• Title/Summary/Keyword: failure pressure

Search Result 1,655, Processing Time 0.032 seconds

Eleutheroside E Content in Eleutherococcus spp. (오갈피속(屬) 식물(植物)의 Eleutheroside E 함양(含量))

  • Kim, Young-Jin;Park, Moon-Soo;Park, Ho-Ki;Kim, Sun;Sung, Chung-Ki
    • Korean Journal of Medicinal Crop Science
    • /
    • v.4 no.4
    • /
    • pp.333-339
    • /
    • 1996
  • The root and stem bark of Eleutherococcus spp. is used for the treatment of paralysis, rheumatism, arthritis, diabetes, stamina failure, high blood pressure, etc. This study was con­ducted to identify botanical origins and to select standard variety of Eleutherococcus spp. with analyzing eleutheroside E content(%) of root bark and that of Eleutherococcus senticosus at different collected area, time, part and grown area. The content of eleutheroside E in the root bark was determined by HPLC, and it was 0.1925% in Eleutherococcus senticosus, 0.1103% in E. chiisanensis, 0.0348% in E. koreanum and 0.0236% in E. sieboldianum. In seasonal change of eleutheroside E content, it was higher in autumn product than summer product in Eleutherococcus senticosus. It also was higher in root bark than stem bark in different part. To investigate eleutheroside E content of root bark among different collected local area in E. sen­ticosus, it was high order to Mt. Deokyu, Hokkaido and Mt. Seolak as a 0.1625%. 0.0493% and 0.027 %, respectively. The growth of Eleutherococcus senticosus was good at grown Unbong (altitude 10m), but eleu­theroside E content was high at grown Nogodan (altitude 1, 450m).

  • PDF

Continuum Based Plasticity Models for Cubic Symmetry Lattice Materials Under Multi-Surface Loading (다중면 하중하에 정방향 대층구조를 가진 격자재료의 연속적인 소성모델)

  • Seon, Woo-Hyun;Hu, Jong-Wan
    • Journal of the Korean Society for Advanced Composite Structures
    • /
    • v.2 no.3
    • /
    • pp.1-11
    • /
    • 2011
  • The typical truss-lattice material successively packed by repeated cubic symmetric unit cells consists of sub-elements (SE) proposed in this study. The representative continuum model for this truss-lattice material such as the effective strain and stress relationship can be formulated by the homogenization procedure based on the notation of averaged mechanical properties. The volume fractions of micro-scale struts have a significant influence on the effective strength as well as the relative density in the lattice plate with replicable unit cell structures. Most of the strength contribution in the lattice material is induced by axial stiffness under uniform stretching or compression responses. Therefore, continuum based constitutive models composed of homogenized member stiffness include these mechanical characteristics with respect to strength, internal stress state, material density based on the volume fraction and even failure modes. It can be also recognized that the stress state of micro-scale struts is directly associated with the continuum constitutive model. The plastic flow at the micro-scale stress can extend the envelope of the analytical stress function on the surface of macro-scale stress derived from homogenized constitutive equations. The main focus of this study is to investigate the basic topology of unit cell structures with the cubic symmetric system and to formulate the plastic models to predict pressure dependent macro-scale stress surface functions.

A Case of Mitochondrial Myopathy Showing Severe Hypoxemia during REM Sleep (렘수면중 심한 저산소혈증을 보인 사립체근병증 1례)

  • Kim, Ju-Sang;Kim, Sung-Kyung;Lee, Sang-Haak;Ahn, Joong-Hyun;Kim, Chi-Hong;Moon, Hwa-Sik
    • Sleep Medicine and Psychophysiology
    • /
    • v.14 no.1
    • /
    • pp.49-53
    • /
    • 2007
  • Mitochondrial myopathy is characterized by variable clinical manifestations from mild limb weakness to fatal respiratory failure and central nervous system sequela. But it is a rare event that sleep disordered breathing become a clue of diagnosis for mitochondrial myopathy. We report a case of a 21 year-old man who was diagnosed as mitochondrial myopathy during the investigation for the possible cause of chronic hypoventilation syndrome. Before being admitted to our hospital, he was suspected as having sleep apnea syndrome in another hospital. We re-evaluated the history, physical examination, laboratoy findings and polysomnography in detail. Severe hypoxemia was noted during REM sleep on nocturnal polysomnography and the diagnosis of mitochondrial myopathy was made by muscle biopsy in rectus abdominis muscle. We treated him with bilevel positive airway pressure therapy during sleep and it could reverse the hypoxemia during REM sleep. He could be discharged with improved condition and is being well with the use of this ventilatory assistance.

  • PDF

A Case of Primary Pulmonary Hypertension in Pregnancy Presented as Massive Hemoptysis (임신 중 대량객혈로 발현된 원발성 폐고혈압 1예)

  • Kim, Myung Sook;Kim, Hyoung Doo;Kim, Seok Chan;Kwan, Soon Suk;Kim, Young Kyoon;Kim, Kwan Hyoung;Moon, Hwa Sik;Song, Jeong Sup;Park, Sung Hak
    • Tuberculosis and Respiratory Diseases
    • /
    • v.57 no.1
    • /
    • pp.66-71
    • /
    • 2004
  • Primary pulmonary hypertension (PPH) is a rare, progressive and incurable disease, which is characterized by an increase in the pulmonary artery pressure without a demonstrable cause. The most common presenting symptom is dyspnea on exertion, with other symptoms comprising of chest pain, syncope and hemoptysis. The diagnosis is one of exclusion of any of the known causes of pulmonary hypertension. When associated with pregnancy, the maternal mortality ranges from 30 to 50%. Because pregnancy and labor are very serious problems for patients with PPH, the available evidence suggests that pregnancy when afflicted with PPH should be avoided. In account the case of a 33-year old patient, reporting with massive hemoptysis, and diagnosed with PPH during her twenty seventh week of gestation, is presented. She was treated with conservative management, including oxygen and a vasodilator, and underwent a pregnancy termination. However, due to aggravation of right heart failure, she presented with severe systemic hypotension and hypoxemia, and eventually died. This case is reported, with brief review of the literature.

FE Analysis on the Screwed Safety of a Valve for a LPG Bombe (LPG 용기용 밸브의 체결안전성에 관한 유한요소해석)

  • Kim, Chung-Kyun;Oh, Kyong-Seok
    • Journal of the Korean Institute of Gas
    • /
    • v.11 no.4
    • /
    • pp.79-84
    • /
    • 2007
  • In this paper, the finite element analysis of a valve screw for a LPG cylinder has been presented on the leakage safety and strength one, which are computed and investigated by a contact normal stress and von Mises stress between a female screw of a valve and a male screw of a neck ring in a LPG bombe. The LP gas charging pressure of a LPG bombe is $8{\sim}9kg/cm^2$, which is pressurized to the screw sealing contact areas between a valve and a LP gas cylinder. The peak failures of the screw tooth height due to a scratch wear and chipping loss of the contact area may decrease screw tooth strength and increase a leakage of a LP gas. These are strongly affect to the contact normal and von Mises stresses of the valve screws. The FEM computed results show that the tooth height loss due to a wear and chipping failure of the screw peak does not affect to the LP gas leak and strength of a valve screw theoretically. But if the tooth wear of the screw height of a brass valve overpasses the critical strength safety of the valve, the valve screw may be failed in fastening the valve and a LP gas bombe suddenly.

  • PDF

Evaluation on Stress-Strain-Strength Behavior of the Textile Encased Soils via Triaxial Compression Tests (삼축압축시험을 통한 섬유로 구속된 흙의 응력-변형률-강도 거동 평가)

  • Yoo, Wan-Kyu;Kim, Byoung-Il;Cho, Wanjei
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.33 no.2
    • /
    • pp.643-653
    • /
    • 2013
  • Recently, there are an increasing number of studies on the method of wrapping the outer wall of granular piles with geosynthetic fibers such as geotextile or geogrid that has a certain level of tensile strength as an alternative method for the ground improvement techniques. In this study, triaxial compression tests are performed on the sand and clay specimen encased with various textiles to evaluate the reinforcing effect with regard to the tensile strength of the textile. Furthermore, triaxial compression tests are performed on the clay specimen inserted by sand only and sand encased with geosynthetics to compare behavioral differences between the conventional sand compaction pile and geosynthetic encased sand pile with regard to the replacement ratio, ${\alpha}_s$ and the tensile strength of the geosynthetics. Based on the experimental results, the strength enhancement due to the textile is affected by the longitudinal tensile strength rather than the transverse one of the applied textile. The effect of the confinement by the textile encasement results in the large increase of the cohesions. The overall behaviors, such as shear strength, pore pressure parameter at failure and stress ratio, of the geosynthetic encased sand pile is quite different from those of the conventional sand compaction pile.

The clinical study for the postoperative tracheal stenosis (수술후성 기관협착증에 관한 임사적 고찰)

  • 김기령;홍원표;이정권
    • Proceedings of the KOR-BRONCHOESO Conference
    • /
    • 1977.06a
    • /
    • pp.9.1-10
    • /
    • 1977
  • Many etiological factors playa significant role in the development of tracheal stenosis; too high tracheostomy (Jackson, 1921), too small stoma (Greisen, 1966), the treatment with respirator using cuffed tube (Pearson et al., 1968; Lindholm, 1966; Bryce, 1972) and infection (Pearson, 1968). Although the incidence has been reduced due to development of surgical technique and antibiotics, the frequency of tracheal stenosis which produces symptoms after tracheostomy ranges from 1.5 per cent (Lindholm, 1967). In the management of the stenosis, mild cases are treated by mechanical dilatation with silicon tube or stent (Schmigelow, 1929; Montgomery, 1965) combined steroid (Birck, 1970), and in the cases of stenosis causes, these removed under the are bronchoscopy. But in severe stenosis, transverse resection with subsequent end-to-end anastomosis has been used in recent years (Pearson et al., 1968). During about 10 years, 1967 to 1977, a total of 23 patients with tracheal stenosis complicated among the 1, 514 tracheostomies have been treated in Severance Hospital. Now, we have obtained following conclusions by means of clinical analysis of 23 cases of tracheal stenosis. 1. The frequency of tracheal stenosis was 23 cases among 1, 514 cases of tracheostomy (1.5%). 2. Under the age of 5, these are 12 cases (52.2 %). 3. The sex incidence was comprised of 18 males and 5 females. 4. The duration of tracheostomy ranges from 4 days to 16 months. 5. The primary diseases requiring tracheostomy were following; central nerve system lesions 11 cases, upper air way obstruction 10 cases, extrinsic respiratory failure 2 cases. 6. Severe wound infections were only 2 cases. 7. The methods of treatment applied to tracheal stenosis were following; closed observation only 5 cases, nasotracheal intubation combined steroid 5 cases, T-tube stent combined steroid 3 cases, fenestration op. 4 cases, revision 4 cases and transverse resection and end-to-end anastomosis 2 cases.

  • PDF

Reference Ranges of Microalbumin Using Fasting Urine (Fasting Urine을 사용한 Microalbumin의 참고치에 관한 연구)

  • Kim, Ji-Young;Jin, Kwang-Ho;Bae, Ae-Young;Kim, Ye-Na;Seo, Sang-Won;Lee, Na-Ree;Jeon, Ha-Young;Shin, Sook-Hee
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.38 no.3
    • /
    • pp.208-211
    • /
    • 2006
  • Microalbuminuria is most frequently caused by kidney damage from diabetes. Moreover, many other conditions can lead to kidney damage, such as high blood pressure, heart failure, cirrhosis, or systemic lupus erythematosus (SLE). The measurement of the microalbumin in urine may be useful for the early diagnosis or as a predictor of nephropathy in diabetes. The most common method for getting a quantitative measurement of urinary protein relies on a 24-hour urine collection. The result of this method is accurate. But 24hr urine collection is difficult to obtain and variations in volume are frequent. Also the patients complain about urine collection. We tried to measure reference values for microalbumin using fasting urine and compare them with the albumin/creatinine ratio using 24hr urine. The concentrations of microalbumin in fasting urine and 24hr urine were $7.1{\pm}3.8mg/L$, $5.7{\pm}2.9mg/L$ (r=0.61, p=0.27), respectively. The albumin/creatinine ratios using fasting urine and 24hr urine were $8.7{\pm}4.2{\mu}g/mg$, $8.7{\pm}4.0{\mu}g/mg$ (r=0.76, p=0.88), respectively. This study indicated that the measurement of microalbumin in fasting urine was an easy and simple method for early diagnosis or to predict nephropathy in diabetes. Thus, setting up the reference value using fasting urine may be useful in the screening test for the diabetic nephropathy patients instead of using the 24hr albumin excretion rate (AER).

  • PDF

GEOTECHNICAL DESIGNS OF THE SHIP IMPACT PROTECTION SYSTEM FOR INCHEON BRIDGE

  • Choi, Sung-Min;Oh, Seung-Tak;Park, Sang-Il;Kim, Sung-Hwan
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2010.09c
    • /
    • pp.72-77
    • /
    • 2010
  • The Incheon Bridge, which was opened to the traffic in October 2009, is an 18.4 km long sea-crossing bridge connecting the Incheon International Airport with the expressway networks around the Seoul metropolitan area by way of Songdo District of Incheon City. This bridge is an integration of several special featured bridges and the major part of the bridge consists of cable-stayed spans. This marine cable-stayed bridge has a main span of 800 m wide to cross the vessel navigation channel in and out of the Incheon Port. In waterways where ship collision is anticipated, bridges shall be designed to resist ship impact forces, and/or, adequately protected by ship impact protection (SIP) systems. For the Incheon Bridge, large diameter circular dolphins as SIP were made at 44 locations of the both side of the main span around the piers of the cable-stayed bridge span. This world's largest dolphin-type SIP system protects the bridge against the collision with 100,000 DWT tanker navigating the channel with speed of 10 knots. Diameter of the dolphin is up to 25 m. Vessel collision risk was assessed by probability based analysis with AASHTO Method-II. The annual frequency of bridge collapse through the risk analysis for 71,370 cases of the impact scenario was less than $0.5{\times}10^{-4}$ and satisfies design requirements. The dolphin is the circular sheet pile structure filled with crushed rock and closed at the top with a robust concrete cap. The structural design was performed with numerical analyses of which constitutional model was verified by the physical model experiment using the geo-centrifugal testing equipment. 3D non-linear finite element models were used to analyze the structural response and energy-dissipating capability of dolphins which were deeply embedded in the seabed. The dolphin structure secures external stability and internal stability for ordinary loads such as wave and current pressure. Considering failure mechanism, stability assessment was performed for the strength limit state and service limit state of the dolphins. The friction angle of the crushed stone as a filling material was reduced to $38^{\circ}$ considering the possibility of contracting behavior as the impact.

  • PDF

Shear Strength Characteristics of Artificial Soil Mixture with Pond Ash (매립석탄회가 혼합된 인공혼합토의 전단특성)

  • Kim, Kyoungo;Park, Seongwan
    • Journal of the Korean GEO-environmental Society
    • /
    • v.14 no.10
    • /
    • pp.39-47
    • /
    • 2013
  • Recently, there have been various domestic construction activities related to the reclamation of the dredged soils to expand the land use. However, the reclaimed grounds made of the dredged soils cause various problems due to highly compressible and low shear strength nature. Particularly, this nature induces huge problems in case of the harbor facilities and road construction on the reclaimed sites. Furthermore, in the reclamation activities, the marine dredged soils are often used instead of the well sorted sand, which induces problems of compressibilities. Therefore, in this study, the mechanical characteristics of artificial soil mixture of kaolinite representing the marine dredged soils and the pond ash. A large consolidometer is designed and manufactured to produce the artificial soil mixture. To represent various mixing ratio between the fly ash and bottom ash in the pond ash, six samples with the same stress history are made with different mixing ratio among kaolinite, bottom ash and fly ash. Isotropically consolidated and undrained compression tests are performed to investigate the shear characteristics of soil mixtures. Based on the experimental results, as the components of mixed ash increase, the friction angle increase and the cohesion values decrease. Also, the porepressure parameters at failure, Af increase with the mixing components of the pond ash. The portion of bottom ash has more impact on the shear behavior than that of fly ash.