• 한국환경과학회지
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• 제11권7호
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• pp.669-677
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• 2002

This study was conducted to investigate the characteristics of role of transport on aerosol concentration at Crate Lake, Oregon USA for 1988.3~1999. 5. The IMPROVE program is a cooperative measurement effort governed by a steering committee composed of representatives from USA federal and regional-state organizations. Also IMPROVE sampler is designed to obtain a complete signature of the composition of the airborne particles affecting visibility. According to 10-day backward isentropic trajectory analysis, the frequency of local, marine and Asian trajectory showed 33.1%(335 cases), 47%(478 cases), 5.2%(53 cases) respectively. The monthly variation of nss $SO_4^{2-}$, nss S, $NO_3^-$, K and C showed the double peak pattern, high in April~May and August~september and showed the lowest concentration in Winter. The other constituents concentration except for Cl$^{[-10]}$ , Na, Mg was high in local trajectory than marine trajectory. A ratio nss $SO_4^{2-}$ to $SO_4^{2-}$ was 90.5% in marine trajectory and 98% in local trajectory. It suggest that the aerosol in Crater Lake was effected by salt. The annual mean concentration of nss $SO_4^{2-}$ and nss S decreased but the springtime concentration increased.

• 분석과학
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• 제21권4호
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• pp.304-315
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• 2008

한라산 1100 고지에서 채취한 대기 부유분진의 조성은 인위적 기원의 성분들이 가장 높고, 다음으로 해양 기원 성분과 토양 기원 성분들이 높은 함량을 나타내었다. 계절별로는 봄철에 토양 성분인 nss-$Ca^{2+}$, Al, Fe, Ca 성분의 농도가 크게 증가하였고, 인위적 기원의 $NH{_4}^+$, $K^+$, nss-$SO{_4}^{2-}$은 6월에 가장 높은 농도를 보였다. 반면에 $NO{_3}^-$은 봄철에 nss-$Ca^{2+}$과 함께 농도가 상승하였고, 이는 중국으로부터 장거리 이동에 의한 영향으로 추정된다. 황사와 비황사 때의 농도를 비교해 본 결과, 황사 때에 nss-$Ca^{2+}$, Al, Ca, Fe 농도가 7.2~9.5배 증가하였고, nss-$SO{_4}^{2-}$과 $NO{_3}^-$은 각각 1.3, 3.8배 정도 더 증가한 것으로 확인되었다. 요인분석법으로 분진성분의 발생기원을 조사해 본 결과, 한라산 1100 고지 부유분진은 토양의 영향을 가장 많이 받고, 다음으로 인위적 영향과 해염 영향을 많이 받고 있는 것으로 추정된다. 역궤적분석에 의해 분진 성분의 유입경로를 조사한 결과, 공기덩어리가 중국대륙을 거쳐 제주지역으로 이동한 북서풍 계열의 풍향일 때 주요 인위적 기원의 성분과 토양 성분의 농도가 상승하고, 공기가 북태평양을 거쳐 제주지역으로 유입되었을 때 이들 성분들의 농도가 상대적으로 감소하는 경향을 보였다.

• 분석과학
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• 제23권4호
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• pp.371-382
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• 2010

제주도 고산지역에서 TSP (total suspended particulate), PM2.5 (particulate matter, below $2.5\;{\mu}m$ particle size) 대기에어로졸을 채취, 분석하여 에어로졸의 조성과 오염 특성을 조사하였다. 고산지역 대기에어로졸에서 nss(non-sea salt)-$SO_4^{2-}$과 $NH_4^+$은 다른 국내 청정지역 및 도시지역에 비해 높은 조성비를보이고 $NO_3^-$는 상대적으로 낮은 조성비를 나타내었다. 에어로졸 성분의 입경별 분포를 비교해 본 결과, 인위적 기원의 nss-$SO_4^{2-}$, $NO3_^-$, $NH_4^+$ 성분들은 대체적으로 미세입자에, 토양기원의 nss-$Ca^{2+}$과 해염기원의 $Na^+$, $Cl^-$, $Mg^{2+}$은 상대적으로 조대입자에 많이 분포하고 있는 것으로 확인되었다. 계절별로는 봄철에 nss-$Ca^{2+}$, Al, Fe, Ca, $NO_3^-$ 성분의 농도가 크게 상승하고, nss-$SO_4^{2-}$은 여름과 봄철에 높은 농도를 나타내었다. 인자분석 결과, 에어로졸은 대체적으로 인위적 발생원의 영향을 많이 받고, 다음으로 해양 및 토양 영향을 많이 받았다. 또한 역궤적 분석법으로 에어로졸 성분의 유입경로를 조사해 본 결과, nss-$SO_4^{2-}$, $NO_3^-$, Pb, nss-$Ca^{2+}$ 성분들은 대체적으로 기류가 중국대륙으로부터 제주지역으로 이동할 때 훨씬 더 높은 농도를 나타낸 반면, 북태평양에서 제주지역으로 이동할 때 상대적으로 낮은 농도를 나타내었다.

• Journal of Animal Science and Technology
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• 제45권4호
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• pp.627-632
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• 2003

본 연구는 수유 후 30분에 NSS와 NSSCS를 분만 후 1일, 7일 및 14일차에 모돈과 포유자돈에게 재생하였을 때 모돈과 포유자돈의 행동반응을 관찰하고 분석함으로써 수 포유행동을 유발시키는데 보다 효과적인 소리를 규명하기 위하여 수행되었다. 분만 1일차의 모돈에서는 SI와 ST가 차이가 없었으나(p<0.05), 분만 7일차의 모돈에서는 SI가 NSS구에 비하여 NSSCS구에서 높았을 뿐만 아니라(p<0.05) ST도 NSS구에 비하여 NSSCS구에서 유의적으로 높았다(p<0.05). 그리고 분만 14일차의 모돈에서도 SI가 NSS구에 비하여 NSSCS구에서 고도로 높았으며(p<0.01), ST도 NSS구에 비하여 NSSCS구에서 유의적으로 높게 나타났다(p<0.05). 포유자돈의 경우 포유행동과 밀접하게 관련 있는 M이 NSS구에 비하여 NSSCS구에서 일령에 관계없이 높았는데 7일령과 14일령에서는 유의차가 나타났으며(p<0.01), W는 7일령에서만 유의적으로 높았다(p<0.05). 따라서, 모돈의 수유행동과 포유자돈의 포유행동을 유발시키는데 NSS도 효과가 있을 것으로 판단이 되지만 NSSCS가 NSS보다 더 효과적일 것으로 판단된다.

• 대기
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• 제27권1호
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• pp.29-40
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• 2017

The $PM_{10}$ and $PM_{2.5}$ particles over the Yellow Sea of Korea were collected by ship-borne observation during two cruises in spring, 2015. Their water-soluble ionic components such as $NH_4^+$, $Na^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $SO_4^{2-}$, $NO_3^-$, $Cl^-$, $F^-$, $CH_3COO^-$, $HCOO^-$, and $CH_3SO_3^-$ were analyzed, in order to examine the pollution characteristics of the secondary aerosol components. The comparative study of particle size distribution has resulted that $NH_4^+$, $nss-SO_4^{2-}$, $nss-Mg2+$, $nss-K^+$, $HCOO^-$, and $CH_3SO_3^-$ species mostly existed in fine particle mode. Meanwhile, nss-F-and sea-salt species were distributed in both fine and coarse particle mode, $NO_3^-$, $nss-Ca^{2+}$, $CH_3COO^-$ species were rich in coarse particle mode. The concentrations of secondary pollutants($nss-SO_4^{2-}$, $NO_3^-$, $NH_4^+$) increased in fine particles, and those of natural components ($nss-Ca^{2+}$, Sea-salt) increased in coarse particles. $NH_4^+$ exists as the form of $(NH_4)_2SO_4$ and $NH_4NO_3$, and mostly as $(NH_4)_2SO_4$ in fine particles. $NH_4NO_3$ has lower content compared to $(NH_4)_2SO_4$, and it mostly existed in fine particles at Yellow Sea I and in coarse particles at Yellow Sea II. The concentration ratios of $NO_3^-/nss-SO_4^{2-}$ for Yellow Sea I and Yellow Sea II were 0.52 and 0.16 in coarse particles, and they were 0.64 and 0.38 in fine particles, respectively, showing that the stationary source emissions were more important than mobile source emissions in Yellow Sea II (except Passage II-4).

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.315.1-315.1
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• 2014

The use of cellulose papers has recently attracted much attention in various device applications owing to their natural advantageous properties of earth's abundance, bio-friendly, large-scale production, and flexibility. Conventional metal oxides with novel structures of nanorods, nanospindles, nanowires and nanobelts are being developed for emerging electronic and chemical sensing applications. In this work, both ZnO (n-type) nanorod arrays (NRAs) and CuO (p-type) nanospindles (NSs) were synthesized on cellulose papers and the p-n junction property was investigated using the electrode of indium tin oxide coated polyethylene terephthalate film. To synthesize ZnO and CuO nanostructures on cellulose paper, a simple and facile hydrothermal method was utilized. First, the CuO NSs were synthesized on cellulose paper by a simple soaking process, yielding the well adhered CuO NSs on cellulose paper. After that, the ZnO NRAs were grown on CuO NSs/cellulose paper via a facile hydrothermal route. The as-grown ZnO/CuO NSs on cellulose paper exhibited good crystalline and optical properties. The fabricated p-n junction device showed the I-V characteristics with a rectifying behaviour.

• 말소리와 음성과학
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• 제4권1호
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• pp.3-11
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• 2012

The aim of this paper is to examine the phonetic realizations of English unstressed vowels produced by advanced Korean learners (KLs) of English compared with English native speakers (NSs) focusing on the comparative study of English words and English loanwords. The result shows that KLs are usually not native-like in producing the English unstressed vowel /ə/ and loanword orthography affects the way the KLs produce /?/. The vowel quality of the unstressed vowels produced by the KLs is different from that of the NSs. In duration and pitch, KLs show significantly less difference between the stressed and unstressed vowels than do the NSs. The KLs usually have a high pitch in the stressed and the last syllable while the NSs usually produce peak F0 in the stressed syllable. When the KLs have a similar vowel quality with that of the NSs, they produce a shorter duration of the unstressed vowels. However, there is no correlation between the realization of the pitch and the vowel quality in KLs speech.

• 청정기술
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• 제26권4호
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• pp.257-262
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• 2020

Two-dimensional (2D) metal organic framework (MOF) nanosheets (NSs) have recently gained considerable interest owing to their structural advantages, such as large surface area and exposed active sites. Two different types of 2D MOF NSs have been reported, including inherently layered MOFs and non-layered ones. Although several studies on inherently layered 2D MOFs have been reported, non-layered 2D MOFs have been rarely studied. This may be because the non-layered MOFs have a strong preference to form three-dimensionality intrinsically. Furthermore, the non-layered MOFs are typically synthesized in the presence of the surfactant or modulator, and thus developing facile and clean synthetic routes is highly pursued. In this study, a facile and clean synthetic methodology to grow non-layered 2D cobalt-based zeolitic imidazolate framework (ZIF-67) NSs is suggested, without using any surfactant and modulator at room temperature. This is achieved by directly converting ultrathin α-Co(OH)2 layered hydroxide salt (LHS) NSs into non-layered 2D ZIF-67 NSs. The comprehensive characterizations were conducted to elucidate the conversion mechanism, structural information, thermal stability, and chemical composition of the non-layered 2D ZIF-67. This facile and clean approach could produce a variety of non-layered 2D MOF NS families to extend potential applications of MOF materials.

• Mass Spectrometry Letters
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• 제15권1호
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• pp.26-39
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• 2024

Gold nanostructures (Au NSs) are useful and interesting matrices for mass spectrometric analysis of various biomolecules based on organic matrix-free laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF-MS). Au NSs provide high efficiency and versatility in LDI-TOF-MS analysis based on their well-established synthesis and surface functionalization, large surface area, high laser absorption capacity, and photothermal conversion efficiency. Therefore, Au NSs based LDI-TOF-MS can be a facile, functional, and efficient analytical method for important small biomolecules owing to its simple preparation, rapid analysis, salt-tolerance, signal reproducibility, and quantitative analysis. This review chronologically summarizes the important advance of Au NSs-based LDI-TOF-MS platforms in terms of in-depth mechanism, signal enhancement, quantitative analysis, and disease diagnosis.

• Journal of Nutrition and Health
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• 제33권8호
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• pp.864-872
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• 2000

This study intended to evaluate the validity of the simple nutrition screening test that had been developed with the elderly living in Cheongju as a subject. Nutrition screening score(NSS) and reference standards for nutritional and health status(nutrient intakes, mean adequacy ratio, perceive health, and serum albumin, hematocrit, and hemoglobin) were estimated by using the date obtained in 1996 from the 174 elderly living in Taejon, Statistical analysis showed significant correlations between mean adequacy ratio(MAR) and NSS(r=0.341) and also between NSS and biological indices such as albumin and hematocrit, Around 65-75% of the elderly with perceive health and low level of serum albumin, hemoglobin and hematocrit had NSS$\leq$ll. Sensitivity, specificity, and positive predictive values(PPV) were calculated from the crosstabulation of the three categories of NSS(high, moderate, and low nutritional risk) and low categories MAR(< 0.75, undernutrition;$\geq$0.75, normal) to validate the cut-off point for high or low nutritional risk by NSS. It was suggested that point l1 was appropriate as a criterion to determine high risk of undernutrition, but point 16 was better than 17 as criterion to determine low nutritional risk in the Taejon elderly. When point ll was used as a criterion of high nutritional risk, sensitivity, specificity, and PPV are 59.5, 60.5 and 82.1 respectively. When point 16 was used as a criterion of low nutritional risk, sensitivity, specificity, and PPV are 25.6, 95.4, and 64.7%, respectively. In conclusion, nutrition screening test that had been developed can be a simple, easy, and proper instrument to classify the high risk group of undernutrition. A further validation study seems to be required among other groups of individuals for the screening test to the finalized as a more valid instrument identifying Korean elderly at nutrition and health risk(Korean J Nutrition 33(8) : 864-872, 2000)