A user-friendly LabVIEW software platform for grating based X-ray phase-contrast imaging.

PubMed

Wang, Shenghao; Han, Huajie; Gao, Kun; Wang, Zhili; Zhang, Can; Yang, Meng; Wu, Zhao; Wu, Ziyu

2015-01-01

X-ray phase-contrast imaging can provide greatly improved contrast over conventional absorption-based imaging for weakly absorbing samples, such as biological soft tissues and fibre composites. In this study, we introduced an easy and fast way to develop a user-friendly software platform dedicated to the new grating-based X-ray phase-contrast imaging setup at the National Synchrotron Radiation Laboratory of the University of Science and Technology of China. The control of 21 motorized stages, of a piezoelectric stage and of an X-ray tube are achieved with this software, it also covers image acquisition with a flat panel detector for automatic phase stepping scan. Moreover, a data post-processing module for signals retrieval and other custom features are in principle available. With a seamless integration of all the necessary functions in one software package, this platform greatly facilitate users' activities during experimental runs with this grating based X-ray phase contrast imaging setup.

A dedicated AMS setup for 53Mn/60Fe at the Cologne FN tandem accelerator

NASA Astrophysics Data System (ADS)

Schiffer, M.; Dewald, A.; Feuerstein, C.; Altenkirch, R.; Stolz, A.; Heinze, S.

2015-10-01

Following demands for AMS measurements of medium mass isotopes, especially for 53Mn and 60Fe, we started to build a dedicated AMS setup at the Cologne FN tandem accelerator. This accelerator with a maximum terminal voltage of 10 MV can be reliably operated at a terminal voltage of 9.5 MV which corresponds to energies of 93-102 MeV for 60Fe or 53Mn beams using the 9+ or 10+ charge state. These charge states can be obtained by foil stripping with efficiencies of 30% and 20%, respectively. Energies around 100 MeV are sufficient to effectively suppress the stable isobars 60Ni and 53Cr by (dE/dx) techniques using combinations of energy degrader foils and dispersive elements like electrostatic analyzers and time of flight (TOF) systems as well as (dE/dx)E ion detectors. In this contribution we report on the actual status of the AMS setup and discuss details and expected features.

Development of a versatile user-friendly IBA experimental chamber

NASA Astrophysics Data System (ADS)

Kakuee, Omidreza; Fathollahi, Vahid; Lamehi-Rachti, Mohammad

2016-03-01

Reliable performance of the Ion Beam Analysis (IBA) techniques is based on the accurate geometry of the experimental setup, employment of the reliable nuclear data and implementation of dedicated analysis software for each of the IBA techniques. It has already been shown that geometrical imperfections lead to significant uncertainties in quantifications of IBA measurements. To minimize these uncertainties, a user-friendly experimental chamber with a heuristic sample positioning system for IBA analysis was recently developed in the Van de Graaff laboratory in Tehran. This system enhances IBA capabilities and in particular Nuclear Reaction Analysis (NRA) and Elastic Recoil Detection Analysis (ERDA) techniques. The newly developed sample manipulator provides the possibility of both controlling the tilt angle of the sample and analyzing samples with different thicknesses. Moreover, a reasonable number of samples can be loaded in the sample wheel. A comparison of the measured cross section data of the 16O(d,p1)17O reaction with the data reported in the literature confirms the performance and capability of the newly developed experimental chamber.

A Compton scattering setup for pulse shape discrimination studies in germanium detectors.

PubMed

von Sturm, K; Belogurov, S; Brugnera, R; Garfagnini, A; Lippi, I; Modenese, L; Rosso, D; Turcato, M

2017-07-01

Pulse shape discrimination is an important handle to improve sensitivity in low background experiments. A dedicated setup was built to investigate the response of high-purity germanium detectors to single Compton scattered events. Using properly collimated γ-ray sources, it is possible to select events with known interaction location. The aim is to correlate the position dependent signal shape with geometrical and electrical properties of the detector. We report on design and performance of the setup with a first look on data. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of frequency tuning and double-frequency heating on ions extracted from an electron cyclotron resonance ion source

NASA Astrophysics Data System (ADS)

Maimone, F.; Celona, L.; Lang, R.; Mäder, J.; Roßbach, J.; Spädtke, P.; Tinschert, K.

2011-12-01

The electromagnetic field within the plasma chamber of an electron cyclotron resonance ion source (ECRIS) and the properties of the plasma waves affect the plasma properties and ion beam production. We have experimentally investigated the "frequency tuning effect" and "double frequency heating" on the CAPRICE ECRIS device. A traveling wave tube amplifier, two microwave sweep generators, and a dedicated experimental set-up were used to carry out experiments in the 12.5-16.5 GHz frequency range. During the frequency sweeps the evolution of the intensity and shape of the extracted argon beam were measured together with the microwave reflection coefficient. A range of different ion source parameter settings was used. Here we describe these experiments and the resultant improved understanding of these operational modes of the ECR ion source.

Influence of frequency tuning and double-frequency heating on ions extracted from an electron cyclotron resonance ion source.

PubMed

Maimone, F; Celona, L; Lang, R; Mäder, J; Rossbach, J; Spädtke, P; Tinschert, K

2011-12-01

The electromagnetic field within the plasma chamber of an electron cyclotron resonance ion source (ECRIS) and the properties of the plasma waves affect the plasma properties and ion beam production. We have experimentally investigated the "frequency tuning effect" and "double frequency heating" on the CAPRICE ECRIS device. A traveling wave tube amplifier, two microwave sweep generators, and a dedicated experimental set-up were used to carry out experiments in the 12.5-16.5 GHz frequency range. During the frequency sweeps the evolution of the intensity and shape of the extracted argon beam were measured together with the microwave reflection coefficient. A range of different ion source parameter settings was used. Here we describe these experiments and the resultant improved understanding of these operational modes of the ECR ion source.

SPR based hybrid electro-optic biosensor for β-lactam antibiotics determination in water

NASA Astrophysics Data System (ADS)

Galatus, Ramona; Feier, Bogdan; Cristea, Cecilia; Cennamo, Nunzio; Zeni, Luigi

2017-09-01

The present work aims to provide a hybrid platform capable of complementary and sensitive detection of β-lactam antibiotics, ampicillin in particular. The use of an aptamer specific to ampicillin assures good selectivity and sensitivity for the detection of ampicillin from different matrice. This new approach is dedicated for a portable, remote sensing platform based on low-cost, small size and low-power consumption solution. The simple experimental hybrid platform integrates the results from the D-shape surface plasmon resonance plastic optical fiber (SPR-POF) and from the electrochemical (bio)sensor, for the analysis of ampicillin, delivering sensitive and reliable results. The SPR-POF already used in many previous applications is embedded in a new experimental setup with fluorescent fibers emitters, for broadband wavelength analysis, low-power consumption and low-heating capabilities of the sensing platform.

NaNet-10: a 10GbE network interface card for the GPU-based low-level trigger of the NA62 RICH detector.

NASA Astrophysics Data System (ADS)

Ammendola, R.; Biagioni, A.; Fiorini, M.; Frezza, O.; Lonardo, A.; Lamanna, G.; Lo Cicero, F.; Martinelli, M.; Neri, I.; Paolucci, P. S.; Pastorelli, E.; Piandani, R.; Pontisso, L.; Rossetti, D.; Simula, F.; Sozzi, M.; Tosoratto, L.; Vicini, P.

2016-03-01

A GPU-based low level (L0) trigger is currently integrated in the experimental setup of the RICH detector of the NA62 experiment to assess the feasibility of building more refined physics-related trigger primitives and thus improve the trigger discriminating power. To ensure the real-time operation of the system, a dedicated data transport mechanism has been implemented: an FPGA-based Network Interface Card (NaNet-10) receives data from detectors and forwards them with low, predictable latency to the memory of the GPU performing the trigger algorithms. Results of the ring-shaped hit patterns reconstruction will be reported and discussed.

Deep X-ray lithography for the fabrication of microstructures at ELSA

NASA Astrophysics Data System (ADS)

Pantenburg, F. J.; Mohr, J.

2001-07-01

Two beamlines at the Electron Stretcher Accelerator (ELSA) of Bonn University are dedicated for the production of microstructures by deep X-ray lithography with synchrotron radiation. They are equipped with state-of-the-art X-ray scanners, maintained and used by Forschungszentrum Karlsruhe. Polymer microstructure heights between 30 and 3000 μm are manufactured regularly for research and industrial projects. This requires different characteristic energies. Therefore, ELSA operates routinely at 1.6, 2.3 and 2.7 GeV, for high-resolution X-ray mask fabrication, deep and ultra-deep X-ray lithography, respectively. The experimental setup, as well as the structure quality of deep and ultra deep X-ray lithographic microstructures are described.

Absolute Photoionization Cross Section for Fe6+ to Fe10+ Ions in the Photon Energy Region of the 2p–3d Resonance Lines

NASA Astrophysics Data System (ADS)

Blancard, C.; Cubaynes, D.; Guilbaud, S.; Bizau, J.-M.

2018-01-01

Resonant single photoionization cross sections of Fen+ (n = 6 to 10) ions have been measured in absolute values using a merged-beams setup at the SOLEIL synchrotron radiation facility. Photon energies were between about 710 and 780 eV, covering the range of the 2p–3d transitions. The experimental cross sections are compared to calculations we performed using a multi-configuration Dirac–Fock code and the OPAS code dedicated to radiative opacity calculations. Comparisons are also done with the Chandra X-ray observatory NGC 3783 spectra and with the results of previously published calculations.

THz QCL-based active imaging dedicated to non-destructive testing of composite materials used in aeronautics

NASA Astrophysics Data System (ADS)

Destic, F.; Petitjean, Y.; Massenot, S.; Mollier, J.-C.; Barbieri, S.

2010-08-01

This paper presents a CW raster-scanning THz imaging setup, used to perform Non-Destructive Testing of KevlarTMand carbon fibre samples. The setup uses a 2.5 THz Quantum Cascade Laser as a source. Delamination defect in a Kevlar sample was detected showing a sensitivity to laser polarization orientation. Detection of a break in a carbon/epoxy sample was also performed.

Wageningen Urban Rainfall Experiment 2014 (WURex14): Experimental setup and preliminary results

NASA Astrophysics Data System (ADS)

van Leth, Thomas C.; Uijlenhoet, Remko; Overeem, Aart; Leijnse, Hidde; Hazenberg, Pieter; Berne, Alexis

2016-04-01

Microwave links from cellular communication networks have been shown to be able to provide valuable information concerning the space-time variability of rainfall. In particular over urban areas, where network densities are generally high, they have the potential to complement existing dedicated infrastructure to measure rainfall (gauges, radars). In addition, microwave links provide a great opportunity for ground-based rainfall measurement for those land surface areas of the world where gauges and radars are generally lacking. Such information is not only crucial for water management and agriculture, but also for instance for ground validation of space-borne rainfall estimates such as those provided by the GPM (Global Precipitation Measurement) mission. WURex14 is dedicated to address several errors and uncertainties associated with such quantitative precipitation estimates in detail. The core of the experiment is provided by three co-located microwave links installed between two major buildings on the Wageningen University campus, approximately 2 km apart: a 38 GHz commercial microwave link, provided by T-Mobile NL, and 26 GHz and 38 GHz (dual-polarization) research microwave links from RAL. Transmitting and receiving antennas have been attached to masts installed on the roofs of the two buildings, about 30 m above the ground. This setup has been complemented with a Scintec infrared Large-Aperture Scintillometer, installed over the same path, as well as 5 Parsivel optical disdrometers and an automated rain gauge positioned at several locations along the path. Temporal sampling of the received signals was performed at a rate of 20 Hz. The setup is being monitored by time-lapse cameras to assess the state of the antennas as well as the atmosphere. Finally, data is available from the KNMI weather radars and an automated weather station situated just outside Wageningen. The experiment has been active between August 2014 and December 2015. We give a global overview of the preliminary results.

Influence of the spectral distribution of light on the characteristics of photovoltaic panel. Comparison between simulation and experimental

NASA Astrophysics Data System (ADS)

Chadel, Meriem; Bouzaki, Mohammed Moustafa; Chadel, Asma; Petit, Pierre; Sawicki, Jean-Paul; Aillerie, Michel; Benyoucef, Boumediene

2017-02-01

We present and analyze experimental results obtained with a laboratory setup based on a hardware and smart instrumentation for the complete study of performance of PV panels using for illumination an artificial radiation source (Halogen lamps). Associated to an accurate analysis, this global experimental procedure allows the determination of effective performance under standard conditions thanks to a simulation process originally developed under Matlab software environment. The uniformity of the irradiated surface was checked by simulation of the light field. We studied the response of standard commercial photovoltaic panels under enlightenment measured by a spectrometer with different spectra for two sources, halogen lamps and sunlight. Then, we bring a special attention to the influence of the spectral distribution of light on the characteristics of photovoltaic panel, that we have performed as a function of temperature and for different illuminations with dedicated measurements and studies of the open circuit voltage and short-circuit current.

A multi-layered active target for the study of neutron-unbound nuclides at NSCL

NASA Astrophysics Data System (ADS)

Freeman, Jessica; Gueye, Paul; Redpath, Thomas; MoNA Collaboration

2017-01-01

The characteristics of neutron-unbound nuclides were investigated using a multi-layered Si/Be active target designed for use with the MoNA/LISA setup at the National Superconducting Cyclotron (NSCL). The setup consists of the MoNA/LISA arrays (for neutron detection) and a superconducting sweeper magnet (for charged separation) to identify products following the decay of neutron unbound states. The segmented target consisted of three 700 mg/cm2 beryllium targets and four 0.14 mm thick 62x62 mm2 silicon detectors. As a commissioning experiment for the target the decay of two-neutron unbound 26O populated in a one-proton removal reaction from a radioactive 27F beam was performed. The 27F secondary radioactive beam from the NSCL's Coupled Cyclotron Facility was produced from the fragmentation of a 140 MeV/u 48Ca beam incident on a thick beryllium target and then cleanly selected by the A1900 fragment separator. The energy loss and position spectra of the incoming beam and reaction products were used to calibrate the Silicon detectors to within 1.5% in both energy and position. A dedicated Geant4 model of the target was developed to simulate the energy loss within the target. A description of the experimental setup, simulation work, and energy and position calibration will be presented. DoE/NNSA - DE-NA0000979.

A low-noise measurement system for scanning thermal microscopy resistive nanoprobes based on a transformer ratio-arm bridge

NASA Astrophysics Data System (ADS)

Świątkowski, Michał; Wojtuś, Arkadiusz; Wielgoszewski, Grzegorz; Rudek, Maciej; Piasecki, Tomasz; Jóźwiak, Grzegorz; Gotszalk, Teodor

2018-04-01

Atomic force microscopy (AFM) is a widely used technology for the investigation and characterization of nanomaterials. Its functionality can be easily expanded by applying dedicated extension modules, which can measure the electrical conductivity or temperature of a sample. In this paper, we introduce a transformer ratio-arm bridge setup dedicated to AFM-based thermal imaging. One of the key features of the thermal module is the use of a low-power driving signal that prevents undesirable tip heating during resistance measurement, while the other is the sensor location in a ratio-arm transformer bridge working in the audio frequency range and ensuring galvanic isolation of the tip, enabling contact-mode scanning of electronic circuits. The proposed expansion module is compact and it can be integrated onto the AFM head close to the cantilever. The calibration process and the resolution of 11 mK of the proposed setup are shown.

Identifying Genotype-by-Environment Interactions in the Metabolism of Germinating Arabidopsis Seeds Using Generalized Genetical Genomics 1[C][W][OA

PubMed Central

Joosen, Ronny Viktor Louis; Arends, Danny; Li, Yang; Willems, Leo A.J.; Keurentjes, Joost J.B.; Ligterink, Wilco; Jansen, Ritsert C.; Hilhorst, Henk W.M.

2013-01-01

A complex phenotype such as seed germination is the result of several genetic and environmental cues and requires the concerted action of many genes. The use of well-structured recombinant inbred lines in combination with “omics” analysis can help to disentangle the genetic basis of such quantitative traits. This so-called genetical genomics approach can effectively capture both genetic and epistatic interactions. However, to understand how the environment interacts with genomic-encoded information, a better understanding of the perception and processing of environmental signals is needed. In a classical genetical genomics setup, this requires replication of the whole experiment in different environmental conditions. A novel generalized setup overcomes this limitation and includes environmental perturbation within a single experimental design. We developed a dedicated quantitative trait loci mapping procedure to implement this approach and used existing phenotypical data to demonstrate its power. In addition, we studied the genetic regulation of primary metabolism in dry and imbibed Arabidopsis (Arabidopsis thaliana) seeds. In the metabolome, many changes were observed that were under both environmental and genetic controls and their interaction. This concept offers unique reduction of experimental load with minimal compromise of statistical power and is of great potential in the field of systems genetics, which requires a broad understanding of both plasticity and dynamic regulation. PMID:23606598

Light-ion therapy in the U.S.: From the Bevalac to ??

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

Alonso, Jose R.; Castro, Joseph R.

2002-09-24

While working with E.O. Lawrence at Berkeley, R.R. Wilson in 1946 noted the potential for using the Bragg-peak of protons (or heavier ions) for radiation therapy. Thus began the long history of contributions from Berkeley to this field. Pioneering work by C.A. Tobias et al at the 184-Inch Synchrocyclotron led ultimately to clinical applications of proton and helium beams, with over 1000 patients treated through 1974 with high-energy plateau radiation; placing the treatment volume (mostly pituitary fields) at the rotational center of a sophisticated patient positioner. In 1974 the SuperHILAC and Bevatron accelerators at the Lawrence Berkeley Laboratory were joinedmore » by the construction of a 250-meter transfer line, forming the Bevalac, a facility capable of accelerating ions of any atomic species to relativistic energies. With the advent of these new beams, and better diagnostic tools capable of more precise definition of tumor volume and determination of the stopping point of charged-particle beams, large-field Bragg-peak therapy with ion beams became a real possibility. A dedicated Biomedical experimental area was developed, ultimately consisting of three distinct irradiation stations; two dedicated to therapy and one to radiobiology and biophysics. These facilities included dedicated support areas for patient setup and staging of animal and cell samples, and a central control area linked to the main Bevatron control room.« less

PSICHE: a new beamline dedicated to X-ray diffraction and tomography at high pressure at synchrotron SOLEIL

NASA Astrophysics Data System (ADS)

Guignot, N.; Itié, J.; Zerbino, P.; Delmotte, A.; Moreno, T.

2013-12-01

The PSICHE beamline (for 'Pressure, Structure and Imaging by Contrast at High Energy') is a new facility opened for high pressure experiments at synchrotron SOLEIL (St-Aubin, France). With its source, optics, detectors and 3 experimental stations, it can handle a large variety of experimental setups. High energy photons are produced with an in-vacuum wiggler. The white beam obtained, with photons energy ranging continuously from 15 to 80 keV (from a 2.75 GeV machine), is used on the first experimental station for energy dispersive X-ray diffraction (EDX) measurements using different pressure cells. The main setup is a 1200 tons load capacity multi-anvil press featuring a (100) DIA compression module with a 15° horizontal aperture, allowing measurements up to 30° in 2theta by rotating the press. Other setups are a Paris-Edinburgh (PE) large volume press and diamond anvil cells (DACs). On the detection side we have a rotating Ge detector, based on the CAESAR design described by Wang et al. (2004) (combination of EDX and angular dispersive X-ray diffraction, ADX). One of the difficulties when building such setups is the rotation mechanism which cannot be physically attached to the rotation axis, potentially leading to large circle of confusions on the horizontal position of this axis. Thanks to translation corrections done at each angle step, the circle of confusion is minimized to 3x6 μm2 along the 35° travel, making possible measurements on very small objects. Combining EDX and ADX has a lot of advantages and we will present our first results obtained using this setup. The PSICHE focusing optics and monochromator are also used to focus monochromatic beams (up to 52 keV) on 2 different experimental stations. The first focal point at 31 m gives a beam size of 100x50 μm2 (HxV) and is useful for low pressure experiments and experiments done with the PE press associated with Soller slits. A PerkinElmer flatpanel detector can be precisely scanned in 3 directions, making ADX measurements at the highest possible resolution on this beamline. This station will also be used for diffraction tomography experiments. The second focal point at 37.6 m is located behind KB mirrors on the third experimental station. 10x10 μm2 beam sizes (full width) are expected. This station will be used for DAC experiments, with or without our future laser heating setup. Finally, parallel beams can be produced with sizes up to 15x5 mm2 (HxV) for tomography experiments, in pink (filtered white) beam or monochromatic beam. We plan to use rotating anvils presses such as the rotoPEc (J. Philippe et al., 2013) to take full advantage of this beam mode, but it can be opened to other techniques. The PSICHE beamline is opened for users since July 2013. Some stations are not available yet, and will be opened through 2014 and 2015. References X. Dong et al., Ray tracing application in hard x-ray optical development: Soleil first wiggler beamline (PSICHÉ) case" (2011), Proc. SPIE 8141, 814113 Y. Wang et al., A new technique for angle-dispersive powder diffraction using an energy-dispersive setup and synchrotron radiation (2004), J. Appl. Cryst. 37, 947-956 J. Philippe, Y. Le Godec, F. Bergame et M. Morand, Patent INPI 11 62335 (2013)

Dynamic provisioning of a HEP computing infrastructure on a shared hybrid HPC system

NASA Astrophysics Data System (ADS)

Meier, Konrad; Fleig, Georg; Hauth, Thomas; Janczyk, Michael; Quast, Günter; von Suchodoletz, Dirk; Wiebelt, Bernd

2016-10-01

Experiments in high-energy physics (HEP) rely on elaborate hardware, software and computing systems to sustain the high data rates necessary to study rare physics processes. The Institut fr Experimentelle Kernphysik (EKP) at KIT is a member of the CMS and Belle II experiments, located at the LHC and the Super-KEKB accelerators, respectively. These detectors share the requirement, that enormous amounts of measurement data must be processed and analyzed and a comparable amount of simulated events is required to compare experimental results with theoretical predictions. Classical HEP computing centers are dedicated sites which support multiple experiments and have the required software pre-installed. Nowadays, funding agencies encourage research groups to participate in shared HPC cluster models, where scientist from different domains use the same hardware to increase synergies. This shared usage proves to be challenging for HEP groups, due to their specialized software setup which includes a custom OS (often Scientific Linux), libraries and applications. To overcome this hurdle, the EKP and data center team of the University of Freiburg have developed a system to enable the HEP use case on a shared HPC cluster. To achieve this, an OpenStack-based virtualization layer is installed on top of a bare-metal cluster. While other user groups can run their batch jobs via the Moab workload manager directly on bare-metal, HEP users can request virtual machines with a specialized machine image which contains a dedicated operating system and software stack. In contrast to similar installations, in this hybrid setup, no static partitioning of the cluster into a physical and virtualized segment is required. As a unique feature, the placement of the virtual machine on the cluster nodes is scheduled by Moab and the job lifetime is coupled to the lifetime of the virtual machine. This allows for a seamless integration with the jobs sent by other user groups and honors the fairshare policies of the cluster. The developed thin integration layer between OpenStack and Moab can be adapted to other batch servers and virtualization systems, making the concept also applicable for other cluster operators. This contribution will report on the concept and implementation of an OpenStack-virtualized cluster used for HEP workflows. While the full cluster will be installed in spring 2016, a test-bed setup with 800 cores has been used to study the overall system performance and dedicated HEP jobs were run in a virtualized environment over many weeks. Furthermore, the dynamic integration of the virtualized worker nodes, depending on the workload at the institute's computing system, will be described.

Muon background studies for shallow depth Double - Chooz near detector

NASA Astrophysics Data System (ADS)

Gómez, H.

2015-08-01

Muon events are one of the main concerns regarding background in neutrino experiments. The placement of experimental set-ups in deep underground facilities reduce considerably their impact on the research of the expected signals. But in the cases where the detector is installed on surface or at shallow depth, muon flux remains high, being necessary their precise identification for further rejection. Total flux, mean energy or angular distributions are some of the parameters that can help to characterize the muons. Empirically, the muon rate can be measured in an experiment by a number of methods. Nevertheless, the capability to determine the muons angular distribution strongly depends on the detector features, while the measurement of the muon energy is quite difficult. Also considering that on-site measurements can not be extrapolated to other sites due to the difference on the overburden and its profile, it is necessary to find an adequate solution to perform the muon characterization. The method described in this work to obtain the main features of the muons reaching the experimental set-up, is based on the muon transport simulation by the MUSIC software, combined with a dedicated sampling algorithm for shallow depth installations based on a modified Gaisser parametrization. This method provides all the required information about the muons for any shallow depth installation if the corresponding overburden profile is implemented. In this work, the method has been applied for the recently commissioned Double - Chooz near detector, which will allow the cross-check between the simulation and the experimental data, as it has been done for the far detector.

Ionization chamber correction factors for MR-linacs

NASA Astrophysics Data System (ADS)

Pojtinger, Stefan; Steffen Dohm, Oliver; Kapsch, Ralf-Peter; Thorwarth, Daniela

2018-06-01

Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B. The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0–2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

Ionization chamber correction factors for MR-linacs.

PubMed

Pojtinger, Stefan; Dohm, Oliver Steffen; Kapsch, Ralf-Peter; Thorwarth, Daniela

2018-06-07

Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B . The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0-2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

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

Gómez, H.

Muon events are one of the main concerns regarding background in neutrino experiments. The placement of experimental set-ups in deep underground facilities reduce considerably their impact on the research of the expected signals. But in the cases where the detector is installed on surface or at shallow depth, muon flux remains high, being necessary their precise identification for further rejection. Total flux, mean energy or angular distributions are some of the parameters that can help to characterize the muons. Empirically, the muon rate can be measured in an experiment by a number of methods. Nevertheless, the capability to determine themore » muons angular distribution strongly depends on the detector features, while the measurement of the muon energy is quite difficult. Also considering that on-site measurements can not be extrapolated to other sites due to the difference on the overburden and its profile, it is necessary to find an adequate solution to perform the muon characterization. The method described in this work to obtain the main features of the muons reaching the experimental set-up, is based on the muon transport simulation by the MUSIC software, combined with a dedicated sampling algorithm for shallow depth installations based on a modified Gaisser parametrization. This method provides all the required information about the muons for any shallow depth installation if the corresponding overburden profile is implemented. In this work, the method has been applied for the recently commissioned Double - Chooz near detector, which will allow the cross-check between the simulation and the experimental data, as it has been done for the far detector.« less

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.

Optimized 31P MRS in the human brain at 7 T with a dedicated RF coil setup

PubMed Central

van de Bank, Bart L.; Orzada, Stephan; Smits, Frits; Lagemaat, Miriam W.; Rodgers, Christopher T.; Bitz, Andreas K.

2015-01-01

The design and construction of a dedicated RF coil setup for human brain imaging (1H) and spectroscopy (31P) at ultra‐high magnetic field strength (7 T) is presented. The setup is optimized for signal handling at the resonance frequencies for 1H (297.2 MHz) and 31P (120.3 MHz). It consists of an eight‐channel 1H transmit–receive head coil with multi‐transmit capabilities, and an insertable, actively detunable 31P birdcage (transmit–receive and transmit only), which can be combined with a seven‐channel receive‐only 31P array. The setup enables anatomical imaging and 31P studies without removal of the coil or the patient. By separating transmit and receive channels and by optimized addition of array signals with whitened singular value decomposition we can obtain a sevenfold increase in SNR of 31P signals in the occipital lobe of the human brain compared with the birdcage alone. These signals can be further enhanced by 30 ± 9% using the nuclear Overhauser effect by B 1‐shimmed low‐power irradiation of water protons. Together, these features enable acquisition of 31P MRSI at high spatial resolutions (3.0 cm3 voxel) in the occipital lobe of the human brain in clinically acceptable scan times (~15 min). © 2015 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd. PMID:26492089

Microtomography imaging of an isolated plant fiber: a digital holographic approach.

PubMed

Malek, Mokrane; Khelfa, Haithem; Picart, Pascal; Mounier, Denis; Poilâne, Christophe

2016-01-20

This paper describes a method for optical projection tomography for the 3D in situ characterization of micrometric plant fibers. The proposed approach is based on digital holographic microscopy, the holographic capability being convenient to compensate for the runout of the fiber during rotations. The setup requires a telecentric alignment to prevent from the changes in the optical magnification, and calibration results show the very good experimental adjustment. Amplitude images are obtained from the set of recorded and digitally processed holograms. Refocusing of blurred images and correction of both runout and jitter are carried out to get appropriate amplitude images. The 3D data related to the plant fiber are computed from the set of images using a dedicated numerical processing. Experimental results exhibit the internal and external shapes of the plant fiber. These experimental results constitute the first attempt to obtain 3D data of flax fiber, about 12  μm×17  μm in apparent diameter, with a full-field optical tomography approach using light in the visible range.

Real-time soft error rate measurements on bulk 40 nm SRAM memories: a five-year dual-site experiment

NASA Astrophysics Data System (ADS)

Autran, J. L.; Munteanu, D.; Moindjie, S.; Saad Saoud, T.; Gasiot, G.; Roche, P.

2016-11-01

This paper reports five years of real-time soft error rate experimentation conducted with the same setup at mountain altitude for three years and then at sea level for two years. More than 7 Gbit of SRAM memories manufactured in CMOS bulk 40 nm technology have been subjected to the natural radiation background. The intensity of the atmospheric neutron flux has been continuously measured on site during these experiments using dedicated neutron monitors. As the result, the neutron and alpha component of the soft error rate (SER) have been very accurately extracted from these measurements, refining the first SER estimations performed in 2012 for this SRAM technology. Data obtained at sea level evidence, for the first time, a possible correlation between the neutron flux changes induced by the daily atmospheric pressure variations and the measured SER. Finally, all of the experimental data are compared with results obtained from accelerated tests and numerical simulation.

Fast high-energy X-ray imaging for Severe Accidents experiments on the future PLINIUS-2 platform

NASA Astrophysics Data System (ADS)

Berge, L.; Estre, N.; Tisseur, D.; Payan, E.; Eck, D.; Bouyer, V.; Cassiaut-Louis, N.; Journeau, C.; Tellier, R. Le; Pluyette, E.

2018-01-01

The future PLINIUS-2 platform of CEA Cadarache will be dedicated to the study of corium interactions in severe nuclear accidents, and will host innovative large-scale experiments. The Nuclear Measurement Laboratory of CEA Cadarache is in charge of real-time high-energy X-ray imaging set-ups, for the study of the corium-water and corium-sodium interaction, and of the corium stratification process. Imaging such large and high-density objects requires a 15 MeV linear electron accelerator coupled to a tungsten target creating a high-energy Bremsstrahlung X-ray flux, with corresponding dose rate about 100 Gy/min at 1 m. The signal is detected by phosphor screens coupled to high-framerate scientific CMOS cameras. The imaging set-up is established using an experimentally-validated home-made simulation software (MODHERATO). The code computes quantitative radiographic signals from the description of the source, object geometry and composition, detector, and geometrical configuration (magnification factor, etc.). It accounts for several noise sources (photonic and electronic noises, swank and readout noise), and for image blur due to the source spot-size and to the detector unsharpness. In a view to PLINIUS-2, the simulation has been improved to account for the scattered flux, which is expected to be significant. The paper presents the scattered flux calculation using the MCNP transport code, and its integration into the MODHERATO simulation. Then the validation of the improved simulation is presented, through confrontation to real measurement images taken on a small-scale equivalent set-up on the PLINIUS platform. Excellent agreement is achieved. This improved simulation is therefore being used to design the PLINIUS-2 imaging set-ups (source, detectors, cameras, etc.).

A Multisensing Setup for the Intelligent Tire Monitoring.

PubMed

Coppo, Francesco; Pepe, Gianluca; Roveri, Nicola; Carcaterra, Antonio

2017-03-12

The present paper offers the chance to experimentally measure, for the first time, the internal tire strain by optical fiber sensors during the tire rolling in real operating conditions. The phenomena that take place during the tire rolling are in fact far from being completely understood. Despite several models available in the technical literature, there is not a correspondently large set of experimental observations. The paper includes the detailed description of the new multi-sensing technology for an ongoing vehicle measurement, which the research group has developed in the context of the project OPTYRE. The experimental apparatus is mainly based on the use of optical fibers with embedded Fiber Bragg Gratings sensors for the acquisition of the circumferential tire strain. Other sensors are also installed on the tire, such as a phonic wheel, a uniaxial accelerometer, and a dynamic temperature sensor. The acquired information is used as input variables in dedicated algorithms that allow the identification of key parameters, such as the dynamic contact patch, instantaneous dissipation and instantaneous grip. The OPTYRE project brings a contribution into the field of experimental grip monitoring of wheeled vehicles, with implications both on passive and active safety characteristics of cars and motorbikes.

A Multisensing Setup for the Intelligent Tire Monitoring

PubMed Central

Coppo, Francesco; Pepe, Gianluca; Roveri, Nicola; Carcaterra, Antonio

2017-01-01

The present paper offers the chance to experimentally measure, for the first time, the internal tire strain by optical fiber sensors during the tire rolling in real operating conditions. The phenomena that take place during the tire rolling are in fact far from being completely understood. Despite several models available in the technical literature, there is not a correspondently large set of experimental observations. The paper includes the detailed description of the new multi-sensing technology for an ongoing vehicle measurement, which the research group has developed in the context of the project OPTYRE. The experimental apparatus is mainly based on the use of optical fibers with embedded Fiber Bragg Gratings sensors for the acquisition of the circumferential tire strain. Other sensors are also installed on the tire, such as a phonic wheel, a uniaxial accelerometer, and a dynamic temperature sensor. The acquired information is used as input variables in dedicated algorithms that allow the identification of key parameters, such as the dynamic contact patch, instantaneous dissipation and instantaneous grip. The OPTYRE project brings a contribution into the field of experimental grip monitoring of wheeled vehicles, with implications both on passive and active safety characteristics of cars and motorbikes. PMID:28287503

TAMOAS: In Situ Gasometry in the Atmosphere with Solid Electrolyte Sensors on BEXUS-19

NASA Astrophysics Data System (ADS)

Bronowski, A.; Clemens, R.; Jaster, T.; Kosel, F.; Matyash, I.; Westphal, A.

2015-09-01

A student experiment developed for testing gas sensors in the stratosphere is described. The setup consists of a measurement electronic running miniaturized in situ amperiometric gas sensors based on different solid state electrolytes dedicated for oxygen, ozone and atomic oxygen. The experiment took place at Esrange Space Center in October 2014. The setup was attached to the high-altitude balloon BEXUS-19 and reached an altitude of 27 km at night. The primary objective was to test the prototype sensors and to gain data during flight.

High speed systems for time-resolved experiments with synchrotron radiation

NASA Astrophysics Data System (ADS)

Koziol, Anna; Maj, Piotr

2018-02-01

The UFXC32k is a single photon counting hybrid pixel detector with 75 μm pixel pitch. It was designed to cope with high X-ray intensities and therefore it is a very good candiate for synchrotron applications. In order to use this detector in an application, a dedicated setup must be designed and built allowing proper operation of the detector within the experiment. The paper presents two setups built for the purpose of Pump-Probe-Probe experiments at the Synchrotron SOLEIL and XPCS experiments at the APS.

Development of a TOF SIMS setup at the Zagreb heavy ion microbeam facility

NASA Astrophysics Data System (ADS)

Tadić, Tonči; Bogdanović Radović, Iva; Siketić, Zdravko; Cosic, Donny Domagoj; Skukan, Natko; Jakšić, Milko; Matsuo, Jiro

2014-08-01

We describe a new Time-of-flight Secondary Ion Mass Spectrometry (TOF SIMS) setup for MeV SIMS application, which is constructed and installed at the heavy ion microbeam facility at the Ruđer Bošković Institute in Zagreb. The TOF-SIMS setup is developed for high sensitivity molecular imaging using a heavy ion microbeam that focuses ion beams (from C to I) with sub-micron resolution. Dedicated pulse processing electronics for MeV SIMS application have been developed, enabling microbeam-scanning control, incoming ion microbeam pulsing and molecular mapping. The first results showing measured MeV SIMS spectra as well as molecular maps for samples of interest are presented and discussed.

Towards integration of PET/MR hybrid imaging into radiation therapy treatment planning

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

Paulus, Daniel H., E-mail: daniel.paulus@imp.uni-erlangen.de; Thorwath, Daniela; Schmidt, Holger

2014-07-15

Purpose: Multimodality imaging has become an important adjunct of state-of-the-art radiation therapy (RT) treatment planning. Recently, simultaneous PET/MR hybrid imaging has become clinically available and may also contribute to target volume delineation and biological individualization in RT planning. For integration of PET/MR hybrid imaging into RT treatment planning, compatible dedicated RT devices are required for accurate patient positioning. In this study, prototype RT positioning devices intended for PET/MR hybrid imaging are introduced and tested toward PET/MR compatibility and image quality. Methods: A prototype flat RT table overlay and two radiofrequency (RF) coil holders that each fix one flexible body matrixmore » RF coil for RT head/neck imaging have been evaluated within this study. MR image quality with the RT head setup was compared to the actual PET/MR setup with a dedicated head RF coil. PET photon attenuation and CT-based attenuation correction (AC) of the hardware components has been quantitatively evaluated by phantom scans. Clinical application of the new RT setup in PET/MR imaging was evaluated in anin vivo study. Results: The RT table overlay and RF coil holders are fully PET/MR compatible. MR phantom and volunteer imaging with the RT head setup revealed high image quality, comparable to images acquired with the dedicated PET/MR head RF coil, albeit with 25% reduced SNR. Repositioning accuracy of the RF coil holders was below 1 mm. PET photon attenuation of the RT table overlay was calculated to be 3.8% and 13.8% for the RF coil holders. With CT-based AC of the devices, the underestimation error was reduced to 0.6% and 0.8%, respectively. Comparable results were found within the patient study. Conclusions: The newly designed RT devices for hybrid PET/MR imaging are PET and MR compatible. The mechanically rigid design and the reproducible positioning allow for straightforward CT-based AC. The systematic evaluation within this study provides the technical basis for the clinical integration of PET/MR hybrid imaging into RT treatment planning.« less

Calculation to experiment comparison of SPND signals in various nuclear reactor environments

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

Barbot, Loic; Radulovic, Vladimir; Fourmentel, Damien

2015-07-01

In the perspective of irradiation experiments in the future Jules Horowitz Reactor (JHR), the Instrumentation Sensors and Dosimetry Laboratory of CEA Cadarache (France) is developing a numerical tool for SPND design, simulation and operation. In the frame of the SPND numerical tool qualification, dedicated experiments have been performed both in the Slovenian TRIGA Mark II reactor (JSI) and very recently in the French CEA Saclay OSIRIS reactor, as well as a test of two detectors in the core of the Polish MARIA reactor (NCBJ). A full description of experimental set-ups and neutron-gamma calculations schemes are provided in the first partmore » of the paper. Calculation to experiment comparison of the various SPNDs in the different reactors is thoroughly described and discussed in the second part. Presented comparisons show promising final results. (authors)« less

Fast emission spectroscopy for monitoring condensed carbon in detonation products of oxygen-deficient high explosives

NASA Astrophysics Data System (ADS)

Poeuf, Sandra; Baudin, Gerard; Genetier, Marc; Lefrançois, Alexandre; Cinnayya, Ashwin; Laurent, Jacquet

2017-06-01

A new thermochemical code, SIAME, dedicated to the study of high explosives, is currently being developed. New experimental data relative to the expansion of detonation products are required to validate the code, and a particular focus is made on solid carbon products. Two different high explosive formulations are used: a melt-cast one (RDX/TNT 60/40 % wt.) and a pressed one (HMX/VitonR 96/4 % wt.). The experimental setup allows the expansion of the products at pressures below 1 GPa in an inert medium (vacuum, helium, nitrogen and PMMA). The results of fast emission dynamic spectroscopy measurements used to monitor the detonation carbon products are reported. Two spectral signatures are identified: the first is associated to ionized gases and the second to carbon thermal radiation. The experimental spectral lines are compared with simulated spectra. The trajectory of the shock wave front is continuously recorded with a high frequency interferometer. Comparisons with numerical simulations on the hydrodynamic code Ouranoshave been done. These two measurements, using the different inert media, enable to make one step forward in the validation of the detonation products equation of state implemented in the SIAME code.

So ware-Defined Network Solutions for Science Scenarios: Performance Testing Framework and Measurements

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

Settlemyer, Bradley; Kettimuthu, R.; Boley, Josh

High-performance scientific work flows utilize supercomputers, scientific instruments, and large storage systems. Their executions require fast setup of a small number of dedicated network connections across the geographically distributed facility sites. We present Software-Defined Network (SDN) solutions consisting of site daemons that use dpctl, Floodlight, ONOS, or OpenDaylight controllers to set up these connections. The development of these SDN solutions could be quite disruptive to the infrastructure, while requiring a close coordination among multiple sites; in addition, the large number of possible controller and device combinations to investigate could make the infrastructure unavailable to regular users for extended periods ofmore » time. In response, we develop a Virtual Science Network Environment (VSNE) using virtual machines, Mininet, and custom scripts that support the development, testing, and evaluation of SDN solutions, without the constraints and expenses of multi-site physical infrastructures; furthermore, the chosen solutions can be directly transferred to production deployments. By complementing VSNE with a physical testbed, we conduct targeted performance tests of various SDN solutions to help choose the best candidates. In addition, we propose a switching response method to assess the setup times and throughput performances of different SDN solutions, and present experimental results that show their advantages and limitations.« less

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.

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

Feasibility study of 235U and 239Pu characterization in radioactive waste drums using neutron-induced fission delayed gamma rays

NASA Astrophysics Data System (ADS)

Nicol, T.; Pérot, B.; Carasco, C.; Brackx, E.; Mariani, A.; Passard, C.; Mauerhofer, E.; Collot, J.

2016-10-01

This paper reports a feasibility study of 235U and 239Pu characterization in 225 L bituminized waste drums or 200 L concrete waste drums, by detecting delayed fission gamma rays between the pulses of a deuterium-tritium neutron generator. The delayed gamma yields were first measured with bare samples of 235U and 239Pu in REGAIN, a facility dedicated to the assay of 118 L waste drums by Prompt Gamma Neutron Activation Analysis (PGNAA) at CEA Cadarache, France. Detectability in the waste drums is then assessed using the MCNPX model of MEDINA (Multi Element Detection based on Instrumental Neutron Activation), another PGNAA cell dedicated to 200 L drums at FZJ, Germany. For the bituminized waste drum, performances are severely hampered by the high gamma background due to 137Cs, which requires the use of collimator and shield to avoid electronics saturation, these elements being very penalizing for the detection of the weak delayed gamma signal. However, for lower activity concrete drums, detection limits range from 10 to 290 g of 235U or 239Pu, depending on the delayed gamma rays of interest. These detection limits have been determined by using MCNPX to calculate the delayed gamma useful signal, and by measuring the experimental gamma background in MEDINA with a 200 L concrete drum mock-up. The performances could be significantly improved by using a higher interrogating neutron emission and an optimized experimental setup, which would allow characterizing nuclear materials in a wide range of low and medium activity waste packages.

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

Peratt, A.L.; Mostrom, M.A.

With the availability of 80--125 MHz microprocessors, the methodology developed for the simulation of problems in pulsed power and plasma physics on modern day supercomputers is now amenable to application on a wide range of platforms including laptops and workstations. While execution speeds with these processors do not match those of large scale computing machines, resources such as computer-aided-design (CAD) and graphical analysis codes are available to automate simulation setup and process data. This paper reports on the adaptation of IVORY, a three-dimensional, fully-electromagnetic, particle-in-cell simulation code, to this platform independent CAD environment. The primary purpose of this talk ismore » to demonstrate how rapidly a pulsed power/plasma problem can be scoped out by an experimenter on a dedicated workstation. Demonstrations include a magnetically insulated transmission line, power flow in a graded insulator stack, a relativistic klystron oscillator, and the dynamics of a coaxial thruster for space applications.« less

The scanning cryomacroscope - A device prototype for the study of cryopreservation

NASA Astrophysics Data System (ADS)

Feig, Justin S. G.; Rabin, Yoed

2014-07-01

A new cryomacroscope prototype-a visualization device for the in situ analysis of cryopreserved biological samples-is presented in the current study. In order to visualize samples larger than the field of view of the optical setup, a scanning mechanism is integrated into the system, which represents a key improvement over previous cryomacroscope prototypes. Another key feature of the new design is in its compatibility with available top-loading controlled-rate cooling chambers, which eliminates the need for a dedicated cooling mechanism. The objective for the current development is to create means to generate a single digital movie of an experimental investigation, with all relevant data overlaid. The visualization capabilities of the scanning cryomacroscope are demonstrated in the current study on the cryoprotective agent dimethyl sulfoxide and the cryoprotective cocktail DP6. Demonstrated effects include glass formation, various regimes of crystallization, thermal contraction, and fracture formation.

The AMERE project: Enabling real-time detection of radiation effects in individual cells in deep space

NASA Astrophysics Data System (ADS)

De Vos, Winnok H.; Meesen, Geert; Szpirer, Cedric; Scohy, Sophie; Cherukuri, Chaitanya; Evrard, Olivier; Hutsebaut, Xavier; Beghuin, Didier

2012-12-01

A major concern for long-term deep space missions is the detrimental impact of cosmic radiation on human health. Especially the presence of high-energy particles of high atomic mass (HZE) represents a serious threat. To contribute to a fundamental understanding of space radiation effects and to help improving risk assessment for humans on the Moon, the ESA Lunar Lander mission model payload includes a package dedicated to cell-based radiobiology experiments in the form of an Autonomous Microscope for Examination of Radiation Effects (AMERE). The purpose of this setup is to enable real-time visualization of DNA damage repair in living cells after traversal of HZE particles on the Moon. To assess the feasibility of this challenging experiment, we have analysed the biological and technological demands. In this article, we discuss the experimental concept, the biological considerations and describe the implications for system design.

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.

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)

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.

Experimental characterization and macro-modeling of mechanical strength of multi-sheets and multi-materials spot welds under pure and mixed modes I and II

NASA Astrophysics Data System (ADS)

Chtourou, Rim; Haugou, Gregory; Leconte, Nicolas; Zouari, Bassem; Chaari, Fahmi; Markiewicz, Eric

2015-09-01

Resistance Spot Welding (RSW) of multiple sheets with multiple materials are increasingly realized in the automotive industry. The mechanical strength of such new generation of spot welded assemblies is not that much dealt with. This is true in particular for experiments dedicated to investigate the mechanical strength of spot weld made by multi sheets of different grades, and their macro modeling in structural computations. Indeed, the most published studies are limited to two sheet assemblies. Therefore, in the first part of this work an advanced experimental set-up with a reduced mass is proposed to characterize the quasi-static and dynamic mechanical behavior and rupture of spot weld made by several sheets of different grades. The proposed device is based on Arcan test, the plates contribution in the global response is, thus, reduced. Loading modes I/II are, therefore, combined and well controlled. In the second part a simplified spot weld connector element (macroscopic modeling) is proposed to describe the nonlinear response and rupture of this new generation of spot welded assemblies. The weld connector model involves several parameters to be set. The remaining parameters are finally identified through a reverse engineering approach using mechanical responses of experimental tests presented in the first part of this work.

A new high temperature reactor for operando XAS: Application for the dry reforming of methane over Ni/ZrO2 catalyst.

PubMed

Aguilar-Tapia, Antonio; Ould-Chikh, Samy; Lahera, Eric; Prat, Alain; Delnet, William; Proux, Olivier; Kieffer, Isabelle; Basset, Jean-Marie; Takanabe, Kazuhiro; Hazemann, Jean-Louis

2018-03-01

The construction of a high-temperature reaction cell for operando X-ray absorption spectroscopy characterization is reported. A dedicated cell was designed to operate as a plug-flow reactor using powder samples requiring gas flow and thermal treatment at high temperatures. The cell was successfully used in the reaction of dry reforming of methane (DRM). We present X-ray absorption results in the fluorescence detection mode on a 0.4 wt. % Ni/ZrO 2 catalyst under realistic conditions at 750 °C, reproducing the conditions used for a conventional dynamic microreactor for the DRM reaction. The setup includes a gas distribution system that can be fully remotely operated. The reaction cell offers the possibility of transmission and fluorescence detection modes. The complete setup dedicated to the study of catalysts is permanently installed on the Collaborating Research Groups French Absorption spectroscopy beamline in Material and Environmental sciences (CRG-FAME) and French Absorption spectroscopy beamline in Material and Environmental sciences at Ultra-High Dilution (FAME-UHD) beamlines (BM30B and BM16) at the European Synchrotron Radiation Facility in Grenoble, France.

A new high temperature reactor for operando XAS: Application for the dry reforming of methane over Ni/ZrO2 catalyst

NASA Astrophysics Data System (ADS)

Aguilar-Tapia, Antonio; Ould-Chikh, Samy; Lahera, Eric; Prat, Alain; Delnet, William; Proux, Olivier; Kieffer, Isabelle; Basset, Jean-Marie; Takanabe, Kazuhiro; Hazemann, Jean-Louis

2018-03-01

The construction of a high-temperature reaction cell for operando X-ray absorption spectroscopy characterization is reported. A dedicated cell was designed to operate as a plug-flow reactor using powder samples requiring gas flow and thermal treatment at high temperatures. The cell was successfully used in the reaction of dry reforming of methane (DRM). We present X-ray absorption results in the fluorescence detection mode on a 0.4 wt. % Ni/ZrO2 catalyst under realistic conditions at 750 °C, reproducing the conditions used for a conventional dynamic microreactor for the DRM reaction. The setup includes a gas distribution system that can be fully remotely operated. The reaction cell offers the possibility of transmission and fluorescence detection modes. The complete setup dedicated to the study of catalysts is permanently installed on the Collaborating Research Groups French Absorption spectroscopy beamline in Material and Environmental sciences (CRG-FAME) and French Absorption spectroscopy beamline in Material and Environmental sciences at Ultra-High Dilution (FAME-UHD) beamlines (BM30B and BM16) at the European Synchrotron Radiation Facility in Grenoble, France.

Laser-induced damage threshold of camera sensors and micro-optoelectromechanical systems

NASA Astrophysics Data System (ADS)

Schwarz, Bastian; Ritt, Gunnar; Koerber, Michael; Eberle, Bernd

2017-03-01

The continuous development of laser systems toward more compact and efficient devices constitutes an increasing threat to electro-optical imaging sensors, such as complementary metal-oxide-semiconductors (CMOS) and charge-coupled devices. These types of electronic sensors are used in day-to-day life but also in military or civil security applications. In camera systems dedicated to specific tasks, micro-optoelectromechanical systems, such as a digital micromirror device (DMD), are part of the optical setup. In such systems, the DMD can be located at an intermediate focal plane of the optics and it is also susceptible to laser damage. The goal of our work is to enhance the knowledge of damaging effects on such devices exposed to laser light. The experimental setup for the investigation of laser-induced damage is described in detail. As laser sources, both pulsed lasers and continuous-wave (CW)-lasers are used. The laser-induced damage threshold is determined by the single-shot method by increasing the pulse energy from pulse to pulse or in the case of CW-lasers, by increasing the laser power. Furthermore, we investigate the morphology of laser-induced damage patterns and the dependence of the number of destructive device elements on the laser pulse energy or laser power. In addition to the destruction of single pixels, we observe aftereffects, such as persistent dead columns or rows of pixels in the sensor image.

Experimental Setup and Commissioning of a Test Facility for Gain Evaluation of Microchannel-Plate Photomultipliers in High Magnetic Field at Jefferson Lab

NASA Astrophysics Data System (ADS)

Bringley, Eric; Cao, Tongtong; Ilieva, Yordonka; Nadel-Turonski, Pawel; Park, Kijun; Zorn, Carl

2014-09-01

At the Thomas Jefferson National Accelerator Facility (JLab) a research and development project for a Detector of Internally-Reflected Cherenkov light for the upcoming Electron Ion Collider is underway. One goal is the development of a compact readout camera that can operate in high magnetic fields. Small-size photon sensors, such as Microchannel-Plate Photomultipliers (MCP-PMT), are key components of the readout. Here we present our work to set up and commission a dedicated test facility at JLab where MCP-PMT gain is evaluated in magnetic fields of up to 5 T, and to develop a test procedure and analysis software to determine the gain. We operate the setup in a single-photon mode, where a light-emitting diode delivers photons to the sensor's photocathode. The PMT spectrum is measured with a flash Analog-to-Digital converter (fADC). We model the spectrum as a sum of an exponential background and a convolution of Poisson and Gaussian distributions of the pedestal and multiple photoelectron peaks, respectively. We determine the PMT's gain from the position of the single-photoelectron peak obtained by fitting the fADC spectrum to the model. Our gain uncertainty is <10%. The facility is now established and will have a long-lasting value for sensor tests and beyond-nuclear-physics applications.

Non-destructive phase and intensity distributed measurements of the nonlinear stage of modulation instability in optical fibers

NASA Astrophysics Data System (ADS)

Mussot, Arnaud; Naveau, Corentin; Szriftgiser, Pascal; Copie, François; Kudlinski, Alexandre; Conforti, Matteo; Trillo, Stefano

2018-02-01

We report a novel experimental setup to perform distributed characterization in intensity and phase of the nonlinear stage of modulation instability by means of a non-invasive experimental setup : a heterodyne time domain reflectometer.

Development of a sensitive setup for laser spectroscopy studies of very exotic calcium isotopes

NASA Astrophysics Data System (ADS)

Garcia Ruiz, R. F.; Gorges, C.; Bissell, M.; Blaum, K.; Gins, W.; Heylen, H.; Koenig, K.; Kaufmann, S.; Kowalska, M.; Krämer, J.; Lievens, P.; Malbrunot-Ettenauer, S.; Neugart, R.; Neyens, G.; Nörtershäuser, W.; Yordanov, D. T.; Yang, X. F.

2017-04-01

An experimental setup for sensitive high-resolution measurements of hyperfine structure spectra of exotic calcium isotopes has been developed and commissioned at the COLLAPS beam line at ISOLDE, CERN. The technique is based on the radioactive detection of decaying isotopes after optical pumping and state selective neutralization (ROC) (Vermeeren et al 1992 Phys. Rev. Lett. 68 1679). The improvements and developments necessary to extend the applicability of the experimental technique to calcium isotopes produced at rates as low as few ions s-1 are discussed. Numerical calculations of laser-ion interaction and ion-beam simulations were explored to obtain the optimum performance of the experimental setup. Among the implemented features are a multi-step optical pumping region for sensitive measurements of isotopes with hyperfine splitting, a high-voltage platform for adequate control of low-energy ion beams and simultaneous β-detection of neutralized and remaining ions. The commissioning of the experimental setup, and the first online results on neutron-rich calcium isotopes are presented.

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.

Non-destructive analysis of museum objects by fibre-optic Raman spectroscopy

PubMed Central

Tate, Jim; Moens, Luc

2006-01-01

Raman spectroscopy is a versatile technique that has frequently been applied for the investigation of art objects. By using mobile Raman instrumentation it is possible to investigate the artworks without the need for sampling. This work evaluates the use of a dedicated mobile spectrometer for the investigation of a range of museum objects in museums in Scotland, including antique Egyptian sarcophagi, a panel painting, painted surfaces on paper and textile, and the painted lid and soundboard of an early keyboard instrument. The investigations of these artefacts illustrate some analytical challenges that arise when analysing museum objects, including fluorescing varnish layers, ambient sunlight, large dimensions of artefacts and the need to handle fragile objects with care. Analysis of the musical instrument (the Mar virginals) was undertaken in the exhibition gallery, while on display, which meant that interaction with the public and health and safety issues had to be taken into account. Experimental set-up for the non-destructive Raman spectroscopic investigation of a textile banner in the National Museums of Scotland PMID:16953310

ACTS Aeronautical Terminal Experiment (AERO-X)

NASA Technical Reports Server (NTRS)

1995-01-01

During the summer of 1994, the performance of an experimental mobile satellite communication system was demonstrated. Using the Advanced Communications Technology Satellite (ACTS) and the ACTS Mobile Terminal (AMT), the system demonstrated an active Monolithic Microwave Integrated Circuit (MMIC) phased-array antenna system. The antenna system was installed onboard one of NASA Lewis Research Center's research aircraft, a Learjet Model 25. It proved the viability of in-flight satellite communications services via small, flush, mountable electronic phased-array antennas. The overall system setup for the ACTS Aeronautical Terminal Experiment (AERO-X) is illustrated. The Link Evaluation Terminal (LET) at Lewis in Cleveland, Ohio, interfaced with fixed-AMT equipment, providing a seamless connection with the Public Service Telephone Network. As the Learjet was flown over several major cities across the U.S., this demonstration system allowed passengers onboard to make telephone calls as if they were using a cellular system. ACTS was operated in its microwave switch matrix mode with a spot beam for the Learjet and another spot beam dedicated to the LET.

Measurement of trace impurities in ultra pure hydrogen and deuterium at the parts-per-billion level using gas chromatography

NASA Astrophysics Data System (ADS)

Ganzha, V.; Ivshin, K.; Kammel, P.; Kravchenko, P.; Kravtsov, P.; Petitjean, C.; Trofimov, V.; Vasilyev, A.; Vorobyov, A.; Vznuzdaev, M.; Wauters, F.

2018-02-01

A series of muon experiments at the Paul Scherrer Institute in Switzerland deploy ultra-pure hydrogen active targets. A new gas impurity analysis technique was developed, based on conventional gas chromatography, with the capability to measure part-per-billion (ppb) traces of nitrogen and oxygen in hydrogen and deuterium. Key ingredients are a cryogenic admixture accumulation, a directly connected sampling system and a dedicated calibration setup. The dependence of the measured concentration on the sample volume was investigated, confirming that all impurities from the sample gas are collected in the accumulation column and measured with the gas chromatograph. The system was calibrated utilizing dynamic dilution of admixtures into the gas flow down to sub-ppb level concentrations. The total amount of impurities accumulated in the purification system during a three month long experimental run was measured and agreed well with the calculated amount based on the measured concentrations in the flow.

Low-aberration beamline optics for synchrotron infrared nanospectroscopy.

PubMed

Freitas, Raul O; Deneke, Christoph; Maia, Francisco C B; Medeiros, Helton G; Moreno, Thierry; Dumas, Paul; Petroff, Yves; Westfahl, Harry

2018-04-30

Synchrotron infrared nanospectroscopy is a recently developed technique that enables new possibilities in the broadband chemical analysis of materials in the nanoscale, far beyond the diffraction limit in this frequency domain. Synchrotron infrared ports have exploited mainly the high brightness advantage provided by electron storage rings across the whole infrared range. However, optical aberrations in the beam produced by the source depth of bending magnet emission at large angles prevent infrared nanospectroscopy to reach its maximum capability. In this work we present a low-aberration optical layout specially designed and constructed for a dedicated synchrotron infrared nanospectroscopy beamline. We report excellent agreement between simulated beam profiles (from standard wave propagation and raytracing optics simulations) with experimental measurements. We report an important improvement in the infrared nanospectroscopy experiment related to the improved beamline optics. Finally, we demonstrate the performance of the nanospectroscopy endstation by measuring a hyperspectral image of a polar material and we evaluate the setup sensitivity by measuring ultra-thin polymer films down to 6 nm thick.

Non-destructive analysis of museum objects by fibre-optic Raman spectroscopy.

PubMed

Vandenabeele, Peter; Tate, Jim; Moens, Luc

2007-02-01

Raman spectroscopy is a versatile technique that has frequently been applied for the investigation of art objects. By using mobile Raman instrumentation it is possible to investigate the artworks without the need for sampling. This work evaluates the use of a dedicated mobile spectrometer for the investigation of a range of museum objects in museums in Scotland, including antique Egyptian sarcophagi, a panel painting, painted surfaces on paper and textile, and the painted lid and soundboard of an early keyboard instrument. The investigations of these artefacts illustrate some analytical challenges that arise when analysing museum objects, including fluorescing varnish layers, ambient sunlight, large dimensions of artefacts and the need to handle fragile objects with care. Analysis of the musical instrument (the Mar virginals) was undertaken in the exhibition gallery, while on display, which meant that interaction with the public and health and safety issues had to be taken into account. Experimental set-up for the non-destructive Raman spectroscopic investigation of a textile banner in the National Museums of Scotland.

Mobile messaging services-based personal electrocardiogram monitoring system.

PubMed

Tahat, Ashraf A

2009-01-01

A mobile monitoring system utilizing Bluetooth and mobile messaging services (MMS/SMSs) with low-cost hardware equipment is proposed. A proof of concept prototype has been developed and implemented to enable transmission of an Electrocardiogram (ECG) signal and body temperature of a patient, which can be expanded to include other vital signs. Communication between a mobile smart-phone and the ECG and temperature acquisition apparatus is implemented using the popular personal area network standard specification Bluetooth. When utilizing MMS for transmission, the mobile phone plots the received ECG signal and displays the temperature using special application software running on the client mobile phone itself, where the plot can be captured and saved as an image before transmission. Alternatively, SMS can be selected as a transmission means, where in this scenario, dedicated application software is required at the receiving device. The experimental setup can be operated for monitoring from anywhere in the globe covered by a cellular network that offers data services.

Mobile Messaging Services-Based Personal Electrocardiogram Monitoring System

PubMed Central

Tahat, Ashraf A.

2009-01-01

A mobile monitoring system utilizing Bluetooth and mobile messaging services (MMS/SMSs) with low-cost hardware equipment is proposed. A proof of concept prototype has been developed and implemented to enable transmission of an Electrocardiogram (ECG) signal and body temperature of a patient, which can be expanded to include other vital signs. Communication between a mobile smart-phone and the ECG and temperature acquisition apparatus is implemented using the popular personal area network standard specification Bluetooth. When utilizing MMS for transmission, the mobile phone plots the received ECG signal and displays the temperature using special application software running on the client mobile phone itself, where the plot can be captured and saved as an image before transmission. Alternatively, SMS can be selected as a transmission means, where in this scenario, dedicated application software is required at the receiving device. The experimental setup can be operated for monitoring from anywhere in the globe covered by a cellular network that offers data services. PMID:19707531

Pump-probe experiments at the TEMPO beamline using the low-α operation mode of Synchrotron SOLEIL.

PubMed

Silly, Mathieu G; Ferté, Tom; Tordeux, Marie Agnes; Pierucci, Debora; Beaulieu, Nathan; Chauvet, Christian; Pressacco, Federico; Sirotti, Fausto; Popescu, Horia; Lopez-Flores, Victor; Tortarolo, Marina; Sacchi, Maurizio; Jaouen, Nicolas; Hollander, Philippe; Ricaud, Jean Paul; Bergeard, Nicolas; Boeglin, Christine; Tudu, Bharati; Delaunay, Renaud; Luning, Jan; Malinowski, Gregory; Hehn, Michel; Baumier, Cédric; Fortuna, Franck; Krizmancic, Damjan; Stebel, Luigi; Sergo, Rudi; Cautero, Giuseppe

2017-07-01

The SOLEIL synchrotron radiation source is regularly operated in special filling modes dedicated to pump-probe experiments. Among others, the low-α mode operation is characterized by shorter pulse duration and represents the natural bridge between 50 ps synchrotron pulses and femtosecond experiments. Here, the capabilities in low-α mode of the experimental set-ups developed at the TEMPO beamline to perform pump-probe experiments with soft X-rays based on photoelectron or photon detection are presented. A 282 kHz repetition-rate femtosecond laser is synchronized with the synchrotron radiation time structure to induce fast electronic and/or magnetic excitations. Detection is performed using a two-dimensional space resolution plus time resolution detector based on microchannel plates equipped with a delay line. Results of time-resolved photoelectron spectroscopy, circular dichroism and magnetic scattering experiments are reported, and their respective advantages and limitations in the framework of high-time-resolution pump-probe experiments compared and discussed.

A Simple Experimental Setup to Clearly Show that Light Does Not Recombine After Passing Through Two Prisms

NASA Astrophysics Data System (ADS)

Garcia-Molina, Rafael; del Mazo, Alejandro; Velasco, Santiago

2018-01-01

We present a simple and cheap experimental setup that clearly shows how the colors of the white light spectrum after passing a prism do not recombine when emerging from an identical second prism, as it is still found in many references.

A Simple Experimental Setup to Clearly Show That Light Does Not Recombine after Passing through Two Prisms

ERIC Educational Resources Information Center

Garcia-Molina, Rafael; del Mazo, Alejandro; Velasco, Santiago

2018-01-01

We present a simple and cheap experimental setup that clearly shows how the colors of the white light spectrum after passing a prism do not recombine when emerging from an identical second prism, as it is still found in many references.

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.

Comparative Monte Carlo study on the performance of integration- and list-mode detector configurations for carbon ion computed tomography

NASA Astrophysics Data System (ADS)

Meyer, Sebastian; Gianoli, Chiara; Magallanes, Lorena; Kopp, Benedikt; Tessonnier, Thomas; Landry, Guillaume; Dedes, George; Voss, Bernd; Parodi, Katia

2017-02-01

Ion beam therapy offers the possibility of a highly conformal tumor-dose distribution; however, this technique is extremely sensitive to inaccuracies in the treatment procedures. Ambiguities in the conversion of Hounsfield units of the treatment planning x-ray CT to relative stopping power (RSP) can cause uncertainties in the estimated ion range of up to several millimeters. Ion CT (iCT) represents a favorable solution allowing to directly assess the RSP. In this simulation study we investigate the performance of the integration-mode configuration for carbon iCT, in comparison with a single-particle approach under the same set-up. The experimental detector consists of a stack of 61 air-filled parallel-plate ionization chambers, interleaved with 3 mm thick PMMA absorbers. By means of Monte Carlo simulations, this design was applied to acquire iCTs of phantoms of tissue-equivalent materials. An optimization of the acquisition parameters was performed to reduce the dose exposure, and the implications of a reduced absorber thickness were assessed. In order to overcome limitations of integration-mode detection in the presence of lateral tissue heterogeneities a dedicated post-processing method using a linear decomposition of the detector signal was developed and its performance was compared to the list-mode acquisition. For the current set-up, the phantom dose could be reduced to below 30 mGy with only minor image quality degradation. By using the decomposition method a correct identification of the components and a RSP accuracy improvement of around 2.0% was obtained. The comparison of integration- and list-mode indicated a slightly better image quality of the latter, with an average median RSP error below 1.8% and 1.0%, respectively. With a decreased absorber thickness a reduced RSP error was observed. Overall, these findings support the potential of iCT for low dose RSP estimation, showing that integration-mode detectors with dedicated post-processing strategies can provide a RSP accuracy comparable to list-mode configurations.

Laser-induced damage threshold of camera sensors and micro-opto-electro-mechanical systems

NASA Astrophysics Data System (ADS)

Schwarz, Bastian; Ritt, Gunnar; Körber, Michael; Eberle, Bernd

2016-10-01

The continuous development of laser systems towards more compact and efficient devices constitutes an increasing threat to electro-optical imaging sensors such as complementary metal-oxide-semiconductors (CMOS) and charge-coupled devices (CCD). These types of electronic sensors are used in day-to-day life but also in military or civil security applications. In camera systems dedicated to specific tasks, also micro-opto-electro-mechanical systems (MOEMS) like a digital micromirror device (DMD) are part of the optical setup. In such systems, the DMD can be located at an intermediate focal plane of the optics and it is also susceptible to laser damage. The goal of our work is to enhance the knowledge of damaging effects on such devices exposed to laser light. The experimental setup for the investigation of laser-induced damage is described in detail. As laser sources both pulsed lasers and continuous-wave (CW) lasers are used. The laser-induced damage threshold (LIDT) is determined by the single-shot method by increasing the pulse energy from pulse to pulse or in the case of CW-lasers, by increasing the laser power. Furthermore, we investigate the morphology of laser-induced damage patterns and the dependence of the number of destructed device elements on the laser pulse energy or laser power. In addition to the destruction of single pixels, we observe aftereffects like persisting dead columns or rows of pixels in the sensor image.

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.

Studies of LSO:Tb radio-luminescence properties using white beam hard X-ray synchrotron irradiation

NASA Astrophysics Data System (ADS)

Cecilia, A.; Rack, A.; Pelliccia, D.; Douissard, P.-A.; Martin, T.; Couchaud, M.; Dupré, K.; Baumbach, T.

A radio-luminescence set-up was installed at the synchrotron light source ANKA to characterise scintillators under the high X-ray photon flux density of white beam synchrotron radiation. The system allows for investigating the radio-luminescence spectrum of the material under study as well as analysing in situ changes of its scintillation behaviour (e.g. under heat load and/or intensive ionising radiation). In this work we applied the radio-luminescence set-up for investigating the radiation damage effects on the luminescence properties of a new kind of thin single crystal scintillator for high resolution X-ray imaging based on a layer of modified Lu2SiO5 grown by liquid phase epitaxy on a dedicated substrate within the framework of an EC project (SCINTAX).

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.

Computational fluid dynamics modeling of laboratory flames and an industrial flare.

PubMed

Singh, Kanwar Devesh; Gangadharan, Preeti; Chen, Daniel H; Lou, Helen H; Li, Xianchang; Richmond, Peyton

2014-11-01

A computational fluid dynamics (CFD) methodology for simulating the combustion process has been validated with experimental results. Three different types of experimental setups were used to validate the CFD model. These setups include an industrial-scale flare setups and two lab-scale flames. The CFD study also involved three different fuels: C3H6/CH/Air/N2, C2H4/O2/Ar and CH4/Air. In the first setup, flare efficiency data from the Texas Commission on Environmental Quality (TCEQ) 2010 field tests were used to validate the CFD model. In the second setup, a McKenna burner with flat flames was simulated. Temperature and mass fractions of important species were compared with the experimental data. Finally, results of an experimental study done at Sandia National Laboratories to generate a lifted jet flame were used for the purpose of validation. The reduced 50 species mechanism, LU 1.1, the realizable k-epsilon turbulence model, and the EDC turbulence-chemistry interaction model were usedfor this work. Flare efficiency, axial profiles of temperature, and mass fractions of various intermediate species obtained in the simulation were compared with experimental data and a good agreement between the profiles was clearly observed. In particular the simulation match with the TCEQ 2010 flare tests has been significantly improved (within 5% of the data) compared to the results reported by Singh et al. in 2012. Validation of the speciated flat flame data supports the view that flares can be a primary source offormaldehyde emission.

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.

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.

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

Experimental setup for Single Event Effects at the São Paulo 8UD Pelletron Accelerator

NASA Astrophysics Data System (ADS)

Aguiar, V. A. P.; Added, N.; Medina, N. H.; Macchione, E. L. A.; Tabacniks, M. H.; Aguirre, F. R.; Silveira, M. A. G.; Santos, R. B. B.; Seixas, L. E.

2014-08-01

In this work we present an experimental setup mounted in one of the beam lines at the São Paulo 8UD Pelletron Accelerator in order to study Single Event Effects in electronic devices. The basic idea is to use elastic scattering collisions to achieve a low-flux with a high-uniformity ion beam to irradiate several devices. 12C, 16O, 28Si, 35Cl and 63Cu beams were used to test the experimental setup. In this system it is possible to use efficiently LET values of 17 MeV/mg/cm2 for an external beam arrangement and up to 32 MeV/mg/cm2 for in-vacuum irradiation.

An undergraduate laboratory experiment for measuring ɛ 0, μ 0 and speed of light c with do-it-yourself catastrophe machines: electrostatic and magnetostatic pendula

NASA Astrophysics Data System (ADS)

Mishonov, Todor M.; Varonov, Albert M.; Maksimovski, Dejan D.; Manolev, Stojan G.; Gourev, Vassil N.; Yordanov, Vasil G.

2017-03-01

An experimental set-up for electrostatic measurement of {\\varepsilon }0, separate magnetostatic measurement of {μ }0 and determination of the speed of light c=1/\\sqrt{{\\varepsilon }0{μ }0} according to Maxwell’s theory with percent accuracy is described. No forces are measured with the experimental set-up, therefore there is no need for a scale, and the experiment cost of less than £20 is mainly due to the batteries used. Multiplied 137 times, this experimental set-up was given at the Fourth Open International Experimental Physics Olympiad (EPO4) and a dozen high school students performed successful experiments. The experimental set-up actually contains two different pendula for electric and magnetic measurements. In the magnetic experiment the pendulum is constituted by a magnetic coil attracted to a fixed one. In the electrostatic pendulum when the distance between the plates becomes shorter than a critical value the suspended plate catastrophically sticks to the fixed one, while in the magnetic pendulum the same occurs when the current in the coils becomes greater than a certain critical value. The basic idea of the methodology is to use the loss of stability as a tool for the determination of fundamental constants.

The potential of urban rainfall monitoring with crowdsourced automatic weather stations in Amsterdam

NASA Astrophysics Data System (ADS)

de Vos, Lotte; Leijnse, Hidde; Overeem, Aart; Uijlenhoet, Remko

2017-02-01

The high density of built-up areas and resulting imperviousness of the land surface makes urban areas vulnerable to extreme rainfall, which can lead to considerable damage. In order to design and manage cities to be able to deal with the growing number of extreme rainfall events, rainfall data are required at higher temporal and spatial resolutions than those needed for rural catchments. However, the density of operational rainfall monitoring networks managed by local or national authorities is typically low in urban areas. A growing number of automatic personal weather stations (PWSs) link rainfall measurements to online platforms. Here, we examine the potential of such crowdsourced datasets for obtaining the desired resolution and quality of rainfall measurements for the capital of the Netherlands. Data from 63 stations in Amsterdam (˜ 575 km2) that measure rainfall over at least 4 months in a 17-month period are evaluated. In addition, a detailed assessment is made of three Netatmo stations, the largest contributor to this dataset, in an experimental setup. The sensor performance in the experimental setup and the density of the PWS network are promising. However, features in the online platforms, like rounding and thresholds, cause changes from the original time series, resulting in considerable errors in the datasets obtained. These errors are especially large during low-intensity rainfall, although they can be reduced by accumulating rainfall over longer intervals. Accumulation improves the correlation coefficient with gauge-adjusted radar data from 0.48 at 5 min intervals to 0.60 at hourly intervals. Spatial rainfall correlation functions derived from PWS data show much more small-scale variability than those based on gauge-adjusted radar data and those found in similar research using dedicated rain gauge networks. This can largely be attributed to the noise in the PWS data resulting from both the measurement setup and the processes occurring in the data transfer to the online PWS platform. A double mass comparison with gauge-adjusted radar data shows that the median of the stations resembles the rainfall reference better than the real-time (unadjusted) radar product. Averaging nearby raw PWS measurements further improves the match with gauge-adjusted radar data in that area. These results confirm that the growing number of internet-connected PWSs could successfully be used for urban rainfall monitoring.

Urban rainfall monitoring with crowdsourced automatic weather stations in Amsterdam

NASA Astrophysics Data System (ADS)

de Vos, Lotte; Leijnse, Hidde; Overeem, Aart; Uijlenhoet, Remko

2017-04-01

The high density of built-up areas and resulting imperviousness of the land surface makes urban areas vulnerable to extreme rainfall, which can lead to considerable damage. In order to design and manage cities to be able to deal with the growing number of extreme rainfall events, rainfall data is required at higher temporal and spatial resolutions than those needed for rural catchments. However, the density of operational rainfall monitoring networks managed by local or national authorities is typically low in urban areas. A growing number of automatic personal weather stations (PWSs) link rainfall measurements to online platforms. Here, we examine the potential of such crowdsourced datasets for obtaining the desired resolution and quality of rainfall measurements for the capital of the Netherlands. Data from 63 stations in Amsterdam (˜575 km2}) that measure rainfall over at least 4 months in a 17-month period are evaluated. In addition, a detailed assessment is made of three Netatmo stations, the largest contributor to this dataset, in an experimental set-up. The sensor performance in the experimental set-up and the density of the PWS-network are promising. However, features in the online platforms, like rounding and thresholds, cause changes from the original time series, resulting in considerable errors in the datasets obtained. These errors are especially large during low intensity rainfall, although they can be reduced by accumulating rainfall over longer intervals. Accumulation improves the correlation coefficient with gauge-adjusted radar data from 0.48 at 5 min intervals to 0.60 at hourly intervals. Spatial rainfall correlation functions derived from PWS data show much more small-scale variability than those based on gauge-adjusted radar data and those found in similar research using dedicated rain gauge networks. This can largely be attributed to the noise in the PWS data resulting from both the measurement setup and the processes occurring in the data transfer to the online PWS-platform. A double mass comparison with gauge-adjusted radar data shows that the median of the stations resembles the rainfall reference better than the real-time (unadjusted) radar product. Averaging nearby raw PWS measurements further improves the match with gauge-adjusted radar data in that area. These results confirm that the growing number of internet-connected PWSs could successfully be used for urban rainfall monitoring.

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.

Probing the E2 properties of the scissors mode with real photons

NASA Astrophysics Data System (ADS)

Beck, Tobias; Pietralla, Norbert; Beller, Jacob; Derya, Vera; Löher, Bastian; Savran, Deniz; Tornow, Werner; Werner, Volker; Zilges, Andreas

2018-05-01

The E2/M1 multipole mixing ratio δ1→2 of the 1+ sc → 2+ 1 γ-ray transition of 156Gd and 164Dy has been measured using the linearly polarized photon beams of the HIγS facility. The employed method of photonscattering experiments in combination with polarized, quasi-monochromatic beams and a dedicated detector setup is highly sensitive to the electric quadrupole-decay properties of the scissors mode.

Towards open-source, low-cost haptics for surgery simulation.

PubMed

Suwelack, Stefan; Sander, Christian; Schill, Julian; Serf, Manuel; Danz, Marcel; Asfour, Tamim; Burger, Wolfgang; Dillmann, Rüdiger; Speidel, Stefanie

2014-01-01

In minimally invasive surgery (MIS), virtual reality (VR) training systems have become a promising education tool. However, the adoption of these systems in research and clinical settings is still limited by the high costs of dedicated haptics hardware for MIS. In this paper, we present ongoing research towards an open-source, low-cost haptic interface for MIS simulation. We demonstrate the basic mechanical design of the device, the sensor setup as well as its software integration.

Large aluminium convex mirror for the cryo-optical test of the Planck primary reflector

NASA Astrophysics Data System (ADS)

Gloesener, P.; Flébus, C.; Cola, M.; Roose, S.; Stockman, Y.; de Chambure, D.

2017-11-01

In the frame of the PLANCK mission telescope development, it is requested to measure the reflector changes of the surface figure error (SFE) with respect to the best ellipsoid, between 293 K and 50 K, with 1 μm RMS accuracy. To achieve this, Infra Red interferometry has been selected and a dedicated thermo mechanical set-up has been constructed. In order to realise the test set-up for this reflector, a large aluminium convex mirror with radius of 19500 mm has been manufactured. The mirror has to operate in a cryogenic environment lower than 30 K, and has a contribution to the RMS WFE with less than 1 μm between room temperature and cryogenic temperature. This paper summarises the design, manufacturing and characterisation of this mirror, showing it has fulfilled its requirements.

Tangible interactive system for document browsing and visualisation of multimedia data

NASA Astrophysics Data System (ADS)

Rytsar, Yuriy; Voloshynovskiy, Sviatoslav; Koval, Oleksiy; Deguillaume, Frederic; Topak, Emre; Startchik, Sergei; Pun, Thierry

2006-01-01

In this paper we introduce and develop a framework for document interactive navigation in multimodal databases. First, we analyze the main open issues of existing multimodal interfaces and then discuss two applications that include interaction with documents in several human environments, i.e., the so-called smart rooms. Second, we propose a system set-up dedicated to the efficient navigation in the printed documents. This set-up is based on the fusion of data from several modalities that include images and text. Both modalities can be used as cover data for hidden indexes using data-hiding technologies as well as source data for robust visual hashing. The particularities of the proposed robust visual hashing are described in the paper. Finally, we address two practical applications of smart rooms for tourism and education and demonstrate the advantages of the proposed solution.

Optical setup for two-colour experiments at the low density matter beamline of FERMI

NASA Astrophysics Data System (ADS)

Finetti, Paola; Demidovich, Alexander; Plekan, Oksana; Di Fraia, Michele; Cucini, Riccardo; Callegari, Carlo; Cinquegrana, Paolo; Sigalotti, Paolo; Ivanov, Rosen; Danailov, Miltcho B.; Fava, Claudio; De Ninno, Giovanni; Coreno, Marcello; Grazioli, Cesare; Feifel, Raimund; Squibb, Richard J.; Mazza, Tommaso; Meyer, Michael; Prince, Kevin C.

2017-11-01

The low density matter beamline of the free electron laser facility FERMI is dedicated to the study of atomic, molecular and cluster systems, and here we describe the optical setup available for two-colour experiments. Samples can be exposed to ultrashort pulses from a Ti:Sapphire source (fundamental, or second or third harmonic), and ultrashort light pulses of FERMI in the EUV/soft x-ray region with a well-defined temporal delay, and negligible jitter (<10 fs) compared to the pulse durations (40-100 fs). Detection schemes available include electron, ion and optical spectroscopy. The majority of experiments using this apparatus are pump-and-probe, where either wavelength can be pump or probe, but the system is also useful for other techniques, such as multi-photon spectroscopy, cross-correlation measurements and alignment of molecules in space.

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

Moura, Eduardo S., E-mail: emoura@wisc.edu; Micka, John A.; Hammer, Cliff G.

Purpose: This work presents the development of a phantom to verify the treatment planning system (TPS) algorithms used for high-dose-rate (HDR) brachytherapy. It is designed to measure the relative dose in a heterogeneous media. The experimental details used, simulation methods, and comparisons with a commercial TPS are also provided. Methods: To simulate heterogeneous conditions, four materials were used: Virtual Water™ (VM), BR50/50™, cork, and aluminum. The materials were arranged in 11 heterogeneity configurations. Three dosimeters were used to measure the relative response from a HDR {sup 192}Ir source: TLD-100™, Gafchromic{sup ®} EBT3 film, and an Exradin™ A1SL ionization chamber. Tomore » compare the results from the experimental measurements, the various configurations were modeled in the PENELOPE/penEasy Monte Carlo code. Images of each setup geometry were acquired from a CT scanner and imported into BrachyVision™ TPS software, which includes a grid-based Boltzmann solver Acuros™. The results of the measurements performed in the heterogeneous setups were normalized to the dose values measured in the homogeneous Virtual Water™ setup and the respective differences due to the heterogeneities were considered. Additionally, dose values calculated based on the American Association of Physicists in Medicine-Task Group 43 formalism were compared to dose values calculated with the Acuros™ algorithm in the phantom. Calculated doses were compared at the same points, where measurements have been performed. Results: Differences in the relative response as high as 11.5% were found from the homogeneous setup when the heterogeneous materials were inserted into the experimental phantom. The aluminum and cork materials produced larger differences than the plastic materials, with the BR50/50™ material producing results similar to the Virtual Water™ results. Our experimental methods agree with the PENELOPE/penEasy simulations for most setups and dosimeters. The TPS relative differences with the Acuros™ algorithm were similar in both experimental and simulated setups. The discrepancy between the BrachyVision™, Acuros™, and TG-43 dose responses in the phantom described by this work exceeded 12% for certain setups. Conclusions: The results derived from the phantom measurements show good agreement with the simulations and TPS calculations, using Acuros™ algorithm. Differences in the dose responses were evident in the experimental results when heterogeneous materials were introduced. These measurements prove the usefulness of the heterogeneous phantom for verification of HDR treatment planning systems based on model-based dose calculation algorithms.« less

Measurement of sound velocity made easy using harmonic resonant frequencies with everyday mobile technology

NASA Astrophysics Data System (ADS)

Hirth, Michael; Kuhn, Jochen; Müller, Andreas

2015-02-01

Recent articles about smartphone experiments have described their applications as experimental tools in different physical contexts.1-4 They have established that smartphones facilitate experimental setups, thanks to the small size and diverse functions of mobile devices, in comparison to setups with computer-based measurements. In the experiment described in this article, the experimental setup is reduced to a minimum. The objective of the experiment is to determine the speed of sound with a high degree of accuracy using everyday tools. An article published recently proposes a time-of-flight method where sound or acoustic pulses are reflected at the ends of an open tube.5 In contrast, the following experiment idea is based on the harmonic resonant frequencies of such a tube, simultaneously triggered by a noise signal.

Spying on photons with photons: quantum interference and information

NASA Astrophysics Data System (ADS)

Ataman, Stefan

2016-07-01

The quest to have both which-path knowledge and interference fringes in a double-slit experiment dates back to the inception of quantum mechanics (QM) and to the famous Einstein-Bohr debates. In this paper we propose and discuss an experiment able to spy on one photon's path with another photon. We modify the quantum state inside the interferometer as opposed to the traditional physical modification of the "wave-like" or "particle-like" experimental setup. We are able to show that it is the ability to harvest or not which-path information that finally limits the visibility of the interference pattern and not the "wave-like" or "particle-like" experimental setups. Remarkably, a full "particle-like" experimental setup is able to show interference fringes with 100% visibility if the quantum state is carefully engineered.

An ultra-stable optical frequency reference for space

NASA Astrophysics Data System (ADS)

Schuldt, T.; Döringshoff, K.; Kovalchuk, E.; Pahl, J.; Gohlke, M.; Weise, D.; Johann, U.; Peters, A.; Braxmaier, C.

2017-11-01

We realized ultra-stable optical frequency references on elegant breadboard (EBB) and engineering model (EM) level utilizing Doppler-free spectroscopy of molecular iodine near 532nm. A frequency stability of about 1•10-14 at an integration time of 1 s and below 5•10-15 at integration times between 10 s and 100 s was achieved. These values are comparable to the currently best laboratory setups. Both setups use a baseplate made of glass material where the optical components are joint using a specific assembly-integration technology. Compared to the EBB setup, the EM setup is further developed with respect to compactness and mechanical and thermal stability. The EM setup uses a baseplate made of fused silica with dimensions of 380 x 180 x 40 mm3 and a specifically designed 100 x 100 x 30 mm3 rectangular iodine cell in nine-pass configuration with a specific robust cold finger design. The EM setup was subjected to thermal cycling and vibrational testing. Applications of such an optical frequency reference in space can be found in fundamental physics, geoscience, Earth observation, and navigation & ranging. One example is the proposed mSTAR (mini SpaceTime Asymmetry Research) mission, dedicated to perform a Kennedy-Thorndike experiment on a satellite in a sunsynchronous low-Earth orbit. By comparing an iodine standard to a cavity-based frequency reference and integration over 2 year mission lifetime, the Kennedy-Thorndike coefficient will be determined with up to two orders of magnitude higher accuracy than the current best ground experiment. In a current study, the compatibility of the payload with the SaudiSat-4 host vehicle is investigated.

A Novel Experimental Setup to Investigate Magnetized Dusty Plasmas

NASA Astrophysics Data System (ADS)

Romero-Talamas, C. A.; Larocque, P.; Alvarez, J.; Sardin, J.

2013-10-01

Progress on the design and construction of a novel experimental setup to investigate dusty plasmas at the University of Maryland, Baltimore County (UMBC) is presented. The setup includes separation adjustability of discharge electrodes and their orientation with respect to gravity without breaking vacuum, and a pair of water-cooled coils to produce magnetic fields with strengths of up to several Tesla. The coils' orientation is also designed to be adjustable with respect to gravity. A pulse-forming network to power the coils with flattop times of several seconds is under design. The setup is mounted inside a large glass bell jar to provide wide optical access to the dusty plasmas, and to minimize interference of chamber walls and mounts with imposed electric or magnetic fields. Planned experiments include crystallization and wave propagation under strong magnetic fields.

Novel Anaerobic Wastewater Treatment System for Energy Generation at Forward Operating Bases

DTIC Science & Technology

2016-08-01

AnMBR) technology with clinoptilolite ion exchange and GreenBox™ ammonia electrolysis. The system generates both methane and hydrogen fuels...experimental setup. ................................................ 21 Figure 10. Methane phase semi batch experimental setup, a total of three reactors were...set up for PS + solid, Bioc and ADS methane phase reactors. .................... 21 Figure 11. Dried PS solid for the control, Bioc blend for the

Center for Hybrid Communications and Networks

DTIC Science & Technology

2016-09-08

Transmission loop experimental setup to study coded modulation and turbo equalization for metro and long-haul networks, 3) Experimental setup for...undertaking fundamental studies of QKD systems that use ( hyper -) entangled photon pairs or weak coherent states (WCS) as the quantum resources...onlinelibrary.wiley.com/doi/10.1002/047134608X.W8291/abstract] The real-time scope and AWG are also used in fiber-optics transmission loop experiment we

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

Chen, Jingguang; Frenkel, Anatoly; Rodriguez, Jose

Synchrotron spectroscopies offer unique advantages over conventional techniques, including higher detection sensitivity and molecular specificity, faster detection rate, and more in-depth information regarding the structural, electronic and catalytic properties under in-situ reaction conditions. Despite these advantages, synchrotron techniques are often underutilized or unexplored by the catalysis community due to various perceived and real barriers, which will be addressed in the current proposal. Since its establishment in 2005, the Synchrotron Catalysis Consortium (SCC) has coordinated significant efforts to promote the utilization of cutting-edge catalytic research under in-situ conditions. The purpose of the current renewal proposal is aimed to provide assistance, andmore » to develop new sciences/techniques, for the catalysis community through the following concerted efforts: Coordinating the implementation of a suite of beamlines for catalysis studies at the new NSLS-II synchrotron source; Providing assistance and coordination for catalysis users at an SSRL catalysis beamline during the initial period of NSLS to NSLS II transition; Designing in-situ reactors for a variety of catalytic and electrocatalytic studies; Assisting experimental set-up and data analysis by a dedicated research scientist; Offering training courses and help sessions by the PIs and co-PIs.« less

First results on Ge resonant laser photoionization in hollow cathode lamp

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

Scarpa, Daniele, E-mail: daniele.scarpa@lnl.infn.it; Andrighetto, Alberto; Barzakh, Anatoly

2016-02-15

In the framework of the research and development activities of the SPES project regarding the optimization of the radioactive beam production, a dedicated experimental study has been recently started in order to investigate the possibility of in-source ionization of germanium using a set of tunable dye lasers. Germanium is one of the beams to be accelerated by the SPES ISOL facility, which is under construction at Legnaro INFN Laboratories. The three-step, two color ionization schemes have been tested using a Ge hollow cathode lamp. The slow and the fast optogalvanic signals were detected and averaged by an oscilloscope as amore » proof of the laser ionization inside the lamp. As a result, several wavelength scans across the resonances of ionization schemes were collected with the fast optogalvanic signal. Some comparisons of ionization efficiency for different ionization schemes were made. Furthermore, saturation curves of the first excitation transitions have been obtained. This investigation method and the setup built in the laser laboratory of the SPES project can be applied for the photo-ionization scheme studies also for the other possible radioactive elements.« less

A setup for combined multiphoton laser scanning microscopic and multi-electrode patch clamp experiments on brain slices

NASA Astrophysics Data System (ADS)

Helm, P. Johannes; Reppen, Trond; Heggelund, Paul

2009-02-01

Multi Photon Laser Scanning Microscopy (MPLSM) appears today as one of the most powerful experimental tools in cellular neurophysiology, notably in studies of the functional dynamics of signal processing in single neurons. Simultaneous recording of fluorescence signals at high spatial and temporal resolution and electric signals by means of multi electrode patch clamp techniques have provided new paths for the systematic investigation of neuronal mechanisms. In particular, this approach has opened for direct studies of dendritic signal processing in neurons. We report about a setup optimized for simultaneous electrophysiological multi electrode patch clamp and multi photon laser scanning fluorescence microscopic experiments on brain slices. The microscopic system is based on a modified commercially available confocal scanning laser microscope (CLSM). From a technical and operational point of view, two developments are important: Firstly, in order to reduce the workload for the experimentalist, who in general is forced to concentrate on controlling the electrophysiological parameters during the recordings, a system of shutters has been installed together with dedicated electronic modules protecting the photo detectors against destructive light levels caused by erroneous opening or closing of microscopic light paths by the experimentalist. Secondly, the standard detection unit has been improved by installing the photomultiplier tubes (PMT) in a Peltier cooled thermal box shielding the detector from both room temperature and distortions caused by external electromagnetic fields. The electrophysiological system is based on an industrial standard multi patch clamp unit ergonomically arranged around the microscope stage. The electrophysiological and scanning processes can be time coordinated by standard trigger electronics.

MR-based measurements and simulations of the magnetic field created by a realistic transcranial magnetic stimulation (TMS) coil and stimulator.

PubMed

Mandija, Stefano; Petrov, Petar I; Neggers, Sebastian F W; Luijten, Peter R; van den Berg, Cornelis A T

2016-11-01

Transcranial magnetic stimulation (TMS) is an emerging technique that allows non-invasive neurostimulation. However, the correct validation of electromagnetic models of typical TMS coils and the correct assessment of the incident TMS field (B TMS ) produced by standard TMS stimulators are still lacking. Such a validation can be performed by mapping B TMS produced by a realistic TMS setup. In this study, we show that MRI can provide precise quantification of the magnetic field produced by a realistic TMS coil and a clinically used TMS stimulator in the region in which neurostimulation occurs. Measurements of the phase accumulation created by TMS pulses applied during a tailored MR sequence were performed in a phantom. Dedicated hardware was developed to synchronize a typical, clinically used, TMS setup with a 3-T MR scanner. For comparison purposes, electromagnetic simulations of B TMS were performed. MR-based measurements allow the mapping and quantification of B TMS starting 2.5 cm from the TMS coil. For closer regions, the intra-voxel dephasing induced by B TMS prohibits TMS field measurements. For 1% TMS output, the maximum measured value was ~0.1 mT. Simulations reflect quantitatively the experimental data. These measurements can be used to validate electromagnetic models of TMS coils, to guide TMS coil positioning, and for dosimetry and quality assessment of concurrent TMS-MRI studies without the need for crude methods, such as motor threshold, for stimulation dose determination. Copyright © 2016 John Wiley & Sons, Ltd.

Influence of the Sampling Rate and Noise Characteristics on Prediction of the Maximal Safe Laser Exposure in Human Skin Using Pulsed Photothermal Radiometry

NASA Astrophysics Data System (ADS)

Vidovič, L.; Milanič, M.; Majaron, B.

2013-09-01

Pulsed photothermal radiometry (PPTR) allows for noninvasive determination of the laser-induced temperature depth profile in strongly scattering samples, including human skin. In a recent experimental study, we have demonstrated that such information can be used to derive rather accurate predictions of the maximal safe radiant exposure on an individual patient basis. This has important implications for efficacy and safety of several laser applications in dermatology and aesthetic surgery, which are often compromised by risk of adverse side effects (e.g., scarring, and dyspigmentation) resulting from nonselective absorption of strong laser light in epidermal melanin. In this study, the differences between the individual maximal safe radiant exposure values as predicted from PPTR temperature depth profiling performed using a commercial mid-IR thermal camera (as used to acquire the original patient data) and our customized PPTR setup are analyzed. To this end, the latter has been used to acquire 17 PPTR records from three healthy volunteers, using 1 ms laser irradiation at 532 nm and a signal sampling rate of 20 000 . The laser-induced temperature profiles are reconstructed first from the intact PPTR signals, and then by binning the data to imitate the lower sampling rate of the IR camera (1000 fps). Using either the initial temperature profile in a dedicated numerical model of heat transfer or protein denaturation dynamics, the predicted levels of epidermal thermal damage and the corresponding are compared. A similar analysis is performed also with regard to the differences between noise characteristics of the two PPTR setups.

A new small-footprint external-beam PIXE facility for cultural heritage applications using pulsed proton beams

NASA Astrophysics Data System (ADS)

Vadrucci, M.; Bazzano, G.; Borgognoni, F.; Chiari, M.; Mazzinghi, A.; Picardi, L.; Ronsivalle, C.; Ruberto, C.; Taccetti, F.

2017-09-01

In the framework of the COBRA project, elemental analyses of cultural heritage objects based on the particle induced X-ray emission (PIXE) are planned in a collaboration between the APAM laboratory of ENEA-Frascati and the LABEC laboratory of INFN in Florence. With this aim a 3-7 MeV pulsed proton beam, driven by the injector of the protontherapy accelerator under construction for the TOP-IMPLART project, will be used to demonstrate the feasibility of the technique with a small-footprint pulsed accelerator to Italian small and medium enterprises interested in the composition analysis of ancient artifacts. The experimental set-up for PIXE analysis on the TOP-IMPLART machine consists of a modified assembly of the vertical beam line usually dedicated to radiobiology experiments: the beam produced by the injector (RFQ + DTL, a PL7 ACCSYSHITACHI model) is bent to 90° by a magnet, is collimated by a 300 μm aperture inserted in the end nozzle and extracted into ambient pressure by an exit window consisting of a Upilex foil 7.5 μm thick. The beam is pulsed with a variable pulse duration of 20-100 μs and a repetition rate variable from 10 to 100 Hz. The X-ray detection system is based on a Ketek Silicon Drift Detector (SDD) with 7 mm2 active area and 450 μm thickness, with a thin Beryllium entrance window (8 μm). The results of the calibration of this new PIXE set-up using thick target standards and of the analysis of the preliminary measurements on pigments are presented.

Modeling and testing of a tube-in-tube separation mechanism of bodies in space

NASA Astrophysics Data System (ADS)

Michaels, Dan; Gany, Alon

2016-12-01

A tube-in-tube concept for separation of bodies in space was investigated theoretically and experimentally. The separation system is based on generation of high pressure gas by combustion of solid propellant and restricting the expansion of the gas only by ejecting the two bodies in opposite directions, in such a fashion that maximizes generated impulse. An interior ballistics model was developed in order to investigate the potential benefits of the separation system for a large range of space body masses and for different design parameters such as geometry and propellant. The model takes into account solid propellant combustion, heat losses, and gas phase chemical reactions. The model shows that for large bodies (above 100 kg) and typical separation velocities of 5 m/s, the proposed separation mechanism may be characterized by a specific impulse of 25,000 s, two order of magnitude larger than that of conventional solid rockets. It means that the proposed separation system requires only 1% of the propellant mass that would be needed for a conventional rocket for the same mission. Since many existing launch vehicles obtain such separation velocities by using conventional solid rocket motors (retro-rockets), the implementation of the new separation system design can reduce dramatically the mass of the separation system and increase safety. A dedicated experimental setup was built in order to demonstrate the concept and validate the model. The experimental results revealed specific impulse values of up to 27,000 s and showed good correspondence with the model.

Evaluation of setup uncertainties for single-fraction SRS by comparing two different mask-creation methods

NASA Astrophysics Data System (ADS)

Baek, Jong Geun; Jang, Hyun Soo; Oh, Young Kee; Lee, Hyun Jeong; Kim, Eng Chan

2015-07-01

The purpose of this study was to evaluate the setup uncertainties for single-fraction stereotactic radiosurgery (SF-SRS) based on clinical data with two different mask-creation methods using pretreatment con-beam computed tomography imaging guidance. Dedicated frameless fixation Brain- LAB masks for 23 patients were created as a routine mask (R-mask) making method, as explained in the BrainLAB's user manual. Alternative masks (A-masks), which were created by modifying the cover range of the R-masks for the patient's head, were used for 23 patients. The systematic errors including these for each mask and stereotactic target localizer were analyzed, and the errors were calculated as the means ± standard deviations (SD) from the left-right (LR), superior-inferior (SI), anterior-posterior (AP), and yaw setup corrections. In addition, the frequencies of the threedimensional (3D) vector length were analyzed. The values of the mean setup corrections for the R-mask in all directions were < 0.7 mm and < 0.1°, whereas the magnitudes of the SDs were relatively large compared to the mean values. In contrast, the means and SDs of the A-mask were smaller than those for the R-mask with the exception of the SD in the AP direction. The means and SDs in the yaw rotational direction for the R-mask and the A-mask system were comparable. 3D vector shifts of larger magnitude occurred more frequently for the R-mask than the A-mask. The setup uncertainties for each mask with the stereotactic localizing system had an asymmetric offset towards the positive AP direction. The A-mask-creation method, which is capable of covering the top of the patient's head, is superior to that for the R-mask, so the use of the A-mask is encouraged for SF-SRS to reduce the setup uncertainties. Moreover, careful mask-making is required to prevent possible setup uncertainties.

A novel coil array for combined TMS/fMRI experiments at 3 T.

PubMed

Navarro de Lara, Lucia I; Windischberger, Christian; Kuehne, Andre; Woletz, Michael; Sieg, Jürgen; Bestmann, Sven; Weiskopf, Nikolaus; Strasser, Bernhard; Moser, Ewald; Laistler, Elmar

2015-11-01

To overcome current limitations in combined transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) studies by employing a dedicated coil array design for 3 Tesla. The state-of-the-art setup for concurrent TMS/fMRI is to use a large birdcage head coil, with the TMS between the subject's head and the MR coil. This setup has drawbacks in sensitivity, positioning, and available imaging techniques. In this study, an ultraslim 7-channel receive-only coil array for 3 T, which can be placed between the subject's head and the TMS, is presented. Interactions between the devices are investigated and the performance of the new setup is evaluated in comparison to the state-of-the-art setup. MR sensitivity obtained at the depth of the TMS stimulation is increased by a factor of five. Parallel imaging with an acceleration factor of two is feasible with low g-factors. Possible interactions between TMS and the novel hardware were investigated and were found negligible. The novel coil array is safe, strongly improves signal-to-noise ratio in concurrent TMS/fMRI experiments, enables parallel imaging, and allows for flexible positioning of the TMS on the head while ensuring efficient TMS stimulation due to its ultraslim design. © 2014 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

Status and Prospects of Hirfl Experiments on Nuclear Physics

NASA Astrophysics Data System (ADS)

Xu, H. S.; Zheng, C.; Xiao, G. Q.; Zhan, W. L.; Zhou, X. H.; Zhang, Y. H.; Sun, Z. Y.; Wang, J. S.; Gan, Z. G.; Huang, W. X.; Ma, X. W.

HIRFL is an accelerator complex consisting of 3 accelerators, 2 radioactive beams lines, 1 storage rings and a number of experimental setups. The research activities at HIRFL cover the fields of radio-biology, material science, atomic physics, and nuclear physics. This report mainly concentrates on the experiments of nuclear physics with the existing and planned experimental setups such as SHANS, RIBLL1, ETF, CSRe, PISA and HPLUS at HIRFL.

Including Finite Surface Span Effects in Empirical Jet-Surface Interaction Noise Models

NASA Technical Reports Server (NTRS)

Brown, Clifford A.

2016-01-01

The effect of finite span on the jet-surface interaction noise source and the jet mixing noise shielding and reflection effects is considered using recently acquired experimental data. First, the experimental setup and resulting data are presented with particular attention to the role of surface span on far-field noise. These effects are then included in existing empirical models that have previously assumed that all surfaces are semi-infinite. This extended abstract briefly describes the experimental setup and data leaving the empirical modeling aspects for the final paper.

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.

Integration of prior knowledge into dense image matching for video surveillance

NASA Astrophysics Data System (ADS)

Menze, M.; Heipke, C.

2014-08-01

Three-dimensional information from dense image matching is a valuable input for a broad range of vision applications. While reliable approaches exist for dedicated stereo setups they do not easily generalize to more challenging camera configurations. In the context of video surveillance the typically large spatial extent of the region of interest and repetitive structures in the scene render the application of dense image matching a challenging task. In this paper we present an approach that derives strong prior knowledge from a planar approximation of the scene. This information is integrated into a graph-cut based image matching framework that treats the assignment of optimal disparity values as a labelling task. Introducing the planar prior heavily reduces ambiguities together with the search space and increases computational efficiency. The results provide a proof of concept of the proposed approach. It allows the reconstruction of dense point clouds in more general surveillance camera setups with wider stereo baselines.

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

Large format array controller (aLFA-C): tests and characterisation at ESA

NASA Astrophysics Data System (ADS)

Lemmel, Frédéric; ter Haar, Jörg; van der Biezen, John; Duvet, Ludovic; Nelms, Nick; Blommaert, Sander; Butler, Bart; van der Luijt, Cornelis; Heijnen, Jerko; Smit, Hans; Visser, Ivo

2016-08-01

For future near infrared astronomy missions, ESA is developing a complete detection and conversion chain (photon to SpaceWire chain system): Large Format Array (aLFA-N) based on MCT type detectors. aLFA-C (Astronomy Large Format Array Controller): a versatile cryogenic detector controller. An aLFA-C prototype was developed by Caeleste (Belgium) under ESA contract (400106260400). To validate independently the performances of the aLFA-C prototype and consolidate the definition of the follow-on activity, a dedicated test bench has been designed and developed in ESTEC/ESA within the Payload Technology Validation group. This paper presents the test setup and the performance validation of the first prototype of this controller at room and cryogenic temperature. Test setup and software needed to test the HAWAII-2RG and aLFA-N detectors with the aLFA-C prototype at cryogenic temperature will be also presented.

Eye-in-Hand Manipulation for Remote Handling: Experimental Setup

NASA Astrophysics Data System (ADS)

Niu, Longchuan; Suominen, Olli; Aref, Mohammad M.; Mattila, Jouni; Ruiz, Emilio; Esque, Salvador

2018-03-01

A prototype for eye-in-hand manipulation in the context of remote handling in the International Thermonuclear Experimental Reactor (ITER)1 is presented in this paper. The setup consists of an industrial robot manipulator with a modified open control architecture and equipped with a pair of stereoscopic cameras, a force/torque sensor, and pneumatic tools. It is controlled through a haptic device in a mock-up environment. The industrial robot controller has been replaced by a single industrial PC running Xenomai that has a real-time connection to both the robot controller and another Linux PC running as the controller for the haptic device. The new remote handling control environment enables further development of advanced control schemes for autonomous and semi-autonomous manipulation tasks. This setup benefits from a stereovision system for accurate tracking of the target objects with irregular shapes. The overall environmental setup successfully demonstrates the required robustness and precision that remote handling tasks need.

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.

Experimental study on melting and flowing behavior of thermoplastics combustion based on a new setup with a T-shape trough.

PubMed

Xie, Qiyuan; Zhang, Heping; Ye, Ruibo

2009-07-30

The objective of this work is to quantitatively study the burning characteristics of thermoplastics. A new experimental setup with a T-shape trough is designed. Based on this setup, the loop mechanism between the wall fire and pool fires induced by the melting and dripping of thermoplastic can be well simulated and studied. Additionally, the flowing characteristics of pool fires can also be quantitatively analyzed. Experiments are conducted for PP and PE sheets with different thicknesses. The maximum distances of the induced flowing pool flame in the T-shape trough are recorded and analyzed. The typical fire parameters, such as heat release rates (HRRs), CO concentrations are also monitored. The results show that the softening and clinging of the thermoplastic sheets plays a considerable role for their vertical wall burning. It is illustrated that the clinging of burning thermoplastic sheet may be mainly related with the softening temperatures and the ignition temperatures of the thermoplastics, as well as their viscosity coefficients. Through comparing the maximum distances of flowing flame of induced pool fires in the T-shape trough for thermoplastic sheets with different thicknesses, it is indicated that the pool fires induced by PE materials are easier to flow away than that of PP materials. Therefore, PE materials may be more dangerous for their faster pool fire spread on the floor. These experimental results preliminarily illustrate that this new experimental setup is helpful for quantitatively studying the special burning feature of thermoplastics although further modifications is needed for this setup in the future.

A simple Lissajous curves experimental setup

NASA Astrophysics Data System (ADS)

Şahin Kızılcık, Hasan; Damlı, Volkan

2018-05-01

The aim of this study is to develop an experimental setup to produce Lissajous curves. The setup was made using a smartphone, a powered speaker (computer speaker), a balloon, a laser pointer and a piece of mirror. Lissajous curves are formed as follows: a piece of mirror is attached to a balloon. The balloon is vibrated with the sound signal provided by the speaker that is connected to a smartphone. The laser beam is reflected off the mirror and the reflection is shaped as a Lissajous curve. Because of the intersection of two frequencies (frequency of the sound signal and natural vibration frequency of the balloon), these curves are formed. They can be used to measure the ratio of frequencies.

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

Evaluation and qualification of commercial opto-electronic components for the MOHA subsystem in ESA's SMOS mission

NASA Astrophysics Data System (ADS)

Gutierrez, Francisco; Cordero, Enrique; Sánchez, Carolina; Barbero, Juan; Mosberger, Martin; Boehle, Peter; Tornell, Manuel; Lundmark, Karin

2017-11-01

A dedicated evaluation and qualification campaign has been performed on several optical COTS components in order to use them on ESA's SMOS mission. The evaluation phase consisted of a set of critical tests and analyses and led to the selection of the flight lot component. After selection of the components, one lot of each component has been qualified for the SMOS mission. The overall approach is presented together with a summary of all activities performed. The whole task has been handled in a joint effort between ESA, EADS CASA Espacio (prime contractor), Contraves Space AG (MOHA subsystem), TECNOLOGICA SA (component qualification experts) and the respective manufacturers, each party providing their specific know-how. Test results are presented and the issues discovered and lessons learned are addressed. Special emphasis is given to particular tests for which dedicated setups had to be designed due to the unavailability of standard equipment.

Upgrade of the TITAN EBIT High Voltage Operation

NASA Astrophysics Data System (ADS)

Foster, Matt; Titan Collaboration

2016-09-01

TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) is a setup dedicated to highly precise mass measurements of short-lived isotopes down to 10ms. TITAN's Electron Beam Ion Trap (EBIT) is a charge breeder integrated into the setup to perform in-trap decay spectroscopy of highly charged ions and increase the precision of mass measurements. In its previous configuration TITAN's EBIT could not fulfil its maximum design specification due to high voltage safety restrictions, limiting its obtainable charge states. A recently completed upgrade of the high voltage operation that will allow the EBIT to fulfil its design specification and achieve higher charge states for heavier species is undergoing preliminary tests with stable beam. Simulations were performed to optimise the injection and extraction efficiency at high voltage and initial tests have involved using a Ge detector to identify x-rays produced by charge breeding stable ions. Future work comprises exploring electron capture rates of Ne-, He- and H-like charge states of 64Cu and higher masses, which were not previously accessible. The function of the EBIT within the TITAN setup, the work carried out on the upgrade thus far and its scope for future work will be presented.

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

Development of an experimental setup for analyzing the influence of Magnus effect on the performance of airfoil

NASA Astrophysics Data System (ADS)

Aktharuzzaman, Md; Sarker, Md. Samad; Safa, Wasiul; Sharah, Nahreen; Salam, Md. Abdus

2017-12-01

Magnus effect is a phenomenon where pressure difference is created according to Bernoulli's effect due to induced velocity changes caused by a rotating object in a fluid. Using this concept, the idea of delaying boundary layer separation on airfoil by providing moving surface boundary layer control has been developed. In order to analyze the influence of Magnus effect on the aerodynamic performance of an airfoil, there is no alternative of developing an experimental setup. This paper aims to develop such an experimental setup which will be capable of analyzing the influence of Magnus effect on both symmetric and asymmetric airfoils by placing a cylinder at the leading edge. To provide arrangements for a rotating cylinder at the leading edge of airfoil, necessary modifications and additions have been done in the test section of an AF100 subsonic wind tunnel.

Development of a single ion hit facility at the Pierre Sue Laboratory: a collimated microbeam to study radiological effects on targeted living cells.

PubMed

Daudin, L; Carrière, M; Gouget, B; Hoarau, J; Khodja, H

2006-01-01

A single ion hit facility is being developed at the Pierre Süe Laboratory (LPS) since 2004. This set-up will be dedicated to the study of ionising radiation effects on living cells, which will complete current research conducted on uranium chemical toxicity on renal and osteoblastic cells. The study of the response to an exposure to alpha particles will allow us to distinguish radiological and chemical toxicities of uranium, with a special emphasis on the bystander effect at low doses. Designed and installed on the LPS Nuclear microprobe, up to now dedicated to ion beam microanalysis, this set-up will enable us to deliver an exact number of light ions accelerated by a 3.75 MV electrostatic accelerator. An 'in air' vertical beam permits the irradiation of cells in conditions compatible with cell culture techniques. Furthermore, cellular monolayer will be kept in controlled conditions of temperature and atmosphere in order to diminish stress. The beam is collimated with a fused silica capillary tubing to target pre-selected cells. Motorisation of the collimator with piezo-electric actuators should enable fast irradiation without moving the sample, thus avoiding mechanical stress. An automated epifluorescence microscope, mounted on an antivibration table, allows pre- and post-irradiation cell observation. An ultra thin silicon surface barrier detector has been developed and tested to be able to shoot a cell with a single alpha particle.

Carbapenemase-producing Acinetobacter baumannii: An outbreak report with special highlights on economic burden.

PubMed

Gagnaire, J; Gagneux-Brunon, A; Pouvaret, A; Grattard, F; Carricajo, A; Favier, H; Mattei, A; Pozzetto, B; Nuti, C; Lucht, F; Berthelot, P; Botelho-Nevers, E

2017-06-01

We aimed to describe the management of a carbapenemase-producing Acinetobacter baumannii (CP-AB) outbreak using the Outbreak Reports and Intervention Studies of Nosocomial Infection (ORION) statement. We also aimed to evaluate the cost of the outbreak and simulate costs if a dedicated unit to manage such outbreak had been set-up. We performed a prospective epidemiological study. Multiple interventions were implemented including cohorting measures and limitation of admissions. Cost estimation was performed using administrative local data. Five patients were colonized with CP-AB and hospitalized in the neurosurgery ward. The index case was a patient who had been previously hospitalized in Portugal. Four secondary colonized patients were further observed within the unit. The strains of A. baumannii were shown to belong to the same clone and all of them produced an OXA-23 carbapenemase. The closure of the ward associated with the discharge of the five patients in a cohorting area of the Infectious Diseases Unit with dedicated staff put a stop to the outbreak. The estimated cost of this 17-week outbreak was $474,474. If patients had been managed in a dedicated unit - including specific area for cohorting of patients and dedicated staff - at the beginning of the outbreak, the estimated cost would have been $189,046. Controlling hospital outbreaks involving multidrug-resistant bacteria requires a rapid cohorting of patients. Using simulation, we highlighted cost gain when using a dedicated cohorting unit strategy for such an outbreak. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A long arm for ultrasound: a combined robotic focused ultrasound setup for magnetic resonance-guided focused ultrasound surgery.

PubMed

Krafft, Axel J; Jenne, Jürgen W; Maier, Florian; Stafford, R Jason; Huber, Peter E; Semmler, Wolfhard; Bock, Michael

2010-05-01

Focused ultrasound surgery (FUS) is a highly precise noninvasive procedure to ablate pathogenic tissue. FUS therapy is often combined with magnetic resonance (MR) imaging as MR imaging offers excellent target identification and allows for continuous monitoring of FUS induced temperature changes. As the dimensions of the ultrasound (US) focus are typically much smaller than the targeted volume, multiple sonications and focus repositioning are interleaved to scan the focus over the target volume. Focal scanning can be achieved electronically by using phased-array US transducers or mechanically by using dedicated mechanical actuators. In this study, the authors propose and evaluate the precision of a combined robotic FUS setup to overcome some of the limitations of the existing MRgFUS systems. Such systems are typically integrated into the patient table of the MR scanner and thus only provide an application of the US wave within a limited spatial range from below the patient. The fully MR-compatible robotic assistance system InnoMotion (InnoMedic GmbH, Herxheim, Germany) was originally designed for MR-guided interventions with needles. It offers five pneumatically driven degrees of freedom and can be moved over a wide range within the bore of the magnet. In this work, the robotic system was combined with a fixed-focus US transducer (frequency: 1.7 MHz; focal length: 68 mm, and numerical aperture: 0.44) that was integrated into a dedicated, in-house developed treatment unit for FUS application. A series of MR-guided focal scanning procedures was performed in a polyacrylamide-egg white gel phantom to assess the positioning accuracy of the combined FUS setup. In animal experiments with a 3-month-old domestic pig, the system's potential and suitability for MRgFUS was tested. In phantom experiments, a total targeting precision of about 3 mm was found, which is comparable to that of the existing MRgFUS systems. Focus positioning could be performed within a few seconds. During in vivo experiments, a defined pattern of single thermal lesions and a therapeutically relevant confluent thermal lesion could be created. The creation of local tissue necrosis by coagulation was confirmed by post-FUS MR imaging and histological examinations on the treated tissue sample. During all sonications in phantom and in vivo, reliable MR imaging and online MR thermometry could be performed without compromises due to operation of the combined robotic FUS setup. Compared to the existing MRgFUS systems, the combined robotic FUS approach offers a wide range of spatial flexibility so that highly flexible application of the US wave would be possible, for example, to avoid risk structures within the US field. The setup might help to realize new ways of patient access in MRgFUS therapy. The setup is compatible with any closed-bore MR system and does not require an especially designed patient table.

Dense cold baryonic matter

NASA Astrophysics Data System (ADS)

Stavinskiy, A. V.

2017-09-01

A possibility of studying cold nuclear matter on the Nuclotron-NICA facility at baryonic densities characteristic of and higher than at the center of a neutron star is considered based on the data from cumulative processes. A special rare-event kinematic trigger for collisions of relativistic ions is proposed for effective selection of events accompanied by production of dense baryonic systems. Possible manifestations of new matter states under these unusual conditions and an experimental program for their study are discussed. Various experimental setups are proposed for these studies, and a possibility of using experimental setups at the Nuclotron-NICA facility for this purpose is considered.

Nano-Ignition Torch Applied to Cryogenic H2/O2 Coaxial Jet

DTIC Science & Technology

2016-01-04

developed and ignition of liquid fuel sprays by the torch has been achieved. In this report, we will describe the experimental procedure for producing...ignition that is induced by a compact Xe-flash, including the results for photoignition of a simple fuel spray in air as well as ignition of a coaxial...window. Experimental Setup for Fuel Spray Ignition Three different setups were utilized for the fuel ignition experiments. The first one was used

Note: Setup for chemical atmospheric control during in situ grazing incidence X-ray scattering of printed thin films

DOE PAGES

Pröller, Stephan; Moseguí González, Daniel; Zhu, Chenhuii; ...

2017-06-01

In order to tailor the assembling of polymers and organic molecules, a deeper understanding of the kinetics involved in thin film production is necessary. While post-production characterization only provides insight on the final film structure, more sophisticated experimental setups are needed to probe the structure formation processes in situ during deposition. The drying kinetics of a deposited organic thin film strongly influences the assembling process on the nanometer scale. Lastly, this work presents an experimental setup that enables fine control of the atmosphere composition surrounding the sample during slot die coating, while simultaneously probing the film formation kinetics using inmore » situ grazing incidence X-ray scattering and spectroscopy.« less

Active Optical Zoom for Tracking

DTIC Science & Technology

2008-09-01

optical system. 2. Current Setup Deformable Flat Two Deformable Flat Figure 1. Zemax lens design layout and experimental layout on the...optical bench. Figure 1 is a ZEMAX design and setup on the optical bench of two Deformable Mirrors (DMs) from OKO technologies. These mirrors have

Characterization of the ELIMED Permanent Magnets Quadrupole system prototype with laser-driven proton beams

NASA Astrophysics Data System (ADS)

Schillaci, F.; Pommarel, L.; Romano, F.; Cuttone, G.; Costa, M.; Giove, D.; Maggiore, M.; Russo, A. D.; Scuderi, V.; Malka, V.; Vauzour, B.; Flacco, A.; Cirrone, G. A. P.

2016-07-01

Laser-based accelerators are gaining interest in recent years as an alternative to conventional machines [1]. In the actual ion acceleration scheme, energy and angular spread of the laser-driven beams are the main limiting factors for beam applications and different solutions for dedicated beam-transport lines have been proposed [2,3]. In this context a system of Permanent Magnet Quadrupoles (PMQs) has been realized [2] by INFN-LNS (Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare) researchers, in collaboration with SIGMAPHI company in France, to be used as a collection and pre-selection system for laser driven proton beams. This system is meant to be a prototype to a more performing one [3] to be installed at ELI-Beamlines for the collection of ions. The final system is designed for protons and carbons up to 60 MeV/u. In order to validate the design and the performances of this large bore, compact, high gradient magnetic system prototype an experimental campaign have been carried out, in collaboration with the group of the SAPHIR experimental facility at LOA (Laboratoire d'Optique Appliquée) in Paris using a 200 TW Ti:Sapphire laser system. During this campaign a deep study of the quadrupole system optics has been performed, comparing the results with the simulation codes used to determine the setup of the PMQ system and to track protons with realistic TNSA-like divergence and spectrum. Experimental and simulation results are good agreement, demonstrating the possibility to have a good control on the magnet optics. The procedure used during the experimental campaign and the most relevant results are reported here.

Process Based on SysML for New Launchers System and Software Developments

NASA Astrophysics Data System (ADS)

Hiron, Emmanuel; Miramont, Philippe

2010-08-01

The purpose of this paper is to present the Astrium-ST engineering process based on SysML. This process is currently set-up in the frame of common CNES /Astrium-ST R&T studies related to the Ariane 5 electrical system and flight software modelling. The tool used to set up this process is Rhapsody release 7.3 from IBM-Software firm [1]. This process focuses on the system engineering phase dedicated to Software with the objective to generate both System documents (sequential system design and flight control) and Software specifications.

Robust integration schemes for junction-based modulators in a 200mm CMOS compatible silicon photonic platform (Conference Presentation)

NASA Astrophysics Data System (ADS)

Szelag, Bertrand; Abraham, Alexis; Brision, Stéphane; Gindre, Paul; Blampey, Benjamin; Myko, André; Olivier, Segolene; Kopp, Christophe

2017-05-01

Silicon photonic is becoming a reality for next generation communication system addressing the increasing needs of HPC (High Performance Computing) systems and datacenters. CMOS compatible photonic platforms are developed in many foundries integrating passive and active devices. The use of existing and qualified microelectronics process guarantees cost efficient and mature photonic technologies. Meanwhile, photonic devices have their own fabrication constraints, not similar to those of cmos devices, which can affect their performances. In this paper, we are addressing the integration of PN junction Mach Zehnder modulator in a 200mm CMOS compatible photonic platform. Implantation based device characteristics are impacted by many process variations among which screening layer thickness, dopant diffusion, implantation mask overlay. CMOS devices are generally quite robust with respect to these processes thanks to dedicated design rules. For photonic devices, the situation is different since, most of the time, doped areas must be carefully located within waveguides and CMOS solutions like self-alignment to the gate cannot be applied. In this work, we present different robust integration solutions for junction-based modulators. A simulation setup has been built in order to optimize of the process conditions. It consist in a Mathlab interface coupling process and device electro-optic simulators in order to run many iterations. Illustrations of modulator characteristic variations with process parameters are done using this simulation setup. Parameters under study are, for instance, X and Y direction lithography shifts, screening oxide and slab thicknesses. A robust process and design approach leading to a pn junction Mach Zehnder modulator insensitive to lithography misalignment is then proposed. Simulation results are compared with experimental datas. Indeed, various modulators have been fabricated with different process conditions and integration schemes. Extensive electro-optic characterization of these components will be presented.

Piezoelectric crystal microbalance measurements of enthalpy of sublimation of C2-C9 dicarboxylic acids

NASA Astrophysics Data System (ADS)

Dirri, F.; Palomba, E.; Longobardo, A.; Zampetti, E.

2015-07-01

We present here a novel experimental setup able to measure the enthalpy of sublimation of a given compound by means of Piezoelectric Crystal Microbalances (PCM). This experiment was performed in the TG-Lab facility in IAPS-INAF, dedicated to the development of TGA sensors for space measurements, such as detection of organic and non-organic volatile species and refractory materials in planetary environments. In order to study physical-chemical processes concerning the Volatile Organic Compounds (VOC) present in atmospheric environments, the setup has been tested on Dicarboxylic acids. Acids with low molecular weight are among the components of organic fraction of particulate matter in the atmosphere, coming from different sources (biogenic and anthropogenic). Considering their relative abundance, it is useful to consider Dicarboxylic acid as "markers" to define the biogenic or anthropogenic origin of the aerosol, thus obtaining some information of the emission sources. In this work, a temperature controlled effusion cell was used to sublimate VOC, creating a molecular flux that was collimated onto a cold PCM. The VOC re-condensed onto the PCM quartz crystal allowing the determination of the deposition rate. From the measurements of deposition rates, it was possible to infer the enthalpy of sublimation of Adipic acid, i.e. Δ Hsub: 141.6 ± 0.8 kJ mol-1, Succinic acid, i.e. 113.3 ± 1.3 kJ mol-1, Oxalic acid, i.e. 62.5 ± 3.1 kJ mol-1 and Azelaic acid, i.e. 124.2 ± 1.2 kJ mol-1 (weight average values). The results obtained are in very good agreement with literature within 10 % for the Adipic, Succinic and Oxalic acid.

[Testing the efficacy of disinfectants during drinking water treatment. A new experimental set-up at the German EPA (Umweltbundesamt - UBA)].

PubMed

Grützmacher, G; Bartel, H; Althoff, H W; Clemen, S

2007-03-01

A set-up for experiments in the flow-through mode was constructed in order to test the efficacy of substances used for disinfecting water during drinking water treatment. A flow-through mode - in contrast to experiments under stationary conditions (so-called batch experiments) - was chosen, because this experimental design allows experiments to be carried out under constant conditions for an extended time (up to one week) and because efficacy testing is possible repeatedly, simultaneously and under exactly the same conditions for short (about 0.5 min) and also longer (about 47 min) contact times. With this experimental design the effect of biofilms along the inner pipe surfaces can be included in the observations. The construction of the experimental set-up is based on experience with laboratory flow-through systems that were installed by the UBA's drinking water department (formerly Institute for Water-, Soil- and Air Hygiene (WaBoLu) Institute) for testing disinfection with chlorine. In the first step, a test pipe for the simulation of a water works situation was installed. Water of different qualities can be mixed in large volumes beforehand so that the experimental procedure can be run with constant water quality for a minimum of one week. The kinetics of the disinfection reaction can be observed by extracting samples from eight sampling ports situated along the test pipe. In order to assign exact residence times to each of the sampling ports, tracer experiments were performed prior to testing disinfectant efficacy. This paper gives the technical details of the experimental set-up and presents the results of the tracer experiments to provide an introduction with respect to its potential.

A novel coil array for combined TMS/fMRI experiments at 3 T

PubMed Central

Navarro de Lara, Lucia I.; Windischberger, Christian; Kuehne, Andre; Woletz, Michael; Sieg, Jürgen; Bestmann, Sven; Weiskopf, Nikolaus; Strasser, Bernhard; Moser, Ewald

2014-01-01

Purpose To overcome current limitations in combined transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) studies by employing a dedicated coil array design for 3 Tesla. Methods The state‐of‐the‐art setup for concurrent TMS/fMRI is to use a large birdcage head coil, with the TMS between the subject's head and the MR coil. This setup has drawbacks in sensitivity, positioning, and available imaging techniques. In this study, an ultraslim 7‐channel receive‐only coil array for 3 T, which can be placed between the subject's head and the TMS, is presented. Interactions between the devices are investigated and the performance of the new setup is evaluated in comparison to the state‐of‐the‐art setup. Results MR sensitivity obtained at the depth of the TMS stimulation is increased by a factor of five. Parallel imaging with an acceleration factor of two is feasible with low g‐factors. Possible interactions between TMS and the novel hardware were investigated and were found negligible. Conclusion The novel coil array is safe, strongly improves signal‐to‐noise ratio in concurrent TMS/fMRI experiments, enables parallel imaging, and allows for flexible positioning of the TMS on the head while ensuring efficient TMS stimulation due to its ultraslim design. Magn Reson Med 74:1492–1501, 2015. © 2014 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. PMID:25421603

Quantum Experiments and Graphs: Multiparty States as Coherent Superpositions of Perfect Matchings.

PubMed

Krenn, Mario; Gu, Xuemei; Zeilinger, Anton

2017-12-15

We show a surprising link between experimental setups to realize high-dimensional multipartite quantum states and graph theory. In these setups, the paths of photons are identified such that the photon-source information is never created. We find that each of these setups corresponds to an undirected graph, and every undirected graph corresponds to an experimental setup. Every term in the emerging quantum superposition corresponds to a perfect matching in the graph. Calculating the final quantum state is in the #P-complete complexity class, thus it cannot be done efficiently. To strengthen the link further, theorems from graph theory-such as Hall's marriage problem-are rephrased in the language of pair creation in quantum experiments. We show explicitly how this link allows one to answer questions about quantum experiments (such as which classes of entangled states can be created) with graph theoretical methods, and how to potentially simulate properties of graphs and networks with quantum experiments (such as critical exponents and phase transitions).

Quantum Experiments and Graphs: Multiparty States as Coherent Superpositions of Perfect Matchings

NASA Astrophysics Data System (ADS)

Krenn, Mario; Gu, Xuemei; Zeilinger, Anton

2017-12-01

We show a surprising link between experimental setups to realize high-dimensional multipartite quantum states and graph theory. In these setups, the paths of photons are identified such that the photon-source information is never created. We find that each of these setups corresponds to an undirected graph, and every undirected graph corresponds to an experimental setup. Every term in the emerging quantum superposition corresponds to a perfect matching in the graph. Calculating the final quantum state is in the #P-complete complexity class, thus it cannot be done efficiently. To strengthen the link further, theorems from graph theory—such as Hall's marriage problem—are rephrased in the language of pair creation in quantum experiments. We show explicitly how this link allows one to answer questions about quantum experiments (such as which classes of entangled states can be created) with graph theoretical methods, and how to potentially simulate properties of graphs and networks with quantum experiments (such as critical exponents and phase transitions).

Satellite assisted aerosol correlation in a sequestered CO2 leakage controlled site

NASA Astrophysics Data System (ADS)

Landulfo, Eduardo; da Silva Lopes, Fábio J.; Nakaema, Walter M.; de Medeiros, José A. G.; Moreira, Andrea

2014-10-01

Currently one of the main challenges in CO2 storage research is to grant the development, testing and validation of accurate and efficient Measuring, Monitoring and Verification (MMV) techniques to be deployed at the final storage site, targeting maximum storage efficiency at the minimal leakage risk levels. For such task a mimetic sequestration site has been deployed in Florianopolis, Brazil, in order to verify the performance of monitoring plataforms to detect and quantify leakages of ground injected CO2, namely a Cavity Ring Down System (CRDS) - Los Gatos Research - an Eddy Covariance System (Campbell Scientific and Irgason) and meteorological tower for wind, humidity, precipitation and temperature monitoring onsite. The measurement strategy for detecting CO2 leakages can be very challenging since environmental and phytogenic influence can be very severe and play a role on determining if the values measured are unambiguous or not. One external factor to be considered is the amount of incoming solar radiation which will be the driving force for the whole experimental setup and following this reasoning the amount of aerosols in the atmospheric column can be a determinant factor influencing the experimental results. Thus the investigation of measured fluxes CO2 and its concentration with the aforementioned experimental instruments and their correlation with the aerosol data should be taken into account by means of satellite borne systems dedicated to measure aerosol vertical distribution and its optical properties, in this study we have selected CALIPSO and MODIS instrumentation to help on deriving the aerosol properties and CO2 measurements.

Test measurement on ion-molecule reactions in a ringelectrode ion trap

NASA Astrophysics Data System (ADS)

Savic, I.; Lukic, S. R.; Guth, I.; Gerlich, D.

2006-05-01

Very recently a new experimental setup has been developed allowing studies of astrophysically relevant collisions between neutral atoms and small pure carbon molecules from one side and ions from the other side and first results are obtained (Savić et al., 2005). The ions are stored in a radio- frequency (rf) ring-electrode trap and during reaction time exposed to the effusive carbon beam. In this paper, one of the final tests of the experimental setup is presented.

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.

Preliminary Study of Realistic Blast Impact on Cultured Brain Slices

DTIC Science & Technology

2015-04-01

and/or multiple impacts in water. 3. Experimental Setup 3.1 The Aquarium Setup A 30.5-cm by 34.5- × 65-cm water-filled polymethylmethacrylate ...sodium bicarbonate PAGE polyacrylamide gel electrophoresis PMMA polymethylmethacrylate RDECOM U.S. Army Research Development and Engineering Command

Combination of thermal and electric properties' measurement techniques in a single setup suitable for radioactive materials in controlled environments and based on the 3ω approach

NASA Astrophysics Data System (ADS)

Shrestha, K.; Gofryk, K.

2018-04-01

We have designed and developed a new experimental setup, based on the 3ω method, to measure thermal conductivity, heat capacity, and electrical resistivity of a variety of samples in a broad temperature range (2-550 K) and under magnetic fields up to 9 T. The validity of this method is tested by measuring various types of metallic (copper, platinum, and constantan) and insulating (SiO2) materials, which have a wide range of thermal conductivity values (1-400 W m-1 K-1). We have successfully employed this technique for measuring the thermal conductivity of two actinide single crystals: uranium dioxide and uranium nitride. This new experimental approach for studying nuclear materials will help us to advance reactor fuel development and understanding. We have also shown that this experimental setup can be adapted to the Physical Property Measurement System (Quantum Design) environment and/or other cryocooler systems.

Performance of the Versatile Array of Neutron Detectors at Low Energy (VANDLE)

DOE PAGES

Peters, W. A.; Ilyushkin, S.; Madurga, M.; ...

2016-08-26

The Versatile Array of Neutron Detectors at Low Energy (VANDLE) is a new, highly efficient plastic-scintillator array constructed for decay and transfer reaction experimental setups that require neutron detection. The versatile and modular design allows for customizable experimental setups including beta-delayed neutron spectroscopy and (d,n) transfer reactions in normal and inverse kinematics. The neutron energy and prompt-photon discrimination is determined through the time of flight technique. Fully digital data acquisition electronics and integrated triggering logic enables some VANDLE modules to achieve an intrinsic efficiency over 70% for 300-keV neutrons, measured through two different methods. A custom Geant4 simulation models aspectsmore » of the detector array and the experimental setups to determine efficiency and detector response. Lastly, a low detection threshold, due to the trigger logic and digitizing data acquisition, allowed us to measure the light-yield response curve from elastically scattered carbon nuclei inside the scintillating plastic from incident neutrons with kinetic energies below 2 MeV.« less

Experimental setup for evaluating an adaptive user interface for teleoperation control

NASA Astrophysics Data System (ADS)

Wijayasinghe, Indika B.; Peetha, Srikanth; Abubakar, Shamsudeen; Saadatzi, Mohammad Nasser; Cremer, Sven; Popa, Dan O.

2017-05-01

A vital part of human interactions with a machine is the control interface, which single-handedly could define the user satisfaction and the efficiency of performing a task. This paper elaborates the implementation of an experimental setup to study an adaptive algorithm that can help the user better tele-operate the robot. The formulation of the adaptive interface and associate learning algorithms are general enough to apply when the mapping between the user controls and the robot actuators is complex and/or ambiguous. The method uses a genetic algorithm to find the optimal parameters that produce the input-output mapping for teleoperation control. In this paper, we describe the experimental setup and associated results that was used to validate the adaptive interface to a differential drive robot from two different input devices; a joystick, and a Myo gesture control armband. Results show that after the learning phase, the interface converges to an intuitive mapping that can help even inexperienced users drive the system to a goal location.

Simulation of vortex-induced vibrations of a cylinder using ANSYS CFX rigid body solver

NASA Astrophysics Data System (ADS)

Izhar, Abubakar; Qureshi, Arshad Hussain; Khushnood, Shahab

2017-03-01

This article simulates the vortex-induced oscillations of a rigid circular cylinder with elastic support using the new ANSYS CFX rigid body solver. This solver requires no solid mesh to setup FSI (Fluid Structure Interaction) simulation. The two-way case was setup in CFX only. Specific mass of the cylinder and flow conditions were similar to previous experimental data with mass damping parameter equal to 0.04, specific mass of 1 and Reynolds number of 3800. Two dimensional simulations were setup. Both one-degree-of-freedom and two-degree-of-freedom cases were run and results were obtained for both cases with reasonable accuracy as compared with experimental results. Eight-figure XY trajectory and lock-in behavior were clearly captured. The obtained results were satisfactory.

HoloNetwork: communicating science through holography

NASA Astrophysics Data System (ADS)

Pombo, Pedro; Santos, Emanuel; Magalhães, Carolina

2017-03-01

Since 1997 a program dedicated to holography has been developed and implemented in Portugal. This program started with focus on schools and science education. The HoloNetwork was created and it has been spread at a National level, involving a group of thirty schools and hundreds of students and teachers. In 2009 this network started to work to achieve a new target, the general public. With this goal, a larger program was developed with focus on science and society and on science communication through holography. For the implementation of this new program, special holography outreach activities were built, dedicated to informal learning and seven Science Centers around Portugal were add into the HoloNetwork. During last years, we have been working on holography, based on two main branches, one dedicated to schools and with the aimed to promote physics teaching and to teach how to make holograms, and another dedicated to society and with the aimed to promote holography and to increase scientific literacy. This paper would analyze the educational program, all holography outreach activities, exhibitions or events, all equipments, materials and setups used and it would present the holographic techniques explored with students or with the public. Finally, the results obtained in this work would be present and explored, with focus on students impact and outcomes, taking into account the public engagement on holography and its effect into scientific culture and analyzing the quality of holograms made by students and by the general public. subject.

SU-F-E-17: A Dedicated Teaching and Research Linac as a Stepping Stone to Introduce Medical Physics to Students

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

Beaulieu, L; Archambault, L; Universite Laval, Quebec, Quebec

Purpose: This work describes how a non-clinical, research and teaching Linac is used as an extremely motivating and exciting way to introduce students to medical physics. Methods: The dedicated facility was inaugurated in 2014. The facility is composed of a fully equipped and functional state-of-the-art Varian TrueBeam Linac and a complete set of physics instruments and QA phantoms for the Linac and onboard imaging. The Linac bunker and treatment console are oversized such that a class of 12–15 can comfortably fit, seated if needed for longer sessions. A 3cr undergraduate laboratory course that includes medical imaging, x-ray source characterization (mAs,more » kVp, and filtering) and many others including an introductory Linac laboratory was created. The latter is composed of one general 4-hours session and a weekly 4-hours session for teams of two students. The general session includes a hands-on presentation of the Linac, its environment and a formal safety and radiation protection course (with an exam). Results: Since the winter of 2015, senior undergraduate (total of 15) pursuing either the medical physics or the biomedical engineering tracks can register. At the Linac, the students are allowed full control of the experiments, including set-up and irradiation. Supervisor intervention is limited to safety concerns for students or equipment. Measurements of output factors using two chambers (regular and small field) for various field sizes (1×1 to 30×30 cm{sup 2}) and of detailed depth-dose curves for 6 MV, 6 and 12 MeV beams are to be performed and discussed in a formal report. Conclusion: Full access to, and control of, a Linac is the high point of this course. It provides a glimpse of medical physics and generates an experimental background for those continuing to CAMPEP programs. This dedicated, non-clinical facility further enable enhance CAMPEP graduate teaching and research activities not possible with a clinical device.« less

Quantitative impact of small angle forward scatter on whole blood oximetry using a Beer-Lambert absorbance model.

PubMed

LeBlanc, Serge Emile; Atanya, Monica; Burns, Kevin; Munger, Rejean

2011-04-21

It is well known that red blood cell scattering has an impact on whole blood oximetry as well as in vivo retinal oxygen saturation measurements. The goal of this study was to quantify the impact of small angle forward scatter on whole blood oximetry for scattering angles found in retinal oximetry light paths. Transmittance spectra of whole blood were measured in two different experimental setups: one that included small angle scatter in the transmitted signal and one that measured the transmitted signal only, at absorbance path lengths of 25, 50, 100, 250 and 500 µm. Oxygen saturation was determined by multiple linear regression in the 520-600 nm wavelength range and compared between path lengths and experimental setups. Mean calculated oxygen saturation differences between setups were greater than 10% at every absorbance path length. The deviations to the Beer-Lambert absorbance model had different spectral dependences between experimental setups, with the highest deviations found in the 520-540 nm range when scatter was added to the transmitted signal. These results are consistent with other models of forward scatter that predict different spectral dependences of the red blood cell scattering cross-section and haemoglobin extinction coefficients in this wavelength range.

Automatized set-up procedure for transcranial magnetic stimulation protocols.

PubMed

Harquel, S; Diard, J; Raffin, E; Passera, B; Dall'Igna, G; Marendaz, C; David, O; Chauvin, A

2017-06-01

Transcranial Magnetic Stimulation (TMS) established itself as a powerful technique for probing and treating the human brain. Major technological evolutions, such as neuronavigation and robotized systems, have continuously increased the spatial reliability and reproducibility of TMS, by minimizing the influence of human and experimental factors. However, there is still a lack of efficient set-up procedure, which prevents the automation of TMS protocols. For example, the set-up procedure for defining the stimulation intensity specific to each subject is classically done manually by experienced practitioners, by assessing the motor cortical excitability level over the motor hotspot (HS) of a targeted muscle. This is time-consuming and introduces experimental variability. Therefore, we developed a probabilistic Bayesian model (AutoHS) that automatically identifies the HS position. Using virtual and real experiments, we compared the efficacy of the manual and automated procedures. AutoHS appeared to be more reproducible, faster, and at least as reliable as classical manual procedures. By combining AutoHS with robotized TMS and automated motor threshold estimation methods, our approach constitutes the first fully automated set-up procedure for TMS protocols. The use of this procedure decreases inter-experimenter variability while facilitating the handling of TMS protocols used for research and clinical routine. Copyright © 2017 Elsevier Inc. All rights reserved.

Space Launch System Liftoff and Transition Aerodynamic Characterization in the NASA Langley 14- by 22-Foot Subsonic Wind Tunnel

NASA Technical Reports Server (NTRS)

Pinier, Jeremy T.; Erickson, Gary E.; Paulson, John W.; Tomek, William G.; Bennett, David W.; Blevins, John A.

2015-01-01

A 1.75% scale force and moment model of the Space Launch System was tested in the NASA Langley Research Center 14- by 22-Foot Subsonic Wind Tunnel to quantify the aerodynamic forces that will be experienced by the launch vehicle during its liftoff and transition to ascent flight. The test consisted of two parts: the first was dedicated to measuring forces and moments for the entire range of angles of attack (0deg to 90deg) and roll angles (0 deg. to 360 deg.). The second was designed to measure the aerodynamic effects of the liftoff tower on the launch vehicle for ground winds from all azimuthal directions (0 deg. to 360 deg.), and vehicle liftoff height ratios from 0 to 0.94. This wind tunnel model also included a set of 154 surface static pressure ports. Details on the experimental setup, and results from both parts of testing are presented, along with a description of how the wind tunnel data was analyzed and post-processed in order to develop an aerodynamic database. Finally, lessons learned from experiencing significant dynamics in the mid-range angles of attack due to steady asymmetric vortex shedding are presented.

A composite sensor array impedentiometric electronic tongue Part II. Discrimination of basic tastes.

PubMed

Pioggia, G; Di Francesco, F; Marchetti, A; Ferro, M; Leardi, R; Ahluwalia, A

2007-05-15

An impedentiometric electronic tongue based on the combination of a composite sensor array and chemometric techniques aimed at the discrimination of soluble compounds able to elicit different gustative perceptions is presented. A composite array consisting of chemo-sensitive layers based on carbon nanotubes or carbon black dispersed in polymeric matrices and doped polythiophenes was used. The electrical impedance of the sensor array was measured at a frequency of 150 Hz by means of an impedance meter. The experimental set-up was designed in order to allow the automatic selection of a test solution and dipping of the sensor array following a dedicated measurement protocol. Measurements were carried out on 15 different solutions eliciting 5 different tastes (sodium chloride, citric acid, glucose, glutamic acid and sodium dehydrocholate for salty, sour, sweet, umami and bitter, respectively) at 3 concentration levels comprising the human perceptive range. In order to avoid over-fitting, more than 100 repetitions for each sample were carried in a 4-month period. Principal component analysis (PCA) was used to detect and remove outliers. Classification was performed by linear discriminant analysis (LDA). A fairly good degree of discrimination was obtained.

Tests and foreseen developments of fibered-OSLD gamma heating measurements in low-power reactors

NASA Astrophysics Data System (ADS)

Gruel, A.; Guillou, M. Le; Blaise, P.; Destouches, C.; Magne, S.

2018-01-01

In this paper are presented test measurements of a fibered-OSLD system performed during a dedicated experimental phase in EOLE zero-power reactor. The measurement setup consists of an OSLD crystal connected onto the extremity of an optical fiber and a laser stimulation system, manufactured by the CEA/LIST in Saclay. The OSL sensor is remotely stimulated via an optical fiber using a diode-pumped solid-state laser. The OSL light is collected and guided back along the same fiber to a photomultiplier tube. Results obtained using this system are compared to usual gamma heating measurement protocol using OSLD pellets. The presence of induced radio-luminescence in the OSLD during the irradiation was also observed and could be used to monitor the gamma flux. The feasibility of remote measurements is achieved, whereas further developments could be conducted to improve this technique since the readout procedure still requires to withdraw the OSLD off the gamma flux (hence from the core) on account of the dose rate (around a few Gy.h-1), and the readout time remains quite long for on-line applications. Several improvements are foreseen, and will be tested in the forthcoming years.

A two-factor error model for quantitative steganalysis

NASA Astrophysics Data System (ADS)

Böhme, Rainer; Ker, Andrew D.

2006-02-01

Quantitative steganalysis refers to the exercise not only of detecting the presence of hidden stego messages in carrier objects, but also of estimating the secret message length. This problem is well studied, with many detectors proposed but only a sparse analysis of errors in the estimators. A deep understanding of the error model, however, is a fundamental requirement for the assessment and comparison of different detection methods. This paper presents a rationale for a two-factor model for sources of error in quantitative steganalysis, and shows evidence from a dedicated large-scale nested experimental set-up with a total of more than 200 million attacks. Apart from general findings about the distribution functions found in both classes of errors, their respective weight is determined, and implications for statistical hypothesis tests in benchmarking scenarios or regression analyses are demonstrated. The results are based on a rigorous comparison of five different detection methods under many different external conditions, such as size of the carrier, previous JPEG compression, and colour channel selection. We include analyses demonstrating the effects of local variance and cover saturation on the different sources of error, as well as presenting the case for a relative bias model for between-image error.

Drell-Yan measurement at COMPASS: a place to test the TMD PDFs universality

NASA Astrophysics Data System (ADS)

Andrieux, Vincent

2017-01-01

For the first time ever, the COMPASS experiment (CERN, SPS) collected in 2015 Drell-Yan (DY) data using a 190 GeV/ c pion beam on a transversely polarized NH3 target. The azimuthal modulations of the DY cross-section give access to the set of transverse momentum dependent (TMD) parton distribution functions (PDFs), which describe the spin structure of the nucleon. Those PDFs were already measured in semi-inclusive deep inelastic scattering (SIDIS) by several experiments and especially COMPASS, which dedicated several campaigns between 2002 and 2010 to measure spin (in)dependent azimuthal asymmetries using a 160 GeV/ c polarized muon beam on a transversely polarized 6LiD or NH3 target. A key interest of extracting those TMD PDFs from different processes is to check the universality and the process-dependent features of TMD PDFs. In this aim, COMPASS is a unique place to test the predicted sign-change of the TMD PDFs using a similar experimental setup and comparable kinematic domain. The main focus of this talk will be set on the physics aspects of the COMPASS polarized Drell-Yan program and related SIDIS results. on behalf of the COMPASS collaboration.

Real-time local experimental monitoring of the bleaching process.

PubMed

Rakic, Mario; Klaric, Eva; Sever, Ivan; Rakic, Iva Srut; Pichler, Goran; Tarle, Zrinka

2015-04-01

The purpose of this article was to investigate a new setup for tooth bleaching and monitoring of the same process in real time, so to prevent overbleaching and related sideeffects of the bleaching procedure. So far, known bleaching procedures cannot simultaneously monitor and perform the bleaching process or provide any local control over bleaching. The experimental setup was developed at the Institute of Physics, Zagreb. The setup consists of a camera, a controller, and optical fibers. The bleaching was performed with 25% hydrogen peroxide activated by ultraviolet light diodes, and the light for monitoring was emitted by white light diodes. The collected light was analyzed using a red-green-blue (RGB) index. A K-type thermocouple was used for temperature measurements. Pastilles made from hydroxylapatite powder as well as human teeth served as experimental objects. Optimal bleaching time substantially varied among differently stained specimens. To reach reference color (A1, Chromascop shade guide), measured as an RGB index, bleaching time for pastilles ranged from 8 to >20 min, whereas for teeth it ranged from 3.5 to >20 min. The reflected light intensity of each R, G, and B component at the end of bleaching process (after 20 min) had increased up to 56% of the baseline intensity. The presented experimental setup provides essential information about when to stop the bleaching process to achieve the desired optical results so that the bleaching process can be completely responsive to the characteristics of every individual, leading to more satisfying results.

Dedicated magnetic resonance imaging in the radiotherapy clinic.

PubMed

Karlsson, Mikael; Karlsson, Magnus G; Nyholm, Tufve; Amies, Christopher; Zackrisson, Björn

2009-06-01

To introduce a novel technology arrangement in an integrated environment and outline the logistics model needed to incorporate dedicated magnetic resonance (MR) imaging in the radiotherapy workflow. An initial attempt was made to analyze the value and feasibility of MR-only imaging compared to computed tomography (CT) imaging, testing the assumption that MR is a better choice for target and healthy tissue delineation in radiotherapy. A 1.5-T MR unit with a 70-cm-bore size was installed close to a linear accelerator, and a special trolley was developed for transporting patients who were fixated in advance between the MR unit and the accelerator. New MR-based workflow procedures were developed and evaluated. MR-only treatment planning has been facilitated, thus avoiding all registration errors between CT and MR scans, but several new aspects of MR imaging must be considered. Electron density information must be obtained by other methods. Generation of digitally reconstructed radiographs (DRR) for x-ray setup verification is not straight forward, and reliable corrections of geometrical distortions must be applied. The feasibility of MR imaging virtual simulation has been demonstrated, but a key challenge to overcome is correct determination of the skeleton, which is often needed for the traditional approach of beam modeling. The trolley solution allows for a highly precise setup for soft tissue tumors without the invasive handling of radiopaque markers. The new logistics model with an integrated MR unit is efficient and will allow for improved tumor definition and geometrical precision without a significant loss of dosimetric accuracy. The most significant development needed is improved bone imaging.

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.

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.

Cryptographic salting for security enhancement of double random phase encryption schemes

NASA Astrophysics Data System (ADS)

Velez Zea, Alejandro; Fredy Barrera, John; Torroba, Roberto

2017-10-01

Security in optical encryption techniques is a subject of great importance, especially in light of recent reports of successful attacks. We propose a new procedure to reinforce the ciphertexts generated in double random phase encrypting experimental setups. This ciphertext is protected by multiplexing with a ‘salt’ ciphertext coded with the same setup. We present an experimental implementation of the ‘salting’ technique. Thereafter, we analyze the resistance of the ‘salted’ ciphertext under some of the commonly known attacks reported in the literature, demonstrating the validity of our proposal.

Sub-barrier fusion cross section measurements with STELLA

NASA Astrophysics Data System (ADS)

Heine, M.; Courtin, S.; Fruet, G.; Jenkins, D. G.; Montanari, D.; Adsley, P.; Beck, C.; Della Negra, S.; Dené, P.; Haas, F.; Hammache, F.; Heitz, G.; Kirsebom, O. S.; Krauth, M.; Lesrel, J.; Meyer, A.; Morris, L.; Regan, P. H.; Richer, M.; Rudigier, M.; de Séréville, N.; Stodel, C.

2018-01-01

The experimental setup STELLA (STELlar LAboratory) is designed for the measurement of deep sub-barrier light heavy ion fusion cross sections. For background suppression the γ-particle coincidence technique is used. In this project, LaBr3 detectors from the UK FATIMA (FAst TIMing Array) collaboration are combined with annular silicon strip detectors customized at IPHC-CNRS, Strasbourg, and the setup is located at Andromède, IPN, Orsay. The commissioning of the experimental approach as well as a sub-barrier 12C +12C → 24Mg∗ cross section measurement campaign are carried out.

Experimental investigation of environment-induced entanglement using an all-optical setup

NASA Astrophysics Data System (ADS)

Passos, M. H. M.; Balthazar, W. F.; Khoury, A. Z.; Hor-Meyll, M.; Davidovich, L.; Huguenin, J. A. O.

2018-02-01

We investigate the generation of entanglement between two noninteracting qubits coupled to a common reservoir. An experimental setup was conceived to encode one qubit on the polarization of an optical beam and another qubit on its transverse mode. The action of the reservoir is implemented as conditional operations on these two qubits, controlled by the longitudinal path as an ancillary degree of freedom. An entanglement witness and the two-qubit concurrence are easily evaluated from direct intensity measurements showing an excellent agreement with the theoretical prediction.

Realization of optimized quantum controlled-logic gate based on the orbital angular momentum of light.

PubMed

Zeng, Qiang; Li, Tao; Song, Xinbing; Zhang, Xiangdong

2016-04-18

We propose and experimentally demonstrate an optimized setup to implement quantum controlled-NOT operation using polarization and orbital angular momentum qubits. This device is more adaptive to inputs with various polarizations, and can work both in classical and quantum single-photon regime. The logic operations performed by such a setup not only possess high stability and polarization-free character, they can also be easily extended to deal with multi-qubit input states. As an example, the experimental implementation of generalized three-qubit Toffoli gate has been presented.

First Results & Future Prospects for 30 GeV Gamma Rays from CELESTE

NASA Astrophysics Data System (ADS)

de Naurois, Mathieu

The CELESTE solar farm gamma-ray telescope detected the Crab Nebula at 80 GeV ( Hz) using 18 heliostats in 1998. In March 1999, observations began with a setup extended to 40 heliostats, and with upgraded electronics. Technical delays and bad weather only permitted a very small data set for the Crab nebula. hours of data were taken simultaneously with the CAT imaging telescope showing evidence for a gamma signal. In this talk the analysis method of these data is described. CELESTE has passed major milestones and the groundwork is laid for the blazar and pulsar studies presented elsewhere in this conference (OG 2.1.20, OG 2.2.31). DEDICATION : CELESTE is the brainchild of Eric Pare, who died at the age of 39 in an automobile accident, two weeks after finding our first gamma ray signal. Eric also played a major role in the conception and design of CAT. We dedicate this work to his memory.

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.

The Recommendations for Linear Measurement Techniques on the Measurements of Nonlinear System Parameters of a Joint.

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

Smith, Scott A; Catalfamo, Simone; Brake, Matthew R. W.

2017-01-01

In the study of the dynamics of nonlinear systems, experimental measurements often convolute the response of the nonlinearity of interest and the effects of the experimental setup. To reduce the influence of the experimental setup on the deduction of the parameters of the nonlinearity, the response of a mechanical joint is investigated under various experimental setups. These experiments first focus on quantifying how support structures and measurement techniques affect the natural frequency and damping of a linear system. The results indicate that support structures created from bungees have negligible influence on the system in terms of frequency and damping ratiomore » variations. The study then focuses on the effects of the excitation technique on the response for a linear system. The findings suggest that thinner stingers should not be used, because under the high force requirements the stinger bending modes are excited adding unwanted torsional coupling. The optimal configuration for testing the linear system is then applied to a nonlinear system in order to assess the robustness of the test configuration. Finally, recommendations are made for conducting experiments on nonlinear systems using conventional/linear testing techniques.« less

Clinical comparison of positional accuracy and stability between dedicated versus conventional masks for immobilization in cranial stereotactic radiotherapy using 6-degree-of-freedom image guidance system-integrated platform.

PubMed

Ohtakara, Kazuhiro; Hayashi, Shinya; Tanaka, Hidekazu; Hoshi, Hiroaki; Kitahara, Masashi; Matsuyama, Katsuya; Okada, Hitoshi

2012-02-01

To compare the positioning accuracy and stability of two distinct noninvasive immobilization devices, a dedicated (D-) and conventional (C-) mask, and to evaluate the applicability of a 6-degrees-of-freedom (6D) correction, especially to the C-mask, based on our initial experience with cranial stereotactic radiotherapy (SRT) using ExacTrac (ET)/Robotics integrated into the Novalis Tx platform. The D- and C-masks were the BrainLAB frameless mask system and a general thermoplastic mask used for conventional radiotherapy such as whole brain irradiation, respectively. A total of 148 fractions in 71 patients and 125 fractions in 20 patients were analyzed for the D- and C-masks, respectively. For the C-mask, 3D correction was applied to the initial 10 patients, and thereafter, 6D correction was adopted. The 6D residual errors (REs) in the initial setup, after correction (pre-treatment), and during post-treatment were measured and compared. The D-mask provided no significant benefit for initial setup. The post-treatment median 3D vector displacements (interquatile range) were 0.38 mm (0.22, 0.60) and 0.74 mm (0.49, 1.04) for the D- and C-masks, respectively (p<0.001). The post-treatment maximal translational REs were within 1 mm and 2 mm for the D- and C-masks, respectively, and notably within 1.5 mm for the C-mask with 6D correction. The pre-treatment 3D vector displacements were significantly correlated with those for post-treatment in both masks. The D-mask confers positional stability acceptable for SRT. For the C-mask, 6D correction is also recommended, and an additional setup margin of 0.5 mm to that for the D-mask would be sufficient. The tolerance levels for the pre-treatment REs should similarly be set as small as possible for both systems. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

A DNA Melting Exercise for a Large Laboratory Class

ERIC Educational Resources Information Center

Levine, Lauren A.; Junker, Matthew; Stark, Myranda; Greenleaf, Dustin

2015-01-01

A simple and economical experimental setup is described that enables multiple individuals or groups within a laboratory class to measure the thermal melting of double stranded DNA simultaneously. The setup utilizes a basic spectrophotometer capable of measuring absorbance at 260 nm, UV plastic cuvettes, and a stirring hot plate. Students measure…

Use of microstrip patch antennas in grain permittivity measurement

USGS Publications Warehouse

El Sabbagh, M.A.; Ramahi, O.M.; Trabelsi, S.; Nelson, S.O.; Khan, L.

2003-01-01

In this paper, a compact size free-space setup is proposed for the measurement of complex permittivity of granular materials. The horn antennas in the conventional setup are replaced by microstrip patch antennas which is a step toward system miniaturization. The experimental results obtained are in good agreement with those obtained with horn antennas.

Extended volume and surface scatterometer for optical characterization of 3D-printed elements

NASA Astrophysics Data System (ADS)

Dannenberg, Florian; Uebeler, Denise; Weiß, Jürgen; Pescoller, Lukas; Weyer, Cornelia; Hahlweg, Cornelius

2015-09-01

The use of 3d printing technology seems to be a promising way for low cost prototyping, not only of mechanical, but also of optical components or systems. It is especially useful in applications where customized equipment repeatedly is subject to immediate destruction, as in experimental detonics and the like. Due to the nature of the 3D-printing process, there is a certain inner texture and therefore inhomogeneous optical behaviour to be taken into account, which also indicates mechanical anisotropy. Recent investigations are dedicated to quantification of optical properties of such printed bodies and derivation of corresponding optimization strategies for the printing process. Beside mounting, alignment and illumination means, also refractive and reflective elements are subject to investigation. The proposed measurement methods are based on an imaging nearfield scatterometer for combined volume and surface scatter measurements as proposed in previous papers. In continuation of last year's paper on the use of near field imaging, which basically is a reflective shadowgraph method, for characterization of glossy surfaces like printed matter or laminated material, further developments are discussed. The device has been extended for observation of photoelasticity effects and therefore homogeneity of polarization behaviour. A refined experimental set-up is introduced. Variation of plane of focus and incident angle are used for separation of various the images of the layers of the surface under test, cross and parallel polarization techniques are applied. Practical examples from current research studies are included.

Imaging of spatial distributions of the millimeter wave intensity by using visible continuum radiation from a discharge in a Cs–Xe mixture. Part I: Review of the method and its fundamentals

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

Gitlin, M. S., E-mail: gitlin@appl.sci-nnov.ru

The first part of the review is presented which is dedicated to the time-resolved method of imaging and measuring the spatial distribution of the intensity of millimeter waves by using visible continuum (VC) emitted by the positive column (PC) of a dc discharge in a mixture of cesium vapor with xenon. The review focuses on the operating principles, fundamentals, and applications of this new technique. The design of the discharge tube and experimental setup used to create a wide homogeneous plasma slab with the help of the Cs–Xe discharge at a gas pressure of 45 Torr are described. The millimeter-wavemore » effects on the plasma slab are studied experimentally. The mechanism of microwave-induced variations in the VC brightness and the causes of violation of the local relation between the VC brightness and the intensity of millimeter waves are discussed. Experiments on the imaging of the field patterns of horn antennas and quasi-optical beams demonstrate that this technique can be used for good-quality imaging of millimeter-wave beams in the entire millimeter-wavelength band. The method has a microsecond temporal resolution and a spatial resolution of about 2 mm. Energy sensitivities of about 10 μJ/cm{sup 2} in the Ka-band and about 200 μJ/cm{sup 2} in the D-band have been demonstrated.« less

Blowing Snow Sublimation at a High Altitude Alpine Site and Effects on the Surface Boundary Layer

NASA Astrophysics Data System (ADS)

Vionnet, V.; Guyomarc'h, G.; Sicart, J. E.; Deliot, Y.; Naaim-Bouvet, F.; Bellot, H.; Merzisen, H.

2017-12-01

In alpine terrain, wind-induced snow transport strongly influences the spatial and temporal variability of the snow cover. During their transport, blown snow particles undergo sublimation with an intensity depending on atmospheric conditions (air temperature and humidity). The mass loss due to blowing snow sublimation is a source of uncertainty for the mass balance of the alpine snowpack. Additionally, blowing snow sublimation modifies humidity and temperature in the surface boundary layer. To better quantify these effects in alpine terrain, a dedicated measurement setup has been deployed at the experimental site of Col du Lac Blanc (2720 m a.s.l., French Alps, Cryobs-Clim network) since winter 2015/2016. It consists in three vertical masts measuring the near-surface vertical profiles (0.2-5 m) of wind speed, air temperature and humidity and blowing snow fluxes and size distribution. Observations collected during blowing snow events without concurrent snowfall show only a slight increase in relative humidity (10-20%) and near-surface saturation is never observed. Estimation of blowing snow sublimation rates are then obtained from these measurements. They range between 0 and 5 mmSWE day-1 for blowing snow events without snowfall in agreement with previous studies in different environments (North American prairies, Antarctica). Finally, an estimation of the mass loss due to blowing snow sublimation at our experimental site is proposed for two consecutive winters. Future use of the database collected in this study includes the evaluation of blowing snow models in alpine terrain.

Numerical and experimental study on the dynamics of a μs helium plasma gun with various amounts of O2 admixture

NASA Astrophysics Data System (ADS)

Viegas, Pedro; Damany, Xavier; Iseni, Sylvain; Pouvesle, Jean-Michel; Robert, Eric; Bourdon, Anne

2016-09-01

The use of admixtures (mostly O2 and N2) to a helium buffer has been studied recently to tailor the generation of reactive species in plasma jets for biomedical applications. So far, most experiments have been dedicated to the study of the plasma plume. For endoscopic treatments, it is also important to better understand and optimize the propagation of discharges in long dielectric tubes as catheters. In this work, we present an experimental and numerical study on the dynamics of a μs helium plasma discharge with O2 admixture in a long dielectric tube. In simulations, a 2D fluid model is used. For comparison purposes, the geometries of the set-ups used for simulations and experiments are as close as possible. We compare experiments and simulations for different amounts of O2 admixture added to the buffer gas and present results on the velocity of the discharge front for the various amounts of O2 and different applied voltages. In order to study the influence of different amounts of O2 admixture on the helium discharge dynamics, detailed kinetic schemes have been used. The influence of Penning and charge exchange reactions on the discharge structure and dynamics are studied, as well as the role of negative ions. P.V. is supported by an EDOM fellowship, and X.D. by an INEL/Region Centre-Val de Loire fellowship.

Advanced instrumentation and analysis methods for in-pile thermal and nuclear measurements: from out-of-pile studies to irradiation campaigns

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

Reynard-Carette, C.; Lyoussi, A.

Research and development on nuclear fuel behavior under irradiations and accelerated ageing of structure materials is a key issue for sustainable nuclear energy in order to meet specific needs by keeping the best level of safety. A new Material Testing Reactor (MTR), the Jules Horowitz Reactor (JHR) currently under construction in the South of France in the CEA Cadarache research centre will offer a real opportunity to perform R and D programs and hence will crucially contribute to the selection, optimization and qualification of innovative materials and fuels. To perform such programs advanced accurate and innovative experiments, irradiation devices thatmore » contain material and fuel samples are required to be set up inside or beside the reactor core. These experiments needs beforehand in situ and on line sophisticated measurements to accurately reach specific and determining parameters such as thermal and fast neutron fluxes, nuclear heating and temperature conditions to precisely monitor and control the conducted assays. Consequently, since 2009 CEA and Aix-Marseille University collaborate in order to design and develop a new multi-sensor device which will be dedicated to measuring profiles of such conditions inside the experimental channels of the JHR. These works are performed in the framework of two complementary joint research programs called MAHRI-BETHY and INCORE. These programs couple experimental studies carried out both out-of nuclear fluxes (in laboratory) and under irradiation conditions (in OSIRIS MTR reactor in France and MARIA MTR reactor in Poland) with numerical works realized by thermal simulations (CAST3M code) and Monte Carlo simulations (MCNP code). These programs deal with three main aims. The first one corresponds to the design and/or the test of new in-pile instrumentation. The second one concerns the development of advanced calibration procedures in particular in the case of one specific sensor: a differential calorimeter used to quantify nuclear heating. The last one consists in the development of accurate measurement and analysis methods. The paper will be dedicated to a complete review of the experimental and numerical works performed since 2009 thanks to two parts. The first part will detail a new thermal approach implemented to improve nuclear heating measurements by radiometric calorimeters. New experimental tools (calorimeter prototypes and set-ups such BETHY Bench) developed to perform preliminary out-of-pile studies under suitable conditions will be presented (temperature and velocity of the external cooling fluid, heat source localization and intensity inside the calorimetric cells). Then the response of two kinds of sensors, their calibrations curves and their thermal behaviors will be compared for various parameters. Finally validated numerical thermal and Monte Carlo works will be discussed to propose new improvements. The second parts of the paper will focus on works realized in order to design, develop and test the first prototype of the multi-sensor device called CARMEN [7-9]. The two mock-ups dedicated respectively to neutron measurements and photon measurements will be detailed. The results obtained during two irradiation campaigns inside the periphery of OSIRIS reactor will be shown. The new analysis method will be discussed. (authors)« less

Experimental Study of a Pulse Detonation Engine Driven Ejector

NASA Technical Reports Server (NTRS)

Santoro, Robert J.; Pal, Sibtosh; Shehadeh, R.; Saretto, S.; Lee, S.-Y.

2005-01-01

Results of an experimental effort on pulse detonation driven ejectors are presented and discussed. The experiments were conducted using a pulse detonation engine (PDE)/ejector setup that was specifically designed for the study. The results of various experiments designed to probe different aspects of the PDE/ejector setup are reported. The baseline PDE was operated using ethylene (C2H4) as the fuel and an oxygen/nitrogen (O2 + N2) mixture at an equivalence ratio of one. The PDE only experiments included propellant mixture characterization using a laser absorption technique, high fidelity thrust measurements using an integrated spring-damper system, and shadowgraph imaging of the detonation/shock wave structure emanating from the tube. The baseline PDE thrust measurement results are in excellent agreement with experimental and modeling results reported in the literature. These PDE setup results were then used as a basis for quantifying thrust augmentation for various PDE/ejector setups with constant diameter ejector tubes and various detonation tube/ejector tube overlap distances. The results show that for the geometries studied here, a maximum thrust augmentation of 24% is achieved. Further increases are possible by tailoring the ejector geometry based on CFD predictions conducted elsewhere. The thrust augmentation results are complemented by shadowgraph imaging of the flowfield in the ejector tube inlet area and high frequency pressure transducer measurements along the length of the ejector tube.

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

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.

High speed stereovision setup for position and motion estimation of fertilizer particles leaving a centrifugal spreader.

PubMed

Hijazi, Bilal; Cool, Simon; Vangeyte, Jürgen; Mertens, Koen C; Cointault, Frédéric; Paindavoine, Michel; Pieters, Jan G

2014-11-13

A 3D imaging technique using a high speed binocular stereovision system was developed in combination with corresponding image processing algorithms for accurate determination of the parameters of particles leaving the spinning disks of centrifugal fertilizer spreaders. Validation of the stereo-matching algorithm using a virtual 3D stereovision simulator indicated an error of less than 2 pixels for 90% of the particles. The setup was validated using the cylindrical spread pattern of an experimental spreader. A 2D correlation coefficient of 90% and a Relative Error of 27% was found between the experimental results and the (simulated) spread pattern obtained with the developed setup. In combination with a ballistic flight model, the developed image acquisition and processing algorithms can enable fast determination and evaluation of the spread pattern which can be used as a tool for spreader design and precise machine calibration.

A novel experimental setup for energy loss and charge state measurements in dense moderately coupled plasma using laser-heated hohlraum targets

NASA Astrophysics Data System (ADS)

Ortner, A.; Schumacher, D.; Cayzac, W.; Frank, A.; Basko, M. M.; Bedacht, S.; Blazevic, A.; Faik, S.; Kraus, D.; Rienecker, T.; Schaumann, G.; Tauschwitz, An.; Wagner, F.; Roth, M.

2016-03-01

We report on a new experimental setup for ion energy loss measurements in dense moderately coupled plasma which has recently been developed and tested at GSI Darmstadt. A partially ionized, moderately coupled carbon plasma (ne ≤ 0.8• 1022 cm-3, Te = 15 eV, z = 2.5, Γ = 0.5) is generated by volumetrical heating of two thin carbon foils with soft X-rays. This plasma is then probed by a bunched heavy ion beam. For that purpose, a special double gold hohlraum target of sub-millimeter size has been developed which efficiently converts intense laser light into thermal radiation and guarantees a gold-free interaction path for the ion beam traversing the carbon plasma. This setup allows to do precise energy loss measurements in non-ideal plasma at the level of 10 percent solid-state density.

Studies for a Dedicated B Detector at the Fermilab Collider

NASA Astrophysics Data System (ADS)

McBride, Patricia

1996-06-01

The observation of CP violation in the B system is one of the great experimental challenges of the next decade. Several B factories are already planned, however, there will be many interesting measurements awaiting a second generation of B exeriments. Studies are being carried out to design a dedicated collider B experiment for the Tevatron at Fermilab. A dedicated B detector at a hadron collider will have a physics reach beyond that of experiments scheduled to begin operation before the end of the decade.

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.

Development of an experimental setup for testing the properties of γ/γ' superalloys

NASA Astrophysics Data System (ADS)

Christophe, Siret; Bernard, Viguier; Claude, Salabura Jean; Eric, Andrieu; Sandrine, Lesterlin

2010-07-01

Certification tests on turboshaft engines for helicopters can expose components as high pressure turbine blades to very high temperature during short time periods. To simulate these complex temperature and mechanical stress loadings and to study dimensional and microstructural stability under severe testing conditions, an experimental set-up has been recently developed. In this paper, we first present this new device and describe its performances. Then, the device is used to study the effect of heating procedure on creep results at 1200°C and rafting during primary creep on the single crystal nickel-based superalloy MC2.

Millimeter- and submillimeter-wave characterization of various fabrics.

PubMed

Dunayevskiy, Ilya; Bortnik, Bartosz; Geary, Kevin; Lombardo, Russell; Jack, Michael; Fetterman, Harold

2007-08-20

Transmission measurements of 14 fabrics are presented in the millimeter-wave and submillimeter-wave electromagnetic regions from 130 GHz to 1.2 THz. Three independent sources and experimental set-ups were used to obtain accurate results over a wide spectral range. Reflectivity, a useful parameter for imaging applications, was also measured for a subset of samples in the submillimeter-wave regime along with polarization sensitivity of the transmitted beam and transmission through doubled layers. All of the measurements were performed in free space. Details of these experimental set-ups along with their respective challenges are presented.

COSY-11: an Experimental Facility for Studying Meson Production in Free and Quasi-free Nucleon-Nucleon Collisions

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

Klaja, P.; Janusz, M.; Jarczyk, L.

2005-10-26

The COSY-11 experimental setup is an internal facility installed at the COoler SYnchrotron COSY in Juelich. It allows to investigate meson production in free and quasi-free nucleon-nucleon collisions, eg. pp {yields} pp meson and pd {yields} pspnp meson reactions. Drift chambers and scintillators permit to measure outgoing protons, separated in the magnetic field of the COSY-11 dipole. Neutrons are registered in the neutron modular detector installed downstream from the target. Recently, the experimental setup has been extended with spectator detector, deuteron drift chamber and polarization monitoring system, and since then meson production can be investigated also as a function ofmore » spin and isospin of colliding nucleons.« less

Artificial cochlea and acoustic black hole travelling waves observation: Model and experimental results

NASA Astrophysics Data System (ADS)

Foucaud, Simon; Michon, Guilhem; Gourinat, Yves; Pelat, Adrien; Gautier, François

2014-07-01

An inhomogeneous fluid structure waveguide reproducing passive behaviour of the inner ear is modelled with the help of the Wentzel-Kramers-Brillouin method. A physical setup is designed and built. Experimental results are compared with a good correlation to theoretical ones. The experimental setup is a varying width plate immersed in fluid and terminated with an acoustic black hole. The varying width plate provides a spatial repartition of the vibration depending on the excitation frequency. The acoustic black hole is made by decreasing the plate's thickness with a quadratic profile and by covering this region with a thin film of viscoelastic material. Such a termination attenuates the flexural wave reflection at the end of the waveguide, turning standing waves into travelling waves.

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

Reliable measurement of E. coli single cell fluorescence distribution using a standard microscope set-up.

PubMed

Cortesi, Marilisa; Bandiera, Lucia; Pasini, Alice; Bevilacqua, Alessandro; Gherardi, Alessandro; Furini, Simone; Giordano, Emanuele

2017-01-01

Quantifying gene expression at single cell level is fundamental for the complete characterization of synthetic gene circuits, due to the significant impact of noise and inter-cellular variability on the system's functionality. Commercial set-ups that allow the acquisition of fluorescent signal at single cell level (flow cytometers or quantitative microscopes) are expensive apparatuses that are hardly affordable by small laboratories. A protocol that makes a standard optical microscope able to acquire quantitative, single cell, fluorescent data from a bacterial population transformed with synthetic gene circuitry is presented. Single cell fluorescence values, acquired with a microscope set-up and processed with custom-made software, are compared with results that were obtained with a flow cytometer in a bacterial population transformed with the same gene circuitry. The high correlation between data from the two experimental set-ups, with a correlation coefficient computed over the tested dynamic range > 0.99, proves that a standard optical microscope- when coupled with appropriate software for image processing- might be used for quantitative single-cell fluorescence measurements. The calibration of the set-up, together with its validation, is described. The experimental protocol described in this paper makes quantitative measurement of single cell fluorescence accessible to laboratories equipped with standard optical microscope set-ups. Our method allows for an affordable measurement/quantification of intercellular variability, whose better understanding of this phenomenon will improve our comprehension of cellular behaviors and the design of synthetic gene circuits. All the required software is freely available to the synthetic biology community (MUSIQ Microscope flUorescence SIngle cell Quantification).

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

Commissioning of the BRIKEN beta-delayed neutron detector for the study of exotic neutron-rich nuclei

NASA Astrophysics Data System (ADS)

Tolosa-Delgado, A.; Agramunt, J.; Ahn, D. S.; Algora, A.; Baba, H.; Bae, S.; Brewer, N. T.; Caballero Folch, R.; Calvino, F.; Coleman-Smith, P. J.; Cortes, G.; Davinson, T.; Dillmann, I.; Domingo-Pardo, C.; Estrade, A.; Fukuda, N.; Go, S.; Griffin, C. J.; Grzywacz, R.; Ha, J.; Hall, O.; Harkness-Brennan, L.; Isobe, T.; Kahl, D.; Kiss, G. G.; Kogimtzis, M.; Kubono, S.; Labiche, M.; Lazarus, I.; Lee, J.; Liu, J.; Lorusso, G.; Matsui, K.; Miernik, K.; Montes, F.; Moon, B.; Morales, A. I.; Nepal, N.; Nishimura, S.; Page, R. D.; Phong, V. H.; Podolyak, Z.; Pucknell, V. F. E.; Rasco, B. C.; Regan, P.; Riego, A.; Rubio, B.; Rykaczewski, K. P.; Saito, Y.; Sakurai, H.; Shimizu, Y.; Simpson, J.; Söderström, P.-A.; Stracener, D. W.; Sumikama, T.; Suzuki, H.; Tain, J. L.; Takechi, M.; Takeda, H.; Tarifeño-Saldivia, A.; Thomas, S. L.; Woods, P.

2018-01-01

The commissioning of a new setup for β-delayed neutron measurements was carried out successfully in November-2016, at the RIKEN Nishina Center in Japan. The β-decay half-lives and Pn branching ratios of several isotopes in the 78Ni region were measured. Details of the experimental setup and the first results are given.

Quantitative comparisons of analogue models of brittle wedge dynamics

NASA Astrophysics Data System (ADS)

Schreurs, Guido

2010-05-01

Analogue model experiments are widely used to gain insights into the evolution of geological structures. In this study, we present a direct comparison of experimental results of 14 analogue modelling laboratories using prescribed set-ups. A quantitative analysis of the results will document the variability among models and will allow an appraisal of reproducibility and limits of interpretation. This has direct implications for comparisons between structures in analogue models and natural field examples. All laboratories used the same frictional analogue materials (quartz and corundum sand) and prescribed model-building techniques (sieving and levelling). Although each laboratory used its own experimental apparatus, the same type of self-adhesive foil was used to cover the base and all the walls of the experimental apparatus in order to guarantee identical boundary conditions (i.e. identical shear stresses at the base and walls). Three experimental set-ups using only brittle frictional materials were examined. In each of the three set-ups the model was shortened by a vertical wall, which moved with respect to the fixed base and the three remaining sidewalls. The minimum width of the model (dimension parallel to mobile wall) was also prescribed. In the first experimental set-up, a quartz sand wedge with a surface slope of ˜20° was pushed by a mobile wall. All models conformed to the critical taper theory, maintained a stable surface slope and did not show internal deformation. In the next two experimental set-ups, a horizontal sand pack consisting of alternating quartz sand and corundum sand layers was shortened from one side by the mobile wall. In one of the set-ups a thin rigid sheet covered part of the model base and was attached to the mobile wall (i.e. a basal velocity discontinuity distant from the mobile wall). In the other set-up a basal rigid sheet was absent and the basal velocity discontinuity was located at the mobile wall. In both types of experiments, models accommodated initial shortening by a forward- and a backward-verging thrust. Further shortening was taken up by in-sequence formation of forward-verging thrusts. In all experiments, boundary stresses created significant drag of structures along the sidewalls. We therefore compared the surface slope and the location, dip angle and spacing of thrusts in sections through the central part of the model. All models show very similar cross-sectional evolutions demonstrating reproducibility of first-order experimental observations. Nevertheless, there are significant along-strike variations of structures in map view highlighting the limits of interpretations of analogue model results. These variations may be related to the human factor, differences in model width and/or differences in laboratory temperature and especially humidity affecting the mechanical properties of the granular materials. GeoMod2008 Analogue Team: Susanne Buiter, Caroline Burberry, Jean-Paul Callot, Cristian Cavozzi, Mariano Cerca, Ernesto Cristallini, Alexander Cruden, Jian-Hong Chen, Leonardo Cruz, Jean-Marc Daniel, Victor H. Garcia, Caroline Gomes, Céline Grall, Cecilia Guzmán, Triyani Nur Hidayah, George Hilley, Chia-Yu Lu, Matthias Klinkmüller, Hemin Koyi, Jenny Macauley, Bertrand Maillot, Catherine Meriaux, Faramarz Nilfouroushan, Chang-Chih Pan, Daniel Pillot, Rodrigo Portillo, Matthias Rosenau, Wouter P. Schellart, Roy Schlische, Andy Take, Bruno Vendeville, Matteo Vettori, M. Vergnaud, Shih-Hsien Wang, Martha Withjack, Daniel Yagupsky, Yasuhiro Yamada

Optimization and development of solar power system under diffused sunlight condition in rural areas with supercapacitor integration

NASA Astrophysics Data System (ADS)

Castelino, Roystan V.; Jana, Suman; Kumhar, Rajesh; Singh, Niraj K.

2018-04-01

The simulation and hardware based experiment in this presented paper shows a possibility of increasing the reliability of solar power under diffused condition by using super capacitor module. This experimental setup can be used in those areas where the sun light is intermittent and under the diffused radiation condition. Due to diffused radiation, solar PV cells operate very poorly, but by using this setup the power efficiency can be increased greatly. Sometimes dependent numerical models are used to measure the voltage and current response of the hardware setup in MATLAB Simulink based environment. To convert the scattered solar radiation to electricity using the conventional solar PV module, batteries have to be linked with the rapid charging or discharging device like super capacitor module. The conventional method consists of a charging circuit, which dumps the power if the voltage is below certain voltage level, but this circuit utilizes the entire power even if the voltage is low under diffused sun light conditions. There is no power dumped in this circuit. The efficiency and viability of this labscale experimental setup can be examined with further experiment and industrial model.

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

Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector

NASA Technical Reports Server (NTRS)

Santoro, Robert J.; Pal, Sibtosh

2005-01-01

Results of an experimental effort on pulse detonation driven ejectors are presented and discussed. The experiments were conducted using a pulse detonation engine (PDE)/ejector setup that was specifically designed for the study and operated at frequencies up to 50 Hz. The results of various experiments designed to probe different aspects of the PDE/ejector setup are reported. The baseline PDE was operated using ethylene (C2H4) as the fuel and an oxygen/nitrogen O2 + N2) mixture at an equivalence ratio of one. The PDE only experiments included propellant mixture characterization using a laser absorption technique, high fidelity thrust measurements using an integrated spring-damper system, and shadowgraph imaging of the detonation/shock wave structure emanating from the tube. The baseline PDE thrust measurement results at each desired frequency agree with experimental and modeling results reported in the literature. These PDE setup results were then used as a basis for quantifying thrust augmentation for various PDE/ejector setups with constant diameter ejector tubes and various ejector lengths, the radius of curvature for the ejector inlets and various detonation tube/ejector tube overlap distances. For the studied experimental matrix, the results showed a maximum thrust augmentation of 106% at an operational frequency of 30 Hz. The thrust augmentation results are complemented by shadowgraph imaging of the flowfield in the ejector tube inlet area and high frequency pressure transducer measurements along the length of the ejector tube.

Introducing an experimental split-cylinder to study flows with geophysical interest: First steps and first results

NASA Astrophysics Data System (ADS)

Rodriguez-Garcia, Jesus O.; Burguete, Javier

2017-11-01

A new experimental setup has been developed in order to study rotating flows. Our research is derived from the experiments carried out in our group relating to this kind of flows, and the setup is inspired by the simulations performed by Lopez & Gutierrez-Castillo using a split-cylinder flow. In their work they study the different bifurcations taking place into the flow, among others, finding inertial waves in different configurations of the movement of the split-cylinder. Our setup consists in a split-cylinder in which each half can move in co-rotation or in counter-rotation. Moreover, we can set the rotation velocity of each half independently in order to study these different configurations of the flow. The aspect ratio defined as Γ = H / R can be modified, where H is the internal length of the cylinder and R is its radius. With this setup, we study the flow developed inside the split-cylinder depending on the Reynolds number like the different symmetry-breaking that should appear according to Lopez & Gutierrez-Castillo. To obtain the experimental data we use both laser Doppler velocimetry (LDV) and particle image velocimetry (PIV) techniques. The firsts results got are in the co-rotation case rotating one half faster than the other. We acknowledge support from Spanish Government Grant FIS 2014-54101-P. Jesús O. Rodríguez-García acknowledge research Grant from Asociación de Amigos de la Universidad de Navarra.

Study of materials for space processing

NASA Technical Reports Server (NTRS)

Lal, R. B.

1975-01-01

Materials were selected for device applications and their commercial use. Experimental arrangements were also made for electrical characterization of single crystals using electrical resistivity and Hall effect measurements. The experimental set-up was tested with some standard samples.

Experimental investigation of all-optical packet-level time slot assignment using two optical buffers cascaded.

PubMed

Sheng, Xinzhi; Feng, Zhen; Li, Bing

2013-04-20

We proposed and experimentally demonstrated all-optical packet-level time slot assignment scheme with two optical buffers cascaded. The function of time-slot interchange (TSI) was successfully implemented on two and three optical packets at a data rate of 10 Gb/s. Therefore, the functions of TSI on N packets should be implemented easily by the use of N-1 stage optical buffer. On the basis of the above experiment, we carried out the TSI experiment on four packets with the same two-stage experimental setup. Furthermore, packets compression on three optical packets was also carried out with the same experimental setup. The shortest guard time of the packets compression can reach to 13 ns due to the limit of FPGA's control accuracy. Due to the use of the same optical buffer, the proposed scheme has the advantages of simple and scalable configuration, modularization, and easy integration.

Experimental demonstration of the anti-maser

NASA Astrophysics Data System (ADS)

Mazzocco, Anthony; Aviles, Michael; Andrews, Jim; Dawson, Nathan; Crescimanno, Michael

2012-10-01

We denote by ``anti-maser'' a coherent perfect absorption (CPA) process in the radio frequency domain. We demonstrate several experimental realizations of the anti-maser suitable for an advanced undergraduate laboratory. Students designed, assembled and tested these devices, as well as the inexpensive laboratory setup and experimental protocol for displaying various CPA phenomenon.

UFO-a multi-analyser option for IN12

NASA Astrophysics Data System (ADS)

Schmidt, Wolfgang; Rheinstädter, Maikel C.; Raymond, Stephane; Ohl, Michael

2004-07-01

The IN12 instrument is operated by FZ Jülich in collaboration with CEA Grenoble as a CRG-B instrument at the Institut Laue Langevin in Grenoble. As a three-axis spectrometer for cold neutrons it is dedicated for high-resolution studies of low-energy excitations. In the past years the instrument has been continuously improved and it has demonstrated its excellent performance for neutron scattering research. To meet further challenges as a state-of-the-art instrument in the next funding period we will propose to upgrade IN12 with a multi-analyser option similar to planned or existing RITA-type instruments. IN12 will then be optionally equipped with an array of individual analyser blades which can be positioned separately in order to map the scattered beam on a user-chosen path in (Q,ω)-space. We refer to this set-up as IN12-UFO (universal focusing option). Both, the feasibility and the scientific case are currently being studied. On the conference we will show details of the planned instrumental set-up and demonstrate its flexibility and multiplex advantages for specific physical applications.

Experimental tests of coherence and entanglement conservation under unitary evolutions

NASA Astrophysics Data System (ADS)

Černoch, Antonín; Bartkiewicz, Karol; Lemr, Karel; Soubusta, Jan

2018-04-01

We experimentally demonstrate the migration of coherence between composite quantum systems and their subsystems. The quantum systems are implemented using polarization states of photons in two experimental setups. The first setup is based on a linear optical controlled-phase quantum gate and the second scheme utilizes effects of nonlinear optics. Our experiment allows one to verify the relation between correlations of the subsystems and the coherence of the composite system, which was given in terms of a conservation law for maximal accessible coherence by Svozilík et al. [J. Svozilík et al., Phys. Rev. Lett. 115, 220501 (2015), 10.1103/PhysRevLett.115.220501]. We observe that the maximal accessible coherence is conserved for the implemented class of global evolutions of the composite system.

Experimental study of the density of the helium-nitrogen gas system at low temperatures.

NASA Astrophysics Data System (ADS)

Milyutin, V. A.

2017-11-01

At the Department of TOT, an experimental setup was created to measure the density of a binary gas system from 100 to 300 K and pressures up to 16 MPa and with any mixture compositions. Experimental density for the helium-nitrogen system were determined by the piezometer of constant volume method. The amount of substance in the piezometer was measured by volumetric method. In this setup, the mixture of He - N2 was prepared in a special mixer for a series of p-v-T experiments, the concentration was determined by calculation using the equations of state of pure components. In the experiment, mixtures were prepared with molar concentrations, lying close to the range: 0.2, 0.4, 0.6 and 0.8.

Layout and first results of the nanotomography endstation at the P05 beamline at PETRA III

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

Ogurreck, M.; Greving, I.; Beckmann, F.

The Helmholtz-Zentrum Geesthacht operates the P05 Imaging Beamline at the DESY storage ring PETRA III. This beamline is dedicated to micro- and nanotomography with two endstations. This paper will present the nanotomography endstation layout and first results obtained from commissioning and test experiments. First tests have been performed with CRLs as X-ray objectives and newly developed rolled X-ray prism lenses as condenser optics. This setup allows a resolution of 100 nm half period with an effective detector pixel size of 15nm. A first tomograph of a photonic glass sample was measured in early 2014.

Coherent tools for physics-based simulation and characterization of noise in semiconductor devices oriented to nonlinear microwave circuit CAD

NASA Astrophysics Data System (ADS)

Riah, Zoheir; Sommet, Raphael; Nallatamby, Jean C.; Prigent, Michel; Obregon, Juan

2004-05-01

We present in this paper a set of coherent tools for noise characterization and physics-based analysis of noise in semiconductor devices. This noise toolbox relies on a low frequency noise measurement setup with special high current capabilities thanks to an accurate and original calibration. It relies also on a simulation tool based on the drift diffusion equations and the linear perturbation theory, associated with the Green's function technique. This physics-based noise simulator has been implemented successfully in the Scilab environment and is specifically dedicated to HBTs. Some results are given and compared to those existing in the literature.

236U measurement with accelerator mass spectrometry at CIAE

NASA Astrophysics Data System (ADS)

Wang, Xianggao; Jiang, Shan; He, Ming; Dong, Kejun; Wang, Wei; Li, Chaoli; He, Guozhu; Li, Shizhuo; Gong, Jie; Lu, Liyuan; Wu, Shaoyong

2010-07-01

236U is a long-lived radioactive isotope which is produced principally by thermal neutron capture on 235U. 236U may be potentially applied in geological research and nuclear safeguards. Accelerator mass spectrometry is presently the most sensitive technique for the measurement of 236U and a measurement method for long-lived heavy ion 236U has been developed. The set-up uses a dedicated injector and the newly proposed 208Pb 16O2- molecular ions for the simulation of 236U ion transport. A sensitivity of lower than 10 -10 has been achieved for the isotopic ratio 236U/ 238U in present work.

Maximizing neotissue growth kinetics in a perfusion bioreactor: An in silico strategy using model reduction and Bayesian optimization.

PubMed

Mehrian, Mohammad; Guyot, Yann; Papantoniou, Ioannis; Olofsson, Simon; Sonnaert, Maarten; Misener, Ruth; Geris, Liesbet

2018-03-01

In regenerative medicine, computer models describing bioreactor processes can assist in designing optimal process conditions leading to robust and economically viable products. In this study, we started from a (3D) mechanistic model describing the growth of neotissue, comprised of cells, and extracellular matrix, in a perfusion bioreactor set-up influenced by the scaffold geometry, flow-induced shear stress, and a number of metabolic factors. Subsequently, we applied model reduction by reformulating the problem from a set of partial differential equations into a set of ordinary differential equations. Comparing the reduced model results to the mechanistic model results and to dedicated experimental results assesses the reduction step quality. The obtained homogenized model is 10 5 fold faster than the 3D version, allowing the application of rigorous optimization techniques. Bayesian optimization was applied to find the medium refreshment regime in terms of frequency and percentage of medium replaced that would maximize neotissue growth kinetics during 21 days of culture. The simulation results indicated that maximum neotissue growth will occur for a high frequency and medium replacement percentage, a finding that is corroborated by reports in the literature. This study demonstrates an in silico strategy for bioprocess optimization paying particular attention to the reduction of the associated computational cost. © 2017 Wiley Periodicals, Inc.

Photovoltaic-Model-Based Solar Irradiance Estimators: Performance Comparison and Application to Maximum Power Forecasting

NASA Astrophysics Data System (ADS)

Scolari, Enrica; Sossan, Fabrizio; Paolone, Mario

2018-01-01

Due to the increasing proportion of distributed photovoltaic (PV) production in the generation mix, the knowledge of the PV generation capacity has become a key factor. In this work, we propose to compute the PV plant maximum power starting from the indirectly-estimated irradiance. Three estimators are compared in terms of i) ability to compute the PV plant maximum power, ii) bandwidth and iii) robustness against measurements noise. The approaches rely on measurements of the DC voltage, current, and cell temperature and on a model of the PV array. We show that the considered methods can accurately reconstruct the PV maximum generation even during curtailment periods, i.e. when the measured PV power is not representative of the maximum potential of the PV array. Performance evaluation is carried out by using a dedicated experimental setup on a 14.3 kWp rooftop PV installation. Results also proved that the analyzed methods can outperform pyranometer-based estimations, with a less complex sensing system. We show how the obtained PV maximum power values can be applied to train time series-based solar maximum power forecasting techniques. This is beneficial when the measured power values, commonly used as training, are not representative of the maximum PV potential.

The High Energy Materials Science Beamline (HEMS) at PETRA III

NASA Astrophysics Data System (ADS)

Schell, Norbert; King, Andrew; Beckmann, Felix; Ruhnau, Hans-Ulrich; Kirchhof, René; Kiehn, Rüdiger; Müller, Martin; Schreyer, Andreas

2010-06-01

The HEMS Beamline at the German high-brilliance synchrotron radiation storage ring PETRA III is fully tunable between 30 and 250 keV and optimized for sub-micrometer focusing. Approximately 70 % of the beamtime will be dedicated to Materials Research. Fundamental research will encompass metallurgy, physics and chemistry with first experiments planned for the investigation of the relationship between macroscopic and micro-structural properties of polycrystalline materials, grain-grain-interactions, and the development of smart materials or processes. For this purpose a 3D-microsctructure-mapper has been designed. Applied research for manufacturing process optimization will benefit from high flux in combination with ultra-fast detector systems allowing complex and highly dynamic in-situ studies of micro-structural transformations, e.g. during welding processes. The beamline infrastructure allows accommodation of large and heavy user provided equipment. Experiments targeting the industrial user community will be based on well established techniques with standardized evaluation, allowing full service measurements, e.g. for tomography and texture determination. The beamline consists of a five meter in-vacuum undulator, a general optics hutch, an in-house test facility and three independent experimental hutches working alternately, plus additional set-up and storage space for long-term experiments. HEMS is under commissioning as one of the first beamlines running at PETRA III.

Bessel beams with spatial oscillating polarization

PubMed Central

Fu, Shiyao; Zhang, Shikun; Gao, Chunqing

2016-01-01

Bessel beams are widely used in optical metrology mainly because of their large Rayleigh range (focal length). Radial/azimuthal polarization of such beams is of interest in the fields of material processing, plasma absorption or communication. In this paper an experimental set-up is presented, which generates a Bessel-type vector beam with a spatial polarization, oscillating along the optical axis, when propagating in free space. A first holographic axicon (HA) HA1 produces a normal, linearly polarized Bessel beam, which by a second HA2 is converted into the spatial oscillating polarized beam. The theory is briefly discussed, the set-up and the experimental results are presented in detail. PMID:27488174

Real-cinematographic visualization of droplet ejection in thermal ink jets

NASA Astrophysics Data System (ADS)

Rembe, Christian; Patzer, Joachim; Hofer, Eberhard P.; Krehl, Peter

1996-03-01

Although thermal ink jet printers have gained a high market share there are still open questions left in the understanding of the processes in ink jet firing chambers. The experimental investigation of these processes is difficult due to the extremely short time durations of the different phenomena. For example, the bubble life time amounts to approximately 20 microsecond(s) . A new experimental set-up is presented to record phenomena of very short time duration like the bubble nucleation process and the beginning of droplet ejection. This set-up allows realcinematographic visualization with a local resolution of less than 1 micrometers and a time resolution of 10 ns. This also offers the possibility to investigate transient processes like the droplet ejection at high printing frequencies. The essential part of the set-up is a new high speed camera. With an exact evaluation of the digitized images the locus, velocity, and acceleration distributions of the phase interface from liquid to vapor/air can be measured. In addition the results of a numerical model with realistic geometry of the firing chamber and the nozzle have been compared with the experimental results to draw conclusions for pressure propagation in the vapor bubble.

Quasi-isentropic compressibility of a strongly nonideal deuterium plasma at pressures of up to 5500 GPa: Nonideality and degeneracy effects

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

Mochalov, M. A., E-mail: postmaster@ifv.vniief.ru; Il’kaev, R. I.; Fortov, V. E.

We report on the experimental results on the quasi-isentropic compressibility of a strongly nonideal deuterium plasma that have been obtained on setups of cylindrical and spherical geometries in the pressure range of up to P ≈ 5500 GPa. We describe the characteristics of experimental setups, as well as the methods for the diagnostics and interpretation of the experimental results. The trajectory of metal shells that compress the deuterium plasma was detected using powerful pulsed X-ray sources with a maximal electron energy of up to 60 MeV. The values of the plasma density, which varied from ρ ≈ 0.8 g/cm{sup 3}more » to ρ ≈ 6 g/cm{sup 3}, which corresponds to pressure P ≈ 5500 GPa (55 Mbar), were determined from the measured value of the shell radius at the instant that it was stopped. The pressure of the compressed plasma was determined using gasdynamic calculations taking into account the actual characteristics of the experimental setups. We have obtained a strongly compressed deuterium plasma in which electron degeneracy effects under the conditions of strong interparticle interaction are significant. The experimental results have been compared with the theoretical models of a strongly nonideal partly degenerate plasma. We have obtained experimental confirmation of the plasma phase transition in the pressure range near 150 GPa (1.5 Mbar), which is in keeping with the conclusion concerning anomaly in the compressibility of the deuterium plasma drawn in [1].« less

Dosimetric challenges of small animal irradiation with a commercial X-ray unit.

PubMed

Kuess, Peter; Bozsaky, Eva; Hopfgartner, Johannes; Seifritz, Gerhard; Dörr, Wolfgang; Georg, Dietmar

2014-12-01

A commercial X-ray unit was recently installed at the Medical University Vienna for partial and whole body irradiation of small experimental animals. For 200 kV X-rays the dose deviations with respect to the reference dose measured in the geometrical center of the potential available field size was investigated for various experimental setup plates used for mouse irradiations. Furthermore, the HVL was measured in mm Al and mm Cu at 200 kV for two types of filtration. Three different setup constructions for small animal irradiation were dosimetrically characterized, covering field sizes from 9×20 mm2 to 210×200 mm2. Different types of detectors were investigated. Additionally LiF:MG,Ti TLD chips were used for mouse in-vivo dosimetry. The use of an additional 0.5 mm Cu filter reduced the deviation of the dose between each irradiation position on the setup plates. Multiple animals were irradiated at the same time using an individual setup plate for each experimental purpose. The dose deviations of each irradiation position to the center was measured to be ±4% or better. The depth dose curve measured in a solid water phantom was more pronounced for smaller field sizes. The comparison between estimated dose and measured dose in a PMMA phantom regarding the dose decline yielded in a difference of 3.9% at 20 mm depth. In-vivo measurements in a mouse snouts irradiation model confirmed the reference dosimetry, accomplished in PMMA phantoms, in terms of administered dose and deviation within different points of measurement. The outlined experiments dealt with a wide variety of dosimetric challenges during the installation of a new X-ray unit in the laboratory. The depth dose profiles measured for different field sizes were in good agreement with literature data. Different field sizes and spatial arrangement of the animals (depending on each purpose) provide additional challenges for the dosimetric measurements. Thorough dosimetric commissioning has to be performed before a new experimental setup is approved for biological experiments. Copyright © 2014. Published by Elsevier GmbH.

Follow-up of bone lesions in an experimental multiple myeloma mouse model: description of an in vivo technique using radiography dedicated for mammography.

PubMed Central

Vanderkerken, K.; Goes, E.; De Raeve, H.; Radl, J.; Van Camp, B.

1996-01-01

The evolution of bone lesions in transplantable C57BL/KaLwRjj 5T mouse myeloma (MM) has been followed in vivo. Mice were anaesthetised and a radiograph of the pelvis and hind legs was performed by a radiograph dedicated for mammography. This is the first description of an in vivo technique under experimental conditions whereby the development of bone lesions owing to the MM growth was demonstrated. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 PMID:8664113

Application of Controlled Shear Stresses on the Erythrocyte Membrane as a New Approach to Promote Molecule Encapsulation.

PubMed

Casagrande, Giustina; Arienti, Flavio; Mazzocchi, Arabella; Taverna, Francesca; Ravagnani, Fernando; Costantino, MariaLaura

2016-10-01

Human red blood cells (RBCs) have a remarkable capacity to undergo reversible membrane swelling. Resealed erythrocytes have been proposed as carriers and bioreactors to be used in the treatment of various diseases. This work is aimed at developing a setup allowing the encapsulation of test molecules into erythrocytes by inducing reversible pore formation on the RBC membrane through the application of controlled mechanical shear stresses. The designed setup consists of two reservoirs connected by a glass capillary. Each reservoir is connected to a compressor; during the tests, the reservoirs were in turn pressurized to promote erythrocyte flow through the capillary. The setup was filled with a suspension of erythrocytes, phosphate buffer, and FITC-dextran. Dextran was chosen as the diffusive molecule to check membrane pore dimensions. Samples of the suspension were withdrawn at scheduled times while the setup was operating. Flow cytometry and stereo-optical microscopy analyses were used to evaluate the erythrocyte dextran uptake. The setup was shown to be safe, well controlled, and adjustable. The outcomes of the experimental tests showed significant dextran uptake by RBCs up to 8%. Microscopy observations highlighted the formation of echinocytes in the analyzed samples. Erythrocytes from different donors showed different reactions to mechanical stresses. The experimental outcomes proved the possibility to encapsulate test molecules into erythrocytes by applying controlled mechanical shear stresses on the RBC membrane, encouraging further studies. Copyright © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Torque Loss After Miniscrew Placement: An In-Vitro Study Followed by a Clinical Trial.

PubMed

Migliorati, Marco; Drago, Sara; Barberis, Fabrizio; Schiavetti, Irene; Dalessandri, Domenico; Benedicenti, Stefano; Biavati, Armando Silvestrini

2016-01-01

To evaluate torque loss a week after insertion, both in an in vivo and an in vitro experimental setup were designed. In the in vivo setup a total of 29 miniscrews were placed in 20 patients who underwent orthodontic treatment. Maximum insertion torque (MIT) was evaluated at insertion time (T1). A week later, insertion torque was measured again by applying a quarter turn (T2); no load was applied on the screw during the first week. In the in vitro setup a total of 20 miniscrews were placed in pig rib bone samples. MIT was evaluated at insertion time (T1). Bone samples were kept in saline solution and controlled environment for a week during which the solution was refreshed every day. Afterwards, torque was measured again by applying a quarter turn (T2). The comparison of MIT over time was done calculating the percentage difference of the torque values between pre- and post-treatment and using the parametric two independent samples t-test or the non-parametric Mann-Whitney test. After a week unloaded miniscrews showed a mean loss of rotational torque of 36.3% and 40.9% in in vitro and in in vivo conditions, respectively. No statistical differences were found between the two different setups. Torque loss was observed after the first week in both study models; in vitro experimental setup provided a reliable study model for studying torque variation during the first week after insertion.

Torque Loss After Miniscrew Placement: An In-Vitro Study Followed by a Clinical Trial

PubMed Central

Migliorati, Marco; Drago, Sara; Barberis, Fabrizio; Schiavetti, Irene; Dalessandri, Domenico; Benedicenti, Stefano; Biavati, Armando Silvestrini

2016-01-01

To evaluate torque loss a week after insertion, both in an in vivo and an in vitro experimental setup were designed. In the in vivo setup a total of 29 miniscrews were placed in 20 patients who underwent orthodontic treatment. Maximum insertion torque (MIT) was evaluated at insertion time (T1). A week later, insertion torque was measured again by applying a quarter turn (T2); no load was applied on the screw during the first week. In the in vitro setup a total of 20 miniscrews were placed in pig rib bone samples. MIT was evaluated at insertion time (T1). Bone samples were kept in saline solution and controlled environment for a week during which the solution was refreshed every day. Afterwards, torque was measured again by applying a quarter turn (T2). The comparison of MIT over time was done calculating the percentage difference of the torque values between pre- and post-treatment and using the parametric two independent samples t-test or the non-parametric Mann–Whitney test. After a week unloaded miniscrews showed a mean loss of rotational torque of 36.3% and 40.9% in in vitro and in in vivo conditions, respectively. No statistical differences were found between the two different setups. Torque loss was observed after the first week in both study models; in vitro experimental setup provided a reliable study model for studying torque variation during the first week after insertion. PMID:27386011

Rainfall estimation using microwave links. Results from an experimental setup in Luxembourg

NASA Astrophysics Data System (ADS)

Fenicia, Fabrizio; Matgen, Patrick; Pfister, Laurent

2010-05-01

Microwave links represent a valid alternative to traditional rainfall estimation methods. They are commonly used in mobile phone communication, and they constitute built-in widely distributed networks. Due to their ability of providing high temporal and spatial resolution measurements, their use is particularly suitable in urban settings. We here show results from an experimental setup in Luxembourg City, where two dual frequency links have been installed. The links cover a distance of about 4km, and measure power attenuation at 1 min. timestep. The links have been equipped with several recording raingauges, which measure rainfall in real-time communicating through a wireless connection. This set-up has been used to analyze in detail the mapping between attenuation and rainfall intensity, and gain insights into the potential accuracy of these instruments. In addition, we investigated the relation between rainfall and discharge response of the urban area of Luxembourg, which shows the potential utility of high frequency rainfall measurements for urban environments.

A new mechatronic set-up and technique for investigation of firearms

NASA Astrophysics Data System (ADS)

Lesenciuc, Ioan; Suciu, Cornel

2016-12-01

Since ancient times, mankind has manifested interest in the development and improvement of weapons, either for military or hunting purposes. Today, in competition with these legal practices, the number of those who commit crimes by non-compliance with the regime of weapons and ammunition has increased exponentially. This is why the technology and methods employed in the area of judicial ballistics, requires constant research and continuous learning. The present paper advances a new experimental set-up and its corresponding methodology, meant to measure the force deployed by the firing pin. The new experimental set-up and procedure consists of a mechatronic structure, based on a piezoelectric force transducer, which allows to measure, in-situ, the force produced by the firing pin when it is deployed. The obtained information can further be used to establish a correspondence between this force and the imprint left on the firing cap. This correspondence furthers the possibility of elaborating a model that would permit ballistic experts to correctly identify a smoothbore weapon.

A Simple Experimental Setup for Teaching Additive Colors with Arduino

NASA Astrophysics Data System (ADS)

Carvalho, Paulo Simeão; Hahn, Marcelo

2016-04-01

The result of additive colors is always fascinating to young students. When we teach this topic to 14- to 16-year-old students, they do not usually notice we use maximum light quantities of red (R), green (G), and blue (B) to obtain yellow, magenta, and cyan colors in order to build the well-known additive color diagram of Fig. 1. But how about using different light intensities for R, G, and B? What colors do we get? This problem of color mixing has been intensively discussed for decades by several authors, as pointed out by Ruiz's "Color Addition and Subtraction Apps" work and the references included therein. An early LED demonstrator for additive color mixing dates back to 1985, and apps to illustrate color mixing are available online. In this work, we describe an experimental setup making use of a microcontroller device: the Arduino Uno. This setup is designed as a game in order to improve students' understanding of color mixing.

Influence of hydride orientation on fracture toughness of CWSR Zr-2.5%Nb pressure tube material between RT and 300 °C

NASA Astrophysics Data System (ADS)

Sharma, Rishi K.; Sunil, Saurav; Kumawat, B. K.; Singh, R. N.; Tewari, Asim; Kashyap, B. P.

2017-05-01

An experimental setup was designed, fabricated and used to form radial hydrides in Zr-2.5%Nb alloy pressure tube spool. The design of setup was based on ensuring a hoop stress in the spool greater than threshold stress for reorientation of hydrides in this alloy, which was achieved by manipulating the thermal expansion coefficient of the plunger and pressure tube material and diametral interference between them. The experimental setup was loaded on a universal testing machine (UTM) fitted with an environmental chamber and subjected to a temperature cycle for the stress reorientation treatment. The metallographic examination of the hydrogen charged spools subjected to stress re-orientation treatment using this set up revealed formation of predominantly radial hydrides. The variation of fracture toughness of material containing radial hydride with test temperature showed typical 'S' curve behavior with transition temperatures more than that of the material containing circumferential hydride.

Electroanalysis of microbial anodes for bioelectrochemical systems: basics, progress and perspectives.

PubMed

Rimboud, M; Pocaznoi, D; Erable, B; Bergel, A

2014-08-21

Over about the last ten years, microbial anodes have been the subject of a huge number of fundamental studies dealing with an increasing variety of possible application domains. Out of several thousands of studies, only a minority have used 3-electrode set-ups to ensure well-controlled electroanalysis conditions. The present article reviews these electroanalytical studies with the admitted objective of promoting this type of investigation. A first recall of basics emphasises the advantages of the 3-electrode set-up compared to microbial fuel cell devices if analytical objectives are pursued. Experimental precautions specifically relating to microbial anodes are then noted and the existing experimental set-ups and procedures are reviewed. The state-of-the-art is described through three aspects: the effect of the polarisation potential on the characteristics of microbial anodes, the electroanalytical techniques, and the electrode. We hope that the final outlook will encourage researchers working with microbial anodes to strengthen their engagement along the multiple exciting paths of electroanalysis.

RF tissue-heating near metallic implants during magnetic resonance examinations: an approach in the ac limit.

PubMed

Ballweg, Verena; Eibofner, Frank; Graf, Hansjorg

2011-10-01

State of the art to access radiofrequency (RF) heating near implants is computer modeling of the devices and solving Maxwell's equations for the specific setup. For a set of input parameters, a fixed result is obtained. This work presents a theoretical approach in the alternating current (ac) limit, which can potentially render closed formulas for the basic behavior of tissue heating near metallic structures. Dedicated experiments were performed to support the theory. For the ac calculations, the implant was modeled as an RLC parallel circuit, with L being the secondary of a transformer and the RF transmission coil being its primary. Parameters influencing coupling, power matching, and specific absorption rate (SAR) were determined and formula relations were established. Experiments on a copper ring with a radial gap as capacitor for inductive coupling (at 1.5 T) and on needles for capacitive coupling (at 3 T) were carried out. The temperature rise in the embedding dielectric was observed as a function of its specific resistance using an infrared (IR) camera. Closed formulas containing the parameters of the setup were obtained for the frequency dependence of the transmitted power at fixed load resistance, for the calculation of the resistance for optimum power transfer, and for the calculation of the transmitted power in dependence of the load resistance. Good qualitative agreement was found between the course of the experimentally obtained heating curves and the theoretically determined power curves. Power matching revealed as critical parameter especially if the sample was resonant close to the Larmor frequency. The presented ac approach to RF heating near an implant, which mimics specific values for R, L, and C, allows for closed formulas to estimate the potential of RF energy transfer. A first reference point for worst-case determination in MR testing procedures can be obtained. Numerical approaches, necessary to determine spatially resolved heating maps, can be supported.

TEM Cell Testing of Cable Noise Reduction Techniques From 2 MHz to 200 MHz - Part 1

NASA Technical Reports Server (NTRS)

Bradley, Arthur T.; Evans, William C.; Reed, Joshua L.; Shimp, Samuel K.; Fitzpatrick, Fred D.

2008-01-01

This paper presents empirical results of cable noise reduction techniques as demonstrated in a TEM cell operating with radiated fields from 2 - 200 MHz. It is the first part of a two-paper series. This first paper discusses cable types and shield connections. In the second paper, the effects of load and source resistances and chassis connections are examined. For each topic, well established theories are compared to data from a real-world physical system. Finally, recommendations for minimizing cable susceptibility (and thus cable emissions) are presented. There are numerous papers and textbooks that present theoretical analyses of cable noise reduction techniques. However, empirical data is often targeted to low frequencies (e.g. <50 KHz) or high frequencies (>100 MHz). Additionally, a comprehensive study showing the relative effects of various noise reduction techniques is needed. These include the use of dedicated return wires, twisted wiring, cable shielding, shield connections, changing load or source impedances, and implementing load- or source-to-chassis isolation. We have created an experimental setup that emulates a real-world electrical system, while still allowing us to independently vary a host of parameters. The goal of the experiment was to determine the relative effectiveness of various noise reduction techniques when the cable is in the presence of radiated emissions from 2 MHz to 200 MHz. The electronic system (Fig. 1) consisted of two Hammond shielded electrical enclosures, one containing the source resistance, and the other containing the load resistance. The boxes were mounted on a large aluminium plate acting as the chassis. Cables connecting the two boxes measured 81 cm in length and were attached to the boxes using standard D38999 military-style connectors. The test setup is shown in Fig. 2. Electromagnetic fields were created using an HP8657B signal generator, MiniCircuits ZHL-42W-SMA amplifier, and an EMCO 5103 TEM cell. Measurements were taken using an Agilent E4401B spectrum analyzer and HP1141a differential probes.

Experimental and numerical investigation of the nonlinear dynamics of compliant mechanisms for deployable structures

NASA Astrophysics Data System (ADS)

Dewalque, Florence; Schwartz, Cédric; Denoël, Vincent; Croisier, Jean-Louis; Forthomme, Bénédicte; Brüls, Olivier

2018-02-01

This paper studies the dynamics of tape springs which are characterised by a highly geometrical nonlinear behaviour including buckling, the formation of folds and hysteresis. An experimental set-up is designed to capture these complex nonlinear phenomena. The experimental data are acquired by the means of a 3D motion analysis system combined with a synchronised force plate. Deployment tests show that the motion can be divided into three phases characterised by different types of folds, frequencies of oscillation and damping behaviours. Furthermore, the reproducibility quality of the dynamic and quasi-static results is validated by performing a large number of tests. In parallel, a nonlinear finite element model is developed. The required model parameters are identified based on simple experimental tests such as static deformed configurations and small amplitude vibration tests. In the end, the model proves to be well correlated with the experimental results in opposite sense bending, while in equal sense, both the experimental set-up and the numerical model are particularly sensitive to the initial conditions.

Detection of fractional solitons in quantum spin Hall systems

NASA Astrophysics Data System (ADS)

Fleckenstein, C.; Traverso Ziani, N.; Trauzettel, B.

2018-03-01

We propose two experimental setups that allow for the implementation and the detection of fractional solitons of the Goldstone-Wilczek type. The first setup is based on two magnetic barriers at the edge of a quantum spin Hall system for generating the fractional soliton. If then a quantum point contact is created with the other edge, the linear conductance shows evidence of the fractional soliton. The second setup consists of a single magnetic barrier covering both edges and implementing a long quantum point contact. In this case, the fractional soliton can unambiguously be detected as a dip in the conductance without the need to control the magnetization of the barrier.

Room Temperature Erbium-Doped Yttrium Vanadate (Er:YVO4) Laser and Amplifier

DTIC Science & Technology

2016-09-01

perpendicular to the laser cavity axis, was pumped in σ-polarization and lased in π-polarization. The laser operated in a quasi -continuous wave regime...laser, amplifier, quasi -continuous wave 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF...distribution unlimited. iii Contents List of Figures iv 1. Introduction 1 2. Laser Experimental Setup and Results 2 3. Laser Amplifier Setup 6 4

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.

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.

Measurement-device-independent quantum key distribution for Scarani-Acin-Ribordy-Gisin 04 protocol

PubMed Central

Mizutani, Akihiro; Tamaki, Kiyoshi; Ikuta, Rikizo; Yamamoto, Takashi; Imoto, Nobuyuki

2014-01-01

The measurement-device-independent quantum key distribution (MDI QKD) was proposed to make BB84 completely free from any side-channel in detectors. Like in prepare & measure QKD, the use of other protocols in MDI setting would be advantageous in some practical situations. In this paper, we consider SARG04 protocol in MDI setting. The prepare & measure SARG04 is proven to be able to generate a key up to two-photon emission events. In MDI setting we show that the key generation is possible from the event with single or two-photon emission by a party and single-photon emission by the other party, but the two-photon emission event by both parties cannot contribute to the key generation. On the contrary to prepare & measure SARG04 protocol where the experimental setup is exactly the same as BB84, the measurement setup for SARG04 in MDI setting cannot be the same as that for BB84 since the measurement setup for BB84 in MDI setting induces too many bit errors. To overcome this problem, we propose two alternative experimental setups, and we simulate the resulting key rate. Our study highlights the requirements that MDI QKD poses on us regarding with the implementation of a variety of QKD protocols. PMID:24913431

Moving bed reactor setup to study complex gas-solid reactions.

PubMed

Gupta, Puneet; Velazquez-Vargas, Luis G; Valentine, Charles; Fan, Liang-Shih

2007-08-01

A moving bed scale reactor setup for studying complex gas-solid reactions has been designed in order to obtain kinetic data for scale-up purpose. In this bench scale reactor setup, gas and solid reactants can be contacted in a cocurrent and countercurrent manner at high temperatures. Gas and solid sampling can be performed through the reactor bed with their composition profiles determined at steady state. The reactor setup can be used to evaluate and corroborate model parameters accounting for intrinsic reaction rates in both simple and complex gas-solid reaction systems. The moving bed design allows experimentation over a variety of gas and solid compositions in a single experiment unlike differential bed reactors where the gas composition is usually fixed. The data obtained from the reactor can also be used for direct scale-up of designs for moving bed reactors.

Experimental setup for the study of resonant inelastic X-ray scattering of organometallic complexes in gas phase

NASA Astrophysics Data System (ADS)

Ismail, I.; Guillemin, R.; Marchenko, T.; Travnikova, O.; Ablett, J. M.; Rueff, J.-P.; Piancastelli, M.-N.; Simon, M.; Journel, L.

2018-06-01

A new setup has been designed and built to study organometallic complexes in gas phase at the third-generation Synchrotron radiation sources. This setup consists of a new homemade computer-controlled gas cell that allows us to sublimate solid samples by accurately controlling the temperature. This cell has been developed to be a part of the high-resolution X-ray emission spectrometer permanently installed at the GALAXIES beamline of the French National Synchrotron Facility SOLEIL. To illustrate the capabilities of the setup, the cell has been successfully used to record high-resolution Kα emission spectra of gas-phase ferrocene F e (C5H5) 2 and to characterize their dependence with the excitation energy. This will allow to extend resonant X-ray emission to different organometallic molecules.

Automated quantum operations in photonic qutrits

NASA Astrophysics Data System (ADS)

Borges, G. F.; Baldijão, R. D.; Condé, J. G. L.; Cabral, J. S.; Marques, B.; Terra Cunha, M.; Cabello, A.; Pádua, S.

2018-02-01

We report an experimental implementation of automated state transformations on spatial photonic qutrits following the theoretical proposal made by Baldijão et al. [Phys. Rev. A 96, 032329 (2017), 10.1103/PhysRevA.96.032329]. A qutrit state is simulated by using three Gaussian beams, and after some state operations, the transformed state is available in the end in terms of the basis state. The state transformation setup uses a spatial light modulator and a calcite-based interferometer. The results reveal the usefulness of the operation method. The experimental data show a good agreement with theoretical predictions, opening possibilities for explorations in higher dimensions and in a wide range of applications. This is a necessary step in qualifying spatial photonic qudits as a competitive setup for experimental research in the implementation of quantum algorithms which demand a large number of steps.

Experimental setup and procedure for the measurement of the 7Be(n,p)7Li reaction at n_TOF

NASA Astrophysics Data System (ADS)

Barbagallo, M.; Andrzejewski, J.; Mastromarco, M.; Perkowski, J.; Damone, L. A.; Gawlik, A.; Cosentino, L.; Finocchiaro, P.; Maugeri, E. A.; Mazzone, A.; Dressler, R.; Heinitz, S.; Kivel, N.; Schumann, D.; Colonna, N.; Aberle, O.; Amaducci, S.; Audouin, L.; Bacak, M.; Balibrea, J.; Bečvář, F.; Bellia, G.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brown, A.; Caamaño, M.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Cardella, R.; Casanovas, A.; Cerutti, F.; Chen, Y. H.; Chiaveri, E.; Cortés, G.; Cortés-Giraldo, M. A.; Cristallo, S.; Diakaki, M.; Dietz, M.; Domingo-Pardo, C.; Dupont, E.; Durán, I.; Fernández-Domínguez, B.; Ferrari, A.; Ferreira, P.; Furman, V.; Göbel, K.; García, A. R.; Gilardoni, S.; Glodariu, T.; Gonçalves, I. F.; González-Romero, E.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Harada, H.; Heyse, J.; Jenkins, D. G.; Jericha, E.; Johnston, K.; Käppeler, F.; Kadi, Y.; Kalamara, A.; Kavrigin, P.; Kimura, A.; Kokkoris, M.; Krtička, M.; Kurtulgil, D.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Lerendegui-Marco, J.; Lo Meo, S.; Lonsdale, S. J.; Macina, D.; Manna, A.; Marganiec, J.; Martínez, T.; Martins-Correia, J. G.; Masi, A.; Massimi, C.; Mastinu, P.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Musumarra, A.; Negret, A.; Nolte, R.; Oprea, A.; Pappalardo, A. D.; Patronis, N.; Pavlik, A.; Piscopo, M.; Porras, I.; Praena, J.; Quesada, J. M.; Radeck, D.; Rauscher, T.; Reifarth, R.; Robles, M. S.; Rubbia, C.; Ryan, J. A.; Sabaté-Gilarte, M.; Saxena, A.; Schell, J.; Schillebeeckx, P.; Sedyshev, P.; Smith, A. G.; Sosnin, N. V.; Stamatopoulos, A.; Tagliente, G.; Tain, J. L.; Tarifeño-Saldivia, A.; Tassan-Got, L.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Warren, S.; Weiss, C.; Woods, P. J.; Wright, T.; Žugec, P.

2018-04-01

Following the completion of the second neutron beam line and the related experimental area (EAR2) at the n_TOF spallation neutron source at CERN, several experiments were planned and performed. The high instantaneous neutron flux available in EAR2 allows to investigate neutron induced reactions with charged particles in the exit channel even employing targets made out of small amounts of short-lived radioactive isotopes. After the successful measurement of the 7Be(n, α) α cross section, the 7Be(n,p)7Li reaction was studied in order to provide still missing cross section data of relevance for Big Bang Nucleosynthesis (BBN), in an attempt to find a solution to the cosmological Lithium abundance problem. This paper describes the experimental setup employed in such a measurement and its characterization.

Adhesive Bonding for Optical Metrology Systems in Space Applications

NASA Astrophysics Data System (ADS)

Gohlke, Martin; Schuldt, Thilo; Döringshoff, Klaus; Peters, Achim; Johann, Ulrich; Weise, Dennis; Braxmaier, Claus

2015-05-01

Laser based metrology systems become more and more attractive for space applications and are the core elements of planned missions such as LISA (NGO, eLISA) or NGGM where laser interferometry is used for distance measurements between satellites. The GRACE-FO mission will for the first time demonstrate a Laser Ranging Instrument (LRI) in space, starting 2017. Laser based metrology also includes optical clocks/references, either as ultra-stable light source for high sensitivity interferometry or as scientific payload e.g. proposed in fundamental physics missions such as mSTAR (mini SpaceTime Asymmetry Research), a mission dedicated to perform a Kennedy-Thorndike experiment on a satellite in a low-Earth orbit. To enable the use of existing optical laboratory setups, optimization with respect to power consumption, weight and dimensions is necessary. At the same time the thermal and structural stability must be increased. Over the last few years we investigated adhesive bonding of optical components to thermally highly stable glass ceramics as an easy-to-handle assembly integration technology. Several setups were implemented and tested for potential later use in space applications. We realized a heterodyne LISA related interferometer with demonstrated noise levels in the pm-range for translation measurement and nano-radiant-range for tilt measurements and two iodine frequency references on Elegant Breadboard (EBB) and Engineering Model (EM) level with frequency stabilities in the 10-15 range for longer integration times. The EM setup was thermally cycled and vibration tested.

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.

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…

Plasmoid Propagation.

DTIC Science & Technology

1988-02-12

experimentally , a pulsed power system com- prising separate anode and cathode pulsers was designed and assembled. A double diode was developed to produce...be closed. To initiate this assessment, Mission Research Corporation (MRC) performed a two-year primarily experimental investigation of non - neutral...through from the cathode nad to be designed . Experimentation with several materials and setups produced a workable design , using nylon stocking hose

Development of an automated experimental setup for the study of ionic-exchange kinetics. Application to the ionic adsorption, equilibrium attainment and dissolution of apatite compounds.

PubMed

Thomann, J M; Gasser, P; Bres, E F; Voegel, J C; Gramain, P

1990-02-01

An ion-selective electrode and microcomputer-based experimental setup for the study of ionic-exchange kinetics between a powdered solid and the solution is described. The equipment is composed of easily available commercial devices and a data acquisition and regularization computer program is presented. The system, especially developed to investigate the ionic adsorption, equilibrium attainment and dissolution of hard mineralized tissues, provides good reliable results by taking into account the volume changes of the reacting solution and the electrode behaviour under different experimental conditions, and by avoiding carbonation of the solution. A second computer program, using the regularized data and the experimental parameters, calculates the quantities of protons consumed and calcium released in the case of equilibrium attainment and dissolution of apatite-like compounds. Finally, typical examples of ion-exchange and dissolution kinetics under constant pH of enamel and synthetic hydroxyapatite are examined.

Gust wind tunnel study on ballast pick-up by high-speed trains

NASA Astrophysics Data System (ADS)

Navarro-Medina, F.; Sanz-Andres, A.; Perez-Grande, I.

2012-01-01

This paper describes the experimental setup, procedure, and results obtained, concerning the dynamics of a body lying on a floor, attached to a hinge, and exposed to an unsteady flow, which is a model of the initiation of rotational motion of ballast stones due to the wind generated by the passing of a high-speed train. The idea is to obtain experimental data to support the theoretical model developed in Sanz-Andres and Navarro-Medina (J Wind Eng Ind Aerodyn 98, 772-783, (2010), aimed at analyzing the initial phase of the ballast train-induced-wind erosion (BATIWE) phenomenon. The experimental setup is based on an open circuit, closed test section, low-speed wind tunnel, with a new sinusoidal gust generator mechanism concept, designed and built at the IDR/UPM. The tunnel's main characteristic is the ability to generate a flow with a uniform velocity profile and sinusoidal time fluctuation of the speed. Experimental results and theoretical model predictions are in good agreement.

Experimental setup for investigation of nanoclusters at cryogenic temperatures by electron spin resonance and optical spectroscopies

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

Mao, S., E-mail: maoshunghost@tamu.edu; Meraki, A.; McColgan, P. T.

2014-07-15

We present the design and performance of an experimental setup for simultaneous electron spin resonance (ESR) and optical studies of nanoclusters with stabilized free radicals at cryogenic temperatures. A gas mixture of impurities and helium after passing through a RF discharge for dissociation of molecules is directed onto the surface of superfluid helium to form the nanoclusters of impurities. A specially designed ESR cavity operated in the TE{sub 011} mode allows optical access to the sample. The cavity is incorporated into a homemade insert which is placed inside a variable temperature insert of a Janis {sup 4}He cryostat. The temperaturemore » range for sample investigation is 1.25–300 K. A Bruker EPR 300E and Andor 500i optical spectrograph incorporated with a Newton EMCCD camera are used for ESR and optical registration, respectively. The current experimental system makes it possible to study the ESR and optical spectra of impurity-helium condensates simultaneously. The setup allows a broad range of research at low temperatures including optically detected magnetic resonance, studies of chemical processes of the active species produced by photolysis in solid matrices, and investigations of nanoclusters produced by laser ablation in superfluid helium.« less

An experimental study of dependence of hydro turbine vibration parameters on pressure pulsations in the flow path

NASA Astrophysics Data System (ADS)

Dekterev, D.; Maslennikova, A.; Abramov, A.

2017-09-01

The operation modes of the hydraulic power plant water turbine with the formation of a precessing vortex core were studied on the hydrodynamic set-up with the model of hydraulic unit. The dependence of low-frequency vibrations on flow pressure pulsations in the hydraulic unit was established. The results of the air injection effect on the vibrational parameters of the hydrodynamic set-up were presented.

Experiments and Simulations of Exploding Aluminum Wires: Validation of ALEGRA-MHD

DTIC Science & Technology

2010-09-01

ii REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 ...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) September 2010 2. REPORT TYPE Final...List of Tables vi Acknowledgements vii 1 . Introduction 1 2. Experimental Setup 2 3. Computational Setup 5 3.1 Description of ALEGRA

Numerical modelling of distributed vibration sensor based on phase-sensitive OTDR

NASA Astrophysics Data System (ADS)

Masoudi, A.; Newson, T. P.

2017-04-01

A Distributed Vibration Sensor Based on Phase-Sensitive OTDR is numerically modeled. The advantage of modeling the building blocks of the sensor individually and combining the blocks to analyse the behavior of the sensing system is discussed. It is shown that the numerical model can accurately imitate the response of the experimental setup to dynamic perturbations a signal processing procedure similar to that used to extract the phase information from sensing setup.

Comparing student clinical self-efficacy and team process outcomes for a DEU, blended, and traditional clinical setting: A quasi-experimental research study.

PubMed

Plemmons, Christina; Clark, Michele; Feng, Du

2018-03-01

Clinical education is vital to both the development of clinical self-efficacy and the integration of future nurses into health care teams. The dedicated education unit clinical teaching model is an innovative clinical partnership, which promotes skill development, professional growth, clinical self-efficacy, and integration as a team member. Blended clinical teaching models are combining features of the dedicated education unit and traditional clinical model. The aims of this study are to explore how each of three clinical teaching models (dedicated education unit, blended, traditional) affects clinical self-efficacy and attitude toward team process, and to compare the dedicated education unit model and blended model to traditional clinical. A nonequivalent control-group quasi-experimental design was utilized. The convenience sample of 272 entry-level baccalaureate nursing students included 84 students participating in a dedicated education unit model treatment group, 66 students participating in a blended model treatment group, and 122 students participating in a traditional model control group. Perceived clinical self-efficacy was evaluated by the pretest/posttest scores obtained on the General Self-Efficacy scale. Attitude toward team process was evaluated by the pretest/posttest scores obtained on the TeamSTEPPS® Teamwork Attitude Questionnaire. All three clinical teaching models resulted in significant increases in both clinical self-efficacy (p=0.04) and attitude toward team process (p=0.003). Students participating in the dedicated education unit model (p=0.016) and students participating in the blended model (p<0.001) had significantly larger increases in clinical self-efficacy compared to students participating in the traditional model. These findings support the use of dedicated education unit and blended clinical partnerships as effective alternatives to the traditional model to promote both clinical self-efficacy and team process among entry-level baccalaureate nursing students. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental Study of under-platform Damper Kinematics in Presence of Blade Dynamics

NASA Astrophysics Data System (ADS)

Botto, D.; Gastaldi, C.; Gola, M. M.; Umer, M.

2018-01-01

Among the different devices used in the aerospace industries under-platform dampers are widely used in turbo engines to mitigate the blade vibration. Nevertheless, the damper behaviour is not easy to simulate and engineers have been working in order to improve the accuracy with which theoretical contact models predict the damper behaviour. Majority of the experimental setups collect experimental data in terms of blade amplitude reduction which do not increase the knowledge about the damper dynamics and therefore the uncertainty on the damper behaviour remains a big issue. In this paper, a novel test rig has been purposely designed to accommodate a single blade and two under-platform dampers to deeply investigate the damper-blade interactions. In this test bench, a contact force measuring system was designed to extensively measure the damper contact forces. Damper kinematics is rebuilt by using the relative displacement measured between damper and blade. This paper describes the concept behind the new approach, shows the details of new test rig and discusses experimental results by comparing with previously measured results on an old experimental setup.

Characterization and performances of DOSION, a dosimetry equipment dedicated to radiobiology experiments taking place at GANIL

NASA Astrophysics Data System (ADS)

Boissonnat, Guillaume; Fontbonne, Jean-Marc; Balanzat, Emmanuel; Boumard, Frederic; Carniol, Benjamin; Cassimi, Amine; Colin, Jean; Cussol, Daniel; Etasse, David; Fontbonne, Cathy; Frelin, Anne-Marie; Hommet, Jean; Salvador, Samuel

2017-06-01

Currently, radiobiology experiments using heavy ions at GANIL (Grand Accélérateur National d‧Ions Lourds) are conducted under the supervision of the CIMAP (Center for research on Ions, MAterials and Photonics). In this context, a new beam monitoring equipment named DOSION has been developed. It allows to perform measurements of accurate fluence and dose maps in near real time for each biological sample irradiated. In this paper, we present the detection system, its design, performances, calibration protocol and measurements performed during radiobiology experiments. This setup is currently available for any radiobiology experiments if one wishes to correlate one's own sample analysis to state-of-the-art dosimetric references.

Monitoring Malware Activity on the LAN Network

NASA Astrophysics Data System (ADS)

Skrzewski, Mirosław

Many security related organizations periodically publish current network and systems security information, with the lists of top malware programs. These lists raises the question how these threats spreads out, if the worms (the only threat with own communication abilities) are low or missing on these lists. The paper discuss the research on malware network activity, aimed to deliver the answer to the question, what is the main infection channel of modern malware, done with the usage of virtual honeypot systems on dedicated, unprotected network. Systems setup, network and systems monitoring solutions, results of over three months of network traffic and malware monitoring are presented, along with the proposed answer to our research question.

Unified Ultrasonic/Eddy-Current Data Acquisition

NASA Technical Reports Server (NTRS)

Chern, E. James; Butler, David W.

1993-01-01

Imaging station for detecting cracks and flaws in solid materials developed combining both ultrasonic C-scan and eddy-current imaging. Incorporation of both techniques into one system eliminates duplication of computers and of mechanical scanners; unifies acquisition, processing, and storage of data; reduces setup time for repetitious ultrasonic and eddy-current scans; and increases efficiency of system. Same mechanical scanner used to maneuver either ultrasonic or eddy-current probe over specimen and acquire point-by-point data. For ultrasonic scanning, probe linked to ultrasonic pulser/receiver circuit card, while, for eddy-current imaging, probe linked to impedance-analyzer circuit card. Both ultrasonic and eddy-current imaging subsystems share same desktop-computer controller, containing dedicated plug-in circuit boards for each.

A gated LaBr3(Ce) detector for border protection applications

NASA Astrophysics Data System (ADS)

Etile, A.; Denis-Petit, D.; Gaudefroy, L.; Meot, V.; Roig, O.

2018-01-01

We report on the dedicated implementation of the blocking technique for a LaBr3(Ce) detector as well as associated electronics and data acquisition system for border protection applications. The detector is meant to perform delayed γ-ray spectroscopy of fission fragments produced via photofission induced by a high intensity pulsed photon beam. The gating technique avoids saturation of the detection chain during irradiation. The resulting setup allows us to successfully perform delayed γ-ray spectroscopy starting only 30 ns after the gating operation. The measured energy resolution ranges from 5% to 6.5% at 662 keV depending on the γ-ray detection time after the gating operation.

[N.K. Kol'tsov and experimental embryology (dedicated to the 140th anniversary of his birth)].

PubMed

Pomelova, M A

2012-01-01

It is common knowledge that the majority ofN.K. Kol'tsov's studies investigated the structure of a cell through the methods of physical chemistry and cytogenetics. At the same time, Kol'tsov was also interested in the development of experimental biology, specifically experimental embryology.

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.

Refractive Index Compensation in Over-Determined Interferometric Systems

PubMed Central

Lazar, Josef; Holá, Miroslava; Číp, Ondřej; Čížek, Martin; Hrabina, Jan; Buchta, Zdeněk

2012-01-01

We present an interferometric technique based on a differential interferometry setup for measurement under atmospheric conditions. The key limiting factor in any interferometric dimensional measurement are fluctuations of the refractive index of air representing a dominating source of uncertainty when evaluated indirectly from the physical parameters of the atmosphere. Our proposal is based on the concept of an over-determined interferometric setup where a reference length is derived from a mechanical frame made from a material with a very low thermal coefficient. The technique allows one to track the variations of the refractive index of air on-line directly in the line of the measuring beam and to compensate for the fluctuations. The optical setup consists of three interferometers sharing the same beam path where two measure differentially the displacement while the third evaluates the changes in the measuring range, acting as a tracking refractometer. The principle is demonstrated in an experimental setup. PMID:23202037

Refractive index compensation in over-determined interferometric systems.

PubMed

Lazar, Josef; Holá, Miroslava; Číp, Ondřej; Čížek, Martin; Hrabina, Jan; Buchta, Zdeněk

2012-10-19

We present an interferometric technique based on a differential interferometry setup for measurement under atmospheric conditions. The key limiting factor in any interferometric dimensional measurement are fluctuations of the refractive index of air representing a dominating source of uncertainty when evaluated indirectly from the physical parameters of the atmosphere. Our proposal is based on the concept of an over-determined interferometric setup where a reference length is derived from a mechanical frame made from a material with a very low thermal coefficient. The technique allows one to track the variations of the refractive index of air on-line directly in the line of the measuring beam and to compensate for the fluctuations. The optical setup consists of three interferometers sharing the same beam path where two measure differentially the displacement while the third evaluates the changes in the measuring range, acting as a tracking refractometer. The principle is demonstrated in an experimental setup.

Engineering platform and experimental protocol for design and evaluation of a neurally-controlled powered transfemoral prosthesis.

PubMed

Zhang, Fan; Liu, Ming; Harper, Stephen; Lee, Michael; Huang, He

2014-07-22

To enable intuitive operation of powered artificial legs, an interface between user and prosthesis that can recognize the user's movement intent is desired. A novel neural-machine interface (NMI) based on neuromuscular-mechanical fusion developed in our previous study has demonstrated a great potential to accurately identify the intended movement of transfemoral amputees. However, this interface has not yet been integrated with a powered prosthetic leg for true neural control. This study aimed to report (1) a flexible platform to implement and optimize neural control of powered lower limb prosthesis and (2) an experimental setup and protocol to evaluate neural prosthesis control on patients with lower limb amputations. First a platform based on a PC and a visual programming environment were developed to implement the prosthesis control algorithms, including NMI training algorithm, NMI online testing algorithm, and intrinsic control algorithm. To demonstrate the function of this platform, in this study the NMI based on neuromuscular-mechanical fusion was hierarchically integrated with intrinsic control of a prototypical transfemoral prosthesis. One patient with a unilateral transfemoral amputation was recruited to evaluate our implemented neural controller when performing activities, such as standing, level-ground walking, ramp ascent, and ramp descent continuously in the laboratory. A novel experimental setup and protocol were developed in order to test the new prosthesis control safely and efficiently. The presented proof-of-concept platform and experimental setup and protocol could aid the future development and application of neurally-controlled powered artificial legs.

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.

Laboratory grown subaerial biofilms on granite: application to the study of bioreceptivity.

PubMed

Vázquez-Nion, Daniel; Silva, Benita; Troiano, Federica; Prieto, Beatriz

2017-01-01

Simulated environmental colonisation of granite was induced under laboratory conditions in order to develop an experimental protocol for studying bioreceptivity. The experimental set-up proved suitable for producing subaerial biofilms by inoculating granite blocks with planktonic multi-species phototrophic cultures derived from natural biofilms. The ability of four different cultures to form biofilms was monitored over a three-month growth period via colour measurements, quantification of photosynthetic pigments and EPS, and CLSM observations. One of the cultures under study, which comprised several taxa including Bryophyta, Charophyta, Chlorophyta and Cyanobacteria, was particularly suitable as an inoculum, mainly because of its microbial richness, its rapid adaptability to the substratum and its high colonisation capacity. The use of this culture as an inoculum in the proposed experimental set-up to produce subaerial biofilms under laboratory conditions will contribute to standardising the protocols involved, thus enabling more objective assessment of the bioreceptivity of granite in further experiments.

An introduction to photocatalysis through methylene blue photodegradation

NASA Astrophysics Data System (ADS)

Petit, Matthieu; Michez, Lisa; Raimundo, Jean-Manuel; Malinowski, Tuhiti; Dumas, Philippe

2016-11-01

We described a simple experimental set-up for lab work on the photocatalytic degradation of methylene blue by TiO2 nanoparticles. The photocatalysis process can be used for many applications. Treatments for diluted wastewater industries, air purifying in underground car parks, and preventing fouling on glass surfaces, are some of the potential applications of this phenomenon. The described experiment is easy to perform and the interpretation can be easily adapted to different levels of students, from high school students demonstrating their interest in sustainable development, to students obtaining a Masters in science departments who want to propose a full explanation for all phenomena of the photocatalytic process. Starting with a description of the experimental set-up, we analysed the photocatalyst nanoparticles and applied the Langmuir-Hinshelwood model to our experimental data. Finally we briefly discussed the respective energetic levels of the photocatalyst semiconductor and methylene blue.

Generation of a tunable environment for electrical oscillator systems.

PubMed

León-Montiel, R de J; Svozilík, J; Torres, Juan P

2014-07-01

Many physical, chemical, and biological systems can be modeled by means of random-frequency harmonic oscillator systems. Even though the noise-free evolution of harmonic oscillator systems can be easily implemented, the way to experimentally introduce, and control, noise effects due to a surrounding environment remains a subject of lively interest. Here, we experimentally demonstrate a setup that provides a unique tool to generate a fully tunable environment for classical electrical oscillator systems. We illustrate the operation of the setup by implementing the case of a damped random-frequency harmonic oscillator. The high degree of tunability and control of our scheme is demonstrated by gradually modifying the statistics of the oscillator's frequency fluctuations. This tunable system can readily be used to experimentally study interesting noise effects, such as noise-induced transitions in systems driven by multiplicative noise, and noise-induced transport, a phenomenon that takes place in quantum and classical coupled oscillator networks.

Prospective study of cone-beam computed tomography image-guided radiotherapy for prone accelerated partial breast irradiation.

PubMed

Jozsef, Gabor; DeWyngaert, J Keith; Becker, Stewart J; Lymberis, Stella; Formenti, Silvia C

2011-10-01

To report setup variations during prone accelerated partial breast irradiation (APBI). New York University (NYU) 07-582 is an institutional review board-approved protocol of cone-beam computed tomography (CBCT) to deliver image-guided ABPI in the prone position. Eligible are postmenopausal women with pT1 breast cancer excised with negative margins and no nodal involvement. A total dose of 30 Gy in five daily fractions of 6 Gy are delivered to the planning target volume (the tumor cavity with 1.5-cm margin) by image-guided radiotherapy. Patients are set up prone, on a dedicated mattress, used for both simulation and treatment. After positioning with skin marks and lasers, CBCTs are performed and the images are registered to the planning CT. The resulting shifts (setup corrections) are recorded in the three principal directions and applied. Portal images are taken for verification. If they differ from the planning digital reconstructed radiographs, the patient is reset, and a new CBCT is taken. 70 consecutive patients have undergone a total of 343 CBCTs: 7 patients had four of five planned CBCTs performed. Seven CBCTs (2%) required to be repeated because of misalignment in the comparison between portal and digital reconstructed radiograph image after the first CBCT. The mean shifts and standard deviations in the anterior-posterior (AP), superior-inferior (SI), and medial-lateral (ML) directions were -0.19 (0.54), -0.02 (0.33), and -0.02 (0.43) cm, respectively. The average root mean squares of the daily shifts were 0.50 (0.28), 0.29 (0.17), and 0.38 (0.20). A conservative margin formula resulted in a recommended margin of 1.26, 0.73, 0.96 cm in the AP, SI, and ML directions. CBCTs confirmed that the NYU prone APBI setup and treatment technique are reproducible, with interfraction variation comparable to those reported for supine setup. The currently applied margin (1.5 cm) adequately compensates for the setup variation detected. Copyright © 2011 Elsevier Inc. All rights reserved.

WE-H-BRA-05: Investigation of LET Spectral Dependence of the Biological Effects of Therapeutic Protons

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

Guan, F; Bronk, L; Kerr, M

Purpose: To investigate the dependence of biologic effect (BE) of therapeutic protons on LET spectra by comparing BEs with equal dose-averaged LET (LETd) derived from different LET spectra using high-throughput in vitro clonogenic survival assays. Methods: We used Geant4 to design the relevant experimental setups and perform the dose, LETd, and LET spectra calculations for spot-scanning protons. The clonogenic assay was performed using the H460 lung cancer cell line cultured in 96-well plates. In the first experimental setup (S1), cells were irradiated using 127.4 MeV protons with a 93.22 mm Lucite buildup resulting in a LETd value of 3.4 keV/µmmore » in the cell layer. In the second experimental setup (S2), cells were irradiated by a combination of 127.4 MeV and 136.4 MeV protons with a 96.61 mm Lucite buildup. The LETd values in the cell layer were 11.4 keV/µm and 1.5 keV/µm respectively, but an average LETd of 3.4 keV/µm was obtained by adjusting the relative fluence of each beam. Ten discrete dose levels with 0.5 Gy increments were delivered. Results: In the two setups, the energies or LET spectra were different but resulted in identical LETd values. We quantified the dose contributions from high-LET (≥10 keV/µm, threshold determined by previous experiments) events in the LET spectra separately for these two setups as 3.2% and 10.5%. The biologic effects at each identical dose level yielded statistically significant different survival curves (extra sum-of-squares F-test, P<0.0001). The second setup with a higher contribution from high-LET events exhibited the higher biologic effect with a dose enhancement factor of 1.17±0.03 at 0.10 surviving fraction. Conclusion: The dose-averaged LET may not be an accurate indicator of the biological effects of protons. Detailed LET spectra may need to be considered explicitly to accurately quantify the biologic effects of protons. Funding Support: U19 CA021239-35, R21 CA187484-01 and MDACC-IRG.« less

The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae)

PubMed Central

2013-01-01

Background Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light traps. Methods Here we test a previously described mathematical model (Model I) and two novel models for the attraction of vectors to light traps (Model II and III). In Model I, Culicoides fly to the nearest trap from within a fixed range of attraction. In Model II Culicoides fly towards areas with greater light intensity, and in Model III Culicoides evaluate light sources in the field of view and fly towards the strongest. Model II and III incorporated the directionally dependent light field created around light traps with fluorescent light tubes. All three models were fitted to light trap collections obtained from two novel experimental setups in the field where traps were placed in different configurations. Results Results showed that overlapping ranges of attraction of neighboring traps extended the shared range of attraction. Model I did not fit data from any of the experimental setups. Model II could only fit data from one of the setups, while Model III fitted data from both experimental setups. Conclusions The model with the best fit, Model III, indicates that Culicoides continuously evaluate the light source direction and intensity. The maximum range of attraction of a single 4W CDC light trap was estimated to be approximately 15.25 meters. The attraction towards light traps is different from the attraction to host animals and thus light trap catches may not represent the vector species and numbers attracted to hosts. PMID:23497628

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

The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae).

PubMed

Kirkeby, Carsten; Græsbøll, Kaare; Stockmarr, Anders; Christiansen, Lasse E; Bødker, René

2013-03-15

Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light traps. Here we test a previously described mathematical model (Model I) and two novel models for the attraction of vectors to light traps (Model II and III). In Model I, Culicoides fly to the nearest trap from within a fixed range of attraction. In Model II Culicoides fly towards areas with greater light intensity, and in Model III Culicoides evaluate light sources in the field of view and fly towards the strongest. Model II and III incorporated the directionally dependent light field created around light traps with fluorescent light tubes. All three models were fitted to light trap collections obtained from two novel experimental setups in the field where traps were placed in different configurations. Results showed that overlapping ranges of attraction of neighboring traps extended the shared range of attraction. Model I did not fit data from any of the experimental setups. Model II could only fit data from one of the setups, while Model III fitted data from both experimental setups. The model with the best fit, Model III, indicates that Culicoides continuously evaluate the light source direction and intensity. The maximum range of attraction of a single 4W CDC light trap was estimated to be approximately 15.25 meters. The attraction towards light traps is different from the attraction to host animals and thus light trap catches may not represent the vector species and numbers attracted to hosts.

Dedicated operating room for emergency surgery generates more utilization, less overtime, and less cancellations.

PubMed

van Veen-Berkx, Elizabeth; Elkhuizen, Sylvia G; Kuijper, Bart; Kazemier, Geert

2016-01-01

Two approaches prevail for reserving operating room (OR) capacity for emergency surgery: (1) dedicated emergency ORs and (2) evenly allocating capacity to all elective ORs, thereby creating a virtual emergency team. Previous studies contradict which approach leads to the best performance in OR utilization. Quasi-experimental controlled time-series design with empirical data from 3 university medical centers. Four different time periods were compared with analysis of variance with contrasts. Performance was measured based on 467,522 surgical cases. After closing the dedicated emergency OR, utilization slightly increased; overtime also increased. This was in contrast to earlier simulated results. The 2 control centers, maintaining a dedicated emergency OR, showed a higher increase in utilization and a decrease in overtime, along with a smaller ratio of case cancellations because of emergency surgery. This study shows that in daily practice a dedicated emergency OR is the preferred approach in performance terms regarding utilization, overtime, and case cancellations. Copyright © 2016 Elsevier Inc. All rights reserved.

Indigenously developed bending strain setup for I-V characterization of superconducting tapes and wires

NASA Astrophysics Data System (ADS)

Panchal, Arun; Bano, Anees; Ghate, Mahesh; Raj, Piyush; Pradhan, Subrata

2017-04-01

An indigenously developed bending strain setup to examine the effect of pure bending on critical current of superconducting tapes and strands has been presented in this paper. This set up is capable of applying various bending radius in situ at cryogenic temperature with rack and pinion gear mechanism. The bending strain applied on samples can be controlled externally by rotational input which is transferred in the form of bending radius during experiments. The working principle, design and optimization of this set up have been discussed. The performance and validation of this setup has been done on various HTS tapes and copper strands at 77 K in actual experimental facility. Effect of bending radius (15.5 mm - 48 mm) i.e. strains and ramp rate (2 A/s - 8 A/s) is observed on current capability of various HTS Tapes. It is observed that in uniform bending condition, degradation in current carrying capacity BSCCO and Di-BSCCO (˜ 30 %) is more as compare to YBCO (˜ 2.75 %) at 77 K. The effect of pure mechanical strain has been experimentally observed and presented.

Chromophore Poling in Thin Films of Organic Glasses. 2. Two-Electrode Corona Discharge Setup

NASA Astrophysics Data System (ADS)

Vilitis, O.; Muzikante, I.; Rutkis, M.; Vembris, A.

2012-01-01

In Part 1 of the article we provided description of the corona discharge physics and overview of the methods used for corona poling in thin organic films. Subsequent sections describe comparatively simple technical methods for poling the organic nonlinear optical polymers using a two-electrode (point-to-plate or wire-to-plate) technique. The polarization build-up was studied by the DC positive corona method for poling the nonlinear optical (NLO) polymers. The experimental setup provides the corona discharge current from 0.5 μA up to 3 μA by applying 3 kV - 12 kV voltage to the corona electrode and makes possible selection among the types of corona electrodes (needle, multi-needle, wire, etc.). The results of experimental testing of the poling setup show that at fixed optimal operational parameters of poling - the sample orientation temperature and the discharge current - the corona charging of polymeric materials can successfully be performed applying the two-electrode technique. To study the dynamics of both poling and charge transport processes the three-electrode charging system - a corona triode - should be applied.

Note: 4-bounce neutron polarizer for reflectometry applications

NASA Astrophysics Data System (ADS)

Nagy, B.; Merkel, D. G.; Jakab, L.; Füzi, J.; Veres, T.; Bottyán, L.

2018-05-01

A neutron polarizer using four successive reflections on m = 2.5 supermirrors was built and installed at the GINA neutron reflectometer at the Budapest Neutron Centre. This simple setup exhibits 99.6% polarizing efficiency with 80% transmitted intensity of the selected polarization state. Due to the geometry, the higher harmonics in the incident beam are filtered out, while the optical axis of the beam remains intact for easy mounting and dismounting the device in an existing experimental setup.

A catheter friction tester using balance sensor: Combined evaluation of the effects of mechanical properties of tubing materials and surface coatings.

PubMed

Røn, Troels; Jacobsen, Kristina Pilgaard; Lee, Seunghwan

2018-04-24

In this study, we introduce a new experimental approach to characterize the forces emerging from simulated catherization. This setup allows for a linear translation of urinary catheters in vertical direction as controlled by an actuator. By employing silicone-based elastomer with a duct of comparable diameter with catheters as urethra model, sliding contacts during the translation of catheters along the duct is generated. A most unique design and operation feature of this setup is that a digital balance was employed as the sensor to detect emerging forces from simulated catherization. Moreover, the possibility to give a variation in environment (ambient air vs. water), clearance, elasticity, and curvature of silicone-based urethra model allows for the detection of forces arising from diverse simulated catherization conditions. Two types of commercially available catheters varying in tubing materials and surface coatings were tested together with their respective uncoated catheter tubing. The first set of testing on the catheter samples showed that this setup can probe the combined effect from flexural strain of bulk tubing materials and slipperiness of surface coatings, both of which are expected to affect the comfort and smooth gliding in clinical catherization. We argue that this new experimental setup can provide unique and valuable information in preclinical friction testing of urinary catheters. Copyright © 2018 Elsevier Ltd. All rights reserved.

The development of the experimental setup for measuring the cell membrane electrical potential by Sucrose-Gap Technique

NASA Astrophysics Data System (ADS)

Yuzhakov, AD; Nosarev, AV; Aleinik, AN

2017-11-01

This article describes the development of the experimental setup for measuring the cell membrane electrical potential by Double -Sucrose-Gap Technique. The double-gap isolation method allows the simultaneous measurement of electrical activity and tension output from contracting segments of muscle fibers. This technique has been widely used as a convenient tool for recording of the membrane activities from myelinated or unmyelinated nerves and muscle preparations. This device can be an effective way to provide undergraduate biomedical engineering students with invaluable experiences in neurophysiology. The installation design and its main characteristics are described. The advantages of the described device are the simplicity of the experiment, relatively low cost, the possibility of long-term experiment.

Stable thermophoretic trapping of generic particles at low pressures

NASA Astrophysics Data System (ADS)

Fung, Long Fung Frankie

2017-04-01

We demonstrate levitation and three-dimensionally stable trapping of a wide variety of particles in medium vacuum through thermophoresis. Typical sizes of the trapped particles are between 10 μm and 1 mm; air pressure is between 1 and 10 Torr. We describe the experimental setup used to produce the temperature gradient, as well as our procedure for introducing particles into the experimental setup. To determine the levitation force and test various theoretical models, we examine the levitation heights of spherical polyethylene spheres under various conditions. A good agreement with two theoretical models is concluded. Our system offers a platform to discover various thermophoretic phenomena and to simulate dynamics of interacting many-body systems in a microgravity environment. NSF MRSEC Grant No. DMR-1420709.

Velocity Measurements in Nasal Cavities by Means of Stereoscopic Piv - Preliminary Tests

NASA Astrophysics Data System (ADS)

Cozzi, Fabio; Felisati, Giovanni; Quadrio, Maurizio

2017-08-01

The prediction of detailed flow patterns in human nasal cavities using computational fluid dynamics (CFD) can provide essential information on the potential relationship between patient-specific geometrical characteristics of the nasal anatomy and health problems, and ultimately led to improved surgery. The complex flow structure and the intricate geometry of the nasal cavities make achieving such goals a challenge for CFD specialists. The need for experimental data to validate and improve the numerical simulations is particularly crucial. To this aim an experimental set-up based on Stereo PIV and a silicon phantom of nasal cavities have been designed and realized at Politecnico di Milano. This work describes the main features and challenges of the set-up along with some preliminary results.

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

Bahena, A.; Villasenor, L.

We describe a simple experimental setup to measure the rate of arrival of muons at the surface of the Earth by using a single water Cerenkov detector and home-made electronics. We find a strong anti-correlation between the muon rates averaged over one-hour periods and the atmospheric pressure, with a measured correlation coefficient of -0.67% per hPa. After applying this correction we achieve sufficient sensitivity to observe long term (hours) variations in the averaged muon rates which are greater than 2%. Forbush decreases as big as 4% have been observed with muon detectors located at similar magnetic rigidities compared to Morelia,more » therefore our experimental setup will detect Forbush decreases as soon as the Sun enters into a more active phase.« less

Calibration of a Background Oriented Schlieren (BOS) Set-up

NASA Astrophysics Data System (ADS)

Porta, David; Echeverría, Carlos; Cardoso, Hiroki; Aguayo, Alejandro; Stern, Catalina

2014-11-01

We use two materials with different known indexes of refraction to calibrate a Background Oriented Schlieren (BOS) experimental set-up, and to validate the Lorenz-Lorentz equation. BOS is used in our experiments to determine local changes of density in the shock pattern of an axisymmetric supersonic air jet. It is important to validate, in particular, the Gladstone Dale approximation (index of refraction close to one) in our experimental conditions and determine the uncertainty of our density measurements. In some cases, the index of refraction of the material is well known, but in others the density is measured and related to the displacement field. We acknowledge support from UNAM through DGAPA PAPIIT IN117712 and the Graduate Program in Mechanical Engineering.

Coherent properties of ultraweak photon emission from biological system and its application in medicine

NASA Astrophysics Data System (ADS)

Zhu, Yanbin; Ma, Junfu; Guo, Zhouyi

2001-10-01

In the paper the research status and viewpoints about the coherent of the ultra-weak photon emission from biological system (UPE) were simply introduced. For proving the biophotons indeed have coherent from another side, an experimental setup for testing UPE in different spectral region was designed. Using the experimental setup the test data of different several spectral regions from 300nm to 1060nm has been got. These test results show that UPE of living biological system exists in wide spectra region from UV-visible to infrared. Using the test data, we also can obtain the important conclusion of UPE has coherence. In the end of this paper, the UPE's application in medicine was discussed.

Detecting technology of biophotons

NASA Astrophysics Data System (ADS)

Ma, Junfu; Zhu, Zhaohui; Zhu, Yanbin

2002-03-01

A key technique of detecting the ultra-weak photon emission from biological system (UPE) is to change the light signal of an extremely weak level into electric signal of a considerable level when the photo-electric detecting system were be applied. This paper analyzed the difficult for detecting the ultra-weak photon emission from biological system (UPE) mainly is in the absence of high sensitivity detector in UV-visible-infra spectra region. An experimental setup for testing UPE in different spectral region was designed. Using the experimental setup the test data of different several spectral regions from 300 nm to 1060 nm has were tested. The test result show the UPE of living biological system exists in wide spectra region from UV- visible to infrared.

Design and calibration of zero-additional-phase SPIDER

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

Baum, Peter; Riedle, Eberhard

2005-09-01

Zero-additional-phase spectral phase interferometry for direct electric field reconstruction (ZAP-SPIDER) is a novel technique for measuring the temporal shape and phase of ultrashort optical pulses directly at the interaction point of a spectroscopic experiment. The scheme is suitable for an extremely wide wavelength region from the ultraviolet to the near infrared. We present a comprehensive description of the experimental setup and design guidelines to effectively apply the technique to various wavelengths and pulse durations. The calibration of the setup and procedures to check the consistency of the measurement are discussed in detail. We show experimental data for various center wavelengthsmore » and pulse durations down to 7 fs to verify the applicability to a wide range of pulse parameters.« less

External audits of electron beams using mailed TLD dosimetry: preliminary results.

PubMed

Gomola, I; Van Dam, J; Isern-Verdum, J; Verstraete, J; Reymen, R; Dutreix, A; Davis, B; Huyskens, D

2001-02-01

A feasibility study has been performed to investigate the possibility of using mailed thermoluminescence dosimetry (TLD) for external audits of clinical electron beams in Europe. In the frame of the EC Network Project for Quality Assurance in Radiotherapy, instruction sheets and mailing procedures have been defined for mailed TLD dosimetry using the dedicated holder developed by a panel of experts of the International Atomic Energy Agency (IAEA). Three hundred and thirty electron beam set-ups have been checked in the reference centres and some local centres of the EC Network Project and in addition through the centres participating to the EORTC Radiotherapy Group trial 22922. The mean ratio of measured dose to stated dose is 0.2% and the standard deviation of measured dose to stated dose is 3.2%. In seven beam set-ups, deviations greater than 10% were observed (max. 66%), showing the usefulness of these checks. The results of this feasibility study (instruction sheets, mailing procedures, holder) are presently endorsed by the EQUAL-ESTRO structure in order to offer in the future to all ESTRO members the possibility to request external audits of clinical electron beams.

Construction and beam-tests of silicon-tungsten prototype modules for the CMS High Granularity Calorimeter for HL-LHC

NASA Astrophysics Data System (ADS)

Quast, Thorben

2018-02-01

As part of its HL-LHC upgrade program, CMS is developing a High Granularity Calorimeter (HGCAL) to replace the existing endcap calorimeters. The HGCAL will be realised as a sampling calorimeter, including an electromagnetic compartment comprising 28 layers of silicon pad detectors with pad areas of 0.5-1.0 cm2 interspersed with absorbers. Prototype modules, based on 6-inch hexagonal silicon pad sensors with 128 channels, have been constructed and include many of the features required for this challenging detector. In 2016, beam tests of sampling configurations made from these modules have been conducted both at FNAL and at CERN using the Skiroc2 front-end ASIC (designed by the CALICE collaboration for ILC). In 2017, the setup has been extended with CALICE's AHCAL prototype, a scinitillator based sampling calorimeter, and it was further tested in dedicated beam tests at CERN. There, the new Skiroc2-CMS front-end ASIC was used for the first time. We highlight final results from our studies in 2016, including position resolution as well as precision timing-measurements. Furthermore, the extended setup in 2017 is discussed and first results from beam tests with electrons and pions are shown.

Real-Time Capabilities of a Digital Analyzer for Mixed-Field Assay Using Scintillation Detectors

NASA Astrophysics Data System (ADS)

Aspinall, M. D.; Joyce, M. J.; Lavietes, A.; Plenteda, R.; Cave, F. D.; Parker, H.; Jones, A.; Astromskas, V.

2017-03-01

Scintillation detectors offer a single-step detection method for fast neutrons and necessitate real-time acquisition, whereas this is redundant in two-stage thermal detection systems using helium-3 and lithium-6, where the fast neutrons need to be thermalized prior to detection. The relative affordability of scintillation detectors and the associated fast digital acquisition systems have enabled entirely new measurement setups that can consist of sizeable detector arrays. These detectors in most cases rely on photomultiplier tubes, which have significant tolerances and result in variations in detector response functions. The detector tolerances and other environmental instabilities must be accounted for in measurements that depend on matched detector performance. This paper presents recent advances made to a high-speed FPGA-based digitizer. The technology described offers a complete solution for fast-neutron scintillation detectors by integrating multichannel high-speed data acquisition technology with dedicated detector high-voltage supplies. This configuration has significant advantages for large detector arrays that require uniform detector responses. We report on bespoke control software and firmware techniques that exploit real-time functionality to reduce setup and acquisition time, increase repeatability, and reduce statistical uncertainties.

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.

Networked Experiments and Scientific Resource Sharing in Cooperative Knowledge Spaces

ERIC Educational Resources Information Center

Cikic, Sabine; Jeschke, Sabina; Ludwig, Nadine; Sinha, Uwe; Thomsen, Christian

2007-01-01

Cooperative knowledge spaces create new potentials for the experimental fields in natural sciences and engineering because they enhance the accessibility of experimental setups through virtual laboratories and remote technology, opening them for collaborative and distributed usage. A concept for extending existing virtual knowledge spaces for the…

Getting Shocks: Teaching Secondary School Physics through History.

ERIC Educational Resources Information Center

Heering, Peter

2000-01-01

Uses several replicas of experimental set-ups that were originally used in electrostatic research in teaching electrostatics through history on secondary school level. Makes visible the change of the style of electrostatic experimentation that took place at the end of the 18th century. (Contains 25 references.) (ASK)

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, ...

Cognitive and Pedagogical Benefits of Argument Mapping: L.A.M.P. Guides the Way to Better Thinking

NASA Astrophysics Data System (ADS)

Rider, Yanna; Thomason, Neil

Experimental evidence shows that in dedicated Critical Thinking courses “Lots of Argument Mapping Practice” (LAMP) using a software tool like Rationale considerably improves students’ critical thinking skills. We believe that teaching with LAMP has additional cognitive and pedagogical benefits, even outside dedicated Critical Thinking subjects. Students learn to better understand and critique arguments, improve in their reading and writing, become clearer in their thinking and, perhaps, even gain meta-cognitive skills that ultimately make them better learners. We discuss some of the evidence for these claims, explain how, as we believe, LAMP confers these benefits, and call for proper experimental and educational research.

Toward a 35-years North American Precipitation and Surface Reanalysis

NASA Astrophysics Data System (ADS)

Gasset, N.; Fortin, V.

2017-12-01

In support of the International Watersheds Initiative (IWI) of the International Joint Commission (IJC), a 35-years precipitation and surface reanalysis covering North America at a 3-hours and 15-km resolution is currently being developed at the Canadian Meteorological Centre (CMC). A deterministic reforecast / dynamical downscaling approach is followed where a global reanalysis (ERA-Interim) is used as initial condition of the Global Environmental Multi-scale model (GEM). Moreover, the latter is coupled with precipitation and surface data assimilation systems, i.e. the Canadian Precipitation Analysis (CaPA) and the Canadian Land Data Assimilation System (CaLDAS). While optimized to be more computationally efficient in the context of a reforecast experiment, all systems used are closely related to model versions and configurations currently run operationally at CMC, meaning they have undergone a strict and thorough validation procedure.As a proof of concept and in order to identify the optimal set-up before achieving the 35-years reanalysis, several configurations of the approach are evaluated for the years 2010-2014 using both standard CMC validation methodology as well as more dedicated scores such as comparison against the currently available products (North American Regional Reanalysis, MERRA-Land and the newly released ERA5 reanalysis). A special attention is dedicated to the evaluation of analysed variables, i.e. precipitation, snow depth, surface/ground temperature and moisture over the whole domain of interest. Results from these preliminary samples are very encouraging and the optimal set-up is identified. The coupled approach, i.e. GEM+CaPA/CaLDAS, always shows clear improvements over classical reforecast and dynamical downscaling where surface observations are present. Furthermore, results are inline or better than currently available products and the reference CMC operational approach that was operated from 2012 to 2016 (GEM 3.3, 10-km resolution). This reanalysis will allow for bias correction of current estimates and forecasts, and help decision maker understand and communicate by how much the current forecasted state of the system differs from the recent past.

New experimental methodology, setup and LabView program for accurate absolute thermoelectric power and electrical resistivity measurements between 25 and 1600 K: application to pure copper, platinum, tungsten, and nickel at very high temperatures.

PubMed

Abadlia, L; Gasser, F; Khalouk, K; Mayoufi, M; Gasser, J G

2014-09-01

In this paper we describe an experimental setup designed to measure simultaneously and very accurately the resistivity and the absolute thermoelectric power, also called absolute thermopower or absolute Seebeck coefficient, of solid and liquid conductors/semiconductors over a wide range of temperatures (room temperature to 1600 K in present work). A careful analysis of the existing experimental data allowed us to extend the absolute thermoelectric power scale of platinum to the range 0-1800 K with two new polynomial expressions. The experimental device is controlled by a LabView program. A detailed description of the accurate dynamic measurement methodology is given in this paper. We measure the absolute thermoelectric power and the electrical resistivity and deduce with a good accuracy the thermal conductivity using the relations between the three electronic transport coefficients, going beyond the classical Wiedemann-Franz law. We use this experimental setup and methodology to give new very accurate results for pure copper, platinum, and nickel especially at very high temperatures. But resistivity and absolute thermopower measurement can be more than an objective in itself. Resistivity characterizes the bulk of a material while absolute thermoelectric power characterizes the material at the point where the electrical contact is established with a couple of metallic elements (forming a thermocouple). In a forthcoming paper we will show that the measurement of resistivity and absolute thermoelectric power characterizes advantageously the (change of) phase, probably as well as DSC (if not better), since the change of phases can be easily followed during several hours/days at constant temperature.

New experimental methodology, setup and LabView program for accurate absolute thermoelectric power and electrical resistivity measurements between 25 and 1600 K: Application to pure copper, platinum, tungsten, and nickel at very high temperatures

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

Abadlia, L.; Mayoufi, M.; Gasser, F.

2014-09-15

In this paper we describe an experimental setup designed to measure simultaneously and very accurately the resistivity and the absolute thermoelectric power, also called absolute thermopower or absolute Seebeck coefficient, of solid and liquid conductors/semiconductors over a wide range of temperatures (room temperature to 1600 K in present work). A careful analysis of the existing experimental data allowed us to extend the absolute thermoelectric power scale of platinum to the range 0-1800 K with two new polynomial expressions. The experimental device is controlled by a LabView program. A detailed description of the accurate dynamic measurement methodology is given in thismore » paper. We measure the absolute thermoelectric power and the electrical resistivity and deduce with a good accuracy the thermal conductivity using the relations between the three electronic transport coefficients, going beyond the classical Wiedemann-Franz law. We use this experimental setup and methodology to give new very accurate results for pure copper, platinum, and nickel especially at very high temperatures. But resistivity and absolute thermopower measurement can be more than an objective in itself. Resistivity characterizes the bulk of a material while absolute thermoelectric power characterizes the material at the point where the electrical contact is established with a couple of metallic elements (forming a thermocouple). In a forthcoming paper we will show that the measurement of resistivity and absolute thermoelectric power characterizes advantageously the (change of) phase, probably as well as DSC (if not better), since the change of phases can be easily followed during several hours/days at constant temperature.« less

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.

The EuroSprite2005 Observational Campaign: an example of training and outreach opportunities for CAL young scientists

NASA Astrophysics Data System (ADS)

Chanrion, O.; Crosby, N. B.; Arnone, E.; Boberg, F.; van der Velde, O.; Odzimek, A.; Mika, Á.; Enell, C.-F.; Berg, P.; Ignaccolo, M.; Steiner, R. J.; Laursen, S.; Neubert, T.

2007-07-01

The four year "Coupling of Atmospheric Layers (CAL)" EU FP5 Research Training Network project studied unanswered questions related to transient luminous events (sprites, jets and elves) in the upper atmosphere. Consisting of ten scientific work-packages CAL also included intensive training and outreach programmes for the young scientists hired. Educational activities were based on the following elements: national PhD programmes, activities at CAL and other meetings, a dedicated summer school, and two European sprite observational campaigns. The young scientists were strongly involved in the latter and, as an example, the "EuroSprite2005" observational campaign is presented in detail. Some of the young scientists participated in the instrument set-up, others in the campaign logistics, some coordinated the observations, and others gathered the results to build a catalogue. During the four-month duration of this campaign, all of them took turns in operating the system and making their own night observations. The ongoing campaign activities were constantly advertised and communicated via an Internet blog. In summary the campaign required all the CAL young scientists to embark on experimental work, to develop their organisational skills, and to enhance their ability to communicate their activities. The campaign was a unique opportunity to train and strengthen skills that will be an asset to their future careers and, overall, was most successful.

TEM Cell Testing of Cable Noise Reduction Techniques from 2 MHz to 200 MHz -- Part 2

NASA Technical Reports Server (NTRS)

Bradley, Arthur T.; Evans, William C.; Reed, Joshua L.; Shimp, Samuel K., III; Fitzpatrick, Fred D.

2008-01-01

This paper presents empirical results of cable noise reduction techniques as demonstrated in a TEM cell operating with radiated fields from 2 - 200 MHz. It is the second part of a two-paper series. The first paper discussed cable types and shield connections. In this second paper, the effects of load and source resistances and chassis connections are examined. For each topic, well established theories are compared to data from a real-world physical system. Finally, recommendations for minimizing cable susceptibility (and thus cable emissions) are presented. There are numerous papers and textbooks that present theoretical analyses of cable noise reduction techniques. However, empirical data is often targeted to low frequencies (e.g. <50 KHz) or high frequencies (>100 MHz). Additionally, a comprehensive study showing the relative effects of various noise reduction techniques is needed. These include the use of dedicated return wires, twisted wiring, cable shielding, shield connections, changing load or source impedances, and implementing load- or source-to-chassis isolation. We have created an experimental setup that emulates a real-world electrical system, while still allowing us to independently vary a host of parameters. The goal of the experiment was to determine the relative effectiveness of various noise reduction techniques when the cable is in the presence of radiated emissions from 2 MHz to 200 MHz.

The new NCPSS BL19U2 beamline at the SSRF for small-angle X-ray scattering from biological macromolecules in solution.

PubMed

Li, Na; Li, Xiuhong; Wang, Yuzhu; Liu, Guangfeng; Zhou, Ping; Wu, Hongjin; Hong, Chunxia; Bian, Fenggang; Zhang, Rongguang

2016-10-01

The beamline BL19U2 is located in the Shanghai Synchrotron Radiation Facility (SSRF) and is its first beamline dedicated to biological material small-angle X-ray scattering (BioSAXS). The electrons come from an undulator which can provide high brilliance for the BL19U2 end stations. A double flat silicon crystal (111) monochromator is used in BL19U2, with a tunable monochromatic photon energy ranging from 7 to 15 keV. To meet the rapidly growing demands of crystallographers, biochemists and structural biologists, the BioSAXS beamline allows manual and automatic sample loading/unloading. A Pilatus 1M detector (Dectris) is employed for data collection, characterized by a high dynamic range and a short readout time. The highly automated data processing pipeline SASFLOW was integrated into BL19U2, with help from the BioSAXS group of the European Molecular Biology Laboratory (EMBL, Hamburg), which provides a user-friendly interface for data processing. The BL19U2 beamline was officially opened to users in March 2015. To date, feedback from users has been positive and the number of experimental proposals at BL19U2 is increasing. A description of the new BioSAXS beamline and the setup characteristics is given, together with examples of data obtained.

Search of GRB with AGILE Minicalorimeter

NASA Astrophysics Data System (ADS)

Fuschino, F.; Labanti, C.; Galli, M.; Marisaldi, M.; Bulgarelli, A.; Gianotti, F.; Trifoglio, M.; Argan, A.; Del Monte, E.; Donnarumma, I.; Feroci, M.; Lazzarotto, F.; Pacciani, L.; Tavani, M.; Trois, A.

2008-04-01

AGILE, the small scientific mission of the Italian Space Agency devoted to Hard-X and Gamma-ray astrophysics, was successfully launched on April 23, 2007. The AGILE payload is composed of a tungsten-silicon tracker (ST), operating in the gamma-ray energy range 30 MeV 50 GeV; Super-AGILE, an X-ray imager operating in the energy range 15 45 keV; the Minicalorimeter (MCAL) and an Anticoincidence shield. MCAL is a detector of about 1400 cm2 sensitive in the range 0.3 200 MeV, that can be used both as a slave of the ST to contribute to the AGILE Gamma Ray imaging Detector (GRID operative mode) and autonomously for detection of transient events (BURST operative mode). MCAL is made of 30 CsI(Tl) bar-shaped scintillation detectors with photodiode readout at both ends, arranged in two orthogonal layers. Energy and position of interaction can be derived from a proper composition of the signals readout at the bar's ends, absolute time tagging can be achieved with a μs resolution. The Burst logic deals with various rate-meters on different time scales, energy bands, and MCAL spatial zones. Different algorithms can be chosen for Burst triggering considering also the contribution of other detectors like Super AGILE. In this paper the various trigger logic will be reviewed as well as their on-ground test performed with a dedicated experimental setup.

Optimization of Experiment Detecting Kaon and Pion Internal Structure

NASA Astrophysics Data System (ADS)

Wacht, Jacob

2016-09-01

Pions and kaons are the lightest two-quark systems in Nature. Scientists believe that the rules governing the strong interaction are chirally, symmetric. If this were true, the pion would have no mass. The chiral symmetry is broken dynamically by quark-gluon interactions, giving the pion mass. The pion is thus seen as the key to confirm the mechanism that dynamically generates nearly all of the mass of hadrons and central to the effort to understand hadron structure. The most prominent observables are the meson form factors. Experiments are planned at the 12 GeV Jefferson Lab. An experiment aimed at shedding light on the kaon's internal structure is scheduled to run in 2017. The experimental setup has been optimized for detecting kaons, but it may allow for detecting pions between values of Q2 of 0.4 and 5.5 GeV2. Measurements of the separated pion cross section and exploratory extraction of the pion form factor from electroproduction at low Q2 could be compared to earlier e-pi scattering data, and thus help validating the method. At high Q2, these measurements provide the first L/T separated cross sections and could help guide planned dedicated pion experiments. I will present possible parasitic studies with the upcoming kaon experiment. This work was supported in part by NSF Grant PHY-1306227.

Warped frequency transform analysis of ultrasonic guided waves in long bones

NASA Astrophysics Data System (ADS)

De Marchi, L.; Baravelli, E.; Xu, K.; Ta, D.; Speciale, N.; Marzani, A.; Viola, E.

2010-03-01

Long bones can be seen as irregular hollow tubes, in which, for a given excitation frequency, many ultrasonic Guided Waves (GWs) can propagate. The analysis of GWs is potential to reflect more information on both geometry and material properties of the bone than any other method (such as dual-energy X-ray absorptiometry, or quantitative computed tomography), and can be used in the assessment of osteoporosis and in the evaluation of fracture healing. In this study, time frequency representations (TFRs) were used to gain insights into the expected behavior of GWs in bones. To this aim, we implemented a dedicated Warped Frequency Transform (WFT) which decomposes the spectrotemporal components of the different propagating modes by selecting an appropriate warping map to reshape the frequency axis. The map can be designed once the GWs group velocity dispersion curves can be predicted. To this purpose, the bone is considered as a hollow cylinder with inner and outer diameter of 16.6 and 24.7 mm, respectively, and linear poroelastic material properties in agreement with the low level of stresses induced by the waves. Timetransient events obtained experimentally, via a piezoelectric ultrasonic set-up applied to bovine tibiae, are analyzed. The results show that WFT limits interference patterns which appear with others TFRs (such as scalograms or warpograms) and produces a sparse representation suitable for characterization purposes. In particular, the mode-frequency combinations propagating with minimal losses are identified.

In vivo evaluation of the potential neurotoxicity of aerosols released from mechanical stress of nano-TiO2 additived paints in mice chronically exposed by inhalation

NASA Astrophysics Data System (ADS)

Manixay, S.; Delaby, S.; Gaie-Levrel, F.; Wiart, M.; Motzkus, C.; Bencsik, A.

2017-06-01

Engineered Nanomaterials (ENM) provide technical and specific benefits due to their physical-chemical properties at the nanometer scale. For instance, many ENM are used to improve products in the building industry. Nanoscaled titanium dioxide (TiO2) is one of the most used ENM in this industry. Incorporated in different matrix, cement, glass, paints… TiO2 nanoparticles (NPs) provide the final product with anti-UV, air purification and self-cleaning properties, thanks to their photocatalytic activity. However, ageing processes of such products, as photocatalytic paints, during a mechanical stress have been shown to release TiO2 NPs from this matrix associated with sanding dust. Thus, workers who sand painted walls could be exposed to TiO2 NPs through inhalation. As inhalation may lead to a translocation of particulate matter to the brain via olfactory or trigeminal nerves, there is an urgent need for evaluating a potential neurotoxicity. In order to provide new knowledge on this topic, we developed a dedicated experimental set-up using a rodent model exposed via inhalation. The aerosol released from a mechanical stress of photocatalytic paints containing TiO2 NPs was characterized and coupled to an exposition chamber containing group of mice free to move and chronically exposed (2 hours per day for 5 days a week during 8 weeks).

Laboratory reconnection experiments

NASA Astrophysics Data System (ADS)

Grulke, Olaf

Laboratory experiments dedicated for the study of magnetic reconnection have been contributed considerably to a more detailed understanding of the involved processes. Their strength is to disentangle parameter dependencies, to diagnose in detail the plasma and field response, and to form an excellent testbed for the validation of numerical simulations. In the present paper recent results obtained from the new cylindrical reconnection experiment VINETA II are presented. The experimental setup allows to independently vary plasma parameters, reconnection drive strength/timescale, and current sheet amplitude. Current research objectives focus on two major scientific issues: Guide field effects on magnetic reconnection and the evolution of electromagnetic fluctuations. The superimposed homogeneous magnetic guide field has a strong influence on the spatiotemporal evolution of the current sheet, predominantly due to magnetic pitch angle effects, which leads to a strong elongation of the sheet along the separatrices and results in axial gradients of the reconnection rates. Within the current sheet, incoherent electromagnetic fluctuations are observed. Their magnetic signature is characterized by a broad spectrum somewhat centered around the lower-hybrid frequency and extremely short spatial correlation lengths being typically smaller than the local ion sound radius. The fluctuation amplitude correlates with the local current density and, thus, for low guide fields, displays also axial gradients. Despite the quantitatively different parameter regime and geometry the basic fluctuation properties are in good agreement with studies conducted at the MRX experiment (PPPL).

Laboratory simulation to support the search for organic molecules at the surface of Mars

NASA Astrophysics Data System (ADS)

Poch, Olivier; Szopa, Cyril; Coll, Patrice; Jaber, Maguy; Georgelin, Thomas; Lambert, Jean-Francois; Stalport, Fabien

The search for organic carbon at the surface of Mars, as clues of past habitability or remnants of life, is a major science goal of Mars’ exploration. Understanding the chemical evolution of organic molecules under current Martian environmental conditions is essential to support the analyses performed in situ. What molecule can be preserved? What is the timescale of organic evolution at the surface? Here we present results of laboratory investigations dedicated to monitor qualitative and quantitative evolutions of several organic molecules under simulated Martian surface ultraviolet incident light, mean ground temperature and pressure, using the Mars Organic Molecules Irradiation and Evolution setup (1) . For each organic molecule studied, the nature of the evolution products (solid or gaseous) and the kinetic parameters (extrapolated half-life at Mars, quantum yields) were experimentally determined. The results show that when exposed to UV radiation, specific organic molecules lead to the formation of solid residues, probably of macromolecular nature, which could reach long term stability. On the other hand, the study of the evolution of molecules in presence of nontronite, a clay mineral detected at the surface of Mars, highlights a strong protective effect of the clay reducing dissociation rates for some molecules, whereas a possible catalytic effect is tentatively observed for one studied molecule. These results are essential to support the analyses performed in situ during the past, current and future exploration missions. Moreover, the experimentally determined kinetic parameters provide new inputs for numerical modeling of current reservoirs of organic molecules on Mars. (1) O. Poch et al., Planetary and Space Science 85, 188-197, http://dx.doi.org/10.1016/j.pss.2013.06.013

Experimental investigation by laser ultrasonics for high speed train axle diagnostics.

PubMed

Cavuto, A; Martarelli, M; Pandarese, G; Revel, G M; Tomasini, E P

2015-01-01

The present paper demonstrates the applicability of a laser-ultrasonic procedure to improve the performances of train axle ultrasonic inspection. The method exploits an air-coupled ultrasonic probe that detects the ultrasonic waves generated by a high-power pulsed laser. As a result, the measurement chain is completely non-contact, from generation to detection, this making it possible to considerably speed up inspection time and make the set-up more flexible. The main advantage of the technique developed is that it works in thermo-elastic regime and it therefore can be considered as a non-destructive method. The laser-ultrasonic procedure investigated has been applied for the inspection of a real high speed train axle provided by the Italian railway company (Trenitalia), on which typical fatigue defects have been expressly created according to standard specifications. A dedicated test bench has been developed so as to rotate the axle with the angle control and to speed up the inspection of the axle surface. The laser-ultrasonic procedure proposed can be automated and is potentially suitable for regular inspection of train axles. The main achievements of the activity described in this paper are: – the study of the effective applicability of laser-ultrasonics for the diagnostic of train hollow axles with variable sections by means of a numerical FE model, – the carrying out of an automated experiment on a real train axle, – the analysis of the sensitivity to experimental parameters, like laser source – receiving probe distance and receiving probe angular position, – the demonstration that the technique is suitable for the detection of surface defects purposely created on the train axle. Copyright © 2014 Elsevier B.V. All rights reserved.

High-rate dead-time corrections in a general purpose digital pulse processing system

PubMed Central

Abbene, Leonardo; Gerardi, Gaetano

2015-01-01

Dead-time losses are well recognized and studied drawbacks in counting and spectroscopic systems. In this work the abilities on dead-time correction of a real-time digital pulse processing (DPP) system for high-rate high-resolution radiation measurements are presented. The DPP system, through a fast and slow analysis of the output waveform from radiation detectors, is able to perform multi-parameter analysis (arrival time, pulse width, pulse height, pulse shape, etc.) at high input counting rates (ICRs), allowing accurate counting loss corrections even for variable or transient radiations. The fast analysis is used to obtain both the ICR and energy spectra with high throughput, while the slow analysis is used to obtain high-resolution energy spectra. A complete characterization of the counting capabilities, through both theoretical and experimental approaches, was performed. The dead-time modeling, the throughput curves, the experimental time-interval distributions (TIDs) and the counting uncertainty of the recorded events of both the fast and the slow channels, measured with a planar CdTe (cadmium telluride) detector, will be presented. The throughput formula of a series of two types of dead-times is also derived. The results of dead-time corrections, performed through different methods, will be reported and discussed, pointing out the error on ICR estimation and the simplicity of the procedure. Accurate ICR estimations (nonlinearity < 0.5%) were performed by using the time widths and the TIDs (using 10 ns time bin width) of the detected pulses up to 2.2 Mcps. The digital system allows, after a simple parameter setting, different and sophisticated procedures for dead-time correction, traditionally implemented in complex/dedicated systems and time-consuming set-ups. PMID:26289270

The PMIP4 contribution to CMIP6 - Part 3: The last millennium, scientific objective, and experimental design for the PMIP4 past1000 simulations

NASA Astrophysics Data System (ADS)

Jungclaus, Johann H.; Bard, Edouard; Baroni, Mélanie; Braconnot, Pascale; Cao, Jian; Chini, Louise P.; Egorova, Tania; Evans, Michael; Fidel González-Rouco, J.; Goosse, Hugues; Hurtt, George C.; Joos, Fortunat; Kaplan, Jed O.; Khodri, Myriam; Klein Goldewijk, Kees; Krivova, Natalie; LeGrande, Allegra N.; Lorenz, Stephan J.; Luterbacher, Jürg; Man, Wenmin; Maycock, Amanda C.; Meinshausen, Malte; Moberg, Anders; Muscheler, Raimund; Nehrbass-Ahles, Christoph; Otto-Bliesner, Bette I.; Phipps, Steven J.; Pongratz, Julia; Rozanov, Eugene; Schmidt, Gavin A.; Schmidt, Hauke; Schmutz, Werner; Schurer, Andrew; Shapiro, Alexander I.; Sigl, Michael; Smerdon, Jason E.; Solanki, Sami K.; Timmreck, Claudia; Toohey, Matthew; Usoskin, Ilya G.; Wagner, Sebastian; Wu, Chi-Ju; Leng Yeo, Kok; Zanchettin, Davide; Zhang, Qiong; Zorita, Eduardo

2017-11-01

The pre-industrial millennium is among the periods selected by the Paleoclimate Model Intercomparison Project (PMIP) for experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6) and the fourth phase of the PMIP (PMIP4). The past1000 transient simulations serve to investigate the response to (mainly) natural forcing under background conditions not too different from today, and to discriminate between forced and internally generated variability on interannual to centennial timescales. This paper describes the motivation and the experimental set-ups for the PMIP4-CMIP6 past1000 simulations, and discusses the forcing agents orbital, solar, volcanic, and land use/land cover changes, and variations in greenhouse gas concentrations. The past1000 simulations covering the pre-industrial millennium from 850 Common Era (CE) to 1849 CE have to be complemented by historical simulations (1850 to 2014 CE) following the CMIP6 protocol. The external forcings for the past1000 experiments have been adapted to provide a seamless transition across these time periods. Protocols for the past1000 simulations have been divided into three tiers. A default forcing data set has been defined for the Tier 1 (the CMIP6 past1000) experiment. However, the PMIP community has maintained the flexibility to conduct coordinated sensitivity experiments to explore uncertainty in forcing reconstructions as well as parameter uncertainty in dedicated Tier 2 simulations. Additional experiments (Tier 3) are defined to foster collaborative model experiments focusing on the early instrumental period and to extend the temporal range and the scope of the simulations. This paper outlines current and future research foci and common analyses for collaborative work between the PMIP and the observational communities (reconstructions, instrumental data).

An experimental study to support the search for organics at Mars

NASA Astrophysics Data System (ADS)

Poch, Olivier; Stalport, Fabien; Noblet, Audrey; Szopa, Cyril; Coll, Patrice

2012-07-01

Several evidences suggest that early Mars offered favorable conditions for long-term sustaining water. As a consequence, we can assume that processes related to prebiotic chemistry, and even the emergence of life, may have occurred on early Mars. In those days, organic matter may have been widespread on Mars, due to exogenous delivery from small bodies, or endogenous chemical processes. The search for these organic relics is one of the main objectives of Mars exploration missions to come. But for about 3 Gy, due to the harsh environmental conditions of the Mars surface (UV radiation, oxidants etc.), the inventory of organic compounds at the current surface or subsurface of Mars may have been narrowed. Two major questions raised by this putative evolution are: What is the evolution pattern of organics in the Martian environment? What types of molecules would have been preserved, and if so, in which conditions? We address these questions using an experimental device dedicated to simulate the processes susceptible to have an effect on organic matter in the current environmental conditions of the Mars surface and subsurface. This experimental setup is part of a project called MOMIE, for Mars Organic Molecules Irradiation and Evolution. We study the evolution of some of the most likely molecular compounds potentially synthesized or brought to Mars (amino acids, hydrocarbons, nucleobases etc.). Nanometers thin deposits of a molecular compound or of a mineral in which the molecular compound has been embedded are allowed to evolve at mean Martian pressure and temperature, under a UV radiation environment similar to the Martian one. Qualitative and quantitative changes of the sample are monitored during the simulation, especially using infrared spectroscopy. We will present and compare the evolution of several organics submitted to these conditions. These experiments will provide essential insights to guide and discuss in situ analyses at Mars, particularly during the upcoming exploration of Gale Crater by Curiosity, the rover of the NASA Mars Science Laboratory mission.

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.

Detection prospects for the Cosmic Neutrino Background using laser interferometers

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

Domcke, Valerie; Spinrath, Martin, E-mail: valerie.domcke@apc.univ-paris7.fr, E-mail: martin.spinrath@cts.nthu.edu.tw

The cosmic neutrino background is a key prediction of Big Bang cosmology which has not been observed yet. The movement of the earth through this neutrino bath creates a force on a pendulum, as if it were exposed to a cosmic wind. We revise here estimates for the resulting pendulum acceleration and compare it to the theoretical sensitivity of an experimental setup where the pendulum position is measured using current laser interferometer technology as employed in gravitational wave detectors. We discuss how a significant improvement of this setup can be envisaged in a micro gravity environment. The proposed setup couldmore » also function as a dark matter detector in the sub-MeV range, which currently eludes direct detection constraints.« less

Using refraction in thick glass plates for optical path length modulation in low coherence interferometry.

PubMed

Kröger, Niklas; Schlobohm, Jochen; Pösch, Andreas; Reithmeier, Eduard

2017-09-01

In Michelson interferometer setups the standard way to generate different optical path lengths between a measurement arm and a reference arm relies on expensive high precision linear stages such as piezo actuators. We present an alternative approach based on the refraction of light at optical interfaces using a cheap stepper motor with high gearing ratio to control the rotation of a glass plate. The beam path is examined and a relation between angle of rotation and change in optical path length is devised. As verification, an experimental setup is presented, and reconstruction results from a measurement standard are shown. The reconstructed step height from this setup lies within 1.25% of the expected value.

Note: Near infrared spectral and transient measurements of PbS quantum dots luminescence.

PubMed

Parfenov, P S; Litvin, A P; Ushakova, E V; Fedorov, A V; Baranov, A V; Berwick, K

2013-11-01

We describe an experimental setup for the characterization of luminescence from nanostructures. The setup is intended for steady-state and time-resolved luminescence measurements in the near-infrared region. The setup allows us to study spectral luminescence properties in the spectral range of 0.8-2.0 μm with high spectral resolution and kinetic luminescence properties between 0.8 and 1.7 μm with a time resolution of 3 ns. The capabilities of the system are illustrated by taking luminescence measurements from PbS quantum dots. We established the size dependencies of the optical properties of the PbS quantum dots over a wide spectral range. Finally, the energy transfer process was studied with a high temporal and spectral resolution.

Search for hybrid baryons with CLAS12 experimental setup

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

Lanza, Lucille

It is crucial to study the meson electroproduction in the kinematic region dominated by the formation of resonances. CLAS12 setup in Hall B at Jefferson Lab is particularly suitable for this task, since it is able to detect scattered electrons at low polar angles thanks to the Forward Tagger (FT) component. The process that we propose to study is ep → e'K +Λ, where the electron beam will be provided by the CEBAF accelerator with energies of 6.6, 8.8, and 11 GeV. This thesis work describes the setup and calibration of the FT calorimeter and the studies related to themore » search of hybrid baryons through the measurement of the K + Λ electroproduction cross section.« less

An electron energy loss spectrometer based streak camera for time resolved TEM measurements.

PubMed

Ali, Hasan; Eriksson, Johan; Li, Hu; Jafri, S Hassan M; Kumar, M S Sharath; Ögren, Jim; Ziemann, Volker; Leifer, Klaus

2017-05-01

We propose an experimental setup based on a streak camera approach inside an energy filter to measure time resolved properties of materials in the transmission electron microscope (TEM). In order to put in place the streak camera, a beam sweeper was built inside an energy filter. After exciting the TEM sample, the beam is swept across the CCD camera of the filter. We describe different parts of the setup at the example of a magnetic measurement. This setup is capable to acquire time resolved diffraction patterns, electron energy loss spectra (EELS) and images with total streaking times in the range between 100ns and 10μs. Copyright © 2016 Elsevier B.V. All rights reserved.

Detection prospects for the Cosmic Neutrino Background using laser interferometers

NASA Astrophysics Data System (ADS)

Domcke, Valerie; Spinrath, Martin

2017-06-01

The cosmic neutrino background is a key prediction of Big Bang cosmology which has not been observed yet. The movement of the earth through this neutrino bath creates a force on a pendulum, as if it were exposed to a cosmic wind. We revise here estimates for the resulting pendulum acceleration and compare it to the theoretical sensitivity of an experimental setup where the pendulum position is measured using current laser interferometer technology as employed in gravitational wave detectors. We discuss how a significant improvement of this setup can be envisaged in a micro gravity environment. The proposed setup could also function as a dark matter detector in the sub-MeV range, which currently eludes direct detection constraints.

Assessment of the Tensile Properties for Single Fibers

DTIC Science & Technology

2018-02-01

Approved for public release; distribution is unlimited. 14. ABSTRACT A novel experimental test method is presented to assess the tensile properties...distribution is unlimited. iii Contents List of Figures iv List of Tables v Acknowledgments vi 1. Introduction 1 2. Experimental Procedure 2 2.1 Test...fiber diameter measurements .............................. 7 Fig. 5 The coordinate system defining the experimental setup with the x- direction along

Experimental Study of the Moment of Inertia of a Cone--Angular Variation and Inertia Ellipsoid

ERIC Educational Resources Information Center

Pintao, Carlos A. F.; de Souza Filho, Moacir P.; Usida, Wesley F.; Xavier, Jose A.

2007-01-01

In this paper, an experimental set-up which differs from the traditional ones is established in order to determine the moment of inertia of a right circular cone. Its angular variation and inertia ellipsoid are determined by means of an experimental study. In addition, a system that allows for the evaluation of the angular acceleration and torque…

Can We Falsify the Consciousness-Causes-Collapse Hypothesis in Quantum Mechanics?

NASA Astrophysics Data System (ADS)

de Barros, J. Acacio; Oas, Gary

2017-10-01

In this paper we examine some proposals to disprove the hypothesis that the interaction between mind and matter causes the collapse of the wave function, showing that such proposals are fundamentally flawed. We then describe a general experimental setup retaining the key features of the ones examined, and show that even a more general case is inadequate to disprove the mind-matter collapse hypothesis. Finally, we use our setup provided to argue that, under some reasonable assumptions about consciousness, such hypothesis is unfalsifiable.

A microprocessor-based table lookup approach for magnetic bearing linearization

NASA Technical Reports Server (NTRS)

Groom, N. J.; Miller, J. B.

1981-01-01

An approach for producing a linear transfer characteristic between force command and force output of a magnetic bearing actuator without flux biasing is presented. The approach is microprocessor based and uses a table lookup to generate drive signals for the magnetic bearing power driver. An experimental test setup used to demonstrate the feasibility of the approach is described, and test results are presented. The test setup contains bearing elements similar to those used in a laboratory model annular momentum control device.

Simulating interfering fringe displacements by lateral shifts of a camera for educational purposes

NASA Astrophysics Data System (ADS)

Rivera-Ortega, Uriel

2018-07-01

In this manuscript we propose a simple method to emulate fringe displacements in a fringe pattern, due to the interference of two plane waves, by using lateral shifts of a CMOS detector under the scheme of a Twyman–Green interferometric setup, avoiding unwanted vibrations and the need for specific and expensive devices in order to accomplish the task. The simplicity of the proposed experimental setup allows it to be easily replicated and used for teaching or demonstrative purposes, essentially for undergraduate students.

Contactless ultrasonic device to measure surface acoustic wave velocities versus temperature.

PubMed

Hubert, C; Nadal, M H; Ravel-Chapuis, G; Oltra, R

2007-02-01

A complete optical experimental setup for generating and detecting surface acoustic waves [Rayleigh waves (RWs)] in metals versus temperature up to the melting point is described. The RWs were excited by a pulsed Nd:YAG laser and detected by a high sensitivity subangstrom heterodyne interferometer. A special furnace was used to heat the sample using infrared radiation with a regulation of the sample temperature less than 0.1 K. First measurements on an aluminum alloy sample are presented to validate the setup.

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

Remote laboratories for optical metrology: from the lab to the cloud

NASA Astrophysics Data System (ADS)

Osten, W.; Wilke, M.; Pedrini, G.

2012-10-01

The idea of remote and virtual metrology has been reported already in 2000 with a conceptual illustration by use of comparative digital holography, aimed at the comparison of two nominally identical but physically different objects, e.g., master and sample, in industrial inspection processes. However, the concept of remote and virtual metrology can be extended far beyond this. For example, it does not only allow for the transmission of static holograms over the Internet, but also provides an opportunity to communicate with and eventually control the physical set-up of a remote metrology system. Furthermore, the metrology system can be modeled in the environment of a 3D virtual reality using CAD or similar technology, providing a more intuitive interface to the physical setup within the virtual world. An engineer or scientist who would like to access the remote real world system can log on to the virtual system, moving and manipulating the setup through an avatar and take the desired measurements. The real metrology system responds to the interaction between the avatar and the 3D virtual representation, providing a more intuitive interface to the physical setup within the virtual world. The measurement data are stored and interpreted automatically for appropriate display within the virtual world, providing the necessary feedback to the experimenter. Such a system opens up many novel opportunities in industrial inspection such as the remote master-sample-comparison and the virtual assembling of parts that are fabricated at different places. Moreover, a multitude of new techniques can be envisaged. To them belong modern ways for documenting, efficient methods for metadata storage, the possibility for remote reviewing of experimental results, the adding of real experiments to publications by providing remote access to the metadata and to the experimental setup via Internet, the presentation of complex experiments in classrooms and lecture halls, the sharing of expensive and complex infrastructure within international collaborations, the implementation of new ways for the remote test of new devices, for their maintenance and service, and many more. The paper describes the idea of remote laboratories and illustrates the potential of the approach on selected examples with special attention to optical metrology.

Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts

NASA Astrophysics Data System (ADS)

Mayr, Lukas; Rameshan, Raffael; Klötzer, Bernhard; Penner, Simon; Rameshan, Christoph

2014-05-01

An ultra-high vacuum (UHV) setup for "real" and "inverse" model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, "magic angle") and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown.

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.

Frequency domain fluorescence diffuse tomography of small animals

NASA Astrophysics Data System (ADS)

Orlova, Anna G.; Turchin, Ilya V.; Kamensky, Vladislav A.; Plehanov, Vladimir I.; Balalaeva, Irina V.; Sergeeva, Ekaterina A.; Shirmanova, Marina V.; Kleshnin, Michail S.

2007-05-01

Fluorescent compounds for selective cancer cell marking are used for development of novel medical diagnostic methods, investigation of the influence of external factors on tumor growth, regress and metastasis. Only special tools for turbid media imaging, such as optical diffusion tomography permit noninvasive monitoring of fluorescent-labeled tumor alterations deep in animal tissue. In this work, the results of preliminary experiments utilizing frequency-domain fluorescent diffusion tomography (FD FDT) experimental setup in small animal are presented. Low-frequency modulated light (1 kHz) from Nd:YAG laser with second harmonic generation at the wavelength of 532 nm was used in the setup. The transilluminative planar configuration was used in the setup. A series of model experiments has been conducted and show good agreement between theoretical and experimental fluorescence intensity. Models of deep tumors were created by two methods: (1) glass capsules containing fluorophore solution were inserted into esophagus of small animals to simulate marked tumors; (2) a suspension of transfected HEΚ293-Turbo-RFP cells was subcutaneously injected to small animal. The conducted experiments have shown that FD FDT allows one to detect the presence of labeled tumor cells in small animals, to determine the volume of an experimental tumor, to perform 3D tumor reconstruction, as well as to conduct monitoring investigations. The obtained results demonstrate the potential capability of the FD FDT method for noninvasive whole-body imaging in cancer studies, diagnostics and therapy.

Stimulation of bone repair with ultrasound: a review of the possible mechanic effects.

PubMed

Padilla, Frédéric; Puts, Regina; Vico, Laurence; Raum, Kay

2014-07-01

In vivo and in vitro studies have demonstrated the positive role that ultrasound can play in the enhancement of fracture healing or in the reactivation of a failed healing process. We review the several options available for the use of ultrasound in this context, either to induce a direct physical effect (LIPUS, shock waves), to deliver bioactive molecules such as growth factors, or to transfect cells with osteogenic plasmids; with a main focus on LIPUS (or Low Intensity Pulsed Ultrasound) as it is the most widespread and studied technique. The biological response to LIPUS is complex as numerous cell types respond to this stimulus involving several pathways. Known to-date mechanotransduction pathways involved in cell responses include MAPK and other kinases signaling pathways, gap-junctional intercellular communication, up-regulation and clustering of integrins, involvement of the COX-2/PGE2, iNOS/NO pathways and activation of ATI mechanoreceptor. The mechanisms by which ultrasound can trigger these effects remain intriguing. Possible mechanisms include direct and indirect mechanical effects like acoustic radiation force, acoustic streaming, and propagation of surface waves, fluid-flow induced circulation and redistribution of nutrients, oxygen and signaling molecules. Effects caused by the transformation of acoustic wave energy into heat can usually be neglected, but heating of the transducer may have a potential impact on the stimulation in some in-vitro systems, depending on the coupling conditions. Cavitation cannot occur at the pressure levels delivered by LIPUS. In-vitro studies, although not appropriate to identify the overall biological effects, are of great interest to study specific mechanisms of action. The diversity of current experimental set-ups however renders this analysis very complex, as phenomena such as transducer heating, inhomogeneities of the sound intensity in the near field, resonances in the transmission and reflection through the culture dish walls and the formation of standing waves will greatly affect the local type and amplitude of the stimulus exerted on the cells. A future engineering challenge is therefore the design of dedicated experimental set-ups, in which the different mechanical phenomena induced by ultrasound can be controlled. This is a prerequisite to evaluate the biological effects of the different phenomena with respect to particular parameters, like intensity, frequency, or duty cycle. By relating the variations of these parameters to the induced physical effects and to the biological responses, it will become possible to derive an 'acoustic dose' and propose a quantification and cross-calibration of the different experimental systems. Improvements in bone healing management will probably also come from a combination of ultrasound with a 'biologic' components, e.g. growth factors, scaffolds, gene therapies, or drug delivery vehicles, the effects of which being potentiated by the ultrasound. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

What to see and where to find it on the Priest River Experimental Forest Idaho

Treesearch

C. A. Wellner; R. F. Watt; A. E. Helmers

1951-01-01

Dedicated to the development of better methods of management and protection of forested lands, the Priest River Experimental Forest is maintained for research and demonstration purposes by the Northern Rocky Mountain Forest and Range Experiment Station of the Forest Service, U. S. Department of Agriculture. The chart on the opposite page shows where the Experimental...

Procedures for cryogenic X-ray ptychographic imaging of biological samples

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

Yusuf, M.; Zhang, F.; Chen, B.

Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This paper describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

Cultures of Experimental Practice--An Approach in a Museum.

ERIC Educational Resources Information Center

Heering, Peter; Muller, Falk

2002-01-01

Describes generations and experiences of an exhibition presented in Spring 1998 at the Oldenburg Museum of Natural History and Pre-History. Discusses the thematic leitmotiv of this exhibition which was to present experiments from the history of physics as a cultural activity. Describes how reconstructions of historical experimental set-ups were…

Procedures for cryogenic X-ray ptychographic imaging of biological samples

DOE PAGES

Yusuf, M.; Zhang, F.; Chen, B.; ...

2017-01-12

Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This paper describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

The fluid mechanics of channel fracturing flows: experiment

NASA Astrophysics Data System (ADS)

Rashedi, Ahmadreza; Tucker, Zachery; Ovarlez, Guillaume; Hormozi, Sarah

2017-11-01

We show our preliminary experimental results on the role of fluid mechanics in channel fracturing flows, particularly yield stress fracturing fluids. Recent trends in the oil industry have included the use of cyclic pumping of a proppant slurry interspersed with a yield stress fracturing fluid, which is found to increase wells productivity, if particles disperse in a certain fashion. Our experimental study aims to investigate the physical mechanisms responsible for dispersing the particles (proppant) within a yield stress carrier fluid, and to measure the dispersion of proppant slugs in various fracturing regimes. To this end we have designed and built a unique experimental setup that resembles a fracture configuration coupled with a particle image/tracking velocimetry setup operating at micro to macro dimensions. Moreover, we have designed optically engineered suspensions of complex fluids with tunable yield stress and consistency, well controlled density match-mismatch properties and refractive indices for both X-rays and visible lights. We present our experimental system and preliminary results. NSF (Grant No. CBET-1554044- CAREER), ACS PRF (Grant No. 55661-DNI9).

Check the Lambert-Beer-Bouguer law: a simple trick to boost the confidence of students toward both exponential laws and the discrete approach to experimental physics

NASA Astrophysics Data System (ADS)

Di Capua, R.; Offi, F.; Fontana, F.

2014-07-01

Exponential decay is a prototypical functional behaviour for many physical phenomena, and therefore it deserves great attention in physics courses at an academic level. The absorption of the electromagnetic radiation that propagates in a dissipative medium provides an example of the decay of light intensity, as stated by the law of Lambert-Beer-Bourguer. We devised a very simple experiment to check this law. The experimental setup, its realization, and the data analysis of the experiment are definitely simple. Our main goal was to create an experiment that is accessible to all students, including those in their first year of academic courses and those with poorly equipped laboratories. As illustrated in this paper, our proposal allowed us to develop a deep discussion about some general mathematical and numerical features of exponential decay. Furthermore, the special setup of the absorbing medium (sliced in finite thickness slabs) and the experimental outcomes allow students to understand the transition from the discrete to the continuum approach in experimental physics.

Photonic crystal enhanced silicon cell based thermophotovoltaic systems

DOE PAGES

Yeng, Yi Xiang; Chan, Walker R.; Rinnerbauer, Veronika; ...

2015-01-30

We report the design, optimization, and experimental results of large area commercial silicon solar cell based thermophotovoltaic (TPV) energy conversion systems. Using global non-linear optimization tools, we demonstrate theoretically a maximum radiative heat-to-electricity efficiency of 6.4% and a corresponding output electrical power density of 0.39 W cm⁻² at temperature T = 1660 K when implementing both the optimized two-dimensional (2D) tantalum photonic crystal (PhC) selective emitter, and the optimized 1D tantalum pentoxide – silicon dioxide PhC cold-side selective filter. In addition, we have developed an experimental large area TPV test setup that enables accurate measurement of radiative heat-to-electricity efficiency formore » any emitter-filter-TPV cell combination of interest. In fact, the experimental results match extremely well with predictions of our numerical models. Our experimental setup achieved a maximum output electrical power density of 0.10W cm⁻² and radiative heat-to-electricity efficiency of 1.18% at T = 1380 K using commercial wafer size back-contacted silicon solar cells.« less

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.

Optical differential reflectance spectroscopy for photochromic molecules on solid surfaces

NASA Astrophysics Data System (ADS)

Nickel, Fabian; Bernien, Matthias; Lipowski, Uwe; Kuch, Wolfgang

2018-03-01

Optical reflectance of thin adsorbates on solid surfaces is able to reveal fundamental changes of molecular properties compared to bulk systems. The detection of very small changes in the optical reflectance required several technical improvements in the past decades. We present an experimental setup that is capable of high-quality measurements of submonolayers and ultrathin layers of photochromic molecules on surfaces as well as quantifying their isomerization kinetics. By using photomultipliers as detectors, an enhancement of the signal-to-noise ratio by a factor of three with a total reduction of light exposure on the sample by at least four orders of magnitude is achieved. The potential of the experimental setup is demonstrated by a characterization of the photoswitching and thermal switching of a spirooxazine derivate on a bismuth surface.

Cell optoporation with a sub-15 fs and a 250-fs laser

NASA Astrophysics Data System (ADS)

Breunig, Hans Georg; Batista, Ana; Uchugonova, Aisada; König, Karsten

2016-06-01

We employed two commercially available femtosecond lasers, a Ti:sapphire and a ytterbium-based oscillator, to directly compare from a user's practical point-of-view in one common experimental setup the efficiencies of transient laser-induced cell membrane permeabilization, i.e., of so-called optoporation. The experimental setup consisted of a modified multiphoton laser-scanning microscope employing high-NA focusing optics. An automatic cell irradiation procedure was realized with custom-made software that identified cell positions and controlled relevant hardware components. The Ti:sapphire and ytterbium-based oscillators generated broadband sub-15-fs pulses around 800 nm and 250-fs pulses at 1044 nm, respectively. A higher optoporation rate and posttreatment viability were observed for the shorter fs pulses, confirming the importance of multiphoton effects for efficient optoporation.

Dynamic MTF, an innovative test bench for detector characterization

NASA Astrophysics Data System (ADS)

Emmanuel, Rossi; Raphaël, Lardière; Delmonte, Stephane

2017-11-01

PLEIADES HR are High Resolution satellites for Earth observation. Placed at 695km they reach a 0.7m spatial resolution. To allow such performances, the detectors are working in a TDI mode (Time and Delay Integration) which consists in a continuous charge transfer from one line to the consecutive one while the image is passing on the detector. The spatial resolution, one of the most important parameter to test, is characterized by the MTF (Modulation Transfer Function). Usually, detectors are tested in a staring mode. For a higher level of performances assessment, a dedicated bench has been set-up, allowing detectors' MTF characterization in the TDI mode. Accuracy and reproducibility are impressive, opening the door to new perspectives in term of HR imaging systems testing.

CRLH-TL Sensors for Flow Inhomogeneties Detection of Pneumatic Conveyed Pulverized Solids

NASA Astrophysics Data System (ADS)

Angelovski, Aleksandar; Penirschke, Andreas; Jakoby, Rolf

2011-08-01

This paper presents an application of a Composite Right/Left-Handed (CRLH) Transmission Line resonator for a compact mass flow detector which is able to detect inhomogeneous flows. In this concept, series capacitors and shunt inductors are used to synthesize a medium with simultaneously negative permeability and permittivity - the so called metamaterial. The helix shape of the cylindrical CRLH-TL sensor offers the possibility to detect flow inhomogeneities within the pipeline which can be used to correct the detected massflow rate. A combination of two CRLH-TL structures within the same cross-section of the pipeline can improve the angular sensitivity of the sensor. A prototype was realized and tested in a dedicated measurement setup to prove the concept.

Development and integration of high straightness flexure guiding mechanisms dedicated to the METAS watt balance Mark II

NASA Astrophysics Data System (ADS)

Cosandier, F.; Eichenberger, A.; Baumann, H.; Jeckelmann, B.; Bonny, M.; Chatagny, V.; Clavel, R.

2014-04-01

There is a firm will in the metrology community to redefine the kilogram in the International System of units by linking it to a fundamental physical constant. The watt balance is a promising way to link the mass unit to the Planck constant h. At the Federal Institute of Metrology METAS a second watt balance experiment is under development. A decisive part of the METAS Mark II watt balance is the mechanical linear guiding system. The present paper discusses the development and the metrological characteristics of two guiding systems that were conceived by the Laboratoire de Systèmes Robotiques of EPFL and built using flexure mechanical elements. Integration in the new setup is also described.

Real time 3D scanner: investigations and results

NASA Astrophysics Data System (ADS)

Nouri, Taoufik; Pflug, Leopold

1993-12-01

This article presents a concept of reconstruction of 3-D objects using non-invasive and touch loss techniques. The principle of this method is to display parallel interference optical fringes on an object and then to record the object under two angles of view. According to an appropriated treatment one reconstructs the 3-D object even when the object has no symmetrical plan. The 3-D surface data is available immediately in digital form for computer- visualization and for analysis software tools. The optical set-up for recording the 3-D object, the 3-D data extraction and treatment, as well as the reconstruction of the 3-D object are reported and commented on. This application is dedicated for reconstructive/cosmetic surgery, CAD, animation and research purposes.

Setting up a clinic to assess children and young people for female genital mutilation.

PubMed

Hodes, Deborah; Creighton, Sarah M

2017-02-01

It is now mandatory for health, social care professionals and teachers to report to the police all under-18s where female genital mutilation (FGM) has been disclosed by the child or where physical signs of FGM are seen. Such referrals are likely to result in a request for medical examination. New multiagency statutory guidance sets out instructions for physical examination but provides no details how services should be set-up. This review gives practical guidance learnt from the first year of the UK's only dedicated children's FGM service. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

SETI-ITALIA 2008: On-going searches and future prospects

NASA Astrophysics Data System (ADS)

Montebugnoli, S.; Bartolini, M.; Bianchi, G.; Cosmovici, C.; Monari, J.; Orlati, A.; Perini, F.; Pluchino, S.; Pupillo, G.; Salerno, E.; Schillirò, F.; Zoni, L.

2010-12-01

The Medicina Radioastronomical Station is located nearby Bologna, in Italy. It consists of two receiving antennas currently dedicated to the astronomical research at radio frequencies. The 32 m diameter parabolic dish performs observations from 1.4 to 22 GHz whereas the Northern Cross (a 30.000 m 2 wide T-shaped array transit antenna) works at 408 MHz. So far SETI observations have been performed using a SERENDIP IV high resolution spectrometer connected to the parabolic antenna. Data acquisition were performed meanwhile the antenna was employed in ordinary astronomical observations (piggy-back mode). An innovative method to search for possible extraterrestrial signals could be provided by using the UHF Northern Cross transit telescope. In this paper observational modalities and the required technological set-up are investigated.

Optimising the Inflammatory Bowel Disease Unit to Improve Quality of Care: Expert Recommendations.

PubMed

Louis, Edouard; Dotan, Iris; Ghosh, Subrata; Mlynarsky, Liat; Reenaers, Catherine; Schreiber, Stefan

2015-08-01

The best care setting for patients with inflammatory bowel disease [IBD] may be in a dedicated unit. Whereas not all gastroenterology units have the same resources to develop dedicated IBD facilities and services, there are steps that can be taken by any unit to optimise patients' access to interdisciplinary expert care. A series of pragmatic recommendations relating to IBD unit optimisation have been developed through discussion among a large panel of international experts. Suggested recommendations were extracted through systematic search of published evidence and structured requests for expert opinion. Physicians [n = 238] identified as IBD specialists by publications or clinical focus on IBD were invited for discussion and recommendation modification [Barcelona, Spain; 2014]. Final recommendations were voted on by the group. Participants also completed an online survey to evaluate their own experience related to IBD units. A total of 60% of attendees completed the survey, with 15% self-classifying their centre as a dedicated IBD unit. Only half of respondents indicated that they had a defined IBD treatment algorithm in place. Key recommendations included the need to develop a multidisciplinary team covering specifically-defined specialist expertise in IBD, to instil processes that facilitate cross-functional communication and to invest in shared care models of IBD management. Optimising the setup of IBD units will require progressive leadership and willingness to challenge the status quo in order to provide better quality of care for our patients. IBD units are an important step towards harmonising care for IBD across Europe and for establishing standards for disease management programmes. © European Crohn’s and Colitis Organisation 2015.

Optimising the Inflammatory Bowel Disease Unit to Improve Quality of Care: Expert Recommendations

PubMed Central

Dotan, Iris; Ghosh, Subrata; Mlynarsky, Liat; Reenaers, Catherine; Schreiber, Stefan

2015-01-01

Introduction: The best care setting for patients with inflammatory bowel disease [IBD] may be in a dedicated unit. Whereas not all gastroenterology units have the same resources to develop dedicated IBD facilities and services, there are steps that can be taken by any unit to optimise patients’ access to interdisciplinary expert care. A series of pragmatic recommendations relating to IBD unit optimisation have been developed through discussion among a large panel of international experts. Methods: Suggested recommendations were extracted through systematic search of published evidence and structured requests for expert opinion. Physicians [n = 238] identified as IBD specialists by publications or clinical focus on IBD were invited for discussion and recommendation modification [Barcelona, Spain; 2014]. Final recommendations were voted on by the group. Participants also completed an online survey to evaluate their own experience related to IBD units. Results: A total of 60% of attendees completed the survey, with 15% self-classifying their centre as a dedicated IBD unit. Only half of respondents indicated that they had a defined IBD treatment algorithm in place. Key recommendations included the need to develop a multidisciplinary team covering specifically-defined specialist expertise in IBD, to instil processes that facilitate cross-functional communication and to invest in shared care models of IBD management. Conclusions: Optimising the setup of IBD units will require progressive leadership and willingness to challenge the status quo in order to provide better quality of care for our patients. IBD units are an important step towards harmonising care for IBD across Europe and for establishing standards for disease management programmes. PMID:25987349

JANUS - A setup for low-energy Coulomb excitation at ReA3

NASA Astrophysics Data System (ADS)

Lunderberg, E.; Belarge, J.; Bender, P. C.; Bucher, B.; Cline, D.; Elman, B.; Gade, A.; Liddick, S. N.; Longfellow, B.; Prokop, C.; Weisshaar, D.; Wu, C. Y.

2018-03-01

A new experimental setup for low-energy Coulomb excitation experiments was constructed in a collaboration between the National Superconducting Cyclotron Laboratory (NSCL), Lawrence Livermore National Laboratory (LLNL), and the University of Rochester and was commissioned at the general purpose beam line of NSCL's ReA3 reaccelerator facility. The so-called JANUS setup combines γ-ray detection with the Segmented Ge Array (SeGA) and scattered particle detection using a pair of segmented double-sided Si detectors (Bambino 2). The low-energy Coulomb excitation program that JANUS enables will complement intermediate-energy Coulomb excitation studies that have long been performed at NSCL by providing access to observables that quantify collectivity beyond the first excited state, including the sign and magnitude of excited-state quadrupole moments. In this work, the setup and its performance will be described based on the commissioning run that used stable 78Kr impinging onto a 1.09 mg/cm2208Pb target at a beam energy of 3.9 MeV/u.

Biogas from mesophilic digestion of cow dung using charcoal and gelatin as additives

NASA Astrophysics Data System (ADS)

Islam, Md Rashedul; Salam, Bodius; Rahman, Md Mizanur; Mamun, Abdullah Al

2017-06-01

Biogas, a source of renewable energy is produced from bacteria in the process of biodegradation of organic matter under anaerobic conditions. A research work was performed to find out the production of biogas from cow dung using charcoal and gelatin as additives. Five laboatory scale experimental set-up were constructed using 0, 0.2, 0.4, 0.6 and 0.8% gelatin with cow dung as additive to perform the research work. For all the set-up 0.5% charcoal was also added. All the set-ups were made from 1-liter capacity conical flask. The amount of water and cow dung was used respectively 382 gm. and 318 gm. in every set-up. Total solid content was maintained 8% throughout all set-ups. The digesters were operated at ambient temperature of 26°-32°C. The total gas yield without using gelatin additive was found to be 12 L/kg cow dung. The maximum gas yield was found from 0.2% gelatin additive and 23% more as compared to without gelatin gas production. The retention time varied from 28 to 79 days for the experiments.

Investigation of the γ-decay behavior of 52Cr with the γ 3 setup at HIγS

NASA Astrophysics Data System (ADS)

Wilhelmy, J.; Erbacher, P.; Gayer, U.; Isaak, J.; Löher, B.; Müscher, M.; Pickstone, S. G.; Pietralla, N.; Ries, P.; Romig, C.; Savran, D.; Spieker, M.; Tornow, W.; Werner, V.; Zilges, A.; Zweidinger, M.

2018-02-01

The γ-ray strength function is an important input parameter for the calculation of nucleosynthesis processes. To study the dipole response in more detail, the γ-decay behavior of the fp shell nucleus 52Cr was investigated with the high-efficiency γ 3 setup at the High Intensity γ-ray Source facility at TUNL in Durham, USA. The highly intense quasi mono-energetic γ-ray beam allows for excitations selective in multipolarity (J=1 and J=2) and energy. The γ 3 setup is a multi-detector array consisting of HPGe and LaBr3 detectors with high efficiency and enables the measurement of γ-γ coincidences. Experimental results of 52Cr will be presented and discussed in this contribution.

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.

Thermographic measurements of high-speed metal cutting

NASA Astrophysics Data System (ADS)

Mueller, Bernhard; Renz, Ulrich

2002-03-01

Thermographic measurements of a high-speed cutting process have been performed with an infrared camera. To realize images without motion blur the integration times were reduced to a few microseconds. Since the high tool wear influences the measured temperatures a set-up has been realized which enables small cutting lengths. Only single images have been recorded because the process is too fast to acquire a sequence of images even with the frame rate of the very fast infrared camera which has been used. To expose the camera when the rotating tool is in the middle of the camera image an experimental set-up with a light barrier and a digital delay generator with a time resolution of 1 ns has been realized. This enables a very exact triggering of the camera at the desired position of the tool in the image. Since the cutting depth is between 0.1 and 0.2 mm a high spatial resolution was also necessary which was obtained by a special close-up lens allowing a resolution of app. 45 microns. The experimental set-up will be described and infrared images and evaluated temperatures of a titanium alloy and a carbon steel will be presented for cutting speeds up to 42 m/s.

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.

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.

Model Based Inference for Wire Chafe Diagnostics

NASA Technical Reports Server (NTRS)

Schuet, Stefan R.; Wheeler, Kevin R.; Timucin, Dogan A.; Wysocki, Philip F.; Kowalski, Marc Edward

2009-01-01

Presentation for Aging Aircraft conference covering chafing fault diagnostics using Time Domain Reflectometry. Laboratory setup and experimental methods are presented, along with initial results that summarize fault modeling and detection capabilities.

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.

Multicolour LEDs in educational demonstrations of physics and optometry

NASA Astrophysics Data System (ADS)

Paulins, Paulis; Ozolinsh, Maris

2014-07-01

LED light sources are used to design experimental setup for university courses teaching human color vision. The setup allows to demonstrate various vision characteristics and to apply for student practical exercises to study eye spectral sensitivity in different spectral range using heterochromatic flicker photometry. Technique can be used in laboratory works for students to acquire knowledge in visual perception, basics of electronics and measuring, or it can be applied as fully computer control experiment. Besides studies of the eye spectral sensitivity students can practice in trichromatic color matching and other visual perception tasks

Torsion sensing setup based on a Mach-Zehnder interferometer with photonics crystal fiber

NASA Astrophysics Data System (ADS)

Pacheco-Chacon, Eliana I.; Gallegos-Arellano, E.; Sierra-Hernandez, Juan M.; Rojas-Laguna, Roberto; Estudillo-Ayala, Julian M.; Hernandez, Emmanuel; Jauregui-Vazquez, D.; Hernandez-Garcia, J. C.

2017-02-01

A torsion experimental sensing setup based on a Mach-Zehnder interferometer (MZI) with photonics crystal fiber is presented. The MZI was fabricated by fusion splicing a piece of photonic crystal fiber (PCF) between two segments of a single-mode fiber (SMF). Here, a spectral MZI fringe shifting is induced by applying torsion over the SMF-PCF-SMF. As a result a torsion sensitivity of 35.79 pm/ and a high visibility of 10 dB were achieved. Finally, it is shown that the sensing arrangement is compact and robust.

Measurement of the {sup 214}Po half-life by the DEVIS track setup

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

Belov, V. A.; Brakhman, E. V.; Zeldovich, O. Ya.

2013-04-15

Measurement of the {sup 214}Po half-life with the DEVIS track setup at the Institute of Theoretical and Experimental Physics (ITEP, Moscow) by means of a procedure based on determining lifetimes of individual nuclei is described. The value obtained for the {sup 214}Po half-life is 163.8 {+-} 3.0 Micro-Sign s. The possibility of reaching the accuracy of the measurements that is required for testing the statement that the decay of some nuclei has a nonexponential character and the source intensity necessary for this are discussed.

Self-powered electrospinning apparatus based on a hand-operated Wimshurst generator

NASA Astrophysics Data System (ADS)

Han, Wen-Peng; Huang, Yuan-Yuan; Yu, Miao; Zhang, Jun-Cheng; Yan, Xu; Yu, Gui-Feng; Zhang, Hong-Di; Yan, Shi-Ying; Long, Yun-Ze

2015-03-01

A conventional electrospinning setup cannot work without a plug (electricity supply). In this article, we report a self-powered electrospinning setup based on a hand-operated Wimshurst generator. The new device has better applicability and portability than a typical conventional electrospinning setup because it is lightweight and can work without an external power supply. Experimental parameters of the apparatus such as the minimum number of handle turns to generate enough energy to spin, rotation speed of the handle and electrospinning distance were investigated. Different polymers such as polystyrene (PS), poly(vinylidene fluoride) (PVDF), polycaprolactone (PCL) and polylactic acid (PLA) were electrospun into ultrathin fibers successfully by this apparatus. The stability, reliability, and repeatability of the new apparatus demonstrate that it can be used as not only a demonstrator for an electrospinning process, but also a beneficial complement to conventional electrospinning especially where or when without a power supply, and may be used in wound healing and rapid hemostasis, etc.A conventional electrospinning setup cannot work without a plug (electricity supply). In this article, we report a self-powered electrospinning setup based on a hand-operated Wimshurst generator. The new device has better applicability and portability than a typical conventional electrospinning setup because it is lightweight and can work without an external power supply. Experimental parameters of the apparatus such as the minimum number of handle turns to generate enough energy to spin, rotation speed of the handle and electrospinning distance were investigated. Different polymers such as polystyrene (PS), poly(vinylidene fluoride) (PVDF), polycaprolactone (PCL) and polylactic acid (PLA) were electrospun into ultrathin fibers successfully by this apparatus. The stability, reliability, and repeatability of the new apparatus demonstrate that it can be used as not only a demonstrator for an electrospinning process, but also a beneficial complement to conventional electrospinning especially where or when without a power supply, and may be used in wound healing and rapid hemostasis, etc. Electronic supplementary information (ESI) available: The video of the electrospinning process by this new self-powered electrospinning apparatus and the vivid details were recorded by a high-speed digital video camera. See DOI: 10.1039/c5nr00387c

Melt electrospinning of poly(lactic acid) and polycaprolactone microfibers by using a hand-operated Wimshurst generator

NASA Astrophysics Data System (ADS)

Qin, Chong-Chong; Duan, Xiao-Peng; Wang, Le; Zhang, Li-Hua; Yu, Miao; Dong, Rui-Hua; Yan, Xu; He, Hong-Wei; Long, Yun-Ze

2015-10-01

A conventional melt electrospinning setup usually needs a large, heavy high-voltage power supply and cannot work without a plug (electricity supply). In this article, we report a new melt electrospinning setup based on a small hand-operated Wimshurst generator, which can avoid electrical interference between the high-voltage spinning system and the heating system, and make the setup very portable and safe. Poly(lactic acid) (PLA) and polycaprolactone (PCL) fibers with diameters of 15-45 μm were fabricated successfully by using this apparatus. Experimental parameters such as the rotational speed of the generator handle (a half turn to two turns per second) and the spinning distance (2-14 cm) were investigated. In addition, PLA and PCL fibers were directly melt-electrospun onto a pork liver, and the temperature and adhesiveness of the deposited fibers were studied. The results indicate that the apparatus and melt-electrospun polymer microfibers may be used in dressing for wound healing.A conventional melt electrospinning setup usually needs a large, heavy high-voltage power supply and cannot work without a plug (electricity supply). In this article, we report a new melt electrospinning setup based on a small hand-operated Wimshurst generator, which can avoid electrical interference between the high-voltage spinning system and the heating system, and make the setup very portable and safe. Poly(lactic acid) (PLA) and polycaprolactone (PCL) fibers with diameters of 15-45 μm were fabricated successfully by using this apparatus. Experimental parameters such as the rotational speed of the generator handle (a half turn to two turns per second) and the spinning distance (2-14 cm) were investigated. In addition, PLA and PCL fibers were directly melt-electrospun onto a pork liver, and the temperature and adhesiveness of the deposited fibers were studied. The results indicate that the apparatus and melt-electrospun polymer microfibers may be used in dressing for wound healing. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05367f

Kane Experimental Forest

Treesearch

Northeastern Research Station

1999-01-01

The 1,737 acres of forest land that comprise the Kane Experimental Forest (KEF), were originally part of the Allegheny National Forest. On March 23, 1932, the land was formally dedicated to research use for the Allegheny Forest Experiment Station (now the Northeastern Research Station). The KEF was established to promote the study of the unglaciated portion of the...

Technical Note: Mobile accelerator guidance using an optical tracker during docking in IOERT procedures.

PubMed

Marinetto, Eugenio; Victores, Juan González; García-Sevilla, Mónica; Muñoz, Mercedes; Calvo, Felipe Ángel; Balaguer, Carlos; Desco, Manuel; Pascau, Javier

2017-10-01

Intraoperative electron radiation therapy (IOERT) involves the delivery of a high radiation dose during tumor resection in a shorter time than other radiation techniques, thus improving local control of tumors. However, a linear accelerator device is needed to produce the beam safely. Mobile linear accelerators have been designed as dedicated units that can be moved into the operating room and deliver radiation in situ. Correct and safe dose delivery is a key concern when using mobile accelerators. The applicator is commonly fixed to the patient's bed to ensure that the dose is delivered to the prescribed location, and the mobile accelerator is moved to dock the applicator to the radiation beam output (gantry). In a typical clinical set-up, this task is time-consuming because of safety requirements and the limited degree of freedom of the gantry. The objective of this study was to present a navigation solution based on optical tracking for guidance of docking to improve safety and reduce procedure time. We used an optical tracker attached to the mobile linear accelerator to track the prescribed localization of the radiation collimator inside the operating room. Using this information, the integrated navigation system developed computes the movements that the mobile linear accelerator needs to perform to align the applicator and the radiation gantry and warns the physician if docking is unrealizable according to the available degrees of freedom of the mobile linear accelerator. Furthermore, we coded a software application that connects all the necessary functioning elements and provides a user interface for the system calibration and the docking guidance. The system could safeguard against the spatial limitations of the operating room, calculate the optimal arrangement of the accelerator and reduce the docking time in computer simulations and experimental setups. The system could be used to guide docking with any commercial linear accelerator. We believe that the docking navigator we present is a major contribution to IOERT, where docking is critical when attempting to reduce surgical time, ensure patient safety and guarantee that the treatment administered follows the radiation oncologist's prescription. © 2017 American Association of Physicists in Medicine.

The Hydrological Open Air Laboratory (HOAL) in Petzenkirchen: a hypothesis-driven observatory

NASA Astrophysics Data System (ADS)

Blöschl, G.; Blaschke, A. P.; Broer, M.; Bucher, C.; Carr, G.; Chen, X.; Eder, A.; Exner-Kittridge, M.; Farnleitner, A.; Flores-Orozco, A.; Haas, P.; Hogan, P.; Kazemi Amiri, A.; Oismüller, M.; Parajka, J.; Silasari, R.; Stadler, P.; Strauss, P.; Vreugdenhil, M.; Wagner, W.; Zessner, M.

2016-01-01

Hydrological observatories bear a lot of resemblance to the more traditional research catchment concept, but tend to differ in providing more long-term facilities that transcend the lifetime of individual projects, are more strongly geared towards performing interdisciplinary research, and are often designed as networks to assist in performing collaborative science. This paper illustrates how the experimental and monitoring set-up of an observatory, the 66 ha Hydrological Open Air Laboratory (HOAL) in Petzenkirchen, Lower Austria, has been established in a way that allows meaningful hypothesis testing. The overarching science questions guided site selection, identification of dissertation topics and the base monitoring. The specific hypotheses guided the dedicated monitoring and sampling, individual experiments, and repeated experiments with controlled boundary conditions. The purpose of the HOAL is to advance the understanding of water-related flow and transport processes involving sediments, nutrients and microbes in small catchments. The HOAL catchment is ideally suited for this purpose, because it features a range of different runoff generation processes (surface runoff, springs, tile drains, wetlands), the nutrient inputs are known, and it is convenient from a logistic point of view as all instruments can be connected to the power grid and a high-speed glassfibre local area network (LAN). The multitude of runoff generation mechanisms in the catchment provides a genuine laboratory where hypotheses of flow and transport can be tested, either by controlled experiments or by contrasting sub-regions of different characteristics. This diversity also ensures that the HOAL is representative of a range of catchments around the world, and the specific process findings from the HOAL are applicable to a variety of agricultural catchment settings. The HOAL is operated jointly by the Vienna University of Technology and the Federal Agency for Water Management and takes advantage of the Vienna Doctoral Programme on Water Resource Systems funded by the Austrian Science Funds. The paper presents the science strategy of the set-up of the observatory, discusses the implementation of the HOAL, gives examples of the hypothesis testing and summarises the lessons learned. The paper concludes with an outlook on future developments.

The Hydrological Open Air Laboratory (HOAL) in Petzenkirchen: a hypotheses driven observatory

NASA Astrophysics Data System (ADS)

Blöschl, G.; Blaschke, A. P.; Broer, M.; Bucher, C.; Carr, G.; Chen, X.; Eder, A.; Exner-Kittridge, M.; Farnleitner, A.; Flores-Orozco, A.; Haas, P.; Hogan, P.; Kazemi Amiri, A.; Oismüller, M.; Parajka, J.; Silasari, R.; Stadler, P.; Strauß, P.; Vreugdenhil, M.; Wagner, W.; Zessner, M.

2015-07-01

Hydrological observatories bear a lot of resemblance to the more traditional research catchment concept but tend to differ in providing more long term facilities that transcend the lifetime of individual projects, are more strongly geared towards performing interdisciplinary research, and are often designed as networks to assist in performing collaborative science. This paper illustrates how the experimental and monitoring setup of an observatory, the 66 ha Hydrological Open Air Laboratory (HOAL) in Petzenkirchen, Lower Austria, has been established in a way that allows meaningful hypothesis testing. The overarching science questions guided site selection, identifying dissertation topics and the base monitoring. The specific hypotheses guided the dedicated monitoring and sampling, individual experiments, and repeated experiments with controlled boundary conditions. The purpose of the HOAL is to advance the understanding of water related flow and transport processes involving sediments, nutrients and microbes in small catchments. The HOAL catchment is ideally suited for this purpose, because it features a range of different runoff generation processes (surface runoff, springs, tile drains, wetlands), the nutrient inputs are known, and it is convenient from a logistic point of view as all instruments can be connected to the power grid and a high speed glassfibre Local Area Network. The multitude of runoff generation mechanisms in the catchment provide a genuine laboratory where hypotheses of flow and transport can be tested, either by controlled experiments or by contrasting sub-regions of different characteristics. This diversity also ensures that the HOAL is representative of a range of catchments around the world and the specific process findings from the HOAL are applicable to a variety of agricultural catchment settings. The HOAL is operated jointly by the Vienna University of Technology and the Federal Agency for Water Management and takes advantage of the Vienna Doctoral Programme on Water Resource Systems funded by the Austrian Science Funds. The paper presents the science strategy of the setup of the observatory, discusses the implementation of the HOAL, gives examples of the hypothesis testing and summarises the lessons learned. The paper concludes with an outlook on future developments.

Generation of low-temperature air plasma for food processing

NASA Astrophysics Data System (ADS)

Stepanova, Olga; Demidova, Maria; Astafiev, Alexander; Pinchuk, Mikhail; Balkir, Pinar; Turantas, Fulya

2015-11-01

The project is aimed at developing a physical and technical foundation of generating plasma with low gas temperature at atmospheric pressure for food industry needs. As known, plasma has an antimicrobial effect on the numerous types of microorganisms, including those that cause food spoilage. In this work an original experimental setup has been developed for the treatment of different foods. It is based on initiating corona or dielectric-barrier discharge in a chamber filled with ambient air in combination with a certain helium admixture. The experimental setup provides various conditions of discharge generation (including discharge gap geometry, supply voltage, velocity of gas flow, content of helium admixture in air and working pressure) and allows for the measurement of the electrical discharge parameters. Some recommendations on choosing optimal conditions of discharge generation for experiments on plasma food processing are developed.

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.

Geometric Limitations Of Ultrasonic Measurements

NASA Astrophysics Data System (ADS)

von Nicolai, C.; Schilling, F.

2006-12-01

Laboratory experiments are a key for interpreting seismic field observations. Due to their potential in many experimental set-ups, the determination of elastic properties of minerals and rocks by ultrasonic measurements is common in Geosciences. The quality and thus use of ultrasonic data, however, strongly depends on the sample geometry and wavelength of the sound wave. Two factors, the diameter-to-wavelength- ratio and the diameter-to-length-ratio, are believed to be the essential parameters to affect ultrasonic signal quality. In this study, we determined under well defined conditions the restricting dimensional parameters to test the validity of published assumptions. By the use of commercial ultrasonic transducers a number of experiments were conducted on aluminium, alumina, and acrylic glass rods of varying diameter (30-10 mm) and constant length. At each diameter compressional wave travel times were measured by pulse- transmission method. From the observed travel times ultrasonic wave velocities were calculated. One additional experiment was performed with a series of square-shaped aluminium blocks in order to investigate the effect of the geometry of the samples cross-sectional area. The experimental results show that the simple diameter-to-wavelength ratios are not valid even under idealized experimental conditions and more complex relation has to be talen into account. As diameter decreases the P-waves direct phase is increasingly interfered and weakened by sidewall reflections. At very small diameters compressional waves are replaced by bar waves and P-wave signals become non resolvable. Considering the suppression of both effects, a critical D/ë-ratio was determined and compared to experimental set-ups from various publications. These tests indicate that some published and cited data derived from small diameter set-ups are out off the range of physical possibility.

A novel method for assessment of fragmentation and beam-material interactions in helium ion radiotherapy with a miniaturized setup.

PubMed

Gallas, Raya R; Arico, Giulia; Burigo, Lucas N; Gehrke, Tim; Jakůbek, Jan; Granja, Carlos; Tureček, Daniel; Martišíková, Maria

2017-10-01

Radiotherapy with protons and carbon ions enables to deliver dose distributions of high conformation to the target. Treatment with helium ions has been suggested due to their physical and biological advantages. A reliable benchmarking of the employed physics models with experimental data is required for treatment planning. However, experimental data for helium interactions is limited, in part due to the complexity and large size of conventional experimental setups. We present a novel method for the investigation of helium interactions with matter using miniaturized instrumentation based on highly integrated pixel detectors. The versatile setup consisted of a monitoring detector in front of the PMMA phantom of varying thickness and a detector stack for investigation of outgoing particles. The ion type downstream from the phantom was determined by high-resolution pattern recognition analysis of the single particle signals in the pixelated detectors. The fractions of helium and hydrogen ions behind the used targets were determined. As expected for the stable helium nucleus, only a minor decrease of the primary ion fluence along the target depth was found. E.g. the detected fraction of hydrogen ions on axis of a 220MeV/u 4 He beam was below 6% behind 24.5cm of PMMA. Monte-Carlo simulations using Geant4 reproduce the experimental data on helium attenuation and yield of helium fragments qualitatively, but significant deviations were found for some combinations of target thickness and beam energy. The presented method is promising to contribute to the reduction of the uncertainty of treatment planning for helium ion radiotherapy. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Multigeneration effects of insect growth regulators on the springtail Folsomia candida.

PubMed

Campiche, Sophie; L'Ambert, Grégory; Tarradellas, Joseph; Becker-van Slooten, Kristin

2007-06-01

Multigeneration tests are very useful for the assessment of long term toxicity of pollutants such as endocrine disruptor compounds. In this study, multigeneration reproduction tests adapted from the ISO standard 11267 were conducted with the Collembola Folsomia candida. Springtails were exposed to artificial soil contaminated with four insect growth regulators (methoprene, fenoxycarb, teflubenzuron, and precocene II) according to two different experimental set-ups. In the first set-up, the parental generation (F(0)) of Collembola was exposed to a pollutant for 28 days. Juveniles from the F(1) generation were transferred to uncontaminated soil for another 28-day period to generate the F(2) generation. In the second set-up, the F(0) generation was exposed to a pollutant for 10 days before being transferred to uncontaminated soil to reproduce. After 18-28 days, juveniles from the F(1) were transferred to clean soil to generate the F(2) generation. An effect on the number of hatched juveniles of the F(2) generation was observed for methoprene after exposure of the F(0) for 28 days and hatching of F(1) in contaminated soil. For methoprene and teflubenzuron, significant effects were even observed on the F(2) generation with the second experimental set-up, when only the F(0) generation was exposed for 10 days. This shows that the impact of these substances is transgenerational, which can have important consequences for the population of these or other organisms. No effect on the F(2) generation was observed with fenoxycarb and precocene II with the 10-day exposure experiment. Our results show that the developed experimental procedures are appropriate to assess the long term effects of endocrine disrupting compounds on the reproduction of the non-target species F. candida. Another important finding is that two substances with the same predicted mode of action (i.e., the two juvenile hormone analogues fenoxycarb and methoprene) do not necessarily affect the same endpoints in F. candida.

MicroMegascope.

PubMed

Canale, L; Laborieux, A; Mogane, A Aroul; Jubin, L; Comtet, J; Lainé, A; Bocquet, L; Siria, A; Niguès, A

2018-08-31

Atomic force microscopy (AFM) allows us to reconstruct the topography of surfaces with resolution in the nanometer range. The exceptional resolution attainable with the AFM makes this instrument a key tool in nanoscience and technology. The core of a standard AFM set-up relies on the detection of the change of the mechanical motion of a micro-oscillator when approaching the sample to image. This is despite the fact that AFM is nowadays a very common instrument for both fundamental and applied research. The fabrication of the micrometric scale mechanical oscillator is still a very complicated and expensive task requiring dedicated platforms. Being able to perform AFM with a macroscopic oscillator would make the instrument more versatile and accessible for an even larger spectrum of applications and audience. Here, we present atomic force imaging with a centimetric oscillator, an aluminum tuning fork of centimeter size as a sensor on which an accelerometer is glued on one prong to measure the oscillations. We show that it is possible to perform topographic images of nanometric resolution with a gram tuning fork. In addition to the stunning sensitivity, we show the high versatility of such an oscillator by imaging both in air and liquid. The set-up proposed here can be extended to numerous experiments where the probe has to be heavy and/or very complex, and so too the environment.

The use of low cost compact cameras with focus stacking functionality in entomological digitization projects

PubMed Central

Mertens, Jan E.J.; Roie, Martijn Van; Merckx, Jonas; Dekoninck, Wouter

2017-01-01

Abstract Digitization of specimen collections has become a key priority of many natural history museums. The camera systems built for this purpose are expensive, providing a barrier in institutes with limited funding, and therefore hampering progress. An assessment is made on whether a low cost compact camera with image stacking functionality can help expedite the digitization process in large museums or provide smaller institutes and amateur entomologists with the means to digitize their collections. Images of a professional setup were compared with the Olympus Stylus TG-4 Tough, a low-cost compact camera with internal focus stacking functions. Parameters considered include image quality, digitization speed, price, and ease-of-use. The compact camera’s image quality, although inferior to the professional setup, is exceptional considering its fourfold lower price point. Producing the image slices in the compact camera is a matter of seconds and when optimal image quality is less of a priority, the internal stacking function omits the need for dedicated stacking software altogether, further decreasing the cost and speeding up the process. In general, it is found that, aware of its limitations, this compact camera is capable of digitizing entomological collections with sufficient quality. As technology advances, more institutes and amateur entomologists will be able to easily and affordably catalogue their specimens. PMID:29134038

xPIPE--Reception of DICOM Data from any Sender via the Internet.

PubMed

Czwoydzinski, J; Eßeling, R; Meier, N; Heindel, W; Lenzen, H

2015-05-01

Various technologies have been established for DICOM data exchange in radiology. In addition to the patient CD, online transfers via VPN (virtual private network) or DICOM email are common practice. However, dedicated network solutions are generally not appropriate for data exchange with occasional and spontaneous partners due to missing infrastructure at the partner institutions and/or complex setup procedures. The purpose was to develop a practical solution to complement the established technologies to allow users worldwide to transfer images without registration. The development of the xPIPE system is based on Java and various software libraries. A client hosted on a website enables sending DICOM data to a receiving system of the hospital. The new xPIPE system creates a gateway to a receiving hospital which is accessible from any point worldwide, giving other hospitals, clinics and patients a simple and secure method to transmit DICOM data without intermediate storage on external servers. The system was deployed at the University Hospital Münster and subsequently widely used even without information events and training. Data protection during transfer is ensured by the use of signatures and encryption. From the user's perspective the system has only minor technical requirements and can be used with minimal setup effort. © Georg Thieme Verlag KG Stuttgart · New York.

The pre-launch characterization of SIMBIO-SYS/VIHI imaging spectrometer for the BepiColombo mission to Mercury. I. Linearity, radiometry, and geometry calibrations.

PubMed

Filacchione, Gianrico; Capaccioni, Fabrizio; Altieri, Francesca; Carli, Cristian; Ficai Veltroni, Iacopo; Dami, Michele; Tommasi, Leonardo; Aroldi, Gianluca; Borrelli, Donato; Barbis, Alessandra; Baroni, Marco; Pastorini, Guia; Mugnuolo, Raffaele

2017-09-01

Before integration aboard European Space Agency BepiColombo mission to Mercury, the visible and near infrared hyperspectral imager underwent an intensive calibration campaign. We report in Paper I about the radiometric and linearity responses of the instrument including the optical setups used to perform them. Paper II [F. Altieri et al., Rev. Sci. Instrum. 88, 094503 (2017)] will describe complementary spectral response calibration. The responsivity is used to calculate the expected instrumental signal-to-noise ratio for typical observation scenarios of the BepiColombo mission around Mercury. A description is provided of the internal calibration unit that will be used to verify the relative response during the instrument's lifetime. The instrumental spatial response functions as measured along and across the spectrometer's slit direction were determined by means of spatial scans performed with illuminated test slits placed at the focus of a collimator. The dedicated optical setup used for these measurements is described together with the methods used to derive the instrumental spatial responses at different positions within the 3.5 ° field of view and at different wavelengths in the 0.4-2.0 μm spectral range. Finally, instrument imaging capabilities and Modulated Transfer Function are tested by using a standard mask as a target.

Advanced Optics for a Full Quasi-Optical Front Steering ECRH Upper Launcher for ITER

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

Moro, A.; Alessi, E.; Bruschi, A.

2009-11-26

A full quasi-optical setup for the internal optics of the Front Steering Electron Cyclotron Resonance Heating (ECRH) Upper Launcher for ITER was designed, proving to be feasible and favorable in terms of additional flexibility and cost reduction with respect to the former design. This full quasi-optical solution foresees the replacement of the mitre-bends in the final section of the launcher with dedicated free-space mirrors to realize the last changes of directions in the launcher. A description of the launcher is given and its advantages presented. The parameters of the expected output beams as well as preliminary evaluations of truncation effectsmore » with the physical optics GRASP code are shown. Moreover, a study of mitre-bends replacement with single mirrors for multiple beams is described. In principle it could allow the beams to be larger at the mirror locations (with a further decrease of the peak power density due to partial overlapping) and has the additional advantage to get a larger opening with compressed beams to avoid conflicts with side-walls port. Constraints on the setup, arising both from the resulting beam characteristics in the space of free parameters and from mechanical requirements are taken into account in the analysis.« less

Spatial encoding using the nonlinear field perturbations from magnetic materials.

PubMed

Karimi, Hirad; Dominguez-Viqueira, William; Cunningham, Charles H

2014-08-01

A proof-of-concept study was performed to assess the technical feasibility of using magnetic materials to generate spatial encoding fields. Spatially varying magnetic fields were generated by the placement of markers with different volume susceptibilities within the imaging volume. No linear gradients were used for spatial encoding during the signal acquisition. A signal-encoding model is described for reconstructing the images encoded with these field perturbations. Simulation and proof-of-concept experimental results are presented. Experiments were performed using field perturbations from a cylindrical marker as an example of the new encoding fields. Based on this experimental setup, annular rings were reconstructed from signals encoded with the new fields. Simulation results were presented for different acquisition parameters. Proof-of-concept was supported by the correspondence of regions in an image reconstructed from experimental data compared to those in a conventional gradient-echo image. Experimental results showed that inclusions of dimensions 1.5 mm in size could be resolved with the experimental setup. This study shows the technical feasibility of using magnetic markers to produce encoding fields. Magnetic materials will allow generating spatial encoding fields, which can be tailored to an imaging application with less complexity and at lower cost compared to the use of gradient inserts. Copyright © 2013 Wiley Periodicals, Inc.

Life on rock. Scaling down biological weathering in a new experimental design at Biosphere-2

NASA Astrophysics Data System (ADS)

Zaharescu, D. G.; Dontsova, K.; Burghelea, C. I.; Chorover, J.; Maier, R.; Perdrial, J. N.

2012-12-01

Biological colonization and weathering of bedrock on Earth is a major driver of landscape and ecosystem development, its effects reaching out into other major systems such climate and geochemical cycles of elements. In order to understand how microbe-plant-mycorrhizae communities interact with bedrock in the first phases of mineral weathering we developed a novel experimental design in the Desert Biome at Biosphere-2, University of Arizona (U.S.A). This presentation will focus on the development of the experimental setup. Briefly, six enclosed modules were designed to hold 288 experimental columns that will accommodate 4 rock types and 6 biological treatments. Each module is developed on 3 levels. A lower volume, able to withstand the weight of both, rock material and the rest of the structure, accommodates the sampling elements. A middle volume, houses the experimental columns in a dark chamber. A clear, upper section forms the habitat exposed to sunlight. This volume is completely sealed form exterior and it allows a complete control of its air and water parameters. All modules are connected in parallel with a double air purification system that delivers a permanent air flow. This setup is expected to provide a model experiment, able to test important processes in the interaction rock-life at grain-to- molecular scale.

Dedicated Laboratory Setup for CO{sub 2} TEA Laser Propulsion Experiments at Rensselaer Polytechnic Institute

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

Salvador, Israel I.; Kenoyer, David; Myrabo, Leik N.

Laser propulsion research progress has traditionally been hindered by the scarcity of photon sources with desirable characteristics, as well as integrated specialized flow facilities in a dedicated laboratory environment. For TEA CO{sub 2} lasers, the minimal requirements are time-average powers of >100 W), and pulse energies of >10 J pulses with short duration (e.g., 0.1 to 1 {mu}s); furthermore, for the advanced pulsejet engines of interest here, the laser system must simulate pulse repetition frequencies of 1-10 kilohertz or more, at least for two (carefully sequenced) pulses. A well-equipped laser propulsion laboratory should have an arsenal of sensor and diagnosticsmore » tools (such as load cells, thrust stands, moment balances, pressure and heat transfer gages), Tesla-level electromagnet and permanent magnets, flow simulation facilities, and high-speed visualization systems, in addition to other related equipment, such as optics and gas supply systems. In this paper we introduce a cutting-edge Laser Propulsion Laboratory created at Rensselaer Polytechnic Institute, one of the very few in the world to be uniquely set up for beamed energy propulsion (BEP) experiments. The present BEP research program is described, along with the envisioned research strategy that will exploit current and expanded facilities in the near future.« less

Materials characterisation by angle-resolved scanning transmission electron microscopy.

PubMed

Müller-Caspary, Knut; Oppermann, Oliver; Grieb, Tim; Krause, Florian F; Rosenauer, Andreas; Schowalter, Marco; Mehrtens, Thorsten; Beyer, Andreas; Volz, Kerstin; Potapov, Pavel

2016-11-16

Solid-state properties such as strain or chemical composition often leave characteristic fingerprints in the angular dependence of electron scattering. Scanning transmission electron microscopy (STEM) is dedicated to probe scattered intensity with atomic resolution, but it drastically lacks angular resolution. Here we report both a setup to exploit the explicit angular dependence of scattered intensity and applications of angle-resolved STEM to semiconductor nanostructures. Our method is applied to measure nitrogen content and specimen thickness in a GaN x As 1-x layer independently at atomic resolution by evaluating two dedicated angular intervals. We demonstrate contrast formation due to strain and composition in a Si- based metal-oxide semiconductor field effect transistor (MOSFET) with Ge x Si 1-x stressors as a function of the angles used for imaging. To shed light on the validity of current theoretical approaches this data is compared with theory, namely the Rutherford approach and contemporary multislice simulations. Inconsistency is found for the Rutherford model in the whole angular range of 16-255 mrad. Contrary, the multislice simulations are applicable for angles larger than 35 mrad whereas a significant mismatch is observed at lower angles. This limitation of established simulations is discussed particularly on the basis of inelastic scattering.

Contact Angle Measurements Using a Simplified Experimental Setup

ERIC Educational Resources Information Center

Lamour, Guillaume; Hamraoui, Ahmed; Buvailo, Andrii; Xing, Yangjun; Keuleyan, Sean; Prakash, Vivek; Eftekhari-Bafrooei, Ali; Borguet, Eric

2010-01-01

A basic and affordable experimental apparatus is described that measures the static contact angle of a liquid drop in contact with a solid. The image of the drop is made with a simple digital camera by taking a picture that is magnified by an optical lens. The profile of the drop is then processed with ImageJ free software. The ImageJ contact…

Control of the collapse distance in atmospheric propagation

NASA Astrophysics Data System (ADS)

Fibich, Gadi; Sivan, Yonatan; Ehrlich, Yosi; Louzon, Einat; Fraenkel, Moshe; Eisenmann, Shmuel; Katzir, Yiftach; Zigler, Arie

2006-06-01

We show experimentally for ultrashort laser pulses propagating in air, that the collapse/filamentation distance of intense laser pulses in the atmosphere can be extended and controlled with a simple double-lens setup. We derive a simple formula for the filamentation distance, and confirm its agreement with the experimental results. We also observe that delaying the onset of filamentation increases the filament length.

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.

An innovative experimental setup for Large Scale Particle Image Velocimetry measurements in riverine environments

NASA Astrophysics Data System (ADS)

Tauro, Flavia; Olivieri, Giorgio; Porfiri, Maurizio; Grimaldi, Salvatore

2014-05-01

Large Scale Particle Image Velocimetry (LSPIV) is a powerful methodology to nonintrusively monitor surface flows. Its use has been beneficial to the development of rating curves in riverine environments and to map geomorphic features in natural waterways. Typical LSPIV experimental setups rely on the use of mast-mounted cameras for the acquisition of natural stream reaches. Such cameras are installed on stream banks and are angled with respect to the water surface to capture large scale fields of view. Despite its promise and the simplicity of the setup, the practical implementation of LSPIV is affected by several challenges, including the acquisition of ground reference points for image calibration and time-consuming and highly user-assisted procedures to orthorectify images. In this work, we perform LSPIV studies on stream sections in the Aniene and Tiber basins, Italy. To alleviate the limitations of traditional LSPIV implementations, we propose an improved video acquisition setup comprising a telescopic, an inexpensive GoPro Hero 3 video camera, and a system of two lasers. The setup allows for maintaining the camera axis perpendicular to the water surface, thus mitigating uncertainties related to image orthorectification. Further, the mast encases a laser system for remote image calibration, thus allowing for nonintrusively calibrating videos without acquiring ground reference points. We conduct measurements on two different water bodies to outline the performance of the methodology in case of varying flow regimes, illumination conditions, and distribution of surface tracers. Specifically, the Aniene river is characterized by high surface flow velocity, the presence of abundant, homogeneously distributed ripples and water reflections, and a meagre number of buoyant tracers. On the other hand, the Tiber river presents lower surface flows, isolated reflections, and several floating objects. Videos are processed through image-based analyses to correct for lens distortions and analyzed with a commercially available PIV software. Surface flow velocity estimates are compared to supervised measurements performed by visually tracking objects floating on the stream surface and to rating curves developed by the Ufficio Idrografico e Mareografico (UIM) at Regione Lazio, Italy. Experimental findings demonstrate that the presence of tracers is crucial for surface flow velocity estimates. Further, considering surface ripples and patterns may lead to underestimations in LSPIV analyses.

Cryogenic Characterization of FBK RGB-HD SiPMs

DOE PAGES

Aalseth, C. E.

2017-09-26

We report on the cryogenic characterization of Red Green Blue - High Density (RGB-HD) SiPMs developed at Fondazione Bruno Kessler (FBK) as part of the DarkSide program of dark matter searches with liquid argon time projection chambers. A dedicated setup was used to measure the primary dark noise, the correlated noise, and the gain of the SiPMs at varying temperatures. A custom-made data acquisition system and analysis software were used to precisely characterize these parameters. We demonstrate that FBK RGB-HD SiPMs with low quenching resistance (RGB-HD-LRmore » $$_q$$) can be operated from 40 K to 300 K with gains in the range $10^5$ to $10^6$ and noise rates on the order of a few Hz/mm$^2$.« less

Non-Uniform Microstrip Antenna Array for DSRC in Single-Lane Structures.

PubMed

Varum, Tiago; Matos, João N; Pinho, Pedro

2016-12-11

Vehicular communications have been subject to a great development in recent years, with multiple applications, such as electronic payments, improving the convenience and comfort of drivers. Its communication network is supported by dedicated short range communications (DSRC), a system composed of onboard units (OBU) and roadside units (RSU). A recently conceived different set-up for the tolling infrastructures consists of placing them in highway access roads, allowing a number of benefits over common gateway infrastructures, divided into several lanes and using complex systems. This paper presents an antenna array whose characteristics are according to the DSRC standards. Additionally, the array holds an innovative radiation pattern adjusted to the new approach requirements, with an almost uniform wide beamwidth along the road width, negligible side lobes, and operating in a significant bandwidth.

Non-Uniform Microstrip Antenna Array for DSRC in Single-Lane Structures

PubMed Central

Varum, Tiago; Matos, João N.; Pinho, Pedro

2016-01-01

Vehicular communications have been subject to a great development in recent years, with multiple applications, such as electronic payments, improving the convenience and comfort of drivers. Its communication network is supported by dedicated short range communications (DSRC), a system composed of onboard units (OBU) and roadside units (RSU). A recently conceived different set-up for the tolling infrastructures consists of placing them in highway access roads, allowing a number of benefits over common gateway infrastructures, divided into several lanes and using complex systems. This paper presents an antenna array whose characteristics are according to the DSRC standards. Additionally, the array holds an innovative radiation pattern adjusted to the new approach requirements, with an almost uniform wide beamwidth along the road width, negligible side lobes, and operating in a significant bandwidth. PMID:27973424

Experimental verification of Pyragas-Schöll-Fiedler control.

PubMed

von Loewenich, Clemens; Benner, Hartmut; Just, Wolfram

2010-09-01

We present an experimental realization of time-delayed feedback control proposed by Schöll and Fiedler. The scheme enables us to stabilize torsion-free periodic orbits in autonomous systems, and to overcome the so-called odd number limitation. The experimental control performance is in quantitative agreement with the bifurcation analysis of simple model systems. The results uncover some general features of the control scheme which are deemed to be relevant for a large class of setups.

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 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.

Determination of the magnetocaloric entropy change by field sweep using a heat flux setup

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

Monteiro, J. C. B., E-mail: jolmiui@gmail.com; Reis, R. D. dos; Mansanares, A. M.

2014-08-18

We report on a simple setup using a heat flux sensor adapted to a Quantum Design Physical Property Measurement System to determine the magnetocaloric entropy change (ΔS). The major differences for the existing setups are the simplicity of this assembly and the ease to obtain the isothermal entropy change either by a field sweep or a temperature sweep process. We discuss the use of these two processes applied to Gd and Gd{sub 5}Ge{sub 2}Si{sub 2} samples. The results are compared to the temperature sweep measurements and they show the advantages of this setup and of the field sweep procedure. Wemore » found a significant reduction of ΔS and on the refrigerating cooling power (RCP) at low field changes in a field sweep process when the sample is not driven to the same initial state for each temperature. We show that the field sweep process without any measuring protocol is the only correct way to experimentally determine ΔS and RCP for a practical regenerative refrigerator.« less

JANUS — A setup for low-energy Coulomb excitation at ReA3

DOE PAGES

Lunderberg, E.; Belarge, J.; Bender, P. C.; ...

2017-12-21

We report that a new experimental setup for low-energy Coulomb excitation experiments was constructed in a collaboration between the National Superconducting Cyclotron Laboratory (NSCL), Lawrence Livermore National Laboratory (LLNL), and the University of Rochester and was commissioned at the general purpose beam line of NSCL's ReA3 reaccelerator facility. The so-called JANUS setup combines γ-ray detection with the Segmented Ge Array (SeGA) and scattered particle detection using a pair of segmented double-sided Si detectors (Bambino 2). The low-energy Coulomb excitation program that JANUS enables will complement intermediate-energy Coulomb excitation studies that have long been performed at NSCL by providing access tomore » observables that quantify collectivity beyond the first excited state, including the sign and magnitude of excited-state quadrupole moments. Here, in this work, the setup and its performance will be described based on the commissioning run that used stable 78Kr impinging onto a 1.09 mg/cm 2 208Pb target at a beam energy of 3.9 MeV/u.« less

A novel setup for femtosecond pump-repump-probe IR spectroscopy with few cycle CEP stable pulses.

PubMed

Bradler, Maximilian; Werhahn, Jasper C; Hutzler, Daniel; Fuhrmann, Simon; Heider, Rupert; Riedle, Eberhard; Iglev, Hristo; Kienberger, Reinhard

2013-08-26

We present a three-color mid-IR setup for vibrational pump-repump-probe experiments with a temporal resolution well below 100 fs and a freely selectable spectral resolution of 20 to 360 cm(-1) for the pump and repump. The usable probe range without optical realignment is 900 cm(-1). The experimental design employed is greatly simplified compared to the widely used setups, highly robust and includes a novel means for generation of tunable few-cycle pulses with stable carrier-envelope phase. A Ti:sapphire pump system operating with 1 kHz and a modest 150 fs pulse duration supplies the total pump energy of just 0.6 mJ. The good signal-to-noise ratio of the setup allows the determination of spectrally resolved transient probe changes smaller than 6·10(-5) OD at 130 time delays in just 45 minutes. The performance of the spectrometer is demonstrated with transient IR spectra and decay curves of HDO molecules in lithium nitrate trihydrate and ice and a first all MIR pump-repump-probe measurement.

Avian research on Experimental Forests and Ranges: Emergent themes, opportunities, and challenges

Treesearch

Scott H. Stoleson; David I. King; Monica. Tomosy

2011-01-01

Since 1908, U.S. Forest Service Experimental Forests and Ranges have been dedicated to long-term inter-disciplinary research on a variety of ecological and management questions. They encompass a wide diversity of life zones and ecoregions, and provide access to research infrastructure, opportunities for controlled manipulations, and integration with other types of long...

Design and numerical characterization of a crossover EBIS

NASA Astrophysics Data System (ADS)

Geyer, Sabrina; Langbein, A.; Meusel, Oliver; Kester, Oliver

2015-01-01

For the investigation of highly charged ions, a crossover EBIS (XEBIS) was developed at the University of Frankfurt. In contrast to conventional EBIS/T devices the compression of the electron beam is achieved by electrostatic focusing to a crossover point in the interaction region. This concept allows a compact and simple design. Simulations performed with EGUN show a perveance of 2.1×10-7 A/V3/2 for the realized gun system. In the interaction region the electron beam has a density of around 10 A/cm2 and a minimum radius of 0.15 mm. The XEBIS has a total length of 112 mm with a trap length of 26 mm. It is designed for electron beam energies of up to 6 keV/q. The storage capacity of the trap region is in the order of 1×108 charges. Charge state breeding studies with CBSIM indicate for the noble gases as maximal achievable charge state Ar16+, Kr30+ and Xe35+. Thus ion beam currents of around 2.04 nA assuming 50 Hz repetition rate can be expected. The emittance of the extracted beam is approximated to 8 mm mrad. After completion of the construction phase, the XEBIS will be installed for first performance investigations at a dedicated test bench, equipped with a fast Faraday Cup (FC), a retarding field spectrometer, a luminescence screen and optical diagnostics. Subsequently the XEBIS will serve as source for highly charged ions at different experimental setups.

New insights on the propagation of pulsed atmospheric plasma streams: From single jet to multi jet arrays

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

Robert, E.; Darny, T.; Dozias, S.

2015-12-15

Atmospheric pressure plasma propagation inside long dielectric tubes is analyzed for the first time through nonintrusive and nonperturbative time resolved bi-directional electric field (EF) measurements. This study unveils that plasma propagation occurs in a region where longitudinal EF exists ahead the ionization front position usually revealed from plasma emission with ICCD measurement. The ionization front propagation induces the sudden rise of a radial EF component. Both of these EF components have an amplitude of several kV/cm for helium or neon plasmas and are preserved almost constant along a few tens of cm inside a capillary. All these experimental measurements aremore » in excellent agreement with previous model calculations. The key roles of the voltage pulse polarity and of the target nature on the helium flow patterns when plasma jet is emerging in ambient air are documented from Schlieren visualization. The second part of this work is then dedicated to the development of multi jet systems, using two different setups, based on a single plasma source. Plasma splitting in dielectric tubes drilled with sub millimetric orifices, but also plasma transfer across metallic tubes equipped with such orifices are reported and analyzed from ICCD imaging and time resolved EF measurements. This allows for the design and the feasibility validation of plasma jet arrays but also emphasizes the necessity to account for voltage pulse polarity, target potential status, consecutive helium flow modulation, and electrostatic influence between the produced secondary jets.« less

Hierarchical multimodal tomographic x-ray imaging at a superbend

NASA Astrophysics Data System (ADS)

Stampanoni, M.; Marone, F.; Mikuljan, G.; Jefimovs, K.; Trtik, P.; Vila-Comamala, J.; David, C.; Abela, R.

2008-08-01

Over the last decade, synchrotron-based X-ray tomographic microscopy has established itself as a fundamental tool for non-invasive, quantitative investigations of a broad variety of samples, with application ranging from space research and materials science to biology and medicine. Thanks to the brilliance of modern third generation sources, voxel sizes in the micrometer range are routinely achieved by the major X-ray microtomography devices around the world, while the isotropic 100 nm barrier is reached and trespassed only by few instruments. The beamline for TOmographic Microscopy and Coherent rAdiology experiments (TOMCAT) of the Swiss Light Source at the Paul Scherrer Institut, operates a multimodal endstation which offers tomographic capabilities in the micrometer range in absorption contrast - of course - as well as phase contrast imaging. Recently, the beamline has been equipped with a full field, hard X-rays microscope with a theoretical pixel size down to 30 nm and a field of view of 50 microns. The nanoscope performs well at X-ray energies between 8 and 12 keV, selected from the white beam of a 2.9 T superbend by a [Ru/C]100 fixed exit multilayer monochromator. In this work we illustrate the experimental setup dedicated to the nanoscope, in particular the ad-hoc designed X-ray optics needed to produce a homogeneous, square illumination of the sample imaging plane as well as the magnifying zone plate. Tomographic reconstructions at 60 nm voxel size will be shown and discussed.

Recent approaches for bridging the pressure gap in photoelectron microspectroscopy

PubMed Central

Kolmakov, Andrei; Gregoratti, Luca; Kiskinova, Maya; Günther, Sebastian

2016-01-01

Ambient-pressure photoelectron spectroscopy (APPES) and microscopy are at the frontier of modern chemical analysis at liquid-gas, solid-liquid and solid-gas interfaces, bridging science and engineering of functional materials. Complementing the current state-of-the art of the instruments, we survey in this short review several alternative APPES approaches, developed recently in the scanning photoelectron microscope (SPEM) at the Elettra laboratory. In particular, we report on experimental setups for dynamic near-ambient pressure environment, using pulsed-gas injection in the vicinity of samples or reaction cells with very small apertures, allowing for experiments without introducing additional differential pumping stages. The major part of the review is dedicated to the construction and performance of novel environmental cells using ultrathin electron-transparent but molecularly impermeable membranes to isolate the gas or liquid ambient from the electron detector operating in ultra-high vacuum (UHV). We demonstrate that two dimensional materials, such as graphene and derivatives, are mechanically robust to withstand atmospheric - UHV pressure differences and are sufficiently transparent for the photoelectrons emitted from samples immersed in the liquid or gaseous media. There are many unique opportunities for APPES using X-rays over a wide energy range. We show representative results that illustrate the potential of these ‘ambient-pressure’ approaches. Combined with the ca 100 nm lateral resolution of SPEM, they can overcome the pressure gap challenges and address the evolution of chemical composition and electronic structure at surface and interfaces under realistic operation conditions with unprecedented lateral and spectral resolution. PMID:28008215

New portable instrument for combined reflectance, time-resolved and steady-state luminescence measurements on works of art

NASA Astrophysics Data System (ADS)

Romani, Aldo; Grazia, Chiara; Anselmi, Chiara; Miliani, Costanza; Brunetti, Brunetto Giovanni

2011-06-01

In this paper a new compact and portable instrument for combined reflectance, time-resolved and steady-state fluorescence is presented. All the optical parts of the apparatus, carefully described in the text, were chosen after an extensive market survey in order to obtain the best performances coupled with the smallest dimensions. This instrument through the use of a dedicated multiple fiber optic probe, allows the complete photophysical behaviors of investigated materials to be collected from the same point of the analyzed surface. In this way, the resultant instrumental setup is a portable device, usable in situ for non destructive and non invasive diagnostic purposes in the field of cultural heritage. Preliminary results concerning organic dyes characterization, which is the main application of luminescence-based diagnostic techniques in artworks, are presented and compared with those previously obtained using separate devices. Concerning reflectance data, improvements in the deep detectable UV spectral range have been achieved switching from the integrating sphere of the old instrument to bifurcated optical fibers used as probe in the new one. Special attention was devoted to test the instrument capability in order to obtain the true emission spectrum, corrected for the selfabsorption effect, for which good results were found. This particular experimental procedure is strongly recommended, by a diagnostic point of view, to avoid distortions in the instrumental responses, namely the spectral shape and emission maximum wavelength of a fluorophore as function of the color saturation.

Applications of the VUV Fourier Transform Spectrometer at Synchrotron Soleil

NASA Astrophysics Data System (ADS)

de Oliveira, Nelson; Joyeux, Denis; Ito, Kenji; Gans, Berenger; Nahon, Laurent

2015-06-01

Fourier transform spectrometers (FTS) are usually based upon amplitude division interferometers through beamsplitters (BS) as in the Michelson interferometer geometry. However, the manufacture of broadband BS is difficult and even impossible in the far VUV (below λ = 140 nm). We therefore conceived an instrument based upon an original design involving only reflective plane surfaces, giving access to the whole VUV range without the restrictions associated with BS. The VUV- FTS is a permanent endstation connected to one of the three experimental branches of the DESIRS beamline and devoted to high resolution photoabsorption in the UV-VUV spectral range, typically between λ = 300 and 40 nm Since 2008, a large international community of users interested in laboratory measurements with applications in astrophysics, molecular physics or planetary atmospheres has been attracted by the VUV - FTS capabilities including its efficiency in terms of signal to noise ratio, even when high spectral resolution was not an issue. A large number of dedicated gas phase sample environments have been developed including a windowless cell that can be cooled down, a heated windowless cell, a free molecular jet set-up and various windowed cells. Besides, a new discharge gas cell for production and study of transient species gave recently its first results. As an illustration, the VUV absorption spectrum of the CH_3 radical down to 140 nm will be shown in this presentation. Nahon et al., J. Synchrotron Radiat., 19, 508(2012) De Oliveira et al., Nat. Photonics, 5, 149(2011)

Experimental generation of partially coherent beams with different complex degrees of coherence.

PubMed

Wang, Fei; Liu, Xianlong; Yuan, Yangsheng; Cai, Yangjian

2013-06-01

We established an experimental setup for generating partially coherent beams with different complex degrees of coherence, and we report experimental generation of an elliptical Gaussian Schell-model (GSM) beam and a Laguerre-GSM beam for the first time. It has been demonstrated experimentally that an elliptical GSM beam and a Laguerre-GSM beam produce an elliptical beam spot and a dark hollow beam spot in the focal plane (or in the far field), respectively, which agrees with theoretical predictions. Our results are useful for beam shaping and particle trapping.

A Direct Method for Viewing Ferromagnetic Phase Transition.

ERIC Educational Resources Information Center

Lue, Chin-Shan

1994-01-01

Provides a method, using the Rowland ring as a specimen, to observe the phase transition process directly on the oscilloscope and even extract the critical exponent of ferromagnetic transition. Includes theory, experimental setup, and results. (MVL)

Scintillator Detector Development at Central Michigan University

NASA Astrophysics Data System (ADS)

McClain, David; Estrade, Alfredo; Neupane, Shree

2017-09-01

Experimental nuclear physics relies both on the accuracy and precision of the instruments for radiation detection used in experimental setups. At Central Michigan University we have setup a lab to work with scintillator detectors for radioactive ion beam experiments, using a Picosecond Laser and radioactive sources for testing. We have tested the resolution for prototypes of large area scintillators that could be used for fast timing measurements in the focal plane of spectrometers, such as the future High Rigidity Spectrometer at the Facility for Rare Isotope Beams (FRIB). We measured the resolution as a function of the length of the detector, and also the position of the beam along the scintillator. We have also designed a scintillating detector to veto light ion background in beta-decay experiments with the Advanced Implantation Detector Array (AIDA) at RIKEN in Japan. We tested different configurations of Silicon Photomultipliers and scintillating fiber optics to find the best detection efficiency.

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.

Fission Fragment characterization with FALSTAFF at NFS

NASA Astrophysics Data System (ADS)

Doré, D.; Farget, F.; Lecolley, F.-R.; Ledoux, X.; Lehaut, G.; Materna, T.; Pancin, J.; Panebianco, S.

2013-03-01

The Neutrons for Science (NFS) facility will be one of the first installations of the SPIRAL2 facility. NFS will be composed of a time-of-flight baseline and irradiation stations and will allow studying neutron-induced reactions for energies going from some hundreds of keV up to 40 MeV. Continuous and quasi-monoenergetic energy neutron beams will be available. Taking advantage of this new installation, the development of an experimental setup for a full characterization of actinide fission fragments in this energy domain has been undertaken. To achieve this goal a new detection system called FALSTAFF (Four Arm cLover for the STudy of Actinide Fission Fragments) in under development. In this paper, the characteristics of the NFS facility will be exposed and the motivations for the FALSTAFF experiment will be presented. The experimental setup will be described and the expected resolutions based on realistic GEANT4 simulations will be discussed.

Object recognition through a multi-mode fiber

NASA Astrophysics Data System (ADS)

Takagi, Ryosuke; Horisaki, Ryoichi; Tanida, Jun

2017-04-01

We present a method of recognizing an object through a multi-mode fiber. A number of speckle patterns transmitted through a multi-mode fiber are provided to a classifier based on machine learning. We experimentally demonstrated binary classification of face and non-face targets based on the method. The measurement process of the experimental setup was random and nonlinear because a multi-mode fiber is a typical strongly scattering medium and any reference light was not used in our setup. Comparisons between three supervised learning methods, support vector machine, adaptive boosting, and neural network, are also provided. All of those learning methods achieved high accuracy rates at about 90% for the classification. The approach presented here can realize a compact and smart optical sensor. It is practically useful for medical applications, such as endoscopy. Also our study indicated a promising utilization of artificial intelligence, which has rapidly progressed, for reducing optical and computational costs in optical sensing systems.

Digital image compression for a 2f multiplexing optical setup

NASA Astrophysics Data System (ADS)

Vargas, J.; Amaya, D.; Rueda, E.

2016-07-01

In this work a virtual 2f multiplexing system was implemented in combination with digital image compression techniques and redundant information elimination. Depending on the image type to be multiplexed, a memory-usage saving of as much as 99% was obtained. The feasibility of the system was tested using three types of images, binary characters, QR codes, and grey level images. A multiplexing step was implemented digitally, while a demultiplexing step was implemented in a virtual 2f optical setup following real experimental parameters. To avoid cross-talk noise, each image was codified with a specially designed phase diffraction carrier that would allow the separation and relocation of the multiplexed images on the observation plane by simple light propagation. A description of the system is presented together with simulations that corroborate the method. The present work may allow future experimental implementations that will make use of all the parallel processing capabilities of optical systems.

Using smartphones and tablet PCs for β--spectroscopy in an educational experimental setup

NASA Astrophysics Data System (ADS)

Gröber, Sebastian; Molz, Alexander; Kuhn, Jochen

2014-11-01

A magnetic spectrometer is used to gather the β--spectrum of 90 Sr /Y with a focus on two aspects. (1) The intensity of β--radiation is measured by the camera sensor module of a tablet PC together with the RadioactivityCounter app and by a Geiger-Müller tube. We evaluate the quality of mobile devices as radioactive radiation detectors by using polyenergetic β--radiation as an example and by comparing the spectra measured with the two detector types. (2) For educational purposes we implement a simple experimental setup, which consists of separate devices for measuring the electron’s kinetic energy and intensity, which are available in laboratories in educational settings. Comparison of the measured β--spectra published in the literature should encourage students to think about the energy resolution power of the β--spectrometer. Theoretical considerations show the low, yet sufficient energy resolution power of this spectrometer, especially for low energy levels.

Quantitative evaluation of statistical errors in small-angle X-ray scattering measurements

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

Sedlak, Steffen M.; Bruetzel, Linda K.; Lipfert, Jan

A new model is proposed for the measurement errors incurred in typical small-angle X-ray scattering (SAXS) experiments, which takes into account the setup geometry and physics of the measurement process. The model accurately captures the experimentally determined errors from a large range of synchrotron and in-house anode-based measurements. Its most general formulation gives for the variance of the buffer-subtracted SAXS intensity σ 2(q) = [I(q) + const.]/(kq), whereI(q) is the scattering intensity as a function of the momentum transferq;kand const. are fitting parameters that are characteristic of the experimental setup. The model gives a concrete procedure for calculating realistic measurementmore » errors for simulated SAXS profiles. In addition, the results provide guidelines for optimizing SAXS measurements, which are in line with established procedures for SAXS experiments, and enable a quantitative evaluation of measurement errors.« less

Microwave-mediated magneto-optical trap for polar molecules

NASA Astrophysics Data System (ADS)

Dizhou, Xie; Wenhao, Bu; Bo, Yan

2016-05-01

Realizing a molecular magneto-optical trap has been a dream for cold molecular physicists for a long time. However, due to the complex energy levels and the small effective Lande g-factor of the excited states, the traditional magneto-optical trap (MOT) scheme does not work very well for polar molecules. One way to overcome this problem is the switching MOT, which requires very fast switching of both the magnetic field and the laser polarizations. Switching laser polarizations is relatively easy, but fast switching of the magnetic field is experimentally challenging. Here we propose an alternative approach, the microwave-mediated MOT, which requires a slight change of the current experimental setup to solve the problem. We calculate the MOT force and compare it with the traditional MOT and the switching MOT scheme. The results show that we can operate a good MOT with this simple setup. Project supported by the Fundamental Research Funds for the Central Universities of China.

Contribution of religiousness in the prediction and interpretation of mystical experiences in a sensory deprivation context: activation of religious schemas.

PubMed

Granqvist, Pehr; Larsson, Marcus

2006-07-01

M. A. Persinger (2002) claimed that transcranial magnetic stimulation with weak, complex magnetic fields evokes mystical experiences. However, in a double-blind experiment, P. Granqvist, M. Fredrikson, P. Unge, A. Hagenfeldt, S. Valind., et al. (2005) found no effects of field exposure on mystical experiences (N = 89), though a minority of participants reported spontaneous mystical experiences. Following the conclusion of null effects from magnetic field exposure, the setup of this experiment, including pre-experimental assessments of religiousness and sensory deprivation, can be viewed as a prime/setting for such experiences. The authors analyzed subsets of experimental data from P. Granqvist and colleagues with emphasis on the contribution of religiousness in the prediction and interpretation of mystical experiences. They found that a higher degree of religiousness predicted a higher occurrence of mystical experiences with a religious quality, but not of mystical experiences without such a quality. The authors discuss findings in terms of the experimental setup serving as a prime/setting activating the religious schemas of religious participants.

Getting a grip on the transverse motion in a Zeeman decelerator

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

Dulitz, Katrin; Softley, Timothy P., E-mail: tim.softley@chem.ox.ac.uk; Motsch, Michael

2014-03-14

Zeeman deceleration is an experimental technique in which inhomogeneous, time-dependent magnetic fields generated inside an array of solenoid coils are used to manipulate the velocity of a supersonic beam. A 12-stage Zeeman decelerator has been built and characterized using hydrogen atoms as a test system. The instrument has several original features including the possibility to replace each deceleration coil individually. In this article, we give a detailed description of the experimental setup, and illustrate its performance. We demonstrate that the overall acceptance in a Zeeman decelerator can be significantly increased with only minor changes to the setup itself. This ismore » achieved by applying a rather low, anti-parallel magnetic field in one of the solenoid coils that forms a temporally varying quadrupole field, and improves particle confinement in the transverse direction. The results are reproduced by three-dimensional numerical particle trajectory simulations thus allowing for a rigorous analysis of the experimental data. The findings suggest the use of a modified coil configuration to improve transverse focusing during the deceleration process.« less

Development of an Experimental Setup for the Measurement of the Coefficient of Restitution under Vacuum Conditions

PubMed Central

Drücker, Sven; Krautstrunk, Isabell; Paulick, Maria; Saleh, Khashayar; Morgeneyer, Martin; Kwade, Arno

2016-01-01

The Discrete Element Method is used for the simulation of particulate systems to describe and analyze them, to predict and afterwards optimize their behavior for single stages of a process or even an entire process. For the simulation with occurring particle-particle and particle-wall contacts, the value of the coefficient of restitution is required. It can be determined experimentally. The coefficient of restitution depends on several parameters like the impact velocity. Especially for fine particles the impact velocity depends on the air pressure and under atmospheric pressure high impact velocities cannot be reached. For this, a new experimental setup for free-fall tests under vacuum conditions is developed. The coefficient of restitution is determined with the impact and rebound velocity which are detected by a high-speed camera. To not hinder the view, the vacuum chamber is made of glass. Also a new release mechanism to drop one single particle under vacuum conditions is constructed. Due to that, all properties of the particle can be characterized beforehand. PMID:27077671

Numerical solution of a coefficient inverse problem with multi-frequency experimental raw data by a globally convergent algorithm

NASA Astrophysics Data System (ADS)

Nguyen, Dinh-Liem; Klibanov, Michael V.; Nguyen, Loc H.; Kolesov, Aleksandr E.; Fiddy, Michael A.; Liu, Hui

2017-09-01

We analyze in this paper the performance of a newly developed globally convergent numerical method for a coefficient inverse problem for the case of multi-frequency experimental backscatter data associated to a single incident wave. These data were collected using a microwave scattering facility at the University of North Carolina at Charlotte. The challenges for the inverse problem under the consideration are not only from its high nonlinearity and severe ill-posedness but also from the facts that the amount of the measured data is minimal and that these raw data are contaminated by a significant amount of noise, due to a non-ideal experimental setup. This setup is motivated by our target application in detecting and identifying explosives. We show in this paper how the raw data can be preprocessed and successfully inverted using our inversion method. More precisely, we are able to reconstruct the dielectric constants and the locations of the scattering objects with a good accuracy, without using any advanced a priori knowledge of their physical and geometrical properties.

Development of an Experimental Setup for the Measurement of the Coefficient of Restitution under Vacuum Conditions.

PubMed

Drücker, Sven; Krautstrunk, Isabell; Paulick, Maria; Saleh, Khashayar; Morgeneyer, Martin; Kwade, Arno

2016-03-29

The Discrete Element Method is used for the simulation of particulate systems to describe and analyze them, to predict and afterwards optimize their behavior for single stages of a process or even an entire process. For the simulation with occurring particle-particle and particle-wall contacts, the value of the coefficient of restitution is required. It can be determined experimentally. The coefficient of restitution depends on several parameters like the impact velocity. Especially for fine particles the impact velocity depends on the air pressure and under atmospheric pressure high impact velocities cannot be reached. For this, a new experimental setup for free-fall tests under vacuum conditions is developed. The coefficient of restitution is determined with the impact and rebound velocity which are detected by a high-speed camera. To not hinder the view, the vacuum chamber is made of glass. Also a new release mechanism to drop one single particle under vacuum conditions is constructed. Due to that, all properties of the particle can be characterized beforehand.

Kalman filter based control for Adaptive Optics

NASA Astrophysics Data System (ADS)

Petit, Cyril; Quiros-Pacheco, Fernando; Conan, Jean-Marc; Kulcsár, Caroline; Raynaud, Henri-François; Fusco, Thierry

2004-12-01

Classical Adaptive Optics suffer from a limitation of the corrected Field Of View. This drawback has lead to the development of MultiConjugated Adaptive Optics. While the first MCAO experimental set-ups are presently under construction, little attention has been paid to the control loop. This is however a key element in the optimization process especially for MCAO systems. Different approaches have been proposed in recent articles for astronomical applications : simple integrator, Optimized Modal Gain Integrator and Kalman filtering. We study here Kalman filtering which seems a very promising solution. Following the work of Brice Leroux, we focus on a frequential characterization of kalman filters, computing a transfer matrix. The result brings much information about their behaviour and allows comparisons with classical controllers. It also appears that straightforward improvements of the system models can lead to static aberrations and vibrations filtering. Simulation results are proposed and analysed thanks to our frequential characterization. Related problems such as model errors, aliasing effect reduction or experimental implementation and testing of Kalman filter control loop on a simplified MCAO experimental set-up could be then discussed.

The Moment of Inertia of a Rectangular Rod

NASA Astrophysics Data System (ADS)

Takeuchi, Takao

2007-11-01

Recently an inexpensive setup to obtain the moment of inertia of a rotating system was proposed by Peter E. Banks. An equally simple and inexpensive experiment to obtain the moment of inertia of a uniform rod is proposed in this paper. A rectangular rod with a hole somewhere in the rod was used for this purpose. The moment of inertia of a rectangular rod around the hole location was attempted. The experimental setup is shown in Fig. 1. Various supporting rods, clamps, and rubber stoppers to hold the rectangular rod in place at point p are not shown.

Large atom number Bose-Einstein condensate machines

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

Streed, Erik W.; Chikkatur, Ananth P.; Gustavson, Todd L.

2006-02-15

We describe experimental setups for producing large Bose-Einstein condensates of {sup 23}Na and {sup 87}Rb. In both, a high-flux thermal atomic beam is decelerated by a Zeeman slower and is then captured and cooled in a magneto-optical trap. The atoms are then transferred into a cloverleaf-style Ioffe-Pritchard magnetic trap and cooled to quantum degeneracy with radio-frequency-induced forced evaporation. Typical condensates contain 20x10{sup 6} atoms. We discuss the similarities and differences between the techniques used for producing large {sup 87}Rb and {sup 23}Na condensates in the context of nearly identical setups.

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.

Characterization of the Medley setup for measurements of neutron-induced fission cross sections at the GANIL-NFS facility

NASA Astrophysics Data System (ADS)

Tarrío, Diego; Prokofiev, Alexander V.; Gustavsson, Cecilia; Jansson, Kaj; Andersson-Sundén, Erik; Al-Adili, Ali; Pomp, Stephan

2017-09-01

Neutron-induced fission cross sections of 235U and 238U are widely used as standards for monitoring of neutron beams and fields. An absolute measurement of these cross sections at an absolute scale, i.e., versus the H(n,p) scattering cross section, is planned with the white neutron beam under construction at the Neutrons For Science (NFS) facility in GANIL. The experimental setup, based on PPACs and ΔE-ΔE-E telescopes containing Silicon and CsI(Tl) detectors, is described. The expected uncertainties are discussed.

Measuring the Newtonian constant of gravitation with a differential free-fall gradiometer: A feasibility study

NASA Astrophysics Data System (ADS)

Rothleitner, Christian; Francis, Olivier

2014-04-01

An original setup is presented to measure the Newtonian Constant of Gravitation G. It is based on the same principle as used in ballistic absolute gravimeters. The differential acceleration of three simultaneously freely falling test masses is measured in order to determine G. In this paper, a description of the experimental setup is presented. A detailed uncertainty budget estimates the relative uncertainty to be of the order of 5.3 × 10-4, however with some improvements a relative uncertainty in G of one part in 104 could be feasible.

a New Set-Up for Total Reaction Cross Section Measuring

NASA Astrophysics Data System (ADS)

Sobolev, Yu. G.; Ivanov, M. P.; Kugler, A.; Penionzhkevich, Yu. E.

2013-06-01

The experimental method and set-up based on 4 n-Υ-technique for direct and modelindependent measuring of the total reaction cross section σR have been presented. The excitation function σR(E) for 6He+197Au reaction at the Coulomb barrier energy region has been measured. The measured data are compared with the summarized cross section which has been prepared by summing of measured cross sections of main reaction channels: 1n-transfer and 197Au(6He, xn)203-xnT1 with x = 2÷7 evaporation reaction channels.

Forward hadron calorimeter at MPD/NICA

NASA Astrophysics Data System (ADS)

Golubeva, M.; Guber, F.; Ivashkin, A.; Izvestnyy, A.; Kurepin, A.; Morozov, S.; Parfenov, P.; Petukhov, O.; Taranenko, A.; Selyuzhenkov, I.; Svintsov, I.

2017-01-01

Forward hadron calorimeter (FHCAL) at MPD/NICA experimental setup is described. The main purpose of the FHCAL is to provide an experimental measurement of a heavy-ion collision centrality (impact parameter) and orientation of its reaction plane. Precise event-by-event estimate of these basic observables is crucial for many physics phenomena studies to be performed by the MPD experiment. The simulation results of FHCAL performance are presented.

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.

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

Optical Microwave Interactions in Semiconductor Devices.

DTIC Science & Technology

1980-11-01

geometry can be used in microwave-optical analog T signal processing systems. A theoretical and experimental study of mode locking in (GaAI)As injection... STUDY OF MODE-LOCKING IN (GaAl)As INJECTION LASER .......... ......................... ... 55 A. Experimental Set-Up and DC Characteristics...modulation and 4 detection of optical beams at microwave frequencies. Our approach for modulating the optical beam has been to study the modulation capability

Quantum tomography for measuring experimentally the matrix elements of an arbitrary quantum operation.

PubMed

D'Ariano, G M; Lo Presti, P

2001-05-07

Quantum operations describe any state change allowed in quantum mechanics, including the evolution of an open system or the state change due to a measurement. We present a general method based on quantum tomography for measuring experimentally the matrix elements of an arbitrary quantum operation. As input the method needs only a single entangled state. The feasibility of the technique for the electromagnetic field is shown, and the experimental setup is illustrated based on homodyne tomography of a twin beam.

Experimental and Theoretical Probing of Molecular Dynamics at Catalytic and Ionic Liquid Interfaces

DTIC Science & Technology

2014-04-01

15. SUBJECT TERMS Surface, interface,  photocatalysis , fluorescence yield, ionic liquid, reactive force field    16. SECURITY CLASSIFICATION OF: 17...2, 3 which are promising photocatalysts for hydrogen production via photocatalytic water splitting. 1. Experimental The new experimental setup...Wang, G. Liu, G. Q. Lu, H.-M. Cheng, Int. J. of Hydrogen Energ., 2010, 35, 8199- 8205. 3. F. Xu, Y. Yuan, H. Han, D. Wu, Z. Gao, K. Jiang, CrystEngComm

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.

A Simple and Reliable Setup for Monitoring Corrosion Rate of Steel Rebars in Concrete

PubMed Central

Jibran, Mohammed Abdul Azeem; Azad, Abul Kalam

2014-01-01

The accuracy in the measurement of the rate of corrosion of steel in concrete depends on many factors. The high resistivity of concrete makes the polarization data erroneous due to the Ohmic drop. The other source of error is the use of an arbitrarily assumed value of the Stern-Geary constant for calculating corrosion current density. This paper presents the outcomes of a research work conducted to develop a reliable and low-cost experimental setup and a simple calculation procedure that can be utilised to calculate the corrosion current density considering the Ohmic drop compensation and the actual value of the Stern-Geary constants calculated using the polarization data. The measurements conducted on specimens corroded to different levels indicate the usefulness of the developed setup to determine the corrosion current density with and without Ohmic drop compensation. PMID:24526907

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.

Combining in situ characterization methods in one set-up: looking with more eyes into the intricate chemistry of the synthesis and working of heterogeneous catalysts.

PubMed

Bentrup, Ursula

2010-12-01

Several in situ techniques are known which allow investigations of catalysts and catalytic reactions under real reaction conditions using different spectroscopic and X-ray methods. In recent years, specific set-ups have been established which combine two or more in situ methods in order to get a more detailed understanding of catalytic systems. This tutorial review will give a summary of currently available set-ups equipped with multiple techniques for in situ catalyst characterization, catalyst preparation, and reaction monitoring. Besides experimental and technical aspects of method coupling including X-ray techniques, spectroscopic methods (Raman, UV-vis, FTIR), and magnetic resonance spectroscopies (NMR, EPR), essential results will be presented to demonstrate the added value of multitechnique in situ approaches. A special section is focussed on selected examples of use which show new developments and application fields.

Broadband interferometric characterisation of nano-positioning stages with sub-10 pm resolution

NASA Astrophysics Data System (ADS)

Li, Zhi; Brand, Uwe; Wolff, Helmut; Koenders, Ludger; Yacoot, Andrew; Puranto, Prabowo

2017-06-01

A traceable calibration setup for investigation of the quasi-static and the dynamic performance of nano-positioning stages is detailed, which utilizes a differential plane-mirror interferometer with double-pass configuration from the National Physical Laboratory (NPL). An NPL-developed FPGA-based interferometric data acquisition and decoding system has been used to enable traceable quasi-static calibration of nano-positioning stages with high resolution. A lockin based modulation technique is further introduced to quantitatively calibrate the dynamic response of moving stages with a bandwidth up to 100 kHz and picometer resolution. First experimental results have proven that the calibration setup can achieve under nearly open-air conditions a noise floor lower than 10 pm/sqrt(Hz). A pico-positioning stage, that is used for nanoindentation with indentation depths down to a few picometers, has been characterized with this calibration setup.

Pixel detectors in double beta decay experiments, a new approach for background reduction

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

Jose, J. M.; Čermák, P.; Štekl, I.

Double beta decay (ββ) experiments are challenging frontiers in contemporary physics. These experiments have the potential to investigate more about neutrinos (eg. nature and mass). The main challenge for these experiments is the reduction of background. The group at IEAP, CTU in Prague is investigating a new approach using pixel detectors Timepix. Pixel detector offer background reduction capabilities with its ability to identify the particle interaction (from the 2D signature it generates). However, use of pixel detectors has some challenges such as the presence of readout electronics near the sensing medium and heat dissipation. Different aspects of pixel setup (identificationmore » of radio-impurities, selection of radio-pure materials) and proposed experimental setup are presented. Also, results of preliminary background measurements (performed on the surface and in the underground laboratories) using the prototype setups are presented.« less

Hypernuclear Spectroscopy with Electron Beam at JLab Hall C

NASA Astrophysics Data System (ADS)

Fujii, Y.; Chiba, A.; Doi, D.; Gogami, T.; Hashimoto, O.; Kanda, H.; Kaneta, M.; Kawama, D.; Maeda, K.; Maruta, T.; Matsumura, A.; Nagao, S.; Nakamura, S. N.; Shichijo, A.; Tamura, H.; Taniya, N.; Yamamoto, T.; Yokota, K.; Kato, S.; Sato, Y.; Takahashi, T.; Noumi, H.; Motoba, T.; Hiyama, E.; Albayrak, I.; Ates, O.; Chen, C.; Christy, M.; Keppel, C.; Kohl, M.; Li, Y.; Liyanage, A.; Tang, L.; Walton, T.; Ye, Z.; Yuan, L.; Zhu, L.; Baturin, P.; Boeglin, W.; Dhamija, S.; Markowitz, P.; Raue, B.; Reinhold, J.; Hungerford, Ed. V.; Ent, R.; Fenker, H.; Gaskell, D.; Horn, T.; Jones, M.; Smith, G.; Vulcan, W.; Wood, S. A.; Johnston, C.; Simicevic, N.; Wells, S.; Samanta, C.; Hu, B.; Shen, J.; Wang, W.; Zhang, X.; Zhang, Y.; Feng, J.; Fu, Y.; Zhou, J.; Zhou, S.; Jiang, Y.; Lu, H.; Yan, X.; Ye, Y.; Gan, L.; Ahmidouch, A.; Danagoulian, S.; Gasparian, A.; Elaasar, M.; Wesselmann, F. R.; Asaturyan, A.; Margaryan, A.; Mkrtchyan, A.; Mkrtchyan, H.; Tadevosyan, V.; Androic, D.; Furic, M.; Petkovic, T.; Seva, T.; Niculescu, G.; Niculescu, I.; López, V. M. Rodríguez; Cisbani, E.; Cusanno, F.; Garibaldi, F.; Uuciuoli, G. M.; de Leo, R.; Maronne, S.

2010-10-01

Hypernuclear spectroscopy with electron beam at JLab Hall C has been studied since 2000. The first experiment, JLab E89-009, demonstrated the possibility of the (e,e'K+) reaction for hypernuclear spectroscopy by achieving an energy resolution of better than 1 MeV (FWHM). The second experiment, JLab E01-011 employed a newly constructed high resolution kaon spectrometer and introduced a vertically tilted electron arm setup to avoid electrons from bremsstrahlung and Moeller scattering. The setup allowed us to have 10 times yield rate and 4 times better signal to accidental ratio with expected energy resolution of 400 keV (FWHM). The third experiment, JLab E05-11B will be performed in 2009 with employing newly constructed high resolution electron spectrometer and a new charge-separation magnet. With the fully customized third generation experimental setup, we can study a variety of targets up to medium-heavy ones such as 52Cr.

Hypernuclear Spectroscopy with Electron Beam at JLab Hall C

NASA Astrophysics Data System (ADS)

Fujii, Y.; Chiba, A.; Doi, D.; Gogami, T.; Hashimoto, O.; Kanda, H.; Kaneta, M.; Kawama, D.; Maeda, K.; Maruta, T.; Matsumura, A.; Nagao, S.; Nakamura, S. N.; Shichijo, A.; Tamura, H.; Taniya, N.; Yamamoto, T.; Yokota, K.; Kato, S.; Sato, Y.; Takahashi, T.; Noumi, H.; Motoba, T.; Hiyama, E.; Albayrak, I.; Ates, O.; Chen, C.; Christy, M.; Keppel, C.; Kohl, M.; Li, Y.; Liyanage, A.; Tang, L.; Walton, T.; Ye, Z.; Yuan, L.; Zhu, L.; Baturin, P.; Boeglin, W.; Dhamija, S.; Markowitz, P.; Raue, B.; Reinhold, J.; Hungerford, Ed. V.; Ent, R.; Fenker, H.; Gaskell, D.; Horn, T.; Jones, M.; Smith, G.; Vulcan, W.; Wood, S. A.; Johnston, C.; Simicevic, N.; Wells, S.; Samanta, C.; Hu, B.; Shen, J.; Wang, W.; Zhang, X.; Zhang, Y.; Feng, J.; Fu, Y.; Zhou, J.; Zhou, S.; Jiang, Y.; Lu, H.; Yan, X.; Ye, Y.; Gan, L.; Ahmidouch, A.; Danagoulian, S.; Gasparian, A.; Elaasar, M.; Wesselmann, F. R.; Asaturyan, A.; Margaryan, A.; Mkrtchyan, A.; Mkrtchyan, H.; Tadevosyan, V.; Androic, D.; Furic, M.; Petkovic, T.; Seva, T.; Niculescu, G.; Niculescu, I.; Rodríguez López, V. M.; Cisbani, E.; Cusanno, F.; Garibaldi, F.; Uuciuoli, G. M.; de Leo, R.; Maronne, S.

Hypernuclear spectroscopy with electron beam at JLab Hall C has been studied since 2000. The first experiment, JLab E89-009, demonstrated the possibility of the (e, e‧ K+) reaction for hypernuclear spectroscopy by achieving an energy resolution of better than 1 MeV (FWHM). The second experiment, JLab E01-011 employed a newly constructed high resolution kaon spectrometer and introduced a vertically tilted electron arm setup to avoid electrons from bremsstrahlung and Moeller scattering. The setup allowed us to have 10 times yield rate and 4 times better signal to accidental ratio with expected energy resolution of 400 keV (FWHM). The third experiment, JLab E05-115 will be performed in 2009 with employing newly constructed high resolution electron spectrometer and a new charge-separation magnet. With the fully customized third generation experimental setup, we can study a variety of targets up to medium-heavy ones such as 52Cr.

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.

Creation of quantum-degenerate gases of ytterbium in a compact 2D-/3D-magneto-optical trap setup

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

Doerscher, Soeren; Thobe, Alexander; Hundt, Bastian

2013-04-15

We report on the first experimental setup based on a 2D-/3D-magneto-optical trap (MOT) scheme to create both Bose-Einstein condensates and degenerate Fermi gases of several ytterbium isotopes. Our setup does not require a Zeeman slower and offers the flexibility to simultaneously produce ultracold samples of other atomic species. Furthermore, the extraordinary optical access favors future experiments in optical lattices. A 2D-MOT on the strong {sup 1}S{sub 0}{yields}{sup 1}P{sub 1} transition captures ytterbium directly from a dispenser of atoms and loads a 3D-MOT on the narrow {sup 1}S{sub 0}{yields}{sup 3}P{sub 1} intercombination transition. Subsequently, atoms are transferred to a crossed opticalmore » dipole trap and cooled evaporatively to quantum degeneracy.« less

Culvert roughness elements for native Utah fish passage : phase I.

DOT National Transportation Integrated Search

2011-01-01

Laboratory flume testing of native Utah non-salmonid fish was performed to observe how : they use altered flow around obstacles to swim upstream. Three experimental setups included : a bare Plexiglas flume, vertical cylinders, and natural substrate p...

Large-scale laboratory observations of wave forces on a highway bridge superstructure.

DOT National Transportation Integrated Search

2011-10-01

The experimental setup and data are presented for a laboratory experiment conducted to examine realistic wave forcing on a highway bridge : superstructure. The experiments measure wave conditions along with the resulting forces, pressures, and struct...

NREL's Energy Systems Integration Facility Garners LEED® Platinum | News

Science.gov Websites

U.S. Green Building Council (USGBC), a non-profit organization dedicated to sustainable building experimental laboratories and several outdoor test beds, including an interactive hardware-in-the-loop system

Evaluation of an exposure setup for studying effects of diesel exhaust in humans.

PubMed

Rudell, B; Sandström, T; Hammarström, U; Ledin, M L; Hörstedt, P; Stjernberg, N

1994-01-01

Diesel exhaust is a common air pollutant and work exposure has been reported to cause discomfort and affect lung function. The aim of this study was to develop an experimental setup which would allow investigation of acute effects on symptoms and lung function in humans exposed to diluted diesel exhaust. Diluted diesel exhaust was fed from an idling lorry through heated tubes into an exposure chamber. During evaluations of the setup we found the size and the shape of the exhaust particles to appear unchanged during the transport from the tail pipe to the exposure chamber. The composition of the diesel exhaust expressed as the ratios CO/NO, total hydrocarbons/NO, particles/NO, NO2/NO, and formaldehyde/NO were almost constant at different dilutions. The concentrations of NO2 and particles in the exposure chamber showed no obvious gradients. New steady state concentrations in the exposure chamber were obtained within 5-7 min. In a separate experiment eight healthy nonsmoking subjects were exposed to diluted exhaust at a median steady state concentration of 1.6 ppm NO2 for the duration of 1 h in the exposure chamber. All subjects experienced unpleasant smell, eye irritation, and nasal irritation. Throat irritation, headache, dizziness, nausea, tiredness, and coughing were experienced by some subjects. Lung function was not found to be affected during the exposure. The experimental setup was found to be appropriate for creating different predetermined steady state concentrations in the exposure chamber of diluted exhaust from a continuously idling vehicle. The acute symptoms reported by the subjects were relatively similar to what patients reported at different workplaces.

Characterisation of the responsive properties of two running-specific prosthetic models.

PubMed

Grobler, Lara; Ferreira, Suzanne; Vanwanseele, Benedicte; Terblanche, Elmarie E

2017-04-01

The need for information regarding running-specific prosthetic properties has previously been voiced. Such information is necessary to assist in athletes' prostheses selection. This study aimed to describe the characteristics of two commercially available running-specific prostheses. The running-specific prostheses were tested (in an experimental setup) without the external interference of athlete performance variations. Four stiffness categories of each running-specific prosthetic model (Xtend ™ and Xtreme ™ ) were tested at seven alignment setups and three drop masses (28, 38 and 48 kg). Results for peak ground reaction force (GRF peak ), contact time ( t c ), flight time ( t f ), reactive strength index (RSI) and maximal compression (Δ L) were determined during controlled dropping of running-specific prostheses onto a force platform with different masses attached to the experimental setup. No statistically significant differences were found between the different setups of the running-specific prostheses. Statistically significant differences were found between the two models for all outcome variables (GRF peak , Xtend > Xtreme; t c , Xtreme > Xtend; t f , Xtreme > Xtend; RSI, Xtend > Xtreme; Δ L, Xtreme > Xtend; p < 0.05). These findings suggest that the Xtreme stores more elastic energy than the Xtend, leading to a greater performance response. The specific responsive features of blades could guide sprint athletes in their choice of running-specific prostheses. Clinical relevance Insights into the running-specific prosthesis (RSP) properties and an understanding of its responsive characteristics have implications for athletes' prosthetic choice. Physiologically and metabolically, a short sprint event (i.e. 100 m) places different demands on the athlete than a long sprint event (i.e. 400 m), and the RSP should match these performance demands.

Frequency domain fluorescent diffuse tomography of small animals with DsRed2-expressed tumors

NASA Astrophysics Data System (ADS)

Turchin, Ilya V.; Savitsky, Alexander P.; Kamensky, Vladislav A.; Plehanov, Vladimir I.; Orlova, Anna G.; Sergeeva, Ekaterina A.; Kleshnin, Mikhail S.; Shirmanova, Marina V.

2006-02-01

The main applications of fluorescent proteins (FPs) are monitoring tumor growth, angiogenesis, metastases formation and effects of new classes of drugs. Different types of tomography allow fluorescence imaging of tumors located deep in human or animal tissue. These techniques were used for investigation of the distribution of near-infrared fluorescent probes, but only a few works are devoted to fluorescence tomography in visible light. In this work, preliminary results of the frequency domain fluorescent diffuse tomography (FD FDT) method in application to DsRed2 protein as a fluorescent agent are presented. For the first step of our experiments we utilized second harmonic generation of Nd:YAG laser (532 nm) modulated by low frequency (1 kHz) in the experimental setup. The transilluminative planar configuration was used in the setup. A series of model experiments has been conducted and show good agreement between theoretical and experimental fluorescence intensity. Post mortem experiments with capsules containing DsRed2 and scattering solution introduced into esophagus of rats to simulate tumor formation have been conducted. The results of these experiments show that sensitivity of the setup is sufficient to detect DsRed2 in concentrations similar to those in FP-expressed tumor, but the contrast is not enough high to separate fluorescence of DsRed2 and surrounding tissues. The setup can be significantly improved by utilizing high-frequency modulation (110 MHz using acousto-optical modulator) of the excitation light and precise phase measurements due to difference in fluorescence life-time of FPs and surrounding tissues. An algorithm of processing a fluorescent image based on calculating zero of maximum curvature was employed for detection of fluorescent inclusions boundaries in the image.

Measurement of the secondary electron emission from CVD diamond films using phosphor screen detectors

NASA Astrophysics Data System (ADS)

Vaz, R.; May, P. W.; Fox, N. A.; Harwood, C. J.; Chatterjee, V.; Smith, J. A.; Horsfield, C. J.; Lapington, J. S.; Osbourne, S.

2015-03-01

Diamond-based photomultipliers have the potential to provide a significant improvement over existing devices due to diamond's high secondary electron yield and narrow energy distribution of secondary electrons which improves energy resolution creating extremely fast response times. In this paper we describe an experimental apparatus designed to study secondary electron emission from diamond membranes only 400 nm thick, observed in reflection and transmission configurations. The setup consists of a system of calibrated P22 green phosphor screens acting as radiation converters which are used in combination with photomultiplier tubes to acquire secondary emission yield data from the diamond samples. The superior signal voltage sampling of the phosphor screen setup compared with traditional Faraday Cup detection allows the variation in the secondary electron yield across the sample to be visualised, allowing spatial distributions to be obtained. Preliminary reflection and transmission yield data are presented as a function of primary electron energy for selected CVD diamond films and membranes. Reflection data were also obtained from the same sample set using a Faraday Cup detector setup. In general, the curves for secondary electron yield versus primary energy for both measurement setups were comparable. On average a 15-20% lower signal was recorded on our setup compared to the Faraday Cup, which was attributed to the lower photoluminescent efficiency of the P22 phosphor screens when operated at sub-kilovolt bias voltages.

High-precision horizontally directed force measurements for high dead loads based on a differential electromagnetic force compensation system

NASA Astrophysics Data System (ADS)

Vasilyan, Suren; Rivero, Michel; Schleichert, Jan; Halbedel, Bernd; Fröhlich, Thomas

2016-04-01

In this paper, we present an application for realizing high-precision horizontally directed force measurements in the order of several tens of nN in combination with high dead loads of about 10 N. The set-up is developed on the basis of two identical state-of-the-art electromagnetic force compensation (EMFC) high precision balances. The measurement resolution of horizontally directed single-axis quasi-dynamic forces is 20 nN over the working range of  ±100 μN. The set-up operates in two different measurement modes: in the open-loop mode the mechanical deflection of the proportional lever is an indication of the acting force, whereas in the closed-loop mode it is the applied electric current to the coil inside the EMFC balance that compensates deflection of the lever to the offset zero position. The estimated loading frequency (cutoff frequency) of the set-up in the open-loop mode is about 0.18 Hz, in the closed-loop mode it is 0.7 Hz. One of the practical applications that the set-up is suitable for is the flow rate measurements of low electrically conducting electrolytes by applying the contactless technique of Lorentz force velocimetry. Based on a previously developed set-up which uses a single EMFC balance, experimental, theoretical and numerical analyses of the thermo-mechanical properties of the supporting structure are presented.

Simple Apparatus for Measuring the Critical Properties of Gases

ERIC Educational Resources Information Center

Donaldson, G. B.

1973-01-01

Describes the construction and operational procedures of a simple setup which enables undergraduate students to conduct experiments on critical phenomena in gases. Indicates that the experimental features are proved comparable to those of the Reamer and Sage apparatus. (CC)

Optical techniques for determination of normal shock position in supersonic flows for aerospace applications

NASA Technical Reports Server (NTRS)

Adamovsky, Grigory; Eustace, John G.

1990-01-01

Techniques for the quantitative determination of shock position in supersonic flows using direct and indirect methods is presented. A description of an experimental setup is also presented, different configurations of shock position sensing systems are explained, and some experimental results are given. All of the methods discussed are analyzed to determine the ease of technology transfer from the laboratory to in-flight operation.

An Experimental Investigation of Computer Program Development Approaches and Computer Programming Metrics.

DTIC Science & Technology

1979-12-01

team progranming in reducing software dleveloup- ment costs relative to ad hoc approaches and improving software product quality relative to...are interpreted as demonstrating the advantages of disciplined team programming in reducing software development costs relative to ad hoc approaches...is due oartialty to the cost and imoracticality of a valiI experimental setup within a oroauct ion environment. Thus the question remains, are

Comparative Analysis of THOR-NT ATD vs. Hybrid III ATD in Laboratory Vertical Shock Testing

DTIC Science & Technology

2013-09-01

were taken both pretest and post - test for each test event (figure 5). Figure 5. Rigid fixture placed on the drop table with ATD seated: Hybrid III...6 3. Experimental Procedure 6 3.1 Test Setup...frames per second and with a Vision Research Phantom V9.1 (Wayne, NJ) high-speed video camera, sampling 1000 frames per second. 3. Experimental

Experimental identification of the behaviour of and lateral forces from freely-walking pedestrians on laterally oscillating structures in a virtual reality environment.

PubMed

Bocian, Mateusz; Macdonald, John H G; Burn, Jeremy F; Redmill, David

2015-12-15

Modelling pedestrian loading on lively structures such as bridges remains a challenge. This is because pedestrians have the capacity to interact with vibrating structures which can lead to amplification of the structural response. Current design guidelines are often inaccurate and limiting as they do not sufficiently acknowledge this effect. This originates in scarcity of data on pedestrian behaviour on vibrating ground and uncertainty as to the accuracy of results from previous experimental campaigns aiming to quantify pedestrian behaviour in this case. To this end, this paper presents a novel experimental setup developed to evaluate pedestrian actions on laterally oscillating ground in the laboratory environment while avoiding the implications of artificiality and allowing for unconstrained gait. A biologically-inspired approach was adopted in its development, relying on appreciation of operational complexities of biological systems, in particular their adaptability and control requirements. In determination of pedestrian forces to the structure consideration was given to signal processing issues which have been neglected in past studies. The results from tests conducted on the setup are related to results from previous experimental investigations and outputs of the inverted pendulum pedestrian model for walking on laterally oscillating ground, which is capable of generating self-excited forces.

Time-dependent sorption of two novel fungicides in soils within a regulatory framework.

PubMed

Gulkowska, Anna; Buerge, Ignaz J; Poiger, Thomas; Kasteel, Roy

2016-12-01

Convincing experimental evidence suggests increased sorption of pesticides on soil over time, which, so far, has not been considered in the regulatory assessment of leaching to groundwater. Recently, Beulke and van Beinum (2012) proposed a guidance on how to conduct, analyse and use time-dependent sorption studies in pesticide registration. The applicability of the recommended experimental set-up and fitting procedure was examined for two fungicides, penflufen and fluxapyroxad, in four soils during a 170 day incubation experiment. The apparent distribution coefficient increased by a factor of 2.5-4.5 for penflufen and by a factor of 2.5-2.8 for fluxapyroxad. The recommended two-site, one-rate sorption model adequately described measurements of total mass and liquid phase concentration in the calcium chloride suspension and the calculated apparent distribution coefficient, passing all prescribed quality criteria for model fit and parameter reliability. The guidance is technically mature regarding the experimental set-up and parameterisation of the sorption model for the two moderately mobile and relatively persistent fungicides under investigation. These parameters can be used for transport modelling in soil, thereby recognising the existence of the experimentally observed, but in the regulatory leaching assessment of pesticides not yet routinely considered phenomenon of time-dependent sorption. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

BlackOPs: increasing confidence in variant detection through mappability filtering.

PubMed

Cabanski, Christopher R; Wilkerson, Matthew D; Soloway, Matthew; Parker, Joel S; Liu, Jinze; Prins, Jan F; Marron, J S; Perou, Charles M; Hayes, D Neil

2013-10-01

Identifying variants using high-throughput sequencing data is currently a challenge because true biological variants can be indistinguishable from technical artifacts. One source of technical artifact results from incorrectly aligning experimentally observed sequences to their true genomic origin ('mismapping') and inferring differences in mismapped sequences to be true variants. We developed BlackOPs, an open-source tool that simulates experimental RNA-seq and DNA whole exome sequences derived from the reference genome, aligns these sequences by custom parameters, detects variants and outputs a blacklist of positions and alleles caused by mismapping. Blacklists contain thousands of artifact variants that are indistinguishable from true variants and, for a given sample, are expected to be almost completely false positives. We show that these blacklist positions are specific to the alignment algorithm and read length used, and BlackOPs allows users to generate a blacklist specific to their experimental setup. We queried the dbSNP and COSMIC variant databases and found numerous variants indistinguishable from mapping errors. We demonstrate how filtering against blacklist positions reduces the number of potential false variants using an RNA-seq glioblastoma cell line data set. In summary, accounting for mapping-caused variants tuned to experimental setups reduces false positives and, therefore, improves genome characterization by high-throughput sequencing.

Mixing behavior of a model cellulosic biomass slurry during settling and resuspension

DOE PAGES

Crawford, Nathan C.; Sprague, Michael A.; Stickel, Jonathan J.

2016-01-29

Thorough mixing during biochemical deconstruction of biomass is crucial for achieving maximum process yields and economic success. However, due to the complex morphology and surface chemistry of biomass particles, biomass mixing is challenging and currently it is not well understood. This study investigates the bulk rheology of negatively buoyant, non-Brownian α-cellulose particles during settling and resuspension. The torque signal of a vane mixer across two distinct experimental setups (vane-in-cup and vane-in-beaker) was used to understand how mixing conditions affect the distribution of biomass particles. During experimentation, a bifurcated torque response as a function of vane speed was observed, indicating thatmore » the slurry transitions from a “settling-dominant” regime to a “suspension-dominant” regime. The torque response of well-characterized fluids (i.e., DI water) were then used to empirically identify when sufficient mixing turbulence was established in each experimental setup. The predicted critical mixing speeds were in agreement with measured values, suggesting that secondary flows are required in order to keep the cellulose particles fully suspended. In addition, a simple scaling relationship was developed to model the entire torque signal of the slurry throughout settling and resuspension. Furthermore, qualitative and semi-quantitative agreement between the model and experimental results was observed.« less

Mechanical characterization of a short fiber-reinforced polymer at room temperature: experimental setups evaluated by an optical measurement system

NASA Astrophysics Data System (ADS)

Röhrig, C.; Scheffer, T.; Diebels, S.

2017-09-01

Composite materials are of great interest for industrial applications because of their outstanding properties. Each composite material has its own characteristics due to the large number of possible combinations of matrix and filler. As a result of their compounding, composites usually show a complex material behavior. This work is focused on the experimental testing of a short fiber-reinforced thermoplastic composite at room temperature. The characteristic behavior of this material class is often based on a superposition of typical material effects. The predicted characteristic material properties such as elasto-plasticity, damage and anisotropy of the investigated material are obtained from results of cyclic uniaxial tensile tests at constant strain rate. Concerning the manufacturing process as well as industrial applications, the experimental investigations are extended to multiaxial loading situations. Therefore, the composite material is examined with a setup close to a deep-drawing process, the Nakajima test (Nakazima et al. in Study on the formability of steel sheets. Yawate Technical Report No. 264, pp 8517-8530, 1968). The evaluation of the experimental investigations is provided by an optical analysis system using a digital image correlation software. Finally, based on the results of the uniaxial tensile tests, a one-dimensional macroscopic model is introduced and first results of the simulation are provided.

Experimental data for the slug two-phase flow characteristics in horizontal pipeline.

PubMed

Mohmmed, Abdalellah O; Nasif, Mohammad S; Al-Kayiem, Hussain H

2018-02-01

The data presented in this article were the basis for the study reported in the research articles entitled "Statistical assessment of experimental observation on the slug body length and slug translational velocity in a horizontal pipe" (Al-Kayiem et al., 2017) [1] which presents an experimental investigation of the slug velocity and slug body length for air-water tow phase flow in horizontal pipe. Here, in this article, the experimental set-up and the major instruments used for obtaining the computed data were explained in details. This data will be presented in the form of tables and videos.

Experimental study of the robust global synchronization of Brockett oscillators

NASA Astrophysics Data System (ADS)

Ahmed, Hafiz; Ushirobira, Rosane; Efimov, Denis

2017-12-01

This article studies the experimental synchronization of a family of a recently proposed oscillator model, i.e. the Brockett oscillator [R. Brockett, Synchronization without periodicity, in Mathematical Systems Theory, A Volume in Honor of U. Helmke, edited by K. Huper, J. Trumpf (CreateSpace, Seattle, USA, 2013), pp. 65-74]. Due to its structural property, Brockett oscillator can be considered as a promising benchmark nonlinear model for investigating synchronization and the consensus phenomena. Our experimental setup consists of analog circuit realizations of a network of Brockett oscillators. Experimental results obtained in this work correspond to the prior theoretical findings.

A new AMS facility at Inter University Accelerator Centre, New Delhi

NASA Astrophysics Data System (ADS)

Kumar, Pankaj; Chopra, S.; Pattanaik, J. K.; Ojha, S.; Gargari, S.; Joshi, R.; Kanjilal, D.

2015-10-01

Inter University Accelerator Centre (IUAC), a national facility of government of India, is having a 15UD Pelletron accelerator for multidisciplinary ion beam based research programs. Recently, a new accelerator mass spectrometry (AMS) facility has been developed after incorporating many changes in the existing 15UD Pelletron accelerator. A clean chemistry laboratory for 10Be and 26Al with all the modern facilities has also been developed for the chemical processing of samples. 10Be measurements on sediment samples, inter laboratory comparison results and 26Al measurements on standard samples are presented in this paper. In addition to the 10Be and 26Al AMS facilities, a new 14C AMS facility based on a dedicated 500 kV tandem ion accelerator with two cesium sputter ion sources, is also being setup at IUAC.

Influence of mechanical noise inside a scanning electron microscope.

PubMed

de Faria, Marcelo Gaudenzi; Haddab, Yassine; Le Gorrec, Yann; Lutz, Philippe

2015-04-01

The scanning electron microscope is becoming a popular tool to perform tasks that require positioning, manipulation, characterization, and assembly of micro-components. However, some of these applications require a higher level of performance with respect to dynamics and precision of positioning. One limiting factor is the presence of unidentified noises and disturbances. This work aims to study the influence of mechanical disturbances generated by the environment and by the microscope, identifying how these can affect elements in the vacuum chamber. To achieve this objective, a dedicated setup, including a high-resolution vibrometer, was built inside the microscope. This work led to the identification and quantification of main disturbances and noise sources acting on a scanning electron microscope. Furthermore, the effects of external acoustic excitations were analysed. Potential applications of these results include noise compensation and real-time control for high accuracy tasks.

Electromagnetic navigational bronchoscopy and robotic-assisted thoracic surgery.

PubMed

Christie, Sara

2014-06-01

With the use of electromagnetic navigational bronchoscopy and robotics, lung lesions can be diagnosed and resected during one surgical procedure. Global positioning system technology allows surgeons to identify and mark a thoracic tumor, and then robotics technology allows them to perform minimally invasive resection and cancer staging procedures. Nurses on the perioperative robotics team must consider the logistics of providing safe and competent care when performing combined procedures during one surgical encounter. Instrumentation, OR organization and room setup, and patient positioning are important factors to consider to complete the procedure systematically and efficiently. This revolutionary concept of combining navigational bronchoscopy with robotics requires a team of dedicated nurses to facilitate the sequence of events essential for providing optimal patient outcomes in highly advanced surgical procedures. Copyright © 2014 AORN, Inc. Published by Elsevier Inc. All rights reserved.

A fast response, low heat generating activation method for LHe level sensors

NASA Astrophysics Data System (ADS)

Choudhury, Anup; Sahu, Santosh; Kanjilal, Dinakar

2018-06-01

A superconducting liquid helium (LHe) level sensor of length 300 mm has been fabricated based on the principle of differential heat transfer characteristic in helium gas compared to that in liquid. The sensor wire used has a diameter of 38 μm, and the wire was obtained from a pack of multifilament wires. A full thermo-electrical characterisation of the sensor was carried out in a dedicated setup. Its dynamic thermal response was also studied to understand its timing characteristics at different liquid levels and excitation currents. Based on the sensor characterisation, a new level measurement technique is evaluated which can reduce the heat load going to LHe during sensor activation without compromising on its sensitivity or accuracy. The timing response with this technique will make the level detection faster compared to the conventional techniques.

Fibre optic sensor based measurements of flow-induced vibration in a liquid metal cooled nuclear reactor set-up

NASA Astrophysics Data System (ADS)

De Pauw, B.; Vanlanduit, S.; Van Tichelen, K.; Geernaert, T.; Thienpont, H.; Berghmans, F.

2017-04-01

Fuel assembly vibrations in nuclear reactor cores should not be excessive as these can compromise the lifetime of the assembly and lead to safety hazards. This issue is particularly relevant to new reactor designs that use liquid metal coolants. We therefore demonstrate accurate measurements of the vibrations of a fuel assembly in a lead-bismuth eutectic cooled installation with fibre Bragg grating (FBG) based sensors. The use of FBGs in combination with a dedicated sensor integration approach allows accounting for the severe geometrical constraints and providing for the required minimal intrusiveness of the instrumentation, identifying the vibration modes with required accuracy and observing the differences between the vibration amplitudes of the individual fuel pins as well as evidencing a low frequency fuel pin vibration mode resulting from the supports.

Development of traceable measurement of the diffuse optical properties of solid reference standards for biomedical optics at National Institute of Standards and Technology.

PubMed

Lemaillet, Paul; Bouchard, Jean-Pierre; Allen, David W

2015-07-01

The development of a national reference instrument dedicated to the measurement of the scattering and absorption properties of solid tissue-mimicking phantoms used as reference standards is presented. The optical properties of the phantoms are measured with a double-integrating sphere setup in the steady-state domain, coupled with an inversion routine of the adding-doubling procedure that allows for the computation of the uncertainty budget for the measurements. The results are compared to the phantom manufacturer's values obtained by a time-resolved approach. The results suggest that the agreement between these two independent methods is within the estimated uncertainties. This new reference instrument will provide optical biomedical research laboratories with reference values for absolute diffuse optical properties of phantom materials.

Focusing effect of bent GaAs crystals for γ-ray Laue lenses: Monte Carlo and experimental results

NASA Astrophysics Data System (ADS)

Virgilli, E.; Frontera, F.; Rosati, P.; Bonnini, E.; Buffagni, E.; Ferrari, C.; Stephen, J. B.; Caroli, E.; Auricchio, N.; Basili, A.; Silvestri, S.

2016-02-01

We report on results of observation of the focusing effect from the planes (220) of Gallium Arsenide (GaAs) crystals. We have compared the experimental results with the Monte Carlo simulations of the focusing capability of GaAs tiles performed with a dedicated ray-tracer. The GaAs tiles were bent using a lapping process developed at the cnr/imem - Parma (Italy) in the framework of the laue project, funded by ASI, dedicated to build a broad band Laue lens prototype for astrophysical applications in the hard X-/soft γ-ray energy range (80-600 keV). We present and discuss the results obtained from their characterization, mainly in terms of focusing capability. Bent crystals will significantly increase the signal to noise ratio of a telescope based on a Laue lens, consequently leading to an unprecedented enhancement of sensitivity with respect to the present non focusing instrumentation.

One-dimensional scanning of moisture in heated porous building materials with NMR.

PubMed

van der Heijden, G H A; Huinink, H P; Pel, L; Kopinga, K

2011-02-01

In this paper we present a new dedicated NMR setup which is capable of measuring one-dimensional moisture profiles in heated porous materials. The setup, which is placed in the bore of a 1.5 T whole-body scanner, is capable of reaching temperatures up to 500 °C. Moisture and temperature profiles can be measured quasi simultaneously with a typical time resolution of 2-5 min. A methodology is introduced for correcting temperature effects on NMR measurements at these elevated temperatures. The corrections are based on the Curie law for paramagnetism and the observed temperature dependence of the relaxation mechanisms occurring in porous materials. Both these corrections are used to obtain a moisture content profile from the raw NMR signal profile. To illustrate the methodology, a one-sided heating experiment of concrete with a moisture content in equilibrium with 97% RH is presented. This kind of heating experiment is of particular interest in the research on fire spalling of concrete, since it directly reveals the moisture and heat transport occurring inside the concrete. The obtained moisture profiles reveal a moisture peak building up behind the boiling front, resulting in a saturated layer. To our knowledge the direct proof of the formation of a moisture peak and subsequent moisture clogging has not been reported before. Copyright © 2010 Elsevier Inc. All rights reserved.

Space-time variability of raindrop size distributions along a 2.2 km microwave link path

NASA Astrophysics Data System (ADS)

van Leth, Tommy; Uijlenhoet, Remko; Overeem, Aart; Leijnse, Hidde; Berne, Alexis

2017-04-01

The Wageningen Urban Rainfall Experiment (WURex14-15) was dedicated to address several errors and uncertainties associated with quantitative precipitation estimates from microwave links. The core of the experiment consisted of three co-located microwave links installed between two major buildings on the Wageningen University campus, approximately 2.2 km apart: a 38 GHz commercial microwave link, provided by T-Mobile NL, and 26 GHz and 38 GHz (dual-polarization) research microwave links from RAL. Transmitting and receiving antennas were attached to masts installed on the roofs of the two buildings, about 30 m above the ground. This setup was complemented with a Scintec infrared Large-Aperture Scintillometer, installed over the same path, an automatic rain gauge, as well as 5 Parsivel optical disdrometers positioned at several locations along the path. Temporal sampling of the received signals was performed at a rate of 20 Hz. The setup was being monitored by time-lapse cameras to assess the state of the antennas as well as the atmosphere. Finally, data were available from the KNMI weather radars and an automated weather station situated just outside Wageningen. The experiment has been active between August 2014 and December 2015. We present preliminary results regarding the space-time variability of raindrop size distributions from the Parsivel disdrometers along the 2.2 km microwave link path.

A far-field radio-frequency experimental exposure system with unrestrained mice.

PubMed

Hansen, Jared W; Asif, Sajid; Singelmann, Lauren; Khan, Muhammad Saeed; Ghosh, Sumit; Gustad, Tom; Doetkott, Curt; Braaten, Benjamin D; Ewert, Daniel L

2015-01-01

Many studies have been performed on exploring the effects of radio-frequency (RF) energy on biological function in vivo. In particular, gene expression results have been inconclusive due, in part, to a lack of a standardized experimental procedure. This research describes a new far field RF exposure system for unrestrained murine models that reduces experimental error. The experimental procedure includes the materials used, the creation of a patch antenna, the uncertainty analysis of the equipment, characterization of the test room, experimental equipment used and setup, power density and specific absorption rate experiment, and discussion. The result of this research is an experimental exposure system to be applied to future biological studies.

Santa Rita Experimental Range: 100 years (1903 to 2003) of accomplishments and contributions; conference proceedings; 2003 October 30-November 1; Tucson, AZ

Treesearch

Mitchel P. McClaran; Peter F. Ffolliott; Carleton B. Edminster

2003-01-01

The purpose of this conference was to celebrate the 100 years of accomplishments and contributions of the Santa Rita Experimental Range, the longest continuously operating research area dedicated to the sustainable management of North American rangelands. The conference consisted of one-and-a-half days of invited synthesis papers and contributed poster presentations...

Montaje Experimental de Optica Adaptiva con Tecnología FPGA

NASA Astrophysics Data System (ADS)

Rodriguez Brizuela, F.; Verasay, J. P.; Recabarren, P.

An experimental platform based on FPGA devices, dedicated to implement active and adaptive optic software in HDL has been developed. The devel- oped assembly is the first of a series of works focused on this important area of instrumental astronomy. The exposed development is part of a Final Project of Electronic Engineering of the National University of Cordoba. FULL TEXT IN SPANISH

Design and Fabrication of a Magnetic System to Investigate Magnetized Dusty Plasmas

NASA Astrophysics Data System (ADS)

Bates, Evan M.; Romero-Talamas, Carlos A.

2013-10-01

The interest in researching the dynamics and equilibrium of magnetized dusty plasma crystallization has led to the design and fabrication of a novel experimental setup at UMBC. The proposed magnets will be an important subsystem of this setup, and will produce a uniform magnetic field of several tesla for a duration of several seconds. The magnets will be arranged in the Helmholtz configuration and will have a cooling system for temperature compensation of the coils, as well as the ability to adjust the orientation of the magnetic field with respect to gravity. Planned experiments include propagation of magnetized waves in dusty plasma crystals under various boundary conditions.

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.

Column experiments on organic micropollutants - applications and limitations

NASA Astrophysics Data System (ADS)

Banzhaf, Stefan; Hebig, Klaus

2016-04-01

As organic micropollutants become more and more ubiquitous in the aquatic environment, a sound understanding of their fate and transport behaviour is needed. This is to assure both safe and clean drinking water supply for mankind in the future and to protect the aquatic environment from pollution and negative consequences caused by manmade contamination. Apart from countless field studies, column experiments were and are frequently used to study transport of organic micropollutants. As the transport of (organic) solutes in groundwater is controlled by the chemical and physical properties of the compounds, the solvent (the groundwater including all solutes), and the substrate (the aquifer material), the adjustment and control of these boundary conditions allow to study a multitude of different experimental setups and to address specific research questions. The main purpose, however, remains to study the transport of a specific compound and its sorption and degradation behaviour in a specific sediment or substrate. Apart from the effective control of the individual boundary conditions, the main advantage of columns studies compared to other experimental setups (such as field studies, batch/microcosm studies), is that conservative and reactive solute breakthrough curves are obtained, which represent the sum of the transport processes. The analysis of these curves is well-developed and established. Additionally, limitations of this experimental method are presented here: the effects observed in column studies are often a result of dynamic, non-equilibrium processes. Time (or flow velocity) plays a major role in contrast to batch experiments, in which all processes will be observed until equilibrium is reached in the substrate-solution-system. Slightly modifying boundary conditions in different experiments have a strong influence on transport and degradation behaviour of organic micropollutants. This is a significant severe issue when it comes to general findings on the transport behaviour of a specific organic compound that are transferable to any given hydrogeochemical environment. Unfortunately, results of most column experiments therefore remain restricted to their specific setup. Column experiments can provide good estimates of all relevant transport parameters. However, the obtained results will almost always be limited to the scale they were obtained from. This means that direct application to field scale studies is infeasible as too many parameters are exclusive for the laboratory column setup. The remaining future challenge is to develop standard column experiments on organic micropollutants that overcome this issue. Here, we present a review of column experiments on organic micropollutants. We present different setups and discuss weaknesses, problems and advantages and provide ideas how to obtain more comparable results on the transport of organic micropollutants in the future.

Status of the Nanoscopium scanning nanoprobe beamline of Synchrotron Soleil

NASA Astrophysics Data System (ADS)

Somogyi, A.; Medjoubi, K.; Kewish, C. M.; Leroux, V.; Ribbens, M.; Baranton, G.; Polack, F.; Samama, J. P.

2013-09-01

The Nanoscopium 155 m-long scanning nanoprobe beamline of Synchrotron Soleil (St Aubin, France) is dedicated to quantitative multi-modal imaging. Dedicated experimental stations, working in consecutive operation mode, will provide coherent scatter imaging and spectro-microscopy techniques in the 5-20 keV energy range for various user communities. Next to fast scanning, cryogenic cooling will reduce the radiation damage of sensitive samples during the measurements. Nanoscopium is in the construction phase, the first user experiments are expected in 2014. The main characteristics of the beamline and an overview of its status are given in this contribution.

Facility for Heavy Ion Collision Experiment at RAON

NASA Astrophysics Data System (ADS)

Kim, Young Jin; Kim, Do Gyun; Kim, Gi Dong; Kim, Yong Hak; Kim, Young-Jin; Kim, Yong Kyun; Kwon, Young Kwan; Yun, Chong Cheol; Hong, Byungsik; Sei Lee, Kyung; Kim, Eun Joo; Ahn, Jung Keun; Lee, Hyo Sang

2014-03-01

The Rare Isotope Science Project (RISP) was established in December 2011 in order to carry out the technical design and the establishment of the accelerator complex (RAON) for the rare isotope science in Korea. The rare isotope accelerator at RAON will provide both stable and rare isotope heavy-ion beams the energy range from a few MeV/nucleon to a few hundreds of MeV/nucleon for researches in fields of basic and applied science. Large Acceptance Multipurpose Spectrometer (LAMPS) at RAON is a heavy-ion collision experimental facility for studying nuclear symmetry energy by using rare isotope beams. Two different experimental setups of LAMPS are designed for covering entire energy range at RAON. One is for low energy (< 18.5 MeV/nucleon) heavy-ion collision experiment for day-1 experiments. This experimental setup consists of an array of ΔE-E Si-CsI detectors, a gamma array to cover backward polar angle, and a forward neutron wall. The other is for completing an event reconstruction by detecting all the particles produced in high energy heavy-ion collisions within a large acceptance angle to measure particle spectrum, yield, ratio and collective flow of pions, protons, neutrons, and intermediate fragments at the same time. The experimental setup consists of a superconducting spectrometer, a dipole spectrometer, and a forward neutron wall. A Time Projection Chamber (TPC) will be placed inside of superconducting solenoid magnet of 0.6 T for charged particle tracking. The dipole spectrometer will be located forward of the superconducting spectrometer and it will be composed of a combination of quadrupole, dipole magnets, focal plane detector, tracking stations, and Time-of-Flight (ToF) detector at the end. The neutron wall will be made of 10 layers of plastic scintillators for neutron tracking. In this presentation, the detail physics and design of LAMPS at RAON will be discussed.

Fate and transport of manure-borne microorganisms

USDA-ARS?s Scientific Manuscript database

This lecture presents the overview of the recent research results on the environmental microbial fate and transport in the Environmental Microbial and Food Safety Laboratory. The overview of experimental sites in Maryland and Pennsylvania, and laboratory setups will be given. The emphasis on envir...

Using a biomimetic membrane surface experiment to investigate the activity of the magnetite biomineralisation protein Mms6† †Electronic supplementary information (ESI) available: Including Mms6 protein and peptide sequences, additional QCM-D and SEM data and protein modelling. See DOI: 10.1039/c5ra16469a Click here for additional data file.

PubMed Central

Bird, Scott M.; Rawlings, Andrea E.; Galloway, Johanna M.

2016-01-01

Magnetotactic bacteria are able to synthesise precise nanoparticles of the iron oxide magnetite within their cells. These particles are formed in dedicated organelles termed magnetosomes. These lipid membrane compartments use a range of biomineralisation proteins to nucleate and regulate the magnetite crystallisation process. A key component is the membrane protein Mms6, which binds to iron ions and helps to control the formation of the inorganic core. We have previously used Mms6 on gold surfaces patterned with a self-assembled monolayer to successfully produce arrays of magnetic nanoparticles. Here we use this surface system as a mimic of the interior face of the magnetosome membrane to study differences between intact Mms6 and the acid-rich C-terminal peptide subregion of the Mms6 protein. When immobilised on surfaces, the peptide is unable to reproduce the particle size or homogeneity control exhibited by the full Mms6 protein in our experimental setup. Moreover, the peptide is unable to support anchoring of a dense array of nanoparticles to the surface. This system also allows us to deconvolute particle binding from particle nucleation, and shows that Mms6 particle binding is less efficient when supplied with preformed magnetite nanoparticles when compared to particles precipitated from solution in the presence of the surface immobilised Mms6. This suggests that Mms6 binds to iron ions rather than to magnetite surfaces in our system, and is perhaps a nucleating agent rather than a controller of magnetite crystal growth. The comparison between the peptide and the protein under identical experimental conditions indicates that the full length sequence is required to support the full function of Mms6 on surfaces. PMID:27019707

Dedicated cardiac rehabilitation wearable sensor and its clinical potential.

PubMed

Lee, Hooseok; Chung, Heewon; Ko, Hoon; Jeong, Changwon; Noh, Se-Eung; Kim, Chul; Lee, Jinseok

2017-01-01

We describe a wearable sensor developed for cardiac rehabilitation (CR) exercise. To effectively guide CR exercise, the dedicated CR wearable sensor (DCRW) automatically recommends the exercise intensity to the patient by comparing heart rate (HR) measured in real time with a predefined target heart rate zone (THZ) during exercise. The CR exercise includes three periods: pre-exercise, exercise with intensity guidance, and post-exercise. In the pre-exercise period, information such as THZ, exercise type, exercise stage order, and duration of each stage are set up through a smartphone application we developed for iPhones and Android devices. The set-up information is transmitted to the DCRW via Bluetooth communication. In the period of exercise with intensity guidance, the DCRW continuously estimates HR using a reflected pulse signal in the wrist. To achieve accurate HR measurements, we used multichannel photo sensors and increased the chances of acquiring a clean signal. Subsequently, we used singular value decomposition (SVD) for de-noising. For the median and variance of RMSEs in the measured HRs, our proposed method with DCRW provided lower values than those from a single channel-based method and template-based multiple-channel method for the entire exercise stage. In the post-exercise period, the DCRW transmits all the measured HR data to the smartphone application via Bluetooth communication, and the patient can monitor his/her own exercise history.

Experimental investigation on emission reduction in neem oil biodiesel using selective catalytic reduction and catalytic converter techniques.

PubMed

Viswanathan, Karthickeyan

2018-05-01

In the present study, non-edible seed oil namely raw neem oil was converted into biodiesel using transesterification process. In the experimentation, two biodiesel blends were prepared namely B25 (25% neem oil methyl ester with 75% of diesel) and B50 (50% neem oil methyl ester with 50% diesel). Urea-based selective catalytic reduction (SCR) technique with catalytic converter (CC) was fixed in the exhaust tail pipe of the engine for the reduction of engine exhaust emissions. Initially, the engine was operated with diesel as a working fluid and followed by refilling of biodiesel blends B25 and B50 to obtain the baseline readings without SCR and CC. Then, the same procedure was repeated with SCR and CC technique for emission reduction measurement in diesel, B25 and B50 sample. The experimental results revealed that the B25 blend showed higher break thermal efficiency (BTE) and exhaust gas temperature (EGT) with lower break-specific fuel consumption (BSFC) than B50 blend at all loads. On comparing with biodiesel blends, diesel experiences increased BTE of 31.9% with reduced BSFC of 0.29 kg/kWh at full load. A notable emission reduction was noticed for all test fuels in SCR and CC setup. At full load, B25 showed lower carbon monoxide (CO) of 0.09% volume, hydrocarbon (HC) of 24 ppm, and smoke of 14 HSU and oxides of nitrogen (NOx) of 735 ppm than diesel and B50 in SCR and CC setup. On the whole, the engine with SCR and CC setup showed better performance and emission characteristics than standard engine operation.

Quantifying the Contribution of Entire Free-Living Nematode Communities to Carbon Mineralization under Contrasting C and N Availability

PubMed Central

Gebremikael, Mesfin Tsegaye; Steel, Hanne; Bert, Wim; Maenhout, Peter; Sleutel, Steven; De Neve, Stefaan

2015-01-01

To understand the roles of nematodes in organic matter (OM) decomposition, experimental setups should include the entire nematode community, the native soil microflora, and their food sources. Yet, published studies are often based on either simplified experimental setups, using only a few selected species of nematode and their respective prey, despite the multitude of species present in natural soil, or on indirect estimation of the mineralization process using O2 consumption and the fresh weight of nematodes. We set up a six-month incubation experiment to quantify the contribution of the entire free living nematode community to carbon (C) mineralization under realistic conditions. The following treatments were compared with and without grass-clover amendment: defaunated soil reinoculated with the entire free living nematode communities (+Nem) and defaunated soil that was not reinoculated (-Nem). We also included untreated fresh soil as a control (CTR). Nematode abundances and diversity in +Nem was comparable to the CTR showing the success of the reinoculation. No significant differences in C mineralization were found between +Nem and -Nem treatments of the amended and unamended samples at the end of incubation. Other related parameters such as microbial biomass C and enzymatic activities did not show significant differences between +Nem and -Nem treatments in both amended and unamended samples. These findings show that the collective contribution of the entire nematode community to C mineralization is small. Previous reports in literature based on simplified experimental setups and indirect estimations are contrasting with the findings of the current study and further investigations are needed to elucidate the extent and the mechanisms of nematode involvement in C mineralization. PMID:26393517

Experimental Studies of Instability Development in Magnetically Driven Systems

DOE PAGES

Awe, Thomas James

2015-03-01

The author highlights results from a variety of experiments on the Z Machine, for which he served as the lead experimentalist. All experiments on Z take dedicated effort from a large collaboration of scientists, engineers, and technicians.

Development of a PET cyclotron based irradiation setup for proton radiobiology

NASA Astrophysics Data System (ADS)

Ghithan, Sharif; Crespo, Paulo; do Carmo, S. J. C.; Ferreira Marques, Rui; Fraga, F. A. F.; Simões, Hugo; Alves, Francisco; Rachinhas, P. J. B. M.

2015-02-01

An out-of-yoke irradiation setup using the proton beam from a cyclotron that ordinary produces radioisotopes for positron emission tomography (PET) has been developed, characterized, calibrated and validated. The current from a 20 μm thick aluminum transmission foil is readout by home-made transimpedance electronics, providing online dose information. The main monitoring variables, delivered in real-time, include beam current, integrated charge and dose rate. Hence the dose and integrated current delivered at a given instant to an experimental setup can be computer-controlled with a shutter. In this work, we report on experimental results and Geant4 simulations of a setup which exploits for the first time the 18 MeV proton beam from a PET cyclotron to irradiate a selected region of a target using the developed irradiation system. By using this system, we are able to deliver a homogeneous beam on targets with 18 mm diameter, allowing to achieve the controlled irradiation of cell cultures located in biological multi-well dishes of 16 mm diameter. We found that the magnetic field applied inside the cyclotron plays a major role for achieving the referred to homogeneity. The quasi-Gaussian curve obtained by scanning the magnet current and measuring the corresponding dose rate must be measured before any irradiation procedure, with the shutter closed. At the optimum magnet current, which corresponds to the center of the Gaussian, a homogenous dose is observed over the whole target area. Making use of a rotating disk with a slit of 0.5 mm at a radius of 150 mm, we could measure dose rates on target ranging from 500 mGy/s down to 5 mGy/s. For validating the developed irradiation setup, several Gafchromic® EBT2 films were exposed to different values of dose. The absolute dose in the irradiated films were assessed in the 2D film dosimetry system of the Department of Radiotherapy of Coimbra University Hospital Center with a precision better than 2%. In the future, we plan to irradiate small animals, cell cultures, or other materials or samples.

Investigation of the flow turning loss in unstable solid propellant rocket motors

NASA Astrophysics Data System (ADS)

Matta, Lawrence Mark

The goal of this study was to improve the understanding of the flow turning loss, which contributes to the damping of axial acoustic instabilities in solid propellant rocket motors. This understanding is needed to develop practical methods for designing motors that do not exhibit such instabilities. The flow turning loss results from the interaction of the flow of combustion products leaving the surface of the propellant with the acoustic field in an unstable motor. While state of the art solid rocket stability models generally account for the flow turning loss, its magnitude and characteristics have never been fully investigated. This thesis describes a combined theoretical, numerical, and experimental investigation of the flow turning loss and its dependence upon various motor design and operating parameters. First, a one dimensional acoustic stability equation that verifies the existence of the flow turning loss was derived for a chamber with constant mean pressure and temperature. The theoretical development was then extended to include the effects of mean temperature gradients to accommodate combustion systems in which mean temperature gradients and heat losses are significant. These analyses provided the background and expressions necessary to guide an experimental study. The relevant equations were then solved for the developed experimental setup to predict the behavior of the flow turning loss and the other terms of the developed acoustic stability equation. This was followed by and experimental study in which the flow turning region of an unstable solid propellant rocket motor was simulated. The setup was used, with and without combustion, to determine the dependence of the flow turning loss upon operating conditions. These studies showed that the flow turning loss strongly depends upon the gas velocity at the propellant surface and the location of the flow turning region relative to the standing acoustic wave. The flow turning loss measured in the experiment was found to be small relative to other mechanisms. This, however, was characteristic of the experimental setup and is not representative of actual rocket motors, in which the flow turning loss is often a significant part of the overall stability.

Multi-parameter fibre Bragg grating sensor-array for thermal vacuum cycling test

NASA Astrophysics Data System (ADS)

Cheng, L.; Ahlers, B.; Toet, P.; Casarosa, G.; Appolloni, M.

2017-11-01

Fibre Bragg Grating (FBG) sensor systems based on optical fibres are gaining interest in space applications. Studies on Structural Health Monitoring (SHM) of the reusable launchers using FBG sensors have been carried out in the Future European Space Transportation Investigations Programme (FESTIP). Increasing investment in the development on FBG sensor applications is foreseen for the Future Launchers Preparatory Programme (FLPP). TNO has performed different SHM measurements with FBGs including on the VEGA interstage [1, 2] in 2006. Within the current project, a multi-parameter FBG sensor array demonstrator system for temperature and strain measurements is designed, fabricated and tested under ambient as well as Thermal Vacuum (TV) conditions in a TV chamber of the European Space Agency (ESA), ESTEC site. The aim is the development of a multi-parameters measuring system based on FBG technology for space applications. During the TV tests of a Space Craft (S/C) or its subsystems, thermal measurements, as well as strain measurements are needed by the engineers in order to verify their prediction and to validate their models. Because of the dimensions of the test specimen and the accuracy requested to the measurement, a large number of observation/measuring points are needed. Conventional sensor systems require a complex routing of the cables connecting the sensors to their acquisition unit. This will add extra weight to the construction under test. FBG sensors are potentially light-weight and can easily be multiplexed in an array configuration. The different tasks comply of a demonstrator system design; its component selection, procurement, manufacturing and finally its assembly. The temperature FBG sensor is calibrated in a dedicated laboratory setup down to liquid nitrogen (LN2) temperature at TNO. A temperature-wavelength calibration curve is generated. After a test programme definition a setup in thermal vacuum is realised at ESA premises including a mechanical strain transducer to generate strain via a dedicated feed through in the chamber. Thermocouples are used to log the temperature for comparison to the temperature FBG sensor. Extreme temperature ranges from -150°C and +70°C at a pressure down to 10-4 Pa (10-6 mbar) are covered as well as testing under ambient conditions. In total five thermal cycles during a week test are performed. The FBG temperature sensor test results performed in the ESA/ESTEC TV chamber reveal high reproducibility (within 1 °C) within the test temperature range without any evidence of hysteresis. Differences are detected to the previous calibration curve. Investigation is performed to find the cause of the discrepancy. Differences between the test set-ups are identified. Equipment of the TNO test is checked and excluded to be the cause. Additional experiments are performed. The discrepancy is most likely caused by a 'thermal shock' due to rapid cooling down to LN2 temperature, which results in a wavelength shift. Test data of the FBG strain sensor is analysed. The read-out of the FBG strain sensor varies with the temperature during the test. This can be caused by temperature induced changes in the mechanical setup (fastening of the mechanical parts) or impact of temperature to the mechanical strain transfer to the FBG. Improvements are identified and recommendations given for future activities.

Commissioning and initial experimental program of the BGO-OD experiment at ELSA

NASA Astrophysics Data System (ADS)

Alef, S.; Bauer, P.; Bayadilov, D.; Beck, R.; Becker, M.; Bella, A.; Bielefeldt, P.; Böse, S.; Braghieri, A.; Brinkmann, K.; Cole, P.; Di Salvo, R.; Dutz, H.; Elsner, D.; Fantini, A.; Freyermuth, O.; Friedrich, S.; Frommberger, F.; Ganenko, V.; Geffers, D.; Gervino, G.; Ghio, F.; Görtz, S.; Gridnev, A.; Gutz, E.; Hammann, D.; Hannappel, J.; Hillert, W.; Ignatov, A.; Jahn, R.; Joosten, R.; Jude, T. C.; Klein, F.; Knaust, J.; Kohl, K.; 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.; Schaerf, C.; Scheluchin, G.; Schmieden, H.; Stugelev, A.; Sumachev, V.; Tarakanov, V.; Vegna, V.; Walther, D.; Watts, D.; Zaunick, H.; Zimmermann, T.

2016-11-01

BGO-OD is a new meson photoproduction experiment at the ELSA facility of Bonn University. It aims at the investigation of non strange and strange baryon excitations, and is especially designed to be able to detect weekly bound meson-baryon type structures. The setup for the BGO-OD experiment is presented, the characteristics of the photon beam and the detector performances are shown and the initial experimental program is discussed.

Evaluation of a Belt-Cast Austenitic Steel Alloy from Salzgitter Mannesmann Forschung: Effect of Hardness on the Ballistic Resistance against Two 0.30-cal. Projectile Types

DTIC Science & Technology

2017-08-01

obtained from Salzgitter Mannesmann Forschung, a German steel manufacturing concern. The steel samples were subjected to microstructural and quasi ... Experimental Procedures 4 4. Results and Discussion 7 4.1 Microstructural and Mechanical Properties 7 4.2 Ballistic Testing 14 5. Summary and Conclusions...austenitic steels. Reprinted with permission. ................................................................... 2 Fig. 2 Experimental setup. A

Experimental aspects of the thermochemical conversion of solar energy - Decarbonation of CaCO3

NASA Astrophysics Data System (ADS)

Flamant, G.; Hernandez, D.; Bonet, C.; Traverse, J.-P.

1980-01-01

The feasibility of thermochemical conversion of concentrated solar energy is investigated. Consideration is given to heterogeneous systems in the range 500-1500 C. A reaction volume is on a laboratory scale about 30 cu cm. An experimental set-up selected is a fluid bed and a rotary kiln. An endothermal reaction, namely, decarbonation of CaCO3, is selected as a possible application for solar power plants.

Investigation of blown boundary layers with an improved wall jet system. Ph.D. Thesis. Final Technical Report, 1 Jul. 1978 - Dec. 1979; [to prevent turbulent boundary layer separation

NASA Technical Reports Server (NTRS)

Saripalli, K. R.; Simpson, R. L.

1979-01-01

The behavior of two dimensional incompressible turbulent wall jets submerged in a boundary layer when they are used to prevent boundary layer separation on plane surfaces is investigated. The experimental set-up and instrumentation are described. Experimental results of zero pressure gradient flow and adverse pressure gradient flow are presented. Conclusions are given and discussed.

How to Evaluate and Synthesize Literature Data on Physical Properties.

DTIC Science & Technology

1980-09-01

experimental set-up, refined technique for fabri - cating and installing the specimen heater so as to minimize heat leakage, technique for installing...Conductivity of Gadolinium Figure 3 shows another type of disagreement in experimental data from the literature. Here the two sets of thermal conductivity data...for gadolinium are for the same one piece of specimen measured in the same laboratory which S-" is one of the best known internationally, and published

An optimized adaptive optics experimental setup for in vivo retinal imaging

NASA Astrophysics Data System (ADS)

Balderas-Mata, S. E.; Valdivieso González, L. G.; Ramírez Zavaleta, G.; López Olazagasti, E.; Tepichin Rodriguez, E.

2012-10-01

The use of Adaptive Optics (AO) in ophthalmologic instruments to image human retinas has been probed to improve the imaging lateral resolution, by correcting both static and dynamic aberrations inherent in human eyes. Typically, the configuration of the AO arm uses an infrared beam from a superluminescent diode (SLD), which is focused on the retina, acting as a point source. The back reflected light emerges through the eye optical system bringing with it the aberrations of the cornea. The aberrated wavefront is measured with a Shack - Hartmann wavefront sensor (SHWFS). However, the aberrations in the optical imaging system can reduced the performance of the wave front correction. The aim of this work is to present an optimized first stage AO experimental setup for in vivo retinal imaging. In our proposal, the imaging optical system has been designed in order to reduce spherical aberrations due to the lenses. The ANSI Standard is followed assuring the safety power levels. The performance of the system will be compared with a commercial aberrometer. This system will be used as the AO arm of a flood-illuminated fundus camera system for retinal imaging. We present preliminary experimental results showing the enhancement.

A polychromatic adaption of the Beer-Lambert model for spectral decomposition

NASA Astrophysics Data System (ADS)

Sellerer, Thorsten; Ehn, Sebastian; Mechlem, Korbinian; Pfeiffer, Franz; Herzen, Julia; Noël, Peter B.

2017-03-01

We present a semi-empirical forward-model for spectral photon-counting CT which is fully compatible with state-of-the-art maximum-likelihood estimators (MLE) for basis material line integrals. The model relies on a minimum calibration effort to make the method applicable in routine clinical set-ups with the need for periodic re-calibration. In this work we present an experimental verifcation of our proposed method. The proposed method uses an adapted Beer-Lambert model, describing the energy dependent attenuation of a polychromatic x-ray spectrum using additional exponential terms. In an experimental dual-energy photon-counting CT setup based on a CdTe detector, the model demonstrates an accurate prediction of the registered counts for an attenuated polychromatic spectrum. Thereby deviations between model and measurement data lie within the Poisson statistical limit of the performed acquisitions, providing an effectively unbiased forward-model. The experimental data also shows that the model is capable of handling possible spectral distortions introduced by the photon-counting detector and CdTe sensor. The simplicity and high accuracy of the proposed model provides a viable forward-model for MLE-based spectral decomposition methods without the need of costly and time-consuming characterization of the system response.