• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제25회 추계학술대회논문집
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• pp.329-334
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• 2005

고농도 과산화수소는 별도의 산화제가 필요치 않은 단일추진제로써 상온에서 액상인 장점이 있어 다양한 장치의 추진제로 이용되고 있다. 본 연구에서는 고온촉매인 $La_{0.8}Sr_{0.2}CoO_3(LSC)$촉매의 저온 시동성능의 보완을 위해 은, 백금, LSC, 망간계열촉매를 후보군으로 하여 과산화수소 가스발생기의 기화기 촉매를 실험적으로 선정하였다. 또한 이 때 발견된 망간계열촉매의 접착문제를 해결하고자 알루미나 졸-겔법을 이용한 촉매 합성법과 코팅 방법을 개발하였다. 그리고 코팅된 $K_2MnO_4/Al_2O_3$촉매와 LSC와의 드롭-테스트를 통해 상온에서의 반응성과 응답특성을 비교하였고, 가스발생기를 이용한 반응실험을 통해 설계유량에 적합한 기화기의 길이를 측정하였다.

• 대한영양사협회학술지
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• 제27권4호
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• pp.232-247
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• 2021

This study attempted to examine the nutrition knowledge of caregivers for the elderly and the diet-related medical treatment and dietary assistance given by them. Thus, this research is a descriptive study focusing on the current nutritional knowledge of caregivers and the dietary assistance given by them. The survey included a questionnaire (nutritional knowledge level of digestive system diseases, diabetes, cardiovascular risk, brain disease, bone disease, and meal assistance performance status) for caregivers working in nursing homes for the elderly. Self-administered questionnaires were completed by 235 caregivers between February and March 2020. The results were analyzed using the SPSS 25.0, and the significance test of each question was verified by the Friedman test and the Chi-square independence test. The number of elderly people who needed meal assistance from caregivers was 4.4 more than the average. The most common types of meal assistance were partial assistance (59.20%) and the task of when to stop eating for the elderly (58.71%). Besides, the higher nutritional knowledge level of the caregivers, the more the time spent on services related to meal assistance (P<0.001), and the higher the meal assistance level. The disease state of the elderly was considered the most relevant (P<0.001). Caregivers with high levels of knowledge and offering significant meal assistance were found to have received nutrition education (P<0.001). Up to 80% of the respondents needed nutrition education, and most of them answered that they needed education on appropriate management methods for the specific disease state of the elderly (P<0.01). Accordingly, providing nutrition education for caregivers for the elderly should be a means to improve their ability to offer meal assistance.

• Animal Bioscience
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• 제35권9호
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• pp.1418-1425
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• 2022

Objective: An experiment was conducted to determine the standardized ileal digestibility (SID) of amino acids (AA) in fish meal (FM) and blood-derived protein sources including spray-dried porcine plasma (SDPP), porcine red blood cells (PRBC), and blood meal (BM) fed to growing pigs. Methods: Ten barrows (mean initial body weight of 22.1±1.54 kg) surgically fitted with T-cannulas at the distal ileum were allotted to a duplicated 5×4 incomplete Latin square design with 5 experimental diets and 4 periods. Four experimental diets were prepared to contain FM, SDPP, PRBC, or BM as the sole source of nitrogen. A nitrogen-free diet was prepared and included to estimate the basal ileal endogenous losses of AA. For the 7-day experimental period, pigs were fed for 5 days as adaptation, and ileal digesta samples were collected for 9 hours on days 6 and 7. Results: The SID of crude protein in BM (48.0%) was less (p<0.05) than in FM, SDPP, and PRBC (83.4%, 83.9%, and 87.3%, respectively). Pigs fed the diet containing BM had less (p<0.05) SID of AA, except isoleucine and proline, than those fed the diet containing FM, SDPP, or PRBC. Among FM, SDPP, and PRBC, there was no difference in the SID of crude protein and all AA, except isoleucine. The SID of isoleucine in PRBC and BM (62.7% and 48.3%, respectively) was less (p<0.05) than in FM and SDPP (88.0% and 84.9%, respectively). The SID of lysine in FM, SDPP, PRBC, and BM was 85.4%, 84.9%, 89.7%, and 51.9%, respectively. Conclusion: The SID of most AA was not different among FM, SDPP, and PRBC, but BM had lower SID of most AA than FM, SDPP, and PRBC.

• Tuberculosis and Respiratory Diseases
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• 제87권3호
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• pp.386-397
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• 2024

Background: Despite the global increase in nontuberculous mycobacterial pulmonary disease (NTM-PD), clinical characteristics show geographical variations. We investigated the clinical characteristics of patients with NTM-PD in South Korea. Methods: We systematically reviewed articles concerning patients with NTM-PD in South Korea until February 2022. Individual participant data, regardless of treatment, were collected using a standard case report form. Results: Data of 6,489 patients from 11 hospitals between 2002 and 2019 were analyzed. The mean age was 61.5±11.7 years, of whom 57.7% were women. Mycobacterium avium (41.4%) and Mycobacterium intracellulare (38.4%) comprised most of the causative species, followed by Mycobacterium abscessus subspecies abscessus (8.6%) and M. abscessus subspecies massiliense (7.8%). Bronchiectasis (59.4%) was the most common pulmonary comorbidity. Although reported cases of NTM-PD increased over the years, the proportions of causative species and radiologic forms remained similar. Distinct clinical characteristics were observed according to age and sex. Men were older at the time of diagnosis (median 63.8 years vs. 59.9 years, p<0.001), and had more cavitary lesions than women (38.8% vs. 21.0%, p<0.001). The older group (≥65 years) had higher proportions of patients with body mass index <18.5 kg/m² (27.4% vs. 18.6%, p<0.001) and cavitary lesions (29.9% vs. 27.6%, p=0.009) than the younger group. Conclusion: We conducted a meta-analysis of the clinical characteristics of patients with NTM-PD in South Korea, and found age- and sex-related differences in disease-specific severity. Further investigation would enhance our comprehension of the nature of the disease, and inherited and acquired host factors.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.187-195
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• 2018

$Sr_{0.92}Y_{0.08}Ti_{1-x}Ni_xO_{3-{\delta}}$ (SYTN) was investigated in the presence of $H_2S$ containing fuels to assess the feasibility of employing oxide materials as alternative anodes. Aliovalent substitution of $Ni^{2+}$ into $Ti^{4+}$ increased the ionic conductivity of perovskite, leading to improved electrochemical performance of the SYTN anode. The maximum power densities were 32.4 and $45.3mW/cm^2$ in $H_2$ at $900^{\circ}C$ for the SYT anode and the SYTN anode, respectively. However, the maximum power densities in 300 ppm of $H_2S$ decreased by 7% and by 46% in the SYT and the SYTN anodes, respectively. To enhance the sulfur tolerance and to improve the electrochemical properties, the surface of SYTN anode was modified with samarium doped ceria (SDC) using the sol-gel coating method. For the SDC-modified SYTN anode, the cell performance was mostly recovered in the pure $H_2$ condition after 500-ppm $H_2S$ exposure in contrast to the irreversible cell performance degradation exhibited in the unmodified SYTN anode.

• 전기학회논문지
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• 제60권9호
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• pp.1770-1776
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• 2011

In this study, a new method that can estimate ICG data from a subject's both hands to measure Cardiac Output under convenient sensor environment. With this aim, a grip-type electrode was implemented to measure ICG. To improve the accuracy of measurement, the regression equation was extracted using multiple bio-parameters and our result was compared with the thoracic ICG equipment(Physio Flow$^{(R)}$, PF104D, Manatec Biomedical, France), which is being used in clinics. The subjects consist of 26 men and 4 women(age in $22.0{\pm}3.32$). They are no cardiac disease. Parameters available for regression model were used gender, BMI, MBP, LVET, dZ/dt(max), distance between the measured electrodes, body impedance, and PTT. As a result of analyzing the ICG measurement value on thorax and both hands, the correlation with stroke volume, heart rate, and cardiac output was $R^2$=0.853, $R^2$=0.958 and $R^2$=0.899, respectively.

• 신재생에너지
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• 제1권4호
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• pp.19-24
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• 2005

수소 여과용 치밀질 membrane의 제조는 기존의 SC($SrCeO_3$)보다 높은 여과특성을 가지는 BC($BaCeO_3$)구조의 재료를 이용하여 시편을 제조하였고, 시편의 물성은 기공율, 수분에 대한 내구성 그리고 여과 특성을 측정하였다. 우선 열적 안정성 및 수분에 대한 내구성 향상은 $Y_2O_3$를 0.1mol첨가 하였을 때 1% 이내의 기공율을 가지고 있었으며 수분에 대한 안정성을 위해 boiling test에서도 균열이 발생되지 않고 안정적인 것을 확인할 수 있었다. 또한 여과 특성을 향상시키기 위해 Ce과 치환이 가능하고 전도성을 향상시킬 수 있는 $Ga_2O_3$, $La_2O_3$을 치환하여 물성을 측정한 결과 $Ga_2O_3$은 0.05, $La_2O_3$ 0.1mol%가 최적이었으며, 이들 중 $Ga_2O_3$가 0.05mol 첨가 되었을 때 가장 높은 이온 전도도 값을 얻었으며, $La_2O_3$이 첨가된 경우가 다음으로 높게 나타났다. 전자 전도성을 높이기 위하여 Pt를 sol로 만들어 나노 입자로 분산 시키는 방법으로 실험을 실시 $500^{\circ}C$ 이상의 온도에서는 복합전도에 의해 전도도가 향상되어지는 것을 확인할 수 있다. 또한 이들 시편의 여과 특성을 측정한 전도도 측정의 결과와 동일한 결과를 얻을 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권4호
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• pp.546-553
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• 2017

Objective: An experiment was conducted to determine digestible energy (DE) and metabolizable energy (ME) of different byproduct feed ingredients fed to growing pigs, and to generate prediction equations for the DE and ME in feed ingredients. Methods: Twelve barrows with an initial mean body weight of 31.8 kg were individually housed in metabolism crates that were equipped with a feeder and a nipple drinker. A $12{\times}10$ incomplete Latin square design was employed with 12 dietary treatments, 10 periods, and 12 animals. A basal diet was prepared to mainly contain the corn and soybean meal (SBM). Eleven additional diets were formulated to contain 30% of each test ingredient. All diets contained the same proportion of corn:SBM ratio at 4.14:1. The difference procedure was used to calculate the DE and ME in experimental ingredients. The in vitro dry matter disappearance for each test ingredient was determined. Results: The DE and ME values in the SBM sources were greater (p<0.05) than those in other ingredients except high-protein distillers dried grains. However, DE and ME values in tapioca distillers dried grains (TDDG) were the lowest (p<0.05). The most suitable regression equations for the DE and ME concentrations (kcal/kg on the dry matter [DM] basis) in the test ingredients were: $DE=5,528-(156{\times}ash)-(32.4{\times}neutral\;detergent\;fiber\;[NDF])$ with root mean square error = 232, $R^2=0.958$, and p<0.001; $ME=5,243-(153 ash)-(30.7{\times}NDF)$ with root mean square error = 277, $R^2=0.936$, and p<0.001. All independent variables are in % on the DM basis. Conclusion: The energy concentrations were greater in the SBM sources and were the least in the TDDG. The ash and NDF concentrations can be used to estimate the energy concentrations in the byproducts from oil-extraction and distillation processes.

• 한국세라믹학회지
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• 제32권5호
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• pp.594-600
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• 1995

Spherical alumina gel powders were produced by hydrolysis of aluminum sec-butoxide (Al(sec-OC4H9)3) in a n-octanol/acetonitrile mixed solvent. The enlargement of particle size was induced by increasing HPC (hydroypropylcellulose) concentration (0.005, 0.1, and 0.05 g/ι) and emulsion-state aging time (10 min and 360 min). Mean particle sizes of dried alumina gel powders increased from 1.4 ${\mu}{\textrm}{m}$ to 3.5${\mu}{\textrm}{m}$ at 10-min emulsion-state aging time and from 1.9${\mu}{\textrm}{m}$ to 4.1${\mu}{\textrm}{m}$ at 360-min emulsion-state aging time as HPC concentration increased from 0.005 g/ι to 0.05 g/ι. At the same HPC concentration, particle size of dried alumina gel powder increased with increasing of emulsion-state aging time from 10 min to 360 min. The increase in the average particle size of dried alumina gel powder with increase in HPC concentration was interpreted as the enlargement of particles from alkoxide emulsions unprotected by HPC. The produced dried gel powder calcined at 115$0^{\circ}C$ for one hour transformed to $\alpha$-alumina.

• 대한치과교정학회지
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• 제47권4호
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• pp.256-267
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• 2017

Objective: To evaluate transverse skeletal and dental changes, including those in the buccolingual dental axis, between patients with skeletal Class III malocclusion and facial asymmetry after bilateral intraoral vertical ramus osteotomy with and without presurgical orthodontic treatment. Methods: This retrospective study included 29 patients with skeletal Class III malocclusion and facial asymmetry including menton deviation > 4 mm from the midsagittal plane. To evaluate changes in transverse skeletal and dental variables (i.e., buccolingual inclination of the upper and lower canines and first molars), the data for 16 patients who underwent conventional orthognathic surgery (CS) were compared with those for 13 patients who underwent preorthodontic orthognathic surgery (POGS), using three-dimensional computed tomography at initial examination, 1 month before surgery, and at 7 days and 1 year after surgery. Results: The 1-year postsurgical examination revealed no significant changes in the postoperative transverse dental axis in the CS group. In the POGS group, the upper first molar inclined lingually on both sides (deviated side, $-1.8^{\circ}{\pm}2.8^{\circ}$, p = 0.044; nondeviated side, $-3.7^{\circ}{\pm}3.3^{\circ}$, p = 0.001) and the lower canine inclined lingually on the nondeviated side ($4.0^{\circ}{\pm}5.4^{\circ}$, p = 0.022) during postsurgical orthodontic treatment. There were no significant differences in the skeletal and dental variables between the two groups at 1 year after surgery. Conclusions: POGS may be a clinically acceptable alternative to CS as a treatment to achieve stable transverse axes of the dentition in both arches in patients with skeletal Class III malocclusion and facial asymmetry.