• 청정기술
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• 제14권4호
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• pp.248-255
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• 2008

초임계이산화탄소의 존재 하에서 세 가지 이온성액체(IL)의 부피팽창을 압력 32 MPa까지, 온도 313.15에서 333.15 K까지 뷰셀(view cell) 내에서 측정하였다. 이미다졸유도체 이온성액체인 육불화 1-부틸-3-메틸이미다졸([bmim][$PF_6$]), 사불화 1-부틸-3-메틸이미다졸([bmim][$BF_4$]), 사불화 1-옥틸-3-메틸이미다졸([omim][$BF_4$])을 연구에 사용하여, 압력, 온도, 양이온과 음이온의 성질, 그리고 수분 함량이 $CO_2$의 흡수에 의한 이온성액체의 부피팽창에 미치는 영향을 실험적으로 조사하였다. 부피팽창은 긴 양이온 알킬그룹을 가지고 있는 이온성액체 및 음이온 극성이 작은 이온성액체에서 크게 나타났다. 수분함량이 적을수록, 온도가 낮을수록, 그리고 압력이 높을수록 이온성액체상의 부피는 더 크게 나타났다.

• Computers and Concrete
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• 제33권4호
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• pp.471-479
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• 2024

In urban areas, appropriate backfilling design is necessary to prevent surface subsidence and subsurface cavities after excavation. Expandable foam grout (EFG), a mixture of cement, water, and an admixture, can be used for cavity filling because of its high flowability and volume expansion. EFG volume expansion induces a porous structure that can be quantified by the entrapped air content. This study observed the unit weight variations in the EFG before and after expansion depending on the various admixture-cement and water-cement ratios. Subsequently, the air content before and after expansion and the gravimetric expansion ratios were estimated from the measured unit weights. The air content before expansion linearly increased with an increase in the admixture-cement ratio, resulting in a decrease in the unit weight. The air content after the expansion and the expansion ratio increased nonlinearly, and the curves stabilized at a relatively high admixture-cement ratio. In particular, a reduced water-cement ratio limits the air content generation and expansion ratio, primarily because of the short setting time, even at a high admixture-cement ratio. Based on the results, the relationship between the maximum expansion ratio of EFG and the mixture ingredients (water-cement and admixture-cement ratios) was introduced.

• 한국진공학회지
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• 제20권5호
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• pp.313-321
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• 2011

한국표준과학연구원(Korea Research Institute of Standards and Science, KRISS)에는 초음파간섭 수은주압력계(ultrasonic interferometer manometer, UIM), 정적형표준기(static volume expansion system, SVES), 오리피스형 정압표준기(orifice-type dynamic expansion system, ODES) 등 세 개의 주요한 국가 진공표준기가 있다. 이 장치들의 불확도 평가를 위해 각각 변수들의 측정 및 계산 모델을 개발하였다. 국제표준화기구(International Organization for Standardization, ISO) 지침에 따라 표준기들의 확장불확도(expanded uncertainty, U)를 계산하였다.

• 제어로봇시스템학회논문지
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• 제12권12호
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• pp.1191-1196
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• 2006

In this work the kinetics of volume changes of fluid spaces associated with infusion of Ringer's solution are analyzed using the body fluid space model. During infusion of Ringer's solution, the human body is assumed to be characterized by the fluid space model into which fluid is fed and from which fluid is left. Various infusion types were tested to accommodate different medical situations. Volunteers were given Ringer's solution and the changes in blood hemoglobin were detected. From the comparison with experimental data, the single- and two-fluid space models were found to represent adequately the kinetics of human volume expansion during infusion of Ringer's solution.

• The Journal of Korean Physical Therapy
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• 제21권3호
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• pp.25-32
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• 2009

Purpose: This study examined whether breathing exercises might increase the chest expansion and pulmonary function of stroke patients. Methods: Twenty four patients with stroke were assigned randomly into two groups: a combination of diaphragmatic resistive breathing and pursed-lip breathing exercise (CB) group (n=10) and control group (n=14). The CB group completed a 4-week program of diaphragmatic resistive breathing and pursed-lip breathing exercise. The subjects were assessed using the pre-test and post-test measurements of the chest expansion (length for resting, deep inspiration, deep expiration, deep expiration-inspiration) and pulmonary function (forced vital capacity (FVC), forced expiratory volume at one second (FEV1), FEV1/FVC, peak expiratory flow (PEF), vital capacity (VC), tidal volume (TV), expiratory reserve volume (ERV), inspiratory reserve volume (IRV)). Results: A comparison of the chest expansion between the pre and post tests revealed similar rest, deep inspiration, deep expiration, and deep expiration-inspiration lengths in the CB and control groups (p>0.05). A comparison of the pulmonary function between pre and post tests, revealed significant improvements in the FVC, FEV, PEF, VC, IRV, and ERV in the CB group (p<0.05). There was a significant difference in the FVC, FEV1, PEF, VC and IRV between the 2 groups (p<0.05). Conclusion: These findings suggest that breathing exercise should help improve the pulmonary function, such as the volume and capacity. This suggests that the pulmonary functions of stroke patients might be improved further by a continued respiratory exercise program.

• 자원리싸이클링
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• 제8권4호
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• pp.3-10
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• 1999

생활하수처리장에서 발생하는 슬러지연소재(SA)에 정유공장의 폐촉매(RFCC)를 첨가시켜 제조하려는 실험.연구를 행하였다. SA만의 경우에는 $1250^{\circ}C$에서 열처리하였을 때 비중이 1.67인 골재를 얻을 수 있었으며, 부피팽창률은 승온속도에 큰 영향이 없었고 소성시간에 따라서는 다소 저하하는 경향을 보였다. SA에 RFCC를 10 wt% 첨가한 경우에 $1250^{\circ}C$에서 비중이 1.07인 경량골재를 얻을 수 있었으며 소성시간에 따라 부피팽창율이 다소 증가하였다. 경량골재를 제조하기 위한 최적 RFCC 첨가량은 10 wt%이었으며 최대 부피팽창율을 보인 조건은 승온속도; $20^{\circ}C/min$, 소성온도; $1250^{\circ}C$, 유지시간; 50분의 경우였다. RFCC의 첨가량에 따라 제조된 시편의 압축강도는 30 wt% RFCC>SA>20 wt% RFCC>10 wt% RFCC의 경향을 보였다.

• 한국세라믹학회지
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• 제23권4호
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• pp.41-46
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• 1986

When barium titanate was synthesized in solid-solid reaction the abnormal expansion occurred from 90$0^{\circ}C$ to 110$0^{\circ}C$. The equi molecular mixture of $BaCo_3$ and $TiO_2$ was sintered from 90$0^{\circ}C$ to 130$0^{\circ}C$ on the condition of air vacuum and $CO_2$ atomosphere. After that the specimens were tested closely with XDR Dilatometer and SEM The result indicated that: 1, Volume expansion to be synthesized barium titanate in solid-solid reaction was affected by atomosphere sintering. 2. The solid reaction ot fiorm barium titanate in vacuum atomosphere occurred faster than that in air atomosphere. In vacuum atomosphere the maxium volume expansion was about 30% at 90$0^{\circ}C$ for 2hrs, 3. The solid reaction to form barium titanate in 4CO_2$ atomosphere occurred slower than that in air atomosphere. In $CO_2$ atomosphere the maximum volume expansion was 13% at 100$0^{\circ}C$ for 2 hrs. 4. According to the result of x-ray the expanison was caused by the reaction to form $BaTiO_3$ and change $Ba_2TiO_4$ into 4BaTiO_3$.

• Imaging Science in Dentistry
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• 제42권2호
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• pp.83-88
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• 2012

Purpose : The aim of this study was to investigate the initial effects of maxillary expansion therapy with Hyrax appliance and to evaluate the related changes in maxillary sinus volume. Materials and Methods : Thirty patients (20 females, 10 males; 13.8 years) requiring maxillary expansion therapy, as part of their comprehensive orthodontic treatment, were examined. Each patient had cone-beam computed tomography (CBCT) images taken before (T1) and after (T2) maxillary expansion therapy with a banded Hyrax appliance. Multiplanar slices were used to measure linear dimensions and palatal vault angle. Volumetric analysis was used to measure maxillary sinus volumes. Student t tests were used to compare the pre- and post-treatment measurements. Additionally, differences between two age groups were compared with Mann-Whitney U test. The level of significance was set at p=0.05. Results : Comparison of pre-treatment to post-treatment variables revealed significant changes in the transverse dimension related to both maxillary skeletal and dental structures and palatal vault angle, resulting in a widened palatal vault (p<0.05). Hard palate showed no significant movement in the vertical and anteroposterior planes. Nasal cavity width increased on a mean value of 0.93mm(SD=0.23, p<0.05). Maxillary sinus volume remained virtually stable. No significant age differences were observed in the sample. Conclusion : Hyrax expansion therapy did not have a significant impact on maxillary sinus volume.

• 한국수소및신에너지학회논문집
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• 제27권4호
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• pp.349-356
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• 2016

Volumetric capacity metrics at cryogenic condition are critical for technological and commercial development. It must be calculated and reported in a uniform and consistent manner to allow comparisons among different materials. In this paper, we propose a simple and universal protocol for the determination of volumetric capacity of sorbent materials at cryogenic condition. Usually, the sample container volume containing porous sample at RT can be directly determined by a helium expansion test. At cryogenic temperatures, however, this direct helium expansion test results in inaccurate values of the sample container volume for microporous materials due to a significant helium adsorption, resulting significant errors in hydrogen uptake. For reducing this container volume error, therefore, we introduced and applied the indirect method such as 'volume correction using a non-porous material', showing a reliable cold volume correction.

• 한국재난정보학회 논문집
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• 제13권1호
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• pp.35-42
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• 2017

본 연구에서는 연약지반이나 부분침하의 복원에 사용되는 팽창약액의 강도특성을 정량적으로 평가하기 위하여 팽창성능을 구분한 팽창약액을 제작하여 강도특성을 조건에 따라 분석하였다. 상대적 고팽창군과 저팽창군으로 구분하여 실험을 실시하였으며, 각각 최대 팽창부피에 대해 10~30%의 부피를 제어한 공시체를 제작하여 강도 평가를 수행한 결과 시간에 따라 강도가 증진되는 것을 확인하였고, 고팽창군과 저팽창군의 압축강도는 약 2.1배의 차이를 보였다.