• Journal of Korean Society of Forest Science
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• v.110 no.1
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• pp.43-52
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• 2021

In this study, carbon (C) and nitrogen (N) inputs by the litterfall of Japanese cypress (Chamaecyparis obtusa Endlicher) planted in pine wilt disease-disturbed forests were determined. The study sites were located in Sacheon-si, Gyeongsangnam-do. Eight plots under two regeneration sites (DR: four plots of C. obtusa planted under slightly disturbed Pinus thunbergii stands; CR: four plots of C. obtusa planted following the clear-cutting of severely disturbed pine stands) were established to collect litterfall from December 2018 to December 2019. The growth of diameter at breast height (DBH) was significantly higher in the CR treatment (12.10 cm) than that in the DR treatment (9.42 cm). C and N concentrations and the C/N ratio in C. obtusa leaf litter did not differ significantly between the two regeneration treatments, but the C/N ratio was significantly lower in the leaf litter collected in October (93) relative to that collected in December (143). The C concentration of litterfall components was significantly higher in C. obtusa leaf litter and in P. thunbergii needle litter than in broadleaved and miscellaneous litter, whereas the N concentration in broadleaved and miscellaneous litter was significantly higher than that in the leaf litter of C. obtusa and in branch litter. Thus, the C/N ratio was significantly higher in C. obtusa leaf litter and branch litter compared with that in miscellaneous and broadleaved litter. Respective C and N inputs by leaf litter were 773 kg C ha-1 yr-1 and 6.95 kg N ha-1 yr-1 for the CR treatments, and 78 kg C ha-1 yr-1 and 0.70 kg N ha-1 yr-1 for the DR treatment. Total C and N inputs were higher for the DR treatment (3,765 kg C ha-1 yr-1 and 47.6 kg N ha-1 yr-1, respectively) than for the CR treatment (1,290 kg C ha-1 yr-1 and 17.2 kg N ha-1 yr-1, respectively). These results indicate that, for C. obtusa, the DBH growth in the CR treatment was superior to that in the DR treatment, but the C and N inputs by litterfall were considerably reduced in CR treatments.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.143-151
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• 2022

This study was carried out to investigate quantitative characteristics of the cooling effect in a single-span arch greenhouse with roll-up side vents depending on operation of circulation and exhaust fans during ventilation, in order to suggest a practical strategy regarding installation or operation of forced ventilation systems. The examination was conducted under 3 different ventilation conditions (side vents only, side vents + circulation fans, and side vents + circulation fans + exhaust fans). In each condition, variations of internal and external air temperatures and exogenous environmental factors were recorded during ventilation, and the cooling effects were investigated by comparing the normalized temperature difference (NTD) of each ventilation condition. In the morning time (11:00-12:00), a temporary peak in the temperature difference was observed at the beginning of ventilation regardless of ventilation methods. The time taken to the maximum NTD was decreased from 340 s to 110s, and the NTD was dropped from 1.158 to 1.037 as the more forced ventilation systems were operated. The more operations caused the passing time over specific NTD values reduced by 60% as the time was reduced from 1,030 s to 550 s at NTD = 0.8, 1,610 s to 915 s at NTD = 0.6, and 2,315 s to 1,360 s at NTD = 0.4. The temporary peak in NTD was not observed in the afternoon time (14:00-15:00) but it was dropped as quickly as the ventilation started. Also the more operations resulted in the passing time over specific NTD values reduced by 70% as the time was reduced from 560 s to 345 s at NTD = 0.8, from 825 s to 540 s at NTD = 0.6, and from 1,145 s to 810 s at NTD = 0.4. Conclusively, the intervention of the forced ventilation system is recommended in the morning time or in high thermal conditions to achieve more effective and economical ventilation.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.2
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• pp.147-155
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• 2024

Gallium-68-prostate-specific membrane antigen-11 (⁶⁸Ga-PSMA-11) is a positron emission tomography radiopharmaceutical that labels a Glu-urea-Lys-based ligand with ⁶⁸Ga, binding specifically to the PSMA. It is used widely for imaging recurrent prostate cancer and metastases. On the other hand, the preparation and quality control testing of ⁶⁸Ga-PSMA-11 in medical institutions takes over 60 minutes, limiting the daily capacity of ⁶⁸Ge/⁶⁸Ga generators. While the generator provides 1,110 MBq (30 mCi) nominally, its activity decreases over time, and the labeling yield declines irregularly. Consequently, additional preparations are needed, increasing radiation exposure for medical technicians, prolonging patient wait times, and necessitating production schedule adjustments. This study aimed to reduce the ⁶⁸Ga-PSMA-11 preparation time and optimize the automated synthesis system. By shortening the reaction time between ⁶⁸Ga and the PSMA-11 precursor and adjusting the number of purification steps, a faster and more cost-effective method was tested while maintaining quality. The final synthesis time was reduced from 30 to 20 minutes, meeting the standards for the HEPES content, residual solvent EtOH content, and radiochemical purity. This optimized procedure minimizes radiation exposure for medical technicians, reduces patient wait times, and maintains consistent production schedules, making it suitable for clinical application.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8455-8460
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• 2014

Background: The National Central Cancer Registry of China (NCCR) affiliated to the Bureau of Disease Control, National Health and Family Planning Commission of China is responsible for cancer surveillance in the entire country. Cancer registration data from each local registry located in each province are collected by NCCR annually to be analyzed and published to provide useful information for policy makers and cancer researchers. Materials and Methods: Until 1st June, 2013, 219 population-based cancer registries submitted data of 2010 to the National Central Cancer Registry of China covering about 207,229,403 population, and 145 cancer registries were selected after quality evaluation for this study. Colorectal cancer cases were selected from the database according to ICD-10 coded as "C18-C20". We calculated the crude incidence and mortality rates by sex, age groups and location (urban/rural). The China population in 2000 and Segi's population were used as standardized populations for the calculation of age-standardized rates. The 6th National Population Census data of China was used to combined with the cancer registries' data to estimate the colorectal cancer burden in China in 2010. Results: Colorectal cancer was the sixth most common cancer in China. It was estimated that there were 274,841 new cases diagnosed in 2010 (157,355 in males and 117,486 in females), with the crude incidence rate of 20.1/100,000, highest in males in urban areas. Age-standardized rates by China standard population of 2000 (ASRcn) and World standard population (Segi's population, ASRwld) for incidence were 16.1/100,000 and 15.9/100,000 respectively. There were 132,110 cases estimated to have died from colorectal cancer in China in 2010 (76,646 men and 55,464 women) with the crude mortality rate of 10.1/100,000. The ASRcn and ASRwld for mortality were 7.55/100,000 and 7.44/100,000 respectively, higher in males and urban areas than in females and rural areas. The incidence and mortality rates increased with age, reaching peaksin the 80-84 year old, and oldest age groups, respectively. Conclusions: Colorectal cancer is one of the most common incident cancers and cause of cancer death in China. Primary and secondary prevention, with attention to a health lifestyle, physical activity and screening should be enhanced in the general population.

• Applied Chemistry for Engineering
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• v.4 no.4
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• pp.823-829
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• 1993

The basic medium oil modified alkyd resin was synthesized from linseed oil fatty acid(LOFA), phthalic anhydride(PAA), trimellitic anhydride(TMA ), and trimthylol propane(TMP) by condensation polymerization at $230^{\circ}C$. TMPTA modified water-reducible alkyd resins were synthesized with TMPTA graft copolymerization onto the basic resin at $180^{\circ}C$. Acid value of the resin was controlled by the addition of TMA and N,N-Dimethylethanol amino(DMEA) was used as an neutralizing agent to prepare water-reducible alkyd. To evaluate the optimum formulation for anionic alkyd resin, water proofness and water reducibility were estimated from the acid value or TMA contents. The effect of TMPTA on the graft copoymerization of the resin was studied by measuring molecular weight, glass transition temperature(Tg), viscosity, and gel contents. The suitable balance of water proofness and water reducibility of the resin was obtained at range of 5.3~7.0wt.% of TMA contents or 40~50 of acid value of basic resin. The molecular weight, viscosity, and gel contents of water-reducible alkyd resin were increased according to the TMPTA graft copolymerization, but Tg was decreased.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.3
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• pp.42-51
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• 1981

Boron was predeposited into p (100) Si wafer at 94$0^{\circ}C$ for 60minutes to make the back surface field. High tempreature diffusion process at 1145$^{\circ}C$ for 3 hours was immediately followed without removing boron glass to obtain high surface concentration Back boron was annealed at 110$0^{\circ}C$ for 40minutes after boron glass was removed. N+ layer was formed by predepositing with POCI3 source at 90$0^{\circ}C$ for 7~15 minutes and annealed at 80$0^{\circ}C$ for 60min1es under dry Of ambient. The triple metal layers were made by evaporating Ti, Pd, Ag in that order onto front and back of diffused wafer to form the front grid and back electrode respectively. Silver was electroplated on front and back to increase the metal thickness form 1~2$\mu$m to 3~4$\mu$m and the metal electrodes are alloyed in N2 /H2 ambient at 55$0^{\circ}C$ and followed by silicon nitride antireflection film deposition process. Under artificial illumination of 100mW/$\textrm{cm}^2$ fabricated N+PP+ cells showed typically the open circuit voltage of 0.59V and short circuit current of 103 mA with fill factor of 0.80 from the whole cell area of 3.36$\textrm{cm}^2$. These numbers can be used to get the actual total area(active area) conversion efficiency of 14.4%(16.2%) which has been improved from the provious N+P cell with 11% total area efficiency by adding P+ back.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.486-491
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• 2015

In this study, we evaluated the differences in fruit development and quality indices of fruits subjected to blossom thinning before full bloom in 'Hanareum' and 'Niitaka' pears (Pyrus pyrifolia Nakai). We carried out a thinning treatments at 5 days before full bloom, targeting the blossoms at the 1st and 2nd position (T1) or the blossoms at the 6th and 7th position (T2) from the basal part of the flower cluster in both cultivars. Blossom thinning treatments increased the average fruit weight of early-season Asian pear 'Hanareum' up to 10.5% (T1) and 11.0% (T2) at harvest time (110 days after full bloom). The mid-season 'Niitaka' pear showed increased fruit weight of up to 12.6% (T1) and 16.8% (T2) at harvest time (170 days after full bloom). Moreover, these treatments increased the production rate of bigger sized fruits in both cultivars. Removal of blooms also affected fruit quality indices; the bloom-thinned fruits showed higher soluble solids contents (about $1^{\circ}Brix$) and higher skin color redness ($a^*$) especially in 'Niitaka' pears when compared to the non-thinned controls. Overall, the treatments increased the fruit size and weight as well as fruit quality including soluble solids and skin color. Bloom thinning treatment targeting the 6th to 7th blossom from the basal part of the flower cluster may be recommended as the practical thinning method in Asian pear 'Hanareum' and 'Niitaka'.

• Korean Journal of Ichthyology
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• v.28 no.2
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• pp.110-115
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• 2016

This study was conducted in order to investigate the growth and morphological development of Cypselurus hiraii larvae and to obtain basic data for taxonomic research. Specimens for this study were collected using a scoop net (aperture Ø60 cm) at the Geomun Island in Yeosu-si, Jollanam-do in July and August of 2013, and the mean water temperature was $20.6{\pm}1.84^{\circ}C$ and the mean salinity was $32.1{\pm}0.46$‰ during the collection. In post-larvae of total length 9.58~9.69 mm (average $9.63{\pm}0.04mm$, n=5), the mouth was opened, and the maxilla was shorter than the mandible. The length of the dorsal fin did not exceed that of the ventral fin, and the dorsal fin was on the same line as that of the ventral fin. In post-larvae of total length 18.0~18.5 mm (average $18.2{\pm}0.22mm$, n=5), with the growth accelerated, the pectoral fin was developed broadly and their caudal fin was differentiated into the heterocercal tail. These characteristics suggest the development of swimming ability and resultant active feeding activities. In post-larvae of total length 22.4~23.0 mm (average $22.7{\pm}0.21mm$, n=5), striped melanophores deposited in the pectoral fin, and small spot-like melanophores expanded in the processes formed on the mandible. The dorsal and anal fins were on the same line, and the anal fin was situated behind the dorsal fin.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.108-108
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• 2000

급증하는 무선통신 정보수요는 특히, 고주파대역 (300NHz-300GHz)에서 사용되는 공진기, 필터, 발진기 등과 같은 소자의 품질향상을 요구하고 있다. 고주파용 유전체 중 ZrTiO4 는 $\alpha$-PbO2 계열의 사방정구조를 갖고 있는 유전체로서 높은 유전율 ($\varepsilon$=40)과 높은 품질계수 (Q=1/tan$\delta$=4700 at 7GHz)를 갖고 있고, Sn 첨가시 0ppm/$^{\circ}C$의 공진주파수 온도계수를 얻을 수 있다고 보고되어 있다. 본 연구에서는 약 110$0^{\circ}C$ 이상에서 안정한 상으로 존재하는 ZrTiO4를 저온에서 증착하여 준안정한 상태로 결정화되게 한후, 유전손실 (tan$\delta$)과 유전율($\varepsilon$)을 측정하였다. 또한 증착온도와 열처리과정에 따른 박막의 us형 (Strain) 정도의 변화를 X-선 회절결과로부터 분석하였으며 이를 측정된 유전특성 값과 비교하였다. ZrTiO4 박막은 DC magnetron reactive sputter로 Zr과 Ti 타겟으로부터 high phosphorous doped Si (100) 기판위에 증착하였다. 압력은 4mTorr로 유지하고 박막의 화학양론적 조성비를 맞추기 위해 각 타겟에 가해지는 power는 Zr/Ti=500W/650W로 고정하고, 반응가스의 비율을 Ar/O2=17sccm/3.5sccm으로 유지하여 박막내에 인입되는 산소량을 제어하였다. 증착 직후와 열처리 후의 박막특성을 비교하기 위해 증착온도를 상온에서부터 $600^{\circ}C$까지 변호시키고 증착후 각각의 시편을 80$0^{\circ}C$ 산소분위기에서 2시간동안 열처리하여 시편을 준비하였다. 박막의 상형성 여부와 결정성변화는 $ heta$-2$\theta$X-선 회절법을 사용하여 조사하였고, EPMA를 이용하여 박막의 조성을 확인하였다. 유전특성의 측정을 위해 백금 상부전극을 증착한 후, impedance analyzer를 이용하여 100kHz 영역에서의 유전손실을 측정하고, 측정된 정전용량과 박막의 두께로부터 유전율을 계산하였다. ZrTiO4 박막은 증착온도 20$0^{\circ}C$ 이상에서 결정성을 보이기 시작했으며, 열처리 이후에는 상온에서 비정질이었던 시편이 $650^{\circ}C$ 이상의 온도에서 결정화되기 시작하였다. 증착온도에 따라 유전손실은 0.038에서 0.017 정도로 감소하는 경향을 나타냈으며, 각각 열처리에 의해서 0.034, 0.005 정도로 다시 감소하였다. 박막의 유전율은 약 35 정도의 값을 나타내었으며 X-선 회절 data로부터 분석한 박막의 변형은 증온도에 따라 7.2%에서 0.04%로 감소하였고 이 이경향은 유전손실은 감소경향과 일치하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.431-432
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• 2012

In the era of 20 nm scaled semiconductor volume manufacturing, Microelectronics Manufacturing Engineering Education is presented in this paper. The purpose of microelectronic engineering education is to educate engineers to work in the semiconductor industry; it is therefore should be considered even before than technology development. Three Microelectronics Manufacturing Engineering related courses are introduced, and how undergraduate students acquired hands-on experience on Microelectronics fabrication and manufacturing. Conventionally employed wire bonding was recognized as not only an additional parasitic source in high-frequency mobile applications due to the increased inductance caused from the wiring loop, but also a huddle for minimizing IC packaging footprint. To alleviate the concerns, chip bumping technologies such as flip chip bumping and pillar bumping have been suggested as promising chip assembly methods to provide high-density interconnects and lower signal propagation delay [1,2]. Aluminum as metal interconnecting material over the decades in integrated circuits (ICs) manufacturing has been rapidly replaced with copper in majority IC products. A single copper metal layer with various test patterns of lines and vias and $400{\mu}m$ by $400{\mu}m$ interconnected pads are formed. Mask M1 allows metal interconnection patterns on 4" wafers with AZ1512 positive tone photoresist, and Cu/TiN/Ti layers are wet etched in two steps. We employed WPR, a thick patternable negative photoresist, manufactured by JSR Corp., which is specifically developed as dielectric material for multi- chip packaging (MCP) and package-on-package (PoP). Spin-coating at 1,000 rpm, i-line UV exposure, and 1 hour curing at $110^{\circ}C$ allows about $25{\mu}m$ thick passivation layer before performing wafer level soldering. Conventional Si3N4 passivation between Cu and WPR layer using plasma CVD can be an optional. To practice the board level flip chip assembly, individual students draw their own fan-outs of 40 rectangle pads using Eagle CAD, a free PCB artwork EDA. Individuals then transfer the test circuitry on a blank CCFL board followed by Cu etching and solder mask processes. Negative dry film resist (DFR), Accimage$^{(R)}$, manufactured by Kolon Industries, Inc., was used for solder resist for ball grid array (BGA). We demonstrated how Microelectronics Manufacturing Engineering education has been performed by presenting brief intermediate by-product from undergraduate and graduate students. Microelectronics Manufacturing Engineering, once again, is to educating engineers to actively work in the area of semiconductor manufacturing. Through one semester senior level hands-on laboratory course, participating students will have clearer understanding on microelectronics manufacturing and realized the importance of manufacturing yield in practice.