Investigating the Commercial Instrument Market

2008 ◽  
pp. 22-22-11
Author(s):  
HC Simmons
Keyword(s):  
Commercial Instrument

Electrostatic optics and aberration correction in the 1940s and today

1992 ◽  
Vol 50 (1) ◽  
pp. 6-7
Author(s):  
Gertrude F. Rempfer
Keyword(s):  
Electron Microscope ◽  
Focal Point ◽  
Focal Length ◽  
High Vacuum ◽  
Electron Optics ◽  
Applied Physics ◽  
Electrostatic Lenses ◽  
Commercial Instrument ◽  
The University ◽  
Theory And Experiment

I became involved in electron optics in early 1945, when my husband Robert and I were hired by the Farrand Optical Company. My husband had a mathematics Ph.D.; my degree was in physics. My main responsibilities were connected with the development of an electrostatic electron microscope. Fortunately, my thesis research on thermionic and field emission, in the late 1930s under the direction of Professor Joseph E. Henderson at the University of Washington, provided a foundation for dealing with electron beams, high vacuum, and high voltage.At the Farrand Company my co-workers and I used an electron-optical bench to carry out an extensive series of tests on three-electrode electrostatic lenses, as a function of geometrical and voltage parameters. Our studies enabled us to select optimum designs for the lenses in the electron microscope. We early on discovered that, in general, electron lenses are not “thin” lenses, and that aberrations of focal point and aberrations of focal length are not the same. I found electron optics to be an intriguing blend of theory and experiment. A laboratory version of the electron microscope was built and tested, and a report was given at the December 1947 EMSA meeting. The micrograph in fig. 1 is one of several which were presented at the meeting. This micrograph also appeared on the cover of the January 1949 issue of Journal of Applied Physics. These were exciting times in electron microscopy; it seemed that almost everything that happened was new. Our opportunities to publish were limited to patents because Mr. Farrand envisaged a commercial instrument. Regrettably, a commercial version of our laboratory microscope was not produced.

Atomic Spectroscopy in the FIM

1986 ◽  
Vol 44 ◽  
pp. 758-761
Author(s):  
J. J. Hren ◽  
S. D. Walck
Keyword(s):  
Electron Microscope ◽  
Electric Fields ◽  
Atom Probe ◽  
Atomic Spectroscopy ◽  
Single Atom ◽  
Statistical Sampling ◽  
Commercial Instrument ◽  
Available Technology ◽  
High Electric Fields ◽  
Field Ion Microscope

The field ion microscope (FIM) has had the ability to routinely image the surface atoms of metals since Mueller perfected it in 1956. Since 1967, the TOF Atom Probe has had single atom sensitivity in conjunction with the FIM. “Why then hasn't the FIM enjoyed the success of the electron microscope?” The answer is closely related to the evolution of FIM/Atom Probe techniques and the available technology. This paper will review this evolution from Mueller's early discoveries, to the development of a viable commercial instrument. It will touch upon some important contributions of individuals and groups, but will not attempt to be all inclusive. Variations in instrumentation that define the class of problems for which the FIM/AP is uniquely suited and those for which it is not will be described. The influence of high electric fields inherent to the technique on the specimens studied will also be discussed. The specimen geometry as it relates to preparation, statistical sampling and compatibility with the TEM will be examined.

scholarly journals A Theoretical Study of Carryover in Discrete and Continuous-Flow Systems

1982 ◽  
Vol 19 (4) ◽  
pp. 224-226 ◽  
Author(s):  
K Dixon
Keyword(s):  
Continuous Flow ◽  
Theoretical Study ◽  
Correction Algorithm ◽  
Analytical Results ◽  
Flow Systems ◽  
Commercial Instrument ◽  
Computer Controlled

The Broughton equation for carryover constant k contains an assumption. It is shown that a slightly different equation can be derived in which there are no assumptions. A procedure is described whereby knowledge of the carryover constant k can be used to correct analytical results in computer-controlled instruments. In a commercial instrument, use of the wrong correction algorithm can lead to errors of 10% in the carryover correction.

scholarly journals Design and performance of a three-wavelength LED-based total scatter and backscatter integrating nephelometer

2010 ◽  
Vol 3 (6) ◽  
pp. 4835-4864 ◽  
Author(s):  
T. Müller ◽  
M. Laborde ◽  
G. Kassell ◽  
A. Wiedensohler
Keyword(s):  
Signal To Noise Ratio ◽  
Ambient Air ◽  
Light Sources ◽  
Light Emitting ◽  
Sensitivity Functions ◽  
A Value ◽  
Commercial Instrument ◽  
And Performance ◽  
Comparison Measurements

Abstract. Integrating nephelometers are instruments that directly measure a value close to the light scattering coefficient of airborne particles. Different models of nephelometers have been used for decades for monitoring and research applications. Now, a series of nephelometers (Ecotech models M9003, Aurora 1000 and Aurora 3000) with newly designed light sources based on light emitting diodes are available. This article reports on the design of these integrating nephelometers and a comparison of the Aurora 3000 to another commercial instrument (TSI model 3563) that uses an incandescent lamp. Both instruments are three-wavelength, total and backscatter integrating nephelometers. We present a characterization of the new light source design of the Aurora 3000 and provide parameterizations for its angular sensitivity functions. These parameterizations facilitate to correct for measurement artefacts using Mie-theory. Comparison measurements against the TSI 3563 with laboratory generated white particles and ambient air are shown and discussed. Both instruments agree well within the calibration uncertainties and detection limit for total scattering with differences less than 5%. Differences for backscattering are higher by up to 11%. Highest differences were found for the longest wavelengths, where the signal to noise ratio is lowest. Differences at the blue and green wavelengths are less than 4% and 3%, respectively, for both total and backscattering.

Flow cytometer in the infrared: Inexpensive modifications to a commercial instrument

2005 ◽  
Vol 67A (2) ◽  
pp. 104-111 ◽  
Author(s):  
Carleton C. Stewart ◽  
Mitchell L. Woodring ◽  
Edward Podniesinski ◽  
Brian Gray
Keyword(s):  
Flow Cytometer ◽  
Commercial Instrument

scholarly journals PEMODELAN KURVA IMBAL HASIL OBLIGASI KORPORASI RATING AA DAN A DENGAN NELSON SIEGEL SVENSSON DAN CUBIC SPLINE SMOOTHING

2009 ◽  
Vol 11 (4) ◽  
pp. 293-322
Author(s):  
Denny Permatasari ◽  
Nur Iriawan
Keyword(s):  
Yield Curve ◽  
Stock Exchange ◽  
Corporate Bonds ◽  
Cubic Spline ◽  
Corporate Bond ◽  
Spline Smoothing ◽  
Bond Price ◽  
Market Prices ◽  
Corporate Bond Market ◽  
Commercial Instrument

Bond is one of commercial instrument that influence economic sector in Indonesia. Bond transaction can't be made in the market directly, but it has been traded through securities. On average, there are only few bond transactions with the various market prices. Benchmarking is, therefore, needed to be created to determining bond price through yield curve. Through yield curve, the relation between yield of bond with same credit risk (rating) and different time to maturity can be seen. This research is conducted by employing time to maturity to model the yield of some selected corporate bonds with rating of AA and A. Two methods, Nelson Siegel Svensson (NSS) method couple with Levenberg-Marquardt optimization and Cubic Spline Smoothing (CSS) are employed here. These two methods have been applied to data from Indonesian Stock Exchange (IDX) ranging September to November 2008. The results show that CSS give smallest RMSE and MAE. In contrast, Nelson Siegel Svensson reports a model which more parsimony, more easily to be explained, and more adaptable to keep upfoward maturity than CSS. This research takes into account that NSS is better to be to model corporate bonds yield curve than CSS. Another importance conclusion that can be gather is that corporate bonds (with rating of AA and A) yield are hang about under IGSYC in certain period. Its means, that corporate bond market in Indonesia is not good for investment comparing to government bond.

scholarly journals Measurement of straylight for glare assessment and driving.

2017 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Thomas JTP Van den Berg
Keyword(s):  
Cataract Surgery ◽  
Safety Issue ◽  
Large Degree ◽  
Limit Values ◽  
The Road ◽  
Quality Of Vision ◽  
Basic Quality ◽  
Commercial Instrument ◽  
Driver Licensing

In this review an overview of straylight as method to assess glare sensitivity for driver licensing will be given. Glare is an important safety issue while driving. It is well known that people stop driving at night because of glare when early cataract develops. It has been found to derive from the physical process of light scattering in the eye, causing a veil of straylight over the road scene. This veil lessens visibility, potentially up till complete blinding. By international agreement, glare is to be quantified by straylight based on the “equivalent luminance” concept. Normal standards have been defined, including age and cataract dependence. Straylight can be measured accurately with the psychophysical 2AFC “compensation comparison” method, including a reliability check. A commercial instrument called C-Quant is marketed.  As straylight is a basic quality of the eye, also other aspects of quality of vision, such as face recognition, contrast sensitivity, etc. depend on it. Straylight is used in ophthalmology as early indication for cataract surgery. It is to a large degree independent from acuity. Practical aspects of straylight measurement and limit values for occupational testing will be discussed. Normal young values are around log(s)=0.9. For demanding professions a limit elevation of 2x (0.3 log, corresponding to 3 standard deviations) is proposed. For normal driving a limit elevation of 4x is proposed, corresponding to log(s)=1.5. Cataract surgery is indicated at log(s)=1.4.

Microcontroller-Based System for Estimate of Calcium in Serum Samples

2010 ◽  
Vol 44 (5) ◽  
pp. 433-439
Author(s):  
Periyaswmy Neelamegam ◽  
Abdul Sheriff Jamaludeen ◽  
Annamalai Ragendran ◽  
Krishanamoorthy Murugrananthan
Keyword(s):  
Calcium Binding ◽  
Limit Of Detection ◽  
Light Emitting Diode ◽  
Red Light ◽  
Control Unit ◽  
Arsenazo Iii ◽  
Serum Samples ◽  
Light Emitting ◽  
Commercial Instrument ◽  
Ph Range

Abstract In this study, a microcontroller-based control unit was designed and constructed for the estimation of serum calcium in blood samples. The proposed optoelectronic instrument used a red light emitting diode (LED) as a light source and photodiode as a sensor. The performance of the system was compared with that of a commercial instrument in measuring calcium ion. The quantitative analysis of calcium in a catalyst using arsenazo III as colorimetric reagent was used to test the device. The calibration curve for calcium binding with arsenazo III was drawn to check the range of linearity, which was between 0.1 to 4.5 mM L−1. The limit of detection (LOD) is 0.05 mM L−1. Absorbance changes over the pH range of 2–12 were determined to optimize the assay, with maximum absorption at pH 9.0. Interferences in absorbance from monovalent (K+ and Na+) and divalent (Mg2+) cations were also studied. The results show that the system works successfully.

Sign in / Sign up

Export Citation Format

Share Document