• 산업기술연구
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• 제43권1호
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• pp.15-23
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• 2023

Lithium-ion batteries are predominantly employed in electric vehicles and energy storage devices, offering the advantage of high energy density. However, they are susceptible to efficiency degradation when operated at high temperatures due to their sensitivity to the external environment. In this study, we conducted experiments using an indirect cooling method to prevent thermal runaway and explosions in lithium-ion batteries. The results were validated by comparing them with heat transfer simulations conducted through a commercial finite element analysis program. The experiments included single-cell exothermic tests and cooling experiments on a battery pack with 10 cells connected in series, utilizing 21700 lithium-ion batteries. To block external temperature influences, the experimental environment featured an extrusion method insulation in the environmental chamber. The cooling system, suitable for indirect cooling, was constructed with copper tubes and pins. The heat transfer analysis began by presenting a single-cell heating model using commercial software, which was then employed to analyze the heating and cooling of the battery pack.

• Molecules and Cells
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• 제44권5호
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• pp.328-334
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• 2021

The advent of the major histocompatibility complex (MHC) multimer technology has led to a breakthrough in the quantification and analysis of antigen-specific T cells. In particular, this technology has dramatically advanced the measurement and analysis of CD8 T cells and is being applied more widely. In addition, the scope of application of MHC multimer technology is gradually expanding to other T cells such as CD4 T cells, natural killer T cells, and mucosal-associated invariant T cells. MHC multimer technology acts by complementing the T-cell receptor-MHC/peptide complex affinity, which is relatively low compared to antigen-antibody affinity, through a multivalent interaction. The application of MHC multimer technology has expanded to include various functions such as quantification and analysis of antigen-specific T cells, cell sorting, depletion, stimulation to replace antigen-presenting cells, and single-cell classification through DNA barcodes. This review aims to provide the latest knowledge of MHC multimer technology, which is constantly evolving, broaden understanding of this technology, and promote its widespread use.

• 한국세라믹학회지
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• 제43권12호
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• pp.775-780
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• 2006

Mechanical and electrical performance of anode-supported SOFC single cells were analyzed after thermal cyclic operation. The experiments of thermal cyclic cell-operation were carried out four times and performance of each cell was measured at different temperatures of 650, 700, and $750^{\circ}C$, respectively. As increasing the number of thermal cycle test, single cells showed poor I-V characteristics and lower 4-point bending strength. The anode polarization was also measured by AC-impedance analysis. The observation of the microstructure of the anodes in single cells proved that the average particle size of Ni decreased and the porosity of anode increased. It is thought that the thermal cycle caused the degradation of performance of single cells by reducing the density of three-phase boundary region.

• 한국태양에너지학회 논문집
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• 제30권6호
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• pp.16-21
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• 2010

It is well-known that Boron-doped Cz Si solar cells suffer light-induced degradation due to boron-oxygen defect which is responsible of a reduction in lifetime and hence efficiency. In this paper, we assume that PV solar cell has been connected with variable load to account the real operating condition and it shows different light-induced degradation of Si solar cell. To evaluate the effect of light-induced degradation for solar cell with various load, Single crystalline solar cells are connected with open and short circuits during light exposure. Isc-Voc curve evaluate light induced degradation of solar cells and the reason is explained as a change for serial resistance. From the results, Electrical characteristics of solar cells show better performance under short circuit conditions, after light exposure.

• 대한방사선기술학회지:방사선기술과학
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• 제45권5호
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• pp.433-438
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• 2022

Targeted radionuclides treatment (TRT) requires the establishment of treatment plans that consider various factors, such as the type of radionuclides, target organs, and administration methods. For this reason, in this study, the absorption dose of a single cell was analyzed according to the type of radioisotope used to treat target radionuclides. In this study, a simulation was performed on beta rays used in the treatment of target radionuclides at the cell level using MCNPX (ver. 2.5.0). First, according to the calculation formula, the beam path according to the type of radioisotope for treatment was calculated. Second, the amount of self-radiation by beta rays emitted from cell diameters of 5 ㎛ and 10 ㎛ cell nuclei was evaluated. As a result, it showed a high range proportional to the maximum energy of the beta-ray, and the highest self-dose distribution from 177 Lu radiation sources among therapeutic radioisotopes. This was analyzed as a result that is inversely proportional to the maximum energy of the beta-ray, and it suggests that the selection of a nuclide considering the range of the beta-ray is necessary in the treatment of target radionuclides in the future.

• Journal of Power Electronics
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• 제11권1호
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• pp.82-89
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• 2011

Differences in the frequency characteristic applied to a ripple current may shorten fuel cell life span and worsen the fuel efficiency. Therefore, this paper presents an experimental analysis of the ripple current applied variable frequency characteristic in a polymer electrolyte membrane fuel cell (PEMFC). This paper provides the first attempt to examine the impact of ripple current through immediate measurements on a single cell test. After cycling for hours at three frequencies, each polarization and impedance curve is obtained and compared with those of a fuel cell. Through experimental results, it can be absolutely concluded that low frequency ripple current leads to long-term degradation of a fuel cell. Three different PEMFC failures such as membrane dehydration, flooding and carbon monoxide (CO) poisoning that lead to an increase in the impedance magnitude at low frequencies are simply introduced.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권11호
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• pp.5301-5323
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• 2017

Small cell deployment offers a low-cost solution for the boosted traffic demand in heterogeneous cellular networks (HCNs). Besides improved spatial spectrum efficiency and energy efficiency, future HCNs are also featured with the trend of network architecture convergence and feasibility for flexible mobile applications. To achieve these goals, dual connectivity (DC) is playing a more and more important role to support control/user-plane splitting, which enables maintaining fixed control channel connections for reliability. In this paper, we develop a tractable framework for the downlink SINR analysis of DC assisted HCN. Based on stochastic geometry model, the data-control joint coverage probabilities under multi-frequency and single-frequency tiering are derived, which involve quick integrals and admit simple closed-forms in special cases. Monte Carlo simulations confirm the accuracy of the expressions. It is observed that the increase in mobility robustness of DC is at the price of control channel SINR degradation. This degradation severely worsens the joint coverage performance under single-frequency tiering, proving multi-frequency tiering a more feasible networking scheme to utilize the advantage of DC effectively. Moreover, the joint coverage probability can be maximized by adjusting the density ratio of small cell and macro cell eNBs under multi-frequency tiering, though changing cell association bias has little impact on the level of the maximal coverage performance.

• 한국전기전자재료학회논문지
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• 제25권5호
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• pp.372-376
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• 2012

This study focused on the performance characteristics of solar cell using the impedance technique. We measured an impedance according to frequency from 1 Hz until 1 MHz. It could know that the impedance was decreased according to the frequency increases in solar cell. The impedance of single crystal solar cell was 0.61 ${\Omega}$ at 1 Hz, and kept almost settled value to $1{\times}10^2$ Hz. However, the impedance of polycrystal solar cell was $7{\times}10^3{\Omega}$ at 1 Hz.

• Journal of Genetic Medicine
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• 제2권1호
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• pp.35-39
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• 1998

Duchenne/Becker muscular dystrophy are the major neuromuscular disorders with X-linked recessive inheritance. Preimplantation diagnosis of sex determination has been generally used to avoid male pregnancies with these diseases. However, in order to determine if the embryo is normal, carrier or affected regardless of the sex, there is a need for a combined analysis of specific exon on dystrophin gene as well as sex determination of embryo using the same biopsied blastomere. If the exon deletion is not determinable, further diagnosis of carrier or patient can be performed by haplotype analysis. In this study, we applied the primer extension preamplification (PEP) method, which amplifies the whole genome, in 40 cases of single amniocyte and 40 cases of chorionic villus cell. We analysed haplotypes using two (CA)n dinucleotide polymorphic markers located at the end of 5' and 3' region of the dystrophin gene. Exon 46 of dystrophin gene and DYZ3 on chromosome Y were chosen as a target sequence for coamplification PCR. Upon optimizing the conditions, the amplification rates were 91.25% (73/80) for haplotypes (92.5% in amniocyte, 90% in chorionic villus cell) and 88.75% (71/80) for coamplification (85% in amniocyte, 92.5% in chorionic villus cell). The result of the study indicates that haplotypes analysis and coamplification of dystrophin and Y-specific gene using PEP can be applied to prenatal and preimplantation diagnosis in Duchenne/Becker muscular dystrophy making it possible to determine if the fetus is a carrier or an affected one.

• Genomics & Informatics
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• 제14권4호
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• pp.205-210
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• 2016

Interleukin-10 (IL10) plays an important role in initiating and maintaining an appropriate immune response to non-Hodgkin lymphoma (NHL). Previous studies have revealed that the transcription of IL10 mRNA and its protein expression may be infl uenced by several single-nucleotide polymorphisms in the promoter and intron regions, including rs1800896, rs1800871, and rs1800872. However, the impact of polymorphisms of the IL10 gene on NHL prognosis has not been fully elucidated. Here, we investigated the association between IL10 polymorphisms and NHL prognosis. This study involved 112 NHL patients treated at the National Cancer Center, Korea. The median age was 57 years, and 70 patients (62.5%) were men. Clinical characteristics, including age, performance status, stage, and extra-nodal involvement, as well as cell lineage and International Prognostic Index (IPI), were evaluated. A total of four polymorphisms in IL10 with heterozygous alleles were analyzed for hazard ratios of overall survival (OS) and progression-free survival (PFS) using Cox proportional hazards regression analysis. Diffuse large B-cell lymphoma was the most common histologic type (n = 83), followed by T-cell lymphoma (n = 18), mantle cell lymphoma (n = 6), and others (n = 5). Cell lineage, IPI, and extra-nodal involvement were predictors of prognosis. In the additive genetic model results for each IL10 polymorphism, the rs1800871 and rs1800872 polymorphisms represented a marginal association with OS (p = 0.09 and p = 0.06) and PFS (p = 0.05 and p = 0.08) in B-cell lymphoma patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). These findings suggest that IL10 polymorphisms might be prognostic indicators for patients with B-cell NHL treated with R-CHOP.