷工艺焕发新生,探索锔瓷工艺的可持续发展路径。     

Solution of the Landau–Ginzburg Equations Using Lattice–Boltzmann

In this paper, we solve the time dependent Ginzburg–Landau (TDGL) equations in two dimensions, using Lattice–Boltzmann (LB) technique and the velocity discretization scheme D2Q9, for a square region with periodic boundary conditions. In order to obtain the solution, we use three distribution functions, each of them obeying the LB equation, and making a proper redefinition of the tensor Π ⁰, we find the (TDGL) equations. Further, we obtain the equilibrium distribution functions for the three LB equations, and then the solution for the components of the magnetic potential vector and the order parameter.     

Furnaces for calibrating metal thermocouples up to 2000–2500°C

Conclusions Furnaces have been developed which are suitable for calibrating high-melting-point thermocouples at temperatures of the order of 2200–2500C. A technique has been suggested for calibrating thermocouples without the use of an insulating ceramic, thus making it possible to raise the upper calibration limit of metal thermocouples to temperatures of the order of 2400–2500C.Furnaces used at the Central Automation Laboratory for calibrating high-temperature thermocouples made of tungsten and molybdenum alloys with rhenium can also be utilized at various plants and research institutes which employ in their work high-temperature thermocouples.     

Making the business case for process safety using value-at-risk concepts

An increasing emphasis on chemical process safety over the last two decades has led to the development and application of powerful risk assessment tools. Hazard analysis and risk evaluation techniques have developed to the point where quantitatively meaningful risks can be calculated for processes and plants. However, the results are typically presented in semi-quantitative "ranked list" or "categorical matrix" formats, which are certainly useful but not optimal for making business decisions. A relatively new technique for performing valuation under uncertainty, value at risk (VaR), has been developed in the financial world. VaR is a method of evaluating the probability of a gain or loss by a complex venture, by examining the stochastic behavior of its components. We believe that combining quantitative risk assessment techniques with VaR concepts will bridge the gap between engineers and scientists who determine process risk and business leaders and policy makers who evaluate, manage, or regulate risk. We present a few basic examples of the application of VaR to hazard analysis in the chemical process industry.     

Developments on standoff detection of explosive materials by differential reflectometry

Differential reflectometry (DR) is an effective tool to supplement existing explosives detection systems thus making the combined unit more effective than one tool alone. It is an optical technique in which the light beam (UV) emanates from an extended distance onto the substance under investigation, thus rendering it to be a standoff method. DR allows the measurement of the energies that electrons absorb from photons as they are raised into higher, allowed energy states. These electron transitions serve as a "fingerprint" for identifying substances. The device can be made portable; it is fast, safe for the public, does not require human involvement, is cost effective, and most of all, does not require ingestion of a suspicious substance into an instrument. Various embodiments are presented.     

Electroanalysis of metabolic flux from single cells in simple picoliter-volume microsystems

A picoliter-volume electrochemical analytical chamber has been developed for detecting the metabolic flux resulting from the stress responses of a single plant cell. Electrochemical cells, with volumes as small as 100 pL, were fabricated by controlled electrochemical dissolution of a gold wire sealed in glass (the back-etching of the metal realizing an ultralow-volume titer chamber). In the first instance, the electrode contained within the chamber was characterized by the microinjection of standard aliquots of either ascorbic acid or hydrogen peroxide. In all cases, experimental currents obtained correlated well with theoretical calculations. Subsequently, single plant cells were micromanipulated into the chambers and were exposed to amounts of the detergent SDS (which permeabilized the cell membrane and released the intracellular contents). The flux of metabolite released from a single cell was estimated by using electrochemical-linked assays based upon the enzymes catalase, ascorbate oxidase, and horseradish peroxidase (in each case), in the presence of a mediator. In so doing, we investigated the activity of the cellular protection mechanisms through the determination of peroxides, while the individual cell was "stressed". The technique was found to provide a reliable and reproducible method for making single-cell measurements, using fabrication procedures that are both simple and do not require photolithographic methods.