Development of accuracy enhancement system for boron meters using multisensitive detector for reactor safety

Boric acid is used as a coolant for pressurized-water reactors, and the degree of burnup is controlled by the concentration of boric acid. Therefore, accurate measurement of the concentration of boric acid is an important factor in reactor safety. An improved system was proposed for the accurate determination of boron concentration. A new boron-concentration measurement technique, called multisensitive detection, was developed to improve the measurement accuracy of boron meters. In previous studies, laboratory-scale experiments were performed based on different sensitivity detectors, confirming a 65% better accuracy than conventional single-detector boron meters. Based on these experimental results, an experimental system simulating the coolant-circulation environment in the reactor was constructed; accuracy analysis of the boron meter with a multisensitivity detector was performed at the actual coolant pressure and temperature. In this study, the boron concentration conversion equation was derived from the calibration test, and the accuracy of the boron concentration conversion equation was examined through a repeatability test. Through the experiment, it was confirmed that the accuracy was up to 87.5% higher than the conventional single-detector boron meter

Particulate counter electrode system for enhanced light harvesting in dye-sensitized solar cells

A particulate counter electrode with photo scattering and redox catalytic properties is applied to dye sensitized solar cells (DSSCs) in order to improve photo conversion efficiency and simplify the assembly process. Our particulate counter electrode acts as both a photo reflecting layer and a catalyst for reduction of electrolyte. The reflective and catalytic properties of the electrode are investigated through optical and electrochemical analysis, respectively. A short circuit current density enhancement is observed in the DSSCs without the need to add an additional reflecting layer to the electrode. This leads to a simplified assembly process. (C) 2013 Optical Society of Americ

Asymmetric impact of Atlantic Multidecadal Oscillation on El Nino and La Nina characteristics

The long-lasting cold surface conditions of North Atlantic, i.e., the negative phase of Atlantic Multidecadal Oscillation (AMO), can intensify the El Nino-Southern Oscillation through the enhanced air-sea coupling under the increased central-to-eastern tropical Pacific mean sea surface temperature. However, the impact of warmer mean sea surface temperature (SST) is more efficient in the intensifying El Nino than La Nina, because of the nature of the exponential growth of atmospheric convection to SST change. Moreover, the farther eastward shift of the atmospheric convection during the negative AMO leads to the stronger El Nino due to the longer delayed negative feedback by oceanic waves. Therefore, the AMO mainly influences the El Nino intensity rather than La Nina intensity.△1122Ysciescopu

Decoding EEG-based Workload Levels Using Spatio-temporal Features Under Flight Environment

The detection of pilots' mental states is important due to the potential for their abnormal mental states to result in catastrophic accidents. This study introduces the feasibility of employing deep learning techniques to classify different workload levels, specifically normal state, low workload, and high workload. To the best of our knowledge, this study is the first attempt to classify workload levels of pilots. Our approach involves the hybrid deep neural network that consists of five convolutional blocks and one long short-term memory block to extract the significant features from electroencephalography signals. Ten pilots participated in the experiment, which was conducted within the simulated flight environment. In contrast to four conventional models, our proposed model achieved a superior grand--average accuracy of 0.8613, surpassing other conventional models by at least 0.0597 in classifying workload levels across all participants. Our model not only successfully classified workload levels but also provided valuable feedback to the participants. Hence, we anticipate that our study will make the significant contributions to the advancement of autonomous flight and driving leveraging artificial intelligence technology in the future.Comment: 5 pages, 3 figures, 1 table, 1 algorith

Optimization of airborne alpha beta detection system modeling using MCNP simulation

An airborne alpha beta detection system using passivated implanted planar silicon (PIPS) detector was modeled with the MCNP6 code and its resolution and detection efficiency were analyzed. Simulation of the resolution performed using the Gaussian energy broadening (GEB) function showed that the full width at half maximum (FWHM) of 35.214 keV for alpha particles was within 34-38 KeV, which is the FWHM range of the actual detector, and the FWHM of 15.1 keV for beta particles was constructed with a similar model to 17 keV, which is the FWHM range of an actual detector. In addition, the detection efficiency and the resolution were simulated according to the distance between the detector and the air filter. When the distance was decreased to 0.2 cm from 0.8 cm, the efficiency of the alpha and beta particles detection decreased from 5.33% to 4.89% and from 5.64% to 4.27%, respectively, and the FWHM of the alpha and beta particles improved from 40.9 KeV to 29.84 keV and 25.76 keV-13.27 keV, respectively. (C) 2019 Korean Nuclear Society, Published by Elsevier Korea LLC

Wave energy system using piezoelectric panel

In this research, we research the characteristics of a new type of wave-power generation system that\ud deducts ocean wave energy to the front part by installing a piezo-electric element on the outside of the existing harbor\ud structure. The wave-power generation system proposed in this research might be applied to a variety of marine structure,\ud which makes it possible to add wave-power generation capacity to the original structural function. Furthermore, it cost\ud relatively less to build multiple generators, which makes its wave-power generation for a bigger launch. Moreover, it\ud might be developed in link with a tourism complex by adopting the wave-power generation system. Accordingly, we\ud analyze the usability of the existing marine structure and characteristics and current research trend in the ocean wave\ud energy retrieval of the wave-power generation system. In addition, in order to review hydrographic characteristics of the\ud proposed system, seen from the result of carrying out 2-D cross-section hydrographic model test, it is confirmed that the\ud maximum wave pressure and voltage increase when in the cases of higher wave and longer period. The result from\ud hydrographic model test indicates that wave-power generation system using piezoelectric element has different\ud generation volume depending upon crushing wave height rather than incidence cycle. It also indicates that the\ud generation volume increase in positive proportion to the size of ocean wave energy

Reliable and cost effective design of intermetallic Ni2Si nanowires and direct characterization of its mechanical properties

We report that a single crystal Ni2 Si nanowire (NW) of intermetallic compound can be reliably designed using simple three-step processes: casting a ternary Cu-Ni-Si alloy, nucleate and growth of Ni2 Si NWs as embedded in the alloy matrix via designing discontinuous precipitation (DP) of Ni2 Si nanoparticles and thermal aging, and finally chemical etching to decouple the Ni2 Si NWs from the alloy matrix. By direct application of uniaxial tensile tests to the Ni2 Si NW we characterize its mechanical properties, which were rarely reported in previous literatures. Using integrated studies of first principles density functional theory (DFT) calculations, high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray spectroscopy (EDX) we accurately validate the experimental measurements. Our results indicate that our simple three-step method enables to design brittle Ni2 Si NW with high tensile strength of 3.0 GPa and elastic modulus of 60.6GPa. We propose that the systematic methodology pursued in this paper significantly contributes to opening innovative processes to design various kinds of low dimensional nanomaterials leading to advancement of frontiers in nanotechnology and related industry sectors.1