• Title/Summary/Keyword: capillary number

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Successful Treatment of a Large Pulmonary Arteriovenous Malformation by Repeated Coil Embolization

  • Park, Jimyung;Kim, Hyung-Jun;Kim, Jee min;Park, Young Sik
    • Tuberculosis and Respiratory Diseases
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    • v.78 no.4
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    • pp.408-411
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    • 2015
  • Pulmonary arteriovenous malformations (AVMs) are caused by abnormal vascular communications between the pulmonary arteries and pulmonary veins, which lead to the blood bypassing the normal pulmonary capillary beds. Pulmonary AVMs result in right-to-left shunts, resulting in hypoxemia, cyanosis, and dyspnea. Clinical signs and symptoms vary depending on the size, number, and flow of the AVMs. Transcatheter embolization is the treatment of choice for pulmonary AVMs. However, this method can fail if the AVM is large or has multiple complex feeding arteries. Surgical resection is necessary in those kind of cases. Here, we report the case of a patient with a 6-cm pulmonary AVM with multiple feeding arteries that was successfully treated by repeated coil embolization without surgery.

Stiffness Characteristics of Salt Cementation according to Depth (깊이에 따른 소금의 고결화 강성특성)

  • Eom, Yong-Hun;Byun, Yong-Hoon;Truong, Q. Hung;Lee, Jong-Sub
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.472-481
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    • 2009
  • Cementation phenomenon has a huge influence on geotechnical stiffness and strength under low confining pressure. The goal of this study is to evaluate the characteristics of stiffness according to the depth. The piezo disk elements are installed at each layer of the cell for the detection of the compressional waves. The change of compressional wave velocity is classified by three stages. The compressional wave velocities are shown different according to the depth. The compressional wave velocity is especially influenced by cementation, effective stress, and coordinate number. Furthermore, the electrical conductivity and cone tip resistance are measured according to the depth. The electrical conductivity and the cone tip resistance show the similar trend with the compressional wave velocity. This study shows that the cementation by salt is affected by the depth on the granular materials.

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THE EFFECTS OF DIABETES ON THE RAT PAROTID GLAND (당뇨병이 백서의 이하선에 미치는 영향에 관한 실험적 연구)

  • Park Chull-Jea;Hwang Eui-Hwan;Lee Sang-Rae
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.26 no.2
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    • pp.75-90
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    • 1996
  • The purpose of this study was to observe microscopic change of salivary gland tissue, which is a cause of xerostomia in diabetic condition; for this target, the author injected streptozotocin 0.1ml/100 gm b.w. on the rat, Sprague Dawley, to induce diabetes, and then observed microscopic changes in parotid gland tissue using light microscopy and electron microscopy. The results were as follows : 1. Parotid gland tissue of the diabetic rat was atrophied or degenerated in lapse of experimental time, but began to repair from 14 days after diabetic induction. 2. In the basal lamina of the vessel of parotid gland tissue in the diabetic rat, lamina lucida was discontinued and lamina densa was increased in thickness, but the number of capillary was gradually increased and dilated. 3. In acinic and intercalated ductal cells of parotid gland in the diabetic rat, changes of mitochondria, RER, secretory granule, free ribosome were prominent. In conclusion, the present study demonstrated that degenerative changes of the parotid gland tissue were due to not completely thickening of the basal lamina of vessels, but many other causal factors, because thickness of the basal lamina of vessels was not related with degenerative changes.

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Durability characteristics of recycled aggregate concrete

  • Saravanakumar, Palaniraj;Dhinakaran, Govindasamy
    • Structural Engineering and Mechanics
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    • v.47 no.5
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    • pp.701-711
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    • 2013
  • People started to replace natural aggregate with recycled aggregate for a number of years due to disposal problem and certain other potential benefits. Though there are number of drawbacks with use of recycled aggregates like lesser modulus of elasticity, low compressive strength, increase in shrinkage, there are results of earlier studies that use of chemical and mineral admixtures improves the strength and durability of recycled concrete. The use of recycled aggregate from construction and demolition wastes is showing prospective application in construction as alternative to natural aggregates. It conserves lot of natural resources and reduces the space required for the landfill disposal. In the present research work, the effect of recycled aggregate on strength and durability aspects of concrete is studied. Grade of concrete chosen for the present work is M50 (with a characteristic compressive strength of 50 MPa). The recycled aggregates were collected from demolished structure with 20 years of age. Natural Aggregate (NA) was replaced with Recycled Aggregate (RA) in different percentages such as 25, 50 and 100 to understand its effect. The experiments were conducted for different ages of concrete such as 7, 14, 28, 56 days to assess the compressive and tensile strength. Durability characteristics of recycled aggregate concrete were studied with Rapid chloride penetration test (as per ASTMC1202), sorptivity test and acid test to assess resistance against chloride ion penetration, capillary suction and chemical attack respectively. Mix design for 50 MPa gives around 35 MPa after replacing natural aggregate with recycled aggregate in concrete mix and the chloride penetration range also lies in moderate limit. Hence it is understood from the results that replacement of NA with RA is very much possible and will be ecofriendly.

A Comparative Study of Two Different Heel Lancet Devices for Blood Collection in Preterm Infants (미숙아에서 채혈을 위한 발뒤꿈치 천자시 두 종류 천자 기구의 비교)

  • Lim, Hyo-Bin;Rhu, Mi-Joo;Jung, Ji-Mi;Jeon, Ga-Won;Sin, Jong-Beom
    • Neonatal Medicine
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    • v.17 no.2
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    • pp.239-244
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    • 2010
  • Purpose: To evaluate two different heel lancet device in terms of pain response and success of the procedure in the preterm infants undergoing heel puncture. Methods: 100 preterm infants undergoing capillary blood gas analysis or capillary bilirubin monitoring underwent heel puncture, were randomly allocated to blood sampling from the heel with either a conventional manual lancet or an automatic incision device. Primary outcome measures included the Premature Infants Pain Profile (PIPP) score, total duration of procedure, number of heel puncture and number of bruise. The pain response was evaluated using PIPP score and the effectiveness was evaluated using three criteria: total duration of blood sampling, number of puncture, bruising of the heel or ankle. Statistical analysis was performed using the SPSS ver. 13.0 program. Difference between the groups were analysed with t test (continuous variables) and the Chi square test or Fisher test (categorical variables). Results: The mean PIPP score was 4.91 for the automatic lancet group compared with 5.84 for the conventional manual lancet group (P=0.0255).The number of pain scores above 7 during blood collection did not differ between two groups (P=0.2167). The procedure took less time to perform in the automatic lancet group (mean, 30.69 seconds) than in the conventional lancet group (mean, 48.92 seconds) (P<0.0001). Conclusion: This study demonstrated that the automatic lancet device causes less pain and a shorter procedure time than the conventional manual lancet in preterm infants undergoing heel puncture. On the basis of these results the automatic lancet device is very useful method for blood collection in preterm infants by heel puncture.

AN EXPERIMENTAL STUDY OF THE IRRADIATION EFFECTS ON THE MICROVASCULATURE OF THE RAT SUBMANDIBULAR GLAND (방사선 조사가 백서 악하선 미세혈관계에 미치는 영향에 관한 실험적 연구)

  • Choi Karp Shik;Choi Soon Chul;Park Tae won
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.22 no.1
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    • pp.43-53
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    • 1992
  • The purpose of this study was to investigate the effects of irradiation on the microvascular structure of the submandibular gland in rats. For this study, 110 male rats were singly irradiated with the dose of 10Gy or 20Gy to their neck region by 6MV X-irradiation and sacrificed on the 1st, 3rd, 7th, 14th and 28th day after irradiation. The author observed distribution and structural changes of the microvasculature in rat submandibular glands using a scanning electron microscope by forming vascular resin casting. The author observed ultrastructural changes of the endothelial cells using a transmission electron microscope, and also histologic changes using a light microscope at Hematoxylin and Eosin staining and PAS staining process. The results of the irradiation effects on the microvasculature in rat submandibular gland were as follows: By light microscopic examination, the dilation of small vessels were observed until the 7th day after irradiation. After then, the vascular constriction and decrease in number of small vessels were noticed. Changes were greater on 20Gy irradiated group than on lOGy irradiated group. The reaction to PAS staining at acinar cells was decreased just after irradiation, but gradually recovered with days. There was no specific difference between two irradiated groups. By scanning electron microscopic examination, general findings on the two irradiated groups were similar. The dilation of conduits and meandering were observed on the 3rd day after irradiation. Decrease of capillary density and blunt ended small vessels were appeared on the 7th day after irradiation. After that, findings of the tortuous and twisted vascular running and coarseness of capillary lumen were increased. Changes were greater on 20Gy irradiated group than on l0Gy irradiated group. By transmission electron microscopic examination, increase of the formation of cytoplasmic process was observed on the 3rd day after irradiation. After that, swelling of endothelial cell and bridge formation of cytoplasmic processes were also observed, but destruction of endothelial cell and loss of basement membrane were observed only on 20Gy irradiated group on the 28th day after irradiation.

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Development of Diagnostic Techniques for Newcastle Disease in Chickens by In Situ RT-PCR and In Situ Hybridization (In situ RT-PCR 및 In situ hybridization 기법에 의한 닭 뉴캣슬병의 진단법 개발)

  • Park, Nam-Yong;Choi, Hyo-Im;Cho, Ho-Seong;Kang, Sung-Kwi;Cho, Kyoung-Oh;Brown, Corrie
    • Korean Journal of Veterinary Research
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    • v.42 no.3
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    • pp.351-362
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    • 2002
  • Newcastle disease (ND) is a highly contagious infection of poultry, Two pathology-based techniques, in situ RT-PCR and in situ hybridization (ISH) were applied to formalin-fixed, paraffin-embedded tissues from chickens naturally infected with velogenic ND virus (VNDV). Two pairs of primers and a probe for ISH and in situ RT-PCR, respectively, were selected from highly conserved region of matrix gene of NDV. The ISH experiment was carried out using MicroProbe$^{TM}$ capillary action system within 2 hours. In situ RT-PCR was performed using MicroProbe$^{TM}$ capillary action system and GeneAmp In Situ PCR system. With ISH and in situ RT-PCR, viral nucleic acid was detected in the central nervous system of chickens from infected with neurotropic velogenic Newcastle disease virus (NVNDV), whereas viral nucleic acid was detected in various organs or tissues of chickens from infected with viscerotropic velogenic Newcastle disease virus (VVNDV). In the NVND group, positive signals were characteristically defined in the cytoplasm of neuron, vascular endothelial cells, and perivascular mononuclear macrophages in the central nervous system. One of NVND group, chicken from one farm exhibited positive signals in the bronchial epithelium. The VVND group chickens showed positive reaction in the macrophages, vascular endothelium, and bronchiolar epithelium. Markedly, viral nucleic acid was detected in the macrophages of morphologically normal tissues which were peripheral or located in distant areas from lesions. The central nervous system of chickens infected with VVND virus had positive signals in the vascular endothelial cell, perivascular mononuclear macrophages and some neuron. The number and intensity of the positive cells by in situ RT-PCR were more and stronger, respectively, in comparison with those by ISH. Particularly, positive reaction was detected in macrophages infiltrating in cardiac muscle by in situ RT-PCR, but not obtained by ISH. Therefore, these results demonstrated that ISH is a rapid diagnostic method for detection of NDV and in situ RT-PCR can be used as an efficient method for detection of low viral load infection or subclinical viral infection of NDV.

A Study of Cosmetic Sustainability Evaluation of Powder Base Make-up Products (파우더 베이스 메이크업 제품의 지속성 평가 방법 연구)

  • Lee, Sang Gil;Kim, Ki Jung;Kim, Young Ho;Pyo, Hyeong Bae;Lee, Dong Kyu
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.41 no.3
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    • pp.209-218
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    • 2015
  • Once powder base makeup products are applied to the skin, the products are formed a film and attached on the skin for 8 to 12 hours. The makeup film is deformed by secretions such as sweat and sebum secreted from the skin. Thus, durability of the film is an important quality factor in the makeup and its evaluation is also important. In this study, characteristics of the semi-finished powder products such as water absorption, oil absorption, water repellent and oil repellent were evaluated in a number of ways. Also, simple methods, which are not affected by evaluation conditions such as a difference between sweat and sebum secretion, temperature and humidity, were examined to predict the durability of the products. We measured water absorption, oil absorption, water repellent and oil-repellent properties of semifinished product by tablet, capillary and dipping method and then compared with the data of color difference meter and ROBO skin analyzer. Results showed that the durability of powder base makeup products was associated with more oil absorption and water-repellent characteristics than water absorption and oil-repellent. Oil absorption characteristics by tablet and capillary method and water-repellent characteristics by dipping method provides a simple and quick method to precdict the durability of the makeup products.

The Physical Characteristics of the flow field and the Form of Arrested Salt Wedge (정상 염수쇄기의 형상과 흐름 장의 물리적 특성)

  • 이문옥
    • 한국해양학회지
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    • v.25 no.2
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    • pp.62-73
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    • 1990
  • An experimental study is performed in order to catch the characteristics of the flow field at arrested salt wedge, using a rectangular open channel. Arrested salt wedge is generally so stable that the observations are easy, but velocities and interfacial waves are measured with the aid of visualization method, by injection of fluorescent dyes. The density interface, which is defined as the zone of maximum density variation with depth, exists in about 0.5 cm below the visual interface, and vertical density profile is quite well satisfied with Homeborn model. Interfacial layer has high turbulent intensity and its thickness decreases as the overall Richardson number increases and has magnitude of roughly 17% of upper layer. Cross-sectional velocity distribution just shows the influence of a side-wall friction and in the upper layer vertical velocity profile also becomes uniformly as Reynolds number increases, but in the lower layer it shows nearly parabolic type. Supposes that we divide salt wedge into three domains, that is, river mouth, intermediate and tip zone, entertainment coefficient is small at the intermediate zone and large at the river mouth and the tip zone. River mouth or intermediate zone has comparatively stable interface and capillary wave therefore s produced and propagated downstream. On the other hand, tip zone is very unstable, cusping ripple or bursting ripple is then produced incessantly. Arrested salt wedge form is nearly linear and has no relation to densimetric Froude number and Reynolds number.

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Reinforced Polymer/Clay Nanocomposite Foams with Open Cell Prepared via High Internal Phase Emulsion Polymerization (고내상 에멀션 중합에 의해 제조된 열린 기공을 갖는 고장도 고분자/점토 나노복합 발포체)

  • Song, In-Hee;Kim, Byung-Chul;Lee, Seong-Jae
    • Polymer(Korea)
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    • v.32 no.2
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    • pp.183-188
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    • 2008
  • Reinforced open cell micro structured foams were prepared by the polymerization of high internal phase emulsions incorporating inorganic thickeners. Organoclays were used as oil phase thickener, and sodium montmorillonite was used as aqueous phase thickener. Rheological properties of emulsions increased as oil phase thickener concentration and agitation speed increased, due to the reduced drop size reflecting both competition between continuous and dispersed phase viscosities and increase of shear force. Drop size variation with thickener concentration could be explained by a dimensional analysis between capillary number and viscosity ratio. Upon the foams polymerized by the emulsions, compression properties, such as crush strength and Young's modulus were measured and compared. Among the microcellular foams, the foam incorporated with an organoclay having reactive group showed outstanding properties. It is speculated that the exfoliated silicate layers inside polystyrene matrix, resulting in nanocomposite foam, are the main reason why this foam has enhanced properties.