• Title/Summary/Keyword: Opposed-flow

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Effects of Initial Condition and Opening Geometry of a Compartment on the Gravity Current in the Backdraft (백드래프트의 중력흐름에 미치는 구획실 내부 초기조건 및 개구부 형상의 영향)

  • Park, Ji-Woong;Oh, Chang Bo;Han, Yong Shik;Do, Kyu Hyung
    • Journal of the Korean Society of Safety
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    • v.30 no.6
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    • pp.18-25
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    • 2015
  • Computational study of a gravity current prior to the backdraft was conducted using fire dynamic simulator (FDS). Various initial conditions of mixture compositions and compartment temperature as well as four opening geometries (Horizontal, Door, Vertical, and Full opening) were considered to figure out their effects on the gravity current. The density difference ratio (${\beta}$) between inside and outside of compartment, the gravity current time ($t_{grav}$) and velocity ($v_{grav}$), and non-dimensional velocity ($v^*$) were introduced to quantify the flow characteristics of the gravity current. Overall fluid structure of the gravity current at the fixed opening geometry showed similar development process for different ${\beta}$ conditions. However, $t_{grav}$ for entering air to reach the opposed wall to the opening geometry increased with ${\beta}$. Door, Vertical, and Horizontal openings where openings are attached on the ground showed similar development process of the gravity current except for Horizontal opening, which located on the middle of the opening wall. The magnitude of $v_{grav}$ at fixed ${\beta}$ was, from largest to smallest, Full > Vertical > Door > Horizontal, but it depended on both the size and location of the opening. On the other hand, $v^*$ was found to be independent to ${\beta}$, and only depended on the geometry of the opening.

ALEX1 Regulates Proliferation and Apoptosis in Breast Cancer Cells

  • Gao, Yue;Wu, Jia-Yan;Zeng, Fan;Liu, Ge-Li;Zhang, Han-Tao;Yun, Hong;Song, Fang-Zhou
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.8
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    • pp.3293-3299
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    • 2015
  • Background: Arm protein lost in epithelial cancers, on chromosome X (ALEX) is a novel subgroup within the armadillo (ARM) family, which has one or two ARM repeat domains as opposed to more than six-thirteen repeats in the classical Armadillo family members. Materials and Methods: In the study, we explore the biological functions of ALEX1 in breast cancer cells. Overexpression of ALEX1 and silencing of ALEX1 were performed with SK-BR3 and MCF-7 cell lines. Cell proliferation and colony formation assays, along with flow cytometry, were carried out to evaluate the roles of ALEX1. Results: ALEX1 overexpression in SK-BR3 breast cancer cells inhibited proliferation and induced apoptosis. Furthermore, depletion of ALEX1 in MCF-7 breast cancer cells increased proliferation and inhibited apoptosis. Additional analyses demonstrated that the overexpression of ALEX1 activated the intrinsic apoptosis cascades through up-regulating the expression of Bax, cytosol cytochrome c, active caspase-9 and active caspase-3 and down-regulating the levels of Bcl-2 and mitochondria cytochrome c. Simultaneouly, silencing of ALEX1 inhibited intrinsic apoptosis cascades through down-regulating the expression of Bax, cytosol cytochrome c, active caspase-9, and active caspase-3 and up-regulating the level of Bcl-2 and mitochondria cytochrome c. Conclusions: Our data suggest that ALEX1 as a crucial tumor suppressor gene has been involved in cell proliferation and apoptosis in breast cancer, which may serve as a novel candidate therapeutic target.

Evaluation of the Microbiological Quality of Glazed Spanish Mackerel in Teriyaki Sauce by Adding Lemon Juice Using Sous Vide Cook-chill Method (Sous Vide Cook-chill 법으로 생산된 삼치 데리야끼 조림의 레몬즙 첨가에 따른 미생물적 품질평가)

  • Kim, Heh-Young;Ko, Sung-Hee;Lee, Kyung-Yeoun
    • Korean journal of food and cookery science
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    • v.24 no.5
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    • pp.713-721
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    • 2008
  • The principal objective of this study was to evaluate the microbiological quality of Glazed Spanish Mackerel in Teriyaki sauce by adding Lemon juice, using a Sous vide Cook-chill method. The control was prepared by mixing 100 g of cut Spanish Mackerel and 15 mL of Teriyaki sauce. 1.5 mL lemon juice was added to 15 mL of Teriyaki sauce. The product was stored at below $3^{\circ}C$, and its microbiological quality was assessed over varying storage periods (0, 5, 10, 15 days). Total Plate Counts at product flow showed no significant difference between the control and the lemon juice-added sample. However, the coliform counts at the end of mixing each sauce were detected at low levels of 1.65 Log CFU/g in the lemon juice-added sample, as opposed to 2.63 Log CFU/g in the controls (p<0.05). The microbiological quality by storage day was relatively high in the lemon juice-added samples. After reheating, the Total Plate Counts and Coliform counts of the lemon juice-added samples satisfied the standard applied in the processed food (5.0 and 2.0 Log CFU/g, respectively). It can be concluded that the addition of Lemon juice was more effective in ensuring the safety and extending the shelf life of Sous vide Glazed Spanish Mackerel in Teriyaki sauce.

Facial Color Control based on Emotion-Color Theory (정서-색채 이론에 기반한 게임 캐릭터의 동적 얼굴 색 제어)

  • Park, Kyu-Ho;Kim, Tae-Yong
    • Journal of Korea Multimedia Society
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    • v.12 no.8
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    • pp.1128-1141
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    • 2009
  • Graphical expressions are continuously improving, spurred by the astonishing growth of the game technology industry. Despite such improvements, users are still demanding a more natural gaming environment and true reflections of human emotions. In real life, people can read a person's moods from facial color and expression. Hence, interactive facial colors in game characters provide a deeper level of reality. In this paper we propose a facial color adaptive technique, which is a combination of an emotional model based on human emotion theory, emotional expression pattern using colors of animation contents, and emotional reaction speed function based on human personality theory, as opposed to past methods that expressed emotion through blood flow, pulse, or skin temperature. Experiments show this of expression of the Facial Color Model based on facial color adoptive technique and expression of the animation contents is effective in conveying character emotions. Moreover, the proposed Facial Color Adaptive Technique can be applied not only to 2D games, but to 3D games as well.

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Synthesis and Evaluation of Superhydrophobic ODA/PDMS Dip Coating on PET for Liquid-Solid Contact Electrification (액체-고체 접촉대전을 위한 PET 기판 기반 ODA/PDMS 딥 코팅 제조 및 평가)

  • Park, Sunyoung;Kang, Hyungyu;Byun, Doyoung;Cho, Dae-Hyun
    • Tribology and Lubricants
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    • v.37 no.2
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    • pp.71-76
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    • 2021
  • As opposed to using fossil fuels, we need to use eco-friendly resources such as sunlight, raindrops and wind to produce electricity and combat environmental pollution. A triboelectric nanogenerator (TENG) is a device that converts mechanical energy into electricity by inducing repetitive contact and separation of two dissimilar materials. During the contact and separation processes, electron flow occurs owing to a change in electric potential of the contacting surface caused by contact electrification and electrostatic induction mechanisms. A solid-solid contact TENG is widely known, but it is possible to generate electricity via liquid-solid contact. Therefore, by designing a hydrophobic TENG, we can gather electricity from raindrop energy in a feasible manner. To fabricate the superhydrophobic surface of TENGs, we employ a dip coating technique to synthesize an octadecylamine (ODA)- and polydimethylsiloxane (PDMS)-based coating on polyethylene terephthalate (PET). The synthesized coating exhibits superhydrophobicity with a contact angle greater than 150° and generates a current of 2.2 ㎂/L while water droplets fall onto it continuously. Hence, we prepare a box-type TENG, with the ODA/PDMS coating deposited on the inside, and place a 1.5 mL water droplet into it. Resultantly, we confirm that the induced vibration causes continuous impacts between the ODA/PDMS coating and the water, generating approximately 100 pA for each impact.

The Conversion of Narrative Strategy: from "An Outpost of Progress" to Heart of Darkness (서술 전략의 전환-「진보의 전초기지」에서 『어둠의 핵심』으로)

  • Lee, Man Sik
    • Journal of English Language & Literature
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    • v.57 no.4
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    • pp.625-649
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    • 2011
  • Even though "An Outpost of Progress" and Heart of Darkness were based upon Joseph Conrad the sailor's same experience in Congo Free State, their narrative strategies are quite different. The realistic representation of "An Outpost of Progress," with which Conrad was not satisfied at all, was converted into the modernistic narrative strategy of Heart of Darkness so that the sympathetic power of the story should be improved. The conservative value system of realism is expressed by the omniscient author in "An Outpost of Progress," whereas the frame narrator of Heart of Darkness is proved to be an unreliable one whose norms and behavior are not in accordance with the implied author. The glorious history of the British Empire, which was proudly presented by the frame narrator at the beginning of Heart of Darkness, was strongly opposed by Marlow, another narrator, who said that the British Empire had been "one of the dark places of the earth" when ruled by the Roman Empire. The feeling of the frame narrator was uneasily changed into the gloomy mood when he described the Thames as the flow which "seemed to lead into the heart of an immense darkness" at the end of Heart of Darkness. Similar to the straightforward narrative strategy of representation in "An Outpost of Progress," the realistic approach of Part I in Heart of Darkness is considered by Conrad as insufficient to reveal the darkest truth of imperialism, which was declared by Kurtz as "The Horror! The Horror!" Thus Conrad uses the Chinese-box structure, in which Kurtz' episode is enveloped by Marlow's tale which is enclosed by the frame narrator's story, in order to penetrate into the mind of ordinary readers in the novelist's age of New Colonialism, while attacking the ideology itself of imperialism instead of critisizing its inefficiency and individualism.

A Study on Legal Issues in Telecommunication and Direct Broadcasting by Uses of Artificial Satellites (정보화(情報化) 시대(時代)에서의 통신(通信) 및 방송위성이용(放送衛星利用)에 따르는 법적(法的) 문제(問題) 분석(分析)과 대응방안 연구(硏究))

  • Lee, Young-Jin
    • The Korean Journal of Air & Space Law and Policy
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    • v.9
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    • pp.445-488
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    • 1997
  • In the forthcoming 21st century new technical and scientific developments in outer space demands new approaches towards the problems arising in several fields of the use and exploitation of outer space including practical applications. The main purposes of this study are to analyze the legal problems of geostationary orbital position, telecommunication, direct television broadcasting by uses of artificial satellites. Communication via artificial Earth satellites was one of the first applications of space technology and is now one of the most developed field. From the technical and economic standpoints the advantages of world-wide satellites communication system are too all obvious. However, as the practical uses of space technology become more freguent, the legal conflicts among nations have become more divisive. One of the problem grown in uses of artificial satellites is that of the increasing shortage of suitable orbital slot positions for satellites, especially in geostationary orbit. Legal status of geostationary orbit as a limited resourece have to be reviewed in consideration of the side effect of the "First use, first-served" principle. The geostationary orbit is to be used for the benifits of all mankind and to be guaranteed for each state institutionaly in order to have eguitable access to the use of the orbit. Rapid increase of satellites broadcasting system in not only developed countries but also in developing countries opened up new possibilities with one another's scientific and cultural achievements. But there is also a potential danger that this powerful new instrument of influencing public opinion will be abused. Such a danger incudes spill-over or harmful interference. This controversial issue brings about the question whether prior consent from the receiver nation is needed to broadcast across international boundaries. Some states have rejected prior consent because it interfere with the free flow of information. Many other countries have opposed that opinion as an invasion and violation of sovereignty and as a violation of the 1967 Treaty and the UN Charter. Since declaration of the First Year of Outer Space in 1985, our country have promoted the plan of launching communication and broadcasting satellites. With the Koreasat launched in 1995 as the start, a real satellite-telecommunication era was opened in korea. According to this new development of our country, there will also rise various legal problems related to satellite broadcasting and telecommunication such as the inflow of foreign programs, the permeation of culture and the infringement of program copyright. Consequently the effective reactions to these problems in satellite-communication era should be tried including international cooperation. It is therefore to take into careful consideration the legal issues which may arise in outer space activities and to formulate positive policy on international cooperation with surrounding or advanced countries and international organization concerned. For this purpose the United Nations also prepares the UNISPACE III in 1999, to enable the international community to meet a more promising 21st century.

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Continuous Time Markov Process Model for Nuclide Decay Chain Transport in the Fractured Rock Medium (균열 암반 매질에서의 핵종의 붕괴사슬 이동을 위한 연속시간 마코프 프로세스 모델)

  • Lee, Y.M.;Kang, C.H.;Hahn, P.S.;Park, H.H.;Lee, K.J.
    • Nuclear Engineering and Technology
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    • v.25 no.4
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    • pp.539-547
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    • 1993
  • A stochastic approach using continuous time Markov process is presented to model the one-dimensional nuclide transport in fractured rock media as a further extension for previous works[1-3]. Nuclide transport of decay chain of arbitrary length in the single planar fractured rock media in the vicinity of the radioactive waste repository is modeled using a continuous time Markov process. While most of analytical solutions for nuclide transport of decay chain deal with the limited length of decay chain, do not consider the case of having rock matrix diffusion, and have very complicated solution form, the present model offers rather a simplified solution in the form of expectance and its variance resulted from a stochastic modeling. As another deterministic way, even numerical models of decay chain transport, in most cases, show very complicated procedure to get the solution and large discrepancy for the exact solution as opposed to the stochastic model developed in this study. To demonstrate the use of the present model and to verify the model by comparing with the deterministic model, a specific illustration was made for the transport of a chain of three member in single fractured rock medium with constant groundwater flow rate in the fracture, which ignores the rock matrix diffusion and shows good capability to model the fractured media around the repository.

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Helmholtz Coil and Performance of Magnetic Compass (인공자장발생장치와 자기 컴퍼스의 성능)

  • Ahn, Young-wha;Jeong, Kong-heun;Ahn, Jang-young;Sin, Hyeong-il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.19 no.2
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    • pp.111-116
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    • 1983
  • In order to furnish the fundamental data for the domestic production of magnetic compass and the prescription of standardization about it in Korea, authors made the helmholtz coil and investigated the characteristics of them. Subsequently, the damping curves of T190 and T165 compasses in the helmholtz coil were measured and analyzed the performance of those compass. The results obtained are as follows; 1. The relation between electric current (I sub I) to flow in the helmholtz coils, that the thickness of coil is 1mm, diameter 1m, winding number 117, and intensity of magnetic field is presented as follows. Vertical magnetic force: Z(Gauss)=0.34+1.506 I sub(i) Horizontal magnetic force: H(Gauss)=0.183+1.506 I sub(i) 2. Period of T190 compass is longer than T165 compass in all horizontal magnetic force. In the amplitude, the former is larger than the latter above 0.08 Gauss, but this phenomenon is opposed to that below 0.08 Gauss. 3. As the porizontal magnetic force is intensive, period of magnetic compass is short, amplitude is large, and damping degree and damping factor are small. The time elapsed to the principal points of damping curve is proportional to the -0.65 power of the horizontal magnetic force.

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Comparison of hypertonic saline treatment in meningitis with cerebral edema (뇌수막염에서 발생한 뇌부종 치료에서 고장성 식염수 비교)

  • Kim, Hyung Su;Kim, Hee Ra
    • Clinical and Experimental Pediatrics
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    • v.49 no.12
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    • pp.1275-1281
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    • 2006
  • Purpose : Cerebral edema in meningitis is a potentially complication. Hypertonic saline of various concentrations are frequently used to treat cerebral edemas in meningitis. We analyzed the safety and efficacy of osmotic therapy in cerebral edema by comparison of various hypertonic saline concentrations and mannitol. Methods : The medical records of 42 patients, who were followed up in the Department of Pediatrics, Busan Medical Center, from Jan. 2002 to Oct. 2005, were analyzed retrospectively. We measured intracranial pressure, mean flow velocity, and various laboratory parameters. Results : In cerebral edema developed in meningitis, intracranial pressure and symptoms were improved in treatment of hypertonic saline and mannitol. Serial bolus infusion of 3 percent hypertonic saline resulted in the best outcome. There was not a statistically considerable difference on the mean values of the intracranial pressure gap. On transcranial doppler, mean flow velocity was increased and pulsatilty index was decreased. Laboratory findings (osmolarity, Na, Cl, pH, lactic acid, Ca) were diffenent during the treatment period as opposed to K, Hb, bicarbonate, base excess. There was not a specific form of hypertonic saline used in meningitis treatment with cerebral edema. Conclusion : The therapy for cerebral edema in meningitis remains largely empirical. Serial bolus infusion of 3 percent hypertonic saline is better than other hypertonic salines. Various concentrations and different infusion methods of hypertonic saline statistically does not influence the result of treatment. More research aimed at improving cerebral edema treatment is needed to identify new, effective forms of treatment.