• 한국환경과학회지
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• 제24권5호
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• pp.679-687
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• 2015

Atmospheric aerosol particles were investigated at GNTECH university in Jinju city. Samples were collected using the Nanosampler period from January to December 2014. The Nanosampler is a 6 stage cascade impactor(1 stage : > $10{\mu}m$, 2 stage : $2.5{\sim}10{\mu}m$, 3 stage : $1.0{\sim}2.5{\mu}m$, 4 stage : $0.5{\sim}10{\mu}m$, 5 stage : $0.1{\sim}0.5{\mu}m$, back-up : < $0.1{\mu}m$) with the stages having 50% cut-off ranging from 0.1 to $10{\mu}m$ in aerodynamic diameter. The mass size distribution of Atmospheric aerosol particles was unimodal with peak at $1.0{\sim}2.5{\mu}m$ or $0.5{\sim}1.0{\mu}m$. The annual average concentrations of TSP, $PM_{10}$, $PM_{2.5}$, $PM_1$, $PM_{0.5}$ and $PM_{0.1}$ were $44.0{\mu}g/m^3$, $40.3{\mu}g/m^3$, $31.4{\mu}g/m^3$, $18.0{\mu}g/m^3$, $8.0{\mu}g/m^3$, $3.0{\mu}g/m^3$, respectively. On average $PM_{10}$, $PM_{2.5}$, $PM_1$, $PM_{0.5}$ and $PM_{0.1}$ make up 0.91, 0.70, 0.41, 0.19 and 0.07 of TSP, respectively. The annual average of $PM_{2.5}/PM_{10}$ ratio was 0.77.

• Journal of Animal Science and Technology
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• 제63권3호
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• pp.491-500
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• 2021

The objective of this study was to evaluate the effects of low protein diets added with protease on growth performance, nutrient digestibility, and blood profiles of weaned piglets and growing-finishing pigs. A total of 96 weaned pigs ([Yorkshire × Landrace] × Duroc) with average body weight (BW) of 6.99 ± 0.21 kg were used in a 20-week experiment. The dietary treatments were arranged in a 2 × 3 factorial design. Treatments were as follows: In phase 1 (1-2 weeks), two protein levels as high protein (HP; 19.0%), low protein (LP; 17.0%), and three protease (PT) levels (PT0, 0%; PT1, 0.3%; and PT2, 0.5%); in phase 2 (3-4 weeks), protein levels (HP, 18.05%; LP, 16.15%) and protease levels (0%, 0.3%, and 0.5%); in phase 3 (5-12 weeks), protein levels (HP, 17.1%; LP, 15.3%) and protease level (0%, 0.15%, and 0.3%); in phase 4 (13-20 weeks), protein levels (HP, 16.15%; LP, 14.45%) and protease level (0%, 0.15%, and 0.3%). At 4 weeks and 20 weeks after treatment, BW was higher (p < 0.050) in the PT2 group than PT0 group. From weeks 0 to 4, average daily gain (ADG) and feed efficiency (G/F) were higher (p = 0.006 and p = 0.014; p = 0.014 and p = 0.044, respectively) in the PT2 group than PT0 and PT1 groups. From weeks 16 to 20, ADG and G/F were higher (p < 0.001 and p = 0.009; p = 0.004 and p = 0.033, respectively) in the PT2 group than PT0 and PT1 groups. Crude protein (CP) digestibility was higher (p = 0.013, p = 0.014, and p = 0.035, respectively) in the low protein (LP) group than high protein (HP) group at weeks 4, 12, and 20. At weeks 4 and 20, the LP diet group had lower (p < 0.001 and p = 0.001, respectively) blood urea nitrogen (BUN) levels than the HP diet group. Therefore, a low CP diet added with protease could increase growth performance and CP digestibility of weaned piglets and growing-finishing pigs.

• Korean Journal of Radiology
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• 제25권3호
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• pp.243-256
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• 2024

Objective: We aimed to investigate whether 2-[¹⁸F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (2-[¹⁸F]FDG PET/CT) can aid in evaluating the risk of malignancy in ampullary tumors detected by endoscopy. Materials and Methods: This single-center retrospective cohort study analyzed 155 patients (79 male, 76 female; mean age, 65.7 ± 12.7 years) receiving 2-[¹⁸F]FDG PET/CT for endoscopy-detected ampullary tumors 5-87 days (median, 7 days) after the diagnostic endoscopy between June 2007 and December 2020. The final diagnosis was made based on histopathological findings. The PET imaging parameters were compared with clinical data and endoscopic features. A model to predict the risk of malignancy, based on PET, endoscopy, and clinical findings, was generated and validated using multivariable logistic regression analysis and an additional bootstrapping method. The final model was compared with standard endoscopy for the diagnosis of ampullary cancer using the DeLong test. Results: The mean tumor size was 17.1 ± 7.7 mm. Sixty-four (41.3%) tumors were benign, and 91 (58.7%) were malignant. Univariable analysis found that ampullary neoplasms with a blood-pool corrected peak standardized uptake value in earlyphase scan (SUVe) ≥ 1.7 were more likely to be malignant (odds ratio [OR], 16.06; 95% confidence interval [CI], 7.13-36.18; P < 0.001). Multivariable analysis identified the presence of jaundice (adjusted OR [aOR], 4.89; 95% CI, 1.80-13.33; P = 0.002), malignant traits in endoscopy (aOR, 6.80; 95% CI, 2.41-19.20; P < 0.001), SUVe ≥ 1.7 in PET (aOR, 5.43; 95% CI, 2.00-14.72; P < 0.001), and PET-detected nodal disease (aOR, 5.03; 95% CI, 1.16-21.86; P = 0.041) as independent predictors of malignancy. The model combining these four factors predicted ampullary cancers better than endoscopic diagnosis alone (area under the curve [AUC] and 95% CI: 0.925 [0.874-0.956] vs. 0.815 [0.732-0.873], P < 0.001). The model demonstrated an AUC of 0.921 (95% CI, 0.816-0.967) in candidates for endoscopic papillectomy. Conclusion: Adding 2-[¹⁸F]FDG PET/CT to endoscopy can improve the diagnosis of ampullary cancer and may help refine therapeutic decision-making, particularly when contemplating endoscopic papillectomy.

• 인간식물환경학회지
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• 제22권1호
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• pp.65-73
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• 2019

The purpose of the study was to examine the effects of the Horticulture Job Skill course based on the employment practice model on personal performance indicator of vocational rehabilitation for university students with disabilities. In the first step of this study, an employment practice model was developed by a focus group composed of six specialists from the industry and academia. The second step consisted of selecting the items of personal performance indicator related to horticulture vocational rehabilitation among all items of vocational rehabilitation. The third step was selecting students to participate in the study. The next step was coming up with a pilot instructional design based on the employment practice model. The final step was examining the effects of pilot course (horticulture job skill) based on the employment practice model on personal performance indicator of vocational rehabilitation for university students with disabilities. As a result, there were significant improvements after treatment in the experimental group with indicator 1 (managing) from 1.8±0.155 to 4.2±0.267, indicator 2 (planting) from 1.5±0.114 to 4.45±0.153, indicator 3 (using tool) from 3.2±0.186 to 4.6±0.112, indicator 4 (packing) from 2.05±0.153 to 4.45±0.114, indicator 5 (decorating) from 2.65±0.150 to 5.5±0.114, indicator 6 (cleaning) from 2.85±0.131 to 4.45±0.114, indicator 7 (observing) from 2.4±0.112 to 4.45±0.112, and indicator 8 (laboring) from 2.35±0.109 to 4.1±0.180. However, the control group did not show any significant improvement after 15 weeks of the program. This study determined that the Horticulture Job Skill course based on the employment practice model has an effect on improving the individual performance of vocational rehabilitation for university students with disabilities. Finally, horticulture education-based on the employment practice model will contribute to vocational rehabilitation for university student with disabilities.

• 한국식품영양과학회지
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• 제25권6호
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• pp.915-921
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• 1996

한국재래간장으로부터 분리한 Bacillus subtilis CCKS-111이 생성하는 protease 생산의 최적 배양조건은 2% soluble starch, 0.2% peptone, 0.1%(MH$_4$)$_2$S$_2$O$_{8}$ , 0.2% MgSO$_4$, pH 7.0, 35$^{\circ}C$ 에서 24시간 배양했을 때이다. 효소의 최적 작용 pH와 온도는 pH 9.0, 5$0^{\circ}C$였으며 , pH 6.0~11.0의 범위와 5$0^{\circ}C$이상에서 불안정하였다. 금속이온 중 Cu$^{2+}$에 의하여 활성이 증대되었으나 $K^{2+}$, Hg$^{2+}$등에 의하여 효소활성이 저해되었다. Ethylenediamineteraacetic acid 와 phenylmethane sulfonyl fluoride 처리에 의해 활성이 저해되어 금속이온의 영향을 받는 serine protease로 확인되었다. Km값은 2.313$\times$$10^{-4}$ M, V$_{max}$ 값은 39.216$\mu\textrm{g}$/min이었으며, hemoglobin보다 casein을 더 잘 가수분해하였다.

• Journal of Animal Science and Technology
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• 제44권5호
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• pp.523-530
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• 2002

본 연구는 1999년 8월부터 2000년 2월까지 공인 제2종돈능력검정소에서 검정 종료된 Duroc종, Landrace종 및 Yorkshire종에 대하여 체중, 등지방두께, 일당증체량 및 정육율을 측정하여, 동일 개체의 반복측정치 간의 반복력과, 상관 및 순위상관을 추정하였으며, 그 결과를 요약하면 다음과 같다. 1. 평균능력은 측정시 체중이 각각 91.0, 114.7, 123.2kg이였으며, 측정시 일령은 각각 142.1, 173.7, 182.5일이였으며, 정육율은 각각 57.9, 56.2, 55.2%였으며, 등지방두께는 각각 1.33, 1.61, 1.63cm였으며, 일당증체량은 각각 946.6, 879.2, 879.4g으로 나타났다. 2. 각 형질의 측정차수간 상관은 정육율의 경우, 1차와 2차, 1차와 3차, 2차와 3차간 각각 0.493, 0.471, 0.619로 나타났고, 등지방두께의 경우, 각각 0.424, 0.424, 0.700으로 나타났으며, 일당증체량의 경우, 각각 0.716, 0.601, 0.861로 모든 형질에서 1차와 2차간, 1차와 3차간 보다는 2차와 3차간에 높게 추정되었다. 3. 각 측정차수의 형질간 상관은 1차 측정의 경우, 정육율과 등지방두께, 정육율과 일당증체량, 등지방두께와 일당증체량이 각각 －0.597, －0.291, 0.303으로 나타났고, 2차 측정의 경우, 각각 －0.667, －0.292, 0.396으로 나타났으며, 3차 측정의 경우, 각각 －0.711, －0.369, 0.409로 정육율과 등지방두께 및 일당증체량은 부의 상관관계에 있으며, 등지방두께와 일당증체량은 정의 상관관계에 있고, 일령이 증가할수록 상관이 높게 추정되었다. 4. 각 형질의 반복력 추정치를 살펴보면, 등지방두께가 0.374, 정육율이 0.428, 일당증체량이 0.673으로 추정되었으며, 일당증체량의 반복력은 상당히 높게 추정되어, 110kg까지 검정의 필요성이 인정되지 않으나, 등지방두께와 정육율의 추정치는 낮게 추정되어 더욱 많은 연구가 필요할 것으로 사료된다.

• 한국전기전자재료학회논문지
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• 제25권6호
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• pp.435-438
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• 2012

As lead-free piezoelectric materials, $Ag_2O$ doped $0.95(K_{0.5}Na_{0.5})NbO_3-0.05LiNbO_3+x$ mol% (where x = 0, 0.5, 1, 1.5, 2, 2.5 and 3, respectively) ceramics were fabricated by a conventional sintering process. The doping effects on the microstructure and electrical properties of the $0.95(K_{0.5}Na_{0.5})NbO_3-0.05LiNbO_3$ ceramics were systematically investigated. When the 3 mol % $Ag_2O$ doped $0.95(K_{0.5}Na_{0.5})NbO_3-0.05LiNbO_3$ samples were sintered at $1,080^{\circ}C$ for 5 hrs in air, these ceramics showed excellent values of density=4.20 $g/cm^3$, piezoelectric constant ($d_{33}$)=174 pC/N and phase transition temperature$(T_c)=421.6^{\circ}C$, respectively.

• Bulletin of the Korean Chemical Society
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• 제13권6호
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• pp.593-595
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• 1992

To improve the lifetime and output power in a sealed-off $CO_2$ laser, a series of Nd$_{1-x}$Sr$_x$CoO$_3$(x = 0.0, 0.25, 0.40, 0.50, 0.60, 0.75) perovskite-type compounds has been synthesized and used for a cathode material. Using a typical method samples were sintered at 1150$^{\circ}$C and their structures were determined as a cubic form by means of XRD analysis. The degrees of $CO_2$ dissociation were measured by PAS (photoacoustic spectroscopy) with the lapse of time. In the case of $Nd_{0.4}$Sr$_{0.6}$$CoO_3$, which showed the highest catalytic cathode effect, only 7% of the initial $CO_2$ concentration were dissociated at 30 torr of gas mixture and 5 mA of discharge current. The more the gas pressure decreased and the discharge current increased, the more the degree of dissociation occurred. The ability of catalytic cathode to regenerate CO$_2$ in the laser cavity lies in order for x, 0.60 > 0.50 > 0.40 > 0.75 > 0.25 ${\gg}$ 0.0. Except for the case of x = 0.0 the amounts of $CO_2$ dissociation were found to be within 7-15% of the initial $CO_2$ concentration.

• 한국환경과학회지
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• 제23권5호
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• pp.903-910
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• 2014

This study examined the treatment characteristics of hard-to-degrade pollutants such as TCE which are found in organic solvent and cleaning wastewater by nZVI that have excellent oxidation and reduction characteristics. In addition, this study tried to find out the degradation characteristics of TCE by Fenton-like process, in which $H_2O_2$ is dosed additionally. In this study, different ratios of nZVI and $H_2O_2$, such as 1.0 mM : 0.5 mM, 1.0 mM : 1.0 mM, and 1.0 mM : 2.0 mM were used. When 1.0 mM of nZVI was dosed with 1.0 mM of $H_2O_2$, the removal efficiency of TOC was the highest and the first order rate constant was also the highest. When 1mM of nZVI was dosed with 0.5 mM of $H_2O_2$, the first order rate constant and removal efficiency were the lowest. The size of first order rate constant and removal efficiency was in the order of nZVI 1.0 mM : $H_2O_2$ 1.0 mM > nZVI 1.0 mM : $H_2O_2$ 2.0 mM > nZVI 1.0 mM : $H_2O_2$ 0.5 mM > $H_2O_2$ 1.0 mM > nZVI 1.0 mM. It is estimated that when 1.0 mM of nZVI is dosed with 1.0 mM of $H_2O_2$, $Fe^{2+}$ ion generated by nZVI and $H_2O_2$ react in the stoichiometric molar ratio of 1:1, thus the first order rate constant and removal efficiency are the highest. And when 1.0 mM of nZVI is dosed with 2.0 mM of $H_2O_2$, excessive $H_2O_2$ work as a scavenger of OH radicals and excessive $H_2O_2$ reduce $Fe^{3+}$ into $Fe^{2+}$. As for the removal efficiency of TOC in TCE by simultaneous dose and sequential dose of nZVI and $H_2O_2$, sequential dose showed higher first order reaction rate and removal efficiency than simultaneous dose. It is estimated that when nZVI is dosed 30 minutes in advance, pre-treatment occurs and nanoscale $Fe^0$ is oxidized to $Fe^{2+}$ and TCE is pre-reduced and becomes easier to degrade. When $H_2O_2$ is dosed at this time, OH radicals are generated and degrade TCE actively.

• 한국재료학회지
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• 제9권10호
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• pp.1041-1046
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• 1999

(Zr(sub)0.8Sn(sub)0.2)$TiO_4$세라믹스와 소결조제로서 ($B_2$$O_3$.Li$_2$O)의 첨가에 따른 마이크로파 유전특성 및 미세구조에 미치는 영향에 대하여 연구하였다. 1.0 mol.% $Sb_2$O(sub)5를 첨가하고 130$0^{\circ}C$에서 5시간 소결한 (Zr(sub)0.8Sn(sub)0.2)$TiO_4$세라믹스의 경우 ($B_2$$O_3$.Li$_2$O)첨가량 증가에 따라 치밀화 및 결정립 성장에 의해 유전상수와 Q.f값은 증가하여 첨가량이 0.35wt.%에서 최대값인 38과 59,000을 각각 나타내었으며, 0.50wt.% 이상 첨가한 경우에서는 제 2상의 생성으로 인하여 감소하였다. 1.0 mol% Sb$_2$O(sub)5와 0.35wt.% ($B_2$$O_3$.$Li_2$O)를 첨가한 (Zr(sub)0.8Sn(sub)0.2)TiO$_4$세라믹스를 125$0^{\circ}C$와 135$0^{\circ}C$에서 5시간 소결한 경우에는 각각 미반응 TiO$_2$의 존재와 과대입자성장에 의한 결정립내기공의 생성으로 인하여 마이크로파 유전특성은 저하되었다.