• Title/Summary/Keyword: Critical limit

Search Result 651, Processing Time 0.023 seconds

Fabrication and characterization of NbTi-Au-NbTi Josephson junctions

  • Pyeong Kang, Kim;Heechan, Bang;Bongkeon, Kim;Yong-Joo, Doh
    • Progress in Superconductivity and Cryogenics
    • /
    • v.24 no.4
    • /
    • pp.6-10
    • /
    • 2022
  • We report on the fabrication and measurements of metallic Josephson junctions (JJs) consisting of Au nanoribbon and NbTi superconducting electrodes. The maximum supercurrent density in the junction reaches up to ~ 3×105 A/cm2 at 2.5 K, much larger than that of JJ using single-crystalline Au nanowire. Temperature dependence of the critical current exhibits an exponential decay behavior with increasing temperature, which is consistent with a long and diffusive junction limit. Under the application of a magnetic field, monotonous decrease of the critical current was observed due to a narrow width of the Au nanoribbon. Our observatons suggest that NbTi/Au/NbTi JJ would be a useful platform to develop an integrated superconducing quantum circuit combined with the superconducting coplanar waveguide and ferromagnetic π junctions.

Expression of Identity in Martin Gutierrez's Fashion Media Works -Focused on Judith Butler and Athena Athanasiou's Concept of Dispossession- (마틴 구티에레즈의 패션미디어 작품에 나타난 정체성 표현 -주디스 버틀러와 아테나 아타나시오우의 박탈(Dispossession) 개념을 중심으로-)

  • Myeongseon Yi;Eunhyuk Yim
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.47 no.2
    • /
    • pp.232-243
    • /
    • 2023
  • The boundaries between fashion and contemporary art are increasingly blurred showing their interchangeability. This study examines Judith Butler and Athena Athanasiou's concept of dispossession to analyze expressions of gender, racial, and class identity in Martine Gutierrez's representative work, Indigenous Woman. First, gender expressions in Indigenous Woman emphasize the possibility of performative and practical gender as an image that rejects norms that grant authority according to the possession of innate body parts. Second, racial identity is expressed through resistance to the ideology of whiteness and imperialism reinforced by fashion media. The author aims to overcome normative stereotypes through the media she creates, which reveals her identity as a person of color. Third, class identity is represented through stereotypes that limit the lives of indigenous people to primitive and natural things. The author reveals a critical awareness of the hierarchical structure and cultural appropriation these stereotypes have created. This study analyzed contemporary artworks using fashion media through the concept of dispossession. The significance of this study lies in raising a critical awareness of the practices that diffuse minority identities in fashion media.

Effect of Bending Test Procedure on the Degradation Behavior of Critical Current in ReBCO Coated Conductor Tapes

  • Shin, H.S.;Dedicatoria, M.J.;Lee, N.J.;Oh, S.S.
    • Progress in Superconductivity and Cryogenics
    • /
    • v.11 no.4
    • /
    • pp.12-15
    • /
    • 2009
  • The $I_c$ degradation behavior of critical current in differently processed YBCO and SmBCO CC tapes with IBAD template has been investigated. It has been known that the residual strain in the CC tape will influence the shape of the $I_c$-strain window; $I_c$ may show a peak value if there exist a residual strain induced in the tape during manufacturing. The difference of residual strain may be resulted from the adopted different deposition techniques. In this study, bending test of CC tapes has been done using the Goldacker bending test rig which can produce both compressive and tensile bending strain continuously or alternately to the sample. For SmBCO CC tapes, in continuous compressive bending test, $I_c$ showed a minimal increase and did not degrade up to the largest strain that can be applied using the bending rig equivalent to 1.15% based on the sample thickness. However, in the case of alternate application of compressive and tensile bending strain, $I_c$ showed a larger degradation and a lower reversible limit when compared with the case of continuous application of the bending strain. When $I_c$ started to degrade significantly at the tension side, the reversibility ended, also at the compression side which is resulted from the permanent deformation like delamination or cracks that was induced due to tensile bending strain.

Effect of flexure-extension coupling on the elastic instability of a composite laminate plate

  • H. Mataich;A. El Amrani;J. El Mekkaoui;B. El Amrani
    • Structural Engineering and Mechanics
    • /
    • v.90 no.4
    • /
    • pp.391-401
    • /
    • 2024
  • The present study focuses on the effect of extension-bending coupling on the elastic stability (buckling) of laminated composite plates. These plates will be loaded under uni-axial or bi-axial in-plane mechanical loads, especially in the orthotropic or anti-symmetric cross-angle cases. The main objective is to find a limit where we can approximate the elastic stability behavior of angularly crossed anti-symmetric plates by the simple behavior of specially orthotropic plates. The contribution of my present study is to predict the explicit effect of extension-flexion coupling on the elastic stability of this type of panel. Critically, a parametric study is carried out, involving the search for the critical buckling load as a function of deformation mode, aspect ratio, plate anisotropy ratio and finally the study of the effect of lamination angle and number of layers on the contribution of extension-flexure coupling in terms of plate buckling stability. We use first-order shear deformation theory (FSDT) with a correction factor of 5/6. Simply supported conditions along the four boundaries are adopted where we can develop closed-form analytical solutions obtained by a Navier development.

Numerical Simulations of Nonlinear Behaviors of Pulsating Instabilities in Counterflow Diffusion Flames (대향류 확산화염에서 맥동 불안정성의 비선형 거동에 대한 수치해석)

  • Lee, Su-Ryong
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.34 no.9
    • /
    • pp.859-866
    • /
    • 2010
  • Nonlinear dynamics of pulsating instability-diffusional-thermal instability with Lewis numbers sufficiently higher than unity-in counterflow diffusion flames, is numerically investigated by imposing a Damkohler number perturbation. The flame evolution exhibits three types of nonlinear behaviors, namely, decaying pulsating behavior, diverging behavior (which leads to extinction), and stable limit-cycle behavior. The stable limit-cycle behavior is observed in counterflow diffusion flames, but not in diffusion flames with a stagnant mixing layer. The critical value of the perturbed Damkohler number, which indicates the region where the three different flame behaviors can be observed, is obtained. A stable simple limit cycle, in which two supercritical Hopf bifurcations exist, is found in a narrow range of Damkohler numbers. As the flame temperature is increased, the stable simple limit cycle disappears and an unstable limit cycle corresponding to subcritical Hopf bifurcation appears. The period-doubling bifurcation is found to occur in a certain range of Damkohler numbers and temperatures, which leads to extend the lower boundary of supercritical Hopf bifurcation.

Evaluation of hazardous factors for the application of HACCP on production and transportation flow in home-delivered meals for the elderly (노인을 위한 가정배달급식의 생산 및 배송단계에 HACCP 적용을 위한 위해요인 분석 1)

  • 김혜영;류시현
    • Korean journal of food and cookery science
    • /
    • v.19 no.2
    • /
    • pp.195-209
    • /
    • 2003
  • The purpose of this study was to identify the hazard analysis critical control point on food production and transportation flow, applied to home-delivered meals for the elderly. To carry out this study, 1) pan-fried oak mushroom and meat, soy sauce glazed hair tail, and roasted dodok were selected as high nutrient and preferred foods for the elderly and 2) time, temperature, and microbiological quality(standard plate count, coliform, Salmonella spp, Vibrio parahaemolyticus, Staphylococcus spp., Escherichia coli O157:H7, and Listeria monocytogenes) were measured at various phases of the home-delivered meal production and its transportation flows. The results of this experiments are as follows: The temperature measured at cooling phases during the home-delivered meal production flows was 19.2 ∼ 20.0$^{\circ}C$ for the pan- fried oak mushroom and meat and the roasted dodok and was 24.0 ∼ 25.2$^{\circ}C$ for the soy sauce glazed hair tail. These temperature were in the potentially dangerous zone. Microbiological analysis showed that S. spp. was higher in the raw ingredients, including oak mushroom, hair tail, radish, and dodok, than the standard limit. SPC was lower than the standard limit from cooking to transportation phase, but SPC increased significantly during the cooling and packaging phase. The level of coliform detected was far lower than the standard limit and was not detected at all during the transportation phase. Few S. spp. was detected in the pan-fried oak mushroom and meat, but was found in above standards limit during the wrap packaging phase in the soy sauce glazed hair tail and roasted dodok. The level decreased rapidly during the holding and transportation phase. Sal. spp., V. parahaemolyticus, S. spp., E. coli O157:H7, and L. monocytogenes were not detected. For the pan-fried oak mushroom and meat, the critical control points were during the purchasing and receiving of raw ingredients, cooling, and packaging phases. For the soy sauce glazed hair tail and roasted dodok, the critical control points were during the purchasing and receiving of raw ingredients, preparation, cooling, and packaging phases.

An Explorative Study of Application of Habermas's Critical Theory to the Social Work Practice : Focused on the Theory of Communicative Behaviors (하버마스 비판이론의 사회복지 실천에의 적용가능성에 관한 탐색적 연구: 의사소통행위이론을 중심으로)

  • Kim, Gi-Duk
    • Korean Journal of Social Welfare
    • /
    • v.58 no.4
    • /
    • pp.119-139
    • /
    • 2006
  • The main purpose of this study is to examine the implications of Habermas's Critical Theory, which has been considered as modern descendant of enlightenment thought, on the social work profession. The focus of this paper is a critical examination on expected perceptual and practical gain provided by communicative theory for the professional relations between social workers and clients. This paper proves that Habermas's theory has failed to sufficiently grasp the scope and functions of social work practice. First, in regard to perceptual gains, Habermas's theory commits some kind of reductionism which considers communicative behaviors as only and original one. It is likely to limit the scope and extent of the function and mission of social work into a kind of communication performed by humans with communicative ability. Second, in regard of practical gains, Habermas's theory does not provide detail procedure of power-free communication nor critical criteria to evaluate the degree of ideal speech situation. Without these ones, Habermas's critical theory might play a role of liberal conservatism, which is trying to replace the substantial contents with procedural formality. In sum, to be a adequate theoretical and practical framework for social work, Habermas's theory needs to combine additional humanitarian considerations into communicative paradigm with more detail requirements and preconditions for ideal speech situations between professional and clients.

  • PDF

An Experimental Study on the Effects of Bolted Connection Type on the Block Shear Failure (볼트이음방식의 블록전단파괴에 미치는 영향에 대한 실험적 연구)

  • Lee, Chin-Ok;Park, Gyung-Hyeon;Moon, Jiho;Lee, Hak-Eun;Lim, Nam-Hyoung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.13 no.11
    • /
    • pp.5566-5571
    • /
    • 2012
  • Block shear failure is one of limit states, and demands great caution in designing the tension member or connection joint of steel structures. From many studies and design specification, it is shown that the effect of the bolted connection type on the block shear failure was not considered. In order to investigate the effect of the bolted connection type(bearing type connection and slip critical connection) on the mode/strength of the block shear failure, tensile experiment is conducted in this study. Differences about the failure mode according to the design specification, bearing type connection, and slip critical connection are proposed from the analysis of test results. The variation of the block shear failure strength due to the frictional force in the slip critical connection is also investigated.

The upper critical field (($H_{c2}$) study of intermetallic $YNi_{2}$$B_{2}$C superconductor (중간금속성 $YNi_{2}$$B_{2}$C 초전도체의 상부임계자기장($H_{c2}$) 연구)

  • Song, K.J.;Lee, N.J.;Ko, R.K.;Park, C;Ha, H.S.;Ha, D.W.;Oh, S.S.;Kwon, Y.K
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
    • /
    • 2002.02a
    • /
    • pp.168-170
    • /
    • 2002
  • Magnetization studies were conducted on a single crystal of $YNi_{2}$$B_{2}$C superconductor. The 17 mg crystal was studied at temperatures T from above $T_{c}$ (15.5 K) to 3 K, in the magnetic fields H // c-axis up to 6 tesla. The crystal exhibited little magnetic irreversibility, with a critical current density $CO_{3}$ ~ $10^{-4}$ $\times$ $CO_{3}$, the depairing current density. Near $T_{c}$, the equilibrium magnetization M was London-like with M $\infty$ In(H). The upper critical field $H_{c2}$ of the single crystal $YNi_{2}$$B_{2}$C was estimated by the several alternative approaches such as standard London limit, Ginzburg-Landau, and Abrikosov relations. The estimated $H_{c2}$values agree relatively well with each other approaches.

  • PDF

A Study on Microbiological Risk Assessment for the HACCP System Construction of Seasoned Laver (조미김의 HACCP 시스템 구축을 위한 생물학적 위해도 평가 연구)

  • Kim, Kang-Yul;Yoon, Sung-Yee
    • Journal of Environmental Health Sciences
    • /
    • v.39 no.3
    • /
    • pp.268-278
    • /
    • 2013
  • Objectives: The purpose of this study was to apply the Hazard Analysis Critical Control Point (HACCP) system to the production of seasoned laver products. The hazard analysis examined microbial evaluations and developed a HACCP management plan through the heating process. Methods: In this study we chose three companies and performed the analysis thrice. During this study, general bacteria along with other food poisoning bacteria such as Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, E.coil, O157:H7, Vibrio parahaemolyticus, were studied at varying temperatures from 100 to $300^{\circ}C$. Results: The presence of general bacteria was detected in raw laver in the samples analyzed from all the three companies, and the number ranged from $10^5-10^7$. Bacillus cereus was detected in samples from only two of the three companies analyzed. However, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, E.coil, O157:H7, and Vibrio parahaemolyticus were all negative. General bacteria was reduced to $10^5$ after being subjected to temperatures of $100-250^{\circ}C$, but heating to over $270^{\circ}C$ reduced the number to below $10^3$, and the other microbes such as Bacillus cereus were not detected. Conclusions: In conclusion, the heating process ($270-280^{\circ}C$) along with RPM of 100-1200 were identified as CCP to reduce biological hazards.