• Title/Summary/Keyword: Critical state

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Effect of Abdominal Breathing on Postoperative Pain, State Anxiety, Blood Pressure, and Heart Rate of Patients Undergoing Cardiac Surgery (복식호흡이 심장 수술후 36시간 이내 환자의 통증, 상태불안, 혈압 및 심박동수에 미치는 효과)

  • Lee, Min-Jee;Kim, Keum-Soon
    • Journal of Korean Critical Care Nursing
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    • v.4 no.1
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    • pp.37-50
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    • 2011
  • Purpose: This study is to evaluate the effect of abdominal breathing on postoperative pain, state anxiety, blood pressure, and heart rate of cardiac surgery patients treated in intensive care unit. Methods: A non-synchronized design of nonequivalent control group pre-post test was used. Participants were divided into an experimental group(n=22) and a control group(n=21). Just usual postoperative treatments were provided to the control group, while abdominal breathing interventions were provided to the experimental group, in addition to usual treatments. The intervention was consisted of 4 stages-introductions, breathing perception, breathing training, and closing-and it lasted twelve minutes in total. Pain, state anxiety, blood pressure and heart rate were the dependent variables of the abdominal breathing. Results: Those who carried out abdominal breathing showed a significant reduction in pain, as well as decrease of systolic blood pressure. However, it turned out to have no effect on state anxiety, diastolic blood pressure and heart rate. Conclusion: Abdominal breathing is simple and harmless and is effective for reducing postoperative pain.

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Natural Frequencies of a Spinning Disk Misaligned with the Axis of Rotation (회전축 정렬불량을 가지는 유연 회전디스크의 고유치 해석)

  • 허진욱;정진태;김원석
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.817-825
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    • 2001
  • The natural frequencies of a flexible spinning disk misaligned with the axis of rotation are studied in an analytic manner. The effects of misalignment on the natural frequency need to be investigated, because the misalignment between the axis of symmetry and the axis of rotation cannot be avoided in the removable disks such as CD-R, CD-RW or DVD disks. Assuming that the in-plane displacements are in steady state and the out-of-plane displacement is in dynamic state, the equations of motion are derived for the misaligned spinning disk. After the exact solutions are obtained for the steady-state in-plane displacements, they are plugged into the equation for the dynamic-state out-of-plane motion. The resultant equation is a linear equation for the out-of-plane displacement, which is discretized by the Galerkin method. Based on the discretized equations, the effects of the misalignment are analyzed on the vibration characteristics of the spinning disk, i.e., the natural frequencies and the critical speed

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Maintaining the close-to-critical state of thorium fuel core of hybrid reactor operated under control by D-T fusion neutron flux

  • Bedenko, Sergey V.;Arzhannikov, Andrey V.;Lutsik, Igor O.;Prikhodko, Vadim V.;Shmakov, Vladimir M.;Modestov, Dmitry G.;Karengin, Alexander G.;Shamanin, Igor V.
    • Nuclear Engineering and Technology
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    • v.53 no.6
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    • pp.1736-1746
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    • 2021
  • The results of full-scale numerical experiments of a hybrid thorium-containing fuel cell facility operating in a close-to-critical state due to a controlled source of fusion neutrons are discussed in this work. The facility under study was a complex consisting of two blocks. The first block was based on the concept of a high-temperature gas-cooled thorium reactor core. The second block was an axially symmetrical extended plasma generator of additional neutrons that was placed in the near-axial zone of the facility blanket. The calculated models of the blanket and the plasma generator of D-T neutrons created within the work allowed for research of the neutronic parameters of the facility in stationary and pulse-periodic operation modes. This research will make it possible to construct a safe facility and investigate the properties of thorium fuel, which can be continuously used in the epithermal spectrum of the considered hybrid fusion-fission reactor.

A Constitutive Model Using the Spacing Ratio of Critical State (한계상태 간격비를 이용한 구성모델)

  • Lee, Seung-Rae;O, Se-Bung;Gwan, Gi-Cheol
    • Geotechnical Engineering
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    • v.8 no.2
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    • pp.45-58
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    • 1992
  • An elasto-plastic constitutive model for geological materials, which satisfies the flezibility and stability at the same time, can be used in a number of geotechnical problems. Using the spacing ratio of critical state, a flexible model is proposed based on the stability of modified Camflay model. The spacing ratio of critical state can be simply evaluated, and practically used in describing the undrained shearing behavior of clay. The proposed model has precisely predicted the stress paths and stress -strain relationships, compared with the modified Camflay model, with respect to undrained triaxial test results. Besides, the effects of strain rate, creep, and relaxation can also be considered. Using the quasi-state boundary surface, the constitutive relations are well predicted. Therefore, it is found that the assumption of associative flow rule is well posed for undrained behavior of normally consolidated clay.

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Numerical investigation of the critical heat flux in a 5 × 5 rod bundle with multi-grid

  • Liu, Wei;Shang, Zemin;Yang, Shihao;Yang, Lixin;Tian, Zihao;Liu, Yu;Chen, Xi;Peng, Qian
    • Nuclear Engineering and Technology
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    • v.54 no.5
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    • pp.1914-1928
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    • 2022
  • To improve the heat transfer efficiency of the reactor fuel assembly, it is necessary to accurately calculate the two-phase flow boiling characteristics and the critical heat flux (CHF) in the fuel assembly. In this paper, a Eulerian two-fluid model combined with the extended wall boiling model was used to numerically simulate the 5 × 5 fuel rod bundle with spacer grids (four sets of mixing vane grids and four sets of simple support grids without mixing vanes). We calculated and analyzed 11 experimental conditions under different pressure, inlet temperature, and mass flux. After comparing the CHF and the location of departure from the nucleate boiling obtained by the numerical simulation with the experimental results, we confirmed the reliability of computational fluid dynamic analysis for the prediction of the CHF of the rod bundle and the boiling characteristics of the two-phase flow. Subsequently, we analyzed the influence of the spacer grid and mixing vanes on the void fraction, liquid temperature, and secondary flow distribution. The research in this article provides theoretical support for the design of fuel assemblies.

Culture, Empire, and Nation: A Critical Appropriation of Edward Said's Culture and Imperialism (문화, 제국, 민족 -비판적 전유를 위한 에드워드 사이드의 『문화와 제국주의』 읽기)

  • Koh, Boo Eung
    • Journal of English Language & Literature
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    • v.58 no.5
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    • pp.903-941
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    • 2012
  • This essay examines Edward Said's Culture and Imperialism focusing on the concepts of 'culture,' 'empire,' and 'nation'. The approach is critical, theoretical, and historical rather than explicatory. Consequently, the range of the essay is not limited to Said's own explanation and argument about Western imperialism and its culture presented in the book. In doing this, this essay finally purposes to be a discursive resistance to the current global empire, the United States, via a critical reading of Said's work. Said's notion of culture is set upon to disclose the function of culture as an apparatus of ideological consent of the dominated to the dominant. When applied to imperial practice, Western culture functions to subject the colonized to the colonizer. Said's geographical approach to imperialism complements the historical understanding of imperialism. Imperialism is not only the practice of Western-centered historicism but also the spatially mutual interaction between the West and the rest of the world. Along with European imperialism, Said poses the current global empire of the United States as his main target of criticism. Said's problem is that he takes the United States as a nation-state. When examined, the United States is not a nation-state, but today's empire. The empire in the appearance of the nation-state United States does not work for the interest of the American nation, that is, the American people. The empire is the transnational and postnational political and economic institution that works for the interest of global capital. In order to resist the current global empire, this essay suggests that the building or restoration of nation-states with its basic principle of people's sovereignty is in need.

Causal Loop-Based Structural Analyses of Marginal Ageing and Critical Mass Simulations for Demographic Extinction Scenarios in Eup and Myeon Regions (읍·면지역 한계고령화의 인과순환적 구조분석과 인구소멸 임계점에 대한 시뮬레이션)

  • Choi, Nam-Hee
    • Korean System Dynamics Review
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    • v.17 no.1
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    • pp.107-134
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    • 2016
  • Accelerated ageing with low fertility is one of the most critical problems in Korea. Because of ageing via low fertility, Korea will face a serious demographic cliff. This research primarily focus on the analyzing the dynamics of the marginal ageing state and decreasing population especially in Eup and Myeon region. This study based on the system dynamics approaches for finding causal loop structure of marginal ageing and critical mass of population disappearing. The results of this study are summarized as follows. First, demographic marginalization trends have already begun in the Eups and Myons of Gun. Second, marginal aging speed in Eup/Myeon areas is causing an population disappearing in the near future. Third, critical mass of population disappearing will begin when the rate of marginal aging is exceed 82% after 2023.

Critical Moisture and Pore Structure of Clay Based Consolidated Body (점토계 고형화소지의 임계함수율과 기공구조)

  • 이기강;박천주;김유택;김석범;김정환
    • Journal of the Korean Ceramic Society
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    • v.34 no.5
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    • pp.528-534
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    • 1997
  • There have been many studies on the preparation of slip, forming and drying in the slip casting process. However, is has not been yet on the rheological properties of consolidated body which largely affect on the workability. It was investugated that the rheological properties of the consolidated bodies formed by slip casting in the form of cakes from well dispersed(slip C) and weakly agglomerated slip(slip B) in the clay and clay-fly ash systems. The state of dispersion of slip was found to affected the critical moisture content which was largely affected by the pore and moisture distribution of the consolidated body. The cake C show lower critical moisture content than cake B in the clay system. However, the cake B gives lower critical moisture content than cake C in the clay-fly ash system.

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Determination of the Kinetic Energy Release Originating from the Reverse Critical Energy in Unimolecular ion Dissociation

  • Yeh, In-Chul;Lee, Tae-Geol;Kim, Myung-Soo
    • Bulletin of the Korean Chemical Society
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    • v.15 no.3
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    • pp.241-245
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    • 1994
  • A method has been developed to estimate the kinetic energy release originating from the reverse critical energy in unimolecular ion dissociation. Contribution from the excess energy was estimated by RRKM theory, the statistical adiabatic model and the modified phase space calculation. This was subtracted from the experimental kinetic energy release distribution (KERD) via deconvolution. The present method has been applied to the KERDs in $H_2$, loss from $C_6H_6^+$ and HF loss from ${CH_2CF_2}^+$. In the present formalism, not only the energy in the reaction coordinate but also the energy in some transitional vibrational degrees of freedom at the transition state is thought to contribute to the experimental kinetic energy release. Details of the methods for treating the transitional modes are found not to be critical to the final outcome. For a reaction with small excess energy and large reverse critical energy. KERD is shown to be mainly governed by the reverse critical energy.

Top Management Commitment in Enterprise Resource Planning Implementation Success : Preliminary Study in Indonesian State-Owned Enterprises

  • Hartijasti, Yanki
    • Journal of Information Technology Applications and Management
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    • v.18 no.3
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    • pp.41-59
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    • 2011
  • This preliminary study held in two Indonesian state-owned enterprises (SOEs) showed empirical evidence that top management commitment was perceived to be the most important critical factor contributing to enterprise resource planning (ERP) implementation success, compared to top management support and top management involvement. Therefore, top management and middle management must continually show commitment during the ERP implementation process. This finding could serve as a reference for further study in a larger number of Indonesian SOEs.