• Title/Summary/Keyword: Finishing

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Effects of different surface finishing protocols for zirconia on surface roughness and bacterial biofilm formation

  • Lee, Du-Hyeong;Mai, Hang-Nga;Thant, Phyu Pwint;Hong, Su-Hyung;Kim, Jaewon;Jeong, Seung-Mi;Lee, Keun-Woo
    • The Journal of Advanced Prosthodontics
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    • v.11 no.1
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    • pp.41-47
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    • 2019
  • PURPOSE. Surface finishing of a zirconia restoration is essential after clinical adjustment. Herein, we investigated the effects of a surface finishing protocol for monolithic zirconia on final roughness and bacterial adherence. MATERIALS AND METHODS. Forty-eight disk-shaped monolithic zirconia specimens were fabricated and divided into four groups (n = 12) based on initial surface treatment, finishing, and polishing protocols: diamond bur+polishing bur (DP group), diamond bur+stone grinding bur+polishing bur (DSP group), no diamond bur+polishing bur (NP group), and no diamond bur+stone grinding bur+polishing bur (NSP group). Initial and final surface roughness was measured with a profilometer, and shown using scanning electron microscope. Bacterial adhesion was evaluated by quantifying Streptococcus mutans in the biofilm. Kruskal-Wallis and Mann-Whitney U tests were used to compare results among groups, and two-way analysis of variance was used to evaluate the effects of grinding burs on final roughness (${\alpha}=.05$). RESULTS. The DP group had the highest final Ra value, followed by the DSP, NP, and NSP groups. Use of the stone grinding bur as a coarse-finishing step significantly decreased final Ra values when a diamond bur was used (P<.001). Omission of the stone grinding bur increased biofilm formation on specimen surfaces. Combining a stone grinding bur with silicone polishing burs produced the smallest final biofilm values, regardless of the use of a diamond bur in initial surface treatment. CONCLUSION. Coarse finishing of monolithic zirconia with a stone grinding bur significantly decreased final Ra values and bacterial biofilm formation when surfaces had been roughened by a diamond bur.

Effects of a pineapple (Ananas comosus L.) cannery by-product on growth performance and carcass characteristics in finishing Hanwoo steers

  • Choi, Yongjun;Lee, Sangrak;Na, Youngjun
    • Animal Bioscience
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    • v.34 no.2
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    • pp.233-242
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    • 2021
  • Objective: The aim of this study was to determine the effect of pineapple cannery by-product (PCB) level on the growth performance and carcass characteristics of finishing Hanwoo steers. Methods: The feeding stage was divided into early and late finishing stages. A total of 60 castrated Hanwoo steers (13.9±0.8 months old, 418.8±36.5 kg initial body weight [BW]) were blocked by initial BW and then randomly allotted into 12 pens (five head/pen). The pens were randomly assigned to control (CONT), low PCB (LPCB), or high PCB (HPCB) treatments. These diets contained 0%, 1.5%, or 3.0% of PCB (on a dry matter [DM] basis; as-fed basis was 0%, 10.6%, or 21.2%), respectively. Results: For the early finishing stage, body weight gain (BWG) and average daily gain (ADG) of the CONT and LPCB feeding groups were greater (p<0.05) than those of the HPCB feeding group. In addition, there were linear and quadratic effects on BWG and ADG with increasing dietary PCB level (p<0.05). The gain to feed (G:F) ratio tends to quadratically decrease with an increasing PCB level in the early finishing stage (p = 0.076). Growth performances of late finishing stage were not affected by PCB level. The marbling score of the LPCB feeding group was similar to that of the CONT feeding group. However, there was a linear decrease (p< 0.05) in marbling score and quality grade among treatments as PCB was increased in the diet. In the longissimus muscle free amino acid profile, histidine composition increased linearly (p<0.05) with an increasing level of PCB. Conclusion: The level of PCB 1.5% DM in diet can be used for finishing steers without any adverse effects on growth and carcass performances. However, there were some negative effects on growth and carcass performance in the HPCB feeding group.

Observation of surface roughness and grinding angle by automatic barrel finishing process of dental 3D printed resin (3D 프린터로 출력된 치과용 레진의 자동바렐연마공정에 따른 표면 거칠기 및 연마도 관찰)

  • Yu-Jin Park;An-Na Jung
    • Journal of Technologic Dentistry
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    • v.45 no.2
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    • pp.39-47
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    • 2023
  • Purpose: This study aimed to confirm the applicability of gloss polishing using automatic barrel finishing with respect to three-dimensional (3D)-printed resin specimens. The surface roughness and grinding angle of the 3D-printed resin specimens were observed with respect to gloss polishing time using automatic dental barrel finishing. Methods: Herein, experiments were conducted on four types of 3D-printed resin specimens. The specimens, with a thickness of 100 ㎛ each, were printed using a 3D printer. Subsequently, light polymerization was performed on these specimens for 15 min. Post this surface treatment, the specimens underwent grinding for 25 min. This process was followed by gloss polishing at 5-min intervals for up to 25 min using automatic dental barrel finishing. The specimens were photographed using a 3D optical microscope, and their surface roughness and grinding angle were measured. Results: The Ra (centerline average roughness) values of all the specimens, except for crown & bridge 10 group and those in the control group that were not polished using automatic barrel finishing, were <0.2 ㎛. However, polishing time needs to be controlled to realize the desired surface roughness and grinding amount considering the hardness of the resin used. Conclusion: Gloss polishing of 3D-printed resin can be realized using automatic dental barrel finishing. However, polishing time needs to be controlled to realize the desired surface roughness and grinding amount considering the hardness of the resin used.

Effects of Floor Type and Increasing Market Weight on Performance and Pork Quality of Finishing Pigs (돈방바닥과 출하체중 증가가 비육돈의 생산효율과 돈육품질에 미치는 영향)

  • Kim D. H.;Kang J. D.;Ha D. M.
    • Journal of Animal Environmental Science
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    • v.11 no.3
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    • pp.153-160
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    • 2005
  • This study was conducted to determine the effect of floor type of finishing building and increasing market weight of finishing Pigs on Performance, carcass traits and pork quality. Four hundred and forty-four finishing pigs were confined and administered with different floor type(concrete slat and bedded with sawdust) and increasing market weight(110kg to 130kg) of finishing building. The result obtained from this study were summarized as follows; 1. There was no significant difference between the floor type of finishing building in the body weight gain, feed intake and gain per feed. And also increasing market weight of finishing pigs was not affected the performance of finishing pigs. 2. Increasing market weight of finishing pigs affect the carcass yield. The market weight at 130kg showed more amount of each cut of carcass, especially the belly portion was higher, but backfat thickness was not different. 3. Carcass traits did not show any significant difference due to the difference of market weight of finishing pig and floor type of finishing building. 4. There was no significant difference in the chemical compositions and meat color of pork loin between the floor type of finishing building and increasing market weight of finishing pigs.

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A Study on the Application of Finishing Materials According to the Locational Function of the Chapel in Church Space (교회공간 예배실의 위치적 기능에 따른 마감재 적용 연구)

  • Yeo, Mi;Lee, Chang No
    • Korean Institute of Interior Design Journal
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    • v.24 no.1
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    • pp.178-188
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    • 2015
  • This study has the main objective of being of help as a reference data for the application of the finishing materials when designing the interior of the chapel of the church space through analysis of the finishing materials against the chapels of church space which has complex function. As precedent studies for this, the composition of the function and concept of the church space was surveyed and the complex function of the church space was surveyed. The theoretical surveyed was performed according to the casual composition, behavior of the community and role and location of the duties of the church members. The case objects were 10 chapels constructed by 5 professional interior design companies. The content of the analysis was the finishing materials in the chapels and their application characteristics. The detailed considerations to be referred to when designing the interior of the chapels of church space in the future were proposed. The analysis result of the application of the finishing materials according to the locational function of the chapels of church space can be explained as follows. First, the platform area was the characteristic of applying finishing materials which induce visual immersion. As for the floor materials in the platform, in order to minimize the floor sound and vibration phenomenon occurring during movements, noise insulation and dust protection rubber sheet was place and on top of it the floor or the carpet was placed. Second, the Choir area had the difficult problem of having to consider the appropriate sound absorption occurring due to the proliferation of sound and performance of classical instruments at the same time. However, in the case, this problem was solved through the sculptures of convex shape. Third, since the scheelite is a space where many people move around, the finishing material which absorbs sound was mainly used. Fourth, the entrance area was composed of thick wall materials compared to other walls, and the sound absorption character was most significantly considered when applying the finishing material. Fifth, the broadcasting room was composed either in independent type or an open type and performed its function and the main finishing materials was transparent glass which was highest use frequency.

Alternative Evaluation Model for Tower Crane Operation Plan in Modular Construction - Focusing on Modular Unit Installation and Finishing works - (모듈러 건축 타워크레인 운용 계획의 대안 평가 모델 - 유닛 설치 및 마감공사를 중심으로 -)

  • Kim, Joo Ho;Park, Moonseo;Lee, Hyun-Soo;Hyun, Hosang
    • Korean Journal of Construction Engineering and Management
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    • v.19 no.2
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    • pp.50-60
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    • 2018
  • Recently, modular construction method has been widely applied to projects with repetitive processes including dormitory, the residential facility, and the hotel construction due to reduced labor input and shortened construction schedule. Generally, about 40% of total on-site construction cost excluding unit installation cost, is put on exterior finishing work, and thus management of finishing work is deemed important in maintaining the targeted schedule and cost. Since limited equipment is shared so that subsequent activities are not affected while carrying out on-site installation and finishing work, lifting plan becomes more important for modular projects with greater portion of finishing work load. In this regard, tower crane operation plan may take the form of a single cycle or multiple cycles in which equipment efficiency can be affected. However, difficulties exist in evaluating alternatives to tower crane operation plans supporting unit installation and finishing work. Therefore, this study aims to evaluate the alternative of tower crane operation method according to the cyclic period setting in modular building site to determine the effect on T/C uptime and process by parameterizing lifting time for unit and exterior finishing material, lift cycle for unit and exterior finishing material and time required for finishing work. Accordingly, this study develops a simulation model that can increase the tower crane efficiency by controlling the work speed. An academic contribution of this study is to suggest a resource leveling method applying the concept of lifting cycle, and further is expected to be managerially used as a basis for an alternative evaluation of equipment plan.

Analysis of the Finishing Failure in the Railway Station Platform and Deduction of Improvement Plans (철도역사 승강장 연단부 마감 탈락에 대한 원인 분석 및 개선 방안)

  • Ko, Sewon;Yu, Youngsu;Koo, Bonsang;Kim, Jihwan
    • Korean Journal of Construction Engineering and Management
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    • v.23 no.1
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    • pp.46-53
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    • 2022
  • The railway platform is an important facility closely related to the safety of passengers, trains, and images of railway facilities, and requires thorough facility management. However, the problem that the finishing material (plastering mortar) for the joint finishing of dissimilar materials (concrete+granite) falls off in the direction of the track at the platform podium is occurring multiple times across the country. Since these problems threaten the safety of train operation and the safety of passengers, immediate and continuous management is required. This study tried to derive improvement plans through the analysis of the drop-off problem of finishing materials occurring at the platform podium. The status of missing finishing materials for the platform podiums of about 200 railway stations and the related design and construction standards of the Korea National Railway were investigated. After that, the cause of the drop-off of the finishing material was analyzed, and as a result, it was found that the main cause was the boundary between the roadbed and the architectural process that occurred during construction. Subsequently, in connection with the derived causes and design, construction standards, (1) improvement of finishing materials or construction methods, (2) design of finishing materials that are easy to adjust height, (3) design of separate finishing methods, (4) improvement methods and durability were suggested.