• 제목/요약/키워드: effective clearance

검색결과 205건 처리시간 0.026초

로터리 드로우 벤더를 이용한 타원형 튜브의 유한요소 벤딩 해석 (Finite Element Bending Analysis of Oval Tubes Using Rotary Draw Bender for Hydroforming Applications)

  • 이호국
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2005년도 추계학술대회 논문집
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    • pp.71-74
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    • 2005
  • In manufacturing automotive parts, such as engine cradles, frame rails, subframes, cross-members, and other parts from circular tubes, pre-bending and pre-forming operations are often required prior to the subsequent tubular hydroforming process. During some pre-forming operations, the cross section of a bent circular tube is crushed into an oval-like shape to ensure proper geometry and sufficient clearance in the hydroforming dies. For such applications, the use of oval Instead of circular tubes could be an effective means of eliminating the pre-forming step. The oval tube could also be produced with less thinning and with less strain on the outside of the bend when controlled by a booster system without the use of mandrel. Hence, the understanding of the issues that occur in the bending of oval tubes is worthy of Investigation. This paper presents parametric studies on the bending of oval tubes without a mandrel. The finite element modeling technique is used to examine the deformation characteristics for both circular and oval tubes. In the simulations, the bending process parameters of bend radius, aspect ratio of the tube ovalness, and tube wall thickness are varied. Observations are made to obtain a hoop-buckle limit diagram in terms of a non-dimensional shape degradation factor. Suggestions based upon developed criteria are made on the acceptability of bend tubes suitable for hydroforming applications without the need ofa pre-forming step or the used of a mandrel.

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Effects of Caffeine and Pentoxifylline on Pharmacokinetics of Propentofylline

  • Kwon, Oh-Seung;Kim, Min-Hee;Ryu, Jae-Chun;Chung, Youn-Bok
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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    • pp.122-122
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    • 1998
  • Propentofylline (PPF), a xanthine derivative, has been reported to be effective for the treatment of both vascular dementia and Alzheimer's disease. The elimination half-life of PPF was ranged from 15 to 45 min in rabbit and human, and PPF was rapidly disappeared from the blood. The objective of this experiment is to investigate whether xanthine analogues have effects on the profile of plasma concentration and metabolism of PPF. Caffeine (50 mg/kg, ip) was treated to Sprague-Dawley rats for consecutive 7 days and PPF was intravenously administered to rats 2 hr after the last dose of caffeine. In the other group, PPF was intravenously administered to rats 1 hr after a single dose of pentoxifylline (50 mg/kg, iv). Control group was treated with saline vehicle for the same period as in treatment groups. Blood was withdrawn at specific time intervals. PPF and one of its metabolite (POH) in plasma were determined by gas chromatography/nitrogen phosphorus detector. Plasma concentrations and pharmacokinetic parameters were compared between groups. The area under the curve (AUC) of PPF in rats treated sub chronically with caffeine was significantly decreased compared to control rats. Caffeine treatment results in a significant increase of total body clearance. The AUC of POH was significantly decreased in the caffeine-treated group. A single dose of pentoxifylline has no effect on the phramacokinetics of PPF. Reduction of the AUCs of PPF and POH both suggests that caffeine may increase the excretion of PPF with no affecting the metabolism of PPF to POH.

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Comparative efficacy of photo-activated disinfection and calcium hydroxide for disinfection of remaining carious dentin in deep cavities: a clinical study

  • Sharma, Sidhartha;Logani, Ajay;Shah, Naseem
    • Restorative Dentistry and Endodontics
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    • 제39권3호
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    • pp.195-200
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    • 2014
  • Objectives: To comparatively evaluate the efficacy of photo-activated disinfection (PAD), calcium hydroxide (CH) and their combination on the treatment outcome of indirect pulp treatment (IPT). Materials and Methods: Institutional ethical clearance and informed consent of the patients were taken. The study was also registered with clinical registry of India. Sixty permanent molars exhibiting deep occlusal carious lesion in patients with the age range of 18 - 22 yr were included. Clinical and radiographic evaluation and set inclusion and exclusion criteria's were followed. Gross caries excavation was accomplished. In group I (n = 20) PAD was applied for sixty seconds. In group II (n = 20), CH was applied to the remaining carious dentin, while in group III (n = 20), PAD application was followed by CH placement. The teeth were permanently restored. They were clinically and radiographically followed-up at 45 day, 6 mon and 12 mon. Relative density of the remaining affected dentin was measured by 'Radiovisiography (RVG) densitometric' analysis. Results: Successful outcome with an increase in radiographic grey values were observed in all three groups. However, on inter-group comparison, this change was not significant (p > 0.05). Conclusions: PAD and CH both have equal disinfection efficacy in the treatment of deep carious dentin. PAD alone is as effective for treatment of deep carious lesion as calcium hydroxide and hence can be used as an alternative to CH. They can be used independently in IPT, since combining both does not offer any additional therapeutic benefits.

마행의감탕(麻杏薏甘湯)과 Trichloroacetic acid (TCA) 병행치료를 이용한 심상성 사마귀의 한방 치험 1례 (A Case Report of Verruca Vulgaris patient treated with Mahaengeuigam-tang and Trichloroacetic acid(TCA))

  • 강은정;감은영;최정화;김종한;박수연;정민영
    • 한방안이비인후피부과학회지
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    • 제33권2호
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    • pp.156-163
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    • 2020
  • Objectives : The purpose of this study is to report the effects of Mahaengeuigam-tang and Trichloroacetic acid(TCA) on hand warts. Exfoliation, such as TCA is a method developed from traditional medicine and used to treat hyperkeratosis skin in this patient. Methods : A patient with Verruca Vulgaris was treated with herbal medicine, including Mahaengeuigam-tang and application of TCA on wart lesions. Changes in lesions were evaluated by photographs. Results : After 3 months of treatment, The patient's lesions showed complete clearance. There are no adverse effects and no relapse of Verruca Vulgaris after 57 days of last treatment. Conclusions : According to the result, Mahaengeuigam-tang and External treatment such as TCA developed from traditional medicine can be effective for Verruca Vulgaris.

Evidence to Support the Therapeutic Potential of Bacteriophage Kpn5 in Burn Wound Infection Caused by Klebsiella pneumoniae in BALB/c Mice

  • Kumar, Seema;Harja, Kusum;Chhibber, Sanjay
    • Journal of Microbiology and Biotechnology
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    • 제20권5호
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    • pp.935-941
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    • 2010
  • The emergence of antibiotic-resistant bacterial strains is one of the most critical problems of modern medicine. Bacteriophages have been suggested as an alternative therapeutic agent for such bacterial infections. In the present study, we examined the therapeutic potential of phage Kpn5 in the treatment of Klebsiella pneumoniae B5055-induced burn wound infection in a mouse model. An experimental model of contact burn wound infection was established in mice employing K. pneumoniae B5055 to assess the efficacy of phage Kpn5 in vivo. Survival and stability of phage Kpn5 were evaluated in mice and the maximum phage count in various organs was obtained at 6 h and persisted until 36 h. The Kpn5 phage was found to be effective in the treatment of Klebsiella-induced burn wound infection in mice when phage was administered immediately after bacterial challange. Even when treatment was delayed up to 18 h post infection, when all animals were moribund, approximately 26.66% of the mice could be rescued by a single injection of this phage preparation. The ability of this phage to protect bacteremic mice was demonstrated to be due to the functional capabilities of the phage and not due to a nonspecific immune effect. The levels of pro-inflammatory cytokines (IL-$1{\beta}$ and TNF-${\alpha}$) and anti-inflammatory cytokines (IL-10) were significantly lower in sera and lungs of phage-treated mice than phage untreated control mice. The results of the present study bring out the potential of bacteriophage therapy as an alternate preventive approach to treat K. pneumoniae B5055-induced burn wound infections. This approach not only helps in the clearance of bacteria from the host but also protects against the ensuing inflammatory damage due to the exaggerated response seen in any infectious process.

An Assessment of Records Management Practice in Selected Local Government Councils in Ogun State, Nigeria

  • Bakare, Abdullahi A.;Abioye, Abiola A.;Issa, Abdulwahab Olanrewaju
    • Journal of Information Science Theory and Practice
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    • 제4권1호
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    • pp.49-64
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    • 2016
  • What government does/fails to do is conveyed to the public largely by records and information of various types in the public service, without which there will be no government. When records are poorly managed, much time is involved in sorting and locating needed information from large volumes of records. The rate of records misplaced or lost from which useful information for decision making is usually obtained makes it difficult to provide concise and up-to-date records of both past and present operations, raising the challenge of effective record-keeping. Thus this study examined records management practices in selected local government councils in Ogun State, Nigeria, adopting the descriptive survey research method using questionnaires for data collection. Its population comprised 415 records of personnel in the selected councils, of which 208 were sampled using simple random technique. From the 208 copies of the questionnaire administered on the registry personnel, 150 copies were useable, with a 72.12% response rate. Descriptive statistics were used for the analysis. The results indicated a prevalence of paper as the dominant medium for recording/conveying information in the councils with most of these being either in active state, semi-active, and vital and were kept and maintained in the registry, while in-active records were kept in the records store. Storage facilities for record-keeping were insufficient. Security measures against unauthorized access to records were by restrictions and subject users to managerial clearance. The study concluded that council records were in chaos and recommended the formulation of coherent records management policy, adequate budgetary provision, and adequate finance.

폐포 단백증 3예 (Three Cases of Pulmonary Alveolar Proteinosis)

  • 김연재;한춘덕;차승익;김창호;이영석;박재용;정태훈;박태인;손윤경
    • Tuberculosis and Respiratory Diseases
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    • 제40권4호
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    • pp.416-423
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    • 1993
  • 경북대학교 의과대학 호흡기내과에서 운동시 호흡곤란을 호소하며 입원하여 개흉폐생검, 경기관지 폐생검 및 기관폐포세척을 하여 광학현미경 및 전자현미경소견상 특징적인 lamellar body가 보이는 폐포단백증으로 진단된 3예를 경험하였기에 문헌고찰과 함께 보고하였다.

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천진항 사고에 따른 안전한 위험물 관리방안 (Safe Management for Hazardous Cargo in relation to explosions in port of Tianjin)

  • 안정민;이홍훈
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2015년도 추계학술대회
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    • pp.208-210
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    • 2015
  • 최근 중국 천진항에서 발생한 폭발사고로 인하여 위험물에 대해 규제가 강화되고 있다. 이는 국내에서 수출되는 화학제품에도 영향을 주어 국제기준과 상이한 부분까지도 충족해야만 수입통관이 가능한 규제가 되었다. 2004년부터 국제적으로 강제화 된 위험물 운송규정(IMDG Code)을 준수하여 위험물을 수출하고 있는 국내 산업계에도 상당한 피해가 되고 있으나 중국정부의 요구에 따라야만 통관이 가능하기 때문에 물류의 효율성 측면에서 많은 어려움이 가중 되었다. 국내에서도 안전한 위험물 관리 필요성이 대두되고 있지만 단편적인 임시방편의 정책은 오히려 경제적 비용 손실과 불필요한 규제 가중으로 연결되기 되기 때문에 장기적으로 안전한 동시에 효율적인 위험물 관리방안을 찾아야만 국내 화학산업의 지속적인 성장이 가능하다.

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"Inclined Keel" 을 이용한 컨테이너선의 추진효율 향상 (Efficient Propulsion of a Container Ship Using the Inclined Keel Concept)

  • 서광철;;김희정;전호환;강대수
    • 대한조선학회논문집
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    • 제44권4호
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    • pp.379-388
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    • 2007
  • Ever increasing fuel prices and environmental concerns are forcing commercial vessel operators and designers to re-assess current vessel designs with an emphasis on their propulsion systems. The most important parameter determining propulsive efficiency is the diameter of propeller. Many investigations have been carried out to adapt a large and slow turning propeller known as one of the most robust and effective way of achieving high efficiency in ship propulsion system. However, for the same vessel a further increase of propeller diameter would require the modification of the aft end while still paying attention to the hull clearance to prevent excessive propeller excited vibrations. In order to take the advantage of this approach small workboats (e.g. tug boats, fishing vessels etc.) operate in service with a significant increase of aft draught and hence resulting "inclined keel" configuration can be observed. Although it is not unusual to see large vessels sometimes to operate with stern trim to improve their operational performance and fuel efficiency, it is rare to see a such vessel purposely built with an inclined keel feature to fit a large diameter propeller for power saving. This paper investigates the application of the inclined keel configuration to a 3600TEU container vessel with the aim of fitting an 11 % larger diameter propeller (and hence resulting 17.5 % lower rpm) to gain further power saving over the similar size basis container ship with conventional "level keel" configuration.

흰쥐 뇌 소교세포에서 진세노사이드 Rg3의 Type A Macrophage Scavenger Receptor 발현 증진효과 (Enhancement of Type A Macrophage Scavenger Receptor Expression by Ginsenoside Rg3 in Rat Microglia)

  • 주성수;황광우;이도익
    • 약학회지
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    • 제49권2호
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    • pp.147-150
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    • 2005
  • Macrophage scavenger receptors (MSRs) induce microglial interaction with ${\beta}$-amyloid fibrils (fA${\beta}$) that are associated with Alzheimer's disease (AD). Although microglia are know n to have a dual effect on formation of plaque and clearance of fA${\beta}$ in the AD brain, receptor-mediated phagocytosis is a very important tool for preventing amyloid plaque via activated microglia in the early stage of AD. In the study, we examined whether ginsonoside Rg3 enhances the microglial Phagocytosis of A${\beta}$1-42 through Phagocytosis assay, gene expression (RT-PCR) and protein assay (western blots) for the cell responsiveness presented between Rg3-treated and non-treated groups. Fluro-labeled Ac-LDL and E.coli particles were used as control proteins for phagocytosis. In previous studies, this was a particularly interesting property of Rg3 in the stimulation and phagocytosis of macrophages in the periphery. We report here that ginsenoside Rg3 increased the expression of type-A MSR (MSR-A) in microglia and thus accelerated the phagocytosis with an effective degradation of engulfed fA${\beta}$. This result suggests that Rg3 may play an important role in removing fA${\beta}$ by enhancing the receptor-mediated phagocytosis. In addition, Rg3 could be a potential candidate for balancing the rate of production of fA${\beta}$ in AD brain.