• Title/Summary/Keyword: Tube Length

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Construction of an Underground Heat Exchanger for Pig Housing (양돈용 지열교환기의 개발)

  • ;;H. J. Heege
    • Journal of Animal Environmental Science
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    • v.1 no.2
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    • pp.125-136
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    • 1995
  • To use the earth heat for the pig housing, an underground heat exchanger has constructed in depth of 2.5m and 20m length. The temperature of the outlet air was max. 8 kelvin higher than that of inlet air in winter season. In spite of the -7$^{\circ}C$ outside temperature, it could keep the air temperature from the earth tube above zero degree. The heating performance was maximum in value of 3.25Wh/㎥ and average of 1.75Wh/㎥ by the airflow volume of 340㎥/h. The slope of relative humidity from outlet air has shown gentler than that of inlet air. By using the underground heat exchanger, it would be possible to prepare an relatively uniform relative humidity in the swine stalls. The temperatures on the earth, where PVC pipes are buried, have shown 10~12$^{\circ}C$ on March. This can reduce the difference between day and night temperature during this season by using the underground heat exchanger.

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Fabrication of X-ray monocapillary optics for soft X-ray fluorescence analysis (경 X선 형광분석을 위한 모세관 광학소자 제작)

  • Cho, Hyung-Wook;Park, Byung-Hoon;Kim, Yong-Min;Choi, Chul-Hee;Choi, Seong-Hee;Kim, Ki-Hong;Chon, Kwon-Su
    • Journal of the Korean Society of Radiology
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    • v.5 no.6
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    • pp.409-413
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    • 2011
  • An X-ray tube used an X-ray fluorescence analysis system has a low X-ray photon intensity which results in reducing measurement accuracy and increasing exposure time. These shortages can be overcame by using a monocapillary optics. A monocapillary optics was optimally designed for focusing the characteristic X-ray of tungsten (8.4 keV). The monocapillary optics can achieve a gain of 10 at the least. The monocapillary optics was fabricated by using puller and pyrex glass, raw material. In fabrication, a weigh of 45g and a temperature of $650^{\circ}$ was loaded. The total fabrication time was 460 minutes. The fabricated capillary had 87 mm in length and maximum diameter of 300 ${\mu}m$ and minimum diameter of 192 ${\mu}m$. When the fabricated monocapillary optics is applied to an X-ray fluorescence analysis system, the detection accuracy for soft elements, for example sulfur (S), will be improved.

A Prospective Study for Risk Factors Predicting Postoperative Pulmonary Complications (수술 후 폐 합병증 발생의 위험 인자에 대한 연구)

  • Chon, Su Yeon;Kim, Yu Jin;Kyung, Sun Young;Ahn, Chang Hyeok;Lee, Sang Pyo;Park, Jeong Woong;Jeong, Sung Hwan
    • Tuberculosis and Respiratory Diseases
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    • v.62 no.6
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    • pp.516-522
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    • 2007
  • Background: Postoperative pulmonary complications are important problems that prolong the length of the hospital stay and increase patient mortality. However, our knowledge of the postoperative factors that increase the risk of these complications is less than complete. Methods: We conducted a prospective study to determine the risk factors for postoperative pulmonary complications. A total of 199 patients were referred to the Pulmonology Department for preoperative pulmonary evaluation. We reviewed the perioperative variables according to the National Surgical Quality Improvement Program (NSQIP). Postoperatively, we collected data on the occurrence of postoperative pulmonary complications and we evaluated the relationship between the perioperative variables and outcomes. Results: Twenty two patients (11%) had pulmonary complications; 6 had respiratory failure, 4 had pneumonia, 13 had pleural effusion and, 2 had atelectasis. Five variables were statistically significantly associated with pulmonary complications on the bivariate analyses. Multiple logistic regression analyses revealed that three of these variables were independently associated with an increased risk of pulmonary complications; a high cardiac risk index (OR 16.5, p=0.002), emergency surgery (OR 10.3, p=0.017), and thoracic/abdominal surgery (OR 3.8, p=0.047). Conclusion: The risk factors for postoperative pulmonary complications are a high cardiac risk index, emergency surgery and thoracic/abdominal surgery.

Special quality research about action output waveform change by gap (1.0mm and 1.6mm)difference of skin excessive expense $CO_2$ Laser (피부과용$CO_2$ 레이저의 공극(1.0mm및 1.6mm)차이에 따른 동작출력 파형변화에 관한 특성 연구)

  • Kim, Whi-Young
    • Journal of the Korea Computer Industry Society
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    • v.8 no.2
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    • pp.107-112
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    • 2007
  • Laser wave length can have evaporation effect by absorption because outer skin or tissue of focus is consisted of water almost though absorption of water occurs more than 90% almost in formation thickness of very thin floor. Can operate outer skin, steam by floor and correct incision of formation is available. Suture surgical operation is available to vein or lymph system and surgical operation region can dry and see as eye and radish bleeding surgical operation is available. Specially, stability of tube both end output about pulse by weight very, this research can cause various curative effect because can reduce bulk and control easily current wave style of medical laser using electric power conversion device of high frequency way. If introduce ZVS (Zero Voltage Switching) or ZVZCS (Zero Voltage and Zero Current Switching), is more profitable because can reduce switching damage. Because electric power department of proposed medical laser can do stable soft-switching in wide subordinate extent introducing ZVZCS technique by the first help and control department composes microcontroller, output current waveform user have free form make Result that experiment because design and manufacture, brought result that improve of 20% than existing equipment, and will be bought to get into superior result if supplement as systematic late.

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Evaluation of Fire Resistance of Unprotected Concrete-filled Rectangular Steel Tubular Columns under Axial Loading (재하가열시험에 의한 무내화피복 콘크리트충전 각형강관기둥의 내화성능평가)

  • Ahn, Jae Kwon;Lee, Cheol Ho
    • Journal of Korean Society of Steel Construction
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    • v.26 no.4
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    • pp.323-334
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    • 2014
  • In this paper, experimental program and associated numerical study were carried out to evaluate the fire resistance of unprotected concrete-filled rectangular steel tubular (CFT) columns subjected to the standard fire. The key testing parameters included the length effect, the load ratio, and the sectional dimensions of the CFT columns. Temperature distribution and axial deformation of the CFT column specimens were measured and analyzed. Rather early local buckling of steel tubes was observed in all the specimens. This caused subsequent load transfer from steel tube to concrete, and eventually triggered concrete crushing, or complete loss of the load bearing capacity of the column. This implies that the limit state of local buckling as well as overall flexural buckling should be incorporated in fire design procedure. As expected, the fire resistance time of specimen with higher load ratio consistently lessened. The prediction of fire resistance time of unprotected CFT columns based on the limiting steel temperature in current design codes or the formula proposed by previous studies is slightly conservative compared to the fire test results available. To establish the finite element analysis model that can be used to predict the thermal and structural behaviour of unprotected CFT columns in fire, the fully coupled thermal-stress analysis was also tried by using the commercial code ABAQUS. The numerical results showed a reasonable global correlation with the experimental results.

Needle Decompression for Trauma Patients: Chest Wall Thickness and Size of the Needle (외상 환자에 대한 바늘감압술에서 흉벽 두께와 바늘 길이의 관계)

  • Kim, Jee-Wan;Jeong, Jin-Woo;Cho, Suck-Ju;Yeom, Seok-Ran;Han, Sang-Kyoon;Park, Sung-Wook
    • Journal of Trauma and Injury
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    • v.23 no.2
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    • pp.63-67
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    • 2010
  • Purpose: A tension pneumothorax is a fatal condition that requires immediate intervention. Although a definitive treatment for a tension pneumothorax is a tube thoracostomy, needle decompression can provide temporary relief, that is lifesaving. The traditional procedure for needle decompression involves inserting a needle or catheter at the second intercostal space, the midclavicular line. Recent evidence suggests that the commonly used catheters do not have sufficiently penetrate the chest wall. There are also claims that a lateral approach to needle decompression is easier and safer than the traditional anterior approach. The purpose of this study is to evaluate the optimal approach for needle decompression for the Korean population by measuring chest wall thicknesses at the points used for both the anterior and the lateral approaches. Methods: The chest wall thickness (CWT) of trauma victims who visited the Emergency Center of Pusan National University Hospital was measured by computed tomography (CT) images. The CWT was measured at the points used for the anterior and the lateral methods and was compared with the length of commonly used catheters, which is 45 mm. Results: The mean CWT at the second intercostal space, the midclavicular line, was shorter than the CWT at the 5th intercostal space, the anterior axillary line. However, the percentage of patients whose CWT was greater than 45 mm was larger when measured anteriorly (8.2%) that when measure laterally (5.7%). Female patients and those older than 60 were more likely to have an anterior CWT greater than 45 mm (28.2% for females and 15.5% for those older than 60). Conclusion: The percentage of trauma victims in Korea whose CWT is greater than 45 mm is lower than the values previously reported by other countries. However, females and older patients tend to have thicker chest walls, so the lateral approach would be suggested when performing needle decompression for such patients with suspected tension pneumothoraces.

Evaluation of Neutron Flux Distributions of SMART-P IST Region for the Design of Ex-Core Detector (SMART 연구로 노외계측기 설계를 위한 IST 영역의 중성자속 분포 평가)

  • Koo, Bon-Seung;Kim, Kyo-Youn;Lee, Chung-Chan;Zee, Sung-Quun
    • Journal of Radiation Protection and Research
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    • v.30 no.2
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    • pp.55-60
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    • 2005
  • The evaluation of neutron flux distribution was performed for the ex-core detector design of SMART-P. DORT and MCNP code were used for the calculation of energy-dependent neutron flux distribution at 100% full power condition. Two code results show that maximum thermal flux appears at the $1^{st}$ water region in IST region and agree within 10% difference. In addition, another evaluation was performed code with assumptions that cote was composed of fission source and control rod without fuel assemblies. These assumptions make neutron count rate to be minimized. As a results, maximum thermal flux showed $6.99{\times}10^{-2}(n/cm^2-sec)$, when the strength of initial fission source was assumed as $1.0{\times}10^8(n/sec)$. The main reason of these results is due to the thermalization of fast neutrons in the water region and thermal flux is proportional to 80% of total neutron flux. Therefore, optimization of filler material of detector guide tube, position of installation and axial length of detector segments is necessary for the design of ex-core detector to enhance the neutron count rate and above results could be used in ex-core detector design as a fluence requirement.

The Cross Ability and the Phenotypic Characteristics of F1 Hybrid in the Interspecific Crosses between Brassica napus and B. campestris, B. rapa (Brassica 속 식물 내 종간교잡에 따른 교잡효율 및 F1잡종의 표현형질)

  • Kim, Kwang-Soo;Lee, Yong-Hwa;Jang, Young-Seok;Choi, In-Hu
    • Korean Journal of Plant Resources
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    • v.28 no.1
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    • pp.119-125
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    • 2015
  • Interspecific crosses between rapeseed (Brassica napus L.) and chinese cabbage (B. campestris var. pekinensis Makino) and turnip (B. rapa L.) were made in order to examine the cross possibility and morphological phenotype of $F_1$ hybrid. The growth of pollen tube of cross between rapeseed and chinese cabbage was more rapid than cross between rapeseed and turnip. Silique formation and seed setting in silique were relatively high in the cross between rapeseed and chinese cabbage. The percentage of silique set from interspecific cross between rapeseed and chinese cabbage was 90.6% and higher 23.3% than the percentage of silique from interspecific cross rapeseed and turnip. The average number of seed per silique obtained from the cross rapeseed and chinese cabbage, and rapeseed and turnip reached 15.5 and 11.6, respectively. The morphological phenotypes of $F_1$ hybrid plants obtained from seeds in the cross between rapeseed and chinese cabbage resembled rapeseed mainly, but leaf length and leaf width were increased. The size, shape and lobation of leaves of $F_1$ hybrid plants from interspecific cross between rapeseed and turnip were intermediated between their parent species, but color of leaves was dark-green.

EXPERIMENTAL STUDY OF PERIPHERAL NERVE REGENERATION BY USING NON-TUBULAR NATURAL CELLULOSE MEMBRANE NERVE CONDUIT (비관형 천연 셀룰로오스막 도관을 이용한 말초신경 재생에 대한 실험적 연구)

  • Kim, Soung-Min;Lee, Jong-Ho;Lee, Suk-Keun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.32 no.4
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    • pp.295-307
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    • 2006
  • Styela clava, called non-native tunicate or sea squirt, is habitat which include bays and harbors in Korea and several sites in the sea faced world. We fabricate cellulose membrane nerve conduit (CMNC) from this native sea squirt skin, and evaluate the capacity of promoting peripheral nerve regeneration in the rat sciatic nerve defect model. After processing the pure cellulose membrane from the sea squirt skin as we already published before, CMNC was designed as a non-tubular sheet with 14 mm length and 4 mm width. Total eleven male Spraque-Dawley rats (12 weeks, weighing 250 to 300g) were divided into sham group (n=2), silicone tube grafted control group (n=3) and experimental group (n=6). Each CMNC grafted nerve was evaluated after 4, 8 and 12 weeks in the experimental group, and after 12 weeks, sciatic function was evaluated with sciatic function index (SFI) and gait analysis, and histomorphology of nerve conduit and the innervated tissues of sciatic nerve were all examined using image analyzer and electromicroscopic methods in the all groups. The regenerated axon and nerve sheath were found only in the inner surface of the CMNC after 4 weeks and became more thicker after 8 and 12 weeks. In the TEM study, CMNC grafted group showed more abundant organized myelinated nerve fibers with thickened extracellular matrix than silicone conduit grafted group after 12 weeks. The sciatic function index (SFI) and ankle stance angle (ASA) in the functional evaluation were $-47.2{\pm}3.9$, $35.5^{\circ}{\pm}4.9^{\circ}$ in CMNC grafted group (n=2) and $-80.4{\pm}7.4$, $29.2^{\circ}{\pm}5.3^{\circ}$ in silicone conduit grafted group (n=3), respectively. And the myelinated axon was 41.59% in CMNC group and 9.51% in silicone conduit group to the sham group. The development of a bioactive CMNC to replace autogenous nerve grafts offers a potential and available approach to improved peripheral nerve regeneration. As we already published before, small peptide fragment derived from the basement membrane matrix proteins of squirt skin, which is a kind of anchoring protein composed of glycocalyx, induced the effective axonal regeneration with rapid growth of Schwann cells beneath the inner surface of CMNC. So the possibilities of clinical application as a peripheral nerve regeneration will be able to be suggested.

Development of FURA Code and Application for Load Follow Operation (FURA 코드 개발과 부하 추종 운전에 대한 적용)

  • Park, Young-Seob;Lee, Byong-Whi
    • Nuclear Engineering and Technology
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    • v.20 no.2
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    • pp.88-104
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    • 1988
  • The FUel Rod Analysis(FURA) code is developed using two-dimensional finite element methods for axisymmetric and plane stress analysis of fuel rod. It predicts the thermal and mechanical behavior of fuel rod during normal and load follow operations. To evaluate the exact temperature distribution and the inner gas pressure, the radial deformation of pellet and clad, the fission gas release are considered over the full-length of fuel rod. The thermal element equation is derived using Galerkin's techniques. The displacement element equation is derived using the principle of virtual works. The mechanical analysis can accommodate various components of strain: elastic, plastic, creep and thermal strain as well as strain due to swelling, relocation and densification. The 4-node quadratic isoparametric elements are adopted, and the geometric model is confined to a half-pellet-height region with the assumption that pellet-pellet interaction is symmetrical. The pellet cracking and crack healing, pellet-cladding interaction are modelled. The Newton-Raphson iteration with an implicit algorithm is applied to perform the analysis of non-linear material behavior accurately and stably. The pellet and cladding model has been compared with both analytical solutions and experimental results. The observed and predicted results are in good agreement. The general behavior of fuel rod is calculated by axisymmetric system and the cladding behavior against radial crack is used by plane stress system. The sensitivity of strain aging of PWR fuel cladding tube due to load following is evaluated in terms of linear power, load cycle frequency and amplitude.

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