• Title/Summary/Keyword: Shock Process

Search Result 574, Processing Time 0.033 seconds

The Flight Model of the NISS onboard NEXTSat-1

  • Jeong, Woong-Seob;Park, Sung-Joon;Moon, Bongkon;Lee, Dae-Hee;Pyo, Jeonghyun;Park, Won-Kee;Kim, Il-Joong;Park, Youngsik;Lee, Duk-Hang;Ko, Kyeongyeon;Kim, Mingyu;Nam, Ukwon;Kim, Minjin;Ko, Jongwan;Im, Myungshin;Lee, Hyung Mok;Lee, Jeong-Eun;Shin, Goo-Hwan;Chae, Jangsoo;Matsumoto, Toshio
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.41 no.2
    • /
    • pp.64.3-65
    • /
    • 2016
  • The NISS (Near-infrared Imaging Spectrometer for Star formation history) is the near-infrared instrument optimized to the Next Generation of small satellite series (NEXTSat). The capability of both imaging and low spectral resolution spectroscopy in the near-infrared range is a unique function of the NISS. The major scientific mission is to study the cosmic star formation history in local and distant universe. For those purposes, the main observational targets are nearby galaxies, galaxy clusters, star-forming regions and low background regions. The off-axis optical design is optimized to have a wide field of view ($2deg.{\times}2deg.$) as well as the wide wavelength range from 0.95 to $3.8{\mu}m$. Two linear variable filters are used to realize the imaging spectroscopy with the spectral resolution of ~20. The mechanical structure is considered to endure the launching condition as well as the space environment. The compact dewar is confirmed to operate the infrared detector as well as filters at 80K stage. The electronics is tested to obtain and process the signal from infrared sensor and to communicate with the satellite. After the test and calibration of the engineering qualification model (EQM), the flight model of the NSS is assembled and integrated into the satellite. To verify operations of the satellite in space, the space environment tests such as the vibration, shock and thermal-vacuum test were performed. Here, we report the test results of the flight model of the NISS.

  • PDF

A Level-set Parameterization for Any 3D Complex Interface Related to a Fire Spread in Building Structures (복잡한 CAD 형상의 매개변수화를 통한 3차원 경계면 레벨-셋 알고리즘 개발 및 적용)

  • Kim, Hyun-Jun;Cho, Soo-Yeong;Lee, Young-hun;Yoh, Jai-ick
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.48 no.2
    • /
    • pp.135-146
    • /
    • 2020
  • To define an interface in a conventional level-set method, an analytical function must be revealed for an interfacial geometry. However, it is not always possible to define a functional form of level sets when interfaces become complex in a Cartesian coordinate system. To overcome this difficulty, we have developed a new level-set formalism that discriminates the interior from the exterior of a CAD modeled interface by parameterizing the stereolithography (STL) file format. The work outlined here confirms the accuracy and scalability of the hydrodynamic reactive solver that utilizes the new level set concept through a series of tests. In particular, the complex interaction between shock and geometrical confinements towards deflagration-to-detonation transition is numerically investigated. Also, a process of flame spreading and damages caused by point source detonation in a real-sized plant facility have been simulated to confirm the validity of the new method built for reactive hydrodynamic simulation in any complex three-dimensional geometries.

해상풍속측정용 마스트의 충격해석에 관한 연구

  • Lee, Gang-Su;Kim, Man-Eung;Son, Chung-Ryeol
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2009.04a
    • /
    • pp.108-108
    • /
    • 2009
  • The main object of this research is to minimize the shock effects which frequently result in fatal damage in wind met mast on impact of barge. The collision between wind met mast and barge is generally a complex problem and it is often not practical to perform rigorous finite element analyses to include all effects and sequences during the collision. LS-dyna generally purpose explicit finite element code, which is a product of ANSYS software, is used to model and analyze the non-linear response of the met mast due to barge collision. A significant part of the collision energy is dissipated as strain energy and except for global deformation modes, the contribution from elastic straining can normally be neglected. On applying impact force of a barge to wind met mast, the maximum acceleration, internal energy and plastic strain were calculated for each load cases using the finite element method and then compare it, varying to the velocity of barge, with one varying to the thickness of rubber fender conditions. Hence, we restrict the present research mainly to the wind met mast and also parametric study has been carried out with various velocities of barge, thickness of wind met mast, thickness and Mooney-Rivlin coefficient of rubber fender with experimental data. The equation of motion of the wind met mast is derived under the assumption that it was ignored vertical movement effect of barge on sea water. Such an analyzing method which was developed so far, make it possible to determine the proper size and material properties of rubber fender and the optimal moving conditions of barge, and finally, application method can be suggested in designing process of rubber fender considering barge impact.

  • PDF

Disseminated Intravascular Coagulation in Experimental Fowl Cholera of Chickens (닭의 가금(家禽) 콜레라 감염시(感染時)의 파종성(播種性) 혈관내(血管內) 응고증(凝固症))

  • Park, Nam-Yong
    • Korean Journal of Veterinary Research
    • /
    • v.22 no.2
    • /
    • pp.211-219
    • /
    • 1982
  • Chickens from 10 to 32 weeks of age were inoculated with P. multocida via seven routs(intravenous, intramuscular, intraperitoneal, subcutaneous, into ear, intranasal, per oral). The development or distribution of disseminated intravascular coagulation (DIC) in multiple organs and the role of P. multocida endotoxins in disease process of fowl cholera were studied. The histological diagnosis of DIC was made by demonstration of fibrinous in arterioles, capillaries, venules and medium-sized blood vessels. The presence of fibrinous thrombi in blood vessels of multiple organs was observed in chickens which died within approximately 3 days post inoculation. Fibrinous thrombi were observed most frequently in the lung(90% of all cases with DIC) followed by liver (70%), kidney (60%), heart(20%), spleen, brain, pancreas, thymus and thyroid gland. The density of fibrinous thrombi (i.e. the number of thrombi per section) was greatest in the lung, followed by spleen, kidney, liver and heart. It is thought that the widespread hemorrhage of acute fowl cholera is also caused by P. multocida endotoxin which initiates DIC in variety of organs. The cause of death for the chickens after infection with acute fowl cholera is probably due to an endotoxin (septic) shock accompanied with DIC in multiple organs.

  • PDF

A Study on the Children's Adaptation in the Foster Care : An Approach based on Grounded Theory (일반위탁가정 아동의 적응에 대한 연구: 근거이론적 접근)

  • Kim, Jin-Sook;Lee, Hyuk-Koo
    • Korean Journal of Social Welfare
    • /
    • v.59 no.1
    • /
    • pp.87-116
    • /
    • 2007
  • The purpose of this study is to identify the adaptation experience of foster children. This qualitative research was conducted through in-depth interview of 8 foster children in and over 4th grade. In data analysis of this qualitative study, the grounded theory suggested by Strauss and Corbin(1998) was used. The raw data collected from in-depth interview with the participants were analyzed in open coding, through theoretically sensitive and constant comparisons method. As a result, total 11 categories, 30 subcategories and 96 concepts were generated. In summary, the casual condition that caused the core phenomenon was 'family stability collapse'. The core phenomenon that foster children experience during the process of adaptation was 'marginalization'. The contextual condition that affected the outcome was 'cultural shock' and 'loyalty conflict.' The intervening condition that promote or restrain the action/interaction on core phenomenon were, 'support system', 'resilience menifestation', 'negative predestination'. The action/interaction strategy on core phenomenon were 'will to power' and 'pursuing moral superiority'. As a result, two concepts, 'mechanical adaptation to foster care environment' and 'active formation' of foster care environment' were assumed.

  • PDF

Development of the Standard Model of a Stated Period Check and Precise Safety Diagnosis in the Research Lab for Prevention to Electrical Accidents (전기사고방지를 위한 연구실험실 정기점검/정밀안전진단 표준모델개발)

  • Lee, Dong-Yoon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.12 no.2
    • /
    • pp.858-864
    • /
    • 2011
  • There is no standard model for a Stated Period Check and a Precise Safety Diagnosis to remove electric fire and shock in the university Lab and institute. Especially, the research for the Stated Period Check and the Precise Safety Diagnosis of the Lab related to electrical field is very weak currently, and it is very necessary to build a detail safety plan. This paper informs the specific standard guideline of the safety check list, method and equipment and it shows the way to evaluate safety grade too. This paper also provides the information of R&D process through the analysis of electrical safety check list of ordinary R&D Lab. It shows a new detail guideline to R&D Lab, and the new guideline removes existing problem and deliver the effective standard model to each R&D Lab. The standard model developed in this research adopts the clear guideline of each check list for the electrical environment of current R&D Lab. This standard model can be applied for every R&D Lab to detect routine safety check and detail safety check immediately. This Research will generally improve not only the effective safety check, but also the safety level for R&D Lab to prevent the electrical accidents.

Accelerated Growth of Corynebacterium glutamicum by Up-Regulating Stress-Responsive Genes Based on Transcriptome Analysis of a Fast-Doubling Evolved Strain

  • Park, Jihoon;Lee, SuRin;Lee, Min Ju;Park, Kyunghoon;Lee, Seungki;Kim, Jihyun F.;Kim, Pil
    • Journal of Microbiology and Biotechnology
    • /
    • v.30 no.9
    • /
    • pp.1420-1429
    • /
    • 2020
  • Corynebacterium glutamicum, an important industrial strain, has a relatively slower reproduction rate. To acquire a growth-boosted C. glutamicum, a descendant strain was isolated from a continuous culture after 600 generations. The isolated descendant C. glutamicum, JH41 strain, was able to double 58% faster (td=1.15 h) than the parental type strain (PT, td=1.82 h). To understand the factors boosting reproduction, the transcriptomes of JH41 and PT strains were compared. The mRNAs involved in respiration and TCA cycle were upregulated. The intracellular ATP of the JH41 strain was 50% greater than the PT strain. The upregulation of NCgl1610 operon (a putative dyp-type heme peroxidase, a putative copper chaperone, and a putative copper importer) that presumed to role in the assembly and redox control of cytochrome c oxidase was found in the JH41 transcriptome. Plasmid-driven expression of the operon enabled the PT strain to double 19% faster (td=1.82 h) than its control (td=2.17 h) with 14% greater activity of cytochrome c oxidase and 27% greater intracellular ATP under the oxidative stress conditions. Upregulations of genes those might enhance translation fitness were also found in the JH41 transcriptome. Plasmid-driven expressions of NCgl0171 (encoding a cold-shock protein) and NCgl2435 (encoding a putative peptidyl-tRNA hydrolase) enabled the PT to double 22% and 32% faster than its control, respectively (empty vector: td=1.93 h, CspA: td=1.58 h, and Pth: td=1.44 h). Based on the results, the factors boosting growth rate in C. gluctamicum were further discussed in the viewpoints of cellular energy state, oxidative stress management, and translation.

A Study on the Thermal Shock Resistance of Sintered Zirconia for Electron Beam Deposition (전자빔 증착을 위한 소결체 지르코니아의 열충격 저항성 연구)

  • Oh, Yoonsuk;Han, Yoonsoo;Chae, Jungmin;Kim, Seongwon;Lee, Sungmin;Kim, Hyungtae;Ahn, Jongkee;Kim, Taehyung;Kim, Donghoon
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.19 no.3
    • /
    • pp.83-88
    • /
    • 2015
  • Coating materials used in the electron beam (EB) deposition method, which is being studied as one of the fabrication methods of thermal barrier coating, are exposed to high power electron beam at focused area during the EB deposition. Therefore the coating source for EB process is needed to form as ingot with appropriate density and microstructure to sustain their shape and stable melts status during EB deposition. In this study, we tried to find the optimum powder condition for fabrication of ingot of 8 wt% yttria stabilized zirconia which can be used for EB irradiation. It seems that the ingot, which is fabricated through bi-modal type initial powder mixture which consists of tens of micro and nano size particles, was shown better performance than the ingot which is fabricated using monolithic nanoscale powder when exposed to high power EB.

A Study on Vibration & Noise Reduction of Fast Back Feeding Device for Manufacturing Process (제조공정용 Fast Back 이송장치 진동·소음 저감에 관한 연구)

  • Han, Doo-Hee;Lee, Seung-Hun;Son, Yung-Deug
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.8
    • /
    • pp.642-648
    • /
    • 2019
  • This paper presents a fast back-type transfer device for snack food processing that uses the inertia of transferred material. A conventional conveying system is a drive system that uses a belt conveyor and mechanical crank, which generate noise and vibration and cause environmental pollution. Vibration and noise are reduced in the proposed fast back feeding device by using a counterweight. The crank drive unit was replaced with a linear servomotor, and an equilibrium device was designed to balance the force due to acceleration. This makes it is possible to adjust the forward and backward speed and acceleration through PLC control. A vibration damper device offsets the vibration force of the periodic shock form. The main cause of the vibration was identified through vibration analysis, and reduction measures were established. We verified the effectiveness of the vibration by making a prototype and performing about 10 vibration tests. Because no mechanical transducer is needed, energy loss, noise, and vibration do not occur, and the operating speed is not limited.

Integrative analysis of cellular responses of Pseudomonas sp. HK-6 to explosive RDX using its xenA knockout mutant (Pseudomonas sp. HK-6의 xenA 돌연변이체를 이용하여 RDX 폭약에 노출된 세포반응들의 통합적 분석)

  • Lee, Bheong-Uk;Choi, Moon-Seop;Seok, Ji-Won;Oh, Kye-Heon
    • Korean Journal of Microbiology
    • /
    • v.54 no.4
    • /
    • pp.343-353
    • /
    • 2018
  • Our previous research demonstrated the essential role of the xenB gene in stress response to RDX by using Pseudomonas sp. HK-6 xenB knockout. We have extended this work to examine the cellular responses and altered proteomic profiles of the HK-6 xenA knockout mutant under RDX stress. The xenA mutant degraded RDX about 2-fold more slowly and its growth and survival rates were several-fold lower than the wild-type HK-6 strain. SEM revealed more severe morphological damages on the surface of the xenA mutant cells under RDX stress. The wild-type cells expressed proportionally-increased two stress shock proteins, DnaK and GroEL from the initial incubation time point or the relatively low RDX concentrations, but slightly less expressed at prolonged incubation period or higher RDX. However the xenA mutant did not produced DnaK and GroEL as RDX concentrations were gradually increased. The wild-type cells well maintained transcription levels of dnaA and groEL under increased RDX stress while those in the xenA mutant were decreased and eventually disappeared. The altered proteome profiles of xenA mutant cells under RDX stress also observed so that the 27 down-regulated plus the 3 up-regulated expression proteins were detected in 2-DE PAGE. These all results indicated that the intact xenA gene is necessary for maintaining cell integrity under the xenobiotic stress as well as performing an efficient RDX degradation process.