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1

Neighborhood History as a Factor Shaping Syringe Distribution Networks Among Drug Users at a U.S. Syringe Exchange1  

PubMed Central

Throughout the US, high-visibility drug markets are concentrated in neighborhoods with few economic opportunities, while drug buyers/users are widely dispersed. A study of Pittsburgh Syringe Exchange participants provides data on travel between and network linkages across neighborhoods with different levels of drug activity. There are distinct racial patterns to syringe distribution activity within networks and across neighborhoods. Pittsburgh’s history suggests these patterns emerge from historical patterns of social and economic development. Study data demonstrate the ability of IDUs to form long term social ties across racial and geographic boundaries and use them to reduce the risk of HIV transmission. PMID:19578475

Braine, Naomi; Acker, Caroline; Goldblatt, Cullen; Yi, Huso; Friedman, Samuel; DesJarlais, Don C.

2008-01-01

2

Adsorption of 99mTc-Sestamibi onto Plastic Syringes: Evaluation of Factors Affecting the Degree of Adsorption and Their Impact on Clinical Studies*  

PubMed Central

The purpose of this study was to document the extent of adhesion of 99mTc-sestamibi to syringes in patient procedures, determine factors that influence the degree of adhesion, and evaluate alternatives to our current practice that would either result in a more reproducible degree of adhesion or, ideally, eliminate adhesion. Methods The extent of adhesion was documented in 216 patient procedures and evaluated in detail in an additional 73 patient procedures. We evaluated the nature of the adhesion and its possible causes, including the location of adhesion in injection sets, the effect of syringe type, and the effect of prerinsing of syringes with various solutions of nonradiolabeled sestamibi and 99mTc-sestamibi. The extent of adhesion was reevaluated in 50 procedures performed using the syringe type that demonstrated the lowest adhesion rate. Results The degree of adhesion of 99mTc-sestamibi to the injection set was found to be 20.1% ± 8.0%, with a range (10th–90th percentiles) of 9%–31%. The primary cause of adhesion appeared to be the lubricant used inside the syringe barrel. Evaluation of 6 different syringe types identified a brand with a lower adhesion rate. Reevaluation in patient procedures using this brand showed a 5.2% ± 2.5% degree of adhesion, with a range (10th–90th percentiles) of 2.5%–7.7%. Conclusion Selection of the appropriate type of syringe can significantly reduce the magnitude and variability of residual 99mTc-sestamibi activity. With more reproducible residual activities, we have been able to achieve an approximately 20% reduction in the dispensed dose of 99mTc-sestamibi used in clinical procedures and a more consistent injected dose with less interpatient variation. The frequent changes in syringe design by manufacturers require that a quality control program for monitoring of residual activity be incorporated into clinical practice. This program has allowed us to maintain image quality and achieve more consistent injected patient doses in clinical procedures that use 99mTc-sestamibi. PMID:24212450

Swanson, Tiffinee N.; Troung, Duong T.; Paulsen, Andrew; Hruska, Carrie B.; O’Connor, Michael K.

2014-01-01

3

SWIR calibration of Spectralon reflectance factor  

NASA Astrophysics Data System (ADS)

Satellite instruments operating in the reflective solar wavelength region require accurate and precise determination of the Bidirectional Reflectance Factor (BRF) of laboratory-based diffusers used in their pre-flight and on-orbit radiometric calibrations. BRF measurements are required throughout the reflected-solar spectrum from the ultraviolet through the shortwave infrared. Spectralon diffusers are commonly used as a reflectance standard for bidirectional and hemispherical geometries. The Diffuser Calibration Laboratory (DCaL) at NASA's Goddard Space Flight Center is a secondary calibration facility with reflectance measurements traceable to those made by the Spectral Tri-function Automated Reference Reflectometer (STARR) facility at the National Institute of Standards and Technology (NIST). For more than two decades, the DCaL has provided numerous NASA projects with BRF data in the ultraviolet (UV), visible (VIS) and the Near InfraRed (NIR) spectral regions. Presented in this paper are measurements of BRF from 1475 nm to 1625 nm obtained using an indium gallium arsenide detector and a tunable coherent light source. The sample was a 50.8 mm (2 in) diameter, 99% white Spectralon target. The BRF results are discussed and compared to empirically generated data from a model based on NIST certified values of 6°directional-hemispherical spectral reflectance factors from 900 nm to 2500 nm. Employing a new NIST capability for measuring bidirectional reflectance using a cooled, extended InGaAs detector, BRF calibration measurements of the same sample were also made using NIST's STARR from 1475 nm to 1625 nm at an incident angle of 0° and at viewing angle of 45°. The total combined uncertainty for BRF in this ShortWave Infrared (SWIR) range is less than 1%. This measurement capability will evolve into a BRF calibration service in SWIR region in support of NASA remote sensing missions.

Georgiev, Georgi T.; Butler, James J.; Cooksey, Catherine; Ding, Leibo; Thome, Kurtis J.

2011-11-01

4

Patient Safety Threat - Syringe Reuse  

MedlinePLUS

... About CDC.gov . Injection Safety Share Compartir A Patient Safety Threat – Syringe Reuse Important Information! Please read this ... References Information for Patients FAQs for Patients A Patient Safety Threat - Syringe Reuse Preventing Unsafe Injection Practices Safe ...

5

Gas ampoule-syringe  

DOEpatents

A gas ampoule for the shipment and delivery of radioactive gases. The gas ampoule having a glass tube with serum bottle stopper on one and a plunger tip in the opposite end all fitting in a larger plastic tube threaded on each end with absorbent between the tubes, is seated onto the internal needle assembly via a bushing associated with the plunger and locked into the syringe barrel via barrel-bushing locking caps. The design practically eliminates the possibility of personnel contamination due to an inadvertent exposure of such personnel to the contained radioactive gas.

Gay, D.D.

1985-02-02

6

Aquagenic syringeal acrokeratoderma.  

PubMed

Aquagenic syringeal acrokeratoderma is a rare, transient, and usually bilaterally symmetric, palmoplantar keratoderma. Patients complain of tingling and pain in the hands starting a few minutes after exposure to water and lasting for 20-30 minutes after removal. Clinically, there is marked wrinkling with edematous white papules on the palms or, less often, the soles. We present the case of a 21-year-old woman who used spironolactone for polycystic ovary syndrome and had similar clinical features 2 weeks later, after withdrawing the drug. PMID:25484422

Uyar, Belkiz

2014-11-01

7

Gas ampoule-syringe  

DOEpatents

A gas ampoule for the shipment and delivery of radioactive gases. The gas ampoule having a glass tube with serum bottle stopper on one end and a plunger tip in the opposite end all fitting in a larger plastic tube threaded on each end with absorbent between the tubes, is seated onto the internal needle assembly via a bushing associated with the plunger and locked into the syringe barrel via barrel-bushing locking caps. The design practically eliminates the possibility of personnel contamination due to an inadvertent exposure of such personnel to the contained radioactive gas.

Gay, Don D. (Aiken, SC)

1986-01-01

8

Automated application of calibration factors on telemetered data  

SciTech Connect

A long standing problem in telemetry post processing is the application of correct calibration factors to telemetered data generated on a system which has had a history of hardware changes. These calibration problems become most exacerbated when old test data is being examined and there is uncertainty as to hardware configuration at the time of the test. In this paper a mechanism for introducing a high degree of reliability in the application of calibration factors is described in an implementation done for Brilliant Pebbles Flight Experiment Three (FE-3).

Kalibjian, J.R.; Voss, T.J.; Yio, J.J.

1993-04-26

9

Experiments with Disposable Hypodermic Syringes.  

ERIC Educational Resources Information Center

Lists five experiments or demonstrations involving hypodermic syringes. The titles of experiments are Boyle's Law, Charles' Law, Atmospheric Pressure, Expansion of Gases, and Boiling at Reduced Pressure. Provides a list of materials, the typical data, and graphs where appropriate. (YP)

Clayton, G. T.; And Others

1988-01-01

10

Illinois PER Interactive Examples: Syringe  

NSDL National Science Digital Library

This is an interactive homework problem for introductory physics relating to the kinetic theory of gases. It features a syringe that has just been used and now lies empty. The syringe must be heated to high temperatures to sterilize it. When the syringe is at its maximum temperature, the number of oxygen molecules is 6.5 x 1019. Using the information given in the problem, the user is asked to find the rms speed of the oxygen molecules. This problem is accompanied by a Socratic-dialog "help" sequence designed to encourage critical thinking as users do a guided conceptual analysis before attempting the mathematics. It is part of a larger collection of interactive problems developed by the Illinois Physics Education Research Group.

Gladding, Gary

2009-01-16

11

Development of syringe pump assisted headspace sampler.  

PubMed

This report describes a new platform for headspace sampling technique, i.e. a syringe pump assisted headspace sampler (SPHS). The stand type pump's syringe itself was used as a sealed sample vial and a needle trap device (NTD) was adopted as a miniaturized sorbent tube. The NTD was directly used to inject trapped VOCs into a gas chromatograph. The proposed sampler was designed to take a whole headspace volume instead of a portion of it so as to enhance easily the extraction efficiency. The performance of the SPHS-NTD system was evaluated and compared with the solid-phase microextraction (SPME) with a static headspace (HS) sampling technique. Calibration curves were obtained for aqueous TEX (toluene, ethylbenzene, and o-xylene) solutions in the concentration range of ?0.1-45 ng/mL. The calculated limit of detections (LOD, S/N=3) for TEX were 0.13 ng/mL or less. This SPHS-NTD was successfully applied to analyze aqueous TEX in river water samples and showed highly good recovery ranged from 97.2% to 105.8% for all tested VOCs. PMID:25155066

Go, Un Jeong; Eom, In-Yong

2014-09-26

12

jasonSWIR Calibration of Spectralon Reflectance Factor  

NASA Technical Reports Server (NTRS)

Satellite instruments operating in the reflective solar wavelength region require accurate and precise determination of the Bidirectional Reflectance Factor (BRF) of laboratory-based diffusers used in their pre-flight and on-orbit radiometric calibrations. BRF measurements are required throughout the reflected-solar spectrum from the ultraviolet through the shortwave infrared. Spectralon diffusers are commonly used as a reflectance standard for bidirectional and hemispherical geometries. The Diffuser Calibration Laboratory (DCaL) at NASA's Goddard Space Flight Center is a secondary calibration facility with reflectance measurements traceable to those made by the Spectral Tri-function Automated Reference Reflectometer (STARR) facility at the National Institute of Standards and Technology (NIST). For more than two decades, the DCaL has provided numerous NASA projects with BRF data in the ultraviolet (UV), visible (VIS) and the Near infraRed (NIR) spectral regions. Presented in this paper are measurements of BRF from 1475nm to 1625nm obtained using an indium gallium arsenide detector and a tunable coherent light source. The sample was a 2 inch diameter, 99% white Spectralon target. The BRF results are discussed and compared to empirically generated data from a model based on NIST certified values of 6deg directional/hemispherical spectral reflectance factors from 900nm to 2500nm. Employing a new NIST capability for measuring bidirectional reflectance using a cooled, extended InGaAs detector, BRF calibration measurements of the same sample were also made using NIST's STARR from 1475nm to 1625nm at an incident angle of 0deg and at viewing angles of 40deg, 45deg, and 50deg. The total combined uncertainty for BRF in this ShortWave Infrared (SWIR) range is less than 1%. This measurement capability will evolve into a BRF calibration service in SWIR region in support of NASA remote sensing missions. Keywords: BRF, BRDF, Calibration, Spectralon, Reflectance, Remote Sensing.

Georgiev, Georgi T.; Butler, James J.; Cooksey, Cahterine; Ding, Leibo; Thome, Kurtis J.

2011-01-01

13

A syringe that self-destructs.  

PubMed

The reuse of unsterilized syringes is spreading AIDS, hepatitis B and the African Ebola-Marburg virus. In the US 25% of the AIDS cases are related to intravenous drug abuse. In developing countries syringe reuse is related to poor health care delivery systems. In these countries syringes are used over 5 times before sterilization; in some countries the syringes are distributed by people who sell injections of vitamins and antibiotics. In 1986 Halsey challenged the medical community to design a syringe that would not transmit these diseases, and shortly thereafter a separate challenge was issued by the World Health Organization. The requirements of this syringe are its self destruction after use, little requiring retraining of medical personal, and no more than 1 cent to the cost, and be simple to make. These challenges brought 70 various syringe entries and all but 3 were eliminated. The Hopkins syringe is similar to a regular syringe except it has a polymer insert that seals up after one use. When water flows around the polymer insert it swells and closes off the passageway preventing any liquid from flowing in or out of the syringe. Another syringe seals up in 2.5 minutes which allows the health worker time to draw and inject a patient before the syringe destructs. By using hydrogels that are already approved for use in contact lenses and food substances, the safety has been tested. Companies looking at production costs estimate that the polymer insert will add only 1/4 of a cent to the cost of a syringe. PMID:12282933

Newman, A

1989-02-01

14

Syringe drivers: incorrect selection of syringe type from the syringe menu may result in significant errors in drug delivery.  

PubMed

There have been many reported adverse incidents due to syringe driver use, most of which have been attributable to human error. In this paper we present a previously unreported, but potentially widespread practice which may result in significant over or under-delivery of medication. Even with the naked eye it is evident that syringes of equal volume have different dimensions and to quantify this we sectioned a range of syringes and measured the inner and outer dimensions. Extensive menus for syringe brand and volumes are available on syringe drivers, offering users greater flexibility. However, this feature also allows users to select an incorrect syringe brand with potential consequences for drug delivery. We measured outputs under all selectable permutations, to determine the degree of fluid delivery variation and discovered inaccuracies in volumes ranging from 10% under-delivery to 24% over-delivery. There is a wide variation in syringe metrics and complex syringe menus may increase errors, resulting in significant under or over-delivery of medication. Availability of more than one brand of syringe in a clinical area increases the risk of adverse drug delivery events. Systems need to be implemented to minimise the risk of adverse events. PMID:24967761

Tooke, L J; Howell, L

2014-07-01

15

Who purchases nonprescription syringes? Characterizing customers of the Expanded Syringe Access Program (ESAP).  

PubMed

This study represents the first attempt in the USA to survey pharmacy nonprescription syringe customers at their point of purchase. We surveyed 62 individuals purchasing nonprescription syringes in seven pharmacies located in NYC and Albany, NY, USA. Three quarters of respondents purchased for illicit use, and 36% purchased for medical use, with differences found by race and gender. Half got their syringes from pharmacies "most of the time." Half had ever been refused a syringe purchase in a NYS pharmacy, with men, Blacks, and Hispanics reporting higher levels of refusals than women or whites. Two thirds reported syringe reuse but very few reported sharing. While approximately one quarter safely obtained and disposed of syringes "most of the time," two thirds used both safe and unsafe methods. Pharmacy-based syringe access programs are essential in areas not served by syringe exchanges. PMID:19434499

Battles, Haven B; Rowe, Kirsten A; Ortega-Peluso, Christina; Klein, Susan J; Tesoriero, James M

2009-11-01

16

Don't Throw Away Syringes!  

ERIC Educational Resources Information Center

Describes a variety of laboratory experiments including carbon dioxide reduction, animal respiration, atmospheric pressure determination, and others, that can be performed using discarded syringes. (GS)

John, E.

1975-01-01

17

Use and misuse of syringes in anaesthesia  

Microsoft Academic Search

Using data from the literature, a fairly accurate estimate of the risk of transmission of bloodborne infections associated with the reuse of syringes in anaesthesia can be made. In anaesthesia, most of the time, syringes are used to administer medications into injection ports or three-way stopcocks of iv tubing that might be contaminated with the patient's blood. That situation differs

Martin R. Lessard; Claude A. Trépanier

1997-01-01

18

21 CFR 870.1670 - Syringe actuator for an injector.  

...2014-04-01 2014-04-01 false Syringe actuator for an injector. 870.1670 Section...Diagnostic Devices § 870.1670 Syringe actuator for an injector. (a) Identification. A syringe actuator for an injector is an...

2014-04-01

19

21 CFR 870.1670 - Syringe actuator for an injector.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Syringe actuator for an injector. 870.1670 Section...Diagnostic Devices § 870.1670 Syringe actuator for an injector. (a) Identification. A syringe actuator for an injector is an...

2013-04-01

20

Techniques for Calibration of the Scale Factor and Image Center for High Accuracy 3-D Machine Vision Metrology  

Microsoft Academic Search

Techniques are described for calibrating certain intrinsic camera parameters for machine vision. The parameters to be calibrated are the horizontal scale factor, and the image center. The scale factor calibration uses a one-dimensional fast Fourier transform and is accurate and efficient. It also permits the use of only one coplanar set of calibration points for general camera calibration. Three groups

REIMAR K. LENZ; Roger Y. Tsai

1988-01-01

21

Syringe and Needle Size, Syringe Type, Vacuum Generation, and Needle Control in Aspiration Procedures  

SciTech Connect

Purpose: Syringes are used for diagnostic fluid aspiration and fine-needle aspiration biopsy in interventional procedures. We determined the benefits, disadvantages, and patient safety implications of syringe and needle size on vacuum generation, hand force requirements, biopsy/fluid yield, and needle control during aspiration procedures. Materials and Methods: Different sizes (1, 3, 5, 10, and 20 ml) of the conventional syringe and aspirating mechanical safety syringe, the reciprocating procedure device, were studied. Twenty operators performed aspiration procedures with the following outcomes measured: (1) vacuum (torr), (2) time to vacuum (s), (3) hand force to generate vacuum (torr-cm{sup 2}), (4) operator difficulty during aspiration, (5) biopsy yield (mg), and (6) operator control of the needle tip position (mm). Results: Vacuum increased tissue biopsy yield at all needle diameters (P < 0.002). Twenty-milliliter syringes achieved a vacuum of -517 torr but required far more strength to aspirate, and resulted in significant loss of needle control (P < 0.002). The 10-ml syringe generated only 15% less vacuum (-435 torr) than the 20-ml device and required much less hand strength. The mechanical syringe generated identical vacuum at all syringe sizes with less hand force (P < 0.002) and provided significantly enhanced needle control (P < 0.002). Conclusions: To optimize patient safety and control of the needle, and to maximize fluid and tissue yield during aspiration procedures, a two-handed technique and the smallest syringe size adequate for the procedure should be used. If precise needle control or one-handed operation is required, a mechanical safety syringe should be considered.

Haseler, Luke J., E-mail: l.haseler@griffith.edu.au [Griffith University, Heart Foundation Research Centre, Griffith Health Institute (Australia); Sibbitt, Randy R., E-mail: THESIBB2@aol.com [Montana Interventional and Dgnstc Radiation (United States); Sibbitt, Wilmer L., E-mail: wsibbitt@salud.unm.edu [University of New Mexico Health Sciences Center, Department of Internal Medicine (United States); Michael, Adrian A., E-mail: adrian_a_michael@yahoo.com [Texas Tech University Health Sciences Center, Department of Internal Medicine (United States); Gasparovic, Charles M., E-mail: chuck@unm.edu [University of New Mexico Health Sciences Center, MIND Institute at the University of New Mexico (United States); Bankhurst, Arthur D., E-mail: abankhurst@salud.unm.edu [University of New Mexico Health Sciences Center, Department of Internal Medicine (United States)

2011-06-15

22

Self-calibration of divided circles on the basis of a prime factor algorithm  

NASA Astrophysics Data System (ADS)

A new method for the self-calibration of divided circles is presented which is based on a known prime factor algorithm for the discrete Fourier transform (DFT). The method, called prime factor division (PFD) calibration, is of interest in angle metrology specially for self-calibrating angle encoders, and generally for a significant shortening of the cross-calibration between two divided circles. It requires that the circular division number N can be expressed as a product N = R × S, whereby the factors R and S are relatively prime integer numbers. For the self-calibration of a divided circle, N difference measurements between R angle positions in a regular distribution and one reference angle position determined by S are evaluated by a two-dimensional DFT, yielding the N absolute division errors. The factor R is preferably chosen small, down to a minimum of R = 2, whereas the factor S may be as large as appropriate for the division number N of interest. In the case of a cross-calibration between two divided circles, the PFD method reduces the number of measurements necessary from N2 to (R + 1) × N. Experimental results are demonstrated for the calibrations of an optical polygon with 24 faces (prime factor product 3 × 8) and a gearwheel with 44 teeth (prime factor product 4 × 11).

Probst, R.

2008-01-01

23

Determination of conditions for the production scale sterilization of prefilled syringes.  

PubMed

External and internal differences in pressure of prefilled syringes can cause plunger movement during sterilization, which might cause drug product contamination. Consequently the pressure inside the autoclave during sterilization should be controlled carefully to prevent contamination of the drug product by microorganism and particulates. A previously determined theoretical relationship of temperature to pressure in sealed bottles was modified for prefilled syringes to take plunger movement into account. This modification yielded a correction factor that includes a coefficient of linear thermal expansion for the syringe, thermal expansion of the plunger, and friction between the plunger and the syringe wall. To confirm the accuracy of this modified relationship, 100 mL polypropylene prefilled syringes with butyl rubber plungers, some of which carried pressure and temperature sensors, were used to test various sterilization conditions at the experimental scale. The results showed that the major problem in establishing the pressure conditions for production scale sterilization is temperature distribution throughout the load. However, an over pressure sterilization cycle at 121 degrees C and 0.34 MPa showed the best results. Microbial challenge and light-obscuration particle count tests were performed on the syringes from the worst-case location predicted from modified relationship; the results show that these conditions preserved the sterility of the drug product and protected it from particulate contamination. PMID:14677630

Nishimoto, Norihiro; Maekawa, Tatsuyuki

2003-01-01

24

Prefilled syringes: An innovation in parenteral packaging  

PubMed Central

Parenteral administration of pharmaceutical products is one of the most popular methods used to produce quick onset of action and also 100% bioavailability. Main problem occurs with the parenteral drug delivery is lack of convenience, affordability, accuracy, sterility, safety etc. Such drawbacks with this delivery system makes it less preferable. Hence, all the disadvantages of these systems can be easily overcome by use of prefilled syringes. The objective of this review article is to provide information regarding prefilled syringes; it's method of preparation, direction to use, advantages, its future scope, and development. PMID:23071944

Makwana, Sagar; Basu, Biswajit; Makasana, Yogita; Dharamsi, Abhay

2011-01-01

25

The Disposable Syringe: More Experiments and Uses  

ERIC Educational Resources Information Center

Describes a variety of experiments that can be performed using the disposable syringe. Among others, these include the removal of oxygen during rusting, convection in a liquid and in air, gas collection in an electrolysis cell, small scale production of a fog, and hydrogen/oxygen extraction from a voltameter. (JR)

Farmer, Andrew

1973-01-01

26

Adiabatic Compression in a Fire Syringe.  

ERIC Educational Resources Information Center

Suggests using better materials in fire syringes to obtain more effective results during demonstrations which show the elevation in temperature upon a very rapid (adiabatic) compression of air. Also describes an experiment (using ignition temperatures) which introduces students to the use of thermocouples for high temperature measurements. (DH)

Hayn, Carl H.; Baird, Scott C.

1985-01-01

27

Open-Source Syringe Pump Library  

PubMed Central

This article explores a new open-source method for developing and manufacturing high-quality scientific equipment suitable for use in virtually any laboratory. A syringe pump was designed using freely available open-source computer aided design (CAD) software and manufactured using an open-source RepRap 3-D printer and readily available parts. The design, bill of materials and assembly instructions are globally available to anyone wishing to use them. Details are provided covering the use of the CAD software and the RepRap 3-D printer. The use of an open-source Rasberry Pi computer as a wireless control device is also illustrated. Performance of the syringe pump was assessed and the methods used for assessment are detailed. The cost of the entire system, including the controller and web-based control interface, is on the order of 5% or less than one would expect to pay for a commercial syringe pump having similar performance. The design should suit the needs of a given research activity requiring a syringe pump including carefully controlled dosing of reagents, pharmaceuticals, and delivery of viscous 3-D printer media among other applications. PMID:25229451

Wijnen, Bas; Hunt, Emily J.; Anzalone, Gerald C.; Pearce, Joshua M.

2014-01-01

28

Accelerometer calibration with nonlinear scale factor based on multi-position observation  

NASA Astrophysics Data System (ADS)

The calibration of an inertial measurement unit (IMU) is a key technique to improve the accuracy of an inertial navigation system. Adding more parameters into the model and reducing the estimation errors is essential for improving the calibration methods. Given its advantage of not requiring high-precision equipment, the multi-position calibration method has been widely discussed and has shown great potential in recent years. In this paper, the multi-position calibration method is improved by introducing the accelerometer nonlinear scale factor. The observation equations for the improved multi-position calibration method are established based on a nonlinear accelerometer model. The particle swarm optimization algorithm is adopted to solve the complicated nonlinear equations. In addition, Allan variance is used to determine the optimal data collection time. The accuracy and the robustness of the proposed calibration method are verified by the simulation test. The laboratory and field experiment results for a navigation-grade IMU prove that the proposed method can successfully identify the accelerometer nonlinear scale factor and improve the multi-position calibration accuracy. The comparison of several other calibration methods highlights the superior performance of the proposed method without precise orientation control.

Cai, Qingzhong; Song, Ningfang; Yang, Gongliu; Liu, Yiliang

2013-10-01

29

Deriving a Latitude-Optimized Pyranometer Calibration Factor  

NASA Astrophysics Data System (ADS)

Work in recent years has produced improvements in determining the solar resource by better characterizing the responsivity of pyranometers. The calibration process can characterize a common responsivity dependency on the solar zenith angle, which can then be used to compensate for sensor variations during instrument deployment. However, daily compensation throughout the range of zenith angles might not be necessary for applications requiring only annual irradiance. This paper describes a method of identifying a measurement bias due to latitude of deployment and optimizing an instrument's clear-sky responsivity for annual solar radiation measurements based on the relationship between solar zenith angles and the latitude.

Wilcox, S. M.; Myers, D. R.; Reda, I. M. A.

2002-03-01

30

Factors affecting the repeatability of gamma camera calibration for quantitative imaging applications using a sealed source.  

PubMed

Several applications in nuclear medicine require absolute activity quantification of single photon emission computed tomography images. Obtaining a repeatable calibration factor that converts voxel values to activity units is essential for these applications. Because source preparation and measurement of the source activity using a radionuclide activity meter are potential sources of variability, this work investigated instrumentation and acquisition factors affecting repeatability using planar acquisition of sealed sources. The calibration factor was calculated for different acquisition and geometry conditions to evaluate the effect of the source size, lateral position of the source in the camera field-of-view (FOV), source-to-camera distance (SCD), and variability over time using sealed Ba-133 sources. A small region of interest (ROI) based on the source dimensions and collimator resolution was investigated to decrease the background effect. A statistical analysis with a mixed-effects model was used to evaluate quantitatively the effect of each variable on the global calibration factor variability. A variation of 1?cm in the measurement of the SCD from the assumed distance of 17?cm led to a variation of 1-2% in the calibration factor measurement using a small disc source (0.4?cm diameter) and less than 1% with a larger rod source (2.9?cm diameter). The lateral position of the source in the FOV and the variability over time had small impacts on calibration factor variability. The residual error component was well estimated by Poisson noise. Repeatability of better than 1% in a calibration factor measurement using a planar acquisition of a sealed source can be reasonably achieved. The best reproducibility was obtained with the largest source with a count rate much higher than the average background in the ROI, and when the SCD was positioned within 5?mm of the desired position. In this case, calibration source variability was limited by the quantum noise. PMID:25592130

Anizan, N; Wang, H; Zhou, X C; Wahl, R L; Frey, E C

2015-02-01

31

Factors affecting the repeatability of gamma camera calibration for quantitative imaging applications using a sealed source  

NASA Astrophysics Data System (ADS)

Several applications in nuclear medicine require absolute activity quantification of single photon emission computed tomography images. Obtaining a repeatable calibration factor that converts voxel values to activity units is essential for these applications. Because source preparation and measurement of the source activity using a radionuclide activity meter are potential sources of variability, this work investigated instrumentation and acquisition factors affecting repeatability using planar acquisition of sealed sources. The calibration factor was calculated for different acquisition and geometry conditions to evaluate the effect of the source size, lateral position of the source in the camera field-of-view (FOV), source-to-camera distance (SCD), and variability over time using sealed Ba-133 sources. A small region of interest (ROI) based on the source dimensions and collimator resolution was investigated to decrease the background effect. A statistical analysis with a mixed-effects model was used to evaluate quantitatively the effect of each variable on the global calibration factor variability. A variation of 1?cm in the measurement of the SCD from the assumed distance of 17?cm led to a variation of 1–2% in the calibration factor measurement using a small disc source (0.4?cm diameter) and less than 1% with a larger rod source (2.9?cm diameter). The lateral position of the source in the FOV and the variability over time had small impacts on calibration factor variability. The residual error component was well estimated by Poisson noise. Repeatability of better than 1% in a calibration factor measurement using a planar acquisition of a sealed source can be reasonably achieved. The best reproducibility was obtained with the largest source with a count rate much higher than the average background in the ROI, and when the SCD was positioned within 5?mm of the desired position. In this case, calibration source variability was limited by the quantum noise.

Anizan, N.; Wang, H.; Zhou, X. C.; Wahl, R. L.; Frey, E. C.

2015-02-01

32

Development of Syringe/Bottle Hybrids for Sampling Slurries  

SciTech Connect

A convenient and effective sample bottle system based on simple modifications of disposable plastic syringes and bottles has been devised and tested for slurry samples. Syringe/ bottle hybrids (hereafter referred to as syringe bottles) have the convenience of regular flat-bottom bottles with screw cap closures. In addition, the syringe imparts a sliding and adjustable bottom to the bottle that forces the entire contents from the bottle. The system was designed especially to collect samples for high temperature work-ups of DWPF slurry samples. The syringe bottles together with fixed-bottom sample vial inserts would provide the DWPF with convenient and reliable methods for dealing with slurry samples.

Coleman, C.J. [Westinghouse Savannah River Company, AIKEN, SC (United States)

1998-01-08

33

Direct calibration in megavoltage photon beams using Monte Carlo conversion factor: validation and clinical implications.  

PubMed

The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) has established a method for ionisation chamber calibrations using megavoltage photon reference beams. The new method will reduce the calibration uncertainty compared to a (60)Co calibration combined with the TRS-398 energy correction factor. The calibration method employs a graphite calorimeter and a Monte Carlo (MC) conversion factor to convert the absolute dose to graphite to absorbed dose to water. EGSnrc is used to model the linac head and doses in the calorimeter and water phantom. The linac model is validated by comparing measured and modelled PDDs and profiles. The relative standard uncertainties in the calibration factors at the ARPANSA beam qualities were found to be 0.47% at 6?MV, 0.51% at 10?MV and 0.46% for the 18?MV beam. A comparison with the Bureau International des Poids et Mesures (BIPM) as part of the key comparison BIPM.RI(I)-K6 gave results of 0.9965(55), 0.9924(60) and 0.9932(59) for the 6, 10 and 18?MV beams, respectively, with all beams within 1? of the participant average. The measured kQ values for an NE2571 Farmer chamber were found to be lower than those in TRS-398 but are consistent with published measured and modelled values. Users can expect a shift in the calibration factor at user energies of an NE2571 chamber between 0.4-1.1% across the range of calibration energies compared to the current calibration method. PMID:25565406

Wright, Tracy; Lye, Jessica E; Ramanathan, Ganesan; Harty, Peter D; Oliver, Chris; Webb, David V; Butler, Duncan J

2015-01-21

34

Direct calibration in megavoltage photon beams using Monte Carlo conversion factor: validation and clinical implications  

NASA Astrophysics Data System (ADS)

The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) has established a method for ionisation chamber calibrations using megavoltage photon reference beams. The new method will reduce the calibration uncertainty compared to a 60Co calibration combined with the TRS-398 energy correction factor. The calibration method employs a graphite calorimeter and a Monte Carlo (MC) conversion factor to convert the absolute dose to graphite to absorbed dose to water. EGSnrc is used to model the linac head and doses in the calorimeter and water phantom. The linac model is validated by comparing measured and modelled PDDs and profiles. The relative standard uncertainties in the calibration factors at the ARPANSA beam qualities were found to be 0.47% at 6?MV, 0.51% at 10?MV and 0.46% for the 18?MV beam. A comparison with the Bureau International des Poids et Mesures (BIPM) as part of the key comparison BIPM.RI(I)-K6 gave results of 0.9965(55), 0.9924(60) and 0.9932(59) for the 6, 10 and 18?MV beams, respectively, with all beams within 1? of the participant average. The measured kQ values for an NE2571 Farmer chamber were found to be lower than those in TRS-398 but are consistent with published measured and modelled values. Users can expect a shift in the calibration factor at user energies of an NE2571 chamber between 0.4–1.1% across the range of calibration energies compared to the current calibration method.

Wright, Tracy; Lye, Jessica E.; Ramanathan, Ganesan; Harty, Peter D.; Oliver, Chris; Webb, David V.; Butler, Duncan J.

2015-01-01

35

HIV Risk Behavior among Amphetamine Injectors at U.S. Syringe Exchange Programs  

ERIC Educational Resources Information Center

The goal of this study was to compare HIV risk behaviors of amphetamine and non-amphetamine injectors at syringe exchange programs (SEP) in the United States and to identify factors associated with injection risk. This analysis is based on data from a random cross-section of participants at 13 SEPs in different parts of the country. All interviews…

Braine, Naomi; Des Jarlais, Don C.; Goldblatt, Cullen; Zadoretzky, Cathy; Turner, Charles

2005-01-01

36

Sedimentary Rock From Sand: Syringe Simulation  

NSDL National Science Digital Library

This activity will allow students to simulate the formation of sedimentary rocks by compressing sand, water, and other materials in a syringe. The products are allowed to dry, and students will investigate how the properties of the samples of sedimentary rocks so formed are dependent on the extent of their compaction and cementation. The activity will help to explain that for most sediments to become rocks the grains need to be squeezed together (compacted) and/or glued together (cemented) and that the extent of the compaction and the strength of the cementation affect the properties of sedimentary rocks.

37

21 CFR 870.1650 - Angiographic injector and syringe.  

Code of Federal Regulations, 2013 CFR

...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1650 Angiographic injector and syringe. (a)...

2013-04-01

38

A technical study of TLD beta calibration factor for exposures to depleted uranium  

SciTech Connect

The beta calibration factor for converting light output (on reading a thermoluminescent dosimeter) to shallow dose equivalent has been reexamined through theoretical calculations and experimental measurements. The results support the previously determined value for contact with a depleted uranium slab but indicate that for many actual workplace situations, the contact value may be overly conservative.

Ashley, J.C.; Turner, J.E.; McMahan, K.L. [Oak Ridge National Lab., TN (United States); Souleyrette, M.L.; Bogard, R.S. [Oak Ridge Y-12 Plant, TN (United States)

1995-06-01

39

Liquid Drugs and High Dead Space Syringes May Keep HIV and HCV Prevalence High – A Comparison of Hungary and Lithuania  

PubMed Central

Despitevery similar political, drug policy and HIV prevention backgrounds, HIV and HCV prevalence is considerably different in Hungary (low HIV and moderate HCV prevalence) and Lithuania (high HCV and moderate HIV prevalence). Wecompared the drug use profile of Hungarian (n = 215) and Lithuanian (n = 300) injecting drug users (IDUs). Overall, compared with IDUs in Hungary, IDUs in Lithuania often injected opiates purchased in liquid form (‘shirka’), used and shared 2-piece syringes (vs. 1-piece syringes) disproportionately more often, were less likely to acquire their syringes from legal sources and had significantly more experience with injected and less experience with non-injected drugs. It may not be liquid drugs per se that contribute to a higher prevalence of HCV and/or HIV, but it is probably factors associated with the injecting of liquid drugs, such as the wide-spread use and sharing of potentially contaminated 2-piece syringes acquired often from non-legal sources, and syringe-mediated drug sharing with 2-piece syringes. Scaling up substitution therapy, especially heroin replacement, combined with reducing the supply of liquid drugs may decrease the prevalence of high-risk injecting behaviours related to the injecting of liquid drugs and drug injecting-related infections among IDUs in Lithuania. PMID:20798543

Gyarmathy, V. Anna; Neaigus, Alan; Li, Nan; Ujhelyi, Eszter; Caplinskiene, Irma; Caplinskas, Saulius; Latkin, Carl A.

2010-01-01

40

Real-time particle monitor calibration factors and PM2.5 emission factors for multiple indoor sources.  

PubMed

Indoor sources can greatly contribute to personal exposure to particulate matter less than 2.5 ?m in diameter (PM2.5). To accurately assess PM2.5 mass emission factors and concentrations, real-time particle monitors must be calibrated for individual sources. Sixty-six experiments were conducted with a common, real-time laser photometer (TSI SidePak™ Model AM510 Personal Aerosol Monitor) and a filter-based PM2.5 gravimetric sampler to quantify the monitor calibration factors (CFs), and to estimate emission factors for common indoor sources including cigarettes, incense, cooking, candles, and fireplaces. Calibration factors for these indoor sources were all significantly less than the factory-set CF of 1.0, ranging from 0.32 (cigarette smoke) to 0.70 (hamburger). Stick incense had a CF of 0.35, while fireplace emissions ranged from 0.44-0.47. Cooking source CFs ranged from 0.41 (fried bacon) to 0.65-0.70 (fried pork chops, salmon, and hamburger). The CFs of combined sources (e.g., cooking and cigarette emissions mixed) were linear combinations of the CFs of the component sources. The highest PM2.5 emission factors per time period were from burned foods and fireplaces (15-16 mg min(-1)), and the lowest from cooking foods such as pizza and ground beef (0.1-0.2 mg min(-1)). PMID:23784066

Dacunto, Philip J; Cheng, Kai-Chung; Acevedo-Bolton, Viviana; Jiang, Ruo-Ting; Klepeis, Neil E; Repace, James L; Ott, Wayne R; Hildemann, Lynn M

2013-08-01

41

Techniques for calibration of the scale factor and image center for high accuracy 3D machine vision metrology  

Microsoft Academic Search

This paper describes techniques for calibrating certain intrinsic camera parameters for machine vision. The parameters to be calibrated are the horizontal scale factor, i.e. the factor that relates the sensor element spacing of a discrete array camera to the picture element spacing after sampling by the image acquisition circuitry, and the image center, i.e. the intersection of the optical axis

Reimar K. Lenz; Roger Y. Tsai

1987-01-01

42

An accurate calibration method for accelerometer nonlinear scale factor on a low-cost three-axis turntable  

NASA Astrophysics Data System (ADS)

Strapdown inertial navigation system (SINS) requirements are very demanding on gyroscopes and accelerometers as well as on calibration. To improve the accuracy of SINS, high-accuracy calibration is needed. Adding the accelerometer nonlinear scale factor into the model and reducing estimation errors is essential for improving calibration methods. In this paper, the inertial navigation error model is simplified, including only velocity and tilt errors. Based on the simplified error model, the relationship between the navigation errors (the rates of change of velocity errors) and the inertial measurement unit (IMU) calibration parameters is presented. A tracking model is designed to estimate the rates of change of velocity errors. With a special calibration procedure consisting of six rotation sequences, the accelerometer nonlinear scale factor errors can be computed by the estimates of the rates of change of velocity errors. Simulation and laboratory test results show that the accelerometer nonlinear scale factor can be calibrated with satisfactory accuracy on a low-cost three-axis turntable in several minutes. The comparison with the traditional calibration method highlights the superior performance of the proposed calibration method without precise orientation control. In addition, the proposed calibration method saves a lot of time in comparison with the multi-position calibration method.

Pan, Jianye; Zhang, Chunxi; Cai, Qingzhong

2014-02-01

43

Column Calibration Factor to Study the Composition Dependence of the Thermal Diffusion Factors of Inert Gas Mixtures  

NASA Astrophysics Data System (ADS)

The experimental thermal diffusion factors ?T of He4-Ar40 and Ne20-Xe132 gas mixtures at different compositions of the lighter components and an isotopic natural mixture of Ne20-Ne22 are estimated at the mean temperature \\bar{T}{=}340 K by the column calibration factor method from the available values of ln qe(qe being the equilibrium separation factor) for those mixtures at different pressures in atmosphere for each composition, measured by J. M. Saviron et al. in a thermal diffusion column with the column calibration factor Fs{=}3.946, the value (at \\bar{T}{=}340 K) derived from the formula Fs{=}68.94796-0.3174514 \\bar{T}+3.71383× 10-4T2 as obtained by S. Acharyya et al. It is shown that the experimental ?T’s, thus estimated with the help of Fs and ln qmax, agree excellently with those due to the existing methods using molecular models as well as with those due to Slieher’s model-independent method, so far as their magnitudes and the trends of their variation with the mole fraction of the lighter components are concerned. This suggests that the present method is a unique one which can safely be used to study the composition dependence of ?T in both the isotopic and nonisotopic cases.

Datta, A. K.; Dasgupta, G.; Acharyya, S.

1990-10-01

44

Note: Calibration of atomic force microscope cantilevers using only their resonant frequency and quality factor.  

PubMed

A simplified method for calibrating atomic force microscope cantilevers was recently proposed by Sader et al. [Rev. Sci. Instrum. 83, 103705 (2012); Sec. III D] that relies solely on the resonant frequency and quality factor of the cantilever in fluid (typically air). This method eliminates the need to measure the hydrodynamic function of the cantilever, which can be time consuming given the wide range of cantilevers now available. Using laser Doppler vibrometry, we rigorously assess the accuracy of this method for a series of commercially available cantilevers and explore its performance under non-ideal conditions. This shows that the simplified method is highly accurate and can be easily implemented to perform fast, robust, and non-invasive spring constant calibration. PMID:25430150

Sader, John E; Friend, James R

2014-11-01

45

Note: Calibration of atomic force microscope cantilevers using only their resonant frequency and quality factor  

NASA Astrophysics Data System (ADS)

A simplified method for calibrating atomic force microscope cantilevers was recently proposed by Sader et al. [Rev. Sci. Instrum. 83, 103705 (2012); Sec. III D] that relies solely on the resonant frequency and quality factor of the cantilever in fluid (typically air). This method eliminates the need to measure the hydrodynamic function of the cantilever, which can be time consuming given the wide range of cantilevers now available. Using laser Doppler vibrometry, we rigorously assess the accuracy of this method for a series of commercially available cantilevers and explore its performance under non-ideal conditions. This shows that the simplified method is highly accurate and can be easily implemented to perform fast, robust, and non-invasive spring constant calibration.

Sader, John E.; Friend, James R.

2014-11-01

46

21 CFR 870.1650 - Angiographic injector and syringe.  

Code of Federal Regulations, 2012 CFR

...a syringe and a high-pressure injector which are used to inject contrast material into the heart, great vessels, and coronary arteries to study the heart and vessels by x-ray photography. (b) Classification. Class II (performance...

2012-04-01

47

21 CFR 870.1650 - Angiographic injector and syringe.  

...a syringe and a high-pressure injector which are used to inject contrast material into the heart, great vessels, and coronary arteries to study the heart and vessels by x-ray photography. (b) Classification. Class II (performance...

2014-04-01

48

21 CFR 870.1650 - Angiographic injector and syringe.  

Code of Federal Regulations, 2011 CFR

...a syringe and a high-pressure injector which are used to inject contrast material into the heart, great vessels, and coronary arteries to study the heart and vessels by x-ray photography. (b) Classification. Class II (performance...

2011-04-01

49

21 CFR 880.6920 - Syringe needle introducer.  

Code of Federal Regulations, 2010 CFR

...needle introducer. (a) Identification. A syringe needle introducer is a device that uses a spring-loaded mechanism to drive a hypodermic needle into a patient to a predetermined depth below the skin surface. (b) Classification....

2010-04-01

50

Developing biotechnology company's future positioning strategy in prefilled syringe market  

E-print Network

The primary goal for the thesis is to develop a recommendation for Amgen's future prefilled syringe strategy related to its drug process development, supplier relationship management plan, supply and sourcing, and procurement. ...

Lee, Joonhaeng, S.M. Massachusetts Institute of Technology

2010-01-01

51

Structure of the syringeal muscles in jungle crow (corvus macrorhynchos)  

Microsoft Academic Search

Birds’ vocalizations are produced by the syrinx, which is located between the trachea and the two primary bronchi. Oscine\\u000a birds have multiple pairs of syringeal muscles in the syrinx. To determine the detailed structure of the syringeal muscle\\u000a in jungle crows, an oscine bird, a histological study and gross examination of the syrinx were performed. In the histological\\u000a study, sections

Naoki Tsukahara; Qian Yang; Shoei Sugita

2008-01-01

52

Monte Carlo modeling provides accurate calibration factors for radionuclide activity meters.  

PubMed

Accurate determination of calibration factors for radionuclide activity meters is crucial for quantitative studies and in the optimization step of radiation protection, as these detectors are widespread in radiopharmacy and nuclear medicine facilities. In this work we developed the Monte Carlo model of a widely used activity meter, using the Geant4 simulation toolkit. More precisely the "PENELOPE" EM physics models were employed. The model was validated by means of several certified sources, traceable to primary activity standards, and other sources locally standardized with spectrometry measurements, plus other experimental tests. Great care was taken in order to accurately reproduce the geometrical details of the gas chamber and the activity sources, each of which is different in shape and enclosed in a unique container. Both relative calibration factors and ionization current obtained with simulations were compared against experimental measurements; further tests were carried out, such as the comparison of the relative response of the chamber for a source placed at different positions. The results showed a satisfactory level of accuracy in the energy range of interest, with the discrepancies lower than 4% for all the tested parameters. This shows that an accurate Monte Carlo modeling of this type of detector is feasible using the low-energy physics models embedded in Geant4. The obtained Monte Carlo model establishes a powerful tool for first instance determination of new calibration factors for non-standard radionuclides, for custom containers, when a reference source is not available. Moreover, the model provides an experimental setup for further research and optimization with regards to materials and geometrical details of the measuring setup, such as the ionization chamber itself or the containers configuration. PMID:25195174

Zagni, F; Cicoria, G; Lucconi, G; Infantino, A; Lodi, F; Marengo, M

2014-12-01

53

Placing the Dynamics of Syringe Exchange Programs in the United States  

PubMed Central

Drawing upon the broader health, social, and political geography literature this paper outlines a framework for considering place-based processes through which syringe exchange availability may be understood. It is argued that the geographic distribution of syringe exchange programs (SEPs) in the United States is linked to the social and political conditions of particular localities through three place characteristics: (1) structural constraints; (2) social and spatial distancing of injection drug users; and (3) localized action. Although SEPs remain a controversial issue and face ongoing obstacles from the government, law enforcement and local communities, they continue to operate through the efforts of grassroots organizations and local activists. Action on this issue occurs locally, and the characteristics of place-based factors will affect whether particular areas adopt SEPs. PMID:16797217

2007-01-01

54

Applications of spectral band adjustment factors (SBAF) for cross-calibration  

USGS Publications Warehouse

To monitor land surface processes over a wide range of temporal and spatial scales, it is critical to have coordinated observations of the Earth's surface acquired from multiple spaceborne imaging sensors. However, an integrated global observation framework requires an understanding of how land surface processes are seen differently by various sensors. This is particularly true for sensors acquiring data in spectral bands whose relative spectral responses (RSRs) are not similar and thus may produce different results while observing the same target. The intrinsic offsets between two sensors caused by RSR mismatches can be compensated by using a spectral band adjustment factor (SBAF), which takes into account the spectral profile of the target and the RSR of the two sensors. The motivation of this work comes from the need to compensate the spectral response differences of multispectral sensors in order to provide a more accurate cross-calibration between the sensors. In this paper, radiometric cross-calibration of the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and the Terra Moderate Resolution Imaging Spectroradiometer (MODIS) sensors was performed using near-simultaneous observations over the Libya 4 pseudoinvariant calibration site in the visible and near-infrared spectral range. The RSR differences of the analogous ETM+ and MODIS spectral bands provide the opportunity to explore, understand, quantify, and compensate for the measurement differences between these two sensors. The cross-calibration was initially performed by comparing the top-of-atmosphere (TOA) reflectances between the two sensors over their lifetimes. The average percent differences in the long-term trends ranged from $-$5% to $+$6%. The RSR compensated ETM+ TOA reflectance (ETM+$^{ast}$) measurements were then found to agree with MODIS TOA reflectance to within 5% for all bands when Earth Observing-1 Hy- erion hyperspectral data were used to produce the SBAFs. These differences were later reduced to within 1% for all bands (except band 2) by using Environmental Satellite Scanning Imaging Absorption Spectrometer for Atmospheric Cartography hyperspectral data to produce the SBAFs.

Chander, Gyanesh

2013-01-01

55

Experimental derivation of wall correction factors for ionization chambers used in high dose rate 192Ir source calibration.  

PubMed

At present there are no specific primary standards for 192Ir high dose rate sources used in brachytherapy. Traceability to primary standards is guaranteed through the method recommended by the AAPM that derives the air kerma calibration factor for the 192Ir gamma rays as the average of the air kerma calibration factors for x-rays and 137Cs gamma-rays or the Maréchal et al. method that uses the energy-weighted air kerma calibration factors for 250 kV x rays and 60Co gamma rays as the air kerma calibration factor for the 192Ir gamma rays. In order to use these methods, it is necessary to use the same buildup cap for all energies and the appropriate wall correction factor for each chamber. This work describes experimental work used to derive the A(W) for four different ionization chambers and different buildup cap materials for the three energies involved in the Maréchal et al. method. The A(W) for the two most common ionization chambers used in hospitals, the Farmer NE 2571 and PTW N30001 is 0.995 and 0.997, respectively, for 250 kV x rays, 0.982 and 0.985 for 192Ir gamma rays, and 0.979 and 0.991 for 60Co gamma rays, all for a PMMA build-up cap of 0.550 gm cm(-2). A comparison between the experimental values and Monte Carlo calculations shows an agreement better than 0.9%. Availability of the A(W) correction factors for all commercial chambers allows users of the in-air calibration jig, provided by the manufacturer, to alternatively use the Maréchal et al. method. Calibration laboratories may also used this method for calibration of a well-type ionization chamber with a comparable accuracy to the AAPM method. PMID:11833542

Maréchal, M H; de Almeida, C E; Ferreira, I H; Sibata, C H

2002-01-01

56

Impact of probe configuration and calibration techniques on quality factor determination of on-wafer inductors for GHz applications  

Microsoft Academic Search

We demonstrate that the quality factors measured on on-wafer (spiral) inductor test-structures are largely influenced by the choice between ground-signal and ground-signal-ground probe configuration. In particular when the SOLT network analyzer calibration technique is used in combination with ground-signal probing, the quality factor value can be overestimated significantly.

R. J. Havens; L. F. Tiemeijer; L. Garnbus

2002-01-01

57

Calibration of relative sensitivity factors for impact ionization detectors with high-velocity silicate microparticles  

NASA Astrophysics Data System (ADS)

Impact ionization mass spectrometers, e.g., the Cosmic Dust Analyzer (CDA) onboard the Cassini spacecraft can quantitatively analyze the chemical composition of impacting particles, if the ionization efficiencies of the elements to be quantified are appropriately calibrated. Although silicates are an abundant dust species inside and outside the Solar System, an experimental calibration was not available for elements typically found in silicates. We performed such a calibration by accelerating orthopyroxene dust of known composition with a modified Van de Graaff accelerator to velocities of up to 37.9 km s-1 and subsequent analyses by a high resolution impact ionization mass spectrometer, the Large Area Mass Analyzer (LAMA). The orthopyroxene dust, prepared from a natural rock sample, contains ?90% orthopyroxene and ?10% additional mineral species, such as clinopyroxene, spinel, amphibole, olivine and glasses, which are present as impurities within the orthopyroxene, due to inclusion or intergrowth. Hence, the dust material can be regarded as a multi-mineral mixture. After analyses, we find that most particle data cluster at a composition ascribed to pure orthopyroxene. Some data scatter is caused by stochastic effects, other data scatter is caused by the chemically different mineral impurities. Our data indicate that these minor mineral phases can be recognized within a multi-mineral mixture. Here, for the first time, we present experimentally derived relative sensitivity factors (RSFs) for impact ionization mass spectroscopy of silicates, enabling the quantitative determination of the composition of cosmic dust grains. Orthopyroxene data were used to infer RSFs for Na, Mg, Al, Si, Ca, Ti, Fe and K, for particles with radii ranging from 0.04 ?m to 0.2 ?m and velocities between 19 and 37.9 km s-1, impacting on a Rh-target.

Fiege, Katherina; Trieloff, Mario; Hillier, Jon K.; Guglielmino, Massimo; Postberg, Frank; Srama, Ralf; Kempf, Sascha; Blum, Jürgen

2014-10-01

58

Lamp mapping technique for independent determination of the water vapor mixing ratio calibration factor for a Raman lidar system.  

PubMed

We have investigated a technique that allows for the independent determination of the water vapor mixing ratio calibration factor for a Raman lidar system. This technique utilizes a procedure whereby a light source of known spectral characteristics is scanned across the aperture of the lidar system's telescope and the overall optical efficiency of the system is determined. Direct analysis of the temperature-dependent differential scattering cross sections for vibration and vibration-rotation transitions (convolved with narrowband filters) along with the measured efficiency of the system, leads to a theoretical determination of the water vapor mixing ratio calibration factor. A calibration factor was also obtained experimentally from lidar measurements and radiosonde data. A comparison of the theoretical and experimentally determined values agrees within 5%. We report on the sensitivity of the water vapor mixing ratio calibration factor to uncertainties in parameters that characterize the narrowband transmission filters, the temperature-dependent differential scattering cross section, and the variability of the system efficiency ratios as the lamp is scanned across the aperture of the telescope used in the Howard University Raman Lidar system. PMID:21833140

Venable, Demetrius D; Whiteman, David N; Calhoun, Monique N; Dirisu, Afusat O; Connell, Rasheen M; Landulfo, Eduardo

2011-08-10

59

[Diabetes mellitus and the use of syringes and needles].  

PubMed

Among the diseases that produce a great amount of garbage of health, the individuals bearers of diabetes insulino-dependent mellittus are important producers of solid garbage of health. The main objective of this study is to identify how the insulino-dependent diabetics do the discard of the syringes and needles used in their residences. The method of the research was the descriptive study. The researched population was constituted of 70 insulino-dependent individuals. The collection of data was accomplished through questionnaire, in the period of October of 2006 to March of 2007. Inside of the relevant results, in which 100% do not know what biological garbage is and 51.43% discard in the common garbage the needles and syringes and ignore the course of the garbage to the embankment, the importance is demonstrated by becoming aware and educating the population of the risks of this practice being fundamental for the environment. PMID:20027954

Tapia, Carmen Elisa Villalobos

2009-06-01

60

Additional information on the dripper design -Syringe pump: Harvard Apparatus / Modified 702019 LEADSCREW & 1/2 NUT =  

E-print Network

Apparatus syringe pump carries two syringes in opposite directions (infuse versus refill). It reports SyringePump.com/NE-1000 single syringe pump) with a 3-way check valve to accomplish infuse and refill when the pump reverses from the infuse to the refill mode. The NE-1000 pump allows you to specify

Lee, Xuhui

61

Wall correction factors for calibration of plane-parallel ionization chambers with high-energy photon beams  

NASA Astrophysics Data System (ADS)

Most dosimetry protocols recommend that calibration of plane-parallel ionization chambers be performed in an electron beam of sufficiently high energy by comparison with cylindrical chambers. For various plane-parallel chambers, the 1997 IAEA TRS-381 protocol includes an overall perturbation factor pQ for electron beams, a wall correction factor pwall for a 60Co beam and the product of two wall corrections kattkm for 60Co in-air calibration. The recommended values of pwall for plane-parallel chambers, however, are limited to certain phantom materials and a 60Co beam, and are not given for other phantom materials and x-ray beams. In this work, the pwall values of the commercially available NACP, PTW/Markus and PTW/Roos plane-parallel chambers in a solid water phantom have been determined with 60Co and 4 and 10 MV photon beams. The kattkm values for the NACP and PTW/Markus chambers have also been obtained. The wall correction factors pwall and kattkm have been determined by intercomparison with a calibrated Farmer chamber. The average value of pwall for these plane-parallel chambers was 1.005±0.1% (1 SD) for 60Co beams and 1.007±0.2% (1 SD) for both 4 MV and 10 MV photons. The kattkm values for the NACP and PTW/Markus chambers were about 1.5% lower than other published data.

Araki, Fujio; Ikeda, Ryuji; Shirakawa, Yuichi; Shimonobou, Toshiaki; Moribe, Nobuyuki; Takada, Takao; Takahashi, Mutsumasa; Oura, Hiroki; Matoba, Masaru

2000-09-01

62

Nonprescription Syringe Sales: A Missed Opportunity for HIV Prevention in California  

PubMed Central

Background California Senate Bill 41 (SB41), effective January 2012, is an HIV prevention measure designed to expand syringe access among injection drug users (IDUs) by allowing pharmacists to sell up to 30 syringes without a prescription. Objective We assessed SB41 implementation in two inland California counties where prevalence of injection drug use is among the highest in the nation. Design Syringe purchase trial. Setting Fresno and Kern counties, California. Participants All retail pharmacies (N=248). Main outcome measure Successful or unsuccessful syringe purchase attempt. Results Only 52 (21.0%) syringe purchase attempts were successful. The proportion of successful attempts did not vary by county or by data collector ethnicity. The most common reasons for unsuccessful syringe purchase attempts were prescription requirements (45.7%), the requested syringe size was not available (10.7%), and the pharmacy did not sell syringes (9.7%). In addition, some syringe purchase attempts (4.1%) were unsuccessful because the data collector was asked to purchase more syringes than allowed by law. Although 80% and 78% of Fresno and Kern residents, respectively, live within a 5-minute drive of a retail pharmacy, less than half live within a 5-minute drive of a pharmacy that sold syringes. Conclusion SB41 has not resulted in broad pharmacy-based syringe access in California's inland counties, where a disproportionate number of HIV/AIDS cases are associated with injection drug use. Additional steps by legislative bodies, regulatory agencies, and professional organizations are needed to actively engage pharmacies in expanding nonprescription syringe sales to reduce HIV transmission among IDUs. PMID:25575149

Pollini, Robin A.; Rudolph, Abby E.; Case, Patricia

2014-01-01

63

The Flawed Nature of the Calibration Factor in Breath-Alcohol Analysis  

NASA Astrophysics Data System (ADS)

Breath-alcohol analyzers used by law enforcement agencies to evaluate suspected driving-while-intoxicated (DWI) drivers are routinely calibrated with standard, dilute aqueous solutions of ethanol known as simulator solutions. The analyzers are deemed accurate if they generate results within an established margin of error consistent with ethanol concentrations equivalent to the actual concentrations of the simulator solutions. The fundamental flaw of this protocol is that it ignores the fact that a simulator solution is an ideal Henry’s law system, whereas a human test subject is not. Since breath-alcohol analysis is an application of Henry’s law, the level of accuracy ascribed to simulator-based calibrations cannot be applied to analyses involving humans because they are affected by physiological variables that can significantly impact the results of such analyses. This article addresses the importance of these variables, including blood:breath ratio variability, body temperature, and breathing pattern. Moreover, the article notes that, when standard ethanol-in-nitrogen compressed gas mixtures are used instead of aqueous simulator solutions to calibrate breath-alcohol analyzers, the same limitations of accuracy apply. Finally, emphasis is placed on the nature of the ideal calibration standard, namely that it should mimic the system to be analyzed, which is clearly not the case with the calibration protocol employed in breath-alcohol analysis.

Labianca, Dominick A.

2002-10-01

64

Appendix A. Flow Analysis Documents MERIT SYRINGE FLOW ANALYSIS  

E-print Network

=34.3 cm Dh=1.10 inches A=6.10 cm2 Flex Hose Nozzle tubing for variable density systems. (3 of 5) A-5 #12;AFT Fathom 5.0 Output 4/25/2006 SNS MERIT SYRINGE FLOW ANALYSIS.0750 38.9 38.8 0.08005390 37.83 3.77E+01 0.08005390 11 Nozzle tubing 1/2 inch 1.57 3.81 0.694 2,263.76 1

McDonald, Kirk

65

A national physician survey on prescribing syringes as an HIV prevention measure  

PubMed Central

Background Access to sterile syringes is a proven means of reducing the transmission of human immunodeficiency virus (HIV), viral hepatitis, and bacterial infections among injection drug users. In many U.S. states and territories, drug paraphernalia and syringe prescription laws are barriers to syringe access for injection drug users (IDUs): pharmacists may be reluctant to sell syringes to suspected IDUs, and police may confiscate syringes or arrest IDUs who cannot demonstrate a "legitimate" medical need for the syringes they possess. These barriers can be addressed by physician prescription of syringes. This study evaluates physicians' willingness to prescribe syringes, using the theory of planned behavior to identify key behavioral influences. Methods We mailed a survey to a representative sample of physicians from the American Medical Association physician database. Non-responding physicians were then called, faxed, or re-sent the survey, up to four times. Results Twenty percent responded to the survey. Although less than 1 percent of respondents had ever prescribed syringes to a known injection drug user, more than 60% of respondents reported that they would be willing to do so. Physicians' willingness to prescribe syringes was best predicted by the belief that it was a feasible and effective intervention, but individual and peer attitudes were also significant. Conclusion This was the first nationwide survey of the physician willingness to prescribe syringes to IDUs. While the majority of respondents were willing to consider syringe prescription in their clinical practices, multiple challenges need to be addressed in order to improve physician knowledge and attitudes toward IDUs. PMID:19505336

Macalino, GE; Sachdev, D Dhawan; Rich, JD; Becker, C; Tan, LJ; Beletsky, L; Burris, S

2009-01-01

66

The Flawed Nature of the Calibration Factor in Breath-Alcohol Analysis  

Microsoft Academic Search

Breath-alcohol analyzers used by law enforcement agencies to evaluate suspected driving-while-intoxicated (DWI) drivers are routinely calibrated with standard, dilute aqueous solutions of ethanol known as simulator solutions. The analyzers are deemed accurate if they generate results within an established margin of error consistent with ethanol concentrations equivalent to the actual concentrations of the simulator solutions. The fundamental flaw of this

Dominick A. Labianca

2002-01-01

67

Mechanical properties of composites as functions of the syringe storage temperature and energy dose.  

PubMed

Objective: To investigate the mechanical properties of different classifications of composites indicated for posterior application as functions of the storage condition and of the energy dose. Material and Methods: Specimens (8x2x2 mm) were obtained according to the factors: I) Composites (3M ESPE): Filtek P60, Filtek Z350XT, and Filtek Silorane; II) Syringe storage conditions: room temperature, aged, oven, refrigerator, and freezer; and III) Energy dose: 24 J/cm2 and 48 J/cm2. After photoactivation, the specimens were stored at 37ºC for 24 h. After storage, a three-point bending test was carried out in a universal testing machine at 0.5 mm/min. Flexural strength (S) and flexural modulus (E) were calculated. Data were analyzed by three-way ANOVA and Tukey's test (?=0.05). Results: Different storage conditions significantly affected the silorane composite for S; conversely, no effects were noted in terms of E. The accelerated aging protocol significantly increased the S of Filtek P60 and Filtek Silorane, whereas storage in the oven significantly decreased the S for all of the composites tested. Filtek P60 was the only composite not affected by the lower storage temperatures tested for S, whereas for the silorane this parameter was impacted at the same conditions. The factor "dose" was not statistically significant. Conclusions: The syringe storage at different temperature conditions proved to influence mostly the flexural strength, a clinically important characteristic considering the posterior indication of the materials tested. The silorane composite should not be stored at lower temperatures. PMID:25075673

Chaves, Fernanda Oliveira; Farias, Natália Coelho de; Medeiros, Luciano Marcelo de Mello; Alonso, Roberta Caroline Bruschi; DI Hipólito, Vinicius; D'Alpino, Paulo Henrique Perlatti

2014-07-29

68

Determination of the Specific Heat Ratio of a Gas in a Plastic Syringe  

ERIC Educational Resources Information Center

The rapid compression or expansion of a gas in a plastic syringe is a poor approximation of an adiabatic process. Heat exchange with the walls of the syringe brings the gas to equilibrium in an amount of time that is not significantly greater than the length of the compression or expansion itself. Despite this limitation, it is still possible to…

Chamberlain, Jeff

2010-01-01

69

Syringeal muscles fit the trill in ring doves (Streptopelia risoria L.).  

PubMed

In contrast to human phonation, the virtuoso vocalizations of most birds are modulated at the level of the sound generator, the syrinx. We address the hypothesis that syringeal muscles are physiologically capable of controlling the sound-generating syringeal membranes in the ring dove (Streptopelia risoria) syrinx. We establish the role of the tracheolateralis muscle and propose a new function for the sternotrachealis muscle. The tracheolateralis and sternotrachealis muscles have an antagonistic mechanical effect on the syringeal aperture. Here, we show that both syringeal muscles can dynamically control the full syringeal aperture. The tracheolateralis muscle is thought to directly alter position and tension of the vibrating syringeal membranes that determine the gating and the frequency of sound elements. Our measurements of the muscle's contractile properties, combined with existing electromyographic and endoscopic evidence, establish its modulating role during the dove's trill. The muscle delivers the highest power output at cycle frequencies that closely match the repetition rates of the fastest sound elements in the coo. We show that the two syringeal muscles share nearly identical contraction characteristics, and that sternotrachealis activity does not clearly modulate during the rapid trill. We propose that the sternotrachealis muscle acts as a damper that stabilizes longitudinal movements of the sound-generating system induced by tracheolateralis muscle contraction. The extreme performance of both syringeal muscles implies that they play an important role in fine-tuning membrane position and tension, which determines the quality of the sound for a conspecific mate. PMID:16481585

Elemans, C P H; Spierts, I L Y; Hendriks, M; Schipper, H; Müller, U K; van Leeuwen, J L

2006-03-01

70

The Washington Needle Depot: fitting healthcare to injection drug users rather than injection drug users to healthcare: moving from a syringe exchange to syringe distribution model  

PubMed Central

Needle exchange programs chase political as well as epidemiological dragons, carrying within them both implicit moral and political goals. In the exchange model of syringe distribution, injection drug users (IDUs) must provide used needles in order to receive new needles. Distribution and retrieval are co-existent in the exchange model. Likewise, limitations on how many needles can be received at a time compel addicts to have multiple points of contact with professionals where the virtues of treatment and detox are impressed upon them. The centre of gravity for syringe distribution programs needs to shift from needle exchange to needle distribution, which provides unlimited access to syringes. This paper provides a case study of the Washington Needle Depot, a program operating under the syringe distribution model, showing that the distribution and retrieval of syringes can be separated with effective results. Further, the experience of IDUs is utilized, through paid employment, to provide a vulnerable population of people with clean syringes to prevent HIV and HCV. PMID:20047690

2010-01-01

71

Pharmacy access to syringes among injecting drug users: follow-up findings from Hartford, Connecticut.  

PubMed Central

OBJECTIVE: To break the link between drug use and the human immunodeficiency virus (HIV), in 1992 the state of Connecticut rescinded a 14-year ban on pharmacy sales of syringes without a physician's prescription. In 1993, the Center for Disease Control and Prevention (CDC) evaluated the impact of the new legislation on access to syringes among injecting drug users (IDUs) and found an initial pattern of expanded access. However, it also found that some pharmacies, after negative experiences with IDU customers, reverted to requiring a prescription. This chapter reports findings from a four-year follow-up study of current IDU access to over-the-counter (OTC) pharmacy syringes in Hartford, Connecticut. METHODS: Through structured interviews, brief telephone interviews, and mailed surveys, data on nonprescription syringe sale practices were collected on 27 pharmacies, including 18 of the 21 pharmacies in Hartford and none from pharmacies in contiguous towns, during June and July 1997. Interview data on pharmacy syringe purchase from two sample of IDUs, a group of out-of-treatment injectors recruited through street outreach, and a sample of users of the Hartford Needle Exchange Program, also are reported. RESULTS: The study found that, while market trends as well as negative experiences have further limited pharmacy availability of nonprescription syringes, pharmacies remain an important source of sterile syringes for IDUs. However, the distribution of access in not even; in some areas of the city it is much easier to purchase nonprescription syringes than in other. All of the seven pharmacies located on the north end of Hartford reported that they had a policy of selling OTC syringes, whereas only six (54.5%) of the II pharmacies located on the south end have such a policy. Overt racial discrimination was not found to be a barrier to OTC access to syringes. CONCLUSIONS: To further decrease acquired immunodeficiency syndrome (AIDS) risk among IDUs, there is a need for public education to counter empirically unsupported stereotypes about IDUs that diminish their access to health care and AIDS prevention resources and services. In states or cities where pharmacy sale of nonprescription syringes is illegal, policy makers should examine the benefits of removing existing barriers to sterile syringe acquisition. In cases in which pharmacy sale of nonprescription syringes is legal, local health departments should implement educational programs to inform pharmacy staff and management about the critically important role low-cost (or cost-free), sterile syringe access can play in HIV prevention. PMID:9722813

Singer, M; Baer, H A; Scott, G; Horowitz, S; Weinstein, B

1998-01-01

72

Dual Syringe Electrospinning of FNfds-modified Hyaluronic Acid  

NASA Astrophysics Data System (ADS)

We described the fabrication of a unique HA nanofibrous scaffold using dual syringe reactive electrospinning. 3^'-dithiobis(propanoic dihydrazide)-modified HA (HA-DTPH) and Poly (ethylene glycol)-diacrylate (PEGDA) were selected as the cross-linking system. PEO was blended with HA-DTPH to facilitate the fiber formation. Fibronectin functional domains (FNfds) were incorporated with PEGDA and covalently linked to HA via conjugate addition to improve the cell attachment. The as-spun scaffold was soaked into DI water to remove PEO and yield an FNfds-modified HA-DTPH nanofibrous scaffold. Human dermal fibroblasts CF31 were seeded on FNfds-modified HA-DTPH scaffolds. The CF31 fibroblasts showed a unique extended dendritic morphology which is opposed to the typical flattened morphology of cells on regular 2D geometries. Supported by NSF-MRSEC.

Ji, Yuan; Ghosh, Kaustabh; Shu, Xiaozheng; Sokolov, Jonathan; Prestwich, Glenn; Clark, Richard; Rafailovich, Miriam

2006-03-01

73

Pre-filled syringes: a review of the history, manufacturing and challenges.  

PubMed

Abstract Pre-filled syringes are convenient devices for the delivery of parenteral medications. They are small which makes them easy to carry and are dependable for delivering a precise dose of medication. These and many other reasons are leading to their growth in the pharmaceutical market. There are a number of review articles that describe the advantages and disadvantages of pre-filled syringes. However, there are few journal articles that present information on their manufacturing and challenges. The intent of this review article is to provide information on the history of the pre-filled syringe, methods of their manufacture, methods of filling syringes as a drug product and to examine the types of syringes available. This type of knowledge can familiarize the formulation scientist with the choices available and their possible challenges. PMID:25589433

Sacha, Gregory; Rogers, J Aaron; Miller, Reagan L

2015-01-01

74

Syringe-pump-induced fluctuation in all-aqueous microfluidic system implications for flow rate accuracy.  

PubMed

We report a new method to display the minute fluctuations induced by syringe pumps on microfluidic flows by using a liquid-liquid system with an ultralow interfacial tension. We demonstrate that the stepper motor inside the pump is a source of fluctuations in microfluidic flows by comparing the frequencies of the ripples observed at the interface to that of the pulsation of the stepper motor. We also quantify the fluctuations induced at different flow rates, using syringes of different diameters, and using different syringe pumps with different advancing distances per step. Our work provides a way to predict the frequency of the fluctuation that the driving syringe pump induces on a microfluidic system and suggests that syringe pumps can be a source of fluctuations in microfluidic flows, thus contributing to the polydispersity of the resulting droplets. PMID:24382584

Li, Zida; Mak, Sze Yi; Sauret, Alban; Shum, Ho Cheung

2014-02-21

75

Plausible authentication of manuka honey and related products by measuring leptosperin with methyl syringate.  

PubMed

Manuka honey, obtained from Leptospermum scoparium flowers in New Zealand, has strong antibacterial properties. In this study, plausible authentication of the manuka honey was inspected by measuring leptosperin, methyl syringate 4-O-?-D-gentiobiose, along with methyl syringate. Despite a gradual decrease in methyl syringate content over 30 days at 50 °C, even at moderate 37 °C, leptosperin remained stable. A considerable correlation between nonperoxide antibacterial activity and leptosperin content was observed in 20 certified manuka honey samples. Leptosperin and methyl syringate in manuka honey and related products were analyzed using HPLC connected with mass spectrometry. One noncertified brand displayed significant variations in the leptosperin and methyl syringate contents between two samples obtained from different regions. Therefore, certification is clearly required to protect consumers from disguised and/or low-quality honey. Because leptosperin is stable during storage and specific to manuka honey, its measurement may be applicable for manuka honey authentication. PMID:24941263

Kato, Yoji; Fujinaka, Rie; Ishisaka, Akari; Nitta, Yoko; Kitamoto, Noritoshi; Takimoto, Yosuke

2014-07-01

76

Capillary Isoelectric Focusing Coupled Offline to Matrix Assisted Laser Desoprtion/Ionization Mass Spectrometry with Syringe Pump Mobilization  

PubMed Central

This work presents several critical details for making cIEF-MALDI-MS a robust technique which will allow for more routine application and aid in automation. This includes emphasis on the hardware necessary for syringe pump mobilization and proper protocol for preventing disruption from gas bubbles. Following these guidelines, excellent elution time reproducibility is demonstrated for six pI markers (RSD < 5%). Additionally, the pI markers are used to calibrate the pH gradient and determine experimental pIs of proteins detected offline by mass spectrometry. This was demonstrated using a standard protein mixture of myoglobin and two forms of ?-lactoglobulin. Experimental determination of protein pIs and molecular weights were found to be in agreement with literature values. The technical details discussed provide a sound foundation for applying the offline coupling of MALDI-MS with cIEF. PMID:19945710

Weiss, Noah G.; Zwick, Nicole L.; Hayes, Mark A.

2012-01-01

77

Approval of Syringe Exchange Programs in California: Results From a Local Approach to HIV Prevention  

PubMed Central

Objectives. We studied the effect of local approval of syringe exchange programs in California (through Assembly AB136) on program availability and performance. Methods. We determined the number of active syringe exchange programs in California by conducting Internet searches and obtaining information from the state and from local programs. To track changes in program availability and performance between 2000 and 2002, we interviewed 24 program directors annually for 3 years about program characteristics, syringe exchange policies, law enforcement contact, and other issues. We conducted multivariate analyses to determine whether AB136 approval status was associated with changes in performance. Results. Fifteen local governments (13 counties and 2 cities) enacted the new law by 2002, and operating syringe exchange programs increased from 24 to 35. The proportion of these programs that were not locally approved declined from 54% to 40%. No new approved programs were started in high-need counties. Total syringes exchanged increased by more than 1 million per year, average annual budgets increased by more than 50%, and police harassment of the program volunteers, clients, and operators declined. Improvements at approved syringe exchange programs accounted for these changes. Conclusions. Statewide approval and funding appears necessary to further syringe exchange availability in California. PMID:17538068

Bluthenthal, Ricky N.; Heinzerling, Keith G.; Anderson, Rachel; Flynn, Neil M.; Kral, Alex H.

2008-01-01

78

Accuracy and reproducibility of low dose insulin administration using pen-injectors and syringes.  

PubMed

Many children with diabetes require small doses of insulin administered with syringes or pen-injector devices (at the Booth Hall Paediatric Diabetic Clinic, 20% of children aged 0-5 years receive 1-2 U insulin doses). To determine how accurately and reproducibly small doses are delivered, 1, 2, 5, and 10 U doses of soluble insulin (100 U/ml) were dispensed in random order 15 times from five new NovoPens (1.5 ml), five BD-Pens (1.5 ml), and by five nurses using 30 U syringes. Each dose was weighed, and intended and actual doses compared. The two pen-injectors delivered less insulin than syringes, differences being inversely proportional to dose. For 1 U (mean (SD)): 0.89 (0.04) U (NovoPen), 0.92 (0.03) U (BD-Pen), 1.23 (0.09) U (syringe); and for 10 U: 9.8 (0.1) U (NovoPen), 9.9 (0.1) U (BD-Pen), 10.1 (0.1) U (syringe). The accuracy (percentage errors) of the pen-injectors was similar and more accurate than syringes delivering 1, 2, and 5 U of insulin. Errors for 1 U: 11(4)% (NovoPen), 8(3)% (BD-Pen), 23(9)% (syringe). The reproducibility (coefficient of variation) of actual doses was similar (< 7%) for all three devices, which were equally consistent at underdosing (pen-injectors) or overdosing (syringes) insulin. All three devices, especially syringes, are unacceptably inaccurate when delivering 1 U doses of insulin. Patients on low doses need to be educated that their dose may alter when they transfer from one device to another. PMID:9771255

Gnanalingham, M G; Newland, P; Smith, C P

1998-07-01

79

Accuracy and reproducibility of low dose insulin administration using pen-injectors and syringes  

PubMed Central

Many children with diabetes require small doses of insulin administered with syringes or pen-injector devices (at the Booth Hall Paediatric Diabetic Clinic, 20% of children aged 0-5 years receive 1-2 U insulin doses). To determine how accurately and reproducibly small doses are delivered, 1, 2, 5, and 10 U doses of soluble insulin (100 U/ml) were dispensed in random order 15times from five new NovoPens (1.5 ml), five BD-Pens (1.5 ml), and by five nurses using 30 U syringes. Each dose was weighed, and intended and actual doses compared. The two pen-injectors delivered less insulin than syringes, differences being inversely proportional to dose. For 1 U (mean (SD)): 0.89 (0.04) U (NovoPen), 0.92 (0.03) U (BD-Pen), 1.23 (0.09) U (syringe); and for 10 U: 9.8 (0.1) U (NovoPen), 9.9 (0.1) U (BD-Pen), 10.1 (0.1) U (syringe). The accuracy (percentage errors) of the pen-injectors was similar and more accurate than syringes delivering 1, 2, and 5 U of insulin. Errors for 1 U: 11(4)% (NovoPen), 8(3)% (BD-Pen), 23(9)% (syringe). The reproducibility (coefficient of variation) of actual doses was similar (< 7%) for all three devices, which were equally consistent at underdosing (pen-injectors) or overdosing (syringes) insulin. All three devices, especially syringes, are unacceptably inaccurate when delivering 1 U doses of insulin. Patients on low doses need to be educated that their dose may alter when they transfer from one device to another.?? PMID:9771255

Gnanalingham, M; Newland, P; Smith, C

1998-01-01

80

Vertebroplasty: reusable flange converter with hub lock for injection of polymethylmethacrylate with screw-plunger syringe.  

PubMed

During percutaneous vertebroplasty, a screw-plunger syringe provides a powerful controlled injection, but coupling of the screw plunger with interchangeable disposable standard syringe barrels results in syringe flange bending failure during the middle of the injection. A flange converter produced from stainless steel and a hub lock produced from plastic or aluminum were used during vertebroplasty at 172 levels in 86 patient-treatment sessions. The flange converter and hub lock increase the achievable volume that can be injected, can be fabricated with hand machining, and cost much less than other commercially available devices. PMID:11867812

Schallen, Eric H; Gilula, Louis A

2002-03-01

81

Empirical Calibration of the P-Factor for Cepheid Radii Determined Using the IR Baade-Wesselink Method  

NASA Astrophysics Data System (ADS)

We have used 41 galactic Cepheids for which parallax or cluster/association distances are available, and for which pulsation parallaxes can be calculated, to calibrate the p-factor to be used in K-band Baade-Wesselink radius calculations. Our sample includes the 10 Cepheids from Benedict et al. (2007), and three additional Cepheids with Hipparcos parallaxes derived from van Leeuwen et al. (2007). Turner and Burke (2002) list cluster distances for 33 Cepheids for which radii have been or (in a few cases) can be calculated. Revised cluster distances from Turner (2010), Turner and Majaess (2008, 2012), and Majaess and Turner (2011, 2012a, 2012b) have been used where possible. Radii have been calculated using the methods described in Laney and Stobie (1995) and converted to K-band absolute magnitudes using the methods described in van Leeuwen et al. (2007), Feast et al. (2008), and Laney and Joner (2009). The resulting pulsation parallaxes have been used to estimate the p-factor for each Cepheid. These new results stand in contradiction to those derived by Storm et al. (2011), but are in good agreement with theoretical predictions by Nardetto et al. (2009) and with interferometric estimates of the p-factor, as summarized in Groenewegen (2007). We acknowledge the Brigham Young University College of Physical and Mathematical Sciences for continued support of research done using the facilities and personnel at the West Mountain Observatory. This support is connected with NSF/AST grant #0618209.

Joner, Michael D.; Laney, C. D.

2012-05-01

82

g factor of the first excited state in {sup 56}Fe and implications for transient-field calibration in the Fe region  

SciTech Connect

The transient-field technique has been used to measure the g factor of the 2{sub 1}{sup +} state in {sup 56}Fe relative to the independently determined g factor of the first 5/2{sup -} state in {sup 57}Fe. The new result for {sup 56}Fe agrees with previous measurements but is more precise. Implications for calibrating the transient field and g-factor measurements in the fp region are discussed.

East, M. C.; Stuchbery, A. E.; Chamoli, S. K.; Kibedi, T. [Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University Canberra, ACT 0200 (Australia); Wilson, A. N. [Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University Canberra, ACT 0200 (Australia); Department of Physics, Australian National University, Canberra, ACT 0200 (Australia); Crawford, H. L.; Pinter, J. S.; Mantica, P. F. [NSCL and Department of Chemistry, Michigan State University, Michigan 48824 (United States)

2009-02-15

83

The analysis and design of a pressure-measuring syringe utilizing elastomeric bellows  

E-print Network

Endotracheal tube insertion requires the measurement of very low pressure. Currently, there exists no reliable method or device that is integral with the inflation syringe for measuring this pressure. Thus, a device for ...

Duffley, Samuel C

2009-01-01

84

Syringe exchange in the United States: a national level economic evaluation of hypothetical increases in investment.  

PubMed

To examine whether increasing investment in needle/syringe exchange programs (NSPs) in the US would be cost-effective for HIV prevention, we modeled HIV incidence in hypothetical cases with higher NSP syringe supply than current levels, and estimated number of infections averted, cost per infection averted, treatment costs saved, and financial return on investment. We modified Pinkerton's model, which was an adaptation of Kaplan's simplified needle circulation theory model, to compare different syringe supply levels, account for syringes from non-NSP sources, and reflect reduction in syringe sharing and contamination. With an annual $10 to $50 million funding increase, 194-816 HIV infections would be averted (cost per infection averted $51,601-$61,302). Contrasted with HIV treatment cost savings alone, the rate of financial return on investment would be 7.58-6.38. Main and sensitivity analyses strongly suggest that it would be cost-saving for the US to invest in syringe exchange expansion. PMID:24824043

Nguyen, Trang Quynh; Weir, Brian W; Des Jarlais, Don C; Pinkerton, Steven D; Holtgrave, David R

2014-11-01

85

A syringe injection rate detector employing a dual Hall-effect sensor configuration.  

PubMed

Injection of fluids in the body using needle syringes is a standard clinical practice. The rate of injection can have various pathological effects on the body such as the pain perceived or in case of anesthesia, the amount of akinesia attained. Hence, a training system with a modified syringe employing a simple measurement scheme where a trainee can observe and practice the rate of injection prior to administering on actual human subjects, can be of great value towards reduction of complications in real life situations. In this paper, we develop a system for measurement of syringe injection rate with two Hall-effect sensors. Ring magnets attached to the body of the syringe along with the dual Hall-effect sensor configuration help in determining the position of the piston with respect to the syringe body. The two Hall-sensors are arranged in a differential configuration such that a linear relationship is obtained between the volume of liquid in the syringe (in ml) and the Hall-effect sensor output voltages. A prototype developed validated the measurement scheme. The rate of injection was displayed in real-time with a LabVIEW based Virtual Instrument. The error was within acceptable limits illustrating its efficacy for practical training purposes. PMID:24110792

Mukherjee, Biswarup; George, Boby; Sivaprakasam, Mohanasankar

2013-01-01

86

In-syringe-assisted dispersive liquid-liquid microextraction coupled to gas chromatography with mass spectrometry for the determination of six phthalates in water samples.  

PubMed

A fully automated method for the determination of six phthalates in environmental water samples is described. It is based in the novel sample preparation concept of in-syringe dispersive liquid-liquid microextraction, coupled as a front end to GC-MS, enabling the integration of the extraction steps and sample injection in an instrumental setup that is easy to operate. Dispersion was achieved by aspiration of the organic (extractant and disperser) and the aqueous phase into the syringe very rapidly. The denser-than-water organic droplets released in the extraction step, were accumulated at the head of the syringe, where the sedimented fraction was transferred to a rotary micro-volume injection valve where finally was introduced by an air stream into the injector of the GC through a stainless-steel tubing used as interface. Factors affecting the microextraction efficiency were optimized using multivariate optimization. Figures of merit of the proposed method were evaluated under optimal conditions, achieving a detection limit in the range of 0.03-0.10 ?g/L, while the RSD% value was below 5% (n = 5). A good linearity (0.9956 ? r(2) ? 0.9844) and a broad linear working range (0.5-120 ?g/L) were obtained. The method exhibited enrichment factors and recoveries, ranging from 14.11-16.39 and 88-102%, respectively. PMID:24520043

Clavijo, Sabrina; del Rosario Brunetto, María; Cerdà, Víctor

2014-04-01

87

SUMS calibration test report  

NASA Technical Reports Server (NTRS)

Calibration was performed on the shuttle upper atmosphere mass spectrometer (SUMS). The results of the calibration and the as run test procedures are presented. The output data is described, and engineering data conversion factors, tables and curves, and calibration on instrument gauges are included. Static calibration results which include: instrument sensitive versus external pressure for N2 and O2, data from each scan of calibration, data plots from N2 and O2, and sensitivity of SUMS at inlet for N2 and O2, and ratios of 14/28 for nitrogen and 16/32 for oxygen are given.

Robertson, G.

1982-01-01

88

SCORE Study Report 7: Incidence of Intravitreal Silicone Oil Droplets Associated With Staked-on Versus Luer Cone Syringe Design  

PubMed Central

PURPOSE To evaluate the incidence of intravitreal silicone oil (SO) droplets associated with intravitreal injections using a staked-on versus luer cone syringe design in the Standard Care versus COrticosteroid in REtinal Vein Occlusion (SCORE) Study. DESIGN Prospective, randomized, phase III clinical trial. METHODS The incidence of intravitreal SO was compared among participants exposed to the staked-on syringe design, the luer cone syringe design, or both of the syringe designs in the SCORE Study, which evaluated intravitreal triamcinolone acetonide injection(s) for vision loss secondary to macular edema associated with central or branch retinal vein occlusion. Injections were given at baseline and 4-month intervals, based on treatment assignment and study-defined re-treatment criteria. Because intravitreal SO was observed following injections in some participants, investigators were instructed, on September 22, 2006, to look for intravitreal SO at all study visits. On November 1, 2007, the luer cone syringe design replaced the staked-on syringe design. RESULTS 464 participants received a total of 1205 injections between November 4, 2004 and February 28, 2009. Intravitreal SO was noted in 141/319 (44%) participants exposed only to staked-on syringes, 11/87 (13%) exposed to both syringe designs, and 0/58 exposed only to luer cone syringes (p<0.0001). Among participants with first injections after September 22, 2006, intravitreal SO was noted in 65/114 (57%) injected only with staked-on syringes compared with 0/58 injected only with luer cone syringes. Differential follow-up is unlikely to explain these results. CONCLUSION In the SCORE Study, luer cone syringe design is associated with a lower frequency of intravitreal SO droplet occurrence compared with the staked-on syringe design, likely due to increased residual space in the needle hub with the luer cone design. PMID:19674727

Scott, Ingrid U.; Oden, Neal L.; VanVeldhuisen, Paul C.; Ip, Michael S.; Blodi, Barbara A.; Antoszyk, Andrew N.

2009-01-01

89

Syringe Access, Syringe Sharing, and Police Encounters among People Who Inject Drugs in New York City: A Community-Level Perspective  

PubMed Central

Background Injection drug user (IDU) experience and perceptions of police practices may alter syringe exchange program (SEP) use or influence risky behaviour. Previously, no community-level data had been collected to identify the prevalence or correlates of police encounters reported by IDUs in the United States. Methods New York City IDUs recruited through respondent-driven sampling were asked about past-year police encounters and risk behaviours, as part of the National HIV Behavioural Surveillance study. Data were analysed using multiple logistic regression. Results A majority (52%) of respondents (n=514) reported being stopped by police officers; 10% reported syringe confiscation. In multivariate modelling, IDUs reporting police stops were less likely to use SEPs consistently (adjusted odds ratio [AOR]=0.59; 95% confidence interval [CI]=0.40–0.89), and IDUs who had syringes confiscated may have been more likely to share syringes (AOR=1.76; 95% CI=0.90–3.44), though the finding did not reach statistical significance. Conclusions Findings suggest that police encounters may influence consistent SEP use. The frequency of IDU-police encounters highlights the importance of including contextual and structural measures in infectious disease risk surveillance, and the need to develop approaches harmonizing structural policing and public health. PMID:23916801

Beletsky, Leo; Heller, Daliah; Jenness, Samuel M.; Neaigus, Alan; Gelpi-Acosta, Camila; Hagan, Holly

2013-01-01

90

Automatic determination of copper by in-syringe dispersive liquid-liquid microextraction of its bathocuproine-complex using long path-length spectrophotometric detection.  

PubMed

The recently proposed concept of automatic in-syringe dispersive liquid-liquid microextraction was successfully applied to the determination of copper in environmental water samples. Bathocuproine was added to the organic phase as a selective reagent, resulting in the formation of a complex with copper. Dispersion was achieved by aspiration of the organic phase and then the watery phase into the syringe as rapidly as possible. After aggregation of the solvent droplets at the head of the syringe, the organic phase was pushed into a liquid waveguide capillary cell for highly sensitive spectrophotometric detection. The entire analytical procedure was carried out automatically on a multisyringe flow-injection analysis platform and a copper determination was accomplished in less than 220 s. A limit of detection of 5 nmol L(-1) was achieved at an extraction efficiency >90% and a preconcentration factor of 30. A linear working range for concentrations of up to 500 nmol L(-1) and an average standard deviation of 7% in peak height were found. The method proved to be well-suited for the determination of copper in water samples, with an average analyte recovery of 100.6%. PMID:22967563

Horstkotte, Burkhard; Alexovi?, Michal; Maya, Fernando; Duarte, Carlos M; Andruch, Vasil; Cerdá, Víctor

2012-09-15

91

The TRPA1 Agonist, Methyl Syringate Suppresses Food Intake and Gastric Emptying  

PubMed Central

Transient receptor potential channel ankryn 1 (TRPA1) expressed in the gastrointestinal tract is associated with gastric motility, gastric emptying, and food intake. In this study, we investigated the effects of methyl syringate, a specific and selective TRPA1 agonist, on food intake, gastric emptying, and gut hormone levels in imprinting control region (ICR) mice. The administration of methyl syringate suppressed cumulative food intake and gastric emptying. In addition, treatment with ruthenium red (RR), a general cation channel blocker, and HC-030031, a selective TRPA1 antagonist, inhibited methyl syringate-induced reduction of food intake and delayed gastric emptying in ICR mice. Methyl syringate also increased plasma peptide YY (PYY) levels, but not glucagon-like peptide-1 (GLP-1) levels. The elevation in PYY was blocked by treatment with RR and HC-030031. The present findings indicate that methyl syringate regulates food intake and gastric emptying through a TRPA1-mediated pathway and, by extension, can contribute to weight suppression. PMID:23990963

Song, Seo Hyeon; Jung, Myungji; Kim, Yiseul; Rhyu, Mee-Ra

2013-01-01

92

Accuracy and precision of low-dose insulin administration using syringes, pen injectors, and a pump.  

PubMed

We compared the accuracy and precision of low-dose insulin administration using various devices including, for the first time, an insulin pump. We dispensed 1, 2, and 5 unit(s) of soluble insulin (100 units/mL) 15 times each from a NovoPen (3.0 mL), a BD-Mini Pen (1.5 mL), a Humalog Pen (100 units/mL), 30G Precision Sure-Dose Insulin Syringes, 30G BD Ultra-Fine II Short Needle Syringes, and a H-TRON-plus V100 insulin pump. Each dose was weighed on an analytical scale, and the delivered and target doses were compared. Accuracy was defined by the absolute percent difference from the target dose. Precision was defined as the absolute percent difference from the group sample mean. Overall, we found that the pen and pump devices were more accurate, and the pump more precise, than the syringes at the 1- and 2-unit doses. Syringes were dangerously inaccurate, clinically, at the 1-unit dose. The use of pens and syringes with very fine increment markings (1/2 unit) did not improve accuracy or precision. Earlier researchers used multiple individuals to draw and weigh the samples. In an effort to eliminate the potential introduction of significant error; our study used only 2 investigators: 1 to draw up the doses and another to weigh them. The conclusions in our study were similar to prior studies. PMID:14968895

Keith, Katherine; Nicholson, David; Rogers, Douglas

2004-01-01

93

Negotiating access: Social barriers to purchasing syringes at pharmacies in Tijuana, Mexico  

PubMed Central

Background One common public health response to the emergence of HIV has been the provision of sterile syringes to people who inject drugs. In Mexico specialized syringe exchanges are rare, and the sale of needles through pharmacies is often the only way people who inject drugs can obtain sterile syringes. However, people who inject drugs in Tijuana, Mexico report considerable social barriers to successfully purchasing syringes at pharmacies. Methods Between October 2008 and March 2009 we conducted seven in-depth focus groups with 47 people who inject drugs in Tijuana, Mexico. Focus group transcripts were analysed using a descriptive and thematic approach rooted in grounded theory. Results We found that injectors offered a number of explanations for why pharmacies were reluctant to sell them syringes, including fear of police; attitudes toward drug use; fear of stereotypical drug user behaviour such as petty theft, violence, or distressing behaviour; and related fears that an obvious drug using clientèle would drive away other customers. Injectors described a range of ways of attempting to re-frame or negotiate interactions with pharmacy staff so that these and related concerns were ameliorated. These included tactics as simple as borrowing cleaner clothing, through to strategies for becoming ‘known’ to pharmacy staff as an individual rather than as a member of a stigmatized group. Conclusion Increasing the ability of pharmacy staff and people who inject drugs to successfully negotiate syringe sales are highly desirable. Interventions designed to improve this likelihood need to capitalize on existing solutions developed ad-hoc by people who inject drugs and pharmacy staff, and should focus on broadening the range of ‘identities’ which pharmacy staff are able to accept as legitimate customers. Approaches to achieve this end might include sensitizing pharmacy staff to the needs of people who inject drugs; facilitating individual drug users meeting individual pharmacy staff; and working with drug users to reduce behaviours seen as problematic by pharmacy staff. PMID:22676968

Davidson, Peter J.; Lozada, Remedios; Rosen, Perth C.; Macias, Armando; Gallardo, Manuel; Pollini, Robin A.

2012-01-01

94

Calibration and test of DIFAR sonobuoys  

Microsoft Academic Search

In this paper, a method for calibrating and testing DIFAR sonobuoy multiplexer without sea or water is proposed. For this purpose; the architecture of DIFAR sonobuoy is introduced, calibration factors are expressed, calibration and test environment in terms of hardware and software are described, calibration and test procedure is explained, and finally, advantages and disadvantages of the proposed calibration and

Ahmet Kuzu; Uveys Danis; Engin Kurt; Engin Karabulut; Demet Sahinkaya; Eyup Bilgic; Ahmet Kaplaner; Serdar Birecik

2011-01-01

95

SAR calibration technology review  

NASA Technical Reports Server (NTRS)

Synthetic Aperture Radar (SAR) calibration technology including a general description of the primary calibration techniques and some of the factors which affect the performance of calibrated SAR systems are reviewed. The use of reference reflectors for measurement of the total system transfer function along with an on-board calibration signal generator for monitoring the temporal variations of the receiver to processor output is a practical approach for SAR calibration. However, preliminary error analysis and previous experimental measurements indicate that reflectivity measurement accuracies of better than 3 dB will be difficult to achieve. This is not adequate for many applications and, therefore, improved end-to-end SAR calibration techniques are required.

Walker, J. L.; Larson, R. W.

1981-01-01

96

Community Impact of Pharmacy-Randomized Intervention to Improve Access to Syringes and Services for Injection Drug Users  

ERIC Educational Resources Information Center

Objectives: In an effort to reduce HIV transmission among injection drug users (IDUs), New York State deregulated pharmacy syringe sales in 2001 through the Expanded Syringe Access Program by removing the requirement of a prescription. With evidence suggesting pharmacists' ability to expand their public health role, a structural,…

Crawford, Natalie D.; Amesty, Silvia; Rivera, Alexis V.; Harripersaud, Katherine; Turner, Alezandria; Fuller, Crystal M.

2014-01-01

97

cross infectionEvaluation of the effectiveness of decontamination of dental syringes  

Microsoft Academic Search

Aim Steam autoclaving is the gold standard for decontaminating dental instruments, but worldwide disinfection is still widely employed. We have evaluated a range of procedures for their ability to inactivate duck hepatitis B virus contaminating dental syringes.Methods Residual infectivity of virus suspensions following 2% glutaraldehyde treatment, ultrasonication or steam sterilisation at 121° or 134° was assayed by injecting day-old ducklings

K Vickery; A Pajkos; Y Cossart

2000-01-01

98

Residual Injection Risk Behavior, HIV Infection, and the Evaluation of Syringe Exchange Programs  

ERIC Educational Resources Information Center

This study assessed relationships between residual risk behavior (risk behavior among persons participating in effective HIV prevention programs) and HIV infection. Structured interviews and HIV tests were obtained from participants in six large U.S. syringe exchange programs. Program characteristics were obtained through interviews with the…

Des Jarlais, Don C.; Braine, Naomi; Yi, Huso; Turner, Charles

2007-01-01

99

Homicide by Sch from a syringe-like dart ejected by a compound crossbow.  

PubMed

The compound crossbow can be used to eject syringe-like dart loaded with poisonous solution. Succinylcholine (Sch) is a short-acting neuromuscular blocker medically used to achieve complete relaxation of muscle for a good intubation condition. Without the help of an artificial respirator, intramuscular injection of a large dose of Sch can paralyze the respiratory muscle and result in the receiver's death. In this paper, we present the homicide case of a young male killed by Sch from a syringe-like dart ejected by a compound crossbow. The subcutaneous and muscular hemorrhages observed around the entry were more severe than that caused by a medical injection. Additionally, other autopsy results showed the external appearance of a pinhole, general asphyxia signs and pathological findings which were not characteristic. The discovery of a syringe-like dart at the scene is the critical clue and reason for analyzing for Sch, which is commonly used to load syringe-like dart to paralyze and steal dog in the countryside of China. PMID:25623191

Guo, Wei; Luo, Guochang; Wang, Hao; Meng, Xiangzhi

2015-02-01

100

Calibrating Dark Energy  

E-print Network

Exploring the diversity of dark energy dynamics, we discover a calibration relation, a uniform stretching of the amplitude of the equation of state time variation with scale factor. This defines homogeneous families of dark energy physics. The calibration factor has a close relation to the standard time variation parameter w_a, and we show that the new, calibrated w_a describes observables, i.e. distance and Hubble parameter as a function of redshift, typically to an accuracy level of 10^{-3}. We discuss implications for figures of merit for dark energy science programs.

Roland de Putter; Eric V. Linder

2008-08-01

101

Safety, effectiveness and ease of use of a non-reusable syringe in a developing country immunization programme.  

PubMed Central

Unsterile needles and syringes may transmit blood-borne infectious agents such as HIV and hepatitis B virus. The emergence of these diseases as major public health concerns and the risk of nosocomial transmission has heightened interest in the development of single-use injection devices. WHO and UNICEF embarked on a programme to develop and introduce these devices in 1987. We report on a field trial in Karachi, Pakistan, of the SoloShot (SS) plastic disposable syringe, which has a metal clip in the syringe barrel to prevent second-time withdrawal of the plunger. A conventional disposable syringe (CS) was used as a comparison. We observed 48 vaccinators giving 2400 injections with the SS and 1440 with the CS; 98.7% of SS performed as designed. The average volume required per delivered dose was comparable for the two syringes and was delivered more quickly with SS. Training and experience had a small but statistically significant effect on several aspects of SS use. Vaccinators who indicated a syringe preference preferred SS on 7 out of 9 indicators. SS is safe and effective in preventing reuse and is easier and quicker to use than the CS. Vaccinators require little, if any, special training. It could directly replace disposable syringes in expanded programmes on immunization (EPI) in countries where use of unsterile disposable devices occurs or when sterilization is not practical. PMID:7704926

Steinglass, R.; Boyd, D.; Grabowsky, M.; Laghari, A. G.; Khan, M. A.; Qavi, A.; Evans, P.

1995-01-01

102

New BRP for human plasma calibrated for coagulation factors V, VIII, XI and XIII - collaborative study for establishment of batches 1 and 2.  

PubMed

A human plasma reference preparation in International Units (IU) must be used in each potency assay of the human coagulation factors V, VIII and XI in human plasma pooled and treated for virus inactivation, according to the European Pharmacopoeia (Ph. Eur.) monograph 1646 and general chapters 2.7.4 and 2.7.22 respectively, and in the potency assay of human coagulation factor XIII in fibrin sealant kits, according to Ph. Eur. monograph 0903. International reference standards for all of these factors are now established, however, regional reference standards were not available for the required routine use. It was therefore proposed by European OMCLs and manufacturers to establish a European reference preparation, and it was the goal of this study to accomplish that. Two candidate biological reference preparations (BRPs), separate lyophilisation lots of the same normal human plasma bulk material, were calibrated against the International Standards (ISs) for human coagulation factors V, VIII, XI and XIII. Twelve European laboratories including OMCLs and manufacturers participated. The candidate material was tested against the ISs in 4 separate assays for each factor using the methods described in the relevant Ph. Eur. monographs and general chapters. No discernable difference was noted between the activities of the 2 candidates. They were shown to be suitable for their intended use and it was recommended to assign to both batches a potency of 0.73 IU/mL for factor V, 0.74 IU/mL for factor VIII, 0.59 IU/mL for factor XI and 0.79 IU/mL for factor XIII. Candidate batch B is proposed to be used first as lot 1, followed upon its depletion by candidate batch A (lot 2). The BRP batches will be monitored regularly for potency throughout their lifetime. EDQM BRP batches 1 and 2 of coagulation factors V, VIII, XI and XIII plasma were formally adopted by the Ph. Eur. Commission at their session in June 2011. PMID:22225765

Bayer, P; Daas, A; Milne, C

2011-11-01

103

Determination of pyrethroid metabolites in human urine using liquid phase microextraction coupled in-syringe derivatization followed by gas chromatography/electron capture detection.  

PubMed

Metabolites of synthetic pyrethroids such as cis-3-(2,2-dibromovinyl)-2,2-di-methylcyclo-propane-1-carboxylic acid, cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid), 3-phenoxybenzoic acid (3-PBA), and 4-fluoro-3-PBA are biomarkers for exposure to phenothrin, tetramethrin, cyfluthrin, cypermethrin, deltamethrin, and permethrin. In this study, the pyrethroid metabolites in workers' urine samples were monitored for the first time with a novel sample pretreatment process combining hollow fiber liquid phase microextraction (HF-LPME) and in-syringe derivatization (ISD) followed by gas chromatography-electron capture detector (GC-ECD) analysis. A micro-syringe pre-filled with derivatizing agents and syringe needle connected to an extracting solvent impregnated hollow fiber segment was used as the LPME probe. Pyrethroid metabolites were extracted and enriched simultaneously from urine samples by HF-LPME sampling and acid hydrolysis at 70 °C for 10 min. After sampling, the ISD was performed by mixing the extracting solution and derivatizing agents through plunger movements, followed by GC-ECD analysis. Parameters influencing the HF-LPME efficiency and ISD were investigated and optimized. Under optimum conditions, the method provided enrichment factors of 69.8-154.6, repeatability from 5.0 to 12% (n = 5), and good linearity (R(2) = 0.9980-0.9998) for interested analytes spiked in urine samples. The method detection limits ranged from 1.6 to 17 ng/mL. A comparison was performed between the proposed method and conventional methods. The proposed method was applied to analyze pyrethroid metabolites in the urine samples collected from workers of pesticide formulation plants. The results suggested that the proposed HF-LPME coupled ISD method was a rapid, simple, efficient, and eco-friendly technique in the biomonitoring of metabolites of pyrethroids in workers' urine. PMID:21667061

Lin, Chiu-Hwa; Yan, Cheing-Tong; Kumar, Ponnusamy Vinoth; Li, Hong-Ping; Jen, Jen-Fon

2011-08-01

104

Photocatalytic ozonation of phenolic wastewaters: Syringic acid, tyrosol and gallic acid.  

PubMed

The photocatalytic ozonation of a mixture of 3 phenols (gallic acid, tyrosol and syringic acid) has been conducted under different operating conditions. The individual adsorption of the phenol type compounds onto titanium dioxide (photocatalyst) has been first evaluated. Equilibrium conditions are attained in less than an hour while the isotherm curves reveal that adsorption intensity increases in order: syringic acid < tyrosol < gallic acid. When the photocatalytic ozonation is applied, an optimum in titanium dioxide concentration is experienced (1.5 g L(-1)). Direct comparison of the photocatalytic ozonation to other less sophisticated oxidation systems (i.e., single ozonation, catalytic ozonation, photo-ozonation, etc.) indicates a higher efficiency of the former in terms of ozone uptake. PMID:18161559

Gimeno, Olga; Fernandez, Lidia A; Carbajo, Maria; Beltran, Fernando; Rivas, Javier

2008-01-01

105

Effects of Syringe Material, Sample Storage Time, and Temperature on Blood Gases and Oxygen Saturation in Arterialized Human Blood Samples  

Microsoft Academic Search

BACKGROUND: The practice of on-ice storage of arterial-blood samples in plastic syringes for delayed analysis continues, and the effects of storage time and temperature on the measurement of blood-oxygen-saturation values (SaO2) have not been adequately described. OBJECTIVE: To de- termine the effects of syringe material, storage time, and storage temperature on normal arterial- ized blood gas and SaO2 values. METHODS:

Thomas P Knowles; RRT RPSGT; F Herbert Douce

106

Needle-free transdermal delivery using PLGA nanoparticles: Effect of particle size, injection pressure and syringe orifice diameter.  

PubMed

The aim of this study is to investigate the effects of particle size and other injection factors on the skin penetration of nanoparticles delivered with a needle-free injector. Experimental and simulation tests were carried out at various parameters. In addition to testing different sizes of nanoparticles, we also observed the effects of several injection pressures and syringe orifice diameters (SOD) on the dispersion pattern of the nanoparticles after injection. Our results showed that as the nanoparticle size increased from 45nm to 452nm, the resulting puncture opening, channel diameter, and depth of the nanoparticle dispersion decreased, but the width of the dispersion increased. Conversely, as the SOD increased, the puncture opening, channel diameter, and depth of the dispersion increased, but width of the dispersion decreased. Increasing the injection pressure also decreased the size, depth, and width of the puncture opening. These results identify how these three parameters affect nanoparticle delivery from a needle-free injector; therefore, our findings will be beneficial for optimization and further study of needle-free injectors as a mechanism for transdermal delivery of nanoparticles. PMID:25456991

Park, Chan Hee; Tijing, Leonard D; Kim, Cheol Sang; Lee, Kang-Min

2014-11-01

107

Spectrophotometric study of the copigmentation of malvidin 3-O-glucoside with p-coumaric, vanillic and syringic acids.  

PubMed

Anthocyanins are a natural source of pigments in plants and their processed food products have become attractive and excellent candidates to replace the synthetic colourants due to their characteristic intense colours and associated health benefits. The intermolecular copigmentation between anthocyanins and other colourless compounds has been reported to be an important way to enhance and stabilise the colour intensity of aqueous solutions. In the present work we report the equilibrium constant, stoichiometric ratio and the thermodynamic parameters (?G°, ?H° and ?S°) related to the intermolecular copigmentation reactions of the anthocyanin malvidin 3-O-glucoside with one hydroxycinnamic acid (p-coumaric acid) and two O-methylated hydroxybenzoic acids (vanillic and syringic acid). Different factors which affect their interactions such as copigment concentration, pH and temperature of the medium are examined at two pH levels (pH=2.50 and 3.65) corresponding to those of the major food mediums where these reactions take place (fruit juices, wine, jams etc.). PMID:23993528

Malaj, Naim; De Simone, Bruna Clara; Quartarolo, Angelo Domenico; Russo, Nino

2013-12-15

108

A Two-Factor Empirical Deterministic Response Surface Calibration Model for Site-Specific Predictions of Lime Requirement  

Microsoft Academic Search

This paper describes the development of an empirical deterministic two-factor response surface model for the Woodruff lime-requirement buffer (WRF). The model may be used to produce variable-rate lime requirement maps, or to predict lime requirements in real-time. Hence it may be suitable as a component of a decision support system (DSS) for the site-specific management of acid soil. The models'

R. A. Viscarra Rossel; A. B. McBratney

2000-01-01

109

Test and calibration of sonobuoys in the air environment  

Microsoft Academic Search

In this paper, a method for calibrating and testing DIFAR sonobuoy multiplexer without sea or water is proposed. For this purpose; the architecture of DIFAR sonobuoy is introduced, calibration factors are expressed, calibration and test environment in terms of hardware and software are described, calibration and test procedure is explained, and finally, laboratory test results of a sonobuoy calibrated in

Ahmet Kuzu; Uveys Danis; Engin Kurt; Engin Karabulut; Demet Sahinkaya; Ahmet Kaplaner; Serdar Birecik; Bulent Ozumut; Eyup Bilgic

2012-01-01

110

Lab-in-a-syringe using gold nanoparticles for rapid immunosensing of protein biomarkers.  

PubMed

We have developed a paper and gold nanoparticle (AuNP)-based lab-in-a-syringe (LIS) for immunosensing of biomarkers. This simple diagnostic device features simultaneous sampling and vertical-flow operation, which means that unlike typical immunosensors, it does not suffer from any delay between sampling and detection. It can handle large-volume, low-concentration samples for analysis in diverse applications (e.g. biomedical, environmental, food, etc.). Furthermore, its operating range for sample concentration can be tuned by simply changing the volume of the syringed sample, which enables on-demand limits of detection (LOD). The LIS contains two nitrocellulose pads: the conjugate pad (which captures the analyte) and the detection pad (which signals the presence of the captured analyte) both embedded into reusable plastic cartridges. We demonstrated its efficiency in detecting human IgG (HIgG) (LOD: 1.0 ng mL(-1)) and prostate-specific antigen (PSA) (spiked urine samples; LOD: 1.9 ng mL(-1)). In the field, the LIS can be used for complete on-site analysis or to obtain partially analyzed samples (AuNPs with captured analyte) for subsequent detailed testing in specialized laboratories. PMID:25375810

Nunes Pauli, Gisele Elias; de la Escosura-Muñiz, Alfredo; Parolo, Claudio; Helmuth Bechtold, Ivan; Merkoçi, Arben

2014-12-16

111

Iterative Magnetometer Calibration  

NASA Technical Reports Server (NTRS)

This paper presents an iterative method for three-axis magnetometer (TAM) calibration that makes use of three existing utilities recently incorporated into the attitude ground support system used at NASA's Goddard Space Flight Center. The method combines attitude-independent and attitude-dependent calibration algorithms with a new spinning spacecraft Kalman filter to solve for biases, scale factors, nonorthogonal corrections to the alignment, and the orthogonal sensor alignment. The method is particularly well-suited to spin-stabilized spacecraft, but may also be useful for three-axis stabilized missions given sufficient data to provide observability.

Sedlak, Joseph

2006-01-01

112

Image Calibration  

NASA Technical Reports Server (NTRS)

Calibrate_Image calibrates images obtained from focal plane arrays so that the output image more accurately represents the observed scene. The function takes as input a degraded image along with a flat field image and a dark frame image produced by the focal plane array and outputs a corrected image. The three most prominent sources of image degradation are corrected for: dark current accumulation, gain non-uniformity across the focal plane array, and hot and/or dead pixels in the array. In the corrected output image the dark current is subtracted, the gain variation is equalized, and values for hot and dead pixels are estimated, using bicubic interpolation techniques.

Peay, Christopher S.; Palacios, David M.

2011-01-01

113

Calibration of human coagulation factor VIII concentrate Ph. Eur. BRP Batch 4 for use in potency assays.  

PubMed

The European Pharmacopoeia Biological Reference Preparation (Ph. Eur. BRP) Batch 4 was established as an international common working standard for potency determination of human coagulation factor VIII (FVIII) preparations to replace the dwindling stocks of the BRP Batch 3, the current European standard. Similarly, stocks of the current World Health Organisation 7th International Standard (WHO 7th IS) were also running low. Therefore a project was jointly organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM, Council of Europe) and the National Institute for Biological Standards and Control (NIBSC, UK) in order to replace both standards concomitantly. The potency of the BRP Batch 4 was assigned during an international collaborative study involving 38 laboratories with reference to the WHO 7th IS and the BRP Batch 3. Four candidate materials, 2 plasma-derived (samples A and C) and 2 recombinant (samples B and D) have been evaluated, sample C being the specific candidate for the replacement of the BRP Batch 3. Participants were instructed to perform 8 independent assays following their own routine validated methods, by either the one-stage clotting assay or the chromogenic assay, or both. Laboratories returned 22 data sets for the clotting assay and 30 data sets for the chromogenic assay. This publication reports the results obtained with both assays but only the results of the chromogenic assay are highlighted in the conclusions, as it is the assay prescribed by the European Pharmacopoeia. Data were analysed separately for both assays. The consensus potency value was calculated as the unweighted geometric mean of the unweighted geometric means of each individual laboratory. For sample C, there was a significant difference in potency estimate between the chromogenic and the clotting assay. It was therefore not possible to reconcile both results. The chromogenic potencies however were in very good agreement being 10.4 IU/ampoule (n = 30), when assessed against both standards. The inter-laboratory geometric coefficient of variation (GCV) was 4.8 % and 7.1 % against the WHO 7th IS and the BRP Batch 3 respectively. The Ph. Eur. BRP Batch 4 is a freeze-dried, plasma-derived concentrate. The material was filled in approximately 20,000 ampoules and lyophilised. The final residual water content is 0.33 %. Based on accelerated degradation studies, the stability of the material is suitable for a reference preparation. The candidate Ph. Eur. BRP Batch 4 was adopted at the 136th session of the European Pharmacopoeia Commission in March 2010. The standard will be available from the EDQM with the catalogue number H0920000 upon exhaustion of the current batch. PMID:21144486

Raut, S; Costanzo, A; Daniels, S; Heath, A; Buchheit, K-H

2010-10-01

114

Portable system of programmable syringe pump with potentiometer for determination of promethazine in pharmaceutical applications  

PubMed Central

A simple and fast-automated method was developed and validated for the assay of promethazine hydrochloride in pharmaceutical formulations, based on the oxidation of promethazine by cerium in an acidic medium. A portable system, consisting of a programmable syringe pump connected to a potentiometer, was constructed. The developed change in potential during promethazine oxidation was monitored. The related optimum working conditions, such as supporting electrolyte concentration, cerium(IV) concentration and flow rate were optimized. The proposed method was successfully applied to pharmaceutical samples as well as synthetic ones. The obtained results were realized by the official British pharmacopoeia (BP) method and comparable results were obtained. The obtained t-value indicates no significant differences between the results of the proposed and BP methods, with the advantages of the proposed method being simple, sensitive and cost effective. PMID:23960787

Saleh, Tawfik A.; Abulkibash, A.M.; Ibrahim, Atta E.

2011-01-01

115

Immunochemical authentication of manuka honey using a monoclonal antibody specific to a glycoside of methyl syringate.  

PubMed

Leptosperin, a novel glycoside of methyl syringate, is exclusively present in manuka honey derived from the Leptospermum species Leptospermum scoparium. Quantification of leptosperin might thus be applicable for authentication of honey. The concentration of leptosperin has high linearity with antibacterial activity. We established a monoclonal antibody to leptosperin and characterized the antibody in detail by a competitive enzyme-linked immunosorbent assay (ELISA), comparing the results with those of the high-performance liquid chromatography (HPLC) method for validation. The antigen in manuka honey was confirmed as leptosperin by HPLC fractionation with quantitation by an ELISA. Leptosperin contents of 50 honey samples were analyzed by an established ELISA, which can handle 20 samples (duplicate) on one 96-well plate. Significant coincidence with the chemical quantitation was observed. Immunochemical quantitation of leptosperin would be an economical and facile method for the possible authentication of manuka honey, allowing many honey samples to be processed and analyzed by an ELISA simultaneously. PMID:25310890

Kato, Yoji; Araki, Yukako; Juri, Maki; Fujinaka, Rie; Ishisaka, Akari; Kitamoto, Noritoshi; Nitta, Yoko; Niwa, Toshio; Takimoto, Yosuke

2014-11-01

116

Characterization of syringe-pump-driven induced pressure fluctuations in elastic microchannels.  

PubMed

We study pressure and flow-rate fluctuations in microchannels, where the flow rate is supplied by a syringe pump. We demonstrate that the pressure fluctuations are induced by the flow-rate fluctuations coming from mechanical oscillations of the pump motor. Also, we provide a mathematical model of the effect of the frequency of the pump on the normalized amplitude of pressure fluctuations and introduce a dimensionless parameter incorporating pump frequency, channel geometry and mechanical properties that can be used to predict the performance of different microfluidic device configurations. The normalized amplitude of pressure fluctuations decreases as the frequency of the pump increases and the elasticity of the channel material decreases. The mathematical model is verified experimentally over a range of typical operating conditions and possible applications are discussed. PMID:25537266

Zeng, Wen; Jacobi, Ian; Beck, David J; Li, Songjing; Stone, Howard A

2015-02-01

117

Syringeal Specialization of Frequency Control during Song Production in the Bengalese Finch (Lonchura striata domestica)  

PubMed Central

Background Singing in songbirds is a complex, learned behavior which shares many parallels with human speech. The avian vocal organ (syrinx) has two potential sound sources, and each sound generator is under unilateral, ipsilateral neural control. Different songbird species vary in their use of bilateral or unilateral phonation (lateralized sound production) and rapid switching between left and right sound generation (interhemispheric switching of motor control). Bengalese finches (Lonchura striata domestica) have received considerable attention, because they rapidly modify their song in response to manipulations of auditory feedback. However, how the left and right sides of the syrinx contribute to acoustic control of song has not been studied. Methodology Three manipulations of lateralized syringeal control of sound production were conducted. First, unilateral syringeal muscular control was eliminated by resection of the left or right tracheosyringeal portion of the hypoglossal nerve, which provides neuromuscular innervation of the syrinx. Spectral and temporal features of song were compared before and after lateralized nerve injury. In a second experiment, either the left or right sound source was devoiced to confirm the role of each sound generator in the control of acoustic phonology. Third, air pressure was recorded before and after unilateral denervation to enable quantification of acoustic change within individual syllables following lateralized nerve resection. Significance These experiments demonstrate that the left sound source produces louder, higher frequency, lower entropy sounds, and the right sound generator produces lower amplitude, lower frequency, higher entropy sounds. The bilateral division of labor is complex and the frequency specialization is the opposite pattern observed in most songbirds. Further, there is evidence for rapid interhemispheric switching during song production. Lateralized control of song production in Bengalese finches may enhance acoustic complexity of song and facilitate the rapid modification of sound production following manipulations of auditory feedback. PMID:22479543

Secora, Kristen R.; Peterson, Jennifer R.; Urbano, Catherine M.; Chung, Boah; Okanoya, Kazuo; Cooper, Brenton G.

2012-01-01

118

Methyl syringate: a chemical marker of asphodel (Asphodelus microcarpus Salzm. et Viv.) monofloral honey.  

PubMed

During the liquid chromatographic study of the phenolic fraction of monofloral honeys was detected in the asphodel honey ( Asphodelus microcarpus Salzm. et Viv.) chromatogram a distinctive peak not detected in other monofloral honeys such as Arbutus unedo L., Hedysarum coronarium , Eucalyptus spp., and Galactites tomentosa . After thin layer chromatography (TLC) purification and characterization by NMR and LC-MS/MS, the compound was identified as methyl syringate (MSYR) and confirmed against an original standard. Levels of MSYR were measured in honeys of 2005, 2006, and 2007 by HPLC-DAD analysis. Level determination of MSYR was repeated in 2008 for 2006 and 2007 honeys to evaluate chemical stability of this phenolic compound. Levels of MSYR measured 1 year after the sampling did not show significant statistical differences (p < 0.05). The stability of MSYR was also confirmed by 12 asphodel honey samples collected in 2005 that showed amounts of methyl syringate comparable with those found in fresh honey. For the evaluation of MSYR origin, samples of nectars were collected from flowers and the content of MSYR was measured. Levels of MSYR in honeys are originated from the nectar with an average contribution of the nectar to the honey of 80%. Melissopalinological analysis did not allow the attribution of the honey monofloral origin because levels of asphodel pollen were <6% for all analyzed samples. Previously reported levels of MSYR for robinia, rape, chestnut, clover, linden blossom, dandelion, sunflower, thyme, manuka, and fir honeys were <5 mg/kg. For this reason, a minimum level of 122.6 mg/kg for MSYR in asphodel honeys can be considered as a chemical marker and, unlike the melissopalynological analysis, can be used for the origin attribution and to evaluate the percent of asphodel nectar in the honey. PMID:19309074

Tuberoso, Carlo I G; Bifulco, Ersilia; Jerkovi?, Igor; Caboni, Pierluigi; Cabras, Paolo; Floris, Ignazio

2009-05-13

119

A Syringe-Like Love Dart Injects Male Accessory Gland Products in a Tropical Hermaphrodite  

PubMed Central

Sexual conflict shapes the evolution of many behaviours and processes involved in reproduction. Nearly all evidence supporting this comes from species where the sexes are separated. However, a substantial proportion of animals and most plants are hermaphroditic, and theoretical work predicts that sexual conflict plays an important role even when the sexes are joined within one individual. This seems to have resulted in bizarre mating systems, sophisticated sperm packaging and complex reproductive morphologies. By far the best-known example of such a strategy in hermaphrodites is the shooting of so-called love-darts in land snails. All known love darts carry a gland product on their outside and enter this into the partner’s hemolymph by stabbing. Here, we show that species of the snail genus Everettia possess a syringe-like dart that serves as a real injection needle. Their dart is round in cross-section, contains numerous channels, and has perforations along its side. Histology and electron microscopy show that these holes connect to the channels inside the dart and run all the way up to the elaborate mucus glands that are attached to the dart sac. This is the first report on a love dart that is used as a syringe to directly inject the gland product into the partner’s hemolymph. Although the exact use and function of this dart remains to be demonstrated, this clearly adds to the complexity of the evolution of reproductive strategies in hermaphrodites in general. Moreover, the perforations on the outside of the love dart resemble features of other injection devices, thus uncovering common design and repeated evolution of such features in animals. PMID:23894565

Koene, Joris M.; Liew, Thor-Seng; Montagne-Wajer, Kora; Schilthuizen, Menno

2013-01-01

120

NIMBY localism and national inequitable exclusion alliances: The case of syringe exchange programs in the United States  

Microsoft Academic Search

Syringe exchange programs (SEPs) aim to reduce the harm associated with injection drug use (IDU). Although they have been accepted as critical components of HIV prevention in many parts of the world, they are often unwelcome and difficult to set up and maintain, even in communities hardest hit by IDU-related HIV transmission. This research examines socio-cultural and political processes that

Barbara Tempalski; Risa Friedman; Marie Keem; Hannah Cooper; Samuel R. Friedman

2007-01-01

121

A computer-controlled syringe driver for use during anaesthesia. A modification of the Graseby MS16A.  

PubMed

The requirements of a drug infusion device for use in theatre are discussed. A modification of the Graseby MS16A syringe pump and an interface circuit permitting its remote control by microcomputer are described. The pump is controlled via a standard computer interface (RS232) which makes it a unique and powerful research tool. Aspects of safety are considered. PMID:3707804

Cohen, A T

1986-06-01

122

Antenna Calibration and Measurement Equipment  

NASA Technical Reports Server (NTRS)

A document describes the Antenna Calibration & Measurement Equipment (ACME) system that will provide the Deep Space Network (DSN) with instrumentation enabling a trained RF engineer at each complex to perform antenna calibration measurements and to generate antenna calibration data. This data includes continuous-scan auto-bore-based data acquisition with all-sky data gathering in support of 4th order pointing model generation requirements. Other data includes antenna subreflector focus, system noise temperature and tipping curves, antenna efficiency, reports system linearity, and instrument calibration. The ACME system design is based on the on-the-fly (OTF) mapping technique and architecture. ACME has contributed to the improved RF performance of the DSN by approximately a factor of two. It improved the pointing performances of the DSN antennas and productivity of its personnel and calibration engineers.

Rochblatt, David J.; Cortes, Manuel Vazquez

2012-01-01

123

Calibration Binaries  

NASA Astrophysics Data System (ADS)

Two Excel Spreadsheet files are offered to help calibrate telescope or camera image scale and orientation with binary stars for any time. One is a personally selected list of fixed position binaries and binaries with well-determined orbits, and the other contains all binaries with published orbits. Both are derived from the web site of the Washington Double Star Library. The spreadsheets give the position angle and separation of the binaries for any entered time by taking advantage of Excel's built in iteration function to solve Kepler's transcendental equation.

Drummond, J.

2011-09-01

124

Monte Carlo calculations of the ionization chamber wall correction factors for 192Ir and 60Co gamma rays and 250 kV x-rays for use in calibration of 192Ir HDR brachytherapy sources.  

PubMed

As in the method for the calibration of 192Ir high-dose-rate (HDR) brachytherapy sources, the ionization chamber wall correction factor A(w), is needed for 192Ir and 60Co gamma rays and 250 kV x-rays. This factor takes into account the variation in chamber response due to the attenuation of the photon beam in the chamber wall and build-up cap and the contribution of scattered photons. Monte Carlo calculations were performed using the EGS4 code system with the PRESTA algorithm, to calculate the A(w) factor for 51 commercial ionization chambers and build-up caps exposed to the typical energy spectrum of 192Ir and 60Co gamma rays and 250 kV x-rays. The calculated A(w) correction factors for 192Ir and 60Co sources and 250 kV x-rays agree very well to within 0.1% with published experimental data (the statistical uncertainty is less than 0.1% of the calculated correction factor value). For the 192Ir sources, A(w) varies from 0.973 to 0.993 and for the 250 kV x-rays the minimum value of A(w) for all chambers studied is 0.983. The calculated A(w) correction factors can be used to calculate the air kerma calibration factor of HDR brachytherapy sources, when interpolative methods are considered, contributing to the reduction in the overall uncertainties in the calibration procedure. PMID:10473203

Ferreira, I H; de Almeida, C E; Marre, D; Marechal, M H; Bridier, A; Chavaudra, J

1999-08-01

125

Are major reductions in new HIV infections possible with people who inject drugs? The case for low dead-space syringes in highly affected countries.  

PubMed

Circumstantial evidence from laboratory studies, mathematical models, ecological studies and bio behavioural surveys, suggests that injection-related HIV epidemics may be averted or reversed if people who inject drugs (PWID) switch from using high dead-space to using low dead-space syringes. In laboratory experiments that simulated the injection process and rinsing with water, low dead space syringes retained 1000 times less blood than high dead space syringes. In mathematical models, switching PWID from high dead space to low dead space syringes prevents or reverses injection-related HIV epidemics. No one knows if such an intervention is feasible or what effect it would have on HIV transmission among PWID. Feasibility studies and randomized controlled trials (RCTs) will be needed to answer these questions definitively, but these studies will be very expensive and take years to complete. Rather than waiting for them to be completed, we argue for an approach similar to that used with needle and syringe programs (NSP), which were promoted and implemented before being tested more rigorously. Before implementation, rapid assessments that involve PWID will need to be conducted to ensure buy-in from PWID and other local stakeholders. This commentary summarizes the existing evidence regarding the protective effects of low dead space syringes and estimates potential impacts on HIV transmission; it describes potential barriers to transitioning PWID from high dead space to low dead space needles and syringes; and it presents strategies for overcoming these barriers. PMID:22884539

Zule, William A; Cross, Harry E; Stover, John; Pretorius, Carel

2013-01-01

126

Syringe filtration methods for examining dissolved and colloidal trace element distributions in remote field locations  

NASA Technical Reports Server (NTRS)

It is well-established that sampling and sample processing can easily introduce contamination into dissolved trace element samples if precautions are not taken. However, work in remote locations sometimes precludes bringing bulky clean lab equipment into the field and likewise may make timely transport of samples to the lab for processing impossible. Straightforward syringe filtration methods are described here for collecting small quantities (15 mL) of 0.45- and 0.02-microm filtered river water in an uncontaminated manner. These filtration methods take advantage of recent advances in analytical capabilities that require only small amounts of waterfor analysis of a suite of dissolved trace elements. Filter clogging and solute rejection artifacts appear to be minimal, although some adsorption of metals and organics does affect the first approximately 10 mL of water passing through the filters. Overall the methods are clean, easy to use, and provide reproducible representations of the dissolved and colloidal fractions of trace elements in river waters. Furthermore, sample processing materials can be prepared well in advance in a clean lab and transported cleanly and compactly to the field. Application of these methods is illustrated with data from remote locations in the Rocky Mountains and along the Yukon River. Evidence from field flow fractionation suggests that the 0.02-microm filters may provide a practical cutoff to distinguish metals associated with small inorganic and organic complexes from those associated with silicate and oxide colloids.

Shiller, Alan M.

2003-01-01

127

Syringe filtration methods for examining dissolved and colloidal trace element distributions in remote field locations.  

PubMed

It is well-established that sampling and sample processing can easily introduce contamination into dissolved trace element samples if precautions are not taken. However, work in remote locations sometimes precludes bringing bulky clean lab equipment into the field and likewise may make timely transport of samples to the lab for processing impossible. Straightforward syringe filtration methods are described here for collecting small quantities (15 mL) of 0.45- and 0.02-microm filtered river water in an uncontaminated manner. These filtration methods take advantage of recent advances in analytical capabilities that require only small amounts of waterfor analysis of a suite of dissolved trace elements. Filter clogging and solute rejection artifacts appear to be minimal, although some adsorption of metals and organics does affect the first approximately 10 mL of water passing through the filters. Overall the methods are clean, easy to use, and provide reproducible representations of the dissolved and colloidal fractions of trace elements in river waters. Furthermore, sample processing materials can be prepared well in advance in a clean lab and transported cleanly and compactly to the field. Application of these methods is illustrated with data from remote locations in the Rocky Mountains and along the Yukon River. Evidence from field flow fractionation suggests that the 0.02-microm filters may provide a practical cutoff to distinguish metals associated with small inorganic and organic complexes from those associated with silicate and oxide colloids. PMID:12967118

Shiller, Alan M

2003-09-01

128

A laser syringe aimed at delivering drug into the outer layer of human skin  

NASA Astrophysics Data System (ADS)

A desire to eliminate hypodermic needle in transdermal drug delivery may now be realized. Imaging of the skin after injection of fluorescent probe and biotin via the bio-ballistic technique revealed the epidermal and dermal layers which were stained well below 60 ?m underneath the abdominal skin of the guinea-pig. An extensive network of cells are shown in the deeper layer of the stained dermis as the distributed fluorescein isothiocyanate (FITC) dose is administered by repeated injection via the laser-based microjet. Here, we show our method of laser-based microjet drug delivery is capable of breaching guinea-pig's skin tissue and then delivering controlled dose of drug to the targeted region between 10 to 400 ?m underneath the outermost layer of the skin. While minimizing pain and tissue damage by reducing the injection volume to ˜100 nl per pulse and the microjet diameter of half the conventional syringe needle in 100 ?m, the optimally controlled delivery of liquid drug by the irradiated laser pulse is shown possible.

Yoh, Jack J.; Jang, Hun-jae; Park, Mi-ae; Han, Tae-hee; Hah, Jung-moo

2012-07-01

129

False selection of syringe-brand compatibility and the method of correction during target-controlled infusion of propofol  

PubMed Central

Background We evaluated volumetric differences of syringe brand compatibilities, and investigated the impact of false brand settings on target-controlled infusion (TCI) and their methods of correction. Methods Gravimetric measurement of 10 ml bolus infusions was performed using BD Plastipak (BDP) and Terumo compatible syringes, while setting to 7 different kinds of brand compatibilities (BDP, Sherwood Monoject, BD Perfusion, Braun Perfusor, Braun Omnifix, Fresenius Injectomat, and Terumo). To investigate the performance of TCI using BDP with a false setting to Terumo (BDPTERUMO) and Terumo to BDP (TERUMOBDP), 24 TCI targeting 4.0 µg/ml of effect-site concentration (Ceff) of propofol were performed. Subsequently, another 24 TCI were evaluated for simple corrections of false settings at 30 min. We also investigated 24 TCI using active corrections (fill-up for BDPTERUMO, evacuation for TERUMOBDP) based on the pharmacokinetics of propofol. The Ceff at 30 min of TCI and time to normalize to ± 5% of target concentration (T±5%target) were compared. Results The Ceff of BDPTERUMO showed negative bias and 17.2% inaccuracy, and the Ceff of TERUMOBDP showed positive bias and 19.5% inaccuracy. The Ceff at 30 min showed no difference between the methods of correction in BDPTERUMO or TERUMOBDP. The T±5%target in both the active corrections was significantly shorter than that of each simple corrections (P < 0.001). Conclusions False brand setting of syringe proportionally maintained different predicted concentrations as much as the volumetric differences of syringe brand. Based on the results, it is proposed that correction methods based on pharmacokinetics could effectively normalize the differences, without giving up the wrong TCI. PMID:23560192

Chae, Yun-Jeong; Kim, Jong-Yeop; Kim, Do-Won; Moon, Bong-Ki

2013-01-01

130

A new syringe pump apparatus for the retrieval and temporal analysis of helium in groundwaters and geothermal fluids  

USGS Publications Warehouse

[1] We present details of a newly designed syringe pump apparatus for the retrieval and temporal analysis of helium (SPARTAH). The device is composed of a commercially available syringe pump connected to coils of Cu tubing, which interface the syringe and the groundwater or geothermal wellhead. Through test deployments at geothermal wells in Iceland and California, we show that well fluids are drawn smoothly, accurately, and continuously into the Cu tubing and can be time-stamped through user-determined operating parameters. In the laboratory, the tubing is sectioned to reveal helium (He) characteristics of the fluids at times and for durations of interest. The device is capable of prolonged deployments, up to 6 months or more, with minimal maintenance. It can be used to produce detailed time series records of He, or any other geochemical parameter, in groundwaters and geothermal fluids. SPARTAH has application in monitoring projects assessing the relationship between external transient events (e.g., earthquakes) and geochemical signals in aqueous fluids. ?? 2009 by the American Geophysical Union.

Barry, P.H.; Hilton, D.R.; Tryon, M.D.; Brown, K.M.; Kulongoski, J.T.

2009-01-01

131

Investigation by improved syringe method of effect of tampons on production in vitro of toxic shock syndrome toxin 1 by Staphylococcus aureus.  

PubMed Central

Twenty-seven types of commercial tampons from five manufacturers were tested in a sealed-syringe method to determine their effect on the growth of Staphylococcus aureus and the production of toxic shock syndrome toxin 1. In this improvement of the syringe method, the available air is limited to that which is contained within the sealed syringe containing the tampon. The culture medium was buffered, and blood and CO2 were included in the incubation to better simulate the vaginal environment during menstruation. Variables of tampon weight, composition, air volume, and absorbency were examined for their effect on the production of toxic shock syndrome toxin 1. Generally, with the exception of brand E, toxin production in the presence of tampons was equal to or lower than that in a sealed control syringe containing air but no tampon. PMID:2808672

Wong, A C; Downs, S A

1989-01-01

132

Calibrating the BOLD response without administering gases: Comparison of hypercapnia calibration with calibration using an asymmetric spin echo.  

PubMed

The calibrated BOLD (blood oxygen level dependent) technique was developed to quantify the BOLD signal in terms of changes in oxygen metabolism. In order to achieve this a calibration experiment must be performed, which typically requires a hypercapnic gas mixture to be administered to the participant. However, an emerging technique seeks to perform this calibration without administering gases using a refocussing based calibration. Whilst hypercapnia calibration seeks to emulate the physical removal of deoxyhaemoglobin from the blood, the aim of refocussing based calibration is to refocus the dephasing effect of deoxyhaemoglobin on the MR signal using a spin echo. However, it is not possible to refocus all of the effects that contribute to the BOLD signal and a scale factor is required to estimate the BOLD scaling parameter M. In this study the feasibility of a refocussing based calibration was investigated. The scale factor relating the refocussing calibration to M was predicted by simulations to be approximately linear and empirically measured to be 0.88±0.36 for the visual cortex and 0.93±0.32 for a grey matter region of interest (mean±standard deviation). Refocussing based calibration is a promising approach for greatly simplifying the calibrated BOLD methodology by eliminating the need for the subject to breathe special gas mixtures, and potentially provides the basis for a wider implementation of quantitative functional MRI. PMID:25451475

Blockley, Nicholas P; Griffeth, Valerie E M; Simon, Aaron B; Dubowitz, David J; Buxton, Richard B

2015-01-01

133

Multi-syringe flow injection solid-phase extraction system for on-line simultaneous spectrophotometric determination of nitro-substituted phenol isomers.  

PubMed

In this paper, a time-based multi-syringe flow injection (MSFI) approach is proposed for automated disk-based sorbent extraction of three nitro-substituted phenol isomers (2-, 3-, and 4-nitrophenol) followed by on-line simultaneous determination of individual species by diode-array spectrophotometry. The method involves the on-line enrichment of the targeted analytes from an acidic medium containing 0.1 mol L(-1) HCl onto a co-polymeric sorbent material, and the concurrent removal of potentially interfering matrix components. The nitrophenol isomers are subsequently eluted with an alkaline solution (0.7 mol L(-1) NaOH), whereupon the eluate is delivered to a diode-array spectrophotometer for recording of the spectral data in the UV-vis region. Deconvolution of strongly overlapped spectra was conducted with multivariate regression models based on multiple linear regression calibration. The analytical performance of the chemometric algorithm was characterized by relative prediction errors and recoveries. The MSFI manifold was coupled to a multiposition selection valve to set a rugged analyzer that ensures minimum operational maintenance via exploitation of membrane switching protocols. As compared with earlier methods for isolation/pre-concentration of nitro-substituted phenols based on liquid-liquid extraction, the proposed flow-through disk-based system should be regarded as an environmentally friendly approach because the use of harmful organic solvents is circumvented. Under the optimized chemical and physical variables, the 3sigma(blank) detection limits for 2-, 3-, and 4-nitrophenol were 1.2, 3.2 and 0.3 micromol L(-1) for a sample loading volume of 1.5 mL, and the relative standard deviations were < or =5.0%. The flowing system, which is able to handle up to 135 samples automatically, was proven suitable for monitoring trace levels of the target isomers in mineral, tap, and seawater. PMID:17386472

Manera, Matías; Miró, Manuel; Estela, José Manuel; Cerdà, Víctor

2007-01-16

134

Improving Viability of Stem Cells During Syringe Needle Flow Through the Design of Hydrogel Cell Carriers  

PubMed Central

Cell transplantation is a promising therapy for a myriad of debilitating diseases; however, current delivery protocols using direct injection result in poor cell viability. We demonstrate that during the actual cell injection process, mechanical membrane disruption results in significant acute loss of viability at clinically relevant injection rates. As a strategy to protect cells from these damaging forces, we hypothesize that cell encapsulation within hydrogels of specific mechanical properties will significantly improve viability. We use a controlled in vitro model of cell injection to demonstrate success of this acute protection strategy for a wide range of cell types including human umbilical vein endothelial cells (HUVEC), human adipose stem cells, rat mesenchymal stem cells, and mouse neural progenitor cells. Specifically, alginate hydrogels with plateau storage moduli (G?) ranging from 0.33 to 58.1?Pa were studied. A compliant crosslinked alginate hydrogel (G?=29.6?Pa) yielded the highest HUVEC viability, 88.9%±5.0%, while Newtonian solutions (i.e., buffer only) resulted in 58.7%±8.1% viability. Either increasing or decreasing the hydrogel storage modulus reduced this protective effect. Further, cells within noncrosslinked alginate solutions had viabilities lower than media alone, demonstrating that the protective effects are specifically a result of mechanical gelation and not the biochemistry of alginate. Experimental and theoretical data suggest that extensional flow at the entrance of the syringe needle is the main cause of acute cell death. These results provide mechanistic insight into the role of mechanical forces during cell delivery and support the use of protective hydrogels in future clinical stem cell injection studies. PMID:22011213

Aguado, Brian A.; Mulyasasmita, Widya; Su, James; Lampe, Kyle J.

2012-01-01

135

Syringic acid ameliorates (L)-NAME-induced hypertension by reducing oxidative stress.  

PubMed

The objective of the present study was to investigate the effects of syringic acid (SA), a phenolic acid, on N(?)-nitro-L-arginine methyl ester (L-NAME)-induced hypertensive rats. Hypertension was induced in adult male albino rats by oral administration of L-NAME (40 mg/kg/day) dissolved in drinking water daily for 4 weeks. Rats were treated with different doses of SA (25, 50, and 100 mg/kg body weight (b.w.)). Systolic blood pressure of control and experimental rats was recorded. Plasma nitric oxide metabolites (NOx), lipid peroxidative products such as thiobarbituric acid reactive substances, lipid hydroperoxides, conjugated dienes, and antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, vitamin C, vitamin E, and reduced glutathione were estimated in erythrocytes, plasma, and tissues of experimental rats. Hepatic marker enzymes such as aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase and renal functional markers such as urea, uric acid, and creatinine were also estimated in serum. The increased levels of blood pressure, lipid peroxidation products, hepatic and renal function markers, and the decreased level of NOx and antioxidants in L-NAME-induced hypertensive rats were reversed upon SA treatment. The protective effect at the dose of the three tested doses (25, 50, and 100 mg/kg) of SA at a dose of 50 mg/kg b.w. exerts optimum protection. Biochemical findings are substantiated by the histological observation. The protective effects of SA are mediated by reducing oxidative stress and retaining the bioavailability of NO in the cardiovascular system. PMID:23079793

Kumar, Subramanian; Prahalathan, Pichavaram; Raja, Boobalan

2012-12-01

136

Measure for Measure: Calibrating Ten Commonly Used Calibration Scores  

ERIC Educational Resources Information Center

This study examined the dimensionality of 10 different calibration measures using confirmatory factor analysis (CFA). The 10 measures were representative of five interpretative families of measures used to assess monitoring accuracy based on a 2 (performance) x 2 (monitoring judgment) contingency table. We computed scores for each of the measures…

Schraw, Gregory; Kuch, Fred; Gutierrez, Antonio P.

2013-01-01

137

Scalar calibration of vector magnetometers  

Microsoft Academic Search

The calibration parameters of a vector magnetometer are estimated only by the use of a scalar reference magnetometer. The method presented in this paper differs from those previously reported in its linearized parametrization. This allows the determination of three offsets or signals in the absence of a magnetic field, three scale factors for normalization of the axes and three non-orthogonality

J. M. G. Merayo; P. Brauer; F. Primdahl; J. R. Petersen; O. V. Nielsen

2000-01-01

138

Individual and socio-environmental factors associated with unsafe injection practices among young adult injection drug users in san diego.  

PubMed

Unsafe injection practices significantly increase the risk of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infection among injection drug users (IDUs). We examined individual and socio-environmental factors associated with unsafe injection practices in young adult IDUs in San Diego, California. Of 494 IDUs, 46.9 % reported receptive syringe sharing and 68.8 % sharing drug preparation paraphernalia in the last 3 months. Unsafe injection practices were associated with increased odds of having friends who injected drugs with used syringes, injecting with friends or sexual partners, and injecting heroin. Perceived high susceptibility to HIV and perceived barriers to obtaining sterile syringes were associated with increased odds of receptive syringe sharing, but not with sharing injection paraphernalia. Over half the IDUs reported unsafe injection practices. Our results suggest that personal relationships might influence IDUs' perceptions that dictate behavior. Integrated interventions addressing individual and socio-environmental factors are needed to promote safe injection practices in this population. PMID:24920342

Muñoz, Fátima; Burgos, José Luis; Cuevas-Mota, Jazmine; Teshale, Eyasu; Garfein, Richard S

2015-01-01

139

Factoring  

NSDL National Science Digital Library

Test your factoring skills Factors and Multiples Jeopardy How much do you know about factoring and multiples? Play Jeopardy and find out! Prime Factoring Turkey Shoot Blast these turkeys using your factoring skills. Help the Professor Super save the planet by "cooking" the Giant Frozen Turkeys of Destruction. Math Lines 12 X-Factor Shoot the ball at the other factors to get a product of 12. You can also ...

Mr Clark

2012-10-31

140

Reduction of Systematic Errors in Diagnostic Receivers Through the Use of Balanced Dicke-Switching and Y-Factor Noise Calibrations  

SciTech Connect

Receivers designed for diagnostic applications range from those having moderate sensitivity to those possessing large dynamic range. Digital receivers have a dynamic range which are a function of the number of bits represented by the ADC and subsequent processing. If some of this range is sacrificed for extreme sensitivity, noise power can then be used to perform two-point load calibrations. Since load temperatures can be precisely determined, the receiver can be quickly and accurately characterized; minute changes in system gain can then be detected, and systematic errors corrected. In addition, using receiver pairs in a balanced approach to measuring X+, X-, Y+, Y-, reduces systematic offset errors from non-identical system gains, and changes in system performance. This paper describes and demonstrates a balanced BPM-style diagnostic receiver, employing Dicke-switching to establish and maintain real-time system calibration. Benefits of such a receiver include wide bandwidth, solid absolute accuracy, improved position accuracy, and phase-sensitive measurements. System description, static and dynamic modelling, and measurement data are presented.

John Musson, Trent Allison, Roger Flood, Jianxun Yan

2009-05-01

141

Improving self-calibration  

NASA Astrophysics Data System (ADS)

Response calibration is the process of inferring how much the measured data depend on the signal one is interested in. It is essential for any quantitative signal estimation on the basis of the data. Here, we investigate self-calibration methods for linear signal measurements and linear dependence of the response on the calibration parameters. The common practice is to augment an external calibration solution using a known reference signal with an internal calibration on the unknown measurement signal itself. Contemporary self-calibration schemes try to find a self-consistent solution for signal and calibration by exploiting redundancies in the measurements. This can be understood in terms of maximizing the joint probability of signal and calibration. However, the full uncertainty structure of this joint probability around its maximum is thereby not taken into account by these schemes. Therefore, better schemes, in sense of minimal square error, can be designed by accounting for asymmetries in the uncertainty of signal and calibration. We argue that at least a systematic correction of the common self-calibration scheme should be applied in many measurement situations in order to properly treat uncertainties of the signal on which one calibrates. Otherwise, the calibration solutions suffer from a systematic bias, which consequently distorts the signal reconstruction. Furthermore, we argue that nonparametric, signal-to-noise filtered calibration should provide more accurate reconstructions than the common bin averages and provide a new, improved self-calibration scheme. We illustrate our findings with a simplistic numerical example.

Enßlin, Torsten A.; Junklewitz, Henrik; Winderling, Lars; Greiner, Maksim; Selig, Marco

2014-10-01

142

Integrated lab-in-syringe platform incorporating a membraneless gas-liquid separator for automatic cold vapor atomic absorption spectrometry.  

PubMed

This manuscript reports the proof-of-concept of a novel integrated lab-in-syringe/gas-liquid separation (LIS/GLS) batch-flow system based on a programmable flow for automatic cold vapor atomic absorption spectrometric assays. Homogeneous mixing of metered volumes of sample and reagent solutions drawn up in a sandwich-type mode along with in situ vapor generation are accomplished inside the microsyringe in a closed manner, while the separation of vapor species is achieved via the membraneless GLS located at the top of the syringe's valve in the upright position. The potentials of the proposed manifold were demonstrated for trace inorganic mercury determination in drinking waters and seawater. For a 3.0 mL sample, the limit of detection and repeatability (RSD) were found to be 0.03 ?g L(-1) Hg(II) and 3.1% (at the 2.0 ?g L(-1) concentration level), respectively, with a dynamic range extending up to 10.0 ?g L(-1). The proposed system fulfills the requirements of US-EPA, WHO, and EU Council Directives for measurements of the maximum allowed concentrations of inorganic mercury in drinking water. PMID:23977837

Giakisikli, Georgia; Miró, Manuel; Anthemidis, Aristidis

2013-10-01

143

NIMBY localism and national inequitable exclusion alliances: The case of syringe exchange programs in the United States  

PubMed Central

Syringe exchange programs (SEPs) aim to reduce the harm associated with injection drug use (IDU). Although they have been accepted as critical components of HIV prevention in many parts of the world, they are often unwelcome and difficult to set up and maintain, even in communities hardest hit by IDU-related HIV transmission. This research examines socio-cultural and political processes that shape community and institutional resistance toward establishing and maintaining SEPs. These processes are configured and reinforced through the socio-spatial stigmatizing of IDUs, and legal and public policy against SEPs. Overarching themes the paper considers are: (1) institutional and/or political opposition based on (a) political and law enforcement issues associated with state drug paraphernalia laws and local syringe laws; (b) harassment of drug users and resistance to services for drug users by local politicians and police; and (c) state and local government (in)action or opposition; and (2) the stigmatization of drug users and location of SEPs in local neighborhoods and business districts. Rather than be explained by “not in my back yard” localism, this pattern seems best conceptualized as an “inequitable exclusion alliance” (IEA) that institutionalizes national and local stigmatizing of drug users and other vulnerable populations. PMID:18978931

Tempalski, Barbara; Friedman, Risa; Keem, Marie; Cooper, Hannah; Friedman, Samuel R.

2007-01-01

144

Spreader Calibration for Turfgrass  

E-print Network

To apply pesticides and fertilizers on turfgrass properly, you must have accurately calibrated equipment. This publication explains how to calibrate rotary and drop spreaders. A list of spreader operation tips is included....

Taylor, Gene R.; Abernathy, Scott

1999-12-08

145

Orifice calibration module  

NASA Technical Reports Server (NTRS)

Module, consisting of transparent plastic cylinder containing separate suction and calibration chambers, allows static-pressure orifices to be calibrated, and rapidly checked for leaks. Device is compact, saves time, and improves accuracy, and reliability of pressure measurements.

Culotta, R.; Posey, D. L.

1979-01-01

146

Calibrated Peer Review  

NSDL National Science Digital Library

What is Calibrated Peer ReviewTM? Calibrated Peer ReviewTM (CPR) (more info) is a web-based writing and peer review tool free to instructors and their classes. Students write short essays on a given topic following ...

147

Analytical multicollimator camera calibration  

USGS Publications Warehouse

Calibration with the U.S. Geological survey multicollimator determines the calibrated focal length, the point of symmetry, the radial distortion referred to the point of symmetry, and the asymmetric characteristiecs of the camera lens. For this project, two cameras were calibrated, a Zeiss RMK A 15/23 and a Wild RC 8. Four test exposures were made with each camera. Results are tabulated for each exposure and averaged for each set. Copies of the standard USGS calibration reports are included. ?? 1978.

Tayman, W.P.

1978-01-01

148

SAR calibration: an overview  

Microsoft Academic Search

Progress in synthetic-aperture radar, (SAR) calibration is reviewed. The difficulties of calibrating both airborne and spaceborne SAR image data are addressed. The quantities measured by a SAR, i.e. radar backscatter, are defined and mathematical formulations for the three basic types of SAR image are developed. The difficulties in establishing science requirements for calibration are discussed. The measurement of SAR image

Anthony Freeman

1992-01-01

149

Assessment of MODIS Reflected Solar Calibration Uncertainty  

NASA Technical Reports Server (NTRS)

Determination of the calibration accuracy and traceability of a remote sensing instrument is a driving issue in the use of satellite data for calibration inter-comparisons and studying climate change. The Terra and Aqua MODerate Resolution Imaging Spectroradiometer (MODIS) instruments have successfully operated for more than 11 and 9 years, respectively. Twenty of the thirty six MODIS spectral bands are in the reflected solar region with center wavelengths ranging from 0.41 to 2.2 microns. MODIS reflective solar band (RSB) on-orbit calibration is reflectance based through the use of an on-board solar diffuser (SO). The calibration uncertainty requirements are +/-2.0% for the RSB reflectance factors at sensor specified typical scene reflectances or radiances. The SO bi-directional reflectance factor (BRF) was characterized pre-launch and its on-orbit changes are tracked by an on-board solar diffuser stability monitor (SDSM). This paper provides an assessment of MODIS RSB on-orbit calibration traceability and uncertainty for its Level 1B (L1B) reflectance factors. It examines in details each of the uncertainty contributors, including those from pre-launch measurements as well as on-orbit observations. Common challenging issues and differences due to individual sensors' specific characteristics and on-orbit performance are also discussed in this paper. Guidance and recommendations are presented, based on lessons from MODIS RSB calibration uncertainty assessment, for the development of future instrument calibration and validation plans.

Xiong, Xiaoxiong; Sun, Junqiang; Butler, James

2011-01-01

150

Nonlinear Observers for Gyro Calibration  

NASA Technical Reports Server (NTRS)

Nonlinear observers for gyro calibration are presented. The first observer estimates a constant gyro bias. The second observer estimates scale factor errors. The third observer estimates the gyro alignment for three orthogonal gyros. The convergence properties of all three observers are discussed. Additionally, all three observers are coupled with a nonlinear control algorithm. The stability of each of the resulting closed loop systems is analyzed. Simulated test results are presented for each system.

Thienel, Julie; Sanner, Robert M.

2003-01-01

151

Direct megavoltage photon calibration service in Australia  

PubMed Central

The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) maintains the Australian primary standard of absorbed dose. Until recently, the standard was used to calibrate ionisation chambers only in 60Co gamma rays. These chambers are then used by radiotherapy clinics to determine linac output, using a correction factor (kQ) to take into account the different spectra of 60Co and the linac. Over the period 2010–2013, ARPANSA adapted the primary standard to work in megavoltage linac beams, and has developed a calibration service at three photon beams (6, 10 and 18 MV) from an Elekta Synergy linac. We describe the details of the new calibration service, the method validation and the use of the new calibration factors with the International Atomic Energy Agency’s TRS-398 dosimetry Code of Practice. The expected changes in absorbed dose measurements in the clinic when shifting from 60Co to the direct calibration are determined. For a Farmer chamber (model 2571), the measured chamber calibration coefficient is expected to be reduced by 0.4, 1.0 and 1.1 % respectively for these three beams when compared to the factor derived from 60Co. These results are in overall agreement with international absorbed dose standards and calculations by Muir and Rogers in 2010 of kQ factors using Monte Carlo techniques. The reasons for and against moving to the new service are discussed in the light of the requirements of clinical dosimetry. PMID:25146559

Ramanathan, G.; Oliver, C.; Cole, A.; Lye, J.; Harty, P. D.; Wright, T.; Webb, D. V.; Followill, D. S.

2014-01-01

152

Factorize  

NSDL National Science Digital Library

This interactive applet allows a student to visually explore the concept of factors by creating different rectangular arrays for a number. The user constructs the array by clicking and dragging on a grid. The length and width of the array are factors of the number. A student can elect an option of a randomly selected number or the student selects his own number between 2 and 50. Exploration questions are included to promote student discovery of mathematical concepts with factors.

2000-01-01

153

Stability of Trisodium Citrate and Gentamicin Solution for Catheter Locks after Storage in Plastic Syringes at Room Temperature  

PubMed Central

Background: Catheter-related infections are a major problem for hemodialysis patients with central venous catheters for vascular access. Catheter lock solutions containing an anticoagulant are used to maintain the patency of the catheter between hemodialysis sessions. There is evidence that the use of lock solutions containing an antibiotic is associated with lower rates of infection but also that these solutions can kill microbes in colonized catheters and thus avoid the risks and costs associated with replacing the catheter. Objective: This stability study was conducted to determine whether an extemporaneously prepared gentamicin–citrate catheter lock solution would retain its potency over time, thus allowing for advance preparation of the solution. Methods: Catheter lock solutions containing gentamicin alone, citrate alone, and the combination of gentamicin and citrate were prepared aseptically and packaged in polyethylene syringes. The syringes were stored at room temperature. At timed intervals over 112 days, samples were withdrawn for analysis by means of validated high-performance liquid chromatography. Results: None of the 3 lock solutions showed any evidence of degradation during the 112-day observation period. In the formulation containing both gentamicin 2.5 mg/mL and sodium citrate 40 mg/mL (4%), there was no change in the concentration of either gentamicin (p = 0.34) or citrate (p = 0.55). Linear regression analysis of the concentration–time data for the combined formulation showed that 99.97% of the labelled amount of gentamicin and 101.30% of the labelled amount of citrate remained at day 112. The lower limit of the 95% confidence intervals indicated that more than 98.17% of the gentamicin and more than 99.57% of the citrate remained on day 112. Conclusion: The results of this study will allow pharmacies to extemporaneously compound the combined gentamicin–citrate catheter lock solution in advance of use. The method described here will yield a stable product for use in clinical applications. PMID:22478993

Cote, Dennis; Lok, Charmaine E; Battistella, Marisa; Vercaigne, Lavern

2010-01-01

154

Identification of epidural space using loss of resistance syringe, infusion drip, and balloon technique: A comparative study  

PubMed Central

Background and Objective: There are various techniques to identify epidural space but superiority of one technique over other has not been adequately studied. We conducted a study to Compare and evaluate the three techniques for epidural space localization that is, loss of resistance (LOR) syringe technique, balloon technique and drip infusion technique. Materials and Methods: Seventy-five patients of either sex, belonging to American Society of Anesthesiologists physical status Class 1 or 2, between 20 and 50 years of age, scheduled to undergo lower abdominal and lower limb surgeries were randomly allocated to one of the three groups (n = 25 each) depending upon epidural space localization. In Group I, epidural space localization was done with LOR syringe technique. In Group II Balloon technique and in Group III drip infusion technique was used. Distance of the epidural space from skin, number of attempts, time taken for epidural space localization and quality of the block were the parameter recorded during the study. Results: First attempt success rate for epidural space localization was highest in Group III (100%). The mean time taken for epidural space localization was least in Group III, and when compared with other groups it was found to be statistically significant with P = 0.016. Number of attempt for space localization and success rate of the block was better in the majority of patients of Group III, but the difference was found to be statistically nonsignificant. Complication rate was almost negligible in all three techniques. Conclusion: We conclude that the time taken to localize the epidural space was least in drip infusion technique. As for number of attempts, quality of the block and complications is concerned, all the three techniques are comparable. PMID:25538520

Singhal, Suresh; Bala, Manju; Kaur, Kiranpreet

2014-01-01

155

Assessment of an in vitro whole cigarette smoke exposure system: The Borgwaldt RM20S 8-syringe smoking machine  

PubMed Central

Background There have been many recent developments of in vitro cigarette smoke systems closely replicating in vivo exposures. The Borgwaldt RM20S smoking machine (RM20S) enables the serial dilution and delivery of cigarette smoke to exposure chambers for in vitro analyses. In this study we have demonstrated reliability and robustness testing of the RM20S in delivering smoke to in vitro cultures using an in-house designed whole smoke exposure chamber. Results The syringe precision and accuracy of smoke dose generated by the RM20S was assessed using a methane gas standard and resulted in a repeatability error of ?9%. Differential electrical mobility particle spectrometry (DMS) measured smoke particles generated from reference 3R4F cigarettes at points along the RM20S. 53% ± 5.9% of particles by mass reached the chamber, the remainder deposited in the syringe or connecting tubing and ~16% deposited in the chamber. Spectrofluorometric quantification of particle deposition within chambers indicated a positive correlation between smoke concentration and particle deposition. In vitro air-liquid interface (ALI) cultures (H292 lung epithelial cells), exposed to whole smoke (1:60 dilution (smoke:air, equivalent to ~5 ?g/cm2)) demonstrated uniform smoke delivery within the chamber. Conclusions These results suggest this smoke exposure system is a reliable and repeatable method of generating and exposing ALI in vitro cultures to cigarette smoke. This system will enable the evaluation of future tobacco products and individual components of cigarette smoke and may be used as an alternative in vitro tool for evaluating other aerosols and gaseous mixtures such as air pollutants, inhaled pharmaceuticals and cosmetics. PMID:21867559

2011-01-01

156

Implementation Study of Patient-Ready Syringes Containing 25?mg/mL Methotrexate Solution for Use in Treating Ectopic Pregnancy  

PubMed Central

Background. Ectopic pregnancy (EP) is a significant cause of morbidity and mortality during the first trimester of pregnancy. Small unruptured tubal pregnancies can be treated medically with a single dose of methotrexate (MTX). Objective. The aim of this study was to evaluate the stability of a 25?mg/mL solution of MTX to devise a secure delivery circuit for the preparation and use of this medication in the management of EP. Method. MTX solutions were packaged in polypropylene syringes, stored over an 84-day period, and protected from light either at +2 to +8°C or at 23°C. We assessed the physical and chemical stability of the solutions at various time points over the storage period. A pharmaceutical delivery circuit was implemented that involved the batch preparation of MTX syringes. Results. We show that 25?mg/mL MTX solutions remain stable over an 84-day period under the storage conditions tested. Standard doses were prepared, ranging from 50?mg to 100?mg. The results of this study suggest that MTX syringes can be prepared in advance by the pharmacy, ready to be dispensed at any time that a diagnosis of EP is made. Conclusion. The high stability of a 25?mg/mL MTX solution in polypropylene syringes makes it possible to implement a flexible and cost-effective delivery circuit for ready-to-use preparations of this drug, providing 24-hour access and preventing treatment delays. PMID:24900977

Respaud, R.; Gaudy, A. S.; Arlicot, C.; Tournamille, J. F.; Viaud-Massuard, M. C.; Elfakir, C.; Antier, D.

2014-01-01

157

Field calibration of reference reflectance panels  

NASA Technical Reports Server (NTRS)

A procedure for calibrating reference reflectance panels using the sun as the radiation source and a pressed-polytetrafluoroethylene powder standard is described. The directional/directional reflectance factor and the directional/hemispheric reflectance factor are examined. Directional/directional voltage responses for pressed-halon are analyzed. Three painted BaSO4 and one painted halon were calibrated using the proposed procedure. The effects of diffuse irradiance on reflectance-factor measurements are investigated. It is determined that the method has an accuracy on the order of 1 percent. The advantages and disadvantages of this method are discussed.

Jackson, Ray D.; Moran, M. Susan; Slater, Philip N.; Biggar, Stuart F.

1987-01-01

158

Syringeless power injector versus dual-syringe power injector: economic evaluation of user performance, the impact on contrast enhanced computed tomography (CECT) workflow exams, and hospital costs  

PubMed Central

Objective The utilization of diagnostic imaging has substantially increased over the past decade in Europe and North America and continues to grow worldwide. The purpose of this study was to develop an economic evaluation of a syringeless power injector (PI) versus a dual-syringe PI for contrast enhanced computed tomography (CECT) in a hospital setting. Materials and methods Patients (n=2379) were enrolled at the Legnano Hospital between November 2012 and January 2013. They had been referred to the hospital for a CECT analysis and were randomized into two groups. The first group was examined with a 256-MDCT (MultiDetector Computed Tomography) scanner using a syringeless power injector, while the other group was examined with a 64-MDCT scanner using a dual-syringe. Data on the operators’ time required in the patient analysis steps as well as on the quantity of consumable materials used were collected. The radiologic technologists’ satisfaction with the use of the PIs was rated on a 10-point scale. A budget impact analysis and sensitivity analysis were performed under the base-case scenario. Results A total of 1,040 patients were examined using the syringeless system, and 1,339 with the dual-syringe system; the CECT examination quality was comparable for both PI systems. Equipment preparation time and releasing time per examination for syringeless PIs versus dual-syringe PIs were 100±30 versus 180±30 seconds and 90±30 and 140±20 seconds, respectively. On average, 10±3 mL of contrast media (CM) wastage per examination was observed with the dual-syringe PI and 0±1 mL with the syringeless PI. Technologists had higher satisfaction with the syringeless PI than with the dual-syringe system (8.8 versus 8.0). The syringeless PI allows a saving of about €6.18 per patient, both due to the lower cost of the devices and to the better performance of the syringeless system. The univariate sensitivity analysis carried out on the base-case results within the standard deviation range confirmed the saving generated by using the syringeless device, with saving values between €5.40 and €6.20 per patient. Conclusion The syringeless PI was found to be more user-friendly and efficient, minimizing contrast wastage and providing similar contrast enhancement quality compared to the dual-syringe injector, with comparable CECT examination quality. PMID:24235851

Colombo, Giorgio L; Andreis, Ivo A Bergamo; Di Matteo, Sergio; Bruno, Giacomo M; Mondellini, Claudio

2013-01-01

159

Are adrenaline autoinjectors fit for purpose? A pilot study of the mechanical and injection performance characteristics of a cartridge-versus a syringe-based autoinjector  

PubMed Central

Background: Adrenaline autoinjectors (AAIs) are prescribed to facilitate the intramuscular administration of adrenaline in patients diagnosed with life-threatening anaphylaxis. This pilot study investigated the injection and functional properties of two AAIs (deploying different delivery systems) under standard conditions, after dynamic and mechanical stresses, and in the presence of denim. Methods: The differences between a cartridge-based AAI (EpiPen® Junior) and a syringe-based AAI (Anapen® Junior) were assessed using three sets of tests. Test 1: under standard conditions, the injection depth and dose were measured in ballistic gelatine (a validated tissue simulant). Test 2: before the safety cap removal and activation forces were measured, AAIs were subjected to either of two preconditioning tests: 1) free-fall drop test; or 2) static load (ie, 400 N, equivalent to 40 kg weight) test; or 3) no preconditioning. Test 3: under standard conditions, injection properties into ballistic gelatine in the presence and absence of denim were investigated. Statistical analyses were performed using the Student’s t-test or Welch’s test. Results: The maximum depth of delivery was significantly greater with cartridge AAI (n = 4, mean 21.09 ± 2.54 mm) than with syringe AAI (n = 5; mean 11.64 ± 0.80 mm; P = 0.003). After 2.5 seconds, cartridge AAI (n = 4) discharged significantly more dose than syringe AAI (n = 3; 74.3% versus 25.7% of total dose; P = 0.001). Both cartridge and syringe AAI withstood the free-fall drop test, but almost all devices failed to activate following the static load test. Under standard conditions, significantly less force was required to remove the safety cap of cartridge AAI than syringe AAI (both n = 15; mean 9.56 ± 2.36 N versus 20.23 ± 6.61 N, respectively; P < 0.001), but a significantly greater activation force was required for cartridge AAI than syringe AAI (mean 23.01 ± 3.96 N versus 8.06 ± 0.51 N, respectively; P < 0.001). The presence of denim did not alter the activation force or effective needle length of either of the AAIs. Conclusion: Cartridge AAI appears significantly more capable of consistently and rapidly delivering a clinically relevant dose of intramuscular adrenaline than syringe AAI. However, both devices showed shortcomings in their ability to sustain mechanical stress similar to that which is likely over their shelf life, and as such, may not be fit for life-saving purpose. PMID:21437050

Schwirtz, Andreas; Seeger, Harald

2010-01-01

160

On-Orbit Calibration of Satellite Gyroscopes  

NASA Technical Reports Server (NTRS)

In order to maneuver satellites accurately from one attitude to another, onboard rate sensing gyroscopes usually must be calibrated after launch. Several algorithms have been used to determine gyro biases, misalignments, and scale factors. This paper describes algorithms that have been used in the past, discusses their advantages and limitations, and describes a new algorithm and the gyro calibration results obtained using this new algorithm. The new algorithm has significant operational advantages in addition to being at least as accurate as other algorithms.

Hashmall, Joseph A.; Radomski, Mark; Sedlak, Joseph; Harman, Richard (Technical Monitor)

2000-01-01

161

Distributed Radio Interferometric Calibration  

E-print Network

Increasing data volumes delivered by a new generation of radio interferometers require computationally efficient and robust calibration algorithms. In this paper, we propose distributed calibration as a way of improving both computational cost as well as robustness in calibration. We exploit the data parallelism across frequency that is inherent in radio astronomical observations that are recorded as multiple channels at different frequencies. Moreover, we also exploit the smoothness of the variation of calibration parameters across frequency. Data parallelism enables us to distribute the computing load across a network of compute agents. Smoothness in frequency enables us reformulate calibration as a consensus optimization problem. With this formulation, we enable flow of information between compute agents calibrating data at different frequencies, without actually passing the data, and thereby improving robustness. We present simulation results to show the feasibility as well as the advantages of distribute...

Yatawatta, Sarod

2015-01-01

162

Metrology and Calibration Standards  

NSDL National Science Digital Library

Equipment calibration issues are the name of the game here. Topics addressed range from "the adjustment dilemma" to terminology (for example "calibration" vs. "verification") to worldwide calibration standards. The site is sponsored by Agilent Technologies, a company that provides the semiconductor, electronics, communications, and related industries with testing solutions for test instruments, systems, equipment and monitoring tools. Users can be sure that every measurement is traceable to National Metrology Institutes (NMIs) through Agilent-engineered calibration procedures that verify instrument specifications. The site allows users to stay up-to-date on changing compliance requirements and their practical applications by working with Agilent meteorologists who collaborate with international standards organizations.

163

Calibration facility safety plan  

NASA Technical Reports Server (NTRS)

A set of requirements is presented to insure the highest practical standard of safety for the Apollo 17 Calibration Facility in terms of identifying all critical or catastrophic type hazard areas. Plans for either counteracting or eliminating these areas are presented. All functional operations in calibrating the ultraviolet spectrometer and the testing of its components are described.

Fastie, W. G.

1971-01-01

164

Improved Regression Calibration  

ERIC Educational Resources Information Center

The likelihood for generalized linear models with covariate measurement error cannot in general be expressed in closed form, which makes maximum likelihood estimation taxing. A popular alternative is regression calibration which is computationally efficient at the cost of inconsistent estimation. We propose an improved regression calibration

Skrondal, Anders; Kuha, Jouni

2012-01-01

165

Photogrammetric camera calibration  

USGS Publications Warehouse

Section 2 (Calibration) of the document "Recommended Procedures for Calibrating Photogrammetric Cameras and Related Optical Tests" from the International Archives of Photogrammetry, Vol. XIII, Part 4, is reviewed in the light of recent practical work, and suggestions for changes are made. These suggestions are intended as a basis for a further discussion. ?? 1984.

Tayman, W.P.; Ziemann, H.

1984-01-01

166

OLI Radiometric Calibration  

NASA Technical Reports Server (NTRS)

Goals: (1) Present an overview of the pre-launch radiance, reflectance & uniformity calibration of the Operational Land Imager (OLI) (1a) Transfer to orbit/heliostat (1b) Linearity (2) Discuss on-orbit plans for radiance, reflectance and uniformity calibration of the OLI

Markham, Brian; Morfitt, Ron; Kvaran, Geir; Biggar, Stuart; Leisso, Nathan; Czapla-Myers, Jeff

2011-01-01

167

Calibration of hydrometers  

Microsoft Academic Search

After a brief description of the different methods employed in periodic calibration of hydrometers used in most cases to measure the density of liquids in the range between 500 kg m-3 and 2000 kg m-3, particular emphasis is given to the multipoint procedure based on hydrostatic weighing, known as well as Cuckow's method. The features of the calibration apparatus and

Salvatore Lorefice; Andrea Malengo

2006-01-01

168

Uncertainty in audiometer calibration  

Microsoft Academic Search

The objective of this work is to present a metrology study necessary for the accreditation of audiometer calibration procedures at the National Brazilian Institute of Metrology Standardization and Industrial Quality—INMETRO. A model for the calculation of measurement uncertainty was developed. Metrological aspects relating to audiometer calibration, traceability and measurement uncertainty were quantified through comparison between results obtained at the Industrial

Marcos Aurélio Pedroso; Samir N Y Gerges; Armando A Gonçalves Jr

2004-01-01

169

Uncertainty in audiometer calibration  

Microsoft Academic Search

The objective of this work is to present a metrology study necessary for the accreditation of audiometer calibration procedures at the National Brazilian Institute of Metrology Standardization and Industrial Quality---INMETRO. A model for the calculation of measurement uncertainty was developed. Metrological aspects relating to audiometer calibration, traceability and measurement uncertainty were quantified through comparison between results obtained at the Industrial

Marcos Aurélio Pedroso; Samir N. Y. Gerges; Armando A. Gonçalves Jr.

2004-01-01

170

Revolving-Pinhole Calibrator  

NASA Technical Reports Server (NTRS)

Revolving-pinhole calibrator used to calibrate instrument called "Forward Scattering Spectrometer Probe" (FSSP). This instrument measures light scattered from water droplets in icing clouds. Scattering patterns used to determine sizes and distribution of sizes of droplets in connection with safety-oriented studies of icing on aircraft. Pinhole serves as diffraction standard for measuring small particles and drops.

Hovenac, Edward A.

1994-01-01

171

Calibration of theodolites  

Microsoft Academic Search

Concepts leading to an accurate, automated system for making 3D measurements of robot position are described. The system is predicated on building complete kinematic models of the measurement apparatus and determining the model parameters from data obtained in a calibration procedure. The two primary calibration procedures required are the determination of the geometric parameters of the individual theodolites and the

J. F. Jarvis

1988-01-01

172

Sandia WIPP calibration traceability  

SciTech Connect

This report summarizes the work performed to establish calibration traceability for the instrumentation used by Sandia National Laboratories at the Waste Isolation Pilot Plant (WIPP) during testing from 1980-1985. Identifying the calibration traceability is an important part of establishing a pedigree for the data and is part of the qualification of existing data. In general, the requirement states that the calibration of Measuring and Test equipment must have a valid relationship to nationally recognized standards or the basis for the calibration must be documented. Sandia recognized that just establishing calibration traceability would not necessarily mean that all QA requirements were met during the certification of test instrumentation. To address this concern, the assessment was expanded to include various activities.

Schuhen, M.D. [Sandia National Labs., Albuquerque, NM (United States)] [Sandia National Labs., Albuquerque, NM (United States); Dean, T.A. [RE/SPEC, Inc., Albuquerque, NM (United States)] [RE/SPEC, Inc., Albuquerque, NM (United States)

1996-05-01

173

GRAVITY: the calibration unit  

NASA Astrophysics Data System (ADS)

We present in this paper the design and characterisation of a new sub-system of the VLTI 2nd generation instrument GRAVITY: the Calibration Unit. The Calibration Unit provides all functions to test and calibrate the beam combiner instrument: it creates two artificial stars on four beams, and dispose of four delay lines with an internal metrology. It also includes artificial stars for the tip-tilt and pupil guiding systems, as well as four metrology pick-up diodes, for tests and calibration of the corresponding sub-systems. The calibration unit also hosts the reference targets to align GRAVITY to the VLTI, and the safety shutters to avoid the metrology light to propagate in the VLTI-lab. We present the results of the characterisation and validtion of these differrent sub-units.

Blind, N.; Eisenhauer, F.; Haug, M.; Gillessen, S.; Lippa, Magdalena; Burtscher, L.; Hans, O.; Haussmann, F.; Huber, S.; Janssen, A.; Kellner, S.; Kok, Y.; Ott, T.; Pfuhl, O.; Sturm, E.; Weber, J.; Wieprecht, E.; Amorim, A.; Brandner, W.; Perrin, G.; Perraut, K.; Straubmeier, C.

2014-07-01

174

Aerosol backscatter lidar calibration and data interpretation  

NASA Technical Reports Server (NTRS)

A treatment of the various factors involved in lidar data acquisition and analysis is presented. This treatment highlights sources of fundamental, systematic, modeling, and calibration errors that may affect the accurate interpretation and calibration of lidar aerosol backscatter data. The discussion primarily pertains to ground based, pulsed CO2 lidars that probe the troposphere and are calibrated using large, hard calibration targets. However, a large part of the analysis is relevant to other types of lidar systems such as lidars operating at other wavelengths; continuous wave (CW) lidars; lidars operating in other regions of the atmosphere; lidars measuring nonaerosol elastic or inelastic backscatter; airborne or Earth-orbiting lidar platforms; and lidars employing combinations of the above characteristics.

Kavaya, M. J.; Menzies, R. T.

1984-01-01

175

New technique for calibrating hydrocarbon gas flowmeters  

NASA Technical Reports Server (NTRS)

A technique for measuring calibration correction factors for hydrocarbon mass flowmeters is described. It is based on the Nernst theorem for matching the partial pressure of oxygen in the combustion products of the test hydrocarbon, burned in oxygen-enriched air, with that in normal air. It is applied to a widely used type of commercial thermal mass flowmeter for a number of hydrocarbons. The calibration correction factors measured using this technique are in good agreement with the values obtained by other independent procedures. The technique is successfully applied to the measurement of differences as low as one percent of the effective hydrocarbon content of the natural gas test samples.

Singh, J. J.; Puster, R. L.

1984-01-01

176

Link calibration against receiver calibration: an assessment of GPS time transfer uncertainties  

NASA Astrophysics Data System (ADS)

We present a direct comparison between two different techniques for the relative calibration of time transfer between remote time scales when using the signals transmitted by the Global Positioning System (GPS). Relative calibration estimates the delay of equipment or the delay of a time transfer link with respect to reference equipment. It is based on the circulation of some travelling GPS equipment between the stations in the network, against which the local equipment is measured. Two techniques can be considered: first a station calibration by the computation of the hardware delays of the local GPS equipment; second the computation of a global hardware delay offset for the time transfer between the reference points of two remote time scales. This last technique is called a ‘link’ calibration, with respect to the other one, which is a ‘receiver’ calibration. The two techniques require different measurements on site, which change the uncertainty budgets, and we discuss this and related issues. We report on one calibration campaign organized during Autumn 2013 between Observatoire de Paris (OP), Paris, France, Observatoire de la Côte d'Azur (OCA), Calern, France, and NERC Space Geodesy Facility (SGF), Herstmonceux, United Kingdom. The travelling equipment comprised two GPS receivers of different types, along with the required signal generator and distribution amplifier, and one time interval counter. We show the different ways to compute uncertainty budgets, leading to improvement factors of 1.2 to 1.5 on the hardware delay uncertainties when comparing the relative link calibration to the relative receiver calibration.

Rovera, G. D.; Torre, J.-M.; Sherwood, R.; Abgrall, M.; Courde, C.; Laas-Bourez, M.; Uhrich, P.

2014-10-01

177

Life After the Ban: An Assessment of US Syringe Exchange Programs’ Attitudes About and Early Experiences With Federal Funding  

PubMed Central

Objectives. We aimed to determine whether syringe exchange programs (SEPs) currently receive or anticipate pursuing federal funding and barriers to funding applications following the recent removal of the long-standing ban on using federal funds for SEPs. Methods. We conducted a telephone-administered cross-sectional survey of US SEPs. Descriptive statistics summarized responses; bivariate analyses examined differences in pursuing funding and experiencing barriers by program characteristics. Results. Of the 187 SEPs (92.1%) that responded, 90.9% were legally authorized. Three received federal funds and 116 intended to pursue federal funding. Perceived federal funding barriers were common and included availability and accessibility of funds, legal requirements such as written police support, resource capacity to apply and comply with funding regulations, local political and structural organization, and concern around altering program culture. Programs without legal authorization, health department affiliation, large distribution, or comprehensive planning reported more federal funding barriers. Conclusions. Policy implementation gaps appear to render federal support primarily symbolic. In practice, funding opportunities may not be available to all SEPs. Increased technical assistance and legal reform could improve access to federal funds, especially for SEPs with smaller capacity and tenuous local support. PMID:22420810

Martin, Erika G.; Bowman, Sarah E.; Mann, Marita R.; Beletsky, Leo

2012-01-01

178

"Hooked on" prescription-type opiates prior to using heroin: results from a survey of syringe exchange clients.  

PubMed

The availability and diversion of prescription-type opioids increased dramatically in the first decade of the twenty-first century. One possible consequence of increased prescription opioid use and accessibility is the associated rise in opioid dependence, potentially resulting in heroin addiction. This study aimed to determine how common initial dependence on prescription-type opioids is among heroin injectors; associations with demographic and drug-using characteristics were also examined. Interview data were collected at syringe exchanges in King County, Washington in 2009. Among the respondents who had used heroin in the prior four months, 39% reported being "hooked on" prescription-type opioids first. Regression analysis indicated that younger age, sedative use and no recent crack use were independently associated with self-report of being hooked on prescription-type opioids prior to using heroin. These data quantify the phenomenon of being hooked on prescription-type opioids prior to initiating heroin use. Further research is needed to characterize the epidemiology, etiology and trajectory of prescription-type opioid and heroin use in the context of continuing widespread availability of prescription-type opioids. PMID:23061326

Peavy, K Michelle; Banta-Green, Caleb J; Kingston, Susan; Hanrahan, Michael; Merrill, Joseph O; Coffin, Phillip O

2012-01-01

179

Reduced risk of hepatitis B and hepatitis C among injection drug users in the Tacoma syringe exchange program.  

PubMed Central

OBJECTIVES. This case-control study examined the association between syringe exchange use and hepatitis B and C in injection drug users. METHODS. Case patients included 28 injection drug users with acute hepatitis B and 20 with acute hepatitis C reported to the health department in a sentinel hepatitis surveillance county; control subjects were injection drug users with no markers of exposure to hepatitis B or C (n = 38 and 26, respectively) attending health department services during the same period. Data were abstracted from clinic records. RESULTS. Seventy-five percent of case patients with hepatitis B and 26% of control subjects had never used the exchange; similar proportions were found for the hepatitis C case and control groups. After adjustment for demographic characteristics and duration of injecting drugs, nonuse of the exchange was associated with a sixfold greater risk of hepatitis B (odds ratio [OR] = 5.5; 95% confidence interval [CI] = 1.5, 20.4) and a sevenfold greater risk of hepatitis C (OR = 7.3; 95% CI = 1.6, 32.8). CONCLUSIONS. The results suggest that use of the exchange led to a significant reduction in hepatitis B and hepatitis C in the county and may have also prevented a substantial proportion of human immunodeficiency virus infections in injection drug users. PMID:7485666

Hagan, H; Jarlais, D C; Friedman, S R; Purchase, D; Alter, M J

1995-01-01

180

Determination of clenbuterol from pork samples using surface molecularly imprinted polymers as the selective sorbents for microextraction in packed syringe.  

PubMed

In this study, a selective sample pretreatment procedure combing surface molecularly imprinted polymers and microextraction in packed syringe (SMIPs-MEPS) was developed for the analysis of clenbuterol (CLB) from pork samples. SMIPs for CLB were synthesized on silica gel particles through a sol-gel process. A series of characterization and adsorption experiments revealed that the SMIPs exhibited porous structures, good thermal stability, high adsorption capacity and a fast mass transfer rate. The obtained SMIPs were employed as selective sorbents of SMIPs-MEPS for extraction of CLB from pork samples. Several parameters affecting the extraction efficiency were investigated, including the pH of sample solution, number of draw-eject cycles, volume of sample, type and volume of washing solution, and the type and volume of elution solution. Under the optimized conditions, a simple and rapid method for the determination of CLB from pork samples was established by coupling with high performance liquid chromatography (HPLC). The whole pretreatment process was rapid and it can be accomplished with 2min. The limit of quantitation and the limit of detection for CLB were 0.02 and 0.009?gkg(-1), respectively. The average recoveries of CLB at three spiked levels ranged from 86.5% to 91.2% with the relative standard deviations (RSD) ?6.3%. PMID:24463040

Du, Wei; Lei, Chunmei; Zhang, Siruo; Bai, Gang; Zhou, Huiyan; Sun, Min; Fu, Qiang; Chang, Chun

2014-03-01

181

Compact radiometric microwave calibrator  

SciTech Connect

The calibration methods for the ARCADE II instrument are described and the accuracy estimated. The Steelcast coated aluminum cones which comprise the calibrator have a low reflection while maintaining 94% of the absorber volume within 5 mK of the base temperature (modeled). The calibrator demonstrates an absorber with the active part less than one wavelength thick and only marginally larger than the mouth of the largest horn and yet black (less than -40 dB or 0.01% reflection) over five octaves in frequency.

Fixsen, D. J.; Wollack, E. J.; Kogut, A.; Limon, M.; Mirel, P.; Singal, J.; Fixsen, S. M. [SSAI Goddard Spaceflight Center, Greenbelt, Maryland 20771 (United States); Code 665, Goddard Spaceflight Center, Greenbelt, Maryland 20771 (United States); SSAI Goddard Spaceflight Center, Greenbelt, Maryland 20771 (United States); University of California Santa Barbara, Santa Barbara, California 93106 (United States); SSAI Goddard Spaceflight Center, Greenbelt, Maryland 20771 (United States)

2006-06-15

182

Airdata Measurement and Calibration  

NASA Technical Reports Server (NTRS)

This memorandum provides a brief introduction to airdata measurement and calibration. Readers will learn about typical test objectives, quantities to measure, and flight maneuvers and operations for calibration. The memorandum informs readers about tower-flyby, trailing cone, pacer, radar-tracking, and dynamic airdata calibration maneuvers. Readers will also begin to understand how some data analysis considerations and special airdata cases, including high-angle-of-attack flight, high-speed flight, and nonobtrusive sensors are handled. This memorandum is not intended to be all inclusive; this paper contains extensive reference and bibliography sections.

Haering, Edward A., Jr.

1995-01-01

183

Hand-held syringe as a portable plastic pump for on-chip continuous-flow PCR: miniaturization of sample injection device.  

PubMed

On-chip continuous-flow polymerase chain reactions (PCRs) generally require peripheral apparatus such as a pump for injecting a sample liquid into the fluidic channel. This makes the overall instrumentation bulky, limiting integration. In this study, we propose a new scheme for injecting a sample employing a hand-held syringe as a portable plastic pump, and apply it to an on-chip continuous-flow PCR. In the proposed injection scheme, sample actuation was realized inside a highly gas-permeable and blunt-ended fluidic conduit connected to a hand-held plastic syringe filled with compressed air. In this system, the degree of air diffusion via the walls of the gas-permeable conduit becomes greater in the anterior (closer to the outlet) end of the sample plug than the posterior (closer to the inlet) end, because a relatively larger quantity of air is retained inside the syringe at the posterior end of the sample plug. This creates a pressure gradient at the inlet and outlet of the fluidic conduit and propels the sample forward toward the outlet. Preliminary experiments were performed for the quantitative analyses and evaluation of the proposed sample injection scheme using gas-permeable silicone tubes. As practical applications, a 230 bp gene fragment from a plasmid vector and the first 282 bp of the interferon-beta (IFN-?) promoter from a human genomic DNA were successfully amplified on a microdevice coupled with a hand-held syringe as a portable sample actuation device, greatly enhancing device portability for on-site analyses. PMID:22186958

Wu, Wenming; Trinh, Kieu The Loan; Lee, Nae Yoon

2012-02-21

184

Determination of ammonium in aqueous samples using new headspace dynamic in-syringe liquid-phase microextraction with in situ derivitazation coupled with liquid chromatography-fluorescence detection.  

PubMed

A new simultaneous derivatization and extraction method for the preconcentration of ammonia using new one-step headspace dynamic in-syringe liquid-phase microextraction with in situ derivatization was developed for the trace determination of ammonium in aqueous samples by liquid chromatography with fluorescence detection (LC-FLD). The acceptor phase (as derivatization reagent) containing o-phthaldehyde and sodium sulfite was held within a syringe barrel and immersed in the headspace of sample container. The gaseous ammonia from the alkalized aqueous sample formed a stable isoindole derivative with the acceptor phase inside the syringe barrel through the reciprocated movements of plunger. After derivatization-cum-extraction, the acceptor phase was directly injected into LC-FLD for analysis. Parameters affecting the ammonia evolution and the extraction/derivatization efficiency such as sample matrix, pH, temperature, sampling time, and the composition of derivatization reagent, reaction temperature, and frequency of reciprocated plunger, were studied thoroughly. Results indicated that the maximum extraction efficiency was obtained by using 100?L derivatization reagent in a 1-mL gastight syringe under 8 reciprocated movements of plunger per min to extract ammonia evolved from a 20mL alkalized aqueous solution at 70°C (preheated 4min) with 380rpm stirring for 8min. The detection was linear in the concentration range of 0.625-10?M with the correlation coefficient of 0.9967 and detection limit of 0.33?M (5.6ng mL(-1)) based on SN(-1)=3. The method was applied successfully to determine ammonium in real water samples without any prior cleanup of the samples, and has been proved to be a simple, sensitive, efficient and cost-effective procedure for trace ammonium determination in aqueous samples. PMID:23140954

Muniraj, Sarangapani; Yan, Cheing-Tong; Shih, Hou-Kung; Ponnusamy, Vinoth Kumar; Jen, Jen-Fon

2012-11-19

185

Comparison of follitropin ? administered by a pen device with follitropin ? administered by a conventional syringe in patients undergoing IVF-ET  

PubMed Central

Objective To compare the effectiveness and convenience of a pen device for the self-administration of follitropin ? with a conventional syringe delivering follitropin ? solution in patients undergoing IVF-ET. Methods GnRH agonist long protocol was used for controlled ovarian stimulation (COS) in all subjects. A total of 100 patients were randomized into the pen device group or the conventional syringe group on the first day of COS. Local tolerance reactions were assessed within 5 minutes, at 1 hour and at 3 hours after each injection. On the day of hCG injection, patients were asked to rate their overall pain and convenience experienced with self-injection on a visual anlaogue scale (VAS). Results There were no differences in patients' characteristics between the two groups. The duration of COS was significantly shorter in the pen device group than in the conventional syringe group. Patients included in the pen device group needed a significantly smaller amount of follitropin ?. However, no differences between the two groups were found in IVF results and pregnancy outcome. The incidence of local pain within 5 minutes, at 1 hour and at 3 hours after the injection was significantly lower in the pen device group. VAS scores indicated that injections using the pen device were significantly less painful and more convenient. Conclusion The pen device for self-administration of follitropin ? is less painful, safer and more convenient for the patients, and can be more effective because of the shorter duration and smaller dose of follitropin ? when compared with the conventional syringe. PMID:22384416

Kang, Hyuk-Jae; Ahn, Jun-Woo; Lee, Hyang-Ah; Kim, Sung-Hoon; Chae, Hee-Dong; Kang, Byung-Moon

2011-01-01

186

The provision of non-needle\\/syringe drug injecting paraphernalia in the primary prevention of HCV among IDU: a systematic review  

Microsoft Academic Search

BACKGROUND: Sharing drug injecting paraphernalia other than needles and syringes (N\\/S) has been implicated in the transmission of Hepatitis C virus (HCV) among injecting drug users (IDU). We aimed to determine whether the provision of sterile non-N\\/S injecting paraphernalia reduces injecting risk behaviours or HCV transmission among IDU. METHODS: A systematic search of seven databases and the grey literature for

Michelle Gillies; Norah Palmateer; Sharon Hutchinson; Syed Ahmed; Avril Taylor; David Goldberg

2010-01-01

187

Subcutaneously administered methotrexate for rheumatoid arthritis, by prefilled syringes versus prefilled pens: patient preference and comparison of the self-injection experience  

PubMed Central

Purpose This multicenter, randomized, crossover study compared preference, ease of use, acceptability, satisfaction, and safety of repeated subcutaneous (SC) self-administrations with prefilled pens and prefilled syringes delivering methotrexate (MTX), in patients with rheumatoid arthritis (RA). Patients and methods The study (ClinicalTrials.gov number NCT01793259) enrolled 120 patients requiring initiation or intensification of MTX therapy for RA. Patients were randomized to receive the test drug, a prefilled pen (Metex® PEN/Metoject® PEN), or the reference drug, a prefilled syringe (Metex®/Metoject®), at doses of 15, 17.5, or 20 mg MTX SC once a week for 3 weeks. This was followed by receipt of the reference drug (prefilled syringe) or the test drug (prefilled pen) in a crossover design, with each patient serving as his/her own control. Questionnaires regarding patient preference, the Self-Injection Assessment Questionnaire (SIAQ), and diaries regarding local tolerability were used to document outcomes. Results Overall patient preference for the MTX prefilled pen was 75% (P<0.0001). In a six-item questionnaire, 73% to 76% of the patients preferred the prefilled pen in relation to use, acceptability, and satisfaction, and 67% of the patients confirmed that it did not take much effort to overcome SC self-injection with the pen. The SIAQ showed no clinical differences, in any domain scores, between both devices. Overall patient attitude towards self-injection at baseline was positive, as was patient experience with both devices during the study. As well, 92% of physicians and study nurses indicated that they would recommend the MTX prefilled pen to patients for future MTX treatment. The formulations were generally well tolerated. Conclusion SC self-injection of MTX with a prefilled pen was generally preferred, by patients with RA, over a prefilled syringe with regard to use, acceptability, and satisfaction. This is supported by the strong appreciation of their attending study nurses and physicians, for its convenience. PMID:25125973

Demary, Winfried; Schwenke, Holger; Rockwitz, Karin; Kästner, Peter; Liebhaber, Anke; Schoo, Ulrich; Hübner, Georg; Pichlmeier, Uwe; Guimbal-Schmolck, Cécile; Müller-Ladner, Ulf

2014-01-01

188

Calibrated Properties Model  

SciTech Connect

The purpose of this Analysis/Model Report (AMR) is to document the Calibrated Properties Model that provides calibrated parameter sets for unsaturated zone (UZ) flow and transport process models for the Yucca Mountain Site Characterization Project (YMP). This work was performed in accordance with the AMR Development Plan for U0035 Calibrated Properties Model REV00 (CRWMS M&O 1999c). These calibrated property sets include matrix and fracture parameters for the UZ Flow and Transport Model (UZ Model), drift seepage models, drift-scale and mountain-scale coupled-processes models, and Total System Performance Assessment (TSPA) models as well as Performance Assessment (PA) and other participating national laboratories and government agencies. These process models provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic and thermal-loading conditions.

C.F. Ahlers, H.H. Liu

2001-12-18

189

Calibrated Properties Model  

SciTech Connect

The purpose of this Analysis/Model Report (AMR) is to document the Calibrated Properties Model that provides calibrated parameter sets for unsaturated zone (UZ) flow and transport process models for the Yucca Mountain Site Characterization Project (YMP). This work was performed in accordance with the ''AMR Development Plan for U0035 Calibrated Properties Model REV00. These calibrated property sets include matrix and fracture parameters for the UZ Flow and Transport Model (UZ Model), drift seepage models, drift-scale and mountain-scale coupled-processes models, and Total System Performance Assessment (TSPA) models as well as Performance Assessment (PA) and other participating national laboratories and government agencies. These process models provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic and thermal-loading conditions.

C. Ahlers; H. Liu

2000-03-12

190

Mass spectrometer calibration standard  

NASA Technical Reports Server (NTRS)

Inert perfluorinated alkane and alkyl ethers mixture is used to calibrate mass spectrometer. Noncontaminating, commercially-available liquid provides series of reproducible reference peaks over broad mass spectrum that ranges over mass numbers from 1 to 200.

Ross, D. S.

1978-01-01

191

SRAM Detector Calibration  

NASA Technical Reports Server (NTRS)

Custom proton sensitive SRAM chips are being flown on the BMDO Clementine missions and Space Technology Research Vehicle experiments. This paper describes the calibration procedure for the SRAM proton detectors and their response to the space environment.

Soli, G. A.; Blaes, B. R.; Beuhler, M. G.

1994-01-01

192

POLARIMETRIC MICROWAVE RADIOMETER CALIBRATION  

E-print Network

POLARIMETRIC MICROWAVE RADIOMETER CALIBRATION by Jinzheng Peng A dissertation submitted in partial........................................................................................................ 1 1.1 Microwave Remote Sensing Overview .................................................................................... 12 1.3 Electromagnetic Wave Propagation through the Atmosphere............................ 14 1

Ruf, Christopher

193

Prefilled certolizumab pegol (Cimzia®) syringes for self-use in the treatment of rheumatoid arthritis  

PubMed Central

A new anti-tumor necrosis factor alpha (TNF-?) inhibitor with a novel mechanism of action has entered phase 3 trials in rheumatoid arthritis (RA). Certolizumab pegol (Cimzia®) is a humanized Fab? antibody fragment against TNF-? with a polyethylene glycol tail that prevents complement-dependent and antibody-dependent cell-mediated cytotoxicity or apoptosis. Four randomized clinical trials have been published so far. Reported results are similar to those published in previous studies with other TNF-? inhibitors, with ACR20, ACR50, and ACR70 responses of around 60%, 40%, and 20%, respectively, when combined with methotrexate and slightly lower when used as monotherapy. Safety was shown to be similar to that seen with TNF-? blockers and some cases of tuberculosis were seen in the trials, stressing the importance of a complete screening in these patients. Although we still need effectiveness and safety data in larger numbers of patients and longer follow-up, this new TNF inhibitor is a welcome addition to our current armamentarium for the treatment of RA. PMID:22915918

Rosa, J; Sabelli, M; Soriano, Enrique R

2010-01-01

194

Integrated calibration sphere and calibration step fixture for improved coordinate measurement machine calibration  

DOEpatents

A method and apparatus for mounting a calibration sphere to a calibration fixture for Coordinate Measurement Machine (CMM) calibration and qualification is described, decreasing the time required for such qualification, thus allowing the CMM to be used more productively. A number of embodiments are disclosed that allow for new and retrofit manufacture to perform as integrated calibration sphere and calibration fixture devices. This invention renders unnecessary the removal of a calibration sphere prior to CMM measurement of calibration features on calibration fixtures, thereby greatly reducing the time spent qualifying a CMM.

Clifford, Harry J. (Los Alamos, NM)

2011-03-22

195

An open-label, multicenter study to evaluate the safe and effective use of the single-use autoinjector with an Avonex® prefilled syringe in multiple sclerosis subjects  

PubMed Central

Background The ability to self-inject in patients with multiple sclerosis (MS) has been associated with a reduced risk of missed injections and drug discontinuation, and a beneficial effect on patients' independence. However, injection anxiety, needle phobia and disease-related disability are major barriers to a patient's ability to self-administer treatment. Use of an autoinjector may improve patients' ability to self-inject. This study evaluated the safe and effective use of Avonex Pen™ (prefilled pen), a single use autoinjector, for intramuscular delivery of interferon beta-1a (IM IFN?-1a, Avonex) in MS patients. Methods This was a Phase IIIb, open-label, single-country, multicenter trial in MS patients currently using IM IFN?-1a prefilled syringes. Patients received weekly 30 mcg IM IFN?-1a treatment over 4 weeks. On Day 1, patients self-administered IM IFN?-1a using a prefilled syringe at the clinic. On Day 8, patients received training on the prefilled pen and self-administered IM IFN?-1a using the device. On Day 15, patients self-administered IM IFN?-1a at home using the prefilled pen. A final injection occurred at the clinic on Day 22 when patients self-administered IM IFN?-1a using the prefilled pen while clinic staff observed and completed a detailed questionnaire documenting patients' ability to self-inject with the device. Serum neopterin levels were evaluated pre and post-injection on Days 1 and 8. Adverse events were monitored throughout. Results Seventy-one (96%) patients completed the study. The overall success rate in safely and effectively using the prefilled pen was 89%. No device malfunctions occurred. One unsuccessful administration occurred at Day 22 due to patient error; no patient injury resulted. Patients gave the prefilled pen high ratings (8.7-9.3) on a 10-point scale for ease of use (0 = extremely difficult, 10 = extremely easy). Ninety-four percent of patients preferred the prefilled pen over the prefilled syringe. Induction of serum neopterin levels, serving as a biomarker for type 1 interferon action, was similar to that of the prefilled syringe. The prefilled pen demonstrated a safety profile comparable to the prefilled syringe. Conclusions The prefilled pen is a safe and effective device for administration of IM IFN?-1a and represents an alternative method for self-injection for MS patients using this therapy. Trial registration This study is registered at clinicaltrials.gov, identifier: NCT00828204 PMID:21999176

2011-01-01

196

Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer. I. The Stellar Calibrator Sample and the 24 ?m Calibration  

NASA Astrophysics Data System (ADS)

We present the stellar calibrator sample and the conversion from instrumental to physical units for the 24 ?m channel of the Multiband Imaging Photometer for Spitzer (MIPS). The primary calibrators are A stars, and the calibration factor based on those stars is 4.54×10-2 MJy sr-1 (DN s-1)-1, with a nominal uncertainty of 2%. We discuss the data reduction procedures required to attain this accuracy; without these procedures, the calibration factor obtained using the automated pipeline at the Spitzer Science Center is 1.6%+/-0.6% lower. We extend this work to predict 24 ?m flux densities for a sample of 238 stars that covers a larger range of flux densities and spectral types. We present a total of 348 measurements of 141 stars at 24 ?m. This sample covers a factor of ~460 in 24 ?m flux density, from 8.6 mJy up to 4.0 Jy. We show that the calibration is linear over that range with respect to target flux and background level. The calibration is based on observations made using 3 s exposures; a preliminary analysis shows that the calibration factor may be 1% and 2% lower for 10 and 30 s exposures, respectively. We also demonstrate that the calibration is very stable: over the course of the mission, repeated measurements of our routine calibrator, HD 159330, show a rms scatter of only 0.4%. Finally, we show that the point-spread function (PSF) is well measured and allows us to calibrate extended sources accurately; Infrared Astronomy Satellite (IRAS) and MIPS measurements of a sample of nearby galaxies are identical within the uncertainties.

Engelbracht, C. W.; Blaylock, M.; Su, K. Y. L.; Rho, J.; Rieke, G. H.; Muzerolle, J.; Padgett, D. L.; Hines, D. C.; Gordon, K. D.; Fadda, D.; Noriega-Crespo, A.; Kelly, D. M.; Latter, W. B.; Hinz, J. L.; Misselt, K. A.; Morrison, J. E.; Stansberry, J. A.; Shupe, D. L.; Stolovy, S.; Wheaton, Wm. A.; Young, E. T.; Neugebauer, G.; Wachter, S.; Pérez-González, P. G.; Frayer, D. T.; Marleau, F. R.

2007-09-01

197

Exploration of new multivariate spectral calibration algorithms.  

SciTech Connect

A variety of multivariate calibration algorithms for quantitative spectral analyses were investigated and compared, and new algorithms were developed in the course of this Laboratory Directed Research and Development project. We were able to demonstrate the ability of the hybrid classical least squares/partial least squares (CLSIPLS) calibration algorithms to maintain calibrations in the presence of spectrometer drift and to transfer calibrations between spectrometers from the same or different manufacturers. These methods were found to be as good or better in prediction ability as the commonly used partial least squares (PLS) method. We also present the theory for an entirely new class of algorithms labeled augmented classical least squares (ACLS) methods. New factor selection methods are developed and described for the ACLS algorithms. These factor selection methods are demonstrated using near-infrared spectra collected from a system of dilute aqueous solutions. The ACLS algorithm is also shown to provide improved ease of use and better prediction ability than PLS when transferring calibrations between near-infrared calibrations from the same manufacturer. Finally, simulations incorporating either ideal or realistic errors in the spectra were used to compare the prediction abilities of the new ACLS algorithm with that of PLS. We found that in the presence of realistic errors with non-uniform spectral error variance across spectral channels or with spectral errors correlated between frequency channels, ACLS methods generally out-performed the more commonly used PLS method. These results demonstrate the need for realistic error structure in simulations when the prediction abilities of various algorithms are compared. The combination of equal or superior prediction ability and the ease of use of the ACLS algorithms make the new ACLS methods the preferred algorithms to use for multivariate spectral calibrations.

Van Benthem, Mark Hilary; Haaland, David Michael; Melgaard, David Kennett; Martin, Laura Elizabeth; Wehlburg, Christine Marie; Pell, Randy J. (The Dow Chemical Company, Midland, MI); Guenard, Robert D. (Merck & Co. Inc., West Point, PA)

2004-03-01

198

Error Modeling and Calibration for Encoded Sun Sensors  

PubMed Central

Error factors in the encoded sun sensor (ESS) are analyzed and simulated. Based on the analysis results, an ESS error compensation model containing structural errors and fine-code algorithm errors is established, and the corresponding calibration method for model parameters is proposed. As external parameters, installation deviation between ESS and calibration equipment are introduced to the ESS calibration model, so that the model parameters can be calibrated accurately. The experimental results show that within plus/minus 60 degree of incident angle, the ESS measurement accuracy after compensation is three times higher on average than that before compensation. PMID:23470486

Fan, Qiaoyun; Zhang, Guangjun; Li, Jian; Wei, Xinguo; Li, Xiaoyang

2013-01-01

199

Calibration Under Uncertainty.  

SciTech Connect

This report is a white paper summarizing the literature and different approaches to the problem of calibrating computer model parameters in the face of model uncertainty. Model calibration is often formulated as finding the parameters that minimize the squared difference between the model-computed data (the predicted data) and the actual experimental data. This approach does not allow for explicit treatment of uncertainty or error in the model itself: the model is considered the %22true%22 deterministic representation of reality. While this approach does have utility, it is far from an accurate mathematical treatment of the true model calibration problem in which both the computed data and experimental data have error bars. This year, we examined methods to perform calibration accounting for the error in both the computer model and the data, as well as improving our understanding of its meaning for model predictability. We call this approach Calibration under Uncertainty (CUU). This talk presents our current thinking on CUU. We outline some current approaches in the literature, and discuss the Bayesian approach to CUU in detail.

Swiler, Laura Painton; Trucano, Timothy Guy

2005-03-01

200

HAWC Timing Calibration  

E-print Network

The High-Altitude Water Cherenkov (HAWC) Experiment is a second-generation highsensitivity gamma-ray and cosmic-ray detector that builds on the experience and technology of the Milagro observatory. Like Milagro, HAWC utilizes the water Cherenkov technique to measure extensive air showers. Instead of a pond filled with water (as in Milagro) an array of closely packed water tanks is used. The event direction will be reconstructed using the times when the PMTs in each tank are triggered. Therefore, the timing calibration will be crucial for reaching an angular resolution as low as 0.25 degrees.We propose to use a laser calibration system, patterned after the calibration system in Milagro. Like Milagro, the HAWC optical calibration system will use ~1 ns laser light pulses. Unlike Milagro, the PMTs are optically isolated and require their own optical fiber calibration. For HAWC the laser light pulses will be directed through a series of optical fan-outs and fibers to illuminate the PMTs in approximately one half o...

Huentemeyer, Petra; Dingus, Brenda

2009-01-01

201

Psychophysical contrast calibration  

PubMed Central

Electronic displays and computer systems offer numerous advantages for clinical vision testing. Laboratory and clinical measurements of various functions and in particular of (letter) contrast sensitivity require accurately calibrated display contrast. In the laboratory this is achieved using expensive light meters. We developed and evaluated a novel method that uses only psychophysical responses of a person with normal vision to calibrate the luminance contrast of displays for experimental and clinical applications. Our method combines psychophysical techniques (1) for detection (and thus elimination or reduction) of display saturating nonlinearities; (2) for luminance (gamma function) estimation and linearization without use of a photometer; and (3) to measure without a photometer the luminance ratios of the display’s three color channels that are used in a bit-stealing procedure to expand the luminance resolution of the display. Using a photometer we verified that the calibration achieved with this procedure is accurate for both LCD and CRT displays enabling testing of letter contrast sensitivity to 0.5%. Our visual calibration procedure enables clinical, internet and home implementation and calibration verification of electronic contrast testing. PMID:23643843

To, Long; Woods, Russell L; Goldstein, Robert B; Peli, Eli

2013-01-01

202

Hydrometer calibration by hydrostatic weighing with automated liquid surface positioning  

NASA Astrophysics Data System (ADS)

We describe an automated apparatus for calibrating hydrometers by hydrostatic weighing (Cuckow's method) in tridecane, a liquid of known, stable density, and with a relatively low surface tension and contact angle against glass. The apparatus uses a laser light sheet and a laser power meter to position the tridecane surface at the hydrometer scale mark to be calibrated with an uncertainty of 0.08 mm. The calibration results have an expanded uncertainty (with a coverage factor of 2) of 100 parts in 106 or less of the liquid density. We validated the apparatus by comparisons using water, toluene, tridecane and trichloroethylene, and found agreement within 40 parts in 106 or less. The new calibration method is consistent with earlier, manual calibrations performed by NIST. When customers use calibrated hydrometers, they may encounter uncertainties of 370 parts in 106 or larger due to surface tension, contact angle and temperature effects.

Aguilera, Jesus; Wright, John D.; Bean, Vern E.

2008-01-01

203

A Comparison of Two Balance Calibration Model Building Methods  

NASA Technical Reports Server (NTRS)

Simulated strain-gage balance calibration data is used to compare the accuracy of two balance calibration model building methods for different noise environments and calibration experiment designs. The first building method obtains a math model for the analysis of balance calibration data after applying a candidate math model search algorithm to the calibration data set. The second building method uses stepwise regression analysis in order to construct a model for the analysis. Four balance calibration data sets were simulated in order to compare the accuracy of the two math model building methods. The simulated data sets were prepared using the traditional One Factor At a Time (OFAT) technique and the Modern Design of Experiments (MDOE) approach. Random and systematic errors were introduced in the simulated calibration data sets in order to study their influence on the math model building methods. Residuals of the fitted calibration responses and other statistical metrics were compared in order to evaluate the calibration models developed with different combinations of noise environment, experiment design, and model building method. Overall, predicted math models and residuals of both math model building methods show very good agreement. Significant differences in model quality were attributable to noise environment, experiment design, and their interaction. Generally, the addition of systematic error significantly degraded the quality of calibration models developed from OFAT data by either method, but MDOE experiment designs were more robust with respect to the introduction of a systematic component of the unexplained variance.

DeLoach, Richard; Ulbrich, Norbert

2007-01-01

204

Deep Impact instrument calibration  

NASA Astrophysics Data System (ADS)

Calibration of NASA's Deep Impact spacecraft instruments allows reliable scientific interpretation of the images and spectra returned from comet Tempel 1. Calibrations of the four onboard remote sensing imaging instruments have been performed in the areas of geometric calibration, spatial resolution, spectral resolution, and radiometric response. Error sources such as noise (random, coherent, encoding, data compression), detector readout artifacts, scattered light, and radiation interactions have been quantified. The point spread functions (PSFs) of the medium resolution instrument and its twin impactor targeting sensor are near the theoretical minimum [~1.7 pixels full width at half maximum (FWHM)]. However, the high resolution instrument camera was found to be out of focus with a PSF FWHM of ~9 pixels. The charge coupled device (CCD) read noise is ~1 DN. Electrical cross-talk between the CCD detector quadrants is correctable to <2 DN. The IR spectrometer response nonlinearity is correctable to ~1%. Spectrometer read noise is ~2 DN. The variation in zero-exposure signal level with time and spectrometer temperature is not fully characterized; currently corrections are good to ~10 DN at best. Wavelength mapping onto the detector is known within 1 pixel; spectral lines have a FWHM of ~2 pixels. About 1% of the IR detector pixels behave badly and remain uncalibrated. The spectrometer exhibits a faint ghost image from reflection off a beamsplitter. Instrument absolute radiometric calibration accuracies were determined generally to <10% using star imaging. Flat-field calibration reduces pixel-to-pixel response differences to ~0.5% for the cameras and <2% for the spectrometer. A standard calibration image processing pipeline is used to produce archival image files for analysis by researchers.

Klaasen, K.; A'Hearn, M. F.; Baca, M.; Delamere, A.; Desnoyer, M.; Farnham, T.; Groussin, O.; Hampton, D.; Ipatov, S.; Li, J.-Y.; Lisse, C.; Mastrodemos, N.; McLaughlin, S.; Sunshine, J.; Thomas, P.; Wellnitz, D.

2008-09-01

205

Autonomous Phase Retrieval Calibration  

NASA Technical Reports Server (NTRS)

The Palomar Adaptive Optics System actively corrects for changing aberrations in light due to atmospheric turbulence. However, the underlying internal static error is unknown and uncorrected by this process. The dedicated wavefront sensor device necessarily lies along a different path than the science camera, and, therefore, doesn't measure the true errors along the path leading to the final detected imagery. This is a standard problem in adaptive optics (AO) called "non-common path error." The Autonomous Phase Retrieval Calibration (APRC) software suite performs automated sensing and correction iterations to calibrate the Palomar AO system to levels that were previously unreachable.

Estlin, Tara A.; Chien, Steve A.; Castano, Rebecca; Gaines, Daniel M.; Doubleday, Joshua R.; Schoolcraft, Josua B.; Oyake, Amalaye; Vaughs, Ashton G.; Torgerson, Jordan L.

2011-01-01

206

Gap Test Calibrations And Their Scalin  

NASA Astrophysics Data System (ADS)

Common tests for measuring the threshold for shock initiation are the NOL large scale gap test (LSGT) with a 50.8-mm diameter donor/gap and the expanded large scale gap test (ELSGT) with a 95.3-mm diameter donor/gap. Despite the same specifications for the explosive donor and polymethyl methacrylate (PMMA) gap in both tests, calibration of shock pressure in the gap versus distance from the donor scales by a factor of 1.75, not the 1.875 difference in their sizes. Recently reported model calculations suggest that the scaling discrepancy results from the viscoelastic properties of PMMA in combination with different methods for obtaining shock pressure. This is supported by the consistent scaling of these donors when calibrated in water-filled aquariums. Calibrations and their scaling are compared for other donors with PMMA gaps and for various donors in water.

Sandusky, Harold

2012-03-01

207

Gap Test Calibrations and Their Scaling  

NASA Astrophysics Data System (ADS)

Common tests for measuring the threshold for shock initiation are the NOL large scale gap test (LSGT) with a 50.8-mm diameter donor/gap and the expanded large scale gap test (ELSGT) with a 95.3-mm diameter donor/gap. Despite the same specifications for the explosive donor and polymethyl methacrylate (PMMA) gap in both tests, calibration of shock pressure in the gap versus distance from the donor scales by a factor of 1.75, not the 1.875 difference in their sizes. Recently reported model calculations suggest that the scaling discrepancy results from the viscoelastic properties of PMMA in combination with different methods for obtaining shock pressure. This is supported by the consistent scaling of these donors when calibrated in water-filled aquariums. Calibrations with water gaps will be provided and compared with PMMA gaps. Scaling for other donor systems will also be provided. Shock initiation data with water gaps will be reviewed.

Sandusky, Harold

2011-06-01

208

Calibration of the Urbana lidar system  

NASA Technical Reports Server (NTRS)

A method for calibrating data obtained by the Urban sodium lidar system is presented. First, an expression relating the number of photocounts originating from a specific altitude range to the soodium concentration is developed. This relation is then simplified by normalizing the sodium photocounts with photocounts originating from the Rayleigh region of the atmosphere. To evaluate the calibration expression, the laser linewidth must be known. Therefore, a method for measuring the laser linewidth using a Fabry-Perot interferometer is given. The laser linewidth was found to be 6 + or - 2.5 pm. Problems due to photomultiplier tube overloading are discussed. Finally, calibrated data is presented. The sodium column abundance exhibits something close to a sinusoidal variation throughout the year with the winter months showing an enhancement of a factor of 5 to 7 over the summer months.

Cerny, T.; Sechrist, C. F., Jr.

1980-01-01

209

MODIS Solar Reflective Calibration Traceability  

NASA Technical Reports Server (NTRS)

Long-term climate data records often consist of observations made by multiple sensors. It is, therefore, extremely important to have instrument overlap, to be able to track instrument stability, to quantify, measurement uncertainties, and to establish absolute scale traceable to the International System of Units (SI). The Moderate Resolution Imaging Spectroradiometer (MODIS) is a key instrument for both the Terra and Aqua missions, which were launched in December 1999 and May 2002, respectively. It has 20 reflective solar bands (RSB) with wavelengths from 0.41 to 2.2 micrometers and observes the Earth at three nadir spatial resolutions: 0.25km, 0.5km, and 1km. MODIS RSB on-orbit calibration is reflectance based with reference to the bidirectional reflectance factor (BRF) of its on-board solar diffuser (SD). The SD BRF characterization was made pre-launch by the instrument vendor using reference samples traceable directly to the National Institute of Standards and Technology (NIST). On-orbit SD reflectance degradation is tracked by an on-board solar diffuser monitor (SDSM). This paper provides details of this calibration chain, from prelaunch to on-orbit operation, and associated uncertainty assessments. Using MODIS as an example, this paper also discusses challenges and key design requirements for future missions developed for accurate climate studies.

Xiong, Xiaoxiong; Butler, Jim

2009-01-01

210

Thermistor mount efficiency calibration  

SciTech Connect

Thermistor mount efficiency calibration is accomplished by use of the power equation concept and by complex signal-ratio measurements. A comparison of thermistor mounts at microwave frequencies is made by mixing the reference and the reflected signals to produce a frequency at which the amplitude and phase difference may be readily measured.

Cable, J.W.

1980-05-01

211

Uncertainty in audiometer calibration  

NASA Astrophysics Data System (ADS)

The objective of this work is to present a metrology study necessary for the accreditation of audiometer calibration procedures at the National Brazilian Institute of Metrology Standardization and Industrial Quality—INMETRO. A model for the calculation of measurement uncertainty was developed. Metrological aspects relating to audiometer calibration, traceability and measurement uncertainty were quantified through comparison between results obtained at the Industrial Noise Laboratory—LARI of the Federal University of Santa Catarina—UFSC and the Laboratory of Electric/acoustics—LAETA of INMETRO. Similar metrological performance of the measurement system used in both laboratories was obtained, indicating that the interlaboratory results are compatible with the expected values. The uncertainty calculation was based on the documents: EA-4/02 Expression of the Uncertainty of Measurement in Calibration (European Co-operation for Accreditation 1999 EA-4/02 p 79) and Guide to the Expression of Uncertainty in Measurement (International Organization for Standardization 1993 1st edn, corrected and reprinted in 1995, Geneva, Switzerland). Some sources of uncertainty were calculated theoretically (uncertainty type B) and other sources were measured experimentally (uncertainty type A). The global value of uncertainty calculated for the sound pressure levels (SPLs) is similar to that given by other calibration institutions. The results of uncertainty related to measurements of SPL were compared with the maximum uncertainties Umax given in the standard IEC 60645-1: 2001 (International Electrotechnical Commission 2001 IEC 60645-1 Electroacoustics—Audiological Equipment—Part 1:—Pure-Tone Audiometers).

Aurélio Pedroso, Marcos; Gerges, Samir N. Y.; Gonçalves, Armando A., Jr.

2004-02-01

212

Calibration loads for ALMA  

Microsoft Academic Search

This paper presents the design of the ALMA Calibration Loads based on the folded cone geometry. The design is supported by ray-tracing simulations of the multilayer absorber cones and comprehensive thermal analysis. Experimental verifications of the Loads' performance included reflection measurements between 30–700 GHz with a vector network analyzer and radiometric tests at different frequencies between 91 GHz and 700

P. Yagoubov; A. Murk; R. Wylde; G. Bell; G. H. Tan

2011-01-01

213

CALIBRATION Galileo Scale Model  

E-print Network

see Jupiter and some of its 4 largest moons, just as Galileo Galilei did in Italy in 1610. While youPRINTING CALIBRATION Galileo Scale Model PARTS SHEET 1: The High-Gain Antenna PRINT ON TRANSPARENCY MATERIAL Galileo's High-Gain Antenna (HGA) was designed to unfold like an umbrella. It needed to be folded

214

The JWST Calibration Pipeline  

NASA Astrophysics Data System (ADS)

The James Webb Space Telescope will launch in 2018 and carry four science instruments that will observe the sky at 0.7 - 29 micron: the Near Infrared Camera (NIRCam), the Near Infrared Imager and Slitless Spectrograph (NIRISS), the Near Infrared Spectrograph (NIRSpec), and the Mid Infrared Instrument (MIRI). The Space Telescope Science Institute (STScI) is currently building a data reduction pipeline that will provide not only basic calibrated data but also higher level science products. All of the JWST detectors will be operated in non-destructive readout mode. Therefore, the first step in the pipeline will be to calculate the slopes of indivudal non-destructive readout ramps or integrations. The next step will be to generate calibrated slope images that are represent the basic calibrated data. The final step will be to combine data taken across multiple integrations and exposure. For the direct imaging and integral field spectroscopy modes, the pipeline will produce calibrated mosaicks. For the coronagraphic modes, the pipeline will produce contrast curves and PSF subtracted images.

Chen, Christine; Muzerolle, James; Van Dyke Dixon, William; Izela Diaz, Rosa; Bushouse, Howard A.

2015-01-01

215

Calibrated Peer Review  

NSDL National Science Digital Library

This site presents a paper-writing and peer review tool that is available free to educators and students. Calibrated Peer Review is a Web-based program that enables frequent writing assignments even in large classes with limited instructional resources. The program is discipline and level independent.

Calibrated Peer Review

216

Optical detector calibrator system  

NASA Technical Reports Server (NTRS)

An optical detector calibrator system simulates a source of optical radiation to which a detector to be calibrated is responsive. A light source selected to emit radiation in a range of wavelengths corresponding to the spectral signature of the source is disposed within a housing containing a microprocessor for controlling the light source and other system elements. An adjustable iris and a multiple aperture filter wheel are provided for controlling the intensity of radiation emitted from the housing by the light source to adjust the simulated distance between the light source and the detector to be calibrated. The geared iris has an aperture whose size is adjustable by means of a first stepper motor controlled by the microprocessor. The multiple aperture filter wheel contains neutral density filters of different attenuation levels which are selectively positioned in the path of the emitted radiation by a second stepper motor that is also controlled by the microprocessor. An operator can select a number of detector tests including range, maximum and minimum sensitivity, and basic functionality. During the range test, the geared iris and filter wheel are repeatedly adjusted by the microprocessor as necessary to simulate an incrementally increasing simulated source distance. A light source calibration subsystem is incorporated in the system which insures that the intensity of the light source is maintained at a constant level over time.

Strobel, James P. (Inventor); Moerk, John S. (Inventor); Youngquist, Robert C. (Inventor)

1996-01-01

217

On the calibration of high dynamic range photography for luminance measurements in indoor daylit scenes  

Microsoft Academic Search

This article describes a study of two issues concerning the calibration of high dynamic range (HDR) photography for luminance measurements in indoor daylit spaces: (i) the selection of a target in a scene for calibration and (ii) the variation of the calibration factor with different daylight levels. Luminance measurements of coloured and grey targets were conducted in a classroom under

Roger T. H. Ng; Tse-ming Chung

2011-01-01

218

Comparison of magnetic probe calibration at nano and millitesla magnitudes  

NASA Astrophysics Data System (ADS)

Magnetic field probes are invaluable diagnostics for pulsed inductive plasma devices where field magnitudes on the order of tenths of tesla or larger are common. Typical methods of providing a broadband calibration of dot{{B}} probes involve either a Helmholtz coil driven by a function generator or a network analyzer. Both calibration methods typically produce field magnitudes of tens of microtesla or less, at least three and as many as six orders of magnitude lower than their intended use. This calibration factor is then assumed constant regardless of magnetic field magnitude and the effects of experimental setup are ignored. This work quantifies the variation in calibration factor observed when calibrating magnetic field probes in low field magnitudes. Calibration of two dot{{B}} probe designs as functions of frequency and field magnitude are presented. The first dot{{B}} probe design is the most commonly used design and is constructed from two hand-wound inductors in a differential configuration. The second probe uses surface mounted inductors in a differential configuration with balanced shielding to further reduce common mode noise. Calibration factors are determined experimentally using an 80.4 mm radius Helmholtz coil in two separate configurations over a frequency range of 100-1000 kHz. A conventional low magnitude calibration using a vector network analyzer produced a field magnitude of 158 nT and yielded calibration factors of 15 663 ± 1.7% and 4920 ± 0.6% {T}/{V {s}} at 457 kHz for the surface mounted and hand-wound probes, respectively. A relevant magnitude calibration using a pulsed-power setup with field magnitudes of 8.7-354 mT yielded calibration factors of 14 615 ± 0.3% and 4507 ± 0.4% {T}/{V {s}} at 457 kHz for the surface mounted inductor and hand-wound probe, respectively. Low-magnitude calibration resulted in a larger calibration factor, with an average difference of 9.7% for the surface mounted probe and 12.0% for the hand-wound probe. The maximum difference between relevant and low magnitude tests was 21.5%.

Pahl, Ryan A.; Rovey, Joshua L.; Pommerenke, David J.

2014-01-01

219

Novel one-step headspace dynamic in-syringe liquid phase derivatization-extraction technique for the determination of aqueous aliphatic amines by liquid chromatography with fluorescence detection.  

PubMed

A novel one-step headspace (HS) dynamic in-syringe (DIS) based liquid-phase derivatization-extraction (LPDE) technique has been developed for the selective determination of two short-chain aliphatic amines (SCAAs) in aqueous samples using high performance liquid chromatography (HPLC) with fluorescence detection (FLD). Methylamine (MA) and dimethylamine (DMA) were selected as model compounds of SCAAs. In this method, a micro-syringe pre-filled with derivatizing reagent solution (9-fluorenylmethyl chloroformate) in the barrel was applied to achieve the simultaneous derivatization and extraction of two methylamines evolved from alkalized aqueous samples through the automated reciprocated movements of syringe plunger. After the derivatization-extraction process, the derivatized phase was directly injected into HPLC-FLD for analysis. Parameters influencing the evolution of methylamines and the HS-DIS-LPDE efficiency, including sample pH and temperature, sampling time, as well as the composition of derivatization reagent, reaction temperature, and frequency of reciprocated plunger movements, were thoroughly examined and optimized. Under optimal conditions, detections were linear in the range of 25-500?gL(-1) for MA and DMA with correlation coefficients all above 0.995. The limits of detection (based on S/N=3) were 5 and 19ngmL(-1) for MA and DMA, respectively. The applicability of the developed method was demonstrated for the determination of MA and DMA in real water samples without any prior cleanup of the sample. The present method provides a simple, selective, automated, low cost and eco-friendly procedure to determine aliphatic amines in aqueous samples. PMID:23591526

Muniraj, Sarangapani; Shih, Hou-Kung; Chen, Ying-Fang; Hsiech, Chunming; Ponnusamy, Vinoth Kumar; Jen, Jen-Fon

2013-06-28

220

Polarimetric SAR calibration experiment using active radar calibrators  

Microsoft Academic Search

Active radar calibrators are used to derive both the amplitude and phase characteristics of a multichannel polarimetric synthetic aperture radar (SAR) from the complex image data. Results are presented from an experiment carried out using the NASA\\/JPL DC-8 aircraft SAR over a calibration site at Goldstone, California. As part of the experiment, polarimetric active radar calibrators (PARCs) with adjustable polarization

Anthony Freeman; Yuhsyen Shen; C. L. Werner

1990-01-01

221

New approach to calibrating bed load samplers ( calibration curves).  

USGS Publications Warehouse

Calibration curves are derived by two independent methods using data collected with prototype versions of the Helley-Smith sampler in a large calibration facility capable of continuously measuring transport rates across a 9ft (2.7m) width. Results from both methods agree. Composite calibration curves are obtained for six different versions of the sampler.-from ASCE Publications Information

Hubbell, D.W.; Stevens, H.H.; Skinner, J.V.

1985-01-01

222

Development of an automatic routine for calibration of thermographic phosphors  

NASA Astrophysics Data System (ADS)

An automated routine for the continuous calibration of thermographic phosphors was developed as a replacement for the conventional calibration scheme that relied on fixed temperature points. The automated calibration routine was validated using Mg3F2GeO4:Mn as a calibration phosphor. Hardware and software aspects of the calibration process were addressed in this development. The hardware aspect included a new substrate design using a high performance alloy, the Hastelloy-C alloy, whereas the software aspect included an automated acquisition system which was capable of acquiring simultaneous thermocouple temperatures and phosphor decay waveform in real time. The design of the calibration process eliminates the need for a system in thermal equilibrium during a phosphor calibration measurement. Temperature ramping rates of up to 4 K min-1 were employed in the oven without a delay in the temperature response being measured between the phosphor and the thermocouples involved. In addition, the automated calibration setup allowed for detailed investigations on the effect of heat being delivered to the phosphor coating by the laser. These findings were confirmed by a simple heat transfer model, based on lumped system analysis. In comparison to the data acquisition performed at several fixed points with the conventional calibration scheme, the experiment duration was shortened by a factor of 4 with the overall accuracy improved by 1-2 K.

Abou Nada, F.; Knappe, C.; Xu, X.; Richter, M.; Aldén, M.

2014-02-01

223

Mercury Calibration System  

SciTech Connect

U.S. Environmental Protection Agency (EPA) Performance Specification 12 in the Clean Air Mercury Rule (CAMR) states that a mercury CEM must be calibrated with National Institute for Standards and Technology (NIST)-traceable standards. In early 2009, a NIST traceable standard for elemental mercury CEM calibration still does not exist. Despite the vacature of CAMR by a Federal appeals court in early 2008, a NIST traceable standard is still needed for whatever regulation is implemented in the future. Thermo Fisher is a major vendor providing complete integrated mercury continuous emissions monitoring (CEM) systems to the industry. WRI is participating with EPA, EPRI, NIST, and Thermo Fisher towards the development of the criteria that will be used in the traceability protocols to be issued by EPA. An initial draft of an elemental mercury calibration traceability protocol was distributed for comment to the participating research groups and vendors on a limited basis in early May 2007. In August 2007, EPA issued an interim traceability protocol for elemental mercury calibrators. Various working drafts of the new interim traceability protocols were distributed in late 2008 and early 2009 to participants in the Mercury Standards Working Committee project. The protocols include sections on qualification and certification. The qualification section describes in general terms tests that must be conducted by the calibrator vendors to demonstrate that their calibration equipment meets the minimum requirements to be established by EPA for use in CAMR monitoring. Variables to be examined include linearity, ambient temperature, back pressure, ambient pressure, line voltage, and effects of shipping. None of the procedures were described in detail in the draft interim documents; however they describe what EPA would like to eventually develop. WRI is providing the data and results to EPA for use in developing revised experimental procedures and realistic acceptance criteria based on actual capabilities of the current calibration technology. As part of the current effort, WRI worked with Thermo Fisher elemental mercury calibrator units to conduct qualification experiments to demonstrate their performance characteristics under a variety of conditions and to demonstrate that they qualify for use in the CEM calibration program. Monitoring of speciated mercury is another concern of this research. The mercury emissions from coal-fired power plants are comprised of both elemental and oxidized mercury. Current CEM analyzers are designed to measure elemental mercury only. Oxidized mercury must first be converted to elemental mercury prior to entering the analyzer inlet in order to be measured. CEM systems must demonstrate the ability to measure both elemental and oxidized mercury. This requires the use of oxidized mercury generators with an efficient conversion of the oxidized mercury to elemental mercury. There are currently two basic types of mercuric chloride (HgCl{sub 2}) generators used for this purpose. One is an evaporative HgCl{sub 2} generator, which produces gas standards of known concentration by vaporization of aqueous HgCl{sub 2} solutions and quantitative mixing with a diluent carrier gas. The other is a device that converts the output from an elemental Hg generator to HgCl{sub 2} by means of a chemical reaction with chlorine gas. The Thermo Fisher oxidizer system involves reaction of elemental mercury vapor with chlorine gas at an elevated temperature. The draft interim protocol for oxidized mercury units involving reaction with chlorine gas requires the vendors to demonstrate high efficiency of oxidation of an elemental mercury stream from an elemental mercury vapor generator. The Thermo Fisher oxidizer unit is designed to operate at the power plant stack at the probe outlet. Following oxidation of elemental mercury from reaction with chlorine gas, a high temperature module reduces the mercuric chloride back to elemental mercury. WRI conducted work with a custom laboratory configured stand-alone oxidized mercury generator unit prov

John Schabron; Eric Kalberer; Joseph Rovani; Mark Sanderson; Ryan Boysen; William Schuster

2009-03-11

224

A Multifunctional Self-calibrated Sensor For Brake Fluid Condition Monitoring  

Microsoft Academic Search

A multifunctional self-calibrated sensor is proposed for on-line monitoring of liquid level and water content of brake fluid using capacitive method. The sensor is characterized by self-calibration ability to influence factors including temperature, water content (to liquid level sensing) and variety of brake fluid without calibration arithmetic supported by database as in conventional intelligent sensor systems. By using mutual calibrated

Chuantong Wang; Katsunori Shida

2006-01-01

225

Absolute radiometric calibration of Landsat using a pseudo invariant calibration site  

USGS Publications Warehouse

Pseudo invariant calibration sites (PICS) have been used for on-orbit radiometric trending of optical satellite systems for more than 15 years. This approach to vicarious calibration has demonstrated a high degree of reliability and repeatability at the level of 1-3% depending on the site, spectral channel, and imaging geometries. A variety of sensors have used this approach for trending because it is broadly applicable and easy to implement. Models to describe the surface reflectance properties, as well as the intervening atmosphere have also been developed to improve the precision of the method. However, one limiting factor of using PICS is that an absolute calibration capability has not yet been fully developed. Because of this, PICS are primarily limited to providing only long term trending information for individual sensors or cross-calibration opportunities between two sensors. This paper builds an argument that PICS can be used more extensively for absolute calibration. To illustrate this, a simple empirical model is developed for the well-known Libya 4 PICS based on observations by Terra MODIS and EO-1 Hyperion. The model is validated by comparing model predicted top-of-atmosphere reflectance values to actual measurements made by the Landsat ETM+ sensor reflective bands. Following this, an outline is presented to develop a more comprehensive and accurate PICS absolute calibration model that can be Système international d'unités (SI) traceable. These initial concepts suggest that absolute calibration using PICS is possible on a broad scale and can lead to improved on-orbit calibration capabilities for optical satellite sensors.

Helder, D.; Thome, K.J.; Mishra, N.; Chander, G.; Xiong, Xiaoxiong; Angal, A.; Choi, Tae-young

2013-01-01

226

Mossbauer vibration calibration systems evaluated  

NASA Technical Reports Server (NTRS)

Mossbauer effect vibration calibrator measures the velocity of high frequency, low amplitude vibration at various velocity and frequency ranges. It contains a highly precise calibrations standard unit and a vibration measuring system and may be applied to ultrafine testing and calibrating prezoelectric shakers, and vibration transducers.

Hobbs, J. V.; Netusil, W. F.

1969-01-01

227

Solar radiation calibration facility.  

NASA Technical Reports Server (NTRS)

A recently completed calibration facility for the NASA Mississippi Test Site is described. It combines the spectrum of water cooled long arc xenon radiation sources with the integration sphere concept covered by a special barium sulfate diffusely reflecting paint. The sphere is six feet in diameter and completely encompasses the four xenon sources (2.5 kW each) and the five pyranometers under calibration. The sources are contained within the base of the central pedestal and allow the radiation to be emitted into the lower hemisphere. Only through diffuse reflection and multiple scattering is the radiation finally incident upon the test zone, which is in the equatorial plane of the sphere on the top of the pedestal. The sphere is temperature controlled.

Hershey, T. L.

1972-01-01

228

Multivariate Regression with Calibration*  

PubMed Central

We propose a new method named calibrated multivariate regression (CMR) for fitting high dimensional multivariate regression models. Compared to existing methods, CMR calibrates the regularization for each regression task with respect to its noise level so that it is simultaneously tuning insensitive and achieves an improved finite-sample performance. Computationally, we develop an efficient smoothed proximal gradient algorithm which has a worst-case iteration complexity O(1/?), where ? is a pre-specified numerical accuracy. Theoretically, we prove that CMR achieves the optimal rate of convergence in parameter estimation. We illustrate the usefulness of CMR by thorough numerical simulations and show that CMR consistently outperforms other high dimensional multivariate regression methods. We also apply CMR on a brain activity prediction problem and find that CMR is as competitive as the handcrafted model created by human experts.

Liu, Han; Wang, Lie; Zhao, Tuo

2014-01-01

229

CUBIC: preflight calibration status  

NASA Astrophysics Data System (ADS)

CUBIC, the cosmic unresolved x ray background instrument using CCDs, is instrumented to make moderate resolution x-ray spectral measurements of diffuse targets at spatial scales of a few degrees. While the energy range is nominally 200 eV - 10 keV, the CCDs have been designed to maximize the soft x ray performance by using novel structures. A two part aperture increases the area-solid angle product above 1 keV to maximize sensitivity to the cosmic component of the diffuse x ray background. Here we report preliminary results of our preflight laboratory calibrations performed at Penn State of the dark current, readnoise, nonlinearity, charge transfer efficiency, energy resolution, and quantum efficiency of the two flight CCDs. We also discuss calibration of the detector field of view and the preliminary area-solid angle product of the instrument.

Skinner, Mark A.; Burrows, David N.; Garmire, Gordon P.; Mendenhall, Jeffrey A.; Lumb, David H.; Holland, Andrew D.; Pool, Peter J.

1995-09-01

230

Calibrated vapor generator source  

SciTech Connect

A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

1995-09-26

231

Calibration of hydrometers  

NASA Astrophysics Data System (ADS)

After a brief description of the different methods employed in periodic calibration of hydrometers used in most cases to measure the density of liquids in the range between 500 kg m-3 and 2000 kg m-3, particular emphasis is given to the multipoint procedure based on hydrostatic weighing, known as well as Cuckow's method. The features of the calibration apparatus and the procedure used at the INRiM (formerly IMGC-CNR) density laboratory have been considered to assess all relevant contributions involved in the calibration of different kinds of hydrometers. The uncertainty is strongly dependent on the kind of hydrometer; in particular, the results highlight the importance of the density of the reference buoyant liquid, the temperature of calibration and the skill of operator in the reading of the scale in the whole assessment of the uncertainty. It is also interesting to realize that for high-resolution hydrometers (division of 0.1 kg m-3), the uncertainty contribution of the density of the reference liquid is the main source of the total uncertainty, but its importance falls under about 50% for hydrometers with a division of 0.5 kg m-3 and becomes somewhat negligible for hydrometers with a division of 1 kg m-3, for which the reading uncertainty is the predominant part of the total uncertainty. At present the best INRiM result is obtained with commercially available hydrometers having a scale division of 0.1 kg m-3, for which the relative uncertainty is about 12 × 10-6.

Lorefice, Salvatore; Malengo, Andrea

2006-10-01

232

Solitons, superpotentials and calibrations  

Microsoft Academic Search

In this paper we study several issues related to the generation of the superpotential induced by background Ramond–Ramond fluxes in compactification of Type IIA string theory on Calabi–Yau four-folds. Identifying BPS solitons with D-branes wrapped over calibrated submanifolds in a Calabi–Yau space, we propose a general formula for the superpotential and justify it comparing the supersymmetry conditions in D=2 and

Sergei Gukov

2000-01-01

233

Calibrated Properties Model  

SciTech Connect

This report has documented the methodologies and the data used for developing rock property sets for three infiltration maps. Model calibration is necessary to obtain parameter values appropriate for the scale of the process being modeled. Although some hydrogeologic property data (prior information) are available, these data cannot be directly used to predict flow and transport processes because they were measured on scales smaller than those characterizing property distributions in models used for the prediction. Since model calibrations were done directly on the scales of interest, the upscaling issue was automatically considered. On the other hand, joint use of data and the prior information in inversions can further increase the reliability of the developed parameters compared with those for the prior information. Rock parameter sets were developed for both the mountain and drift scales because of the scale-dependent behavior of fracture permeability. Note that these parameter sets, except those for faults, were determined using the 1-D simulations. Therefore, they cannot be directly used for modeling lateral flow because of perched water in the unsaturated zone (UZ) of Yucca Mountain. Further calibration may be needed for two- and three-dimensional modeling studies. As discussed above in Section 6.4, uncertainties for these calibrated properties are difficult to accurately determine, because of the inaccuracy of simplified methods for this complex problem or the extremely large computational expense of more rigorous methods. One estimate of uncertainty that may be useful to investigators using these properties is the uncertainty used for the prior information. In most cases, the inversions did not change the properties very much with respect to the prior information. The Output DTNs (including the input and output files for all runs) from this study are given in Section 9.4.

H. H. Liu

2003-02-14

234

Mesoscale hybrid calibration artifact  

DOEpatents

A mesoscale calibration artifact, also called a hybrid artifact, suitable for hybrid dimensional measurement and the method for make the artifact. The hybrid artifact has structural characteristics that make it suitable for dimensional measurement in both vision-based systems and touch-probe-based systems. The hybrid artifact employs the intersection of bulk-micromachined planes to fabricate edges that are sharp to the nanometer level and intersecting planes with crystal-lattice-defined angles.

Tran, Hy D. (Albuquerque, NM); Claudet, Andre A. (Albuquerque, NM); Oliver, Andrew D. (Waltham, MA)

2010-09-07

235

Calibrated Properties Model  

SciTech Connect

The purpose of this model report is to document the calibrated properties model that provides calibrated property sets for unsaturated zone (UZ) flow and transport process models (UZ models). The calibration of the property sets is performed through inverse modeling. This work followed, and was planned in, ''Technical Work Plan (TWP) for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Sections 1.2.6 and 2.1.1.6). Direct inputs to this model report were derived from the following upstream analysis and model reports: ''Analysis of Hydrologic Properties Data'' (BSC 2004 [DIRS 170038]); ''Development of Numerical Grids for UZ Flow and Transport Modeling'' (BSC 2004 [DIRS 169855]); ''Simulation of Net Infiltration for Present-Day and Potential Future Climates'' (BSC 2004 [DIRS 170007]); ''Geologic Framework Model'' (GFM2000) (BSC 2004 [DIRS 170029]). Additionally, this model report incorporates errata of the previous version and closure of the Key Technical Issue agreement TSPAI 3.26 (Section 6.2.2 and Appendix B), and it is revised for improved transparency.

T. Ghezzehej

2004-10-04

236

Syringe Free Vaccination with CAF01 Adjuvated Ag85B-ESAT-6 in Bioneedles Provides Strong and Prolonged Protection Against Tuberculosis  

PubMed Central

Bioneedles are small hollow sugar based needles administered with a simple compressed air device. In the present study we investigate how incorporation of a subunit vaccine based on TB vaccine hybrid Ag85B-ESAT-6 adjuvated with CAF01 into Bioneedles affects its immunogenicity as well as its ability to protect against TB in a mouse model. The CMI response measured by IFN-? and antigen specific CD4+ T-cells was, two weeks after the last vaccination, significantly lower in the group immunized with Bioneedle-incorporated vaccine compared to the conventional vaccine, using syringe and needle. However, at four, nine and 52 weeks after vaccination we observed similar high IFN-? levels in the Bioneedle group and the group vaccinated using syringe and needle and comparable levels of antigen specific T-cells. Furthermore, the protective efficacy for the two vaccination methods was comparable and similar to BCG vaccination both six and 52 weeks after vaccination. These results therefore advocate the further development of the Bioneedle devises and applicators for the delivery of human vaccines. PMID:21124731

Christensen, Dennis; Lindenstrøm, Thomas; van de Wijdeven, Gijsbert; Andersen, Peter; Agger, Else Marie

2010-01-01

237

Simultaneous determination of hydrochlorothiazide and losartan potassium in tablets by high-performance low-pressure chromatography using a multi-syringe burette coupled to a monolithic column.  

PubMed

This contribution describes use of a separation method based on on-line coupling of a multisyringe flow system with a chromatographic monolithic column for simultaneous determination of hydrochlorothiazide and losartan potassium in tablets. The system comprised a multisyringe module, three low-pressure solenoid valves, a monolithic C(18) column (25 mm x 4.6 mm i.d.), and a diode-array detector. The mobile phase was 10 mmol L(-1) potassium dihydrogen phosphate (pH 3.1)-acetonitrile-methanol (65:33:2 v/v/v) at a flow rate 0.8 mL min(-1). UV detection was carried out at 226 nm. The multi-syringe chromatographic (MSC) method with UV spectrophotometric detection was optimized and validated. Results from validation were very good. The analysis time was about 400 s. The method was found to be applicable to routine analysis of both compounds in tablets. The coupling of the monolithic columns with a multi-syringe flow-injection analysis manifold provides an excellent and inexpensive tool to solve the separation problems without use of HPLC instrumentation. PMID:18500512

Obando, María Antonieta; Estela, José Manuel; Cerdà, Víctor

2008-07-01

238

Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer. I. The Stellar Calibrator Sample and the 24 micron Calibration  

E-print Network

We present the stellar calibrator sample and the conversion from instrumental to physical units for the 24 micron channel of the Multiband Imaging Photometer for Spitzer (MIPS). The primary calibrators are A stars, and the calibration factor based on those stars is 4.54*10^{-2} MJy sr^{-1} (DN/s)^{-1}, with a nominal uncertainty of 2%. We discuss the data-reduction procedures required to attain this accuracy; without these procdures, the calibration factor obtained using the automated pipeline at the Spitzer Science Center is 1.6% +/- 0.6% lower. We extend this work to predict 24 micron flux densities for a sample of 238 stars which covers a larger range of flux densities and spectral types. We present a total of 348 measurements of 141 stars at 24 micron. This sample covers a factor of ~460 in 24 micron flux density, from 8.6 mJy up to 4.0 Jy. We show that the calibration is linear over that range with respect to target flux and background level. The calibration is based on observations made using 3-second e...

Engelbracht, C W; Su, K Y L; Rho, J; Rieke, G H; Muzerolle, J; Padgett, D L; Hines, D C; Gordon, K D; Fadda, D; Noriega-Crespo, A; Kelly, D M; Latter, W B; Hinz, J L; Misselt, K A; Morrison, J E; Stansberry, J A; Shupe, D L; Stolovy, S; Wheaton, Wm A; Young, E T; Neugebauer, G; Wachter, S; Pérez-González, P G; Frayer, D T; Marleau, F R

2007-01-01

239

Primary calibration in acoustics metrology  

NASA Astrophysics Data System (ADS)

SI unit in acoustics is realized by the reciprocity calibrations of laboratory standard microphones in pressure field, free field and diffuse field. Calibrations in pressure field and in free field are already consolidated and the Inmetro already done them. Calibration in diffuse field is not yet consolidated, however, some national metrology institutes, including Inmetro, are conducting researches on this subject. This paper presents the reciprocity calibration, the results of Inmetro in recent key comparisons and the research that is being developed for the implementation of reciprocity calibration in diffuse field.

Bacelar Milhomem, T. A.; Defilippo Soares, Z. M.

2015-01-01

240

Automatic temperature-calibration system  

SciTech Connect

A relatively inexpensive, computer-controlled temperature calibration system is described. The system will provide working standard level calibration between -90/sup 0/C and +1100/sup 0/C for multiple resistance thermometers or thermocouples. It is designed to collect the data in a cooldown or ballistic state using either a platinum resistance thermometer (PRT) or a precision thermocouple as a standard. The use of this calibration system increases measurement repeatability, while greatly reducing the man-hours required for a calibration. Construction and basic software details of the temperature calibration system are provided.

Thompson, R.L.; Stant, R.S.

1982-08-23

241

Automatic force balance calibration system  

NASA Technical Reports Server (NTRS)

A system for automatically calibrating force balances is provided. The invention uses a reference balance aligned with the balance being calibrated to provide superior accuracy while minimizing the time required to complete the calibration. The reference balance and the test balance are rigidly attached together with closely aligned moment centers. Loads placed on the system equally effect each balance, and the differences in the readings of the two balances can be used to generate the calibration matrix for the test balance. Since the accuracy of the test calibration is determined by the accuracy of the reference balance and current technology allows for reference balances to be calibrated to within .+-.0.05%, the entire system has an accuracy of a .+-.0.2%. The entire apparatus is relatively small and can be mounted on a movable base for easy transport between test locations. The system can also accept a wide variety of reference balances, thus allowing calibration under diverse load and size requirements.

Ferris, Alice T. (Inventor)

1996-01-01

242

A new solid phase microextraction method using organic ligand in micropipette tip syringe system packed with modified carbon cloth for preconcentration of cadmium in drinking water and blood samples of kidney failure patients.  

PubMed

A simple and efficient miniaturized solid phase microextraction (M-SP?E) in a syringe system was developed for preconcentration of cadmium (Cd) in environmental and biological samples, followed by flame atomic absorption technique. The syringe system contains the micropipette tip packed with activated carbon cloth, coated with modified magnetic nanoparticles of iron oxide Triton X114 (ACC-NPs). Scanning electron microscopy and energy dispersive spectroscopy used for characterization of the size, morphology and elemental composition of ACC-NPs. The sample solution treated with a complexing reagent 8-hydroxyqunilone (8-HQ), and drawn into the syringe, filled with ACC-MNPs and dispensed manually for 2-10 drawing/discharging cycles. The analyte retained on ACC-NPs in micropipette tip-syringe system were then eluted with different volume of 1.5molL(-1) HCl by 1-5 drawing/discharging cycles. The syringe system directly couple with FAAS for analysis. The influence of different variables on the extraction efficiency of Cd, including adsorbent dosage, pH, sample volume, eluent volume and drawing/discharging cycles of syringe system were optimized. At optimized extraction conditions, the method showed good linearity in the range of 5-250?gL(-1), with a limit of detection 0.15?gL(-1). Repeatability of the extraction (%RSD) was <5%, n=5. The validity and accuracy of the method was checked by the certified reference materials. The proposed method was successfully applied for the determination of Cd in different drinking water and biological samples of kidney failure patients and healthy controls. PMID:25498826

Panhwar, Abdul Haleem; Kazi, Tasneem Gul; Afridi, Hassan Imran; Arain, Salma Aslam; Naeemullah; Brahman, Kapil Dev; Arain, Mariam Shahzadi

2015-03-01

243

A new solid phase microextraction method using organic ligand in micropipette tip syringe system packed with modified carbon cloth for preconcentration of cadmium in drinking water and blood samples of kidney failure patients  

NASA Astrophysics Data System (ADS)

A simple and efficient miniaturized solid phase microextraction (M-SP?E) in a syringe system was developed for preconcentration of cadmium (Cd) in environmental and biological samples, followed by flame atomic absorption technique. The syringe system contains the micropipette tip packed with activated carbon cloth, coated with modified magnetic nanoparticles of iron oxide Triton X114 (ACC-NPs). Scanning electron microscopy and energy dispersive spectroscopy used for characterization of the size, morphology and elemental composition of ACC-NPs. The sample solution treated with a complexing reagent 8-hydroxyqunilone (8-HQ), and drawn into the syringe, filled with ACC-MNPs and dispensed manually for 2-10 drawing/discharging cycles. The analyte retained on ACC-NPs in micropipette tip-syringe system were then eluted with different volume of 1.5 mol L-1 HCl by 1-5 drawing/discharging cycles. The syringe system directly couple with FAAS for analysis. The influence of different variables on the extraction efficiency of Cd, including adsorbent dosage, pH, sample volume, eluent volume and drawing/discharging cycles of syringe system were optimized. At optimized extraction conditions, the method showed good linearity in the range of 5-250 ?g L-1, with a limit of detection 0.15 ?g L-1. Repeatability of the extraction (%RSD) was <5%, n = 5. The validity and accuracy of the method was checked by the certified reference materials. The proposed method was successfully applied for the determination of Cd in different drinking water and biological samples of kidney failure patients and healthy controls.

Panhwar, Abdul Haleem; Kazi, Tasneem Gul; Afridi, Hassan Imran; Arain, Salma Aslam; Naeemullah; Brahman, Kapil Dev; Arain, Mariam Shahzadi

2015-03-01

244

An Enclosed Laser Calibration Standard  

NASA Astrophysics Data System (ADS)

We have designed, evaluated and calibrated an enclosed, safety-interlocked laser calibration standard for use in US Army Secondary Reference Calibration Laboratories. This Laser Test Set Calibrator (LTSC) represents the Army's first-generation field laser calibration standard. Twelve LTSC's are now being fielded world-wide. The main requirement on the LTSC is to provide calibration support for the Test Set (TS3620) which, in turn, is a GO/NO GO tester of the Hand-Held Laser Rangefinder (AN/GVS-5). However, we believe it's design is flexible enough to accommodate the calibration of other laser test, measurement and diagnostic equipment (TMDE) provided that single-shot capability is adequate to perform the task. In this paper we describe the salient aspects and calibration requirements of the AN/GVS-5 Rangefinder and the Test Set which drove the basic LTSC design. Also, we detail our evaluation and calibration of the LTSC, in particular, the LTSC system standards. We conclude with a review of our error analysis from which uncertainties were assigned to the LTSC calibration functions.

Adams, Thomas E.; Fecteau, M. L.

1985-02-01

245

Dynamic Torque Calibration Unit  

NASA Technical Reports Server (NTRS)

Proposed dynamic torque calibration unit (DTCU) measures torque in rotary actuator components such as motors, bearings, gear trains, and flex couplings. Unique because designed specifically for testing components under low rates. Measures torque in device under test during controlled steady rotation or oscillation. Rotor oriented vertically, supported by upper angular-contact bearing and lower radial-contact bearing that floats axially to prevent thermal expansion from loading bearings. High-load capacity air bearing available to replace ball bearings when higher load capacity or reduction in rate noise required.

Agronin, Michael L.; Marchetto, Carl A.

1989-01-01

246

Performance comparison of accelerometer calibration algorithms based on 3D-ellipsoid fitting methods.  

PubMed

Calibration of accelerometers can be reduced to 3D-ellipsoid fitting problems. Changing extrinsic factors like temperature, pressure or humidity, as well as intrinsic factors like the battery status, demand to calibrate the measurements permanently. Thus, there is a need for fast calibration algorithms, e.g. for online analyses. The primary aim of this paper is to propose a non-iterative calibration algorithm for accelerometers with the focus on minimal execution time and low memory consumption. The secondary aim is to benchmark existing calibration algorithms based on 3D-ellipsoid fitting methods. We compared the algorithms regarding the calibration quality and the execution time as well as the number of quasi-static measurements needed for a stable calibration. As evaluation criterion for the calibration, both the norm of calibrated real-life measurements during inactivity and simulation data was used. The algorithms showed a high calibration quality, but the execution time differed significantly. The calibration method proposed in this paper showed the shortest execution time and a very good performance regarding the number of measurements needed to produce stable results. Furthermore, this algorithm was successfully implemented on a sensor node and calibrates the measured data on-the-fly while continuously storing the measured data to a microSD-card. PMID:23566707

Gietzelt, Matthias; Wolf, Klaus-Hendrik; Marschollek, Michael; Haux, Reinhold

2013-07-01

247

A self-calibrating optomechanical force sensor with femtonewton resolution  

NASA Astrophysics Data System (ADS)

We report the development of an ultrasensitive optomechanical sensor designed to improve the accuracy and precision of force measurements with atomic force microscopy. The sensors reach quality factors of 4.3 × 106 and force resolution on the femtonewton scale at room temperature. Self-calibration of the sensor is accomplished using radiation pressure to create a reference force. Self-calibration enables in situ calibration of the sensor in extreme environments, such as cryogenic ultra-high vacuum. The senor technology presents a viable route to force measurements at the atomic scale with uncertainties below the percent level.

Melcher, John; Stirling, Julian; Cervantes, Felipe Guzmán; Pratt, Jon R.; Shaw, Gordon A.

2014-12-01

248

Automatic meter proving and calibration system  

SciTech Connect

A liquid dispenser apparatus is described comprising: liquid measuring means for providing an output measurement signal in correlation with a dispensed volume of liquid, calibration means for determining a correction factor by which to modify the output measurement signal and generate a corrected signal, the correction factor being automatically determined at predetermined dispenser operating intervals to provide correction of the output measurement signal; and means, responsive data display means including a register means, resonsive to the corrected signal, for indicating the dispensed volume of liquid, whereby the register means accurately indicates the dispensed volume of liquid despite variations in the accuracy of measurement of the liquid measuring means.

Forkert, M.J.; Key, W.D

1989-05-23

249

CP-50 calibration facility radiological safety assessment document  

SciTech Connect

The CP-50 Calibration Facility Radiological Safety Assessment document, prepared at the request of the Nevada Operations Office of the US Department of Energy to satisfy provisions of ERDA Manual Chapter 0531, presents design features, systems controls, and procedures used in the operation of the calibration facility. Site and facility characteristics and routine and non-routine operations, including hypothetical incidents or accidents are discussed and design factors, source control systems, and radiation monitoring considerations are described.

Chilton, M.W.; Hill, R.L.; Eubank, B.F.

1980-03-01

250

A Micro-Extraction Technique Using a New Digitally Controlled Syringe Combined with UHPLC for Assessment of Urinary Biomarkers of Oxidatively Damaged DNA  

PubMed Central

The formation of reactive oxygen species (ROS) within cells causes damage to biomolecules, including membrane lipids, DNA, proteins and sugars. An important type of oxidative damage is DNA base hydroxylation which leads to the formation of 8-oxo-7,8-dihydro-2?-deoxyguanosine (8-oxodG) and 5-hydroxymethyluracil (5-HMUra). Measurement of these biomarkers in urine is challenging, due to the low levels of the analytes and the matrix complexity. In order to simultaneously quantify 8-oxodG and 5-HMUra in human urine, a new, reliable and powerful strategy was optimised and validated. It is based on a semi-automatic microextraction by packed sorbent (MEPS) technique, using a new digitally controlled syringe (eVol®), to enhance the extraction efficiency of the target metabolites, followed by a fast and sensitive ultrahigh pressure liquid chromatography (UHPLC). The optimal methodological conditions involve loading of 250 µL urine sample (1?10 dilution) through a C8 sorbent in a MEPS syringe placed in the semi-automatic eVol® syringe followed by elution using 90 µL of 20% methanol in 0.01% formic acid solution. The obtained extract is directly analysed in the UHPLC system using a binary mobile phase composed of aqueous 0.1% formic acid and methanol in the isocratic elution mode (3.5 min total analysis time). The method was validated in terms of selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), extraction yield, accuracy, precision and matrix effect. Satisfactory results were obtained in terms of linearity (r2 > 0.991) within the established concentration range. The LOD varied from 0.00005 to 0.04 µg mL?1 and the LOQ from 0.00023 to 0.13 µg mL?1. The extraction yields were between 80.1 and 82.2 %, while inter-day precision (n?=?3 days) varied between 4.9 and 7.7 % and intra-day precision between 1.0 and 8.3 %. This approach presents as main advantages the ability to easily collect and store urine samples for further processing and the high sensitivity, reproducibility, and robustness of eVol®MEPS combined with UHPLC analysis, thus retrieving a fast and reliable assessment of oxidatively damaged DNA. PMID:23484022

Mendes, Berta; Silva, Pedro; Aveiro, Fernando; Pereira, Jorge; Câmara, José S.

2013-01-01

251

The MISR Calibration Program  

NASA Technical Reports Server (NTRS)

The Multiangle Imaging SpectroRadiometer (MISR) is currently under development for NASA's Earth Observing System. The instrument consists of nine pushbroom cameras, each with four spectral bands in the visible and near-infrared. The cameras point in different view directions to provide measurements from nadir to highly oblique view angles in the along-track plane. Multiple view-angle observations provide a unique resource for studies of clouds, aerosols, and the surface. MISR is built to challenging radiometric and geometric performance specifications. Radiometric accuracy, for example, must be within +/- 3%/ 1 sigma, and polarization insensitivity must be better than +/- 1 %. An onboard calibrator (OBC) provides monthly updates to the instrument gain coefficients. Spectralon diffuse panels are used within the OBC to provide a uniform target for the cameras to view. The absolute radiometric scale is established both preflight and in orbit through the use of detector standards. During the mission, ground data processing to accomplish radiometric calibration, geometric rectification and registration of the nine view-angle imagery, and geophysical retrievals will proceed in an automated fashion. A global dataset is produced every 9 days. This paper details the preflight characterization of the MISR instrument, the design of the OBC, and the radiance product processing.

Bruegge, Carol J.; Diner, David J.; Duval, Valerie G.

1996-01-01

252

An Overview of MODIS Calibration and Characterization  

NASA Technical Reports Server (NTRS)

The MODerate Resolution Imaging Spectroradiometer (MODIS) is one of the key instruments for the NASA s Earth Observing System (EOS). It is currently operating on both EOS Terra and Aqua satellites. The MODIS is a major advance over its heritage sensors in terms of its spectral, spatial, and temporal resolutions with frequent global observations and a broad range of science applications. There are 20 reflective solar bands (RSB) with center wavelengths ranging from 0.41 to 2.l microns and 16 thermal emissive bands (TEB) from 3.7 to 14.4 microns. The absolute radiometric accuracy requirements (lsigma) at the typical spectral radiance levels are plus or minus 2% for the RSB reflectance factors and plus or minus 5% for the RSB radiance products. With few exceptions, the TEB requirements are plus or minus 1%. To verify that the instruments met their specified design requirements both Terra and Aqua MODIS underwent extensive pre-launch calibration and characterization at various levels, including system-level thermal vacuum testing. On-orbit calibration and characterization are performed by the on-board calibrators: a solar diffuser (SD) and a solar diffuser stability monitor (SDSM), a V-groove flat panel blackbody (BB), and a spectro-radiometric calibration assembly (SRCA). In this paper, we present an overview of MODIS calibration and characterization activities, methodologies, and lessons learned from pre-launch testing and on-orbit operations. Key issues to be discussed include our on-orbit efforts of monitoring detectors noise characterization, tracking solar diffuser and optics degradation, and updating sensor s response versus scan-angle. The MODIS experience has provided invaluable lessons that are being used in designing and testing the Visible Infrared Imaging Radiometer Suite (VIIRS), a direct follow-on to the MODIS that will be flown on the National Polar-Orbit Operational Environmental Satellite System (NPOESS) missions.

Xiong, X.; Barnes, W.

2004-01-01

253

Proof-of-concept demonstration of a total internal reflection based module for fluorescence and absorbance detection using a 3D-printed syringe pump  

NASA Astrophysics Data System (ADS)

In this paper we demonstrate the proof-of-concept of an optofluidic module capable of simultaneous laser-induced fluorescence (LIF) and absorbance (ABS) detection based on total internal reflection (TIR) optics. We discuss the design of the optofluidic detection module, its fabrication, and the setup used for the proof-of-concept. The injection of sample under test is done using two 3D printed syringe pumps, managing accurate injection and repeatable sample propagation through the detector module. We discuss the process of development behind these pumps and review their technical specifications. With this demonstrator setup we find that the limits of detection for the ABS and LIF detection of coumarin 480 are 500 nM and 100 nM respectively.

Verschooten, Tom; Ottevaere, Heidi; Vervaeke, Michael; Van Erps, Jürgen; Thienpont, Hugo

2014-05-01

254

Laboratory calibration of field reflectance panels  

NASA Technical Reports Server (NTRS)

A method used for calibrating field reflectance panels in the visible and shortwave infrared wavelength range is described. The directional reflectance factor of painted barium sulfate (BaSO4) panels is determined. The reference for this method is the hemispherical reflectance of pressed polytetrafluoroethylene (halon) powder prepared according to National Bureau of Standards (NBS) directions. The panels and a radiometer are mounted on rotation stages to measure the reflectance factor at different incidence and view angles. The sensor can be any laboratory or field filter radiometer small enough to mount on the apparatus. The method is used to measure the reflectance factors of halon and BaSO4 panels between 0.45 and 0.85 micrometers. These reflectance factors are compared to those measured by a field apparatus. The results agree to within 0.013 in reflectance at incidence angles between 15 and 75 degrees.

Biggar, S. F.; Labed, J.; Santer, R. P.; Slater, P. N.; Jackson, R. D.

1988-01-01

255

Hot-wire calibration in subsonic/transonic flow regimes  

NASA Technical Reports Server (NTRS)

A different approach for calibrating hot-wires, which simplifies the calibration procedure and reduces the tunnel run-time by an order of magnitude was sought. In general, it is accepted that the directly measurable quantities in any flow are velocity, density, and total temperature. Very few facilities have the capability of varying the total temperature over an adequate range. However, if the overheat temperature parameter, a(sub w), is used to calibrate the hot-wire then the directly measurable quantity, voltage, will be a function of the flow variables and the overheat parameter i.e., E = f(u,p,a(sub w), T(sub w)) where a(sub w) will contain the needed total temperature information. In this report, various methods of evaluating sensitivities with different dependent and independent variables to calibrate a 3-Wire hot-wire probe using a constant temperature anemometer (CTA) in subsonic/transonic flow regimes is presented. The advantage of using a(sub w) as the independent variable instead of total temperature, t(sub o), or overheat temperature parameter, tau, is that while running a calibration test it is not necessary to know the recovery factor, the coefficients in a wire resistance to temperature relationship for a given probe. It was deduced that the method employing the relationship E = f (u,p,a(sub w)) should result in the most accurate calibration of hot wire probes. Any other method would require additional measurements. Also this method will allow calibration and determination of accurate temperature fluctuation information even in atmospheric wind tunnels where there is no ability to obtain any temperature sensitivity information at present. This technique greatly simplifies the calibration process for hot-wires, provides the required calibration information needed in obtaining temperature fluctuations, and reduces both the tunnel run-time and the test matrix required to calibrate hotwires. Some of the results using the above techniques are presented in an appendix.

Nagabushana, K. A.; Ash, Robert L.

1995-01-01

256

A proposed standard method for polarimetric calibration and calibration verification  

NASA Astrophysics Data System (ADS)

Accurate calibration of polarimetric sensors is critical to reducing and analyzing phenomenology data, producing uniform polarimetric imagery for deployable sensors, and ensuring predictable performance of polarimetric algorithms. It is desirable to develop a standard calibration method, including verification reporting, in order to increase credibility with customers and foster communication and understanding within the polarimetric community. This paper seeks to facilitate discussions within the community on arriving at such standards. Both the calibration and verification methods presented here are performed easily with common polarimetric equipment, and are applicable to visible and infrared systems with either partial Stokes or full Stokes sensitivity. The calibration procedure has been used on infrared and visible polarimetric imagers over a six year period, and resulting imagery has been presented previously at conferences and workshops. The proposed calibration method involves the familiar calculation of the polarimetric data reduction matrix by measuring the polarimeter's response to a set of input Stokes vectors. With this method, however, linear combinations of Stokes vectors are used to generate highly accurate input states. This allows the direct measurement of all system effects, in contrast with fitting modeled calibration parameters to measured data. This direct measurement of the data reduction matrix allows higher order effects that are difficult to model to be discovered and corrected for in calibration. This paper begins with a detailed tutorial on the proposed calibration and verification reporting methods. Example results are then presented for a LWIR rotating half-wave retarder polarimeter.

Persons, Christopher M.; Jones, Michael W.; Farlow, Craig A.; Morell, L. Denise; Gulley, Michael G.; Spradley, Kevin D.

2007-09-01

257

Quality Management and Calibration  

NASA Astrophysics Data System (ADS)

Good specification of a product’s performance requires adequate characterization of relevant properties. Particulate products are usually characterized by some PSD, shape or porosity parameter(s). For proper characterization, adequate sampling, dispersion, and measurement procedures should be available or developed and skilful personnel should use appropriate, well-calibrated/qualified equipment. The characterization should be executed, in agreement with customers, in a wellorganized laboratory. All related aspects should be laid down in a quality handbook. The laboratory should provide proof for its capability to perform the characterization of stated products and/or reference materials within stated confidence limits. This can be done either by internal validation and audits or by external GLP accreditation.

Merkus, Henk G.

258

Atmospheric optical calibration system  

DOEpatents

An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions. 7 figs.

Hulstrom, R.L.; Cannon, T.W.

1988-10-25

259

Atmospheric optical calibration system  

DOEpatents

An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions.

Hulstrom, Roland L. (Bloomfield, CO); Cannon, Theodore W. (Golden, CO)

1988-01-01

260

Robot geometry calibration  

NASA Technical Reports Server (NTRS)

Autonomous robot task execution requires that the end effector of the robot be positioned accurately relative to a reference world-coordinate frame. The authors present a complete formulation to identify the actual robot geometric parameters. The method applies to any serial link manipulator with arbitrary order and combination of revolute and prismatic joints. A method is also presented to solve the inverse kinematic of the actual robot model which usually is not a so-called simple robot. Experimental results performed by utilizing a PUMA 560 with simple measurement hardware are presented. As a result of this calibration a precision move command is designed and integrated into a robot language, RCCL, and used in the NASA Telerobot Testbed.

Hayati, Samad; Tso, Kam; Roston, Gerald

1988-01-01

261

TOD to TTP calibration  

NASA Astrophysics Data System (ADS)

The TTP (Targeting Task Performance) metric, developed at NVESD, is the current standard US Army model to predict EO/IR Target Acquisition performance. This model however does not have a corresponding lab or field test to empirically assess the performance of a camera system. The TOD (Triangle Orientation Discrimination) method, developed at TNO in The Netherlands, provides such a measurement. In this study, we make a direct comparison between TOD performance for a range of sensors and the extensive historical US observer performance database built to develop and calibrate the TTP metric. The US perception data were collected doing an identification task by military personnel on a standard 12 target, 12 aspect tactical vehicle image set that was processed through simulated sensors for which the most fundamental sensor parameters such as blur, sampling, spatial and temporal noise were varied. In the present study, we measured TOD sensor performance using exactly the same sensors processing a set of TOD triangle test patterns. The study shows that good overall agreement is obtained when the ratio between target characteristic size and TOD test pattern size at threshold equals 6.3. Note that this number is purely based on empirical data without any intermediate modeling. The calibration of the TOD to the TTP is highly beneficial to the sensor modeling and testing community for a variety of reasons. These include: i) a connection between requirement specification and acceptance testing, and ii) a very efficient method to quickly validate or extend the TTP range prediction model to new systems and tasks.

Bijl, Piet; Reynolds, Joseph P.; Vos, Wouter K.; Hogervorst, Maarten A.; Fanning, Jonathan D.

2011-05-01

262

An Improved Metallicity Calibration with UBV Photometry  

NASA Astrophysics Data System (ADS)

We used the data of 701 stars covering the colour index interval 0.32factors, which provide a more accurate metallicity calibration. We reduced the metallicities of 11 different authors to the metallicities of Valenti & Fischer (2005), and thus obtained a homogeneous set of data which increased the accuracy of the calibration, i.e. [Fe/H]=-14.316?0.6 2-3.557?0.6+0.105. Comparison of the metallicity residuals for two sets of data based on the metallicity-dependent guillotine factors with the ones obtained via metal-free guillotine factors shows that metallicities estimated by means of the new guillotine factors are more accurate than the other ones. This advantage can be used in the metallicity gradient investigation of the Galactic components, i.e. thin disc, thick disc, and halo.

Karaali, S.; Bilir, S.; Ak, S.; Yaz, E.; Co?kuno?lu, B.

2011-06-01

263

Raman water vapor lidar calibration  

Microsoft Academic Search

We show here new results of a Raman LIDAR calibration methodology effort putting emphasis in the assessment of the cross-section ratio between water vapor and nitrogen by the use of a calibrated NIST traceable tungsten lamp. Therein we give a step by step procedure of how to employ such equipment by means of a mapping\\/scanning procedure over the receiving optics

E. Landulfo; R. F. da Costa; A. S. Torres; F. J. S. Lopes; D. N. Whiteman; D. D. Venable

2009-01-01

264

Side looking radar calibration study  

NASA Technical Reports Server (NTRS)

Calibration of an airborne sidelooking radar is accomplished by the use of a model that relates the radar parameters to the physical mapping situation. Topics discussed include: characteristics of the transmitters; the antennas; target absorption and reradiation; the receiver and map making or radar data processing; and the calibration process.

Edwards, W. D.

1975-01-01

265

Calibration of a Horizontal Sundial  

ERIC Educational Resources Information Center

This paper describes how a horizontal sundial can be calibrated in a classroom without using the nontrivial equations of projective geometry. If one understands how a simple equatorial sundial works, one will also understand the procedure of calibrating a horizontal (or "garden," as it is also called) sundial.

Rovsek, Barbara

2010-01-01

266

Calibration of a Horizontal Sundial  

NASA Astrophysics Data System (ADS)

This paper describes how a horizontal sundial can be calibrated in a classroom without using the nontrivial equations of projective geometry. If one understands how a simple equatorial sundial works, one will also understand the procedure of calibrating a horizontal (or "garden," as it is also called) sundial.

Rovšek, Barbara

2010-09-01

267

Automated calibration of temperature sensors  

Microsoft Academic Search

This paper concerns the essential problems associated with the automatic calibration of industrial thermometric sensors in the temperature range of 200°C+1300°C carried out by means of the comparison method. The sensors to be calibrated and the reference one should be placed in a uniform and stable temperature field. It is necessary to use a dedicated furnace to generate such a

M. Orzylowski; M. Hering; T. Kaluzniacki; W. Lobodzinski; P. Ostrowski; J. Wiechowski

2000-01-01

268

Calibration of Hubble Space Telescope  

E-print Network

Calibration of Hubble Space Telescope Guidance Sensors: Application of Seminal Ideas of Eichhorn William H. Je#erys 11, Abstract calibration Space Telescope Guidance Sensors (FGS) a challenges. no su's on solving important astrometric problem. Introduction Hubble Telescope Guidance Sensors (FGS) designed

Jefferys, William

269

Calibration of the ARID robot  

NASA Technical Reports Server (NTRS)

The author has formulated a new, general model for specifying the kinematic properties of serial manipulators. The new model kinematic parameters do not suffer discontinuities when nominally parallel adjacent axes deviate from exact parallelism. From this new theory the author develops a first-order, lumped-parameter, calibration-model for the ARID manipulator. Next, the author develops a calibration methodology for the ARID based on visual and acoustic sensing. A sensor platform, consisting of a camera and four sonars attached to the ARID end frame, performs calibration measurements. A calibration measurement consists of processing one visual frame of an accurately placed calibration image and recording four acoustic range measurements. A minimum of two measurement protocols determine the kinematics calibration-model of the ARID for a particular region: assuming the joint displacements are accurately measured, the calibration surface is planar, and the kinematic parameters do not vary rapidly in the region. No theoretical or practical limitations appear to contra-indicate the feasibility of the calibration method developed here.

Doty, Keith L

1992-01-01

270

Calibration of the ARID robot  

NASA Astrophysics Data System (ADS)

The author has formulated a new, general model for specifying the kinematic properties of serial manipulators. The new model kinematic parameters do not suffer discontinuities when nominally parallel adjacent axes deviate from exact parallelism. From this new theory the author develops a first-order, lumped-parameter, calibration-model for the ARID manipulator. Next, the author develops a calibration methodology for the ARID based on visual and acoustic sensing. A sensor platform, consisting of a camera and four sonars attached to the ARID end frame, performs calibration measurements. A calibration measurement consists of processing one visual frame of an accurately placed calibration image and recording four acoustic range measurements. A minimum of two measurement protocols determine the kinematics calibration-model of the ARID for a particular region: assuming the joint displacements are accurately measured, the calibration surface is planar, and the kinematic parameters do not vary rapidly in the region. No theoretical or practical limitations appear to contra-indicate the feasibility of the calibration method developed here.

Doty, Keith L.

1992-09-01

271

Effects of switch leakages upon Nimbus-7 SMMR calibration  

NASA Technical Reports Server (NTRS)

A calibration model for the Nimbus 7 Scanning Multichannel Microwave Radiometer (SMMR) is studied. This model not only removes major drawbacks of the current calibration model but also helps in the understanding of the performance degradation of the aging instrument. The current Nimbus 7 SMMR calibration algorithm was derived without considering the interference effect between the two orthogonally polarized signals merging at a ferrite polarization selector switch. The resulting calibrated brightness temperatures, considered as a function of scan angle, are not symmetric around scan angle = 0. However, neither the origin of the asymmetry nor the manner in which the two orthogonal components are mixed has been fully understood. The new calibration model proposed incorporates all the leakage factors associated with the ferrite switches along the signal paths. The resulting calibration equations clarify how the orthogonal components of surface brightness are coupled at radiometers. As a consequence, the origin of the asymmetry is clearly identified and explained. In addition, the feasibility of absolute calibration using in-orbit data is discussed.

Han, Daesoo; Kim, Seung T.

1988-01-01

272

Effects of switch leakages upon Nimbus-7 SMMR calibration  

NASA Technical Reports Server (NTRS)

A calibration model for the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) is studied. This model not only removes major drawbacks of the current calibration model but also helps us understand the performance degradation of the aging instrument. The current Nimbus-7 SMMR calibration algorithm was derived without considering the interference effect between the two orthogonally polarized signals merging at a ferrite polarization selector switch. The resulting calibrated brightness temperatures, considered as a function of scan angle phi, are not symmetric around phi=0. However, neither the origin of the asymmetry nor the manner in which the two orthogonal components are mixed is fully understood. The proposed calibration model incorporates all the leakage factors associated with the ferrite switches along the signal paths. The resulting calibration equations clarify how the orthogonal components of surface brightness are coupled at radiometers. As a consequence, the origin of the asymmetry is clearly identified and explained. In addition, the feasibility of absolute calibration using in-orbit data is discussed.

Han, Daesoo; Kim, Seung T.

1988-01-01

273

Digital breast tomosynthesis geometry calibration  

NASA Astrophysics Data System (ADS)

Digital Breast Tomosynthesis (DBT) is a 3D x-ray technique for imaging the breast. The x-ray tube, mounted on a gantry, moves in an arc over a limited angular range around the breast while 7-15 images are acquired over a period of a few seconds. A reconstruction algorithm is used to create a 3D volume dataset from the projection images. This procedure reduces the effects of tissue superposition, often responsible for degrading the quality of projection mammograms. This may help improve sensitivity of cancer detection, while reducing the number of false positive results. For DBT, images are acquired at a set of gantry rotation angles. The image reconstruction process requires several geometrical factors associated with image acquisition to be known accurately, however, vibration, encoder inaccuracy, the effects of gravity on the gantry arm and manufacturing tolerances can produce deviations from the desired acquisition geometry. Unlike cone-beam CT, in which a complete dataset is acquired (500+ projections over 180°), tomosynthesis reconstruction is challenging in that the angular range is narrow (typically from 20°-45°) and there are fewer projection images (~7-15). With such a limited dataset, reconstruction is very sensitive to geometric alignment. Uncertainties in factors such as detector tilt, gantry angle, focal spot location, source-detector distance and source-pivot distance can produce several artifacts in the reconstructed volume. To accurately and efficiently calculate the location and angles of orientation of critical components of the system in DBT geometry, a suitable phantom is required. We have designed a calibration phantom for tomosynthesis and developed software for accurate measurement of the geometric parameters of a DBT system. These have been tested both by simulation and experiment. We will present estimates of the precision available with this technique for a prototype DBT system.

Wang, Xinying; Mainprize, James G.; Kempston, Michael P.; Mawdsley, Gordon E.; Yaffe, Martin J.

2007-03-01

274

A Calibration-Free, Noncontact, Disposable Liquid Dispensing Cartridge Featuring an Online Process Control.  

PubMed

We present a noncontact liquid dispenser that uses a disposable cartridge for the calibration-free dosage of diverse biochemical reagents from the nanoliter to the microliter range. The dispensing system combines the advantages of a positive displacement syringe pump (responsible for defining the aliquot's volume with high accuracy) with a highly dynamic noncontact dispenser (providing kinetic energy to detach the liquid from the tip). The disposable, noncontact dispensing cartridge system renders elaborate washing procedures of tips obsolete. A noncontact sensor monitors the dispensing process to enable an online process control. To further increase confidence and reliability for particularly critical biomedical applications, an optional closed-loop control prevents malfunctions. The dispensing performance was characterized experimentally in the range of 0.25 to 10.0 µL using liquids of different rheological properties (viscosity 1.03-16.98 mPas, surface tension 30.49-70.83 mN/m) without adjusting or calibrating the actuation parameters. The precision ranged between a coefficient of variation of 0.5% and 5.3%, and the accuracy was below ±10%. The presented technology has the potential to contribute significantly to the improvement of biochemical liquid handling for laboratory automation in terms of usability, miniaturization, cost reduction, and safety. PMID:23981469

Bammesberger, Stefan Borja; Malki, Imad; Ernst, Andreas; Zengerle, Roland; Koltay, Peter

2013-08-27

275

Calibration of platinum resistance thermometers.  

NASA Technical Reports Server (NTRS)

Results of five years experience in calibrating about 1000 commercial platinum resistance thermometers (PRT) are reported. These PRT were relatively small and rugged, with ice-point resistances from 200 to 5000 ohms. Calibrations normalized in terms of resistance-difference ratios (Cragoe Z function) were found to be remarkably uniform for five of six different types of PRT tested, and to agree very closely with normalized calibrations of the primary reference standard type PRT. The Z function normalization cancels residual resistances which are not temperature dependent and simplifies interpolation between calibration points when the quality of a given type of PRT has been established in terms of uniform values of the Z function. Measurements at five or six well spaced base-point temperatures with Z interpolation will suffice to calibrate a PRT accurately from 4 to 900 K.

Sinclair, D. H.; Terbeek, H. G.; Malone, J. H.

1972-01-01

276

Permanently calibrated interpolating time counter  

NASA Astrophysics Data System (ADS)

We propose a new architecture of an integrated time interval counter that provides its permanent calibration in the background. Time interval measurement and the calibration procedure are based on the use of a two-stage interpolation method and parallel processing of measurement and calibration data. The parallel processing is achieved by a doubling of two-stage interpolators in measurement channels of the counter, and by an appropriate extension of control logic. Such modification allows the updating of transfer characteristics of interpolators without the need to break a theoretically infinite measurement session. We describe the principle of permanent calibration, its implementation and influence on the quality of the counter. The precision of the presented counter is kept at a constant level (below 20?ps) despite significant changes in the ambient temperature (from ?10 to 60?°C), which can cause a sevenfold decrease in the precision of the counter with a traditional calibration procedure.

Jachna, Z.; Szplet, R.; Kwiatkowski, P.; Ró?yc, K.

2015-01-01

277

Gulf of Mexico Climate-History Calibration Study  

USGS Publications Warehouse

Reliable instrumental records of past climate are available for about the last 150 years only. To supplement the instrumental record, reconstructions of past climate are made from natural recorders such as trees, ice, corals, and microfossils preserved in sediments. These proxy records provide information on the rate and magnitude of past climate variability, factors that are critical to distinguishing between natural and human-induced climate change in the present. However, the value of proxy records is heavily dependent on calibration between the chemistry of the natural recorder and of the modern environmental conditions. The Gulf of Mexico Climate and Environmental History Project is currently undertaking a climate-history calibration study with material collected from an automated sediment trap. The primary focus of the calibration study is to provide a better calibration of low-latitude environmental conditions and shell chemistry of calcareous microfossils, such as planktic Foraminifera.

Spear, Jessica W.; Poore, Richard Z.

2010-01-01

278

Cobalt source calibration  

SciTech Connect

The data obtained from these tests determine the dose rate of the two cobalt sources in SRTC. Building 774-A houses one of these sources while the other resides in room C-067 of Building 773-A. The data from this experiment shows the following: (1) The dose rate of the No.2 cobalt source in Building 774-A measured 1.073 x 10{sup 5} rad/h (June 17, 1999). The dose rate of the Shepherd Model 109 Gamma cobalt source in Building 773-A measured 9.27 x 10{sup 5} rad/h (June 25, 1999). These rates come from placing the graduated cylinder containing the dosimeter solution in the center of the irradiation chamber. (2) Two calibration tests in the 774-A source placed the graduated cylinder with the dosimeter solution approximately 1.5 inches off center in the axial direction. This movement of the sample reduced the measured dose rate 0.92% from 1.083 x 10{sup 5} rad/h to 1.073 x 10{sup 5} rad/h. and (3) A similar test in the cobalt source in 773-A placed the graduated cylinder approximately 2.0 inches off center in the axial direction. This change in position reduced the measured dose rate by 10.34% from 1.036 x 10{sup 6} to 9.27 x 10{sup 5}. This testing used chemical dosimetry to measure the dose rate of a radioactive source. In this method, one determines the dose by the chemical change that takes place in the dosimeter. For this calibration experiment, the author used a Fricke (ferrous ammonium sulfate) dosimeter. This solution works well for dose rates to 10{sup 7} rad/h. During irradiation of the Fricke dosimeter solution the Fe{sup 2+} ions ionize to Fe{sup 3+}. When this occurs, the solution acquires a slightly darker tint (not visible to the human eye). To determine the magnitude of the change in Fe ions, one places the solution in an UV-VIS Spectrophotometer. The UV-VIS Spectrophotometer measures the absorbency of the solution. Dividing the absorbency by the total time (in minutes) of exposure yields the dose rate.

Rizvi, H.M.

1999-12-03

279

Calibrating the Cryogenian  

NASA Astrophysics Data System (ADS)

The IGCP 512 sub-commission on the Neoproterozoic is currently discussing criteria for the definition of the Cryogenian period. Herein we provide new U/Pb ID-TIMS ages and carbon and oxygen isotope data from Fifteenmile and Mt. Harper Groups in the Yukon Territory that inform the basis for the placement of the basal Cryogenian “golden spike”. Our U/Pb ages are from volcanic tuffs interbedded within glaciogenic, fossiliferous, and carbonate strata. With the current lack of Neoproterozoic index fossils and the paucity of radiogenic age constraints, chemo-stratigraphic correlations are particularly important for tuning the Neoproterozoic timescale. In an effort to move beyond conventional 'wiggle matching', chemostratigraphic correlations are determined using a new statistical method1, which indicates that the resulting chemo-stratigraphic correlations are statistically significant. These results permit us to refine and integrate Neoproterozoic climate, microfossil, and geochemical proxy records both regionally and globally. The newly calibrated microfossil record points to a eukaryotic radiation roughly coincident with the Bitter Springs isotopic stage and a barren interval between the Sturtian and Marinoan glaciations. 1 Haam, E. & Huybers, P., 2009, A test for the presence of covariance between time-uncertain series of data with applications to the Dongge Cave speleothem and atmospheric radiocarbon records, Paleoceanography, in press.

MacDonald, F. A.; Schmitz, M. D.; Crowley, J. L.; Haam, E.; Huybers, P.; Cohen, P. A.; Johnston, D. T.

2009-12-01

280

Diode calibration manual  

SciTech Connect

This procedure is not for the faint of heart. It is a time consuming, complex series of journeys through advanced GAMANAL and the vagueness of analyzer electronics. A knowledge of TRIX AC, DLTV, and IMP on the Octopus system and DSCOPE, PE2, and Symphony on a PC class machine is required. Be aware that the example in this document is a condensation of information that takes up four feet of shelf space. In the attempt to convert the nomenclature of the 7600 version of GAMANAL to that of the CRAY version, there will be confusion with some of the terms used. The 7600 versions relied on punched cards to a great extent where the CRAY version doesn't use them at all. In order not to introduce a new set of nomenclature, I have changed the reference from card to card image. I hope that this will cause the least impact on the vernacular and cause the least amount of confusion possible. This document is a rewritten update of an unpublished document by Bob Wikkerink in 1980. His document was the only written record of the procedures needed to calibrate the Environmental Sciences Low Level Counting Facility. This document updates and expands this information.

Brunk, J.L.

1989-09-01

281

Integrated calibration of magnetic gradient tensor system  

NASA Astrophysics Data System (ADS)

Measurement precision of a magnetic gradient tensor system is not only connected with the imperfect performance of magnetometers such as bias, scale factor, non-orthogonality and misalignment errors, but also connected with the external soft-iron and hard-iron magnetic distortion fields when the system is used as a strapdown device. So an integrated scalar calibration method is proposed in this paper. In the first step, a mathematical model for scalar calibration of a single three-axis magnetometer is established, and a least squares ellipsoid fitting algorithm is proposed to estimate the detailed error parameters. For the misalignment errors existing at different magnetometers caused by the installation process and misalignment errors aroused by ellipsoid fitting estimation, a calibration method for combined misalignment errors is proposed in the second step to switch outputs of different magnetometers into the ideal reference orthogonal coordinate system. In order to verify effectiveness of the proposed method, simulation and experiment with a cross-magnetic gradient tensor system are performed, and the results show that the proposed method estimates error parameters and improves the measurement accuracy of magnetic gradient tensor greatly.

Gang, Yin; Yingtang, Zhang; Hongbo, Fan; GuoQuan, Ren; Zhining, Li

2015-01-01

282

Calibration of the Oscillating Screen Viscometer  

NASA Technical Reports Server (NTRS)

We have devised a calibration procedure for the oscillating screen viscometer which can provide the accuracy needed for the flight measurement of viscosity near the liquid-vapor critical point of xenon. The procedure, which makes use of the viscometer's wide bandwidth and hydrodynamic similarity, allows the viscometer to be self-calibrating. To demonstrate the validity of this procedure we measured the oscillator's transfer function under a wide variety of conditions. We obtained data using CO2 at temperatures spanning a temperature range of 35 K and densities varying by a factor of 165, thereby encountering viscosity variations as great as 50%. In contrast the flight experiment will be performed over a temperature range of 29 K and at only a single density, and the viscosity is expected to change by less than 40%. The measurements show that, after excluding data above 10 Hz (where frequency-dependent corrections are poorly modeled) and making a plausible adjustment to the viscosity value used at high density, the viscometer's behavior is fully consistent with the use of hydrodynamic similarity for calibration. Achieving this agreement required understanding a 1% anelastic effect present in the oscillator's torsion fiber.

Berg, Robert F.; Moldover, Michael R.

1993-01-01

283

Airdata Measurement and Calibration. Chapter 11  

NASA Technical Reports Server (NTRS)

This Section provides a brief introduction to airdata measurement and calibration. Readers will learn about typical test objectives, quantities to measure, and flight maneuvers and operations for calibration. The Section informs readers about tower-flyby, trailing cone, pacer, radar-tracking, and dynamic airdata calibration maneuvers. Readers will also begin to understand how some data analysis considerations and special airdata cases, including high-angle-of-attack flight, high-speed flight, and nonobtrusive sensors are handled. This section is not intended to be all inclusive; readers should review AGARDograph 300, Volume 1, "Calibration of Airdata Systems and Flow Direction Sensors" for more detailed information. [11-1] References 11-2, 11-3, and 11-4 also supply pertinent information to better understand airdata measurement and calibration and related terminology. Airdata are vital to successfully complete an aircraft's mission and are derived from the air surrounding the aircraft. These airdata encompass indicated and true airspeed, pressure altitude, ambient air temperature, angles of attack and sideslip, Mach number, and rate of climb. Typically, pitot and static pressures are sensed and converted (by mechanical means in the instruments themselves) into indications on the altimeter, vertical speed indicator, airspeed indicator, and Machmeter. Similarly, measured local flow angles establish angles of attack and sideslip, and the outside air temperature is measured and indicated in the cockpit. (Instruments that can perform the conversion, such as airspeed indicators, altimeters, and Machmeters, do not correct for errors in the input values.) These measured parameters are commonly input to the airdata computer which, using appropriate algorithms and correction factors (or calibrations, as discussed later), can provide other parameters, such as true airspeed, required by the aircraft's avionics or flight control system. The presence of the aircraft in the airstream causes input errors to the measuring instruments - the aircraft disturbs the air that it flies through, thereby also disturbing the airdata measurements. Figure 11-1 shows the airflow around an airplane wing. The air above the wing has lower pressure than the ambient air, while the pressure below the wing is higher than the ambient air. Compressibility and shock waves also disturb the air and affect the measurements. Compressibility effects become important above approximately Mach number 0.3. As a result the static pressure around an airplane varies considerably with location. Local flow angles also differ from the free-stream flow direction. In straight-and-level flight the airflow rises to the wing leading edge and falls below the trailing edge, causing errors in flow direction measurements. To some extent these errors can be studied in wind tunnels, but wind-tunnel measurements cannot replace in-flight measurements.

Haering, Edward A., Jr.

2005-01-01

284

Calibration: Practical experience with ERS-1  

NASA Technical Reports Server (NTRS)

Viewgraphs and discussion of calibration:practical experience with ERS-1 are presented. Topics covered include: radiometric calibration, geometric calibration, phase calibration, and polarimetric calibration. Basic synthetic aperture radar (SAR) measurement parameters are radar backscattering, target position, target speed, and polarization. SAR calibration facilitates quantitative measurements needed to derive geophysical parameters of the area under observation from basic SAR measurements (e.g. soil moisture, biomass, ocean wave energy, ocean currents, ice type, and ice flow).

Louet, Jacques

1993-01-01

285

The effect of individual or group guidelines on the calibration accuracy of high school biology students  

NASA Astrophysics Data System (ADS)

The effect of individual or group guidelines on the calibration accuracy of high school biology students was investigated. The study was conducted with 102 International Baccalaureate Middle Years Program biology students in a public school setting. The study was carried out over three testing occasions. Students worked in group or individual settings with and without calibration guidelines. Four intact classes were randomly assigned to one of four conditions: groups calibrating without guidelines; groups calibrating with guidelines; individuals calibrating without guidelines; individuals calibrating with guidelines. The students participated in the calibration activities one block before they actually took each of the three tests. On the day of each test, immediately before taking the test, each student made predictions as to what they thought they would score on the test. Immediately after taking the test each student made postdictions on what they thought they scored on the test. Calibration accuracy was determined by calculating the difference between prediction and postdiction scores and the actual test score achieved. The results indicated that students who calibrated in groups showed trends of more accurate calibration predictions. Although one testing intervention showed significant results for postdiction accuracy, the other two testing interventions showed varied results. Students who calibrated in groups achieved higher scores on tests than did students who calibrated individually. In addition, guidelines were shown to be a significant factor in increasing achievement for students who calibrated individually. For students calibrating in groups guidelines had little impact. The results support the need for more research in metacognition and calibration techniques in order to improve student academic success.

Walck, Camilla C.

286

Constructing and Calibrating a Hydrometer  

NSDL National Science Digital Library

Students construct and calibrate a simple hydrometer using different salt solutions. They then graph their data and determine the density and salinity of an unknown solution using their hydrometer and graphical analysis.

Meghan Hauptli

2012-04-18

287

Recent Developments in Multivariate Calibration  

Microsoft Academic Search

This review covers the area of multivariate calibration; from pre-processing of data prior to modeling and applications of regression methods for calibration and prediction. The importance of pre-treatment of data is highlighted with many of the recently developed methods together with traditional methods. Several articles provide comparisons between different pre-processing methods. Methods for data from coupled chromatographic methods, which have

Jon Gabrielsson; Johan Trygg

2006-01-01

288

Blackbody comparator for thermocouple calibration  

SciTech Connect

MIKES is developing a measurement set-up for calibrating thermocouples in the temperature range 960 °C - 1500 °C. The calibration method is based on direct comparison of thermocouples and radiation thermometers. We have designed a graphite blackbody comparator cell, which is operated in a horizontal single-zone tube furnace. The cell includes two blackbody cavities for radiation temperature measurements. The cavities have openings on opposite sides of the cell, allowing simultaneous measurement with two radiation thermometers. The design of the comparator allows three thermocouples to be calibrated simultaneously. The thermocouples to be calibrated are inserted in thermometer wells around one of the measurement cavities. We characterize the blackbody comparator in terms of repeatability, temperature distribution and emissivity. Finally, we validate the uncertainty analysis by comparing calibration results obtained for type B and S thermocouples to the calibration results reported by Technical Research Institute of Sweden (SP), and MIKES. The agreement in the temperature range 1000 °C - 1500 °C is within 0.90 °C, the average deviation being 0.17 °C.

Ojanen, M.; Hahtela, O. M.; Heinonen, M. [Centre for Metrology and Accreditation (MIKES), P.O.Box 9, FI-02151 Espoo (Finland)

2013-09-11

289

Comparison of Air Temperature Calibrations  

NASA Astrophysics Data System (ADS)

European national metrology institutes use calibration systems of various types for calibrating thermometers in air. These were compared to each other for the first time in a project organized by the European Association of National Metrology Institutes (EURAMET). This EURAMET P1061 comparison project had two main objectives: (1) to study the equivalence of calibrations performed by different laboratories and (2) to investigate correlations between calibration methods and achievable uncertainties. The comparison was realized using a pair of 100 platinum resistance thermometer probes connected to a digital thermometer bridge as the transfer standard. The probes had different dimensions and surface properties. The measurements covered the temperature range between and , but each laboratory chose a subrange most relevant to its scope and performed measurements at five nominal temperature points covering the subrange. To enable comparison between the laboratories, comparison reference functions were determined using weighted least-squares fitting. Various effects related to variations in heat transfer conditions were demonstrated but clear correlations to specific characteristics of calibration system were not identified. Calibrations in air and liquid agreed typically within at and . Expanded uncertainties determined by the participants ranged from to and they were shown to be realistic in most cases.

Heinonen, M.; Anagnostou, M.; Bartolo, J.; Bell, S.; Benyon, R.; Bergerud, R. A.; Bojkovski, J.; Böse, N.; Dinu, C.; Smorgon, D.; Flakiewicz, K.; Martin, M. J.; Nedialkov, S.; Nielsen, M. B.; O?uz Aytekin, S.; Otych, J.; Pedersen, M.; Rujan, M.; Testa, N.; Turzó-András, E.; Vilbaste, M.; White, M.

2014-07-01

290

WFC3: UVIS Dark Calibration  

NASA Astrophysics Data System (ADS)

Wide Field Camera 3 (WFC3), a fourth-generation imaging instrument on board the Hubble Space Telescope (HST), has exhibited excellent performance since its installation during Servicing Mission 4 in May 2009. The UVIS detector, comprised of two e2v CCDs, is one of two channels available on WFC3 and is named for its ultraviolet and visible light sensitivity. We present the various procedures and results of the WFC3/UVIS dark calibration, which monitors the health and stability of the UVIS detector, provides characterization of hot pixels and dark current, and produces calibration files to be used as a correction for dark current in science images. We describe the long-term growth of hot pixels and the impacts that UVIS Charge Transfer Efficiency (CTE) losses, postflashing, and proximity to the readout amplifiers have on the population. We also discuss the evolution of the median dark current, which has been slowly increasing since the start of the mission and is currently ~6 e-/hr/pix, averaged across each chip. We outline the current algorithm for creating UVIS dark calibration files, which includes aggressive cosmic ray masking, image combination, and hot pixel flagging. Calibration products are available to the user community, typically 3-5 days after initial processing, through the Calibration Database System (CDBS). Finally, we discuss various improvements to the calibration and monitoring procedures. UVIS dark monitoring will continue throughout and beyond HST’s current proposal cycle.

Bourque, Matthew; Biretta, John A.; Anderson, Jay; Baggett, Sylvia M.; Gunning, Heather C.; MacKenty, John W.

2014-06-01

291

Evaluation of Procedures for Linking Multidimensional Item Calibrations.  

ERIC Educational Resources Information Center

This paper evaluated multidimensional linking procedures with which multidimensional test data from two separate calibrations were put on a common scale. Data were simulated with known ability distributions varying on two factors which made linking necessary: mean vector differences and variance-covariance (v-c) matrix differences. After the…

Oshima, T. C.; Davey, T. C.

292

REAL-TIME ATTITUDE-INDEPENDENT THREE-AXIS MAGNETOMETER CALIBRATION  

E-print Network

REAL-TIME ATTITUDE-INDEPENDENT THREE-AXIS MAGNETOMETER CALIBRATION John L. Crassidis and Kok-axis magnetometer sensor calibration are de- rived. These approaches rely on a conversion of the magnetometer of the full cal- ibration problem involves the determination of the magnetometer bias vector, scale factors

Crassidis, John L.

293

Hydrologic calibration of paired watersheds using a MOSUM approach  

NASA Astrophysics Data System (ADS)

Paired watershed studies have historically been used to quantify hydrologic effects of land use and management practices by concurrently monitoring two neighboring watersheds (a control and a treatment) during the calibration (pre-treatment) and post-treatment periods. This study characterizes seasonal water table and flow response to rainfall during the calibration period and tests a change detection technique of moving sums of recursive residuals (MOSUM) to select calibration periods for each control-treatment watershed pair when the regression coefficients for daily water table elevation (WTE) were most stable to reduce regression model uncertainty. The control and treatment watersheds included 1-3 year intensively managed loblolly pine (Pinus taeda L.) with natural understory, same age loblolly pine intercropped with switchgrass (Panicum virgatum), 14-15 year thinned loblolly pine with natural understory (control), and switchgrass only. Although monitoring during the calibration period spanned 2009 to 2012, silvicultural operational practices that occurred during this period such as harvesting of existing stand and site preparation for pine and switchgrass establishment may have acted as external factors, potentially shifting hydrologic calibration relationships between control and treatment watersheds. Results indicated that MOSUM was able to detect significant changes in regression parameters for WTE due to silvicultural operations. This approach also minimized uncertainty of calibration relationships which could otherwise mask marginal treatment effects. All calibration relationships developed using this MOSUM method were quantifiable, strong, and consistent with Nash-Sutcliffe Efficiency (NSE) greater than 0.97 for WTE and NSE greater than 0.92 for daily flow, indicating its applicability for choosing calibration periods of paired watershed studies.

Ssegane, H.; Amatya, D. M.; Muwamba, A.; Chescheir, G. M.; Appelboom, T.; Tollner, E. W.; Nettles, J. E.; Youssef, M. A.; Birgand, F.; Skaggs, R. W.

2015-01-01

294

Design, manufacture, and calibration of infrared radiometric blackbody sources  

SciTech Connect

A Radiometric Calibration Station (RCS) is being assembled at the Los Alamos National Laboratories (LANL) which will allow for calibration of sensors with detector arrays having spectral capability from about 0.4-15 {mu}m. The configuration of the LANL RCS. Two blackbody sources have been designed to cover the spectral range from about 3-15 {mu}m, operating at temperatures ranging from about 180-350 K within a vacuum environment. The sources are designed to present a uniform spectral radiance over a large area to the sensor unit under test. The thermal uniformity requirement of the blackbody cavities has been one of the key factors of the design, requiring less than 50 mK variation over the entire blackbody surface to attain effective emissivity values of about 0.999. Once the two units are built and verified to the level of about 100 mK at LANL, they will be sent to the National Institute of Standards and Technology (NIST), where at least a factor of two improvement will be calibrated into the blackbody control system. The physical size of these assemblies will require modifications of the existing NIST Low Background Infrared (LBIR) Facility. LANL has constructed a bolt-on addition to the LBIR facility that will allow calibration of our large aperture sources. Methodology for attaining the two blackbody sources at calibrated levels of performance equivalent to present state of the art will be explained in the following.

Byrd, D.A.; Michaud, F.D.; Bender, S.C. [and others

1996-04-01

295

A positioning free calibration method for mobile laser scanning applications  

NASA Astrophysics Data System (ADS)

Mobile laser scanning are likely to find more and more applications for high density 3D environmental data. A mobile laser scanning system is composed by three subsystems: a GNSS (Global Navigation Satellite System) that provides position information, an INS (Inertial Navigation System) for attitude determination, and a LiDAR (Light Detection And Ranging). The accuracy of the geolocated LiDAR returns depends on the accuracy of each instrument but also on the bore-sighting parameters and the lever arms between the instruments. Indeed, an imperfect calibration may lead to systematic errors. Calibration may then become the limiting factor of Terrestrial Laser scanning if it is not tackled seriously. Moreover [Ø], it is important to have a reliable value of the calibration precision. This paper presents a new positioning free procedure for the estimation of the LiDAR bore-sighting parameters. Since this method is static, lever arms do not affect the boresight calibration and positioning is not required. That makes the methodology immune to GPS errors. Finally, since it is based on a rigorous mathematical model, it can provide a reliable boresight quality factor. First, the boresight determination problem is explained and existing calibration procedures are introduced. After having explained their drawbacks, a new procedure that tries to overcome these limitations is described. Tests from simulations and real datasets are also presented to illustrate our approach.

Le Scouarnec, R.; Touzé, T.; Lacambre, J. B.; Seube, N.

2013-10-01

296

Comparison of two novel in-syringe dispersive liquid-liquid microextraction techniques for the determination of iodide in water samples using spectrophotometry.  

PubMed

Two new, rapid methodologies have been developed and applied successfully for the determination of trace levels of iodide in real water samples. Both techniques are based on a combination of in-syringe dispersive liquid-liquid microextraction (IS-DLLME) and micro-volume UV-Vis spectrophotometry. In the first technique, iodide is oxidized with nitrous acid to the colorless anion of ICl2(-) at high concentration of hydrochloric acid. Rhodamine B is added and by means of one step IS-DLLME, the ion-pair formed was extracted into toluene and measured spectrophotometrically. Acetone is used as dispersive solvent. The second method is based on the IS-DLLME microextraction of iodide as iodide/1, 10-phenanthroline-iron((II)) chelate cation ion-pair (colored) into nitrobenzene. Methanol was selected as dispersive solvent. Optimal conditions for iodide extraction were determined for both approaches. Methods are compared in terms of analytical parameters such as precision, accuracy, speed and limit of detection. Both methods were successfully applied to determining iodide in tap and river water samples. PMID:24239760

Kaykhaii, Massoud; Sargazi, Mona

2014-01-01

297

Assessing the role of syringe dispensing machines and mobile van outlets in reaching hard-to-reach and high-risk groups of injecting drug users (IDUs): a review  

PubMed Central

Reaching hard-to-reach and high-risk injecting drug users (IDUs) is one of the most important challenges for contemporary needle syringe programs (NSPs). The aim of this review is to examine, based upon the available international experience, the effectiveness of syringe vending machines and mobile van/bus based NSPs in making services more accessible to these hard-to-reach and high-risk groups of IDUs. A literature search revealed 40 papers/reports, of which 18 were on dispensing machines (including vending and exchange machines) and 22 on mobile vans. The findings demonstrate that syringe dispensing machines and mobile vans are promising modalities of NSPs, which can make services more accessible to the target group and in particular to the harder-to-reach and higher-risk groups of IDUs. Their anonymous and confidential approaches make services attractive, accessible and acceptable to these groups. These two outlets were found to be complementary to each other and to other modes of NSPs. Services through dispensing machines and mobile vans in strategically important sites are crucial elements in continuing efforts in reducing the spread of HIV and other blood borne viruses among IDUs. PMID:17958894

Islam, Md Mofizul; Conigrave, Katherine M

2007-01-01

298

Spectrophotometric Calibration System for DECam  

NASA Astrophysics Data System (ADS)

We present a spectrophotometric calibration system that will be implemented as part of the DES DECam project at the Blanco 4 meter at CTIO. Our calibration system uses a 2nm wide tunable source to measure the instrumental response function of the telescope from 300nm up to 1100nm. This calibration will be performed at regular interval during the survey to monitor any change in the transmission function. The system consists of a monochromator based tunable light source that provides illumination on a dome flat that is monitored by calibrated photodiodes and allow us to measure the throughput as a function of wavelength. Our system has an output power of 2 mW, equivalent to a flux of approximately 800 photons/s per pixel on DECam. We also present results from the deployment of a prototype of this system at the Swope and DuPont telescopes at Las Campanas Observatory for the calibration of the photometric equipment used in the Carnegie Supernova Project.

Rheault, Jean-Philippe; DePoy, D.; Marshall, J.; Carona, D.; Cook, K.; Behm, T.; Allen, R.

2011-01-01

299

Drift-insensitive distributed calibration of probe microscope scanner in nanometer range: Virtual mode  

E-print Network

A method of distributed calibration of a probe microscope scanner is suggested which main idea consists in a search for a net of local calibration coefficients (LCCs) in the process of automatic measurement of a standard surface, whereby each point of the movement space of the scanner can be characterized by a unique set of scale factors. Feature-oriented scanning (FOS) methodology is used as a basis for implementation of the distributed calibration permitting to exclude in situ the negative influence of thermal drift, creep and hysteresis on the obtained results. Possessing the calibration database enables correcting in one procedure all the spatial distortions caused by nonlinearity, nonorthogonality and spurious crosstalk couplings of the microscope scanner piezomanipulators. To provide high precision of spatial measurements in nanometer range, the calibration is carried out using natural standards - constants of crystal lattice. One of the useful modes of the developed calibration method is a virtual mode...

Lapshin, Rostislav V

2015-01-01

300

Calibration of ionization chamber for ¹?F and ??Ga.  

PubMed

In order to maintain the results of primary activity standardizations carried out in 2011 the LNMRI has determined the calibration factors for a pressurized 4?-ionization chamber for the nuclides (18)F and (68)Ga. This ionization chamber is coupled to a 6517A Keithley electrometer which is controlled by a homemade LabVIEW program. This paper will describe the main issues related to the calibration of an ionization chamber system for positron emitters and short half-life radionuclides such as timing, current measurement, background, decay, and (226)Ra check source measurements. PMID:24361323

da Silva, Carlos J; de Oliveira, Estela M; Iwahara, A; Delgado, José U; Poledna, R; de Oliveira, Antônio E; Moreira, Denise S; da Silva, Ronaldo L; Gomes, Regio dos Santos; de Veras, Eduardo V

2014-05-01

301

Self-calibrating multiplexer circuit  

DOEpatents

A time domain multiplexer system with automatic determination of acceptable multiplexer output limits, error determination, or correction is comprised of a time domain multiplexer, a computer, a constant current source capable of at least three distinct current levels, and two series resistances employed for calibration and testing. A two point linear calibration curve defining acceptable multiplexer voltage limits may be defined by the computer by determining the voltage output of the multiplexer to very accurately known input signals developed from predetermined current levels across the series resistances. Drift in the multiplexer may be detected by the computer when the output voltage limits, expected during normal operation, are exceeded, or the relationship defined by the calibration curve is invalidated.

Wahl, Chris P. (North Huntingdon, PA)

1997-01-01

302

Calibration and Imaging with eigenbeams  

NASA Astrophysics Data System (ADS)

The Australian Square Kilometre Array Pathfinder (ASKAP) is one of the key technology demonstrators on the way to the Square Kilometre Array (SKA). The main feature of the project is the development of the Phased Array Feed (PAF) technology to boost the instantaneous field of view. We consider a non-adaptive (weights are constant) beamforming and show that the majority of information is contained in a small number of linear combinations of the measured voltages. Therefore, a small number of synthetic beams, perhaps an order of magnitude smaller than the number of physical feeds, can be used for imaging and calibration. From the other side, only a small number of gains can be calibrated using the full-beam self-calibration approach.

Voronkov, M.; Cornwell, T.

303

Mariner 9 television calibration - Revisited  

NASA Technical Reports Server (NTRS)

Mariner 9 TV data from the 1971-1972 encounter with Mars, which contain good synoptic coverage of of the planet as well as the highest-resolution images thus far obtained for the south polar region, can lead to more accurate photometric analysis if subjected to improved processing methods. While calibration errors are rather greater than those of the Viking Orbiter cameras, both calibration data and processing software applicable to an improvement program have become available through the USGS's Planetary Image Cartography System.

Herkenhoff, Ken E.; Soderblom, Laurence A.; Murray, Bruce C.; Danielson, G. Edward

1988-01-01

304

Method for calibrating mass spectrometers  

DOEpatents

A method whereby a mass spectra generated by a mass spectrometer is calibrated by shifting the parameters used by the spectrometer to assign masses to the spectra in a manner which reconciles the signal of ions within the spectra having equal mass but differing charge states, or by reconciling ions having known differences in mass to relative values consistent with those known differences. In this manner, the mass spectrometer is calibrated without the need for standards while allowing the generation of a highly accurate mass spectra by the instrument.

Anderson, Gordon A [Benton City, WA; Brands, Michael D [Richland, WA; Bruce, James E [Schwenksville, PA; Pasa-Tolic, Ljiljana [Richland, WA; Smith, Richard D [Richland, WA

2002-12-24

305

pH Meter Calibration  

NSDL National Science Digital Library

The North Carolina Community College System BioNetwork's interactive eLearning tools (IETs) are reusable chunks of training that can be deployed in a variety of courses or training programs. IETs are designed to enhance, not replace hands-on training. Learners are able to enter a hands-on lab experience better prepared and more confident. This particular IET delves into pH Meter Calibration, where visitors practice performing a three point calibration of a pH meter using buffer solutions.

306

Advancing Astrometry: Revisiting the VLBA Calibrator Surveys  

NASA Astrophysics Data System (ADS)

The original VLBA Calibrator Surveys (VCS) were a series of 6 VLBA campaigns from 1994 to 2007 in which more than 2000 compact extragalactic radio sources were observed at X/S bands. The goals were to obtain precise positions (uncertainties ~1 mas or better) of many hundreds of new sources for use as VLBI phase referencing calibrators, and to make snapshot images of them for morphological studies. These VCS campaigns were highly successful, resulting in accurate positions and scientific-grade images maps for a majority of sources. These observations were later used to approximately triple the number of sources contained in the second realization of the International Celestial Reference Frame by VLBI (ICRF2). However, the VCS sources in ICRF2 represent a class of 'single epoch' sources with average position uncertainties ~5 times greater than the other ~1200 ICRF2 sources which are observed much more frequently in geodetic VLBI sessions. In an attempt to greatly reduce their position uncertainties, we are re-observing ~2400 VCS sources at X/S bands on the VLBA in 8 24-hr sessions. With the recent VLBA sensitivity upgrade, the sensitivity is now nearly 5 and 3 times greater at X and S bands than the original VCS sessions. Five of these sessions have been run so far, re-observing 1500 sources. Preliminary analysis shows an improvement in the average position uncertainties by a factor of ~3.2 times for these re-observed sources. We will present and discuss these improvements and their implication for ICRF3 development (planned for 2018). Images are also being produced and examples will be presented. Additional references: VLBA Calibrator Survey : Beasley et al. 2002 2002ApJS..141...13B ICRF1 : 2009ITN....35....1M ICRF2 : 1998AJ....116..516M ICRF3 : 2014rfag.confE...1J GAIA : 2008IAUS..248..217L

Beasley, Anthony J.; Gordon, David; Jacobs, Christopher; Peck, Alison; Hodge, Jackie; Thomas, Brianna; Fey, Alan; Ma, Chopo; Gaume, Ralph; Boboltz, David; Titov, Oleg; Charlot, Patrick

2015-01-01

307

The Calibration Index and the Role of Input Noise in Robot Calibration  

E-print Network

(Norton 1986). The two topics also will be seen to have a relationship. Many kinematic calibration methods method. The literature on camera calibration is usually distinct from that on manipulator calibration

Hollerbach, John M.

308

Stable Calibration of Raman Lidar Water-Vapor Measurements  

NASA Technical Reports Server (NTRS)

A method has been devised to ensure stable, long-term calibration of Raman lidar measurements that are used to determine the altitude-dependent mixing ratio of water vapor in the upper troposphere and lower stratosphere. Because the lidar measurements yield a quantity proportional to the mixing ratio, rather than the mixing ratio itself, calibration is necessary to obtain the factor of proportionality. The present method involves the use of calibration data from two sources: (1) absolute calibration data from in situ radiosonde measurements made during occasional campaigns and (2) partial calibration data obtained by use, on a regular schedule, of a lamp that emits in a known spectrum determined in laboratory calibration measurements. In this method, data from the first radiosonde campaign are used to calculate a campaign-averaged absolute lidar calibration factor (t(sub 1)) and the corresponding campaign-averaged ration (L(sub 1)) between lamp irradiances at the water-vapor and nitrogen wavelengths. Depending on the scenario considered, this ratio can be assumed to be either constant over a long time (L=L(sub 1)) or drifting slowly with time. The absolutely calibrated water-vapor mixing ratio (q) obtained from the ith routine off-campaign lidar measurement is given by q(sub 1)=P(sub 1)/t(sub 1)=LP(sub 1)/P(sup prime)(sub 1) where P(sub 1) is water-vapor/nitrogen measurement signal ration, t(sub 1) is the unknown and unneeded overall efficiency ratio of the lidar receiver during the ith routine off-campaign measurement run, and P(sup prime)(sub 1) is the water-vapor/nitrogen signal ratio obtained during the lamp run associated with the ith routine off-campaign measurement run. If L is assumed constant, then the lidar calibration is routinely obtained without the need for new radiosonde data. In this case, one uses L=L(sub 1) = P(sup prime)(sub 1)/t(sub 1), where P(sub 1)(sup prime) is the water-vapor/nitrogen signal ratio obtained during the lamp run associated with the first radiosonde campaign. If L is assumed to drift slowly, then it is necessary to postpone calculation of a(sub 1) until after a second radiosonde campaign. In this case, one obtains a new value, L(sub 2), from the second radiosonde campaign, and for the ith routine off-campaign measurement run, one uses an intermediate value of L obtained by simple linear time interpolation between L(sub 1) and L(sub 2).

Leblanc, Thierry; McDermid, Iain S.

2008-01-01

309

Efficient use of pure component and interferent spectra in multivariate calibration.  

PubMed

Partial Least Squares (PLS) is by far the most popular regression method for building multivariate calibration models for spectroscopic data. However, the success of the conventional PLS approach depends on the availability of a 'representative data set' as the model needs to be trained for all expected variation at the prediction stage. When the concentration of the known interferents and their correlation with the analyte of interest change in a fashion which is not covered in the calibration set, the predictive performance of inverse calibration approaches such as conventional PLS can deteriorate. This underscores the need for calibration methods that are capable of building multivariate calibration models which can be robustified against the unexpected variation in the concentrations and the correlations of the known interferents in the test set. Several methods incorporating 'a priori' information such as pure component spectra of the analyte of interest and/or the known interferents have been proposed to build more robust calibration models. In the present study, four such calibration techniques have been benchmarked on two data sets with respect to their predictive ability and robustness: Net Analyte Preprocessing (NAP), Improved Direct Calibration (IDC), Science Based Calibration (SBC) and Augmented Classical Least Squares (ACLS) Calibration. For both data sets, the alternative calibration techniques were found to give good prediction performance even when the interferent structure in the test set was different from the one in the calibration set. The best results were obtained by the ACLS model incorporating both the pure component spectra of the analyte of interest and the interferents, resulting in a reduction of the RMSEP by a factor 3 compared to conventional PLS for the situation when the test set had a different interferent structure than the one in the calibration set. PMID:23639394

Sharma, Sandeep; Goodarzi, Mohammad; Wynants, Laure; Ramon, Herman; Saeys, Wouter

2013-05-17

310

Hypersonic Wind Tunnel Calibration Using the Modern Design of Experiments  

NASA Technical Reports Server (NTRS)

A calibration of a hypersonic wind tunnel has been conducted using formal experiment design techniques and response surface modeling. Data from a compact, highly efficient experiment was used to create a regression model of the pitot pressure as a function of the facility operating conditions as well as the longitudinal location within the test section. The new calibration utilized far fewer design points than prior experiments, but covered a wider range of the facility s operating envelope while revealing interactions between factors not captured in previous calibrations. A series of points chosen randomly within the design space was used to verify the accuracy of the response model. The development of the experiment design is discussed along with tactics used in the execution of the experiment to defend against systematic variation in the results. Trends in the data are illustrated, and comparisons are made to earlier findings.

Rhode, Matthew N.; DeLoach, Richard

2005-01-01

311

Combination Interventions to Prevent HCV Transmission Among People Who Inject Drugs: Modeling the Impact of Antiviral Treatment, Needle and Syringe Programs, and Opiate Substitution Therapy  

PubMed Central

Background.?Interventions such as opiate substitution therapy (OST) and high-coverage needle and syringe programs (HCNSP) cannot substantially reduce hepatitis C virus (HCV) prevalence among people who inject drugs (PWID). HCV antiviral treatment may prevent onward transmission. We project the impact of combining OST, HCNSP, and antiviral treatment on HCV prevalence/incidence among PWID. Methods.?An HCV transmission model among PWID was used to project the combinations of OST, HCNSP, and antiviral treatment required to achieve different prevalence and incidence reductions within 10 years for 3 chronic prevalence scenarios and the impact of HCV treatment if only delivered through OST programs. Multivariate and univariate sensitivity analyses were performed. Results.?Large reductions (>45%) in HCV chronic prevalence over 10 years require HCV antiviral treatment. Scaling up OST and HCNSP substantially reduces the treatment rate required to achieve specific HCV prevalence reductions. If OST and HCNSP coverage were increased to 40% each (no coverage at baseline), then annually treating 10, 23, or 42 per 1000 PWID over 10 years would halve prevalence for 20%, 40%, or 60% baseline chronic HCV prevalences, respectively. Approximately 30% fewer treatments are necessary with new direct-acting antivirals. If coverage of OST and HCNSP is 50% at baseline, similar prevalence reductions require higher treatment rates for the same OST and HCNSP coverage. Conclusions.?Combining antiviral treatment with OST with HCNSP is critical for achieving substantial reductions (>50%) in HCV chronic prevalence over 10 years. Empirical studies are required on how best to scale up antiviral treatment and combine treatment with other interventions. PMID:23884064

Martin, Natasha K.; Hickman, Matthew; Hutchinson, Sharon J.; Goldberg, David J.; Vickerman, Peter

2013-01-01

312

ECC Ozonesonde Calibration and Observations: Satellite Validation  

NASA Technical Reports Server (NTRS)

The reliability of the Electrochemical Concentration Cell (ECC) ozonesonde depends on the care exercised in preparing the instrument for use. Although the ECC can be quickly prepared and flown, generally within less then one day if necessary, it is best to prepare the instrument at least one week prior to use, and as our tests have confirmed even 2-3 weeks prior to use may actually be better. There are a number of factors that must be considered when preparing an ECC. These basically are the pump efficiency, volumetric flow rate, temperature of the air entering the pump, and the background current. Also of importance is the concentration of the potassium iodide solution. Tests conducted at Wallops Island (38 N) has enabled us to identify potential problem areas and ways to avoid them. The calibration and pre-flight preparation methods will be discussed. The method of calibrating the ECC also is used at Ascension Island (8 S) and Natal, Brazil (5 S). Comparisons between vertical profiles of the ECC instrument and satellites will be reviewed as well as comparison with ground based instruments, such as, the Dobson Spectrophotometer and hand held Microtops photometers.

Schmidlin, Francis J.; Zukor, Dorothy (Technical Monitor)

2001-01-01

313

Absolute calibration of forces in optical tweezers  

NASA Astrophysics Data System (ADS)

Optical tweezers are highly versatile laser traps for neutral microparticles, with fundamental applications in physics and in single molecule cell biology. Force measurements are performed by converting the stiffness response to displacement of trapped transparent microspheres, employed as force transducers. Usually, calibration is indirect, by comparison with fluid drag forces. This can lead to discrepancies by sizable factors. Progress achieved in a program aiming at absolute calibration, conducted over the past 15 years, is briefly reviewed. Here we overcome its last major obstacle, a theoretical overestimation of the peak stiffness, within the most employed range for applications, and we perform experimental validation. The discrepancy is traced to the effect of primary aberrations of the optical system, which are now included in the theory. All required experimental parameters are readily accessible. Astigmatism, the dominant effect, is measured by analyzing reflected images of the focused laser spot, adapting frequently employed video microscopy techniques. Combined with interface spherical aberration, it reveals a previously unknown window of instability for trapping. Comparison with experimental data leads to an overall agreement within error bars, with no fitting, for a broad range of microsphere radii, from the Rayleigh regime to the ray optics one, for different polarizations and trapping heights, including all commonly employed parameter domains. Besides signaling full first-principles theoretical understanding of optical tweezers operation, the results may lead to improved instrument design and control over experiments, as well as to an extended domain of applicability, allowing reliable force measurements, in principle, from femtonewtons to nanonewtons.

Dutra, R. S.; Viana, N. B.; Maia Neto, P. A.; Nussenzveig, H. M.

2014-07-01

314

Airborne SAR radiometric calibration using point targets  

NASA Astrophysics Data System (ADS)

The trihedral corner reflector, with high stability, large RCS and little change within a wide angle range, is widely used in SAR radiometric calibration. Results from airborne SAR overflights of corner reflectors are utilized to compute calibration constant, transfer function of the system and backscattering coefficient of different targets. The key step of SAR calibration is the derivation of calibration constant. In this paper, we used two methods, the peak and integral method, to compute the calibration constant. Through real flight data, we found that, using point target for SAR calibration is simple and practicable.

Zongmin, Feng; Lei, Huang; Zhihua, Tang; Jiuli, Liu; Liangbo, Zhao

2014-03-01

315

IMU-Based Online Kinematic Calibration of Robot Manipulator  

PubMed Central

Robot calibration is a useful diagnostic method for improving the positioning accuracy in robot production and maintenance. An online robot self-calibration method based on inertial measurement unit (IMU) is presented in this paper. The method requires that the IMU is rigidly attached to the robot manipulator, which makes it possible to obtain the orientation of the manipulator with the orientation of the IMU in real time. This paper proposed an efficient approach which incorporates Factored Quaternion Algorithm (FQA) and Kalman Filter (KF) to estimate the orientation of the IMU. Then, an Extended Kalman Filter (EKF) is used to estimate kinematic parameter errors. Using this proposed orientation estimation method will result in improved reliability and accuracy in determining the orientation of the manipulator. Compared with the existing vision-based self-calibration methods, the great advantage of this method is that it does not need the complex steps, such as camera calibration, images capture, and corner detection, which make the robot calibration procedure more autonomous in a dynamic manufacturing environment. Experimental studies on a GOOGOL GRB3016 robot show that this method has better accuracy, convenience, and effectiveness than vision-based methods. PMID:24302854

2013-01-01

316

IMU-based online kinematic calibration of robot manipulator.  

PubMed

Robot calibration is a useful diagnostic method for improving the positioning accuracy in robot production and maintenance. An online robot self-calibration method based on inertial measurement unit (IMU) is presented in this paper. The method requires that the IMU is rigidly attached to the robot manipulator, which makes it possible to obtain the orientation of the manipulator with the orientation of the IMU in real time. This paper proposed an efficient approach which incorporates Factored Quaternion Algorithm (FQA) and Kalman Filter (KF) to estimate the orientation of the IMU. Then, an Extended Kalman Filter (EKF) is used to estimate kinematic parameter errors. Using this proposed orientation estimation method will result in improved reliability and accuracy in determining the orientation of the manipulator. Compared with the existing vision-based self-calibration methods, the great advantage of this method is that it does not need the complex steps, such as camera calibration, images capture, and corner detection, which make the robot calibration procedure more autonomous in a dynamic manufacturing environment. Experimental studies on a GOOGOL GRB3016 robot show that this method has better accuracy, convenience, and effectiveness than vision-based methods. PMID:24302854

Du, Guanglong; Zhang, Ping

2013-01-01

317

Spectroradiometric calibration of blackbody sources  

NASA Astrophysics Data System (ADS)

An IR camera responds to infrared radiant energy over a waveband determined by the camera optics and detector. Most cameras operate in either the 3 to 5 micrometers or 8 to 12 micrometers wavebands as they represent good atmospheric windows. Temperature measurement using these cameras is performed within the camera, which will correct for target emissivity and background temperatures. The algorithm that does this makes a key assumption: the target is a graybody source (constant emissivity over the waveband of the IR camera). To effect this calculation, modern infrared (IR) cameras are calibrated using blackbody sources. The calibration data set is stored in the camera firmware as a lookup table. To be accurate, blackbody sources must be graybodies with emissivities very close to one. The fact that there are no perfect blackbodies can be overcome as long as the emissivity is constant with wavelength. Spectroradiometric calibration of blackbody sources is the best way to ensure the radiant energy emanating from the source follows Planck's law over the waveband of the IR camera being calibrated (another way of saying graybody). At FLIR Systems, Inc. we used a CI Systems SR-5000 spectroradiometer to spectrally characterize 20 blackbody sources of various manufacturer and type.

Madding, Robert P.

2001-03-01

318

Testing calibrated general equilibrium models  

Microsoft Academic Search

This paper illustrates the philosophy which forms the basis of calibration exercises in general equilibrium macroeconomic models and the details of the procedure, the advantages and the disadvantages of the approach, with particular reference to the issue of testing ``false'' economic models. We provide an overview of the most recent simulation--based approaches to the testing problem and compare them to

Fabio Canova; Eva Ortega

1996-01-01

319

Reflection, Endorsement, Calibration Robert Stalnaker  

E-print Network

Reflection, Endorsement, Calibration Robert Stalnaker Bas van Fraassen's reflection principle has concern is not to defend the principle, but to reflect on the more general issue that the reflection of the reflection principle to a notorious example: the problem of Sleeping Beauty. #12;

Fitelson, Branden

320

CALIBRATION OF SUBMERGED RADIAL GATES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Calibration equations for free-flowing radial gates typically provide sufficient accuracy for irrigation district operations. However, many districts have difficulty in determining accurate discharges when the downstream water level begins to submerge the gate. Based on laboratory studies, we have d...

321

3, 11051124, 2006 Calibration of  

E-print Network

HESSD 3, 1105­1124, 2006 Calibration of hydrological model parameters and PUB A. B´ardossy Title.hydrol-earth-syst-sci-discuss.net/3/1105/2006/ © Author(s) 2006. This work is licensed under a Creative Commons License. Hydrology and Earth System Sciences Discussions Papers published in Hydrology and Earth System Sciences Discussions

Boyer, Edmond

322

Asymptotic Calibration Dean P. Foster  

E-print Network

.S. National Weather Service has been in the habit of making and announcing probability of precipitation (PoP) forecasts. Such a 2 #12;forecast is interpreted to be the probability that precipitation, defined definition of calibration: "Suppose that, in a long (conceptually infinite) sequence of weather forecasts, we

Foster, Dean P.

323

Practical intraoperative stereo camera calibration.  

PubMed

Many of the currently available stereo endoscopes employed during minimally invasive surgical procedures have shallow depths of field. Consequently, focus settings are adjusted from time to time in order to achieve the best view of the operative workspace. Invalidating any prior calibration procedure, this presents a significant problem for image guidance applications as they typically rely on the calibrated camera parameters for a variety of geometric tasks, including triangulation, registration and scene reconstruction. While recalibration can be performed intraoperatively, this invariably results in a major disruption to workflow, and can be seen to represent a genuine barrier to the widespread adoption of image guidance technologies. The novel solution described herein constructs a model of the stereo endoscope across the continuum of focus settings, thereby reducing the number of degrees of freedom to one, such that a single view of reference geometry will determine the calibration uniquely. No special hardware or access to proprietary interfaces is required, and the method is ready for evaluation during human cases. A thorough quantitative analysis indicates that the resulting intrinsic and extrinsic parameters lead to calibrations as accurate as those derived from multiple pattern views. PMID:25485437

Pratt, Philip; Bergeles, Christos; Darzi, Ara; Yang, Guang-Zhong

2014-01-01

324

Timing calibration Light distribution simulation  

E-print Network

Timing calibration Light distribution simulation Bostjan Macek #12;Simulation infrastructure eveything done in an extendable way, so its easy to: change/add geometry use different light source ray uniform over solid angle up to some max-angle light source detection surface #12;simple source ­ angle 1

Browder, Tom

325

INERTIAL MEASUREMENT UNIT CALIBRATION PLATFORM  

E-print Network

and McCarthy, 1998), kinematics and singularity analysis for five-dof parallel manipulators (Wang. By contrast, the current article presents a platform manipulator for off-line calibration of three-dof Athens, OH 45701 Final Manuscript Journal of Robotic Systems June, 2000 Keywords: Platform Manipulator

Williams II, Robert L.

326

Christchurch field data for rockfall model calibration  

NASA Astrophysics Data System (ADS)

The Canterbury earthquake of 2012-2011 triggered devastating rockfalls in the Port Hills in Christchurch, over 8000 boulders resulted in fatalities and severe building damage. There is a requirement for detailed and defensible rockfall hazard analysis to guide planning decisions in response to these rockfall events, most commonly this is performed with the use of a rockfall model. Calibrating a rockfall model requires a robust data set of past rockfall events. Information of rockfall deposit shape and size should be mapped over the affected area, in addition to information on the dynamics of the rockfall events such as jump heights and velocities of rocks. It is often the case that such information is obtained from expensive rock rolling studies; however the dynamics of an event can be estimated from the runout terrain and impact scars. In this study a calibration of a 3D rigid-body rockfall model was performed based on mapped boulder sizes and shapes over the rockfall affected zones of Christchurch, and estimations of boulder velocities gleaned from rock impact scars of individual trajectories and a high resolution digital terrain model produced following the rockfall events. The impact scars were mapped recording their length and depth of penetration into the loess soil cover of the runout zones. Two methods to estimate the boulder velocities have been applied. The first crudely estimates the velocity based on the vertical free fall potential between the rockfall shadow line and the terrain surface, and a velocity correction factor to account for friction. The second uses the impact scars assuming a parabolic trajectory between rock-ground impacts giving an indication of both jump height and velocity. Maximum runout distances produced a shadow angle of 23° in the area. Applying the first method suggests velocities can reach up to ~26 m s-1 and maxima concentrate in gullies and steep terrain. On average the distance between impact scars was 23 m, from which jump heights up to 4 m are estimated. While a first calibration of the rockfall model was possible by matching simulated to mapped deposit locations, many results initially showed unrealistic velocities and jump heights. The additional dynamic data has assisted in refining the calibration to ensure a defensible rockfall hazard analysis.

Vick, L.; Glover, J.; Davies, T. R.

2013-12-01

327

Usefulness of specific calibration coefficients for gamma-emitting sources measured by radionuclide calibrators in nuclear medicine  

SciTech Connect

Purpose: In nuclear medicine, the activity of a radionuclide is measured with a radionuclide calibrator that often has a calibration coefficient independent of the container type and filling. Methods: To determine the effect of the container on the accuracy of measuring the activity injected into a patient, The authors simulated a commercial radionuclide calibrator and 18 container types most typically used in clinical practice. The instrument sensitivity was computed for various container thicknesses and filling levels. Monoenergetic photons and electrons as well as seven common radionuclides were considered. Results: The quality of the simulation with gamma-emitting sources was validated by an agreement with measurements better than 4% in five selected radionuclides. The results show that the measured activity can vary by more than a factor of 2 depending on the type of container. The filling level and the thickness of the container wall only have a marginal effect for radionuclides of high energy but could induce differences up to 4%. Conclusions: The authors conclude that radionuclide calibrators should be tailored to the uncertainty required by clinical applications. For most clinical cases, and at least for the low-energy gamma and x-ray emitters, measurements should be performed with calibration coefficients specific to the container type.

Bochud, Francois O.; Laedermann, Jean-Pascal; Baechler, Sebastien; Kosinski, Marek; Bailat, Claude J. [Institute of Radiation Physics, University Hospital and University of Lausanne, Rue du Grand-Pre 1, CH-1007 Lausanne (Switzerland)

2011-07-15

328

The Atmospheric Lifetime Experiment. II - Calibration  

NASA Technical Reports Server (NTRS)

The calibration standards used in the Atmospheric Lifetime Experiment (ALE) for CFCl3, CF2Cl2, CH3CCl3, and CCl4 are described. This includes the preparation of the primary standards by static dilution and their propagation and stability for the period 1977-1982. Two independent assessments of the absolute concentrations of the primary standards used to initiate the ALE measurements in 1977-1978 are reported. For consistency in the ALE program the values assigned to the primary standards and subsequent working standards used in the field were not altered during the experiment when results of better estimates of the original concentration values were obtained. Rather, the appropriate factors by which the ALE mixing ratios for a given species should be multiplied to obtain the best estimate of the current concentration of a given species, are provided.

Rasmussen, R. A.; Lovelock, J. E.

1983-01-01

329

Calibration Software for Use with Jurassicprok  

NASA Technical Reports Server (NTRS)

The Jurassicprok Interferometric Calibration Software (also called "Calibration Processor" or simply "CP") estimates the calibration parameters of an airborne synthetic-aperture-radar (SAR) system, the raw measurement data of which are processed by the Jurassicprok software described in the preceding article. Calibration parameters estimated by CP include time delays, baseline offsets, phase screens, and radiometric offsets. CP examines raw radar-pulse data, single-look complex image data, and digital elevation map data. For each type of data, CP compares the actual values with values expected on the basis of ground-truth data. CP then converts the differences between the actual and expected values into updates for the calibration parameters in an interferometric calibration file (ICF) and a radiometric calibration file (RCF) for the particular SAR system. The updated ICF and RCF are used as inputs to both Jurassicprok and to the companion Motion Measurement Processor software (described in the following article) for use in generating calibrated digital elevation maps.

Chapin, Elaine; Hensley, Scott; Siqueira, Paul

2004-01-01

330

Calibration and Validation of Measurement System  

E-print Network

Calibration and Validation of Measurement System ­ Wave Dragon, Nissum Bredning Project: Sea +45 98 14 25 55 Hydraulics and Coastal Engineering No. 2 Calibration and Validation of Measurement .......................................................................................................................9 7. STRAIN GAUGES

331

21 CFR 862.1150 - Calibrator.  

Code of Federal Regulations, 2013 CFR

...DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1150 Calibrator. (a) Identification. A calibrator is...

2013-04-01

332

Automated Attitude Sensor Calibration: Progress and Plans  

NASA Technical Reports Server (NTRS)

This paper describes ongoing work a NASA/Goddard Space Flight Center to improve the quality of spacecraft attitude sensor calibration and reduce costs by automating parts of the calibration process. The new calibration software can autonomously preview data quality over a given time span, select a subset of the data for processing, perform the requested calibration, and output a report. This level of automation is currently being implemented for two specific applications: inertial reference unit (IRU) calibration and sensor alignment calibration. The IRU calibration utility makes use of a sequential version of the Davenport algorithm. This utility has been successfully tested with simulated and actual flight data. The alignment calibration is still in the early testing stage. Both utilities will be incorporated into the institutional attitude ground support system.

Sedlak, Joseph; Hashmall, Joseph

2004-01-01

333

Timing Calibration in PET Using a Time Alignment Probe  

SciTech Connect

We evaluate the Scanwell Time Alignment Probe for performing the timing calibration for the LBNL Prostate-Specific PET Camera. We calibrate the time delay correction factors for each detector module in the camera using two methods--using the Time Alignment Probe (which measures the time difference between the probe and each detector module) and using the conventional method (which measures the timing difference between all module-module combinations in the camera). These correction factors, which are quantized in 2 ns steps, are compared on a module-by-module basis. The values are in excellent agreement--of the 80 correction factors, 62 agree exactly, 17 differ by 1 step, and 1 differs by 2 steps. We also measure on-time and off-time counting rates when the two sets of calibration factors are loaded into the camera and find that they agree within statistical error. We conclude that the performance using the Time Alignment Probe and conventional methods are equivalent.

Moses, William W.; Thompson, Christopher J.

2006-05-05

334

On the absolute calibration of SO2 cameras  

NASA Astrophysics Data System (ADS)

Sulphur dioxide emission rate measurements are an important tool for volcanic monitoring and eruption risk assessment. The SO2 camera technique remotely measures volcanic emissions by analysing the ultraviolet absorption of SO2 in a narrow spectral window between 300 and 320 nm using solar radiation scattered in the atmosphere. The SO2 absorption is selectively detected by mounting band-pass interference filters in front of a two-dimensional, UV-sensitive CCD detector. One important step for correct SO2 emission rate measurements that can be compared with other measurement techniques is a correct calibration. This requires conversion from the measured optical density to the desired SO2 column density (CD). The conversion factor is most commonly determined by inserting quartz cells (cuvettes) with known amounts of SO2 into the light path. Another calibration method uses an additional narrow field-of-view Differential Optical Absorption Spectroscopy system (NFOV-DOAS), which measures the column density simultaneously in a small area of the camera's field-of-view. This procedure combines the very good spatial and temporal resolution of the SO2 camera technique with the more accurate column densities obtainable from DOAS measurements. This work investigates the uncertainty of results gained through the two commonly used, but quite different, calibration methods (DOAS and calibration cells). Measurements with three different instruments, an SO2 camera, a NFOV-DOAS system and an Imaging DOAS (I-DOAS), are presented. We compare the calibration-cell approach with the calibration from the NFOV-DOAS system. The respective results are compared with measurements from an I-DOAS to verify the calibration curve over the spatial extent of the image. The results show that calibration cells, while working fine in some cases, can lead to an overestimation of the SO2 CD by up to 60% compared with CDs from the DOAS measurements. Besides these errors of calibration, radiative transfer effects (e.g. light dilution, multiple scattering) can significantly influence the results of both instrument types. The measurements presented in this work were taken at Popocatépetl, Mexico, between 1 March 2011 and 4 March 2011. Average SO2 emission rates between 4.00 and 14.34 kg s-1 were observed.

Lübcke, P.; Bobrowski, N.; Illing, S.; Kern, C.; Alvarez Nieves, J. M.; Vogel, L.; Zielcke, J.; Delgado Granados, H.; Platt, U.

2013-03-01

335

A Calibration Algorithm for Solar Tracking System  

Microsoft Academic Search

Solar tracking systems that use cameras, lenses and mechanical motion stages usually calibrate each device independently. While this scheme allows modular systems characterization it has the disadvantage of using additional expensive calibration patterns. In this work, we present a low cost solar tracking platform integrating on the shelf components. To avoid the use of additional components for system calibration we

Miguel Romero; Rafael Lemuz; Irene O. Ayaquica-Martinez; Griselda Saldana-Gonz´lez

2011-01-01

336

SWAT: Model use, calibration, and validation  

Technology Transfer Automated Retrieval System (TEKTRAN)

SWAT (Soil and Water Assessment Tool) is a comprehensive, semi-distributed river basin model that requires a large number of input parameters which complicates model parameterization and calibration. Several calibration techniques have been developed for SWAT including manual calibration procedures...

337

Self-Calibration of Stationary Cameras  

Microsoft Academic Search

A new practical method is given for the self-calibration of a camera. In this method, at least three images are taken from the same point in space with different orientations of the camera and calibration is computed from an analysis of point matches between the images. The method requires no knowledge of the orientations of the camera. Calibration is based

Richard I. Hartley

1997-01-01

338

A practical method for sensor absolute calibration.  

PubMed

This paper describes a method of performing sensor calibrations using an NBS standard of spectral irradiance. The method shown, among others, was used for calibration of the Mariner IV Canopus sensor. Agreement of inflight response to preflight calibrations performed by this technique has been found to be well within 10%. PMID:20048890

Meisenholder, G W

1966-04-01

339

Camera Self-Calibration: Theory and Experiments  

Microsoft Academic Search

The problem of finding the internal orientation of a camera (camera calibration) is extremely important for practical applications. In this paper a complete method for calibrating a camera is presented. In contrast with existing methods it does not require a calibration object with a known 3D shape. The new method requires only point matches from image sequences. It is shown,

Olivier D. Faugeras; Quang-tuan Luong; Stephen J. Maybank

1992-01-01

340

MODIS On-orbit Calibration Uncertainty Assessment  

NASA Technical Reports Server (NTRS)

MODIS has 20 reflective solar bands (RSB) and 16 thermal emissive bands (TEB). Compared to its heritage sensors, MODIS was developed with very stringent calibration uncertainty requirements. As a result, MODIS was designed and built with a set of on-board calibrators (OBC), which allow key sensor performance parameters and on-orbit calibration coefficients to be monitored and updated. In terms of its calibration traceability, MODIS RSB calibration is reflectance based using an on-board solar diffuser (SD) and the TEB calibration is radiance based using an on-board blackbody (BB). In addition to on-orbit calibration coefficients derived from its OBC, calibration parameters determined from sensor pre-launch calibration and characterization are used in both the RSB and TEB calibration and retrieval algorithms. This paper provides a brief description of MODIS calibration methodologies and an in-depth analysis of its on-orbit calibration uncertainties. Also discussed in this paper are uncertainty contributions from individual components and differences due to Terra and Aqua MODIS instrument characteristics and on-orbit performance.

Chiang, Vincent; Sun, Junqiang; Wu, Aisheng

2011-01-01

341

MODIS Radiometric Calibration and Uncertainty Assessment  

NASA Technical Reports Server (NTRS)

Since launch, Terra and Aqua MODIS have collected more than II and 9 years of datasets for comprehensive studies of the Earth's land, ocean, and atmospheric properties. MODIS observations are made in 36 spectral bands: 20 reflective solar bands (RSB) and 16 thermal emissive bands (TEB). Compared to its heritage sensors, MODIS was developed with very stringent calibration and uncertainty requirements. As a result, MODIS was designed and built with a set of state of the art on-board calibrators (OBC), which allow key sensor performance parameters and on-orbit calibration coefficients to be monitored and updated if necessary. In terms of its calibration traceability, MODIS RSB calibration is reflectance based using an on-board solar diffuser (SD) and the TEB calibration is radiance based using an on-board blackbody (BB). In addition to on-orbit calibration coefficients derived from its OBC, calibration parameters determined from sensor pre-launch calibration and characterization are used in both the RSB and TEB calibration and retrieval algorithms. This paper provides a brief description of MODIS calibration methodologies and discusses details of its on-orbit calibration uncertainties. It assesses uncertainty contributions from individual components and differences between Terra and Aqua MODIS due to their design characteristics and on-orbit periormance. Also discussed in this paper is the use of MODIS LIB uncertainty index CUI) product.

Xiong, Xiaoxiong; Chiang, Vincent; Sun, Junqiang; Wu, Aisheng

2011-01-01

342

Standard Leak Calibration Facility software system  

SciTech Connect

A Standard Leak Calibration Facility Software System has been developed and implemented for controlling, and running a standard Leak Calibration Facility. Primary capabilities provided by the software system include computer control of the vacuum system, automatic leak calibration, and data acquisition, manipulation, and storage.

McClain, S.K.

1989-06-01

343

Sandia\\/NIST reference cell calibration procedure  

Microsoft Academic Search

The Photovoltaic Device Measurement Laboratory (PDML) at Sandia in collaboration with the National Institute of Standards and Technology (NIST) has developed an indoor calibration procedure that improves the accuracy and reduces the time and cost of calibrating photovoltaic reference cells. The calibration procedure involves exposing the reference cell to an accurately known spectral irradiance provided by a 1000 W quartz-tungsten-halogen

David L. King; Bany R Hansen; John K. Jackson

1993-01-01

344

Spinning angle optical calibration apparatus  

DOEpatents

An optical calibration apparatus is provided for calibrating and reproducing spinning angles in cross-polarization, nuclear magnetic resonance spectroscopy. An illuminated magnifying apparatus enables optical setting an accurate reproducing of spinning "magic angles" in cross-polarization, nuclear magnetic resonance spectroscopy experiments. A reference mark scribed on an edge of a spinning angle test sample holder is illuminated by a light source and viewed through a magnifying scope. When the "magic angle" of a sample material used as a standard is attained by varying the angular position of the sample holder, the coordinate position of the reference mark relative to a graduation or graduations on a reticle in the magnifying scope is noted. Thereafter, the spinning "magic angle" of a test material having similar nuclear properties to the standard is attained by returning the sample holder back to the originally noted coordinate position.

Beer, Stephen K. (Morgantown, WV); Pratt, II, Harold R. (Morgantown, WV)

1991-01-01

345

Protocols for calibrating multibeam sonar  

Microsoft Academic Search

The use of multibeam sonar for quantifying scatterers in the water column requires calibration. Principal elements of this include measurement of the directional characteristics of the transducer array or arrays, the determination of dynamic range, the definition of the system sensitivity, and the verification of linearity and time-varied-gain functions. Protocols developed or proposed in the course of a three-year project

Kenneth G. Foote; Dezhang Chu; Kenneth C. Baldwin; Larry A. Mayer; Andrew McLeod; Lawrence C. Hufnagle; J. Michael Jech; William Michaels

2003-01-01

346

Protocols for calibrating multibeam sonar  

NASA Astrophysics Data System (ADS)

The use of multibeam sonar for quantifying scatterers in the water column requires calibration. Principal elements of this include measurement of the directional characteristics of the transducer array or arrays, the determination of dynamic range, the definition of the system sensitivity, and the verification of linearity and time-varied-gain functions. Protocols developed or proposed in the course of a three-year project are reviewed. [Work supported by NSF Grant No. OCE-0002664.

Foote, Kenneth G.; Chu, Dezhang; Baldwin, Kenneth C.; Mayer, Larry A.; McLeod, Andrew; Hufnagle, Lawrence C.; Jech, J. Michael; Michaels, William

2003-10-01

347

Automated Camera Array Fine Calibration  

NASA Technical Reports Server (NTRS)

Using aerial imagery, the JPL FineCalibration (JPL FineCal) software automatically tunes a set of existing CAHVOR camera models for an array of cameras. The software finds matching features in the overlap region between images from adjacent cameras, and uses these features to refine the camera models. It is not necessary to take special imagery of a known target and no surveying is required. JPL FineCal was developed for use with an aerial, persistent surveillance platform.

Clouse, Daniel; Padgett, Curtis; Ansar, Adnan; Cheng, Yang

2008-01-01

348

PACS photometer calibration block analysis  

NASA Astrophysics Data System (ADS)

The absolute stability of the PACS bolometer response over the entire mission lifetime without applying any corrections is about 0.5 % (standard deviation) or about 8 % peak-to-peak. This fantastic stability allows us to calibrate all scientific measurements by a fixed and time-independent response file, without using any information from the PACS internal calibration sources. However, the analysis of calibration block observations revealed clear correlations of the internal source signals with the evaporator temperature and a signal drift during the first half hour after the cooler recycling. These effects are small, but can be seen in repeated measurements of standard stars. From our analysis we established corrections for both effects which push the stability of the PACS bolometer response to about 0.2 % (stdev) or 2 % in the blue, 3 % in the green and 5 % in the red channel (peak-to-peak). After both corrections we still see a correlation of the signals with PACS FPU temperatures, possibly caused by parasitic heat influences via the Kevlar wires which connect the bolometers with the PACS Focal Plane Unit. No aging effect or degradation of the photometric system during the mission lifetime has been found.

Moór, A.; Müller, T. G.; Kiss, C.; Balog, Z.; Billot, N.; Marton, G.

2014-07-01

349

PACS photometer calibration block analysis  

E-print Network

The absolute stability of the PACS bolometer response over the entire mission lifetime without applying any corrections is about 0.5% (standard deviation) or about 8% peak-to-peak. This fantastic stability allows us to calibrate all scientific measurements by a fixed and time-independent response file, without using any information from the PACS internal calibration sources. However, the analysis of calibration block observations revealed clear correlations of the internal source signals with the evaporator temperature and a signal drift during the first half hour after the cooler recycling. These effects are small, but can be seen in repeated measurements of standard stars. From our analysis we established corrections for both effects which push the stability of the PACS bolometer response to about 0.2% (stdev) or 2% in the blue, 3% in the green and 5% in the red channel (peak-to-peak). After both corrections we still see a correlation of the signals with PACS FPU temperatures, possibly caused by parasitic h...

Moór, A; Kiss, Cs; Balog, Z; Billot, N; Marton, G

2013-01-01

350

Updated Calibration and Backgrounds for the WFC3 IR Grisms  

NASA Astrophysics Data System (ADS)

We present new and improved calibration of the WFC IR (G102 and G141) grism mode. These new calibrations were generated by combining data obtained over six observing cycles and include a better sampling of the field of view. The result is a calibration of the spectral trace that has been improved to better than 0.1 detector pixel. A new fiducial wavelength reference spectrum is now used to calibrate the wavelength dispersion of the grisms and we show that the rms of the solution has been reduced to approximately 7 and 14 Angstrom for the G102 and G141 grisms, over the entire field of view. Overall, both the trace and wavelength calibration have been improved by about a factor of two and the G102 and G141 solutions are in better agreement at wavelengths where the two grisms overlap. We demonstrate that the grism calibration can be extrapolated for objects that are outside of the field of view but still result in dispersed spectra on the WFC3 detector.We also present new master sky images that can be used to improve the sky background subtraction from grism exposures. The individual components of the new background model include the zodiacal continuum and a strong He I emission line at 1.083 microns from the upper atmosphere. We find that fitting science exposures with a linear combination of these two background components enables modeling of the WFC3/IR grism background with an accuracy that is better than ~0.01 electrons/s/pix across the detector.

Pirzkal, Norbert; Brammer, Gabriel; Ryan, Russell E.

2015-01-01

351

40 CFR 89.306 - Dynamometer specifications and calibration weights.  

Code of Federal Regulations, 2010 CFR

...Dynamometer specifications and calibration weights. 89.306 Section 89.306 Protection...Dynamometer specifications and calibration weights. (a) Dynamometer specifications...410. (b) Dynamometer calibration weights. A minimum of six calibration...

2010-07-01

352

40 CFR 89.306 - Dynamometer specifications and calibration weights.  

Code of Federal Regulations, 2011 CFR

...Dynamometer specifications and calibration weights. 89.306 Section 89.306 Protection...Dynamometer specifications and calibration weights. (a) Dynamometer specifications...410. (b) Dynamometer calibration weights. A minimum of six calibration...

2011-07-01

353

Genetic Algorithm Calibration of Probabilistic Cellular Automata for Modeling Mining Permit Activity  

USGS Publications Warehouse

We use a genetic algorithm to calibrate a spatially and temporally resolved cellular automata to model mining activity on public land in Idaho and western Montana. The genetic algorithm searches through a space of transition rule parameters of a two dimensional cellular automata model to find rule parameters that fit observed mining activity data. Previous work by one of the authors in calibrating the cellular automaton took weeks - the genetic algorithm takes a day and produces rules leading to about the same (or better) fit to observed data. These preliminary results indicate that genetic algorithms are a viable tool in calibrating cellular automata for this application. Experience gained during the calibration of this cellular automata suggests that mineral resource information is a critical factor in the quality of the results. With automated calibration, further refinements of how the mineral-resource information is provided to the cellular automaton will probably improve our model.

Louis, S.J.; Raines, G.L.

2003-01-01

354

Drift-insensitive distributed calibration of probe microscope scanner in nanometer range: Real mode  

E-print Network

A method is described intended for distributed calibration of a probe microscope scanner consisting in a search for a net of local calibration coefficients (LCCs) in the process of automatic measurement of a standard surface, whereby each point of the movement space of the scanner can be defined by a unique set of scale factors. Feature-oriented scanning (FOS) methodology is used to implement the distributed calibration, which permits to exclude in situ the negative influence of thermal drift, creep and hysteresis on the obtained results. The sensitivity of LCCs to errors in determination of position coordinates of surface features forming the local calibration structure (LCS) is eliminated by performing multiple repeated measurements followed by building regression surfaces. There are no principle restrictions on the number of repeated LCS measurements. Possessing the calibration database enables correcting in one procedure all the spatial distortions caused by nonlinearity, nonorthogonality and spurious cro...

Lapshin, Rostislav V

2015-01-01

355

Drift-insensitive distributed calibration of probe microscope scanner in nanometer range: Approach description  

E-print Network

A method is described intended for distributed calibration of a probe microscope scanner consisting in a search for a net of local calibration coefficients (LCCs) in the process of automatic measurement of a standard surface, whereby each point of the movement space of the scanner can be defined by a unique set of scale factors. Feature-oriented scanning (FOS) methodology is used to implement the distributed calibration, which permits to exclude in situ the negative influence of thermal drift, creep and hysteresis on the obtained results. The sensitivity of LCCs to errors in determination of position coordinates of surface features forming the local calibration structure (LCS) is eliminated by performing multiple repeated measurements followed by building regression surfaces. There are no principle restrictions on the number of repeated LCS measurements. Possessing the calibration database enables correcting in one procedure all the spatial distortions caused by nonlinearity, nonorthogonality and spurious cro...

Lapshin, Rostislav V

2015-01-01

356

Calibration of Pressure Sensor Array Based on Information Fusion  

Microsoft Academic Search

\\u000a It is existence of cross-sensitivity factors such as the temperature, humidity and power fluctuations in pressure sensor array.\\u000a To solve this problem, it is proposed an information fusion based on the pressure sensor array calibration algorithm. By this\\u000a method can effectively eliminate the environmental temperature and voltage disturbances and other non-target parameters, and\\u000a crosstalk between large-scale sensor array signal output

Bing Guo; Xiaohong Zeng

357

Muon Energy Calibration of the MINOS Detectors  

SciTech Connect

MINOS is a long-baseline neutrino oscillation experiment designed to search for conclusive evidence of neutrino oscillations and to measure the oscillation parameters precisely. MINOS comprises two iron tracking calorimeters located at Fermilab and Soudan. The Calibration Detector at CERN is a third MINOS detector used as part of the detector response calibration programme. A correct energy calibration between these detectors is crucial for the accurate measurement of oscillation parameters. This thesis presents a calibration developed to produce a uniform response within a detector using cosmic muons. Reconstruction of tracks in cosmic ray data is discussed. This data is utilized to calculate calibration constants for each readout channel of the Calibration Detector. These constants have an average statistical error of 1.8%. The consistency of the constants is demonstrated both within a single run and between runs separated by a few days. Results are presented from applying the calibration to test beam particles measured by the Calibration Detector. The responses are calibrated to within 1.8% systematic error. The potential impact of the calibration on the measurement of oscillation parameters by MINOS is also investigated. Applying the calibration reduces the errors in the measured parameters by {approx} 10%, which is equivalent to increasing the amount of data by 20%.

Miyagawa, Paul S.; /Oxford U.

2004-09-01

358

Size of spectroscopic calibration samples for cosmic shear photometric redshifts  

E-print Network

Weak gravitational lensing surveys using photometric redshifts can have their cosmological constraints severely degraded by errors in the photo-z scale. We explore the cosmological degradation vs the size of the spectroscopic survey required to calibrate the photo-z probability distribution. Previous work has assumed a simple Gaussian distribution of photo-z errors; here we describe a method for constraining an arbitrary parametric photo-z error model. As an example we allow the photo-z probability distribution to be the sum of $N_g$ Gaussians. To limit cosmological degradation to a fixed level, photo-z models with multiple Gaussians require up to 5 times larger calibration sample than one would estimate from assuming a single-Gaussian model. This degradation saturates at $N_g\\approx 4$. Assuming a single Gaussian when the photo-z distribution has multiple parameters underestimates cosmological parameter uncertainties by up to 35%. The size of required calibration sample also depends upon the shape of the fiducial distribution, even when the RMS photo-z error is held fixed. The required calibration sample size varies up to a factor of 40 among the fiducial models studied, but this is reduced to a factor of a few if the photo-z parameters are forced to be slowly varying with redshift. Finally we show that the size of the required calibration sample can be substantially reduced by optimizing its redshift distribution. We hope this study will help stimulate work on better understanding of photo-z errors.

Zhaoming Ma; Gary Bernstein

2008-09-07

359

Multi-Axis Accelerometer Calibration System  

NASA Technical Reports Server (NTRS)

A low-cost, portable, and simplified system has been developed that is suitable for in-situ calibration and/or evaluation of multi-axis inertial measurement instruments. This system overcomes facility restrictions and maintains or improves the calibration quality for users of accelerometer-based instruments with applications in avionics, experimental wind tunnel research, and force balance calibration applications. The apparatus quickly and easily positions a multi-axis accelerometer system into a precisely known orientation suitable for in-situ quality checks and calibration. In addition, the system incorporates powerful and sophisticated statistical methods, known as response surface methodology and statistical quality control. These methods improve calibration quality, reduce calibration time, and allow for increased calibration frequency, which enables the monitoring of instrument stability over time.

Finley, Tom; Parker, Peter

2010-01-01

360

Camera calibration in photogrammetric practice, introduction  

NASA Astrophysics Data System (ADS)

Laboratory, stellar and ground calibrations are developed to assess accuracy and reliability of photographic systems and their components. Calibration of photographic systems is based on analytic assessment systems and software and calibration of aerial images in close-range photogrammetry. Algorithms to obtain simultaneous calibration of photographic systems and aerial images are developed. System reproduction, film printing plate flatness, filter glass plane parallelism, and definition of image plane or image coordinate system are calibrated in laboratory with a visual procedure using goniometers, theodolites and lens/mirror systems. Stellar calibration with or without filters is influenced by emulsion sensitivity. Ground calibration is based on image measurement and geodetic observations. Economical application of the different procedures is assessed.

Kupfer, G.

361

New calibration method for position detector for simultaneous measurements of force constants and local viscosity in optical tweezers  

NASA Astrophysics Data System (ADS)

We present a new method to calibrate a quadrant photodiode used as position detector to monitor latex beads trapped in optical tweezers. The method combines the dragging Stoke's force with the thermal noise analysis (power spectral density (PSD)) of the Brownian motion of the trapped bead. Position detector calibrations used in other similar methods normally utilise a bead attached to the coverslip: the voltage-position calibration factor is found by translating the bead across the waist of a laser beam. The so determined calibration factor is then assumed to be the same when beads are investigated in the optical trap. This procedure presents some drawbacks since attached beads can be affected by proximity effects due to the coverslip glass surface which alter the position sensor response itself. On the contrary, our method is able to provide, simultaneously, the calibration factor, the trap stiffness, and the local viscosity of the medium making use of a single trapped bead.

Buosciolo, A.; Pesce, G.; Sasso, A.

2004-02-01

362

Gemini Planet Imager Observational Calibrations II: Detector Performance and Calibration  

E-print Network

The Gemini Planet Imager is a newly commissioned facility instrument designed to measure the near-infrared spectra of young extrasolar planets in the solar neighborhood and obtain imaging polarimetry of circumstellar disks. GPI's science instrument is an integral field spectrograph that utilizes a HAWAII-2RG detector with a SIDECAR ASIC readout system. This paper describes the detector characterization and calibrations performed by the GPI Data Reduction Pipeline to compensate for effects including bad/hot/cold pixels, persistence, non-linearity, vibration induced microphonics and correlated read noise.

Ingraham, Patrick; Sadakuni, Naru; Ruffio, Jean-Baptiste; Maire, Jerome; Chilcote, Jeff; Larkin, James; Marchis, Franck; Galicher, Raphael; Weiss, Jason

2014-01-01

363

Acoustic calibration apparatus for calibrating plethysmographic acoustic pressure sensors  

NASA Technical Reports Server (NTRS)

An apparatus for calibrating an acoustic sensor is described. The apparatus includes a transmission material having an acoustic impedance approximately matching the acoustic impedance of the actual acoustic medium existing when the acoustic sensor is applied in actual in-service conditions. An elastic container holds the transmission material. A first sensor is coupled to the container at a first location on the container and a second sensor coupled to the container at a second location on the container, the second location being different from the first location. A sound producing device is coupled to the container and transmits acoustic signals inside the container.

Zuckerwar, Allan J. (inventor); Davis, David C. (inventor)

1995-01-01

364

Providing radiometric traceability for the calibration home base of DLR by PTB  

SciTech Connect

A dedicated calibration technique was applied for the calibration of the spectral radiance transfer standard (RASTA) of the German Aerospace Center (DLR) at the Physikalisch-Technische Bundesanstalt (PTB), consisting of two independent but complementing calibration procedures to provide redundancy and smallest possible calibration uncertainties. Procedure I included two calibration steps: In a first step the optical radiation source of RASTA, an FEL lamp, was calibrated in terms of its spectral irradiance E{sub {lambda}}({lambda}) in the wavelength range from 350 nm to 2400 nm using the PTB Spectral Irradiance Calibration Equipment (SPICE), while in a second step the spectral radiance factor {beta}{sub 0 Degree-Sign :45 Degree-Sign }({lambda}) of the RASTA reflection standard was calibrated in a 0 Degree-Sign :45 Degree-Sign -viewing geometry in the wavelength range from 350 nm to 1700 nm at the robot-based gonioreflectometer facility of PTB. The achieved relative standard uncertainties (k= 1) range from 0.6 % to 3.2 % and 0.1 % to 0.6 % respectively. Procedure II was completely independent from procedure I and allowed to cover the entire spectral range of RASTA from 350 nm to 2500 nm. In the second procedure, the 0 Degree-Sign :45 Degree-Sign -viewing geometry spectral radiance L{sub {lambda},0 Degree-Sign :45 Degree-Sign }({lambda}) of RASTA was directly calibrated at the Spectral Radiance Comparator Facility (SRCF) of PTB. The relative uncertainties for this calibration procedure range from 0.8 % in the visible up to 7.5 % at 2500 nm (k= 1). In the overlapping spectral range of both calibration procedures the calculated spectral radiance L{sub {lambda},0 Degree-Sign :45 Degree-Sign ,calc}({lambda}) from procedure I is in good agreement with the direct measurement of procedure II, i.e. well within the combined expanded uncertainties (k= 2) of both procedures.

Taubert, D. R.; Hollandt, J.; Sperfeld, P.; Pape, S.; Hoepe, A.; Hauer, K.-O. [Physikalisch-Technische Bundesanstalt, Braunschweig und Berlin, 10587 Berlin (Germany); Gege, P.; Schwarzmaier, T.; Lenhard, K.; Baumgartner, A. [Deutsches Zentrum fuer Luft- und Raumfahrt, Institut fuer Methodik der Fernerkundung, 82234 Oberpfaffenhofen (Germany)

2013-05-10

365

Real-Time Attitude Independent Three Axis Magnetometer Calibration  

NASA Technical Reports Server (NTRS)

In this paper new real-time approaches for three-axis magnetometer sensor calibration are derived. These approaches rely on a conversion of the magnetometer-body and geomagnetic-reference vectors into an attitude independent observation by using scalar checking. The goal of the full calibration problem involves the determination of the magnetometer bias vector, scale factors and non-orthogonality corrections. Although the actual solution to this full calibration problem involves the minimization of a quartic loss function, the problem can be converted into a quadratic loss function by a centering approximation. This leads to a simple batch linear least squares solution. In this paper we develop alternative real-time algorithms based on both the extended Kalman filter and Unscented filter. With these real-time algorithms, a full magnetometer calibration can now be performed on-orbit during typical spacecraft mission-mode operations. Simulation results indicate that both algorithms provide accurate integer resolution in real time, but the Unscented filter is more robust to large initial condition errors than the extended Kalman filter. The algorithms are also tested using actual data from the Transition Region and Coronal Explorer (TRACE).

Crassidis, John L.; Lai, Kok-Lam; Harman, Richard R.

2003-01-01

366

Advanced REACH Tool (ART): calibration of the mechanistic model.  

PubMed

The mechanistic model of the Advanced Reach Tool (ART) provides a relative ranking of exposure levels from different scenarios. The objectives of the calibration described in this paper are threefold: to study whether the mechanistic model scores are accurately ranked in relation to exposure measurements; to enable the mechanistic model to estimate actual exposure levels rather than relative scores; and to provide a method of quantifying model uncertainty. Stringent data quality guidelines were applied to the collated data. Linear mixed effects models were used to evaluate the association between relative ART model scores and measurements. A random scenario and company component of variance were introduced to reflect the model uncertainty. Stratified analyses were conducted for different forms of exposure (abrasive dust, dust, vapours and mists). In total more than 2000 good quality measurements were available for the calibration of the mechanistic model. The calibration showed that after calibration the mechanistic model of ART was able to estimate geometric mean (GM) exposure levels with 90% confidence for a given scenario to lie within a factor between two and six of the measured GM depending upon the form of exposure. PMID:21403945

Schinkel, Jody; Warren, Nicholas; Fransman, Wouter; van Tongeren, Martie; McDonnell, Patricia; Voogd, Eef; Cherrie, John W; Tischer, Martin; Kromhout, Hans; Tielemans, Erik

2011-05-01

367

Numerical Analysis of a Radiant Heat Flux Calibration System  

NASA Technical Reports Server (NTRS)

A radiant heat flux gage calibration system exists in the Flight Loads Laboratory at NASA's Dryden Flight Research Center. This calibration system must be well understood if the heat flux gages calibrated in it are to provide useful data during radiant heating ground tests or flight tests of high speed aerospace vehicles. A part of the calibration system characterization process is to develop a numerical model of the flat plate heater element and heat flux gage, which will help identify errors due to convection, heater element erosion, and other factors. A 2-dimensional mathematical model of the gage-plate system has been developed to simulate the combined problem involving convection, radiation and mass loss by chemical reaction. A fourth order finite difference scheme is used to solve the steady state governing equations and determine the temperature distribution in the gage and plate, incident heat flux on the gage face, and flat plate erosion. Initial gage heat flux predictions from the model are found to be within 17% of experimental results.

Jiang, Shanjuan; Horn, Thomas J.; Dhir, V. K.

1998-01-01

368

Automatic calibration of the inlet pressure sensor for the implantable continuous-flow ventricular assist device.  

PubMed

Significant progress in the development of implantable ventricular assist devices using continuous-flow blood pumps has been made recently. However, a control method has not been established. The blood pressure in the inflow cannula (inlet pressure) is one of the candidates for performing an adequate control. This could also provide important information about ventricle sucking. However, no calibration method for an inlet pressure sensor exists. In this study, an automatic calibration algorithm of the inlet pressure sensor from the pressure waveform at the condition of ventricle sucking was proposed. The calibration algorithm was constructed based on the consideration that intrathoracic pressure could be substituted for atmospheric pressure because the lung is open to air. We assumed that the inlet pressure at the releasing point of the sucking would represent the intrathoracic pressure, because the atrial pressure would be low owing to the sucking condition. A special mock circulation system that can reproduce ventricle sucking was developed to validate the calibration algorithm. The calibration algorithm worked well with a maximum SD of 2.1 mmHg for 3-min measurement in the mock circulation system. While the deviation was slightly large for an elaborate calibration, it would still be useful as a primitive calibration. The influence of the respiratory change and other factors as well as the reliability of the calibration value should be investigated with an animal experiment as a next step. PMID:21373781

Shi, Wei; Saito, Itsuro; Isoyama, Takashi; Nakagawa, Hidemoto; Inoue, Yusuke; Ono, Toshiya; Kouno, Akimasa; Imachi, Kou; Abe, Yusuke

2011-06-01

369

Dry calibration of electromagnetic flowmeters based on numerical models combining multiple physical phenomena (multiphysics)  

SciTech Connect

This paper presents a method for dry calibration of an electromagnetic flowmeter (EMF). This method, which determines the voltage induced in the EMF as conductive liquid flows through a magnetic field, numerically solves a coupled set of multiphysical equations with measured boundary conditions for the magnetic, electric, and flow fields in the measuring pipe of the flowmeter. Specifically, this paper details the formulation of dry calibration and an efficient algorithm (that adaptively minimizes the number of measurements and requires only the normal component of the magnetic flux density as boundary conditions on the pipe surface to reconstruct the magnetic field involved) for computing the sensitivity of EMF. Along with an in-depth discussion on factors that could significantly affect the final precision of a dry calibrated EMF, the effects of flow disturbance on measuring errors have been experimentally studied by installing a baffle at the inflow port of the EMF. Results of the dry calibration on an actual EMF were compared against flow-rig calibration; excellent agreements (within 0.3%) between dry calibration and flow-rig tests verify the multiphysical computation of the fields and the robustness of the method. As requiring no actual flow, the dry calibration is particularly useful for calibrating large-diameter EMFs where conventional flow-rig methods are often costly and difficult to implement.

Fu, X.; Hu, L.; Zou, J.; Ruan, X. D.; Yang, H. Y. [State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University, Hangzhou 310027 (China); Lee, K. M. [Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States)

2010-10-15

370

Calibration Report for the WRAP Facility Gamma Energy Analysis System (104-ND-06-102A)  

SciTech Connect

The Waste Receiving And Processing facility (WRAP) adheres to providing gamma-ray spectroscopy instrument calibrations traceable to the National Institute for Standards and Technology (NIST) standard{sup (4)}. The detectors are used to produce quantitative results for the Waste Isolation Pilot Plant (WIPP) and must meet calibration programmatic calibration goals. Instruments must meet portions of ANSI N42.14, 1978 guide for Germanium detectors. The Non-Destructive Assay (NDA) Gamma Energy Analysis (GEA) utilizes NIST traceable line source standards for the detector system calibrations. The counting configuration is a series of drums containing the line sources and different density filler matrices. The drums are used to develop system efficiencies with respect to density. The efficiency and density correction factors are required for the processing of drummed waste materials of similar densities. The calibration verification is carried out after the calibration is deemed final, by counting a second drum of NIST traceable sources. Three in-depth calibrations have been completed on one of the two systems to date, the first being the system acceptance plan. This report has a secondary function; that being the development of the instrument calibration errors which are to be folded into the Total Instrument Uncertainty document, HNF-4050.

WILLS, C.E.

2000-03-13

371

Calibrated parametric medical ultrasound imaging.  

PubMed

The goal of this study was to develop a calibrated on-line technique to extract as much diagnostically-relevant information as possible from conventional video-format echograms. The final aim is to improve the diagnostic potentials of medical ultrasound. Video-output images were acquired by a frame grabber board incorporated in a multiprocessor workstation. Calibration images were obtained from a stable tissue-mimicking phantom with known acoustic characteristics. Using these images as reference, depth dependence of the gray level could fairly be corrected for the transducer performance characteristics, for the observer-dependent equipment settings and for attenuation in the examined tissues. Second-order statistical parameters still displayed some nonconsistent depth dependencies. The results obtained with two echoscanners for the same phantom were different; hence, an a posteriori normalization of clinical data with the phantom data is indicated. Prior to processing of clinical echograms,. the anatomical reflections and echoless voids were removed automatically. The final step in the preprocessing concerned the compensation of the overall attenuation in the tissue. A 'sliding window' processing was then applied to a region of interest (ROI) in the 'back-scan converted' images. A number of first and second order statistical texture parameters and acoustical parameters were estimated in each window and assigned to the central pixel. This procedure results in a set of new 'parametric' images of the ROI, which can be inserted in the original echogram (gray value, color) or presented as a color overlay. A clinical example is presented for illustrating the potentials of the developed technique. Depending on the choice of the parameters, four full resolution calibrated parametric images can be calculated and simultaneously displayed within 5 to 20 seconds. In conclusion, an on-line technique has been developed to estimate acoustic and texture parameters with a reduced equipment dependence and to display acoustical and textural information that is present in conventional echograms. PMID:10823497

Valckx, F M; Thijsse, J M; van Geemen, A J; Rotteveel, J J; Mullaart, R

2000-01-01

372

Proton beam monitor chamber calibration.  

PubMed

The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences-of the order of 3%-were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth-i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers-rather than cylindrical chambers-for the reference dosimetry of pseudo-monoenergetic proton beams. PMID:25109620

Gomà, C; Lorentini, S; Meer, D; Safai, S

2014-09-01

373

Proton beam monitor chamber calibration  

NASA Astrophysics Data System (ADS)

The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences—of the order of 3%—were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth—i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers—rather than cylindrical chambers—for the reference dosimetry of pseudo-monoenergetic proton beams.

Gomà, C.; Lorentini, S.; Meer, D.; Safai, S.

2014-09-01

374

Designing an in-flight airborne calibration site using experience from vicarious radiometric satellite calibration  

NASA Astrophysics Data System (ADS)

Laboratory calibration of electro-optical sensors is preferably complemented by regular in-flight verification. This checks whether the lab calibration parameters remain valid or recalibration is necessary. In-flight verification can be achieved by vicarious calibration using in-flight measurements of calibration targets. We intend to identify and design a set of suitable radiometric calibration targets. For this, we borrow from expertise gained with the PROBA-V satellite calibration system, which uses multiple vicarious methods relying on diverse natural on-ground targets. Besides reflectance based calibration using ground measurements, the PROBA-V calibration methods are unproven for use in airborne calibration. The selected targets should be suitable for the calibration of both multispectral and hyperspectral imagers. We start from general requirements for radiometric targets and investigate their applicability to airborne calibration. From this we identify two possible sets of natural calibration sites in Belgium. One set, located in the Campine region, contains small water bodies and sandy lakesides. Another set is located in the Westhoek region near the Belgian coast. It offers better suitable water bodies, as well as sandy areas, grass fields and dark targets. Airborne calibration lends itself to the use of smaller artifical targets. We propose to complement the natural targets with a portable target consisting of agricultural nets with different densities. The definition of sets of calibration targets, both natural and artificial can facilitate the investigation of the usability of vicarious targets and method for inflight radiometric verification.

Livens, Stefan; Debruyn, Walter; Sterckx, Sindy; Reusen, Ils

2011-11-01

375

An SLF magnetic antenna calibration system  

NASA Astrophysics Data System (ADS)

Calibrating the super low frequency (SLF) magnetic antenna in magnetic free space or an outdoor environment is difficult and complicated due to the large size calibration instruments and lots of measurement times. Aiming to calibrate the SLF magnetic antenna simply and efficiently, a calibration system comprised of a multi-frequency source, an AC constant-current source and a solenoid is proposed according to the characteristic of an SLF magnetic antenna. The static magnetic transfer coefficient of the designed solenoid is calibrated. The measurement of the frequency response characteristics suggests the transfer coefficient remains unchanged in the range of the SLF band and is unaffected by the magnetic antenna internally installed. The CORDIC algorithm implemented in an FPGA is realized to generate a linear evenly-spaced multi-frequency signal with equal energy at each frequency. An AC constant weak current source circuit is designed in order to avoid the impact on the magnetic induction intensity of a calibration system affected by impedance variation when frequency changing, linearity and the precision of the source are measured. The frequency characteristic of a magnetic antenna calibrated by the proposed calibration system agrees with the theoretical result and the standard Glass ring calibration result. The calibration precision satisfies the experimental requirement.

Shimin, Feng; Suihua, Zhou; Zhiyi, Chen; Hongxin, Zhang

2014-05-01

376

NASA metrology and calibration, 1993  

NASA Technical Reports Server (NTRS)

Th sixteenth annual workshop of NASA's Metrology and Calibration Working Group was held April 20-22, 1993. The goals of the Working Group are to provide Agencywide standardization of individual metrology programs, where appropriate; to promote cooperation and exchange of information within NASA, with other Government agencies, and with industry; to serve as the primary Agency interface with the National Institute of Standards and Technology; and to encourage formal quality control techniques such as Measurement Assurance Programs. These proceedings contain unedited reports and presentations from the workshop and are provided for information only.

1993-01-01

377

The calibration of a scanning laser vibrometer by a digital FM demodulation technique  

NASA Astrophysics Data System (ADS)

This paper presents a method to calibrate a scanning laser vibrometer. A zero-crossing method is used to digitally demodulate the two Doppler signals to find out the digital velocity. A sine wave fitter is used to fit both the analog and digital velocity. The calibration factor is obtained by comparing the magnitude of the fitted analog and digital velocity. Simulation and experimental data shows that the presented method is effective and correct.

Zeng, Xian-Di; Dominguez, Jose L.; Wicks, Alfred L.

378

Calibration of the IMB Detector  

SciTech Connect

The IMB detector (named after its founding institutions: University of California, Irvine, the University of Michigan and Brookhaven National Laboratory) collected data on a wide range of phenomena for over eight years. It was the first and the largest of the ring imaging water Cherenkov detectors. The detector consisted of 8000 metric tons of ultra-pure water instrumented with 2048 photomultiplier tubes (PMTs). The PMTs were placed on the roof, floor, and walls of the detector in a lattice of approximately 1 m spacing. It made measurements of contained events that ranged in energy from 15 MeV up to 1.5 GeV. This paper describes the calibration of the IMB detector. This procedure was accurate and stable over a wide range of physical variables. It was used with little change throughout the entire eight-year lifetime of the experiment. The IMB calibration is a model for future large-scale detectors that employ the water Cherenkov technique.

Becker-Szendy, R.; Bionta, R.M.; Bratton, C.B.; Casper, D.; Claus, R.; Cortez, B.; Dye, S.T.; Errede, S.; Foster, G.W.; Gajewski, W.; Ganezer, K.; Goldhaber, M.; Haines, T.J.; Halverson, P.G.; Hazen, E.; Jones, T.W.; Kielczewska, D.; Kropp, W.R.; Learned, J.G.; Losecco, J.M.; Matsuno, S.; /UC, Irvine /Michigan U. /Brookhaven /Boston U. /Hawaii U. /University Coll. London /Warsaw U. /Cleveland State U. /Notre Dame U. /Louisiana State U. /Maryland U. /AT-T Bell Labs, Holmdel /Illinois U., Urbana /Fermilab /LLNL, Livermore /New Mexico U. /SLAC /Adelaide U. /CERN /Cal State, Dominguez Hills

2012-04-03

379

GOES-12 SXI Operational Calibration  

NASA Astrophysics Data System (ADS)

The prototype Solar X-ray Imager (SXI) was lofted into orbit aboard the NOAA GOES-12 spacecraft on 23 July 2001. The results of pre-launch ground-based optical tests have been combined with an extensive set of imagery taken during the post-launch checkout period from late August through mid December 2001 to establish an operational calibration for the full instrument performance. Although the nickel-coated mirror is a conventional Wolter-I grazing incidence optic, the detector consists of an MCP-enhanced CCD configuration not previously used for direct solar imaging. A full set of calibration data for each optical component (mirror, filters, detector) as well as for net system throughput have been derived and are available on the SXI website (http://sec.noaa.gov/sxi/ScienceUserGuide.html). In addition, a wide variety of information on instrument spatial resolution, point-spread function, dynamic range, photon statistics, and gain dependence (related to voltage settings for the MCP) have been derived. An improved background correction has been developed and applied to the recent release of the post-launch data now publicly available in FITS format. Special instrument topics including issues related to solar pointing and image timing aboard a geo-synchronous platform, CCD blooming properties, detector flat-field effects, and response to SEP events are also detailed.

Pizzo, V. J.; Hill, S. M.; Balch, C.

2002-12-01

380

GIFTS SM EDU Radiometric and Spectral Calibrations  

NASA Technical Reports Server (NTRS)

The Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) Sensor Module (SM) Engineering Demonstration Unit (EDU) is a high resolution spectral imager designed to measure infrared (IR) radiance using a Fourier transform spectrometer (FTS). The GIFTS instrument gathers measurements across the long-wave IR (LWIR), short/mid-wave IR (SMWIR), and visible spectral bands. The raw interferogram measurements are radiometrically and spectrally calibrated to produce radiance spectra, which are further processed to obtain atmospheric profiles via retrieval algorithms. This paper describes the processing algorithms involved in the calibration. The calibration procedures can be subdivided into three categories: the pre-calibration stage, the calibration stage, and finally, the post-calibration stage. Detailed derivations for each stage are presented in this paper.

Tian, J.; Reisse, R. a.; Johnson, D. G.; Gazarik, J. J.

2007-01-01

381

Calibration Monitor for Dark Energy Experiments  

SciTech Connect

The goal of this program was to design, build, test, and characterize a flight qualified calibration source and monitor for a Dark Energy related experiment: ACCESS - 'Absolute Color Calibration Experiment for Standard Stars'. This calibration source, the On-board Calibration Monitor (OCM), is a key component of our ACCESS spectrophotometric calibration program. The OCM will be flown as part of the ACCESS sub-orbital rocket payload in addition to monitoring instrument sensitivity on the ground. The objective of the OCM is to minimize systematic errors associated with any potential changes in the ACCESS instrument sensitivity. Importantly, the OCM will be used to monitor instrument sensitivity immediately after astronomical observations while the instrument payload is parachuting to the ground. Through monitoring, we can detect, track, characterize, and thus correct for any changes in instrument senstivity over the proposed 5-year duration of the assembled and calibrated instrument.

Kaiser, M. E.

2009-11-23

382

Radio Interferometric Calibration Using The SAGE Algorithm  

E-print Network

Radio Interferometry is an essential method for astronomical observations. Self-calibration techniques have increased the quality of the radio astronomical observations (and hence the science) by orders of magnitude. Recently, there is a drive towards sensor arrays built using inexpensive hardware and distributed over a wide area acting as radio interferometers. Calibration of such arrays poses new problems in terms of computational cost as well as in performance of existing calibration algorithms. We consider the application of the Space Alternating Generalized Expectation Maximization (SAGE) \\cite{Fess94} algorithm for calibration of radio interferometric arrays. Application to real data shows that this is an improvement over existing calibration algorithms that are based on direct, deterministic non linear optimization. As presented in this paper, we can improve the computational cost as well as the quality of the calibration using this algorithm.

Sarod Yatawatta; Saleem Zaroubi; Ger de Bruyn; Leon Koopmans; Jan Noordam

2008-10-31

383

COBE Final Report: Dirbe Celestial Calibration  

NASA Technical Reports Server (NTRS)

We report the results of a comparative study of the COsmic Background Explorer/Diffuse InfraRed Background Experiment (COBE/DIRBE) photometric calibration over about 100 selected stellar and non-stellar calibration objects across a wide range of the DIRBE instrument dynamic range, wavelength coverage, and source temperature. A statistical comparison of the DIRBE-reported flux to the accepted values from the literature (as summarized in the CIO) provides an independent verification of the DIRBE point source calibration.

Burdick, Shawn V.; Murdock, Thomas L.

1997-01-01

384

COBE Final Report: DIRBE Celestial Calibration  

NASA Astrophysics Data System (ADS)

We report the results of a comparative study of the COsmic Background Explorer/Diffuse InfraRed Background Experiment (COBE/DIRBE) photometric calibration over about 100 selected stellar and non-stellar calibration objects across a wide range of the DIRBE instrument dynamic range, wavelength coverage, and source temperature. A statistical comparison of the DIRBE-reported flux to the accepted values from the literature (as summarized in the CIO) provides an independent verification of the DIRBE point source calibration.

Burdick, Shawn V.; Murdock, Thomas L.

1997-03-01

385

Oxygen-Mass-Flow Calibration Cell  

NASA Technical Reports Server (NTRS)

Proposed calibration standard for mass flow rate of oxygen based on conduction of oxygen ions through solid electrolyte membrane made of zirconia and heated to temperature of 1,000 degrees C. Flow of oxygen ions proportional to applied electric current. Unaffected by variations in temperature and pressure, and requires no measurement of volume. Calibration cell based on concept used to calibrate variety of medical and scientific instruments required to operate with precise rates of flow of oxygen.

Martin, Robert E.

1996-01-01

386

Airborne lidar intensity calibration and application for land use classification  

NASA Astrophysics Data System (ADS)

Airborne Light Detection and Ranging (LiDAR) is an active remote sensing technology which can acquire the topographic information efficiently. It can record the accurate 3D coordinates of the targets and also the signal intensity (the amplitude of backscattered echoes) which represents reflectance characteristics of targets. The intensity data has been used in land use classification, vegetation fractional cover and leaf area index (LAI) estimation. Apart from the reflectance characteristics of the targets, the intensity data can also be influenced by many other factors, such as flying height, incident angle, atmospheric attenuation, laser pulse power and laser beam width. It is therefore necessary to calibrate intensity values before further applications. In this study, we analyze the factors affecting LiDAR intensity based on radar range equation firstly, and then applying the intensity calibration method, which includes the sensor-to-target distance and incident angle, to the laser intensity data over the study area. Finally the raw LiDAR intensity and normalized intensity data are used for land use classification along with LiDAR elevation data respectively. The results show that the classification accuracy from the normalized intensity data is higher than that from raw LiDAR intensity data and also indicate that the calibration of LiDAR intensity data is necessary in the application of land use classification.

Li, Dong; Wang, Cheng; Luo, She-Zhou; Zuo, Zheng-Li

2014-11-01

387

Atmospheric drag model calibrations for spacecraft lifetime prediction  

NASA Technical Reports Server (NTRS)

Although solar activity prediction uncertainty normally dominates decay prediction error budget for near-Earth spacecraft, the effect of drag force modeling errors for given levels of solar activity needs to be considered. Two atmospheric density models, the modified Harris-Priester model and the Jacchia-Roberts model, to reproduce the decay histories of the Solar Mesosphere Explorer (SME) and Solar Maximum Mission (SMM) spacecraft in the 490- to 540-kilometer altitude range were analyzed. Historical solar activity data were used in the input to the density computations. For each spacecraft and atmospheric model, a drag scaling adjustment factor was determined for a high-solar-activity year, such that the observed annual decay in the mean semimajor axis was reproduced by an averaged variation-of-parameters (VOP) orbit propagation. The SME (SMM) calibration was performed using calendar year 1983 (1982). The resulting calibration factors differ by 20 to 40 percent from the predictions of the prelaunch ballistic coefficients. The orbit propagations for each spacecraft were extended to the middle of 1988 using the calibrated drag models. For the Jaccia-Roberts density model, the observed decay in the mean semimajor axis of SME (SMM) over the 4.5-year (5.5-year) predictive period was reproduced to within 1.5 (4.4) percent. The corresponding figure for the Harris-Priester model was 8.6 (20.6) percent. Detailed results and conclusions regarding the importance of accurate drag force modeling for lifetime predictions are presented.

Binebrink, A. L.; Radomski, M. S.; Samii, M. V.

1989-01-01

388

Absolute calibration of the Auger fluorescence detectors  

SciTech Connect

Absolute calibration of the Pierre Auger Observatory fluorescence detectors uses a light source at the telescope aperture. The technique accounts for the combined effects of all detector components in a single measurement. The calibrated 2.5 m diameter light source fills the aperture, providing uniform illumination to each pixel. The known flux from the light source and the response of the acquisition system give the required calibration for each pixel. In the lab, light source uniformity is studied using CCD images and the intensity is measured relative to NIST-calibrated photodiodes. Overall uncertainties are presently 12%, and are dominated by systematics.

Bauleo, P.; Brack, J.; Garrard, L.; Harton, J.; Knapik, R.; Meyhandan, R.; Rovero, A.C.; /Buenos Aires, IAFE; Tamashiro, A.; Warner, D.

2005-07-01

389

Calibration of water-velocity meters  

USGS Publications Warehouse

The U.S. Geological Survey, Department of the Interior, as part of its responsibility to appraise the quantity of water resources in the United States, maintains facilities for the calibration of water-velocity meters at the Gulf Coast Hydroscience Center's Hydraulic Laboratory Facility, NSTL, Mississippi. These meters are used in hydrologic studies by the Geological Survey, U.S. Army Corps of Engineers, U.S. Department of Energy, state agencies, universities, and others in the public and private sector. This paper describes calibration facilities, types of water-velocity meters calibrated, and calibration standards, methods and results.

Kaehrle, William R.; Bowie, James E.

1988-01-01

390

Calibration of ACS Prism Slitless Spectroscopy Modes  

E-print Network

The Advanced Camera for Surveys is equipped with three prisms in the Solar Blind (SBC) and High Resolution (HRC) Channels, which together cover the 1150 - 3500 A range, albeit at highly non-uniform spectral resolution. We present new wavelength- and flux calibrations of the SBC (PR110L and PR130L) and HRC (PR200L) prisms, based on calibration observations obtained in Cycle 13. The calibration products are available to users via the ST-ECF/aXe web pages, and can be used directly with the aXe package. We discuss our calibration strategy and some caveats specific to slitless prism spectroscopy.

S. S. Larsen; M. Kuemmel; J. R. Walsh

2005-12-05

391

Sloan Digital Sky Survey Photometric Calibration Revisited  

SciTech Connect

The Sloan Digital Sky Survey calibration is revisited to obtain the most accurate photometric calibration. A small but significant error is found in the flat-fielding of the Photometric telescope used for calibration. Two SDSS star catalogs are compared and the average difference in magnitude as a function of right ascension and declination exhibits small systematic errors in relative calibration. The photometric transformation from the SDSS Photometric Telescope to the 2.5 m telescope is recomputed and compared to synthetic magnitudes computed from measured filter bandpasses.

Marriner, John; /Fermilab

2012-06-29

392

Calibration of the AXAF Observatory: Overview  

NASA Technical Reports Server (NTRS)

The Advanced X-ray Astrophysics Facility (AXAF) will soon begin its exploration of the x-ray universe, providing unprecedented angular and spectral resolution. Also unprecedented is the ambitious goal of calibrating the AXAF observatory to an accuracy of a few percent. Toward this end, AXAF science and engineering teams undertook an extensive calibration program at component, subsystem, and system levels. This paper is an overview of the system-level calibration activities, conducted over the past year at the Marshall Space Flight Center (MSFC) X-Ray Calibration Facility (XRCF).

Weisskopf, M.C.; ODell, S. L.

1997-01-01

393

Research on vacuum utraviolet calibration technology  

NASA Astrophysics Data System (ADS)

Importance of extreme ultraviolet (EUV) and far ultraviolet (FUV) calibration is growing fast as vacuum ultraviolet payloads are wildly used in national space plan. A calibration device is established especially for the requirement of EUV and FUV metrology and measurement. Spectral radiation and detector relative spectral response at EUV and FUV wavelengths can be calibrated with accuracy of 26% and 20%, respectively. The setup of the device, theoretical model and value retroactive method are introduced and measurement of detector relative spectral response from 30 nm to 200 nm is presented in this paper. The calibration device plays an important role in national space research.

Wang, Jiapeng; Gao, Shumin; Sun, Hongsheng; Chen, Yinghang; Wei, Jianqiang

2014-11-01

394

The 1994 laboratory calibration of TIMS  

NASA Technical Reports Server (NTRS)

This summary describes the spatial, spectral, and radiometric calibration of Thermal Infrared Multispectral Scanner (TIMS) performed at the Jet Propulsion Laboratory (JPL) Thermal Infrared Calibration Facility (TIRCAL) between May and August, 1994. The 1994 calibration of TIMS was the first to make use of the new EXABYTE (8mm helical-scan tape) recording system. With the new recorder, the TIMS data tapes may be read directly on any computer system that has an EXABYTE tape drive. We analyzed the calibration data sets using image processing procedures written in Interactive Data Language.

Realmuto, Vincent J.; Hajek, Pavel; Sinha, Mahadeva P.; Chrien, Thomas G.

1995-01-01

395

New Vacuum Blackbody Cavity for Heat Flux Meter Calibration  

NASA Astrophysics Data System (ADS)

In the field of thermal radiation measurements, blackbody cavities are commonly used as reference standards for the calibration of heat flux meters. Applying the energy balance equation to the closed system including the cavity and the sensor, it is possible to predict the heat flux density absorbed by the heat flux meter. Calibration procedures developed at Laboratoire National de Métrologie et d’Essais (LNE) in recent years have allowed us to propose practical solutions for heat flux meters working below 100 kW · m-2. The best relative uncertainties ( k = 2) over the range of (10-100) kW · m-2 vary from 1.7 % to 3 %. During previous studies, three major facilities were constructed, each one with the objective to respond to different technical problems considering the measuring principle of these heat flux sensors. Following this approach, the sensitivity of these meters to radiation, the sensitivity to radiation and convection, and also the influence of the size of the source or of the positioning of the sensor (horizontally, vertically, etc.) have been investigated. As an outcome of this recent experience, a new vacuum blackbody cavity has been set up. As well as the possibility to calibrate at very low irradiance, there are also some substantive improvements in heating, thermal performance, and calibration methodology. After a summary of the state of the art of calibration methods and their limits, the article presents the preliminary results of the characterization obtained with this new facility for which the objective is to reduce the uncertainties by at least a factor of two for heat flux densities lower than 20 kW · m-2.

Filtz, J.-R.; Valin, T.; Hameury, J.; Dubard, J.

2009-02-01

396

Robust weak-lensing mass calibration of Planck galaxy clusters  

NASA Astrophysics Data System (ADS)

In light of the tension in cosmological constraints reported by the Planck team between their Sunyaev-Zel'dovich-selected cluster counts and Cosmic Microwave Background (CMB) temperature anisotropies, we compare the Planck cluster mass estimates with robust, weak-lensing mass measurements from the Weighing the Giants (WtG) project. For the 22 clusters in common between the Planck cosmology sample and WtG, we find an overall mass ratio of = 0.688 ± 0.072. Extending the sample to clusters not used in the Planck cosmology analysis yields a consistent value of = 0.698 ± 0.062 from 38 clusters in common. Identifying the weak-lensing masses as proxies for the true cluster mass (on average), these ratios are ˜1.6? lower than the default bias factor of 0.8 assumed in the Planck cluster analysis. Adopting the WtG weak-lensing-based mass calibration would substantially reduce the tension found between the Planck cluster count cosmology results and those from CMB temperature anisotropies, thereby dispensing of the need for `new physics' such as uncomfortably large neutrino masses (in the context of the measured Planck temperature anisotropies and other data). We also find modest evidence (at 95 per cent confidence) for a mass dependence of the calibration ratio and discuss its potential origin in light of systematic uncertainties in the temperature calibration of the X-ray measurements used to calibrate the Planck cluster masses. Our results exemplify the critical role that robust absolute mass calibration plays in cluster cosmology, and the invaluable role of accurate weak-lensing mass measurements in this regard.

von der Linden, Anja; Mantz, Adam; Allen, Steven W.; Applegate, Douglas E.; Kelly, Patrick L.; Morris, R. Glenn; Wright, Adam; Allen, Mark T.; Burchat, Patricia R.; Burke, David L.; Donovan, David; Ebeling, Harald

2014-09-01

397

Vicarious calibration of Terra/ASTER/VNIR with desert scenes together with cross calibration  

NASA Astrophysics Data System (ADS)

Fourteen and half years of vicarious calibration and cross calibration for Terra/ASTER/VNIR (Visible and Near Infrared Radiometer, one of three ASTER mission instruments onboard Terra satellite) are summarized together with an error budget analysis. As the results, it is found that Onboard Calibration (OBC) data derived Radiometric Calibration Coefficient (RCC) is situated within a range of uncertainty of vicarious calibration except the period after approximately 4000 days after launch. In other word, uncertainty of OBC RCC is overlapped with uncertainty of vicarious calibration for about 4000 days since launch. Meanwhile, cross calibration with MODIS, MISR and ETM+ supports vicarious calibration of VNIR. In other word, Cross RCC shows much consistent trend to Vicarious RCC than OBC RCC.

Arai, K.

2014-09-01

398

Monitoring GOCE gradiometer calibration parameters using accelerometer and star sensor data: methodology and first results  

NASA Astrophysics Data System (ADS)

The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite, launched on 17 March 2009, is designed to measure the Earth's mean gravity field with unprecedented accuracy at spatial resolutions down to 100 km. The accurate calibration of the gravity gradiometer on-board GOCE is of utmost importance for achieving the mission goals. ESA's baseline method for the calibration uses star sensor and accelerometer data of a dedicated calibration procedure, which is executed every 2 months. In this paper, we describe a method for monitoring the evolution of calibration parameter during that time. The method works with star sensor and accelerometer data and does not require gravity field models, which distinguishes it from other existing methods. We present time series of calibration parameters estimated from GOCE data from 1 November 2009 to 17 May 2010. The time series confirm drifts in the calibration parameters that are present in the results of other methods, including ESA's baseline method. Although these drifts are very small, they degrade the gravity gradients, leading to the conclusion that the calibration parameters of the ESA's baseline method need to be linearly interpolated. Further, we find a correction of -36 × 10-6 for one calibration parameter (in-line differential scale factor of the cross-track gradiometer arm), which improves the gravity gradient performance. The results are validated by investigating the trace of the calibrated gravity gradients and comparing calibrated gravity gradients with reference gradients computed along the GOCE orbit using the ITG-Grace-2010s gravity field model.

Siemes, Christian; Haagmans, Roger; Kern, Michael; Plank, Gernot; Floberghagen, Rune

2012-08-01

399

A Summary of The 2000-2001 NASA Glenn Lear Jet AM0 Solar Cell Calibration Program  

NASA Astrophysics Data System (ADS)

Calibration of solar cells for space is extremely important for satellite power system design. Accurate prediction of solar cell performance is critical to solar array sizing, often required to be within 1%. The NASA Glenn Research Center solar cell calibration airplane facility has been in operation since 1963 with 531 flights to date. The calibration includes real data to Air Mass (AM) 0.2 and uses the Langley plot method plus an ozone correction factor to extrapolate to AM0. Comparison of the AM0 calibration data indicates that there is good correlation with Balloon and Shuttle flown solar cells. This paper will present a history of the airplane calibration procedure, flying considerations, and a brief summary of the previous flying season with some measurement results. This past flying season had a record 35 flights. It will also discuss efforts to more clearly define the ozone correction factor.

Scheiman, David; Brinker, David; Snyder, David; Baraona, Cosmo; Jenkins, Phillip; Rieke, William J.; Blankenship, Kurt S.; Tom, Ellen M.

2002-10-01

400

Accurate camera calibration with distortion models using sphere images  

NASA Astrophysics Data System (ADS)

In order to improve the accuracy of sphere images based camera calibration, a novel approach was proposed in this paper which can calibrate both linear parameters and distortion coefficients simultaneously. The great axis and bitangent lines of the projection conics are applied to solve principal point and sphere center projections. Then the focal length is computed using rotational symmetry of projective cone. Finally distortion coefficients are estimated by optimization search algorithm. Synthetic data experiments analyzed the main error factors and real data results showed that the re-projection error of the proposed method was less than 0.1 pixel which seems to be more accurate than existing methods using spheres and reach the same accuracy level as the planar target method.

Sun, Junhua; Chen, Xu; Gong, Zheng; Liu, Zhen; Zhao, Yuntao

2015-01-01

401

Gearbox Reliability Collaborative Bearing Calibration  

SciTech Connect

NREL has initiated the Gearbox Reliability Collaborative (GRC) to investigate the root cause of the low wind turbine gearbox reliability. The GRC follows a multi-pronged approach based on a collaborative of manufacturers, owners, researchers and consultants. The project combines analysis, field testing, dynamometer testing, condition monitoring, and the development and population of a gearbox failure database. At the core of the project are two 750kW gearboxes that have been redesigned and rebuilt so that they are representative of the multi-megawatt gearbox topology currently used in the industry. These gearboxes are heavily instrumented and are tested in the field and on the dynamometer. This report discusses the bearing calibrations of the gearboxes.

van Dam, J.

2011-10-01

402

A cryogenic infrared calibration target  

NASA Astrophysics Data System (ADS)

A compact cryogenic calibration target is presented that has a peak diffuse reflectance, R ? 0.003, from 800 to 4800 cm-1 (12 - 2 ?m). Upon expanding the spectral range under consideration to 400-10 000 cm-1 (25 - 1 ?m) the observed performance gracefully degrades to R ? 0.02 at the band edges. In the implementation described, a high-thermal-conductivity metallic substrate is textured with a pyramidal tiling and subsequently coated with a thin lossy dielectric coating that enables high absorption and thermal uniformity across the target. The resulting target assembly is lightweight, has a low-geometric profile, and has survived repeated thermal cycling from room temperature to ˜4 K. Basic design considerations, governing equations, and test data for realizing the structure described are provided. The optical properties of selected absorptive materials—Acktar Fractal Black, Aeroglaze Z306, and Stycast 2850 FT epoxy loaded with stainless steel powder—are characterized and presented.

Wollack, E. J.; Kinzer, R. E.; Rinehart, S. A.

2014-04-01

403

James Webb Space Telescope Calibration  

NASA Astrophysics Data System (ADS)

The James Webb Space Telescope (JWST) is the planned successor to the magnificent Hubble Space Telescope and the smaller but remarkably powerful Spitzer Space Telescope. It will extend the Hubble and Spitzer science in many areas, ranging from the first stars and galaxies, to the current formation of stars and planets, and the evolution of planetary systems to conditions capable of supporting life. The JWST is a NASA-led project in partnership with the European and Canadian space agencies. The deployable cooled 6.5 meter telescope will cover the wavelength range from 0.6 to 28 ?m with imaging and spectroscopy. With diffraction-limited image < 10 ?m, the JWST will be the most powerful space observatory yet constructed. To enable the huge telescope to fit into the rocket fairing, it is very carefully folded up for launch. It has a primary mirror with 18 segments, each one able to be positioned with 6 degrees of freedom and a radius of curvature adjustment. While it is quite well protected from thermal variations, it is nevertheless expected that the JWST primary mirror may be readjusted on the order of every two weeks. This design enables a primary mirror larger than the rocket fairing, but also leads to very interesting calibration issues. In the years since JWST was conceived, the potential scientific benefits of greatly improved calibration and stability have become apparent. Now the challenge is to find ways to achieve those improvements with hardware that has already been designed. In this paper, I outline the basic issues and some strategies to pursue.

Mather, John C.

2010-07-01

404

Metrology - Beyond the Calibration Lab  

NASA Technical Reports Server (NTRS)

We rely on data from measurements every day; a gas-pump, a speedometer, and a supermarket weight scale are just three examples of measurements we use to make decisions. We generally accept the data from these measurements as "valid." One reason we can accept the data is the "legal metrology" requirements established and regulated by the government in matters of commerce. The measurement data used by NASA, other government agencies, and industry can be critical to decisions which affect everything from economic viability, to mission success, to the security of the nation. Measurement data can even affect life and death decisions. Metrology requirements must adequately provide for risks associated with these decisions. To do this, metrology must be integrated into all aspects of an industry including research, design, testing, and product acceptance. Metrology, the science of measurement, has traditionally focused on the calibration of instruments, and although instrument calibration is vital, it is only a part of the process that assures quality in measurement data. For example, measurements made in research can influence the fundamental premises that establish the design parameters, which then flow down to the manufacturing processes, and eventually impact the final product. Because a breakdown can occur anywhere within this cycle, measurement quality assurance has to be integrated into every part of the life-cycle process starting with the basic research and ending with the final product inspection process. The purpose of this paper is to discuss the role of metrology in the various phases of a product's life-cycle. For simplicity, the cycle will be divided in four broad phases, with discussions centering on metrology within NASA. .

Mimbs, Scott M.

2008-01-01

405

Measurements of biogenic VOC emissions: sampling, analysis and calibration  

NASA Astrophysics Data System (ADS)

We describe an experimental system and techniques for sampling and analyzing biogenic emissions of volatile organic compounds (VOC). The system uses a Teflon chamber to enclose a single branch of a tree. Temperature, photosynthetic active radiation (PAR), relative humidity and carbon dioxide concentration are continuously monitored with a time resolution of five minutes. VOCs are sampled on tubes containing solid adsorbents (Tenax TA and Carbotrap) with a time resolution of 1 h. Composition and concentration of VOC emissions are measured with a gas chromatographic system equipped with a flame ionization detector (FID) for quantitative and a mass spectrometer (MS) for qualitative analysis. To calibrate the system, a diffusion source was built to produce standard mixtures of up to 36 different compounds with mixing ratios at low concentrations and high accuracy. The diffusion rates were monitored over 17 months and showed variations between 0.2 and 7.6% for monoterpenes (expect for ?-phellandrene, ?-terpinene and ?-terpinene) and between 10.6 and 22.6% for sesquiterpenes. FID response factors calculated from calibration measurements were corrected using correction factors based on the effective carbon number concept. The individual response factors of 23 compounds were combined to a mean response factor (RF m) with a value of 23,100 ?V s ng -1 and a standard deviation of 9%. The system described here was used to measure VOC emission rates of Scots pine ( Pinus sylvestris) in 1998 and 1999.

Komenda, M.; Parusel, E.; Wedel, A.; Koppmann, R.

406

Compliance calibration of the short rod chevron-notch specimen for fracture toughness testing of brittle materials  

NASA Technical Reports Server (NTRS)

The short rod chevron-notch specimen has the advantages of (1) crack development at the chevron tip during the early stage of test loading, and (2) convenient calculation of plane-strain fracture toughness from the maximum test load and from a calibration factor which depends only on the specimen geometry and manner of loading. For generalized application, calibration of the specimen over a range of specimen proportions and chevron-notch configurations is necessary. Such was the objective of this investigation, wherein calibration of the short rod specimen was made by means of experimental compliance measurements converted into dimensionless stress intensity factor coefficients.

Bubsey, R. T.; Pierce, W. S.; Shannon, J. L., Jr.; Munz, D.

1982-01-01

407

Variations on the Davenport Gyroscope Calibration Algorithm  

NASA Technical Reports Server (NTRS)

This paper presents a number of variations on the Davenport algorithm for in-flight gyroscope recalibration, or first order initial calibration, specifically tailored for use with a minimum of satellite telemetry data. Central to one of the techniques described is the use of onboard integration of gyroscope data together with a detailed model of scheduled satellite slew profiles. Methods are presented for determining adjustments to either parameters for the standard linear model (i.e., a drift rate bias vector and/or a scale factor/alignment transformation matrix) or individual gyroscope scale parameters, both linear and nonlinear, in cases where the alignments are well known. The results of applying the methods in an analysis of the temporal evolution and nonlinear response of the gyroscopes installed on the Hubble Space Telescope following its first servicing mission are discussed. The two effects, when working coherently, have been found to result in slew errors of almost 1 arcsecond per degree. Procedures for selecting optimal operational gyroscope parameters subject to the constraint of using a linear model are discussed.

Welter, G.; Boia, J.; Gakenheimer, M.; Kimmer, E.; Channell, D.; Hallock, L.

1996-01-01

408

Reconstruction with the calibrated SYCLOP sensor  

Microsoft Academic Search

In this paper we present a method of calibrating the omnidirectional sensor used in our laboratory and named SYCLOP (“Conic System for Localization and Perception”). In order to have better precision than that obtained in classical applications using this kind of sensor, we highlight the importance of calibration for the whole sensor. After this step we validate our model by

Cyril CAUCHOIS; Eric BRASSART; Laurent DELAHOCHE; Thierry DELHOMMELLE

2000-01-01

409

Multivariate calibrations in UV spectrophotometric analysis.  

PubMed

Calibration allows the user to relate instrumental measurements to the sample of interest. Multivariate calibration allows for the analysis of several measurements from several samples or specimens. The method contributes to the two steps procedure where step one involves the calibration of data and second step involves the prediction that are made or based on the calibration. In calibration, indirect measurements are made from samples where the amount of the analyte has been predetermined, usually by an independent assay or technique. These measurements, along with the predetermined analyte levels, comprise a group known as the calibration set. This set is used to develop a model that relates the amount of sample to the measurements by the instrument. In some cases, the construction of the model is simple due to a certain relationship, such as Beer's Law in the application of UV spectroscopy. Unlike spectroscopy, other cases can be much more complex, and it is in these cases where construction of the model is time-consuming step. Once the model is constructed, it can predict analyte levels based on measurements of new samples. It can be used to separate samples from interferences without the need of highly selective measurements for the analyte. Calibration techniques (used in the calibration step) differ in determining coefficient values for the preceding or similar equations. PMID:17416574

Arayne, M Saeed; Sultana, Najma; Bahadur, Saima Sher

2007-04-01

410

Constraining fossil calibrations for molecular clocks  

E-print Network

Constraining fossil calibrations for molecular clocks Sir, In a recent paper, Mu¨ller and Reisz(1) proposed how fossil calibrations should be selected for application in molecular clock studies. The topic molecules. Nonetheless, we believe that these authors have erred both in their proposal of fossil

Kumar, Sudhir

411

Automatic alignment method for calibration of hydrometers  

Microsoft Academic Search

This paper presents a new method to automatically align specific scale-marks for the calibration of hydrometers. A hydrometer calibration system adopting the new method consists of a vision system, a stepping motor, and software to control the system. The vision system is composed of a CCD camera and a frame grabber, and is used to acquire images. The stepping motor

Y J Lee; K H Chang; J C Chon; C Y Oh

2004-01-01

412

ROBOT CALIBRATION USING LEAST-SQUARES AND  

E-print Network

ROBOT CALIBRATION USING LEAST-SQUARES AND P OLAR-DEC OMP O SITION FILTERING Gregory Ioannldes 1-axis robotic manipulators. The method proposed by the authors is based on a least-square estimation of the Yaskawa Motoman Robot was calibrated. The measurements of the Cartesian coordinates of points were

Flanagan, Randy

413

Self-Calibration from Image Sequences  

Microsoft Academic Search

This thesis develops new algorithms to obtain the calibration parameters of a camerausing only information contained in an image sequence, with the objective of using thecamera calibration to compute a Euclidean reconstruction. This problem is known as selfcalibration.The motivation for this work is to allow the Euclidean reconstruction of a sceneusing only a pre-recorded image sequence where no information is

Martin Neil Armstrong

1996-01-01

414

Uncertainty Analysis of Instrument Calibration and Application  

NASA Technical Reports Server (NTRS)

Experimental aerodynamic researchers require estimated precision and bias uncertainties of measured physical quantities, typically at 95 percent confidence levels. Uncertainties of final computed aerodynamic parameters are obtained by propagation of individual measurement uncertainties through the defining functional expressions. In this paper, rigorous mathematical techniques are extended to determine precision and bias uncertainties of any instrument-sensor system. Through this analysis, instrument uncertainties determined through calibration are now expressed as functions of the corresponding measurement for linear and nonlinear univariate and multivariate processes. Treatment of correlated measurement precision error is developed. During laboratory calibration, calibration standard uncertainties are assumed to be an order of magnitude less than those of the instrument being calibrated. Often calibration standards do not satisfy this assumption. This paper applies rigorous statistical methods for inclusion of calibration standard uncertainty and covariance due to the order of their application. The effects of mathematical modeling error on calibration bias uncertainty are quantified. The effects of experimental design on uncertainty are analyzed. The importance of replication is emphasized, techniques for estimation of both bias and precision uncertainties using replication are developed. Statistical tests for stationarity of calibration parameters over time are obtained.

Tripp, John S.; Tcheng, Ping

1999-01-01

415

Uncertainties in dosimetric data and beam calibration  

Microsoft Academic Search

Recent studies indicate that the calibration of therapeutic beams is one of the main sources of uncertainty in the mean absorbed dose to the target volume in radiotherapy. Interaction coefficients and data used through the different steps in the calibration are pointed out as the main contribution to this uncertainty. Procedures used to select dosimetric data, that is, input parameters

P Andreo

1990-01-01

416

Self Calibrating pressure sensor for biomedical applications  

E-print Network

-tip sensor. This new sensors is based on solid state pressure sensor coupled with an electrostatic actuatorSelf Calibrating pressure sensor for biomedical applications P.YAMEOGO, U.HEIBA Laboratoire d-- In this paper we present for the first time a wireless self calibrating pressure sensor for biomedical

Paris-Sud XI, Université de

417

Virtual Reality Calibration for Telerobotic Servicing  

NASA Technical Reports Server (NTRS)

A virtual reality calibration technique of matching a virtual environment of simulated graphics models in 3-D geometry and perspective with actual camera views of the remote site task environment has been developed to enable high-fidelity preview/predictive displays with calibrated graphics overlay on live video.

Kim, W.

1994-01-01

418

Calibration of silicon atomic force microscope cantilevers  

Microsoft Academic Search

We present a comparison of three different methods to calibrate the spring constant of two different types of silicon beam shaped atomic force microscope (AFM) cantilevers to determine each method’s accuracy, ease of use and potential destructiveness. The majority of research in calibrating AFM cantilevers has been concerned with contact mode levers. The two types of levers we have studied

Christopher T Gibson; D Alastair Smith; Clive J Roberts

2005-01-01

419

MERIS \\/ ENVISAT Vicarious Calibration Over Land  

Microsoft Academic Search

The launch of ESA's ENVISAT in March 2002 was followed by a commissioning phase for all ENVISAT instruments to verify the performance of ENVISAT instruments and recommend possible adjustments of the calibration or the product algorithms before the data was widely distributed. The focus of this paper is on the vicarious calibration of the Medium Resolution Imaging Spectrometer (MERIS) radiance

Mathias Kneubühler; Michael E. Schaepman; Kurtis J. Thome; Daniel Schläpfer

420

Calibration: Respice, Adspice, Prospice Dean P. Foster  

E-print Network

] offers the following intuitive definition of calibration: "Suppose that, in a long (conceptually infinite of precipitation was, say, close to some given value and (assuming these form an infinite sequence) determine- brated than hedgehogs.1 2 Notation The intuitive definition of calibration is meaningless when

Bandyopadhyay, Antar

421

Microfabricated field calibration assembly for analytical instruments  

DOEpatents

A microfabricated field calibration assembly for use in calibrating analytical instruments and sensor systems. The assembly comprises a circuit board comprising one or more resistively heatable microbridge elements, an interface device that enables addressable heating of the microbridge elements, and, in some embodiments, a means for positioning the circuit board within an inlet structure of an analytical instrument or sensor system.

Robinson, Alex L. (Albuquerque, NM); Manginell, Ronald P. (Albuquerque, NM); Moorman, Matthew W. (Albuquerque, NM); Rodacy, Philip J. (Albuquerque, NM); Simonson, Robert J. (Cedar Crest, NM)

2011-03-29

422

High Power Laser Calibrations NIST Measurement Services  

E-print Network

High Power Laser Calibrations at NIST NIST Measurement Services: NIST Special Publication 250 250-77 NIST MEASUREMENT SERVICES: High Power Laser Calibrations at NIST Xiaoyu Li Joshua Hadler ........................................................ 2 3.1.1 NIST Primary Standard for High Power Laser Measurements .................. 3 3

423

Magnetic information calibrates celestial cues during migration  

Microsoft Academic Search

Migratory birds use celestial and geomagnetic directional information to orient on their way between breeding and wintering areas. Cue-conflict experiments involving these two orientation cue systems have shown that directional information can be transferred from one system to the other by calibration. We designed experiments with four species of North American songbirds to: (1) examine whether these species calibrate orientation

Roland Sandberg; Johan Bäckman; Frank R. Moore; Mare Lõhmus

2000-01-01

424

Robot calibration using an automatic theodolite  

Microsoft Academic Search

The Vision Based Automatic Theodolite (VBAT) is an automatic partial pose measurement system for robot calibration. It uses low resolution rotation stages and resolution enhancement from a vision system to determine the line-of-sight to a spherical illuminated target. Automatic tracking, focusing, and centring provide the calibration system with speed, reliability, and repeatability. A kinematic model of the VBAT is described

Morris R. Driels; Uday S. Pathre

1994-01-01

425

Gain calibration methods for radio telescope arrays  

Microsoft Academic Search

In radio telescope arrays, the complex receiver gains and sensor noise powers are initially unknown and have to be calibrated. Gain calibration can enhance the quality of astronomical sky images and, moreover, improve the effectiveness of array signal processing techniques for interference mitigation and spatial filtering. A challenging aspect is that the signal-to-noise ratio (SNR) is usually well below 0

Albert-Jan Boonstra; Alle-Jan van der Veen

2003-01-01

426

An accurate system for onsite calibration of electronic transformers with digital output  

SciTech Connect

Calibration systems with digital output are used to replace conventional calibration systems because of principle diversity and characteristics of digital output of electronic transformers. But precision and unpredictable stability limit their onsite application even development. So fully considering the factors influencing accuracy of calibration system and employing simple but reliable structure, an all-digital calibration system with digital output is proposed in this paper. In complicated calibration environments, precision and dynamic range are guaranteed by A/D converter with 24-bit resolution, synchronization error limit is nanosecond by using the novelty synchronization method. In addition, an error correction algorithm based on the differential method by using two-order Hanning convolution window has good inhibition of frequency fluctuation and inter-harmonics interference. To verify the effectiveness, error calibration was carried out in the State Grid Electric Power Research Institute of China and results show that the proposed system can reach the precision class up to 0.05. Actual onsite calibration shows that the system has high accuracy, and is easy to operate with satisfactory stability.

Zhi Zhang; Li Hongbin [CEEE of HuaZhong University of Science and Technology, Wuhan 430074 (China); State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan 430074 (China)

2012-06-15

427

Leveraging LER to minimize linewidth measurement uncertainty in a calibration exercise  

NASA Astrophysics Data System (ADS)

Many semiconductor metrologists are aware that line edge roughness (LER), and thus linewidth variation (LWV), can be a significant contributor to measurement uncertainty. More generally, the impact of measurand variation and proper sampling is becoming a major player in nearly every area of semiconductor metrology. This paper describes a simple technique of using the LWV of a feature as a fingerprint to uniquely characterize the measurement target in such a way to make the LER contribution negligible in a linewidth calibration exercise. A single crystal critical dimension reference material (SCCDRM) was the calibration artifact used to calibrate the tip width of a critical dimension atomic force microscope (CD-AFM). These samples were released by the National Institute of Standards and Technology (NIST) to SEMATECH member companies in 2004. The specific SCCDRM used for this work had six calibrated linewidths ranging from 100 nm to 270 nm. Our paper shows in detail the overlay of the CD-AFM linewidth data with that of the data used to calibrate the SCCDRM for each linewidth. With the aid of this linewidth fingerprinting, Mandel regression is used to assess the quality of correlation of the CD-AFM to that of the NIST-derived calibration data. An uncertainty budget is presented as a conclusion of the tip width calibration exercise. A combined expanded uncertainty of less than 2 nm with a k = 3 coverage factor is achieved.

Robert, James; Banke, Bill; Dixson, Ronald

2007-03-01

428

An accurate system for onsite calibration of electronic transformers with digital output  

NASA Astrophysics Data System (ADS)

Calibration systems with digital output are used to replace conventional calibration systems because of principle diversity and characteristics of digital output of electronic transformers. But precision and unpredictable stability limit their onsite application even development. So fully considering the factors influencing accuracy of calibration system and employing simple but reliable structure, an all-digital calibration system with digital output is proposed in this paper. In complicated calibration environments, precision and dynamic range are guaranteed by A/D converter with 24-bit resolution, synchronization error limit is nanosecond by using the novelty synchronization method. In addition, an error correction algorithm based on the differential method by using two-order Hanning convolution window has good inhibition of frequency fluctuation and inter-harmonics interference. To verify the effectiveness, error calibration was carried out in the State Grid Electric Power Research Institute of China and results show that the proposed system can reach the precision class up to 0.05. Actual onsite calibration shows that the system has high accuracy, and is easy to operate with satisfactory stability.

Zhi, Zhang; Li, Hong-Bin

2012-06-01

429

Calibration of the NASA Glenn 8- by 6-Foot Supersonic Wind Tunnel (1996 and 1997 Tests)  

NASA Technical Reports Server (NTRS)

There were several physical and operational changes made to the NASA Glenn Research Center 8- by 6-Foot Supersonic Wind Tunnel during the period of 1992 through 1996. Following each of these changes, a facility calibration was conducted to provide the required information to support the research test programs. Due to several factors (facility research test schedule, facility downtime and continued facility upgrades), a full test section calibration was not conducted until 1996. This calibration test incorporated all test section configurations and covered the existing operating range of the facility. However, near the end of that test entry, two of the vortex generators mounted on the compressor exit tailcone failed causing minor damage to the honeycomb flow straightener. The vortex generators were removed from the facility and calibration testing was terminated. A follow-up test entry was conducted in 1997 in order to fully calibrate the facility without the effects of the vortex generators and to provide a complete calibration of the newly expanded low speed operating range. During the 1997 tunnel entry, all planned test points required for a complete test section calibration were obtained. This data set included detailed in-plane and axial flow field distributions for use in quantifying the test section flow quality.

Arrington, E. Allen

2012-01-01

430

Calibration of the ATLAS Muon Chambers  

NASA Astrophysics Data System (ADS)

The high-pressure drift tube chambers for the muon spectrometer of the ATLAS detector at the LHC have to provide a track position resolution of 40 ?m. The chambers consist of two triple or quadruple layers of drift tubes of 30 mm diameter with a average spatial resolution of 80 ?m. The precise knowledge of the space-to-drift-time relation r(t) to better than 20 ?m is mandatory. It has to be recalibrated every few hours during ATLAS data taking using muon tracks from a dedicated data stream. The data of the stream will be processed at three calibration centres such that a new drift chamber calibration will be provided within a few hours after data taking. We shall present the drift-chamber calibration concepts, the key features of the calibration algorithms, and the results of the calibration of cosmic muon data recorded by the ATLAS detector.

Rauscher, Felix

2010-04-01

431

The Second VLBA Calibrator Survey: VCS2  

NASA Astrophysics Data System (ADS)

This paper presents an extension of the Very Long Baseline Array Calibrator Survey, called VCS2, containing 276 sources. This survey fills in regions of the sky that were not completely covered by the previous VCS1 calibrator survey. The VCS2 survey includes calibrator sources near the Galactic plane, -30degcalibrators. The positions have been derived from astrometric analysis of the group delays measured at 2.3 and 8.4 GHz using the Goddard Space Flight Center CALC/SOLVE package. From the VLBA snapshot observations, images of the calibrators are available, and each source is given a quality code for anticipated use. The VCS2 catalog is available from the NRAO Web site.

Fomalont, E. B.; Petrov, L.; MacMillan, D. S.; Gordon, D.; Ma, C.

2003-11-01

432

Assessing students' metacognitive calibration with knowledge surveys  

NASA Astrophysics Data System (ADS)

"Calibration" is an aspect of metacognition that describes how well students assess their own knowledge. One tool that can help to assess student calibration is the knowledge survey (KS). On a KS, students rate their confidence in their ability to answer questions related to course content. A comparison of a student's confidence level with their actual performance on course exams gives an indication of the student's metacognitive calibration. We report on a study that explores students' responses to a KS in introductory physics and chemistry courses serving both STEM and non-STEM populations. In many courses, Delta (the difference between KS-score and final exam score, a measure of calibration) was anti-correlated with final exam performance. No relationship was found between Delta and students' scientific reasoning abilities. We also report preliminary findings on how calibration differs for questions of a quantitative nature vs. those of a more conceptual nature.

Lindsey, Beth A.; Nagel, Megan

2013-01-01

433

Calibration of a polarimetric imaging SAR  

NASA Technical Reports Server (NTRS)

Calibration of polarimetric imaging Synthetic Aperture Radars (SAR's) using point calibration targets is discussed. The four-port network calibration techniques is used to describe the radar error model. The polarimetric ambiguity function of the SAR is then found using a single point target, namely a trihedral corner reflector. Based on this, an estimate for the backscattering coefficient of the terrain is found by a deconvolution process. A radar image taken by the JPL Airborne SAR (AIRSAR) is used for verification of the deconvolution calibration method. The