• Smart Structures and Systems
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• 제26권6호
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• pp.809-817
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• 2020

In cells, the microtubules are surrounded by viscoelastic medium. Microtubules, though very small in size, perform a vital role in transportation of protein and in maintaining the cell shape. During performing these functions waves propagate and this propagation of waves has been investigated using nonlocal elastic theory. But the effect of surrounding medium was not taken into account. To fill this gap, this study considers the viscoelastic medium along with nonlocal elastic theory. The analytical formulas of the velocity of waves, and the results reveal that the presence of medium reduces the velocity. The axisymmetric and nonaxisymmetric waves are separately discussed. Furthermore, the results are compared with the results gained from the studies of free microtubules. The presence of medium around microtubules results in the increase of the flexural rigidity causing a significant decrease in radial wave velocity as compared to axial and circumferential wave velocities. The effect of viscoelastic medium is more obvious on radial wave velocity, to a lesser extent on torsional wave velocity and least on longitudinal wave velocity.

• 대한방사선기술학회지:방사선기술과학
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• 제44권3호
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• pp.239-245
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• 2021

Since the side effects of contrast agents occur in many ways, hospitals must clearly identify the contrast agents and know how to manage them. Storage of contrast media It is common practice to store contrast media in a warm room to reduce viscosity and improve patient comfort. However, it is important to recognize that long-term storage at high temperatures can shorten the shelf life of a product. Therefore, in this study, the presence or absence of chemical changes according to the storage period after using the contrast medium was analyzed. As the analysis equipment, a 500 MHz Nuclear Magnetic Resonance Spectrometer of Bruker Avance (Germany) possessed by Korea Basic Science Institute (KOREA BASIC SCIENCE INSTITUTE; KBSI) was used. For the X-ray iodide contrast medium, Pamiray contrast medium of Iopamidol and Optiray contrast medium of Ioversol, samples remaining after 7 days, 20 days, 30 days, and 1 year were collected, By acquiring the spectrum from the 1H-NMR spectrometer of the contrast medium stimulated by It was compared and analyzed with the standard sample. In conclusion, depending on the storage period of the contrast medium, no peaks of physical and chemical changes were observed in both the Pamiray contrast medium of Iopamidol and the Optiray contrast medium of Ioversol after 7 days, 20 days, 30 days, and 1 year after use.

• 한국지반환경공학회 논문집
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• 제2권3호
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• pp.81-88
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• 2001

다공질 매체의 거동은 선형 열역학적 다공 탄성 거동, 선형 다공 점성-탄성 거동, 다공소성 거동, 그리고 다공 점성-소성 거동 등으로 모형화가 된다. 또한 시간에 따라 그 거동 양상이 복합적인 형태를 띈다. 다공질 매체는 간극 속의 구성물들이 서로 상대속도를 가지며 상호 작용을 하기 때문에 coupling 효과를 고려한 다공질 매체의 변형 거동에 대한 구성모델의 개발이 필수적이다. 본 논문에서는 균질하고 등방성을 가진 재료들로 이루어진 다공질 매체의 3차원적인 거동을 포화도에 따라 완전 포화시와 부분 포화시로 나누어 연속체 다공 역학의 뼈대 위에 지배방정식들을 구한다. 또한 다공질 매체의 거동을 이해하고 해석할 수 있는 구성모델을 개발할 수 있는 토대를 마련한다. 본 연구가 확장될 경우 다공질 매체의 정확한 거동 해석과 변형량 예측이 이루어질 수 있을 것이다. 특히 도시 고형화 폐기물 매립지반의 3차원적인 거동을 해석할 수 있는 기초가 마련되어 비균질하고 이방성을 가진 재료들로 이루어진 다공질 매체 지반의 활용이 활발하게 이루어 질 것으로 기대된다.

• 한국환경보건학회지
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• 제32권1호
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• pp.8-18
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• 2006

The aim of this study is to evaluate the emission characteristics of mercury, lead, arsenic, and selenium from medium size municipal solid waste incinerators(MSWIs) in Korea. The concentrations of mercury, lead, arsenic, and selenium emitted from medium size MSWI stack were $2.67\;{\mu}g/Sm^3,\;0.38\;mg/Sm^3,\;1.33\;{\mu}g/Sm^3,\;0.28\;{\mu}g/Sm^3$, respectively. The concentration levels of mercury, lead, arsenic in flue gas from medium size MSW incinerator stacks selected were nearly detected under the Korea criteria level. Removal efficiencies of mercury, lead, arsenic, and selenium in waste heat boiler(WHE) and cooling tower(CT) were $90.36\%,\;69.76\%,\;43.04\%,\;40.64\%$, respectively. In general, the removal efficiencies of mercury and lead in WHE were higher than those of arsenic and selenium in WHE. Emission gas temperature reduction from waste heat boiler(WHB) and cooling tower(CT) can control mercury and lead of medium size MSWIs. To evaluate the relationship between mercury, lead, arsenic, selenium of fly ash and those of flue gas, it was carried out to correlation analysis of each metal concentration in the fly ash and in the flue gas from medium size MSWIs. From the correlation analysis, the coefficients of mercury, lead, arsenic, and selenium were 0.61, -0.38, 0.87, 0.28, respectively. The results of correlation analysis revealed that it should be highly positive to the correlation coefficients of mercury and arsenic in the fly ash and those of the flue gas emitted from medium size MSWIs. As it were, the concentrations of mercury and arsenic of flue gas from medium size MSWIs are high unless mercury and arsenic in fly ash are properly controlled in dust collection step in medium size MSWIs. It was also concluded that mercury, lead, arsenic, and selenium from MSWIs stacks could be controlled by waste heat boiler(WHE) and dust collecting step in medium size MSWIs.

• Journal of Magnetics
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• 제19권4호
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• pp.372-377
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• 2014

The purpose of the study is to investigate how uptake counts of $^{201}Tl$ of radioisotopes in the human body could change, when taking computed tomography and magnetic resonance imaging right after injecting contrast media. $^{201}Tl$ radioisotope substances of iodine contrast medium, which is a computed tomography contrast medium, and paramagnetic contrast medium, which is an magnetic resonance imaging contrast medium, were used as study materials. First, $^{201}Tl$ was put into 4 cc of normal saline in test tube, and then a computed tomography contrast medium of Iopamidol$^{(R)}$ or Dotarem$^{(R)}$, was put into 2 cc of normal saline in test tube. An magnetic resonance imaging contrast medium of Primovist$^{(R)}$ or Gadovist$^{(R)}$ was also put into 2 cc of normal saline in test tube. Each contrast medium was distributed to make $^{201}Tl$ as 3 mCi, with a total of 4 cc. Gamma camera, low energy high resolution collimator, and pinhole collimator were used to obtain images. The uptake count of $^{201}Tl$ was measured with 1000 frames of images, and obtained after 10 times of repetition. This study revealed that the use of Gadovist$^{(R)}$, which is an magnetic resonance imaging contrast medium, showed the smallest number of uptake count, after measuring $^{201}Tl$ uptake count by low energy high resolution collimator. On the other hand, the use of Iopamidol$^{(R)}$, which is a computed tomography contrast medium, showed the biggest difference in uptake count, when measuring $^{99m}Tc$ uptake count by Pinhole collimator. When examining with gamma camera, using contrast medium and $^{201}Tl$, identifying the changes of uptake count is very important for improving the value of diagnosis.

• 한국버섯학회지
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• 제9권1호
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• pp.44-47
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• 2011

느타리버섯 병 재배용으로 널리 사용되고 있는 미송톱밥, 비트펄프, 면실박(50:30:20) 혼합배지에 춘추느타리 2호를 재배한 배지를 풀버섯 재배 배지인 면실피펠릿, 밀기울, 탄산칼슘분말(90:9:1)배지에 혼합하여 상자재배시험을 통한 배양 및 생육특성을 비교분석한 결과, 느타리버섯 수확 후 배지의 첨가량이 많을수록 배지의 pH는 낮아지는 경향이었고, 총질소 함량이 높아 C/N율이 낮았다. 또한 미생물 밀도는 느타리버섯 수확 후 배지 첨가량 50%일 때 가장 높았으며 오염은 첨가량 0, 25, 50%가 10~13%로 비교적 낮은 오염율을 보였다. 균사배양기간 7일, 초발이 소요일수는 11~14일, 수확기간은 3~5일로 처리 간의 차이가 적어 총 재배기간도 큰 차이를 보이지 않았다. 수량은 기본배지인 면실피 펠릿 발효 배지(대조구, 356g/상자)보다 수확 후 배지 첨가량 50%+기본배지(면실피 펠릿 발효 배지)처리구가 같은 수량을 나타냈으며, 또한 수확 개체수 및 개체중도 대조구와 동등하여 수확 후 배지를 이용한 배지재료 절감효과가 인정되었다.

• Journal of Microbiology and Biotechnology
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• 제23권12호
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• pp.1747-1756
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• 2013

The aim of this paper was to study the effect of spent medium recycle on Spodoptera exigua Se301 cell line proliferation, metabolism, and baculovirus production when grown in batch suspension cultures in Ex-Cell 420 serum-free medium. The results showed that the recycle of 20% of spent medium from a culture in mid-exponential growth phase improved growth relative to a control culture grown in fresh medium. Although both glucose and glutamine were still present at the end of the growth phase, glutamate was always completely exhausted. The pattern of the specific glucose and lactate consumption and production rates, as well as the specific glutamine and glutamate consumption rates, suggests a metabolic shift at spent medium recycle values of over 60%, with a decrease in the efficiency of glucose utilization and an increase in glutamate consumption to fuel energy metabolism. Baculovirus infection provoked a change in the metabolic pattern of Se301 cells, although a beneficial effect of spent medium recycle was also observed. Both growth rate and maximum viable cell density decreased relative to uninfected cultures. The efficiency of glucose utilization was dramatically reduced in those cultures containing the lowest percentages of spent medium, whereas glutamine and glutamate consumption was modulated, thereby suggesting that infected cells were devoted to virus replication, retaining their ability to incorporate the nutrients required to support viral replication. Recycle of 20% of spent medium increased baculovirus production by around 90%, thus showing the link between cell growth and baculovirus production.

• 한국물환경학회지
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• 제36권4호
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• pp.275-283
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• 2020

Fecal coliforms are indicator bacteria to evaluate fecal contamination and microbiological safety in environment water. To examine fecal coliforms by membrane filtration, 1% rosolic acid solution dissolved in sodium hydroxide(0.2 M) should be added to m-FC medium according to Korean standard method. To reduce the exposure of researchers to harmful chemicals and expenditure of unnecessary cost, we evaluated if the rosolic acid solution is required to detect fecal coliforms. For 113 samples collected from five intake sources of Seoul, 42 samples of six tributaries, and 11 samples of sewage, the number of fecal coliforms was compared in medium with or without the reagent. As a result, the number was higher in m-FC medium without the reagent, but there was not a statistically significant difference. In the water intake, m-FC medium without the reagent could be used to examine fecal coliforms except in July, August and in case of rainfall. When heterotrophic plate counts exceeded 1,000 CFU/filter, or during rainfall, there was an effect of background bacteria in two types of the medium. However, it was more appropriate to use m-FC medium with the reagent to suppress gram-positive bacteria that can grow on medium without the reagent. In the tributary and sewage samples, the effect of the background bacteria was low, allowing the use of medium without the reagent regardless rainfall. Thus, it is necessary to present in standard method that the addition of rosolic acid solution in m-FC medium can be selected according to the characteristics of samples.

• 한국초지조사료학회지
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• 제21권1호
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• pp.27-30
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• 2001

알팔파 (Medicago sativa L.)의 줄기부분을 절단하여, SH 배지에 IBA를 첨가한 농도별로 뿌리 유도 정도를 조사한 결과, IBA 농도를 1.0~1.5 mg/$\ell$로 첨가한 처리구에서 뿌리 유도 정도가 70~75%로서 가장 좋았다. 캘러스로부터 shoot를 유도한 다음 줄기를 취하여 처리한 경우에는. 처리 10일째에 1/2 SH-0 배지에서 10개 (50%), SH-0 배지에서 10 (50%), SH-0.5IBA 배지에서 12개 (60%), SH-1.0IBA 배지에서 15개 (75%), SH-1.5IBA 배지에서 15개 (75%), SH-2.0IBA 배지에서 10개 (50%), SH-2.5IBA 배지에서 9개 (45%), SH-3.0IBA 배지에서 8개 (40%)의 뿌리 유도를 나타내었다.

• 디지털융복합연구
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• 제11권11호
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• pp.305-312
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• 2013

이 연구의 목적은 신정보화환경에서의 중소기업의 기술유출에 대한 보안인식 및 보안관리 실태를 측정하고, 대기업과 중소기업간의 수준비교분석을 통해 기술유출 방지대책을 위한 정책의 기초자료를 제시하고자 한다. 분석결과 보안인식 및 보안관리실태 모두 중소기업은 대기업에 비해 열악한 것으로 나타났으며, 정보화환경의 급격한 발달에 따른 부문별 관리가 필요한 상황인 것으로 보인다. 현재 중소기업의 신정보화환경 구축은 도입기에 있으므로, 구축과 동시에 보안시스템을 함께 갖출 수 있는 지원이 필요하며, 동시에 중소기업 자체적 대응이 가능하도록 신정보화환경에 맞는 보안시스템이 필요하다. 중소기업의 경우 급변하는 정보화환경의 변화에 따른 기술보호 역량을 갖추기에는 한계가 있음으로 정부의 체계적인 보안관리 지원이 요구된다.