• 한국진공학회:학술대회논문집
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• 한국진공학회 2007년도 제33회 하계학술대회 초록집
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• pp.160-160
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• 2007

• Asian-Australasian Journal of Animal Sciences
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• 제22권3호
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• pp.428-432
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• 2009

40 goat kid ribcages were held for 7 days in storage conditions ($4^{\circ}C$) and used to determine the effects of three different packaging methods (atmospheric air, vacuum and modified atmosphere package (MAP) 10:70:20 mixture of $N_2:O_2:CO_2$) on meat quality of the chops. L* was affected by the packaging method being lighter than MAP chops. The coordinate a* significantly increased during storage time. For MAP-packed chops and those kept in atmospheric air, b* increased markedly during storage time whereas it remained unaffected throughout storage when in vacuum packages. Final pH values ranged from 5.6 to 5.8 and no effects were found for either storage time or packaging method. WHC means were lowest for the three packaging methods on day 7 of storage and highest on day 1. Storage time increased water loss in vacuum treatments. Trained panel colour acceptability was lower at 3, 5 and 7 days than on day 1 of storage for atmospheric air treatment and vacuum packaging, while for the MAP treatment average values on days 5 and 7 were lower than those observed on days 1 or 3. Trained panel odour was lower for atmospheric air and vacuum packages at 3, 5, and 7 days storage than at 1 day, while no differences were found in trained panel odour acceptability for MAP packages. With reference to consumers, the MAP proposed in the present study is the chosen method for storing goat meat, rather than vacuum or atmospheric air packaging.

• 한국산업융합학회 논문집
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• 제26권4_2호
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• pp.629-637
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• 2023

This study aimed to evaluate the effect of post-curing equipment and time on the flexural strength of 3D printing resins produced by a liquid crystal display(LCD) printer. The three 3D printing resins(DENTCA Denture Teeth, DT; C&B 5.0 hybrid, CH; C&B Permanent A2, CP) were divided into four groups according to post-curing time(10 min and 30 min) and equipment with or without vacuum treatment. For the three-point flexural strength test and biaxial strength test were prepared by method according to ISO 10477, ISO 6872, respectively. Flexural strength was measured with universal testing machine. Comparison between post-curing time of each post-curing equipment was analyzed by independent sample t-test and Mann-Whitney U test(α=.05), and comparison between groups according to each 3D printing resin was performed by Kruskal-Wallis test and post-hoc by Bonferroni-Dunn test(α=.05). The flexural strength of the resin post-curing under vacuum was higher than that of the resin post-curing in air. In the comparison according to the post-curing time, in the case of the post-curing equipment without vacuum, the 30 minute curing time showed significantly higher flexural strength than the 10 minute curing time, except for the biaxial flexural strength of CH(P<.05). In the post-curing equipment with vacuum, the three-point flexural strength of all 3D printing resins(DT, CH, and CP) showed a higher value at 30 minute curing time than at 10 minute curing time.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.207-208
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• 2000

The temporal response of the electroluminescence (EL) has been studied in the organic electroluminescent devices fabricated with a vacuum-deposited poly(p-phenylene) (PPP) thin film upon the application of a rectangular driving voltage. The blue EL emission arises with a delay time of several hundred nanoseconds and then saturates with the rise time of less than microsecond. The EL delay time is considered as the transit time of holes in the PPP thin film since the hole mobility is much larger than the electron mobility in PPP. The hole mobility is estimated to be ${\sim}$ $1{\times}10^{-5}$ $cm^2/Vs$ in the vacuum-deposited PPP film.

• 유기물자원화
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• 제6권1호
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• pp.67-73
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• 1998

본 연구에서는 하수처리장에서 발생하는 하수슬러지의 부피를 감소시키기 위하여 감압건조법을 이용하여 반응압력, 반응시간, 반응온도에 따른 하수슬러지의 탈수효율을 조사하였다. 반응압력이 낮아질수록 슬러지의 함수율은 감소되는 경향을 보였으며, 동일한 반응압력 및 반응온도에서는 반응시간이 길어질수록 탈수효율이 상승하였고 반응온도에 따라서는 $120^{\circ}C$ 이상에서부터 슬러지의 탈수효과가 뛰어남을 알 수가 있었다. 결과적으로 하수슬러지를 감압건조법으로 처리할시에는 탈수효율이 기존의 탈수 방법보다 우수한 결과를 보임으로서 하수슬러지의 처리시 소요되는 비용을 절감할 수 있을 것으로 판단되며 슬러지뿐만 이아니라 음식물쓰레기 등의 유기성폐기물에도 적용이 가능할 것으로 판단된다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권1호
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• pp.19-24
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• 2003

Design and test results of a VRAG(Vacuum Rotary Arc Gap) switch were presented. To control the damage of electrodes caused by the vacuum arc, Lorentz's force by the radial magnetic field between spiral electrodes was used to rotate the vacuum uc. VRAG switch electrodes were made of the material of CuCr and OFHC. Gap distance between two spiral type electrodes for the rotation of the arc discharge is 8, 10, 12mm. In the cathode, one trigger electrode was inserted into each spiral wing. Normal operation of the VRAG switch was confirmed with 10.6[$mutextrm{s}$]of trigger delay and 2~3[$mutextrm{s}$] of the jitter time. The speed of the vacuum arc was measured to be 0.6 ~ 1[km/s] by a motion analyzer.

• 산업기술연구
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• 제21권A호
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• pp.293-301
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• 2001

This paper is experimental results of investigating the efficiency of horizontal vacuum drainage system. Effects of size and shape of drain on horizontal vacuum drainage were studied. Model tests in the laboratory with soft marine clay were carried out with drain pipe of having three different diameters and PBD (Plastic Board Drain) of strip shape so that consolidation settlement of soft clay due to applied vacuum pressure, amount of discharge, ground settlement and distributions of pore pressure and undrained shear strength were measured during testing. From results of model test, amount of discharge due to vacuum pressure was increased with the diameter of pipe drain whereas the drain efficiency of pipe in per unit area of drain surface was decreased with diameter of pipe. The rate of discharge per unit time was reduced very fast with diameter of pipe. Settlement of ground surface with time was increased with diameter of pipe as a result of increase of discharge to drain pipe.

• 열처리공학회지
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• 제26권1호
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• pp.7-13
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• 2013

Vacuum heat treatment(indirect heating method) has long exposure time at high temperature and low quenching rate. Contrarily salt bath heat treatment (direct heating method) has short exposure time at high temperature and fast cooling rate. With these different features of processes, mechanical properties such as hardness, tensile strength and impact strength of products show very different results. In this study, Salt bath heat treated products showed higher tensile strength and impact strength than vacuum heat treated products but hardness was not much different. These lower mechanical properties of vacuum heat treated products are due to differences in heat process and secondary hardening with high temperature tempering process. Consequently, It indicates that salt bath heat treatment is better way than vacuum heat treatment for product to have high mechanical properties.

• 반도체디스플레이기술학회지
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• 제12권2호
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• pp.45-50
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• 2013

This paper focuses on the fundamental issues for improving the efficiency and throughput of the AC PDP (Plasma Display Panel) manufacturing. The properties of the MgO protective layer affect the PDP efficiency. Especially, the secondary electron emission efficiency was affected on the deposition rate of MgO during the evaporation. In this study, the deposition rate of 5 $\AA$/s has given the maximum efficiency value of 0.05 It is demonstrated that the impurity gases such as $H_2O$, $CO_2$, CO or $N_2$, and $O_2$ can be remained inside the PDP panel before sealing and the amount of the impurity gases decreased rapidly as the base vacuum level increased, especially near $10^{-5}$ torr. The fundamental solution in order to overcome these problems is the vacuum in-line sealing process from the MgO evaporation to the final sealing of the panel without breaking the vacuum. We have demonstrated this fundamental process technology and shown the feasibility. The firing voltage was reduced down to 285 V at the base vacuum value of $10^{-6}$ torr, whreras it was about 328 V at the base vacuum value of $10^{-3}$ torr.

• 진공이야기
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• 제2권1호
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• pp.31-34
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• 2015

This article introduces fundamentals of self-diagnosis and predictive (or preventive) maintenance technologies for dry vacuum pumps. The state variables of dry pumps are addressed, such as the pump and motor body temperatures, consumption currents of main and booster pumps, mechanical vibration, and exhaust pressure, etc. The adaptive parametric models of the state variables of the dry pump are exploited to provide dramatic reduction of data size and computation time for self-diagnosis. Two indicators, the Hotelling's $T^2$ and the sum of squares residuals (Q), are illustrated to be quite effective and successful in diagnosing dry pumps used in the semiconductor processes.