• Current Photovoltaic Research
• /
• 제6권4호
• /
• pp.109-118
• /
• 2018

Silicon (Si) solar cells are the most successful technology which are ruling the present photovoltaic (PV) market. In that essence, multijunction (MJ) solar cells provided a new path to improve the state-of-art efficiencies. There are so many hurdles to grow the MJ III-V materials on Si substrate as Si with other materials often demands similar qualities, so it is needed to realize the prospective of Si tandem solar cells. However, Si tandem solar cells with MJ III-V materials have shown the maximum efficiency of 30 %. This work reviews the development of the III-V/Si solar cells with the synopsis of various growth mechanisms i.e hetero-epitaxy, wafer bonding and mechanical stacking of III-V materials on Si substrate. Theoretical approaches to design efficient tandem cell with an analysis of state-of-art silicon solar cells, sensitivity, difficulties and their probable solutions are discussed in this work. An analytical model which yields the practical efficiency values to design the high efficiency III-V/Si solar cells is described briefly.

• 한국초전도ㆍ저온공학회논문지
• /
• 제26권2호
• /
• pp.5-8
• /
• 2024

Recently, Lee et al. claimed that LK-99 isthe first room-temperature superconductor at ambient pressure, which quickly captured the attention of both the scientific community and the general public. We tried to replicate Pb_10-xCu_x(PO₄)₆O, called as LK-99, and characterized its physical properties by measuring the electrical resistance and Meissner effect. The electrical resistance results for different batches exhibited structural phase transitions at different temperatures, and the magnetic measurements indicated weak diamagnetism at 300 K, which is weaker than that of water. Taken together with the structural analysis, these results suggest that the resistivity transitions are incurred by Cu-S compound generated as a byproduct during the synthesis of LK-99 and LK-99 is not a room-temperature superconductor.

• 한국의학물리학회지:의학물리
• /
• 제27권4호
• /
• pp.258-266
• /
• 2016

We have treated various disease sites using wobbling and scanning proton therapy techniques since December 2015 at the Samsung Medical Center. In this study, we analyze the treatment time for each disease site in 65 wobbling and 50 scanning patient treatments. Treatment times are longest for liver and lung patients using the respiratory gating technique in the wobbling treatment and for cranio-spinal irradiation in pediatric patients with anesthesia in the scanning treatment. Moreover, we analyze the number of incidents causing treatment delays and the corresponding treatment delay time. The X-ray panel was the main reason for delays in the wobbling treatment; this decreased continually from January to June 2016, related closely to the proficiency of the human operators involved. The main reason for delays in the scanning treatment was interlocks during scanning pattern delivery; this was resolved by proton machine engineers. Through this work, we hope to provide other institutes with useful insight for initial operation of their proton therapy machines.

• Tuberculosis and Respiratory Diseases
• /
• 제77권3호
• /
• pp.136-140
• /
• 2014

Primary ciliary dyskinesia (PCD) is characterized by the congenital impairment of mucociliary clearance. When accompanied by situs inversus, chronic sinusitis and bronchiectasis, PCD is known as Kartagener syndrome. The main consequence of impaired ciliary function is a reduced mucus clearance from the lungs, and susceptibility to chronic respiratory infections due to opportunistic pathogens, including nontuberculous mycobacteria (NTM). There has been no report of NTM lung disease combined with Kartagener syndrome in Korea. Here, we report an adult patient with Kartagener syndrome complicated with Mycobacterium abscessus lung disease. A 37-year-old female presented to our hospital with chronic cough and sputum. She was ultimately diagnosed with M. abscessus lung disease and Kartagener syndrome. M. abscessus was repeatedly isolated from sputum specimens collected from the patient, despite prolonged antibiotic treatment. The patient's condition improved and negative sputum culture conversion was achieved after sequential bilateral pulmonary resection.

• Journal of Gastric Cancer
• /
• 제16권2호
• /
• pp.105-110
• /
• 2016

Purpose: In the Adjuvant Chemoradiotherapy in Stomach Tumors (ARTIST) trial, we investigated whether chemoradiotherapy after D2 gastrectomy reduces the rate of recurrence. Recently, the ratio of metastatic lymph nodes to examined lymph nodes (N ratio) has been proposed as an independent prognostic factor in gastric cancer (GC). The aim of this study was to investigate the relationship between the metastatic N ratio and prognosis of GC after curative D2 surgery. Materials and Methods: We retrospectively reviewed the data of 458 ARTIST patients who underwent D2 gastrectomy followed by adjuvant chemotherapy (XP, n=228) or chemoradiotherapy (XPRT, n=230). The disease-free survival (DFS) rates of patients were used to evaluate the influence of N ratio on the treatment outcome. To achieve this, 4 different N ratio categories (0%, 1%~9%, 10%~25%, and >25%) were compared on the basis of their influence on the treatment outcome. Results: On multivariate analysis, the N ratio remained an independent prognostic factor for DFS. The hazard ratios (HRs) for the N ratio categories of 0%, 1%~9%, 10%~25%, and >25% were 1, 1.061, 1.202, and 3.571, respectively. In patients having N ratio >25%, the 5-year DFS rates were 55% and 28% for the XPRT and XP arms, respectively (HR, 0.527; 95% confidence interval, 0.307~0.904; P=0.020). Conclusions: In patients with curatively resected GC, the N ratio was independently associated with DFS. Although this finding warrants further investigation in future prospective studies, the benefit of chemoradiotherapy for D2 resected GC appears to be more beneficial in cancers having N ratios >25%.

• Journal of Gastric Cancer
• /
• 제18권4호
• /
• pp.348-355
• /
• 2018

Purpose: We aimed to discuss the roles of radiation and chemotherapy as adjuvant treatment in patients with staged IB GC who were enrolled in the adjuvant chemoradiotherapy in stomach tumors (ARTIST) trial. Materials and Methods: Among the 458 patients who were enrolled in the ARTIST trial, 99 had stage IB disease. The patients were randomly assigned to receive either adjuvant chemoradiotherapy with capecitabine plus cisplatin (XP, n=50) or chemoradiotherapy (XPRT, n=49). Survival analyses were performed in accordance with the AJCC 2010 staging system. Results: According to the AJCC 2010 system, stage migration from IB to II occurred in 71% of the patients; 98% of the T2 N0 cases were reclassified as T3 N0, and 42% of the T1 N1 cases were reclassified as T1 N2. When comparing survival outcomes between the XPRT and XP arms for stage IB cancer (AJCC 2002), no significant difference in 5-year disease-free survival (DFS) between the 2 arms was found. (median 5-year DFS, not reached, P=0.256). The patients classified as having stage IB cancer (AJCC 2002) and reclassified as having stage II cancer (AJCC 2010) exhibited worse prognoses than those who remained in stage IB, although the difference was not statistically significant (5-year DFS rate, 83% vs. 93%). When we compared 5-year DFS in 70 patients with stage II (AJCC 2010), the addition of radiotherapy to XP chemotherapy did not show better outcome than XP alone (P=0.137). Conclusions: The role of adjuvant chemoradiotherapy in the treatment of stage IB GC (AJCC 2002) warrants further investigation.

• Annals of Clinical Neurophysiology
• /
• 제14권1호
• /
• pp.45-48
• /
• 2012

Neurolymphomatosis is a complication of lymphoma and initial presentation of cranial nerve involvement has been rarely reported. We describe a patient with neurolymphomatosis who presented as facial palsy mimicking steroid responsive Bell's palsy, a common and benign condition. This case shows that even minor neurologic deficit of lymphoma patient should not be absolutely regarded as a benign condition.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
• /
• pp.165-165
• /
• 2013

Nickel oxide was deposited on mesoporous silica by atomic layer deposition (ALD) consisting of sequential exposures to Ni(cp)2 and $H_2O$. NiO/silica samples were characterized by inductively coupled plasma-mass spectroscopy (ICP-MS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), etc. The flow-type reactor was used to measure activity of NiO/silica catalyst for catalytic combustion of toluene. The activity of NiO/silica catalyst was evaluated in terms of toluene removal efficiency and selectivity to $CO_2$ and compared with those of bare nickel oxide nanoparticles. In order to investigate influence of reaction temperature on combustion aspect, the catalytic combustion experiments were carried out at various temperatures. We show that both bare and supported NiO can be efficient catalysts for total oxidation of toluene at a temperature as low as $250^{\circ}C$.

• Bulletin of the Korean Chemical Society
• /
• 제29권10호
• /
• pp.1993-1997
• /
• 2008

In the present work, Diels-Alder reaction of cyclopentadiene with ethylacrylate has been carried out by using two types of mesoporous solid acid catalysts (Al-MCM-41, Al-MCM-48) with different pore structures. The specific topology of Al-MCM-48 (cubic Ia3d structure composed of two independent 3-D channel systems) exhibit higher activity and stereo-control than those of Al-MCM-41 (hexagonal packing of 1-D channels). The physical properties of Al-MCM-48 catalyst, such as high accessibility of reactants to the acid sites, spatial confinement in the nanoscopic reactors, and 3-D channel network structure that are effective adsorption and diffusion of reactants, play a crucial role in the present study.

• 한국독성학회:학술대회논문집
• /
• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
• /
• pp.143-144
• /
• 2001

Eukaryotic nuclear transcription factor, NF-B and cyclooxygenase-2 (COX-2) has been implicated in pathogenesis of many human diseases including tumor and are known to be activated by various external stimuli. Recently, increasing evidences have supported that L-ascorbic acid (LAA) is selectively toxic to some types of tumors at pharmacological concentrations as a prooxidant, rather than antioxidant.(omitted)