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Lateral light scattering simulations of printed dots are analyzed using general radiative transfer theory. We investigated the appearance of a printed paper in relation to the medium parameters like thickness of the paper sample, its optical properties, and the asymmetry factor. It was found that the appearance of a print greatly depends on these factors making it either brighter or darker. A thicker substrate with higher single scattering albedo backed with an absorbing surface makes the dots brighter due to increased number of scattering events. Additionally, it is shown that the optical effects of print also depend on illuminating and viewing angles along with the depth of ink penetration. A larger single scattering angle implies less intensity and the dots appear much blurred due to the shadowing effect prominent when viewed from sides. A fully penetrated dot of the same extinction coefficient as a partial penetrated one is darker due to increased absorption. These results can be used in applications dealing with lateral light scattering.

Prior work has established the existence of a color-performance relationship in achievement contexts and has demonstrated its presence in some undergraduate course examinations. This study examines the manifestation of such a relationship in an introductory, 430-student, calculus-based electricity and magnetism course during which the paper color used in examinations was varied. In this report, we analyze three separate exams and differentiate between students’ multiple choice, written response, conceptual, and computational performances. Also considered are factors such as the time students require to complete exams and their confidence levels prior to and immediately following assessment. Performance in all categories appears to be independent of paper color.

This paper constructed a new high speed and power density servo motor design scheme based on magnetic pole eccentricity proposed according to the requirements of electrical performance parameters. The analytical formulae were deduced in view of the theory of thick-walled elastic cylinders and the actual model by analytical calculations and finite element calculations. The structure strength of permanent magnet was analyzed. Furthermore, comprehensively comparing and analyzing the calculation results of the two methods verify the accuracy of the analytical calculation method and the rationality of the permanent magnet structure design. In brief, this paper provides a reference for the design of high-speed motor magnetic pole eccentricity.

The magnificent increase in the performance of integrated circuits is made possible by semiconductor Physics. Due to very large-scale integration, scaling has approached its fundamental limits, which is the biggest challenge for the semiconductor industry. Therefore, in the recent years researchers across the globe are focusing on emerging field of spintronics. In this thrust area of spintronics research, spin field effect transistor (s-FET) is an extensively studied device. In literature, researchers have studied and optimized two main types of spin field effect transistors namely Ballistic and Non-Ballistic spin-field effect transistors. This research paper has presented the recent developments in the field of Ballistic and Non-Ballistic spin-field effect transistors. This paper has briefly explained the approach to design, development and fabrication of s-FET by taking a case study. Firstly, the spin field effect transistor was proposed by Datta–Das, which has proved to be the milestone in the area of spintronic technology. Mainly, spin transistor is prepared using a ballistic semiconductor, sandwiched between ferromagnetic metallic source and drain contacts.The magnificent increase in the performance of integrated circuits is made possible by semiconductor Physics. Due to very large-scale integration, scaling has approached its fundamental limits, which is the biggest challenge for the semiconductor industry. Therefore, in the recent years researchers across the globe are focusing on emerging field of spintronics. In this thrust area of spintronics research, spin field effect transistor (s-FET) is an extensively studied device. In literature, researchers have studied and optimized two main types of spin field effect transistors namely Ballistic and Non-Ballistic spin-field effect transistors. This research paper has presented the recent developments in the field of Ballistic and Non-Ballistic spin-field effect transistors. This paper has briefly explained the approach to design, development and fabrication of s-FET by taking a case study. Firstly, the spin field effect transistor was proposed by Datta–Das, which has proved to be the milestone in the area of ...

Spherical Tokamak (ST) path to Fusion has been proposed [1] and experiments on STs demonstrated feasibility of this approach. Advances in High Temperature Superconductor technology [2] allows significant increase in the toroidal field (TF) which was found to improve confinement in STs. The combination of the high normalised plasma pressure, β, which has been achieved in STs [3], and high TF that can be produced by HTS TF magnets, opens a path to lower-volume fusion reactors, in accordance with the fusion power scaling proportional to β2Bt4V. Modular approach then becomes an alternative to high power, GW-scale Fusion reactors [4,5]. Feasibility of low-power compact ST reactor module and physics and engineering challenges of the accelerated, ST path to Fusion Power are discussed in this paper, on example of the first our prototype on this route, high-field compact spherical tokamak ST40.Spherical Tokamak (ST) path to Fusion has been proposed [1] and experiments on STs demonstrated feasibility of this approach. Advances in High Temperature Superconductor technology [2] allows significant increase in the toroidal field (TF) which was found to improve confinement in STs. The combination of the high normalised plasma pressure, β, which has been achieved in STs [3], and high TF that can be produced by HTS TF magnets, opens a path to lower-volume fusion reactors, in accordance with the fusion power scaling proportional to β2Bt4V. Modular approach then becomes an alternative to high power, GW-scale Fusion reactors [4,5]. Feasibility of low-power compact ST reactor module and physics and engineering challenges of the accelerated, ST path to Fusion Power are discussed in this paper, on example of the first our prototype on this route, high-field compact spherical tokamak ST40.

This paper provides a method for determining the rotational temperature of a molecular ensemble subject to a pump pulse. To implement it, we measure the rotational energy by using the molecular wave function, take the rotational energy as the thermal energy, and extract the rotational temperature. This method is able to follow the dynamics of rotational temperature, calculate the temperature increase during the interaction with the pump pulse, and predict the cause. An accurate rotational temperature ensures better information about molecular ensembles.This paper provides a method for determining the rotational temperature of a molecular ensemble subject to a pump pulse. To implement it, we measure the rotational energy by using the molecular wave function, take the rotational energy as the thermal energy, and extract the rotational temperature. This method is able to follow the dynamics of rotational temperature, calculate the temperature increase during the interaction with the pump pulse, and predict the cause. An accurate rotational temperature ensures better information about molecular ensembles.

This paper investigates the outdoor performance of a new kind of hybrid concentrator photovoltaic module. The concept which we name, EyeCon, uses an array of Fresnel lenses to concentrate direct irradiance onto III-V four-junction solar cells while a large-area silicon cell absorbs diffuse sunlight and also acts as a heat distributing substrate. The preliminary results show that under a high ratio of direct to global irradiance (> 0.9) the concept is capable to convert up to 36.8 % of the global solar resource rather than just the direct beam. Moreover at a low ratio of direct to global irradiance (0.57) the hybrid module generates 30 % additional power with respect to the array of concentrator four-junction solar cells alone. The Eyecon module is applicable to all regions of the world and allows reaching the highest energy yield per module area of any PV technology.This paper investigates the outdoor performance of a new kind of hybrid concentrator photovoltaic module. The concept which we name, EyeCon, uses an array of Fresnel lenses to concentrate direct irradiance onto III-V four-junction solar cells while a large-area silicon cell absorbs diffuse sunlight and also acts as a heat distributing substrate. The preliminary results show that under a high ratio of direct to global irradiance (> 0.9) the concept is capable to convert up to 36.8 % of the global solar resource rather than just the direct beam. Moreover at a low ratio of direct to global irradiance (0.57) the hybrid module generates 30 % additional power with respect to the array of concentrator four-junction solar cells alone. The Eyecon module is applicable to all regions of the world and allows reaching the highest energy yield per module area of any PV technology.

The generator is one of the tools that used in power system circuit. The working system of electrical generators is converted the mechanical energy from an external source into electrical energy as output. The generator works by exploiting the electric flux generated by a magnetic field that passes through the rotation of the coil on the generator engine. Both of these are things that affect the efficiency level of the generator. If the efficiency of a generator is higher so the electrical energy generated is also greater. In this paper will be analyzed theoretically mathematically to improve the efficiency of the alternating current generator. The analytical review will be performed on magnetic field strength and coil rotation speed. With the increase of these two factors is expected to increase generator efficiency is also increasing so that the electrical energy which is the output of the generator system is also higher.The generator is one of the tools that used in power system circuit. The working system of electrical generators is converted the mechanical energy from an external source into electrical energy as output. The generator works by exploiting the electric flux generated by a magnetic field that passes through the rotation of the coil on the generator engine. Both of these are things that affect the efficiency level of the generator. If the efficiency of a generator is higher so the electrical energy generated is also greater. In this paper will be analyzed theoretically mathematically to improve the efficiency of the alternating current generator. The analytical review will be performed on magnetic field strength and coil rotation speed. With the increase of these two factors is expected to increase generator efficiency is also increasing so that the electrical energy which is the output of the generator system is also higher.

This paper studies on the performance of semiconductor optical amplifiers and microfiber Mach-Zehnder interferometer in the loop mirror of multi-wavelength Brillouin fibre laser configuration. The microfiber Mach-Zehnder interferometer is designed by the using the Optisystem and OptiBPM software. This project has shown that the proposed configuration with semiconductor optical amplifiers and Mach-Zehnder interferometer in the loop mirror has the ability to generate multiple signals. Input BP power of 4dBm has been identified as optimum input power for this configuration since it resulted higher number of output signals generation compared to other input BP power which is from -6dBm, -5dBm to 8dBm The configuration also has the capability to generate up to 19 dominant overall number of output signals at injected SOA current of 0.8A, whereas the minimum SOA current of 0.5A is only required to initiate first signal at input BP power - 6dBm. In conclusion, this paper has successfully demonstrates that of semiconductor optical amplifiers and microfiber Mach-Zehnder interferometer in loop mirror multi-wavelength Brillouin fibre laser configuration can effectively act to generated multiple signals. This multi-wavelength Brillouin fibre laser configuration can be utilized in many applications, especially in optical sensing and for optical communication, since this two field need large scale of number of signals in order to accommodate better results.

As an important and complex issue in aero acoustic field, a lot of explorations have been devoted to the wind-induced noise. However, there is still lack of intensive investigations for aerodynamic noise in high-voltage transmission. The overhead transmission line system leads to serious occupational noise exposure in high wind-speed environment, and the noise can even injure the electricians in charge of insulator. By using computational fluid dynamics (CFD) which combined with computational aero acoustics (CAA), this paper predicts the noise generated by insulator of high voltage electricity transmission line which explores in wind environment. The simulation results indicate that the wind velocity, the assembly angle of the insulator and its ribs’ distribution are the main contributory factors for the aerodynamic noise. Specifically, when wind velocity is greater than 15m/s, the alteration of noise is not sensitive to the wind velocity; furthermore, when the assembly angle increases from 0°to 60°, the noise decreases gradually, however, if the angle is happening to be 75°or 90°, it would be even greater than that at 0°. In order to inhibit the aerodynamic noise, it is necessary to control the flow blowing across the boundary of the insulator. Consequently, the result indicates that if the outermost rib is shorter than the second one, the noise reduced evidently. This information expects to provide useful help for the extremely suppression of aerodynamic noise, and also supply practical reference material for the design and application of overhead transmission line system.As an important and complex issue in aero acoustic field, a lot of explorations have been devoted to the wind-induced noise. However, there is still lack of intensive investigations for aerodynamic noise in high-voltage transmission. The overhead transmission line system leads to serious occupational noise exposure in high wind-speed environment, and the noise can even injure the electricians in charge of insulator. By using computational fluid dynamics (CFD) which combined with computational aero acoustics (CAA), this paper predicts the noise generated by insulator of high voltage electricity transmission line which explores in wind environment. The simulation results indicate that the wind velocity, the assembly angle of the insulator and its ribs’ distribution are the main contributory factors for the aerodynamic noise. Specifically, when wind velocity is greater than 15m/s, the alteration of noise is not sensitive to the wind velocity; furthermore, when the assembly angle increases from 0°to 60°, the ...

This paper presents the experimental results of the Cleanergy's C11S solar engine-generator tested in the KTH solar simulator. The paper focuses on the analysis of the thermal performance of the ca ...

Underground pipelines are built all over the world and the knowledge of their thermal interaction with the soil is crucial for their design. This paper studies the “thermal influenced zone” produced by a buried pipeline and the parameters that can influence its extension by 2D-steady state CFD simulations with the aim to improve the design of new pipelines in permafrost. In order to represent a real case, the study is referred to the Eastern Siberia-Pacific Ocean Oil Pipeline at the three stations of Mo’he, Jiagedaqi and Qiqi’har. Different burial depth sand diameters of the pipe are analyzed; the simulation results show that the effect of the oil pipeline diameter on the thermal field increases with the increase of the distance from the starting station.Underground pipelines are built all over the world and the knowledge of their thermal interaction with the soil is crucial for their design. This paper studies the “thermal influenced zone” produced by a buried pipeline and the parameters that can influence its extension by 2D-steady state CFD simulations with the aim to improve the design of new pipelines in permafrost. In order to represent a real case, the study is referred to the Eastern Siberia-Pacific Ocean Oil Pipeline at the three stations of Mo’he, Jiagedaqi and Qiqi’har. Different burial depth sand diameters of the pipe are analyzed; the simulation results show that the effect of the oil pipeline diameter on the thermal field increases with the increase of the distance from the starting station.

The results of an experimental study of the controlled pulsations development in the spanwise modulated boundary layer of a swept wing are presented in the paper. The experiments were conducted at Mach 2 and unit Reynolds number Re1 = 6×106 m−1. The square stickers were applied to induce the spanwise modulation of mean flow in the boundary layer. It was obtained, that the presence of roughness leads to a decrease of the disturbance source efficiency at the subharmonic and fundamental frequency, and the oblique breakdown mechanism begins to appear at smaller values of the longitudinal coordinate × as compared with the case of a smooth wing.The results of an experimental study of the controlled pulsations development in the spanwise modulated boundary layer of a swept wing are presented in the paper. The experiments were conducted at Mach 2 and unit Reynolds number Re1 = 6×106 m−1. The square stickers were applied to induce the spanwise modulation of mean flow in the boundary layer. It was obtained, that the presence of roughness leads to a decrease of the disturbance source efficiency at the subharmonic and fundamental frequency, and the oblique breakdown mechanism begins to appear at smaller values of the longitudinal coordinate × as compared with the case of a smooth wing.

The measurement of geomagnetic field conducted by underwater robot is widely used during cruise, however, it is often influenced by the strong electromagnetic interference of the other large-scale electronic equipment on the robot itself. The leakage magnetic field of high-power brushless DC motor (BLDCM) has been identified as one of the main interference source. To obtain accurate geomagnetic data, it is necessary to analyze the magnetic field characteristics of the leakage field of BLDCM. In this paper, we build a two-dimensional BLDCM model. In addition, we present the rotor’s leakage magnetic field when the BLDCM is static, dynamic leakage magnetic field of the stator and rotor when BLDCM is working and the near-field characteristic of BLDCM’s leakage magnetic field. Finally, this paper studies the relationship between the frequency of the magnetic field change and the speed of the BLDCM, which can be used to eliminate the AC interference magnetic field. Therefore the measuring accuracy of the geomag...

In this paper, lightning leaders have been analyzed from a digital still image, by using our new color analysis method. Applying astronomical photometry, color indices B–G, B–R and G–R of the lightning leaders were defined by B–G= −2.5 log10 FB/FG, B–R= −2.5 log10 FB/FR and G–R= −2.5 log10 FG /FR. Using the brightness V and color indices B–G, B–R and G–R of the lightning leaders, the brightness–color relations (V, B–G), (V, B–R) and (V, G–R) were obtained. To represent the lightning image using the color indices B–G, B–R and G–R, 2D color index images (B–G)2D, (B–R)2D and (G–R)2D were obtained. It was indicated that the lightning channels emit mainly the B and R band light from the brightness-color relations, though the intensity of the G-band light is low. From the 2D color index images, it was found that the color of the lightning leaders changes spatially. Furthermore, it was suggested that the spatial variability of the color of the lightning leaders is related to the lightning channel current, from the 2D color index images (B–G)2D, (B–R)2D and (G–R)2D.In this paper, lightning leaders have been analyzed from a digital still image, by using our new color analysis method. Applying astronomical photometry, color indices B–G, B–R and G–R of the lightning leaders were defined by B–G= −2.5 log10 FB/FG, B–R= −2.5 log10 FB/FR and G–R= −2.5 log10 FG /FR. Using the brightness V and color indices B–G, B–R and G–R of the lightning leaders, the brightness–color relations (V, B–G), (V, B–R) and (V, G–R) were obtained. To represent the lightning image using the color indices B–G, B–R and G–R, 2D color index images (B–G)2D, (B–R)2D and (G–R)2D were obtained. It was indicated that the lightning channels emit mainly the B and R band light from the brightness-color relations, though the intensity of the G-band light is low. From the 2D color index images, it was found that the color of the lightning leaders changes spatially. Furthermore, it was suggested that the spatial variability of the color of the lightning leaders is related to the lightning channel current, from t...

Customized flexure mechanisms and precision thermal expansion compensation are needed for the development of nanopositioning stages for hard x-ray nanofocusing and coherence preservation optics at the APS. Recent progress of such stage development is summarized in this paper, which includes: stages designed for alignment apparatus for K-B mirrors with 20 - 50 nm focal spot; alignment apparatus for six Fresnel zone plates stacking with 20 nm focal spot; stages for switchable multiple nanofocusing system; UHV hard x-ray monochromators for coherence related applications; and four-crystal hard x-ray split-and-delay line with coherence preservation. Preliminary test results for mechanical performance of these nanopositioning stages are also discussed in this paper.

The optical efficiencies of a solar trough concentrator are important to the whole thermal performance of the solar collector, and the outer surface of the tube absorber is a key interface of energy flux. So it is necessary to simulate and analyze the concentrated solar flux density distributions on the tube absorber of a parabolic trough solar collector for various sun beam incident angles, with main optical errors considered. Since the solar trough concentrators are linear focusing, it is much of interest to investigate the solar flux density distribution on the cross-section profile of the tube absorber, rather than the flux density distribution along the focal line direction. Although a few integral approaches based on the “solar cone” concept were developed to compute the concentrated flux density for some simple trough concentrator geometries, all those integral approaches needed special integration routines, meanwhile, the optical parameters and geometrical properties of collectors also couldn’t be changed conveniently. Flexible Monte Carlo ray trace (MCRT) methods are widely used to simulate the more accurate concentrated flux density distribution for compound parabolic solar trough concentrators, while generally they are quite time consuming. In this paper, we first mainly introduce a new backward ray tracing (BRT) method combined with the lumped effective solar cone, to simulate the cross-section flux density on the region of interest of the tube absorber. For BRT, bundles of rays are launched at absorber-surface points of interest, directly go through the glass cover of the absorber, strike on the uniformly sampled mirror segment centers in the close-related surface region of the parabolic reflector, and then direct to the effective solar cone around the incident sun beam direction after the virtual backward reflection. All the optical errors are convoluted into the effective solar cone. The brightness distribution of the effective solar cone is supposed to be circular Gaussian type. Then a parabolic trough solar collector of Euro Trough 150 is used as an example object to apply this BRT method. Euro Trough 150 is composed of RP3 mirror facets, with the focal length of 1.71m, aperture width of 5.77m, outer tube diameter of 0.07m. Also to verify the simulated flux density distributions, we establish a modified MCRT method. For this modified MCRT method, the random rays with weighted energy elements are launched in the close-related rectangle region in the aperture plane of the parabolic concentrator and the optical errors are statistically modeled in the stages of forward ray tracing process. Given the same concentrator geometric parameters and optical error values, the simulated results from these two ray tracing methods are in good consistence. The two highlights of this paper are the new optical simulation method, BRT, and figuring out the close-related mirror surface region for BRT and the close-related aperture region for MCRT in advance to effectively simulate the solar flux distribution on the absorber surface of a parabolic trough collector.

This paper briefly reviews a compact toroid reactor concept that addresses critical issues for forming, stabilizing and sustaining a field reversed configuration (FRC) with the use of plasma merging, plasma shaping, conducting shells, neutral beam injection (NBI). In this concept, an FRC plasma is generated by the merging of counter-helicity spheromaks produced by inductive discharges and sustained by the use of neutral beam injection (NBI). Plasma shaping, conducting shells, and the NBI would provide stabilization to global MHD modes. Although a specific FRC reactor design is outside the scope of the present paper, an example of a promising FRC reactor program is summarized based on the previously developed SPIRIT (Self-organized Plasmas by Induction, Reconnection and Injection Techniques) concept in order to connect this concept to the recently achieved the High Performance FRC plasmas obtained by Tri Alpha Energy [Binderbauer et al, Phys. Plasmas 22,056110, (2015)]. This paper includes a brief summary of the previous concept paper by M. Yamada et al, Plasma Fusion Res. 2, 004 (2007) and the recent experimental results from MRX.

The aim of this paper is to show the invariance on the giant magneto-resistor sensor (GMR) output response in the measurement of different plate thicknesses when the problem is resized. To resize the problem, two different probes were projected, implemented and tested: one, with all the dimensions resized by four times the other. Both probes include a pancake coil for magnetic field sinusoidal excitation and measurements are taken with a sensitive bridge fabricated from four giant magneto-resistors (GMR). It is demonstrated, experimentally and with numerical simulation, that the same response value is obtained for two diferent plate thicknesses if dilation principle is kept in the probe's dimensions and electrical quantities. The paper uses the dilation principle to show the invariance of the magnetic field measured by a similar magnetic sensors when data is acquired with the bigger probe on a plate with a thickness four times of the plate thickness used with the smaller probe.

This paper introduces recent improvements for reactor physics codes in Mitsubishi Heavy Industries, Ltd(MHI). MHI has developed a new neutronics design code system Galaxy/Cosmo-S(GCS) for PWR core analysis. After TEPCO’s Fukushima Daiichi accident, it is required to consider design extended condition which has not been covered explicitly by the former safety licensing analyses. Under these circumstances, MHI made some improvements for GCS code system. A new resonance calculation model of lattice physics code and homogeneous cross section representative model for core simulator have been developed to apply more wide range core conditions corresponding to severe accident status such like anticipated transient without scram (ATWS) analysis and criticality evaluation of dried-up spent fuel pit. As a result of these improvements, GCS code system has very wide calculation applicability with good accuracy for any core conditions as far as fuel is not damaged. In this paper, the outline of GCS code system is described briefly and recent relevant development activities are presented.

Dust cluster is a stable structure of negatively charged dust particles formed in complex plasmas. This paper briefly describes the dynamics of these objects. Dust clusters are confined by external applied and or self consistent electrostatic plasma fields. Dust cluster may be regarded as energy storage device which stores plasma thermal energy in the electrostatic fields of cluster. This energy is recovered when the cluster explodes upon removal of the confining potential. In this paper a model for the dust cluster explosion in the afterglow phase of a complex plasma discharge is described. The model is tested by MD simulations of dust particles in a confining potential. The nature of the explosion (caused by switching off the discharge) and the concomitant dust acceleration is found to depend critically on the pressure of the back ground neutral gas. At low gas pressure, the explosion is due to unshielded Coulomb repulsion between dust particles and yields maximum acceleration while in the high pressure...

The Coherent electron Cooling (CeC) Proof of Principle (PoP) experiment is proposed to be installed in the Relativistic Heavy Ion Collider (RHIC) to demonstrate proton and ion beam cooling with this new technique that may increase the beam luminosity in certain cases, by as much as tenfold. Within the scope of this project, a 112 MHz, 2MeV Superconducting Radio Frequency (SRF) electron gun and a 704 MHz 20MeV 5-cell SRF cavity will be installed at IP2 in the RHIC ring. The superconducting RF electron gun will be cooled in a liquid helium bath at 4.4 K. The 704 MHz 5-cell SRF cavity will be cooled in a super-fluid helium bath at 2.0 K. This paper discusses the cryogenic systems designed for both cavities. For the 112 MHz cavity cryogenic system, a condenser/boiler heat exchanger is used to isolate the cavity helium bath from pressure pulses and microphonics noise sources. For the 704 MHz 5-cell SRF cavity, a heat exchanger is also used to isolate the SRF cavity helium bath from noise sources in the sub-atmospheric pumping system operating at room temperature. Detailed designs, thermal analyses and discussions for both systems will be presented in this paper.

This paper summarizes the activities and the discussion of Working Group 5 at the Advanced Accelerator Conceopts Workshop held in Austin, Texas, in June 2012. The themes of this working group are very broad and we have regrouped the sessions and discussions, as well as the organization of this paper, in four general topics: electron sources, phase space manipulation, diagnostics and radiation generation. Within the latter, ampler space was given to beam-based radiation sources in the spectral range where conventional light sources perform poorly, that includes the THz window and the high energy end of the electromagnetic spectrum (x-rays and γ-rays).

The Impulse Response (IR) method is a well-established form of non-destructive testing (NDT) where the dynamic response of an element resulting from an impact event (hammer blow) is measured with a geophone to make conclusions about the element’s integrity, stiffness, and/or support conditions. The existing ASTM Standard C1740-10 prescribes a set of parameters that can be used to evaluate the conditions above. These parameters are computed from the so-called ‘mobility’ spectrum which is obtained by dividing the measured bridge deck response by the measured impact force in the frequency domain. While applying the test method in the laboratory as well as on an actual in-service concrete bridge deck, the authors of this paper observed several limitations that are presented and discussed in this paper. In order to better understand the underlying physics of the IR method, a Finite Element (FE) model was created. Parameters prescribed in the Standard were then computed from the FE data and are discussed. One main limitation appears to be the use of a fixed upper frequency of 800 Hz. Test data from the real bridge deck as well as the FE model both show that most energy is found above that limit. This paper presents and discusses limitations of the ASTM Standard found by the authors and suggests ways for improving it.

Paper presents discussion of the results of laboratory studies of profile spatial changing and spectrum evolution of a high-intensity pump wave after reflection from the soft boundary. It is considered the case of powerful acoustic beam normal incidence to water-air interface. Acoustic source-to-soft boundary distance approximately meets last diffraction maximum coordinate of the acoustic-field axial distribution at the pump frequency. The acoustic-field intensity was chosen in such a way as to continue nonlinear wave interaction after reflection. Harmonic reflection from the soft boundary approaches antiphased reflection which results in peculiarities of further harmonic interaction. This fact determines the subsequent formation of nonlinear waves and one can observe noticeable nonmonotonicity of the harmonic amplitude decrease according to its numbers. Reflected from soft boundary nonlinear wave has shock profile where negative phase considerably exceeds positive one. The further waveform transformation in the reflected beam results in formation of specific kinds of shocks. The shock formed after reflection is narrower than the shock in an incident wave. The subsequent dynamics of the waveform and the spectrum of the reflected nonlinear wave are also discussed in paper.

In this paper we present an alternative perspective to physics expertise research. Using Lave and Wenger's theoretical perspective of Legitimate Peripheral Participation [4] as a guide to understanding expertise development, we redefine expertise from the perspective of physicists. We analyze data from an ethnographic, qualitative study of a physics research group and draw data from multiple sources to triangulate a definition of expert. Results show that a very critical part of becoming a physics expert in this physics research group is communicating one's scientific ideas through writing. Students perceive scientific writing as an important aspect of participating in the research group and it is a significant discussion point in the research meetings. Thus, it appears that learning to write a scientific paper is a process congruent to developing physics expertise.

The Tropospheric Emission Spectrometer (TES) instrument pulse tube cryocoolers began operation 36 days after launch of the NASA Earth Observing System (EOS) Aura spacecraft on July 15, 2004. TES is designed with four infrared Mercury Cadmium Telluride focal plane arrays in two separate housings cooled by a pair of Northrup Grumman Aerospace Systems (NGAS) single-stage pulse tube cryocoolers. The instrument also makes use of a two-stage passive cooler to cool the optical bench. The instrument is a high-resolution infrared imaging Fourier transform spectrometer with 3.3-15.4 micron spectral coverage. After four weeks of outgassing, the instrument optical bench and focal planes were cooled to their operating temperatures to begin science operations. During the early months of the mission, ice contamination of the cryogenic surfaces including the focal planes led to increased cryocooler loads and the need for periodic decontamination cycles. After a highly successful 5 years of continuous in-space operations, TES was granted a 2 year extension. This paper reports on the TES cryogenic system performance including the two-stage passive cooler. After a brief overview of the cryogenic design, the paper presents detailed data on the highly successful space operation of the pulse tube cryocoolers and instrument thermal design over the past six years since the original turn-on in 2004. The data shows the cryogenic contamination decreased substantially to where decontamination cycles are now performed every six months. The cooler stroke required for constant-temperature operation has not increased indicating nearconstant cooler efficiency and the instrument's thermal design has also provided a nearly constant heat rejection sink. At this time TES continues to operate in space providing important Earth science data. KEYWORDS: TES, EOS, Aura, cryocooler

Since the early'70s AWE has focussed on indirect drive as a means of accessing high energy density regimes. We give a brief historical perspective of this work and the rationale for the construction of the ORION laser. This laser is currently in commissioning and is scheduled to commence experiments in 2012. The ORION laser is configured to provide long pulses (~ 1ns) with a high degree of pulse shape flexibility, together with synchronised short pulse (~1ps) irradiation. The paper describes how this combination should enable pressures in excess of 1 Gb and temperatures of greater than 500 eV to be achieved. The ability to access and diagnose such conditions has applications in many fields; examples are given in planetary science, astrophysics and inertial fusion energy. For these applications we first describe the approach to measuring equation of state and opacity properties in the high energy density regime. Such properties are then incorporated into integrated computer simulation codes and validated against laser experiments, some of which have been conducted recently at the OMEGA laser at the University of Rochester. The paper concludes with a discussion of inertial fusion energy and the new high energy density regimes that this would access, if successful.

Numerical simulations and control of tail‐swaying swim of three‐dimensional biomimetic fish in a viscous flow and the vorticity dynamics of fish swimming have been investigated in this paper, with a computational fluid dynamics package, which combines the adaptive multi‐grid finite volume method and the methods of immersed boundary and volume of fluid, and the control strategy of fish motion. Using boundary vorticity‐flux (BVF) theory, we have studied the mechanism of fish swimming and trace the physical root to the moving body surface. With the change of swimming speed, the effects of fish body and caudalfin on thrust, is analysed quantitatively. Finally the relationship between the forces exerted on fish body and vortex structures of fish swimming has been presented in this paper.

This paper sets out to develop a spider‐type multiple‐rotor system which can be used for attitude control of spacecraft. The multirotor system contains a large number of rotor‐equipped rays, so it was called a “Spider‐type System,” also it can be called “Rotary Hedgehog.” These systems allow using spinups and captures of conjugate rotors to perform compound attitude motion of spacecraft. The paper describes a new method of spacecraft attitude reorientation and new mathematical model of motion in Hamilton form. Hamiltonian dynamics of the system is investigated with the help of Andoyer‐Deprit canonical variables. These variables allow obtaining exact solution for hetero‐ and homoclinic orbits in phase space of the system motion, which are very important for qualitative analysis.

The two science missions Herschel, an observatory‐type mission, and Planck, a survey mission, are combined in one programme within ESAs long‐term science programme.The objective for Planck is to image systematically the whole sky simultaneously with two scientific instruments in nine frequency channels between 30 and 900 GHz to unravel the temperature fluctuations, the anisotropy, of the cosmic background radiation. For both satellites, which have now been launched from the European Space Port in Kourou, French Guiana, on a single Ariane 5 launcher, the orbits will be Lissajous orbits around the 2nd Lagrange Point L2 of the Earth‐Sun system.Having surpassed the technological problems and more generally the development phase, this paper focuses on the extensive assembly, integration and tests undertaken for the Proto‐Flight Model (PFM) of the Planck Satellite. The paper details the early stages of the integration of the PFM until completeness of the assembly. It then describes the logic and the various tes...

The two science missions Herschel, an observatory‐type mission, and Planck, a survey mission, are combined in one program within ESA’s long‐term science program. This paper deals with Planck. The objective for Planck is to image systematically the whole sky simultaneously with two scientific instruments in nine frequency channels between 30 and 900 GHz to unravel the temperature fluctuations, i.e. the anisotropy, of the cosmic background radiation. Both satellites, have been launched together from the European Space Port in Kourou, French Guiana, on a single Ariane 5 launcher, the orbits will be Lissajous orbits around the 2nd Lagrange Point, “so called” L2 of the Earth‐Sun system. This paper gives an overview of the Planck spacecraft including the scientific instruments and the on ground testing.

In this paper we present the perspectives of the development of the XUV laser sources using High‐power laser facilities. We focus our paper on the present statuts of the LASERIX facility and especially its role in the development of the XUV laser sources considering the French “Institut de la Lumiere Extreme “(ILE) and the potential European project Extreme Light Infrastructure (ELI). Finally, we present one typical experiment performed in that context with the facility. It is dedicated to the fundamental study irradiation induced damage in DNA samples.

The manipulation of biological particles (cells, viruses DNA, proteins) is an important research subject in microfluidics. The dielectrophoresis (DEP) based on AC electrokinetics became one of the most widely used tools in particle separation, due to the low operating voltage (1–20 V), which significantly diminishes the Joule heating of the suspension. The present paper presents a 2‐D model for the DEP‐based separation microsystem consisting of a microchannel controlled with an interdigitated electrode array. The dielectrophoretic force produced by the nonuniform electric field acts on the bioparticles in suspension in fluid medium inducing spatial movement. The force depends on a number of parameters such as the geometry of the electrodes, the frequency of the applied electric field, as well as dielectric properties of the particles and the surrounding medium. The behavior of this type of system is numerically investigated. The electrical field distribution, the DEP force and the concentration profile in the microchannel are computed using a code based on the finite element technique. The analysis of the role of different problem parameters confirms the potential applications of DEP in handling and separation of particles.The manipulation of biological particles (cells, viruses DNA, proteins) is an important research subject in microfluidics. The dielectrophoresis (DEP) based on AC electrokinetics became one of the most widely used tools in particle separation, due to the low operating voltage (1–20 V), which significantly diminishes the Joule heating of the suspension. The present paper presents a 2‐D model for the DEP‐based separation microsystem consisting of a microchannel controlled with an interdigitated electrode array. The dielectrophoretic force produced by the nonuniform electric field acts on the bioparticles in suspension in fluid medium inducing spatial movement. The force depends on a number of parameters such as the geometry of the electrodes, the frequency of the applied electric field, as well as dielectric properties of the particles and the surrounding medium. The behavior of this type of system is numerically investigated. The electrical field distribution, the DEP force and the concentration profile in...

The ‘Herschel Space Observatory’ is the fourth cornerstone mission in the ‘Horizons 2000’ program of the European Space Agency (ESA), with the objectives to study the formation of galaxies in the early universe and the creation of stars. It will observe the chemical composition of surfaces and atmospheres of comets, planets and natural satellites, and examine the molecular chemistry of the universe. Herschel was launched into an operational Lissajous orbit around the Earth‐Sun L2 point by an Ariane 5 on May 14th 2009 to perform photometer and spectrometer measurements, covering the full far infrared to sub‐millimeter wavelength range from 60 to 670 micrometers during its operational lifetime of more than four years.This paper gives a short overview of the cryogenic system and summarises the cryogenic aspects of the different phases of the acceptance test campaign, including the launch preparation phase as well as the post‐launch transient cool‐down of the system, the verification of the Passive Phase Separator performance and the evaluation of pressure drop measurements performed on the helium venting system. The impact of thermo‐acoustic oscillations within the helium subsystem is described, which were present during the initial cool‐down test phase. A comparison of measurements to numerical analysis results is shown.The ‘Herschel Space Observatory’ is the fourth cornerstone mission in the ‘Horizons 2000’ program of the European Space Agency (ESA), with the objectives to study the formation of galaxies in the early universe and the creation of stars. It will observe the chemical composition of surfaces and atmospheres of comets, planets and natural satellites, and examine the molecular chemistry of the universe. Herschel was launched into an operational Lissajous orbit around the Earth‐Sun L2 point by an Ariane 5 on May 14th 2009 to perform photometer and spectrometer measurements, covering the full far infrared to sub‐millimeter wavelength range from 60 to 670 micrometers during its operational lifetime of more than four years.This paper gives a short overview of the cryogenic system and summarises the cryogenic aspects of the different phases of the acceptance test campaign, including the launch preparation phase as well as the post‐launch transient cool‐down of the system, the verification of the Passive Phase Sepa...

This paper revisits some content in the First International Symposium on Beamed Energy Propulsion in 2002 related to the concept of propellantless in‐space propulsion utilizing an external high energy laser to provide momentum to an ultralightweight (gossamer) spacecraft. The design and construction of the NanoSail‐D solar sail demonstration spacecraft has demonstrated in space flight hardware the concept of small, very light—yet capable—spacecraft. The results of the Joint High Power Solid State Laser (JHPSSL) have also increased the effectiveness and reduced the cost of an entry level laser source. This paper identifies the impact from improved system parameters on current mission applications.

A precise characterization of optical components generally occurs via interferometric measurements. It is show in this paper that Fourier based deflectometry method can be used for very sensitive and precise wavefront reconstruction. The wavefront is expressed from the raw measurements of the wavefront derivatives as a Zernike polynomial expansion. The form of the polynomials permits absolute instrumental error characterization by repeated measurement of the element under test oriented at several azimuthal angles. It is shown in this paper that nanometric precision of Zernike based reconstructions can be performed and that the air turbulences are the experimental limiting factor to the instrumental precision.

This paper reports on the direct comparison between experimental and numerical results of the ionospheric perturbation associated with red sprites in the mesosphere. The ionospheric perturbation due to the sprite ionization column is observed by a continuous monitoring of the amplitude and phase of distant VLF transmitter signals at several locations in Japan, whilst the numerical computation to calculate the spatio temporal dependence of the observed VLF waves is performed by using a two‐dimensional finite‐difference time‐domain (FDTD) method. As a result, the observed maximum scattered amplitude and phase changes are in close agreement with the numerical results for a carrot sprite. The distance variation of the scattered amplitude from the numerical simulation is found to strongly depend on the spatial dimension of the sprite ionization column due to the different scattering mechanisms. The forward scattering amplitude is significantly larger than that for back scattering for the carrot sprite indicating the nature of Mie scattering, while both backward and forward scatterings are comparable for a column sprite showing the nature of Rayleigh scattering.This paper reports on the direct comparison between experimental and numerical results of the ionospheric perturbation associated with red sprites in the mesosphere. The ionospheric perturbation due to the sprite ionization column is observed by a continuous monitoring of the amplitude and phase of distant VLF transmitter signals at several locations in Japan, whilst the numerical computation to calculate the spatio temporal dependence of the observed VLF waves is performed by using a two‐dimensional finite‐difference time‐domain (FDTD) method. As a result, the observed maximum scattered amplitude and phase changes are in close agreement with the numerical results for a carrot sprite. The distance variation of the scattered amplitude from the numerical simulation is found to strongly depend on the spatial dimension of the sprite ionization column due to the different scattering mechanisms. The forward scattering amplitude is significantly larger than that for back scattering for the carrot sprite indicati...

In present paper, a two‐dimensional numerical study on a standing‐wave thermoacoustic engine was performed with compressible SIMPLE algorithm based on a pressure‐correction method. First, the simulation model was developed, and the time‐dependent compressible thermoacoustic engine system was chosen through substantive numerical tests. Appropriate governing equations for mass, momentum and energy were introduced. Then, the computational results of the onset of the self‐excited oscillations across the entire evolution process and the acoustical characteristics of the pressure and velocity wave were presented and analyzed. In addition, the standing‐wave of the pressure and velocity along the center of the two stacks are investigated. The crucial nonlinear phenomenon that cannot be captured by the existing linear theory, like high harmonic frequencies, is also revealed in present paper. It is concluded that compressible SIMPLE algorithm could be employed in our future work to simulate and optimize thermoacoustic system. The present result is an important step toward development to predict the high‐amplitude thermoacoustic systems and optimize thermoacoustic engine performance.

In this paper, a non‐conventional approach is proposed for organizing the cognitive activity of students—future teachers, in acquiring methods and technique of the school physics experiment. The purpose is to ensure a specific educational environment in which students have positive attitude to work, show willingness for cooperation and mutual aid, and they actively take part in joint activities regardless of their knowledge, abilities and interests. In the paper, some of distinctive characteristics of the organization of cognitive activity in this case are followed and analyzed: work in small groups; implementation of group tasks, in which, problems with entertaining matter are added to the experimental tasks; discussions within a group as well as among the groups; introducing an element of competition among the groups, etc. Conclusions are drawn about advantages of such an interactive approach for increasing effectiveness of education.

In this paper we revisit the known problem of the explosion suppression by a cloud of inert and solid particles. This issue has been so far investigated experimentally where the most important task has been to find the proper suppressant, estimate its quantity, as well as design the quenching device. Also some attention has been paid to numerical investigation where by use of computer simulation the same questions have been asked. In this paper we also focus on the numerical study, where the first moment of the suppressing process is analysed: the exact behaviour of the particle cloud as it reacts with the gas. A mathematical model is presented that bases on the Eulerian‐Lagrangian approach for the description of the both phases: solid and gas. Finally some results are shown: both snapshots of particle location as well statistics.

This paper shall summarize the research conducted employing the high‐purity germanium based small animal imaging system, SmartPET (SMall Animal Reconstructive Tomograph for Positron Emission Tomography). Geant4 simulations of the experimental setup were carried out in order to derive novel analysis procedures and quantify the system limitations. In this paper, we will focus on a gamma ray tracking approach devised to overcome germanium's high Compton scattering cross‐section and on imaging challenging and complex phantom geometries. The potential of the developed tools and of the system itself will be discussed.

Accelerating gradient is a key parameter of the accelerating structure in large linac facilities, like future Linear Collider. In room temperature accelerating structures the gradient is limited mostly by breakdown phenomena, caused by high surface electric fields or pulse surface heating. High power processing is a necessary procedure to clean surface and improve the gradient. In the best tested X-band structures the achieved gradient is exceed 100 MV/m in of {approx}200 ns pulses for breakdown rate of {approx} 10{sup -7}. Gradient limit depends on number of factors and no one theory which can explain all sets of experimental results and predict gradient in new accelerating structure. In paper we briefly overview the recent experimental results of breakdown studies, progress in understanding of gradient limitations and scaling laws. Although superconducting rf technology has been adopted throughout the world for ILC, it has frequently been difficult to reach the predicted performance in these structures due to a number of factors: multipactoring, field emission, Q-slope, thermal breakdown. In paper we are discussing all these phenomena and the ways to increase accelerating gradient in SC cavity, which are a part of worldwide R&D program.

High amplitude coherent electron‐trajectories have been seen in 3D particle‐in‐cell simulations of the colliding pulse injection scheme of laser‐wakefield accelerators in the bubble regime, and explained as a consequence of laser‐driven coherent betatron oscillation in our recent paper [K. Nemeth et al., Phys. Rev. Lett. 100, 095002 (2008)]. In the present paper we provide more details on the shape of the trajectories, their relationship to the phase velocity of the laser and indicate the dependence of the phenomenon on the accuracy of the numerical representation and choice of laser/plasma parameters.

In 1976 J. Heasley and D. Mihalas published a seminal paper devoted to the modeling of solar prominences. They applied their stellar atmospheric code based on the novel complete linearization method to model the radiation‐magnetohydrostatic (RMHS) coupling in prominences, to solve the multilevel transfer problem for a mixture of hydrogen and helium and to investigate the prominence energy balance. Their results served as a benchmark for future developments in this field and today, 33 years after that, we would like to show how significantly they influenced the current research. With the link to this pioneering work, we will discuss recent progress in the RMHS modeling of solar prominences, focused on multidimensional/multithread radiative transfer, coupling of non‐LTE transfer to MHS, the importance of partial redistribution for interpreting strong UV lines etc. New light was shed recently on the issues of energy balance, again having a direct link to the 1976 paper.

The paper discusses the proposed improvement of a High‐Frequency Relic Gravitational Wave (HFRGW) detector designed by Li, Baker, Fang, Stephenson and Chen in order to greatly improve its sensitivity. The improved detector is inspired by the Laser Interferometer Gravitational Observatory or LIGO, but is sensitive to the high‐frequency end of the gravitational‐wave spectrum. As described in prior papers it utilizes the Gertsenshtein effect, which introduces the conversion of gravitational waves to electromagnetic (EM) waves in the presence of a static magnetic field. Such a conversion, if it leads to photons moving in a direction perpendicular to the plane of the EM waves and the magnetic field, will allow for ultra‐high sensitivity HFRGW detection. The use of sensitive microwave, single photon detectors such as a circuit QED and/or the Rydberg Atom Cavity Detector, or off‐the‐shelf detectors, could lead to such detection. When the EM‐detection photons are focused at the microwave detectors by fractal‐membrane reflectors sensitivity is also improved. Noise sources external to the HFRGW detector will be eliminated by placing a tight mosaic of superconducting tiles (e.g., YBCO) and/or fractal membranes on the interior surface of the detector's cryogenic containment vessel in order to provide a perfect Faraday cage. Internal thermal noise will be eliminated by means of a microwave absorbing (or reflecting) interior enclosure shaped to conform to a high‐intensity continuous microwave Gaussian beam (GB), will reduce any background photon flux (BPF) noise radiated normal to the GB's axis. Such BPF will be further attenuated by a series of microwave absorbing baffles forming tunnels to the sensitive microwave detectors on each side of the GB and at right angles to the static magnetic field. A HFGW detector of bandwidth of 1 KHz to 10 KHz or less in the GHz band has been selected. It is concluded that the utilization of the new ultra‐high‐sensitivity microwave detectors, together with the increased microwave power and magnet intensity will allow for a detection of high‐frequency gravitational waves (HFGWs) exhibiting amplitudes, A, of the time‐varying spacetime strains on the order of 10−30 to 10−34.

This paper describes the characteristics of the multihole collimator gamma camera that is simulated using the combination of the Monte Carlo N‐Particles Code (MCNP) version 5 and in‐house software. The model is constructed based on the GCA‐7100A Toshiba Gamma Camera at the Royal Surrey County Hospital, Guildford, Surrey, UK. The characteristics are analyzed based on the spatial resolution of the images detected by the Sodium Iodide (NaI) detector. The result is recorded in a list‐mode file referred to as a PTRAC file within MCNP5. All pertinent nuclear reaction mechanisms, such as Compton and Rayleigh scattering and photoelectric absorption are undertaken by MCNP5 for all materials encountered by each photon. The experiments were conducted on Tl‐201, Co‐57, Tc‐99 m and Cr‐51 radio nuclides. The comparison of full width half maximum value of each datasets obtained from experimental work, simulation and literature are also reported in this paper. The relationship of the simulated data is in agreement with the experimental results and data obtained in the literature. A careful inspection at each of the data points of the spatial resolution of Tc‐99 m shows a slight discrepancy between these sets. However, the difference is very insignificant, i.e. less than 3 mm only, which corresponds to a size of less than 1 pixel only (of the segmented detector).

X‐ray computed tomography is a powerful non‐invasive imaging technique for viewing an object's inner structures in two‐dimensional cross‐section images without the need to physically section it. The invention of CT techniques revolutionised the field of medical diagnostic imaging because it provided more detailed and useful information than any previous non‐invasive imaging techniques. The method is increasingly being used in industry, aerospace, geosciences and archaeology. This paper describes the development of an X‐ray computed tomography system for imaging of industrial materials. The theoretical aspects of CT scanner, the system configurations and the adopted algorithm for image reconstruction are discussed. The penetrating rays from a 160 kV industrial X‐ray machine were used to investigate structures that manifest in a manufactured component or product. Some results were presented in this paper.

The present author has previously published a series of papers at STAIF exploring the interactions of very‐high frequency gravitational waves (VHFGWs, typically around 3 GHz) with superconductors. One important design concept is a novel variable‐focus lens that would be invaluable in the design of advanced GW optics for communications applications. This achieves all‐electrical focusing with no moving parts. The design was based upon the published calculations of Li and Torr (in 1992 and 1993) claiming to show that GWs propagate inside superconductors with a phase velocity reduction by a factor ng≈300× and a corresponding wavenumber increase. Successful demonstration of this lens would also serve as a confirmation of the controversial Li and Torr result. The possibility remains that the Li and Torr result is valid in principle but with a much reduced numerical value of ng arising from the linearizing assumptions made in their papers. (A much increased value of ng arising from the same reason is also possib...

COST (Co-operation in the field of Scientific and Technical Research) is an important instrument supporting co-operation among scientists and researchers across Europe now joining 35 member countries. Scientific projects in the COST framework are called COST Actions and have the objectives embodied in their respective Memorandum of Understanding (MoU). The main objectives of the COST Actions within the European ionospheric and radio propagation community have been: to study the influence of upper atmospheric conditions on terrestrial and Earth-space communications, to develop methods and techniques to improve existing and generate new ionospheric and propagation models over Europe for telecommunication and navigation applications and to transfer the results to the appropriate national and international organizations, institutions and industry dealing with the modern communication systems. This paper summarizes in brief the background and historical context of four ionospheric COST Actions and outlines their main objectives and results. In addition, the paper discusses the dissemination of the results and the collaboration among the participating institutions and researchers.