• 한국축산시설환경학회지
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• 제4권1호
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• pp.9-20
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• 1998

This research was conducted to investigate the effects on the amount of nitrogen and phosphorus and the number of maggots in the feces from the experimental pigs fed probiotics additives, and the variance of NH3-concentration(ppm) generated in the experimental pig-pens. The experiment was performed twice in the W-farm(under the condition of sufficient energy and protein in Spring) and B-farm(insufficient energy and protein in Summer). The experiment was designed with 5 treatments (control and 4 treatments according to the kinds of additives used). In the W-farm experiment, 75 three-way crossbred pigs weighing average 38kg were randomized with 3 replications for 102 days. In the B-farm experiment, 105 three-way crossbred pigs weighing average 33kg were randomized with 3 replications for 130 days. The results obtained are as follows: 1. The amount of dry matter, organic matter, nitrogen and phosphorus in the feces was not significantly different among the treatments. But the amount of OM, N and P shows a tendency to be somewhat lowered in the treatment A. On the otherhand, the amount of dry matter was somewhat lowered in the treatment B. The amount of such matters in the W-farm was somewhat lowered than those in B-farm. But there was not significant difference between W-farm and B-farm. 2. On the variance of the number of maggots developed in the pig's feces according to each treatment, the number of maggots in the treatments added probiotics were markedly decreased in comparison with those of the control(T), and it was significantly different(p＜0.01). Especially the decrease in the treatment A and B was much remarkable. 3. The addition of probiotics to the pigs' feeds made the NH3-concentration generated in the pig-pens decrease markedly. especially the NH3-concentration in the treatment A had the highest decreasing ratio among all the treatments. The decreasing ratio of NH3-concentration of the treatments added probiotics as compared to control(T) was 59.1∼80.0%(average 70.3%) in the treatment A, 56.8∼80.0%(ave. 68.5%) in the treatment B and 24.4∼46.0%(ave. 35.0%) in the treatment C and D. On the variance of the NH3-concentration according to the experimental times)seasonal conditions), the NH3-concentration generated in the pig-pens was gradually increased from April to August, on the other hand it was decreased in the September. By the result of this study, it was appeared that the probiotics added to the pigs' feeds made the NH3-concentration decrease in the pig-pens to the extent of safety degree(25 ppm and less) permitted to swine especially in the treatment A and B.

• 한국환경과학회지
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• 제6권4호
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• pp.351-357
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• 1997

In the Atmosphere under the various physical and chemical condition different chemical reactions occur and there are a number of air pollutants which are generated by photochemical reaction by absorbing solar energy. Therefor various testing simulation was done as foundation work to develop the numerical model for the prediction of concentration of air pollutants. It was shown change of msjor air pollutants concentration In according to variation of photodissociation speed constant, Kl and Initial condition of air pollutants concentration which plays major role In photochemical reaction. The photochemical reaction model which was used In this study Is found to be useful for understanding relationship among the concentration of reacting air pollutants and the prediction of concentration of air pollutants in urban atmosphere.

• Korea-Australia Rheology Journal
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• 제20권3호
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• pp.143-152
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• 2008

Simulations of solutions of flexible polymer molecules during flow in simple or complex confined geometries are performed. Concentrations from ultradilute up to near the overlap concentration are considered. As concentration increases, the hydrodynamic migration effects observed in dilute solution unidirectional flows (Couette flow, Poiseuille flow) become less prominent, virtually vanishing as the overlap concentration is approached. In a grooved channel geometry, the groove is almost completely depleted of polymer chains at high Weissenberg number in the dilute limit, but at finite concentration this depletion effect is dramatically reduced. Only upon inclusion of hydrodynamic interactions can these phenomena be properly captured.

• 방사선산업학회지
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• 제10권1호
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• pp.37-41
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• 2016

The recent prevalence of PET examinations in Korea has led to an increase in the number of cyclotrons. The medical isotope $^{18}F$ produced in most cyclotron facilities currently operating in Korea is emitted into the environment during the production of [$^{18}F$]FDG, a cancerdiagnosis reagent. The amount of [$^{18}F$]FDG synthesized determines the radioactive concentration of $^{18}F$ in the exhaust. At some facilities, this amount temporarily exceeds the emission limit. In this study, we evaluated the $^{18}F$ radioactivity concentration in the exhaust from the cyclotron facility at Chosun University. The $^{18}F$ radioactivity concentration was measured using an air sampler and a HPGe semiconductor detector. The measurements showed that the radioactive concentration of $^{18}F$ in the exhaust at the cyclotron facility at Chosun University was the highest during [$^{18}F$]FDG synthesis but remained under the legal limit of $2,000Bq\;m^{-3}$.

• 한국기계기술학회지
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• 제13권2호
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• pp.107-113
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• 2011

This study was performed for the application of the exposure limit in work field and the relative noxious gas concentration was estimated by using a miniature ship. The noxious gas concentration about light and shade number distribution of measuring subject field was estimated by using floating visualization image from a miniature ship in a large wind tunnel. About the concentration estimation, the correlation of concentration distribution drawn from the existing experimental results was used, the estimation result satisfied LTEL standard.

• 한국습지학회지
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• 제15권3호
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• pp.381-386
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• 2013

멸종위기수생식물 선제비꽃이 증가된 $CO_2$농도와 온도에 생태적으로 어떻게 반응하는지 알아보기 위하여 연구를 실시하였다. 실험은 2007년부터 2012년까지 야외조건인 대조구와 $CO_2$농도 + 온도를 증가시킨 처리구에서 개체생태학적으로 생육반응을 모니터링하였다. 그 결과 지상부 길이, 개체 당 가지 수, 개체 당 열매 수, 열매 당 종자 수, 가지 당 열매 수와 종자무게는 처리구에서 대조구보다 낮았으나, 가지 당 잎 수는 많았고, 꽃대길이, 가지 길이와 개체 당 잎 수는 차이가 없었다. 이러한 결과 $CO_2$농도와 온도가 증가하면 선제비꽃의 가지 수는 줄어들지만 가지에 붙은 잎 수를 늘리는 반응을 하며, 종자생산이 감소하여 번식에 부정적임을 의미한다. 그래서 지구온난화현상은 멸종위기의 주요한 원인 중 하나가 될 것으로 판단된다.

• 핵의학기술
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• 제15권2호
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• pp.111-115
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• 2011

체외 검사는 각 검사 마다 6-7개의 standard 농도를 이용한 표준곡선(Dose response curve)을 사용하여 검사 결과를 분석하며, 표준곡선 사용은 진료재료 소모에 많은 부분을 차지하고 있다. 현재 원내에서 검사하는 검사항목 가운데 일부 검사 항목은, standard 농도를 이용한 환자의 검사 결과 분석수치가 대부분 낮은 결과의 분포를 보이고 있었으며, 이러한 검사 들은 마지막 standard 농도의 사용이 불필요하다고 판단하였다. 이에 낮은 검사 결과의 분포를 보이는 검사항목들을 선정하고, 마지막 standard 농도의 자리에 사용했던 진료 재료를 절감하여 진료재료의 소모비용을 줄였다. 원내 검사 항목 중 11개의 검사 항목을 진료재료 절감 대상항목으로 하였고, 검사가 진행한 횟수 만큼 마지막 standard농도에 사용되었던 진료재료(검사 Tube)를 절감할 수 있었다. 2009년 7월부터 2011년 2월까지 월별 진료재료 절감 개수, 절감 개수를 진료재료 단가로 계산하여 진료재료 절감액과, 절감된 진료재료를 환자 검사용 진료재료로 사용하여 발생한 수익을 ABC 원가계산을 근거로 산정하였다. 2009년 7월부터 2011년 2월까지 절감된 진료 재료는 3,131개였다. 이는 약 31kit의 검사 시약에 해당되는 진료재료를 절감하였다. 이것을 진료재료 단가로 계산하면 약 640만원의 진료재료비가 절감되었고, 이러한 진료 재료는 환자 검사 진료재료로 사용되어 약 1,370만원의 수익이 발생하였다. 환자의 검사 결과가 정상이거나, 낮게 분포하는 검사항목들은 마지막 standard 농도를 사용하지 않고 범위를 줄여서 검사를 진행하여도 검사 결과를 분석하는데는 영향이 없었고, standard 농도 범위 조정이 검사 결과의 신뢰성에는 영향이 없는 것으로 분석 되었다. 따라서 이 활동은 핵의학 체외검사의 진료재료 사용에 효율성을 높이고 진료재료 절감 및 병원 수익에 많은 효과가 있을 것으로 생각한다.

• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.718-724
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• 2006

The heterogeneous association behaviour of various concentration binary mixtures of mono alkyl ethers of ethylene glycol with ethyl alcohol were investigated by dielectric measurement in benzene solutions over the entire concentration range at 25 ${^{\circ}C}$. The values of static dielectric constant $\epsilon_0$ of the mixtures were measured at 1 MHz using a four terminal dielectric liquid test fixture and precision LCR meter. The high frequency limiting dielectric constant $\epsilon_\infty$ values were determined by measurement of refractive index $n_D$ ($\epsilon_\infty\;=\;n_D\;^2$). The measured values of $\epsilon_0$ and $\epsilon_\infty$ were used to evaluate the values of excess dielectric constant $\epsilon^E$, effective Kirkwood correlation factor $g^{eff}$ and corrective correlation factor $g_f$ of the binary polar mixtures to obtain qualitative and quantitative information about the H-bond complex formation. The non-linear behaviour of the observed $\epsilon_0$ values of the polar molecules and their mixtures in benzene solvent confirms the variation in the associated structures with change in polar mixture constituents concentration and also by dilution in non-polar solvents. Appearance of the maximum in $\epsilon^E$ values at different concentration of the polar mixtures suggest the formation of stable adduct complex, which depends on the molecular size of the mono alkyl ethers of ethylene glycol. Further, the observed $\epsilon^E$ < 0 also confirms the heterogeneous H-bond complex formation reduces the effective number of dipoles in these polar binary mixtures. In benzene solutions these polar molecules shows the maximum reduce in effective number of dipoles at 50 percent dilutions. But ethyl alcohol rich binary polar mixtures in benzene solvent show the maximum reduce in effective number of dipoles in benzene rich solutions.

• 한국의류학회지
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• 제20권1호
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• pp.157-169
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• 1996

Polyester yarns and fabrics containing three levels of $TiO_2$ delusterant were hydrolyzed with NaOH and examined for physical and morphological changes. The mechanical propertis and hand values of alkaline hydrolyzed polyester fabrics were measured using KES-FB system. Also, the relationship between the morphology and the mechanical property of alkaline hydrolyzed polyester fabrics was analyzed. The results are as follows: 1. At an initial stage of alkaline treatment, the concentration of $TiO_2$ did not affect the weight loss of the treated yarns. But by increasing treatment time, the effect of the concentration of $TiO_2$ on the weight loss of the fiber became more pronounced. The weight loss were increased in the following order; fulldull> semidull> clear 2. The effect of hydrolysis on yarn tensile strength seems to be more related to the size of the pits on the fibers rather than the number of pits. 3. Axially oriented pits occurred along the hydroyzed, delustered fiber surfaces, while such pitting was absent on hydrolyzed fiber containing no $TiO_2$. The number of voids across the surface of a fiber increased with an increase in the amount of TiOa incorporated into the fibers. The size of the voids depended on the treatment time of hydrolysis rather than the concentration of TiOa. 4. The mechanical properties and hand values of polyester fabrics were changed by alkaline treatment but were identical regardless of the concentration of TiOa. While the mechanical properties of polyester fabrics depended on the structural change of the fibers and the yarns within the fabrics as the fiber diameter became progressively smaller rather than the size and number of pits.

• 대기
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• 제26권2호
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• pp.243-256
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• 2016

Total number concentration of aerosols larger than 10 nm ($N_{CN10}$), 3 nm ($N_{CN3}$), and cloud condensation nuclei ($N_{CCN}$) were measured during four different ship cruises over the Yellow Sea. Average values of $N_{CN10}$ and $N_{CCN}$ at 0.6% supersaturation were 6914 and $3353cm^{-3}$, respectively, and the minimum value of $N_{CN10}$ was $2000cm^{-3}$, suggesting significant anthropogenic influence even at relatively clean marine environment. Although $N_{CN10}$ and $N_{CN3}$ increased near the coast due to anthropogenic influence, $N_{CCN}$ was relatively constant and therefore $N_{CCN}/N_{CN10}$ ratio tended to decrease, suggesting that coastal aerosols were relatively less hygroscopic. In general $N_{CN10}$, $N_{CN3}$, and $N_{CCN}$ during the cruises seemed to be significantly influenced by wet scavenging effects (e.g. fog) and boundary layer height variation. Only one new particle formation (NPF) event was observed during the measurement period. Interestingly, the NPF event occurred during a dust storm event and spatial scale of the NPF event was estimated to be larger than 100 km. These results demonstrate that aerosol and CCN concentration over the Yellow Sea can vary due to various different factors.