• Title/Summary/Keyword: Internal gap

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Internal Flow and Performance Characteristics According to the Runner Gap of a Francis Turbine Model (프란시스 수차 모델의 러너 간극에 따른 내부유동 및 성능 특성)

  • KIM, SEUNG-JUN;CHOI, YOUNG-SEOK;CHO, YONG;CHOI, JONG-WOONG;HYUN, JUNG-JAE;JOO, WON-GU;KIM, JIN-HYUK
    • Journal of Hydrogen and New Energy
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    • v.31 no.3
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    • pp.328-336
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    • 2020
  • In the Francis turbine, the leakage flow through the runner gaps which are between the runner and the stator structure influences the internal flow and hydraulic performance. Thus, the investigation for the flow characteristics induced by the runner gaps is important. However, the runner gaps are often disregarded by considering the time and cost of the numerical analysis. Therefore, in this study, the flow characteristics according to runner gaps of the Francis turbine model were investigated including the leakage flow of the runner cone. The three-dimensional unsteady Reynolds-averaged Navier-Stokes analyses were conducted using a scale-adaptive simulation shear stress transport as a turbulence model for observing the influence of the leakage flow on the internal flow and hydraulic performance. The efficiencies were decreased slightly with runner gaps; and the complicated flows were captured in the gaps.

Semantic Structure of Double Nominative Constructions (이중주격구문의 의미구조)

  • Kim, Kyunghwan
    • The Journal of the Korea Contents Association
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    • v.20 no.5
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    • pp.338-343
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    • 2020
  • This paper provides a semantic account of double nominative constructions in the framework of Autolexical Grammar, which views syntax, semantics, morphology, and other language components as modules generated simultaneously and independently. Some syntactocentric models in the past analyzed double nominatives as a result of possessor raising, ECM or incorporation. This paper provides a semantic explication of double nominatives through function-argument (F/A) structure of internal possession and external possession. The possessum used in double nominatives is a relational noun which takes a possessor as its argument in F/A structure. If the possessor directly combines with the relational noun, then internal possession is generated. If the possessor is a gap in F/A structure, then the argument which is coreferential with the gap combines later with the predicate, resulting in external possession, in which the possessor is in the nominative case. Unlike internal possession, the F/A structure of external possession structurally shows that the sentence is predicated of the possessor.

Growth Promoting Effects of Oriental Medicinal Drugs on Sciatic Nerve Regeneration in the Rat

  • Jo Hyun-Kyung;NamGung Uk;Seol In-Chan;Kim Yoon-Sik
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.6
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    • pp.1666-1672
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    • 2005
  • Oriental medicinal drugs have a broad spectrum of clinical use for the cure of nervous system diseases including brain ischemic damages or neuropathies. Yet, specific drugs or drug components used in the oriental medicine in relation to none fiber regeneration are not known. In the present study, possible growth promoting effects of oriental medicinal drugs were investigated in the injured sciatic nerve system in the rat. By immunofluorescence staining, we found that Jahageo (JHG, Hominis placenta) increased Induction levels of axonal growth associated protein GAP-43 in the rat sciatic none. Small growth promoting activity was found in Golsebo (GSB, Drynariae rhizoma) and Baikhasuo (BHSO, Polygoni multiflori radix) drugs. JHG also increased cell cycle protein Cdc2 levels in the injured area of the sciatic nerves. Immunofluorescence staining indicated that induced Cdc2 protein was mostly localized in the Schwann cells in the injury area, implying that JHG activity might be related to increased Schwann cell proliferation during axonal regeneration. Moreover, levels of phospho-extracellular signal-regulated (ERK) pathway in the injured neNes were elevated by JHG treatment while levels of total ERK were unaltered. In vivo measurement of axonal regeneration using retrograde tracer showed that JHG, GSB and BHSO significantly enhanced Dil-labeled regenerating motor neurons compared with saline control. The present data suggest that oriental medicinal drugs such as JHG, GSB, and BHSO may be a useful target for developing specific drugs of axonal regeneration.

Effect of span length on the fit of zirconia framework fabricated using CAD/CAM system

  • Lee, Jeong-Yol;Choi, Sang-Jin;Kim, Min-Soo;Kim, Ha-Young;Kim, Young-Soo;Shin, Sang-Wan
    • The Journal of Advanced Prosthodontics
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    • v.5 no.2
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    • pp.118-125
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    • 2013
  • PURPOSE. The purpose of this study was to evaluate the effect of the span length on the fit of zirconia framework fabricated using CAD/CAM system. MATERIALS AND METHODS. Abutments for single, 4-unit and 6-unit fixed partial prostheses were fabricated. Ten zirconia frameworks were fabricated for each group. The marginal and internal gap were presented by means of replica technique and measured by measuring microscope ($AXIO^{(R)}$, Carl Zeiss, Rochester, NY) and software (I-$solution^{(R)}$, IMT i-solution Inc., Vancouver, BC, Canada). The results were statistically analyzed by multivariate analysis test and Dunnett T3 test for post hoc test (${\alpha}$=.05). RESULTS. There were statistically significant differences at 2, 4, 7, 8 points (mesio-distal section) and b, d, e, f, g (labio-lingual section). In some marginal reference points of 6-unit group (P<.05), the marginal gap were larger than 120 ${\mu}m$. CONCLUSION. Span length of zirconia core may have an influence on marginal and internal fit. Within the limitation of this study, the increase of span length of zirconia framework of 6 or more-unit fixed partial denture may decrease the marginal and internal fit.

Evaluation of Marginal and Internal Gap of Temporary Prosthesis Fabricated by 3D Printing Method According to Rinsing Method and Rinsing Time (세척 방법 및 세척 시간에 따른 3D 프린팅 방식으로 제작된 임시 보철물의 변연 및 내면 적합도 평가)

  • Ji-Hyeon Bae;Jae-Won Choi
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.4_2
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    • pp.561-570
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    • 2023
  • This study was to evaluate the effect of different rinsing times and methods on the accuracy of temporary prostheses fabricated by 3D printing method. Sixty temporary prostheses were fabricated with LCD types of 3D printer(Halot-Sky, Creality, Shenzhen, China) and divided into six groups (n = 10) based on rinsing times and methods. All specimens were rinsed with 99% isopropanol alcohol for 5 and 10 min using three methods-hand washed, ultrasonic cleaning, and automated washing. All specimens were polymerized for 3 minutes under the same conditions. The marginal and internal gaps of specimens were examined using a replica technique. The light-body silicone thickness was measured at 6 reference points(Absolute marginal discrepancy, Marginal, Chamfer, Axial, Angle, and Occlusal gap). All measurements were performed by a stereomicroscope. Reference point images were taken at 100× magnification and then measured using an image analysis program. Statistical analysis was performed using Two-way ANOVA, One-way ANOVA, and the Kruskal-Wallis test (p = .05). The marginal and internal gaps were statistically different according to the rinsing methods and rinsing times(p < .001). In the rinsing time, the temporary prosthesis rinsed for 5 minutes group showed higher accuracy than 10 minutes group. In the rinsing method, the hand washing group showed higher accuracy than the automated washing group.

Chloride and lactate as prognostic indicators of calf diarrhea from eighty-nine cases

  • Gencay Ekinci;Emre Tufekci;Youssouf Cisse;Ilknur Karaca Bekdik;Ali Cesur Onmaz;Oznur Aslan;Vehbi Gunes;Mehmet Citil;Ihsan Keles
    • Journal of Veterinary Science
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    • v.25 no.3
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    • pp.38.1-38.16
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    • 2024
  • Importance: Deaths due to neonatal calf diarrhea are still one of the most critical problems of cattle breeding worldwide. Determining the parameters that can predict diarrhea-related deaths in calves is especially important in terms of prognosis and treatment strategies for the disease. Objective: The primary purpose of this study was to determine mortality rates and durations, survival status, and predictive prognosis parameters based on vital signs, hematology, and blood gas analyses in neonatal diarrheic calves. Methods: The hospital automation system retrospectively obtained data from 89 neonatal diarrheic calves. Results: It was found that 42.7% (38/89) of the calves brought with the complaint of diarrhea died during hospitalization or after discharge. Short-term and long-term fatalities were a median of 9.25 hours and a median of 51.50 hours, respectively. When the data obtained from this study is evaluated, body temperature (℃), pH, base excess (mmol/L), and sodium bicarbonate (mmol/L) parameters were found to be lower, and hemoglobin (g/dL), hematocrit (%), lactate (mmol/L), chloride (mmol/L), sodium (mmol/L) and anion gap (mmol/L) parameters were found to be higher in dead calves compared to survivors. Accordingly, hypothermia, metabolic acidosis, and dehydration findings were seen as clinical conditions that should be considered. Logistic regression analysis showed that lactate (odds ratio, 1.429) and CI- (odds ratio, 1.232) concentration were significant risk factors associated with death in calves with diarrhea. Conclusions and Relevance: According to the findings obtained from this study, the determination of lactate and Cl- levels can be used as an adjunctive supplementary test in distinguishing calves with diarrhea with a good prognosis.

Evaluation of different approaches for using a laser scanner in digitization of dental impressions

  • Lee, Wan-Sun;Kim, Woong-Chul;Kim, Hae-Young;Kim, Wook-Tae;Kim, Ji-Hwan
    • The Journal of Advanced Prosthodontics
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    • v.6 no.1
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    • pp.22-29
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    • 2014
  • PURPOSE. This study aimed to investigate the potential clinical application of digitized silicone rubber impressions by comparing the accuracy of zirconia 3-unit fixed partial dentures (FPDs) fabricated from 2 types of data (working model and impression) obtained from a laser scanner. MATERIALS AND METHODS. Ten working models and impressions were prepared with epoxy resin and vinyl polysiloxane, respectively. Based on the data obtained from the laser scanner (D-700; 3Shape A/S, Copenhagen, Denmark), a total of 20 zirconia frameworks were prepared using a dental CAD/CAM system (DentalDesigner; 3shape A/S, Copenhagen, Denmark / Ener-mill, Dentaim, Seoul, Korea). The silicone replicas were sectioned into four pieces to evaluate the framework fit. The replicas were imaged using a digital microscope, and the fit of the reference points (P1, P2, P3, P4, P5, P6, and P7) were measured using the program in the device. Measured discrepancies were divided into 5 categories of gaps (MG, CG, AWG, AOTG, OG). Data were analyzed with Student's t-test ($\alpha$=0.05), repeated measures ANOVA and two-way ANOVA (${\alpha}=0.05$). RESULTS. The mean gap of the zirconia framework prepared from the working models presented a narrower discrepancy than the frameworks fabricated from the impression bodies. The mean of the total gap in premolars (P=.003) and molars (P=.002) exhibited a statistical difference between two groups. CONCLUSION. The mean gap dimensions of each category showed statistically significant difference. Nonetheless, the digitized impression bodies obtained with a laser scanner were applicable to clinical settings, considering the clinically acceptable marginal fit ($120{\mu}m$).

Comparison between Accurate Anatomical Reduction and Unsuccessful Reduction with a Remaining Gap after Open Reduction and Plate Fixation of Midshaft Clavicle Fracture

  • Kim, Joon Yub;Choe, Jung Soo;Chung, Seok Won
    • Clinics in Shoulder and Elbow
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    • v.19 no.1
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    • pp.2-7
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    • 2016
  • Background: The purpose of this study is to compare the radiological and clinical outcomes after open reduction and plate fixation of midshaft clavicle fractures between patients who achieved successful anatomical reduction and those who had a remaining fracture gap even after open reduction and plate fixation, and were thus treated with additional demineralized bone matrix (DBM). Methods: This retrospective analysis was conducted on 56 consecutive patients who underwent open reduction and internal fixation using a locking compression plate for acute displaced midshaft clavicle fractures, and who underwent radiographic and clinical outcome evaluations at least 6 months postoperatively. The outcomes between those who achieved perfect anatomical reduction without remnant gap (n=32) and those who had a remaining fracture gap even after open reduction and plate fixation treated with additional DBM (n=24) were evaluated. Results: There were no differences in the use of lag screws or wiring and operation time (all p>0.05) between those with and without remnant gap. No difference in the average radiological union time and clinical outcomes (satisfaction and Constant score) was observed between the two groups (all p>0.05). However, significantly faster union time was observed for AO type A fracture compared with other types (p=0.012), and traffic accident showed association with worse clinical outcomes compared with other causes of injury. Conclusions: Surgical outcome of midshaft clavicle fracture was more affected by initial fracture type and event, and re-reduction and re-fixation of the fracture to obtain a perfect anatomical reduction spending time appears to be unnecessary if rigid fixation is achieved.

Comparison of marginal and internal fit of zirconia abutments with titanium abutments in internal hexagonal implants (내부육각 연결형 임플란트에서 지르코니아 지대주와 티타늄 지대주의 변연 및 내면 적합도의 비교)

  • Kim, Young-Ho;Cho, Hye-Won
    • The Journal of Korean Academy of Prosthodontics
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    • v.54 no.2
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    • pp.93-102
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    • 2016
  • Purpose: The aim of this study was to evaluate the fit accuracy of two zirconia and titanium abutments in internal hexagonal implants. Materials and methods: One titanium abutment and two zirconia abutments were tested in internal hexagonal implants (TSV, Zimmer). Prefabricated zirconia abutments (ZirAce, Acucera) and customized zirconia abutments milled by the Zirkonzahn system (Zirkonzahn Max, Zirkonzahn) were selected and prefabricated titanium abutments (Hex-Lock, Zimmer) were used as a control. Eight abutments per group were connected to implants with 30 Ncm torque. The marginal gaps at abutment-implant interface, the internal gaps at internal hex, vertical and horizontal gaps between screws and screw seats in abutments were measured after sectioning the embedded specimens using a scanning electron microscope. Data analysis included one-way analysis of variance and the Scheffe test (n=16, ${\alpha}=0.05$). Results: The mean marginal gap of customized zirconia abutment was higher than those of two prefabricated zirconia and titanium abutments. The internal gaps at internal hex showed no significant differences between customized and prefabricated abutments and were higher than those of prefabricated titanium abutments. The mean vertical and horizontal gaps at screw in prefabricated zirconia abutment were higher than those of prefabricated titanium abutment. In the case of customized zirconia abutment, the mean horizontal gap at screw was higher than those of both the prefabricated zirconia and the titanium abutment but the mean vertical gap was not even measureable. The screw seats were clearly formed but did not match with abutment screws in prefabricated zirconia abutments. They were not, however, precisely formed in the case of customized zirconia abutments. Conclusion: Within the limitations of this study, the prefabricated titanium abutments showed better fit than the zirconia abutments, regardless of customized or prefabricated. Also, the customized zirconia abutments showed significantly higher marginal gaps and the fit was less accurate between screws and screw seats than the prefabricated abutments, titanium and zirconia.

Performance Tests of Oil Boom at Open Sea (오일붐의 실해역 성능평가 기법 개발)

  • Yu Jeongseok;Lee Moonjin;Kim Jinhwan
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.2 no.1
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    • pp.49-62
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    • 1999
  • The main functions of oil booms are to prevent spreading of the oil slick and to increase the recovering efficiency of oil skimmers. The oil-containment capability of a floating boom on an open sea is affected by environmental parameters such as waves, currents and winds, as well as the motion characteristics of a boom section. In this study, a series of tests were conducted for three kinds of booms (internal foam type, air inflatable type, self-expanded type) at the open sea off Yosu, and the results are presented. Motion characteristics and oversplashing phenomenon were observed for each boom in different environmental conditions. And the tension exerted on towing line of the boom was also measured with a systematic varitation of towing speeds and gap ratios.

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