• Title/Summary/Keyword: Clearance fit

Search Result 15, Processing Time 0.022 seconds

Durability Improvement of Engine Bulkhead by Adjusting Design Parameters (설계인자변화에 따른 엔진 벌크헤드 내구성 향상)

  • Yang, Chull-Ho;Han, Moon-Sik
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.19 no.2
    • /
    • pp.111-116
    • /
    • 2011
  • Three-dimensional finite element analyses have been performed to improve the durability of bulkhead. To keep pace with design changes and concentrate on regions of interest, SUBMODEL technique in ABAQUS was used for analysis. An analysis was conducted with following load cases: 1) Cap press-fit, 2) Bearing crush, 3) Bolt assembly, 4) Hot assembly, 5) Firing load, 6) Alternating firing load, 7) 2nd hot assembly. Fatigue analysis was done using commercial software FEMFAT and fatigue factors at the interested regions such as bolt tip area, counter bore, breathing hole, honing clearance were calculated and compared to aid design validation. Finite element modeling in the area of thread engagement used a simple constraint equations. Increasing bolt length, to a minimum of 39 mm above joint face gives a better fatigue resistance to the bulkhead. Breathing hole helps not only circulate the air in the crankcase but also fatigue resistance of bulkhead by relieving the stress at the critical locations.

Clinical outcomes of rigid and non-rigid telescopic double-crown-retained removable dental prostheses: An analytical review

  • Seo, Jeong-Gyo;Cho, Jin-Hyun
    • The Journal of Advanced Prosthodontics
    • /
    • v.12 no.1
    • /
    • pp.38-48
    • /
    • 2020
  • PURPOSE. The objective of this literature review was to analyze the cumulative survival rates (CSRs) of rigid and non-rigid double-crown-retained removable dental prostheses. MATERIALS AND METHODS. Screening of the literature published from January 1995 to December 2019 was performed by using electronic data base (Pubmed) and manual search. The CSRs of rigid and non-rigid double crown removable dental prostheses were investigated. RESULTS. A total of 403 articles were reviewed and 56 relevant articles of them were selected. Subsequently, 25 articles were included for data extraction. These articles were classified according to rigid and non-rigid type double crowns and further subdivided into teeth, implants, and teeth-implant combination types. The CSRs of rigid type double crown ranged from 68.9% to 95.1% of 5 to 10 years in tooth abutments, 94.02% to 100% over a 3-year mean observation periods in implant abutments, and 81.8% to 97.6% in tooth-implant combination. Non-rigid type double crowns had various CSR ranges from 34% to 94% maximum during 10 years observation in teeth abutment. The CSRs of non-rigid type had over 98% in implant abutments, and ranged from 85% to 100% in tooth-implant combination. CONCLUSION. The CSRs of double crowns varies according to types. With accurate evaluation of the remaining teeth and plan of the strategic implant placement, it could be successful treatment alternatives for partially or completely edentulous patients.

Prediction of pharmacokinetics and drug-drug interaction potential using physiologically based pharmacokinetic (PBPK) modeling approach: A case study of caffeine and ciprofloxacin

  • Park, Min-Ho;Shin, Seok-Ho;Byeon, Jin-Ju;Lee, Gwan-Ho;Yu, Byung-Yong;Shin, Young G.
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.21 no.1
    • /
    • pp.107-115
    • /
    • 2017
  • Over the last decade, physiologically based pharmacokinetics (PBPK) application has been extended significantly not only to predicting preclinical/human PK but also to evaluating the drug-drug interaction (DDI) liability at the drug discovery or development stage. Herein, we describe a case study to illustrate the use of PBPK approach in predicting human PK as well as DDI using in silico, in vivo and in vitro derived parameters. This case was composed of five steps such as: simulation, verification, understanding of parameter sensitivity, optimization of the parameter and final evaluation. Caffeine and ciprofloxacin were used as tool compounds to demonstrate the "fit for purpose" application of PBPK modeling and simulation for this study. Compared to caffeine, the PBPK modeling for ciprofloxacin was challenging due to several factors including solubility, permeability, clearance and tissue distribution etc. Therefore, intensive parameter sensitivity analysis (PSA) was conducted to optimize the PBPK model for ciprofloxacin. Overall, the increase in $C_{max}$ of caffeine by ciprofloxacin was not significant. However, the increase in AUC was observed and was proportional to the administered dose of ciprofloxacin. The predicted DDI and PK results were comparable to observed clinical data published in the literatures. This approach would be helpful in identifying potential key factors that could lead to significant impact on PBPK modeling and simulation for challenging compounds.

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

  • Seo, Kwang-Cheol;Atlar, Mehmet;Kim, Hee-Jung;Chun, Ho-Hwan;Kang, Dae-Soo
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.44 no.4
    • /
    • pp.379-388
    • /
    • 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.

Risk Factors for the First-Year Relapse in Children with Nephrotic Syndrome (신증후군 환아에서 1년내 재발과 관련된 위험 요인)

  • Shin, Hye Kyoung;Kim, Ji Hee;Yoo, Kee Hwan;Hong, Young Sook;Lee, Joo Won;Kim, Soon Kyum
    • Clinical and Experimental Pediatrics
    • /
    • v.46 no.9
    • /
    • pp.889-892
    • /
    • 2003
  • Purpose : This study aimed to evaluate risk factors of the first year relapse in children with nephrotic syndrome(NS) without the need for biopsy. Methods : We reviewed, retrospectively, 78 children diagnosed with steroid responsive nephrotic syndrome between July 1997 and June 2002. Median years to follow up were 4.4 years(range : 1-5 years). We divided the patients into two groups(group I : primary responders with no relapse or with only two relapses in the first year after initial response; group II : initial steroid responders with three or more relapses within the first year). We retrospectively reviewed and compared variables - sex, onset age, serum albumin, serum cholesterol, 24 hours urinary protein, creatinine clearance(Ccr), presence of hematuria and hypertension(HTN), and days from initial attack to remission. Results : Of 78 patients(male : 61(78.2%), female : 17(21.8%), age range 1.1 years to 14 years, median $5.1{\pm}3.0years$), 47(60.3%) were in group I and 31(39.7%) were in group II. There were no statistically significant differences in sex, serum albumin, serum cholesterol, 24 hours urinary protein, Ccr, presence of hematuria or HTN. The median age of onset showed no statistical difference between the two groups. However, if the patients are dividing into two groups according to the age of onset of three-years, patients theree yrs old or less fit into group II, as opposed to patients older than three yrs in age(63.2% vs. 32.2%, P<0.05). The days from initial attack to remission was longer in group II($12.9{\pm}0.5$ vs. $16.2{\pm}1.1$, P<0.05). Conclusion : We may conclude that the age of onset of three yrs old or less, and the longer time remission to initial steroid therapy, are risk factors of the first year relapse.