X-Ray Measurements Of A Thermo Scientific P385 DD Neutron Generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wharton, C. J.; Seabury, E. H.; Chichester, D. L.

2011-06-01

Idaho National Laboratory is experimenting with electrical neutron generators, as potential replacements for californium-252 radioisotopic neutron sources in its PINS prompt gamma-ray neutron activation analysis (PGNAA) system for the identification of military chemical warfare agents and explosives. In addition to neutron output, we have recently measured the x-ray output of the Thermo Scientific P385 deuterium-deuterium neutron generator. X rays are a normal byproduct from neutron generators, but depending on their intensity and energy, x rays can interfere with gamma rays from the object under test, increase gamma-spectrometer dead time, and reduce PGNAA system throughput. The P385 x-ray energy spectrum wasmore » measured with a high-purity germanium (HPGe) detector, and a broad peak is evident at about 70 keV. To identify the source of the x rays within the neutron generator assembly, it was scanned by collimated scintillation detectors along its long axis. At the strongest x-ray emission points, the generator also was rotated 60 deg. between measurements. The scans show the primary source of x-ray emission from the P385 neutron generator is an area 60 mm from the neutron production target, in the vicinity of the ion source. Rotation of the neutron generator did not significantly alter the x-ray count rate, and its x-ray emission appears to be axially symmetric. A thin lead shield, 3.2 mm (1/8 inch) thick, reduced the 70-keV generator x rays to negligible levels.« less

X-Ray Measurements Of A Thermo Scientific P385 DD Neutron Generator

NASA Astrophysics Data System (ADS)

Wharton, C. J.; Seabury, E. H.; Chichester, D. L.; Caffrey, A. J.; Simpson, J.; Lemchak, M.

2011-06-01

Idaho National Laboratory is experimenting with electrical neutron generators, as potential replacements for californium-252 radioisotopic neutron sources in its PINS prompt gamma-ray neutron activation analysis (PGNAA) system for the identification of military chemical warfare agents and explosives. In addition to neutron output, we have recently measured the x-ray output of the Thermo Scientific P385 deuterium-deuterium neutron generator. X rays are a normal byproduct from neutron generators, but depending on their intensity and energy, x rays can interfere with gamma rays from the object under test, increase gamma-spectrometer dead time, and reduce PGNAA system throughput. The P385 x-ray energy spectrum was measured with a high-purity germanium (HPGe) detector, and a broad peak is evident at about 70 keV. To identify the source of the x rays within the neutron generator assembly, it was scanned by collimated scintillation detectors along its long axis. At the strongest x-ray emission points, the generator also was rotated 60° between measurements. The scans show the primary source of x-ray emission from the P385 neutron generator is an area 60 mm from the neutron production target, in the vicinity of the ion source. Rotation of the neutron generator did not significantly alter the x-ray count rate, and its x-ray emission appears to be axially symmetric. A thin lead shield, 3.2 mm (1/8 inch) thick, reduced the 70-keV generator x rays to negligible levels.

Monte Carlo simulation of moderator and reflector in coal analyzer based on a D-T neutron generator.

PubMed

Shan, Qing; Chu, Shengnan; Jia, Wenbao

2015-11-01

Coal is one of the most popular fuels in the world. The use of coal not only produces carbon dioxide, but also contributes to the environmental pollution by heavy metals. In prompt gamma-ray neutron activation analysis (PGNAA)-based coal analyzer, the characteristic gamma rays of C and O are mainly induced by fast neutrons, whereas thermal neutrons can be used to induce the characteristic gamma rays of H, Si, and heavy metals. Therefore, appropriate thermal and fast neutrons are beneficial in improving the measurement accuracy of heavy metals, and ensure that the measurement accuracy of main elements meets the requirements of the industry. Once the required yield of the deuterium-tritium (d-T) neutron generator is determined, appropriate thermal and fast neutrons can be obtained by optimizing the neutron source term. In this article, the Monte Carlo N-Particle (MCNP) Transport Code and Evaluated Nuclear Data File (ENDF) database are used to optimize the neutron source term in PGNAA-based coal analyzer, including the material and shape of the moderator and neutron reflector. The optimized targets include two points: (1) the ratio of the thermal to fast neutron is 1:1 and (2) the total neutron flux from the optimized neutron source in the sample increases at least 100% when compared with the initial one. The simulation results show that, the total neutron flux in the sample increases 102%, 102%, 85%, 72%, and 62% with Pb, Bi, Nb, W, and Be reflectors, respectively. Maximum optimization of the targets is achieved when the moderator is a 3-cm-thick lead layer coupled with a 3-cm-thick high-density polyethylene (HDPE) layer, and the neutron reflector is a 27-cm-thick hemispherical lead layer. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Comparison of Neutron-Based Non-Destructive Assessment Methods for Chemical Warfare Materiel and High Explosives

DOE Office of Scientific and Technical Information (OSTI.GOV)

E.H. Seabury; D.L. Chichester; C.J. Wharton

2008-08-01

Prompt Gamma Neutron Activation Analysis (PGNAA) systems employ neutrons as a probe to interrogate items, e.g. chemical warfare materiel-filled munitions. The choice of a neutron source in field-portable systems is determined by its ability to excite nuclei of interest, operational concerns such as radiological safety and ease-of-use, and cost. Idaho National Laboratory’s PINS Chemical Assay System has traditionally used a Cf-252 isotopic neutron source, but recently a Deuterium-Tritium (DT) Electronic Neutron Generator (ENG) has been tested as an alternate neutron source. This paper presents the results of using both of these neutron sources to interrogate chemical warfare materiel (CWM) andmore » high explosive (HE) filled munitions.« less

A Comparison of Neutron-Based Non-Destructive Assessment Methods for Chemical Warfare Material and High Explosives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seabury, E. H.; Chichester, D. L.; Wharton, C. J.

2009-03-10

Prompt Gamma Neutron Activation Analysis (PGNAA) systems employ neutrons as a probe to interrogate items, e.g. chemical warfare materiel-filled munitions. The choice of a neutron source in field-portable systems is determined by its ability to excite nuclei of interest, operational concerns such as radiological safety and ease-of-use, and cost. Idaho National Laboratory's PINS Chemical Assay System has traditionally used a {sup 252}Cf isotopic neutron source, but recently a deuterium-tritium (DT) electronic neutron generator (ENG) has been tested as an alternate neutron source. This paper presents the results of using both of these neutron sources to interrogate chemical warfare materiel (CWM)more » and high explosive (HE) filled munitions.« less

Performance tests of a large volume cerium tribromide (CeBr3) scintillation detector.

PubMed

Naqvi, A A; Khiari, F Z; Liadi, F A; Khateeb-Ur-Rehman; Isab, A A

2016-08-01

The response of a large cylindrical 76mm×76mm (height×diameter) cerium tribromide (CeBr3) detector was measured for prompt gamma rays. The total intrinsic activity of the CeBr3 detector, which was measured over 0.33-3.33MeV range, was found to be 0.022±0.001 counts/s/cm(3). The partial intrinsic activity ( due to (227)Ac contamination), was measured over a energy range of 1.22-2.20MeV energy, was found to be 0.007±0.001 counts/s/cm(3). Compared to intrinsic activities of LaBr3:Ce and LaCl3:Ce detectors of equivalent volume, the CeBr3 detector has 7-8 times less total intrinsic activity. The detector response for low energy prompt gamma rays was measured over 0.3-0.6MeVgamma energy range using a portable neutron generator-based Prompt Gamma Neutron Activation Analysis (PGNAA) setup. The experimental yield of boron, cadmium and mercury prompt gamma-rays was measured from water samples contaminated with 0.75-2.5wt% mercury, 0.31-2.50wt% boron, and 0.0625-0.500wt% cadmium, respectively. An excellent agreement has been observed between the calculated and experimental yields of the gamma rays. Also minimum detection limit (MDC) of the CeBr3 detector was measured for boron, cadmium and mercury samples. The CeBr3 detector has 23% smaller value of MDCB and 18% larger value of MDCCd than those of a LaBr3:Ce detector of equivalent size. This study has shown that CeBr3 detector has an excellent response for the low energy prompt gamma-rays with almost an order of magnitude low intrinsic activity as compared to LaCl3:Ce and LaBr3:Ce detectors of equivalent volume. Copyright © 2016 Elsevier Ltd. All rights reserved.

HPGe detector shielding optimization with MCNPX for the MEDINA PGNAA cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicol, T.; Perot, B.; Carasco, C.

2015-07-01

Radioactive waste repositories must guarantee the non-toxicity of the waste in the long term, not only regarding radioactivity but also regarding other environmental contamination such as toxic chemicals. Analytical methods already exist for chemical characterization (ICP-MS, ICP-AES...) but they are based on test sampling. A possible alternative, for waste packages with an appropriate gamma radiation level, is to use Prompt Gamma Neutron Activation Analysis (PGNAA), a non-destructive measurement technique sensitive to several toxic chemicals. In view of the characterization of radioactive wastes in Germany and France, collaboration between the CEA Cadarache (France) and the Forschungszentrum Juelich (Germany) was initiated amore » few years ago. FZJ holds a PGNAA graphite cell called MEDINA (Multi Element Detection based on Instrumental Neutron Activation), allowing the characterization of 225 L drums. Fast neutrons are emitted from a D-T pulsed 14 MeV neutron generator and thermalized in graphite to induced radiative captures in the waste materials. Prompt capture gamma rays are detected using a 104% relative efficiency n-type HPGe. However, HPGe crystal is sensitive to fast neutron damage and to thermal neutron activation. A thermal neutron shield made of lithium fluorine and lithium carbonate is already used around the detector. In order to further decrease the current of fast and thermal neutrons coming into the crystal without penalizing MEDINA sensitivity (by decreasing the thermal neutron flux and neutron die away time of the cell, the gamma detection efficiency, or increasing the gamma background), some configurations based on easy-to-implement modifications of MEDINA have been simulated with MCNPX with a model of the cell already validated by experiments. Results show that fast and thermal neutron incoming current in the HPGe could easily be reduced by about a factor of 2 by additional quantities of graphite and by replacing lithium carbonate by lithium fluorine with a higher {sup 6}Li concentration. In addition, these modifications slightly increase the thermal neutron flux in the cell without deteriorating the neutron die away time, and reduce the gamma background about a factor of 2 during the neutron pulse but 5 times less after it. More important changes have also been tested, such as the addition of polyethylene and lead between the neutron generator and the HPGe detector, which is more effective regarding neutron shielding but decreases the neutron die away time, partly compensated by a larger initial thermal neutron flux. Concerning gamma background, hydrogen capture gamma ray (2.23 MeV) is increased due to the presence of polyethylene but lead around the HPGe decreases the total gamma background. In conclusion, simple modifications are possible to improve detector shielding and life time before thermal annealing of the crystal, without reducing MEDINA cell performances. Some of these modifications will be tested in the coming months. (authors)« less

Feasibility study for wax deposition imaging in oil pipelines by PGNAA technique.

PubMed

Cheng, Can; Jia, Wenbao; Hei, Daqian; Wei, Zhiyong; Wang, Hongtao

2017-10-01

Wax deposition in pipelines is a crucial problem in the oil industry. A method based on the prompt gamma-ray neutron activation analysis technique was applied to reconstruct the image of wax deposition in oil pipelines. The 2.223MeV hydrogen capture gamma rays were used to reconstruct the wax deposition image. To validate the method, both MCNP simulation and experiments were performed for wax deposited with a maximum thickness of 20cm. The performance of the method was simulated using the MCNP code. The experiment was conducted with a 252 Cf neutron source and a LaBr 3 : Ce detector. A good correspondence between the simulations and the experiments was observed. The results obtained indicate that the present approach is efficient for wax deposition imaging in oil pipelines. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of a technique using MCNPX code for determination of nitrogen content of explosive materials using prompt gamma neutron activation analysis method

NASA Astrophysics Data System (ADS)

Nasrabadi, M. N.; Bakhshi, F.; Jalali, M.; Mohammadi, A.

2011-12-01

Nuclear-based explosive detection methods can detect explosives by identifying their elemental components, especially nitrogen. Thermal neutron capture reactions have been used for detecting prompt gamma 10.8 MeV following radioactive neutron capture by 14N nuclei. We aimed to study the feasibility of using field-portable prompt gamma neutron activation analysis (PGNAA) along with improved nuclear equipment to detect and identify explosives, illicit substances or landmines. A 252Cf radio-isotopic source was embedded in a cylinder made of high-density polyethylene (HDPE) and the cylinder was then placed in another cylindrical container filled with water. Measurements were performed on high nitrogen content compounds such as melamine (C3H6N6). Melamine powder in a HDPE bottle was placed underneath the vessel containing water and the neutron source. Gamma rays were detected using two NaI(Tl) crystals. The results were simulated with MCNP4c code calculations. The theoretical calculations and experimental measurements were in good agreement indicating that this method can be used for detection of explosives and illicit drugs.

Technical Note: Introduction of variance component analysis to setup error analysis in radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuo, Yukinori, E-mail: ymatsuo@kuhp.kyoto-u.ac.

Purpose: The purpose of this technical note is to introduce variance component analysis to the estimation of systematic and random components in setup error of radiotherapy. Methods: Balanced data according to the one-factor random effect model were assumed. Results: Analysis-of-variance (ANOVA)-based computation was applied to estimate the values and their confidence intervals (CIs) for systematic and random errors and the population mean of setup errors. The conventional method overestimates systematic error, especially in hypofractionated settings. The CI for systematic error becomes much wider than that for random error. The ANOVA-based estimation can be extended to a multifactor model considering multiplemore » causes of setup errors (e.g., interpatient, interfraction, and intrafraction). Conclusions: Variance component analysis may lead to novel applications to setup error analysis in radiotherapy.« less

Design and Analysis of an Experimental Setup for Determining the Burst Strength and Material Properties of Hollow Cylinders

DTIC Science & Technology

2015-12-01

NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited DESIGN AND ANALYSIS...2. REPORT DATE December 2015 3. REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE DESIGN AND ANALYSIS OF AN EXPERIMENTAL SETUP...Approved for public release; distribution is unlimited DESIGN AND ANALYSIS OF AN EXPERIMENTAL SETUP FOR DETERMINING THE BURST STRENGTH AND MATERIAL

The feasibility of in vivo quantification of bone-gadolinium in humans by prompt gamma neutron activation analysis (PGNAA) following gadolinium-based contrast-enhanced MRI

NASA Astrophysics Data System (ADS)

Mostafaei, F.; McNeill, F. E.; Chettle, D. R.; Noseworthy, M. D.; Prestwich, W. V.

2015-11-01

The feasibility of using a 238Pu/Be-based in vivo prompt γ-ray neutron activation analysis (IVNAA) system, previously successfully used for measurements of muscle, for the detection of gadolinium (Gd) in bone was presented. Gd is extensively used in contrast agents in MR imaging. We present phantom measurement data for the measurement of Gd in the tibia. Gd has seven naturally occurring isotopes, of which two have extremely large neutron capture cross sections; 155Gd (14.8% natural abundance (NA), σ= 60,900 barns) and 157Gd (15.65% NA, σ= 254,000 barns). Our previous work focused on muscle but this only informs about the short term kinetics of Gd. We studied the possibility of measuring bone, as it may be a long term storage site for Gd. A human simulating bone phantom set was developed. The phantoms were doped with seven concentrations of Gd of concentrations 0.0, 25, 50, 75, 100, 120 and 150 ppm. Additional elements important for neutron activation analysis, Na, Cl and Ca, were also included to create an overall elemental composition consistent with Reference Man. The overall conclusion is that the potential application of this Pu-Be-based prompt in vivo NAA for the monitoring of the storage and retention of Gd in bone is not feasible.

Development of high flux thermal neutron generator for neutron activation analysis

NASA Astrophysics Data System (ADS)

Vainionpaa, Jaakko H.; Chen, Allan X.; Piestrup, Melvin A.; Gary, Charles K.; Jones, Glenn; Pantell, Richard H.

2015-05-01

The new model DD110MB neutron generator from Adelphi Technology produces thermal (<0.5 eV) neutron flux that is normally achieved in a nuclear reactor or larger accelerator based systems. Thermal neutron fluxes of 3-5 · 107 n/cm2/s are measured. This flux is achieved using four ion beams arranged concentrically around a target chamber containing a compact moderator with a central sample cylinder. Fast neutron yield of ∼2 · 1010 n/s is created at the titanium surface of the target chamber. The thickness and material of the moderator is selected to maximize the thermal neutron flux at the center. The 2.5 MeV neutrons are quickly thermalized to energies below 0.5 eV and concentrated at the sample cylinder. The maximum flux of thermal neutrons at the target is achieved when approximately half of the neutrons at the sample area are thermalized. In this paper we present simulation results used to characterize performance of the neutron generator. The neutron flux can be used for neutron activation analysis (NAA) prompt gamma neutron activation analysis (PGNAA) for determining the concentrations of elements in many materials. Another envisioned use of the generator is production of radioactive isotopes. DD110MB is small enough for modest-sized laboratories and universities. Compared to nuclear reactors the DD110MB produces comparable thermal flux but provides reduced administrative and safety requirements and it can be run in pulsed mode, which is beneficial in many neutron activation techniques.

Low-Cost Manufacturing, Usability, and Security: An Analysis of Bluetooth Simple Pairing and Wi-Fi Protected Setup

NASA Astrophysics Data System (ADS)

Kuo, Cynthia; Walker, Jesse; Perrig, Adrian

Bluetooth Simple Pairing and Wi-Fi Protected Setup specify mechanisms for exchanging authentication credentials in wireless networks. Both Simple Pairing and Protected Setup support multiple setup mechanisms, which increases security risks and hurts the user experience. To improve the security and usability of these specifications, we suggest defining a common baseline for hardware features and a consistent, interoperable user experience across devices.

Huygens' inspired multi-pendulum setups: Experiments and stability analysis

NASA Astrophysics Data System (ADS)

Hoogeboom, F. N.; Pogromsky, A. Y.; Nijmeijer, H.

2016-11-01

This paper examines synchronization of a set of metronomes placed on a lightweight foam platform. Two configurations of the set of metronomes are considered: a row setup containing one-dimensional coupling and a cross setup containing two-dimensional coupling. Depending on the configuration and coupling between the metronomes, i.e., the platform parameters, in- and/or anti-phase synchronized behavior is observed in the experiments. To explain this behavior, mathematical models of a metronome and experimental setups have been derived and used in a local stability analysis. It is numerically and experimentally demonstrated that varying the coupling parameters for both configurations has a significant influence on the stability of the synchronized solutions.

Positron lifetime setup based on DRS4 evaluation board

NASA Astrophysics Data System (ADS)

Petriska, M.; Sojak, S.; Slugeň, V.

2014-04-01

A digital positron lifetime setup based on DRS4 evaluation board designed at the Paul Scherrer Institute has been constructed and tested in the Positron annihilation laboratory Slovak University of Technology Bratislava. The high bandwidth, low power consumption and short readout time make DRS4 chip attractive for positron annihilation lifetime (PALS) setup, replacing traditional ADCs and TDCs. A software for PALS setup online and offline pulse analysis was developed with Qt,Qwt and ALGLIB libraries.

In-air RBS measurements at the LAMFI external beam setup

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silva, T. F.; Added, N.; Moro, M. V.

2014-11-11

This work describes new developments in the external beam setup of the Laboratory of Material Analysis with Ion Beams of the University of São Paulo (LAMFI-USP). This setup was designed to be a versatile analytical station to analyze a broad range of samples. In recent developments, we seek the external beam Rutherford Backscattering Spectroscopy (RBS) analysis to complement the Particle Induced X-ray Emission (PIXE) measurements. This work presents the initial results of the external beam RBS analysis as well as recent developments to improve the energy resolution RBS measurements, in particular tests to seek for sources of resolution degradation. Thesemore » aspects are discussed and preliminary results of in-air RBS analysis of some test samples are presented.« less

Analysis of dispatching rules in a stochastic dynamic job shop manufacturing system with sequence-dependent setup times

NASA Astrophysics Data System (ADS)

Sharma, Pankaj; Jain, Ajai

2014-12-01

Stochastic dynamic job shop scheduling problem with consideration of sequence-dependent setup times are among the most difficult classes of scheduling problems. This paper assesses the performance of nine dispatching rules in such shop from makespan, mean flow time, maximum flow time, mean tardiness, maximum tardiness, number of tardy jobs, total setups and mean setup time performance measures viewpoint. A discrete event simulation model of a stochastic dynamic job shop manufacturing system is developed for investigation purpose. Nine dispatching rules identified from literature are incorporated in the simulation model. The simulation experiments are conducted under due date tightness factor of 3, shop utilization percentage of 90% and setup times less than processing times. Results indicate that shortest setup time (SIMSET) rule provides the best performance for mean flow time and number of tardy jobs measures. The job with similar setup and modified earliest due date (JMEDD) rule provides the best performance for makespan, maximum flow time, mean tardiness, maximum tardiness, total setups and mean setup time measures.

High-resolution continuous-flow analysis setup for water isotopic measurement from ice cores using laser spectroscopy

NASA Astrophysics Data System (ADS)

Emanuelsson, B. D.; Baisden, W. T.; Bertler, N. A. N.; Keller, E. D.; Gkinis, V.

2015-07-01

Here we present an experimental setup for water stable isotope (δ18O and δD) continuous-flow measurements and provide metrics defining the performance of the setup during a major ice core measurement campaign (Roosevelt Island Climate Evolution; RICE). We also use the metrics to compare alternate systems. Our setup is the first continuous-flow laser spectroscopy system that is using off-axis integrated cavity output spectroscopy (OA-ICOS; analyzer manufactured by Los Gatos Research, LGR) in combination with an evaporation unit to continuously analyze water samples from an ice core. A Water Vapor Isotope Standard Source (WVISS) calibration unit, manufactured by LGR, was modified to (1) enable measurements on several water standards, (2) increase the temporal resolution by reducing the response time and (3) reduce the influence from memory effects. While this setup was designed for the continuous-flow analysis (CFA) of ice cores, it can also continuously analyze other liquid or vapor sources. The custom setups provide a shorter response time (~ 54 and 18 s for 2013 and 2014 setup, respectively) compared to the original WVISS unit (~ 62 s), which is an improvement in measurement resolution. Another improvement compared to the original WVISS is that the custom setups have a reduced memory effect. Stability tests comparing the custom and WVISS setups were performed and Allan deviations (σAllan) were calculated to determine precision at different averaging times. For the custom 2013 setup the precision after integration times of 103 s is 0.060 and 0.070 ‰ for δ18O and δD, respectively. The corresponding σAllan values for the custom 2014 setup are 0.030, 0.060 and 0.043 ‰ for δ18O, δD and δ17O, respectively. For the WVISS setup the precision is 0.035, 0.070 and 0.042 ‰ after 103 s for δ18O, δD and δ17O, respectively. Both the custom setups and WVISS setup are influenced by instrumental drift with δ18O being more drift sensitive than δD. The σAllan values for δ18O are 0.30 and 0.18 ‰ for the custom 2013 and WVISS setup, respectively, after averaging times of 104 s (2.78 h). Using response time tests and stability tests, we show that the custom setups are more responsive (shorter response time), whereas the University of Copenhagen (UC) setup is more stable. More broadly, comparisons of different setups address the challenge of integrating vaporizer/spectrometer isotope measurement systems into a CFA campaign with many other analytical instruments.

High-resolution continuous flow analysis setup for water isotopic measurement from ice cores using laser spectroscopy

NASA Astrophysics Data System (ADS)

Emanuelsson, B. D.; Baisden, W. T.; Bertler, N. A. N.; Keller, E. D.; Gkinis, V.

2014-12-01

Here we present an experimental setup for water stable isotopes (δ18O and δD) continuous flow measurements. It is the first continuous flow laser spectroscopy system that is using Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS; analyzer manufactured by Los Gatos Research - LGR) in combination with an evaporation unit to continuously analyze sample from an ice core. A Water Vapor Isotopic Standard Source (WVISS) calibration unit, manufactured by LGR, was modified to: (1) increase the temporal resolution by reducing the response time (2) enable measurements on several water standards, and (3) to reduce the influence from memory effects. While this setup was designed for the Continuous Flow Analysis (CFA) of ice cores, it can also continuously analyze other liquid or vapor sources. The modified setup provides a shorter response time (~54 and 18 s for 2013 and 2014 setup, respectively) compared to the original WVISS unit (~62 s), which is an improvement in measurement resolution. Another improvement compared to the original WVISS is that the modified setup has a reduced memory effect. Stability tests comparing the modified WVISS and WVISS setups were performed and Allan deviations (σAllan) were calculated to determine precision at different averaging times. For the 2013 modified setup the precision after integration times of 103 s are 0.060 and 0.070‰ for δ18O and δD, respectively. For the WVISS setup the corresponding σAllan values are 0.030, 0.060 and 0.043‰ for δ18O, δD and δ17O, respectively. For the WVISS setup the precision is 0.035, 0.070 and 0.042‰ after 103 s for δ18O, δD and δ17O, respectively. Both the modified setups and WVISS setup are influenced by instrumental drift with δ18O being more drift sensitive than δD. The σAllan values for δ18O of 0.30 and 0.18‰ for the modified (2013) and WVISS setup, respectively after averaging times of 104 s (2.78 h). The Isotopic Water Analyzer (IWA)-modified WVISS setup used during the 2013 Roosevelt Island Climate Evolution (RICE) ice core processing campaign achieved high precision measurements, in particular for δD, with high temporal resolution for the upper part of the core, where a seasonally resolved isotopic signal is preserved.

Development of a New Optical Measuring Set-Up

NASA Astrophysics Data System (ADS)

Miroshnichenko, I. P.; Parinov, I. A.

2018-06-01

The paper proposes a description of the developed optical measuring set-up for the contactless recording and processing of measurement results for small spatial (linear and angular) displacements of control surfaces based on the use of laser technologies and optical interference methods. The proposed set-up is designed to solve all the arising measurement tasks in the study of the physical and mechanical properties of new materials and in the process of diagnosing the state of structural materials by acoustic active methods of nondestructive testing. The structure of the set-up, its constituent parts are described, and the features of construction and functioning during measurements are discussed. New technical solutions for the implementation of the components of the set-up under consideration are obtained. The purpose and description of the original specialized software, used to perform a priori analysis of measurement results, are present, while performing measurements, for a posteriori analysis of measurement results. Moreover, the influences of internal and external disturbance effects on the measurement results and correcting measurement results directly in their implementation are determined. The technical solutions, used in the set-up, are protected by the patents of the Russian Federation for inventions, and software is protected by the certificates of state registration of computer programs. The proposed set-up is intended for use in instrumentation, mechanical engineering, shipbuilding, aviation, energy sector, etc.

Computer Series, 107.

ERIC Educational Resources Information Center

Birk, James P., Ed.

1989-01-01

Presented is a simple laboratory set-up for teaching microprocessor-controlled data acquisition as a part of an instrumental analysis course. Discussed are the experimental set-up, experimental procedures, and technical considerations for this technique. (CW)

Efficacy and workload analysis of a fixed vertical couch position technique and a fixed‐action–level protocol in whole‐breast radiotherapy

PubMed Central

Verhoeven, Karolien; Weltens, Caroline; Van den Heuvel, Frank

2015-01-01

Quantification of the setup errors is vital to define appropriate setup margins preventing geographical misses. The no‐action–level (NAL) correction protocol reduces the systematic setup errors and, hence, the setup margins. The manual entry of the setup corrections in the record‐and‐verify software, however, increases the susceptibility of the NAL protocol to human errors. Moreover, the impact of the skin mobility on the anteroposterior patient setup reproducibility in whole‐breast radiotherapy (WBRT) is unknown. In this study, we therefore investigated the potential of fixed vertical couch position‐based patient setup in WBRT. The possibility to introduce a threshold for correction of the systematic setup errors was also explored. We measured the anteroposterior, mediolateral, and superior–inferior setup errors during fractions 1–12 and weekly thereafter with tangential angled single modality paired imaging. These setup data were used to simulate the residual setup errors of the NAL protocol, the fixed vertical couch position protocol, and the fixed‐action–level protocol with different correction thresholds. Population statistics of the setup errors of 20 breast cancer patients and 20 breast cancer patients with additional regional lymph node (LN) irradiation were calculated to determine the setup margins of each off‐line correction protocol. Our data showed the potential of the fixed vertical couch position protocol to restrict the systematic and random anteroposterior residual setup errors to 1.8 mm and 2.2 mm, respectively. Compared to the NAL protocol, a correction threshold of 2.5 mm reduced the frequency of mediolateral and superior–inferior setup corrections with 40% and 63%, respectively. The implementation of the correction threshold did not deteriorate the accuracy of the off‐line setup correction compared to the NAL protocol. The combination of the fixed vertical couch position protocol, for correction of the anteroposterior setup error, and the fixed‐action–level protocol with 2.5 mm correction threshold, for correction of the mediolateral and the superior–inferior setup errors, was proved to provide adequate and comparable patient setup accuracy in WBRT and WBRT with additional LN irradiation. PACS numbers: 87.53.Kn, 87.57.‐s

Analysis of aerobic granular sludge formation based on grey system theory.

PubMed

Zhang, Cuiya; Zhang, Hanmin

2013-04-01

Based on grey entropy analysis, the relational grade of operational parameters with aerobic granular sludge's granulation indicators was studied. The former consisted of settling time (ST), aeration time (AT), superficial gas velocity (SGV), height/diameter (H/D) ratio and organic loading rates (OLR), the latter included sludge volume index (SVI) and set-up time. The calculated result showed that for SVI and set-up time, the influence orders and the corresponding grey entropy relational grades (GERG) were: SGV (0.9935) > AT (0.9921) > OLR (0.9894) > ST (0.9876) > H/D (0.9857) and SGV (0.9928) > H/D (0.9914) > AT (0.9909) > OLR (0.9897) > ST (0.9878). The chosen parameters were all key impact factors as each GERG was larger than 0.98. SGV played an important role in improving SVI transformation and facilitating the set-up process. The influence of ST on SVI and set-up time was relatively low due to its dual functions. SVI transformation and rapid set-up demanded different optimal H/D ratio scopes (10-20 and 16-20). Meanwhile, different functions could be obtained through adjusting certain factors' scope.

Conceptual study of a heavy-ion-ERDA spectrometer for energies below 6 MeV

NASA Astrophysics Data System (ADS)

Julin, Jaakko; Sajavaara, Timo

2017-09-01

Elastic recoil detection analysis (ERDA) is a well established technique and it offers unique capabilities in thin film analysis. Simultaneous detection and depth profiling of all elements, including hydrogen, is possible only with time-of-flight ERDA. Bragg ionization chambers or ΔE - E detectors can also be used to identify the recoiling element if sufficiently high energies are used. The chief limitations of time-of-flight ERDA are the beam induced sample damage and the requirement of a relatively large accelerator. In this paper we propose a detector setup, which could be used with 3 MeV to 6 MeV medium heavy beams from either a single ended accelerator (40Ar) or from a tandem accelerator (39K). The detector setup consists of two timing detectors and a gas ionization chamber energy detector. Compared to use of very heavy low energy ions the hydrogen recoils with this beam have sufficient energy to be detected with current gas ionization chamber energy detector. To reduce the beam induced damage the proposed detector setup covers a solid angle larger than 1 msr, roughly an order of magnitude improvement over most time-of-flight ERDA setups. The setup could be used together with a small accelerator to be used for light element analysis of approximately 50 nm films. The concept is tested with 39K beam from a 1.7 MV Pelletron tandem accelerator with the Jyväskylä ToF-ERDA setup. In addition to the measurements effects related to low energies and increase in the solid angle are simulated with Monte Carlo methods.

Investigating and understanding fouling in a planar setup using ultrasonic methods.

PubMed

Wallhäusser, E; Hussein, M A; Becker, T

2012-09-01

Fouling is an unwanted deposit on heat transfer surfaces and occurs regularly in foodstuff heat exchangers. Fouling causes high costs because cleaning of heat exchangers has to be carried out and cleaning success cannot easily be monitored. Thus, used cleaning cycles in foodstuff industry are usually too long leading to high costs. In this paper, a setup is described with which it is possible, first, to produce dairy protein fouling similar to the one found in industrial heat exchangers and, second, to detect the presence and absence of such fouling using an ultrasonic based measuring method. The developed setup resembles a planar heat exchanger in which fouling can be made and cleaned reproducible. Fouling presence, absence, and cleaning progress can be monitored by using an ultrasonic detection unit. The setup is described theoretically based on electrical and mechanical lumped circuits to derive the wave equation and the transfer function to perform a sensitivity analysis. Sensitivity analysis was done to determine influencing quantities and showed that fouling is measurable. Also, first experimental results are compared with results from sensitivity analysis.

GRAPhEME: a setup to measure (n, xn γ) reaction cross sections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henning, Greg; Bacquias, A.; Capdevielle, O.

2015-07-01

Most of nuclear reactor developments are using evaluated data base for numerical simulations. However, the considered databases present still large uncertainties and disagreements. To improve their level of precision, new measurements are needed, in particular for (n, xn) reactions, which are of great importance as they modify the neutron spectrum, the neutron population, and produce radioactive species. The IPHC group started an experimental program to measure (n, xn gamma) reaction cross sections using prompt gamma spectroscopy and neutron energy determination by time of flight. Measurements of (n, xn gamma) cross section have been performed for {sup 235,238}U, {sup 232}Th, {supmore » nat,182,183,184,186}W, {sup nat}Zr. The experimental setup is installed at the neutron beam at GELINA (Geel, Belgium). The setup has recently been upgraded with the addition of a highly segmented 36 pixels planar HPGe detector. Significant efforts have been made to reduce radiation background and electromagnetic perturbations. The setup is equipped with a high rate digital acquisition system. The analysis of the segmented detector data requires a specific procedure to account for cross signals between pixels. An overall attention is paid to the precision of the measurement. The setup characteristic and the analysis procedure will be presented along with the acquisition and analysis challenges. Examples of results and their impact on models will be discussed. (authors)« less

Status of the Monte Carlo library least-squares (MCLLS) approach for non-linear radiation analyzer problems

NASA Astrophysics Data System (ADS)

Gardner, Robin P.; Xu, Libai

2009-10-01

The Center for Engineering Applications of Radioisotopes (CEAR) has been working for over a decade on the Monte Carlo library least-squares (MCLLS) approach for treating non-linear radiation analyzer problems including: (1) prompt gamma-ray neutron activation analysis (PGNAA) for bulk analysis, (2) energy-dispersive X-ray fluorescence (EDXRF) analyzers, and (3) carbon/oxygen tool analysis in oil well logging. This approach essentially consists of using Monte Carlo simulation to generate the libraries of all the elements to be analyzed plus any other required background libraries. These libraries are then used in the linear library least-squares (LLS) approach with unknown sample spectra to analyze for all elements in the sample. Iterations of this are used until the LLS values agree with the composition used to generate the libraries. The current status of the methods (and topics) necessary to implement the MCLLS approach is reported. This includes: (1) the Monte Carlo codes such as CEARXRF, CEARCPG, and CEARCO for forward generation of the necessary elemental library spectra for the LLS calculation for X-ray fluorescence, neutron capture prompt gamma-ray analyzers, and carbon/oxygen tools; (2) the correction of spectral pulse pile-up (PPU) distortion by Monte Carlo simulation with the code CEARIPPU; (3) generation of detector response functions (DRF) for detectors with linear and non-linear responses for Monte Carlo simulation of pulse-height spectra; and (4) the use of the differential operator (DO) technique to make the necessary iterations for non-linear responses practical. In addition to commonly analyzed single spectra, coincidence spectra or even two-dimensional (2-D) coincidence spectra can also be used in the MCLLS approach and may provide more accurate results.

Single-Camera Stereoscopy Setup to Visualize 3D Dusty Plasma Flows

NASA Astrophysics Data System (ADS)

Romero-Talamas, C. A.; Lemma, T.; Bates, E. M.; Birmingham, W. J.; Rivera, W. F.

2016-10-01

A setup to visualize and track individual particles in multi-layered dusty plasma flows is presented. The setup consists of a single camera with variable frame rate, and a pair of adjustable mirrors that project the same field of view from two different angles to the camera, allowing for three-dimensional tracking of particles. Flows are generated by inclining the plane in which the dust is levitated using a specially designed setup that allows for external motion control without compromising vacuum. Dust illumination is achieved with an optics arrangement that includes a Powell lens that creates a laser fan with adjustable thickness and with approximately constant intensity everywhere. Both the illumination and the stereoscopy setup allow for the camera to be placed at right angles with respect to the levitation plane, in preparation for magnetized dusty plasma experiments in which there will be no direct optical access to the levitation plane. Image data and analysis of unmagnetized dusty plasma flows acquired with this setup are presented.

High yield neutron generators using the DD reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vainionpaa, J. H.; Harris, J. L.; Piestrup, M. A.

2013-04-19

A product line of high yield neutron generators has been developed at Adelphi technology inc. The generators use the D-D fusion reaction and are driven by an ion beam supplied by a microwave ion source. Yields of up to 5 Multiplication-Sign 10{sup 9} n/s have been achieved, which are comparable to those obtained using the more efficient D-T reaction. The microwave-driven plasma uses the electron cyclotron resonance (ECR) to produce a high plasma density for high current and high atomic ion species. These generators have an actively pumped vacuum system that allows operation at reduced pressure in the target chamber,more » increasing the overall system reliability. Since no radioactive tritium is used, the generators can be easily serviced, and components can be easily replaced, providing essentially an unlimited lifetime. Fast neutron source size can be adjusted by selecting the aperture and target geometries according to customer specifications. Pulsed and continuous operation has been demonstrated. Minimum pulse lengths of 50 {mu}s have been achieved. Since the generators are easily serviceable, they offer a long lifetime neutron generator for laboratories and commercial systems requiring continuous operation. Several of the generators have been enclosed in radiation shielding/moderator structures designed for customer specifications. These generators have been proven to be useful for prompt gamma neutron activation analysis (PGNAA), neutron activation analysis (NAA) and fast neutron radiography. Thus these generators make excellent fast, epithermal and thermal neutron sources for laboratories and industrial applications that require neutrons with safe operation, small footprint, low cost and small regulatory burden.« less

High yield neutron generators using the DD reaction

NASA Astrophysics Data System (ADS)

Vainionpaa, J. H.; Harris, J. L.; Piestrup, M. A.; Gary, C. K.; Williams, D. L.; Apodaca, M. D.; Cremer, J. T.; Ji, Qing; Ludewigt, B. A.; Jones, G.

2013-04-01

A product line of high yield neutron generators has been developed at Adelphi technology inc. The generators use the D-D fusion reaction and are driven by an ion beam supplied by a microwave ion source. Yields of up to 5 × 109 n/s have been achieved, which are comparable to those obtained using the more efficient D-T reaction. The microwave-driven plasma uses the electron cyclotron resonance (ECR) to produce a high plasma density for high current and high atomic ion species. These generators have an actively pumped vacuum system that allows operation at reduced pressure in the target chamber, increasing the overall system reliability. Since no radioactive tritium is used, the generators can be easily serviced, and components can be easily replaced, providing essentially an unlimited lifetime. Fast neutron source size can be adjusted by selecting the aperture and target geometries according to customer specifications. Pulsed and continuous operation has been demonstrated. Minimum pulse lengths of 50 μs have been achieved. Since the generators are easily serviceable, they offer a long lifetime neutron generator for laboratories and commercial systems requiring continuous operation. Several of the generators have been enclosed in radiation shielding/moderator structures designed for customer specifications. These generators have been proven to be useful for prompt gamma neutron activation analysis (PGNAA), neutron activation analysis (NAA) and fast neutron radiography. Thus these generators make excellent fast, epithermal and thermal neutron sources for laboratories and industrial applications that require neutrons with safe operation, small footprint, low cost and small regulatory burden.

Multispot single-molecule FRET: High-throughput analysis of freely diffusing molecules

PubMed Central

Panzeri, Francesco

2017-01-01

We describe an 8-spot confocal setup for high-throughput smFRET assays and illustrate its performance with two characteristic experiments. First, measurements on a series of freely diffusing doubly-labeled dsDNA samples allow us to demonstrate that data acquired in multiple spots in parallel can be properly corrected and result in measured sample characteristics consistent with those obtained with a standard single-spot setup. We then take advantage of the higher throughput provided by parallel acquisition to address an outstanding question about the kinetics of the initial steps of bacterial RNA transcription. Our real-time kinetic analysis of promoter escape by bacterial RNA polymerase confirms results obtained by a more indirect route, shedding additional light on the initial steps of transcription. Finally, we discuss the advantages of our multispot setup, while pointing potential limitations of the current single laser excitation design, as well as analysis challenges and their solutions. PMID:28419142

Recent developments of ion beam induced luminescence at the external scanning microbeam facility of the LABEC laboratory in Florence

NASA Astrophysics Data System (ADS)

Colombo, E.; Calusi, S.; Cossio, R.; Giuntini, L.; Giudice, A. Lo; Mandò, P. A.; Manfredotti, C.; Massi, M.; Mirto, F. A.; Vittone, E.

2008-04-01

A new ionoluminescence (IL) apparatus has been successfully installed at the external scanning microbeam facility of the 3 MV Tandetron accelerator of the INFN LABEC in Firenze; the apparatus for photon detection has been fully integrated in the existing ion beam analysis (IBA) set-up, for the simultaneous acquisition of IL and PIXE/PIGE/BS spectra and maps. The potential of the new set-up is illustrated in this paper by some results extracted by the analysis of art objects and advanced semiconductor materials. In particular, the adequacy of the new IBA set-up in the field of cultural heritage is pointed out by the coupled PIXE/IL micro-analysis of a lapis lazuli stone; concerning applications in material science, IL spectra from a N doped diamond sample were acquired and compared with CL analyses to evaluate the relevant sensitivities and the effect of ion damage.

Reducing the overlay metrology sensitivity to perturbations of the measurement stack

NASA Astrophysics Data System (ADS)

Zhou, Yue; Park, DeNeil; Gutjahr, Karsten; Gottipati, Abhishek; Vuong, Tam; Bae, Sung Yong; Stokes, Nicholas; Jiang, Aiqin; Hsu, Po Ya; O'Mahony, Mark; Donini, Andrea; Visser, Bart; de Ruiter, Chris; Grzela, Grzegorz; van der Laan, Hans; Jak, Martin; Izikson, Pavel; Morgan, Stephen

2017-03-01

Overlay metrology setup today faces a continuously changing landscape of process steps. During Diffraction Based Overlay (DBO) metrology setup, many different metrology target designs are evaluated in order to cover the full process window. The standard method for overlay metrology setup consists of single-wafer optimization in which the performance of all available metrology targets is evaluated. Without the availability of external reference data or multiwafer measurements it is hard to predict the metrology accuracy and robustness against process variations which naturally occur from wafer-to-wafer and lot-to-lot. In this paper, the capabilities of the Holistic Metrology Qualification (HMQ) setup flow are outlined, in particular with respect to overlay metrology accuracy and process robustness. The significance of robustness and its impact on overlay measurements is discussed using multiple examples. Measurement differences caused by slight stack variations across the target area, called grating imbalance, are shown to cause significant errors in the overlay calculation in case the recipe and target have not been selected properly. To this point, an overlay sensitivity check on perturbations of the measurement stack is presented for improvement of the overlay metrology setup flow. An extensive analysis on Key Performance Indicators (KPIs) from HMQ recipe optimization is performed on µDBO measurements of product wafers. The key parameters describing the sensitivity to perturbations of the measurement stack are based on an intra-target analysis. Using advanced image analysis, which is only possible for image plane detection of μDBO instead of pupil plane detection of DBO, the process robustness performance of a recipe can be determined. Intra-target analysis can be applied for a wide range of applications, independent of layers and devices.

Evaluation of RSA set-up from a clinical biplane fluoroscopy system for 3D joint kinematic analysis.

PubMed

Bonanzinga, Tommaso; Signorelli, Cecilia; Bontempi, Marco; Russo, Alessandro; Zaffagnini, Stefano; Marcacci, Maurilio; Bragonzoni, Laura

2016-01-01

dinamic roentgen stereophotogrammetric analysis (RSA), a technique currently based only on customized radiographic equipment, has been shown to be a very accurate method for detecting three-dimensional (3D) joint motion. The aim of the present work was to evaluate the applicability of an innovative RSA set-up for in vivo knee kinematic analysis, using a biplane fluoroscopic image system. To this end, the Authors describe the set-up as well as a possible protocol for clinical knee joint evaluation. The accuracy of the kinematic measurements is assessed. the Authors evaluated the accuracy of 3D kinematic analysis of the knee in a new RSA set-up, based on a commercial biplane fluoroscopy system integrated into the clinical environment. The study was organized in three main phases: an in vitro test under static conditions, an in vitro test under dynamic conditions reproducing a flexion-extension range of motion (ROM), and an in vivo analysis of the flexion-extension ROM. For each test, the following were calculated, as an indication of the tracking accuracy: mean, minimum, maximum values and standard deviation of the error of rigid body fitting. in terms of rigid body fitting, in vivo test errors were found to be 0.10±0.05 mm. Phantom tests in static and kinematic conditions showed precision levels, for translations and rotations, of below 0.1 mm/0.2° and below 0.5 mm/0.3° respectively for all directions. the results of this study suggest that kinematic RSA can be successfully performed using a standard clinical biplane fluoroscopy system for the acquisition of slow movements of the lower limb. a kinematic RSA set-up using a clinical biplane fluoroscopy system is potentially applicable and provides a useful method for obtaining better characterization of joint biomechanics.

Benchmarking of a treatment planning system for spot scanning proton therapy: Comparison and analysis of robustness to setup errors of photon IMRT and proton SFUD treatment plans of base of skull meningioma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harding, R., E-mail: ruth.harding2@wales.nhs.uk; Trnková, P.; Lomax, A. J.

Purpose: Base of skull meningioma can be treated with both intensity modulated radiation therapy (IMRT) and spot scanned proton therapy (PT). One of the main benefits of PT is better sparing of organs at risk, but due to the physical and dosimetric characteristics of protons, spot scanned PT can be more sensitive to the uncertainties encountered in the treatment process compared with photon treatment. Therefore, robustness analysis should be part of a comprehensive comparison between these two treatment methods in order to quantify and understand the sensitivity of the treatment techniques to uncertainties. The aim of this work was tomore » benchmark a spot scanning treatment planning system for planning of base of skull meningioma and to compare the created plans and analyze their robustness to setup errors against the IMRT technique. Methods: Plans were produced for three base of skull meningioma cases: IMRT planned with a commercial TPS [Monaco (Elekta AB, Sweden)]; single field uniform dose (SFUD) spot scanning PT produced with an in-house TPS (PSI-plan); and SFUD spot scanning PT plan created with a commercial TPS [XiO (Elekta AB, Sweden)]. A tool for evaluating robustness to random setup errors was created and, for each plan, both a dosimetric evaluation and a robustness analysis to setup errors were performed. Results: It was possible to create clinically acceptable treatment plans for spot scanning proton therapy of meningioma with a commercially available TPS. However, since each treatment planning system uses different methods, this comparison showed different dosimetric results as well as different sensitivities to setup uncertainties. The results confirmed the necessity of an analysis tool for assessing plan robustness to provide a fair comparison of photon and proton plans. Conclusions: Robustness analysis is a critical part of plan evaluation when comparing IMRT plans with spot scanned proton therapy plans.« less

GPU-accelerated automatic identification of robust beam setups for proton and carbon-ion radiotherapy

NASA Astrophysics Data System (ADS)

Ammazzalorso, F.; Bednarz, T.; Jelen, U.

2014-03-01

We demonstrate acceleration on graphic processing units (GPU) of automatic identification of robust particle therapy beam setups, minimizing negative dosimetric effects of Bragg peak displacement caused by treatment-time patient positioning errors. Our particle therapy research toolkit, RobuR, was extended with OpenCL support and used to implement calculation on GPU of the Port Homogeneity Index, a metric scoring irradiation port robustness through analysis of tissue density patterns prior to dose optimization and computation. Results were benchmarked against an independent native CPU implementation. Numerical results were in agreement between the GPU implementation and native CPU implementation. For 10 skull base cases, the GPU-accelerated implementation was employed to select beam setups for proton and carbon ion treatment plans, which proved to be dosimetrically robust, when recomputed in presence of various simulated positioning errors. From the point of view of performance, average running time on the GPU decreased by at least one order of magnitude compared to the CPU, rendering the GPU-accelerated analysis a feasible step in a clinical treatment planning interactive session. In conclusion, selection of robust particle therapy beam setups can be effectively accelerated on a GPU and become an unintrusive part of the particle therapy treatment planning workflow. Additionally, the speed gain opens new usage scenarios, like interactive analysis manipulation (e.g. constraining of some setup) and re-execution. Finally, through OpenCL portable parallelism, the new implementation is suitable also for CPU-only use, taking advantage of multiple cores, and can potentially exploit types of accelerators other than GPUs.

Comparison between infrared optical and stereoscopic X-ray technologies for patient setup in image guided stereotactic radiotherapy.

PubMed

Tagaste, Barbara; Riboldi, Marco; Spadea, Maria F; Bellante, Simone; Baroni, Guido; Cambria, Raffaella; Garibaldi, Cristina; Ciocca, Mario; Catalano, Gianpiero; Alterio, Daniela; Orecchia, Roberto

2012-04-01

To compare infrared (IR) optical vs. stereoscopic X-ray technologies for patient setup in image-guided stereotactic radiotherapy. Retrospective data analysis of 233 fractions in 127 patients treated with hypofractionated stereotactic radiotherapy was performed. Patient setup at the linear accelerator was carried out by means of combined IR optical localization and stereoscopic X-ray image fusion in 6 degrees of freedom (6D). Data were analyzed to evaluate the geometric and dosimetric discrepancy between the two patient setup strategies. Differences between IR optical localization and 6D X-ray image fusion parameters were on average within the expected localization accuracy, as limited by CT image resolution (3 mm). A disagreement between the two systems below 1 mm in all directions was measured in patients treated for cranial tumors. In extracranial sites, larger discrepancies and higher variability were observed as a function of the initial patient alignment. The compensation of IR-detected rotational errors resulted in a significantly improved agreement with 6D X-ray image fusion. On the basis of the bony anatomy registrations, the measured differences were found not to be sensitive to patient breathing. The related dosimetric analysis showed that IR-based patient setup caused limited variations in three cases, with 7% maximum dose reduction in the clinical target volume and no dose increase in organs at risk. In conclusion, patient setup driven by IR external surrogates localization in 6D featured comparable accuracy with respect to procedures based on stereoscopic X-ray imaging. Copyright © 2012 Elsevier Inc. All rights reserved.

Accuracy Evaluation of a 3-Dimensional Surface Imaging System for Guidance in Deep-Inspiration Breath-Hold Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alderliesten, Tanja; Sonke, Jan-Jakob; Betgen, Anja

2013-02-01

Purpose: To investigate the applicability of 3-dimensional (3D) surface imaging for image guidance in deep-inspiration breath-hold radiation therapy (DIBH-RT) for patients with left-sided breast cancer. For this purpose, setup data based on captured 3D surfaces was compared with setup data based on cone beam computed tomography (CBCT). Methods and Materials: Twenty patients treated with DIBH-RT after breast-conserving surgery (BCS) were included. Before the start of treatment, each patient underwent a breath-hold CT scan for planning purposes. During treatment, dose delivery was preceded by setup verification using CBCT of the left breast. 3D surfaces were captured by a surface imaging systemmore » concurrently with the CBCT scan. Retrospectively, surface registrations were performed for CBCT to CT and for a captured 3D surface to CT. The resulting setup errors were compared with linear regression analysis. For the differences between setup errors, group mean, systematic error, random error, and 95% limits of agreement were calculated. Furthermore, receiver operating characteristic (ROC) analysis was performed. Results: Good correlation between setup errors was found: R{sup 2}=0.70, 0.90, 0.82 in left-right, craniocaudal, and anterior-posterior directions, respectively. Systematic errors were {<=}0.17 cm in all directions. Random errors were {<=}0.15 cm. The limits of agreement were -0.34-0.48, -0.42-0.39, and -0.52-0.23 cm in left-right, craniocaudal, and anterior-posterior directions, respectively. ROC analysis showed that a threshold between 0.4 and 0.8 cm corresponds to promising true positive rates (0.78-0.95) and false positive rates (0.12-0.28). Conclusions: The results support the application of 3D surface imaging for image guidance in DIBH-RT after BCS.« less

Impacts of wave-induced circulation in the surf zone on wave setup

NASA Astrophysics Data System (ADS)

Guérin, Thomas; Bertin, Xavier; Coulombier, Thibault; de Bakker, Anouk

2018-03-01

Wave setup corresponds to the increase in mean water level along the coast associated with the breaking of short-waves and is of key importance for coastal dynamics, as it contributes to storm surges and the generation of undertows. Although overall well explained by the divergence of the momentum flux associated with short waves in the surf zone, several studies reported substantial underestimations along the coastline. This paper investigates the impacts of the wave-induced circulation that takes place in the surf zone on wave setup, based on the analysis of 3D modelling results. A 3D phase-averaged modelling system using a vortex force formalism is applied to hindcast an unpublished field experiment, carried out at a dissipative beach under moderate to very energetic wave conditions (Hm 0 = 6m at breaking and Tp = 22s). When using an adaptive wave breaking parameterisation based on the beach slope, model predictions for water levels, short waves and undertows improved by about 30%, with errors reducing to 0.10 m, 0.10 m and 0.09 m/s, respectively. The analysis of model results suggests a very limited impact of the vertical circulation on wave setup at this dissipative beach. When extending this analysis to idealized simulations for different beach slopes ranging from 0.01 to 0.05, it shows that the contribution of the vertical circulation (horizontal and vertical advection and vertical viscosity terms) becomes more and more relevant as the beach slope increases. In contrast, for a given beach slope, the wave height at the breaking point has a limited impact on the relative contribution of the vertical circulation on the wave setup. For a slope of 0.05, the contribution of the terms associated with the vertical circulation accounts for up to 17% (i.e. a 20% increase) of the total setup at the shoreline, which provides a new explanation for the underestimations reported in previously published studies.

A multi-purpose reaction cell for the investigation of reactions under solvothermal conditions

NASA Astrophysics Data System (ADS)

Heidenreich, N.; Rütt, U.; Köppen, M.; Inge, A. Ken; Beier, S.; Dippel, A.-C.; Suren, R.; Stock, N.

2017-10-01

A new versatile and easy-to-use remote-controlled reactor setup aimed at the analysis of chemical reactions under solvothermal conditions has been constructed. The reactor includes a heating system that can precisely control the temperature inside the reaction vessels in a range between ambient temperature and 180 °C. As reaction vessels, two sizes of commercially available borosilicate vessels (Vmax = 5 and 11 ml) can be used. The setup furthermore includes the option of stirring and injecting of up to two liquid additives or one solid during the reaction to initiate very fast reactions, quench reactions, or alter chemical parameters. In addition to a detailed description of the general setup and its functionality, three examples of studies conducted using this setup are presented.

Comparison of six electromyography acquisition setups on hand movement classification tasks

PubMed Central

Pizzolato, Stefano; Tagliapietra, Luca; Cognolato, Matteo; Reggiani, Monica; Müller, Henning

2017-01-01

Hand prostheses controlled by surface electromyography are promising due to the non-invasive approach and the control capabilities offered by machine learning. Nevertheless, dexterous prostheses are still scarcely spread due to control difficulties, low robustness and often prohibitive costs. Several sEMG acquisition setups are now available, ranging in terms of costs between a few hundred and several thousand dollars. The objective of this paper is the relative comparison of six acquisition setups on an identical hand movement classification task, in order to help the researchers to choose the proper acquisition setup for their requirements. The acquisition setups are based on four different sEMG electrodes (including Otto Bock, Delsys Trigno, Cometa Wave + Dormo ECG and two Thalmic Myo armbands) and they were used to record more than 50 hand movements from intact subjects with a standardized acquisition protocol. The relative performance of the six sEMG acquisition setups is compared on 41 identical hand movements with a standardized feature extraction and data analysis pipeline aimed at performing hand movement classification. Comparable classification results are obtained with three acquisition setups including the Delsys Trigno, the Cometa Wave and the affordable setup composed of two Myo armbands. The results suggest that practical sEMG tests can be performed even when costs are relevant (e.g. in small laboratories, developing countries or use by children). All the presented datasets can be used for offline tests and their quality can easily be compared as the data sets are publicly available. PMID:29023548

Comparison of six electromyography acquisition setups on hand movement classification tasks.

PubMed

Pizzolato, Stefano; Tagliapietra, Luca; Cognolato, Matteo; Reggiani, Monica; Müller, Henning; Atzori, Manfredo

2017-01-01

Hand prostheses controlled by surface electromyography are promising due to the non-invasive approach and the control capabilities offered by machine learning. Nevertheless, dexterous prostheses are still scarcely spread due to control difficulties, low robustness and often prohibitive costs. Several sEMG acquisition setups are now available, ranging in terms of costs between a few hundred and several thousand dollars. The objective of this paper is the relative comparison of six acquisition setups on an identical hand movement classification task, in order to help the researchers to choose the proper acquisition setup for their requirements. The acquisition setups are based on four different sEMG electrodes (including Otto Bock, Delsys Trigno, Cometa Wave + Dormo ECG and two Thalmic Myo armbands) and they were used to record more than 50 hand movements from intact subjects with a standardized acquisition protocol. The relative performance of the six sEMG acquisition setups is compared on 41 identical hand movements with a standardized feature extraction and data analysis pipeline aimed at performing hand movement classification. Comparable classification results are obtained with three acquisition setups including the Delsys Trigno, the Cometa Wave and the affordable setup composed of two Myo armbands. The results suggest that practical sEMG tests can be performed even when costs are relevant (e.g. in small laboratories, developing countries or use by children). All the presented datasets can be used for offline tests and their quality can easily be compared as the data sets are publicly available.

Influence of different setups of the Frankfort horizontal plane on 3-dimensional cephalometric measurements.

PubMed

Santos, Rodrigo Mologni Gonçalves Dos; De Martino, José Mario; Haiter Neto, Francisco; Passeri, Luis Augusto

2017-08-01

The Frankfort horizontal (FH) is a plane that intersects both porions and the left orbitale. However, other combinations of points have also been used to define this plane in 3-dimensional cephalometry. These variations are based on the hypothesis that they do not affect the cephalometric analysis. We investigated the validity of this hypothesis. The material included cone-beam computed tomography data sets of 82 adult subjects with Class I molar relationship. A third-party method of cone-beam computed tomography-based 3-dimensional cephalometry was performed using 7 setups of the FH plane. Six lateral cephalometric hard tissue measurements relative to the FH plane were carried out for each setup. Measurement differences were calculated for each pair of setups of the FH plane. The number of occurrences of differences greater than the limits of agreement was counted for each of the 6 measurements. Only 3 of 21 pairs of setups had no occurrences for the 6 measurements. No measurement had no occurrences for the 21 pairs of setups. Setups based on left or right porion and both orbitales had the greatest number of occurrences for the 6 measurements. This investigation showed that significant and undesirable measurement differences can be produced by varying the definition of the FH plane. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Collider shot setup for Run 2 observations and suggestions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Annala, J.; Joshel, B.

1996-01-31

This note is intended to provoke discussion on Collider Run II shot setup. We hope this is a start of activities that will converge on a functional description of what is needed for shot setups in Collider Run II. We will draw on observations of the present shot setup to raise questions and make suggestions for the next Collider run. It is assumed that the reader has some familiarity with the Collider operational issues. Shot setup is defined to be the time between the end of a store and the time the Main Control Room declares colliding beams. This ismore » the time between Tevatron clock events SCE and SCB. This definition does not consider the time experiments use to turn on their detectors. This analysis was suggested by David Finley. The operational scenarios for Run II will require higher levels of reliability and speed for shot setup. See Appendix I and II. For example, we estimate that a loss of 3 pb{sup {minus}1}/week (with 8 hour stores) will occur if shot setups take 90 minutes instead of 30 minutes. In other words: If you do 12 shots for one week and accept an added delay of one minute in each shot, you will loose more than 60 nb{sup {minus}1} for that week alone (based on a normal shot setup of 30 minutes). These demands should lead us to be much more pedantic about all the factors that affect shot setups. Shot setup will be viewed as a distinct process that is composed of several inter- dependent `components`: procedures, hardware, controls, and sociology. These components don`t directly align with the different Accelerator Division departments, but are topical groupings of the needed accelerator functions. Defining these components, and categorizing our suggestions within them, are part of the goal of this document. Of course, some suggestions span several of these components.« less

Clinical experience with a 3D surface patient setup system for alignment of partial-breast irradiation patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bert, Christoph; Metheany, Katherine G.; Doppke, Karen P.

2006-03-15

Purpose: To assess the utility of surface imaging on patient setup for accelerated partial-breast irradiation (APBI). Methods and Material: A photogrammetry system was used in parallel to APBI setup by laser and portal imaging. Surface data were acquired after laser and port-film setup for 9 patients. Surfaces were analyzed in comparison to a reference surface from the first treatment session by use of rigid transformations. The surface model after laser setup was used in a simulated photogrammetry setup procedure. In addition, breathing data were acquired by surface acquisition at a frame rate of 7 Hz. Results: Mean 3D displacement wasmore » 7.3 mm (SD, 4.4 mm) and 7.6 mm (SD, 4.2 mm) for laser and port film, respectively. Simulated setup with the photogrammetry system yielded mean displacement of 1 mm (SD, 1.2 mm). Distance analysis resulted in mean distances of 3.7 mm (SD, 4.9 mm), 4.3 mm (SD, 5.6 mm), and 1.6 mm (SD, 2.4 mm) for laser, port film, and photogrammetry, respectively. Breathing motion at isocenter was smaller than 3.7 mm, with a mean of 1.9 mm (SD, 1.1 mm). Conclusions: Surface imaging for PBI setup appears promising. Alignment of the 3D breast surface achieved by stereo-photogrammetry shows greater breast topology congruence than when patients are set up by laser or portal imaging. A correlation of breast surface and CTV must be quantitatively established.« less

Impact of patient-specific factors, irradiated left ventricular volume, and treatment set-up errors on the development of myocardial perfusion defects after radiation therapy for left-sided breast cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, Elizabeth S.; Prosnitz, Robert G.; Yu Xiaoli

2006-11-15

Purpose: The aim of this study was to assess the impact of patient-specific factors, left ventricle (LV) volume, and treatment set-up errors on the rate of perfusion defects 6 to 60 months post-radiation therapy (RT) in patients receiving tangential RT for left-sided breast cancer. Methods and Materials: Between 1998 and 2005, a total of 153 patients were enrolled onto an institutional review board-approved prospective study and had pre- and serial post-RT (6-60 months) cardiac perfusion scans to assess for perfusion defects. Of the patients, 108 had normal pre-RT perfusion scans and available follow-up data. The impact of patient-specific factors onmore » the rate of perfusion defects was assessed at various time points using univariate and multivariate analysis. The impact of set-up errors on the rate of perfusion defects was also analyzed using a one-tailed Fisher's Exact test. Results: Consistent with our prior results, the volume of LV in the RT field was the most significant predictor of perfusion defects on both univariate (p = 0.0005 to 0.0058) and multivariate analysis (p = 0.0026 to 0.0029). Body mass index (BMI) was the only significant patient-specific factor on both univariate (p = 0.0005 to 0.022) and multivariate analysis (p = 0.0091 to 0.05). In patients with very small volumes of LV in the planned RT fields, the rate of perfusion defects was significantly higher when the fields set-up 'too deep' (83% vs. 30%, p = 0.059). The frequency of deep set-up errors was significantly higher among patients with BMI {>=}25 kg/m{sup 2} compared with patients of normal weight (47% vs. 28%, p = 0.068). Conclusions: BMI {>=}25 kg/m{sup 2} may be a significant risk factor for cardiac toxicity after RT for left-sided breast cancer, possibly because of more frequent deep set-up errors resulting in the inclusion of additional heart in the RT fields. Further study is necessary to better understand the impact of patient-specific factors and set-up errors on the development of RT-induced perfusion defects.« less

A total internal reflection-fluorescence correlation spectroscopy setup with pulsed diode laser excitation

NASA Astrophysics Data System (ADS)

Weger, Lukas; Hoffmann-Jacobsen, Kerstin

2017-09-01

Fluorescence correlation spectroscopy (FCS) measures fluctuations in a (sub-)femtoliter volume to analyze the diffusive behavior of fluorescent particles. This highly sensitive method has proven to be useful for the analysis of dynamic biological systems as well as in chemistry, physics, and material sciences. It is routinely performed with commercial fluorescence microscopes, which provide a confined observation volume by the confocal technique. The evanescent wave of total internal reflectance (TIR) is used in home-built systems to permit a surface sensitive FCS analysis. We present a combined confocal and TIR-FCS setup which uses economic low-power pulsed diode lasers for excitation. Excitation and detection are coupled to time-correlated photon counting hardware. This allows simultaneous fluorescence lifetime and FCS measurements in a surface-sensitive mode. Moreover, the setup supports fluorescence lifetime correlation spectroscopy at surfaces. The excitation can be easily switched between TIR and epi-illumination to compare the surface properties with those in liquid bulk. The capabilities of the presented setup are demonstrated by measuring the diffusion coefficients of a free dye molecule, a labeled polyethylene glycol, and a fluorescent nanoparticle in confocal as well as in TIR-FCS.

Photoacoustic physio-chemical analysis and its implementation in deep tissue with a catheter setup

NASA Astrophysics Data System (ADS)

Xu, Guan; Meng, Zhou-xian; Lin, Jian-die D.; Cheng, Qian; Wang, Xueding

2015-03-01

Photoacoustic (PA) measurements encode the information associated with both physical microstructures and chemical contents in biological tissues. A two-dimensional physio-chemical spectrogram (PCS) can be formulated by combining the power spectra of PA signals acquired at a series of optical wavelengths. The analysis of PCS, or namely PA physio-chemical analysis (PAPCA), enables the quantification of the relative concentrations and the spatial distributions of a variety of chemical components in the tissue. This study validated the feasibility of PAPCA in characterizing liver conditions during the progression of non-alcoholic fatty liver disease. A catheter based setup facilitating measurement in deep tissues was also tested.

Development of a grinding-specific performance test set-up.

PubMed

Olesen, C G; Larsen, B H; Andresen, E L; de Zee, M

2015-01-01

The aim of this study was to develop a performance test set-up for America's Cup grinders. The test set-up had to mimic the on-boat grinding activity and be capable of collecting data for analysis and evaluation of grinding performance. This study included a literature-based analysis of grinding demands and a test protocol developed to accommodate the necessary physiological loads. This study resulted in a test protocol consisting of 10 intervals of 20 revolutions each interspersed with active resting periods of 50 s. The 20 revolutions are a combination of both forward and backward grinding and an exponentially rising resistance. A custom-made grinding ergometer was developed with computer-controlled resistance and capable of collecting data during the test. The data collected can be used to find measures of grinding performance such as peak power, time to complete and the decline in repeated grinding performance.

Analysis of the Accuracy and Robustness of the Leap Motion Controller

PubMed Central

Weichert, Frank; Bachmann, Daniel; Rudak, Bartholomäus; Fisseler, Denis

2013-01-01

The Leap Motion Controller is a new device for hand gesture controlled user interfaces with declared sub-millimeter accuracy. However, up to this point its capabilities in real environments have not been analyzed. Therefore, this paper presents a first study of a Leap Motion Controller. The main focus of attention is on the evaluation of the accuracy and repeatability. For an appropriate evaluation, a novel experimental setup was developed making use of an industrial robot with a reference pen allowing a position accuracy of 0.2 mm. Thereby, a deviation between a desired 3D position and the average measured positions below 0.2 mm has been obtained for static setups and of 1.2 mm for dynamic setups. Using the conclusion of this analysis can improve the development of applications for the Leap Motion controller in the field of Human-Computer Interaction. PMID:23673678

Analysis of the accuracy and robustness of the leap motion controller.

PubMed

Weichert, Frank; Bachmann, Daniel; Rudak, Bartholomäus; Fisseler, Denis

2013-05-14

The Leap Motion Controller is a new device for hand gesture controlled user interfaces with declared sub-millimeter accuracy. However, up to this point its capabilities in real environments have not been analyzed. Therefore, this paper presents a first study of a Leap Motion Controller. The main focus of attention is on the evaluation of the accuracy and repeatability. For an appropriate evaluation, a novel experimental setup was developed making use of an industrial robot with a reference pen allowing a position accuracy of 0.2 mm. Thereby, a deviation between a desired 3D position and the average measured positions below 0.2 mm has been obtained for static setups and of 1.2 mm for dynamic setups. Using the conclusion of this analysis can improve the development of applications for the Leap Motion controller in the field of Human-Computer Interaction.

A Multi-Agent Environment for Negotiation

NASA Astrophysics Data System (ADS)

Hindriks, Koen V.; Jonker, Catholijn M.; Tykhonov, Dmytro

In this chapter we introduce the System for Analysis of Multi-Issue Negotiation (SAMIN). SAMIN offers a negotiation environment that supports and facilitates the setup of various negotiation setups. The environment has been designed to analyse negotiation processes between human negotiators, between human and software agents, and between software agents. It offers a range of different agents, different domains, and other options useful to define a negotiation setup. The environment has been used to test and evaluate a range of negotiation strategies in various domains playing against other negotiating agents as well as humans. We discuss some of the results obtained by means of these experiments.

Uncertainty quantification in operational modal analysis with stochastic subspace identification: Validation and applications

NASA Astrophysics Data System (ADS)

Reynders, Edwin; Maes, Kristof; Lombaert, Geert; De Roeck, Guido

2016-01-01

Identified modal characteristics are often used as a basis for the calibration and validation of dynamic structural models, for structural control, for structural health monitoring, etc. It is therefore important to know their accuracy. In this article, a method for estimating the (co)variance of modal characteristics that are identified with the stochastic subspace identification method is validated for two civil engineering structures. The first structure is a damaged prestressed concrete bridge for which acceleration and dynamic strain data were measured in 36 different setups. The second structure is a mid-rise building for which acceleration data were measured in 10 different setups. There is a good quantitative agreement between the predicted levels of uncertainty and the observed variability of the eigenfrequencies and damping ratios between the different setups. The method can therefore be used with confidence for quantifying the uncertainty of the identified modal characteristics, also when some or all of them are estimated from a single batch of vibration data. Furthermore, the method is seen to yield valuable insight in the variability of the estimation accuracy from mode to mode and from setup to setup: the more informative a setup is regarding an estimated modal characteristic, the smaller is the estimated variance.

Apparatus for Investigating Momentum and Energy Conservation With MBL and Video Analysis

NASA Astrophysics Data System (ADS)

George, Elizabeth; Vazquez-Abad, Jesus

1998-04-01

We describe the development and use of a laboratory setup that is appropriate for computer-aided student investigation of the principles of conservation of momentum and mechanical energy in collisions. The setup consists of two colliding carts on a low-friction track, with one of the carts (the target) attached to a spring, whose extension or compression takes the place of the pendulum's rise in the traditional ballistic pendulum apparatus. Position vs. time data for each cart are acquired either by using two motion sensors or by digitizing images obtained with a video camera. This setup allows students to examine the time history of momentum and mechanical energy during the entire collision process, rather than simply focusing on the before and after regions. We believe that this setup is suitable for helping students gain understanding as the processes involved are simple to follow visually, to manipulate, and to analyze.

SU-E-J-55: End-To-End Effectiveness Analysis of 3D Surface Image Guided Voluntary Breath-Holding Radiotherapy for Left Breast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, M; Feigenberg, S

Purpose To evaluate the effectiveness of using 3D-surface-image to guide breath-holding (BH) left-side breast treatment. Methods Two 3D surface image guided BH procedures were implemented and evaluated: normal-BH, taking BH at a comfortable level, and deep-inspiration-breath-holding (DIBH). A total of 20 patients (10 Normal-BH and 10 DIBH) were recruited. Patients received a BH evaluation using a commercialized 3D-surface- tracking-system (VisionRT, London, UK) to quantify the reproducibility of BH positions prior to CT scan. Tangential 3D/IMRT plans were conducted. Patients were initially setup under free-breathing (FB) condition using the FB surface obtained from the untaged CT to ensure a correct patientmore » position. Patients were then guided to reach the planned BH position using the BH surface obtained from the BH CT. Action-levels were set at each phase of treatment process based on the information provided by the 3D-surface-tracking-system for proper interventions (eliminate/re-setup/ re-coaching). We reviewed the frequency of interventions to evaluate its effectiveness. The FB-CBCT and port-film were utilized to evaluate the accuracy of 3D-surface-guided setups. Results 25% of BH candidates with BH positioning uncertainty > 2mm are eliminated prior to CT scan. For >90% of fractions, based on the setup deltas from3D-surface-trackingsystem, adjustments of patient setup are needed after the initial-setup using laser. 3D-surface-guided-setup accuracy is comparable as CBCT. For the BH guidance, frequency of interventions (a re-coaching/re-setup) is 40%(Normal-BH)/91%(DIBH) of treatments for the first 5-fractions and then drops to 16%(Normal-BH)/46%(DIBH). The necessity of re-setup is highly patient-specific for Normal-BH but highly random among patients for DIBH. Overall, a −0.8±2.4 mm accuracy of the anterior pericardial shadow position was achieved. Conclusion 3D-surface-image technology provides effective intervention to the treatment process and ensures favorable day-to-day setup accuracy. DIBH setup appears to be more uncertain and this would be the patient group who will definitely benefit from the extra information of 3D surface setup.« less

Absolute shape measurements using high-resolution optoelectronic holography methods

NASA Astrophysics Data System (ADS)

Furlong, Cosme; Pryputniewicz, Ryszard J.

2000-01-01

Characterization of surface shape and deformation is of primary importance in a number of testing and metrology applications related to the functionality, performance, and integrity of components. In this paper, a unique, compact, and versatile state-of-the-art fiber-optic-based optoelectronic holography (OEH) methodology is described. This description addresses apparatus and analysis algorithms, especially developed to perform measurements of both absolute surface shape and deformation. The OEH can be arranged in multiple configurations, which include the three-camera, three-illumination, and in-plane speckle correlation setups. With the OEH apparatus and analysis algorithms, absolute shape measurements can be made, using present setup, with a spatial resolution and accuracy of better than 30 and 10 micrometers , respectively, for volumes characterized by a 300-mm length. Optimizing the experimental setup and incorporating equipment, as it becomes available, having superior capabilities to the ones utilized in the present investigations can further increase resolution and accuracy in the measurements. The particular feature of this methodology is its capability to export the measurements data directly into CAD environments for subsequent processing, analysis, and definition of CAD/CAE models.

Sustainable Operation of Arterial Networks

DOT National Transportation Integrated Search

2017-07-14

This report describes operational data analysis and modeling of arterial networks with signalized intersections as follows: The setup for data collection, analysis and simulation is presented in Section 2.1. Detailed analysis of collected signal phas...

Performance test results of noninvasive characterization of Resource Conservation and Recovery Act surrogate waste by prompt gamma neutron activation analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gehrke, R.J.; Streier, G.G.

1997-03-01

During FY-96, a performance test was carried out with funding from the Mixed Waste Focus Area (MWFA) of the Department of Energy (DOE) to determine the noninvasive elemental assay capabilities of commercial companies for Resource Conservation and Recovery Act (RCRA) metals present in 8-gal drums containing surrogate waste. Commercial companies were required to be experienced in the use of prompt gamma neutron activation analysis (PGNAA) techniques and to have a prototype assay system with which to conduct the test assays. Potential participants were identified through responses to a call for proposals advertised in the Commerce Business Daily and through personalmore » contacts. Six companies were originally identified. Two of these six were willing and able to participate in the performance test, as described in the test plan, with some subsidizing from the DOE MWFA. The tests were conducted with surrogate sludge waste because (1) a large volume of this type of waste awaits final disposition and (2) sludge tends to be somewhat homogeneous. The surrogate concentrations of the above RCRA metals ranged from {approximately} 300 ppm to {approximately} 20,000 ppm. The lower limit was chosen as an estimate of the expected sensitivity of detection required by noninvasive, pretreatment elemental assay systems to be of value for operational and compliance purposes and to still be achievable with state-of-the-art methods of analysis. The upper limit of {approximately} 20,000 ppm was chosen because it is the opinion of the author that assay above this concentration level is within current state-of-the-art methods for most RCRA constituents. This report is organized into three parts: Part 1, Test Plan to Evaluate the Technical Status of Noninvasive Elemental Assay Techniques for Hazardous Waste; Part 2, Participants` Results; and Part 3, Evaluation of and Comments on Participants` Results.« less

Integrated trimodal SSEP experimental setup for visual, auditory and tactile stimulation

NASA Astrophysics Data System (ADS)

Kuś, Rafał; Spustek, Tomasz; Zieleniewska, Magdalena; Duszyk, Anna; Rogowski, Piotr; Suffczyński, Piotr

2017-12-01

Objective. Steady-state evoked potentials (SSEPs), the brain responses to repetitive stimulation, are commonly used in both clinical practice and scientific research. Particular brain mechanisms underlying SSEPs in different modalities (i.e. visual, auditory and tactile) are very complex and still not completely understood. Each response has distinct resonant frequencies and exhibits a particular brain topography. Moreover, the topography can be frequency-dependent, as in case of auditory potentials. However, to study each modality separately and also to investigate multisensory interactions through multimodal experiments, a proper experimental setup appears to be of critical importance. The aim of this study was to design and evaluate a novel SSEP experimental setup providing a repetitive stimulation in three different modalities (visual, tactile and auditory) with a precise control of stimuli parameters. Results from a pilot study with a stimulation in a particular modality and in two modalities simultaneously prove the feasibility of the device to study SSEP phenomenon. Approach. We developed a setup of three separate stimulators that allows for a precise generation of repetitive stimuli. Besides sequential stimulation in a particular modality, parallel stimulation in up to three different modalities can be delivered. Stimulus in each modality is characterized by a stimulation frequency and a waveform (sine or square wave). We also present a novel methodology for the analysis of SSEPs. Main results. Apart from constructing the experimental setup, we conducted a pilot study with both sequential and simultaneous stimulation paradigms. EEG signals recorded during this study were analyzed with advanced methodology based on spatial filtering and adaptive approximation, followed by statistical evaluation. Significance. We developed a novel experimental setup for performing SSEP experiments. In this sense our study continues the ongoing research in this field. On the other hand, the described setup along with the presented methodology is a considerable improvement and an extension of methods constituting the state-of-the-art in the related field. Device flexibility both with developed analysis methodology can lead to further development of diagnostic methods and provide deeper insight into information processing in the human brain.

Current-limiting and ultrafast system for the characterization of resistive random access memories.

PubMed

Diaz-Fortuny, J; Maestro, M; Martin-Martinez, J; Crespo-Yepes, A; Rodriguez, R; Nafria, M; Aymerich, X

2016-06-01

A new system for the ultrafast characterization of resistive switching phenomenon is developed to acquire the current during the Set and Reset process in a microsecond time scale. A new electronic circuit has been developed as a part of the main setup system, which is capable of (i) applying a hardware current limit ranging from nanoampers up to miliampers and (ii) converting the Set and Reset exponential gate current range into an equivalent linear voltage. The complete system setup allows measuring with a microsecond resolution. Some examples demonstrate that, with the developed setup, an in-depth analysis of resistive switching phenomenon and random telegraph noise can be made.

Fourier Analysis of a Vibrating String through a Low-Cost Experimental Setup and a Smartphone

ERIC Educational Resources Information Center

Pereyra, C. J.; Osorio, M.; Laguarda, A.; Gau, D. L.

2018-01-01

In this work we present a simple and low-cost setup to illustrate the dependence of the behaviour of a standing wave in a guitar string with the initial conditions. To do so, we impose two kinds of initial conditions; in the first instance, the initial shape of the string is varied. Secondly, different nodes are imposed on the string. This…

Digital micromirror device as programmable rough particle in interferometric particle imaging.

PubMed

Fromager, M; Aït Ameur, K; Brunel, M

2017-04-20

The 2D autocorrelation of the projection of an irregular rough particle can be estimated using the analysis of its interferometric out-of-focus image. We report the development of an experimental setup that creates speckle-like patterns generated by "programmable" rough particles of desired-shape. It should become an important tool for the development of new setups, configurations, and algorithms in interferometric particle imaging.

Automated laser spectrofluorimeter for monitoring of myocardial metabolism

NASA Astrophysics Data System (ADS)

Popov, A. Yu.; Salmin, V. V.; Fursov, A. A.; Stepanenko, A. V.; Sokolovich, A. G.; Salmina, A. B.; Rebenkova, A. A.; Makarov, R. A.; Provorov, A. S.

2006-09-01

Methods of optical biopsy have a series of advantages before other methods of clinical diagnostics. The high accuracy of received results enables registration even small change of concentration of substances, and the opportunity of remote registration makes methods optical biopsy by an optimum means for noninvasive methods of diagnostics in medicine. The method of the fluorescent analysis allows to investigate dynamics of changes of a functional condition of organs and tissue in norm and pathologies, called by the various factors (an inflammation, ischemia, degenerative changes). Bring the results of development of expiremental setup for the laser fluorescent analysis of physiological and functional condition of various organs and tissue of organism. In expiremental setup was used pulse UF nitric laser with length of wave generation = 337 nm. For delivery of radiation to tissue, and, also, collection of a radiation of fluorescence were used various optic fiber scheme. The expiremental setup includes automated tunable monochromator and ADC, receiving a signal from photomultiplier tube. Driving of all blocks and processing of results is realize on IBM-compatible computer with the appropriate software. Was used the synchronous detecting for reducing of a background signal. Myocard at surgical introoperation by an accompanied condition of sharp ischemia was researches on these expiremental setup. Spectrofluorimetric criteria of an estimation of a condition of viscus at peritonitis were development.

Automated qualification and analysis of protective spark gaps for DC accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee, Srutarshi; Rajan, Rehim N.; Dewangan, S.

2014-07-01

Protective spark gaps are used in the high voltage multiplier column of a 3 MeV DC Accelerator to prevent excessive voltage build-ups. Precise gap of 5 mm is maintained between the electrodes in these spark gaps for obtaining 120 kV± 5 kV in 6 kg/cm{sup 2} SF{sub 6} environment which is the dielectric medium. There are 74 such spark gaps used in the multiplier. Each spark gap has to be qualified for electrical performance before fitting in the accelerator to ensure reliable operation. As the breakdown voltage stabilizes after a large number of sparks between the electrodes, the qualification processmore » becomes time consuming and cumbersome. For qualifying large number of spark gaps an automatic breakdown analysis setup has been developed. This setup operates in air, a dielectric medium. The setup consists of a flyback topology based high voltage power supply with maximum rating of 25 kV. This setup works in conjunction with spark detection and automated shutdown circuit. The breakdown voltage is sensed using a peak detector circuit. The voltage breakdown data is recorded and statistical distribution of the breakdown voltage has been analyzed. This paper describes details of the diagnostics and the spark gap qualification process based on the experimental data. (author)« less

COMPARISON OF LAPAROSCOPIC SKILLS PERFORMANCE USING SINGLE-SITE ACCESS (SSA) DEVICES VS. AN INDEPENDENT-PORT SSA APPROACH

PubMed Central

Schill, Matthew R.; Varela, J. Esteban; Frisella, Margaret M.; Brunt, L. Michael

2015-01-01

Background We compared performance of validated laparoscopic tasks on four commercially available single site access (SSA) access devices (AD) versus an independent port (IP) SSA set-up. Methods A prospective, randomized comparison of laparoscopic skills performance on four AD (GelPOINT™, SILS™ Port, SSL Access System™, TriPort™) and one IP SSA set-up was conducted. Eighteen medical students (2nd–4th year), four surgical residents, and five attending surgeons were trained to proficiency in multi-port laparoscopy using four laparoscopic drills (peg transfer, bean drop, pattern cutting, extracorporeal suturing) in a laparoscopic trainer box. Drills were then performed in random order on each IP-SSA and AD-SSA set-up using straight laparoscopic instruments. Repetitions were timed and errors recorded. Data are mean ± SD, and statistical analysis was by two-way ANOVA with Tukey HSD post-hoc tests. Results Attending surgeons had significantly faster total task times than residents or students (p< 0.001), but the difference between residents and students was NS. Pair-wise comparisons revealed significantly faster total task times for the IP-SSA set-up compared to all four AD-SSA’s within the student group only (p<0.05). Total task times for residents and attending surgeons showed a similar profile, but the differences were NS. When data for the three groups was combined, the total task time was less for the IP-SSA set-up than for each of the four AD-SSA set-ups (p < 0.001). Similarly,, the IP-SSA set-up was significantly faster than 3 of 4 AD-SSA set-ups for peg transfer, 3 of 4 for pattern cutting, and 2 of 4 for suturing. No significant differences in error rates between IP-SSA and AD-SSA set-ups were detected. Conclusions When compared to an IP-SSA laparoscopic set-up, single site access devices are associated with longer task performance times in a trainer box model, independent of level of training. Task performance was similar across different SSA devices. PMID:21993938

In vitro quantification of the performance of model-based mono-planar and bi-planar fluoroscopy for 3D joint kinematics estimation.

PubMed

Tersi, Luca; Barré, Arnaud; Fantozzi, Silvia; Stagni, Rita

2013-03-01

Model-based mono-planar and bi-planar 3D fluoroscopy methods can quantify intact joints kinematics with performance/cost trade-off. The aim of this study was to compare the performances of mono- and bi-planar setups to a marker-based gold-standard, during dynamic phantom knee acquisitions. Absolute pose errors for in-plane parameters were lower than 0.6 mm or 0.6° for both mono- and bi-planar setups. Mono-planar setups resulted critical in quantifying the out-of-plane translation (error < 6.5 mm), and bi-planar in quantifying the rotation along bone longitudinal axis (error < 1.3°). These errors propagated to joint angles and translations differently depending on the alignment of the anatomical axes and the fluoroscopic reference frames. Internal-external rotation was the least accurate angle both with mono- (error < 4.4°) and bi-planar (error < 1.7°) setups, due to bone longitudinal symmetries. Results highlighted that accuracy for mono-planar in-plane pose parameters is comparable to bi-planar, but with halved computational costs, halved segmentation time and halved ionizing radiation dose. Bi-planar analysis better compensated for the out-of-plane uncertainty that is differently propagated to relative kinematics depending on the setup. To take its full benefits, the motion task to be investigated should be designed to maintain the joint inside the visible volume introducing constraints with respect to mono-planar analysis.

Economic Analysis of Classical Swine Fever Surveillance in the Netherlands.

PubMed

Guo, X; Claassen, G D H; Oude Lansink, A G J M; Loeffen, W; Saatkamp, H W

2016-06-01

Classical swine fever (CSF) is a highly contagious pig disease that causes economic losses and impaired animal welfare. Improving the surveillance system for CSF can help to ensure early detection of the virus, thereby providing a better initial situation for controlling the disease. Economic analysis is required to compare the benefits of improved surveillance with the costs of implementing a more intensive system. This study presents a comprehensive economic analysis of CSF surveillance in the Netherlands, taking into account the specialized structure of Dutch pig production, differences in virulence of CSF strains and a complete list of possible surveillance activities. The starting point of the analysis is the current Dutch surveillance system (i.e. the default surveillance-setup scenario), including the surveillance activities 'daily clinical observation by the farmer', 'veterinarian inspection after a call', 'routine veterinarian inspection', 'pathology in AHS', 'PCR on tonsil in AHS', 'PCR on grouped animals in CVI' and 'confirmatory PCR by NVWA'. Alternative surveillance-setup scenarios were proposed by adding 'routine serology in slaughterhouses', 'routine serology on sow farms' and 'PCR on rendered animals'. The costs and benefits for applying the alternative surveillance-setup scenarios were evaluated by comparing the annual mitigated economic losses because of intensified CSF surveillance with the annual additional surveillance costs. The results of the cost-effectiveness analysis show that the alternative surveillance-setup scenarios with 'PCR on rendered animals' are effective for the moderately virulent CSF strain, whereas the scenarios with 'routine serology in slaughterhouses' or 'routine serology on sow farms' are effective for the low virulent strain. Moreover, the current CSF surveillance system in the Netherlands is cost-effective for both moderately virulent and low virulent CSF strains. The results of the cost-benefit analysis for the moderately virulent CSF strain indicate that the current surveillance system in the Netherlands is adequate. From an economic perspective, there is little to be gained from intensifying surveillance. © 2014 Blackwell Verlag GmbH.

AQUATOX Features and Tools

EPA Pesticide Factsheets

Numerous features have been included to facilitate the modeling process, from model setup and data input, presentation and analysis of results, to easy export of results to spreadsheet programs for additional analysis.

The influence of the test setup on knee joint kinematics - A meta-analysis of tibial rotation.

PubMed

Hacker, Steffen P; Ignatius, Anita; Dürselen, Lutz

2016-09-06

The human knee is one of the most investigated joints in the human body. Various test setups exist to measure and analyse knee kinematics in vitro which differ in a wide range of parameters. The purpose of this article is to find an answer to the question if the test setup influences the kinematic outcome of studies and to what extend the results can be compared. To answer this question, we compared the tibial rotation as a function of flexion angle presented in 19 published studies. Raw data was extracted via image segmentation from the graphs depicted in these publications and the differences between the publications was analysed. Additionally, all test setups were compared regarding four aspects: method for angle calculation, system for data acquisition, loading condition and testing rig design. The resulting correlation matrix shows the influence of the test setup on the study outcome. Our results indicate that each study needs to collect its own reference data. Finally, we provide a mean internal rotation as a function of flexion angle based on more than 140 specimens tested in 14 different studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simple and inexpensive hardware and software method to measure volume changes in Xenopus oocytes expressing aquaporins.

PubMed

Dorr, Ricardo; Ozu, Marcelo; Parisi, Mario

2007-04-15

Water channels (aquaporins) family members have been identified in central nervous system cells. A classic method to measure membrane water permeability and its regulation is to capture and analyse images of Xenopus laevis oocytes expressing them. Laboratories dedicated to the analysis of motion images usually have powerful equipment valued in thousands of dollars. However, some scientists consider that new approaches are needed to reduce costs in scientific labs, especially in developing countries. The objective of this work is to share a very low-cost hardware and software setup based on a well-selected webcam, a hand-made adapter to a microscope and the use of free software to measure membrane water permeability in Xenopus oocytes. One of the main purposes of this setup is to maintain a high level of quality in images obtained at brief intervals (shorter than 70 ms). The presented setup helps to economize without sacrificing image analysis requirements.

Experimental setup for the measurement of induction motor cage currents

NASA Astrophysics Data System (ADS)

Bottauscio, Oriano; Chiampi, Mario; Donadio, Lorenzo; Zucca, Mauro

2005-04-01

An experimental setup for measurement of the currents flowing in the rotor bars of induction motors during synchronous no-load tests is described in the paper. The experimental verification of the high-frequency phenomena in the rotor cage is fundamental for a deep insight of the additional loss estimation by numerical methods. The attention is mainly focused on the analysis and design of the transducers developed for the cage current measurement.

AC-Induced Bias Potential Effect on Corrosion of Steels

DTIC Science & Technology

2009-02-05

induction, variable conduction Experimental Setup Super- martensitic stainless steel composition Analysis: C Mn Si Cr Ni Mo Cu N Typical 13 Cr ɘ.01 0.6... stainless steel used in pipelines. •Low carbon (ɘ.01): allows the formation of a “soft” martensite that is more resistant than standard martensitic ...Proposed AC Corrosion Models  AC Simulated Corrosion testing  Stainless steel pipe and coating  Cathodic protection  Experimental Setup  Preliminary

Lithium, boron and chlorine as tracers for metasomatism in high-pressure metamorphic rocks: a case study from Syros (Greece)

NASA Astrophysics Data System (ADS)

Marschall, Horst R.; Altherr, Rainer; Gméling, Katalin; Kasztovszky, Zsolt

2009-03-01

High-pressure metamorphic (HPM) rocks (derived from igneous protoliths) and their metasomatised rinds from the island of Syros (Greece) were analysed for their B and Cl whole-rock abundances and their H2O content by prompt-gamma neutron-activation analysis (PGNAA) and for their Li and Be whole-rock abundances by ICP-OES. In the HPM rocks, B /Be and Cl /Be ratios correlate with H2O contents and appear to be controlled by extraction of B and Cl during dehydration and prograde metamorphism. In contrast, samples of the metasomatised rinds show no such correlation. B /Be ratios in the rinds are solely governed by the presence or absence of tourmaline, and Cl /Be ratios vary significantly, possibly related to fluid inclusions. Li/Be ratios do not correlate with H2O contents in the HPM rocks, which may in part be explained by a conservative behaviour of Li during dehydration. However, Li abundances exceed the vast majority of published values for Li abundances in fresh, altered, or differentiated oceanic igneous rocks and presumably result from metasomatic enrichment of Li. High Li concentrations and highly elevated Li/Be ratios in most metasomatised samples demonstrate an enrichment of Li in the Syros HP mélange during fluid infiltration. This study suggests that B and Cl abundances of HPM meta-igneous rocks can be used to trace prograde dehydration, while Li concentrations seem to be more sensitive for retrograde metasomatic processes in such lithologies.

Monitoring plasma treatment of thin films by surface plasmon resonance

NASA Astrophysics Data System (ADS)

Laha, Ranjit; Manivannan, A.; Kasiviswanathan, S.

2014-03-01

We report the surface plasmon resonance (SPR) measurements during plasma treatment of thin films by an indigenously designed setup. From the measurements on Al (6.3 nm)/Ag (38 nm) bi-layer at a pressure of 0.02 mbar, the SPR position was found to be shifted by ˜20° after a plasma treatment of ˜7 h. The formation of oxide layers during plasma oxidation was confirmed by glancing angle x-ray diffraction (GXRD) measurements. Combined analysis of GXRD and SPR data confirmed that while top Al layer enables controlling plasma oxidation of Ag, the setup enables monitoring the same. The setup designed is a first of its kind for in situ SPR studies where creation of low pressure is a prerequisite.

Monitoring plasma treatment of thin films by surface plasmon resonance.

PubMed

Laha, Ranjit; Manivannan, A; Kasiviswanathan, S

2014-03-01

We report the surface plasmon resonance (SPR) measurements during plasma treatment of thin films by an indigenously designed setup. From the measurements on Al (6.3 nm)/Ag (38 nm) bi-layer at a pressure of 0.02 mbar, the SPR position was found to be shifted by ~20° after a plasma treatment of ~7 h. The formation of oxide layers during plasma oxidation was confirmed by glancing angle x-ray diffraction (GXRD) measurements. Combined analysis of GXRD and SPR data confirmed that while top Al layer enables controlling plasma oxidation of Ag, the setup enables monitoring the same. The setup designed is a first of its kind for in situ SPR studies where creation of low pressure is a prerequisite.

Improvement of the polarized neutron interferometer setup demonstrating violation of a Bell-like inequality.

PubMed

Geppert, H; Denkmayr, T; Sponar, S; Lemmel, H; Hasegawa, Y

2014-11-01

For precise measurements with polarised neutrons high efficient spin-manipulation is required. We developed several neutron optical elements suitable for a new sophisticated setup, i.e., DC spin-turners and Larmor-accelerators which diminish thermal disturbances and depolarisation considerably. The gain in performance is exploited demonstrating violation of a Bell-like inequality for a spin-path entangled single-neutron state. The obtained value of [Formula: see text], which is much higher than previous measurements by neutron interferometry, is [Formula: see text] above the limit of S =2 predicted by contextual hidden variable theories. The new setup is more flexible referring to state preparation and analysis, therefore new, more precise measurements can be carried out.

Speckle correlation method used to measure object's in-plane velocity.

PubMed

Smíd, Petr; Horváth, Pavel; Hrabovský, Miroslav

2007-06-20

We present a measurement of an object's in-plane velocity in one direction by the use of the speckle correlation method. Numerical correlations of speckle patterns recorded periodically during motion of the object under investigation give information used to evaluate the object's in-plane velocity. The proposed optical setup uses a detection plane in the image field and enables one to detect the object's velocity within the interval (10-150) microm x s(-1). Simulation analysis shows a way of controlling the measuring range. The presented theory, simulation analysis, and setup are verified through an experiment of measurement of the velocity profile of an object.

An analysis for high speed propeller-nacelle aerodynamic performance prediction. Volume 2: User's manual

NASA Technical Reports Server (NTRS)

Egolf, T. Alan; Anderson, Olof L.; Edwards, David E.; Landgrebe, Anton J.

1988-01-01

A user's manual for the computer program developed for the prediction of propeller-nacelle aerodynamic performance reported in, An Analysis for High Speed Propeller-Nacelle Aerodynamic Performance Prediction: Volume 1 -- Theory and Application, is presented. The manual describes the computer program mode of operation requirements, input structure, input data requirements and the program output. In addition, it provides the user with documentation of the internal program structure and the software used in the computer program as it relates to the theory presented in Volume 1. Sample input data setups are provided along with selected printout of the program output for one of the sample setups.

First clinical experience in carbon ion scanning beam therapy: retrospective analysis of patient positional accuracy.

PubMed

Mori, Shinichiro; Shibayama, Kouichi; Tanimoto, Katsuyuki; Kumagai, Motoki; Matsuzaki, Yuka; Furukawa, Takuji; Inaniwa, Taku; Shirai, Toshiyuki; Noda, Koji; Tsuji, Hiroshi; Kamada, Tadashi

2012-09-01

Our institute has constructed a new treatment facility for carbon ion scanning beam therapy. The first clinical trials were successfully completed at the end of November 2011. To evaluate patient setup accuracy, positional errors between the reference Computed Tomography (CT) scan and final patient setup images were calculated using 2D-3D registration software. Eleven patients with tumors of the head and neck, prostate and pelvis receiving carbon ion scanning beam treatment participated. The patient setup process takes orthogonal X-ray flat panel detector (FPD) images and the therapists adjust the patient table position in six degrees of freedom to register the reference position by manual or auto- (or both) registration functions. We calculated residual positional errors with the 2D-3D auto-registration function using the final patient setup orthogonal FPD images and treatment planning CT data. Residual error averaged over all patients in each fraction decreased from the initial to the last treatment fraction [1.09 mm/0.76° (averaged in the 1st and 2nd fractions) to 0.77 mm/0.61° (averaged in the 15th and 16th fractions)]. 2D-3D registration calculation time was 8.0 s on average throughout the treatment course. Residual errors in translation and rotation averaged over all patients as a function of date decreased with the passage of time (1.6 mm/1.2° in May 2011 to 0.4 mm/0.2° in December 2011). This retrospective residual positional error analysis shows that the accuracy of patient setup during the first clinical trials of carbon ion beam scanning therapy was good and improved with increasing therapist experience.

Dosimetric impact of daily setup variations during treatment of canine nasal tumors using intensity-modulated radiation therapy.

PubMed

Deveau, Michael A; Gutiérrez, Alonso N; Mackie, Thomas R; Tomé, Wolfgang A; Forrest, Lisa J

2010-01-01

Intensity-modulated radiation therapy (IMRT) can be employed to yield precise dose distributions that tightly conform to targets and reduce high doses to normal structures by generating steep dose gradients. Because of these sharp gradients, daily setup variations may have an adverse effect on clinical outcome such that an adjacent normal structure may be overdosed and/or the target may be underdosed. This study provides a detailed analysis of the impact of daily setup variations on optimized IMRT canine nasal tumor treatment plans when variations are not accounted for due to the lack of image guidance. Setup histories of ten patients with nasal tumors previously treated using helical tomotherapy were replanned retrospectively to study the impact of daily setup variations on IMRT dose distributions. Daily setup shifts were applied to IMRT plans on a fraction-by-fraction basis. Using mattress immobilization and laser alignment, mean setup error magnitude in any single dimension was at least 2.5 mm (0-10.0 mm). With inclusions of all three translational coordinates, mean composite offset vector was 5.9 +/- 3.3 mm. Due to variations, a loss of equivalent uniform dose for target volumes of up to 5.6% was noted which corresponded to a potential loss in tumor control probability of 39.5%. Overdosing of eyes and brain was noted by increases in mean normalized total dose and highest normalized dose given to 2% of the volume. Findings suggest that successful implementation of canine nasal IMRT requires daily image guidance to ensure accurate delivery of precise IMRT distributions when non-rigid immobilization techniques are utilized. Unrecognized geographical misses may result in tumor recurrence and/or radiation toxicities to the eyes and brain.

DOSIMETRIC IMPACT OF DAILY SETUP VARIATIONS DURING TREATMENT OF CANINE NASAL TUMORS USING INTENSITY-MODULATED RADIATION THERAPY

PubMed Central

Deveau, Michael A.; Gutiérrez, Alonso N.; Mackie, Thomas R.; Tomé, Wolfgang A.; Forrest, Lisa J.

2009-01-01

Intensity-modulated radiation therapy (IMRT) can be employed to yield precise dose distributions that tightly conform to targets and reduce high doses to normal structures by generating steep dose gradients. Because of these sharp gradients, daily setup variations may have an adverse effect on clinical outcome such that an adjacent normal structure may be overdosed and/or the target may be underdosed. This study provides a detailed analysis of the impact of daily setup variations on optimized IMRT canine nasal tumor treatment plans when variations are not accounted for due to the lack of image guidance. Setup histories of ten patients with nasal tumors previously treated using helical tomotherapy were replanned retrospectively to study the impact of daily setup variations on IMRT dose distributions. Daily setup shifts were applied to IMRT plans on a fraction-by-fraction basis. Using mattress immobilization and laser alignment, mean setup error magnitude in any single dimension was at least 2.5mm (0-10.0mm). With inclusions of all three translational coordinates, mean composite offset vector was 5.9±3.3mm. Due to variations, a loss of equivalent uniform dose (EUD) for target volumes of up to 5.6% was noted which corresponded to a potential loss in TCP of 39.5%. Overdosing of eyes and brain was noted by increases in mean normalized total dose (NTDmean) and highest normalized dose given to 2% of the volume (NTD2%). Findings suggest that successful implementation of canine nasal IMRT requires daily image guidance to ensure accurate delivery of precise IMRT distributions when non-rigid immobilization techniques are utilized. Unrecognized geographical misses may result in tumor recurrence and/or radiation toxicities to the eyes and brain. PMID:20166402

Analysis of Prostate Patient Setup and Tracking Data: Potential Intervention Strategies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su Zhong, E-mail: zsu@floridaproton.org; Zhang Lisha; Murphy, Martin

Purpose: To evaluate the setup, interfraction, and intrafraction organ motion error distributions and simulate intrafraction intervention strategies for prostate radiotherapy. Methods and Materials: A total of 17 patients underwent treatment setup and were monitored using the Calypso system during radiotherapy. On average, the prostate tracking measurements were performed for 8 min/fraction for 28 fractions for each patient. For both patient couch shift data and intrafraction organ motion data, the systematic and random errors were obtained from the patient population. The planning target volume margins were calculated using the van Herk formula. Two intervention strategies were simulated using the tracking data:more » the deviation threshold and period. The related planning target volume margins, time costs, and prostate position 'fluctuation' were presented. Results: The required treatment margin for the left-right, superoinferior, and anteroposterior axes was 8.4, 10.8, and 14.7 mm for skin mark-only setup and 1.3, 2.3, and 2.8 mm using the on-line setup correction, respectively. Prostate motion significantly correlated among the superoinferior and anteroposterior directions. Of the 17 patients, 14 had prostate motion within 5 mm of the initial setup position for {>=}91.6% of the total tracking time. The treatment margin decreased to 1.1, 1.8, and 2.3 mm with a 3-mm threshold correction and to 0.5, 1.0, and 1.5 mm with an every-2-min correction in the left-right, superoinferior, and anteroposterior directions, respectively. The periodic corrections significantly increase the treatment time and increased the number of instances when the setup correction was made during transient excursions. Conclusions: The residual systematic and random error due to intrafraction prostate motion is small after on-line setup correction. Threshold-based and time-based intervention strategies both reduced the planning target volume margins. The time-based strategies increased the treatment time and the in-fraction position fluctuation.« less

The implementation and data analysis of an interferometer for intense short pulse laser experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Jaebum; Baldis, Hector A.; Chen, Hui

We present an interferometry setup and the detailed fringe analysis method for intense short pulse (SP) laser experiments. The interferometry scheme was refined through multiple campaigns to investigate the effects of pre-plasmas on energetic electrons at the Jupiter Laser Facility at Lawrence Livermore National Laboratory. The interferometer used a frequency doubled (more » $${\\it\\lambda}=0.527~{\\rm\\mu}\\text{m}$$) 0.5 ps long optical probe beam to measure the pre-plasma density, an invaluable parameter to better understand how varying pre-plasma conditions affect the characteristics of the energetic electrons. The hardware of the diagnostic, data analysis and example data are presented. Here, the diagnostic setup and the analysis procedure can be employed for any other SP laser experiments and interferograms, respectively.« less

The implementation and data analysis of an interferometer for intense short pulse laser experiments

DOE PAGES

Park, Jaebum; Baldis, Hector A.; Chen, Hui

2016-08-03

We present an interferometry setup and the detailed fringe analysis method for intense short pulse (SP) laser experiments. The interferometry scheme was refined through multiple campaigns to investigate the effects of pre-plasmas on energetic electrons at the Jupiter Laser Facility at Lawrence Livermore National Laboratory. The interferometer used a frequency doubled (more » $${\\it\\lambda}=0.527~{\\rm\\mu}\\text{m}$$) 0.5 ps long optical probe beam to measure the pre-plasma density, an invaluable parameter to better understand how varying pre-plasma conditions affect the characteristics of the energetic electrons. The hardware of the diagnostic, data analysis and example data are presented. Here, the diagnostic setup and the analysis procedure can be employed for any other SP laser experiments and interferograms, respectively.« less

SU-E-J-39: Dosimetric Benefit of Implanted Marker-Based CBCT Setup for Definitive Prostatic Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhen, H; Wu, Z; Bluemenfeld, P

Purpose Daily setup for definitive prostatic radiotherapy is challenged by suboptimal visibility of the prostate boundary and daily variation of rectum shape and position. For patients with improved bowel preparation, we conducted a dosimetric comparison between prostate implanted marker (IM)-based daily setup and anterior rectal wall (ARW)-based setup, with the hypothesis that the former leads to adequate target coverage with better rectal sparing. Methods Five IMRT/VMAT prostate cases with implanted markers were selected for analysis. Daily CBCT showed improvement of the rectal volume compared to planning CT. For each patient, the prostate and rectum were contoured on three CBCT imagesmore » (fraction 5/15/25) with subsequent physician review. The CBCTs were then registered to a planning CT using IM-based registration. The deviation of ARW positions from planning CT to CBCT were analyzed at various sup-inf levels (−1.8 cm to 1.8 cm from level of prostate center). To estimate the potential dosimetric impact from ARW-based setup, the treatment plans were recalculated using A-P shifts ranging from −1mm to +6mm. Clinically important rectum DVH values including Dmax, D3cc and Dmean were computed. Results For the studied patients, we observed on average 32% rectum volume reduction from planning CT to CBCT. As a Results, the ARW on average shifts posteriorly by −1mm to +5mm, depending on the sup-inf level of observation, with larger shifts observed at more superior levels. Recalculation shows that when ARW shifts 1mm posteriorly, ARW-based CBCT setup leads to a 1.0%, 4.2%, and 3.2% increase in rectum Dmax, D3cc, and Dmean, respectively, compared to IM-based setup. The dosimetric deviations increase to 4.7%, 25.8% and 24.7% when ARW shifts 6mm posteriorly. No significant prostate-only dose difference was observed. Conclusion For patients with improved bowel preparation, IM-based CBCT setup leads to accurate prostate coverage along with significantly lower rectal dose, compared to ARW-based setup.« less

Development of a new in-air micro-PIXE set-up with in-vacuum charge measurements in Atomki

NASA Astrophysics Data System (ADS)

Török, Zs.; Huszánk, R.; Csedreki, L.; Dani, J.; Szoboszlai, Z.; Kertész, Zs.

2015-11-01

A new external microbeam set-up has recently been installed as the extension of the existing microprobe system at the Laboratory of Ion Beam Applications of Atomki, Debrecen, Hungary. The external beam set-up, based on the system of Oxford Microbeams (OM), is equipped with two X-ray detectors for PIXE analysis, a digital microscope, two alignment lasers and a precision XYZ stage for easy and reproducible positioning of the sample. Exit windows with different thicknesses and of different materials can be used according to the actual demands, currently silicon-nitride (Si3N4) film with 200 nm thickness is employed in our laboratory. The first application was demonstrated in the field of archaeometry, on Bronze Age hoards from Hungary.

Implementation of a noise reduction circuit for spaceflight IR spectrometers

NASA Technical Reports Server (NTRS)

Ramirez, L.; Hickok, R.; Pain, B.; Staller, C.

1992-01-01

The paper discusses the implementation and analysis of a correlated triple sampling circuit using analog subtractor/integrators. The software and test setup for noise measurements are also described. The correlation circuitry is part of the signal chain for a 256-element InSb line array used in the Visible and Infrared Mapping Spectrometer. Using a focal-plane array (FPA) simulator, system noise measurements of 0.7 DN are obtained. A test setup for FPA/SPE (signal processing electronics) characterization along with noise measurements is demonstrated.

Omega Design and FEA Based Coriolis Mass Flow Sensor (CMFS) Analysis Using Titanium Material

NASA Astrophysics Data System (ADS)

Patil, Pravin P.; Kumar, Ashwani; Ahmad, Faraz

2018-02-01

The main highlight of this research work is evaluation of resonant frequency for titanium omega type coriolis mass flow sensor. Coriolis mass flow sensor is used for measuring direct mass flow in pipe useful for various industrial applications. It works on the principle of Coriolis effect. Finite Element Analysis (FEA) simulation of omega flow sensor was performed using Ansys 14.5 and Solid Edge, Pro-E was used for modelling of omega tube. Titanium was selected as omega tube material. Experimental setup was prepared for omega tube coriolis flow sensor for performing different test. Experimental setup was used for investigation of different parameters effect on CMFS and validation of simulation results.

Six-flow operations for catalyst development in Fischer-Tropsch synthesis: Bridging the gap between high-throughput experimentation and extensive product evaluation

NASA Astrophysics Data System (ADS)

Sartipi, Sina; Jansma, Harrie; Bosma, Duco; Boshuizen, Bart; Makkee, Michiel; Gascon, Jorge; Kapteijn, Freek

2013-12-01

Design and operation of a "six-flow fixed-bed microreactor" setup for Fischer-Tropsch synthesis (FTS) is described. The unit consists of feed and mixing, flow division, reaction, separation, and analysis sections. The reactor system is made of five heating blocks with individual temperature controllers, assuring an identical isothermal zone of at least 10 cm along six fixed-bed microreactor inserts (4 mm inner diameter). Such a lab-scale setup allows running six experiments in parallel, under equal feed composition, reaction temperature, and conditions of separation and analysis equipment. It permits separate collection of wax and liquid samples (from each flow line), allowing operation with high productivities of C5+ hydrocarbons. The latter is crucial for a complete understanding of FTS product compositions and will represent an advantage over high-throughput setups with more than ten flows where such instrumental considerations lead to elevated equipment volume, cost, and operation complexity. The identical performance (of the six flows) under similar reaction conditions was assured by testing a same catalyst batch, loaded in all microreactors.

Principle component analysis and linear discriminant analysis of multi-spectral autofluorescence imaging data for differentiating basal cell carcinoma and healthy skin

NASA Astrophysics Data System (ADS)

Chernomyrdin, Nikita V.; Zaytsev, Kirill I.; Lesnichaya, Anastasiya D.; Kudrin, Konstantin G.; Cherkasova, Olga P.; Kurlov, Vladimir N.; Shikunova, Irina A.; Perchik, Alexei V.; Yurchenko, Stanislav O.; Reshetov, Igor V.

2016-09-01

In present paper, an ability to differentiate basal cell carcinoma (BCC) and healthy skin by combining multi-spectral autofluorescence imaging, principle component analysis (PCA), and linear discriminant analysis (LDA) has been demonstrated. For this purpose, the experimental setup, which includes excitation and detection branches, has been assembled. The excitation branch utilizes a mercury arc lamp equipped with a 365-nm narrow-linewidth excitation filter, a beam homogenizer, and a mechanical chopper. The detection branch employs a set of bandpass filters with the central wavelength of spectral transparency of λ = 400, 450, 500, and 550 nm, and a digital camera. The setup has been used to study three samples of freshly excised BCC. PCA and LDA have been implemented to analyze the data of multi-spectral fluorescence imaging. Observed results of this pilot study highlight the advantages of proposed imaging technique for skin cancer diagnosis.

Fiber array based hyperspectral Raman imaging for chemical selective analysis of malaria-infected red blood cells.

PubMed

Brückner, Michael; Becker, Katja; Popp, Jürgen; Frosch, Torsten

2015-09-24

A new setup for Raman spectroscopic wide-field imaging is presented. It combines the advantages of a fiber array based spectral translator with a tailor-made laser illumination system for high-quality Raman chemical imaging of sensitive biological samples. The Gaussian-like intensity distribution of the illuminating laser beam is shaped by a square-core optical multimode fiber to a top-hat profile with very homogeneous intensity distribution to fulfill the conditions of Koehler. The 30 m long optical fiber and an additional vibrator efficiently destroy the polarization and coherence of the illuminating light. This homogeneous, incoherent illumination is an essential prerequisite for stable quantitative imaging of complex biological samples. The fiber array translates the two-dimensional lateral information of the Raman stray light into separated spectral channels with very high contrast. The Raman image can be correlated with a corresponding white light microscopic image of the sample. The new setup enables simultaneous quantification of all Raman spectra across the whole spatial area with very good spectral resolution and thus outperforms other Raman imaging approaches based on scanning and tunable filters. The unique capabilities of the setup for fast, gentle, sensitive, and selective chemical imaging of biological samples were applied for automated hemozoin analysis. A special algorithm was developed to generate Raman images based on the hemozoin distribution in red blood cells without any influence from other Raman scattering. The new imaging setup in combination with the robust algorithm provides a novel, elegant way for chemical selective analysis of the malaria pigment hemozoin in early ring stages of Plasmodium falciparum infected erythrocytes. Copyright © 2015 Elsevier B.V. All rights reserved.

The KUT meteor radar: An educational low cost meteor observation system by radio forward scattering

NASA Astrophysics Data System (ADS)

Madkour, W.; Yamamoto, M.

2016-01-01

The Kochi University of Technology (KUT) meteor radar is an educational low cost observation system built at Kochi, Japan by successive graduate students since 2004. The system takes advantage of the continuous VHF- band beacon signal emitted from Fukui National College of Technology (FNCT) for scientific usage all over Japan by receiving the forward scattered signals. The system uses the classical forward scattering setup similar to the setup described by the international meteor organization (IMO), gradually developed from the most basic single antenna setup to the multi-site meteor path determination setup. The primary objective is to automate the observation of the meteor parameters continuously to provide amounts of data sufficient for statistical analysis. The developed software system automates the observation of the astronomical meteor parameters such as meteor direction, velocity and trajectory. Also, automated counting of meteor echoes and their durations are used to observe mesospheric ozone concentration by analyzing the duration distribution of different meteor showers. The meteor parameters observed and the methodology used for each are briefly summarized.

Configuration and Sizing of a Test Fixture for Panels Under Combined Loads

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.

2006-01-01

Future air and space structures are expected to utilize composite panels that are subjected to combined mechanical loads, such as bi-axial compression/tension, shear and pressure. Therefore, the ability to accurately predict the buckling and strength failures of such panels is important. While computational analysis can provide tremendous insight into panel response, experimental results are necessary to verify predicted performances of these panels to judge the accuracy of computational methods. However, application of combined loads is an extremely difficult task due to the complex test fixtures and set-up required. Presented herein is a comparison of several test set-ups capable of testing panels under combined loads. Configurations compared include a D-box, a segmented cylinder and a single panel set-up. The study primarily focuses on the preliminary sizing of a single panel test configuration capable of testing flat panels under combined in-plane mechanical loads. This single panel set-up appears to be best suited to the testing of both strength critical and buckling critical panels. Required actuator loads and strokes are provided for various square, flat panels.

Investigating MALDI MSI parameters (Part 2) - On the use of a mechanically shuttered trigger system for improved laser energy stability.

PubMed

Steven, Rory T; Dexter, Alex; Bunch, Josephine

2016-07-15

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) is now widely used to desorb, ionize and detect molecules from complex samples and tissue sections. The detected ion intensity within MALDI MS and MSI is intimately linked to the laser energy per pulse incident upon the sample during analysis. Laser energy/power stability can be significantly affected by the manner in which the laser is operated. High-repetition rate diode-pumped solid-state (DPSS) lasers are being increasingly adopted to enable high-throughput MALDI MSI analysis. Within this work two different laser-triggering setups are used to demonstrate the effect of laser energy instabilities due to spiking and thermal control phenomena and a setup with a shutter to remove these effects. The effect of non-equilibrium laser operation on MALDI MSI data versus the more stable laser pulse energy of the shutter-triggered system is demonstrated in thin films of α-cyano-4-hydroxycinnamic acid (CHCA) and for imaging of murine brain tissue sections. Significant unwanted variations in absolute and relative detected ion intensity are shown where energy variation is introduced by these phenomena, which return to equilibrium within the setup employed here over timescales relevant to MALDI MS analysis. Copyright © 2016 Elsevier Inc. All rights reserved.

Performance analysis of signaling protocols on OBS switches

NASA Astrophysics Data System (ADS)

Kirci, Pinar; Zaim, A. Halim

2005-10-01

In this paper, Just-In-Time (JIT), Just-Enough-Time (JET) and Horizon signalling schemes for Optical Burst Switched Networks (OBS) are presented. These signaling schemes run over a core dWDM network and a network architecture based on Optical Burst Switches (OBS) is proposed to support IP, ATM and Burst traffic. In IP and ATM traffic several packets are assembled in a single packet called burst and the burst contention is handled by burst dropping. The burst length distribution in IP traffic is arbitrary between 0 and 1, and is fixed in ATM traffic at 0,5. Burst traffic on the other hand is arbitrary between 1 and 5. The Setup and Setup ack length distributions are arbitrary. We apply the Poisson model with rate λ and Self-Similar model with pareto distribution rate α to identify inter-arrival times in these protocols. We consider a communication between a source client node and a destination client node over an ingress and one or more multiple intermediate switches.We use buffering only in the ingress node. The communication is based on single burst connections in which, the connection is set up just before sending a burst and then closed as soon as the burst is sent. Our analysis accounts for several important parameters, including the burst setup, burst setup ack, keepalive messages and the optical switching protocol. We compare the performance of the three signalling schemes on the network under as burst dropping probability under a range of network scenarios.

Absorption spectroscopy setup for determination of whole human blood and blood-derived materials spectral characteristics

NASA Astrophysics Data System (ADS)

Wróbel, M. S.; Gnyba, M.; Milewska, D.; Mitura, K.; Karpienko, K.

2015-09-01

A dedicated absorption spectroscopy system was set up using tungsten-halogen broadband source, optical fibers, sample holder, and a commercial spectrometer with CCD array. Analysis of noise present in the setup was carried out. Data processing was applied to the absorption spectra to reduce spectral noise, and improve the quality of the spectra and to remove the baseline level. The absorption spectra were measured for whole blood samples, separated components: plasma, saline, washed erythrocytes in saline and human whole blood with biomarkers - biocompatible nanodiamonds (ND). Blood samples had been derived from a number of healthy donors. The results prove a correct setup arrangement, with adequate preprocessing of the data. The results of blood-ND mixtures measurements show no toxic effect on blood cells, which proves the NDs as a potential biocompatible biomarkers.

Synchronized and noise-robust audio recordings during realtime magnetic resonance imaging scans.

PubMed

Bresch, Erik; Nielsen, Jon; Nayak, Krishna; Narayanan, Shrikanth

2006-10-01

This letter describes a data acquisition setup for recording, and processing, running speech from a person in a magnetic resonance imaging (MRI) scanner. The main focus is on ensuring synchronicity between image and audio acquisition, and in obtaining good signal to noise ratio to facilitate further speech analysis and modeling. A field-programmable gate array based hardware design for synchronizing the scanner image acquisition to other external data such as audio is described. The audio setup itself features two fiber optical microphones and a noise-canceling filter. Two noise cancellation methods are described including a novel approach using a pulse sequence specific model of the gradient noise of the MRI scanner. The setup is useful for scientific speech production studies. Sample results of speech and singing data acquired and processed using the proposed method are given.

Synchronized and noise-robust audio recordings during realtime magnetic resonance imaging scans (L)

PubMed Central

Bresch, Erik; Nielsen, Jon; Nayak, Krishna; Narayanan, Shrikanth

2007-01-01

This letter describes a data acquisition setup for recording, and processing, running speech from a person in a magnetic resonance imaging (MRI) scanner. The main focus is on ensuring synchronicity between image and audio acquisition, and in obtaining good signal to noise ratio to facilitate further speech analysis and modeling. A field-programmable gate array based hardware design for synchronizing the scanner image acquisition to other external data such as audio is described. The audio setup itself features two fiber optical microphones and a noise-canceling filter. Two noise cancellation methods are described including a novel approach using a pulse sequence specific model of the gradient noise of the MRI scanner. The setup is useful for scientific speech production studies. Sample results of speech and singing data acquired and processed using the proposed method are given. PMID:17069275

Initial clinical experience with a video-based patient positioning system.

PubMed

Johnson, L S; Milliken, B D; Hadley, S W; Pelizzari, C A; Haraf, D J; Chen, G T

1999-08-01

To report initial clinical experience with an interactive, video-based patient positioning system that is inexpensive, quick, accurate, and easy to use. System hardware includes two black-and-white CCD cameras, zoom lenses, and a PC equipped with a frame grabber. Custom software is used to acquire and archive video images, as well as to display real-time subtraction images revealing patient misalignment in multiple views. Two studies are described. In the first study, video is used to document the daily setup histories of 5 head and neck patients. Time-lapse cine loops are generated for each patient and used to diagnose and correct common setup errors. In the second study, 6 twice-daily (BID) head and neck patients are positioned according to the following protocol: at AM setups conventional treatment room lasers are used; at PM setups lasers are used initially and then video is used for 1-2 minutes to fine-tune the patient position. Lateral video images and lateral verification films are registered off-line to compare the distribution of setup errors per patient, with and without video assistance. In the first study, video images were used to determine the accuracy of our conventional head and neck setup technique, i.e., alignment of lightcast marks and surface anatomy to treatment room lasers and the light field. For this initial cohort of patients, errors ranged from sigma = 5 to 7 mm and were patient-specific. Time-lapse cine loops of the images revealed sources of the error, and as a result, our localization techniques and immobilization device were modified to improve setup accuracy. After the improvements, conventional setup errors were reduced to sigma = 3 to 5 mm. In the second study, when a stereo pair of live subtraction images were introduced to perform daily "on-line" setup correction, errors were reduced to sigma = 1 to 3 mm. Results depended on patient health and cooperation and the length of time spent fine-tuning the position. An interactive, video-based patient positioning system was shown to reduce setup errors to within 1 to 3 mm in head and neck patients, without a significant increase in overall treatment time or labor-intensive procedures. Unlike retrospective portal image analysis, use of two live-video images provides the therapists with immediate feedback and allows for true 3-D positioning and correction of out-of-plane rotation before radiation is delivered. With significant improvement in head and neck alignment and the elimination of setup errors greater than 3 to 5 mm, margins associated with treatment volumes potentially can be reduced, thereby decreasing normal tissue irradiation.

Cone-Beam Computed Tomography–Guided Positioning of Laryngeal Cancer Patients with Large Interfraction Time Trends in Setup and Nonrigid Anatomy Variations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gangsaas, Anne, E-mail: a.gangsaas@erasmusmc.nl; Astreinidou, Eleftheria; Quint, Sandra

2013-10-01

Purpose: To investigate interfraction setup variations of the primary tumor, elective nodes, and vertebrae in laryngeal cancer patients and to validate protocols for cone beam computed tomography (CBCT)-guided correction. Methods and Materials: For 30 patients, CBCT-measured displacements in fractionated treatments were used to investigate population setup errors and to simulate residual setup errors for the no action level (NAL) offline protocol, the extended NAL (eNAL) protocol, and daily CBCT acquisition with online analysis and repositioning. Results: Without corrections, 12 of 26 patients treated with radical radiation therapy would have experienced a gradual change (time trend) in primary tumor setup ≥4more » mm in the craniocaudal (CC) direction during the fractionated treatment (11/12 in caudal direction, maximum 11 mm). Due to these trends, correction of primary tumor displacements with NAL resulted in large residual CC errors (required margin 6.7 mm). With the weekly correction vector adjustments in eNAL, the trends could be largely compensated (CC margin 3.5 mm). Correlation between movements of the primary and nodal clinical target volumes (CTVs) in the CC direction was poor (r{sup 2}=0.15). Therefore, even with online setup corrections of the primary CTV, the required CC margin for the nodal CTV was as large as 6.8 mm. Also for the vertebrae, large time trends were observed for some patients. Because of poor CC correlation (r{sup 2}=0.19) between displacements of the primary CTV and the vertebrae, even with daily online repositioning of the vertebrae, the required CC margin around the primary CTV was 6.9 mm. Conclusions: Laryngeal cancer patients showed substantial interfraction setup variations, including large time trends, and poor CC correlation between primary tumor displacements and motion of the nodes and vertebrae (internal tumor motion). These trends and nonrigid anatomy variations have to be considered in the choice of setup verification protocol and planning target volume margins. eNAL could largely compensate time trends with minor prolongation of fraction time.« less

SU-E-J-44: A Novel Approach to Quantify Patient Setup and Target Motion for Real-Time Image-Guided Radiotherapy (IGRT)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, S; Charpentier, P; Sayler, E

2015-06-15

Purpose Isocenter shifts and rotations to correct patient setup errors and organ motion cannot remedy some shape changes of large targets. We are investigating new methods in quantification of target deformation for realtime IGRT of breast and chest wall cancer. Methods Ninety-five patients of breast or chest wall cancer were accrued in an IRB-approved clinical trial of IGRT using 3D surface images acquired at daily setup and beam-on time via an in-room camera. Shifts and rotations relating to the planned reference surface were determined using iterative-closest-point alignment. Local surface displacements and target deformation are measured via a ray-surface intersection andmore » principal component analysis (PCA) of external surface, respectively. Isocenter shift, upper-abdominal displacement, and vectors of the surface projected onto the two principal components, PC1 and PC2, were evaluated for sensitivity and accuracy in detection of target deformation. Setup errors for some deformed targets were estimated by superlatively registering target volume, inner surface, or external surface in weekly CBCT or these outlines on weekly EPI. Results Setup difference according to the inner-surface, external surface, or target volume could be 1.5 cm. Video surface-guided setup agreed with EPI results to within < 0.5 cm while CBCT results were sometimes (∼20%) different from that of EPI (>0.5 cm) due to target deformation for some large breasts and some chest walls undergoing deep-breath-hold irradiation. Square root of PC1 and PC2 is very sensitive to external surface deformation and irregular breathing. Conclusion PCA of external surfaces is quick and simple way to detect target deformation in IGRT of breast and chest wall cancer. Setup corrections based on the target volume, inner surface, and external surface could be significant different. Thus, checking of target shape changes is essential for accurate image-guided patient setup and motion tracking of large deformable targets. NIH grant for the first author as cionsultant and the last author as the PI.« less

SU-F-J-142: Proposed Method to Broaden Inclusion Potential of Patients Able to Use the Calypso Tracking System in Prostate Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fiedler, D; Kuo, H; Bodner, W

2016-06-15

Purpose: To introduce a non-standard method of patient setup, using BellyBoard immobilization, to better utilize the localization and tracking potential of an RF-beacon system with EBRT for prostate cancer. Methods: An RF-beacon phantom was imaged using a wide bore CT scanner, both in a standard level position and with a known rotation (4° pitch and 7.5° yaw). A commercial treatment planning system (TPS) was used to determine positional coordinates of each beacon, and the centroid of the three beacons for both setups. For each setup at the Linac, kV AP and Rt Lateral images were obtained. A full characterization ofmore » the RF-beacon system in clinical mode was completed for various beacons’ array-to-centroid distances, which includes vertical, lateral, and longitudinal offset data, as well as pitch and yaw offset measurements for the tilted phantom. For the single patient who has been setup using the proposed BellyBoard method, a supine simulation was first obtained. When abdominal protrusion was found to be exceeding the limits of the RF-Beacon system through distance-based analysis in the TPS, the patient is re-simulated prone with the BellyBoard. Array to centroid distance is measured again in the TPS, and if found to be within the localization or tracking region it is applied. Results: Characterization of limitations for the RF-beacon system in clinical mode showed acceptable consistency of offset determination for phantom setup accuracy. The nonstandard patient setup method reduced the beacons’ centroid-to-array distance by 8.32cm, from 25.13cm to 16.81cm; completely out of tracking range (greater than 20cm) to within setup tracking range (less than 20cm). Conclusion: Using the RF-beacon system in combination with this novel patient setup can allow patients who would otherwise not be candidates for beacon enhanced EBRT to now be able to benefit from the reduced PTV margins of this treatment method.« less

SU-E-T-657: Quantitative Assessment of Plan Robustness for Helical Tomotherapy for Head and Neck Cancer Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matney, J; Lian, J; Chera, B

2015-06-15

Introduction: Geometric uncertainties in daily patient setup can lead to variations in the planned dose, especially when using highly conformal techniques such as helical Tomotherapy. To account for the potential effect of geometric uncertainty, our clinical practice is to expand critical structures by 3mm expansion into planning risk volumes (PRV). The PRV concept assumes the spatial dose cloud is insensitive to patient positioning. However, no tools currently exist to determine if a Tomotherapy plan is robust to the effects of daily setup variation. We objectively quantified the impact of geometric uncertainties on the 3D doses to critical normal tissues duringmore » helical Tomotherapy. Methods: Using a Matlab-based program created and validated by Accuray (Madison, WI), the planned Tomotherapy delivery sinogram recalculated dose on shifted CT datasets. Ten head and neck patients were selected for analysis. To simulate setup uncertainty, the patient anatomy was shifted ±3mm in the longitudinal, lateral and vertical axes. For each potential shift, the recalculated doses to various critical normal tissues were compared to the doses delivered to the PRV in the original plan Results: 18 shifted scenarios created from Tomotherapy plans for three patients with head and neck cancers were analyzed. For all simulated setup errors, the maximum doses to the brainstem, spinal cord, parotids and cochlea were no greater than 0.6Gy of the respective original PRV maximum. Despite 3mm setup shifts, the minimum dose delivered to 95% of the CTVs and PTVs were always within 0.4Gy of the original plan. Conclusions: For head and neck sites treated with Tomotherapy, the use of a 3mm PRV expansion provide a reasonable estimate of the dosimetric effects of 3mm setup uncertainties. Similarly, target coverage appears minimally effected by a 3mm setup uncertainty. Data from a larger number of patients will be presented. Future work will include other anatomical sites.« less

Analysis of image sharpness reproducibility on a novel engineered micro-CT scanner with variable geometry and embedded recalibration software.

PubMed

Panetta, D; Belcari, N; Del Guerra, A; Bartolomei, A; Salvadori, P A

2012-04-01

This study investigates the reproducibility of the reconstructed image sharpness, after modifications of the geometry setup, for a variable magnification micro-CT (μCT) scanner. All the measurements were performed on a novel engineered μCT scanner for in vivo imaging of small animals (Xalt), which has been recently built at the Institute of Clinical Physiology of the National Research Council (IFC-CNR, Pisa, Italy), in partnership with the University of Pisa. The Xalt scanner is equipped with an integrated software for on-line geometric recalibration, which will be used throughout the experiments. In order to evaluate the losses of image quality due to modifications of the geometry setup, we have made 22 consecutive acquisitions by changing alternatively the system geometry between two different setups (Large FoV - LF, and High Resolution - HR). For each acquisition, the tomographic images have been reconstructed before and after the on-line geometric recalibration. For each reconstruction, the image sharpness was evaluated using two different figures of merit: (i) the percentage contrast on a small bar pattern of fixed frequency (f = 5.5 lp/mm for the LF setup and f = 10 lp/mm for the HR setup) and (ii) the image entropy. We have found that, due to the small-scale mechanical uncertainty (in the order of the voxel size), a recalibration is necessary for each geometric setup after repositioning of the system's components; the resolution losses due to the lack of recalibration are worse for the HR setup (voxel size = 18.4 μm). The integrated on-line recalibration algorithm of the Xalt scanner allowed to perform the recalibration quickly, by restoring the spatial resolution of the system to the reference resolution obtained after the initial (off-line) calibration. Copyright © 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Automated patient identification and localization error detection using 2-dimensional to 3-dimensional registration of kilovoltage x-ray setup images.

PubMed

Lamb, James M; Agazaryan, Nzhde; Low, Daniel A

2013-10-01

To determine whether kilovoltage x-ray projection radiation therapy setup images could be used to perform patient identification and detect gross errors in patient setup using a computer algorithm. Three patient cohorts treated using a commercially available image guided radiation therapy (IGRT) system that uses 2-dimensional to 3-dimensional (2D-3D) image registration were retrospectively analyzed: a group of 100 cranial radiation therapy patients, a group of 100 prostate cancer patients, and a group of 83 patients treated for spinal lesions. The setup images were acquired using fixed in-room kilovoltage imaging systems. In the prostate and cranial patient groups, localizations using image registration were performed between computed tomography (CT) simulation images from radiation therapy planning and setup x-ray images corresponding both to the same patient and to different patients. For the spinal patients, localizations were performed to the correct vertebral body, and to an adjacent vertebral body, using planning CTs and setup x-ray images from the same patient. An image similarity measure used by the IGRT system image registration algorithm was extracted from the IGRT system log files and evaluated as a discriminant for error detection. A threshold value of the similarity measure could be chosen to separate correct and incorrect patient matches and correct and incorrect vertebral body localizations with excellent accuracy for these patient cohorts. A 10-fold cross-validation using linear discriminant analysis yielded misclassification probabilities of 0.000, 0.0045, and 0.014 for the cranial, prostate, and spinal cases, respectively. An automated measure of the image similarity between x-ray setup images and corresponding planning CT images could be used to perform automated patient identification and detection of localization errors in radiation therapy treatments. Copyright © 2013 Elsevier Inc. All rights reserved.

Test and Analysis of a Hyper-X Carbon-Carbon Leading Edge Chine

NASA Technical Reports Server (NTRS)

Smith, Russell W.; Sikora, Joseph G.; Lindell, Michael C.

2005-01-01

During parts production for the X43A Mach 10 hypersonic vehicle nondestructive evaluation (NDE) of a leading edge chine detected on imbedded delamination near the lower surface of the part. An ultimate proof test was conducted to verify the ultimate strength of this leading edge chine part. The ultimate proof test setup used a pressure bladder design to impose a uniform distributed pressure field over the bi-planar surface of the chine test article. A detailed description of the chine test article and experimental test setup is presented. Analysis results from a linear status model of the test article are also presented and discussed. Post-test inspection of the specimen revealed no visible failures or areas of delamination.

The characterization of radioactive waste: a critical review of techniques implemented or under development at CEA, France

NASA Astrophysics Data System (ADS)

Pérot, Bertrand; Jallu, Fanny; Passard, Christian; Gueton, Olivier; Allinei, Pierre-Guy; Loubet, Laurent; Estre, Nicolas; Simon, Eric; Carasco, Cédric; Roure, Christophe; Boucher, Lionel; Lamotte, Hervé; Comte, Jérôme; Bertaux, Maïté; Lyoussi, Abdallah; Fichet, Pascal; Carrel, Frédérick

2018-03-01

This review paper describes the destructive and non-destructive measurements implemented or under development at CEA, in view to perform the most complete radioactive waste characterization. First, high-energy photon imaging (radiography, tomography) brings essential information on the waste packages, such as density, position and shape of the waste inside the container and in the possible binder, quality of coating and blocking matrices, presence of internal shields or structures, presence of cracks, voids, or other defects in the container or in the matrix, liquids or other forbidden materials, etc. Radiological assessment is then performed using a series of non-destructive techniques such as gamma-ray spectroscopy, which allows characterizing a wide range of radioactive and nuclear materials, passive neutron coincidence counting and active neutron interrogation with the differential die-away technique, or active photon interrogation with high-energy photons (photofission), to measure nuclear materials. Prompt gamma neutron activation analysis (PGNAA) can also be employed to detect toxic chemicals or elements which can greatly influence the above measurements, such as neutron moderators or absorbers. Digital auto-radiography can also be used to detect alpha and beta contaminated waste. These non-destructive assessments can be completed by gas measurements, to quantify the radioactive and radiolysis gas releases, and by destructive examinations such as coring homogeneous waste packages or cutting the heterogeneous ones, in view to perform visual examination and a series of physical, chemical, and radiochemical analyses on samples. These last allow for instance to check the mechanical and containment properties of the package envelop, or of the waste binder, to measure toxic chemicals, to assess the activity of long-lived radionuclides or pure beta emitters, to determine the isotopic composition of nuclear materials, etc.

Measurement and analysis of chatter in a compliant model of a drillstring equipped with a PDC bit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elsayed, M.A.; Raymond, D.W.

1999-11-09

Typical laboratory testing of Polycrystalline Diamond Compact (PDC) bits is performed on relatively rigid setups. Even in hard rock, PDC bits exhibit reasonable life using such testing schemes. Unfortunately, field experience indicates otherwise. In this paper, the authors show that introducing compliance in testing setups provides better simulation of actual field conditions. Using such a scheme, they show that chatter can be severe even in softer rock, such as sandstone, and very destructive to the cutters in hard rock, such as sierra white granite.

Reducing absorbed dose to eye lenses in head CT examinations: the effect of bismuth shielding.

PubMed

Ciarmatori, Alberto; Nocetti, L; Mistretta, G; Zambelli, G; Costi, T

2016-06-01

The eye lens is considered to be among the most radiosensitive human tissues. Brain CT scans may unnecessarily expose it to radiation even if the area of clinical interest is far from the eyes. The aim of this study is to implement a bismuth eye lens shielding system for Head-CT acquisitions in these cases. The study is focused on the assessment of the dosimetric characteristics of the shielding system as well as on its effect on image quality. The shielding system was tested in two set-ups which differ for distance ("contact" and "4 cm" Set up respectively). Scans were performed on a CTDI phantom and an anthropomorphic phantom. A reference set up without shielding system was acquired to establish a baseline. Image quality was assessed by signal (not HU converted), noise and contrast-to-noise ratio (CNR) evaluation. The overall dose reduction was evaluated by measuring the CTDIvol while the eye lens dose reduction was assessed by placing thermoluminescent dosimeters (TLDs) on an anthropomorphic phantom. The image quality analysis exhibits the presence of an artefact that mildly increases the CT number up to 3 cm below the shielding system. Below the artefact, the difference of the Signal and the CNR are negligible between the three different set-ups. Regarding the CTDI, the analysis demonstrates a decrease by almost 12 % (in the "contact" set-up) and 9 % (in the "4 cm" set-up). TLD measurements exhibit an eye lens dose reduction by 28.5 ± 5 and 21.1 ± 5 % respectively at the "contact" and the "4 cm" distance. No relevant artefact was found and image quality was not affected by the shielding system. Significant dose reductions were measured. These features make the shielding set-up useful for clinical implementation in both studied positions.

Precision assessment of model-based RSA for a total knee prosthesis in a biplanar set-up.

PubMed

Trozzi, C; Kaptein, B L; Garling, E H; Shelyakova, T; Russo, A; Bragonzoni, L; Martelli, S

2008-10-01

Model-based Roentgen Stereophotogrammetric Analysis (RSA) was recently developed for the measurement of prosthesis micromotion. Its main advantage is that markers do not need to be attached to the implants as traditional marker-based RSA requires. Model-based RSA has only been tested in uniplanar radiographic set-ups. A biplanar set-up would theoretically facilitate the pose estimation algorithm, since radiographic projections would show more different shape features of the implants than in uniplanar images. We tested the precision of model-based RSA and compared it with that of the traditional marker-based method in a biplanar set-up. Micromotions of both tibial and femoral components were measured with both the techniques from double examinations of patients participating in a clinical study. The results showed that in the biplanar set-up model-based RSA presents a homogeneous distribution of precision for all the translation directions, but an inhomogeneous error for rotations, especially internal-external rotation presented higher errors than rotations about the transverse and sagittal axes. Model-based RSA was less precise than the marker-based method, although the differences were not significant for the translations and rotations of the tibial component, with the exception of the internal-external rotations. For both prosthesis components the precisions of model-based RSA were below 0.2 mm for all the translations, and below 0.3 degrees for rotations about transverse and sagittal axes. These values are still acceptable for clinical studies aimed at evaluating total knee prosthesis micromotion. In a biplanar set-up model-based RSA is a valid alternative to traditional marker-based RSA where marking of the prosthesis is an enormous disadvantage.

A new setup for the investigation of swift heavy ion induced particle emission and surface modifications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meinerzhagen, F.; Breuer, L.; Bukowska, H.

2016-01-15

The irradiation with fast ions with kinetic energies of >10 MeV leads to the deposition of a high amount of energy along their trajectory (up to several ten keV/nm). The energy is mainly transferred to the electronic subsystem and induces different secondary processes of excitations, which result in significant material modifications. A new setup to study these ion induced effects on surfaces will be described in this paper. The setup combines a variable irradiation chamber with different techniques of surface characterizations like scanning probe microscopy, time-of-flight secondary ion, and neutral mass spectrometry, as well as low energy electron diffraction undermore » ultra high vacuum conditions, and is mounted at a beamline of the universal linear accelerator (UNILAC) of the GSI facility in Darmstadt, Germany. Here, samples can be irradiated with high-energy ions with a total kinetic energy up to several GeVs under different angles of incidence. Our setup enables the preparation and in situ analysis of different types of sample systems ranging from metals to insulators. Time-of-flight secondary ion mass spectrometry enables us to study the chemical composition of the surface, while scanning probe microscopy allows a detailed view into the local electrical and morphological conditions of the sample surface down to atomic scales. With the new setup, particle emission during irradiation as well as persistent modifications of the surface after irradiation can thus be studied. We present first data obtained with the new setup, including a novel measuring protocol for time-of-flight mass spectrometry with the GSI UNILAC accelerator.« less

Development of liquid chromatography high resolution mass spectrometry strategies for the screening of complex organic matter: Application to astrophysical simulated materials.

PubMed

Eddhif, Balkis; Allavena, Audrey; Liu, Sylvie; Ribette, Thomas; Abou Mrad, Ninette; Chiavassa, Thierry; d'Hendecourt, Louis Le Sergeant; Sternberg, Robert; Danger, Gregoire; Geffroy-Rodier, Claude; Poinot, Pauline

2018-03-01

The present work aims at developing two LC-HRMS setups for the screening of organic matter in astrophysical samples. Their analytical development has been demonstrated on a 100-µg residue coming from the photo-thermo chemical processing of a cometary ice analog produced in laboratory. The first 1D-LC-HRMS setup combines a serially coupled columns configuration with HRMS detection. It has allowed to discriminate among different chemical families (amino acids, sugars, nucleobases and oligopeptides) in only one chromatographic run without neither a priori acid hydrolysis nor chemical derivatisation. The second setup is a dual-LC configuration which connects a series of trapping columns with analytical reverse-phase columns. By coupling on-line these two distinct LC units with a HRMS detection, high mass compounds (350

Six-flow operations for catalyst development in Fischer-Tropsch synthesis: Bridging the gap between high-throughput experimentation and extensive product evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sartipi, Sina, E-mail: S.Sartipi@tudelft.nl, E-mail: J.Gascon@tudelft.nl; Jansma, Harrie; Bosma, Duco

2013-12-15

Design and operation of a “six-flow fixed-bed microreactor” setup for Fischer-Tropsch synthesis (FTS) is described. The unit consists of feed and mixing, flow division, reaction, separation, and analysis sections. The reactor system is made of five heating blocks with individual temperature controllers, assuring an identical isothermal zone of at least 10 cm along six fixed-bed microreactor inserts (4 mm inner diameter). Such a lab-scale setup allows running six experiments in parallel, under equal feed composition, reaction temperature, and conditions of separation and analysis equipment. It permits separate collection of wax and liquid samples (from each flow line), allowing operation with highmore » productivities of C5+ hydrocarbons. The latter is crucial for a complete understanding of FTS product compositions and will represent an advantage over high-throughput setups with more than ten flows where such instrumental considerations lead to elevated equipment volume, cost, and operation complexity. The identical performance (of the six flows) under similar reaction conditions was assured by testing a same catalyst batch, loaded in all microreactors.« less

Quantum transport in coupled Majorana box systems

NASA Astrophysics Data System (ADS)

Gau, Matthias; Plugge, Stephan; Egger, Reinhold

2018-05-01

We present a theoretical analysis of low-energy quantum transport in coupled Majorana box devices. A single Majorana box represents a Coulomb-blockaded mesoscopic superconductor proximitizing two or more long topological nanowires. The box thus harbors at least four Majorana zero modes (MZMs). Setups with several Majorana boxes, where MZMs on different boxes are tunnel coupled via short nanowire segments, are key ingredients to recent Majorana qubit and code network proposals. We construct and study the low-energy theory for multiterminal junctions with normal leads connected to the coupled box device by lead-MZM tunnel contacts. Transport experiments in such setups can test the nonlocality of Majorana-based systems and the integrity of the underlying Majorana qubits. For a single box, we recover the previously described topological Kondo effect which can be captured by a purely bosonic theory. For several coupled boxes, however, nonconserved local fermion parities require the inclusion of additional local sets of Pauli operators. We present a renormalization group analysis and develop a nonperturbative strong-coupling approach to quantum transport in such systems. Our findings are illustrated for several examples, including a loop qubit device and different two-box setups.

PSpice Modeling of a Sandwich Piezoelectric Ceramic Ultrasonic Transducer in Longitudinal Vibration

PubMed Central

Wei, Xiaoyuan; Yang, Yuan; Yao, Wenqing; Zhang, Lei

2017-01-01

Sandwiched piezoelectric transducers are widely used, especially in high power applications. For more convenient analysis and design, a PSpice lossy model of sandwiched piezoelectric ultrasonic transducers in longitudinal vibration is proposed by means of the one-dimensional wave and transmission line theories. With the proposed model, the resonance and antiresonance frequencies are obtained, and it is shown that the simulations and measurements have good consistency. For the purpose of further verification the accuracy and application of the PSpice model, a pitch-catch setup and an experimental platform are built. They include two sandwiched piezoelectric ultrasonic transducers and two aluminum cylinders whose lengths are 20 mm and 100 mm respectively. Based on this pitch-catch setup, the impedance and transient analysis are performed. Compared with the measured results, it is shown that the simulated results have good consistency. In addition, the conclusion can be drawn that the optimal excitation frequency for the pitch-catch setup is not necessarily the resonance frequency of ultrasonic transducers, because the resonance frequency is obtained under no load. The proposed PSpice model of the sandwiched piezoelectric transducer is more conveniently applied to combine with other circuits such as driving circuits, filters, amplifiers, and so on. PMID:28973996

PSpice Modeling of a Sandwich Piezoelectric Ceramic Ultrasonic Transducer in Longitudinal Vibration.

PubMed

Wei, Xiaoyuan; Yang, Yuan; Yao, Wenqing; Zhang, Lei

2017-09-30

Sandwiched piezoelectric transducers are widely used, especially in high power applications. For more convenient analysis and design, a PSpice lossy model of sandwiched piezoelectric ultrasonic transducers in longitudinal vibration is proposed by means of the one-dimensional wave and transmission line theories. With the proposed model, the resonance and antiresonance frequencies are obtained, and it is shown that the simulations and measurements have good consistency. For the purpose of further verification the accuracy and application of the PSpice model, a pitch-catch setup and an experimental platform are built. They include two sandwiched piezoelectric ultrasonic transducers and two aluminum cylinders whose lengths are 20 mm and 100 mm respectively. Based on this pitch-catch setup, the impedance and transient analysis are performed. Compared with the measured results, it is shown that the simulated results have good consistency. In addition, the conclusion can be drawn that the optimal excitation frequency for the pitch-catch setup is not necessarily the resonance frequency of ultrasonic transducers, because the resonance frequency is obtained under no load. The proposed PSpice model of the sandwiched piezoelectric transducer is more conveniently applied to combine with other circuits such as driving circuits, filters, amplifiers, and so on.

White-Light Supercontinuum Laser-Based Multiple Wavelength Excitation for TCSPC-FLIM of Cutaneous Nanocarrier Uptake

NASA Astrophysics Data System (ADS)

Volz, Pierre; Brodwolf, Robert; Zoschke, Christian; Haag, Rainer; Schäfer-Korting, Monika; Alexiev, Ulrike

2018-05-01

We report here on a custom-built time-correlated single photon-counting (TCSPC)-based fluorescence lifetime imaging microscopy (FLIM) setup with a continuously tunable white-light supercontinuum laser combined with acousto-optical tunable filters (AOTF) as an excitation source for simultaneous excitation of multiple spectrally separated fluorophores. We characterized the wavelength dependence of the white-light supercontinuum laser pulse properties and demonstrated the performance of the FLIM setup, aiming to show the experimental setup in depth together with a biomedical application. We herein summarize the physical-technical parameters as well as our approach to map the skin uptake of nanocarriers using FLIM with a resolution compared to spectroscopy. As an example, we focus on the penetration study of indocarbocyanine-labeled dendritic core-multishell nanocarriers (CMS-ICC) into reconstructed human epidermis. Unique fluorescence lifetime signatures of indocarbocyanine-labeled nanocarriers indicate nanocarrier-tissue interactions within reconstructed human epidermis, bringing FLIM close to spectroscopic analysis.

An optimal policy for a single-vendor and a single-buyer integrated system with setup cost reduction and process-quality improvement

NASA Astrophysics Data System (ADS)

Shu, Hui; Zhou, Xideng

2014-05-01

The single-vendor single-buyer integrated production inventory system has been an object of study for a long time, but little is known about the effect of investing in reducing setup cost reduction and process-quality improvement for an integrated inventory system in which the products are sold with free minimal repair warranty. The purpose of this article is to minimise the integrated cost by optimising simultaneously the number of shipments and the shipment quantity, the setup cost, and the process quality. An efficient algorithm procedure is proposed for determining the optimal decision variables. A numerical example is presented to illustrate the results of the proposed models graphically. Sensitivity analysis of the model with respect to key parameters of the system is carried out. The paper shows that the proposed integrated model can result in significant savings in the integrated cost.

Characterization of a phantom setup for breast conserving cancer surgery

NASA Astrophysics Data System (ADS)

Chadwell, Jacob T.; Conley, Rebekah H.; Collins, Jarrod A.; Meszoely, Ingrid M.; Miga, Michael I.

2016-03-01

The purpose of this work is to develop an anatomically and mechanically representative breast phantom for the validation of breast conserving surgical therapies, specifically, in this case, image guided surgeries. Using three patients scheduled for lumpectomy and four healthy volunteers in mock surgical presentations, the magnitude, direction, and location of breast deformations was analyzed. A phantom setup was then designed to approximate such deformations in a mock surgical environment. Specifically, commercially available and custom-built polyvinyl alcohol (PVA) phantoms were used to mimic breast tissue during surgery. A custom designed deformation apparatus was then created to reproduce deformations seen in typical clinical setups of the pre- and intra-operative breast geometry. Quantitative analysis of the human subjects yielded a positive correlation between breast volume and amount of breast deformation. Phantom results reflected similar behavior with the custom-built PVA phantom outperforming the commercial phantom.

Three dimensional characterization of laser ablation craters using high resolution X-ray computed tomography

NASA Astrophysics Data System (ADS)

Galmed, A. H.; du Plessis, A.; le Roux, S. G.; Hartnick, E.; Von Bergmann, H.; Maaza, M.

2018-01-01

Laboratory X-ray computed tomography is an emerging technology for the 3D characterization and dimensional analysis of many types of materials. In this work we demonstrate the usefulness of this characterization method for the full three dimensional analysis of laser ablation craters, in the context of a laser induced breakdown spectroscopy setup. Laser induced breakdown spectroscopy relies on laser ablation for sampling the material of interest. We demonstrate here qualitatively (in images) and quantitatively (in terms of crater cone angles, depths, diameters and volume) laser ablation crater analysis in 3D for metal (aluminum) and rock (false gold ore). We show the effect of a Gaussian beam profile on the resulting crater geometry, as well as the first visual evidence of undercutting in the rock sample, most likely due to ejection of relatively large grains. The method holds promise for optimization of laser ablation setups especially for laser induced breakdown spectroscopy.

Action Sport Cameras as an Instrument to Perform a 3D Underwater Motion Analysis.

PubMed

Bernardina, Gustavo R D; Cerveri, Pietro; Barros, Ricardo M L; Marins, João C B; Silvatti, Amanda P

2016-01-01

Action sport cameras (ASC) are currently adopted mainly for entertainment purposes but their uninterrupted technical improvements, in correspondence of cost decreases, are going to disclose them for three-dimensional (3D) motion analysis in sport gesture study and athletic performance evaluation quantitatively. Extending this technology to sport analysis however still requires a methodologic step-forward to making ASC a metric system, encompassing ad-hoc camera setup, image processing, feature tracking, calibration and 3D reconstruction. Despite traditional laboratory analysis, such requirements become an issue when coping with both indoor and outdoor motion acquisitions of athletes. In swimming analysis for example, the camera setup and the calibration protocol are particularly demanding since land and underwater cameras are mandatory. In particular, the underwater camera calibration can be an issue affecting the reconstruction accuracy. In this paper, the aim is to evaluate the feasibility of ASC for 3D underwater analysis by focusing on camera setup and data acquisition protocols. Two GoPro Hero3+ Black (frequency: 60Hz; image resolutions: 1280×720/1920×1080 pixels) were located underwater into a swimming pool, surveying a working volume of about 6m3. A two-step custom calibration procedure, consisting in the acquisition of one static triad and one moving wand, carrying nine and one spherical passive markers, respectively, was implemented. After assessing camera parameters, a rigid bar, carrying two markers at known distance, was acquired in several positions within the working volume. The average error upon the reconstructed inter-marker distances was less than 2.5mm (1280×720) and 1.5mm (1920×1080). The results of this study demonstrate that the calibration of underwater ASC is feasible enabling quantitative kinematic measurements with accuracy comparable to traditional motion capture systems.

Action Sport Cameras as an Instrument to Perform a 3D Underwater Motion Analysis

PubMed Central

Cerveri, Pietro; Barros, Ricardo M. L.; Marins, João C. B.; Silvatti, Amanda P.

2016-01-01

Action sport cameras (ASC) are currently adopted mainly for entertainment purposes but their uninterrupted technical improvements, in correspondence of cost decreases, are going to disclose them for three-dimensional (3D) motion analysis in sport gesture study and athletic performance evaluation quantitatively. Extending this technology to sport analysis however still requires a methodologic step-forward to making ASC a metric system, encompassing ad-hoc camera setup, image processing, feature tracking, calibration and 3D reconstruction. Despite traditional laboratory analysis, such requirements become an issue when coping with both indoor and outdoor motion acquisitions of athletes. In swimming analysis for example, the camera setup and the calibration protocol are particularly demanding since land and underwater cameras are mandatory. In particular, the underwater camera calibration can be an issue affecting the reconstruction accuracy. In this paper, the aim is to evaluate the feasibility of ASC for 3D underwater analysis by focusing on camera setup and data acquisition protocols. Two GoPro Hero3+ Black (frequency: 60Hz; image resolutions: 1280×720/1920×1080 pixels) were located underwater into a swimming pool, surveying a working volume of about 6m3. A two-step custom calibration procedure, consisting in the acquisition of one static triad and one moving wand, carrying nine and one spherical passive markers, respectively, was implemented. After assessing camera parameters, a rigid bar, carrying two markers at known distance, was acquired in several positions within the working volume. The average error upon the reconstructed inter-marker distances was less than 2.5mm (1280×720) and 1.5mm (1920×1080). The results of this study demonstrate that the calibration of underwater ASC is feasible enabling quantitative kinematic measurements with accuracy comparable to traditional motion capture systems. PMID:27513846

Flexibility and utility of pre-processing methods in converting STXM setups for ptychography - Final Paper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fromm, Catherine

2015-08-20

Ptychography is an advanced diffraction based imaging technique that can achieve resolution of 5nm and below. It is done by scanning a sample through a beam of focused x-rays using discrete yet overlapping scan steps. Scattering data is collected on a CCD camera, and the phase of the scattered light is reconstructed with sophisticated iterative algorithms. Because the experimental setup is similar, ptychography setups can be created by retrofitting existing STXM beam lines with new hardware. The other challenge comes in the reconstruction of the collected scattering images. Scattering data must be adjusted and packaged with experimental parameters to calibratemore » the reconstruction software. The necessary pre-processing of data prior to reconstruction is unique to each beamline setup, and even the optical alignments used on that particular day. Pre-processing software must be developed to be flexible and efficient in order to allow experiments appropriate control and freedom in the analysis of their hard-won data. This paper will describe the implementation of pre-processing software which successfully connects data collection steps to reconstruction steps, letting the user accomplish accurate and reliable ptychography.« less

Optimized linear motor and digital PID controller setup used in Mössbauer spectrometer

NASA Astrophysics Data System (ADS)

Kohout, Pavel; Kouřil, Lukáš; Navařík, Jakub; Novák, Petr; Pechoušek, Jiří

2014-10-01

Optimization of a linear motor and digital PID controller setup used in a Mössbauer spectrometer is presented. Velocity driving system with a digital PID feedback subsystem was developed in the LabVIEW graphical environment and deployed on the sbRIO real-time hardware device (National Instruments). The most important data acquisition processes are performed as real-time deterministic tasks on an FPGA chip. Velocity transducer of a double loudspeaker type with a power amplifier circuit is driven by the system. Series of calibration measurements were proceeded to find the optimal setup of the P, I, D parameters together with velocity error signal analysis. The shape and given signal characteristics of the velocity error signal are analyzed in details. Remote applications for controlling and monitoring the PID system from computer or smart phone, respectively, were also developed. The best setup and P, I, D parameters were set and calibration spectrum of α-Fe sample with an average nonlinearity of the velocity scale below 0.08% was collected. Furthermore, the width of the spectral line below 0.30 mm/s was observed. Powerful and complex velocity driving system was designed.

EVA: laparoscopic instrument tracking based on Endoscopic Video Analysis for psychomotor skills assessment.

PubMed

Oropesa, Ignacio; Sánchez-González, Patricia; Chmarra, Magdalena K; Lamata, Pablo; Fernández, Alvaro; Sánchez-Margallo, Juan A; Jansen, Frank Willem; Dankelman, Jenny; Sánchez-Margallo, Francisco M; Gómez, Enrique J

2013-03-01

The EVA (Endoscopic Video Analysis) tracking system is a new system for extracting motions of laparoscopic instruments based on nonobtrusive video tracking. The feasibility of using EVA in laparoscopic settings has been tested in a box trainer setup. EVA makes use of an algorithm that employs information of the laparoscopic instrument's shaft edges in the image, the instrument's insertion point, and the camera's optical center to track the three-dimensional position of the instrument tip. A validation study of EVA comprised a comparison of the measurements achieved with EVA and the TrEndo tracking system. To this end, 42 participants (16 novices, 22 residents, and 4 experts) were asked to perform a peg transfer task in a box trainer. Ten motion-based metrics were used to assess their performance. Construct validation of the EVA has been obtained for seven motion-based metrics. Concurrent validation revealed that there is a strong correlation between the results obtained by EVA and the TrEndo for metrics, such as path length (ρ = 0.97), average speed (ρ = 0.94), or economy of volume (ρ = 0.85), proving the viability of EVA. EVA has been successfully validated in a box trainer setup, showing the potential of endoscopic video analysis to assess laparoscopic psychomotor skills. The results encourage further implementation of video tracking in training setups and image-guided surgery.

Upper-limb biomechanical analysis of wheelchair transfer techniques in two toilet configurations.

PubMed

Tsai, Chung-Ying; Boninger, Michael L; Bass, Sarah R; Koontz, Alicia M

2018-06-01

Using proper technique is important for minimizing upper limb kinetics during wheelchair transfers. The objective of the study was to 1) evaluate the transfer techniques used during toilet transfers and 2) determine the impact of technique on upper limb joint loading for two different toilet configurations. Twenty-six manual wheelchair users (23 men and 3 women) performed transfers in a side and front wheelchair-toilet orientation while their habitual transfer techniques were evaluated using the Transfer Assessment Instrument. A motion analysis system and force sensors were used to record biomechanical data during the transfers. More than 20% of the participants failed to complete five transfer skills in the side setup compared to three skills in the front setup. Higher quality skills overall were associated with lower peak forces and moments in both toilet configurations (-0.68 < r < -0.40, p < 0.05). In the side setup, participants who properly placed their hands in a stable position and used proper leading handgrips had lower shoulder resultant joint forces and moments than participants who did not perform these skills correctly (p ≤ 0.04). In the front setup, positioning the wheelchair within three inches of the transfer target was associated with reduced peak trailing forces and moments across all three upper limb joints (p = 0.02). Transfer skills training, making toilet seats level with the wheelchair seat, positioning the wheelchair closer to the toilet and mounting grab bars in a more ideal location for persons who do sitting pivot transfers may facilitate better quality toilet transfers. Published by Elsevier Ltd.

CMM Data Analysis Tool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Due to the increase in the use of Coordinate Measuring Machines (CMMs) to measure fine details and complex geometries in manufacturing, many programs have been made to compile and analyze the data. These programs typically require extensive setup to determine the expected results in order to not only track the pass/fail of a dimension, but also to use statistical process control (SPC). These extra steps and setup times have been addressed through the CMM Data Analysis Tool, which only requires the output of the CMM to provide both pass/fail analysis on all parts run to the same inspection program asmore » well as provide graphs which help visualize where the part measures within the allowed tolerances. This provides feedback not only to the customer for approval of a part during development, but also to machining process engineers to identify when any dimension is drifting towards an out of tolerance condition during production. This program can handle hundreds of parts with complex dimensions and will provide an analysis within minutes.« less

Cone beam CT-based set-up strategies with and without rotational correction for stereotactic body radiation therapy in the liver.

PubMed

Bertholet, Jenny; Worm, Esben; Høyer, Morten; Poulsen, Per

2017-06-01

Accurate patient positioning is crucial in stereotactic body radiation therapy (SBRT) due to a high dose regimen. Cone-beam computed tomography (CBCT) is often used for patient positioning based on radio-opaque markers. We compared six CBCT-based set-up strategies with or without rotational correction. Twenty-nine patients with three implanted markers received 3-6 fraction liver SBRT. The markers were delineated on the mid-ventilation phase of a 4D-planning-CT. One pretreatment CBCT was acquired per fraction. Set-up strategy 1 used only translational correction based on manual marker match between the CBCT and planning CT. Set-up strategy 2 used automatic 6 degrees-of-freedom registration of the vertebrae closest to the target. The 3D marker trajectories were also extracted from the projections and the mean position of each marker was calculated and used for set-up strategies 3-6. Translational correction only was used for strategy 3. Translational and rotational corrections were used for strategies 4-6 with the rotation being either vertebrae based (strategy 4), or marker based and constrained to ±3° (strategy 5) or unconstrained (strategy 6). The resulting set-up error was calculated as the 3D root-mean-square set-up error of the three markers. The set-up error of the spinal cord was calculated for all strategies. The bony anatomy set-up (2) had the largest set-up error (5.8 mm). The marker-based set-up with unconstrained rotations (6) had the smallest set-up error (0.8 mm) but the largest spinal cord set-up error (12.1 mm). The marker-based set-up with translational correction only (3) or with bony anatomy rotational correction (4) had equivalent set-up error (1.3 mm) but rotational correction reduced the spinal cord set-up error from 4.1 mm to 3.5 mm. Marker-based set-up was substantially better than bony-anatomy set-up. Rotational correction may improve the set-up, but further investigations are required to determine the optimal correction strategy.

Fourier analysis of a vibrating string through a low-cost experimental setup and a smartphone

NASA Astrophysics Data System (ADS)

Pereyra, C. J.; Osorio, M.; Laguarda, A.; Gau, D. L.

2018-07-01

In this work we present a simple and low-cost setup to illustrate the dependence of the behaviour of a standing wave in a guitar string with the initial conditions. To do so, we impose two kinds of initial conditions; in the first instance, the initial shape of the string is varied. Secondly, different nodes are imposed on the string. This dependence was studied using the Fourier analysis of the sound produced by the vibration of the string with a smartphone. The simplicity of the proposed activity makes it suitable to be implemented in any classroom to illustrate the concept of normal modes and as an example of Fourier series in a real system that is also familiar for the students.

Methodological challenges of optical tweezers-based X-ray fluorescence imaging of biological model organisms at synchrotron facilities.

PubMed

Vergucht, Eva; Brans, Toon; Beunis, Filip; Garrevoet, Jan; Bauters, Stephen; De Rijcke, Maarten; Deruytter, David; Janssen, Colin; Riekel, Christian; Burghammer, Manfred; Vincze, Laszlo

2015-07-01

Recently, a radically new synchrotron radiation-based elemental imaging approach for the analysis of biological model organisms and single cells in their natural in vivo state was introduced. The methodology combines optical tweezers (OT) technology for non-contact laser-based sample manipulation with synchrotron radiation confocal X-ray fluorescence (XRF) microimaging for the first time at ESRF-ID13. The optical manipulation possibilities and limitations of biological model organisms, the OT setup developments for XRF imaging and the confocal XRF-related challenges are reported. In general, the applicability of the OT-based setup is extended with the aim of introducing the OT XRF methodology in all research fields where highly sensitive in vivo multi-elemental analysis is of relevance at the (sub)micrometre spatial resolution level.

Isolated heart models: cardiovascular system studies and technological advances.

PubMed

Olejnickova, Veronika; Novakova, Marie; Provaznik, Ivo

2015-07-01

Isolated heart model is a relevant tool for cardiovascular system studies. It represents a highly reproducible model for studying broad spectrum of biochemical, physiological, morphological, and pharmaceutical parameters, including analysis of intrinsic heart mechanics, metabolism, and coronary vascular response. Results obtained in this model are under no influence of other organ systems, plasma concentration of hormones or ions and influence of autonomic nervous system. The review describes various isolated heart models, the modes of heart perfusion, and advantages and limitations of various experimental setups. It reports the improvements of perfusion setup according to Langendorff introduced by the authors.

Application of activation methods on the Dubna experimental transmutation set-ups.

PubMed

Stoulos, S; Fragopoulou, M; Adloff, J C; Debeauvais, M; Brandt, R; Westmeier, W; Krivopustov, M; Sosnin, A; Papastefanou, C; Zamani, M; Manolopoulou, M

2003-02-01

High spallation neutron fluxes were produced by irradiating massive heavy targets with proton beams in the GeV range. The experiments were performed at the Dubna High Energy Laboratory using the nuclotron accelerator. Two different experimental set-ups were used to produce neutron spectra convenient for transmutation of radioactive waste by (n,x) reactions. By a theoretical analysis neutron spectra can be reproduced from activation measurements. Thermal-epithermal and fast-super-fast neutron fluxes were estimated using the 197Au, 238U (n,gamma) and (n,2n) reactions, respectively. Depleted uranium transmutation rates were also studied in both experiments.

Is in vivo analysis of urinary stone composition feasible? Evaluation of an experimental setup of a Raman system coupled to commercial lithotripsy laser fibers.

PubMed

Miernik, Arkadiusz; Eilers, Yvan; Nuese, Christoph; Bolwien, Carsten; Lambrecht, Armin; Hesse, Albrecht; Rassweiler, Jens J; Schlager, Daniel; Wilhelm, Konrad; Wetterauer, Ulrich; Schoenthaler, Martin

2015-10-01

Raman spectroscopy allows immediate analysis of stone composition. In vivo stone analysis during endoscopic treatment may offer advantages concerning surgical strategy and metaphylaxis. Urinary stone components were evaluated utilizing an experimental setup of a Raman system coupled to commercial laser fibers. Samples of paracetamol (acetaminophen) and human urinary stones with known Raman spectra were analyzed using an experimental Raman system coupled to common commercial lithotripsy laser fibers (200 and 940 µm). Two different excitation lasers were used at wavelengths of 532 and 785 nm. Numerical aperture of the fibers, proportion of reflected light reaching the CCD chip, and integration times were calculated. Mathematical signal correction was performed. Both the laser beam profile and the quality of light reflected by the specimens were impaired significantly when used with commercial fibers. Acquired spectra could no longer be assigned to a specific stone composition. Subsequent measurements revealed a strong intrinsic fluorescence of the fibers and poor light acquisition properties leading to a significant decrease in the Raman signal in comparison with a free-beam setup. This was true for both investigated fiber diameters and both wavelengths. Microscopic examination showed highly irregular fiber tip surfaces (both new and used fibers). Our results propose that laser excitation and light acquisition properties of commercial lithotripsy fibers impair detectable Raman signals significantly in a fiber-coupled setting. This study provides essential physical and technological information for the development of an advanced fiber-coupled system able to be used for immediate stone analysis during endoscopic stone therapy.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanabe, S; Utsunomiya, S; Abe, E

Purpose: To assess an accuracy of fiducial maker-based setup using ExacTrac (ExT-based setup) as compared with soft tissue-based setup using Cone-beam CT (CBCT-based setup) for patients with prostate cancer receiving intensity-modulated radiation therapy (IMRT) for the purpose of investigating whether ExT-based setup can be an alternative to CBCT-based setup. Methods: The setup accuracy was analyzed prospectively for 7 prostate cancer patients with implanted three fiducial markers received IMRT. All patients were treated after CBCT-based setup was performed and corresponding shifts were recorded. ExacTrac images were obtained before and after CBCT-based setup. The fiducial marker-based shifts were calculated based on thosemore » two images and recorded on the assumption that the setup correction was carried out by fiducial marker-based auto correction. Mean and standard deviation of absolute differences and the correlation between CBCT and ExT shifts were estimated. Results: A total of 178 image dataset were analyzed. On the differences between CBCT and ExT shifts, 133 (75%) of 178 image dataset resulted in smaller differences than 3 mm in all dimensions. Mean differences in the anterior-posterior (AP), superior-inferior (SI), and left-right (LR) dimensions were 1.8 ± 1.9 mm, 0.7 ± 1.9 mm, and 0.6 ± 0.8 mm, respectively. The percentages of shift agreements within ±3 mm were 76% for AP, 90% for SI, and 100% for LR. The Pearson coefficient of correlation for CBCT and ExT shifts were 0.80 for AP, 0.80 for SI, and 0.65 for LR. Conclusion: This work showed that the accuracy of ExT-based setup was correlated with that of CBCT-based setup, implying that ExT-based setup has a potential ability to be an alternative to CBCT-based setup. The further work is to specify the conditions that ExT-based setup can provide the accuracy comparable to CBCT-based setup.« less

Science in Drama: Using Television Programmes to Teach Concepts and Techniques

ERIC Educational Resources Information Center

Rutter, Gordon

2011-01-01

By using a specific episode of the popular television cartoon series "The Simpsons," a range of techniques can be communicated, including microscope setup and use, simple chemical analysis, observation, and interpretation. Knowledge of blood groups and typing, morphological comparison of hair samples, fingerprint analysis, and DNA fingerprinting…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, M; Kim, T; Kang, S

Purpose: The purpose of this work is to develop a new patient set-up monitoring system using force sensing resistor (FSR) sensors that can confirm pressure of contact surface and evaluate its feasibility. Methods: In this study, we focused on develop the patient set-up monitoring system to compensate for the limitation of existing optical based monitoring system, so the developed system can inform motion in the radiation therapy. The set-up monitoring system was designed consisting of sensor units (FSR sensor), signal conditioning devices (USB cable/interface electronics), a control PC, and a developed analysis software. The sensor unit was made by attachingmore » FSR sensor and dispersing pressure sponge to prevent error which is caused by concentrating specific point. Measured signal from the FSR sensor was sampled to arduino mega 2560 microcontroller, transferred to control PC by using serial communication. The measured data went through normalization process. The normalized data was displayed through the developed graphic user interface (GUI) software. The software was designed to display a single sensor unit intensity (maximum 16 sensors) and display 2D pressure distribution (using 16 sensors) according to the purpose. Results: Changes of pressure value according to motion was confirmed by the developed set-up monitoring system. Very small movement such as little physical change in appearance can be confirmed using a single unit and using 2D pressure distribution. Also, the set-up monitoring system can observe in real time. Conclusion: In this study, we developed the new set-up monitoring system using FSR sensor. Especially, we expect that the new set-up monitoring system is suitable for motion monitoring of blind area that is hard to confirm existing optical system and compensate existing optical based monitoring system. As a further study, an integrated system will be constructed through correlation of existing optical monitoring system. This work was supported by the Industrial R&D program of MOTIE/KEIT. [10048997, Development of the core technology for integrated therapy devices based on real-time MRI guided tumor tracking] and the Mid-career Researcher Program (2014R1A2A1A10050270) through the National Research Foundation of Korea funded by the Ministry of Science, ICT&Future Planning.« less

SU-E-T-261: Development of An Automated System to Detect Patient Identification and Positioning Errors Prior to Radiotherapy Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jani, S; Low, D; Lamb, J

2015-06-15

Purpose: To develop a system that can automatically detect patient identification and positioning errors using 3D computed tomography (CT) setup images and kilovoltage CT (kVCT) planning images. Methods: Planning kVCT images were collected for head-and-neck (H&N), pelvis, and spine treatments with corresponding 3D cone-beam CT (CBCT) and megavoltage CT (MVCT) setup images from TrueBeam and TomoTherapy units, respectively. Patient identification errors were simulated by registering setup and planning images from different patients. Positioning errors were simulated by misaligning the setup image by 1cm to 5cm in the six anatomical directions for H&N and pelvis patients. Misalignments for spine treatments weremore » simulated by registering the setup image to adjacent vertebral bodies on the planning kVCT. A body contour of the setup image was used as an initial mask for image comparison. Images were pre-processed by image filtering and air voxel thresholding, and image pairs were assessed using commonly-used image similarity metrics as well as custom -designed metrics. A linear discriminant analysis classifier was trained and tested on the datasets, and misclassification error (MCE), sensitivity, and specificity estimates were generated using 10-fold cross validation. Results: Our workflow produced MCE estimates of 0.7%, 1.7%, and 0% for H&N, pelvis, and spine TomoTherapy images, respectively. Sensitivities and specificities ranged from 98.0% to 100%. MCEs of 3.5%, 2.3%, and 2.1% were obtained for TrueBeam images of the above sites, respectively, with sensitivity and specificity estimates between 96.2% and 98.4%. MCEs for 1cm H&N/pelvis misalignments were 1.3/5.1% and 9.1/8.6% for TomoTherapy and TrueBeam images, respectively. 2cm MCE estimates were 0.4%/1.6% and 3.1/3.2%, respectively. Vertebral misalignment MCEs were 4.8% and 4.9% for TomoTherapy and TrueBeam images, respectively. Conclusion: Patient identification and gross misalignment errors can be robustly and automatically detected using 3D setup images of two imaging modalities across three commonly-treated anatomical sites.« less

TH-A-9A-05: Initial Setup Accuracy Comparison Between Frame-Based and Frameless Stereotactic Radiosurgery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tseng, T; Sheu, R; Todorov, B

2014-06-15

Purpose: To evaluate initial setup accuracy for stereotactic radiosurgery (SRS) between Brainlab frame-based and frameless immobilization system, also to discern the magnitude frameless system has on setup parameters. Methods: The correction shifts from the original setup were compared for total 157 SRS cranial treatments (69 frame-based vs. 88 frameless). All treatments were performed on a Novalis linac with ExacTrac positioning system. Localization box with isocenter overlay was used for initial setup and correction shift was determined by ExacTrac 6D auto-fusion to achieve submillimeter accuracy for treatment. For frameless treatments, mean time interval between simulation and treatment was 5.7 days (rangemore » 0–13). Pearson Chi-Square was used for univariate analysis. Results: The correctional radial shifts (mean±STD, median) for the frame and frameless system measured by ExacTrac were 1.2±1.2mm, 1.1mm and 3.1±3.3mm, 2.0mm, respectively. Treatments with frameless system had a radial shift >2mm more often than those with frames (51.1% vs. 2.9%; p<.0001). To achieve submillimeter accuracy, 85.5% frame-based treatments did not require shift and only 23.9% frameless treatment could succeed with initial setup. There was no statistical significant system offset observed in any direction for either system. For frameless treatments, those treated ≥ 3 days from simulation had statistically higher rates of radial shifts between 1–2mm and >2mm compared to patients treated in a shorter amount of time from simulation (34.3% and 56.7% vs. 28.6% and 33.3%, respectively; p=0.006). Conclusion: Although image-guided positioning system can also achieve submillimeter accuracy for frameless system, users should be cautious regarding the inherent uncertainty of its capability of immobilization. A proper quality assurance procedure for frameless mask manufacturing and a protocol for intra-fraction imaging verification will be crucial for frameless system. Time interval between simulation and treatment was influential to initial setup accuracy. A shorter time frame for frameless SRS treatment could be helpful in minimizing uncertainties in localization.« less

RF magnetized ring-shaped plasma for target utilization obtained with circular magnet monopole arrangement

NASA Astrophysics Data System (ADS)

Amzad Hossain, Md.; Ohtsu, Yasunori

2018-01-01

We proposed a new setup for generating outer ring-shaped radio frequency (RF) magnetized plasma near the chamber wall using monopole magnet setups. Three monopole magnet setups with (a) R = 5 mm, (b) R = 20 mm, and (c) R = 35 mm were investigated, where R is the gap between the magnets in consecutive circles. The distributions of the two dimensional magnetic flux lines, the absolute value of the horizontal magnetic flux density, and the discharge voltage were investigated for the proposed setups to produce outer ring-shaped plasma. A highly luminous ring-shaped plasma was observed for the setup (a), whereas multi-ring discharges were observed for the setups (b) and (c). It was found that the electron temperature decreases with increasing gas pressure for all cases. The electron temperatures were 2.42, 1.71, and 1.15 eV at an Ar gas pressure of 4 Pa for setups (a), (b), and (c), respectively. The plasma density was approximately the same for setups (b) and (c) at all gas pressures. The highest plasma densities were 6.26 × 1015, 1.06 × 1016, and 1.11 × 1016 m-3 at 5 Pa for setups (a), (b), and (c), respectively. It was found that the electron mean free path was 41.4, 63.17, and 84.66 mm at an Ar gas pressure of 5 Pa for setups (a), (b), and (c), respectively. The electron neutral collision frequency for setup (a) was higher than those for setups (b) and (c) at a constant RF power of 40 W and an axial distance of z = 13 mm from the target surface. The radial profile of the ion saturation current for setup (b) was more uniform than those for setups (a) and (c).

An experimental setup to characterize MR switched gradient-induced potentials.

PubMed

Fokapu, Odette; El-Tatar, Aziz

2013-06-01

We have developed an experimental setup as an in vitro research tool for studying the contamination of electrophysiological signals (EPS) by MRI environment; particularly, when due to the switched gradient-induced potentials. The system is composed of: 1) a MRI compatible module for the transmission of the EPS into the MRI tunnel, 2) a gelatin-based tissue-mimicking phantom, placed inside the tunnel, in which EPS is injected, 3) a detection module composed of a five input channel MRI compatible transmitter placed inside the tunnel, allowing an on-site pre-amplification of the bio-potentials and their transmission, via an optical fiber cable, to a four filtered output per channel receiver (350 Hz, 160 Hz, 80 Hz, and 40 Hz, for a total of 20 channels) placed in the control room, and 4) a signal processing algorithm used to analyze the generated induced potentials. A set of tests were performed to validate the electronic performances of the setup. We also present in this work an interesting application of the setup, i.e., the acquisition and analysis of the induced potentials with respect of the slice orientation for a given MRI sequence. Significant modifications of the time and frequency characteristics were observed with respect to axial, coronal or sagittal orientations.

Elemental mapping of large samples by external ion beam analysis with sub-millimeter resolution and its applications

NASA Astrophysics Data System (ADS)

Silva, T. F.; Rodrigues, C. L.; Added, N.; Rizzutto, M. A.; Tabacniks, M. H.; Mangiarotti, A.; Curado, J. F.; Aguirre, F. R.; Aguero, N. F.; Allegro, P. R. P.; Campos, P. H. O. V.; Restrepo, J. M.; Trindade, G. F.; Antonio, M. R.; Assis, R. F.; Leite, A. R.

2018-05-01

The elemental mapping of large areas using ion beam techniques is a desired capability for several scientific communities, involved on topics ranging from geoscience to cultural heritage. Usually, the constraints for large-area mapping are not met in setups employing micro- and nano-probes implemented all over the world. A novel setup for mapping large sized samples in an external beam was recently built at the University of São Paulo employing a broad MeV-proton probe with sub-millimeter dimension, coupled to a high-precision large range XYZ robotic stage (60 cm range in all axis and precision of 5 μ m ensured by optical sensors). An important issue on large area mapping is how to deal with the irregularities of the sample's surface, that may introduce artifacts in the images due to the variation of the measuring conditions. In our setup, we implemented an automatic system based on machine vision to correct the position of the sample to compensate for its surface irregularities. As an additional benefit, a 3D digital reconstruction of the scanned surface can also be obtained. Using this new and unique setup, we have produced large-area elemental maps of ceramics, stones, fossils, and other sort of samples.

Investigation of the optimum location of external markers for patient setup accuracy enhancement at external beam radiotherapy

PubMed Central

Torshabi, Ahmad Esmaili; Nankali, Saber

2016-01-01

In external beam radiotherapy, one of the most common and reliable methods for patient geometrical setup and/or predicting the tumor location is use of external markers. In this study, the main challenging issue is increasing the accuracy of patient setup by investigating external markers location. Since the location of each external marker may yield different patient setup accuracy, it is important to assess different locations of external markers using appropriate selective algorithms. To do this, two commercially available algorithms entitled a) canonical correlation analysis (CCA) and b) principal component analysis (PCA) were proposed as input selection algorithms. They work on the basis of maximum correlation coefficient and minimum variance between given datasets. The proposed input selection algorithms work in combination with an adaptive neuro‐fuzzy inference system (ANFIS) as a correlation model to give patient positioning information as output. Our proposed algorithms provide input file of ANFIS correlation model accurately. The required dataset for this study was prepared by means of a NURBS‐based 4D XCAT anthropomorphic phantom that can model the shape and structure of complex organs in human body along with motion information of dynamic organs. Moreover, a database of four real patients undergoing radiation therapy for lung cancers was utilized in this study for validation of proposed strategy. Final analyzed results demonstrate that input selection algorithms can reasonably select specific external markers from those areas of the thorax region where root mean square error (RMSE) of ANFIS model has minimum values at that given area. It is also found that the selected marker locations lie closely in those areas where surface point motion has a large amplitude and a high correlation. PACS number(s): 87.55.km, 87.55.N PMID:27929479

Spectroscopic micro-tomography of metallic-organic composites by means of photon-counting detectors

NASA Astrophysics Data System (ADS)

Pichotka, M.; Jakubek, J.; Vavrik, D.

2015-12-01

The presumed capabilities of photon counting detectors have aroused major expectations in several fields of research. In the field of nuclear imaging ample benefits over standard detectors are to be expected from photon counting devices. First of all a very high contrast, as has by now been verified in numerous experiments. The spectroscopic capabilities of photon counting detectors further allow material decomposition in computed tomography and therefore inherently adequate beam hardening correction. For these reasons measurement setups featuring standard X-ray tubes combined with photon counting detectors constitute a possible replacement of the much more cost intensive tomographic setups at synchrotron light-sources. The actual application of photon counting detectors in radiographic setups in recent years has been impeded by a number of practical issues, above all by restrictions in the detectors size. Currently two tomographic setups in Czech Republic feature photon counting large-area detectors (LAD) fabricated in Prague. The employed large area hybrid pixel-detector assemblies [1] consisting of 10×10/10×5 Timepix devices have a surface area of 143×143 mm2 / 143×71,5 mm2 respectively, suitable for micro-tomographic applications. In the near future LAD devices featuring the Medipix3 readout chip as well as heavy sensors (CdTe, GaAs) will become available. Data analysis is obtained by a number of in house software tools including iterative multi-energy volume reconstruction.In this paper tomographic analysis of of metallic-organic composites is employed to illustrate the capabilities of our technology. Other than successful material decomposition by spectroscopic tomography we present a method to suppress metal artefacts under certain conditions.

[Feasibility analysis on the discipline of acupuncture-moxibustion and Tuina to be the top-grade discipline].

PubMed

Wang, Fu-Chun

2012-10-01

By reviewing the historical evolution of the major catalogue adjustment of the discipline of acupuncture-moxibustion and Tuina for the graduate students, the current situation of the development of the discipline of acupuncture-moxibustion and Tuina is analyzed deeply in this paper. Based on the basic requirements of the setup and the adjustment of the top-grade discipline in the Discipline Catalogue Setup and Administrative Measures for the Academic Degree Award and Personnel Training (Academic Degree [2009] No. 10 Document) issued by the Academic Degree Committee of the State Council and the Ministry of Education, with the strictly analysis, the author proposed that the discipline of acupuncture-moxibustion and Tuina should be set up to be the top-grade discipline. The author stated that the discipline of acupuncture-moxibustion and Tuina possessed the explicit study object and had many assignable second-grade disciplines. It could be acknowledged extensively in the academic field in terms of the setup of the top-grade discipline. The author expounded adequately the necessity of the stable and urgent requirements for the talents of the discipline of acupuncture-moxibustion and Tuina in the society, which provided the reference evidences for the adjustments of the discipline and major catalogue in the future.

A periodic review integrated inventory model with controllable safety stock and setup cost under service level constraint and distribution-free demand

NASA Astrophysics Data System (ADS)

Kurdhi, N. A.; Jamaluddin, A.; Jauhari, W. A.; Saputro, D. R. S.

2017-06-01

In this study, we consider a stochastic integrated manufacturer-retailer inventory model with service level constraint. The model analyzed in this article considers the situation in which the vendor and the buyer establish a long-term contract and strategic partnership to jointly determine the best strategy. The lead time and setup cost are assumed can be controlled by an additional crashing cost and an investment, respectively. It is assumed that shortages are allowed and partially backlogged on the buyer’s side, and that the protection interval (i.e., review period plus lead time) demand distribution is unknown but has given finite first and second moments. The objective is to apply the minmax distribution free approach to simultaneously optimize the review period, the lead time, the setup cost, the safety factor, and the number of deliveries in order to minimize the joint total expected annual cost. The service level constraint guarantees that the service level requirement can be satisfied at the worst case. By constructing Lagrange function, the analysis regarding the solution procedure is conducted, and a solution algorithm is then developed. Moreover, a numerical example and sensitivity analysis are given to illustrate the proposed model and to provide some observations and managerial implications.

Performance analysis of gamma ray spectrometric parameters on digital signal and analog signal processing based MCA systems using NaI(Tl) detector.

PubMed

Kukreti, B M; Sharma, G K

2012-05-01

Accurate and speedy estimations of ppm range uranium and thorium in the geological and rock samples are most useful towards ongoing uranium investigations and identification of favorable radioactive zones in the exploration field areas. In this study with the existing 5 in. × 4 in. NaI(Tl) detector setup, prevailing background and time constraints, an enhanced geometrical setup has been worked out to improve the minimum detection limits for primordial radioelements K(40), U(238) and Th(232). This geometrical setup has been integrated with the newly introduced, digital signal processing based MCA system for the routine spectrometric analysis of low concentration rock samples. Stability performance, during the long counting hours, for digital signal processing MCA system and its predecessor NIM bin based MCA system has been monitored, using the concept of statistical process control. Monitored results, over a time span of few months, have been quantified in terms of spectrometer's parameters such as Compton striping constants and Channel sensitivities, used for evaluating primordial radio element concentrations (K(40), U(238) and Th(232)) in geological samples. Results indicate stable dMCA performance, with a tendency of higher relative variance, about mean, particularly for Compton stripping constants. Copyright © 2012 Elsevier Ltd. All rights reserved.

Improvements of low-level radioxenon detection sensitivity by a state-of-the art coincidence setup.

PubMed

Cagniant, A; Le Petit, G; Gross, P; Douysset, G; Richard-Bressand, H; Fontaine, J-P

2014-05-01

The ability to quantify isotopic ratios of 135, 133 m, 133 and 131 m radioxenon is essential for the verification of the Comprehensive Nuclear-Test Ban Treaty (CTBT). In order to improve detection limits, CEA has developed a new on-site setup using photon/electron coincidence (Le Petit et al., 2013. J. Radioanal. Nucl. Chem., DOI : 10.1007/s 10697-013-2525-8.). Alternatively, the electron detection cell equipped with large silicon chips (PIPS) can be used with HPGe detector for laboratory analysis purpose. This setup allows the measurement of β/γ coincidences for the detection of (133)Xe and (135)Xe; and K-shell Conversion Electrons (K-CE)/X-ray coincidences for the detection of (131m)Xe, (133m)Xe and (133)Xe as well. Good energy resolution of 11 keV at 130 keV and low energy threshold of 29 keV for the electron detection were obtained. This provides direct discrimination between K-CE from (133)Xe, (133m)Xe and (131m)Xe. Estimation of Minimum Detectable Activity (MDA) for (131m)Xe is in the order of 1mBq over a 4 day measurement. An analysis of an environmental radioxenon sample using this method is shown. © 2013 The Authors. Published by Elsevier Ltd All rights reserved.

The reliability and validity of a designed setup for the assessment of static back extensor force and endurance in older women with and without hyperkyphosis.

PubMed

Roghani, Taybeh; Khalkhali Zavieh, Minoo; Rahimi, Abbas; Talebian, Saeed; Manshadi, Farideh Dehghan; Akbarzadeh Baghban, Alireza; King, Nicole; Katzman, Wendy

2018-01-25

The purpose of this study was to investigate the intra-rater reliability and validity of a designed load cell setup for the measurement of back extensor muscle force and endurance. The study sample included 19 older women with hyperkyphosis, mean age 67.0 ± 5.0 years, and 14 older women without hyperkyphosis, mean age 63.0 ± 6.0 years. Maximum back extensor force and endurance were measured in a sitting position with a designed load cell setup. Tests were performed by the same examiner on two separate days within a 72-hour interval. The intra-rater reliability of the measurements was analyzed using intraclass correlation coefficient (ICC), standard errors of measurement (SEM), and minimal detectable change (MDC). The validity of the setup was determined using Pearson correlation analysis and independent t-test. Using our designed load cell, the values of ICC indicated very high reliability of force measurement (hyperkyphosis group: 0.96, normal group: 0.97) and high reliability of endurance measurement (hyperkyphosis group: 0.82, normal group: 0.89). For all tests, the values of SEM and MDC were low in both groups. A significant correlation between two documented forces (load cell force and target force) and significant differences in the muscle force and endurance among the two groups were found. The measurements of static back muscle force and endurance are reliable and valid with our designed setup in older women with and without hyperkyphosis.

Assessment of image quality of a radiotherapy-specific hardware solution for PET/MRI in head and neck cancer patients.

PubMed

Winter, René M; Leibfarth, Sara; Schmidt, Holger; Zwirner, Kerstin; Mönnich, David; Welz, Stefan; Schwenzer, Nina F; la Fougère, Christian; Nikolaou, Konstantin; Gatidis, Sergios; Zips, Daniel; Thorwarth, Daniela

2018-05-07

Functional PET/MRI has great potential to improve radiotherapy planning (RTP). However, data integration requires imaging with radiotherapy-specific patient positioning. Here, we investigated the feasibility and image quality of radiotherapy-customized PET/MRI in head-and-neck cancer (HNC) patients using a dedicated hardware setup. Ten HNC patients were examined with simultaneous PET/MRI before treatment, with radiotherapy and diagnostic scan setup, respectively. We tested feasibility of radiotherapy-specific patient positioning and compared the image quality between both setups by pairwise image analysis of 18 F-FDG-PET, T1/T2-weighted and diffusion-weighted MRI. For image quality assessment, similarity measures including average symmetric surface distance (ASSD) of PET and MR-based tumor contours, MR signal-to-noise ratio (SNR) and mean apparent diffusion coefficient (ADC) value were used. PET/MRI in radiotherapy position was feasible - all patients were successfully examined. ASSD (median/range) of PET and MR contours was 0.6 (0.4-1.2) and 0.9 (0.5-1.3) mm, respectively. For T2-weighted MRI, a reduced SNR of -26.2% (-39.0--11.7) was observed with radiotherapy setup. No significant difference in mean ADC was found. Simultaneous PET/MRI in HNC patients using radiotherapy positioning aids is clinically feasible. Though SNR was reduced, the image quality obtained with a radiotherapy setup meets RTP requirements and the data can thus be used for personalized RTP. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

Set-up uncertainties: online correction with X-ray volume imaging.

PubMed

Kataria, Tejinder; Abhishek, Ashu; Chadha, Pranav; Nandigam, Janardhan

2011-01-01

To determine interfractional three-dimensional set-up errors using X-ray volumetric imaging (XVI). Between December 2007 and August 2009, 125 patients were taken up for image-guided radiotherapy using online XVI. After matching of reference and acquired volume view images, set-up errors in three translation directions were recorded and corrected online before treatment each day. Mean displacements, population systematic (Σ), and random (σ) errors were calculated and analyzed using SPSS (v16) software. Optimum clinical target volume (CTV) to planning target volume (PTV) margin was calculated using Van Herk's (2.5Σ + 0.7 σ) and Stroom's (2Σ + 0.7 σ) formula. Patients were grouped in 4 cohorts, namely brain, head and neck, thorax, and abdomen-pelvis. The mean vector displacement recorded were 0.18 cm, 0.15 cm, 0.36 cm, and 0.35 cm for brain, head and neck, thorax, and abdomen-pelvis, respectively. Analysis of individual mean set-up errors revealed good agreement with the proposed 0.3 cm isotropic margins for brain and 0.5 cm isotropic margins for head-neck. Similarly, 0.5 cm circumferential and 1 cm craniocaudal proposed margins were in agreement with thorax and abdomen-pelvic cases. The calculated mean displacements were well within CTV-PTV margin estimates of Van Herk (90% population coverage to minimum 95% prescribed dose) and Stroom (99% target volume coverage by 95% prescribed dose). Employing these individualized margins in a particular cohort ensure comparable target coverage as described in literature, which is further improved if XVI-aided set-up error detection and correction is used before treatment.

Techniques for Measuring Solubility and Electrical Conductivity in Molten Salts

NASA Astrophysics Data System (ADS)

Su, Shizhao; Villalon, Thomas; Pal, Uday; Powell, Adam

Eutectic MgF2-CaF2 based salt containing YF3, CaO and Al2O3 additions were used in this study. The electrical conductivity was measured as a function of temperature by a calibration-free coaxial electrode setup. The materials selection and setup design were optimized to accurately measure the electrical conductivity of the highly conductive molten salts (>1 S/cm). The solubility and diffusion behavior of alumina and zirconia in the molten salts were investigated by drawing and holding the molten salt for different lengths of time within capillary tubes made of alumina and zirconia, respectively. After the time-dependent high temperature holds, the samples were cooled and the solubility of the solute within the molten salt was determined using scanning electron microscopy, energy-dispersive X-ray spectroscopy analysis and wavelength-dispersive X-ray spectroscopy analysis.

Thermal Testing and Model Correlation for Advanced Topographic Laser Altimeter Instrument (ATLAS)

NASA Technical Reports Server (NTRS)

Patel, Deepak

2016-01-01

The Advanced Topographic Laser Altimeter System (ATLAS) part of the Ice Cloud and Land Elevation Satellite 2 (ICESat-2) is an upcoming Earth Science mission focusing on the effects of climate change. The flight instrument passed all environmental testing at GSFC (Goddard Space Flight Center) and is now ready to be shipped to the spacecraft vendor for integration and testing. This topic covers the analysis leading up to the test setup for ATLAS thermal testing as well as model correlation to flight predictions. Test setup analysis section will include areas where ATLAS could not meet flight like conditions and what were the limitations. Model correlation section will walk through changes that had to be made to the thermal model in order to match test results. The correlated model will then be integrated with spacecraft model for on-orbit predictions.

A multiscale approach for the reconstruction of the fiber architecture of the human brain based on 3D-PLI

PubMed Central

Reckfort, Julia; Wiese, Hendrik; Pietrzyk, Uwe; Zilles, Karl; Amunts, Katrin; Axer, Markus

2015-01-01

Structural connectivity of the brain can be conceptionalized as a multiscale organization. The present study is built on 3D-Polarized Light Imaging (3D-PLI), a neuroimaging technique targeting the reconstruction of nerve fiber orientations and therefore contributing to the analysis of brain connectivity. Spatial orientations of the fibers are derived from birefringence measurements of unstained histological sections that are interpreted by means of a voxel-based analysis. This implies that a single fiber orientation vector is obtained for each voxel, which reflects the net effect of all comprised fibers. We have utilized two polarimetric setups providing an object space resolution of 1.3 μm/px (microscopic setup) and 64 μm/px (macroscopic setup) to carry out 3D-PLI and retrieve fiber orientations of the same tissue samples, but at complementary voxel sizes (i.e., scales). The present study identifies the main sources which cause a discrepancy of the measured fiber orientations observed when measuring the same sample with the two polarimetric systems. As such sources the differing optical resolutions and diverging retardances of the implemented waveplates were identified. A methodology was implemented that enables the compensation of measured different systems' responses to the same birefringent sample. This opens up new ways to conduct multiscale analysis in brains by means of 3D-PLI and to provide a reliable basis for the transition between different scales of the nerve fiber architecture. PMID:26388744

Refractive index measurements of single, spherical cells using digital holographic microscopy.

PubMed

Schürmann, Mirjam; Scholze, Jana; Müller, Paul; Chan, Chii J; Ekpenyong, Andrew E; Chalut, Kevin J; Guck, Jochen

2015-01-01

In this chapter, we introduce digital holographic microscopy (DHM) as a marker-free method to determine the refractive index of single, spherical cells in suspension. The refractive index is a conclusive measure in a biological context. Cell conditions, such as differentiation or infection, are known to yield significant changes in the refractive index. Furthermore, the refractive index of biological tissue determines the way it interacts with light. Besides the biological relevance of this interaction in the retina, a lot of methods used in biology, including microscopy, rely on light-tissue or light-cell interactions. Hence, determining the refractive index of cells using DHM is valuable in many biological applications. This chapter covers the main topics that are important for the implementation of DHM: setup, sample preparation, and analysis. First, the optical setup is described in detail including notes and suggestions for the implementation. Following that, a protocol for the sample and measurement preparation is explained. In the analysis section, an algorithm for the determination of quantitative phase maps is described. Subsequently, all intermediate steps for the calculation of the refractive index of suspended cells are presented, exploiting their spherical shape. In the last section, a discussion of possible extensions to the setup, further measurement configurations, and additional analysis methods are given. Throughout this chapter, we describe a simple, robust, and thus easily reproducible implementation of DHM. The different possibilities for extensions show the diverse fields of application for this technique. Copyright © 2015 Elsevier Inc. All rights reserved.

Study on the quality and stability of compost through a Demo Compost Plant.

PubMed

Hasan, K M M; Sarkar, G; Alamgir, M; Bari, Q H; Haedrich, G

2012-11-01

This study is concerned with the performance of a Demo Compost Plant for the development of acceptable composting technology in Bangladesh. The Demo Compost Plant was setup at the adjacent area of an existing compost plant located at Khulna city in Bangladesh. Four different composting technologies were considered, where Municipal Solid Waste (MSW) were used as a raw material for composting, collected from the adjacent areas of the plant. Initially the whole composting system was conducted through two experimental setups. In the 1st setup three different types of aerators (horizontal and vertical passively aerator and forced aerator) were selected. For a necessary observation four piles, using only MSW as the input materials in the first three compost pile, the fourth one was the existing Samadhan's compost pile. Based on the analysis of the experimental findings, the horizontal passively aerated composting technique is suitable for Bangladesh as it had better performance for reducing composting period than that of the others. It was being observed from the quality parameters of compost in the both 1st and 2nd setup that as the waste directly come from kitchen, degradation rate of waste shows a positive result for reducing this waste and there is no possibility of toxic contamination, when it would be used as a soil conditioner. Though there is no significant improvement in the quality of the final product in the 2nd setup as comparing with the 1st setup but it fulfills one of the main objectives of this study is to reduce the whole composting period as well as immediate management of the increasing amount of waste and reducing load on landfill. Selfheating tests reveal that degree of stability of compost with respect to maturation period was remained in the acceptable level, which was further accelerated due to the use of organic additives. Copyright © 2012 Elsevier Ltd. All rights reserved.

Stress testing of electrically active FlexMEAs with simultaneous electrical recording in fluidic environment: Introduction of a new measurement setup

NASA Astrophysics Data System (ADS)

Westerhausen, Markus; Martin, Tanja; Kappel, Marcel; Hofmann, Boris

2018-02-01

We present a measurement setup consisting of two fluid-filled pressure chambers to mimic the mechanical stress likely to that of small body movements on biomedical flexible micro-electrode arrays for the analysis of various degradation mechanisms. Our main goal was the simulation of micro-motions in fluid conditions, while maintaining an electric access to the device. These micro-motions would be likely to those occurring in the human body caused by the intracranial pressure in magnitudes of 7-25 mmHg, which translates to a fluid pressure of 9-33 mbar. Furthermore, severe mechanical stress can be administered to the samples under the previously mentioned environment. Therefore, a flexible, polyimide-based sample with various metal test structures was fabricated and analyzed in the presented measurement setup. A comparison of the elongation of the sample's surface as a function of the applied hydrostatic pressure is given with computer simulations.

Contrasting environments associated with storm prediction center tornado outbreak forecasts using synoptic-scale composite analysis

NASA Astrophysics Data System (ADS)

Bates, Alyssa Victoria

Tornado outbreaks have significant human impact, so it is imperative forecasts of these phenomena are accurate. As a synoptic setup lays the foundation for a forecast, synoptic-scale aspects of Storm Prediction Center (SPC) outbreak forecasts of varying accuracy were assessed. The percentages of the number of tornado outbreaks within SPC 10% tornado probability polygons were calculated. False alarm events were separately considered. The outbreaks were separated into quartiles using a point-in-polygon algorithm. Statistical composite fields were created to represent the synoptic conditions of these groups and facilitate comparison. Overall, temperature advection had the greatest differences between the groups. Additionally, there were significant differences in the jet streak strengths and amounts of vertical wind shear. The events forecasted with low accuracy consisted of the weakest synoptic-scale setups. These results suggest it is possible that events with weak synoptic setups should be regarded as areas of concern by tornado outbreak forecasters.

Raman Spectroscopic Analysis of Cupriavidus metallidurans LMG 1195 (CH34) Cultured in Low-shear Microgravity Conditions

NASA Astrophysics Data System (ADS)

De Gelder, Joke; Vandenabeele, Peter; De Boever, Patrick; Mergeay, Max; Moens, Luc; De Vos, Paul

2009-07-01

In this study, the effect of low-shear microgravity on the metabolism of Cupriavidus metallidurans LMG 1195 was studied with Raman spectroscopy. Therefore, the strain was cultured for 24 or 48 h in a rotating wall vessel to simulate microgravity (SMG) and in a control setup. The differences in Raman spectra recorded from both setups after 24 h of culturing were small. The most prominent features in a difference spectrum, calculated between the mean spectra from the microgravity and the control setup separately, could be assigned to the presence of poly-β-hydroxybutyrate (PHB). SMG seems to yield a higher PHB production after 24 h of culturing. Additional processing of the spectra suggested that SMG induced also other changes in the carbon-metabolism. After 48 h, similar results were found for the carbon metabolism, while PHB concentrations were reduced in SMG compared to the control. However, these differences could also be caused by interfering effects that may occur in the bioreactors after a prolonged incubation time.

Laboratory-based micro-X-ray fluorescence setup using a von Hamos crystal spectrometer and a focused beam X-ray tube

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kayser, Y., E-mail: yves.kayser@psi.ch; Paul Scherrer Institut, 5232 Villigen-PSI; Błachucki, W.

2014-04-15

The high-resolution von Hamos bent crystal spectrometer of the University of Fribourg was upgraded with a focused X-ray beam source with the aim of performing micro-sized X-ray fluorescence (XRF) measurements in the laboratory. The focused X-ray beam source integrates a collimating optics mounted on a low-power micro-spot X-ray tube and a focusing polycapillary half-lens placed in front of the sample. The performances of the setup were probed in terms of spatial and energy resolution. In particular, the fluorescence intensity and energy resolution of the von Hamos spectrometer equipped with the novel micro-focused X-ray source and a standard high-power water-cooled X-raymore » tube were compared. The XRF analysis capability of the new setup was assessed by measuring the dopant distribution within the core of Er-doped SiO{sub 2} optical fibers.« less

SCA security verification on wireless sensor network node

NASA Astrophysics Data System (ADS)

He, Wei; Pizarro, Carlos; de la Torre, Eduardo; Portilla, Jorge; Riesgo, Teresa

2011-05-01

Side Channel Attack (SCA) differs from traditional mathematic attacks. It gets around of the exhaustive mathematic calculation and precisely pin to certain points in the cryptographic algorithm to reveal confidential information from the running crypto-devices. Since the introduction of SCA by Paul Kocher et al [1], it has been considered to be one of the most critical threats to the resource restricted but security demanding applications, such as wireless sensor networks. In this paper, we focus our work on the SCA-concerned security verification on WSN (wireless sensor network). A detailed setup of the platform and an analysis of the results of DPA (power attack) and EMA (electromagnetic attack) is presented. The setup follows the way of low-cost setup to make effective SCAs. Meanwhile, surveying the weaknesses of WSNs in resisting SCA attacks, especially for the EM attack. Finally, SCA-Prevention suggestions based on Differential Security Strategy for the FPGA hardware implementation in WSN will be given, helping to get an improved compromise between security and cost.

Setup for polarized neutron imaging using in situ 3He cells at the Oak Ridge National Laboratory High Flux Isotope Reactor CG-1D beamline

NASA Astrophysics Data System (ADS)

Dhiman, I.; Ziesche, Ralf; Wang, Tianhao; Bilheux, Hassina; Santodonato, Lou; Tong, X.; Jiang, C. Y.; Manke, Ingo; Treimer, Wolfgang; Chatterji, Tapan; Kardjilov, Nikolay

2017-09-01

In the present study, we report a new setup for polarized neutron imaging at the ORNL High Flux Isotope Reactor CG-1D beamline using an in situ 3He polarizer and analyzer. This development is very important for extending the capabilities of the imaging instrument at ORNL providing a polarized beam with a large field-of-view, which can be further used in combination with optical devices like Wolter optics, focusing guides, or other lenses for the development of microscope arrangement. Such a setup can be of advantage for the existing and future imaging beamlines at the pulsed neutron sources. The first proof-of-concept experiment is performed to study the ferromagnetic phase transition in the Fe3Pt sample. We also demonstrate that the polychromatic neutron beam in combination with in situ 3He cells can be used as the initial step for the rapid measurement and qualitative analysis of radiographs.

Setup for polarized neutron imaging using in situ 3He cells at the Oak Ridge National Laboratory High Flux Isotope Reactor CG-1D beamline.

PubMed

Dhiman, I; Ziesche, Ralf; Wang, Tianhao; Bilheux, Hassina; Santodonato, Lou; Tong, X; Jiang, C Y; Manke, Ingo; Treimer, Wolfgang; Chatterji, Tapan; Kardjilov, Nikolay

2017-09-01

In the present study, we report a new setup for polarized neutron imaging at the ORNL High Flux Isotope Reactor CG-1D beamline using an in situ 3 He polarizer and analyzer. This development is very important for extending the capabilities of the imaging instrument at ORNL providing a polarized beam with a large field-of-view, which can be further used in combination with optical devices like Wolter optics, focusing guides, or other lenses for the development of microscope arrangement. Such a setup can be of advantage for the existing and future imaging beamlines at the pulsed neutron sources. The first proof-of-concept experiment is performed to study the ferromagnetic phase transition in the Fe 3 Pt sample. We also demonstrate that the polychromatic neutron beam in combination with in situ 3 He cells can be used as the initial step for the rapid measurement and qualitative analysis of radiographs.

Combining EEG, MIDI, and motion capture techniques for investigating musical performance.

PubMed

Maidhof, Clemens; Kästner, Torsten; Makkonen, Tommi

2014-03-01

This article describes a setup for the simultaneous recording of electrophysiological data (EEG), musical data (MIDI), and three-dimensional movement data. Previously, each of these three different kinds of measurements, conducted sequentially, has been proven to provide important information about different aspects of music performance as an example of a demanding multisensory motor skill. With the method described here, it is possible to record brain-related activity and movement data simultaneously, with accurate timing resolution and at relatively low costs. EEG and MIDI data were synchronized with a modified version of the FTAP software, sending synchronization signals to the EEG recording device simultaneously with keypress events. Similarly, a motion capture system sent synchronization signals simultaneously with each recorded frame. The setup can be used for studies investigating cognitive and motor processes during music performance and music-like tasks--for example, in the domains of motor control, learning, music therapy, or musical emotions. Thus, this setup offers a promising possibility of a more behaviorally driven analysis of brain activity.

Spine stereotactic body radiotherapy utilizing cone-beam CT image-guidance with a robotic couch: intrafraction motion analysis accounting for all six degrees of freedom.

PubMed

Hyde, Derek; Lochray, Fiona; Korol, Renee; Davidson, Melanie; Wong, C Shun; Ma, Lijun; Sahgal, Arjun

2012-03-01

To evaluate the residual setup error and intrafraction motion following kilovoltage cone-beam CT (CBCT) image guidance, for immobilized spine stereotactic body radiotherapy (SBRT) patients, with positioning corrected for in all six degrees of freedom. Analysis is based on 42 consecutive patients (48 thoracic and/or lumbar metastases) treated with a total of 106 fractions and 307 image registrations. Following initial setup, a CBCT was acquired for patient alignment and a pretreatment CBCT taken to verify shifts and determine the residual setup error, followed by a midtreatment and posttreatment CBCT image. For 13 single-fraction SBRT patients, two midtreatment CBCT images were obtained. Initially, a 1.5-mm and 1° tolerance was used to reposition the patient following couch shifts which was subsequently reduced to 1 mm and 1° degree after the first 10 patients. Small positioning errors after the initial CBCT setup were observed, with 90% occurring within 1 mm and 97% within 1°. In analyzing the impact of the time interval for verification imaging (10 ± 3 min) and subsequent image acquisitions (17 ± 4 min), the residual setup error was not significantly different (p > 0.05). A significant difference (p = 0.04) in the average three-dimensional intrafraction positional deviations favoring a more strict tolerance in translation (1 mm vs. 1.5 mm) was observed. The absolute intrafraction motion averaged over all patients and all directions along x, y, and z axis (± SD) were 0.7 ± 0.5 mm and 0.5 ± 0.4 mm for the 1.5 mm and 1 mm tolerance, respectively. Based on a 1-mm and 1° correction threshold, the target was localized to within 1.2 mm and 0.9° with 95% confidence. Near-rigid body immobilization, intrafraction CBCT imaging approximately every 15-20 min, and strict repositioning thresholds in six degrees of freedom yields minimal intrafraction motion allowing for safe spine SBRT delivery. Copyright © 2012 Elsevier Inc. All rights reserved.

ASD FieldSpec Calibration Setup and Techniques

NASA Technical Reports Server (NTRS)

Olive, Dan

2001-01-01

This paper describes the Analytical Spectral Devices (ASD) Fieldspec Calibration Setup and Techniques. The topics include: 1) ASD Fieldspec FR Spectroradiometer; 2) Components of Calibration; 3) Equipment list; 4) Spectral Setup; 5) Spectral Calibration; 6) Radiometric and Linearity Setup; 7) Radiometric setup; 8) Datadets Required; 9) Data files; and 10) Field of View Measurement. This paper is in viewgraph form.

Infant multiple breath washout using a new commercially available device: Ready to replace the previous setup?

PubMed

Kentgens, Anne-Christianne; Guidi, Marisa; Korten, Insa; Kohler, Lena; Binggeli, Severin; Singer, Florian; Latzin, Philipp; Anagnostopoulou, Pinelopi

2018-05-01

Multiple breath washout (MBW) is a sensitive test to measure lung volumes and ventilation inhomogeneity from infancy on. The commonly used setup for infant MBW, based on ultrasonic flowmeter, requires extensive signal processing, which may reduce robustness. A new setup may overcome some previous limitations but formal validation is lacking. We assessed the feasibility of infant MBW testing with the new setup and compared functional residual capacity (FRC) values of the old and the new setup in vivo and in vitro. We performed MBW in four healthy infants and four infants with cystic fibrosis, as well as in a Plexiglas lung simulator using realistic lung volumes and breathing patterns, with the new (Exhalyzer D, Spiroware 3.2.0, Ecomedics) and the old setup (Exhalyzer D, WBreath 3.18.0, ndd) in random sequence. The technical feasibility of MBW with the new device-setup was 100%. Intra-subject variability in FRC was low in both setups, but differences in FRC between the setups were considerable (mean relative difference 39.7%, range 18.9; 65.7, P = 0.008). Corrections of software settings decreased FRC differences (14.0%, -6.4; 42.3, P = 0.08). Results were confirmed in vitro. MBW measurements with the new setup were feasible in infants. However, despite attempts to correct software settings, outcomes between setups were not interchangeable. Further work is needed before widespread application of the new setup can be recommended. © 2018 Wiley Periodicals, Inc.

Investigation of periodically driven systems by x-ray absorption spectroscopy using asynchronous data collection mode

NASA Astrophysics Data System (ADS)

Singh, H.; Donetsky, D.; Liu, J.; Attenkofer, K.; Cheng, B.; Trelewicz, J. R.; Lubomirsky, I.; Stavitski, E.; Frenkel, A. I.

2018-04-01

We report the development, testing, and demonstration of a setup for modulation excitation spectroscopy experiments at the Inner Shell Spectroscopy beamline of National Synchrotron Light Source - II. A computer algorithm and dedicated software were developed for asynchronous data processing and analysis. We demonstrate the reconstruction of X-ray absorption spectra for different time points within the modulation pulse using a model system. This setup and the software are intended for a broad range of functional materials which exhibit structural and/or electronic responses to the external stimulation, such as catalysts, energy and battery materials, and electromechanical devices.

Feasibility of line-ratio spectroscopy on helium and neon as edge diagnostic tool for Wendelstein 7-X

DOE PAGES

Barbui, T.; Krychowiak, M.; König, R.; ...

2016-09-27

A beam emission spectroscopy system on thermal helium (He) and neon (Ne) has been set up at Wendelstein 7-X to measure edge electron temperature and density profiles utilizing the line-ratio technique or its extension by the analysis of absolutely calibrated line emissions. The setup for a first systematic test of these techniques of quantitative atomic spectroscopy in the limiter startup phase (OP1.1) is reported together with first measured profiles. Lastly, this setup and the first results are an important test for developing the technique for the upcoming high density, low temperature island divertor regime.

Study of heating capacity of focused IR light soldering systems.

PubMed

Anguiano, C; Félix, M; Medel, A; Bravo, M; Salazar, D; Márquez, H

2013-10-07

An experimental study about four optical setups used for developing a Focused IR Light Soldering System (FILSS) for Surface Mount Technology (SMT) lead-free electronic devices specifically for Ball Grid Arrays (BGA) is presented. An analysis of irradiance and infrared thermography at BGA surface is presented, as well as heat transfer by radiation and conduction process from the surface of the BGA to the solder balls. The results of this work show that the heating provided by our proposed optical setups, measured at the BGA under soldering process, meets the high temperature and uniform thermal distribution requirements, which are defined by the reflow solder method for SMT devices.

Road Anomalies Detection System Evaluation.

PubMed

Silva, Nuno; Shah, Vaibhav; Soares, João; Rodrigues, Helena

2018-06-21

Anomalies on road pavement cause discomfort to drivers and passengers, and may cause mechanical failure or even accidents. Governments spend millions of Euros every year on road maintenance, often causing traffic jams and congestion on urban roads on a daily basis. This paper analyses the difference between the deployment of a road anomalies detection and identification system in a “conditioned” and a real world setup, where the system performed worse compared to the “conditioned” setup. It also presents a system performance analysis based on the analysis of the training data sets; on the analysis of the attributes complexity, through the application of PCA techniques; and on the analysis of the attributes in the context of each anomaly type, using acceleration standard deviation attributes to observe how different anomalies classes are distributed in the Cartesian coordinates system. Overall, in this paper, we describe the main insights on road anomalies detection challenges to support the design and deployment of a new iteration of our system towards the deployment of a road anomaly detection service to provide information about roads condition to drivers and government entities.

Rapid test for the detection of hazardous microbiological material

NASA Astrophysics Data System (ADS)

Mordmueller, Mario; Bohling, Christian; John, Andreas; Schade, Wolfgang

2009-09-01

After attacks with anthrax pathogens have been committed since 2001 all over the world the fast detection and determination of biological samples has attracted interest. A very promising method for a rapid test is Laser Induced Breakdown Spectroscopy (LIBS). LIBS is an optical method which uses time-resolved or time-integrated spectral analysis of optical plasma emission after pulsed laser excitation. Even though LIBS is well established for the determination of metals and other inorganic materials the analysis of microbiological organisms is difficult due to their very similar stoichiometric composition. To analyze similar LIBS-spectra computer assisted chemometrics is a very useful approach. In this paper we report on first results of developing a compact and fully automated rapid test for the detection of hazardous microbiological material. Experiments have been carried out with two setups: A bulky one which is composed of standard laboratory components and a compact one consisting of miniaturized industrial components. Both setups work at an excitation wavelength of λ=1064nm (Nd:YAG). Data analysis is done by Principal Component Analysis (PCA) with an adjacent neural network for fully automated sample identification.

The effect of systematic set-up deviations on the absorbed dose distribution for left-sided breast cancer treated with respiratory gating

NASA Astrophysics Data System (ADS)

Edvardsson, A.; Ceberg, S.

2013-06-01

The aim of this study was 1) to investigate interfraction set-up uncertainties for patients treated with respiratory gating for left-sided breast cancer, 2) to investigate the effect of the inter-fraction set-up on the absorbed dose-distribution for the target and organs at risk (OARs) and 3) optimize the set-up correction strategy. By acquiring multiple set-up images the systematic set-up deviation was evaluated. The effect of the systematic set-up deviation on the absorbed dose distribution was evaluated by 1) simulation in the treatment planning system and 2) measurements with a biplanar diode array. The set-up deviations could be decreased using a no action level correction strategy. Not using the clinically implemented adaptive maximum likelihood factor for the gating patients resulted in better set-up. When the uncorrected set-up deviations were simulated the average mean absorbed dose was increased from 1.38 to 2.21 Gy for the heart, 4.17 to 8.86 Gy to the left anterior descending coronary artery and 5.80 to 7.64 Gy to the left lung. Respiratory gating can induce systematic set-up deviations which would result in increased mean absorbed dose to the OARs if not corrected for and should therefore be corrected for by an appropriate correction strategy.

Dakota Graphical User Interface v. 1.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friedman-Hill, Ernest; Glickman, Matthew; Gibson, Marcus

Graphical analysis environment for Sandia’s Dakota software for optimization and uncertainty quantification. The Dakota GUI is an interactive graphical analysis environment for creating, running, and interpreting Dakota optimization and uncertainty quantification studies. It includes problem (Dakota study) set-up, option specification, simulation interfacing, analysis execution, and results visualization. Through the use of wizards, templates, and views, Dakota GUI helps uses navigate Dakota’s complex capability landscape.

BANSAI - An optofluidic approach for biomedical analysis

NASA Astrophysics Data System (ADS)

Knoerzer, Markus; Prokop, Christoph; Rodrigues Ribeiro, Graciete M.; Mayer, Horst; Brümmer, Jens; Mitchell, Arnan; Rabus, Dominik G.; Karnutsch, Christian

2015-12-01

Lab-on-a-chip based portable blood analysis systems would allow point-of-care measurements, e.g. in an ambulance, or in remote areas with no fast access to medical care. Such a systemwould provide much faster information about the health of a patient. Here,we present a system that is based on absorption spectroscopy and uses an organic laser, which is tunable in the visible range. The feasibility of the system is shown with a table-top setup using laboratory equipment. Measurements of human albumin show linear behaviour in a range from 2.5 g/L to 60 g/L. In a consecutive setup the system is implemented on a microfluidic chip and is capable of measuring simultaneously transmitted and side scattered intensities, even with ambient light present. Air-suspended grating couplers on polymers are shown as the first element of a lab-on-a-chip implementation.

BANSAI - An optofluidic approach for biomedical analysis

NASA Astrophysics Data System (ADS)

Knoerzer, Markus; Prokop, Christoph; Rodrigues Ribeiro, Graciete M.; Mayer, Horst; Brümmer, Jens; Mitchell, Arnan; Rabus, Dominik G.; Karnutsch, Christian

2016-02-01

Lab-on-a-chip based portable blood analysis systems would allow point-of-care measurements, e.g. in an ambulance, or in remote areas with no fast access to medical care. Such a systemwould provide much faster information about the health of a patient. Here,we present a system that is based on absorption spectroscopy and uses an organic laser, which is tunable in the visible range. The feasibility of the system is shown with a table-top setup using laboratory equipment. Measurements of human albumin show linear behaviour in a range from 2.5 g/L to 60 g/L. In a consecutive setup the system is implemented on a microfluidic chip and is capable of measuring simultaneously transmitted and side scattered intensities, even with ambient light present. Air-suspended grating couplers on polymers are shown as the first element of a lab-on-a-chip implementation.

Transcriptome analysis and related databases of Lactococcus lactis.

PubMed

Kuipers, Oscar P; de Jong, Anne; Baerends, Richard J S; van Hijum, Sacha A F T; Zomer, Aldert L; Karsens, Harma A; den Hengst, Chris D; Kramer, Naomi E; Buist, Girbe; Kok, Jan

2002-08-01

Several complete genome sequences of Lactococcus lactis and their annotations will become available in the near future, next to the already published genome sequence of L. lactis ssp. lactis IL 1403. This will allow intraspecies comparative genomics studies as well as functional genomics studies aimed at a better understanding of physiological processes and regulatory networks operating in lactococci. This paper describes the initial set-up of a DNA-microarray facility in our group, to enable transcriptome analysis of various Gram-positive bacteria, including a ssp. lactis and a ssp. cremoris strain of Lactococcus lactis. Moreover a global description will be given of the hardware and software requirements for such a set-up, highlighting the crucial integration of relevant bioinformatics tools and methods. This includes the development of MolGenIS, an information system for transcriptome data storage and retrieval, and LactococCye, a metabolic pathway/genome database of Lactococcus lactis.

Portal imaging based definition of the planning target volume during pelvic irradiation for gynecological malignancies.

PubMed

Mock, U; Dieckmann, K; Wolff, U; Knocke, T H; Pötter, R

1999-08-01

Geometrical accuracy in patient positioning can vary substantially during external radiotherapy. This study estimated the set-up accuracy during pelvic irradiation for gynecological malignancies for determination of safety margins (planning target volume, PTV). Based on electronic portal imaging devices (EPID), 25 patients undergoing 4-field pelvic irradiation for gynecological malignancies were analyzed with regard to set-up accuracy during the treatment course. Regularly performed EPID images were used in order to systematically assess the systematic and random component of set-up displacements. Anatomical matching of verification and simulation images was followed by measuring corresponding distances between the central axis and anatomical features. Data analysis of set-up errors referred to the x-, y-,and z-axes. Additionally, cumulative frequencies were evaluated. A total of 50 simulation films and 313 verification images were analyzed. For the anterior-posterior (AP) beam direction mean deviations along the x- and z-axes were 1.5 mm and -1.9 mm, respectively. Moreover, random errors of 4.8 mm (x-axis) and 3.0 mm (z-axis) were determined. Concerning the latero-lateral treatment fields, the systematic errors along the two axes were calculated to 2.9 mm (y-axis) and -2.0 mm (z-axis) and random errors of 3.8 mm and 3.5 mm were found, respectively. The cumulative frequency of misalignments < or =5 mm showed values of 75% (AP fields) and 72% (latero-lateral fields). With regard to cumulative frequencies < or =10 mm quantification revealed values of 97% for both beam directions. During external pelvic irradiation therapy for gynecological malignancies, EPID images on a regular basis revealed acceptable set-up inaccuracies. Safety margins (PTV) of 1 cm appear to be sufficient, accounting for more than 95% of all deviations.

Assuring high quality treatment delivery in clinical trials - Results from the Trans-Tasman Radiation Oncology Group (TROG) study 03.04 "RADAR" set-up accuracy study.

PubMed

Haworth, Annette; Kearvell, Rachel; Greer, Peter B; Hooton, Ben; Denham, James W; Lamb, David; Duchesne, Gillian; Murray, Judy; Joseph, David

2009-03-01

A multi-centre clinical trial for prostate cancer patients provided an opportunity to introduce conformal radiotherapy with dose escalation. To verify adequate treatment accuracy prior to patient recruitment, centres submitted details of a set-up accuracy study (SUAS). We report the results of the SUAS, the variation in clinical practice and the strategies used to help centres improve treatment accuracy. The SUAS required each of the 24 participating centres to collect data on at least 10 pelvic patients imaged on a minimum of 20 occasions. Software was provided for data collection and analysis. Support to centres was provided through educational lectures, the trial quality assurance team and an information booklet. Only two centres had recently carried out a SUAS prior to the trial opening. Systematic errors were generally smaller than those previously reported in the literature. The questionnaire identified many differences in patient set-up protocols. As a result of participating in this QA activity more than 65% of centres improved their treatment delivery accuracy. Conducting a pre-trial SUAS has led to improvement in treatment delivery accuracy in many centres. Treatment techniques and set-up accuracy varied greatly, demonstrating a need to ensure an on-going awareness for such studies in future trials and with the introduction of dose escalation or new technologies.

A Study of Vicon System Positioning Performance.

PubMed

Merriaux, Pierre; Dupuis, Yohan; Boutteau, Rémi; Vasseur, Pascal; Savatier, Xavier

2017-07-07

Motion capture setups are used in numerous fields. Studies based on motion capture data can be found in biomechanical, sport or animal science. Clinical science studies include gait analysis as well as balance, posture and motor control. Robotic applications encompass object tracking. Today's life applications includes entertainment or augmented reality. Still, few studies investigate the positioning performance of motion capture setups. In this paper, we study the positioning performance of one player in the optoelectronic motion capture based on markers: Vicon system. Our protocol includes evaluations of static and dynamic performances. Mean error as well as positioning variabilities are studied with calibrated ground truth setups that are not based on other motion capture modalities. We introduce a new setup that enables directly estimating the absolute positioning accuracy for dynamic experiments contrary to state-of-the art works that rely on inter-marker distances. The system performs well on static experiments with a mean absolute error of 0.15 mm and a variability lower than 0.025 mm. Our dynamic experiments were carried out at speeds found in real applications. Our work suggests that the system error is less than 2 mm. We also found that marker size and Vicon sampling rate must be carefully chosen with respect to the speed encountered in the application in order to reach optimal positioning performance that can go to 0.3 mm for our dynamic study.

Residual stress analysis of energy-dispersive diffraction data using a two-detector setup: Part I - Theoretical concept

NASA Astrophysics Data System (ADS)

Apel, Daniel; Meixner, Matthias; Liehr, Alexander; Klaus, Manuela; Degener, Sebastian; Wagener, Guido; Franz, Christian; Zinn, Wolfgang; Genzel, Christoph; Scholtes, Berthold

2018-01-01

A new goniometer setup for energy-dispersive X-ray diffraction is introduced which is based on simultaneous data acquisition with two detectors D1 and D2, both of them freely movable in a horizontal as well as in a vertical plane. From the multitude of measurement configurations that can be realised with this setup, we figured out three efficient concepts which aim at the fast analysis of residual stress depth profiles by combining the diffraction data gathered with the two detectors. The characteristic feature of the first two configurations consists in the vertical (horizontal) positioning of the first (second) detector, which results in a diffraction geometry where the two scattering vectors span a plane that coincides with the X-circle used for sample tilt. Because each detector does see the sample under another viewing angle, both the positive and the negative ψ-branch are covered by just one χ-tilt between 0°and 90°(configuration 1) and 0°and 60°(configuration 2), thus allowing for the simultaneous analysis of the in- and out-of-plane residual stress depth gradients σii(τ) and σi3(τ) (i = 1 , 2), respectively, from data sets dD1hkl(χ) and dD2hkl(χ). The third configuration introduced in this paper is based on a ϕ-rotation of the sample under a constant tilt angle χ and enables a fast and reliable tracing of shear stress fields σi3(τ) (i = 1, 2).

SU-E-J-22: A Feasibility Study On KV-Based Whole Breast Radiation Patient Setup

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Q; Zhang, M; Yue, N

Purpose: In room kilovoltage x-ray (kV) imaging provides higher contrast than Megavoltage (MV) imaging with faster acquisition time compared with on-board cone-beam computed tomography (CBCT), thus improving patient setup accuracy and efficiency. In this study we evaluated the clinical feasibility of utilizing kV imaging for whole breast radiation patient setup. Methods: For six breast cancer patients with whole breast treatment plans using two opposed tangential fields, MV-based patient setup was conducted by aligning patient markers with in room lasers and MV portal images. Beam-eye viewed kV images were acquired using Varian OBI system after the set up process. In housemore » software was developed to transfer MLC blocks information overlaying onto kV images to demonstrate the field shape for verification. KV-based patient digital shift was derived by performing rigid registration between kV image and the digitally reconstructed radiography (DRR) to align the bony structure. This digital shift between kV-based and MV-based setup was defined as setup deviation. Results: Six sets of kV images were acquired for breast patients. The mean setup deviation was 2.3mm, 2.2mm and 1.8mm for anterior-posterior, superior-inferior and left-right direction respectively. The average setup deviation magnitude was 4.3±1.7mm for six patients. Patient with large breast had a larger setup deviation (4.4–6.2mm). There was no strong correlation between MV-based shift and setup deviation. Conclusion: A preliminary clinical workflow for kV-based whole breast radiation setup was established and tested. We observed setup deviation of the magnitude below than 5mm. With the benefit of providing higher contrast and MLC block overlaid on the images for treatment field verification, it is feasible to use kV imaging for breast patient setup.« less

[Comparison of four identical electronic noses and three measurement set-ups].

PubMed

Koczulla, R; Hattesohl, A; Biller, H; Hofbauer, J; Hohlfeld, J; Oeser, C; Wirtz, H; Jörres, R A

2011-08-01

Volatile organic compounds (VOCs) can be used as biomarkers in exhaled air. VOC profiles can be detected by an array of nanosensors of an electronic nose. These profiles can be analysed using bioinformatics. It is, however, not known whether different devices of the same model measure identically and to which extent different set-ups and the humidity of the inhaled air influence the VOC profile. Three different measuring set-ups were designed and three healthy control subjects were measured with each of them, using four devices of the same model (Cyranose 320™, Smiths Detection). The exhaled air was collected in a plastic bag. Either ambient air was used as reference (set-up Leipzig), or the reference air was humidified (100% relative humidity) (set-up Marburg and set-up Munich). In the set-up Marburg the subjects inhaled standardised medical air (Aer medicinalis Linde, AGA AB) out of a compressed air bottle through a demand valve; this air (after humidification) was also used as reference. In the set-up Leipzig the subjects inhaled VOC-filtered ambient air, in the set-up Munich unfiltered room air. The data were evaluated using either the real-time data or the changes in resistance as calculated by the device. The results were clearly dependent on the set-up. Apparently, humidification of the reference air could reduce the variance between devices, but this result was also dependent on the evaluation method used. When comparing the three subjects, the set-ups Munich and Marburg mapped these in a similar way, whereas not only the signals but also the variance of the set-up Leipzig were larger. Measuring VOCs with an electronic nose has not yet been standardised and the set-up significantly affects the results. As other researchers use further methods, it is currently not possible to draw generally accepted conclusions. More systematic tests are required to find the most sensitive and reliable but still feasible set-up so that comparability is improved. © Georg Thieme Verlag KG Stuttgart · New York.

Method for measurement of radon diffusion and solubility in solid materials

NASA Astrophysics Data System (ADS)

Maier, Andreas; Weber, Uli; Dickmann, Jannis; Breckow, Joachim; van Beek, Patrick; Schardt, Dieter; Kraft, Gerhard; Fournier, Claudia

2018-02-01

In order to study the permeation i.e. the diffusion and solubility of radon gas in biological material, a new setup was constructed and a novel analysis was applied to obtain diffusion and solubility coefficients. Thin slabs of solid materials were installed between detector housing and the surrounding radon exposure chamber of 50 Ls volume. In this setup radon can diffuse through thin test samples into a cylindrical volume of 5 mm height and 20 mm diameter and reach an α-particle detector. There the 5.49 MeV α-decay of the penetrating radon atoms is measured by a silicon surface barrier detector. The time dependent activities inside the small detector volume are recorded after injection of a known radon activity concentration into the outer chamber. Analyzing the time behavior of the integral α-activity from radon in the small vessel, both, the diffusion coefficient and solubility of the test material can be determined, based on a new mathematical model of the diffusion process concerning the special boundary conditions given by the experimental setup. These first measurements were intended as proof of concept for the detection system and the data analysis. Thin polyethylene foils (LDPE) were selected as material for the diffusion measurements and the results were in agreement with data from literature. In further measurements, we will concentrate on biological material like bone, fat and other tissues.

Are annual layers preserved in NorthGRIP Eemian ice?

NASA Astrophysics Data System (ADS)

Kettner, E.; Bigler, M.; Nielsen, M. E.; Steffensen, J. P.; Svensson, A.

2009-04-01

A newly developed setup for continuous flow analysis (CFA) of ice cores in Copenhagen is optimized for high resolution analysis of four components: Soluble sodium (mainly deriving from sea salt), soluble ammonium (related to biological processes and biomass burning events), insoluble dust particles (basically transported from Asian deserts to Greenland), and the electrolytic melt water conductivity (which is a bulk signal for all ionic constituents). Furthermore, we are for the first time implementing a flow cytometer to obtain high quality dust concentration and size distribution profiles based on individual dust particle measurements. Preliminary measurements show that the setup is able to resolve annual layers of 1 cm thickness. Ice flow models predict that annual layers in the Eemian section of the Greenland NorthGRIP ice core (130-115 ka BP) have a thickness of around 1 cm. However, the visual stratigraphy of the ice core indicates that the annual layering in the Eemian section may be disturbed by micro folds and rapid crystal growth. In this case study we will measure the impurity content of an Eemian segment of the NorthGRIP ice core with the new CFA setup. This will allow for a comparison to well-known impurity levels of the Holocene in both Greenland and Antarctic ice and we will attempt to determine if annual layers are still present in the ice.

Biphasic Scaffolds from Marine Collagens for Regeneration of Osteochondral Defects.

PubMed

Bernhardt, Anne; Paul, Birgit; Gelinsky, Michael

2018-03-13

Collagens of marine origin are applied increasingly as alternatives to mammalian collagens in tissue engineering. The aim of the present study was to develop a biphasic scaffold from exclusively marine collagens supporting both osteogenic and chondrogenic differentiation and to find a suitable setup for in vitro chondrogenic and osteogenic differentiation of human mesenchymal stroma cells (hMSC). Biphasic scaffolds from biomimetically mineralized salmon collagen and fibrillized jellyfish collagen were fabricated by joint freeze-drying and crosslinking. Different experiments were performed to analyze the influence of cell density and TGF-β on osteogenic differentiation of the cells in the scaffolds. Gene expression analysis and analysis of cartilage extracellular matrix components were performed and activity of alkaline phosphatase was determined. Furthermore, histological sections of differentiated cells in the biphasic scaffolds were analyzed. Stable biphasic scaffolds from two different marine collagens were prepared. An in vitro setup for osteochondral differentiation was developed involving (1) different seeding densities in the phases; (2) additional application of alginate hydrogel in the chondral part; (3) pre-differentiation and sequential seeding of the scaffolds and (4) osteochondral medium. Spatially separated osteogenic and chondrogenic differentiation of hMSC was achieved in this setup, while osteochondral medium in combination with the biphasic scaffolds alone was not sufficient to reach this ambition. Biphasic, but monolithic scaffolds from exclusively marine collagens are suitable for the development of osteochondral constructs.

Application of Particle Swarm Optimization in Computer Aided Setup Planning

NASA Astrophysics Data System (ADS)

Kafashi, Sajad; Shakeri, Mohsen; Abedini, Vahid

2011-01-01

New researches are trying to integrate computer aided design (CAD) and computer aided manufacturing (CAM) environments. The role of process planning is to convert the design specification into manufacturing instructions. Setup planning has a basic role in computer aided process planning (CAPP) and significantly affects the overall cost and quality of machined part. This research focuses on the development for automatic generation of setups and finding the best setup plan in feasible condition. In order to computerize the setup planning process, three major steps are performed in the proposed system: a) Extraction of machining data of the part. b) Analyzing and generation of all possible setups c) Optimization to reach the best setup plan based on cost functions. Considering workshop resources such as machine tool, cutter and fixture, all feasible setups could be generated. Then the problem is adopted with technological constraints such as TAD (tool approach direction), tolerance relationship and feature precedence relationship to have a completely real and practical approach. The optimal setup plan is the result of applying the PSO (particle swarm optimization) algorithm into the system using cost functions. A real sample part is illustrated to demonstrate the performance and productivity of the system.

Analysis of pure tar substances (polycyclic aromatic hydrocarbons) in the gas stream using ultraviolet visible (UV-Vis) spectroscopy and multivariate curve resolution (MCR).

PubMed

Weide, Tobias; Guschin, Viktor; Becker, Wolfgang; Koelle, Sabine; Maier, Simon; Seidelt, Stephan

2015-01-01

The analysis of tar, mostly characterized as polycyclic aromatic hydrocarbons (PAHs), describes a topic that has been researched for years. An online analysis of tar in the gas stream in particular is needed to characterize the tar conversion or formation in the biomass gasification process. The online analysis in the gas is carried out with ultraviolet-visible (UV-Vis) spectroscopy (190-720 nm). This online analysis is performed with a measuring cell developed by the Fraunhofer Institute for Chemical Technology (ICT). To this day, online tar measurements using UV-Vis spectroscopy have not been carried out in detail. Therefore, PAHs are analyzed as follows. The measurements are split into different steps. The first step to prove the online method is to vaporize single tar substances. These experiments show that a qualitative analysis of PAHs in the gas stream with the used measurement setup is possible. Furthermore, it is shown that the method provides very exact results, so that a differentiation of various PAHs is possible. The next step is to vaporize a PAH mixture. This step consists of vaporizing five pure substances almost simultaneously. The interpretation of the resulting data is made using a chemometric interpretation method, the multivariate curve resolution (MCR). The verification of the calculated results is the main aim of this experiment. It has been shown that the tar mixture can be analyzed qualitatively and quantitatively (in arbitrary units) in detail using the MCR. Finally it is the main goal of this paper to show the first steps in the applicability of the UV-Vis spectroscopy and the measurement setup on online tar analysis in view of characterizing the biomass gasification process. Due to that, the gasification plant (at the laboratory scale), developed and constructed by the Fraunhofer ICT, has been used to vaporize these substances. Using this gasification plant for the experiments enables the usage of the measurement setup also for the spectroscopic analysis of the tar formation during the biomass gasification.

Length matters: Improved high field EEG-fMRI recordings using shorter EEG cables.

PubMed

Assecondi, Sara; Lavallee, Christina; Ferrari, Paolo; Jovicich, Jorge

2016-08-30

The use of concurrent EEG-fMRI recordings has increased in recent years, allowing new avenues of medical and cognitive neuroscience research; however, currently used setups present problems with data quality and reproducibility. We propose a compact experimental setup for concurrent EEG-fMRI at 4T and compare it to a more standard reference setup. The compact setup uses short EEG cables connecting to the amplifiers, which are placed right at the back of the head RF coil on a form-fitting extension force-locked to the patient MR bed. We compare the two setups in terms of sensitivity to MR-room environmental noise, interferences between measuring devices (EEG or fMRI), and sensitivity to functional responses in a visual stimulation paradigm. The compact setup reduces the system sensitivity to both external noise and MR-induced artefacts by at least 60%, with negligible EEG noise induced from the mechanical vibrations of the cryogenic cooling compression pump. The compact setup improved EEG data quality and the overall performance of MR-artifact correction techniques. Both setups were similar in terms of the fMRI data, with higher reproducibility for cable placement within the scanner in the compact setup. This improved compact setup may be relevant to MR laboratories interested in reducing the sensitivity of their EEG-fMRI experimental setup to external noise sources, setting up an EEG-fMRI workplace for the first time, or for creating a more reproducible configuration of equipment and cables. Implications for safety and ergonomics are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques

NASA Astrophysics Data System (ADS)

Baier, S.; Rochet, A.; Hofmann, G.; Kraut, M.; Grunwaldt, J.-D.

2015-06-01

We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies.

Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques.

PubMed

Baier, S; Rochet, A; Hofmann, G; Kraut, M; Grunwaldt, J-D

2015-06-01

We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies.

Humidity measurements in passive heat and moisture exchangers applications: a critical issue.

PubMed

Dubini, G; Fumero, R

2000-01-01

A reliable, quantitative assessment of humidification performances of passive heat and moisture exchangers in mechanically-ventilated patients is still to be achieved, although relevant efforts have been made to date. One of the major problems to tackle consists in the difficulty of humidity measurements, both in vivo (during either anaesthesia or intensive care unit treatments) and in vitro set-ups. In this paper a review of the basic operation principles of humidity sensors as well as an analysis of their usage within in vivo and in vitro tests are presented. Particular attention is devoted to the limitations arising from the specific measurement set-up, as they may affect the results notably.

Integrated three-dimensional shape and reflection properties measurement system.

PubMed

Krzesłowski, Jakub; Sitnik, Robert; Maczkowski, Grzegorz

2011-02-01

Creating accurate three-dimensional (3D) digitalized models of cultural heritage objects requires that information about surface geometry be integrated with measurements of other material properties like color and reflectance. Up until now, these measurements have been performed in laboratories using manually integrated (subjective) data analyses. We describe an out-of-laboratory bidirectional reflectance distribution function (BRDF) and 3D shape measurement system that implements shape and BRDF measurement in a single setup with BRDF uncertainty evaluation. The setup aligns spatial data with the angular reflectance distribution, yielding a better estimation of the surface's reflective properties by integrating these two modality measurements into one setup using a single detector. This approach provides a better picture of an object's intrinsic material features, which in turn produces a higher-quality digitalized model reconstruction. Furthermore, this system simplifies the data processing by combining structured light projection and photometric stereo. The results of our method of data analysis describe the diffusive and specular attributes corresponding to every measured geometric point and can be used to render intricate 3D models in an arbitrarily illuminated scene.

Device-independent secret-key-rate analysis for quantum repeaters

NASA Astrophysics Data System (ADS)

Holz, Timo; Kampermann, Hermann; Bruß, Dagmar

2018-01-01

The device-independent approach to quantum key distribution (QKD) aims to establish a secret key between two or more parties with untrusted devices, potentially under full control of a quantum adversary. The performance of a QKD protocol can be quantified by the secret key rate, which can be lower bounded via the violation of an appropriate Bell inequality in a setup with untrusted devices. We study secret key rates in the device-independent scenario for different quantum repeater setups and compare them to their device-dependent analogon. The quantum repeater setups under consideration are the original protocol by Briegel et al. [Phys. Rev. Lett. 81, 5932 (1998), 10.1103/PhysRevLett.81.5932] and the hybrid quantum repeater protocol by van Loock et al. [Phys. Rev. Lett. 96, 240501 (2006), 10.1103/PhysRevLett.96.240501]. For a given repeater scheme and a given QKD protocol, the secret key rate depends on a variety of parameters, such as the gate quality or the detector efficiency. We systematically analyze the impact of these parameters and suggest optimized strategies.

A novel portable energy dispersive X-ray fluorescence spectrometer with triaxial geometry

NASA Astrophysics Data System (ADS)

Pessanha, S.; Alves, M.; Sampaio, J. M.; Santos, J. P.; Carvalho, M. L.; Guerra, M.

2017-01-01

The X-ray fluorescence technique is a powerful analytical tool with a broad range of applications such as quality control, environmental contamination by heavy metals, cultural heritage, among others. For the first time, a portable energy dispersive X-ray fluorescence spectrometer was assembled, with orthogonal triaxial geometry between the X-ray tube, the secondary target, the sample and the detector. This geometry reduces the background of the measured spectra by reducing significantly the Bremsstrahlung produced in the tube through polarization in the secondary target and in the sample. Consequently, a practically monochromatic excitation energy is obtained. In this way, a better peak-background ratio is obtained compared to similar devices, improving the detection limits and leading to superior sensitivity. The performance of this setup is compared with the one of a benchtop setup with triaxial geometry and a portable setup with planar geometry. Two case studies are presented concerning the analysis of a 18th century paper document, and the bone remains of an individual buried in the early 19th century.

In vitro evaluation of flow patterns and turbulent kinetic energy in trans-catheter aortic valve prostheses.

PubMed

Giese, Daniel; Weiss, Kilian; Baeßler, Bettina; Madershahian, Navid; Choi, Yeong-Hoon; Maintz, David; Bunck, Alexander C

2018-02-01

The objective of the current work was to evaluate flow and turbulent kinetic energy in different transcatheter aortic valve implants using highly undersampled time-resolved multi-point 3-directional phase-contrast measurements (4D Flow MRI) in an in vitro setup. A pulsatile flow setup was used with a compliant tubing mimicking a stiff left ventricular outflow tract and ascending aorta. Five different implants were measured using a highly undersampled multi-point 4D Flow MRI sequence. Velocities and turbulent kinetic energy values were analysed and compared. Strong variations of turbulent kinetic energy distributions between the valves were observed. Maximum turbulent kinetic energy values ranged from 100 to over 500 J/m 3 while through-plane velocities were similar between all valves. Highly accelerated 4D Flow MRI for the measurement of velocities and turbulent kinetic energy values allowed for the assessment of hemodynamic parameters in five different implant models. The presented setup, measurement protocol and analysis methods provides an efficient approach to compare different valve implants and could aid future novel valve designs.

SU-F-J-24: Setup Uncertainty and Margin of the ExacTrac 6D Image Guide System for Patients with Brain Tumors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, S; Oh, S; Yea, J

Purpose: This study evaluated the setup uncertainties for brain sites when using BrainLAB’s ExacTrac X-ray 6D system for daily pretreatment to determine the optimal planning target volume (PTV) margin. Methods: Between August 2012 and April 2015, 28 patients with brain tumors were treated by daily image-guided radiotherapy using the BrainLAB ExacTrac 6D image guidance system of the Novalis-Tx linear accelerator. DUONTM (Orfit Industries, Wijnegem, Belgium) masks were used to fix the head. The radiotherapy was fractionated into 27–33 treatments. In total, 844 image verifications were performed for 28 patients and used for the analysis. The setup corrections along with themore » systematic and random errors were analyzed for six degrees of freedom in the translational (lateral, longitudinal, and vertical) and rotational (pitch, roll, and yaw) dimensions. Results: Optimal PTV margins were calculated based on van Herk et al.’s [margin recipe = 2.5∑ + 0.7σ − 3 mm] and Stroom et al.’s [margin recipe = 2∑ + 0.7σ] formulas. The systematic errors (∑) were 0.72, 1.57, and 0.97 mm in the lateral, longitudinal, and vertical translational dimensions, respectively, and 0.72°, 0.87°, and 0.83° in the pitch, roll, and yaw rotational dimensions, respectively. The random errors (σ) were 0.31, 0.46, and 0.54 mm in the lateral, longitudinal, and vertical rotational dimensions, respectively, and 0.28°, 0.24°, and 0.31° in the pitch, roll, and yaw rotational dimensions, respectively. According to van Herk et al.’s and Stroom et al.’s recipes, the recommended lateral PTV margins were 0.97 and 1.66 mm, respectively; the longitudinal margins were 1.26 and 3.47 mm, respectively; and the vertical margins were 0.21 and 2.31 mm, respectively. Conclusion: Therefore, daily setup verifications using the BrainLAB ExacTrac 6D image guide system are very useful for evaluating the setup uncertainties and determining the setup margin.∑σ.« less

SU-E-J-15: A Patient-Centered Scheme to Mitigate Impacts of Treatment Setup Error

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, L; Southern Medical University, Guangzhou; Tian, Z

2014-06-01

Purpose: Current Intensity Modulated Radiation Therapy (IMRT) is plan-centered. At each treatment fraction, we position the patient to match the setup in treatment plan. Inaccurate setup can compromise delivered dose distribution, and hence leading to suboptimal treatments. Moreover, current setup approach via couch shift under image guidance can correct translational errors, while rotational and deformation errors are hard to address. To overcome these problems, we propose in this abstract a patient-centered scheme to mitigate impacts of treatment setup errors. Methods: In the patient-centered scheme, we first position the patient on the couch approximately matching the planned-setup. Our Supercomputing Online Replanningmore » Environment (SCORE) is then employed to design an optimal treatment plan based on the daily patient geometry. It hence mitigates the impacts of treatment setup error and reduces the requirements on setup accuracy. We have conducted simulations studies in 10 head-and-neck (HN) patients to investigate the feasibility of this scheme. Rotational and deformation setup errors were simulated. Specifically, 1, 3, 5, 7 degrees of rotations were put on pitch, roll, and yaw directions; deformation errors were simulated by splitting neck movements into four basic types: rotation, lateral bending, flexion and extension. Setup variation ranges are based on observed numbers in previous studies. Dosimetric impacts of our scheme were evaluated on PTVs and OARs in comparison with original plan dose with original geometry and original plan recalculated dose with new setup geometries. Results: With conventional plan-centered approach, setup error could lead to significant PTV D99 decrease (−0.25∼+32.42%) and contralateral-parotid Dmean increase (−35.09∼+42.90%). The patientcentered approach is effective in mitigating such impacts to 0∼+0.20% and −0.03∼+5.01%, respectively. Computation time is <128 s. Conclusion: Patient-centered scheme is proposed to mitigate setup error impacts using replanning. Its superiority in terms of dosimetric impacts and feasibility has been shown through simulation studies on HN cases.« less

SU-E-CAMPUS-J-05: Quantitative Investigation of Random and Systematic Uncertainties From Hardware and Software Components in the Frameless 6DBrainLAB ExacTrac System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keeling, V; Jin, H; Hossain, S

2014-06-15

Purpose: To evaluate setup accuracy and quantify individual systematic and random errors for the various hardware and software components of the frameless 6D-BrainLAB ExacTrac system. Methods: 35 patients with cranial lesions, some with multiple isocenters (50 total lesions treated in 1, 3, 5 fractions), were investigated. All patients were simulated with a rigid head-and-neck mask and the BrainLAB localizer. CT images were transferred to the IPLAN treatment planning system where optimized plans were generated using stereotactic reference frame based on the localizer. The patients were setup initially with infrared (IR) positioning ExacTrac system. Stereoscopic X-ray images (XC: X-ray Correction) weremore » registered to their corresponding digitally-reconstructed-radiographs, based on bony anatomy matching, to calculate 6D-translational and rotational (Lateral, Longitudinal, Vertical, Pitch, Roll, Yaw) shifts. XC combines systematic errors of the mask, localizer, image registration, frame, and IR. If shifts were below tolerance (0.7 mm translational and 1 degree rotational), treatment was initiated; otherwise corrections were applied and additional X-rays were acquired to verify patient position (XV: X-ray Verification). Statistical analysis was used to extract systematic and random errors of the different components of the 6D-ExacTrac system and evaluate the cumulative setup accuracy. Results: Mask systematic errors (translational; rotational) were the largest and varied from one patient to another in the range (−15 to 4mm; −2.5 to 2.5degree) obtained from mean of XC for each patient. Setup uncertainty in IR positioning (0.97,2.47,1.62mm;0.65,0.84,0.96degree) was extracted from standard-deviation of XC. Combined systematic errors of the frame and localizer (0.32,−0.42,−1.21mm; −0.27,0.34,0.26degree) was extracted from mean of means of XC distributions. Final patient setup uncertainty was obtained from the standard deviations of XV (0.57,0.77,0.67mm,0.39,0.35,0.30degree). Conclusion: Statistical analysis was used to calculate cumulative and individual systematic errors from the different hardware and software components of the 6D-ExacTrac-system. Patients were treated with cumulative errors (<1mm,<1degree) with XV image guidance.« less

Site‐specific tolerance tables and indexing device to improve patient setup reproducibility

PubMed Central

James, Joshua A.; Cetnar, Ashley J.; McCullough, Mark A.; Wang, Brian

2015-01-01

While the implementation of tools such as image‐guidance and immobilization devices have helped to prevent geometric misses in radiation therapy, many treatments remain prone to error if these items are not available, not utilized for every fraction, or are misused. The purpose of this project is to design a set of site‐specific treatment tolerance tables to be applied to the treatment couch for use in a record and verify (R&V) system that will insure accurate patient setup with minimal workflow interruption. This project also called for the construction of a simple indexing device to help insure reproducible patient setup for patients that could not be indexed with existing equipment. The tolerance tables were created by retrospective analysis on a total of 66 patients and 1,308 treatments, separating them into five categories based on disease site: lung, head and neck (H&N), breast, pelvis, and abdomen. Couch parameter tolerance tables were designed to encompass 95% of treatments, and were generated by calculating the standard deviation of couch vertical, longitudinal, and lateral values using the first day of treatment as a baseline. We also investigated an alternative method for generating the couch tolerances by updating the baseline values when patient position was verified with image guidance. This was done in order to adapt the tolerances to any gradual changes in patient setup that would not correspond with a mistreatment. The tolerance tables and customizable indexing device were then implemented for a trial period in order to determine the feasibility of the system. During this trial period we collected data from 1,054 fractions from 65 patients. We then analyzed the number of treatments that would have been out of tolerance, as well as whether or not the tolerances or setup techniques should be adjusted. When the couch baseline values were updated with every imaging fraction, the average rate of tolerance violations was 10% for the lung, H&N, abdomen, and pelvis treatments. Using the indexing device, tolerances for patients with pelvic disease decreased (e.g., from 5.3 cm to 4.3 cm longitudinally). Unfortunately, the results from breast patients were highly variable due to the complexity of the setup technique, making the couch an inadequate surrogate for measuring setup accuracy. In summary, we have developed a method to turn the treatment couch parameters within the R&V system into a useful alert tool, which can be implemented at other institutions, in order to identify potential errors in patient setup. PACS numbers: 87.53Kn, 87.55.kh, 87.55.ne, 87.55.km, 87.55K‐, 87.55.Qr PMID:26103475

Range verification for eye proton therapy based on proton-induced x-ray emissions from implanted metal markers

NASA Astrophysics Data System (ADS)

La Rosa, Vanessa; Kacperek, Andrzej; Royle, Gary; Gibson, Adam

2014-06-01

Metal fiducial markers are often implanted on the back of the eye before proton therapy to improve target localization and reduce patient setup errors. We aim to detect characteristic x-ray emissions from metal targets during proton therapy to verify the treatment range accuracy. Initially gold was chosen for its biocompatibility properties. Proton-induced x-ray emissions (PIXE) from a 15 mm diameter gold marker were detected at different penetration depths of a 59 MeV proton beam at the CATANA proton facility at INFN-LNS (Italy). The Monte Carlo code Geant4 was used to reproduce the experiment and to investigate the effect of different size markers, materials, and the response to both mono-energetic and fully modulated beams. The intensity of the emitted x-rays decreases with decreasing proton energy and thus decreases with depth. If we assume the range to be the depth at which the dose is reduced to 10% of its maximum value and we define the residual range as the distance between the marker and the range of the beam, then the minimum residual range which can be detected with 95% confidence level is the depth at which the PIXE peak is equal to 1.96 σbkg, which is the standard variation of the background noise. With our system and experimental setup this value is 3 mm, when 20 GyE are delivered to a gold marker of 15 mm diameter. Results from silver are more promising. Even when a 5 mm diameter silver marker is placed at a depth equal to the range, the PIXE peak is 2.1 σbkg. Although these quantitative results are dependent on the experimental setup used in this research study, they demonstrate that the real-time analysis of the PIXE emitted by fiducial metal markers can be used to derive beam range. Further analysis are needed to demonstrate the feasibility of the technique in a clinical setup.

Evaluation of transverse dispersion effects in tank experiments by numerical modeling: parameter estimation, sensitivity analysis and revision of experimental design.

PubMed

Ballarini, E; Bauer, S; Eberhardt, C; Beyer, C

2012-06-01

Transverse dispersion represents an important mixing process for transport of contaminants in groundwater and constitutes an essential prerequisite for geochemical and biodegradation reactions. Within this context, this work describes the detailed numerical simulation of highly controlled laboratory experiments using uranine, bromide and oxygen depleted water as conservative tracers for the quantification of transverse mixing in porous media. Synthetic numerical experiments reproducing an existing laboratory experimental set-up of quasi two-dimensional flow through tank were performed to assess the applicability of an analytical solution of the 2D advection-dispersion equation for the estimation of transverse dispersivity as fitting parameter. The fitted dispersivities were compared to the "true" values introduced in the numerical simulations and the associated error could be precisely estimated. A sensitivity analysis was performed on the experimental set-up in order to evaluate the sensitivities of the measurements taken at the tank experiment on the individual hydraulic and transport parameters. From the results, an improved experimental set-up as well as a numerical evaluation procedure could be developed, which allow for a precise and reliable determination of dispersivities. The improved tank set-up was used for new laboratory experiments, performed at advective velocities of 4.9 m d(-1) and 10.5 m d(-1). Numerical evaluation of these experiments yielded a unique and reliable parameter set, which closely fits the measured tracer concentration data. For the porous medium with a grain size of 0.25-0.30 mm, the fitted longitudinal and transverse dispersivities were 3.49×10(-4) m and 1.48×10(-5) m, respectively. The procedures developed in this paper for the synthetic and rigorous design and evaluation of the experiments can be generalized and transferred to comparable applications. Copyright © 2012 Elsevier B.V. All rights reserved.

Diffusing-wave spectroscopy in a standard dynamic light scattering setup

NASA Astrophysics Data System (ADS)

Fahimi, Zahra; Aangenendt, Frank J.; Voudouris, Panayiotis; Mattsson, Johan; Wyss, Hans M.

2017-12-01

Diffusing-wave spectroscopy (DWS) extends dynamic light scattering measurements to samples with strong multiple scattering. DWS treats the transport of photons through turbid samples as a diffusion process, thereby making it possible to extract the dynamics of scatterers from measured correlation functions. The analysis of DWS data requires knowledge of the path length distribution of photons traveling through the sample. While for flat sample cells this path length distribution can be readily calculated and expressed in analytical form; no such expression is available for cylindrical sample cells. DWS measurements have therefore typically relied on dedicated setups that use flat sample cells. Here we show how DWS measurements, in particular DWS-based microrheology measurements, can be performed in standard dynamic light scattering setups that use cylindrical sample cells. To do so we perform simple random-walk simulations that yield numerical predictions of the path length distribution as a function of both the transport mean free path and the detection angle. This information is used in experiments to extract the mean-square displacement of tracer particles in the material, as well as the corresponding frequency-dependent viscoelastic response. An important advantage of our approach is that by performing measurements at different detection angles, the average path length through the sample can be varied. For measurements performed on a single sample cell, this gives access to a wider range of length and time scales than obtained in a conventional DWS setup. Such angle-dependent measurements also offer an important consistency check, as for all detection angles the DWS analysis should yield the same tracer dynamics, even though the respective path length distributions are very different. We validate our approach by performing measurements both on aqueous suspensions of tracer particles and on solidlike gelatin samples, for which we find our DWS-based microrheology data to be in good agreement with rheological measurements performed on the same samples.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trofimov, A; Carpenter, K; Shih, HA

Purpose: To quantify daily set-up variations in fractionated proton therapy of ocular melanomas, and to assess the effect on the fidelity of delivered distribution to the plan. Methods: In a typical five-fraction course, daily set-up is achieved by matching the position of fiducial markers in orthogonal radiographs to the images generated by treatment planning program. A patient maintains the required gaze direction voluntarily, without the aid of fixation devices. Confirmation radiographs are acquired to assess intrafractional changes. For this study, daily radiographs were analyzed to determine the daily iso-center position and apparent gaze direction, which were then transferred to themore » planning system to calculate the dose delivered in individual fractions, and accumulated dose for the entire course. Dose-volume metrics were compared between the planned and accumulated distributions for the tumor and organs at risk, for representative cases that varied by location within the ocular globe. Results: The analysis of the first set of cases (3 posterior, 3 transequatorial and 4 anterior tumors) revealed varying dose deviation patterns, depending on the tumor location. For anterior and posterior tumors, the largest dose increases were observed in the lens and ciliary body, while for the equatorial tumors, macula, optic nerve and disk, were most often affected. The iso-center position error was below 1.3 mm (95%-confidence interval), and the standard deviation of daily polar and azimuthal gaze set-up were 1.5 and 3 degrees, respectively. Conclusion: We quantified interfractional and intrafractional set-up variation, and estimated their effect on the delivered dose for representative cases. Current safety margins are sufficient to maintain the target coverage, however, the dose delivered to critical structures often deviates from the plan. The ongoing analysis will further explore the patterns of dose deviation, and may help to identify particular treatment scenarios which are at a higher risk for such deviations.« less

Piezoelectric and optical setup to measure an electrical field: application to the longitudinal near-field generated by a tapered coax.

PubMed

Euphrasie, S; Vairac, P; Cretin, B; Lengaigne, G

2008-03-01

We propose a new setup to measure an electrical field in one direction. This setup is made of a piezoelectric sintered lead zinconate titanate film and an optical interferometric probe. We used this setup to investigate how the shape of the extremity of a coaxial cable influences the longitudinal electrical near-field generated by it. For this application, we designed our setup to have a spatial resolution of 100 microm in the direction of the electrical field. Simulations and experiments are presented.

On-line carbon balance of yeast fermentations using miniaturized optical sensors.

PubMed

Beuermann, Thomas; Egly, Dominik; Geoerg, Daniel; Klug, Kerris Isolde; Storhas, Winfried; Methner, Frank-Juergen

2012-03-01

Monitoring of microbiological processes using optical sensors and spectrometers has gained in importance over the past few years due to its advantage in enabling non-invasive on-line analysis. Near-infrared (NIR) and mid-infrared (MIR) spectrometer set-ups in combination with multivariate calibrations have already been successfully employed for the simultaneous determination of different metabolites in microbiological processes. Photometric sensors, in addition to their low price compared to spectrometer set-ups, have the advantage of being compact and are easy to calibrate and operate. In this work, the detection of ethanol and CO(2) in the exhaust gas during aerobic yeast fermentation was performed by two photometric gas analyzers, and dry yeast biomass was monitored using a fiber optic backscatter set-up. The optical sensors could be easily fitted to the bioreactor and exhibited high robustness during measuring. The ethanol content of the fermentation broth was monitored on-line by measuring the ethanol concentration in the fermentation exhaust and applying a conversion factor. The vapor/liquid equilibrium and the associated conversion factor strongly depend on the process parameter temperature but not on aeration and stirring rate. Dry yeast biomass was determined in-line by a backscattering signal applying a linear calibration. An on-line balance with a recovery rate of 95-97% for carbon was achieved with the use of three optical sensors (two infrared gas analyzers and one fiber optic backscatter set-up). Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Kilovoltage cone-beam CT imaging dose during breast radiotherapy: A dose comparison between a left and right breast setup

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quinn, Alexandra, E-mail: Alexandra.quinn@health.nsw.gov.au; Centre for Medical Radiation Physics, University of Wollongong, NSW; Liverpool and Macarthur Cancer Therapy Centres, NSW

2014-07-01

The purpose of this study was to investigate the delivered dose from a kilovoltage cone-beam computed tomography (kV-CBCT) acquired in breast treatment position for a left and right breast setup. The dose was measured with thermoluminescent dosimeters positioned within a female anthropomorphic phantom at organ locations. Imaging was performed on an Elekta Synergy XVI system with the phantom setup on a breast board. The image protocol involved 120 kVp, 140 mAs, and a 270° arc rotation clockwise 0° to 270° for the left breast setup and 270° to 180° for the right breast setup (maximum arc rotations possible). The dosemore » delivered to the left breast, right breast, and heart was 5.1 mGy, 3.9 mGy, and 4.0 mGy for the left breast setup kV-CBCT, and 6.4 mGy, 6.0 mGy, and 4.8 mGy for the right breast setup kV-CBCT, respectively. The rotation arc of the kV-CBCT influenced the dose delivered, with the right breast setup kV-CBCT found to deliver a dose of up to 4 mGy or 105% higher to the treated breast′s surface in comparison with the left breast setup. This is attributed to the kV-CBCT source being more proximal to the anterior of the phantom for a right breast setup, whereas the source is more proximal to the posterior of the patient for a left-side scan.« less

Poster - 33: Dosimetry Comparison of Prone Breast Forward and Inverse Treatment planning considering daily setup variations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Runqing; Zhan, Lixin; Osei, Ernest

2016-08-15

Introduction: The purpose of this study is to investigate the effects of daily setup variations on prone breast forward field-in-field (FinF) and inverse IMRT treatment planning. Methods: Rando Phantom (Left breast) and Pixy phantom (Right breast) were built and CT scanned in prone position. The treatment planning (TP) is performed in Eclipse TP system. Forward FinF plan and inverse IMRT plan were created to satisfy the CTV coverage and OARs criteria. The daily setup variations were assumed to be 5 mm at left-right, superior-inferior, and anterior-posterior directions. The DVHs of CTV coverage and OARs were compared for both forward FinFmore » plan and inverse IMRT plans due to 5mm setup variation. Results and Discussions: DVHs of CTV coverage had fewer variations for 5m setup variation for forward FinF and inverse IMRT plan for both phantoms. However, for the setup variations in the left-right direction, the DVH of CTV coverage of IMRT plan showed the worst variation due to lateral setup variation for both phantoms. For anterior-posterior variation, the CTV could not get full coverage when the breast chest wall is shallow; however, with the guidance of MV imaging, breast chest wall will be checked during the MV imaging setup. So the setup variations have more effects on inverse IMRT plan, compared to forward FinF plan, especially in the left-right direction. Conclusions: The Forward FinF plan was recommended clinically considering daily setup variation.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ribezzi-Crivellari, M.; Huguet, J. M.; Ritort, F.

We present a dual-trap optical tweezers setup which directly measures forces using linear momentum conservation. The setup uses a counter-propagating geometry, which allows momentum measurement on each beam separately. The experimental advantages of this setup include low drift due to all-optical manipulation, and a robust calibration (independent of the features of the trapped object or buffer medium) due to the force measurement method. Although this design does not attain the high-resolution of some co-propagating setups, we show that it can be used to perform different single molecule measurements: fluctuation-based molecular stiffness characterization at different forces and hopping experiments on molecularmore » hairpins. Remarkably, in our setup it is possible to manipulate very short tethers (such as molecular hairpins with short handles) down to the limit where beads are almost in contact. The setup is used to illustrate a novel method for measuring the stiffness of optical traps and tethers on the basis of equilibrium force fluctuations, i.e., without the need of measuring the force vs molecular extension curve. This method is of general interest for dual trap optical tweezers setups and can be extended to setups which do not directly measure forces.« less

Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baier, S.; Rochet, A.; Hofmann, G.

2015-06-15

We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor formore » in situ studies.« less

Improved classification and visualization of healthy and pathological hard dental tissues by modeling specular reflections in NIR hyperspectral images

NASA Astrophysics Data System (ADS)

Usenik, Peter; Bürmen, Miran; Fidler, Aleš; Pernuš, Franjo; Likar, Boštjan

2012-03-01

Despite major improvements in dental healthcare and technology, dental caries remains one of the most prevalent chronic diseases of modern society. The initial stages of dental caries are characterized by demineralization of enamel crystals, commonly known as white spots, which are difficult to diagnose. Near-infrared (NIR) hyperspectral imaging is a new promising technique for early detection of demineralization which can classify healthy and pathological dental tissues. However, due to non-ideal illumination of the tooth surface the hyperspectral images can exhibit specular reflections, in particular around the edges and the ridges of the teeth. These reflections significantly affect the performance of automated classification and visualization methods. Cross polarized imaging setup can effectively remove the specular reflections, however is due to the complexity and other imaging setup limitations not always possible. In this paper, we propose an alternative approach based on modeling the specular reflections of hard dental tissues, which significantly improves the classification accuracy in the presence of specular reflections. The method was evaluated on five extracted human teeth with corresponding gold standard for 6 different healthy and pathological hard dental tissues including enamel, dentin, calculus, dentin caries, enamel caries and demineralized regions. Principal component analysis (PCA) was used for multivariate local modeling of healthy and pathological dental tissues. The classification was performed by employing multiple discriminant analysis. Based on the obtained results we believe the proposed method can be considered as an effective alternative to the complex cross polarized imaging setups.

Pulsed field probe of real time magnetization dynamics in magnetic nanoparticle systems

NASA Astrophysics Data System (ADS)

Foulkes, T.; Syed, M.; Taplin, T.

2015-05-01

Magnetic nanoparticles (MNPs) are extensively used in biotechnology. These applications rely on magnetic properties that are a keen function of MNP size, distribution, and shape. Various magneto-optical techniques, including Faraday Rotation (FR), Cotton-Mouton Effect, etc., have been employed to characterize magnetic properties of MNPs. Generally, these measurements employ AC or DC fields. In this work, we describe the results from a FR setup that uses pulsed magnetic fields and an analysis technique that makes use of the entire pulse shape to investigate size distribution and shape anisotropy. The setup employs a light source, polarizing components, and a detector that are used to measure the rotation of light from a sample that is subjected to a pulsed magnetic field. This magnetic field "snapshot" is recorded alongside the intensity pulse of the sample's response. This side by side comparison yields useful information about the real time magnetization dynamics of the system being probed. The setup is highly flexible with variable control of pulse length and peak magnitude. Examining the raw data for the response of bare Fe3O4 and hybrid Au and Fe3O4 nanorods reveals interesting information about Brownian relaxation and the hydrodynamic size of these nanorods. This analysis exploits the self-referencing nature of this measurement to highlight the impact of an applied field on creating a field induced transparency for a longitudinal measurement. Possible sources for this behavior include shape anisotropy and field assisted aggregate formation.

AQUATOX Setup Guide

EPA Pesticide Factsheets

The new Guidance in AQUATOX Setup and Application provides a quick start guide to introduce major model features, as well as being a type of cookbook to guide basic model setup, calibration, and validation.

SU-E-T-292: Sensitivity of Fractionated Lung IMPT Treatments to Setup Uncertainties and Motion Effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dowdell, S; Grassberger, C; Paganetti, H

2014-06-01

Purpose: Evaluate the sensitivity of intensity-modulated proton therapy (IMPT) lung treatments to systematic and random setup uncertainties combined with motion effects. Methods: Treatment plans with single-field homogeneity restricted to ±20% (IMPT-20%) were compared to plans with no restriction (IMPT-full). 4D Monte Carlo simulations were performed for 10 lung patients using the patient CT geometry with either ±5mm systematic or random setup uncertainties applied over a 35 × 2.5Gy(RBE) fractionated treatment course. Intra-fraction, inter-field and inter-fraction motions were investigated. 50 fractionated treatments with systematic or random setup uncertainties applied to each fraction were generated for both IMPT delivery methods and threemore » energy-dependent spot sizes (big spots - BS σ=18-9mm, intermediate spots - IS σ=11-5mm, small spots - SS σ=4-2mm). These results were compared to a Monte Carlo recalculation of the original treatment plan, with results presented as the difference in EUD (ΔEUD), V{sub 95} (ΔV{sub 95}) and target homogeneity (ΔD{sub 1}–D{sub 99}) between the 4D simulations and the Monte Carlo calculation on the planning CT. Results: The standard deviations in the ΔEUD were 1.95±0.47(BS), 1.85±0.66(IS) and 1.31±0.35(SS) times higher in IMPT-full compared to IMPT-20% when ±5mm systematic setup uncertainties were applied. The ΔV{sub 95} variations were also 1.53±0.26(BS), 1.60±0.50(IS) and 1.38±0.38(SS) times higher for IMPT-full. For random setup uncertainties, the standard deviations of the ΔEUD from 50 simulated fractionated treatments were 1.94±0.90(BS), 2.13±1.08(IS) and 1.45±0.57(SS) times higher in IMPTfull compared to IMPT-20%. For all spot sizes considered, the ΔD{sub 1}-D{sub 99} coincided within the uncertainty limits for the two IMPT delivery methods, with the mean value always higher for IMPT-full. Statistical analysis showed significant differences between the IMPT-full and IMPT-20% dose distributions for the majority of scenarios studied. Conclusion: Lung IMPT-full treatments are more sensitive to both systematic and random setup uncertainties compared to IMPT-20%. This work was supported by the NIH R01 CA111590.« less

Theoretical studies of solar lasers and converters

NASA Technical Reports Server (NTRS)

Heinbockel, John

1988-01-01

The geometry and setup for the n-C3F7I iodine laser are illustrated. The mathematical modeling of this system is described. The chemical kinetics are summarized. A sensitivity analysis was performed on the parameters occurring in the differential equations describing the chemical kinetics.

High-throughput heterodyne thermoreflectance: Application to thermal conductivity measurements of a Fe-Si-Ge thin film alloy library.

PubMed

d'Acremont, Quentin; Pernot, Gilles; Rampnoux, Jean-Michel; Furlan, Andrej; Lacroix, David; Ludwig, Alfred; Dilhaire, Stefan

2017-07-01

A High-Throughput Time-Domain ThermoReflectance (HT-TDTR) technique was developed to perform fast thermal conductivity measurements with minimum user actions required. This new setup is based on a heterodyne picosecond thermoreflectance system. The use of two different laser oscillators has been proven to reduce the acquisition time by two orders of magnitude and avoid the experimental artefacts usually induced by moving the elements present in TDTR systems. An amplitude modulation associated to a lock-in detection scheme is included to maintain a high sensitivity to thermal properties. We demonstrate the capabilities of the HT-TDTR setup to perform high-throughput thermal analysis by mapping thermal conductivity and interface resistances of a ternary thin film silicide library Fe x Si y Ge 100-x-y (20

Microneedle-based analysis of the micromechanics of the metaphase spindle assembled in Xenopus laevis egg extracts

PubMed Central

Shimamoto, Yuta; Kapoor, Tarun M.

2014-01-01

SUMMARY To explain how micron-sized cellular structures generate and respond to forces we need to characterize their micromechanical properties. Here we provide a protocol to build and use a dual force-calibrated microneedle-based set-up to quantitatively analyze the micromechanics of a metaphase spindle assembled in Xenopus laevis egg extracts. This cell-free extract system allows for controlled biochemical perturbations of spindle components. We describe how the microneedles are prepared and how they can be used to apply and measure forces. A multi-mode imaging system allows tracking of microtubules, chromosomes and needle tips. This set-up can be used to analyze the viscoelastic properties of the spindle on time-scales ranging from minutes to sub-seconds. A typical experiment, along with data analysis, is also detailed. We anticipate that our protocol can be readily extended to analyze the micromechanics of other cellular structures assembled in cell-free extracts. The entire procedure can take 3-4 days. PMID:22538847

High-throughput heterodyne thermoreflectance: Application to thermal conductivity measurements of a Fe-Si-Ge thin film alloy library

NASA Astrophysics Data System (ADS)

d'Acremont, Quentin; Pernot, Gilles; Rampnoux, Jean-Michel; Furlan, Andrej; Lacroix, David; Ludwig, Alfred; Dilhaire, Stefan

2017-07-01

A High-Throughput Time-Domain ThermoReflectance (HT-TDTR) technique was developed to perform fast thermal conductivity measurements with minimum user actions required. This new setup is based on a heterodyne picosecond thermoreflectance system. The use of two different laser oscillators has been proven to reduce the acquisition time by two orders of magnitude and avoid the experimental artefacts usually induced by moving the elements present in TDTR systems. An amplitude modulation associated to a lock-in detection scheme is included to maintain a high sensitivity to thermal properties. We demonstrate the capabilities of the HT-TDTR setup to perform high-throughput thermal analysis by mapping thermal conductivity and interface resistances of a ternary thin film silicide library FexSiyGe100-x-y (20

Metallic Induction Reaction Engine.

DTIC Science & Technology

1984-12-28

FODA CLAIJ TY Figure 2: Experimental Setup 2 A EML Research Metallic Induction Reaction Engine page 3 Figure 3: Aluminum Reaction Mass Ring in Flight...reaction mass materials. Furthur analysis performed with the *] numerical model indicates that there exists a back EMF saturation effect which inhibits the...instrumentation difficulties, a detailed analysis of it’s performance has not been established. r Outer Coil Projectile- Coil Inner Coil Figure 4

Experimental setup for investigation of two-phase (water-air) flows in a tube

NASA Astrophysics Data System (ADS)

Kazunin, D. V.; Lashkov, V. A.; Mashek, I. Ch.; Khoronzhuk, R. S.

2018-05-01

A special setup was designed and built at St. Petersburg State University for providing experimental research in flow dynamics of the of air-water mixtures in a pipeline. The test section of the setup allows simulating a wide range of flow regimes of a gas-liquid mixture. The parameters of the experimental setup are given; the initial test results are discussed.

Feasibility study of a take-home array-based functional electrical stimulation system with automated setup for current functional electrical stimulation users with foot-drop.

PubMed

Prenton, Sarah; Kenney, Laurence P; Stapleton, Claire; Cooper, Glen; Reeves, Mark L; Heller, Ben W; Sobuh, Mohammad; Barker, Anthony T; Healey, Jamie; Good, Timothy R; Thies, Sibylle B; Howard, David; Williamson, Tracey

2014-10-01

To investigate the feasibility of unsupervised community use of an array-based automated setup functional electrical stimulator for current foot-drop functional electrical stimulation (FES) users. Feasibility study. Gait laboratory and community use. Participants (N=7) with diagnosis of unilateral foot-drop of central neurologic origin (>6mo) who were regular users of a foot-drop FES system (>3mo). Array-based automated setup FES system for foot-drop (ShefStim). Logged usage, logged automated setup times for the array-based automated setup FES system and diary recording of problems experienced, all collected in the community environment. Walking speed, ankle angles at initial contact, foot clearance during swing, and the Quebec User Evaluation of Satisfaction with Assistive Technology version 2.0 (QUEST version 2.0) questionnaire, all collected in the gait laboratory. All participants were able to use the array-based automated setup FES system. Total setup time took longer than participants' own FES systems, and automated setup time was longer than in a previous study of a similar system. Some problems were experienced, but overall, participants were as satisfied with this system as their own FES system. The increase in walking speed (N=7) relative to no stimulation was comparable between both systems, and appropriate ankle angles at initial contact (N=7) and foot clearance during swing (n=5) were greater with the array-based automated setup FES system. This study demonstrates that an array-based automated setup FES system for foot-drop can be successfully used unsupervised. Despite setup's taking longer and some problems, users are satisfied with the system and it would appear as effective, if not better, at addressing the foot-drop impairment. Further product development of this unique system, followed by a larger-scale and longer-term study, is required before firm conclusions about its efficacy can be reached. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Accuracy of off-line bioluminescence imaging to localize targets in preclinical radiation research.

PubMed

Tuli, Richard; Armour, Michael; Surmak, Andrew; Reyes, Juvenal; Iordachita, Iulian; Patterson, Michael; Wong, John

2013-04-01

In this study, we investigated the accuracy of using off-line bioluminescence imaging (BLI) and tomography (BLT) to guide irradiation of small soft tissue targets on a small animal radiation research platform (SARRP) with on-board cone beam CT (CBCT) capability. A small glass bulb containing BL cells was implanted as a BL source in the abdomen of 11 mouse carcasses. Bioluminescence imaging and tomography were acquired for each carcass. Six carcasses were setup visually without immobilization and 5 were restrained in position with tape. All carcasses were setup in treatment position on the SARRP where the centroid position of the bulb on CBCT was taken as "truth". In the 2D visual setup, the carcass was setup by aligning the point of brightest luminescence with the vertical beam axis. In the CBCT assisted setup, the pose of the carcass on CBCT was aligned with that on the 2D BL image for setup. For both 2D setup methods, the offset of the bulb centroid on CBCT from the vertical beam axis was measured. In the BLT-CBCT fusion method, the 3D torso on BLT and CBCT was registered and the 3D offset of the respective source centroids was calculated. The setup results were independent of the carcass being immobilized or not due to the onset of rigor mortis. The 2D offset of the perceived BL source position from the CBCT bulb position was 2.3 mm ± 1.3 mm. The 3D offset between BLT and CBCT was 1.5 mm ± 0.9 mm. Given the rigidity of the carcasses, the setup results represent the best that can be achieved with off-line 2D BLI and 3D BLT. The setup uncertainty would require the use of undesirably large margin of 4-5 mm. The results compel the implementation of on-board BLT capability on the SARRP to eliminate setup error and to improve BLT accuracy.

Accuracy of Off-Line Bioluminescence Imaging to Localize Targets in Preclinical Radiation Research

PubMed Central

Tuli, Richard; Armour, Michael; Surmak, Andrew; Reyes, Juvenal; Iordachita, Iulian; Patterson, Michael; Wong, John

2013-01-01

In this study, we investigated the accuracy of using off-line bioluminescence imaging (BLI) and tomography (BLT) to guide irradiation of small soft tissue targets on a small animal radiation research platform (SARRP) with on-board cone beam CT (CBCT) capability. A small glass bulb containing BL cells was implanted as a BL source in the abdomen of 11 mouse carcasses. Bioluminescence imaging and tomography were acquired for each carcass. Six carcasses were setup visually without immobilization and 5 were restrained in position with tape. All carcasses were setup in treatment position on the SARRP where the centroid position of the bulb on CBCT was taken as “truth”. In the 2D visual setup, the carcass was setup by aligning the point of brightest luminescence with the vertical beam axis. In the CBCT assisted setup, the pose of the carcass on CBCT was aligned with that on the 2D BL image for setup. For both 2D setup methods, the offset of the bulb centroid on CBCT from the vertical beam axis was measured. In the BLT-CBCT fusion method, the 3D torso on BLT and CBCT was registered and the 3D offset of the respective source centroids was calculated. The setup results were independent of the carcass being immobilized or not due to the onset of rigor mortis. The 2D offset of the perceived BL source position from the CBCT bulb position was 2.3 mm ± 1.3 mm. The 3D offset between BLT and CBCT was 1.5 mm ± 0.9 mm. Given the rigidity of the carcasses, the setup results represent the best that can be achieved with off-line 2D BLI and 3D BLT. The setup uncertainty would require the use of undesirably large margin of 4–5 mm. The results compel the implementation of on-board BLT capability on the SARRP to eliminate setup error and to improve BLT accuracy. PMID:23578189

Commissioning and quality assurance of an integrated system for patient positioning and setup verification in particle therapy.

PubMed

Pella, A; Riboldi, M; Tagaste, B; Bianculli, D; Desplanques, M; Fontana, G; Cerveri, P; Seregni, M; Fattori, G; Orecchia, R; Baroni, G

2014-08-01

In an increasing number of clinical indications, radiotherapy with accelerated particles shows relevant advantages when compared with high energy X-ray irradiation. However, due to the finite range of ions, particle therapy can be severely compromised by setup errors and geometric uncertainties. The purpose of this work is to describe the commissioning and the design of the quality assurance procedures for patient positioning and setup verification systems at the Italian National Center for Oncological Hadrontherapy (CNAO). The accuracy of systems installed in CNAO and devoted to patient positioning and setup verification have been assessed using a laser tracking device. The accuracy in calibration and image based setup verification relying on in room X-ray imaging system was also quantified. Quality assurance tests to check the integration among all patient setup systems were designed, and records of daily QA tests since the start of clinical operation (2011) are presented. The overall accuracy of the patient positioning system and the patient verification system motion was proved to be below 0.5 mm under all the examined conditions, with median values below the 0.3 mm threshold. Image based registration in phantom studies exhibited sub-millimetric accuracy in setup verification at both cranial and extra-cranial sites. The calibration residuals of the OTS were found consistent with the expectations, with peak values below 0.3 mm. Quality assurance tests, daily performed before clinical operation, confirm adequate integration and sub-millimetric setup accuracy. Robotic patient positioning was successfully integrated with optical tracking and stereoscopic X-ray verification for patient setup in particle therapy. Sub-millimetric setup accuracy was achieved and consistently verified in daily clinical operation.

Long Endurance Underwater Power System

DTIC Science & Technology

1989-09-01

Figures 7.3 through 7.8. Data analysis was done using the Excel spreadsheet program on an IBM compatible computer -w.d utsported to a MALcintosh for...shall be compared with data obtained from non-leaking gill carridges for a mor complete analysis . 4) The pump attached to the test setup was not...BACKGROUND 5 V. ANALYSIS 6 VI. RESULTS AND CONCLUSIONS 6 )Preferred Method 7 VI. REFERENCES 11 App- nd.x-.1 12 SECTION - II ALWATT HY.HG•N GENERATOR I

Remote-Controlled Rotorcraft Blade Vibration and Modal Analysis at Low Frequencies

DTIC Science & Technology

2016-02-01

modal analysis, remote-controlled helicopter , remote-controlled rotorcraft, HUMS for rotorcraft 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...Experimental Setup 1 4. Results 4 4.1 Rotor Blade Acceleration 4 4.2 Modal Analysis: Using an Impact Hammer 7 4.3 Dynamic Response Revisited 8 5... Rotor blade response to shaker outputting 1-V sine wave at 100 Hz ....5 Fig. 6 Rotor blade response to shaker outputting 1-V sine sweep from 20- to 100

[Statistical Process Control (SPC) can help prevent treatment errors without increasing costs in radiotherapy].

PubMed

Govindarajan, R; Llueguera, E; Melero, A; Molero, J; Soler, N; Rueda, C; Paradinas, C

2010-01-01

Statistical Process Control (SPC) was applied to monitor patient set-up in radiotherapy and, when the measured set-up error values indicated a loss of process stability, its root cause was identified and eliminated to prevent set-up errors. Set up errors were measured for medial-lateral (ml), cranial-caudal (cc) and anterior-posterior (ap) dimensions and then the upper control limits were calculated. Once the control limits were known and the range variability was acceptable, treatment set-up errors were monitored using sub-groups of 3 patients, three times each shift. These values were plotted on a control chart in real time. Control limit values showed that the existing variation was acceptable. Set-up errors, measured and plotted on a X chart, helped monitor the set-up process stability and, if and when the stability was lost, treatment was interrupted, the particular cause responsible for the non-random pattern was identified and corrective action was taken before proceeding with the treatment. SPC protocol focuses on controlling the variability due to assignable cause instead of focusing on patient-to-patient variability which normally does not exist. Compared to weekly sampling of set-up error in each and every patient, which may only ensure that just those sampled sessions were set-up correctly, the SPC method enables set-up error prevention in all treatment sessions for all patients and, at the same time, reduces the control costs. Copyright © 2009 SECA. Published by Elsevier Espana. All rights reserved.

SU-F-J-130: Margin Determination for Hypofractionated Partial Breast Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geady, C; Keller, B; Hahn, E

2016-06-15

Purpose: To determine the Planning Target Volume (PTV) margin for Hypofractionated Partial Breast Irradiation (HPBI) using the van Herk formalism (M=2.5∑+0.7σ). HPBI is a novel technique intended to provide local control in breast cancer patients not eligible for surgical resection, using 40 Gy in 5 fractions prescribed to the gross disease. Methods: Setup uncertainties were quantified through retrospective analysis of cone-beam computed tomography (CBCT) data sets, collected prior to (prefraction) and after (postfraction) treatment delivery. During simulation and treatment, patients were immobilized using a wing board and an evacuated bag. Prefraction CBCT was rigidly registered to planning 4-dimensional computed tomographymore » (4DCT) using the chest wall and tumor, and translational couch shifts were applied as needed. This clinical workflow was faithfully reproduced in Pinnacle (Philips Medical Systems) to yield residual setup and intrafractional error through translational shifts and rigid registrations (ribs and sternum) of prefraction CBCT to 4DCT and postfraction CBCT to prefraction CBCT, respectively. All ten patients included in this investigation were medically inoperable; the median age was 84 (range, 52–100) years. Results: Systematic (and random) setup uncertainties (in mm) detected for the left-right, craniocaudal and anteroposterior directions were 0.4 (1.5), 0.8 (1.8) and 0.4 (1.0); net uncertainty was determined to be 0.7 (1.5). Rotations >2° in any axis occurred on 8/72 (11.1%) registrations. Conclusion: Preliminary results suggest a non-uniform setup margin (in mm) of 2.2, 3.3 and 1.7 for the left-right, craniocaudal and anteroposterior directions is required for HPBI, given its immobilization techniques and online setup verification protocol. This investigation is ongoing, though published results from similar studies are consistent with the above findings. Determination of margins in breast radiotherapy is a paradigm shift, but a necessary step in moving towards hypofractionated regiments, which may ultimately redefine the standard of care for this select patient population.« less

Automatic detection of patient identification and positioning errors in radiation therapy treatment using 3-dimensional setup images.

PubMed

Jani, Shyam S; Low, Daniel A; Lamb, James M

2015-01-01

To develop an automated system that detects patient identification and positioning errors between 3-dimensional computed tomography (CT) and kilovoltage CT planning images. Planning kilovoltage CT images were collected for head and neck (H&N), pelvis, and spine treatments with corresponding 3-dimensional cone beam CT and megavoltage CT setup images from TrueBeam and TomoTherapy units, respectively. Patient identification errors were simulated by registering setup and planning images from different patients. For positioning errors, setup and planning images were misaligned by 1 to 5 cm in the 6 anatomical directions for H&N and pelvis patients. Spinal misalignments were simulated by misaligning to adjacent vertebral bodies. Image pairs were assessed using commonly used image similarity metrics as well as custom-designed metrics. Linear discriminant analysis classification models were trained and tested on the imaging datasets, and misclassification error (MCE), sensitivity, and specificity parameters were estimated using 10-fold cross-validation. For patient identification, our workflow produced MCE estimates of 0.66%, 1.67%, and 0% for H&N, pelvis, and spine TomoTherapy images, respectively. Sensitivity and specificity ranged from 97.5% to 100%. MCEs of 3.5%, 2.3%, and 2.1% were obtained for TrueBeam images of the above sites, respectively, with sensitivity and specificity estimates between 95.4% and 97.7%. MCEs for 1-cm H&N/pelvis misalignments were 1.3%/5.1% and 9.1%/8.6% for TomoTherapy and TrueBeam images, respectively. Two-centimeter MCE estimates were 0.4%/1.6% and 3.1/3.2%, respectively. MCEs for vertebral body misalignments were 4.8% and 3.6% for TomoTherapy and TrueBeam images, respectively. Patient identification and gross misalignment errors can be robustly and automatically detected using 3-dimensional setup images of different energies across 3 commonly treated anatomical sites. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Setup errors and effectiveness of Optical Laser 3D Surface imaging system (Sentinel) in postoperative radiotherapy of breast cancer.

PubMed

Wei, Xiaobo; Liu, Mengjiao; Ding, Yun; Li, Qilin; Cheng, Changhai; Zong, Xian; Yin, Wenming; Chen, Jie; Gu, Wendong

2018-05-08

Breast-conserving surgery (BCS) plus postoperative radiotherapy has become the standard treatment for early-stage breast cancer. The aim of this study was to compare the setup accuracy of optical surface imaging by the Sentinel system with cone-beam computerized tomography (CBCT) imaging currently used in our clinic for patients received BCS. Two optical surface scans were acquired before and immediately after couch movement correction. The correlation between the setup errors as determined by the initial optical surface scan and CBCT was analyzed. The deviation of the second optical surface scan from the reference planning CT was considered an estimate for the residual errors for the new method for patient setup correction. The consequences in terms for necessary planning target volume (PTV) margins for treatment sessions without setup correction applied. We analyzed 145 scans in 27 patients treated for early stage breast cancer. The setup errors of skin marker based patient alignment by optical surface scan and CBCT were correlated, and the residual setup errors as determined by the optical surface scan after couch movement correction were reduced. Optical surface imaging provides a convenient method for improving the setup accuracy for breast cancer patient without unnecessary imaging dose.

Multipurpose setup for low-temperature conversion electron Mössbauer spectroscopy

NASA Astrophysics Data System (ADS)

Augustyns, V.; Trekels, M.; Gunnlaugsson, H. P.; Masenda, H.; Temst, K.; Vantomme, A.; Pereira, L. M. C.

2017-05-01

We describe an experimental setup for conversion electron Mössbauer spectroscopy (CEMS) at low temperature. The setup is composed of a continuous flow cryostat (temperature range of 4.2-500 K), detector housing, three channel electron multipliers, and corresponding electronics. We demonstrate the capabilities of the setup with CEMS measurements performed on a sample consisting of a thin enriched 57Fe film, with a thickness of 20 nm, deposited on a silicon substrate. We also describe exchangeable adaptations (lid and sample holder) which extend the applicability of the setup to emission Mössbauer spectroscopy as well as measurements under an applied magnetic field.

Claims and Appeals (Medicare)

MedlinePlus

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1000540

NASA Image and Video Library

2010-04-13

ERIC EARHART (AEROSPACE ENGINEER, ER41 PROPULSION STRUCTURAL & DYNAMICS ANALYSIS BRANCH) DISCUSSES DATA PRODUCED BY A UNIQUE MECHANICAL TEST SETUP THAT MEASURES STRAIN ON A SINGLE SAMPLE, USING TWO DIFFERENT TECHNIQUES AT THE SAME TIME. THE TEST FIXTURE HOLDS A SPECIMEN THAT REPRESENTS A LIQUID OXYGEN (LOX) BEARING FROM THE J2-X ENGINE

Water level effects on breaking wave setup for Pacific Island fringing reefs

NASA Astrophysics Data System (ADS)

Becker, J. M.; Merrifield, M. A.; Ford, M.

2014-02-01

The effects of water level variations on breaking wave setup over fringing reefs are assessed using field measurements obtained at three study sites in the Republic of the Marshall Islands and the Mariana Islands in the western tropical Pacific Ocean. At each site, reef flat setup varies over the tidal range with weaker setup at high tide and stronger setup at low tide for a given incident wave height. The observed water level dependence is interpreted in the context of radiation stress gradients specified by an idealized point break model generalized for nonnormally incident waves. The tidally varying setup is due in part to depth-limited wave heights on the reef flat, as anticipated from previous reef studies, but also to tidally dependent breaking on the reef face. The tidal dependence of the breaking is interpreted in the context of the point break model in terms of a tidally varying wave height to water depth ratio at breaking. Implications for predictions of wave-driven setup at reef-fringed island shorelines are discussed.

Comparative evaluation of user interfaces for robot-assisted laser phonomicrosurgery.

PubMed

Dagnino, Giulio; Mattos, Leonardo S; Becattini, Gabriele; Dellepiane, Massimo; Caldwell, Darwin G

2011-01-01

This research investigates the impact of three different control devices and two visualization methods on the precision, safety and ergonomics of a new medical robotic system prototype for assistive laser phonomicrosurgery. This system allows the user to remotely control the surgical laser beam using either a flight simulator type joystick, a joypad, or a pen display system in order to improve the traditional surgical setup composed by a mechanical micromanipulator coupled with a surgical microscope. The experimental setup and protocol followed to obtain quantitative performance data from the control devices tested are fully described here. This includes sets of path following evaluation experiments conducted with ten subjects with different skills, for a total of 700 trials. The data analysis method and experimental results are also presented, demonstrating an average 45% error reduction when using the joypad and up to 60% error reduction when using the pen display system versus the standard phonomicrosurgery setup. These results demonstrate the new system can provide important improvements in terms of surgical precision, ergonomics and safety. In addition, the evaluation method presented here is shown to support an objective selection of control devices for this application.

Mid-Infrared Photoacoustic Detection of Glucose in Human Skin: Towards Non-Invasive Diagnostics

PubMed Central

Kottmann, Jonas; Rey, Julien M.; Sigrist, Markus W.

2016-01-01

Diabetes mellitus is a widespread metabolic disease without cure. Great efforts are being made to develop a non-invasive monitoring of the blood glucose level. Various attempts have been made, including a number of non-optical approaches as well as optical techniques involving visible, near- and mid-infrared light. However, no true breakthrough has been achieved so far, i.e., there is no fully non-invasive monitoring device available. Here we present a new study based on mid-infrared spectroscopy and photoacoustic detection. We employ two setups, one with a fiber-coupled photoacoustic (PA) cell and a tunable quantum cascade laser (QCL), and a second setup with two QCLs at different wavelengths combined with PA detection. In both cases, the PA cells are in direct skin contact. The performance is tested with an oral glucose tolerance test. While the first setup often gives reasonable qualitative agreement with ordinary invasive blood glucose measurements, the dual-wavelength approach yields a considerably improved stability and an uncertainty of only ±30 mg/dL of the blood glucose concentration level at a confidence level of 90%. This result is achieved without advanced data treatment such as principal component analysis involving extended wavelength ranges. PMID:27735878

Optical digital to analog conversion performance analysis for indoor set-up conditions

NASA Astrophysics Data System (ADS)

Dobesch, Aleš; Alves, Luis Nero; Wilfert, Otakar; Ribeiro, Carlos Gaspar

2017-10-01

In visible light communication (VLC) the optical digital to analog conversion (ODAC) approach was proposed as a suitable driving technique able to overcome light-emitting diode's (LED) non-linear characteristic. This concept is analogous to an electrical digital-to-analog converter (EDAC). In other words, digital bits are binary weighted to represent an analog signal. The method supports elementary on-off based modulations able to exploit the essence of LED's non-linear characteristic allowing simultaneous lighting and communication. In the ODAC concept the reconstruction error does not simply rely upon the converter bit depth as in case of EDAC. It rather depends on communication system set-up and geometrical relation between emitter and receiver as well. The paper describes simulation results presenting the ODAC's error performance taking into account: the optical channel, the LED's half power angle (HPA) and the receiver field of view (FOV). The set-up under consideration examines indoor conditions for a square room with 4 m length and 3 m height, operating with one dominant wavelength (blue) and having walls with a reflection coefficient of 0.8. The achieved results reveal that reconstruction error increases for higher data rates as a result of interference due to multipath propagation.

An experimental investigation of convective heat transfer at evaporation of kerosene and water in the closed volume

NASA Astrophysics Data System (ADS)

Trushlyakov, V. I.; Lesnyak, I. Y.; Galfetti, L.

2017-09-01

An evaporation of kerosene and water was investigated based on convective heat transfer in the experimental setup simulating a typical volume of the fuel tank of the launch vehicle. Basic criteria of similarity used in choosing the design parameters of the setup, parameters of the coolant and model liquids, were numbers of Reynolds, Prandtl, Biot, and Nusselt. The used coolants were gases, including air and nitrogen; in addition, at the stage of preliminary experiments, products of combustion of hydroxyl-terminated polybutadiene (HTPB) were considered. Boundary conditions were taken for the liquid located on the plate in the form of "drop" and at its uniform film spread in the experimental model setup. On the basis of experimental investigations, the temperature values were obtained for the system "gas-liquid-wall", and areas of mass transfer surface and heat transfer coefficients of "gas-liquid" and "gas-plate" were determined for coolants (air and nitrogen) and for liquids (water and kerosene). The comparative analysis of the obtained results and the known data was carried out. Proposals for experiments using coolants based on HTPB combustion products have been formulated.

Impact of uncertainties in free stream conditions on the aerodynamics of a rectangular cylinder

NASA Astrophysics Data System (ADS)

Mariotti, Alessandro; Shoeibi Omrani, Pejman; Witteveen, Jeroen; Salvetti, Maria Vittoria

2015-11-01

The BARC benchmark deals with the flow around a rectangular cylinder with chord-to-depth ratio equal to 5. This flow configuration is of practical interest for civil and industrial structures and it is characterized by massively separated flow and unsteadiness. In a recent review of BARC results, significant dispersion was observed both in experimental and numerical predictions of some flow quantities, which are extremely sensitive to various uncertainties, which may be present in experiments and simulations. Besides modeling and numerical errors, in simulations it is difficult to exactly reproduce the experimental conditions due to uncertainties in the set-up parameters, which sometimes cannot be exactly controlled or characterized. Probabilistic methods and URANS simulations are used to investigate the impact of the uncertainties in the following set-up parameters: the angle of incidence, the free stream longitudinal turbulence intensity and length scale. Stochastic collocation is employed to perform the probabilistic propagation of the uncertainty. The discretization and modeling errors are estimated by repeating the same analysis for different grids and turbulence models. The results obtained for different assumed PDF of the set-up parameters are also compared.

Development of a remote laser-induced breakdown spectroscopy system for investigation of calcified tissue samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hrdlicka, Ales; Prokes, Lubomir; Stankova, Alice

2010-05-01

The development of a remote laser-induced breakdown spectroscopy (LIBS) setup with an off-axis Newtonian collection optics, Galilean-based focusing telescope, and a 532 nm flattop laser beam source is presented. The device was tested at a 6 m distance on a slice of bone to simulate its possible use in the field, e.g., during archaeological excavations. It is shown that this setup is sufficiently sensitive to both major (P, Mg) and minor elements (Na, Zn, Sr). The measured quantities of Mg, Zn, and Sr correspond to the values obtained by reference laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) measurements within an approximatelymore » 20% range of uncertainty. A single point calibration was performed by use of a bone meal standard . The radial element distribution is almost invariable by use of LA-ICP-MS, whereas the LIBS measurement showed a strong dependence on the sample porosity. Based on these results, this remote LIBS setup with a relatively large (350 mm) collecting mirror is capable of semiquantitative analysis at the level of units of mg kg{sup -1}.« less

Preventive Visit and Yearly Wellness Exams

MedlinePlus

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Local Setup Reproducibility of the Spinal Column When Using Intensity-Modulated Radiation Therapy for Craniospinal Irradiation With Patient in Supine Position

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoiber, Eva Maria, E-mail: eva.stoiber@med.uni-heidelberg.de; Department of Medical Physics, German Cancer Research Center, Heidelberg; Giske, Kristina

Purpose: To evaluate local positioning errors of the lumbar spine during fractionated intensity-modulated radiotherapy of patients treated with craniospinal irradiation and to assess the impact of rotational error correction on these uncertainties for one patient setup correction strategy. Methods and Materials: 8 patients (6 adults, 2 children) treated with helical tomotherapy for craniospinal irradiation were retrospectively chosen for this analysis. Patients were immobilized with a deep-drawn Aquaplast head mask. Additionally to daily megavoltage control computed tomography scans of the skull, once-a-week positioning of the lumbar spine was assessed. Therefore, patient setup was corrected by a target point correction, derived frommore » a registration of the patient's skull. The residual positioning variations of the lumbar spine were evaluated applying a rigid-registration algorithm. The impact of different rotational error corrections was simulated. Results: After target point correction, residual local positioning errors of the lumbar spine varied considerably. Craniocaudal axis rotational error correction did not improve or deteriorate these translational errors, whereas simulation of a rotational error correction of the right-left and anterior-posterior axis increased these errors by a factor of 2 to 3. Conclusion: The patient fixation used allows for deformations between the patient's skull and spine. Therefore, for the setup correction strategy evaluated in this study, generous margins for the lumbar spinal target volume are needed to prevent a local geographic miss. With any applied correction strategy, it needs to be evaluated whether or not a rotational error correction is beneficial.« less

Personalized monitoring of therapeutic salicylic acid in dried blood spots using a three-layer setup and desorption electrospray ionization mass spectrometry.

PubMed

Siebenhaar, Markus; Küllmer, Kai; Fernandes, Nuno Miguel de Barros; Hüllen, Volker; Hopf, Carsten

2015-09-01

Desorption electrospray ionization (DESI) mass spectrometry is an emerging technology for direct therapeutic drug monitoring in dried blood spots (DBS). Current DBS methods require manual application of small molecules as internal standards for absolute drug quantification. With industrial standardization in mind, we superseded the manual addition of standard and built a three-layer setup for robust quantification of salicylic acid directly from DBS. We combined a dioctyl sodium sulfosuccinate weave facilitating sample spreading with a cellulose layer for addition of isotope-labeled salicylic acid as internal standard and a filter paper for analysis of the standard-containing sample by DESI-MS. Using this setup, we developed a quantification method for salicylic acid from whole blood with a validated linear curve range from 10 to 2000 mg/L, a relative standard deviation (RSD%) ≤14%, and determination coefficients of 0.997. The limit of detection (LOD) was 8 mg/L and the lower limit of quantification (LLOQ) was 10 mg/L. Recovery rates in method verification by LC-MS/MS were 97 to 101% for blinded samples. Most importantly, a study in healthy volunteers after administration of a single dose of Aspirin provides evidence to suggest that the three-layer setup may enable individual pharmacokinetic and endpoint testing following blood collection by finger pricking by patients at home. Taken together, our data suggests that DBS-based quantification of drugs by DESI-MS on pre-manufactured three-layer cartridges may be a promising approach for future near-patient therapeutic drug monitoring.

Recent developments in heterodyne laser interferometry at Harbin Institute of Technology

NASA Astrophysics Data System (ADS)

Hu, P. C.; Tan, J. B. B.; Yang, H. X. X.; Fu, H. J. J.; Wang, Q.

2013-01-01

In order to fulfill the requirements for high-resolution and high-precision heterodyne interferometric technologies and instruments, the laser interferometry group of HIT has developed some novel techniques for high-resolution and high-precision heterodyne interferometers, such as high accuracy laser frequency stabilization, dynamic sub-nanometer resolution phase interpolation and dynamic nonlinearity measurement. Based on a novel lock point correction method and an asymmetric thermal structure, the frequency stabilized laser achieves a long term stability of 1.2×10-8, and it can be steadily stabilized even in the air flowing up to 1 m/s. In order to achieve dynamic sub-nanometer resolution of laser heterodyne interferometers, a novel phase interpolation method based on digital delay line is proposed. Experimental results show that, the proposed 0.62 nm, phase interpolator built with a 64 multiple PLL and an 8-tap digital delay line achieves a static accuracy better than 0.31nm and a dynamic accuracy better than 0.62 nm over the velocity ranging from -2 m/s to 2 m/s. Meanwhile, an accuracy beam polarization measuring setup is proposed to check and ensure the light's polarization state of the dual frequency laser head, and a dynamic optical nonlinearity measuring setup is built to measure the optical nonlinearity of the heterodyne system accurately and quickly. Analysis and experimental results show that, the beam polarization measuring setup can achieve an accuracy of 0.03° in ellipticity angles and an accuracy of 0.04° in the non-orthogonality angle respectively, and the optical nonlinearity measuring setup can achieve an accuracy of 0.13°.

In vivo stimulus presentation to the mouse vomeronasal system: Surgery, experiment, setup, and software.

PubMed

Yoles-Frenkel, Michal; Cohen, Oksana; Bansal, Rohini; Horesh, Noa; Ben-Shaul, Yoram

2017-06-15

Achieving controlled stimulus delivery is a major challenge in the physiological analysis of the vomeronasal system (VNS). We provide a comprehensive description of a setup allowing controlled stimulus delivery into the vomeronasal organ (VNO) of anesthetized mice. VNO suction is achieved via electrical stimulation of the sympathetic nerve trunk (SNT) using cuff electrodes, followed by flushing of the nasal cavity. Successful application of this methodology depends on several aspects including the surgical preparation, fabrication of cuff electrodes, experimental setup modifications, and the stimulus delivery and flushing. Here, we describe all these aspects in sufficient detail to allow other researchers to readily adopt it. We also present a custom written MATLAB based software with a graphical user interface that controls all aspects of the actual experiment, including trial sequencing, hardware control, and data logging. The method allows measurement of stimulus evoked sensory responses in brain regions that receive vomeronasal inputs. An experienced investigator can complete the entire surgical procedure within thirty minutes. This is the only approach that allows repeated and controlled stimulus delivery to the intact VNO, employing the natural mode of stimulus uptake. The approach is economical with respect to stimuli, requiring stimulus volumes as low as 1-2μl. This comprehensive description will allow other investigators to adapt this setup to their own experimental needs and can thus promote our physiological understanding of this fascinating chemosensory system. With minor changes it can also be adapted for other rodent species. Copyright © 2017 Elsevier B.V. All rights reserved.

Measurement of electromagnetic tracking error in a navigated breast surgery setup

NASA Astrophysics Data System (ADS)

Harish, Vinyas; Baksh, Aidan; Ungi, Tamas; Lasso, Andras; Baum, Zachary; Gauvin, Gabrielle; Engel, Jay; Rudan, John; Fichtinger, Gabor

2016-03-01

PURPOSE: The measurement of tracking error is crucial to ensure the safety and feasibility of electromagnetically tracked, image-guided procedures. Measurement should occur in a clinical environment because electromagnetic field distortion depends on positioning relative to the field generator and metal objects. However, we could not find an accessible and open-source system for calibration, error measurement, and visualization. We developed such a system and tested it in a navigated breast surgery setup. METHODS: A pointer tool was designed for concurrent electromagnetic and optical tracking. Software modules were developed for automatic calibration of the measurement system, real-time error visualization, and analysis. The system was taken to an operating room to test for field distortion in a navigated breast surgery setup. Positional and rotational electromagnetic tracking errors were then calculated using optical tracking as a ground truth. RESULTS: Our system is quick to set up and can be rapidly deployed. The process from calibration to visualization also only takes a few minutes. Field distortion was measured in the presence of various surgical equipment. Positional and rotational error in a clean field was approximately 0.90 mm and 0.31°. The presence of a surgical table, an electrosurgical cautery, and anesthesia machine increased the error by up to a few tenths of a millimeter and tenth of a degree. CONCLUSION: In a navigated breast surgery setup, measurement and visualization of tracking error defines a safe working area in the presence of surgical equipment. Our system is available as an extension for the open-source 3D Slicer platform.

Brillouin Optical Correlation Domain Analysis in Composite Material Beams

PubMed Central

Stern, Yonatan; London, Yosef; Preter, Eyal; Antman, Yair; Diamandi, Hilel Hagai; Silbiger, Maayan; Adler, Gadi; Shalev, Doron; Zadok, Avi

2017-01-01

Structural health monitoring is a critical requirement in many composites. Numerous monitoring strategies rely on measurements of temperature or strain (or both), however these are often restricted to point-sensing or to the coverage of small areas. Spatially-continuous data can be obtained with optical fiber sensors. In this work, we report high-resolution distributed Brillouin sensing over standard fibers that are embedded in composite structures. A phase-coded, Brillouin optical correlation domain analysis (B-OCDA) protocol was employed, with spatial resolution of 2 cm and sensitivity of 1 °K or 20 micro-strain. A portable measurement setup was designed and assembled on the premises of a composite structures manufacturer. The setup was successfully utilized in several structural health monitoring scenarios: (a) monitoring the production and curing of a composite beam over 60 h; (b) estimating the stiffness and Young’s modulus of a composite beam; and (c) distributed strain measurements across the surfaces of a model wing of an unmanned aerial vehicle. The measurements are supported by the predictions of structural analysis calculations. The results illustrate the potential added values of high-resolution, distributed Brillouin sensing in the structural health monitoring of composites. PMID:28974041

Extending the application of DSAM to atypical stopping media

NASA Astrophysics Data System (ADS)

Das, S.; Samanta, S.; Bhattacharjee, R.; Raut, R.; Ghugre, S. S.; Sinha, A. K.; Garg, U.; Chakrabarti, R.; Mukhopadhyay, S.; Dhal, A.; Raju, M. Kumar; Madhavan, N.; Muralithar, S.; Singh, R. P.; Suryanarayana, K.; Rao, P. V. Madhusudhana; Palit, R.; Saha, S.; Sethi, J.

2017-01-01

A methodology that manifolds the possibilities of level lifetime measurements using the Doppler Shift Attenuation Method (DSAM), and extends its application beyond the conventional thin-target-on-thick-elemental-backing setups, is presented. This has been achieved primarily through application of the TRIM code to simulate the stopping of the recoils in the target and the backing media. Using the TRIM code, primarily adopted in the domain of materials research, in the context of lifetime analysis require rendition of the simulation results into a representation that appropriately incorporates the nuances of nuclear reaction along with the associated kinematics, besides the transformation from an energy-coordinate representation to a velocity-direction profile as required for lifetime analysis. The present development makes it possible to practice DSAM in atypical experimental scenarios such as those using molecular or multi-layered target and/or backing as the stopping medium. These aberrant cases, that were beyond representation in the customary Doppler shape analysis can, in the light of the present work, be conveniently used in the DSAM based investigations. The new approach has been validated through re-examination of known lifetimes measured both in the conventional as well as in the deviant setups.

Brillouin Optical Correlation Domain Analysis in Composite Material Beams.

PubMed

Stern, Yonatan; London, Yosef; Preter, Eyal; Antman, Yair; Diamandi, Hilel Hagai; Silbiger, Maayan; Adler, Gadi; Levenberg, Eyal; Shalev, Doron; Zadok, Avi

2017-10-02

Structural health monitoring is a critical requirement in many composites. Numerous monitoring strategies rely on measurements of temperature or strain (or both), however these are often restricted to point-sensing or to the coverage of small areas. Spatially-continuous data can be obtained with optical fiber sensors. In this work, we report high-resolution distributed Brillouin sensing over standard fibers that are embedded in composite structures. A phase-coded, Brillouin optical correlation domain analysis (B-OCDA) protocol was employed, with spatial resolution of 2 cm and sensitivity of 1 °K or 20 micro-strain. A portable measurement setup was designed and assembled on the premises of a composite structures manufacturer. The setup was successfully utilized in several structural health monitoring scenarios: (a) monitoring the production and curing of a composite beam over 60 h; (b) estimating the stiffness and Young's modulus of a composite beam; and (c) distributed strain measurements across the surfaces of a model wing of an unmanned aerial vehicle. The measurements are supported by the predictions of structural analysis calculations. The results illustrate the potential added values of high-resolution, distributed Brillouin sensing in the structural health monitoring of composites.

Laser-Based Measurement of Refractive Index Changes: Kinetics of 2,3-Epoxy-1-propanol Hydrolysis.

ERIC Educational Resources Information Center

Spencer, Bert; Zare, Richard N.

1988-01-01

Describes an experiment in which a simple laser-based apparatus is used for measuring the change in refractive index during the acid-catalyzed hydrolysis of glycidol into glycerine. Gives a schematic of the experimental setup and discusses the kinetic analysis. (MVL)

Velocity Plume Profiles for Hall Thrusters Using Laser Diagnostic

DTIC Science & Technology

2010-06-01

53 Collecting LIF Using Fiber Optics .............................................................................58 Vacuum ...54 Figure 40. Etalon Issue Through Vacuum Chamber Window [25]. ................................. 55 Figure 41. Collimator with Adapter in a...Methodology Facility Set-up Vacuum Chamber Testing took place within a vacuum chamber located at the AFIT Space Propulsion Analysis and System Simulation

Common Ada Programming Support Environment (APSE) Interface Set (CAIS) Implementation Validation Capability (CIVC2)

DTIC Science & Technology

1992-06-01

Paper, Version 2.0, December 1989. [Woodcock90] Gary Woodcock , Automated Generation of Hypertext Documents, CIVC Technical Report (working paper...environment setup, performance testing, assessor testing, and analysis) of the ACEC. A captive scenario example could be developed that would guide the

Performance Analysis of the HTTP Protocol on Geostationary Satellite Links

NASA Technical Reports Server (NTRS)

Krus, Hans; Allman, Mark; Griner, Jim; Tran, Diepchi

1998-01-01

Various issues associated with HTTP protocol on geostationary satellite links are presented in viewgraph form. Specific topics include: 1) Network reference points; 2) The HTTP 1.0 and 1.1 mechanisms; 3) Experimental setup; 4) TCP and HTTP configuration; 5) Modelling slow start and 6) Results and future work.

Why the Weak Win Wars: A Study of the Factors That Drive Strategy in Asymmetric Conflict

DTIC Science & Technology

2009-12-01

Armour Press, 1998), 49. 171 Tilford, Setup: What the Air Force did in Vietnam and Why, 234. 172 Ibid., 238. 67...North Vietnam, 1972. London: Arms & Armour Press, 1998. Summers, Harry G. On Strategy: A Critical Analysis of the Vietnam War. Novato, CA

An Introduction to Fast Fourier Transforms through the Study of Oscillating Reactions.

ERIC Educational Resources Information Center

Eastman, M. P.; And Others

1986-01-01

Discusses an experiment designed to introduce students to the basic principles of the fast Fourier transform and Fourier smoothing through transformation of time-dependent optical absorption data from an oscillating reaction. Uses the Belousov-Zhabotinskii reaction. Describes the experimental setup and data analysis techniques.

Meta-analysis as a tool to study crop productivity response to poultry litter application

USDA-ARS?s Scientific Manuscript database

Extensive research on the use of poultry litter (PL) under different agricultural practices in the USA has shown both negative and positive effects on crop productivity (either yield or aboveground biomass). However, these experimental results are substantially dependent on the experimental set-up, ...

Marathon Group Therapy: Potential for University Counseling Centers and Beyond

ERIC Educational Resources Information Center

Stanger, Thomas; Harris, Rafael S., Jr.

2005-01-01

A descriptive analysis of marathon group therapy was conducted, specifying issues of set-up, screening, preparation, start-up, introduction to group process, facilitating therapeutic moments throughout the weekend, termination, and follow-up. Factors and dynamics unique to this modality are outlined for marathon groups in university counseling…

Safety review package for University of Central Florida flat-plate heat pipe experiment

NASA Technical Reports Server (NTRS)

Chow, Louis C.

1998-01-01

A flat-plate heat pipe (FPHP) experiment has been set up for micro-gravity tests on a NASA supplied aircraft. This report presents an analysis on various components of the experimental setup to certify that it will satisfy the flight safety and operation requirements.

The TROPOMI Telescope

NASA Astrophysics Data System (ADS)

Nijkerk, David; van Venrooy, Bart; Van Doorn, Peter; Henselmans, Rens; Draaisma, Folkert; Hoogstrate, André

2017-11-01

In this paper, we discuss the two-mirror pushbroom telescope for TROPOMI. Using freeform optics, it has unprecedented resolution. The complete cycle of freeform optical design, analysis, manufacturing, metrology and functional test on a breadboard setup is described, focusing on the specific complexities concerning freeforms. The TROPOMI flight telescope will be manufactured in summer 2012.

Functional materials analysis using in situ and in operando X-ray and neutron scattering

PubMed Central

Peterson, Vanessa K.; Papadakis, Christine M.

2015-01-01

In situ and in operando studies are commonplace and necessary in functional materials research. This review highlights recent developments in the analysis of functional materials using state-of-the-art in situ and in operando X-ray and neutron scattering and analysis. Examples are given covering a number of important materials areas, alongside a description of the types of information that can be obtained and the experimental setups used to acquire them. PMID:25866665

Cavity-Enhanced Raman Spectroscopy for Food Chain Management

PubMed Central

Sandfort, Vincenz; Goldschmidt, Jens; Wöllenstein, Jürgen

2018-01-01

Comprehensive food chain management requires the monitoring of many parameters including temperature, humidity, and multiple gases. The latter is highly challenging because no low-cost technology for the simultaneous chemical analysis of multiple gaseous components currently exists. This contribution proposes the use of cavity enhanced Raman spectroscopy to enable online monitoring of all relevant components using a single laser source. A laboratory scale setup is presented and characterized in detail. Power enhancement of the pump light is achieved in an optical resonator with a Finesse exceeding 2500. A simulation for the light scattering behavior shows the influence of polarization on the spatial distribution of the Raman scattered light. The setup is also used to measure three relevant showcase gases to demonstrate the feasibility of the approach, including carbon dioxide, oxygen and ethene. PMID:29495501

Data acquisition system for the socal plane detector of the mass separator MASHA

NASA Astrophysics Data System (ADS)

Novoselov, A. S.; Rodin, A. M.; Motycak, S.; Podshibyakin, A. V.; Krupa, L.; Belozerov, A. V.; Vedeneyev, V. Yu.; Gulyaev, A. V.; Gulyaeva, A. V.; Kliman, J.; Salamatin, V. S.; Stepantsov, S. V.; Chernysheva, E. V.; Yukhimchuk, S. A.; Komarov, A. B.; Kamas, D.

2016-09-01

The results of the development and the general information about the data acquisition system which was recently created at the MASHA setup (Flerov laboratory of nuclear reactions at Joint institute for nuclear research) are presented. The main difference from the previous system is that we use a new modern platform, National Instruments PXI with XIA multichannel high-speed digitizers (250 MHz 12 bit 16 channels). At this moment system has 448 spectrometric channels. The software and its features for the data acquisition and analysis are also described. The new DAQ system expands precision measuring capabilities of alpha decays and spontaneous fission at the focal plane position-sensitive silicon strip detector which, in turn, increases the capabilities of the setup in such a field as low-yield registration of elements.

Experimental investigation of the flow dynamics and rheology of complex fluids in pipe flow by hybrid multi-scale velocimetry

NASA Astrophysics Data System (ADS)

Haavisto, Sanna; Cardona, Maria J.; Salmela, Juha; Powell, Robert L.; McCarthy, Michael J.; Kataja, Markku; Koponen, Antti I.

2017-11-01

A hybrid multi-scale velocimetry method utilizing Doppler optical coherence tomography in combination with either magnetic resonance imaging or ultrasound velocity profiling is used to investigate pipe flow of four rheologically different working fluids under varying flow regimes. These fluids include water, an aqueous xanthan gum solution, a softwood fiber suspension, and a microfibrillated cellulose suspension. The measurement setup enables not only the analysis of the rheological (bulk) behavior of a studied fluid but gives simultaneously information on their wall layer dynamics, both of which are needed for analyzing and solving practical fluid flow-related problems. Preliminary novel results on rheological and boundary layer flow properties of the working fluids are reported and the potential of the hybrid measurement setup is demonstrated.

Fabrication of optical microlenses by a new inkjet printing technique based on pyro-electrohydrodynamic (PEHD) effect

NASA Astrophysics Data System (ADS)

Coppola, S.; Vespini, V.; Grimaldi, I. A.; Loffredo, F.; Villani, F.; Miccio, L.; Grilli, S.; Ferraro, P.

2012-06-01

Here the pyroelectric functionality of a Lithium Niobate (LN) substrate is used for non-contact manipulation of liquids. In this work we introduced the use of a pyro-electrohydrodynamc (PEHD) dispenser for the manipulation of high viscous polymer materials leading to the fabrication of arrays of microlenses. The set-up used for the experiment is described and the fabricated microlenses are analyzed by means of the Digital Holography (DH) set-up in transmission mode and through profilometric analysis. PMMA based ink was employed for the realization of optical quality microsctructures whose geometrical properties and, hence, the focal lengths were controlled by modifying the printing configuration of the PEHD method. The profilometric results are in agreement with those calculated using the digital holography technique.

A computational analysis of lower bounds for the economic lot sizing problem in remanufacturing with separate setups

NASA Astrophysics Data System (ADS)

Aishah Syed Ali, Sharifah

2017-09-01

This paper considers economic lot sizing problem in remanufacturing with separate setup (ELSRs), where remanufactured and new products are produced on dedicated production lines. Since this problem is NP-hard in general, which leads to computationally inefficient and low-quality of solutions, we present (a) a multicommodity formulation and (b) a strengthened formulation based on a priori addition of valid inequalities in the space of original variables, which are then compared with the Wagner-Whitin based formulation available in the literature. Computational experiments on a large number of test data sets are performed to evaluate the different approaches. The numerical results show that our strengthened formulation outperforms all the other tested approaches in terms of linear relaxation bounds. Finally, we conclude with future research directions.

Multiqubit subradiant states in N -port waveguide devices: ɛ-and-μ-near-zero hubs and nonreciprocal circulators

NASA Astrophysics Data System (ADS)

Liberal, Iñigo; Engheta, Nader

2018-02-01

Quantum emitters interacting through a waveguide setup have been proposed as a promising platform for basic research on light-matter interactions and quantum information processing. We propose to augment waveguide setups with the use of multiport devices. Specifically, we demonstrate theoretically the possibility of exciting N -qubit subradiant, maximally entangled, states with the use of suitably designed N -port devices. Our general methodology is then applied based on two different devices: an epsilon-and-mu-near-zero waveguide hub and a nonreciprocal circulator. A sensitivity analysis is carried out to assess the robustness of the system against a number of nonidealities. These findings link and merge the designs of devices for quantum state engineering with classical communication network methodologies.

Wave setup over a Pacific Island fringing reef

NASA Astrophysics Data System (ADS)

Vetter, O.; Becker, J. M.; Merrifield, M. A.; Pequignet, A.-C.; Aucan, J.; Boc, S. J.; Pollock, C. E.

2010-12-01

Measurements obtained across a shore-attached, fringing reef on the southeast coast of the island of Guam are examined to determine the relationship between incident waves and wave-driven setup during storm and nonstorm conditions. Wave setup on the reef flat correlates well (r > 0.95) and scales near the shore as approximately 35% of the incident root mean square wave height in 8 m water depth. Waves generated by tropical storm Man-Yi result in a 1.3 m setup during the peak of the storm. Predictions based on traditional setup theory (steady state, inviscid cross-shore momentum and depth-limited wave breaking) and an idealized model of localized wave breaking at the fore reef are in agreement with the observations. The reef flat setup is used to estimate a similarity parameter at breaking that is in agreement with observations from a steeply sloping sandy beach. A weak (˜10%) increase in setup is observed across the reef flat during wave events. The inclusion of bottom stress in the cross-shore momentum balance may account for a portion of this signal, but this assessment is inconclusive as the reef flat currents in some cases are in the wrong direction to account for the increase. An independent check of fringing reef setup dynamics is carried out for measurements at the neighboring island of Saipan with good agreement.

On-Line Use of Three-Dimensional Marker Trajectory Estimation From Cone-Beam Computed Tomography Projections for Precise Setup in Radiotherapy for Targets With Respiratory Motion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Worm, Esben S., E-mail: esbeworm@rm.dk; Department of Medical Physics, Aarhus University Hospital, Aarhus; Hoyer, Morten

2012-05-01

Purpose: To develop and evaluate accurate and objective on-line patient setup based on a novel semiautomatic technique in which three-dimensional marker trajectories were estimated from two-dimensional cone-beam computed tomography (CBCT) projections. Methods and Materials: Seven treatment courses of stereotactic body radiotherapy for liver tumors were delivered in 21 fractions in total to 6 patients by a linear accelerator. Each patient had two to three gold markers implanted close to the tumors. Before treatment, a CBCT scan with approximately 675 two-dimensional projections was acquired during a full gantry rotation. The marker positions were segmented in each projection. From this, the three-dimensionalmore » marker trajectories were estimated using a probability based method. The required couch shifts for patient setup were calculated from the mean marker positions along the trajectories. A motion phantom moving with known tumor trajectories was used to examine the accuracy of the method. Trajectory-based setup was retrospectively used off-line for the first five treatment courses (15 fractions) and on-line for the last two treatment courses (6 fractions). Automatic marker segmentation was compared with manual segmentation. The trajectory-based setup was compared with setup based on conventional CBCT guidance on the markers (first 15 fractions). Results: Phantom measurements showed that trajectory-based estimation of the mean marker position was accurate within 0.3 mm. The on-line trajectory-based patient setup was performed within approximately 5 minutes. The automatic marker segmentation agreed with manual segmentation within 0.36 {+-} 0.50 pixels (mean {+-} SD; pixel size, 0.26 mm in isocenter). The accuracy of conventional volumetric CBCT guidance was compromised by motion smearing ({<=}21 mm) that induced an absolute three-dimensional setup error of 1.6 {+-} 0.9 mm (maximum, 3.2) relative to trajectory-based setup. Conclusions: The first on-line clinical use of trajectory estimation from CBCT projections for precise setup in stereotactic body radiotherapy was demonstrated. Uncertainty in the conventional CBCT-based setup procedure was eliminated with the new method.« less

Optimization-based manufacturing scheduling with multiple resources and setup requirements

NASA Astrophysics Data System (ADS)

Chen, Dong; Luh, Peter B.; Thakur, Lakshman S.; Moreno, Jack, Jr.

1998-10-01

The increasing demand for on-time delivery and low price forces manufacturer to seek effective schedules to improve coordination of multiple resources and to reduce product internal costs associated with labor, setup and inventory. This study describes the design and implementation of a scheduling system for J. M. Product Inc. whose manufacturing is characterized by the need to simultaneously consider machines and operators while an operator may attend several operations at the same time, and the presence of machines requiring significant setup times. The scheduling problem with these characteristics are typical for many manufacturers, very difficult to be handled, and have not been adequately addressed in the literature. In this study, both machine and operators are modeled as resources with finite capacities to obtain efficient coordination between them, and an operator's time can be shared by several operations at the same time to make full use of the operator. Setups are explicitly modeled following our previous work, with additional penalties on excessive setups to reduce setup costs and avoid possible scraps. An integer formulation with a separable structure is developed to maximize on-time delivery of products, low inventory and small number of setups. Within the Lagrangian relaxation framework, the problem is decomposed into individual subproblems that are effectively solved by using dynamic programming with additional penalties embedded in state transitions. Heuristics is then developed to obtain a feasible schedule following on our previous work with new mechanism to satisfy operator capacity constraints. The method has been implemented using the object-oriented programming language C++ with a user-friendly interface, and numerical testing shows that the method generates high quality schedules in a timely fashion. Through simultaneous consideration of machines and operators, machines and operators are well coordinated to facilitate the smooth flow of parts through the system. The explicit modeling of setups and the associated penalties let parts with same setup requirements clustered together to avoid excessive setups.

Effect of patient setup errors on simultaneously integrated boost head and neck IMRT treatment plans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siebers, Jeffrey V.; Keall, Paul J.; Wu Qiuwen

2005-10-01

Purpose: The purpose of this study is to determine dose delivery errors that could result from random and systematic setup errors for head-and-neck patients treated using the simultaneous integrated boost (SIB)-intensity-modulated radiation therapy (IMRT) technique. Methods and Materials: Twenty-four patients who participated in an intramural Phase I/II parotid-sparing IMRT dose-escalation protocol using the SIB treatment technique had their dose distributions reevaluated to assess the impact of random and systematic setup errors. The dosimetric effect of random setup error was simulated by convolving the two-dimensional fluence distribution of each beam with the random setup error probability density distribution. Random setup errorsmore » of {sigma} = 1, 3, and 5 mm were simulated. Systematic setup errors were simulated by randomly shifting the patient isocenter along each of the three Cartesian axes, with each shift selected from a normal distribution. Systematic setup error distributions with {sigma} = 1.5 and 3.0 mm along each axis were simulated. Combined systematic and random setup errors were simulated for {sigma} = {sigma} = 1.5 and 3.0 mm along each axis. For each dose calculation, the gross tumor volume (GTV) received by 98% of the volume (D{sub 98}), clinical target volume (CTV) D{sub 90}, nodes D{sub 90}, cord D{sub 2}, and parotid D{sub 50} and parotid mean dose were evaluated with respect to the plan used for treatment for the structure dose and for an effective planning target volume (PTV) with a 3-mm margin. Results: Simultaneous integrated boost-IMRT head-and-neck treatment plans were found to be less sensitive to random setup errors than to systematic setup errors. For random-only errors, errors exceeded 3% only when the random setup error {sigma} exceeded 3 mm. Simulated systematic setup errors with {sigma} = 1.5 mm resulted in approximately 10% of plan having more than a 3% dose error, whereas a {sigma} = 3.0 mm resulted in half of the plans having more than a 3% dose error and 28% with a 5% dose error. Combined random and systematic dose errors with {sigma} = {sigma} = 3.0 mm resulted in more than 50% of plans having at least a 3% dose error and 38% of the plans having at least a 5% dose error. Evaluation with respect to a 3-mm expanded PTV reduced the observed dose deviations greater than 5% for the {sigma} = {sigma} = 3.0 mm simulations to 5.4% of the plans simulated. Conclusions: Head-and-neck SIB-IMRT dosimetric accuracy would benefit from methods to reduce patient systematic setup errors. When GTV, CTV, or nodal volumes are used for dose evaluation, plans simulated including the effects of random and systematic errors deviate substantially from the nominal plan. The use of PTVs for dose evaluation in the nominal plan improves agreement with evaluated GTV, CTV, and nodal dose values under simulated setup errors. PTV concepts should be used for SIB-IMRT head-and-neck squamous cell carcinoma patients, although the size of the margins may be less than those used with three-dimensional conformal radiation therapy.« less

Feedforward operation of a lens setup for large defocus and astigmatism correction

NASA Astrophysics Data System (ADS)

Verstraete, Hans R. G. W.; Almasian, MItra; Pozzi, Paolo; Bilderbeek, Rolf; Kalkman, Jeroen; Faber, Dirk J.; Verhaegen, Michel

2016-04-01

In this manuscript, we present a lens setup for large defocus and astigmatism correction. A deformable defocus lens and two rotational cylindrical lenses are used to control the defocus and astigmatism. The setup is calibrated using a simple model that allows the calculation of the lens inputs so that a desired defocus and astigmatism are actuated on the eye. The setup is tested by determining the feedforward prediction error, imaging a resolution target, and removing introduced aberrations.

Laser-induced transient grating setup with continuously tunable period

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vega-Flick, A.; Applied Physics Department, CINVESTAV-Unidad Mérida, Carretera Antigua a Progreso Km 6, Cordemex, Mérida, Yucatán 97310 Mexico; Eliason, J. K.

2015-12-15

We present a modification of the laser-induced transient grating setup enabling continuous tuning of the transient grating period. The fine control of the period is accomplished by varying the angle of the diffraction grating used to split excitation and probe beams. The setup has been tested by measuring dispersion of bulk and surface acoustic waves in both transmission and reflection geometries. The presented modification is fully compatible with optical heterodyne detection and can be easily implemented in any transient grating setup.

Pragmatic setup for bioparticle responses by dielectrophoresis for resource limited environment application

NASA Astrophysics Data System (ADS)

Ali, Mohd Anuar Md; Yeop Majlis, Burhanuddin; Kayani, Aminuddin Ahmad

2017-12-01

Various dielectrophoretic responses of bioparticles, including cell-chain, spinning, rotation and clustering, are of high interest in the field due to their benefit into application for biomedical and clinical implementation potential. Numerous attempts using sophisticated equipment setup have been studied to perform those dielectrophoretic responses, however, for development into resource limited environment application, such as portable, sustainable and environmental friendly diagnostic tools, establishment of pragmatic setup using standard, non-sophisticated and low-cost equipment is of important task. Here we show the advantages in the judicious design optimization of tip microelectrode, also with selection of suspending medium and optimization of electric signal configuration in establishing setup that can promote the aforementioned dielectrophoretic responses within standard equipments, i.e. pragmatic setup.

Noiseless amplification of weak coherent fields exploiting energy fluctuations of the field

NASA Astrophysics Data System (ADS)

Partanen, Mikko; Häyrynen, Teppo; Oksanen, Jani; Tulkki, Jukka

2012-12-01

Quantum optics dictates that amplification of a pure state by any linear deterministic amplifier always introduces noise in the signal and results in a mixed output state. However, it has recently been shown that noiseless amplification becomes possible if the requirement of a deterministic operation is relaxed. Here we propose and analyze a noiseless amplification scheme where the energy required to amplify the signal originates from the stochastic fluctuations in the field itself. In contrast to previous amplification setups, our setup shows that a signal can be amplified even if no energy is added to the signal from external sources. We investigate the relation between the amplification and its success rate as well as the statistics of the output states after successful and failed amplification processes. Furthermore, we also optimize the setup to find the maximum success rates in terms of the reflectivities of the beam splitters used in the setup and discuss the relation of our setup with the previous setups.

Combinatorial preparation and characterization of thin-film multilayer electro-optical devices.

PubMed

Neuber, Christian; Bäte, Markus; Thelakkat, Mukundan; Schmidt, Hans-Werner; Hänsel, Helmut; Zettl, Heiko; Krausch, Georg

2007-07-01

In this article we present a setup for the combinatorial vapor deposition of thin-film multilayer devices as well as methods for the fast and efficient analytic screening of the libraries obtained. The preparation setup is based on a commercially available evaporation chamber equipped with various evaporation sources for both organic and metallic materials. The combinatorial approach is realized by the combination of a rotation stage for the substrate, a five-mask sampler, and an additional mask whose position can be deliberately varied along one axis during the evaporation process. The latter is used to evaporate linear as well as step gradients by continuous or stepwise movement of a shutter mask. The mask sampler allows to define the sectors of the library and to evaporate more complex structures, e.g., an electrode layout. Finally, the simultaneous evaporation of two or more materials enables us to produce layers of varying composition ratio in general and doped materials, in particular. For the control of the evaporation process we have developed an automation software, which is particularly helpful for complex library designs and which grants excellent repeatability of experiments. Efficient and fast characterization of the obtained libraries is realized by (i) a purely optical setup and (ii) an electro-optical setup. (i) The UV/vis reader FLASHScan 530 permits to map out the UV/vis absorbance or fluorescence of the whole library. The UV/vis absorbance is primarily used to determine layer thicknesses and to confirm thickness uniformity across larger regions. The fluorescence measurements are used to determine the composition of layers containing fluorescent dyes. (ii) For a detailed short- and long-term electro-optical analysis we have developed an automated measurement system, which allows the characterization of 8x8 optoelectronic devices and to study their degradation behavior. Both solar cells and organic light-emitting diodes can be tested. Finally, we have developed a data analysis software to extract characteristic values from the huge amount of data and with this facilitate the finding of systematic dependencies.

ANALYSIS OF STANDARD MULTI-PORT VS. SINGLE SITE ACCESS FOR LAPAROSCOPIC SKILLS TRAINING

PubMed Central

Cox, Daniel R; Zeng, Wenjing; Frisella, Margaret M; Brunt, L. Michael

2015-01-01

Introduction Single site access (SSA) laparoscopy is more challenging to perform than multi-port(MP) laparoscopy. We examined MP versus SSA skills training on laparoscopic performance in surgically naive individuals. Methods Forty end-of-1st year medical students were randomized into two groups. Both were trained on 4 basic laparoscopic drills (peg, rope, bean drop, pattern cutting) using a standard MP setup (Group 1) or SSA approach (Group 2). Time to proficiency and number of repetitions (reps) were recorded. Each group then crossed over to the alternate approach where the sequence was repeated. Data are mean ± SD and statistical analysis was with two-tailed, unpaired t-test. Results Total times to proficiency for the SSA and MP approaches was not significantly different between groups (Group 1 M-P 234.0 ± 114.9 min vs Group 2 SSA 216.4 ± 106.5 min, p=0.67). The MP-trained group took less time to reach proficiency on the standard MP setup than the SSA group on the SSA approach (119.1 ± 69.7 min vs 178.0 ± 93.4 min, p=0.058) with significantly fewer repetitions (77.6 ± 42.6 vs. 118.8 ± 54.3, p=0.027). The SSA-trained group took significantly less time to reach proficiency on the MP setup than the standard MP-trained group (38.4 ± 29.4 min vs. 119.1 ± 69.7 min; p=0.0013) requiring only a mean of 26.9 total repetitions. When the standard MP group crossed over to the SSA setup, they took significantly less time to reach proficiency with the SSA approach than the SSA-trained group (114.8 ± 50.5 min vs. 178.0 ± 93.4 min, p=0.026) but with more total repetitions than with the M-P approach (86.2 ± 35.2 vs 77.6 ± 42.6, p= NS). Conclusions Laparoscopic single site access skills training results in longer times and more repetitions to achieve proficiency than multi-port training, but the skills acquired transfer well to the multi-port approach. PMID:20872019

Modeling the Total Dose Radiation Effects of Hg(1-x)Cd(x)Te Photodiodes Using Numerical Device Simulators

DTIC Science & Technology

1994-01-01

Dosimetry : Analysis of dosimetry in two dewar/liquid nitrogen systems. TIME Estimate: One hour for setup, irradiation and TLD reading/analysis. IV...point indicates both electron and hole trapping at the boundary ........................ 12 3.3 Relationship between current and dose for irradiated...peak value. Carriers are collected across the vertical junction within a diffusion length. Since the electron diffusion length is much larger than for

Code-switched English Pronunciation Modeling for Swahili Spoken Term Detection (Pub Version, Open Access)

DTIC Science & Technology

2016-05-03

using additional English resources. 2. Background The Babel program1 is an international collaborative effort sponsored by the US Intelligence Advanced...phenomenon is not as well studied for English / African language pairs, but some results are available8,9. 3. Experimental Setup The Swahili analysis...word pronunciations. From the analysis it was concluded that in most cases English words were pronounced using standard English letter-to-sound rules

Measuring uncertainty in dose delivered to the cochlea due to setup error during external beam treatment of patients with cancer of the head and neck.

PubMed

Yan, M; Lovelock, D; Hunt, M; Mechalakos, J; Hu, Y; Pham, H; Jackson, A

2013-12-01

To use Cone Beam CT scans obtained just prior to treatments of head and neck cancer patients to measure the setup error and cumulative dose uncertainty of the cochlea. Data from 10 head and neck patients with 10 planning CTs and 52 Cone Beam CTs taken at time of treatment were used in this study. Patients were treated with conventional fractionation using an IMRT dose painting technique, most with 33 fractions. Weekly radiographic imaging was used to correct the patient setup. The authors used rigid registration of the planning CT and Cone Beam CT scans to find the translational and rotational setup errors, and the spatial setup errors of the cochlea. The planning CT was rotated and translated such that the cochlea positions match those seen in the cone beam scans, cochlea doses were recalculated and fractional doses accumulated. Uncertainties in the positions and cumulative doses of the cochlea were calculated with and without setup adjustments from radiographic imaging. The mean setup error of the cochlea was 0.04 ± 0.33 or 0.06 ± 0.43 cm for RL, 0.09 ± 0.27 or 0.07 ± 0.48 cm for AP, and 0.00 ± 0.21 or -0.24 ± 0.45 cm for SI with and without radiographic imaging, respectively. Setup with radiographic imaging reduced the standard deviation of the setup error by roughly 1-2 mm. The uncertainty of the cochlea dose depends on the treatment plan and the relative positions of the cochlea and target volumes. Combining results for the left and right cochlea, the authors found the accumulated uncertainty of the cochlea dose per fraction was 4.82 (0.39-16.8) cGy, or 10.1 (0.8-32.4) cGy, with and without radiographic imaging, respectively; the percentage uncertainties relative to the planned doses were 4.32% (0.28%-9.06%) and 10.2% (0.7%-63.6%), respectively. Patient setup error introduces uncertainty in the position of the cochlea during radiation treatment. With the assistance of radiographic imaging during setup, the standard deviation of setup error reduced by 31%, 42%, and 54% in RL, AP, and SI direction, respectively, and consequently, the uncertainty of the mean dose to cochlea reduced more than 50%. The authors estimate that the effects of these uncertainties on the probability of hearing loss for an individual patient could be as large as 10%.

Measuring uncertainty in dose delivered to the cochlea due to setup error during external beam treatment of patients with cancer of the head and neck

PubMed Central

Yan, M.; Lovelock, D.; Hunt, M.; Mechalakos, J.; Hu, Y.; Pham, H.; Jackson, A.

2013-01-01

Purpose: To use Cone Beam CT scans obtained just prior to treatments of head and neck cancer patients to measure the setup error and cumulative dose uncertainty of the cochlea. Methods: Data from 10 head and neck patients with 10 planning CTs and 52 Cone Beam CTs taken at time of treatment were used in this study. Patients were treated with conventional fractionation using an IMRT dose painting technique, most with 33 fractions. Weekly radiographic imaging was used to correct the patient setup. The authors used rigid registration of the planning CT and Cone Beam CT scans to find the translational and rotational setup errors, and the spatial setup errors of the cochlea. The planning CT was rotated and translated such that the cochlea positions match those seen in the cone beam scans, cochlea doses were recalculated and fractional doses accumulated. Uncertainties in the positions and cumulative doses of the cochlea were calculated with and without setup adjustments from radiographic imaging. Results: The mean setup error of the cochlea was 0.04 ± 0.33 or 0.06 ± 0.43 cm for RL, 0.09 ± 0.27 or 0.07 ± 0.48 cm for AP, and 0.00 ± 0.21 or −0.24 ± 0.45 cm for SI with and without radiographic imaging, respectively. Setup with radiographic imaging reduced the standard deviation of the setup error by roughly 1–2 mm. The uncertainty of the cochlea dose depends on the treatment plan and the relative positions of the cochlea and target volumes. Combining results for the left and right cochlea, the authors found the accumulated uncertainty of the cochlea dose per fraction was 4.82 (0.39–16.8) cGy, or 10.1 (0.8–32.4) cGy, with and without radiographic imaging, respectively; the percentage uncertainties relative to the planned doses were 4.32% (0.28%–9.06%) and 10.2% (0.7%–63.6%), respectively. Conclusions: Patient setup error introduces uncertainty in the position of the cochlea during radiation treatment. With the assistance of radiographic imaging during setup, the standard deviation of setup error reduced by 31%, 42%, and 54% in RL, AP, and SI direction, respectively, and consequently, the uncertainty of the mean dose to cochlea reduced more than 50%. The authors estimate that the effects of these uncertainties on the probability of hearing loss for an individual patient could be as large as 10%. PMID:24320510

U.S. Naval Research Laboratory Final Analysis Report to NATO Above Water Warfare Capabilities Group 2016 Naval Electromagnetic Operations Trials

DTIC Science & Technology

2017-05-23

Systems and the NRL Code 5763 Radio Frequency (RF) Stimulator. It includes and covers system descriptions , setup, data collection, and test goals that...6 4. Test Asset Descriptions ...7 4.1. Description of FOXTROT Anti-ship Missile (ASM) Simulator ......................................... 7

Game Theory, Decision Theory, and Social Choice Theory in the Context of a New Theory of Equity

DTIC Science & Technology

1978-12-01

Press of Harvard University. Sen , Amartya , 1977, "On Weights and Measures: Informational Constraints in Social Welfare Analysis," Econometrica, Vol...this requirement is a natural consequence of a setup that rules out cardinal utility, as Arrow (1978) and Sen (1977) have pointed out in different

Strengthening Statistics Graduate Programs with Statistical Collaboration--The Case of Hawassa University, Ethiopia

ERIC Educational Resources Information Center

Goshu, Ayele Taye

2016-01-01

This paper describes the experiences gained from the established statistical collaboration canter at Hawassa University in May 2015 as part of LISA 2020 [Laboratory for Interdisciplinary Statistical Analysis] network. The center has got similar setup as LISA of Virginia Tech. Statisticians are trained on how to become more effective scientific…

Targeted Information Dissemination

DTIC Science & Technology

2008-03-01

SETUP, RESULTS AND PERFORMANCE ANALYSIS .......................................... 36 APPENDIX C: TID API SPECIFICATION...are developed using FreePastry1. FreePastry provides an API for a structured P2P overlay network. Information Routing and address resolution is...the TID architecture to demonstrate its key features. TID interface API specifications are described in Appendix C. RSS feeds were used to obtain

Measuring the effect of spray plume angle on the accuracy of droplet size data

USDA-ARS?s Scientific Manuscript database

Analysis of droplet size data using laser diffraction allows for quick and easy assessment of droplet size for agricultural spray nozzles and pesticides; however, operation and setup of the instrument and test system can potentially influence the accuracy of the data. One of the factors is the orie...

Prototype solar heating and combined heating and cooling systems

NASA Technical Reports Server (NTRS)

1977-01-01

Schedules and technical progress in the development of eight prototype solar heating and combined solar heating and cooling systems are reported. Particular emphasis is given to the analysis and preliminary design for the cooling subsystem, and the setup and testing of a horizontal thermal energy storage tank configuration and collector shroud evaluation.

Proton-proton bremsstrahlung towards the elastic limit

NASA Astrophysics Data System (ADS)

Mahjour-Shafiei, M.; Amir-Ahmadi, H. R.; Bacelar, J. C. S.; Castelijns, R.; Ermisch, K.; van Garderen, E.; Gašparić, I.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Kiš, M.; Löhner, H.

2005-05-01

In oder to study proton-proton bremsstrahlung moving towards the elastic limit, a detection system, consisting of Plastic-ball and SALAD, was set up and an experiment at 190 MeV incident beam energy was performed. Here, the experimental setup and the data analysis procedure along with some results obtained in the measurement are discussed.

Cavity Ring down Spectroscopy Experiment for an Advanced Undergraduate Laboratory

ERIC Educational Resources Information Center

Stacewicz, T.; Wasylczyk, P.; Kowalczyk, P.; Semczuk, M.

2007-01-01

A simple experiment is described that permits advanced undergraduates to learn the principles and applications of the cavity ring down spectroscopy technique. The apparatus is used for measurements of low concentrations of NO[subscript 2] produced in air by an electric discharge. We present the setup, experimental procedure, data analysis and some…

TANGRA - an experimental setup for basic and applied nuclear research by means of 14.1 MeV neutrons

NASA Astrophysics Data System (ADS)

Ruskov, Ivan; Kopatch, Yury; Bystritsky, Vyacheslav; Skoy, Vadim; Shvetsov, Valery; Hambsch, Franz-Josef; Oberstedt, Stephan; Noy, Roberto Capote; Grozdanov, Dimitar; Zontikov, Artem; Rogov, Yury; Zamyatin, Nikolay; Sapozhnikov, Mikhail; Slepnev, Vyacheslav; Bogolyubov, Evgeny; Sadovsky, Andrey; Barmakov, Yury; Ryzhkov, Valentin; Yurkov, Dimitry; Valković, Vladivoj; Obhođaš, Jasmina; Aliyev, Fuad

2017-09-01

For investigation of the basic characteristics of 14.1 MeV neutron induced nuclear reactions on a number of important isotopes for nuclear science and engineering, a new experimental setup TANGRA has been constructed at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research in Dubna. For testing its performance, the angular distribution of γ-rays (and neutrons) from the inelastic scattering of 14.1 MeV neutrons on high-purity carbon was measured and the angular anisotropy of γ-rays from the reaction 12C(n, n'γ)12C was determined. This reaction is important from fundamental (differential cross-sections) and practical (non-destructive elemental analysis of materials containing carbon) point of view. The preliminary results for the anisotropy of the γ-ray emission from the inelastic scattering of 14.1- MeV neutrons on carbon are compared with already published literature data. A detailed data analysis for determining the correlations between inelastic scattered neutron and γ-ray emission will be published elsewhere.

Fluorescence correlation spectroscopy: principles and applications.

PubMed

Bacia, Kirsten; Haustein, Elke; Schwille, Petra

2014-07-01

Fluorescence correlation spectroscopy (FCS) is used to study the movements and the interactions of biomolecules at extremely dilute concentrations, yielding results with good spatial and temporal resolutions. Using a number of technical developments, FCS has become a versatile technique that can be used to study a variety of sample types and can be advantageously combined with other methods. Unlike other fluorescence-based techniques, the analysis of FCS data is not based on the average intensity of the fluorescence emission but examines the minute intensity fluctuations caused by spontaneous deviations from the mean at thermal equilibrium. These fluctuations can result from variations in local concentrations owing to molecular mobility or from characteristic intermolecular or intramolecular reactions of fluorescently labeled biomolecules present at low concentrations. Here, we provide a basic introduction to FCS, including its technical development and theoretical basis, experimental setup of an FCS system, adjustment of a setup, data acquisition, and analysis of FCS measurements. Finally, the application of FCS to the study of lipid bilayer membranes and to living cells is discussed. © 2014 Cold Spring Harbor Laboratory Press.

A dual wavelength imaging system for plasma-surface interaction studies on the National Spherical Torus Experiment Upgrade

DOE PAGES

Scotti, F.; Soukhanovskii, V. A.

2015-12-09

A two-channel spectral imaging system based on a charge injection device radiation-hardened intensified camera was built for studies of plasma-surface interactions on divertor plasma facing components in the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak. By means of commercially available mechanically referenced optical components, the two-wavelength setup images the light from the plasma, relayed by a fiber optic bundle, at two different wavelengths side-by-side on the same detector. Remotely controlled filter wheels are used for narrow band pass and neutral density filters on each optical path allowing for simultaneous imaging of emission at wavelengths differing in brightness up to 3more » orders of magnitude. Applications on NSTX-U will include the measurement of impurity influxes in the lower divertor strike point region and the imaging of plasma-material interaction on the head of the surface analysis probe MAPP (Material Analysis and Particle Probe). Furthermore, the diagnostic setup and initial results from its application on the lithium tokamak experiment are presented.« less

Collective dynamics and transport in extremely magnetized dusty plasmas

NASA Astrophysics Data System (ADS)

Hartmann, Peter

2016-09-01

We have built an experimental setup to realize and observe rotating dusty plasmas in a co-rotating frame. Based on the Larmor theorem, the ``RotoDust'' setup is able to create effective magnetizations, mimicked by the Coriolis inertial force, in strongly coupled dusty plasmas that are impossible to approach with superconducting magnets. At the highest rotation speed, we have achieved effective magnetic fields of 3200 T. The effective magnetization β =ωc /ωp (ratio of cyclotron to plasma frequency) reaches 0.76 which is typical for many strongly magnetized and strongly correlated plasmas in compact astrophysical objects. The analysis of the wave spectra as observed in the rotating frame clearly shows the equivalence of the rotating dust cloud and a magnetized plasma. Further, the analysis of the mean square displacement (MSD) and the velocity autocorrelation function (VAC) revealed the transport parameters diffusion and viscosity, which are in reasonable agreement with numerical predictions for magnetized 2D Yukawa systems. Small degree of super-diffusion is observed. This research was supported by grant NKFIH K-115805 and the Janos Bolyai Research Scholarship of the HAS.

Setup and use of a two-laser multiphoton microscope for multichannel intravital fluorescence imaging

PubMed Central

Entenberg, David; Wyckoff, Jeffrey; Gligorijevic, Bojana; Roussos, Evanthia T; Verkhusha, Vladislav V; Pollard, Jeffrey W; Condeelis, John

2014-01-01

Characterizing biological mechanisms dependent upon the interaction of many cell types in vivo requires both multiphoton microscope systems capable of expanding the number and types of fluorophores that can be imaged simultaneously while removing the wavelength and tunability restrictions of existing systems, and enhanced software for extracting critical cellular parameters from voluminous 4D data sets. We present a procedure for constructing a two-laser multiphoton microscope that extends the wavelength range of excitation light, expands the number of simultaneously usable fluorophores and markedly increases signal to noise via ‘over-clocking’ of detection. We also utilize a custom-written software plug-in that simplifies the quantitative tracking and analysis of 4D intravital image data. We begin by describing the optics, hardware, electronics and software required, and finally the use of the plug-in for analysis. We demonstrate the use of the setup and plug-in by presenting data collected via intravital imaging of a mouse model of breast cancer. The procedure may be completed in ~24 h. PMID:21959234

Thallium as a tracer for preindustrial volcanic eruptions in an ice core record from Illimani, Bolivia.

PubMed

Kellerhals, Thomas; Tobler, Leonhard; Brütsch, Sabina; Sigl, Michael; Wacker, Lukas; Gäggeler, Heinz W; Schwikowski, Margit

2010-02-01

Trace element records from glacier and ice sheet archives provide insights into biogeochemical cycles, atmospheric circulation changes, and anthropogenic pollution history. We present the first continuous high-resolution thallium (Tl) record, derived from an accurately dated ice core from tropical South America, and discuss Tl as a tracer for volcanic eruptions. We identify four prominent Tl peaks and propose that they represent signals from the massive explosive eruptions of the "unknown 1258" A.D. volcano, of Kuwae ( approximately 1450 A.D.), Tambora (1815 A.D.), and Krakatoa (1883 A.D.). The highly resolved record was obtained with an improved setup for the continuous analysis of trace elements in ice with inductively coupled plasma sector field mass spectrometry (ICP-SFMS). The new setup allowed for a stronger initial acidification of the meltwater and shorter tubing length, thereby reducing the risk of memory effects and losses of analytes to the capillary walls. With a comparison of the continuous method to the established conventional decontamination and analysis procedure for discrete samples, we demonstrate the accuracy of the continuous method for Tl analyses.

The Compact and Inexpensive "Arrowhead" Setup for Holographic Interferometry

ERIC Educational Resources Information Center

Ladera, Celso L.; Donoso, Guillermo

2011-01-01

Hologram recording and holographic interferometry are intrinsically sensitive to phase changes, and therefore both are easily perturbed by minuscule optical path perturbations. It is therefore very convenient to bank on holographic setups with a reduced number of optical components. Here we present a compact off-axis holographic setup that…

Cryocooler based test setup for high current applications

NASA Astrophysics Data System (ADS)

Pradhan, Jedidiah; Das, Nisith Kr.; Roy, Anindya; Duttagupta, Anjan

2018-04-01

A cryo-cooler based cryogenic test setup has been designed, fabricated, and tested. The setup incorporates two numbers of cryo-coolers, one for sample cooling and the other one for cooling the large magnet coil. The performance and versatility of the setup has been tested using large samples of high-temperature superconductor magnet coil as well as short samples with high current. Several un-calibrated temperature sensors have been calibrated using this system. This paper presents the details of the system along with results of different performance tests.

Tissue type determination by impedance measurement: A bipolar and monopolar comparison

PubMed Central

Sharp, Jack; Bouazza-Marouf, Kaddour; Noronha, Dorita; Gaur, Atul

2017-01-01

Background: In certain medical applications, it is necessary to be able to determine the position of a needle inside the body, specifically with regards to identifying certain tissue types. By measuring the electrical impedance of specific tissue types, it is possible to determine the type of tissue the tip of the needle (or probe) is at. Materials and Methods: Two methods have been investigated for electric impedance detection; bipolar and monopolar. Commercially available needle electrodes are of a monopolar type. Although many patents exist on the bipolar setups, these have not as yet been commercialized. This paper reports a comparison of monopolar and bipolar setups for tissue type determination. In vitro experiments were carried out on pork to compare this investigation with other investigations in this field. Results: The results show that both monopolar and bipolar setups are capable of determining tissue type. However, the bipolar setup showed slightly better results; the difference between the different soft tissue type impedances was greater compared to the monopolar method. Conclusion: Both monopolar and bipolar electrical impedance setups work very similarly in inhomogeneous volumes such as biological tissue. There is a clear potential for clinical applications with impedance-based needle guidance, with both the monopolar and bipolar setups. It is, however, worth noting that the bipolar setup is more versatile. PMID:28217047

Numerical investigation of a scalable setup for efficient terahertz generation using a segmented tilted-pulse-front excitation.

PubMed

Pálfalvi, László; Tóth, György; Tokodi, Levente; Márton, Zsuzsanna; Fülöp, József András; Almási, Gábor; Hebling, János

2017-11-27

A hybrid-type terahertz pulse source is proposed for high energy terahertz pulse generation. It is the combination of the conventional tilted-pulse-front setup and a transmission stair-step echelon-faced nonlinear crystal with a period falling in the hundred-micrometer range. The most important advantage of the setup is the possibility of using plane parallel nonlinear optical crystal for producing good-quality, symmetric terahertz beam. Another advantage of the proposed setup is the significant reduction of imaging errors, which is important in the case of wide pump beams that are used in high energy experiments. A one dimensional model was developed for determining the terahertz generation efficiency, and it was used for quantitative comparison between the proposed new hybrid setup and previously introduced terahertz sources. With lithium niobate nonlinear material, calculations predict an approximately ten-fold increase in the efficiency of the presently described hybrid terahertz pulse source with respect to that of the earlier proposed setup, which utilizes a reflective stair-step echelon and a prism shaped nonlinear optical crystal. By using pump pulses of 50 mJ pulse energy, 500 fs pulse length and 8 mm beam spot radius, approximately 1% conversion efficiency and 0.5 mJ terahertz pulse energy can be reached with the newly proposed setup.

Using MASHA+TIMEPIX Setup for Registration Beta Decay Isotopes Produced in Heavy Ion Induced Reactions

NASA Astrophysics Data System (ADS)

Rodin, A. M.; Belozerov, A. V.; Chernysheva, E. V.; Dmitriev, S. N.; Gulyaev, A. V.; Gulyaeva, A. V.; Itkis, M. G.; Novoselov, A. S.; Oganessian, Yu. Ts.; Salamatin, V. S.; Stepantsov, S. V.; Vedeneev, V. Yu.; Yukhimchuk, S. A.; Krupa, L.; Granja, C.; Pospisil, S.; Kliman, J.; Motycak, S.; Sivacek, I.

2015-06-01

Radon and mercury isotopes were produced in multi nucleon transfer (48Ca + 232Th) and complete fusion (48Ca + naturalNd) reactions, respectively. The isotopes with given masses were detected using two detectors: a multi-strip detector of the well-type (made in CANBERRA) and a position-sensitive quantum counting hybrid pixel detector of the TIMEPIX type. The isotopes implanted into the detectors then emit alpha- and betaparticles until reaching the long lived isotopes. The position of the isotopes, the tracks, the time and energy of beta-particles were measured and analyzed. A new software for the particle recognition and data analysis of experimental results was developed and used. It was shown that MASHA+ TIMEPIX setup is a powerful instrument for investigation of neutron-rich isotopes far from stability limits.

Hydroelectric System Response to Part Load Vortex Rope Excitation

NASA Astrophysics Data System (ADS)

Alligné, S.; Nicolet, C.; Bégum, A.; Landry, C.; Gomes, J.; Avellan, F.

2016-11-01

The prediction of pressure and output power fluctuations amplitudes on Francis turbine prototype is a challenge for hydro-equipment industry since it is subjected to guarantees to ensure smooth and reliable operation of the hydro units. The European FP7 research project Hyperbole aims to setup a methodology to transpose the pressure fluctuations induced by the cavitation vortex rope on the reduced scale model to the prototype generating units. A Francis turbine unit of 444MW with a specific speed value of v = 0.29, is considered as case study. A SIMSEN model of the power station including electrical system, controllers, rotating train and hydraulic system with transposed draft tube excitation sources is setup. Based on this model, a frequency analysis of the hydroelectric system is performed to analyse potential interactions between hydraulic excitation sources and electrical components.

An Artificial Nose Based on Microcantilever Array Sensors

NASA Astrophysics Data System (ADS)

Lang, H. P.; Ramseyer, J. P.; Grange, W.; Braun, T.; Schmid, D.; Hunziker, P.; Jung, C.; Hegner, M.; Gerber, C.

2007-03-01

We used microfabricated cantilever array sensors for an artificial nose setup. Each cantilever is coated on its top surface with a polymer layer. Volatile gaseous analytes are detected by tracking the diffusion process of the molecules into the polymer layers, resulting in swelling of the polymer layers and therewith bending of the cantilevers. From the bending pattern of all cantilevers in the array, a characteristic 'fingerprint' of the analyte is obtained, which is evaluated using principal component analysis. In a flow of dry nitrogen gas, the bending of the cantilevers is reverted to its initial state before exposure to the analyte, which allows reversible and reproducible operation of the sensor. We show examples of detection of solvents, perfume essences and beverage flavors. In a medical application, the setup provides indication of presence of diseases in patient's breath samples.

Characterization of a neutron imaging setup at the INES facility

NASA Astrophysics Data System (ADS)

Durisi, E. A.; Visca, L.; Albertin, F.; Brancaccio, R.; Corsi, J.; Dughera, G.; Ferrarese, W.; Giovagnoli, A.; Grassi, N.; Grazzi, F.; Lo Giudice, A.; Mila, G.; Nervo, M.; Pastrone, N.; Prino, F.; Ramello, L.; Re, A.; Romero, A.; Sacchi, R.; Salvemini, F.; Scherillo, A.; Staiano, A.

2013-10-01

The Italian Neutron Experimental Station (INES) located at the ISIS pulsed neutron source (Didcot, United Kingdom) provides a thermal neutron beam mainly used for diffraction analysis. A neutron transmission imaging system was also developed for beam monitoring and for aligning the sample under investigation. Although the time-of-flight neutron diffraction is a consolidated technique, the neutron imaging setup is not yet completely characterized and optimized. In this paper the performance for neutron radiography and tomography at INES of two scintillator screens read out by two different commercial CCD cameras is compared in terms of linearity, signal-to-noise ratio, effective dynamic range and spatial resolution. In addition, the results of neutron radiographies and a tomography of metal alloy test structures are presented to better characterize the INES imaging capabilities of metal artifacts in the cultural heritage field.

Defining robustness protocols: a method to include and evaluate robustness in clinical plans

NASA Astrophysics Data System (ADS)

McGowan, S. E.; Albertini, F.; Thomas, S. J.; Lomax, A. J.

2015-04-01

We aim to define a site-specific robustness protocol to be used during the clinical plan evaluation process. Plan robustness of 16 skull base IMPT plans to systematic range and random set-up errors have been retrospectively and systematically analysed. This was determined by calculating the error-bar dose distribution (ebDD) for all the plans and by defining some metrics used to define protocols aiding the plan assessment. Additionally, an example of how to clinically use the defined robustness database is given whereby a plan with sub-optimal brainstem robustness was identified. The advantage of using different beam arrangements to improve the plan robustness was analysed. Using the ebDD it was found range errors had a smaller effect on dose distribution than the corresponding set-up error in a single fraction, and that organs at risk were most robust to the range errors, whereas the target was more robust to set-up errors. A database was created to aid planners in terms of plan robustness aims in these volumes. This resulted in the definition of site-specific robustness protocols. The use of robustness constraints allowed for the identification of a specific patient that may have benefited from a treatment of greater individuality. A new beam arrangement showed to be preferential when balancing conformality and robustness for this case. The ebDD and error-bar volume histogram proved effective in analysing plan robustness. The process of retrospective analysis could be used to establish site-specific robustness planning protocols in proton therapy. These protocols allow the planner to determine plans that, although delivering a dosimetrically adequate dose distribution, have resulted in sub-optimal robustness to these uncertainties. For these cases the use of different beam start conditions may improve the plan robustness to set-up and range uncertainties.

Model-based setup assistant for progressive tools

NASA Astrophysics Data System (ADS)

Springer, Robert; Gräler, Manuel; Homberg, Werner; Henke, Christian; Trächtler, Ansgar

2018-05-01

In the field of production systems, globalization and technological progress lead to increasing requirements regarding part quality, delivery time and costs. Hence, today's production is challenged much more than a few years ago: it has to be very flexible and produce economically small batch sizes to satisfy consumer's demands and avoid unnecessary stock. Furthermore, a trend towards increasing functional integration continues to lead to an ongoing miniaturization of sheet metal components. In the industry of electric connectivity for example, the miniaturized connectors are manufactured by progressive tools, which are usually used for very large batches. These tools are installed in mechanical presses and then set up by a technician, who has to manually adjust a wide range of punch-bending operations. Disturbances like material thickness, temperatures, lubrication or tool wear complicate the setup procedure. In prospect of the increasing demand of production flexibility, this time-consuming process has to be handled more and more often. In this paper, a new approach for a model-based setup assistant is proposed as a solution, which is exemplarily applied in combination with a progressive tool. First, progressive tools, more specifically, their setup process is described and based on that, the challenges are pointed out. As a result, a systematic process to set up the machines is introduced. Following, the process is investigated with an FE-Analysis regarding the effects of the disturbances. In the next step, design of experiments is used to systematically develop a regression model of the system's behaviour. This model is integrated within an optimization in order to calculate optimal machine parameters and the following necessary adjustment of the progressive tool due to the disturbances. Finally, the assistant is tested in a production environment and the results are discussed.

Acoustic Noise Levels of Dental Equipments and Its Association with Fear and Annoyance Levels among Patients Attending Different Dental Clinic Setups in Jaipur, India

PubMed Central

Ganta, Shravani; Nagaraj, Anup; Pareek, Sonia; Atri, Mansi; Singh, Kushpal; Sidiq, Mohsin

2014-01-01

Background: Noise is a source of pervasive occupational hazard for practicing dentists and the patients. The sources of dental sounds by various dental equipments can pose as a potential hazard to hearing system and add to the annoyance levels of the patients. The aim of the study was to analyze the noise levels from various equipments and evaluate the effect of acoustic noise stimulus on dental fear and annoyance levels among patients attending different dental clinic setups in Jaipur, India. Methodology: The sampling frame comprised of 180 patients, which included 90 patients attending 10 different private clinics and 90 patients attending a Dental College in Jaipur. The levels of Acoustic Noise Stimulus originating from different equipments were determined using a precision sound level meter/decibulometer. Dental fear among patients was measured using Dental Fear Scale (DFS). Results: Statistical analysis was performed using chi square test and unpaired t-test. The mean background noise levels were found to be maximum in the pre-clinical setup/ laboratory areas (69.23+2.20). Females and the patients attending dental college setup encountered more fear on seeing the drill as compared to the patients attending private clinics (p<0.001). Conclusion: The sources of dental sounds can pose as a potential hazard to hearing system. It was analyzed that the environment in the clinics can directly have an effect on the fear and annoyance levels of patients. Hence it is necessary control the noise from various dental equipments to reduce the fear of patients from visiting a dental clinic. PMID:24959512

Improved human observer performance in digital reconstructed radiograph verification in head and neck cancer radiotherapy.

PubMed

Sturgeon, Jared D; Cox, John A; Mayo, Lauren L; Gunn, G Brandon; Zhang, Lifei; Balter, Peter A; Dong, Lei; Awan, Musaddiq; Kocak-Uzel, Esengul; Mohamed, Abdallah Sherif Radwan; Rosenthal, David I; Fuller, Clifton David

2015-10-01

Digitally reconstructed radiographs (DRRs) are routinely used as an a priori reference for setup correction in radiotherapy. The spatial resolution of DRRs may be improved to reduce setup error in fractionated radiotherapy treatment protocols. The influence of finer CT slice thickness reconstruction (STR) and resultant increased resolution DRRs on physician setup accuracy was prospectively evaluated. Four head and neck patient CT-simulation images were acquired and used to create DRR cohorts by varying STRs at 0.5, 1, 2, 2.5, and 3 mm. DRRs were displaced relative to a fixed isocenter using 0-5 mm random shifts in the three cardinal axes. Physician observers reviewed DRRs of varying STRs and displacements and then aligned reference and test DRRs replicating daily KV imaging workflow. A total of 1,064 images were reviewed by four blinded physicians. Observer errors were analyzed using nonparametric statistics (Friedman's test) to determine whether STR cohorts had detectably different displacement profiles. Post hoc bootstrap resampling was applied to evaluate potential generalizability. The observer-based trial revealed a statistically significant difference between cohort means for observer displacement vector error ([Formula: see text]) and for [Formula: see text]-axis [Formula: see text]. Bootstrap analysis suggests a 15% gain in isocenter translational setup error with reduction of STR from 3 mm to [Formula: see text]2 mm, though interobserver variance was a larger feature than STR-associated measurement variance. Higher resolution DRRs generated using finer CT scan STR resulted in improved observer performance at shift detection and could decrease operator-dependent geometric error. Ideally, CT STRs [Formula: see text]2 mm should be utilized for DRR generation in the head and neck.

Consequences of uncontrolled cooling during sterlet (Acipenser ruthenus) sperm cryopreservation on post-thaw motility and fertilizing ability.

PubMed

Horokhovatskyi, Yevhen; Rodina, Marek; Asyabar, Hadiseh Dadras; Boryshpolets, Sergii; Dzyuba, Borys

2017-06-01

The significant influence of the number and position of fish sperm sample straws in uncontrolled cooling devices on post-thaw spermatozoa parameters, such as motility and fertilizing ability, is presented in this study. The two most popular uncontrolled cooling devices were used in this study: a Styrofoam box setup with a polystyrene floating raft on liquid nitrogen and the dry shipper setup with a straw holder. We tested the effect of different quantities of straws (6 or 60) placed on the polystyrene floating raft and the position of the straws in the holder (on the periphery or in the centre). Using these cooling methods, sperm of 10 male sterlets diluted with methanol containing cryoprotective medium was frozen. All temperature changes were recorded by a thermocouple inside the straw, and the thermogram intervals were analysed. Spermatozoa motility was evaluated by video microscopy with integrated computer-assisted sperm analysis software. Fertilization trials were conducted at a 10 5 spermatozoa/egg ratio. Post-thaw spermatozoa parameters, including the percent of motile spermatozoa, curvilinear velocity, velocity according to the smoothed path, linearity of track, beat-cross frequency and fertilization rate, were significantly decreased in the 60-straw floating raft setup in comparison to all of the other cooling methods. The freezing rate between -10 °C and -30 °C was significantly decreased by up to 18.6 ± 0.61 °C/min for the 60-straw floating raft setup in comparison to the other freezing conditions. Considering the above results, efforts to standardize cryopreservation protocols using uncontrolled cooling devices should take into account the amount of straws subjected to freezing. Copyright © 2017. Published by Elsevier Inc.

fMRI brain mapping during motion capture and FES induced motor tasks: signal to noise ratio assessment.

PubMed

Gandolla, Marta; Ferrante, Simona; Casellato, Claudia; Ferrigno, Giancarlo; Molteni, Franco; Martegani, Alberto; Frattini, Tiziano; Pedrocchi, Alessandra

2011-10-01

Functional Electrical Stimulation (FES) is a well known clinical rehabilitation procedure, however the neural mechanisms that underlie this treatment at Central Nervous System (CNS) level are still not completely understood. Functional magnetic resonance imaging (fMRI) is a suitable tool to investigate effects of rehabilitative treatments on brain plasticity. Moreover, monitoring the effective executed movement is needed to correctly interpret activation maps, most of all in neurological patients where required motor tasks could be only partially accomplished. The proposed experimental set-up includes a 1.5 T fMRI scanner, a motion capture system to acquire kinematic data, and an electro-stimulation device. The introduction of metallic devices and of stimulation current in the MRI room could affect fMRI acquisitions so as to prevent a reliable activation maps analysis. What we are interested in is that the Blood Oxygenation Level Dependent (BOLD) signal, marker of neural activity, could be detected within a given experimental condition and set-up. In this paper we assess temporal Signal to Noise Ratio (SNR) as image quality index. BOLD signal change is about 1-2% as revealed by a 1.5 T scanner. This work demonstrates that, with this innovative set-up, in the main cortical sensorimotor regions 1% BOLD signal change can be detected at least in the 93% of the sub-volumes, and almost 100% of the sub-volumes are suitable for 2% signal change detection. The integrated experimental set-up will therefore allows to detect FES induced movements fMRI maps simultaneously with kinematic acquisitions so as to investigate FES-based rehabilitation treatments contribution at CNS level. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

TU-EF-304-09: Quantifying the Biological Effects of Therapeutic Protons by LET Spectrum Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guan, F; Bronk, L; Kerr, M

2015-06-15

Purpose: To correlate in vitro cell kill with linear energy transfer (LET) spectra using Monte Carlo simulations and knowledge obtained from previous high-throughput in vitro proton relative biological effectiveness (RBE) measurements. Methods: The Monte Carlo simulation toolkit Geant4 was used to design the experimental setups and perform the dose, dose-averaged LET, and LET spectra calculations. The clonogenic assay was performed using the H460 lung cancer cell line in standard 6-well plates. Using two different experimental setups, the same dose and dose-averaged LET (12.6 keV/µm) was delivered to the cell layer; however, each respective energy or LET spectrum was different. Wemore » quantified the dose contributions from high-LET (≥10 keV/µm, threshold determined by previous RBE measurements) events in the LET spectra separately for these two setups as 39% and 53%. 8 dose levels with 1 Gy increments were delivered. The photon reference irradiation was performed using 6 MV x-rays from a LINAC. Results: The survival curves showed that both proton irradiations demonstrated an increased RBE compared to the reference photon irradiation. Within the proton-irradiated cells, the setup with 53% dose contribution from high-LET events exhibited the higher biological effectiveness. Conclusion: The experimental results indicate that the dose-averaged LET may not be an appropriate indicator to quantify the biological effects of protons when the LET spectrum is broad enough to contain both low- and high-LET events. Incorporating the LET spectrum distribution into robust intensity-modulated proton therapy optimization planning may provide more accurate biological dose distribution than using the dose-averaged LET. NIH Program Project Grant 2U19CA021239-35.« less

Non-linear transfer characteristics of stimulation and recording hardware account for spurious low-frequency artifacts during amplitude modulated transcranial alternating current stimulation (AM-tACS).

PubMed

Kasten, Florian H; Negahbani, Ehsan; Fröhlich, Flavio; Herrmann, Christoph S

2018-05-31

Amplitude modulated transcranial alternating current stimulation (AM-tACS) has been recently proposed as a possible solution to overcome the pronounced stimulation artifact encountered when recording brain activity during tACS. In theory, AM-tACS does not entail power at its modulating frequency, thus avoiding the problem of spectral overlap between brain signal of interest and stimulation artifact. However, the current study demonstrates how weak non-linear transfer characteristics inherent to stimulation and recording hardware can reintroduce spurious artifacts at the modulation frequency. The input-output transfer functions (TFs) of different stimulation setups were measured. Setups included recordings of signal-generator and stimulator outputs and M/EEG phantom measurements. 6 th -degree polynomial regression models were fitted to model the input-output TFs of each setup. The resulting TF models were applied to digitally generated AM-tACS signals to predict the frequency of spurious artifacts in the spectrum. All four setups measured for the study exhibited low-frequency artifacts at the modulation frequency and its harmonics when recording AM-tACS. Fitted TF models showed non-linear contributions significantly different from zero (all p < .05) and successfully predicted the frequency of artifacts observed in AM-signal recordings. Results suggest that even weak non-linearities of stimulation and recording hardware can lead to spurious artifacts at the modulation frequency and its harmonics. These artifacts were substantially larger than alpha-oscillations of a human subject in the MEG. Findings emphasize the need for more linear stimulation devices for AM-tACS and careful analysis procedures, taking into account low-frequency artifacts to avoid confusion with effects of AM-tACS on the brain. Copyright © 2018 Elsevier Inc. All rights reserved.

The Effect of Vegetation on Sea-Swell Waves, Infragravity Waves and Wave-Induced Setup

NASA Astrophysics Data System (ADS)

Roelvink, J. A.; van Rooijen, A.; McCall, R. T.; Van Dongeren, A.; Reniers, A.; van Thiel de Vries, J.

2016-02-01

Aquatic vegetation in the coastal zone (e.g. mangrove trees) attenuates wave energy and thereby reduces flood risk along many shorelines worldwide. However, in addition to the attenuation of incident-band (sea-swell) waves, vegetation may also affect infragravity-band (IG) waves and the wave-induced water level setup (in short: wave setup). Currently, knowledge on the effect of vegetation on IG waves and wave setup is lacking, while they are they are key parameters for coastal risk assessment. In this study, the process-based storm impact model XBeach was extended with formulations for attenuation of sea-swell and IG waves as well as the effect on the wave setup, in two modes: the sea-swell wave phase-resolving (non-hydrostatic) and the phase-averaged (surfbeat) mode. In surfbeat mode a wave shape model was implemented to estimate the wave phase and to capture the intra-wave scale effect of emergent vegetation and nonlinear waves on the wave setup. Both modeling modes were validated using data from two flume experiments and show good skill in computing the attenuation of both sea-swell and IG waves as well as the effect on the wave-induced water level setup. In surfbeat mode, the prediction of nearshore mean water levels greatly improved when using the wave shape model, while in non-hydrostatic mode this effect is directly accounted for. Subsequently, the model was used to study the influence of the bottom profile slope and the location of the vegetation field on the computed wave setup with and without vegetation. It was found that the reduction is wave setup is strongly related to the location of vegetation relative to the wave breaking point, and that the wave setup is lower for milder slopes. The extended version of XBeach developed within this study can be used to study the nearshore hydrodynamics on coasts fronted by vegetation such as mangroves. It can also serve as tool for storm impact studies on coasts with aquatic vegetation, and can help to quantify the coastal protection function of vegetation.

Robust artifactual independent component classification for BCI practitioners.

PubMed

Winkler, Irene; Brandl, Stephanie; Horn, Franziska; Waldburger, Eric; Allefeld, Carsten; Tangermann, Michael

2014-06-01

EEG artifacts of non-neural origin can be separated from neural signals by independent component analysis (ICA). It is unclear (1) how robustly recently proposed artifact classifiers transfer to novel users, novel paradigms or changed electrode setups, and (2) how artifact cleaning by a machine learning classifier impacts the performance of brain-computer interfaces (BCIs). Addressing (1), the robustness of different strategies with respect to the transfer between paradigms and electrode setups of a recently proposed classifier is investigated on offline data from 35 users and 3 EEG paradigms, which contain 6303 expert-labeled components from two ICA and preprocessing variants. Addressing (2), the effect of artifact removal on single-trial BCI classification is estimated on BCI trials from 101 users and 3 paradigms. We show that (1) the proposed artifact classifier generalizes to completely different EEG paradigms. To obtain similar results under massively reduced electrode setups, a proposed novel strategy improves artifact classification. Addressing (2), ICA artifact cleaning has little influence on average BCI performance when analyzed by state-of-the-art BCI methods. When slow motor-related features are exploited, performance varies strongly between individuals, as artifacts may obstruct relevant neural activity or are inadvertently used for BCI control. Robustness of the proposed strategies can be reproduced by EEG practitioners as the method is made available as an EEGLAB plug-in.

Three-dimensional analysis of the surface registration accuracy of electromagnetic navigation systems in live endoscopic sinus surgery.

PubMed

Chang, C M; Fang, K M; Huang, T W; Wang, C T; Cheng, P W

2013-12-01

Studies on the performance of surface registration with electromagnetic tracking systems are lacking in both live surgery and the laboratory setting. This study presents the efficiency in time of the system preparation as well as the navigational accuracy of surface registration using electromagnetic tracking systems. Forty patients with bilateral chronic paranasal pansinusitis underwent endoscopic sinus surgery after undergoing sinus computed tomography scans. The surgeries were performed under electromagnetic navigation guidance after the surface registration had been carried out on all of the patients. The intraoperative measurements indicate the time taken for equipment set-up, surface registration and surgical procedure, as well as the degree of navigation error along 3 axes. The time taken for equipment set-up, surface registration and the surgical procedure was 179 +- 23 seconds, 39 +- 4.8 seconds and 114 +- 36 minutes, respectively. A comparison of the navigation error along the 3 axes showed that the deviation in the medial-lateral direction was significantly less than that in the anterior-posterior and cranial-caudal directions. The procedures of equipment set-up and surface registration in electromagnetic navigation tracking are efficient, convenient and easy to manipulate. The system accuracy is within the acceptable ranges, especially on the medial-lateral axis.

Land use patterns and urbanization in the holy city of Varanasi, India: a scenario.

PubMed

Kumar, Manoj; Mukherjee, Nivedita; Sharma, Gyan Prakash; Raghubanshi, A S

2010-08-01

Rapid urbanization and increasing land use changes due to population and economic growth in selected landscapes is being witnessed of late in India and other developing countries. The cities are expanding in all directions resulting in large-scale urban sprawl and changes in urban land use. The spatial pattern of such changes is clearly noticed on the urban fringes or city peripheral rural areas than in the city center. In fact, this is reflected in changing urban land use patterns. There is an urgent need to accurately describe land use changes for planning and sustainable management. In the recent times, remote sensing is gaining importance as vital tool in the analysis and integration of spatial data. This study intends to estimate land use pattern in a planned and unplanned urban setup and also to analyze the impact of change in land use pattern in the Varanasi urban environment. The results indicate that the planned urban setup had a higher tree cover to that of unplanned area in the Varanasi City, although a considerable disparity existed within the planned urban setups. The results emphasize the need to critically review concepts of urban planning and give more consideration to the preservation and management of urban tree cover/greenspace.

Analysis of mixing in high-explosive fireballs using small-scale pressurised spheres

NASA Astrophysics Data System (ADS)

Courtiaud, S.; Lecysyn, N.; Damamme, G.; Poinsot, T.; Selle, L.

2018-02-01

After the detonation of an oxygen-deficient homogeneous high explosive, a phase of turbulent combustion, called afterburning, takes place at the interface between the rich detonation products and air. Its modelling is instrumental for the accurate prediction of the performance of these explosives. Because of the high temperature of detonation products, the chemical reactions are mixing-driven. Modelling afterburning thus relies on the precise description of the mixing process inside fireballs. This work presents a joint numerical and experimental study of a non-reacting reduced-scale set-up, which uses the compressed balloon analogy and does not involve the detonation of a high explosive. The set-up produces a flow similar to the one caused by a spherical detonation and allows focusing on the mixing process. The numerical work is composed of 2D and 3D LES simulations of the set-up. It is shown that grid independence can be reached by imposing perturbations at the edge of the fireball. The results compare well with the existing literature and give new insights on the mixing process inside fireballs. In particular, they highlight the fact that the mixing layer development follows an energetic scaling law but remains sensitive to the density ratio between the detonation products and air.

Biodegradation of paper waste using Eisenia foetida by vermicomposting Technology

NASA Astrophysics Data System (ADS)

Mathivanan, Mahalakshmi; Aravind Vishnu Saravanan, G.; Baji, Aravindh; Manoj kumar, J.

2017-07-01

The paper wastes are being a big concern over past decades. The process of reuse of the paper wastes is employed by ‘eisenia foetida’ in Vermiculture. The paper waste in SASTRA is collected around 50kg and organic wastes like vegetable wastes and cow dung wastes are also collected. In the adjacent area of Nirman Vihar, SASTRA, the experimental setup is done in a Geosynthetic polymer bag. The area is divided into three segments and in each segment appropriate amount of paper waste and organic waste were added along with 25 numbers of earthworms. The setup is watered daily and monitored periodically and it is kindled for proper aeration. The soil samples were collected on 20 days, 45 days and 60 days from the day the earthworms were added. After 60 days of the experiment, the paper wastes, compost and earthworms are separated. The quantity of the wastes was compared to the initial amount and the composts are collected. The elemental analysis of the soil used as Vermi-bed is analyzed for improvement of soil nutrients. The vermiwashed water of the setup is analyzed for total protein. The number of earthworm is also compared to initial quantity. Out of all, the loss percentage of the organic waste and paper waste shows the degradation of the paper wastes.

Simple setup for gas-phase H/D exchange mass spectrometry coupled to electron transfer dissociation and ion mobility for analysis of polypeptide structure on a liquid chromatographic time scale.

PubMed

Mistarz, Ulrik H; Brown, Jeffery M; Haselmann, Kim F; Rand, Kasper D

2014-12-02

Gas-phase hydrogen/deuterium exchange (HDX) is a fast and sensitive, yet unharnessed analytical approach for providing information on the structural properties of biomolecules, in a complementary manner to mass analysis. Here, we describe a simple setup for ND3-mediated millisecond gas-phase HDX inside a mass spectrometer immediately after ESI (gas-phase HDX-MS) and show utility for studying the primary and higher-order structure of peptides and proteins. HDX was achieved by passing N2-gas through a container filled with aqueous deuterated ammonia reagent (ND3/D2O) and admitting the saturated gas immediately upstream or downstream of the primary skimmer cone. The approach was implemented on three commercially available mass spectrometers and required no or minor fully reversible reconfiguration of gas-inlets of the ion source. Results from gas-phase HDX-MS of peptides using the aqueous ND3/D2O as HDX reagent indicate that labeling is facilitated exclusively through gaseous ND3, yielding similar results to the infusion of purified ND3-gas, while circumventing the complications associated with the use of hazardous purified gases. Comparison of the solution-phase- and gas-phase deuterium uptake of Leu-Enkephalin and Glu-Fibrinopeptide B, confirmed that this gas-phase HDX-MS approach allows for labeling of sites (heteroatom-bound non-amide hydrogens located on side-chains, N-terminus and C-terminus) not accessed by classical solution-phase HDX-MS. The simple setup is compatible with liquid chromatography and a chip-based automated nanoESI interface, allowing for online gas-phase HDX-MS analysis of peptides and proteins separated on a liquid chromatographic time scale at increased throughput. Furthermore, online gas-phase HDX-MS could be performed in tandem with ion mobility separation or electron transfer dissociation, thus enabling multiple orthogonal analyses of the structural properties of peptides and proteins in a single automated LC-MS workflow.

Optimizing Mouse Surgery with Online Rectal Temperature Monitoring and Preoperative Heat Supply. Effects on Post-Ischemic Acute Kidney Injury.

PubMed

Marschner, Julian A; Schäfer, Hannah; Holderied, Alexander; Anders, Hans-Joachim

2016-01-01

Body temperature affects outcomes of tissue injury. We hypothesized that online body core temperature recording and selective interventions help to standardize peri-interventional temperature control and the reliability of outcomes in experimental renal ischemia reperfusion injury (IRI). We recorded core temperature in up to seven mice in parallel using a Thermes USB recorder and ret-3-iso rectal probes with three different protocols. Setup A: Heating pad during ischemia time; Setup B: Heating pad from incision to wound closure; Setup C: A ventilated heating chamber before surgery and during ischemia time with surgeries performed on a heating pad. Temperature profile recording displayed significant declines upon installing anesthesia. The profile of the baseline experimental setup A revealed that <1% of the temperature readings were within the target range of 36.5 to 38.5°C. Setup B and C increased the target range readings to 34.6 ± 28.0% and 99.3 ± 1.5%, respectively. Setup C significantly increased S3 tubular necrosis, neutrophil influx, and mRNA expression of kidney injury markers. In addition, using setup C different ischemia times generated a linear correlation with acute tubular necrosis parameters at a low variability, which further correlated with the degree of kidney atrophy 5 weeks after surgery. Changing temperature control setup A to C was equivalent to 10 minutes more ischemia time. We conclude that body temperature drops quickly in mice upon initiating anesthesia. Immediate heat supply, e.g. in a ventilated heating chamber, and online core temperature monitoring can help to standardize and optimize experimental outcomes.

A Flexible Pilot-Scale Setup for Real-Time Studies in Process Systems Engineering

ERIC Educational Resources Information Center

Panjapornpon, Chanin; Fletcher, Nathan; Soroush, Masoud

2006-01-01

This manuscript describes a flexible, pilot-scale setup that can be used for training students and carrying out research in process systems engineering. The setup allows one to study a variety of process systems engineering concepts such as design feasibility, design flexibility, control configuration selection, parameter estimation, process and…

Treatability Study Pilot Test Operation Field Photos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jun

Photos in each group are in chronological order as captured: Group I Tank Platform Setup, November 14, 2017; Group II Tank Setup, November 15, 2017; Group III Aboveground Injestion System (AIS) Setup, November 20, 2017; Group IV Chemical Mixing, November 21, 2017; Group V KB-1 Bacteria Injection, November 27, 2017; Group VI Miscellaneous.

Field instrumentation and testing to study set-up phenomenon of piles driven into Louisiana clayey soils : final report.

DOT National Transportation Integrated Search

2016-07-01

This research study aims to investigate the pile set-up phenomenon for clayey soils and develop empirical models to predict pile set-up : resistance at certain time after end of driving (EOD). To fulfill the objective, a total number of twelve prestr...

Design and development of radioactive xenon gas purification and analysis system based on molecular sieves.

PubMed

Sabzian, M; Nasrabadi, M N; Haji-Hosseini, M

2018-10-01

The dynamic adsorption of xenon on molecular sieve packed columns was investigated. The modified Wheeler-Jonas equation was used to describe adsorption parameters such as adsorption capacity and adsorption rate coefficient. Different experimental conditions were accomplished to study their effects and to touch appropriate adsorbing circumstances. Respectable consistency was reached between experimental and modeled values. A purification and analysis setup was developed for radioactive xenon gas determination. Standard sample analysis results approved acceptable quantification accuracy. Copyright © 2018. Published by Elsevier Ltd.

User's manual for the Shuttle Electric Power System analysis computer program (SEPS), volume 2 of program documentation

NASA Technical Reports Server (NTRS)

Bains, R. W.; Herwig, H. A.; Luedeman, J. K.; Torina, E. M.

1974-01-01

The Shuttle Electric Power System Analysis SEPS computer program which performs detailed load analysis including predicting energy demands and consumables requirements of the shuttle electric power system along with parameteric and special case studies on the shuttle electric power system is described. The functional flow diagram of the SEPS program is presented along with data base requirements and formats, procedure and activity definitions, and mission timeline input formats. Distribution circuit input and fixed data requirements are included. Run procedures and deck setups are described.

BrainCycles: Experimental Setup for the Combined Measurement of Cortical and Subcortical Activity in Parkinson's Disease Patients during Cycling.

PubMed

Gratkowski, Maciej; Storzer, Lena; Butz, Markus; Schnitzler, Alfons; Saupe, Dietmar; Dalal, Sarang S

2016-01-01

Recently, it has been demonstrated that bicycling ability remains surprisingly preserved in Parkinson's disease (PD) patients who suffer from freezing of gait. Cycling has been also proposed as a therapeutic means of treating PD symptoms, with some preliminary success. The neural mechanisms behind these phenomena are however not yet understood. One of the reasons is that the investigations of neuronal activity during pedaling have been up to now limited to PET and fMRI studies, which restrict the temporal resolution of analysis, and to scalp EEG focused on cortical activation. However, deeper brain structures like the basal ganglia are also associated with control of voluntary motor movements like cycling and are affected by PD. Deep brain stimulation (DBS) electrodes implanted for therapy in PD patients provide rare and unique access to directly record basal ganglia activity with a very high temporal resolution. In this paper we present an experimental setup allowing combined investigation of basal ganglia local field potentials (LFPs) and scalp EEG underlying bicycling in PD patients. The main part of the setup is a bike simulator consisting of a classic Dutch-style bicycle frame mounted on a commercially available ergometer. The pedal resistance is controllable in real-time by custom software and the pedal position is continuously tracked by custom Arduino-based electronics using optical and magnetic sensors. A portable bioamplifier records the pedal position signal, the angle of the knee, and the foot pressure together with EEG, EMG, and basal ganglia LFPs. A handlebar-mounted display provides additional information for patients riding the bike simulator, including the current and target pedaling rate. In order to demonstrate the utility of the setup, example data from pilot recordings are shown. The presented experimental setup provides means to directly record basal ganglia activity not only during cycling but also during other movement tasks in patients who have undergone DBS treatment. Thus, it can facilitate studies comparing bicycling and walking, to elucidate why PD patients often retain the ability to bicycle despite severe freezing of gait. Moreover it can help clarifying the mechanism through which cycling may have therapeutic benefits.

BrainCycles: Experimental Setup for the Combined Measurement of Cortical and Subcortical Activity in Parkinson's Disease Patients during Cycling

PubMed Central

Gratkowski, Maciej; Storzer, Lena; Butz, Markus; Schnitzler, Alfons; Saupe, Dietmar; Dalal, Sarang S.

2017-01-01

Recently, it has been demonstrated that bicycling ability remains surprisingly preserved in Parkinson's disease (PD) patients who suffer from freezing of gait. Cycling has been also proposed as a therapeutic means of treating PD symptoms, with some preliminary success. The neural mechanisms behind these phenomena are however not yet understood. One of the reasons is that the investigations of neuronal activity during pedaling have been up to now limited to PET and fMRI studies, which restrict the temporal resolution of analysis, and to scalp EEG focused on cortical activation. However, deeper brain structures like the basal ganglia are also associated with control of voluntary motor movements like cycling and are affected by PD. Deep brain stimulation (DBS) electrodes implanted for therapy in PD patients provide rare and unique access to directly record basal ganglia activity with a very high temporal resolution. In this paper we present an experimental setup allowing combined investigation of basal ganglia local field potentials (LFPs) and scalp EEG underlying bicycling in PD patients. The main part of the setup is a bike simulator consisting of a classic Dutch-style bicycle frame mounted on a commercially available ergometer. The pedal resistance is controllable in real-time by custom software and the pedal position is continuously tracked by custom Arduino-based electronics using optical and magnetic sensors. A portable bioamplifier records the pedal position signal, the angle of the knee, and the foot pressure together with EEG, EMG, and basal ganglia LFPs. A handlebar-mounted display provides additional information for patients riding the bike simulator, including the current and target pedaling rate. In order to demonstrate the utility of the setup, example data from pilot recordings are shown. The presented experimental setup provides means to directly record basal ganglia activity not only during cycling but also during other movement tasks in patients who have undergone DBS treatment. Thus, it can facilitate studies comparing bicycling and walking, to elucidate why PD patients often retain the ability to bicycle despite severe freezing of gait. Moreover it can help clarifying the mechanism through which cycling may have therapeutic benefits. PMID:28119591

MO-G-BRE-03: Automated Continuous Monitoring of Patient Setup with Second-Check Independent Image Registration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, X; Fox, T; Schreibmann, E

2014-06-15

Purpose: To create a non-supervised quality assurance program to monitor image-based patient setup. The system acts a secondary check by independently computing shifts and rotations and interfaces with Varian's database to verify therapist's work and warn against sub-optimal setups. Methods: Temporary digitally-reconstructed radiographs (DRRs) and OBI radiographic image files created by Varian's treatment console during patient setup are intercepted and used as input in an independent registration module customized for accuracy that determines the optimal rotations and shifts. To deal with the poor quality of OBI images, a histogram equalization of the live images to the DDR counterparts is performedmore » as a pre-processing step. A search for the most sensitive metric was performed by plotting search spaces subject to various translations and convergence analysis was applied to ensure the optimizer finds the global minima. Final system configuration uses the NCC metric with 150 histogram bins and a one plus one optimizer running for 2000 iterations with customized scales for translations and rotations in a multi-stage optimization setup that first corrects and translations and subsequently rotations. Results: The system was installed clinically to monitor and provide almost real-time feedback on patient positioning. On a 2 month-basis uncorrected pitch values were of a mean 0.016° with standard deviation of 1.692°, and couch rotations of − 0.090°± 1.547°. The couch shifts were −0.157°±0.466° cm for the vertical, 0.045°±0.286 laterally and 0.084°± 0.501° longitudinally. Uncorrected pitch angles were the most common source of discrepancies. Large variations in the pitch angles were correlated with patient motion inside the mask. Conclusion: A system for automated quality assurance of therapist's registration was designed and tested in clinical practice. The approach complements the clinical software's automated registration in terms of algorithm configuration and performance and constitutes a practical approach to implement safe and cost-effective radiotherapy.« less

SU-F-J-192: A Quick and Effective Method to Validate Patient’s Daily Setup and Geometry Changes Prior to Proton Treatment Delivery Based On Water Equivalent Thickness Projection Imaging (WETPI) for Head Neck Cancer (HNC) Patient

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, G; Qin, A; Zhang, J

Purpose: With the implementation of Cone-beam Computed-Tomography (CBCT) in proton treatment, we introduces a quick and effective tool to verify the patient’s daily setup and geometry changes based on the Water-Equivalent-Thickness Projection-Image(WETPI) from individual beam angle. Methods: A bilateral head neck cancer(HNC) patient previously treated via VMAT was used in this study. The patient received 35 daily CBCT during the whole treatment and there is no significant weight change. The CT numbers of daily CBCTs were corrected by mapping the CT numbers from simulation CT via Deformable Image Registration(DIR). IMPT plan was generated using 4-field IMPT robust optimization (3.5% rangemore » and 3mm setup uncertainties) with beam angle 60, 135, 300, 225 degree. WETPI within CTV through all beam directions were calculated. 3%/3mm gamma index(GI) were used to provide a quantitative comparison between initial sim-CT and mapped daily CBCT. To simulate an extreme case where human error is involved, a couch bar was manually inserted in front of beam angle 225 degree of one CBCT. WETPI was compared in this scenario. Results: The average of GI passing rate of this patient from different beam angles throughout the treatment course is 91.5 ± 8.6. In the cases with low passing rate, it was found that the difference between shoulder and neck angle as well as the head rest often causes major deviation. This indicates that the most challenge in treating HNC is the setup around neck area. In the extreme case where a couch bar is accidently inserted in the beam line, GI passing rate drops to 52 from 95. Conclusion: WETPI and quantitative gamma analysis give clinicians, therapists and physicists a quick feedback of the patient’s setup accuracy or geometry changes. The tool could effectively avoid some human errors. Furthermore, this tool could be used potentially as an initial signal to trigger plan adaptation.« less

Effect of Body Mass Index on Magnitude of Setup Errors in Patients Treated With Adjuvant Radiotherapy for Endometrial Cancer With Daily Image Guidance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Lilie L., E-mail: lin@uphs.upenn.edu; Hertan, Lauren; Rengan, Ramesh

2012-06-01

Purpose: To determine the impact of body mass index (BMI) on daily setup variations and frequency of imaging necessary for patients with endometrial cancer treated with adjuvant intensity-modulated radiotherapy (IMRT) with daily image guidance. Methods and Materials: The daily shifts from a total of 782 orthogonal kilovoltage images from 30 patients who received pelvic IMRT between July 2008 and August 2010 were analyzed. The BMI, mean daily shifts, and random and systematic errors in each translational and rotational direction were calculated for each patient. Margin recipes were generated based on BMI. Linear regression and spearman rank correlation analysis were performed.more » To simulate a less-than-daily IGRT protocol, the average shift of the first five fractions was applied to subsequent setups without IGRT for assessing the impact on setup error and margin requirements. Results: Median BMI was 32.9 (range, 23-62). Of the 30 patients, 16.7% (n = 5) were normal weight (BMI <25); 23.3% (n = 7) were overweight (BMI {>=}25 to <30); 26.7% (n = 8) were mildly obese (BMI {>=}30 to <35); and 33.3% (n = 10) were moderately to severely obese (BMI {>=} 35). On linear regression, mean absolute vertical, longitudinal, and lateral shifts positively correlated with BMI (p = 0.0127, p = 0.0037, and p < 0.0001, respectively). Systematic errors in the longitudinal and vertical direction were found to be positively correlated with BMI category (p < 0.0001 for both). IGRT for the first five fractions, followed by correction of the mean error for all subsequent fractions, led to a substantial reduction in setup error and resultant margin requirement overall compared with no IGRT. Conclusions: Daily shifts, systematic errors, and margin requirements were greatest in obese patients. For women who are normal or overweight, a planning target margin margin of 7 to 10 mm may be sufficient without IGRT, but for patients who are moderately or severely obese, this is insufficient.« less

SU-E-J-88: The Study of Setup Error Measured by CBCT in Postoperative Radiotherapy for Cervical Carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Runxiao, L; Aikun, W; Xiaomei, F

2015-06-15

Purpose: To compare two registration methods in the CBCT guided radiotherapy for cervical carcinoma, analyze the setup errors and registration methods, determine the margin required for clinical target volume(CTV) extending to planning target volume(PTV). Methods: Twenty patients with cervical carcinoma were enrolled. All patients were underwent CT simulation in the supine position. Transfering the CT images to the treatment planning system and defining the CTV, PTV and the organs at risk (OAR), then transmit them to the XVI workshop. CBCT scans were performed before radiotherapy and registered to planning CT images according to bone and gray value registration methods. Comparedmore » two methods and obtain left-right(X), superior-inferior(Y), anterior-posterior (Z) setup errors, the margin required for CTV to PTV were calculated. Results: Setup errors were unavoidable in postoperative cervical carcinoma irradiation. The setup errors measured by method of bone (systemic ± random) on X(1eft.right),Y(superior.inferior),Z(anterior.posterior) directions were(0.24±3.62),(0.77±5.05) and (0.13±3.89)mm, respectively, the setup errors measured by method of grey (systemic ± random) on X(1eft-right), Y(superior-inferior), Z(anterior-posterior) directions were(0.31±3.93), (0.85±5.16) and (0.21±4.12)mm, respectively.The spatial distributions of setup error was maximum in Y direction. The margins were 4 mm in X axis, 6 mm in Y axis, 4 mm in Z axis respectively.These two registration methods were similar and highly recommended. Conclusion: Both bone and grey registration methods could offer an accurate setup error. The influence of setup errors of a PTV margin would be suggested by 4mm, 4mm and 6mm on X, Y and Z directions for postoperative radiotherapy for cervical carcinoma.« less

Evaluation of overall setup accuracy and adequate setup margins in pelvic image-guided radiotherapy: Comparison of the male and female patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laaksomaa, Marko, E-mail: marko.laaksomaa@pshp.fi; Kapanen, Mika; Department of Medical Physics, Tampere University Hospital

We evaluated adequate setup margins for the radiotherapy (RT) of pelvic tumors based on overall position errors of bony landmarks. We also estimated the difference in setup accuracy between the male and female patients. Finally, we compared the patient rotation for 2 immobilization devices. The study cohort included consecutive 64 male and 64 female patients. Altogether, 1794 orthogonal setup images were analyzed. Observer-related deviation in image matching and the effect of patient rotation were explicitly determined. Overall systematic and random errors were calculated in 3 orthogonal directions. Anisotropic setup margins were evaluated based on residual errors after weekly image guidance.more » The van Herk formula was used to calculate the margins. Overall, 100 patients were immobilized with a house-made device. The patient rotation was compared against 28 patients immobilized with CIVCO's Kneefix and Feetfix. We found that the usually applied isotropic setup margin of 8 mm covered all the uncertainties related to patient setup for most RT treatments of the pelvis. However, margins of even 10.3 mm were needed for the female patients with very large pelvic target volumes centered either in the symphysis or in the sacrum containing both of these structures. This was because the effect of rotation (p ≤ 0.02) and the observer variation in image matching (p ≤ 0.04) were significantly larger for the female patients than for the male patients. Even with daily image guidance, the required margins remained larger for the women. Patient rotations were largest about the lateral axes. The difference between the required margins was only 1 mm for the 2 immobilization devices. The largest component of overall systematic position error came from patient rotation. This emphasizes the need for rotation correction. Overall, larger position errors and setup margins were observed for the female patients with pelvic cancer than for the male patients.« less

A versatile setup using femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Yujie, E-mail: styojm@physics.tamu.edu; Voronine, Dmitri V.; Sokolov, Alexei V.

2015-08-15

We report a versatile setup based on the femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman scattering. The setup uses a femtosecond Ti:Sapphire oscillator source and a folded 4f pulse shaper, in which the pulse shaping is carried out through conventional optical elements and does not require a spatial light modulator. Our setup is simple in alignment, and can be easily switched between the collinear single-beam and the noncollinear two-beam configurations. We demonstrate the capability for investigating both transparent and highly scattering samples by detecting transmitted and reflected signals, respectively.

SU-F-T-680: Radiobiological Analysis of the Impact of Daily Patient Deformation and Setup Variations Through the Use of the Cone Beam CT and Deformable Image Registration in Lung Cancer IMRT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jurkovic, I; Stathakis, S; Markovic, M

Purpose: To estimate the dose distributions delivered to the patient in each treatment fraction using deformable image registration (DIR) and assess the radiobiological impact of the inter-fraction variations due to patient deformation and setup. Methods: The work is based on the cone beam CT (CBCT) images and treatment plans of two lung cancer patients. Both patients were treated with intensity modulated radiation therapy (IMRT) to 66Gy in 2Gy/fraction. The treatment plans were exported from the treatment planning system (TPS) to the Velocity AI where DIR was performed and the same deformation matrix was used for the deformation of the plannedmore » dose distribution and organ contours to each CBCT dataset. A radiobiological analysis was performed based on the radiobiological parameters of the involved organs at risk (OARs) and planning target volume (PTV). Using the complication free tumor control probability (P+) index, differences in P+ were observed between each CBCT as well as between CBCT and planning dose distributions. Results: The optimal CBCT P? values ranged from 91.6 % to 94.8 % for patient #1 and from 88.8 % to 90.6 % for patient #2. At the dose level of the clinical prescription, the CBCT P+ values ranged from 80.3% to 80.7% for patient #1 and from 80.7% to 81.0% for the patient #2. The planning CT P+ values were 81.0% and 80.7% for the two patients, respectively. These differences emphasize the significance of using the radiobiological analysis when assessing changes in the dose distribution due to the tumor motion and lung deformations. Conclusion: Daily setup variations yield to differences in the actual dose delivered versus the planned one. The observed differences were rather small when only looking at the dosimetric comparison of the dose distributions, however the radiobiology analysis was able to detect clinically relevant differences among the studied dose distributions.« less

Design and Mechanical Stability Analysis of the Interaction Region for the Inverse Compton Scattering Gamma-Ray Source Using Finite Element Method

NASA Astrophysics Data System (ADS)

Khizhanok, Andrei

Development of a compact source of high-spectral brilliance and high impulse frequency gamma rays has been in scope of Fermi National Accelerator Laboratory for quite some time. Main goal of the project is to develop a setup to support gamma rays detection test and gamma ray spectroscopy. Potential applications include but not limited to nuclear astrophysics, nuclear medicine, oncology ('gamma knife'). Present work covers multiple interconnected stages of development of the interaction region to ensure high levels of structural strength and vibrational resistance. Inverse Compton scattering is a complex phenomenon, in which charged particle transfers a part of its energy to a photon. It requires extreme precision as the interaction point is estimated to be 20 microm. The slightest deflection of the mirrors will reduce effectiveness of conversion by orders of magnitude. For acceptable conversion efficiency laser cavity also must have >1000 finesse value, which requires a trade-off between size, mechanical stability, complexity, and price of the setup. This work focuses on advantages and weak points of different designs of interaction regions as well as in-depth description of analyses performed. This includes laser cavity amplification and finesse estimates, natural frequency mapping, harmonic analysis. Structural analysis is required as interaction must occur under high vacuum conditions.

Mass transport properties of the tetrahydronaphthalene/n-dodecane mixture measured by investigating non-equilibrium fluctuations

NASA Astrophysics Data System (ADS)

Croccolo, Fabrizio; Scheffold, Frank; Bataller, Henri

2013-04-01

We present preliminary near-field light scattering (NFS) data concerning the analysis of the static power spectrum and of the relaxation time constant as a function of the wave vector for non-equilibrium fluctuations (NEFs). The goal of these measurements is to obtain information about the Soret and the mass diffusion coefficients of a binary mixture undergoing thermodiffusion. In particular, we show how the interaction between NEFs and the gravity force gives rise to a critical wavelength that provides additional information about the Soret coefficient. We suggest that a quantitative analysis can be performed by means of this non-invasive optical technique. In our setup, the sample is monitored parallel to the imposed temperature gradient, thus being insensitive to the refractive index profile along the vertical axis, while at the same time we are able to detect the light scattered by the refractive index fluctuations in horizontal planes. We select a shadowgraph layout for the NFS setup due to the extremely small wave vectors we aim to analyze. From a double-frame differential analysis of the acquired images, we obtain both the static power spectrum and the dynamics of NEFs. As a proof-of-principle experiment, we present Soret and diffusion coefficient data on a liquid mixture of tetrahydronaphthalene/n-dodecane.

Resolution power in digital in-line holography

NASA Astrophysics Data System (ADS)

Garcia-Sucerquia, J.; Xu, W.; Jericho, S. K.; Jericho, M. H.; Klages, P.; Kreuzer, H. J.

2006-01-01

Digital in-line holographic microscopy (DIHM) can achieve wavelength resolution both laterally and in depth with the simple optical setup consisting of a laser illuminating a wavelength-sized pinhole and a CCD camera for recording the hologram. The reconstruction is done numerically on the basis of the Kirchhoff-Helmholtz transform which yields a three-dimensional image of the objects throughout the sample volume. Resolution in DIHM depends on several controllable factors or parameters: (1) pinhole size controlling spatial coherence, (2) numerical aperture given by the size and positioning of the recording CCD chip, (3) pixel density and dynamic range controlling fringe resolution and noise level in the hologram and (4) wavelength. We present a detailed study of the individual and combined effects of these factors by doing an analytical analysis coupled with numerical simulations of holograms and their reconstruction. The result of this analysis is a set of criteria, also in the form of graphs, which can be used for the optimum design of the DIHM setup. We will also present a series of experimental results that test and confirm our theoretical analysis. The ultimate resolution to date is the imaging of the motion of submicron spheres and bacteria, a few microns apart, with speeds of hundreds of microns per second.

A setup for simultaneous measurement of infrared spectra and light scattering signals: Watching amyloid fibrils grow from intact proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yang; Maurer, Jürgen; Roth, Andreas

A setup for the simultaneous measurement of mid-infrared spectra and static light scattering is described that can be used for the analysis of the formation of nanoscale and microscopic aggregates from smaller molecules to biopolymers. It can be easily integrated into sample chambers of infrared spectrometers or combined with laser beams from tunable infrared lasers. Here, its use for the analysis of the formation of amyloid fibrils from intact proteins is demonstrated. The formation of amyloid fibrils or plaques from proteins is a widespread and pathogenetic relevant process, and a number of diseases are caused and correlated with the depositionmore » of amyloid fibrils in cells and tissues. The molecular mechanisms of these transformations, however, are still unclear. We report here the simultaneous measurement of infrared spectra and static light scattering for the analysis of fibril formation from egg-white lysozyme. The transformation of the native form into non-native forms rich in β-sheet structure is measured by analysis of the amide I spectral region in the infrared spectra, which is sensitive for local structures. At the same time, light scattering signals at forward direction as well as the forward/backward ratio, which are sensitive for the number of scattering centers and their approximate sizes, respectively, are collected for the analysis of fibril growth. Thermodynamic and kinetic parameters as well as mechanistic information are deduced from the combination of the two complementary techniques.« less

A setup for simultaneous measurement of infrared spectra and light scattering signals: Watching amyloid fibrils grow from intact proteins

NASA Astrophysics Data System (ADS)

Li, Yang; Maurer, Jürgen; Roth, Andreas; Vogel, Vitali; Winter, Ernst; Mäntele, Werner

2014-08-01

A setup for the simultaneous measurement of mid-infrared spectra and static light scattering is described that can be used for the analysis of the formation of nanoscale and microscopic aggregates from smaller molecules to biopolymers. It can be easily integrated into sample chambers of infrared spectrometers or combined with laser beams from tunable infrared lasers. Here, its use for the analysis of the formation of amyloid fibrils from intact proteins is demonstrated. The formation of amyloid fibrils or plaques from proteins is a widespread and pathogenetic relevant process, and a number of diseases are caused and correlated with the deposition of amyloid fibrils in cells and tissues. The molecular mechanisms of these transformations, however, are still unclear. We report here the simultaneous measurement of infrared spectra and static light scattering for the analysis of fibril formation from egg-white lysozyme. The transformation of the native form into non-native forms rich in β-sheet structure is measured by analysis of the amide I spectral region in the infrared spectra, which is sensitive for local structures. At the same time, light scattering signals at forward direction as well as the forward/backward ratio, which are sensitive for the number of scattering centers and their approximate sizes, respectively, are collected for the analysis of fibril growth. Thermodynamic and kinetic parameters as well as mechanistic information are deduced from the combination of the two complementary techniques.

Reconstruction of gene regulatory modules from RNA silencing of IFN-α modulators: experimental set-up and inference method.

PubMed

Grassi, Angela; Di Camillo, Barbara; Ciccarese, Francesco; Agnusdei, Valentina; Zanovello, Paola; Amadori, Alberto; Finesso, Lorenzo; Indraccolo, Stefano; Toffolo, Gianna Maria

2016-03-12

Inference of gene regulation from expression data may help to unravel regulatory mechanisms involved in complex diseases or in the action of specific drugs. A challenging task for many researchers working in the field of systems biology is to build up an experiment with a limited budget and produce a dataset suitable to reconstruct putative regulatory modules worth of biological validation. Here, we focus on small-scale gene expression screens and we introduce a novel experimental set-up and a customized method of analysis to make inference on regulatory modules starting from genetic perturbation data, e.g. knockdown and overexpression data. To illustrate the utility of our strategy, it was applied to produce and analyze a dataset of quantitative real-time RT-PCR data, in which interferon-α (IFN-α) transcriptional response in endothelial cells is investigated by RNA silencing of two candidate IFN-α modulators, STAT1 and IFIH1. A putative regulatory module was reconstructed by our method, revealing an intriguing feed-forward loop, in which STAT1 regulates IFIH1 and they both negatively regulate IFNAR1. STAT1 regulation on IFNAR1 was object of experimental validation at the protein level. Detailed description of the experimental set-up and of the analysis procedure is reported, with the intent to be of inspiration for other scientists who want to realize similar experiments to reconstruct gene regulatory modules starting from perturbations of possible regulators. Application of our approach to the study of IFN-α transcriptional response modulators in endothelial cells has led to many interesting novel findings and new biological hypotheses worth of validation.

Interactive Internet Based Pendulum for Learning Mechatronics

NASA Astrophysics Data System (ADS)

Sethson, Magnus R.

2003-01-01

This paper describes an Internet based remote experimental setup of a double lined pendulum mechanism for students experiments at the M. Sc. Level. Some of the first year experience using this web-based setup in classes is referred. In most of the courses given at the division of mechanical engineering systems at Linkoeping Institute of Technology we provide experimental setups to enhance the teaching Of M.Sc. students. Many of these experimental setups involve mechatronical systems. Disciplines like fluid power, electronics, and mechanics and also software technologies are used in each experiment. As our campus has recently been split into two different cities some new concepts for distance learning have been studied. The one described here tries to implement remotely controlled mechatronic setups for teaching basic programming of real-time operating systems and analysis of the dynamics of mechanical systems. The students control the regulators for the pendulum through a web interface and get measurement results and a movie back through their email. The present setup uses a double linked pendulum that is controlled by a DC-motor and monitored through both camera and angular position sensors. All software needed is hosted on a double-processor PC running the RedHat 7.1. distribution complemented with real-time scheduling using DIAPM-RTAI 1.7. The Internet site is presented to the students using PHP, Apache and MySQL. All of the used software originates from the open source domain. The experience from integrating these technologies and security issues is discussed together with the web-camera interface. One of the important experiences from this project so far is the need for a good visual feedback. This is both in terms of video speed but also in resolution. It has been noticed that when the students makes misstates and wants to search the failure they want clear, large images with high resolution to support their personal believes in the cause of the failure. Even if the student does not need a high resolution image to get the idea of the mechanics and the function of the pendulum, they need such high quality images to get confidence in the hardware. It is important to support this when the ability to direct hand-on contact with the hardware is taken away. Some of the experiences in combining open source software; real-time scheduling and measurement hardware into a cost efficient way is also discussed. The pendulum has been available publicly on the Internet but has now been removed due to security issues.

A computer-aided movement analysis system.

PubMed

Fioretti, S; Leo, T; Pisani, E; Corradini, M L

1990-08-01

Interaction with biomechanical data concerning human movement analysis implies the adoption of various experimental equipments and the choice of suitable models, data processing, and graphical data restitution techniques. The integration of measurement setups with the associated experimental protocols and the relative software procedures constitutes a computer-aided movement analysis (CAMA) system. In the present paper such integration is mapped onto the causes that limit the clinical acceptance of movement analysis methods. The structure of the system is presented. A specific CAMA system devoted to posture analysis is described in order to show the attainable features. Scientific results obtained with the support of the described system are also reported.

Urban and regional land use analysis: CARETS and census cities experiment package

NASA Technical Reports Server (NTRS)

Alexander, R. (Principal Investigator); Lins, H. F., Jr.; Gallagher, D. B.

1975-01-01

The author has identified the following significant results. Temperatures in degrees Celsius were derived from PCM counts using the Pease's modified gray window technique. The Outcalt simulator was setup on the USGS computer. The input data to the model are basically meteorological and geographical in nature. The output data is presented in three matrices.

Modelling, Simulation and Construction of a DC/DC Boost Power Converter: A School Experimental System

ERIC Educational Resources Information Center

Silva-Ortigoza, R.; Silva-Ortigoza, G.; Hernandez-Guzman, V. M.; Saldana-Gonzalez, G.; Marcelino-Aranda, M.; Marciano-Melchor, M.

2012-01-01

We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders…

When a Problem Is More than a Teacher's Question

ERIC Educational Resources Information Center

Olson, Jo Clay; Knott, Libby

2013-01-01

Not only are the problems teachers pose throughout their teaching of great importance but also the ways in which they use those problems make this a critical component of teaching. A problem-posing episode includes the problem setup, the statement of the problem, and the follow-up questions. Analysis of problem-posing episodes of precalculus…

Analysis of Cisco Open Network Environment (ONE) OpenFlow Controller Implementation

DTIC Science & Technology

2014-08-01

Software - Defined Networking ( SDN ), when fully realized, offer many improvements over the current rigid and...functionalities like handshake, connection setup, switch management, and security. 15. SUBJECT TERMS OpenFlow, software - defined networking , Cisco ONE, SDN ...innovating packet-forwarding technologies. Network device roles are strictly defined with little or no flexibility. In Software - Defined Networks ( SDNs ),

Adaptive Multi-Layer LMS Controller Design and Application to Active Vibration Suppression on a Truss and Proposed Impact Analysis Technique

DTIC Science & Technology

2001-06-01

Setup and Initiation ........................................................ 83 2. Simulation 1 (19 Hz, Y-axis of Node 18, Piezo #2...175 INITIAL DISTRIBUTION LIST ................................................................................... 187 ix...system for the sake of testing and simplicity. The Adaptive Multi-Layered LMS Controller was developed one piece at a time. After initial experimental

1000539

NASA Image and Video Library

2010-04-13

AYMAN GIRGIS (EM10 MATERIALS TEST ENGINEER, JACOBS ESTS GROUP/JTI) AND ERIC EARHART (AEROSPACE ENGINEER, ER41 PROPULSION STRUCTURAL & DYNAMICS ANALYSIS BRANCH) DISCUSS DATA PRODUCED BY A UNIQUE MECHANICAL TEST SETUP THAT MEASURES STRAIN ON A SINGLE SAMPLE, USING TWO DIFFERENT TECHNIQUES AT THE SAME TIME. THE TEST FIXTURE HOLDS A SPECIMEN THAT REPRESENTS A LIQUID OXYGEN (LOX) BEARING FROM THE J2-X ENGINE.

Investigating Convective Heat Transfer with an Iron and a Hairdryer

ERIC Educational Resources Information Center

Gonzalez, Manuel I.; Lucio, Jesus H.

2008-01-01

A simple experimental set-up to study free and forced convection in undergraduate physics laboratories is presented. The flat plate of a domestic iron has been chosen as the hot surface, and a hairdryer is used to generate an air stream around the plate. Several experiments are proposed and typical numerical results are reported. An analysis and…

A Modification of the Oersted Experiment

ERIC Educational Resources Information Center

Stoyanov, Dimitar G.

2009-01-01

The paper describes a simple set-up of the Oersted experiment. A planar coil of wires has been used to deflect vigorously the magnetic needle (more than 80 angular degrees) when a current of up to 1 A flows along it. Based on theoretical analysis the torque on the magnetic field is analytically expressed taking into account the inhomogeneity of…

Optimizing Mouse Surgery with Online Rectal Temperature Monitoring and Preoperative Heat Supply. Effects on Post-Ischemic Acute Kidney Injury

PubMed Central

Holderied, Alexander; Anders, Hans-Joachim

2016-01-01

Body temperature affects outcomes of tissue injury. We hypothesized that online body core temperature recording and selective interventions help to standardize peri-interventional temperature control and the reliability of outcomes in experimental renal ischemia reperfusion injury (IRI). We recorded core temperature in up to seven mice in parallel using a Thermes USB recorder and ret-3-iso rectal probes with three different protocols. Setup A: Heating pad during ischemia time; Setup B: Heating pad from incision to wound closure; Setup C: A ventilated heating chamber before surgery and during ischemia time with surgeries performed on a heating pad. Temperature profile recording displayed significant declines upon installing anesthesia. The profile of the baseline experimental setup A revealed that <1% of the temperature readings were within the target range of 36.5 to 38.5°C. Setup B and C increased the target range readings to 34.6 ± 28.0% and 99.3 ± 1.5%, respectively. Setup C significantly increased S3 tubular necrosis, neutrophil influx, and mRNA expression of kidney injury markers. In addition, using setup C different ischemia times generated a linear correlation with acute tubular necrosis parameters at a low variability, which further correlated with the degree of kidney atrophy 5 weeks after surgery. Changing temperature control setup A to C was equivalent to 10 minutes more ischemia time. We conclude that body temperature drops quickly in mice upon initiating anesthesia. Immediate heat supply, e.g. in a ventilated heating chamber, and online core temperature monitoring can help to standardize and optimize experimental outcomes. PMID:26890071

Gas diffusion electrode setup for catalyst testing in concentrated phosphoric acid at elevated temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiberg, Gustav K. H., E-mail: gustav.wiberg@gmail.com, E-mail: m.arenz@chem.ku.dk; Fleige, Michael; Arenz, Matthias, E-mail: gustav.wiberg@gmail.com, E-mail: m.arenz@chem.ku.dk

2015-02-15

We present a detailed description of the construction and testing of an electrochemical cell setup allowing the investigation of a gas diffusion electrode containing carbon supported high surface area catalysts. The setup is designed for measurements in concentrated phosphoric acid at elevated temperature, i.e., very close to the actual conditions in high temperature proton exchange membrane fuel cells (HT-PEMFCs). The cell consists of a stainless steel flow field and a PEEK plastic cell body comprising the electrochemical cell, which exhibits a three electrode configuration. The cell body and flow field are braced using a KF-25 vacuum flange clamp, which allowsmore » an easy assembly of the setup. As demonstrated, the setup can be used to investigate temperature dependent electrochemical processes on high surface area type electrocatalysts, but it also enables quick screening tests of HT-PEMFC catalysts under realistic conditions.« less

Design of experimental setup for supercritical CO2 jet under high ambient pressure conditions

NASA Astrophysics Data System (ADS)

Shi, Huaizhong; Li, Gensheng; He, Zhenguo; Wang, Haizhu; Zhang, Shikun

2016-12-01

With the commercial extraction of hydrocarbons in shale and tight reservoirs, efficient methods are needed to accelerate developing process. Supercritical CO2 (SC-CO2) jet has been considered as a potential way due to its unique fluid properties. In this article, a new setup is designed for laboratory experiment to research the SC-CO2 jet's characteristics in different jet temperatures, pressures, standoff distances, ambient pressures, etc. The setup is composed of five modules, including SC-CO2 generation system, pure SC-CO2 jet system, abrasive SC-CO2 jet system, CO2 recovery system, and data acquisition system. Now, a series of rock perforating (or case cutting) experiments have been successfully conducted using the setup about pure and abrasive SC-CO2 jet, and the results have proven the great perforating efficiency of SC-CO2 jet and the applications of this setup.

Design of experimental setup for supercritical CO2 jet under high ambient pressure conditions.

PubMed

Shi, Huaizhong; Li, Gensheng; He, Zhenguo; Wang, Haizhu; Zhang, Shikun

2016-12-01

With the commercial extraction of hydrocarbons in shale and tight reservoirs, efficient methods are needed to accelerate developing process. Supercritical CO 2 (SC-CO 2 ) jet has been considered as a potential way due to its unique fluid properties. In this article, a new setup is designed for laboratory experiment to research the SC-CO 2 jet's characteristics in different jet temperatures, pressures, standoff distances, ambient pressures, etc. The setup is composed of five modules, including SC-CO 2 generation system, pure SC-CO 2 jet system, abrasive SC-CO 2 jet system, CO 2 recovery system, and data acquisition system. Now, a series of rock perforating (or case cutting) experiments have been successfully conducted using the setup about pure and abrasive SC-CO 2 jet, and the results have proven the great perforating efficiency of SC-CO 2 jet and the applications of this setup.

Advanced setup for high-pressure and low-temperature neutron diffraction at hydrostatic conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lokshin, Konstantin A.; Zhao Yusheng

2005-06-15

We describe a design of the experimental setup for neutron diffraction studies at low temperatures and hydrostatic pressure. The significant benefit of the setup, compared to the previous methods, is that it makes possible the simultaneous collection of neutrons diffracted at the 30 deg. -150 deg. range with no contamination by the primary scattering from the sample surroundings and without cutting out the incident and diffracted beams. The suggested design is most useful for third-generation time-of-flight diffractometers and constant wavelength instruments. Application of the setup expands the capabilities of high-pressure neutron diffraction, allowing time-resolved kinetics and structural studies, multihistogram Rietveld,more » and pair distribution function and texture analyses. The high efficiency of the setup was proven for the HIPPO diffractometer at Los Alamos Neutron Science Center under pressures up to 10 kbar and temperatures from 4 to 300 K.« less

Gas diffusion electrode setup for catalyst testing in concentrated phosphoric acid at elevated temperatures

NASA Astrophysics Data System (ADS)

Wiberg, Gustav K. H.; Fleige, Michael; Arenz, Matthias

2015-02-01

We present a detailed description of the construction and testing of an electrochemical cell setup allowing the investigation of a gas diffusion electrode containing carbon supported high surface area catalysts. The setup is designed for measurements in concentrated phosphoric acid at elevated temperature, i.e., very close to the actual conditions in high temperature proton exchange membrane fuel cells (HT-PEMFCs). The cell consists of a stainless steel flow field and a PEEK plastic cell body comprising the electrochemical cell, which exhibits a three electrode configuration. The cell body and flow field are braced using a KF-25 vacuum flange clamp, which allows an easy assembly of the setup. As demonstrated, the setup can be used to investigate temperature dependent electrochemical processes on high surface area type electrocatalysts, but it also enables quick screening tests of HT-PEMFC catalysts under realistic conditions.

A versatile and reconfigurable setup for all-terahertz time-resolved pump-probe spectroscopy.

PubMed

Elezzabi, A Y; Maraghechi, P

2012-05-01

A versatile optical setup for all-terahertz (THz) time resolved pump-probe spectroscopy was designed and tested. By utilizing a dual THz pulse generator emitter module, independent and synchronized THz radiation pump and probe pulses were produced, thus eliminating the need for THz beam splitters and the limitations associated with their implementation. The current THz setup allows for precise control of the electric fields splitting ratio between the THz radiation pump and probe pulses, as well as in-phase, out-of-phase, and polarization dependent pump-probe spectroscopy. Since the present THz pump-probe setup does not require specialized THz radiation optical components, such as phase shifters, polarization rotators, or wide bandwidth beam splitters, it can be easily implemented with minimal alterations to a conventional THz time domain spectroscopy system. The present setup is valuable for studying the time dynamics of THz coherent phenomena in solid-state, chemical, and biological systems.

Computer Controlled Magnetotransport Setup for the Characterization of Semiconductor Thin Films

NASA Technical Reports Server (NTRS)

Ducoudray, G. O.; Collazo, R.; Martinez, A.

1997-01-01

We have considered a computer controlled magnetotransport setup using LabWindows environment. It allows for measurements of resistivity, Hall resistance, carrier concentration and charge mobility in semiconductor thin films using a van der Pauw configuration. The setup features an electromagnet (B = 0.7 Tesla) a 80486-DX 33 computer with a National Instrument AT-MIO 16 AD/DA and a GPIB interface board. A Keithely 224 current source and a Keithley 196 digital voltmeter were also used in the setup. Plans for the addition of capabilities to allow for magnetic field sweeping and the performance of measurements as a function of temperature will be presented.

Measuring the Earth’s magnetic field dip angle using a smartphone-aided setup: a simple experiment for introductory physics laboratories

NASA Astrophysics Data System (ADS)

Arabasi, Sameer; Al-Taani, Hussein

2017-03-01

Measurement of the Earth’s magnetic field dip angle is a widely used experiment in most introductory physics laboratories. In this paper we propose a smartphone-aided setup that takes advantage of the smartphone’s magnetometer sensor to measure the Earth’s magnetic field dip angle. This set-up will help students visualize the vector nature of the Earth’s magnetic field, especially high school and first year college students who are not quite experienced with vectors. This set-up is affordable and easy to use and could be easily produced by any high school or college physics instructor.

Qualified measurement setup of polarization extinction ratio for Panda PMF with LC/UPC connector

NASA Astrophysics Data System (ADS)

Thongdaeng, Rutsuda; Worasucheep, Duang-rudee; Ngiwprom, Adisak

2018-03-01

Polarization Extinction Ratio (PER) is one of the key parameters for Polarization Maintaining Fiber (PMF) connector. Based on our previous studies, the bending radius of fiber greater than 1.5 cm will not affect the insertion loss of PMF [1]. Moreover, the measured PER of Panda PMF with LC/UPC connectors is more stable when that PMF is coiled around a hot rod with a minimum of 3-cm in diameter at 75°C temperature [2]. Hence, the hot rod with less constrained 6-cm in diameter at constant 75°C was selected for this PER measurement. Two PER setups were verified and compared for measuring LC/UPC PMF connectors. The Polarized Laser Source (PLS) at 1550 nm wavelength and PER meter from OZ Optics were used in both setups, in which the measured connector was connected to PLS at 0° angle while the other end was connected to PER meter. In order to qualify our setups, the percentage of Repeatability and Reproducibility (%R&R) were tested and calculated. In each setup, the PER measurement was repeated 3 trials by 3 appraisers using 10 LC/UPC PMF connectors (5 LC/UPC PMF patchcords with 3.5+/-0.5 meters in length) in random order. The 1st setup, PMF was coiled at a larger 20-cm diameter for 3 to 5 loops and left in room temperature during the test. The 2nd setup, PMF was coiled around a hot rod at constant 75°C with 6-cm diameter for 8 to 10 loops for at least 5 minutes before testing. There are 3 ranges of %R&R acceptation guide line: <10% is acceptable, between 10% - 30% is marginal, and <30% is unacceptable. According to our results, the %R&R of the 1st PER test setup was 16.2% as marginality, and the 2nd PER test setup was 8.9% as acceptance. Thus, providing the better repeatability and reproducibility, this 2nd PER test setup having PMF coiled around a hot rod at constant 75°C with 6-cm diameter was selected for our next study of the impact of hot temperature on PER in LC/UPC PMF connector.

Blood proteins analysis by Raman spectroscopy method

NASA Astrophysics Data System (ADS)

Artemyev, D. N.; Bratchenko, I. A.; Khristoforova, Yu. A.; Lykina, A. A.; Myakinin, O. O.; Kuzmina, T. P.; Davydkin, I. L.; Zakharov, V. P.

2016-04-01

This work is devoted to study the possibility of plasma proteins (albumin, globulins) concentration measurement using Raman spectroscopy setup. The blood plasma and whole blood were studied in this research. The obtained Raman spectra showed significant variation of intensities of certain spectral bands 940, 1005, 1330, 1450 and 1650 cm-1 for different protein fractions. Partial least squares regression analysis was used for determination of correlation coefficients. We have shown that the proposed method represents the structure and biochemical composition of major blood proteins.

Thermal APU/hydraulics analysis program. User's guide and programmer's manual

NASA Technical Reports Server (NTRS)

Deluna, T. A.

1976-01-01

The User's Guide information plus program description necessary to run and have a general understanding of the Thermal APU/Hydraulics Analysis Program (TAHAP) is described. This information consists of general descriptions of the APU/hydraulic system and the TAHAP model, input and output data descriptions, and specific subroutine requirements. Deck setups and input data formats are included and other necessary and/or helpful information for using TAHAP is given. The math model descriptions for the driver program and each of its supporting subroutines are outlined.

Modeling and analysis of wet friction clutch engagement dynamics

NASA Astrophysics Data System (ADS)

Iqbal, Shoaib; Al-Bender, Farid; Ompusunggu, Agusmian P.; Pluymers, Bert; Desmet, Wim

2015-08-01

In recent years, there has been a significant increase in the usage of wet-friction clutches. Presently researchers across the globe are involved in improving the performance and lifetime of clutches through testing and simulation. To understand the clutch vibrational and dynamical behavior, an SAE#2 test setup mathematical model based on extended reset-integrator friction model is developed in this paper. In order to take into account the different phases of fluid lubrication during engagement cycle, the model includes the experimentally determined Stribeck function. In addition the model considers the viscous effect and the delay in the actuation pressure signal. The model is validated with the experiments performed on the SAE#2 test setup in both time and frequency domains. By analyzing the set of experimental results, we confirmed that the amplitude of shudder vibration is independent of the amplitude of applied contact pressure fluctuation.

Improved Temperature Diagnostic for Non-Neutral Plasmas with Single-Electron Resolution

NASA Astrophysics Data System (ADS)

Shanman, Sabrina; Evans, Lenny; Fajans, Joel; Hunter, Eric; Nelson, Cheyenne; Sierra, Carlos; Wurtele, Jonathan

2016-10-01

Plasma temperature diagnostics in a Penning-Malmberg trap are essential for reliably obtaining cold, non-neutral plasmas. We have developed a setup for detecting the initial electrons that escape from a trapped pure electron plasma as the confining electrode potential is slowly reduced. The setup minimizes external noise by using a silicon photomultiplier to capture light emitted from an MCP-amplified phosphor screen. To take advantage of this enhanced resolution, we have developed a new plasma temperature diagnostic analysis procedure which takes discrete electron arrival times as input. We have run extensive simulations comparing this new discrete algorithm to our existing exponential fitting algorithm. These simulations are used to explore the behavior of these two temperature diagnostic procedures at low N and at high electronic noise. This work was supported by the DOE DE-FG02-06ER54904, and the NSF 1500538-PHY.

Validation of enhanced kinect sensor based motion capturing for gait assessment

PubMed Central

Müller, Björn; Ilg, Winfried; Giese, Martin A.

2017-01-01

Optical motion capturing systems are expensive and require substantial dedicated space to be set up. On the other hand, they provide unsurpassed accuracy and reliability. In many situations however flexibility is required and the motion capturing system can only temporarily be placed. The Microsoft Kinect v2 sensor is comparatively cheap and with respect to gait analysis promising results have been published. We here present a motion capturing system that is easy to set up, flexible with respect to the sensor locations and delivers high accuracy in gait parameters comparable to a gold standard motion capturing system (VICON). Further, we demonstrate that sensor setups which track the person only from one-side are less accurate and should be replaced by two-sided setups. With respect to commonly analyzed gait parameters, especially step width, our system shows higher agreement with the VICON system than previous reports. PMID:28410413

Production layout improvement in emergency services: a participatory approach.

PubMed

Zanatta, Mateus; Amaral, Fernando Gonçalves

2012-01-01

Volunteer fire department is a service that responds emergency situations in places where there are no military emergency services. These services need to respond quickly, because time is often responsible for the operation success besides work environment and setup time interfere with the prompt response to these calls and care efficiency. The layout design is one factor that interferes with the quick setup. In this case, the spaces arrangement can result in excessive or unnecessary movements; also the equipment provision may hinder the selection and collection of these or even create movement barriers for the workers. This work created a new layout for the emergency assistance service, considering the human factors related to work through the task analysis and workers participation on the alternatives of improvement. The results showed an alternate layout with corridors and minimization of unusable sites, allowing greater flexibility and new possibilities of requirements.

Adaptive resolution simulation of oligonucleotides

NASA Astrophysics Data System (ADS)

Netz, Paulo A.; Potestio, Raffaello; Kremer, Kurt

2016-12-01

Nucleic acids are characterized by a complex hierarchical structure and a variety of interaction mechanisms with other molecules. These features suggest the need of multiscale simulation methods in order to grasp the relevant physical properties of deoxyribonucleic acid (DNA) and RNA using in silico experiments. Here we report an implementation of a dual-resolution modeling of a DNA oligonucleotide in physiological conditions; in the presented setup only the nucleotide molecule and the solvent and ions in its proximity are described at the atomistic level; in contrast, the water molecules and ions far from the DNA are represented as computationally less expensive coarse-grained particles. Through the analysis of several structural and dynamical parameters, we show that this setup reliably reproduces the physical properties of the DNA molecule as observed in reference atomistic simulations. These results represent a first step towards a realistic multiscale modeling of nucleic acids and provide a quantitatively solid ground for their simulation using dual-resolution methods.

PIXE microbeam analysis of the metallic debris release around endosseous implants

NASA Astrophysics Data System (ADS)

Buso, G. P.; Galassini, S.; Moschini, G.; Passi, P.; Zadro, A.; Uzunov, N. M.; Doyle, B. L.; Rossi, P.; Provencio, P.

2005-10-01

The mechanical friction that occurs during the surgical insertion of endosseous implants, both in dentistry and orthopaedics, may cause the detachment of metal debris which are dislodged into the peri-implant tissues and can lead to adverse clinical effects. This phenomenon more likely happens with coated or roughened implants that are the most widely employed. In the present study were studied dental implants screws made of commercially pure titanium and coated using titanium plasma-spray (TPS) technique. The implants were inserted in the tibia of rabbits, and removed "en bloc" with the surrounding bone after one month. After proper processing and mounting on plastic holders, samples from bones were analysed by EDXRF setup at of National Laboratories of Legnaro, INFN, Italy, and consequently at 3 MeV proton microbeam setup at Sandia National Laboratories. Elemental maps were drawn, showing some occasional presence of metal particles in the peri-implant bone.

Geometrical pose and structural estimation from a single image for automatic inspection of filter components

NASA Astrophysics Data System (ADS)

Liu, Yonghuai; Rodrigues, Marcos A.

2000-03-01

This paper describes research on the application of machine vision techniques to a real time automatic inspection task of air filter components in a manufacturing line. A novel calibration algorithm is proposed based on a special camera setup where defective items would show a large calibration error. The algorithm makes full use of rigid constraints derived from the analysis of geometrical properties of reflected correspondence vectors which have been synthesized into a single coordinate frame and provides a closed form solution to the estimation of all parameters. For a comparative study of performance, we also developed another algorithm based on this special camera setup using epipolar geometry. A number of experiments using synthetic data have shown that the proposed algorithm is generally more accurate and robust than the epipolar geometry based algorithm and that the geometric properties of reflected correspondence vectors provide effective constraints to the calibration of rigid body transformations.

Combined In Situ Illumination-NMR-UV/Vis Spectroscopy: A New Mechanistic Tool in Photochemistry.

PubMed

Seegerer, Andreas; Nitschke, Philipp; Gschwind, Ruth M

2018-06-18

Synthetic applications in photochemistry are booming. Despite great progress in the development of new reactions, mechanistic investigations are still challenging. Therefore, we present a fully automated in situ combination of NMR spectroscopy, UV/Vis spectroscopy, and illumination to allow simultaneous and time-resolved detection of paramagnetic and diamagnetic species. This optical fiber-based setup enables the first acquisition of combined UV/Vis and NMR spectra in photocatalysis, as demonstrated on a conPET process. Furthermore, the broad applicability of combined UVNMR spectroscopy for light-induced processes is demonstrated on a structural and quantitative analysis of a photoswitch, including rate modulation and stabilization of transient species by temperature variation. Owing to the flexibility regarding the NMR hardware, temperature, and light sources, we expect wide-ranging applications of this setup in various research fields. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Particle identification using digital pulse shape discrimination in a nTD silicon detector with a 1 GHz sampling digitizer

NASA Astrophysics Data System (ADS)

Mahata, K.; Shrivastava, A.; Gore, J. A.; Pandit, S. K.; Parkar, V. V.; Ramachandran, K.; Kumar, A.; Gupta, S.; Patale, P.

2018-06-01

In beam test experiments have been carried out for particle identification using digital pulse shape analysis in a 500 μm thick Neutron Transmutation Doped (nTD) silicon detector with an indigenously developed FPGA based 12 bit resolution, 1 GHz sampling digitizer. The nTD Si detector was used in a low-field injection setup to detect light heavy-ions produced in reactions of ∼ 5 MeV/A 7Li and 12C beams on different targets. Pulse height, rise time and current maximum have been obtained from the digitized charge output of a high bandwidth charge and current sensitive pre-amplifier. Good isotopic separation have been achieved using only the digitized charge output in case of light heavy-ions. The setup can be used for charged particle spectroscopy in nuclear reactions involving light heavy-ions around the Coulomb barrier energies.

Setup, Validation and Quality Control of a Centralized WGS laboratory - Lessons Learned.

PubMed

Arnold, Cath; Edwards, Kirstin; Desai, Meeta; Platt, Steve; Green, Jonathan; Conway, David

2018-04-25

Routine use of Whole Genome analysis for infectious diseases can be used to enlighten various scenarios pertaining to Public Health, including identification of microbial pathogens; relating individual cases to an outbreak of infectious disease; establishing an association between an outbreak of food poisoning and a specific food vehicle; inferring drug susceptibility; source tracing of contaminants and study of variations in the genome affect pathogenicity/virulence. We describe the setup, validation and ongoing verification of a centralised WGS laboratory to carry out the sequencing for these public health functions for the National Infection Services, Public Health England in the UK. The performance characteristics and Quality Control metrics measured during validation and verification of the entire end to end process (accuracy, precision, reproducibility and repeatability) are described and include information regarding the automated pass and release of data to service users without intervention. © Crown copyright 2018.

A technique for the measurement of organic aerosol hygroscopicity, oxidation level, and volatility distributions

NASA Astrophysics Data System (ADS)

Cain, Kerrigan P.; Pandis, Spyros N.

2017-12-01

Hygroscopicity, oxidation level, and volatility are three crucial properties of organic pollutants. This study assesses the feasibility of a novel measurement and analysis technique to determine these properties and establish their relationship. The proposed experimental setup utilizes a cloud condensation nuclei (CCN) counter to quantify hygroscopic activity, an aerosol mass spectrometer to measure the oxidation level, and a thermodenuder to evaluate the volatility. The setup was first tested with secondary organic aerosol (SOA) formed from the ozonolysis of α-pinene. The results of the first experiments indicated that, for this system, the less volatile SOA contained species that had on average lower O : C ratios and hygroscopicities. In this SOA system, both low- and high-volatility components can have comparable oxidation levels and hygroscopicities. The method developed here can be used to provide valuable insights about the relationships among organic aerosol hygroscopicity, oxidation level, and volatility.

Determination of effective complex refractive index of a turbid liquid with surface plasmon resonance phase detection.

PubMed

Yingying, Zhang; Jiancheng, Lai; Cheng, Yin; Zhenhua, Li

2009-03-01

The dependence of the surface plasmon resonance (SPR) phase difference curve on the complex refractive index of a sample in Kretschmann configuration is discussed comprehensively, based on which a new method is proposed to measure the complex refractive index of turbid liquid. A corresponding experiment setup was constructed to measure the SPR phase difference curve, and the complex refractive index of turbid liquid was determined. By using the setup, the complex refractive indices of Intralipid solutions with concentrations of 5%, 10%, 15%, and 20% are obtained to be 1.3377+0.0005 i, 1.3427+0.0028 i, 1.3476+0.0034 i, and 1.3496+0.0038 i, respectively. Furthermore, the error analysis indicates that the root-mean-square errors of both the real and the imaginary parts of the measured complex refractive index are less than 5x10(-5).

Comparison of Fiber Optic and Conduit Attenuated Total Reflection (ATR) Fourier Transform Infrared (FT-IR) Setup for In-Line Fermentation Monitoring.

PubMed

Koch, Cosima; Posch, Andreas E; Herwig, Christoph; Lendl, Bernhard

2016-12-01

The performance of a fiber optic and an optical conduit in-line attenuated total reflection mid-infrared (IR) probe during in situ monitoring of Penicillium chrysogenum fermentation were compared. The fiber optic probe was connected to a sealed, portable, Fourier transform infrared (FT-IR) process spectrometer via a plug-and-play interface. The optical conduit, on the other hand, was connected to a FT-IR process spectrometer via a knuckled probe with mirrors that had to be adjusted prior to each fermentation, which were purged with dry air. Penicillin V (PenV) and its precursor phenoxyacetic acid (POX) concentrations were determined by online high-performance liquid chromatography and the obtained concentrations were used as reference to build partial least squares regression models. Cross-validated root-mean-square errors of prediction were found to be 0.2 g L -1 (POX) and 0.19 g L -1 (PenV) for the fiber optic setup and 0.17 g L -1 (both POX and PenV) for the conduit setup. Higher noise-levels and spectrum-to-spectrum variations of the fiber optic setup lead to higher noise of estimated (i.e., unknown) POX and PenV concentrations than was found for the conduit setup. It seems that trade-off has to be made between ease of handling (fiber optic setup) and measurement accuracy (optical conduit setup) when choosing one of these systems for bioprocess monitoring. © The Author(s) 2016.

Thai National Telescope beam simulator testbed development status

NASA Astrophysics Data System (ADS)

Buisset, Christophe; Prasit, Apirat; Lépine, Thierry; Poshyachinda, Saran; Leckngam, A.

2016-07-01

The Thai National Telescope (TNT) is a Ritchey-Chretien Telescope with a clear aperture ΦM1 = 2.3 m, a focal ratio f/10 and a central obstruction Obsc = 0.3. The TNT is the main instrument of the Thai National Observatory (TNO) which is located near the summit of the Doi Inthanon, situated in the Chiang Mai Province of Thailand at altitude 2,457 meters. The median seeing on this site is approximately 0.9" and is remarkably stable on most nights, rarely exceeding 2". We decided to develop an optical setup to simulate in laboratory conditions the geometry of the TNT output beam. This, in order to carefully prepare and to improve the efficiency of the test to be performed in real conditions at the TNT focal plane level. We specified the setup to be representative of the TNT optical design, beam aperture, central obscuration, geometry of the spider, wavefront quality and PSF size under various seeing conditions. This setup comprises 2 identical Cassegrain telescopes mounted on dedicated supports with 5 degree-of-Freedom. The first application of this setup will be the preparation of the TNT optical alignment. The second application of this setup will be the development and the test of the future instruments for the TNT such as a focal reducer or a spectrograph. In this paper, we discuss the setup specifications we describe the setup optical and mechanical design and we present the performance.

Setup Instructions for the Applied Anomaly Detection Tool (AADT) Web Server

DTIC Science & Technology

2016-09-01

ARL-TR-7798 ● SEP 2016 US Army Research Laboratory Setup Instructions for the Applied Anomaly Detection Tool (AADT) Web Server...for the Applied Anomaly Detection Tool (AADT) Web Server by Christian D Schlesiger Computational and Information Sciences Directorate, ARL...SUBTITLE Setup Instructions for the Applied Anomaly Detection Tool (AADT) Web Server 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

MO-FG-CAMPUS-JeP3-02: A Novel Setup Approach to Improve C-Spine Curvature Reproducibility for Head and Neck Radiotherapy Using Optical Surface Imaging with Two Regions of Interest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryan, K; Gil, M; Li, G

Purpose: To develop a novel approach to improve cervical spine (c-spine) curvature reproducibility for head and neck (HN) patients using optical surface imaging (OSI) with two regions of interests (ROIs). Methods: The OSI-guided, two-step setup procedure requires two ROIs: ROI-1 of the shoulders and ROI-2 of the face. The neck can be stretched or squeezed in superior-inferior (SI) direction using a specially-designed sliding head support. We hypothesize that when these two ROIs are aligned, the c-spine should fall into a naturally reproducible position under same setup conditions. An anthropomorphous phantom test was performed to examine neck pitch angles comparing withmore » the calculated angles. Three volunteers participated in the experiments, which start with conventional HN setup using skin markers and room lasers. An OSI image and lateral photo-picture were acquired as the references. In each of the three replicate tests, conventional setup was first applied after volunteers got on the couch. ROI-1 was aligned by moving the body, followed by ROI-2 alignment via adjusting head position and orientation under real-time OSI guidance. A final static OSI image and lateral picture were taken to evaluate both anterior and posterior surface alignments. Three degrees of freedom can be adjusted if an open-face mask was applied, including head SI shift using the sliding head support and pitch-and-roll rotations using a commercial couch extension. Surface alignment was analyzed comparing with conventional setup. Results: The neck pitch angle measured by OSI is consistent with the calculated (0.2±0.6°). Volunteer study illustrated improved c-spine setup reproducibility using OSI comparing with conventional setup. ROI alignments with 2mm/1° tolerance are achieved within 3 minutes. Identical knee support is important to achieve ROI-1 pitch alignment. Conclusion: The feasibility of this novel approach has been demonstrated for c-spine curvature setup reproducibility. Further evaluation is necessary with bony alignment variation in patient studies. This study is in part supported by the NIH (U54CA137788).« less

A managed clinical network for cardiac services: set-up, operation and impact on patient care.

PubMed

Stc Hamilton, Karen E; Sullivan, Frank M; Donnan, Peter T; Taylor, Rex; Ikenwilo, Divine; Scott, Anthony; Baker, Chris; Wyke, Sally

2005-01-01

To investigate the set up and operation of a Managed Clinical Network for cardiac services and assess its impact on patient care. This single case study used process evaluation with observational before and after comparison of indicators of quality of care and costs. The study was conducted in Dumfries and Galloway, Scotland and used a three-level framework. Process evaluation of the network set-up and operation through a documentary review of minutes; guidelines and protocols; transcripts of fourteen semi-structured interviews with health service personnel including senior managers, general practitioners, nurses, cardiologists and members of the public. Outcome evaluation of the impact of the network through interrupted time series analysis of clinical data of 202 patients aged less than 76 years admitted to hospital with a confirmed myocardial infarction one-year pre and one-year post, the establishment of the network. The main outcome measures were differences between indicators of quality of care targeted by network protocols. Economic evaluation of the transaction costs of the set-up and operation of the network and the resource costs of the clinical care of the 202 myocardial infarction patients from the time of hospital admission to 6 months post discharge through interrupted time series analysis. The outcome measure was different in National Health Service resource use. Despite early difficulties, the network was successful in bringing together clinicians, patients and managers to redesign services, exhibiting most features of good network management. The role of the energetic lead clinician was crucial, but the network took time to develop and 'bed down'. Its primary "modus operand" was the development of a myocardial infarction pathway and associated protocols. Of sixteen clinical care indicators, two improved significantly following the launch of the network and nine showed improvements, which were not statistically significant. There was no difference in resource use. The Managed Clinical Network made a difference to ways of working, particularly in breaching traditional boundaries and involving the public, and made modest changes in patient care. However, it required a two-year "set-up" period. Managed clinical networks are complex initiatives with an increasing profile in health care policy. This study suggests that they require energetic leadership and improvements are likely to be slow and incremental.

A service evaluation of on-line image-guided radiotherapy to lower extremity sarcoma: Investigating the workload implications of a 3 mm action level for image assessment and correction prior to delivery.

PubMed

Taylor, C; Parker, J; Stratford, J; Warren, M

2018-05-01

Although all systematic and random positional setup errors can be corrected for in entirety during on-line image-guided radiotherapy, the use of a specified action level, below which no correction occurs, is also an option. The following service evaluation aimed to investigate the use of this 3 mm action level for on-line image assessment and correction (online, systematic set-up error and weekly evaluation) for lower extremity sarcoma, and understand the impact on imaging frequency and patient positioning error within one cancer centre. All patients were immobilised using a thermoplastic shell attached to a plastic base and an individual moulded footrest. A retrospective analysis of 30 patients was performed. Patient setup and correctional data derived from cone beam CT analysis was retrieved. The timing, frequency and magnitude of corrections were evaluated. The population systematic and random error was derived. 20% of patients had no systematic corrections over the duration of treatment, and 47% had one. The maximum number of systematic corrections per course of radiotherapy was 4, which occurred for 2 patients. 34% of episodes occurred within the first 5 fractions. All patients had at least one observed translational error during their treatment greater than 0.3 cm, and 80% of patients had at least one observed translational error during their treatment greater than 0.5 cm. The population systematic error was 0.14 cm, 0.10 cm, 0.14 cm and random error was 0.27 cm, 0.22 cm, 0.23 cm in the lateral, caudocranial and anteroposterial directions. The required Planning Target Volume margin for the study population was 0.55 cm, 0.41 cm and 0.50 cm in the lateral, caudocranial and anteroposterial directions. The 3 mm action level for image assessment and correction prior to delivery reduced the imaging burden and focussed intervention on patients that exhibited greater positional variability. This strategy could be an efficient deployment of departmental resources if full daily correction of positional setup error is not possible. Copyright © 2017. Published by Elsevier Ltd.

Birefringence of Cellotape: Jones Representation and Experimental Analysis

ERIC Educational Resources Information Center

Belendez, Augusto; Fernandez, Elena; Frances, Jorge; Neipp, Cristian

2010-01-01

In this paper, we analyse a simple experiment to study the effects of polarized light. A simple optical system composed of a polarizer, a retarder (cellotape) and an analyser is used to study the effect on the polarization state of the light which impinges on the setup. The optical system is characterized by means of a Jones matrix, and a simple…

Quantum contextuality in N-boson systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benatti, Fabio; Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34014 Trieste; Floreanini, Roberto

2011-09-15

Quantum contextuality in systems of identical bosonic particles is explicitly exhibited via the maximum violation of a suitable inequality of Clauser-Horne-Shimony-Holt type. Unlike the approaches considered so far, which make use of single-particle observables, our analysis involves collective observables constructed using multiboson operators. An exemplifying scheme to test this violation with a quantum optical setup is also discussed.

Musical Make-Believe Playing: Three Preschoolers Collaboratively Initiating Play "In-Between"

ERIC Educational Resources Information Center

Lagerlöf, Pernilla

2015-01-01

This study presents an analysis of a video observation of three six-year-olds interacting in front of a synthesizer in a Swedish preschool and using a new music technology ("MIROR-Impro"). It investigates how a musical role-play unfolds as an intermediate activity when there is a malfunction with the set-up of the technology and how it…

Multipurpose, dual-mode imaging in the 3-5 μm range (MWIR) for artwork diagnostics: A systematic approach

NASA Astrophysics Data System (ADS)

Daffara, Claudia; Parisotto, Simone; Ambrosini, Dario

2018-05-01

We present a multi-purpose, dual-mode imaging method in the Mid-Wavelength Infrared (MWIR) range (from 3 μm to 5 μm) for a more efficient nondestructive analysis of artworks. Using a setup based on a MWIR thermal camera and multiple radiation sources, two radiometric image datasets are acquired in different acquisition modalities, the image in quasi-reflectance mode (TQR) and the thermal sequence in emission mode. Here, the advantages are: the complementarity of the information; the use of the quasi-reflectance map for calculating the emissivity map; the use of TQR map for a referentiation to the visible of the thermographic images. The concept of the method is presented, the practical feasibility is demonstrated through a custom imaging setup, the potentiality for the nondestructive analysis is shown on a notable application to cultural heritage. The method has been used as experimental tool in support of the restoration of the mural painting "Monocromo" by Leonardo da Vinci. Feedback from the operators and a comparison with some conventional diagnostic techniques is also given to underline the novelty and potentiality of the method.

Simultaneous small- and wide-angle scattering at high X-ray energies.

PubMed

Daniels, J E; Pontoni, D; Hoo, Rui Ping; Honkimäki, V

2010-07-01

Combined small- and wide-angle X-ray scattering (SAXS/WAXS) is a powerful technique for the study of materials at length scales ranging from atomic/molecular sizes (a few angstroms) to the mesoscopic regime ( approximately 1 nm to approximately 1 microm). A set-up to apply this technique at high X-ray energies (E > 50 keV) has been developed. Hard X-rays permit the execution of at least three classes of investigations that are significantly more difficult to perform at standard X-ray energies (8-20 keV): (i) in situ strain analysis revealing anisotropic strain behaviour both at the atomic (WAXS) as well as at the mesoscopic (SAXS) length scales, (ii) acquisition of WAXS patterns to very large q (>20 A(-1)) thus allowing atomic pair distribution function analysis (SAXS/PDF) of micro- and nano-structured materials, and (iii) utilization of complex sample environments involving thick X-ray windows and/or samples that can be penetrated only by high-energy X-rays. Using the reported set-up a time resolution of approximately two seconds was demonstrated. It is planned to further improve this time resolution in the near future.

Analysis of Invasion Dynamics of Matrix-Embedded Cells in a Multisample Format.

PubMed

Van Troys, Marleen; Masuzzo, Paola; Huyck, Lynn; Bakkali, Karima; Waterschoot, Davy; Martens, Lennart; Ampe, Christophe

2018-01-01

In vitro tests of cancer cell invasion are the "first line" tools of preclinical researchers for screening the multitude of chemical compounds or cell perturbations that may aid in halting or treating cancer malignancy. In order to have predictive value or to contribute to designing personalized treatment regimes, these tests need to take into account the cancer cell environment and measure effects on invasion in sufficient detail. The in vitro invasion assays presented here are a trade-off between feasibility in a multisample format and mimicking the complexity of the tumor microenvironment. They allow testing multiple samples and conditions in parallel using 3D-matrix-embedded cells and deal with the heterogeneous behavior of an invading cell population in time. We describe the steps to take, the technical problems to tackle and useful software tools for the entire workflow: from the experimental setup to the quantification of the invasive capacity of the cells. The protocol is intended to guide researchers to standardize experimental set-ups and to annotate their invasion experiments in sufficient detail. In addition, it provides options for image processing and a solution for storage, visualization, quantitative analysis, and multisample comparison of acquired cell invasion data.

Optimizing qPlus sensor assemblies for simultaneous scanning tunneling and noncontact atomic force microscopy operation based on finite element method analysis

DOE PAGES

Dagdeviren, Omur E.; Schwarz, Udo D.

2017-03-20

Quartz tuning forks that have a probe tip attached to the end of one of its prongs while the other prong is arrested to a holder (“qPlus” configuration) have gained considerable popularity in recent years for high-resolution atomic force microscopy imaging. The small size of the tuning forks and the complexity of the sensor architecture, however, often impede predictions on how variations in the execution of the individual assembly steps affect the performance of the completed sensor. Extending an earlier study that provided numerical analysis of qPlus-style setups without tips, this work quantifies the influence of tip attachment on themore » operational characteristics of the sensor. The results using finite element modeling show in particular that for setups that include a metallic tip that is connected via a separate wire to enable the simultaneous collection of local forces and tunneling currents, the exact realization of this wire connection has a major effect on sensor properties such as spring constant, quality factor, resonance frequency, and its deviation from an ideal vertical oscillation.« less

Optimizing qPlus sensor assemblies for simultaneous scanning tunneling and noncontact atomic force microscopy operation based on finite element method analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dagdeviren, Omur E.; Schwarz, Udo D.

Quartz tuning forks that have a probe tip attached to the end of one of its prongs while the other prong is arrested to a holder (“qPlus” configuration) have gained considerable popularity in recent years for high-resolution atomic force microscopy imaging. The small size of the tuning forks and the complexity of the sensor architecture, however, often impede predictions on how variations in the execution of the individual assembly steps affect the performance of the completed sensor. Extending an earlier study that provided numerical analysis of qPlus-style setups without tips, this work quantifies the influence of tip attachment on themore » operational characteristics of the sensor. The results using finite element modeling show in particular that for setups that include a metallic tip that is connected via a separate wire to enable the simultaneous collection of local forces and tunneling currents, the exact realization of this wire connection has a major effect on sensor properties such as spring constant, quality factor, resonance frequency, and its deviation from an ideal vertical oscillation.« less

Silicon drift detectors as a tool for time-resolved fluorescence XAFS on low-concentrated samples in catalysis.

PubMed

Kappen, Peter; Tröger, Larc; Materlik, Gerhard; Reckleben, Christian; Hansen, Karsten; Grunwaldt, Jan-Dierk; Clausen, Bjerne S

2002-07-01

A silicon drift detector (SDD) was used for ex situ and time-resolved in situ fluorescence X-ray absorption fine structure (XAFS) on low-concentrated catalyst samples. For a single-element and a seven-element SDD the energy resolution and the peak-to-background ratio were verified at high count rates, sufficient for fluorescence XAFS. An experimental set-up including the seven-element SDD without any cooling and an in situ cell with gas supply and on-line gas analysis was developed. With this set-up the reduction and oxidation of a zeolite supported catalyst containing 0.3 wt% platinum was followed by fluorescence near-edge scans with a time resolution of 10 min each. From ex situ experiments on low-concentrated platinum- and gold-based catalysts fluorescence XAFS scans could be obtained with sufficient statistical quality for a quantitative analysis. Structural information on the gold and platinum particles could be extracted by both the Fourier transforms and the near-edge region of the XAFS spectra. Moreover, it was found that with the seven-element SDD concentrations of the element of interest as low as 100 ppm can be examined by fluorescence XAFS.

Analysis of SEL on Commercial SRAM Memories and Mixed-Field Characterization of a Latchup Detection Circuit for LEO Space Applications

NASA Astrophysics Data System (ADS)

Secondo, R.; Alía, R. Garcia; Peronnard, P.; Brugger, M.; Masi, A.; Danzeca, S.; Merlenghi, A.; Vaillé, J.-R.; Dusseau, L.

2017-08-01

A single event latchup (SEL) experiment based on commercial static random access memory (SRAM) memories has recently been proposed in the framework of the European Organization for Nuclear Research (CERN) Latchup Experiment and Student Satellite nanosatellite low Earth orbit (LEO) space mission. SEL characterization of three commercial SRAM memories has been carried out at the Paul Scherrer Institut (PSI) facility, using monoenergetic focused proton beams and different acquisition setups. The best target candidate was selected and a circuit for SEL detection has been proposed and tested at CERN, in the CERN High Energy AcceleRator Mixed-field facility (CHARM). Experimental results were carried out at test locations representative of the LEO environment, thus providing a full characterization of the SRAM cross sections, together with the analysis of the single-event effect and total ionizing dose of the latchup detection circuit in relation to the particle spectra expected during mission. The setups used for SEL monitoring are described, and details of the proposed circuit components and topology are presented. Experimental results obtained both at PSI and at CHARM facilities are discussed.

Quantum noise spectra for periodically driven cavity optomechanics

NASA Astrophysics Data System (ADS)

Aranas, E. B.; Akram, M. Javed; Malz, Daniel; Monteiro, T. S.

2017-12-01

A growing number of experimental setups in cavity optomechanics exploit periodically driven fields. However, such setups are not amenable to analysis by using simple, yet powerful, closed-form expressions of linearized optomechanics, which have provided so much of our present understanding of experimental optomechanics. In the present paper, we formulate a method to calculate quantum noise spectra in modulated optomechanical systems, which we analyze, compare, and discuss with two other recently proposed solutions: we term these (i) frequency-shifted operators, (ii) Floquet [Phys. Rev. A 94, 023803 (2016), 10.1103/PhysRevA.94.023803], and (iii) iterative analysis [New J. Phys. 18, 113021 (2016), 10.1088/1367-2630/18/11/113021]. We prove that (i) and (ii) yield equivalent noise spectra and find that (iii) is an analytical approximation to (i) for weak modulations. We calculate the noise spectra of a doubly modulated system describing experiments of levitated particles in hybrid electro-optical traps. We show excellent agreement with Langevin stochastic simulations in the thermal regime and predict squeezing in the quantum regime. Finally, we reveal how otherwise-inaccessible spectral components of a modulated system can be measured in heterodyne detection through an appropriate choice of modulation frequencies.

Animal Robot Assisted-therapy for Rehabilitation of Patient with Post-Stroke Depression

NASA Astrophysics Data System (ADS)

Zikril Zulkifli, Winal; Shamsuddin, Syamimi; Hwee, Lim Thiam

2017-06-01

Recently, the utilization of therapeutic animal robots has expanded. This research aims to explore robotics application for mental healthcare in Malaysia through human-robot interaction (HRI). PARO, the robotic seal PARO was developed to give psychological effects on humans. Major Depressive Disorder (MDD) is a common but severe mood disorder. This study focuses on the interaction protocol between PARO and patients with MDD. Initially, twelve rehabilitation patients gave subjective evaluation on their first interaction with PARO. Next, therapeutic interaction environment was set-up with PARO in it to act as an augmentation strategy with other psychological interventions for post-stroke depression. Patient was exposed to PARO for 20 minutes. The results of behavioural analysis complemented with information from HRI survey question. The analysis also observed that the individual interactors engaged with the robot in diverse ways based on their needs Results show positive reaction toward the acceptance of an animal robot. Next, therapeutic interaction is set-up for PARO to contribute as an augmentation strategy with other psychological interventions for post-stroke depression. The outcome is to reduce the stress level among patients through facilitated therapy session with PARO

Femtosecond pump/supercontinuum-probe spectroscopy: optimized setup and signal analysis for single-shot spectral referencing.

PubMed

Dobryakov, A L; Kovalenko, S A; Weigel, A; Pérez-Lustres, J L; Lange, J; Müller, A; Ernsting, N P

2010-11-01

A setup for pump/supercontinuum-probe spectroscopy is described which (i) is optimized to cancel fluctuations of the probe light by single-shot referencing, and (ii) extends the probe range into the near-uv (1000-270 nm). Reflective optics allow 50 μm spot size in the sample and upon entry into two separate spectrographs. The correlation γ(same) between sample and reference readings of probe light level at every pixel exceeds 0.99, compared to γ(consec)<0.92 reported for consecutive referencing. Statistical analysis provides the confidence interval of the induced optical density, ΔOD. For demonstration we first examine a dye (Hoechst 33258) bound in the minor groove of double-stranded DNA. A weak 1.1 ps spectral oscillation in the fluorescence region, assigned to DNA breathing, is shown to be significant. A second example concerns the weak vibrational structure around t=0 which reflects stimulated Raman processes. With 1% fluctuations of probe power, baseline noise for a transient absorption spectrum becomes 25 μOD rms in 1 s at 1 kHz, allowing to record resonance Raman spectra of flavine adenine dinucleotide in the S(0) and S(1) state.

R4SA for Controlling Robots

NASA Technical Reports Server (NTRS)

Aghazarian, Hrand

2009-01-01

The R4SA GUI mentioned in the immediately preceding article is a userfriendly interface for controlling one or more robot(s). This GUI makes it possible to perform meaningful real-time field experiments and research in robotics at an unmatched level of fidelity, within minutes of setup. It provides such powerful graphing modes as that of a digitizing oscilloscope that displays up to 250 variables at rates between 1 and 200 Hz. This GUI can be configured as multiple intuitive interfaces for acquisition of data, command, and control to enable rapid testing of subsystems or an entire robot system while simultaneously performing analysis of data. The R4SA software establishes an intuitive component-based design environment that can be easily reconfigured for any robotic platform by creating or editing setup configuration files. The R4SA GUI enables event-driven and conditional sequencing similar to those of Mars Exploration Rover (MER) operations. It has been certified as part of the MER ground support equipment and, therefore, is allowed to be utilized in conjunction with MER flight hardware. The R4SA GUI could also be adapted to use in embedded computing systems, other than that of the MER, for commanding and real-time analysis of data.

SFC-APLI-(TOF)MS: Hyphenation of Supercritical Fluid Chromatography to Atmospheric Pressure Laser Ionization Mass Spectrometry.

PubMed

Klink, Dennis; Schmitz, Oliver Johannes

2016-01-05

Atmospheric-pressure laser ionization mass spectrometry (APLI-MS) is a powerful method for the analysis of polycyclic aromatic hydrocarbon (PAH) molecules, which are ionized in a selective and highly sensitive way via resonance-enhanced multiphoton ionization. APLI was presented in 2005 and has been hyphenated successfully to chromatographic separation techniques like high performance liquid chromatography (HPLC) and gas chromatography (GC). In order to expand the portfolio of chromatographic couplings to APLI, a new hyphenation setup of APLI and supercritical-fluid chromatography (SFC) was constructed and aim of this work. Here, we demonstrate the first hyphenation of SFC and APLI in a simple designed way with respect to different optimization steps to ensure a sensitive analysis. The new setup permits qualitative and quantitative determination of native and also more polar PAH molecules. As a result of the altered ambient characteristics within the source enclosure, the quantification of 1-hydroxypyrene (1-HP) in human urine is possible without prior derivatization. The limit of detection for 1-HP by SFC-APLI-TOF(MS) was found to be 0.5 μg L(-1), which is lower than the 1-HP concentrations found in exposed persons.

A temperature-jump NMR probe setup using rf heating optimized for the analysis of temperature-induced biomacromolecular kinetic processes

NASA Astrophysics Data System (ADS)

Rinnenthal, Jörg; Wagner, Dominic; Marquardsen, Thorsten; Krahn, Alexander; Engelke, Frank; Schwalbe, Harald

2015-02-01

A novel temperature jump (T-jump) probe operational at B0 fields of 600 MHz (14.1 Tesla) with an integrated cage radio-frequency (rf) coil for rapid (<1 s) heating in high-resolution (HR) liquid-state NMR-spectroscopy is presented and its performance investigated. The probe consists of an inner 2.5 mm "heating coil" designed for generating rf-electric fields of 190-220 MHz across a lossy dielectric sample and an outer two coil assembly for 1H-, 2H- and 15N-nuclei. High B0 field homogeneities (0.7 Hz at 600 MHz) are combined with high heating rates (20-25 K/s) and only small temperature gradients (<±1.5 K, 3 s after 20 K T-jump). The heating coil is under control of a high power rf-amplifier within the NMR console and can therefore easily be accessed by the pulse programmer. Furthermore, implementation of a real-time setup including synchronization of the NMR spectrometer's air flow heater with the rf-heater used to maintain the temperature of the sample is described. Finally, the applicability of the real-time T-jump setup for the investigation of biomolecular kinetic processes in the second-to-minute timescale is demonstrated for samples of a model 14mer DNA hairpin and a 15N-selectively labeled 40nt hsp17-RNA thermometer.

Questionnaire layout and wording influence prevalence and risk estimates of respiratory symptoms in a population cohort.

PubMed

Ekerljung, Linda; Rönmark, Eva; Lötvall, Jan; Wennergren, Göran; Torén, Kjell; Lundbäck, Bo

2013-01-01

Results of epidemiological studies are greatly influenced by the chosen methodology. The study aims to investigate how two frequently used questionnaires (Qs), with partly different layout, influence the prevalence of respiratory symptoms. A booklet containing two Qs, the Global Allergy and Asthma European Network Q and the Obstructive Lung Disease in Northern Sweden Q, was mailed to 30,000 subjects aged 16-75years in West Sweden; 62% responded. Sixteen questions were included in the analysis: seven identical between the Qs, four different in set-up and five with the same layout but different wording. Comparisons were made using differences in proportions, observed agreement and Kappa statistics.  Identical questions yielded similar prevalences with high observed agreement and kappa values. Questions with different set-up or differences in wording resulted in significantly different prevalences with lower observed agreement and kappa values. In general, the use of follow-up questions, excluding subjects answering no to the initial question, resulted in 2.9-6.7% units lower prevalence. The question set-up has great influences on epidemiological results, and specifically questions that are set up to be excluded based on a previous no answer leads to lower prevalence compared with detached questions. Therefore, Q layout and exact wording of questions has to be carefully considered when comparing studies. © 2012 Blackwell Publishing Ltd.

Optical implementation of (3, 3, 2) regular rectangular CC-Banyan optical network

NASA Astrophysics Data System (ADS)

Yang, Junbo; Su, Xianyu

2007-07-01

CC-Banyan network plays an important role in the optical interconnection network. Based on previous reports of (2, 2, 3) the CC-Banyan network, another rectangular-Banyan network, i.e. (3, 3, 2) rectangular CC-Banyan network, has been discussed. First, according to its construction principle, the topological graph and the routing rule of (3, 3, 2) rectangular CC-Banyan network have been proposed. Then, the optically experimental setup of (3, 3, 2) rectangular CC-Banyan network has been designed and achieved. Each stage of node switch consists of phase spatial light modulator (PSLM) and polarizing beam-splitter (PBS), and fiber has been used to perform connection between adjacent stages. PBS features that s-component (perpendicular to the incident plane) of the incident light beam is reflected, and p-component (parallel to the incident plane) passes through it. According to switching logic, under the control of external electrical signals, PSLM functions to control routing paths of the signal beams, i.e. the polarization of each optical signal is rotated or not rotated 90° by a programmable PSLM. Finally, the discussion and analysis show that the experimental setup designed here can realize many functions such as optical signal switch and permutation. It has advantages of large number of input/output-ports, compact in structure, and low energy loss. Hence, the experimental setup can be used in optical communication and optical information processing.

Evaluation of cross-polarized near infrared hyperspectral imaging for early detection of dental caries

NASA Astrophysics Data System (ADS)

Usenik, Peter; Bürmen, Miran; Fidler, Aleš; Pernuš, Franjo; Likar, Boštjan

2012-01-01

Despite major improvements in dental healthcare and oral hygiene, dental caries remains one of the most prevalent oral diseases and represents the primary cause of oral pain and tooth loss. The initial stages of dental caries are characterized by demineralization of enamel crystals and are difficult to diagnose. Near infrared (NIR) hyperspectral imaging is a new promising technique for detection of early changes in the surfaces of carious teeth. This noninvasive imaging technique can characterize and differentiate between the sound tooth surface and initial or advanced tooth caries. The absorbing and scattering properties of dental tissues reflect in distinct spectral features, which can be measured, quantified and used to accurately classify and map different dental tissues. Specular reflections from the tooth surface, which appear as bright spots, mostly located around the edges and the crests of the teeth, act as a noise factor which can significantly interfere with the spectral measurements and analysis of the acquired images, degrading the accuracy of the classification and diagnosis. Employing cross-polarized imaging setup can solve this problem, however has yet to be systematically evaluated, especially in broadband hyperspectral imaging setups. In this paper, we employ cross-polarized illumination setup utilizing state-of-the-art high-contrast broadband wire-grid polarizers in the spectral range from 900 nm to 1700 nm for hyperspectral imaging of natural and artificial carious lesions of various degrees.

X-ray absorption spectroscopy with time-tagged photon counting: application to study the structure of a Co(i) intermediate of H2 evolving photo-catalyst.

PubMed

Smolentsev, Grigory; Guda, Alexander A; Janousch, Markus; Frieh, Cristophe; Jud, Gaudenz; Zamponi, Flavio; Chavarot-Kerlidou, Murielle; Artero, Vincent; van Bokhoven, Jeroen A; Nachtegaal, Maarten

2014-01-01

In order to probe the structure of reaction intermediates of photochemical reactions a new setup for laser-initiated time-resolved X-ray absorption (XAS) measurements has been developed. With this approach the arrival time of each photon in respect to the laser pulse is measured and therefore full kinetic information is obtained. All X-rays that reach the detector are used to measure this kinetic information and therefore the detection efficiency of this method is high. The newly developed setup is optimized for time-resolved experiments in the microsecond range for samples with relatively low metal concentration (∼1mM). This setup has been applied to study a multicomponent photocatalytic system with a Co(dmgBF(2))(2) catalyst (dmg(2-) = dimethylglyoximato dianion), [Ru(bpy)(3)](2+) chromophore (bpy = 2,2'-bipyridine) and methyl viologen as the electron relay. On the basis of the analysis of hundreds of Co K-edge XAS spectra corresponding to different delay times after the laser excitation of the chromophore, the presence of a Co(i) intermediate is confirmed. The calculated X-ray transient signal for a model of Co(i) state with a 0.14 Å displacement of Co out of the dmg ligand plane and with the closest solvent molecule at a distance of 2.06 Å gives reasonable agreement with the experimental data.

Humidity scanning quartz crystal microbalance with dissipation monitoring setup for determination of sorption-desorption isotherms and rheological changes

NASA Astrophysics Data System (ADS)

Björklund, Sebastian; Kocherbitov, Vitaly

2015-05-01

A new method to determine water sorption-desorption isotherms with high resolution in the complete range of water activities (relative humidities) is presented. The method is based on quartz crystal microbalance with dissipation monitoring (QCM-D). The QCM-D is equipped with a humidity module in which the sample film is kept in air with controlled humidity. The experimental setup allows for continuous scanning of the relative humidity from either dry to humid conditions or vice versa. The amount of water sorbed or desorbed from the sample is determined from the resonance frequencies of the coated quartz sensor, via analysis of the overtone dependence. In addition, the method allows for characterization of hydration induced changes of the rheological properties from the dissipation data, which is closely connected to the viscoelasticity of the film. The accuracy of the humidity scanning setup is confirmed in control experiments. Sorption-desorption isotherms of pig gastric mucin and lysozyme, obtained by the new method, show good agreement with previous results. Finally, we show that the deposition technique used to coat the quartz sensor influences the QCM-D data and how this issue can be used to obtain further information on the effect of hydration. In particular, we demonstrate that spin-coating represents an attractive alternative to obtain sorption-desorption isotherms, while drop-coating provides additional information on changes of the rheological properties during hydration.

Beyond Fourier Transform Infrared Spectroscopy: External Cavity Quantum Cascade Laser-Based Mid-infrared Transmission Spectroscopy of Proteins in the Amide I and Amide II Region.

PubMed

Schwaighofer, Andreas; Montemurro, Milagros; Freitag, Stephan; Kristament, Christian; Culzoni, María J; Lendl, Bernhard

2018-05-24

In this work, we present a setup for mid-IR measurements of the protein amide I and amide II bands in aqueous solution. Employing a latest generation external cavity-quantum cascade laser (EC-QCL) at room temperature in pulsed operation mode allowed implementing a high optical path length of 31 μm that ensures robust sample handling. By application of a data processing routine, which removes occasionally deviating EC-QCL scans, the noise level could be lowered by a factor of 4. The thereby accomplished signal-to-noise ratio is better by a factor of approximately 2 compared to research-grade Fourier transform infrared (FT-IR) spectrometers at equal acquisition times. Employing this setup, characteristic spectral features of three representative proteins with different secondary structures could be measured at concentrations as low as 1 mg mL -1 . Mathematical evaluation of the spectral overlap confirms excellent agreement of the quantum cascade laser infrared spectroscropy (QCL-IR) transmission measurements with protein spectra acquired by FT-IR spectroscopy. The presented setup combines performance surpassing FT-IR spectroscopy with large applicable optical paths and coverage of the relevant spectral range for protein analysis. This holds high potential for future EC-QCL-based protein studies, including the investigation of dynamic secondary structure changes and chemometrics-based protein quantification in complex matrices.

The external scanning proton microprobe of Firenze: A comprehensive description

NASA Astrophysics Data System (ADS)

Giuntini, L.; Massi, M.; Calusi, S.

2007-06-01

An external proton scanning microbeam setup is installed on the -30° line of the new 3 MV tandem accelerator in Firenze; the most relevant features of the line, such as detection setup for IBA measurements, target viewing system, beam diagnostic and transport are described here. With our facility we can work with a beam spot on sample better than 10 μm full-width half-maximum (FWHM) and an intensity of some nanoamperes. Standard beam exit windows are silicon nitride (Si 3N 4) TEM membranes, 100 nm thick and 0.5×0.5 mm 2 wide; we also successfully performed measurements using membranes 1×1 mm 2 wide, 100 nm thick, and 2×2 mm 2 wide, 200 and 500 nm thick. Exploiting the yield of Si X-rays produced by the beam in the exit window as an indirect measurement of the charge, a beam charge monitor system was implemented. The analytical capabilities of the microbeam have been extended by integrating a two-detector PIXE setup with BS and PIGE detectors; the external scanning proton microprobe in Firenze is thus a powerful instrument to fully characterize samples by ion beam analysis, through the simultaneous collection of PIXE, PIGE and BS elemental maps. Its characteristics can make it often competitive with traditional in vacuum microbeam for measurements of thick targets.

QCL spectroscopy combined with the least squares method for substance analysis

NASA Astrophysics Data System (ADS)

Samsonov, D. A.; Tabalina, A. S.; Fufurin, I. L.

2017-11-01

The article briefly describes distinctive features of quantum cascade lasers (QCL). It also describes an experimental set-up for acquiring mid-infrared absorption spectra using QCL. The paper demonstrates experimental results in the form of normed spectra. We tested the application of the least squares method for spectrum analysis. We used this method for substance identification and extraction of concentration data. We compare the results with more common methods of absorption spectroscopy. Eventually, we prove the feasibility of using this simple method for quantitative and qualitative analysis of experimental data acquired with QCL.

Application of genetic algorithm in integrated setup planning and operation sequencing

NASA Astrophysics Data System (ADS)

Kafashi, Sajad; Shakeri, Mohsen

2011-01-01

Process planning is an essential component for linking design and manufacturing process. Setup planning and operation sequencing is two main tasks in process planning. Many researches solved these two problems separately. Considering the fact that the two functions are complementary, it is necessary to integrate them more tightly so that performance of a manufacturing system can be improved economically and competitively. This paper present a generative system and genetic algorithm (GA) approach to process plan the given part. The proposed approach and optimization methodology analyses the TAD (tool approach direction), tolerance relation between features and feature precedence relations to generate all possible setups and operations using workshop resource database. Based on these technological constraints the GA algorithm approach, which adopts the feature-based representation, optimizes the setup plan and sequence of operations using cost indices. Case study show that the developed system can generate satisfactory results in optimizing the setup planning and operation sequencing simultaneously in feasible condition.

Grouping in decomposition method for multi-item capacitated lot-sizing problem with immediate lost sales and joint and item-dependent setup cost

NASA Astrophysics Data System (ADS)

Narenji, M.; Fatemi Ghomi, S. M. T.; Nooraie, S. V. R.

2011-03-01

This article examines a dynamic and discrete multi-item capacitated lot-sizing problem in a completely deterministic production or procurement environment with limited production/procurement capacity where lost sales (the loss of customer demand) are permitted. There is no inventory space capacity and the production activity incurs a fixed charge linear cost function. Similarly, the inventory holding cost and the cost of lost demand are both associated with a linear no-fixed charge function. For the sake of simplicity, a unit of each item is assumed to consume one unit of production/procurement capacity. We analyse a different version of setup costs incurred by a production or procurement activity in a given period of the planning horizon. In this version, called the joint and item-dependent setup cost, an additional item-dependent setup cost is incurred separately for each produced or ordered item on top of the joint setup cost.

Comparison of Different Ion Mobility Setups Using Poly (Ethylene Oxide) PEO Polymers: Drift Tube, TIMS, and T-Wave

NASA Astrophysics Data System (ADS)

Haler, Jean R. N.; Massonnet, Philippe; Chirot, Fabien; Kune, Christopher; Comby-Zerbino, Clothilde; Jordens, Jan; Honing, Maarten; Mengerink, Ynze; Far, Johann; Dugourd, Philippe; De Pauw, Edwin

2018-01-01

Over the years, polymer analyses using ion mobility-mass spectrometry (IM-MS) measurements have been performed on different ion mobility spectrometry (IMS) setups. In order to be able to compare literature data taken on different IM(-MS) instruments, ion heating and ion temperature evaluations have already been explored. Nevertheless, extrapolations to other analytes are difficult and thus straightforward same-sample instrument comparisons seem to be the only reliable way to make sure that the different IM(-MS) setups do not greatly change the gas-phase behavior. We used a large range of degrees of polymerization (DP) of poly(ethylene oxide) PEO homopolymers to measure IMS drift times on three different IM-MS setups: a homemade drift tube (DT), a trapped (TIMS), and a traveling wave (T-Wave) IMS setup. The drift time evolutions were followed for increasing polymer DPs (masses) and charge states, and they are found to be comparable and reproducible on the three instruments. [Figure not available: see fulltext.

Quantum games with a multi-slit electron diffraction set-up

NASA Astrophysics Data System (ADS)

Iqbal, A.

2003-05-01

A set-up is proposed to play a quantum version of the famous bimatrix game of Prisoners' Dilemma. Multi-slit electron diffraction with each player's pure strategy consisting of opening one of the two slits at his/her disposal are essential features of the set-up. Instead of entanglement the association of waves with travelling material objects is suggested as another resource to play quantum games.

Color structured light system of chest wall motion measurement for respiratory volume evaluation

NASA Astrophysics Data System (ADS)

Chen, Huijun; Cheng, Yuan; Liu, Dongdong; Zhang, Xiaodong; Zhang, Jue; Que, Chengli; Wang, Guangfa; Fang, Jing

2010-03-01

We present a structured light system to dynamically measure human chest wall motion for respiratory volume estimation. Based on a projection of an encoded color pattern and a few active markers attached to the trunk, respiratory volumes are obtained by evaluating the 3-D topographic changes of the chest wall in an anatomically consistent measuring region during respiration. Three measuring setups are established: a single-sided illuminating-recording setup for standing posture, an inclined single-sided setup for supine posture, and a double-sided setup for standing posture. Results are compared with the pneumotachography and show good agreement in volume estimations [correlation coefficient: R>0.99 (P<0.001) for all setups]. The isovolume tests present small variations of the obtained volume during the isovolume maneuver (standard deviation<0.085 L for all setups). After validation by the isovolume test, an investigation of a patient with pleural effusion using the proposed method shows pulmonary functional differences between the diseased and the contralateral sides of the thorax, and subsequent improvement of this imbalance after drainage. These results demonstrate the proposed optical method is capable of not only whole respiratory volume evaluation with high accuracy, but also regional pulmonary function assessment in different chest wall behaviors, with the advantage of whole-field measurement.

Applying a subtraction technique to minimize cochlear implant artifact with soundfield and direct audio input stimulations.

PubMed

Atcherson, Samuel R; Damji, Zohra; Upson, Steve

2011-11-01

We explored the feasibility of a subtraction technique described by Friesen and Picton to remove the cochlear implant (CI) artifact to long duration stimuli in the soundfield and using direct input all through the participant's preferred MAP. Friesen and Picton previously explored this technique by recording cortical potentials in four CI users with 1000 pulse per second (pps) stimuli, bypassing the speech processor. Cortical auditory evoked potentials (N1-P2) to 1000 Hz tones were recorded from a post-lingually deafened adult with three different stimulus presentation setups: soundfield to processor T-mic (SF), soundfield to lapel mic (SF-LM), and direct input (DI). Stimuli were presented at 65 dB SPL(A). The SF setup required stabilizing the head to minimize changes in magnitude for the CI artifact. The SF-LM and DI setups did not require head stabilization, but were evaluated as alternatives to the SF setup. Clear N1-P2 responses were obtained with comparable waveform morphologies, amplitudes, and latencies despite some differences in the magnitude of the CI artifact for the different stimulus presentation setups. The results of this study demonstrate that subtraction technique is feasible for recording N1-P2 responses in CI users, though further studies are needed for the three stimulation setups.

Accurate setup of paraspinal patients using a noninvasive patient immobilization cradle and portal imaging.

PubMed

Lovelock, D Michael; Hua, Chiaho; Wang, Ping; Hunt, Margie; Fournier-Bidoz, Nathalie; Yenice, Kamil; Toner, Sean; Lutz, Wendell; Amols, Howard; Bilsky, Mark; Fuks, Zvi; Yamada, Yoshiya

2005-08-01

Because of the proximity of the spinal cord, effective radiotherapy of paraspinal tumors to high doses requires highly conformal dose distributions, accurate patient setup, setup verification, and patient immobilization. An immobilization cradle has been designed to facilitate the rapid setup and radiation treatment of patients with paraspinal disease. For all treatments, patients were set up to within 2.5 mm of the design using an amorphous silicon portal imager. Setup reproducibility of the target using the cradle and associated clinical procedures was assessed by measuring the setup error prior to any correction. From 350 anterior/posterior images, and 303 lateral images, the standard deviations, as determined by the imaging procedure, were 1.3 m, 1.6 m, and 2.1 in the ant/post, right/left, and superior/inferior directions. Immobilization was assessed by measuring patient shifts between localization images taken before and after treatment. From 67 ant/post image pairs and 49 lateral image pairs, the standard deviations were found to be less than 1 mm in all directions. Careful patient positioning and immobilization has enabled us to develop a successful clinical program of high dose, conformal radiotherapy of paraspinal disease using a conventional Linac equipped with dynamic multileaf collimation and an amorphous silicon portal imager.

The virtual slice setup.

PubMed

Lytton, William W; Neymotin, Samuel A; Hines, Michael L

2008-06-30

In an effort to design a simulation environment that is more similar to that of neurophysiology, we introduce a virtual slice setup in the NEURON simulator. The virtual slice setup runs continuously and permits parameter changes, including changes to synaptic weights and time course and to intrinsic cell properties. The virtual slice setup permits shocks to be applied at chosen locations and activity to be sampled intra- or extracellularly from chosen locations. By default, a summed population display is shown during a run to indicate the level of activity and no states are saved. Simulations can run for hours of model time, therefore it is not practical to save all of the state variables. These, in any case, are primarily of interest at discrete times when experiments are being run: the simulation can be stopped momentarily at such times to save activity patterns. The virtual slice setup maintains an automated notebook showing shocks and parameter changes as well as user comments. We demonstrate how interaction with a continuously running simulation encourages experimental prototyping and can suggest additional dynamical features such as ligand wash-in and wash-out-alternatives to typical instantaneous parameter change. The virtual slice setup currently uses event-driven cells and runs at approximately 2 min/h on a laptop.

Helical tomotherapy setup variations in canine nasal tumor patients immobilized with a bite block.

PubMed

Kubicek, Lyndsay N; Seo, Songwon; Chappell, Richard J; Jeraj, Robert; Forrest, Lisa J

2012-01-01

The purpose of our study was to compare setup variation in four degrees of freedom (vertical, longitudinal, lateral, and roll) between canine nasal tumor patients immobilized with a mattress and bite block, versus a mattress alone. Our secondary aim was to define a clinical target volume (CTV) to planning target volume (PTV) expansion margin based on our mean systematic error values associated with nasal tumor patients immobilized by a mattress and bite block. We evaluated six parameters for setup corrections: systematic error, random error, patient-patient variation in systematic errors, the magnitude of patient-specific random errors (root mean square [RMS]), distance error, and the variation of setup corrections from zero shift. The variations in all parameters were statistically smaller in the group immobilized by a mattress and bite block. The mean setup corrections in the mattress and bite block group ranged from 0.91 mm to 1.59 mm for the translational errors and 0.5°. Although most veterinary radiation facilities do not have access to Image-guided radiotherapy (IGRT), we identified a need for more rigid fixation, established the value of adding IGRT to veterinary radiation therapy, and define the CTV-PTV setup error margin for canine nasal tumor patients immobilized in a mattress and bite block. © 2012 Veterinary Radiology & Ultrasound.

Evaluation of a head-repositioner and Z-plate system for improved accuracy of dose delivery.

PubMed

Charney, Sarah C; Lutz, Wendell R; Klein, Mary K; Jones, Pamela D

2009-01-01

Radiation therapy requires accurate dose delivery to targets often identifiable only on computed tomography (CT) images. Translation between the isocenter localized on CT and laser setup for radiation treatment, and interfractional head repositioning are frequent sources of positioning error. The objective was to design a simple, accurate apparatus to eliminate these sources of error. System accuracy was confirmed with phantom and in vivo measurements. A head repositioner that fixates the maxilla via dental mold with fiducial marker Z-plates attached was fabricated to facilitate the connection between the isocenter on CT and laser treatment setup. A phantom study targeting steel balls randomly located within the head repositioner was performed. The center of each ball was marked on a transverse CT slice on which six points of the Z-plate were also visible. Based on the relative position of the six Z-plate points and the ball center, the laser setup position on each Z-plate and a top plate was calculated. Based on these setup marks, orthogonal port films, directed toward each target, were evaluated for accuracy without regard to visual setup. A similar procedure was followed to confirm accuracy of in vivo treatment setups in four dogs using implanted gold seeds. Sequential port films of three dogs were made to confirm interfractional accuracy. Phantom and in vivo measurements confirmed accuracy of 2 mm between isocenter on CT and the center of the treatment dose distribution. Port films confirmed similar accuracy for interfractional treatments. The system reliably connects CT target localization to accurate initial and interfractional radiation treatment setup.

SU-F-T-642: Sub Millimeter Accurate Setup of More Than Three Vertebrae in Spinal SBRT with 6D Couch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, X; Zhao, Z; Yang, J

Purpose: To assess the initial setup accuracy in treating more than 3 vertebral body levels in spinal SBRT using a 6D couch. Methods: We retrospectively analyzed last 20 spinal SBRT patients (4 cervical, 9 thoracic, 7 lumbar/sacrum) treated in our clinic. These patients in customized immobilization device were treated in 1 or 3 fractions. Initial setup used ExacTrac and Brainlab 6D couch to align target within 1 mm and 1 degree, following by a cone beam CT (CBCT) for verification. Our current standard practice allows treating a maximum of three continuous vertebrae. Here we assess the possibility to achieve submore » millimeter setup accuracy for more than three vertebrae by examining the residual error in every slice of CBCT. The CBCT had a range of 17.5 cm, which covered 5 to 9 continuous vertebrae depending on the patient and target location. In the study, CBCT from the 1st fraction treatment was rigidly registered with the planning CT in Pinnacle. The residual setup error of a vertebra was determined by expanding the vertebra contour on the planning CT to be large enough to enclose the corresponding vertebra on CBCT. The margin of the expansion was considered as setup error. Results: Out of the 20 patients analyzed, initial setup accuracy can be achieved within 1 mm for a span of 5 or more vertebrae starting from T2 vertebra to inferior vertebra levels. 2 cervical and 2 upper thoracic patients showed the cervical spine was difficult to achieve sub millimeter accuracy for multi levels without a customized immobilization headrest. Conclusion: If the curvature of spinal columns can be reproduced in customized immobilization device during treatment as simulation, multiple continuous vertebrae can be setup within 1 mm with the use of a 6D couch.« less

Performance of velocity vector estimation using an improved dynamic beamforming setup

NASA Astrophysics Data System (ADS)

Munk, Peter; Jensen, Joergen A.

2001-05-01

Estimation of velocity vectors using transverse spatial modulation has previously been presented. Initially, the velocity estimation was improved using an approximated dynamic beamformer setup instead of a static combined with a new velocity estimation scheme. A new beamformer setup for dynamic control of the acoustic field, based on the Pulsed Plane Wave Decomposition (PPWD), is presented. The PPWD gives an unambiguous relation between a given acoustic field and the time functions needed on an array transducer for transmission. Applying this method for the receive beamformation results in a setup of the beamformer with different filters for each channel for each estimation depth. The method of the PPWD is illustrated by analytical expressions of the decomposed acoustic field and these results are used for simulation. Results of velocity estimates using the new setup are given on the basis of simulated and experimental data. The simulation setup is an attempt to approximate the situation present when performing a scanning of the carotid artery with a linear array. Measurement of the flow perpendicular to the emission direction is possible using the approach of transverse spatial modulation. This is most often the case in a scanning of the carotid artery, where the situation is handled by an angled Doppler setup in the present ultrasound scanners. The modulation period of 2 mm is controlled for a range of 20-40 mm which covers the typical range of the carotid artery. A 6 MHz array on a 128-channel system is simulated. The flow setup in the simulation is based on a vessel with a parabolic flow profile for a 60 and 90-degree flow angle. The experimental results are based on the backscattered signal from a sponge mounted in a stepping device. The bias and std. Dev. Of the velocity estimate are calculated for four different flow angles (50,60,75 and 90 degrees). The velocity vector is calculated using the improved 2D estimation approach at a range of depths.

Pupil light reflex evoked by light-emitting diode and computer screen: Methodology and association with need for recovery in daily life.

PubMed

Wang, Yang; Zekveld, Adriana A; Wendt, Dorothea; Lunner, Thomas; Naylor, Graham; Kramer, Sophia E

2018-01-01

Pupil light reflex (PLR) has been widely used as a method for evaluating parasympathetic activity. The first aim of the present study is to develop a PLR measurement using a computer screen set-up and compare its results with the PLR generated by a more conventional setup using light-emitting diode (LED). The parasympathetic nervous system, which is known to control the 'rest and digest' response of the human body, is considered to be associated with daily life fatigue. However, only few studies have attempted to test the relationship between self-reported daily fatigue and physiological measurement of the parasympathetic nervous system. Therefore, the second aim of this study was to investigate the relationship between daily-life fatigue, assessed using the Need for Recovery scale, and parasympathetic activity, as indicated by the PLR parameters. A pilot study was conducted first to develop a PLR measurement set-up using a computer screen. PLRs evoked by light stimuli with different characteristics were recorded to confirm the influence of light intensity, flash duration, and color on the PLRs evoked by the system. In the subsequent experimental study, we recorded the PLR of 25 adult participants to light flashes generated by the screen set-up as well as by a conventional LED set-up. PLR parameters relating to parasympathetic and sympathetic activity were calculated from the pupil responses. We tested the split-half reliability across two consecutive blocks of trials, and the relationships between the parameters of PLRs evoked by the two set-ups. Participants rated their need for recovery prior to the PLR recordings. PLR parameters acquired in the screen and LED set-ups showed good reliability for amplitude related parameters. The PLRs evoked by both set-ups were consistent, but showed systematic differences in absolute values of all parameters. Additionally, higher need for recovery was associated with faster and larger constriction of the PLR. This study assessed the PLR generated by a computer screen and the PLR generated by a LED. The good reliability within set-ups and the consistency between the PLRs evoked by the set-ups indicate that both systems provides a valid way to evoke the PLR. A higher need for recovery was associated with faster and larger constricting PLRs, suggesting increased levels of parasympathetic nervous system activity in people experiencing higher levels of need for recovery on a daily basis.

Understanding and predicting the impact of critical dissolution variables for nifedipine immediate release capsules by multivariate data analysis.

PubMed

Mercuri, A; Pagliari, M; Baxevanis, F; Fares, R; Fotaki, N

2017-02-25

In this study the selection of in vivo predictive in vitro dissolution experimental set-ups using a multivariate analysis approach, in line with the Quality by Design (QbD) principles, is explored. The dissolution variables selected using a design of experiments (DoE) were the dissolution apparatus [USP1 apparatus (basket) and USP2 apparatus (paddle)], the rotational speed of the basket/or paddle, the operator conditions (dissolution apparatus brand and operator), the volume, the pH, and the ethanol content of the dissolution medium. The dissolution profiles of two nifedipine capsules (poorly soluble compound), under conditions mimicking the intake of the capsules with i. water, ii. orange juice and iii. an alcoholic drink (orange juice and ethanol) were analysed using multiple linear regression (MLR). Optimised dissolution set-ups, generated based on the mathematical model obtained via MLR, were used to build predicted in vitro-in vivo correlations (IVIVC). IVIVC could be achieved using physiologically relevant in vitro conditions mimicking the intake of the capsules with an alcoholic drink (orange juice and ethanol). The multivariate analysis revealed that the concentration of ethanol used in the in vitro dissolution experiments (47% v/v) can be lowered to less than 20% v/v, reflecting recently found physiological conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

[3D visualization and analysis of vocal fold dynamics].

PubMed

Bohr, C; Döllinger, M; Kniesburges, S; Traxdorf, M

2016-04-01

Visual investigation methods of the larynx mainly allow for the two-dimensional presentation of the three-dimensional structures of the vocal fold dynamics. The vertical component of the vocal fold dynamics is often neglected, yielding a loss of information. The latest studies show that the vertical dynamic components are in the range of the medio-lateral dynamics and play a significant role within the phonation process. This work presents a method for future 3D reconstruction and visualization of endoscopically recorded vocal fold dynamics. The setup contains a high-speed camera (HSC) and a laser projection system (LPS). The LPS projects a regular grid on the vocal fold surfaces and in combination with the HSC allows a three-dimensional reconstruction of the vocal fold surface. Hence, quantitative information on displacements and velocities can be provided. The applicability of the method is presented for one ex-vivo human larynx, one ex-vivo porcine larynx and one synthetic silicone larynx. The setup introduced allows the reconstruction of the entire visible vocal fold surfaces for each oscillation status. This enables a detailed analysis of the three dimensional dynamics (i. e. displacements, velocities, accelerations) of the vocal folds. The next goal is the miniaturization of the LPS to allow clinical in-vivo analysis in humans. We anticipate new insight on dependencies between 3D dynamic behavior and the quality of the acoustic outcome for healthy and disordered phonation.

Design, development, and demonstration of a fully LabVIEW controlled in situ electrochemical Fourier transform infrared setup combined with a wall-jet electrode to investigate the electrochemical interface of nanoparticulate electrocatalysts under reaction conditions.

PubMed

Nesselberger, Markus; Ashton, Sean J; Wiberg, Gustav K H; Arenz, Matthias

2013-07-01

We present a detailed description of the construction of an in situ electrochemical ATR-FTIR setup combined with a wall-jet electrode to investigate the electrocatalytic properties of nanoparticulate catalysts in situ under controlled mass transport conditions. The presented setup allows the electrochemical interface to be probed in combination with the simultaneous determination of reaction rates. At the same time, the high level of automation allows it to be used as a standard tool in electrocatalysis research. The performance of the setup was demonstrated by probing the oxygen reduction reaction on a platinum black catalyst in sulfuric electrolyte.

Setup for irradiation and characterization of materials and Si particle detectors at cryogenic temperatures

NASA Astrophysics Data System (ADS)

Väyrynen, S.; Pusa, P.; Sane, P.; Tikkanen, P.; Räisänen, J.; Kuitunen, K.; Tuomisto, F.; Härkönen, J.; Kassamakov, I.; Tuominen, E.; Tuovinen, E.

2007-03-01

A novel facility for proton irradiation with sample cryocooling has been developed at the Accelerator Laboratory of Helsinki University (equipped with a 5 MV tandem accelerator). The setup enables unique experiments to be carried out within the temperature range of 10-300 K. The setup has been constructed for "on-line" studies of vacancies with positron annihilation spectroscopy (PAS) including the option for optical ionization of the vacancies, and for current-voltage ( IV) measurements of irradiated silicon particle detectors. The setup is described in detail and typical performance characteristics are provided. The facility functionality was tested by performing PAS experiments with high-resistivity silicon and by IV measurements for two types of irradiated silicon particle detectors.

SU-F-T-185: Study of the Robustness of a Proton Arc Technique Based On PBS Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Z; Zheng, Y

Purpose: One potential technique to realize proton arc is through using PBS beams from many directions to form overlaid Bragg peak (OBP) spots and placing these OBP spots throughout the target volume to achieve desired dose distribution. In this study, we analyzed the robustness of this proton arc technique. Methods: We used a cylindrical water phantom of 20 cm in radius in our robustness analysis. To study the range uncertainty effect, we changed the density of the phantom by ±3%. To study the setup uncertainty effect, we shifted the phantom by 3 & 5 mm. We also combined the rangemore » and setup uncertainties (3mm/±3%). For each test plan, we performed dose calculation for the nominal and 6 disturbed scenarios. Two test plans were used, one with single OBP spot and the other consisting of 121 OBP spots covering a 10×10cm{sup 2} area. We compared the dose profiles between the nominal and disturbed scenarios to estimate the impact of the uncertainties. Dose calculation was performed with Gate/GEANT based Monte Carlo software in cloud computing environment. Results: For each of the 7 scenarios, we simulated 100k & 10M events for plans consisting of single OBP spot and 121 OBP spots respectively. For single OBP spot, the setup uncertainty had minimum impact on the spot’s dose profile while range uncertainty had significant impact on the dose profile. For plan consisting of 121 OBP spots, similar effect was observed but the extent of disturbance was much less compared to single OBP spot. Conclusion: For PBS arc technique, range uncertainty has significantly more impact than setup uncertainty. Although single OBP spot can be severely disturbed by the range uncertainty, the overall effect is much less when a large number of OBP spots are used. Robustness optimization for PBS arc technique should consider range uncertainty with priority.« less

Automated PCR setup for forensic casework samples using the Normalization Wizard and PCR Setup robotic methods.

PubMed

Greenspoon, S A; Sykes, K L V; Ban, J D; Pollard, A; Baisden, M; Farr, M; Graham, N; Collins, B L; Green, M M; Christenson, C C

2006-12-20

Human genome, pharmaceutical and research laboratories have long enjoyed the application of robotics to performing repetitive laboratory tasks. However, the utilization of robotics in forensic laboratories for processing casework samples is relatively new and poses particular challenges. Since the quantity and quality (a mixture versus a single source sample, the level of degradation, the presence of PCR inhibitors) of the DNA contained within a casework sample is unknown, particular attention must be paid to procedural susceptibility to contamination, as well as DNA yield, especially as it pertains to samples with little biological material. The Virginia Department of Forensic Science (VDFS) has successfully automated forensic casework DNA extraction utilizing the DNA IQ(trade mark) System in conjunction with the Biomek 2000 Automation Workstation. Human DNA quantitation is also performed in a near complete automated fashion utilizing the AluQuant Human DNA Quantitation System and the Biomek 2000 Automation Workstation. Recently, the PCR setup for casework samples has been automated, employing the Biomek 2000 Automation Workstation and Normalization Wizard, Genetic Identity version, which utilizes the quantitation data, imported into the software, to create a customized automated method for DNA dilution, unique to that plate of DNA samples. The PCR Setup software method, used in conjunction with the Normalization Wizard method and written for the Biomek 2000, functions to mix the diluted DNA samples, transfer the PCR master mix, and transfer the diluted DNA samples to PCR amplification tubes. Once the process is complete, the DNA extracts, still on the deck of the robot in PCR amplification strip tubes, are transferred to pre-labeled 1.5 mL tubes for long-term storage using an automated method. The automation of these steps in the process of forensic DNA casework analysis has been accomplished by performing extensive optimization, validation and testing of the software methods.

Setup calibration and optimization for comparative digital holography

NASA Astrophysics Data System (ADS)

Baumbach, Torsten; Osten, Wolfgang; Kebbel, Volker; von Kopylow, Christoph; Jueptner, Werner

2004-08-01

With increasing globalization many enterprises decide to produce the components of their products at different locations all over the world. Consequently, new technologies and strategies for quality control are required. In this context the remote comparison of objects with regard to their shape or response on certain loads is getting more and more important for a variety of applications. For such a task the novel method of comparative digital holography is a suitable tool with interferometric sensitivity. With this technique the comparison in shape or deformation of two objects does not require the presence of both objects at the same place. In contrast to the well known incoherent techniques based on inverse fringe projection this new approach uses a coherent mask for the illumination of the sample object. The coherent mask is created by digital holography to enable the instant access to the complete optical information of the master object at any wanted place. The reconstruction of the mask is done by a spatial light modulator (SLM). The transmission of the digital master hologram to the place of comparison can be done via digital telecommunication networks. Contrary to other interferometric techniques this method enables the comparison of objects with different microstructure. In continuation of earlier reports our investigations are focused here on the analysis of the constraints of the setup with respect to the quality of the hologram reconstruction with a spatial light modulator. For successful measurements the selection of the appropriate reconstruction method and the adequate optical set-up is mandatory. In addition, the use of a SLM for the reconstruction requires the knowledge of its properties for the accomplishment of this method. The investigation results for the display properties such as display curvature, phase shift and the consequences for the technique will be presented. The optimization and the calibration of the set-up and its components lead to improved results in comparative digital holography with respect to the resolution. Examples of measurements before and after the optimization and calibration will be presented.

Carbon-Ion Pencil Beam Scanning Treatment With Gated Markerless Tumor Tracking: An Analysis of Positional Accuracy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mori, Shinichiro, E-mail: shinshin@nirs.go.jp; Karube, Masataka; Shirai, Toshiyuki

Purpose: Having implemented amplitude-based respiratory gating for scanned carbon-ion beam therapy, we sought to evaluate its effect on positional accuracy and throughput. Methods and Materials: A total of 10 patients with tumors of the lung and liver participated in the first clinical trials at our center. Treatment planning was conducted with 4-dimensional computed tomography (4DCT) under free-breathing conditions. The planning target volume (PTV) was calculated by adding a 2- to 3-mm setup margin outside the clinical target volume (CTV) within the gating window. The treatment beam was on when the CTV was within the PTV. Tumor position was detected inmore » real time with a markerless tumor tracking system using paired x-ray fluoroscopic imaging units. Results: The patient setup error (mean ± SD) was 1.1 ± 1.2 mm/0.6 ± 0.4°. The mean internal gating accuracy (95% confidence interval [CI]) was 0.5 mm. If external gating had been applied to this treatment, the mean gating accuracy (95% CI) would have been 4.1 mm. The fluoroscopic radiation doses (mean ± SD) were 23.7 ± 21.8 mGy per beam and less than 487.5 mGy total throughout the treatment course. The setup, preparation, and irradiation times (mean ± SD) were 8.9 ± 8.2 min, 9.5 ± 4.6 min, and 4.0 ± 2.4 min, respectively. The treatment room occupation time was 36.7 ± 67.5 min. Conclusions: Internal gating had a much higher accuracy than external gating. By the addition of a setup margin of 2 to 3 mm, internal gating positional error was less than 2.2 mm at 95% CI.« less

SU-F-T-509: Investigation into the Impact of the Linear Accelerator Treatment Table On Skin Dose to Prone Breast Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pedersen, K; Irwin, J; Sansourekidou, P

Purpose: To investigate the impact of the treatment table on skin dose for prone breast patients for which the breast contacts the table and to develop a method to decrease skin dose. Methods: We used 12cm stack of 15cmx15cm solid water slabs to imitate breast. Calibrated EBT3 radiochromic film was affixed to the bottom of the phantom. Treatments for 32 patients were analyzed to determine typical prone breast beam parameters. Based on the analysis, a field size and a range of gantry angles were chosen for the test beams. Three experimental setups were used. The first represented the patient setupmore » currently used in our clinics with the phantom directly on the table. The second was the skin sparing setup, with a 1.5cm Styrofoam slab between the phantom and the table. The third used a 7.5cm Styrofoam slab to examine the extent of skin sparing potential. The calibration curve was applied to each film to determine dose. Percent difference in dose between the current and skin sparing setups was calculated for each gantry angle and gantry angle pair. Results: Data showed that beams entering through the table showed a skin dose decrease ranging from 13%–30% with the addition of 7.5cm Styrofoam, while beams exiting through the table showed no significant difference. The addition of 1.5cm Styrofoam resulted in differences ranging from 0.5%–13% with the skin sparing setup. Conclusion: The results demonstrate that skin in contact with the table receives increased dose from beams entering through the table. By creating separation between the breast and the table with Styrofoam the skin dose can be lowered, but 1.5 cm did not fully mitigate the effect. Further investigation will be performed to identify a clinically practical thickness that maximizes this mitigation.« less

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages.

PubMed

Carlton, Holly D; Elmer, John W; Li, Yan; Pacheco, Mario; Goyal, Deepak; Parkinson, Dilworth Y; MacDowell, Alastair A

2016-04-13

Synchrotron radiation micro-tomography (SRµT) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data acquisition times with high spatial resolution. In the electronics industry there is serious interest in performing failure analysis on 3D microelectronic packages, many which contain multiple levels of high-density interconnections. Often in tomography there is a trade-off between image resolution and the volume of a sample that can be imaged. This inverse relationship limits the usefulness of conventional computed tomography (CT) systems since a microelectronic package is often large in cross sectional area 100-3,600 mm(2), but has important features on the micron scale. The micro-tomography beamline at the Advanced Light Source (ALS), in Berkeley, CA USA, has a setup which is adaptable and can be tailored to a sample's properties, i.e., density, thickness, etc., with a maximum allowable cross-section of 36 x 36 mm. This setup also has the option of being either monochromatic in the energy range ~7-43 keV or operating with maximum flux in white light mode using a polychromatic beam. Presented here are details of the experimental steps taken to image an entire 16 x 16 mm system within a package, in order to obtain 3D images of the system with a spatial resolution of 8.7 µm all within a scan time of less than 3 min. Also shown are results from packages scanned in different orientations and a sectioned package for higher resolution imaging. In contrast a conventional CT system would take hours to record data with potentially poorer resolution. Indeed, the ratio of field-of-view to throughput time is much higher when using the synchrotron radiation tomography setup. The description below of the experimental setup can be implemented and adapted for use with many other multi-materials.

Translation of Atherosclerotic Plaque Phase-Contrast CT Imaging from Synchrotron Radiation to a Conventional Lab-Based X-Ray Source

PubMed Central

Saam, Tobias; Herzen, Julia; Hetterich, Holger; Fill, Sandra; Willner, Marian; Stockmar, Marco; Achterhold, Klaus; Zanette, Irene; Weitkamp, Timm; Schüller, Ulrich; Auweter, Sigrid; Adam-Neumair, Silvia; Nikolaou, Konstantin; Reiser, Maximilian F.; Pfeiffer, Franz; Bamberg, Fabian

2013-01-01

Objectives Phase-contrast imaging is a novel X-ray based technique that provides enhanced soft tissue contrast. The aim of this study was to evaluate the feasibility of visualizing human carotid arteries by grating-based phase-contrast tomography (PC-CT) at two different experimental set-ups: (i) applying synchrotron radiation and (ii) using a conventional X-ray tube. Materials and Methods Five ex-vivo carotid artery specimens were examined with PC-CT either at the European Synchrotron Radiation Facility using a monochromatic X-ray beam (2 specimens; 23 keV; pixel size 5.4 µm), or at a laboratory set-up on a conventional X-ray tube (3 specimens; 35-40 kVp; 70 mA; pixel size 100 µm). Tomographic images were reconstructed and compared to histopathology. Two independent readers determined vessel dimensions and one reader determined signal-to-noise ratios (SNR) between PC-CT and absorption images. Results In total, 51 sections were included in the analysis. Images from both set-ups provided sufficient contrast to differentiate individual vessel layers. All PCI-based measurements strongly predicted but significantly overestimated lumen, intima and vessel wall area for both the synchrotron and the laboratory-based measurements as compared with histology (all p<0.001 with slope >0.53 per mm2, 95%-CI: 0.35 to 0.70). Although synchrotron-based images were characterized by higher SNRs than laboratory-based images; both PC-CT set-ups had superior SNRs compared to corresponding conventional absorption-based images (p<0.001). Inter-reader reproducibility was excellent (ICCs >0.98 and >0.84 for synchrotron and for laboratory-based measurements; respectively). Conclusion Experimental PC-CT of carotid specimens is feasible with both synchrotron and conventional X-ray sources, producing high-resolution images suitable for vessel characterization and atherosclerosis research. PMID:24039969

Initialization and Setup of the Coastal Model Test Bed: STWAVE

DTIC Science & Technology

2017-01-01

Laboratory (CHL) Field Research Facility (FRF) in Duck , NC. The improved evaluation methodology will promote rapid enhancement of model capability and focus...Blanton 2008) study . This regional digital elevation model (DEM), with a cell size of 10 m, was generated from numerous datasets collected at different...INFORMATION: For additional information, contact Spicer Bak, Coastal Observation and Analysis Branch, Coastal and Hydraulics Laboratory, 1261 Duck Road

Study of Laminar Flame 2-D Scalar Values at Various Fuel to Air Ratios Using an Imaging Fourier-Transform Spectrometer and 2-D CFD Analysis

DTIC Science & Technology

2013-03-01

NASA- Glenn’s Chemical Equilibrium with Applications (CEA) program. UNICORN CFD predictions were in excellent agreement with CEA calculations at...49 Appendix A – UNICORN CFD Inputs and Instruction .....................................................50 Appendix B – NASA-Glenn...17 Figure 7: Schematic of UNICORN CFD card setup. ........................................................ 18 Figure 8: Averaged flame

Managing numerical errors in random sequential adsorption

NASA Astrophysics Data System (ADS)

Cieśla, Michał; Nowak, Aleksandra

2016-09-01

Aim of this study is to examine the influence of a finite surface size and a finite simulation time on a packing fraction estimated using random sequential adsorption simulations. The goal of particular interest is providing hints on simulation setup to achieve desired level of accuracy. The analysis is based on properties of saturated random packing of disks on continuous and flat surfaces of different sizes.

Calibration of the SphinX experiment at the XACT facility in Palermo

NASA Astrophysics Data System (ADS)

Collura, A.; Barbera, M.; Varisco, S.; Calderone, G.; Reale, F.; Gburek, S.; Kowalinski, M.; Sylwester, J.; Siarkowski, M.; Bakala, J.; Podgorski, P.; Trzebinski, W.; Plocieniak, S.; Kordylewski, Z.

2008-07-01

Three of the four detectors of the SphinX experiment to be flown on the Russian mission Coronas-Photon have been measured at the XACT Facility of the Palermo Observatory at several wavelengths in the soft X-ray band. We describe the instrumental set-up and report some measurements. The analysis work to obtain the final calibration is still in progress.

Measurements of 42 Wide CPM Pairs with a CCD

NASA Astrophysics Data System (ADS)

Harshaw, Richard

2015-11-01

This paper addresses the use of a Skyris 618C color CCD camera as a means of obtaining data for analysis in the measurement of wide common proper motion stars. The equipment setup is described and data collection procedure outlined. Results of the measures of 42 CPM stars are presented, showing the Skyris is a reliable device for the measurement of double stars.

Potential Vorticity Analysis of Low Level Thunderstorm Dynamics in an Idealized Supercell Simulation

DTIC Science & Technology

2009-03-01

Severe Weather, Supercell, Weather Research and Forecasting Model , Advanced WRF 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT...27 A. ADVANCED RESEARCH WRF MODEL .................................................27 1. Data, Model Setup, and Methodology...03/11/2006 GFS model run. Top row: 11/12Z initialization. Middle row: 12 hour forecast valid at 12/00Z. Bottom row: 24 hour forecast valid at

Students' Pilot Laboratory for Homogeneous Chemical Reactor Analysis and Design in Olive Mill Wastewater Treatment

ERIC Educational Resources Information Center

Ochando-Pulido, J. M.

2017-01-01

The Chemical Engineering Department at the University of Granada have endeavored to make a number of high quality experiments to familiarize our students with our latest research and also scale-up of processes. A pilot-scale wastewater treatment plant was set-up to give students a close practical view of the treatments of effluents by-produced in…

Characterization and Dynamic Analysis of Long-Cavity Multi-Section Gain- Levered Quantum-Dot Lasers

DTIC Science & Technology

2013-03-01

test setup .................................................................... 8 Figure 5: Comparison of a Fabry – Perot and distributed feedback...for example Fabry – Perot and distributed-feedback designs), with each possessing advantages and disadvantages that will be discussed in detail in...contrast to Fabry – Perot cavities (two discrete mirrors) that result in lasing over multiple longitudinal modes supported by the cavity. Figure 5 shows

Coplanar waveguide discontinuities for P-I-N diode switches and filter applications

NASA Technical Reports Server (NTRS)

Dib, N. I.; Katehi, P. B.; Ponchak, George E.; Simons, Rainee N.

1990-01-01

A full wave space domain integral equation (SDIE) analysis of coplanar waveguide (CPW) two port discontinuities is presented. An experimental setup to measure the S-parameters of such discontinuities is described. Experimental and theoretical results for CPW realizations of pass-band and stop-band filters are presented. The S-parameters of such structures are plotted in the frequency range 5 to 25 GHz.

Simple 2.5 GHz time-bin quantum key distribution

NASA Astrophysics Data System (ADS)

Boaron, Alberto; Korzh, Boris; Houlmann, Raphael; Boso, Gianluca; Rusca, Davide; Gray, Stuart; Li, Ming-Jun; Nolan, Daniel; Martin, Anthony; Zbinden, Hugo

2018-04-01

We present a 2.5 GHz quantum key distribution setup with the emphasis on a simple experimental realization. It features a three-state time-bin protocol based on a pulsed diode laser and a single intensity modulator. Implementing an efficient one-decoy scheme and finite-key analysis, we achieve record breaking secret key rates of 1.5 kbps over 200 km of standard optical fibers.

Polarized neutron scattering on HYSPEC: the HYbrid SPECtrometer at SNS

DOE PAGES

Zaliznyak, Igor A.; Savici, Andrei T.; Ovidiu Garlea, V.; ...

2017-06-20

Here, we describe some of the first polarized neutron scattering measurements performed at HYSPEC [1-4] spectrometer at the Spallation Neutron Source, Oak Ridge National Laboratory. Furthermore, we discuss details of the instrument setup and the experimental procedures in the mode with full polarization analysis. Examples of polarized neutron diffraction and polarized inelastic neutron data obtained on single crystal samples are presented.

The First Static and Dynamic Analysis of 3-D Printed Sintered Ceramics for Body Armor Applications

DTIC Science & Technology

2016-09-01

evaluate sintered alumina tiles produced by 3-D printing methodology. This report examines the static and quasi -static parameters (including density...Figures iv List of Tables iv Acknowledgments v 1. Introduction 1 2. Processing and Experimental Procedures 1 3. Results and Discussion 7 4...6 Fig. 8 Experimental setup for recording fracture .............................................7 Fig. 9 Rod projectile

Overview of machine vision methods in x-ray imaging and microtomography

NASA Astrophysics Data System (ADS)

Buzmakov, Alexey; Zolotov, Denis; Chukalina, Marina; Nikolaev, Dmitry; Gladkov, Andrey; Ingacheva, Anastasia; Yakimchuk, Ivan; Asadchikov, Victor

2018-04-01

Digital X-ray imaging became widely used in science, medicine, non-destructive testing. This allows using modern digital images analysis for automatic information extraction and interpretation. We give short review of scientific applications of machine vision in scientific X-ray imaging and microtomography, including image processing, feature detection and extraction, images compression to increase camera throughput, microtomography reconstruction, visualization and setup adjustment.

Environmental Durability of Adhesively Bonded Joints

DTIC Science & Technology

1997-10-14

REPORT DOCUMENTATION PAGE Form Approved OMB No. 07040188 Public reporting burden for tis collection of information isestimated to average 1 hour per...transmittance and reflectance spectroscopy was performed using Nicolet’s OMNIC software for the set-up, control, and analysis of spectroscopic scans... publications inciudc: JAhIN’. W S. iind Butjkus, L.M., "Considetring E~nvironmental Condjitions ill the Design ()’ Bonded Structures: A Fracture

Performance analysis of medical video streaming over mobile WiMAX.

PubMed

Alinejad, Ali; Philip, N; Istepanian, R H

2010-01-01

Wireless medical ultrasound streaming is considered one of the emerging application within the broadband mobile healthcare domain. These applications are considered as bandwidth demanding services that required high data rates with acceptable diagnostic quality of the transmitted medical images. In this paper, we present the performance analysis of a medical ultrasound video streaming acquired via special robotic ultrasonography system over emulated WiMAX wireless network. The experimental set-up of this application is described together with the performance of the relevant medical quality of service (m-QoS) metrics.

Structural investigation of a new composite process

NASA Astrophysics Data System (ADS)

Mayer, Philippe; Becker, Eric; Bigot, Régis; Kaïci, Bruno

2017-10-01

This work presents a study done on a new patented forming process, created to produce massive composite parts used for structural applications in automotive and aeronautics industries. The study presented in this paper deals with an experimental setup, used to characterize thick composite cylinders. The author presents the characterization of these cylinders and a new analysis method, in order to understand the consolidation steps of the composite in this forming process. The structural health of the part is illustrated by the analysis of the intra-bundle and inter-bundle porosities, by micrographs characterizations.

On the Possibility of Studying the Reactions of the Thermal Decomposition of Energy Substances by the Methods of High-Resolution Terahertz Spectroscopy

NASA Astrophysics Data System (ADS)

Vaks, V. L.; Domracheva, E. G.; Chernyaeva, M. B.; Pripolzin, S. I.; Revin, L. S.; Tretyakov, I. V.; Anfertyev, V. A.; Yablokov, A. A.; Lukyanenko, I. A.; Sheikov, Yu. V.

2018-02-01

We show prospects for using the method of high-resolution terahertz spectroscopy for a continuous analysis of the decomposition products of energy substances in the gas phase (including short-lived ones) in a wide temperature range. The experimental setup, which includes a terahertz spectrometer for studying the thermal decomposition reactions, is described. The results of analysis of the gaseous decomposition products of energy substances by the example of ammonium nitrate heated from room temperature to 167°C are presented.

Status and results from the OPERA experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ariga, Tomoko

2011-10-06

The OPERA experiment is aiming at the first direct detection of neutrino oscillations in appearance mode through the study of the v{sub {mu}}{yields}v{tau} channel. The OPERA detector is placed in the CNGS long baseline v{sub {mu}} beam 730 km away from the neutrino source. The analysis of a sub-sample of the data taken in the 2008-2009 runs was completed After a brief description of the beam and the experimental setup, we report on event analysis and on a first candidate event, its background estimation and statistical significance.

Patterns of intrafractional motion and uncertainties of treatment setup reference systems in accelerated partial breast irradiation for right- and left-sided breast cancer.

PubMed

Yue, Ning J; Goyal, Sharad; Kim, Leonard H; Khan, Atif; Haffty, Bruce G

2014-01-01

This study investigated the patterns of intrafractional motion and accuracy of treatment setup strategies in 3-dimensional conformal radiation therapy of accelerated partial breast irradiation (APBI) for right- and left-sided breast cancers. Sixteen right-sided and 17 left-sided breast cancer patients were enrolled in an institutional APBI trial in which gold fiducial markers were strategically sutured to the surgical cavity walls. Daily pre- and postradiation therapy kV imaging were performed and were matched to digitally reconstructed radiographs based on bony anatomy and fiducial markers, respectively, to determine the intrafractional motion. The positioning differences of the laser-tattoo and the bony anatomy-based setups with respect to the marker-based setup (benchmark) were determined to evaluate their accuracy. Statistical differences were found between the right- and left-sided APBI treatments in vector directions of intrafractional motion and treatment setup errors in the reference systems, but less in their overall magnitudes. The directional difference was more pronounced in the lateral direction. It was found that the intrafractional motion and setup reference systems tended to deviate in the right direction for the right-sided breast treatments and in the left direction for the left-sided breast treatments. It appears that the fiducial markers placed in the seroma cavity exhibit side dependent directional intrafractional motion, although additional data may be needed to further validate the conclusion. The bony anatomy-based treatment setup improves the accuracy over laser-tattoo. But it is inadequate to rely on bony anatomy to assess intrafractional target motion in both magnitude and direction. Copyright © 2014 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

A novel algorithm for detecting active propulsion in wheelchair users following spinal cord injury.

PubMed

Popp, Werner L; Brogioli, Michael; Leuenberger, Kaspar; Albisser, Urs; Frotzler, Angela; Curt, Armin; Gassert, Roger; Starkey, Michelle L

2016-03-01

Physical activity in wheelchair-bound individuals can be assessed by monitoring their mobility as this is one of the most intense upper extremity activities they perform. Current accelerometer-based approaches for describing wheelchair mobility do not distinguish between self- and attendant-propulsion and hence may overestimate total physical activity. The aim of this study was to develop and validate an inertial measurement unit based algorithm to monitor wheel kinematics and the type of wheelchair propulsion (self- or attendant-) within a "real-world" situation. Different sensor set-ups were investigated, ranging from a high precision set-up including four sensor modules with a relatively short measurement duration of 24 h, to a less precise set-up with only one module attached at the wheel exceeding one week of measurement because the gyroscope of the sensor was turned off. The "high-precision" algorithm distinguished self- and attendant-propulsion with accuracy greater than 93% whilst the long-term measurement set-up showed an accuracy of 82%. The estimation accuracy of kinematic parameters was greater than 97% for both set-ups. The possibility of having different sensor set-ups allows the use of the inertial measurement units as high precision tools for researchers as well as unobtrusive and simple tools for manual wheelchair users. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Survival of occlusal ART restorations in primary molars placed in school environment and hospital dental setup-one year follow-up study.

PubMed

Roshan, Noor-Mohammed; Sakeenabi, Basha

2011-11-01

The objectives of this clinical study were to: evaluate the survival of occlusal atraumatic restorative treatment (ART) restorations, on a longitudinal basis, in the primary molars of children; and compare the success rate of ART restorations placed in school environment and in hospital dental setup. One dentist placed 120 ART restorations in 60 five- to seven year-olds who had bilateral matched pairs of carious primary molars. A split-mouth design was used to place restorations in school and in hospital dental setup, which were assigned randomly to contralateral sides. Restorations were evaluated after 6 and 12 months using the ART criteria. The survival rate of ART restorations placed in school environment was 82.2% at the 6-month assessment and 77.77% at the 12-month assessment. The success rates of ART restorations placed in hospital dental setup in the 2 assessments were 87.7% and 81.48%, respectively. There was no statistically significant difference between the ART restorations placed in school environment and hospital dental setup in both assessments (P > O.05). The main cause of failure was the loss of restoration. The one year success rate of occlusal ART restorations in primary molars was moderately successful. The ART technique's done in hospital dental setup was not proven to be better than restorations placed in school environment.

Development of a fatigue testing setup for dielectric elastomer membrane actuators

NASA Astrophysics Data System (ADS)

Hill, M.; Rizzello, G.; Seelecke, S.

2017-04-01

Dielectric elastomers (DE's) represent a transduction technology with high potential in many fields, including industries, due to their low weight, flexibility, and small energy consumption. For industrial applications, it is of fundamental importance to quantify the lifetime of DE technology, in terms of electrical and mechanical fatigue, when operating in realistic environmental conditions. This work contributes toward this direction, by presenting the development of an experimental setup which permits systematic fatigue testing of DE membranes. The setup permits to apply both mechanical and electrical stimuli to several membranes simultaneously, while measuring at the same time their mechanical (force, deformation) and electrical response (capacitance, resistance). In its final state, the setup will allow to test up to 15 DE membranes at the same time for several thousands of cycles. Control of the modules, monitoring of the actuators, and data acquisition are realized on a cRio FPGA-system running with LabVIEW. The setup is located in a climate chamber, in order to investigate the fatigue mechanisms at different environmental conditions, i.e., in terms of temperature and humidity. The setup consists of two main parts, namely a fatigue group and a measurement group. The fatigue group stays permanently in the climate chamber, while the measurement group is assembled to the fatigue group and allows to perform measurements at 20°C.

An experimental setup for the simultaneous measurement of thermoelectric power of two samples from 77 K to 500 K.

PubMed

Tripathi, T S; Bala, M; Asokan, K

2014-08-01

We report on an experimental setup for the simultaneous measurement of the thermoelectric power (TEP) of two samples in the temperature range from 77 K to 500 K using optimum electronic instruments. The setup consists of two rectangular copper bars in a bridge arrangement for sample mounting, two surface mount (SM) chip resistors for creating alternate temperature gradient, and a type E thermocouple in differential geometry for gradient temperature (ΔT) measurement across the samples. In addition, a diode arrangement has been made for the alternate heating of SM resistors using only one DC current source. The measurement accuracy of ΔT increases with the differential thermocouple arrangement. For the calibration of the setup, measurements of TEP on a high purity (99.99%) platinum wire and type K thermocouple wires Chromel and Alumel have been performed from 77 K to 500 K with respect to copper lead wires. Additionally, this setup can be utilized to calibrate an unknown sample against a sample of known absolute TEP.

An experimental setup for the simultaneous measurement of thermoelectric power of two samples from 77 K to 500 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tripathi, T. S.; Bala, M.; Asokan, K.

2014-08-01

We report on an experimental setup for the simultaneous measurement of the thermoelectric power (TEP) of two samples in the temperature range from 77 K to 500 K using optimum electronic instruments. The setup consists of two rectangular copper bars in a bridge arrangement for sample mounting, two surface mount (SM) chip resistors for creating alternate temperature gradient, and a type E thermocouple in differential geometry for gradient temperature (ΔT) measurement across the samples. In addition, a diode arrangement has been made for the alternate heating of SM resistors using only one DC current source. The measurement accuracy of ΔTmore » increases with the differential thermocouple arrangement. For the calibration of the setup, measurements of TEP on a high purity (99.99%) platinum wire and type K thermocouple wires Chromel and Alumel have been performed from 77 K to 500 K with respect to copper lead wires. Additionally, this setup can be utilized to calibrate an unknown sample against a sample of known absolute TEP.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loehle, Stefan; Lein, Sebastian

A revised scientific instrument to measure simultaneously kinetic temperatures of different atoms from their optical emission profile is reported. Emission lines are simultaneously detected using one single scanning Fabry-Perot-interferometer (FPI) for a combined spectroscopic setup to acquire different emission lines simultaneously. The setup consists in a commercial Czerny-Turner spectrometer configuration which is combined with a scanning Fabry-Perot interferometer. The fast image acquisition mode of an intensified charge coupled device camera allows the detection of a wavelength interval of interest continuously while acquiring the highly resolved line during the scan of the FPI ramp. Results using this new setup are presentedmore » for the simultaneous detection of atomic nitrogen and oxygen in a high enthalpy air plasma flow as used for atmospheric re-entry research and their respective kinetic temperatures derived from the measured line profiles. The paper presents the experimental setup, the calibration procedure, and an exemplary result. The determined temperatures are different, a finding that has been published so far as due to a drawback of the experimental setup of sequential measurements, and which has now to be investigated in more detail.« less

General purpose pulse shape analysis for fast scintillators implemented in digital readout electronics

NASA Astrophysics Data System (ADS)

Asztalos, Stephen J.; Hennig, Wolfgang; Warburton, William K.

2016-01-01

Pulse shape discrimination applied to certain fast scintillators is usually performed offline. In sufficiently high-event rate environments data transfer and storage become problematic, which suggests a different analysis approach. In response, we have implemented a general purpose pulse shape analysis algorithm in the XIA Pixie-500 and Pixie-500 Express digital spectrometers. In this implementation waveforms are processed in real time, reducing the pulse characteristics to a few pulse shape analysis parameters and eliminating time-consuming waveform transfer and storage. We discuss implementation of these features, their advantages, necessary trade-offs and performance. Measurements from bench top and experimental setups using fast scintillators and XIA processors are presented.

Thermodynamics of information exchange between two coupled quantum dots

NASA Astrophysics Data System (ADS)

Kutvonen, Aki; Sagawa, Takahiro; Ala-Nissila, Tapio

2016-03-01

We propose a setup based on two coupled quantum dots where thermodynamics of a measurement can be quantitatively characterized. The information obtained in the measurement can be utilized by performing feedback in a manner apparently breaking the second law of thermodynamics. In this way the setup can be operated as a Maxwell's demon, where both the measurement and feedback are performed separately by controlling an external parameter. This is analogous to the case of the original Szilard engine. Since the setup contains both the microscopic demon and the engine itself, the operation of the whole measurement-feedback cycle can be explained in detail at the level of single realizations. In addition, we derive integral fluctuation relations for both the bare and coarse-grained entropy productions in the setup.

Analysis of Human Body Bipedal Stability for Neuromotor Disabilities

NASA Astrophysics Data System (ADS)

Baritz, Mihaela; Cristea, Luciana; Rogozea, Liliana; Cotoros, Diana; Repanovici, Angela

2009-04-01

The analysis of different biomechanical aspects of balance and equilibrium is presented in the first part of the paper. We analyzed the posture, balance and stability of human body for a normal person and for a person with loco-motor or neuro-motor disabilities (in the second part). In the third part of the paper we presented the methodology and the experimental setup used to record the human body behavior in postural stability for persons with neuro-motors disabilities. The results and the conclusions are presented in the final part of the paper and also in the future work meant to establish the computer analysis for rehabilitation neuromotor disabilities.

The Development of an Optically Active Laser Schlieren System with Application to High Pressure Solid Propellant Combustion.

DTIC Science & Technology

1975-09-01

mass diffusion in the immediate region 13 wmmmm mm/mmn*****^^1 «•PIII^ BPP of the combustion zone remain major points of disagreement for many...setup (S2-2f2a S3 = 2f3 ) virtual image I • (9/2 f3 - i/2f2 ) — Fig.12 Virtual image setup(S2 =0.5 f2 aS3 = 3f3) 38 h v. / V image f + obje

Optimizing and Evaluating an Integrated SPECT-CmT System Dedicated to Improved 3-D Breast Cancer Imaging

DTIC Science & Technology

2010-05-01

mammography," (2008). 4. H. M. Warren-Forward and L. Duggan, "Towards in vivo TLD dosimetry in mammography," Br J Radiol 77, 426-432 (2004). 5. X. Wu, G...thermoluminescent detectors ( TLDs ) were used in the experiments but, after consultation with experts in the field of radiation dosimetry , it was decided...prohibitively expensive to use TLDs for the various study setups and that the dosimetry results from one setup could be extended to similar setups that

Super-resolution with an SLM and two intensity images

NASA Astrophysics Data System (ADS)

Alcalá Ochoa, Noé; de León, Y. Ponce

2018-06-01

It is reported a method which may simplify the optical setups used to achieve super-resolution through the amplitude multiplication of two waves. For this end we decompose a super-resolving pupil into two complex masks and with the aid of a Spatial Light Modulator (LCoS) we obtain two intensity images that are subtracted. With this proposal, the traditional experimental optical setups are considerably simplified, with the additional benefit that different masks can be utilized without needing to perform the setup alignment each time.

Method and apparatus for checking the stability of a setup for making reflection type holograms

NASA Technical Reports Server (NTRS)

Lackner, H. G. (Inventor)

1974-01-01

A method and apparatus are described for checking the stability of a setup for recording reflection-type (white light) holograms. Two sets of interference fringes are simultaneously obtained, one giving information about coherence and stability of the setup alone and the other demonstrating coherence of the entire system, including the holographic recording plate. Special emphasis is given to the stability of the plate, due to the fact that any minute vibration might severely degrade or completely destroy the recording.

The urban boundary-layer field campaign in marseille (ubl/clu-escompte): set-up and first results

NASA Astrophysics Data System (ADS)

Mestayer, P.G.; Durand, P.; Augustin, P.; Bastin, S.; Bonnefond, J.-M.; Benech, B.; Campistron, B.; Coppalle, A.; Delbarre, H.; Dousset, B.; Drobinski, P.; Druilhet, A.; Frejafon, E.; Grimmond, C.S.B.; Groleau, D.; Irvine, M.; Kergomard, C.; Kermadi, S.; Lagouarde, J.-P.; Lemonsu, A.; Lohou, F.; Long, N.; Masson, V.; Moppert, C.; Noilhan, J.; Offerle, B.; Oke, T.R.; Pigeon, G.; Puygrenier, V.; Roberts, S.; Rosant, J.-M.; Sanid, F.; Salmond, J.; Talbaut, M.; Voogt, J.

The UBL/CLU (urban boundary layer/couche limite urbaine) observation and modelling campaign is a side-project of the regional photochemistry campaign ESCOMPTE. UBL/CLU focuses on the dynamics and thermodynamics of the urban boundary layer of Marseille, on the Mediterranean coast of France. The objective of UBL/CLU is to document the four-dimensional structure of the urban boundary layer and its relation to the heat and moisture exchanges between the urban canopy and the atmosphere during periods of low wind conditions, from June 4 to July 16, 2001. The project took advantage of the comprehensive observational set-up of the ESCOMPTE campaign over the Berre-Marseille area, especially the ground-based remote sensing, airborne measurements, and the intensive documentation of the regional meteorology. Additional instrumentation was installed as part of UBL/CLU. Analysis objectives focus on (i) validation of several energy balance computational schemes such as LUMPS, TEB and SM2-U, (ii) ground truth and urban canopy signatures suitable for the estimation of urban albedos and aerodynamic surface temperatures from satellite data, (iii) high resolution mapping of urban land cover, land-use and aerodynamic parameters used in UBL models, and (iv) testing the ability of high resolution atmospheric models to simulate the structure of the UBL during land and sea breezes, and the related transport and diffusion of pollutants over different districts of the city. This paper presents initial results from such analyses and details of the overall experimental set-up.

Reconstruction of dynamic structures of experimental setups based on measurable experimental data only

NASA Astrophysics Data System (ADS)

Chen, Tian-Yu; Chen, Yang; Yang, Hu-Jiang; Xiao, Jing-Hua; Hu, Gang

2018-03-01

Nowadays, massive amounts of data have been accumulated in various and wide fields, it has become today one of the central issues in interdisciplinary fields to analyze existing data and extract as much useful information as possible from data. It is often that the output data of systems are measurable while dynamic structures producing these data are hidden, and thus studies to reveal system structures by analyzing available data, i.e., reconstructions of systems become one of the most important tasks of information extractions. In the past, most of the works in this respect were based on theoretical analyses and numerical verifications. Direct analyses of experimental data are very rare. In physical science, most of the analyses of experimental setups were based on the first principles of physics laws, i.e., so-called top-down analyses. In this paper, we conducted an experiment of “Boer resonant instrument for forced vibration” (BRIFV) and inferred the dynamic structure of the experimental set purely from the analysis of the measurable experimental data, i.e., by applying the bottom-up strategy. Dynamics of the experimental set is strongly nonlinear and chaotic, and itʼs subjects to inevitable noises. We proposed to use high-order correlation computations to treat nonlinear dynamics; use two-time correlations to treat noise effects. By applying these approaches, we have successfully reconstructed the structure of the experimental setup, and the dynamic system reconstructed with the measured data reproduces good experimental results in a wide range of parameters.

An Automatic Image Processing Workflow for Daily Magnetic Resonance Imaging Quality Assurance.

PubMed

Peltonen, Juha I; Mäkelä, Teemu; Sofiev, Alexey; Salli, Eero

2017-04-01

The performance of magnetic resonance imaging (MRI) equipment is typically monitored with a quality assurance (QA) program. The QA program includes various tests performed at regular intervals. Users may execute specific tests, e.g., daily, weekly, or monthly. The exact interval of these measurements varies according to the department policies, machine setup and usage, manufacturer's recommendations, and available resources. In our experience, a single image acquired before the first patient of the day offers a low effort and effective system check. When this daily QA check is repeated with identical imaging parameters and phantom setup, the data can be used to derive various time series of the scanner performance. However, daily QA with manual processing can quickly become laborious in a multi-scanner environment. Fully automated image analysis and results output can positively impact the QA process by decreasing reaction time, improving repeatability, and by offering novel performance evaluation methods. In this study, we have developed a daily MRI QA workflow that can measure multiple scanner performance parameters with minimal manual labor required. The daily QA system is built around a phantom image taken by the radiographers at the beginning of day. The image is acquired with a consistent phantom setup and standardized imaging parameters. Recorded parameters are processed into graphs available to everyone involved in the MRI QA process via a web-based interface. The presented automatic MRI QA system provides an efficient tool for following the short- and long-term stability of MRI scanners.

An investigation of the usability of sound recognition for source separation of packaging wastes in reverse vending machines.

PubMed

Korucu, M Kemal; Kaplan, Özgür; Büyük, Osman; Güllü, M Kemal

2016-10-01

In this study, we investigate the usability of sound recognition for source separation of packaging wastes in reverse vending machines (RVMs). For this purpose, an experimental setup equipped with a sound recording mechanism was prepared. Packaging waste sounds generated by three physical impacts such as free falling, pneumatic hitting and hydraulic crushing were separately recorded using two different microphones. To classify the waste types and sizes based on sound features of the wastes, a support vector machine (SVM) and a hidden Markov model (HMM) based sound classification systems were developed. In the basic experimental setup in which only free falling impact type was considered, SVM and HMM systems provided 100% classification accuracy for both microphones. In the expanded experimental setup which includes all three impact types, material type classification accuracies were 96.5% for dynamic microphone and 97.7% for condenser microphone. When both the material type and the size of the wastes were classified, the accuracy was 88.6% for the microphones. The modeling studies indicated that hydraulic crushing impact type recordings were very noisy for an effective sound recognition application. In the detailed analysis of the recognition errors, it was observed that most of the errors occurred in the hitting impact type. According to the experimental results, it can be said that the proposed novel approach for the separation of packaging wastes could provide a high classification performance for RVMs. Copyright © 2016 Elsevier Ltd. All rights reserved.

X-ray absorption spectroscopy with time-tagged photon counting: Application to study the structure of Co(I) intermediate of H2 evolving photo-catalyst

PubMed Central

Smolentsev, Grigory; Guda, Alexander; Janousch, Markus; Frieh, Cristophe; Jud, Gaudenz; Zamponi, Flavio; Chavarot-Kerlidou, Murielle; Artero, Vincent; van Bokhoven, Jeroen A.; Nachtegaal, Maarten

2015-01-01

In order to probe the structure of reaction intermediates of photochemical reactions a new setup for laser-initiated time-resolved X-ray absorption (XAS) measurements has been developed. With this approach the arrival time of each photon in respect to the laser pulse is measured and therefore full kinetic information is obtained. All X-rays that reach the detector are used to measure this kinetic information and therefore the detection efficiency of this method is high. The newly developed setup is optimized for time-resolved experiments in the microsecond range for samples with relatively low metal concentration (~1mM). This setup has been applied to study a multicomponent photocatalytic system with a Co(dmgBF2)2 catalyst (dmg2− = dimethylglyoximato dianion), [Ru(bpy)3]2+ chromophore (bpy=2,2′-bipyridine) and methyl viologen as the electron relay. On the basis of analysis of hundreds of Co K-edge XAS spectra corresponding to different delay times after the laser excitation of the chromophore, the presence of a Co(I) intermediate is confirmed. The calculated X-ray transient signal for a model of Co(I) state with a 0.14 Å displacement of Co out of the dmg ligand plane and with the closest solvent molecule at a distance of 2.06 Å gives reasonable agreement with the experimental data. PMID:25415460

SU-F-T-383: Robustness for Patient Setup Error in Total Body Irradiation Using Volumetric Modulated Arc Therapy (VMAT)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takahashi, Y; National Cancer Center, Kashiwa, Chiba; Tachibana, H

Purpose: Total body irradiation (TBI) and total marrow irradiation (TMI) using Tomotherapy have been reported. A gantry-based linear accelerator uses one isocenter during one rotational irradiation. Thus, 3–5 isocenter points should be used for a whole plan of TBI-VMAT during smoothing out the junctional dose distribution. IGRT provides accurate and precise patient setup for the multiple junctions, however it is evident that some setup errors should occur and affect accuracy of dose distribution in the area. In this study, we evaluated the robustness for patient’s setup error in VMAT-TBI. Methods: VMAT-TBI Planning was performed in an adult whole-body human phantommore » using Eclipse. Eight full arcs with four isocenter points using 6MV-X were used to cover the entire whole body. Dose distribution was optimized using two structures of patient’s body as PTV and lung. The two arcs were shared with one isocenter and the two arcs were 5 cm-overlapped with the other two arcs. Point absolute dose using ionization-chamber and planer relative dose distribution using film in the junctional regions were performed using water-equivalent slab phantom. In the measurements, several setup errors of (+5∼−5mm) were added. Results: The result of the chamber measurement shows the deviations were within ±3% when the setup errors were within ±3 mm. In the planer evaluation, the pass ratio of gamma evaluation (3%/2mm) shows more than 90% if the errors within ±3 mm. However, there were hot/cold areas in the edge of the junction even with acceptable gamma pass ratio. 5 mm setup error caused larger hot and cold areas and the dosimetric acceptable areas were decreased in the overlapped areas. Conclusion: It can be clinically acceptable for VMAT-TBI when patient setup error is within ±3mm. Averaging effects from patient random error would be helpful to blur the hot/cold area in the junction.« less

Couch height–based patient setup for abdominal radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohira, Shingo; Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita; Ueda, Yoshihiro

2016-04-01

There are 2 methods commonly used for patient positioning in the anterior-posterior (A-P) direction: one is the skin mark patient setup method (SMPS) and the other is the couch height–based patient setup method (CHPS). This study compared the setup accuracy of these 2 methods for abdominal radiation therapy. The enrollment for this study comprised 23 patients with pancreatic cancer. For treatments (539 sessions), patients were set up by using isocenter skin marks and thereafter treatment couch was shifted so that the distance between the isocenter and the upper side of the treatment couch was equal to that indicated on themore » computed tomographic (CT) image. Setup deviation in the A-P direction for CHPS was measured by matching the spine of the digitally reconstructed radiograph (DRR) of a lateral beam at simulation with that of the corresponding time-integrated electronic portal image. For SMPS with no correction (SMPS/NC), setup deviation was calculated based on the couch-level difference between SMPS and CHPS. SMPS/NC was corrected using 2 off-line correction protocols: no action level (SMPS/NAL) and extended NAL (SMPS/eNAL) protocols. Margins to compensate for deviations were calculated using the Stroom formula. A-P deviation > 5 mm was observed in 17% of SMPS/NC, 4% of SMPS/NAL, and 4% of SMPS/eNAL sessions but only in one CHPS session. For SMPS/NC, 7 patients (30%) showed deviations at an increasing rate of > 0.1 mm/fraction, but for CHPS, no such trend was observed. The standard deviations (SDs) of systematic error (Σ) were 2.6, 1.4, 0.6, and 0.8 mm and the root mean squares of random error (σ) were 2.1, 2.6, 2.7, and 0.9 mm for SMPS/NC, SMPS/NAL, SMPS/eNAL, and CHPS, respectively. Margins to compensate for the deviations were wide for SMPS/NC (6.7 mm), smaller for SMPS/NAL (4.6 mm) and SMPS/eNAL (3.1 mm), and smallest for CHPS (2.2 mm). Achieving better setup with smaller margins, CHPS appears to be a reproducible method for abdominal patient setup.« less

Photoacoustic sensor for medical diagnostics

NASA Astrophysics Data System (ADS)

Wolff, Marcus; Groninga, Hinrich G.; Harde, Hermann

2004-03-01

The development of new optical sensor technologies has a major impact on the progress of diagnostic methods. Of the permanently increasing number of non-invasive breath tests, the 13C-Urea Breath Test (UBT) for the detection of Helicobacter pylori is the most prominent. However, many recent developments, like the detection of cancer by breath test, go beyond gastroenterological applications. We present a new detection scheme for breath analysis that employs an especially compact and simple set-up. Photoacoustic Spectroscopy (PAS) represents an offset-free technique that allows for short absorption paths and small sample cells. Using a single-frequency diode laser and taking advantage of acoustical resonances of the sample cell, we performed extremely sensitive and selective measurements. The smart data processing method contributes to the extraordinary sensitivity and selectivity as well. Also, the reasonable acquisition cost and low operational cost make this detection scheme attractive for many biomedical applications. The experimental set-up and data processing method, together with exemplary isotope-selective measurements on carbon dioxide, are presented.

GenomeHubs: simple containerized setup of a custom Ensembl database and web server for any species

PubMed Central

Kumar, Sujai; Stevens, Lewis; Blaxter, Mark

2017-01-01

Abstract As the generation and use of genomic datasets is becoming increasingly common in all areas of biology, the need for resources to collate, analyse and present data from one or more genome projects is becoming more pressing. The Ensembl platform is a powerful tool to make genome data and cross-species analyses easily accessible through a web interface and a comprehensive application programming interface. Here we introduce GenomeHubs, which provide a containerized environment to facilitate the setup and hosting of custom Ensembl genome browsers. This simplifies mirroring of existing content and import of new genomic data into the Ensembl database schema. GenomeHubs also provide a set of analysis containers to decorate imported genomes with results of standard analyses and functional annotations and support export to flat files, including EMBL format for submission of assemblies and annotations to International Nucleotide Sequence Database Collaboration. Database URL: http://GenomeHubs.org PMID:28605774

Hygroscopic analysis of individual Beijing haze aerosol particles by environmental scanning electron microscopy

NASA Astrophysics Data System (ADS)

Bai, Zhangpeng; Ji, Yuan; Pi, Yiqun; Yang, Kaixiang; Wang, Li; Zhang, Yinqi; Zhai, Yadi; Yan, Zhengguang; Han, Xiaodong

2018-01-01

Investigating the hygroscopic behavior of haze aerosol particles is essential for understanding their physicochemical properties and their impacts on regional weather and visibility. An environmental scanning electron microscope equipped with a home-made transmission-scattering electron imaging setup and an energy dispersive spectrometer was used for in-situ observations of pure water-soluble (WS) salts and Beijing haze particles. This imaging setup showed obvious advantages for improving the resolution and acquiring internal information of mixed particles in hydrated environments. We measured the deliquescence relative humidity of pure NaCl, NH4NO3, and (NH4)2SO4 by deliquescence-crystallization processes with an accuracy of up to 0.3% RH. The mixed haze particles showed hygroscopic activation like water uptake and morphological changes when they included WS components such as nitrates, sulfates, halides, ammoniums, and alkali metal salts. In addition, the hygroscopic behavior provides complementary information for analyzing possible phases in mixed haze particles.

Global optimisation methods for poroelastic material characterisation using a clamped sample in a Kundt tube setup

NASA Astrophysics Data System (ADS)

Vanhuyse, Johan; Deckers, Elke; Jonckheere, Stijn; Pluymers, Bert; Desmet, Wim

2016-02-01

The Biot theory is commonly used for the simulation of the vibro-acoustic behaviour of poroelastic materials. However, it relies on a number of material parameters. These can be hard to characterize and require dedicated measurement setups, yielding a time-consuming and costly characterisation. This paper presents a characterisation method which is able to identify all material parameters using only an impedance tube. The method relies on the assumption that the sample is clamped within the tube, that the shear wave is excited and that the acoustic field is no longer one-dimensional. This paper numerically shows the potential of the developed method. It therefore performs a sensitivity analysis of the quantification parameters, i.e. reflection coefficients and relative pressures, and a parameter estimation using global optimisation methods. A 3-step procedure is developed and validated. It is shown that even in the presence of numerically simulated noise this procedure leads to a robust parameter estimation.

Psychological and physiological human responses to simulated and real environments: A comparison between Photographs, 360° Panoramas, and Virtual Reality.

PubMed

Higuera-Trujillo, Juan Luis; López-Tarruella Maldonado, Juan; Llinares Millán, Carmen

2017-11-01

Psychological research into human factors frequently uses simulations to study the relationship between human behaviour and the environment. Their validity depends on their similarity with the physical environments. This paper aims to validate three environmental-simulation display formats: photographs, 360° panoramas, and virtual reality. To do this we compared the psychological and physiological responses evoked by simulated environments set-ups to those from a physical environment setup; we also assessed the users' sense of presence. Analysis show that 360° panoramas offer the closest to reality results according to the participants' psychological responses, and virtual reality according to the physiological responses. Correlations between the feeling of presence and physiological and other psychological responses were also observed. These results may be of interest to researchers using environmental-simulation technologies currently available in order to replicate the experience of physical environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

The LOPES experiment

NASA Astrophysics Data System (ADS)

Link, Katrin; Apel, W. D.; Arteaga, J. C.; Asch, T.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Daumiller, K.; de Souza, V.; Doll, P.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huber, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Krömer, O.; Kuijpers, J.; Lafebre, S.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Melissas, M.; Morello, C.; Nehls, S.; Oehlschläger, J.; Palmieri, N.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Rühle, C.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.

2011-03-01

Cosmic ray particles hit the Earth's atmosphere and induce extensive air showers (EAS). These EAS mainly consist of electrons and positrons that produce radio emission due to their interaction with the Earth's magnetic field. Measuring this radio emission is the purpose of the LOPES (LOFAR Prototype Station) experiment. LOPES is located at Campus North of the Karlsruhe Institute of Technology at the same site as the EAS particle detector KASCADE-Grande. Since the first measurements in 2003, LOPES was improved by various experimental setups and could establish the radio technique. By now, detailed studies of the measured radio signal are performed, like the behaviour of the lateral distribution or the polarization of the electric field. Furthermore, with LOPES the dependence of the radio pulse on properties of the incoming cosmic ray, like primary energy, primary mass, or incoming direction is investigated. In this article we describe the different LOPES setups, next we explain our standard analysis procedure and then we discuss some highlights of our recent results.

A brief discussion about image quality and SEM methods for quantitative fractography of polymer composites.

PubMed

Hein, L R O; Campos, K A; Caltabiano, P C R O; Kostov, K G

2013-01-01

The methodology for fracture analysis of polymeric composites with scanning electron microscopes (SEM) is still under discussion. Many authors prefer to use sputter coating with a conductive material instead of applying low-voltage (LV) or variable-pressure (VP) methods, which preserves the original surfaces. The present work examines the effects of sputter coating with 25 nm of gold on the topography of carbon-epoxy composites fracture surfaces, using an atomic force microscope. Also, the influence of SEM imaging parameters on fractal measurements is evaluated for the VP-SEM and LV-SEM methods. It was observed that topographic measurements were not significantly affected by the gold coating at tested scale. Moreover, changes on SEM setup leads to nonlinear outcome on texture parameters, such as fractal dimension and entropy values. For VP-SEM or LV-SEM, fractal dimension and entropy values did not present any evident relation with image quality parameters, but the resolution must be optimized with imaging setup, accompanied by charge neutralization. © Wiley Periodicals, Inc.

Investigation on the growth and characterization of 4-aminobenzophenone single crystal by the vertical dynamic gradient freeze technique

NASA Astrophysics Data System (ADS)

Prabhakaran, SP.; Ramesh Babu, R.; Sukumar, M.; Bhagavannarayana, G.; Ramamurthi, K.

2014-03-01

Growth of bulk single crystal of 4-Aminobenzophenone (4-ABP) from the vertical dynamic gradient freeze (VDGF) setup designed with eight zone furnace was investigated. The experimental parameters for the growth of 4-ABP single crystal with respect to the design of VDGF setup are discussed. The eight zones were used to generate multiple temperature gradients over the furnace, and video imaging system helped to capture the real time growth and solid-liquid interface. 4-ABP single crystal with the size of 18 mm diameter and 40 mm length was grown from this investigation. Structural and optical quality of grown crystal was examined by high resolution X-ray diffraction and UV-visible spectral analysis, respectively and the blue emission was also confirmed from the photoluminescence spectrum. Microhardness number of the crystal was estimated at different loads using Vicker's microhardness tester. The size and quality of single crystal grown from the present investigation are compared with the vertical Bridgman grown 4-ABP.

SU-F-T-463: Light-Field Based Dynalog Verification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Atwal, P; Ramaseshan, R

2016-06-15

Purpose: To independently verify leaf positions in so-called dynalog files for a Varian iX linac with a Millennium 120 MLC. This verification provides a measure of confidence that the files can be used directly as part of a more extensive intensity modulated radiation therapy / volumetric modulated arc therapy QA program. Methods: Initial testing used white paper placed at the collimator plane and a standard hand-held digital camera to image the light and shadow of a static MLC field through the paper. Known markings on the paper allow for image calibration. Noise reduction was attempted with removal of ‘inherent noise’more » from an open-field light image through the paper, but the method was found to be inconsequential. This is likely because the environment could not be controlled to the precision required for the sort of reproducible characterization of the quantum noise needed in order to meaningfully characterize and account for it. A multi-scale iterative edge detection algorithm was used for localizing the leaf ends. These were compared with the planned locations from the treatment console. Results: With a very basic setup, the image of the central bank A leaves 15–45, which are arguably the most important for beam modulation, differed from the planned location by [0.38±0.28] mm. Similarly, for bank B leaves 15–45 had a difference of [0.42±0.28] mm Conclusion: It should be possible to determine leaf position accurately with not much more than a modern hand-held camera and some software. This means we can have a periodic and independent verification of the dynalog file information. This is indicated by the precision already achieved using a basic setup and analysis methodology. Currently, work is being done to reduce imaging and setup errors, which will bring the leaf position error down further, and allow meaningful analysis over the full range of leaves.« less

Intrafraction Variability and Deformation Quantification in the Breast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glide-Hurst, Carri K., E-mail: churst2@hfhs.org; Shah, Mira M.; Price, Ryan G.

2015-03-01

Purpose: To evaluate intrafraction variability and deformation of the lumpectomy cavity (LC), breast, and nearby organs. Methods and Materials: Sixteen left-sided postlumpectomy and 1 bilateral breast cancer cases underwent free-breathing CT (FBCT) and 10-phase 4-dimensional CT (4DCT). Deformable image registration was used for deformation analysis and contour propagation of breast, heart, lungs, and LC between end-exhale and end-inhale 4DCT phases. Respiration-induced motion was calculated via centroid analysis. Two planning target volumes (PTVs) were compared: PTV{sub FBCT} from the FBCT volume with an isotropic 10 mm expansion (5 mm excursion and 5 mm setup error) and PTV{sub 4DCT} generated from themore » union of 4DCT contours with isotropic 5 mm margin for setup error. Volume and geometry were evaluated via percent difference and bounding box analysis, respectively. Deformation correlations between breast/cavity, breast/lung, and breast/heart were evaluated. Associations were tested between cavity deformation and proximity to chest wall and breast surface. Results: Population-based 3-dimensional vector excursions were 2.5 ± 1.0 mm (range, 0.8-3.8 mm) for the cavity and 2.0 ± 0.8 mm (range, 0.7-3.0 mm) for the ipsilateral breast. Cavity excursion was predominantly in the anterior and superior directions (1.0 ± 0.8 mm and −1.8 ± 1.2 mm, respectively). Similarly, for all cases, LCs and ipsilateral breasts yielded median deformation values in the superior direction. For 14 of 17 patients, the LCs and breast interquartile ranges tended toward the anterior direction. The PTV{sub FBCT} was 51.5% ± 10.8% larger (P<.01) than PTV{sub 4DCT}. Bounding box analysis revealed that PTV{sub FBCT} was 9.8 ± 1.2 (lateral), 9.0 ± 2.2 (anterior–posterior), and 3.9 ± 1.8 (superior–inferior) mm larger than PTV{sub 4DCT}. Significant associations between breast and cavity deformation were found for 6 of 9 axes. No dependency was found between cavity deformation and proximity to chest wall or breast surface. Conclusions: Lumpectomy cavity and breast deformation and motion demonstrated large variability. A PTV{sub 4DCT} approach showed value in patient-specific margins, particularly if robust interfraction setup analysis can be performed.« less

Poster - 30: Use of a Hazard-Risk Analysis for development of a new eye immobilization tool for treatment of choroidal melanoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prooijen, Monique van; Breen, Stephen

Purpose: Our treatment for choroidal melanoma utilizes the GTC frame. The patient looks at a small LED to stabilize target position. The LED is attached to a metal arm attached to the GTC frame. A camera on the arm allows therapists to monitor patient compliance. To move to mask-based immobilization we need a new LED/camera attachment mechanism. We used a Hazard-Risk Analysis (HRA) to guide the design of the new tool. Method: A pre-clinical model was built with input from therapy and machine shop personnel. It consisted of an aluminum frame placed in aluminum guide posts attached to the couchmore » top. Further development was guided by the Department of Defense Standard Practice - System Safety hazard risk analysis technique. Results: An Orfit mask was selected because it allowed access to indexes on the couch top which assist with setup reproducibility. The first HRA table was created considering mechanical failure modes of the device. Discussions with operators and manufacturers identified other failure modes and solutions. HRA directed the design towards a safe clinical device. Conclusion: A new immobilization tool has been designed using hazard-risk analysis which resulted in an easier-to-use and safer tool compared to the initial design. The remaining risks are all low probability events and not dissimilar from those currently faced with the GTC setup. Given the gains in ease of use for therapists and patients as well as the lower costs for the hospital, we will implement this new tool.« less

Complete daVinci versus laparoscopic pyeloplasty: cost analysis.

PubMed

Bhayani, Sam B; Link, Richard E; Varkarakis, John M; Kavoussi, Louis R

2005-04-01

Computer-assisted pyeloplasty with the daVinci system is an emerging technique to treat ureteropelvic junction (UPJ) obstruction. A relative cost analysis was performed assessing this technology in comparison with purely laparoscopic pyeloplasty. Eight patients underwent computer-assisted (daVinci) dismembered pyeloplasty (CP) via a transperitoneal four-port approach. They were compared with 13 patients who underwent purely laparoscopic pyeloplasty (LP). All patients had a primary UPJ obstruction and were matched for age, sex, and body mass index. The cost of equipment and capital depreciation for both procedures, as well as assessment of room set-up time, takedown time, and personnel were analyzed. Surgeons and nursing staff for both groups were experienced in both laparoscopy and daVinci procedures. One- and two-way financial analysis was performed to assess relative costs. The mean set-up and takedown time was 71 minutes for CP and 49 minutes for LP. The mean length of stay was 2.3 days for CP and 2.5 days for LP. The mean operating room (OR) times for CP and LP were 176 and 210 minutes, respectively. There were no complications in either group. One-way cost analysis with an economic model showed that LP is more cost effective than CP at our hospital if LP OR time is <338 minutes. With adjustment to a volume of 500 daVinci cases/year, CP is still not as cost effective as LP. Two-way sensitivity analysis shows that in-room time must still be <130 minutes and yearly cases must be >500 to obtain cost equivalence for CP. Perioperative parameters for CP are encouraging. However, the costs are a clear disadvantage. In our hospital, it is more cost effective to teach and perform LP than to perform CP.

Portfolio: a prototype workstation for development and evaluation of tools for analysis and management of digital portal images.

PubMed

Boxwala, A A; Chaney, E L; Fritsch, D S; Friedman, C P; Rosenman, J G

1998-09-01

The purpose of this investigation was to design and implement a prototype physician workstation, called PortFolio, as a platform for developing and evaluating, by means of controlled observer studies, user interfaces and interactive tools for analyzing and managing digital portal images. The first observer study was designed to measure physician acceptance of workstation technology, as an alternative to a view box, for inspection and analysis of portal images for detection of treatment setup errors. The observer study was conducted in a controlled experimental setting to evaluate physician acceptance of the prototype workstation technology exemplified by PortFolio. PortFolio incorporates a windows user interface, a compact kit of carefully selected image analysis tools, and an object-oriented data base infrastructure. The kit evaluated in the observer study included tools for contrast enhancement, registration, and multimodal image visualization. Acceptance was measured in the context of performing portal image analysis in a structured protocol designed to simulate clinical practice. The acceptability and usage patterns were measured from semistructured questionnaires and logs of user interactions. Radiation oncologists, the subjects for this study, perceived the tools in PortFolio to be acceptable clinical aids. Concerns were expressed regarding user efficiency, particularly with respect to the image registration tools. The results of our observer study indicate that workstation technology is acceptable to radiation oncologists as an alternative to a view box for clinical detection of setup errors from digital portal images. Improvements in implementation, including more tools and a greater degree of automation in the image analysis tasks, are needed to make PortFolio more clinically practical.

Strangeness Photoproduction at the BGO-OD Experiment

NASA Astrophysics Data System (ADS)

Jude, T. C.; Alef, S.; Bayadilov, D.; Beck, R.; Becker, M.; Bella, A.; Bielefeldt, P.; Boese, S.; Braghieri, A.; Brinkmann, K.; Cole, P.; Curciarello, F.; De Leo, V.; Di Salvo, R.; Dutz, H.; Elsner, D.; Fantini, A.; Freyermuth, O.; Friedrich, S.; Frommberger, F.; Ganenko, V.; Gervino, G.; Ghio, F.; Giardina, G.; Goertz, S.; Gridnev, A.; Gutz, E.; Hammann, D.; Hannappel, J.; Hartmann, P.; Hillert, W.; Ignatov, A.; Jahn, R.; Joosten, R.; Klein, F.; Koop, K.; Krusche, B.; Lapik, A.; Levi Sandri, P.; Lopatin, I. V.; Mandaglio, G.; Messi, F.; Messi, R.; Metag, V.; Moricciani, D.; Mushkarenkov, A.; Nanova, M.; Nedorezov, V.; Novinskiy, D.; Pedroni, P.; Reitz, B.; Romaniuk, M.; Rostomyan, T.; Rudnev, N.; Scheluchin, G.; Schmieden, H.; Stugelev, A.; Sumachev, V.; Tarakanov, V.; Vegna, V.; Walther, D.; Watts, D.; Zaunick, H.; Zimmermann, T.

BGO-OD is a newly commissioned experiment to investigate the internal structure of the nucleon, using an energy tagged bremsstrahlung photon beam at the ELSA electron facility. The setup consists of a highly segmented BGO calorimeter surrounding the target, with a particle tracking magnetic spectrometer at forward angles. BGO-OD is ideal for investigating meson photoproduction. The extensive physics programme for open strangeness photoproduction is introduced, and preliminary analysis presented.

Design and Testing of a One-Meter Membrane Mirror with Active Boundary Control (Conference Proceedings)

DTIC Science & Technology

2005-08-01

One type of setup looked into in the past has been the lenticular design, which consists of a clear canopy attached to a reflective film that uses...class lenticular membrane mirror system utilizing active boundary control and stress-coating applications to form a usable aperture for visible...imaging applications. Keywords: Membrane mirror, boundary control, lenticular , lightweight 1. INTRODUCTION Analysis has been conducted to