• 제목/요약/키워드: environments and energy

검색결과 1,151건 처리시간 0.033초

Electrochemical corrosion behavior of atmospheric-plasma-sprayed copper as a coating material for deep geological disposal canisters

  • Sung-Wook Kim;Gha-Young Kim;Young-Ho Lee;Jun-Hyuk Jang;Chung-Won Lee;Jeong-Hyun Woo;Seok Yoon
    • Nuclear Engineering and Technology
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    • 제55권11호
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    • pp.4032-4038
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    • 2023
  • Cu, which exhibits excellent corrosion resistance in underground environments, has been investigated as a canister material for use in the deep geological disposal of spent nuclear fuels. In this study, the technical viability of atmospheric plasma spraying for producing Cu-coated canisters was investigated. A high-purity Cu film (millimeter scale) was deposited onto a stainless-steel substrate using a plasma gun with a shroud structure. Potentiodynamic polarization studies revealed that the Cu film exhibited a sufficiently low corrosion rate in the groundwater electrolyte. In addition, no pitting corrosion was observed on the Cu film surface after accelerated corrosion studies. A prototype cylindrical Cu film was fabricated on a 1/20 scale on a stainless-steel tube to demonstrate the scalability of atmospheric plasma spraying in producing Cu-coated canisters.

Electromagnetic energy harvesting from structural vibrations during earthquakes

  • Shen, Wenai;Zhu, Songye;Zhu, Hongping;Xu, You-lin
    • Smart Structures and Systems
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    • 제18권3호
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    • pp.449-470
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    • 2016
  • Energy harvesting is an emerging technique that extracts energy from surrounding environments to power low-power devices. For example, it can potentially provide sustainable energy for wireless sensing networks (WSNs) or structural control systems in civil engineering applications. This paper presents a comprehensive study on harvesting energy from earthquake-induced structural vibrations, which is typically of low frequency, to power WSNs. A macroscale pendulum-type electromagnetic harvester (MPEH) is proposed, analyzed and experimentally validated. The presented predictive model describes output power dependence with mass, efficiency and the power spectral density of base acceleration, providing a simple tool to estimate harvested energy. A series of shaking table tests in which a single-storey steel frame model equipped with a MPEH has been carried out under earthquake excitations. Three types of energy harvesting circuits, namely, a resistor circuit, a standard energy harvesting circuit (SEHC) and a voltage-mode controlled buck-boost converter were used for comparative study. In ideal cases, i.e., resistor circuit cases, the maximum electric energy of 8.72 J was harvested with the efficiency of 35.3%. In practical cases, the maximum electric energy of 4.67 J was extracted via the buck-boost converter under the same conditions. The predictive model on output power and harvested energy has been validated by the test data.

대사량의 측면에서 본 비만 (Obesity from the viewpoint of metabolic rate)

  • 신상원;김호준;김수진
    • 한방비만학회지
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    • 제3권1호
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    • pp.95-105
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    • 2003
  • The obesity is the matter of the energy balance in essential. The energy balance in human body is energy expenditure subtracted from energy intake. The energy intake is mainly supplied by carbohydrates, proteins and lipids in food, and the energy expenditure is composed of basal metabolic rate or resting energy expenditure, physical activity and thermogenesis including diet-induced thermogenesis. The resting energy expenditure is measured by direct calorimetry and indirect calorimetry. Generally we can simply use predictive equation with the variables of weight, height, age and fat-free mass to yield metabolic rate. But there is discrepancy between the estimate and real metabolic rate because the equations can not reflect individuality and environments. The resting energy expenditure is influenced by many factors but the fundamental factor is fat-free mass. We briefly reviewed the concept and evaluation of the energy balance, intake and expenditure, which are important parts in the study of obesity. Finally, we surveyed the correlation between metabolic rate and obesity and suggested applicable herb medication to increase metabolic rate.

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Adaptive Data Association for Multi-Target Tracking using Relaxation

  • Lee, Yang-Weon;Hong Jeong
    • Journal of Electrical Engineering and information Science
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    • 제3권2호
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    • pp.267-273
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    • 1998
  • This paper introduces an adaptive algorithm determining the measurement-track association problem in multi-target tracking(MTT). We model the target and measurement relationships with mean field theory and then define a MAP estimate for the optimal association. Based on this model, we introduce an energy function defined over the measurement space, that incorporates the natural constraints for target tracking. To find the minimizer of the energy function, we derived a new adaptive algorithm by introducing the Lagrange multipliers and local dual theory. Through the experiments, we show that this algorithm is stable and works well in general environments. Also the advantages of the new algorithm over other algorithms are discussed.

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MANET에서 Time Interval Clustering Control 기법에 관한 연구 (A Study on the TICC(Time Interval Clustering Control) Algorithm which Using a Timing in MANET)

  • 김영삼;두경민;김순국;이강환
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.629-630
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    • 2008
  • MANET is depended on the property as like variable energy, high degree of mobility, location environments of nodes etc. So, in this paper, we propose an algorithm techniques which is TICC (Time Interval Clustering Control) based on energy value in property of each node for solving cluster problem. It provides improving cluster energy efficiency how can being node manage to order each node's energy level. TICC is clustering method. It has shown that Node's energy efficiency and life time are improved in MANET.

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Design of a New Capsule Controlling Neutron Flux and Fluence and Temperature of lest Specimen

  • Choo, Kee-Nam;Kang, Young-Hwan;Taiji Hoshiya;Motoji Niimi;Takashi Saito
    • Nuclear Engineering and Technology
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    • 제29권2호
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    • pp.148-157
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    • 1997
  • A new capsule that has a unique structure in which the test environments including neutron flux and fluence, and irradiation temperature can be controlled precisely during irradiation, was conceptually designed. The capsule structure and instrumentation were successfully designed according to the JMTR's standard procedures of capsule design. Based on the target irradiation, the details of the irradiation such as neutron fluence and irradiation temperature ore calculated and the related capsule safety was evaluated. In addition, the effects of design parameters including the changes in inner-capsule configuration, heater capacity, and Helium gas pressure on the specimen temperature were analyzed with a computer program. Through these thermal and strength evaluations, this capsule was proved to be safe during the irradiation in the JMTR.

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퍼머컬츄어 디자인의 원리 (The Principles of Permaculture Design)

  • Miller, James H.
    • 한국유기농업학회지
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    • 제9권4호
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    • pp.53-69
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    • 2001
  • The word \"permaculture\" is a contraction of \"permanent agriculture\" or \"permanent culture\". Permaculture principles are designed to support (or ensure) the survival of humanity, the earth and all on it, and, to improve our standard of living, Permaculture can be defined as : a design system for creating sustainable human environments that can be (relatively) easily constructed and maintained. The principles of permaculture designs are relative location every element (such as house , rice paddy, road, esc) is placed in relation to each other such that each assists the other : each element performs multiple functions ; each function is supported by many elements : energy efficient planning ; using biological resources rather than fossil fuels : energy cycling on site (both fuel and human energy) : Using and accelerating natural plant succession to establish favourable sites and soils ; poly-culture and diversity of beneficial species for a productive, interactive system ; use of edge and natural patterns for best effect. These principles can be used for any permaculture design, in any climate, and at any scale. There has been very little scientific examination of Permaculture, and as such, it must be viewed as a design philosophy.viewed as a design philosophy.

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Linear and Nonlinear Dielectric Ceramics for High-Power Energy Storage Capacitor Applications

  • Peddigari, Mahesh;Palneedi, Haribabu;Hwang, Geon-Tae;Ryu, Jungho
    • 한국세라믹학회지
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    • 제56권1호
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    • pp.1-23
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    • 2019
  • Dielectric materials with inherently high power densities and fast discharge rates are particularly suitable for pulsed power capacitors. The ongoing multifaceted efforts on developing these capacitors are focused on improving their energy density and storage efficiency, as well as ensuring their reliable operation over long periods, including under harsh environments. This review article summarizes the studies that have been conducted to date on the development of high-performance dielectric ceramics for employment in pulsed power capacitors. The energy storage characteristics of various lead-based and lead-free ceramics belonging to linear and nonlinear dielectrics are discussed. Various strategies such as mechanical confinement, self-confinement, core-shell structuring, glass incorporation, chemical modifications, and special sintering routes have been adopted to tailor the electrical properties and energy storage performances of dielectric ceramics. In addition, this review article highlights the challenges and opportunities associated with the development of pulsed power capacitors.

Development of a real-time mobile gamma-ray measurement system for shipboard use

  • Chang-Jong Kim;Mee Jang;Hyuncheol Kim;Jong-Myoung Lim;Wanno Lee;Gyu-Seong Cho
    • Nuclear Engineering and Technology
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    • 제55권11호
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    • pp.4077-4082
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    • 2023
  • Large areas must be rapidly screened to monitor radiation in marine environments. For this purpose, this study developed a mobile real-time gamma-ray measurement system for shipboard use and evaluated its performance. The system was developed to measure engine or generator cooling water by installing a canister inside the ship. The minimum detectable activity of the system is about 0.8 Bq/L for a 60 s measurement period, and real-time data transmission and remote control are possible. The system was tested in the field and is currently being installed and operated on ships in service. Such a ship-based real-time gamma-radiation measurement system is suitable for a wide range of marine radiation surveillance applications and is expected to be rapidly deployed.

Adaptive Data Aggregation and Compression Scheme for Wireless Sensor Networks with Energy-Harvesting Nodes

  • Jeong, Semi;Kim, Hyeok;Noh, Dong Kun;Yoon, Ikjune
    • 한국컴퓨터정보학회논문지
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    • 제22권3호
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    • pp.115-122
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    • 2017
  • In this paper, we propose an adaptive data aggregation and compression scheme for wireless sensor networks with energy-harvesting nodes, which increases the amount of data arrived at the sink node by efficient use of the harvested energy. In energy-harvesting wireless sensor networks, sensor nodes can have more than necessary energy because they harvest energy from environments continuously. In the proposed scheme, when a node judges that there is surplus energy by estimating its residual energy, the node compresses and transmits the aggregated data so far. Conversely, if the residual energy is estimated to be depleted, the node turns off its transceiver and collects only its own sensory data to reduce its energy consumption. As a result, this scheme increases the amount of data collected at the sink node by preventing the blackout of relay nodes and facilitating data transmission. Through simulation, we show that the proposed scheme suppresses the occurrence of blackout nodes and collect the largest amount of data at the sink node compared to previous schemes.