•Estimation method of the fundamental frequency in the EOL fuel assembly is suggested.•Bending energy is used to identify the fundamental frequency.•Prediction error can be minimized when the ...deflection shape resembles the first mode shape.•Test examples show that the suggested method is reliable.
This paper develops a methodology to predict the End-Of-Life (EOL) fundamental frequency of a Pressurized Water Reactor (PWR) fuel assembly using lateral bending test data. Bending energy, developed from the lateral bending tests, is utilized to predict the first mode natural frequency. It is shown that the estimation provides reasonable results when the deflected shape is close to the first mode shape. One can evaluate the structural integrity against earthquakes by utilizing a simulation tool that uses the physical information of the fuel assembly. One of the important pieces of information for the simulation is the first natural frequency of the fuel assembly, because the dominant frequency components of the reactor motion are close to the fundamental frequency of the fuel assembly. When the EOL information is unavailable, the unknown EOL fundamental frequency can be identified directly through tests. However, it is almost impossible to build a specific fuel assembly when the fuel assembly is no longer produced. Therefore, this paper suggests using the load-to-deflection curve from the static bending test to predict the fundamental frequency of the EOL fuel assembly. Estimation errors are also discussed, and it is shown that the errors can be minimized using the bending energy considering the deflected bending shape that is the most similar to the fundamental mode shape. Two test examples are discussed, and the results show that the suggested method provides reliable results.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
High crystalline ZnO nanorods (NRs) on Zn pre-deposited graphene/Cu sheet without graphene transfer process have been fabricated by self-catalyzed vapor-phase transport synthesis. Here, the ...pre-deposited Zn metal on graphene not only serves as a seed to grow the ZnO NRs, but also passivates the graphene underneath. The temperature-dependent photoluminescence spectra of the fabricated ZnO NRs reveal a dominant peak of 3.88 eV at 10 K associated with the neutral-donor bound exciton, while the redshifted peak by bandgap shrinkage with temperature and electron-lattice interactions leads a strong emission at 382 nm at room temperature. The optical absorption of the ZnO NRs/graphene hetero-nanostructure at this ultraviolet (UV) emission is then theoretically analyzed to quantify the absorption amount depending on the ZnO NR distribution. By simply covering the ZnO NR/graphene/Cu structure with the graphene/glass as a top electrode, it is observed that the current-voltage characteristic of the ZnO NR/graphene hetero-nanojunction device exhibits a photocurrent of 1.03 mA at 3 V under a light illumination of 100 μW/cm
. In particular, the suggested graphene/ZnO NRs/graphene hybrid-nanostructure-based devices reveal comparable photocurrents at a bidirectional bias, which can be a promising platform to integrate 1D and 2D nanomaterials without complex patterning process for UV device applications.
•Uniaxial p–n junction diode in GaN nanorod is made by Hydride vapor phase epitaxy method.•The p–n junction diode property is clearly observed from the fabricated uniaxial p–n junction nanorod GaN ...nanorod.•Graphene is used as a current spreading layer to reduce the lateral resistance up to 700 times when compared with the commercial sapphire substrate, which is clearly explained with the aid of an equivalent circuit.•Kelvin Force Probe microscopy method is employed to visualize the p- and n- regions in a single GaN nanorod.
Mg doped GaN nanorods were grown on undoped n-type GaN nanorods uniaxial on monolayer graphene by hydride vapor phase epitaxy (HVPE) method. The monolayer graphene used as the bottom electrode and a substrate as well provides good electrical contact, acts as a current spreading layer, well suitable for the growth of hexagonal GaN nanorod. In addition it has a work function suitable to that of n-GaN. The formed p–n nanorods show a Schottky behavior with a turn on voltage of 3V. Using graphene as the substrate, the resistance of the nanorod is reduced by 700 times when compared with the case without using graphene as the current spreading layer. The low resistance of graphene acts in parallel with the resistance of the GaN buffer layer, and reduces the resistance drastically. The formed p–n junction in a single GaN nanorod is visualized by Kelvin Force Probe Microscopy (KPFM) to have distinctively contrast p and n regions. The measured contact potential difference of p-and n-region has a difference of 103mV which well confirms the formed regions are electronically different. Low temperature photoluminescence (PL) spectra give evidence of dopant related acceptor bound emission at 3.2eV different from 3.4eV of undoped GaN. The crystalline structure, compositional purity is confirmed by X-ray diffraction (XRD), Transmission and Scanning electron microcopies (SEM), (TEM), Energy dispersive analysis by X-ray (EDAX) and X-ray photoelectron spectroscopy (XPS) as well.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this paper, a new computational reconstruction technique for three-dimensional (3-D) objects in integral imaging using a lenslet array is proposed and its usefulness is discussed. Experimental ...results show that this technique improves the visual quality of a 3-D reconstructed image when compared with that of the conventional technique.
In this paper, we propose a system combining the pickup process using an active sensor and the display process using depth-priority integral imaging (DPII) system to display true three-dimensional ...(3D) objects within large depth through real and virtual image fields. The active sensor provides depth map and color images of 3D objects. Using captured depth map and original color images, elemental images are computationally synthesized and displayed optically in DPII system. Proposed system provides scaling of 3D scenes for true 3D object. To show the usefulness of proposed system, we carry out the experiment for true 3D objects of three character patterns and present the experimental results.
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Four compounds were isolated from Salvia plebeia aerial parts. Silica gel open column chromatography with a gradient elution system was used to isolate and purify these compounds. Nuclear magnetic ...resonance spectroscopy and mass spectroscopy were used for structural elucidation and identification, while electronic circular dichroism was used to confirm the absolute configuration. The structures were determined to be β-sitosterol (1), (-)-1S,5S,8S,10R-1-acetoxy-8-hydroxy-2-oxoeudesman-3,7(11)-dien-8,12-olide (2), ursolic acid (3), and N-methylhydroxylamine (4). Compounds 2 and 4 were isolated for the first time from this plant. Compound 2 was quantitatively analyzed via HPLC/UV. The results showed that the methanol extract of S. plebeia had a higher content of compound 2 (1.20 mg/g) than the ethanol extract (0.55 mg/g). This study could be used as a preliminary step in conducting HPLC/UV analysis of sesquiterpenoids in S. plebeia extract to assess their bioavailability and potency.
In this paper, we propose an enhanced computational integral imaging system by both eliminating the occlusion in the elemental images recorded from the partially occluded 3D object and recovering the ...entire elemental images of the 3D object. In the proposed system, we first obtain the elemental images for partially occluded object using computational integral imaging system and it is transformed to sub-images. Then we eliminate the occlusion within the sub-images by use of an occlusion removal technique. To compensate the removed part from occlusion-removed sub-images, we use a recursive application of PCA reconstruction and error compensation. Finally, we generate the entire elemental images without a loss from the newly reconstructed sub-images and perform the process of object recognition. To show the usefulness of the proposed system, we carry out the computational experiments for face recognition and its results are presented. Our experimental results show that the proposed system might improve the recognition performance dramatically.
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In this paper, we propose a simple correction method of distorted elemental images for computational integral imaging reconstruction (CIIR) method by using surface markers on lenslet array. The ...position information of surface markers is extracted from distorted elemental images with geometric misalignments such as skew, rotation and so on. Then the elemental images can be corrected simply when applying linear transformation calculated from the extracted positions. Therefore, the proposed method can simply correct geometric misalignments such as skew and rotation. The corrected elemental images can provide the precise reconstruction of 3D plane images in CIIR. To show the usefulness of the proposed method, the preliminary experiments are carried out and the experimental results are presented. To the best of our knowledge, this is the first report to deal with compensating for the distorted elemental images recorded by using computational integral imaging.
In this paper, we propose a modified smart pixel mapping (MSPM) method for displaying orthoscopic three-dimensional (3D) images with a function of depth control in integral imaging system. In the ...proposed MSPM, the depth-converted elemental image array (EIA) is obtained through the pixel mapping process and the image interpolation technique. The proposed method gives us the depth conversion at distances different from the position of 3D object and provides various types of EIAs using only an original EIA for orthoscopic images. To show the usefulness of the proposed method, we carry out the preliminary experiments and present the experimental results.
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