Radiation Camera Research Articles

Fluid Flow and Heat Transfer in the Ladle during Teeming

AbstractA two dimensional axisymmetric model was developed to predict the heat flux in a steelmaking ladle during the teeming process. The model predicts dynamically the flow fields in both liquid phase and gas phase along with the movement of the liquid upper surface. The model also predicts the temperature distributions in the liquid metal, gas phase and all layers in the ladle wall. Industrial measurements using infrared radiation camera inside the ladle after teeming and at the wall outside the ladle during the whole process were carried out. The model predictions were found to be in agreement with the measured data. It was found that the heat transfer to the surrounding atmosphere and the conductivity of the highly insulating layer were the most important factors for the heat loss. The decrease of the thickness of the working lining was found to have limited effect on the total heat flux.

Profile Grinding of Difficult-to-Cut Materials Using a Coolant Supplying System from Inside of Grinding Wheel

In general, grinding fluid is supplied from the supplying nozzle to the grinding wheel-workpiece contact zone during the surface grinding process. However, when the profile or curved surfaces need to be machined, the supply of the grinding fluid to the contact zone seems to be more difficult due to the fixed direction of the grinding fluid supplying nozzles. Therefore, the system which can supply the grinding fluid through the grinding wheel was developed and evaluated. In order to evaluate the effectiveness of this system, the maximum workpiece temperature on the backside of the grinding point using the thin wall workpiece was measured by an infrared radiation camera. The flow rate of grinding fluid and grinding parameters showed a significant effect on the temperature and the grinding performance. Moreover, the profile grinding of the turbine blade shape was successfully conducted.

A scale-model experiment of surface temperature characteristics using an infrared radiation camera

An outdoor measurement was performed during fine weather with a scale-model array of cubical obstacles (size 100mm, 25% packing density, lattice-type square layout) that represent an idealized urban tissue. Surface temperature was recorded with high-frequency (10Hz) infrared camera, along with wind speed and solar radiation. Complementarily, air temperature was also measured at three heights in the near-wall region of a block surface using fine-wire thermocouples. Results showed the similarity of distribution between surface temperature and scalar transfer coefficient. We also found that 10s averaging period may be appropriate for the analysis of surface temperature fluctuation affected by turbulent air flow. In the near-wall region under particularly calm wind condition, air temperature fluctuation caused by a hot plume arising from the warmed surface was observed. The method presented in this study seems to be a promising tool to analyze surface temperature characteristics of scale-models in urban climate studies.

적외선 방사 카메라를 이용한 PMMA 트래킹 열화에 관한 연구

Tracking and erosion of Poly Methyl Methacrylate (PMMA) and the suppression mechanism of alumina trihydrate were investigated in the present study The conventional testing as IEC-60587 is widely used in surface aging measurement of outdoor insulator those testing can carry out very short time for Lab testing. Also IEC-60587 testing is able to offer the standard judgement of relative degradation level of outdoor HV system. Therefore it is very useful method compare to previous conventional tracking testing method, But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IRR-Camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis. In this paper, SD occurred from IEC-60587 is measured with the surface temperature of weibull distribution in real time, the degradation grade of SD is analyzed through produced patterns in IEC-60587 using Infrared Radiation(IRR) camera.

紫外線カメラによる海浜の紫外反射率計測

Recently, the development of coastal zone has been advancing, and the chance of human activity has increased near the sea. On the other hand, destruction of ozone layer has resulted in an increase in the amount of ultraviolet radiation reaching the earth surface. The human body is harmfully influenced as skin cancer and eye damage by ultraviolet radiation. Especially, the effect of ultraviolet radiation on beach is higher than that inland area due to the reflection from the sand surface. This report shows measurement method of ultraviolet reflectance on wide sand surface using ultraviolet radiation camera and reflection standard board. From the measurement results, the ultraviolet reflectance on sand is from 3 % to 8 %.

Temporary overvoltage capability of surge arresters for 1000 kV power systems

AbstractInsulation level (LIWV 2250 kV) of 1000 kV gas insulated switchgear will be adopted by installing high performance 1000 kV surge arresters. But when temporary overvoltage (TOV) is generated in power systems at line faults and load rejection including Ferranti effects, high performance surge arresters flow discharge current according to the value of TOV. Therefore, it is important to check TOV discharge capability of surge arresters. This paper describes the screening of zinc oxide elements using thermography (thermal uniformity factor) obtained by an infrared radiation camera, with discharge capability of surge arresters for 1000 kV power system.

Development of CdZnTe energy selective arrays for industrial and medical radiation imaging

Recent advances in the production of CdZnTe using the high pressure Bridgman growth process now make it possible to design and fabricate complex X-ray sensor arrays on large monolithic substrates. These solid state ionization devices have the advantages of improved spatial and energy resolution, and produce significantly higher signals than competitive scintillator-photodiode systems. We have fabricated a number of linear and areal monolithic arrays in our laboratory using vacuum deposited contacts on such material with good success. These arrays operate in a pulse counting mode using hybrid and surface mount circuitry mounted in close proximity to the arrays. Linear devices with pitches of less than 0.8 mm and with 32 elements per substrate have been used for very wide dynamic range radioscopy with excellent results. Images are presented which demonstrate dynamic range in excess of 500:1 and Nyquist limited resolution at diagnostic X-ray energies for a wide variety of samples. Preliminary results demonstrate that the arrays can be used for energy selective radioscopy permitting the identification of differing materials within the image by approximate atomic number. Systems using areal arrays also have been evaluated as radiation cameras and demonstrate good spatial and energy resolution. Examples of data taken with a pin-hole collimator show the ability to distinguish source distributions by energy as well as location and intensity. Ongoing work in the improvement of spatial and energy resolution and the fabrication of larger arrays is discussed.

Visual field information in low-altitude visual flight by line-of-sight slaved helmet-mounted displays

The pilot's ability to derive control-oriented visual field information from teleoperated helmet-mounted displays in nap-of-the-earth flight is investigated in this paper. The visual field with these types of displays, commonly used in Apache and Cobra helicopter night operations, originates from a relatively narrow field-of-view forward looking infrared radiation (FLIR) camera, gimbal-mounted at the nose of the aircraft and slaved to the pilot's line of sight, providing a wide-angle field of regard. Pilots have encountered considerable difficulties in controlling the aircraft by these devices. The experimental simulator results presented here indicate that part of these difficulties can be attributed both to the narrow camera field of view and to head/camera slaving system phase lags and errors. In the presence of voluntary head rotation, these shortcomings are shown to impair the control-oriented visual field information vital in vehicular control, such as the perception of the anticipated flight path or the vehicle yaw rate. Since the pilot will tend to minimize head rotation in the presence of slaving system imperfections, the full wide-angle field of regard of the line-of-sight slaved helmet-mounted display is not always fully utilized. The findings in this paper are valid for a general class of head-slaved displays which are used in teleoperation and virtual environments and in which correct self-motion estimation is an essential part of the operator task.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A synchrotron radiation X-ray diffraction study of the crystallinity of tendon fibres

The equatorial diffraction pattern of tendon collagen fibres was measured during short successive exposures at different lengths using a double focusing X-ray synchrotron radiation camera with film and with an area detector. Similarly, patterns from thin fibres from premature rats were recorded. The patterns unambiguously illustrate the relationship between fibre crystallinity and the age of the animal. Further, the results indicate that in the initial part of the linear region of the stiffness-versus-length curve, the collagen fibres are characterized by a quasihexagonal arrangement of collagen molecules, whereas at the end of this region, the molecular arrangement becomes hexagonal.

The X-ray topography station at Daresbury laboratory

We have collaborated in the development of the instrumentation for the X-ray topography station at the Daresbury synchrotron radiation source (SRS). This comprises: (a) a white radiation camera for X-ray topography and microscopy 1); (b) a double crystal camera for X-ray topography and beam conditioning 1); (c) a video imaging system for real time studies 3); (d) versatile environmental chambers in situ studies 2); and (e) a liquid helium cryostat for deformation and magentics experiments 1,3). The current status of the programme is reviewed and the instruments are briefly described.

A synchrotron radiation camera and data acquisition system for time-resolved X-ray scattering studies

A synchrotron radiation camera and data acquisition system for time-resolved X-ray scattering studies

Fluctuation x-ray scattering from biological particles in frozen solution by using synchrotron radiation.

Determination of the structure of biological particles, randomly oriented in solution, from spatial correlation analysis of fluctuations in x-ray scattering has recently been proposed. The feasibility of scattering fluctuation measurements was evaluated by using an x-ray synchrotron radiation camera to obtain the spatial correlation for a solution of tobacco mosaic virus along a line. The experimental system, analysis of data, and requirements for the determination of structures in solution are discussed using this example.

A synchrotron radiation camera and data acquisition system for time resolved X-ray scattering studies

Until recently, time resolved measurements of X-ray scattering patterns have not been feasible because laboratory X-ray sources were too weak and detectors unavailable. Recent developments in both these fields have changed the situation, and it is now possible to follow changes in X-ray scattering patterns with a time resolution of a few ms. The apparatus used to achieve this is described and some examples from recent biological experiments are given.

High-speed radiation camera using a PTM ruby laser and hydrated electron absorption phenomena

High-speed radiation camera using a PTM ruby laser and hydrated electron absorption phenomena