Ion optics of multipoles

Properties and applications of various kinds of multipoles, in use is mass spectrometry, are discussed; i.e., magnetic as well as electric dipoles and their combinations, quadrupole lenses, hexapole and octupoles. After a short mathematical interlude the dodecapole (12-pole) is introduced: By a proper potential distribution upon the twelve electrodes, it can act as a dipole in an arbitrary direction; as a quadrupole lens, again in an arbitrary direction; as a hexapole; as an octupole; or as a (linear) combination of these devices.An additional feature, however, is the property of the dodecapole, with equal potential on all rods, to act as an einzel lens. In combination with the quadrupole lens function the dodecapole becomes a unique device which can act as a lens focusing in any two mutually perpendicular directions with independent focal strengths.     

Passively Q-switched Nd:YVO(4) laser with a Cr(4+):YAG crystal saturable absorber

We demonstrate, for the first time as far as we know, a passively Q-switched operation of a Nd:YVO(4) laser in which a Cr(4+):YAG crystal and a laser-diode bar are used as the saturable absorber and the pump source, respectively. Stable laser pulses as short as 28 ns with 20-muJ energy can be generated with this laser, which has the advantages of simplicity, high efficiency, and good long-term stability.     

A homogeneity study using NIR spectroscopy: tracking magnesium stearate in Bohle bin-blender

A method was developed for studying mixing of cohesive pharmaceutical mixtures. A combination of accurate sampling and NIR spectroscopic analysis was developed as a suitable method to determine homogenization of magnesium stearate as a function of blending variables. A typical pharmaceutical blend containing a ratio 35:64:1 lactose, avicel, and magnesium stearate was used as a model system. The method accounted for variability of the concentration of magnesium stearate as well as variability of the excipients. Levels of magnesium stearate as low as 0.05% could be resolved by the method, and showed a predicting confidence interval above 98%.     

Theory and laboratory demonstrations on the use of a nematic liquid-crystal phase modulator for controlled turbulence generation and adaptive optics

We discuss the use of liquid-crystal phase modulators (LCPM's) both as a repeatable disturbance test source and as an adaptive optics corrector. LCPM's have the potential to induce controlled, repeatable, dynamic aberrations into optical systems at low cost, low complexity, and high flexibility. Because they are programmable and can be operated as transmissive elements, they can easily be inserted into the optical path of an adaptive optics system and used to generate a disturbance test source. When used as wave-front correctors they act as a piston-only segmented mirror and have a number of advantages. These include low operating power requirements, relatively low cost, and compact size. Laboratory experiments with a Meadowlark LCPM are presented. We first describe use of the LCPM as a repeatable disturbance generator for testing adaptive optics systems. We then describe a closed-loop adaptive optics system using the LCPM as the wave-front corrector. The adaptive optics system includes a Shack-Hartmann wave-front sensor operated with a zonal control algorithm.     

A theoretical description of large viscoplastic shear deformation in metals

In this work, a new 3-dimensional viscoplastic model based on a previous plasticity theory is presented. The proposed constitutive model anticipates the contribution of the main features of plastic behavior, such as yielding, rate effect, isotropic and kinematic hardening, through a new approximation of the constitutive equation with a viscoplastic term, as well as a new consideration of the functional form of the rate of plastic deformation. A high accuracy simulation of shear experimental data at various rates and temperatures for a variety of materials, as well as the sign inversion of normal stress has been postulated.     

Prediction of Thermodynamic Properties of Liquid Air

In this work, a simple equation of state (EoS) has been used to predict some thermodynamic properties of air as a pseudo-pure fluid; as a ternary mixture of nitrogen, oxygen, and argon; and as a binary mixture of nitrogen and oxygen at different temperatures and pressures. A comparison with literature tabulated values has been made. The agreement of calculated densities with corresponding tabulated values is good for which the average absolute deviations are better than 0.06% if we assume air as a pseudo-pure fluid, and 0.9% and 1.2% if we consider air as a ternary mixture and as a binary mixture, respectively. To show the ability of this equation of state to predict density, the calculated densities of air have been compared with those computed by other methods.     

A Homogeneity Study Using NIR Spectroscopy: Tracking Magnesium Stearate in Bohle Bin-Blender

Abstract

A method was developed for studying mixing of cohesive pharmaceutical mixtures. A combination of accurate sampling and NIR spectroscopic analysis was developed as a suitable method to determine homogenization of magnesium stearate as a function of blending variables. A typical pharmaceutical blend containing a ratio 35:64:1 lactose, avicel, and magnesium stearate was used as a model system. The method accounted for variability of the concentration of magnesium stearate as well as variability of the excipients. Levels of magnesium stearate as low as 0.05% could be resolved by the method, and showed a predicting confidence interval above 98%.     

城市音景的鉴定工具-声音漫步

声音存在于城市内的自然和人为环境中,声音来源可分为三个大类形：大自然声诸如风、雨、雷暴等;生命之声诸如鸟类、昆虫、宠物和动物发出的声音;人为之声如人声、音乐声、交通噪声、通风系统之噪声、建筑和拆卸工程之噪声、贸易活动产生的噪声。在最近几年,声音漫步已成为表征城市声景的方法之一。声音漫步通常通过一群人在被研究区内有代表性的典型路径的漫步。漫步者把声音录下来,也将在路径上听到的声音特点和来源记录,以及拍摄照片和在地图上标示。文章旨在为声音漫步提出一个实用指南,方便它成为城市音景的鉴定工具。     

Replica-based crack inspection

Surface replication has been proposed as a method for crack detection in space-shuttle main engine flowliner slots. The results of a feasibility study show that examination of surface replicas with a scanning electron microscope can result in the detection of cracks as small as 0.005 inch, and surface flaws as small as 0.001 inch, for the flowliner material.     

Versatile method for manipulating and contacting nanowires

We present a simple, non-lithographic method for electrically connecting nanowires with electrodes on planar as well as non-planar microsystems. A rigid nanowire is used as a local shadow mask during deposition of metal contacts, which we use to contact structures of widely different conductances: Multiwalled carbon nanotubes, para-hexaphenylene nanofibers, as well as indium arsenide and indium phosphide nanowires. Finally we demonstrate how the method can be extended to different electrode materials on each side of the electrode gap, as well as for investigation of the electromechanical properties of a nanowire integrated in a cantilever.     

Capillary electrophoresis as a second dimension to isoelectric focusing for peptide separation

Capillary zone electrophoresis and carrier ampholytes based capillary electrophoresis have been used as a second separation step to Off-Gel isoelectric focusing for the analysis of complex peptide mixtures. A tryptic digest of four proteins (bovine serum albumin, beta-lactoglobulin, horse myoglobin, cytochrome c) has been chosen as a peptide test mixture. After assessment of different modes of capillary electrophoresis as a second dimension to Off-Gel isoelectric focusing, the optimized two-dimensional platforms provide a degree of orthogonality comparable to state-of-the-art multidimensional liquid chromatography systems as well as a practical peak capacity above 700.     

Edward Steichen

Abstract

‘The camera’, Steichen wrote in 1947, ‘serves as an instrument for waging war and as an historian in recording the war’.¹ He spoke from experience. By this time, as a veteran of both world wars, he was reflecting upon a long life devoted to photography as art, as an advertising medium, as social commentary, and as war documentation. Although Steichen often used his camera as a very effective propaganda device in wartime, his hatred of war motivated him to use the same instrument to persuade people that war would never provide a lasting solution to human problems.²     

Data-driven construction of Convex Region Surrogate models

With the increasing trend of solving more complex and integrated optimization problems, there is a need for developing process models that are sufficiently accurate as well as computationally efficient. In this work, we develop an algorithm for the data-driven construction of a type of surrogate model that can be formulated as a set of mixed-integer linear constraints, yet still provide good approximations of nonlinearities and nonconvexities. In such a surrogate model, which we refer to as Convex Region Surrogate (CRS), the feasible region is given by the union of convex regions in the form of polytopes, and for each region, the corresponding cost function can be approximated by a linear function. The general problem is as follows: given a set of data points in the parameter space and a scalar cost value associated with each data point, find a CRS model that approximates the feasible region and cost function indicated by the given data points. We present a two-phase algorithm to solve this problem and demonstrate its effectiveness with an extensive computational study as well as a real-world case study.     

Waveguide for transmitting and radiating high-frequency, high-power ultrasound using higher mode vibrations of a cylindrical rod

It was shown that a cylindrical solid rod, with a diameter several times larger than the wavelength, can be used as an efficient waveguide for transmitting and radiating high-power ultrasound at higher frequencies. A number of cylindrical rods of varying size and material were tested, and their efficiency as a waveguide was evaluated by the measurements of mechanoacoustic efficiency when the radiating end of the rod was immersed in water for an acoustical load. As an example of waveguide application, a mock-up water atomizer was constructed and shown to work stably at a continuous input of 200 W at 500 kHz. As a consequence of analytical and experimental considerations of the higher mode vibrations of cylindrical rods, a diagram for the optimal design of the waveguides was constructed. For instance, an aluminum alloy rod 6.9 cm in diameter and 23.3 cm in length yielded a mechanoacoustic efficiency as high as 88% at 500 kHz. For high temperature applications, the cylindrical rod can be used as a radiator of heat, as well as for a separator of the piezoelectric transducer from the hot object.     

Influencing factors of synchronization in manufacturing systems

Manufacturing systems exhibit two types of synchronisation phenomena: logistics and physics. Previous research has established synchronisation measures for both types and has shown that they are related to the due date performance. However, there is a lack of knowledge about the factors triggering synchronisation emergence as well as a holistic understanding of synchronisation effects on logistics performance. Thus, this research aims to further explore the relation between synchronisation, its influencing factors and its effect on logistics performance. Based on a profound literature review, we derive first hypotheses on the cause-and-effect-relationships between structural and dynamic properties of a manufacturing system and the emergence of logistics and physics synchronisation as well as logistics performance. By conducting a discrete-event simulation study on diverse manufacturing system types (line, flow shop and job shop production), we are able to test these hypotheses. We conclude that manufacturing network architecture as a structural property as well as processing time variability and system workload as dynamic properties may be exploited for an advanced and synchronisation-oriented manufacturing system design.     

Stress distribution in a segmented coating film on metal fibre under tensile loading

When a coating film on a metal fibre or wire is brittle, it exhibits multiple-fracture under loading. In order to describe the exerted tensile stress on the segments of a coating film as a function of the distance from the end of the segments and as a function of applied stress, a new approximate calculation method is presented, assuming that the interfacial bonding strength is high enough and no interfacial debonding occurs. Using the present calculation method, effects of geometrical factors such as fibre diameter, thickness of coating film and length of segment as well as those of mechanical factors such as Young's modulus, shear modulus and the yield stress of the fibre and the coating film on the exerted tensile stress on the segments and also on the exerted shear stress at the interface are described in a quantitative manner.     

Electrical properties of CFC- and HCFC-substitutes

Electrical properties of refrigerants are of importance as soon as bushings are surrounded by a refrigerant. This is the case e. g. for hermetic sealed motor compressors as well as for some control devices such as liquid level control units or capacity controls for compressors. This paper presents a survey of existing data for HFC refrigerants and presents new measurements for those HFC blends that have been identified as long term replacements for CFCs and HCFCs. The data collection includes permittivity, electrical conductivity and breakdown voltage. Values are given for the HFC blends R404A, R407C, R410A and R507 as well as for R134a.     

SEDUCTIONS AND FLIRTATIONS

Despite much having been written on the subject, a stable theorization of photographic meaning seems as elusive as ever. Can – and should – theory be useful to explain photographs and to understand photography? Taking the concept of the index as one example, this paper proposes a model in which theories, as much as photographs, are situated in the specific historic circumstances of their being made, used, reproduced and circulated within a culture. In this model, the relationship between photography and theory can be understood as reciprocal; one in which actual photographs can inform and transform theories as much as being explained by them. This is only possible, however, if we attend to photographs in their material circumstances, embedded in social and bodily practices that themselves can be understood as a way to “theorize” photography. This is not to suggest that the processes of signification can thus be fixed or reduced to a main one, but that, rather than being seduced by theory, we should embrace the flirtatiousness of photographs, never yielding to one conclusive and stable meaning; and learn to flirt back.     

Voltage effects on the production of nanocarbons by a unique arc-discharge set-up in solution

Well graphitised nanocarbons including onion-like fullerenes and single- and multi-walled carbon nanotubes (CNTs) were synthesised in high yield by automatic arc-discharge method in solution. This technique is considered a low-cost method since it does not require any expensive equipment. Herein, an arc discharge full automatic set-up was used for fabrication of CNTs which enables controlling of the gap between the two electrodes and the voltage as well. Carbon nanostructures under a controlled amount of voltage (from 10 to 30 V) were synthesised where Ni : Mo as a catalyst and LiCl 0.25 M as a solution were used. Subsequently, a modified acid treatment method was applied as purification stage of the products. The production rate of CNTs was as high as 7.7 mg min^?1 while the voltage was set at 30 V. Scanning electron microscopy and transmission electron microscopy as well as Raman spectroscopy were employed to study the morphology of these carbon nanostructures. The results indicated that CNTs synthesised at a voltage of 30 V had the best quality and elongated straight structures. The mechanism of the voltage conditions for preparing nanocarbons as well as their characterisation are discussed.     

Self‐Healing,Adhesive, and Highly Stretchable Ionogel as a Strain Sensor for Extremely Large Deformation

Fabricating a strain sensor that can detect large deformation over a curved object with a high sensitivity is crucial in wearable electronics, human/machine interfaces, and soft robotics. Herein, an ionogel nanocomposite is presented for this purpose. Tuning the composition of the ionogel nanocomposites allows the attainment of the best features, such as excellent self‐healing (>95% healing efficiency), strong adhesion (347.3 N m^?1), high stretchability (2000%), and more than ten times change in resistance under stretching. Furthermore, the ionogel nanocomposite–based sensor exhibits good reliability and excellent durability after 500 cycles, as well as a large gauge factor of 20 when it is stretched under a strain of 800–1400%. Moreover, the nanocomposite can self‐heal under arduous conditions, such as a temperature as low as ?20 °C and a temperature as high as 60 °C. All these merits are achieved mainly due to the integration of dynamic metal coordination bonds inside a loosely cross‐linked network of ionogel nanocomposite doped with Fe₃O₄ nanoparticles.