• Title/Summary/Keyword: Intensity of elements

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Characteristics of Microwave Leaching for the Removal of Bi, As from the Sulfide Mineral Concentrate (황화광물정광으로부터 Bi, As 제거를 위한 마이크로웨이브 용출 특성)

  • On, Hyun-Sung;Togtokhmaa, B.;Park, Cheon-Young
    • Journal of the Mineralogical Society of Korea
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    • v.31 no.3
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    • pp.137-147
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    • 2018
  • The aim of this study was to leach penalty elements, such as Bi and As, effectively through microwave leaching of a gold concentrate sample containing penalty elements with nitric acid solution. For this purpose, the time effect of microwave leaching, nitric acid concentration effect, and sample addition effect in a microwave were examined. The experiment, demonstrated that the leaching rate of penalty elements increased as microwave leaching time and nitric acid concentration increased and concentration addition decreased. When a microwave heating experiment was carried out on the concentrate and ore minerals, Bi was removed by as much as 90%, and the phase of arsenopyrite was transformed in the order of arsenopyrite (FeAsS), pyrrhotite (FeS), and hematite ($Fe_2O_3$). When the X-ray diffraction (XRD) analysis was carried out with solid residue, elemental sulfur and anglesite were identified. The intensity of the XRD peaks of elemental sulfur and anglesite increased, and the peaks were sharper when the microwave leaching time was 12 min instead of 1 min, the nitric acid concentration was 4 M in rather than 0.5 M, and the concentration addition was 30 g rather than 5 g. This was probably because more elemental sulfur and anglesite were generated in the leaching solution as the leaching efficiency increased. Bi can be leached as valuable elements in the leaching solution through microwave leaching processes while they are released to the environment through a microwave heating processes.

Element and Crack Geometry Sensitivities of Finite Element Analysis Results of Linear Elastic Stress Intensity Factor for Surface Cracked Straight Pipes (표면균열이 있는 직관에 대한 선형탄성 응력확대계수 유한요소해석 결과의 요소 및 균열형상 민감도)

  • Ryu, Dongil;Bae, Kyung-Dong;Je, Jin-Ho;An, Joong-Hyok;Kim, Yun-Jae;Song, Tae-Kwang;Kim, Yong-Beum
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.4
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    • pp.521-527
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    • 2013
  • This study provides the elastic stress intensity factors, K, for circumferential and longitudinal surface cracked straight pipes under single or combined loads of internal pressure, bending, and torsion based on three-dimensional (3D) finite element (FE) analyses. FE results are compared with two different types of defect assessment codes (API-579-1 and RCC-MR A16) to prove the accuracy of the FE results and the differences between the codes. Through the 3D FE analysis, it is found that the stress intensity factors are sensitive to the number of elements, which they were believed to not be sensitive to because of path independence. Differences were also found between the FE analysis results for crack defining methods and the results obtained by two different types of defect assessment codes.

Three-Dimensional Virtual Crack Closure Technique Based on Anisoparametric Model for Stress Intensity Factors of Patch Repaired Plates with Cracks at Notches (접착 보강된 노치 균열판의 응력확대계수 산정을 위한 비등매개변수 모델 기반의 3차원 가상균열닫힘법)

  • Ahn, Jae-Seok;Woo, Kwang-Sung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.1A
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    • pp.39-48
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    • 2012
  • This study deals with numerical determination of stress intensity factors of adhesively patch-repaired plates with cracks at V-shaped or semicircular notches. The p-convergent anisoparametric model are considered and then three-dimensional virtual crack closure technique is presented using formulations of anisoparametric elements. In assumed displacement fields of an element, strain-displacement relations and three-dimensional constitutive equations are derived with three-dimensional hierarchical shape functions expanded from one-dimensional Lobatto functions. Transfinite mapping technique is used to represent a circular boundary. The present model provides accuracy and simplicity in terms of stress concentration factor, stress distribution, the number of degrees of freedom, and non-dimensional stress intensity factor as compared with previous works in literatures. Stress intensity factors obtained by the three-dimensional virtual crack closure technique are estimated with respect to the variation of width of finite plate, radius of notch root, angular inclination of V-shaped notch, and crack length.

Integrity Evaluation for 3D Cracked Structures(II) (3차원 균열을 갖는 구조물에 대한 건전성 평가(II))

  • Lee, Joon-Seong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.1
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    • pp.1-6
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    • 2013
  • Three Surface cracks are among the more common flaws in aircraft and pressure vessel components. Accurate stress intensity analyses and crack growth rate data of surface-cracked components are needed for reliable prediction of their fatigue life and fracture strengths. Three Dimensional finite element method (FEM) was used to obtain the stress intensity factor for surface cracks existing in structures. A geometry model, i.e. a solid containing one or several 3D cracks is defined. Nodes are generated by bucket method, and quadratic tetrahedral solid elements are generated by the Delaunay triangulation techniques. To examine accuracy and efficiency of the present system, the stress intensity factor for a semi-elliptical surface crack in cylindrical structures subjected to pressure is calculated. Analysis results by present system showed good agreement with those by ASME equation and Raju-Newman's equation.

Haptic recognition of the palm using ultrasound radiation force and its application (초음파 방사힘을 이용한 손바닥의 촉각 인식과 응용)

  • Kim, Sun Ae;Kim, Tae Yang;Lee, Yeol Eum;Lee, Soo Yeon;Jeong, Mok Kun;Kwon, Sung Jae
    • The Journal of the Acoustical Society of Korea
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    • v.38 no.4
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    • pp.467-475
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    • 2019
  • A high-intensity ultrasound wave generates acoustic streaming and acoustic radiation forces when propagating through a medium. An acoustic radiation force generated in a three-dimensional space can produce a solid tactile sensation, delivering spatial information directly to the human skin. We placed 154 ultrasound transmit elements with a frequency of 40 kHz on a concave circular dish, and generated an acoustic radiation force at the focal point by transmitting the ultrasound wave. To feel the tactile sensation better, the transmit elements were excited by sine waves whose amplitude was modulated by a 60 Hz square wave. As an application of ultrasonic tactile sensing, a region where tactile sense is formed in the air is used as an indicator for the position of the hand. We confirmed the utility of ultrasonic tactile feedback by implementing a system that provides the number of fingers to a machine by receiving the shape of the hand at the focal point where the tactile sense is detected.

A Basic Study on the Pitch-based Sound into Color Image Conversion (피치 기반 사운드-컬러이미지 변환에 관한 기초연구)

  • Kang, Kun-Woo;Kim, Sung-Ill
    • Science of Emotion and Sensibility
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    • v.15 no.2
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    • pp.231-238
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    • 2012
  • This study aims for building an application system of converting sound into color image based on synesthetic perception. As the major features of input sound, both scale and octave elements extracted from F0(fundamental frequency) were converted into both hue and intensity elements of HSI color model, respectively. In this paper, we used the fixed saturation value as 0.5. On the basis of color model conversion theory, the HSI color model was then converted into the RGB model, so that a color image of the BMP format was finally created. In experiments, the basic system was implemented on both software and hardware(TMS320C6713 DSP) platforms based on the proposed sound-color image conversion method. The results revealed that diverse color images with different hues and intensities were created depending on scales and octaves extracted from the F0 of input sound signals. The outputs on the hardware platform were also identical to those on the software platform.

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A Study on the Correlation between Spatial Distance and Cognitive Intensity of High-rise Buildings - Focusing on High-rise Buildings of More than 30 Stories in Seoul - (초고층 랜드마크의 공간적 거리 및 인지강도와의 상관성 분석 - 서울시 30층 이상 고층건물을 대상으로 -)

  • Byeon, Jae-Sang;Im, Seung-Bin;Joo, Shin-Ha
    • Journal of the Korean Institute of Landscape Architecture
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    • v.35 no.4
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    • pp.90-104
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    • 2007
  • Landmarks like high-rise building are one of the important elements for the enhancement of city identity and provides the hierarchy of city streets, playing a central and symbolic role in cities. Research on physical attribute of landmarks, such as height, distance, location and shape, which are suitable for a city scale, can help a city create a distinct image and maintain comprehensible structure. To achieve this purpose, it is necessary to understand the spatial and cognitive characteristics of a landmark for the establishment and management of it. The results of this study can be summarized as follows: 1. The level of representativeness of a landmark increases in proportion to the degree of cognitive intensity on it. The relation between representativeness and cognitive intensity can be explained as the log-function as follows: Log(the number of people who respond "It has representativeness")=$-1.2579+1.5908{\times}$(cognitive intensity); 2. There are a few differences based on the attributes of respondents: while gender has no distinct influence, residential period and age show statistically meaningful influence on cognitive intensity of a vertical landmark Cognitive intensity of an individual landmarks especially, differs according to the class of main users. Because of frequent changes in occupation or employment, respondents consider the distance from a residential area more important than the distance from a working area in evaluating cognitive intensity of landmarks; 3. landmark can be classified into two kinds: a district landmark and an urban landmark A district landmark is closely connected with physical attributes of the landmark itself, such as distance, size and height. An urban landmark is mainly related to cognitive attributes such as the image and identity of a city as a whole. As a result, the landmark analysis data in this research provides spatial order and identity in a city. It is difficult to establish and reinforce the image of a city as a single element ike a landmark. However, withy steady follow-up research, this study could be seen as a systematic and logical model to improve urban landscape and image.

A Study on Application of Dynamic Design Elements for Designing Ambient Media (엠비언트 미디어의 디자인을 위한 동적인 디자인 요소의 활용에 관한 연구)

  • Park, Jin-Yung;Park, Sun-Young;Nam, Tek-Jin
    • 한국HCI학회:학술대회논문집
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    • 2008.02b
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    • pp.233-238
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    • 2008
  • Ambient Media (or ambient displays, Wisneski et al 1998) is one of newly emergent dynamic design objects, representing information through subtle changes of everyday objects and environments. Unlike the existing GUI-based media focusing on the situation that a user is concentrating the media, ambient media enable a user to be peripherally aware of the information without his/her concentration. In order to design ambient media, it is necessary to interpret the basic elements of dynamic changes in physical space and the proper method to apply them for peripherally representing information in ambient media. The aim of this study is to investigate dynamic design elements and the method to apply them for ambient media design in physical space. We explored and refined the type of the dynamic design elements, analyzing dynamic qualities of ambient media cases as well as various time based design fields. As a result, 4 dynamic elements - tempo, connectivity, intensity and rhythm- were proposed. By literature reviews related to peripheral awareness in psychology or ambient media, we analyzed the characteristics of dynamic design elements. Based on that, we developed a new ambient media, 'Cyber Pung-Kyung', and applied dynamic elements for designing the prototype system. The research outcome is expected to contribute designing ambient media which can represent information peripherally or centrally as needed. Understanding the dynamic design elements is helpful for designing various time based design outcomes as well.

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Emission Characteristics of Elemental Constituents in Fine Particulate Matter Using a Semi-continuous Measurement System (준 실시간 측정시스템을 이용한 미세입자 원소성분 배출특성 조사)

  • Park, Seung-Shik;Ondov, John M.
    • Journal of Korean Society for Atmospheric Environment
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    • v.26 no.2
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    • pp.190-201
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    • 2010
  • Fine particulate matter < $1.8{\mu}m$ was collected as a slurry using the Semicontinuous Elements in Aerosol Sampler with time resolution of 30-min between May 23 and 27, 2002 at the Sydney Supersite, Florida, USA. Concentrations of 11 elements, i.e., Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn, in the collected slurry samples were determined off-line by simultaneous multi-element graphite furnace atomic absorption spectrometry. Temporal profiles of $SO_2$ and elemental concentrations combined with meteorological parameters such as wind direction and wind speed indicate that some transient events in their concentrations are highly correlated with the periods when the plume from an animal feed supplement processing facility influenced the Sydney sampling site. The peaking concentrations of the elemental species during the transient events varied clearly as the plume intensity varied, but the relative concentrations for As, Cr, Pb, and Zn with respect to Cd showed almost consistent values. During the transient events, metal concentrations increased by factors of >10~100 due to the influence of consistent plumes from an individual stationary source. Also the multi-variate air dispersion receptor model, which was previously developed by Park et al. (2005), was applied to ambient $SO_2$ and 8 elements (Al, As, Cd, Cr, Cu, Fe, Pb, and Zn) measurements between 20:00 May 23 and 09:30 May 24 when winds blew from between 70 and $85^{\circ}$, in which animal feed processing plant is situated, to determine emission and ambient source contributions rates of $SO_2$ and elements from one animal feed processing plant. Agreement between observed and predicted $SO_2$ concentrations was excellent (R of 0.99; and their ratio, $1.09{\pm}0.35$) when one emission source was used in the model. Average ratios of observed and predicted concentrations for As, Cd, Cr, Pb, and Zn varied from $0.83{\pm}0.26$ for Pb to $1.12{\pm}0.53$ for Cd.

A Study on the Correction of Spectral Line Overlaps for the Determination of Rare Earth Elements by X-Ray Fluorescence Spectrometry (X-선 형광분광법에 의한 희토류원소 분석에서 스펙트럼선 겹침 방해의 보정에 관한 연구)

  • Young-Man Kim;Young-Sang Kim;Yoon-Chang Park;Chong-Wook Lee
    • Journal of the Korean Chemical Society
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    • v.30 no.6
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    • pp.538-547
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    • 1986
  • The 8 rare earth elements were determined in the monazite concentrates by X-ray fluorescence spectrometry. The spectral line overlapping interferences from the other elements were investigated and the correction methods of interferences were studied using line overlap coefficients. The coefficients were calculated from the ratios of the intensities measured at the diffracted angle (2${\theta}$) of the analytical lines of other elements to the intensity of pure rare earth oxide. The coefficients were used to correct the line overlaps by a regression analysis. The linearities of calibration curves from the corrected intensities were remarkably improved, and their standard deviations were decreased. The analytical results agreed with that of the inductively coupled plasma(ICP) spectrometry within an allowable error range.

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