• Nuclear Engineering and Technology
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• 제42권1호
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• pp.89-96
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• 2010

This paper describes the methodology of calculating the internal dose conversion coefficient in order to assess the radiological impact on non-human species. This paper also presents the internal dose conversion coefficients of 25 radionuclides ($^3H,\;^7Be,\;^{14}C,\;^{40}K,\;^{51}Cr,\;^{54}Mn,\;^{59}Fe,\;^{58}Co,\;^{60}Co,\;^{65}Zn,\;^{90}Sr,\;^{95}Nb,\;^{99}Tc,\;^{106}Ru,\;^{129}I,\;^{131}I,\;^{136}Cs,\;^{137}Cs,\;^{140}Ba,\;^{140}La,\;^{144}Ce,\;^{238}U,\;^{239}Pu,\;^{240}Pu$) for domestic seven reference animals (roe deer, rat, frog, snake, Chinese minnow, bee, and earthworm) and one reference plant (pine tree). The uniform isotropic model was applied in order to calculate the internal dose conversion coefficients. The calculated internal dose conversion coefficient (${\mu}Gyd^{-1}$ per $Bqkg^{-1}$) ranged from $10^{-6}$ to $10^{-2}$ according to the type of radionuclides and organisms studied. It turns out that the internal does conversion coefficient was higher for alpha radionuclides, such as $^{238}U,\;^{239}Pu$, and $^{240}Pu$, and for large organisms, such as roe deer and pine tree. The internal dose conversion coefficients of $^{239}U,\;^{240}Pu,\;^{238}U,\;^{14}C,\;^3H$, and $^{99}Tc$ were independent of the organism.

• 대한한방내과학회지
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• 제26권2호
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• pp.489-497
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• 2005

Conversion disorder lacks temperamental grounds and is a type of somatoform disorder that includes alteration or loss of physical functions implicated in physical deficit suggestive psychological conflict. There is high incidence of return of conversion disorder and difficulty in producing exact approaches of cure and apparent effects of remedy with symptomatic treatment alone because of its complex clinical symptoms. The approach of Oriental Medicine in treatment of conversion disorder is to apprehend relative symptoms from the syndrome combined with several annexational symptoms centering around sequential symptoms. Thereupon, author made a Ganyanghwapung comprehensive diagnosis was conducted using Oriental Medicine measures by differential diagnostic methods in psychosomatic patients whose cases are diagnosed as conversion disorder. Then, Cheonmagudeungeum Gagambang was prescribed for them and it brought on satisfactory effects from the first or second treatment. There have been many cases reporting the application of Oriental Medicine treatment to conversion disorder to date and outcomes have also been favorable. Results of this study likewise suggest that this Oriental Medicine treatment for conversion disorder is effective.

• 대한한방내과학회지
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• 제25권3호
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• pp.590-595
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• 2004

Conversion Disorder is a disorder whose predominant feature is a loss or alteration in physical functioning that suggests a physical disorder but that is actually a direct expression of a psychological conflict or need. The Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) guidelines for Conversion Disorder include these definitions: A psychosocial stressor produces a psychological conflict that is believed to help initiate or exacerbate the illness The symptoms are not under conscious control, etc. While functional disabilities are common with conversion disorders, physical and laboratory abnormalities are absent or minor in comparison with the patient's subjective complaints. Symptoms of Conversion Disorder are similar to those of stroke. But the mechanism of Conversion Disorder is similar as that of Stagnation Syndrome of Ki (氣鬱證) in Oriental medicine. Gaegyeolseogyeong-tang has been used to treat women who suffer from Conversion Disorder induced by the Stagnation Syndrome of Ki (氣鬱證). After application of the Gaegyeolseogyeong-tang for 7 days, symptoms and signs improved dramatically.

• Korean Chemical Engineering Research
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• 제52권1호
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• pp.133-140
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• 2014

본 연구의 목적은 국내 화력발전소에서 사용중인 인도네시아 석탄촤의 연소반응율을 연구하는 것이다. 석탄촤의 반응율은 External, Internal effectiveness factor를 고려하여 입자 내부 및 외부확산을 정량적으로 정리하였으며, Random pore model을 사용하여 탄소변환율에 따른 입자내부비표면적의 변화를 반영하였다. 가열 및 측정이 가능한 WHR(Wire Heating Reactor)를 활용하여 반응시간을 측정함으로써 석탄촤의 반응율을 도출하였고 BET(Brunauer-Emmett-Teller) 및 TGA(Thermo-Gravimetric Analysis) 장비를 활용하여 석탄촤의 물리적인 특성인 내부비표면적과 Random pore model의 구조변수(${\Psi}$)를 측정하였다. 석탄 종에 따른 활성화에너지 및 빈도인자를 도출하기 위해 아역청탄인 BARAMULTI, ENERGYMAN, AGM탄을 사용하였다. 본 연구 결과에서 External, Internal effectiveness factors를 통해 확산에 따른 kinetics를 비교한 결과 외부 확산 보다 내부 확산의 영향이 지배적임을 확인하였다. 최종적으로 내부 및 외부 확산에 대한 영향을 고려한 3종의 석탄촤 Intrinsic kinetics의 활성화에너지는 110~118 kJ/mol의 값을 보였다.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.881-885
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• 2014

Photophysics of 10-hydroxybenzo[h]quinoline (HBQ) has been in controversy, in particular, on the nature of the electronic states before and after the excited state intramolecular proton transfer (ESIPT), even though the dynamics and mechanism of the ESIPT have been well established. We report highly time resolved fluorescence spectra over the full emission frequency regions of the enol and keto isomers and the anisotropy in time domain to determine the accurate rates of the population decay, spectral relaxation and anisotropy decay of the keto isomer. We have shown that the ~300 fs component observed frequently in ESIPT dynamics arises from the $S_2{\rightarrow}S_1$ internal conversion in the reaction product keto isomer and that the ESIPT occurs from the enol isomer in $S_1$ state to the keto isomer in $S_2$ state.

• 반도체디스플레이기술학회지
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• 제23권2호
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• pp.50-54
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• 2024

In this paper, we propose a theoretical method to systematically analyze the power conversion efficiency of a single-phase PFC switching rectifier. Boost-type PFC was organized in order of highest correlation with load current using steady-state analysis results and introduced the concept of loss factor. The loss factors for each major element are summarized and presented in a table. This paper makes it easier to understand the internal loss and power conversion efficiency of the rectifier for loss factors. Lastly, to confirm the validity of the efficiency analysis results reflecting the loss factors, loss and efficiency analysis of the 2.5kW PFC rectifier was performed. The results were compared with data from a 2.5kW PFC circuit for evaluation. As a result, the usefulness of power conversion efficiency analysis reflecting the loss factors proposed in this paper was confirmed.

• Tuberculosis and Respiratory Diseases
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• 제86권2호
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• pp.142-149
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• 2023

Background: Coronavirus disease 2019 (COVID-19) is an ongoing global public health threat and different variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been identified. This study aimed to analyse the factors associated with negative conversion of polymerase chain reaction (PCR) and prognosis in critically ill patients according to the SARS-CoV-2 variant. Methods: This study retrospectively analysed 259 critically ill patients with COVID-19 who were admitted to the intensive care unit of a tertiary medical center between January 2020 and May 2022. The Charlson comorbidity index (CCI) was used to evaluate comorbidity, and a negative PCR test result within 2 weeks was used to define negative PCR conversion. The cases were divided into the following three variant groups, according to the documented variant of SARS-CoV-2 at the time of diagnosis: non-Delta (January 20, 2020-July 6, 2021), Delta (July 7, 2021- January 1, 2022), and Omicron (January 30, 2022-April 24, 2022). Results: The mean age of the 259 patients was 67.1 years and 93 (35.9%) patients were female. Fifty (19.3%) patients were smokers, and 50 (19.3%) patients were vaccinated. The CCI (hazard ratio [HR], 1.555; p<0.001), vaccination (HR, 0.492; p=0.033), and Delta variant (HR, 2.469; p=0.002) were significant factors for in-hospital mortality. The Delta variant (odds ratio, 0.288; p=0.003) was associated with fewer negative PCR conversion; however, vaccination (p=0.163) and remdesivir (p=0.124) treatments did not. Conclusion: The Delta variant of SARS-CoV-2 is associated with lower survival and negative PCR conversion. Contrary to expectations, vaccination and remdesivir may not affect negative PCR conversion in critically ill patients with COVID-19.

• 대한한방내과학회지
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• 제22권1호
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• pp.63-71
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• 2001

Objectives : Cordyceps Sinensis (CS) was tested for the effects of antioxidant enzymes and lipid peroxidation in the liver. Methods : We measured the changes in body weight, enzyme activity, lipid peroxide and the death rate in the hydrocortisone acetate-treated rats. Results : In vitro, CS didn't effect levels of lipid peroxide. the activities, and the ratio of type conversion of xanthine oxidase. In the hydrocortisone acetate-treated rats, lipid peroxide, the activities, the ratio of type conversion of xanthine oxidase, and the death rate all increased. But, glutathione peroxidase and superoxide dismutase decreased. In vitro, after CS was administered to hydrocortisone acetatetreated rats, the levels of lipid peroxide in the liver, and the death rate decreased. However, the activities, and the ratio of type conversion of xanthine oxidase decreased. The body weight, glutathione peroxidase, and superoxide dismutase in+creased. The effects of Sinensis Cordyceps Broth did better than the effects of Sinensis Cordyceps Mycelia. Conclusions : These results suggest that CS decrease the activities of free radical generating enzymes which form lipid peroxide and increase the activities of oxygen free radical scavenging enzymes.

• International Journal of Automotive Technology
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• 제8권3호
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• pp.361-373
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• 2007

In previous work, an approach based on maximizing the efficiency of an internal combustion engine while ignoring the power conversion efficiency of other powertrain components, such as the electric motor and power battery or ultracapacitor, was implemented in the steady-state optimization of an internal combustion engine for hybrid electric vehicles. In this paper, a novel control algorithm was developed and successfully justified as the basis for maximal power conversion efficiency of overall powertrain components. Results indicated that fuel economy improvement by 3.9% compared with the conventional control algorithm under China urban transient-state driving-cycle conditions. In addition, using the view of the novel control algorithm, maximal power generation of the electric motor can be chosen.

• 한국산업융합학회 논문집
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• 제25권6_3호
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• pp.1275-1284
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• 2022

This study provides an investigating the electrolyte reaction characteristics during thermal runaway of a lithium-ion battery(LIB). Dimethyl carbonate(DMC) is known as the main substance that makes up the electrolyte. The mono-molecular decomposition characteristics of DMC were derived through numerical analysis. Cobalt oxide can release oxygen under high temperature conditions. Also, DMC is converted to CH₄, H₂, CO, and CO₂. Especially, it was found that the decomposition of the DMC begins at a temperature range of 340-350℃, which dramatically increases the internal pressure of the LIB. In the by-products gases, the molar ratio of CO and CO₂ changed according to the molecular structure of DMC and temperature conditions. The correlation of the [CO]/[CO₂] ratio according to the temperature during thermal runaway was derived, and the characteristics of the reaction temperature could be estimated using the molar ratio as an indicator. In addition, the oxidation and decomposition characteristics of DMC according to the residence time for each temperature were estimated. When DMC is exposed to low temperature for a long time, both oxidation and decomposition may occur. There is possibility of not only increasing the internal pressure of the LIB, but also promoting thermal runaway. In this study, internal environment of LIB was identified and the reaction characteristics between the active materials of the cathode and electrolyte were investigated.