X-ray CT Technology Research Articles

Study on microstructure of rubberized recycled hot mix asphalt based X-ray CT technology

Micro-structural characteristics of recycled asphalt mixture have an important influence on its macro-mechanical performance. In this study, the discreteness, RAP dosage and asphalt film thickness of hot asphalt mixtures with recycled rubber were analyzed through CT scanning together with the IPP software. The recycled asphalt pavement (RAP) content was set as 25%, and the asphalt mixture specimens were produced in the laboratory. Different kinds of hot recycled rubber asphalt mixtures were produced to calculate the film thickness of the asphalt with five different asphalt dosages, 4.2%, 4.5%, 4.8%, 5.1%, and 5.4%, and three different aggregate particle sizes. From the results, it shows that the distribution of rubberized recycled hot mix asphalts can be analyzed by CT and considered as uniform, as the average particle size of aggregate on the left side is 2458.93μm while the right is 2487.38μm. The calculation of RAP dosage by CT technology is reliable. The RAP dosage is calculated to be 23.98%, and the actual error is 4.1%, relatively small. The asphalt film thickness of the rubberized recycled hot mix asphalt obtained by CT is reliable. It has strong, linear correlation with the asphalt film thickness calculated using the Hweem method. Asphalt film thickness increases with the increase in asphalt dosage under similar aggregate particle size, and asphalt film thickness increases with the decrease in aggregate particle size under the same asphalt dosage.

Industrial X-ray CT Technology; Present Status and Future Perspectives

Industrial X-ray CT Technology; Present Status and Future Perspectives

Study on the Influential Factors in and the Optimization of Asphalt Mixture Scanning with X-Ray CT Technology

AbstractThe effects of sample size, aggregate lithology, and compaction pattern on image scanning quality were determined using 225 kV industrial computer tomography equipment. Moreover, the scanning parameters of common Marshall asphalt mixture specimens were optimized. Results show that: (1) a large sample worsens image quality; (2) granite mixtures are more suitable for subsequent image processing analysis than other counterparts are; and (3) compaction patterns can affect imaging quality significantly. Finally, the ideal combination of scanning parameters was determined for Marshall asphalt mixture specimens. This combination can improve scanning accuracy and efficiency.

X射线CT技术体积重构法表征异形泡沫金密度

X射线CT技术体积重构法表征异形泡沫金密度

Density characterization of gold foam sample with abnormal surface using X-ray CT technology

Density characterization of gold foam sample with abnormal surface using X-ray CT technology

Invited: FCEV Development at Nissan

Introduction FCEV, like the Battery EV, is one of the Zero emission vehicle which emit no CO2 during its operation, and is expected to be introduced into market from around 2015. After introduction, further cost reduction would still remain as the big challenge for FCEV full penetration. This paper introduces activities for the cost reduction especially Pt loading reduction through high current density operation.. Current FCEV technology status Toward FCEV commercialization, four issues had been identified to be solved, namely, 1) durability,2) power density,3) cold start up, and 4) cost.Durability: Through more than 1.4M km public road durability test, the causes of the performance reduction are concluded to be 1) Pt dissolution and migration, 2) catalyst carbon support oxidation. The mitigation technology such as carbon support material improvement and cell voltage control would ensure more than 10 years degradation, enough level to initiate commercialization, but further increase would be necessary for full penetration.‚PPower Density: By adapting metal separator, high current density MEA, Nissan announced 2.5kW/L stack in 2011. For FCEV penetration, further increase of the power density would be effective.Cold start: For successful cold start, it is necessary to remove water from FC system before freezing. Water concentration and ice formation visualization and water removal technology application, Nissan confirmed the cold start from -30 deg.C can be possible by unit-test car with 2nd generation stack system. For cost reduction, FC system component cost reduction by parts size reduction or elimination of the parts itself, utilizing mass produced low cost parts, and simplifying the structure are effective. Current estimated best efforts can reach the cost level low enough to start the commercialization, but still not enough to reach the cost level of full penetration, at which FCEVs are cost competitive with HEVs or BEVs. Cost Reduction for market penetration Cost break down of future mass produced PEMFC stack is shown in Fig. 1. Pt and bipolar plates cost are the two biggest portion to be almost 70% of the stack cost. The approach for the stack cost down would be lowering the Pt loading while increasing power density which would contribute to reduce the bipolar plates, the membrane, and the GDL cost.Fig. 2 shows the Pt loading and size reduction approach. Two aspects would be important, (a) Increase ORR kinetics, e.g. increase the catalyst activity, and (b) reduce mass transport resistance reduction, e.g. reduce local oxygen transport resistance and reduce water amount in CL which would prevent Oxygen transport towards catalyst. Nano X-ray CT technology would be very effective to analyze water content and distribution in the cell during the cell operation 2,3. It is very important to be noticed that to evaluate the catalyst activities performance for automotive usage, the test condition should be carefully be set to simulate actual automotive operating conditions4.Fig. 3 shows a research level result of catalyst activity improvement. Almost 8 time increase of specific activity is observed. Summary FCEV technology is reaching to the level of initiation of commercialization.Cost reduction and durability increase would be still necessary for FCEV full penetration after introduction into the market.For cost reduction, catalyst activity improvement and mass transport improvement in CL are important research directions towards FCEV full penetration. REFERENCES .D. Papageorgopoulos, 2013 Annual Merit Review and Peer Evaluation Meeting, May 13, 2013.A. Ohma, T. Mashio, K. Sato, H. Iden, Y. Ono, K. Sakai, K. Akizuki, S. Takaichi, K. Shinohara, Electrochim. Acta 56, 10832 (2011).D. Navvab, T. Kotaka, U. Tabuchi, and U. Pasaogullari, Abs #: 1296, 224th ECS Meeting, San Francisco, CA , Oct 27th—Nov 1st, 2013.S. Sugawara, K. Arihara H. Tanaka, T. Ohwaki, H. Mitsumoto, T. Sekiba, and K. Shinohara, ECS Trans., 58 (1) 49-56 (2013)

基于MARS系统的X射线能谱K-edge特性CT成像技术

The typical conventional CT system employs the digital integrating sensor, for which it is difficult to identify attenuation characteristics of different energy X-ray. This paper focuses on X-ray spectral imaging technology based on MARS X-ray spectral CT system. We scanned some singular element materials and a multi-material phantom with different energy X-ray bins, obtained some material K-edge characteristic curves, and reconstructed CT images of multi-material phantom. By means of CT images based on material K-edge characteristics, we can discriminate different materials or recognize more attenuation information of different materials. Compared to conventional X-ray CT technology, X-ray spectral CT can provide much richer attenuation information.

Upgrading of X-ray CT technology for analyses of irradiated FBR MOX fuel

The X-ray CT technology previously developed by JAEA was upgraded. The shape of the X-ray source beam was changed from a circular shape to an elliptical one and the collimator slit width was decreased from 0.3 to 0.1 mm. The X-ray detector was improved by changing a CdWO4 scintillator to a highly sensitive silicon semiconductor detector. The analysis code of X-ray CT image was revised with respect to the number of points by using two kinds of experimental results and taking into account the effects of crack existence and deviation of the central void position from the radial center of a fuel pellet. As a result, high resolution X-ray CT images could be obtained on the transverse cross section of irradiated fuel assemblies. The error of the dimensional measurement was improved from ±0.1 to ±0.03 mm by upgrading the instrument and revising the analysis code of X-ray CT image. The discriminating accuracy of density difference could be increased, and the low density region (undisturbed region) and high density region (equi-axial and columnar regions) in the X-ray CT image on the cross section of irradiated fuel could be discriminated from each other. The reliability of fuel performance analysis improves because a large number of PIE data can be collected, compared with the conventional destructive PIE.

Mathematical model for coupled reactive flow and solute transport during heap bioleaching of copper sulfide

Based on the momentum and mass conservation equations, a comprehensive model of heap bioleaching process is developed to investigate the interaction between chemical reactions, solution flow, gas flow, and solute transport within the leaching system. The governing equations are solved numerically using the COMSOL Multiphysics software for the coupled reactive flow and solute transport at micro-scale, meso-scale and macro-scale levels. At or near the surface of ore particle, the acid concentration is relatively higher than that in the central area, while the concentration gradient decreases after 72 d of leaching. The flow simulation between ore particles by combining X-ray CT technology shows that the highest velocity in narrow pore reaches 0.375 m/s. The air velocity within the dump shows that the velocity near the top and side surface is relatively high, which leads to the high oxygen concentration in that area. The coupled heat transfer and liquid flow process shows that the solution can act as an effective remover from the heap, dropping the highest temperature from 60 to 38 ℃. The reagent transfer coupled with solution flow is also analyzed. The results obtained allow us to obtain a better understanding of the fundamental physical phenomenon of the bioleaching process.

Increasing the accuracy of surface area estimation using single wax dipping of coral fragments

The measurement of coral surface area is critical to normalising a suit of physiologically significant parameters to greater understand how corals interact with the surrounding environment. The surface area detection from skeletal fragments subsequently needs to be both as accurate as possible, yet practical and robust enough to be performed with minimal laboratory equipment. By using X-Ray CT technology, as a highly accurate surface area standard, 12 coral specimens from 4 different genera were studied using single wax versus double wax dipping methods. Our results reveal that the single wax dipping is far more accurate than the more commonly practised double wax dipping, thereby leading to more accurate estimation of the physiologically active surface.

Characterizing macro-voids of uncompressed mats and finished particleboard panels using response surface methodology and X-ray CT

Abstract Macro-voids in the core of uncompressed particle mats and pressed particleboard manufactured from novel particleboard furnishes were characterized using a response surface method with mixture design and X-ray CT technology. Industrial particles were screened into core-fine, medium, and coarse size classes and their dimensions were measured. Wooden blocks measuring 10 times the mean dimensions of these particles were cut and used as surrogates for the industrial particles. Novel particle mixtures were prepared by mixing together various proportions from each particle size class. The mixtures were packed to simulate particleboard mat formation and a pre-pressed particle mat. Panels were then fabricated from the industrial furnish mixtures. The void fraction of the packed particles and the finished panels were measured and correlated with the IB strength and edge screw withdrawal resistance. Results indicated that densely packed hammer-milled industrial particles had a maximum void fraction of 63.2%. The void fraction of a randomly packed, dense particle mat was described using a full cubic model. In both particle mats without resin and the pressed panels, increasing the core-fine content decreased void volume, whereas increasing coarse particle fraction increased void volume in the mat only. The macro-void ratio in the pressed panels increased exponentially with void fraction for the randomly packed, loose particle mats. Particle mixtures that resulted in boards with the smallest void fraction were not necessarily the strongest boards; low density particleboard panels made from the novel 100% coarse mixture were found to have the highest mechanical properties.

Application of X-Ray CT Technology to the Analysis of Structure and Function of Pharmaceutical Dosage Forms

Application of X-Ray CT Technology to the Analysis of Structure and Function of Pharmaceutical Dosage Forms

３ＤＸ Ｍｕｌｔｉ‐Ｉｍａｇｅ Ｍｉｃｒｏ ＣＴによる顔面神経管の画像

“3DX Multi-Image Micro CT” is a new three dimensional CT method using limited cone beam x-ray CT technology. A sensitive image intensifier transmits 512 X-ray pictures of a complex bony structure such as the temporal bone in a cylindrical area with a height of 30mm and a diameter of 40mm to a personal computer, where the X-ray data are processed into CT images. Axial (X), coronal (Y) and sagittal (Z) CTs along a desired slice plane are simultaneously displayed on the monitor. The author was able to measure the size of the bony facial canal with an image reconstruction. In 28 normal adult volunteers, the diameters of the bony facial canals were measured at the meatal foramen, the cocleariform process, the stapes, the pyramidal eminence and emerging point of the chorda tympani in the vertical segment. The result showed that the facial canal had two narrow sites; one at the meatal foramen and the other at the level of the stapes. From the meatal foramen toward the geniculate ganglion, the canal gradually enlarged. From here, the canal again became narrower until the level of the stapes, and then it gradually enlarged toward the stylomastoid foramen. There were no significant differences between data of the right and left sides. The same measurements were made in 16 patients with Bell's palsy and 8 with Hunt's syndrome. Abnormal enlargement of the facial canal distal and peripheral to the geniculate ganglion was observed only in the paralyzed side. The abnormality was closely associated with the grade of palsy and denervtion. The results suggested that, in these diseases, the pathologic process involved the bony facial canal beside the facial nerve.

B121 高エネルギーX線CTを活用した3次元形状計測

Digital engineering has been utilized in product development to improve the quality. The actual object was measured and digitized into the three-dimensional (3-D) data, and the requirement of evaluating and analyzing the CAD data has been increased in these activities. So, we developed the technology that measures the actual object and obtains the 3-D model data for general automotive parts. The features of this new system are high-speed and high-accuracy by using high energy X-ray CT technology and 3-D model data technology. 3-D model data can be obtained for about 5 hours in case of the engine block and the error is 0.1mm or less. We also show the examples of the new automotive parts development using this technology.

Ｘ線ＣＴスキャナを用いた３次元ＣＡＤデータに基づく内部形状評価

The study deals with X-ray CT technology to inspect the inside parts of workpiece without destroying them. At present, there is few softwares capable of processing X-ray CT scanned data. Therefore, the function was developed to treat the data to evaluate geometric elements such as straight lines, circular arc and others, based on 3-dimensional CAD data as the standard of inspection. After the coordinate system of scanned data is automatically related with the 3-dimensional CAD data, the system evaluates geometric elements considering that a workpiece contour consists of a cluster of segments. Thus, the system cuts the contour of 3-dimensional CAD data on the appointed cross-sectional planes and classifies them into geometric elements. To compare 3-dimensional CAD data with the X-ray CT scanned data, the system calculates the straightness, angle deviation from the direction vector, length and its error of a straight line, and, roundness, deviation of center point, radius and its elTor. In addition, the system offers a visualization interface to display them so that the users utilize the evaluated result comfortably. As a result, the system is found effective to evaluate 2-dimensional geometric elements.

A Review of X-Ray Computed Tomography and Its Applications in Mineral Processing

X-ray Computed Tomography, a technique widely used in the field of medical technology, can be used successfully in the field of mineral processing. A short review of the fundamental principles used in CT scanning and image reconstruction is presented. The advantages and limitations of current CT technology are discussed and areas that need improvement are identified. Finally, specific applications such as the use of CT for liberation analysis and for density gradient determinations in process equipment operating at steady state are discussed as examples of areas where X-ray CT technology can be used to improve our understanding of mineral processing phenomena.