• Title/Summary/Keyword: NPS

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A Study on the Reduction Effect of Vibration of NPS Blasting Method on Andesite, Granite and Granitic Gneiss (안산암, 화강암, 화강편마암에서의 NPS 발파법의 진동감쇠효과에 관한 연구)

  • 심동수;강대우
    • Explosives and Blasting
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    • v.22 no.2
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    • pp.13-20
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    • 2004
  • 도심지 굴착과 같은 환경적 제약과 사회적 문제가 존재하는 현장에 대하여. 암반제거작업에 있어서 가장 경제적이고 효율적인 발파공법을 적용하기 위해서, 본 연구는 기존의 발파방진기술인 Line Drilling과 Presplitting의 상점을 살리면서, 단점을 보안한 새로운 발파방진 기술인 NPS(New Presplitting)발파법의 효과에 대하여 연구하였다. NPS 발파법의 분석은 안산암과 화강암, 화강편마암의 3종류의 암반을 대상으로 NPS 발파법의 열수를 1열, 2열, 3열, 4열을 적용하여 발파로 인한 진동을 NPS 발파법의 적용전과 후의 발파진동값을 기준으로 NPS 발파법의 전, 후 진동감쇠 효과를 비교하고, 동일 조건을 가정한 경제성을 살펴보았다. 그 결과 NPS 발파법의 3가지 암석에 대한 현장적용 결과 암종에 따른 NPS 발파공법의 진동감쇠효과의 변화보다, NPS 발파법의 적용 pattern에 대한 진동감쇠효과의 변화가 크게 나타났으며 NPS 발파공열이 2열일 때 감쇠범위는 40%∼80%로 가장 효율적으로 나타났으며 3열과 4열의 경우에도 진동감쇠효과는 있으나 그 효율이 크게 향상되지 않을 뿐 아니라 2열에 비하여 경제적으로 불리함을 알 수 있었다. 또한 NPS 발파법은 보안물과의 거리가 가까울수록 더 경제성이 큰 것으로 분석되었다.

Green Synthesis of Silver and Gold Nanoparticles Using Lonicera Japonica Flower Extract

  • Nagajyothi, P.C.;Lee, Seong-Eon;An, Minh;Lee, Kap-Duk
    • Bulletin of the Korean Chemical Society
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    • v.33 no.8
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    • pp.2609-2612
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    • 2012
  • A simple green method was developed for rapid synthesis of silver and gold nanoparticles (AgNPs and AuNPs) has been reported using Lonicera japonica flower extract as a reducing and a capping agent. AgNPs and AuNPs were carried out at $70^{\circ}C$. The successful formation of AgNPs and AuNPs have been confirmed by UV-Vis spectro photometer, fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray Analysis (EDAX), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). To our knowledge, this is the first report where Lonicera japonica flower was found to be a suitable plant source for the green synthesis of AgNPs and AuNPs.

A Computational Approach to Definite NPs

  • Lee, Yong-Hun
    • Korean Journal of English Language and Linguistics
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    • v.3 no.1
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    • pp.89-108
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    • 2003
  • As pronouns are resolved with their antecedents, definite NPs may enter into the anaphora-antecedent relations with indefinite NPs. This paper is to provide faster and more efficient computational algorithms by which definite NPs are resolved effectively, For this purpose, this paper extends Chierchia's Binding Theory in Categorial Grammar, and definite NPs are resolved with their antecedents by similar algorithms that are used to reflexive resolution. In these algorithms, the relations between indefinite NP and definite NP are represented with λ-expressions, and definite NPs are resolved with their antecedent by λ-conversions.

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A Comparative Study of Gas Sensing Properties of Au-loaded ZnO and Au@ZnO Core-shell Nanoparticles

  • Majhi, Sanjit Manohar;Dao, Dung Van;Lee, Hu-Jun;Yu, Yeon Tae
    • Journal of Sensor Science and Technology
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    • v.27 no.2
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    • pp.76-81
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    • 2018
  • Au@ZnO core-shell nanoparticles (NPs) were prepared by a simple method followed by heat-treatment for gas sensor applications. The advantage of the core-shell morphology was investigated by comparing the gas sensing performances of Au@ZnO core-shell NPs with pure ZnO NPs and different wt% of Au-loaded ZnO NPs. The crystal structures, shapes, sizes, and morphologies of all sensing materials were characterized by XRD, TEM, and HAADF-STEM. Au@ZnO core-shell NPs were nearly spherical in shape and Au NPs were encapsulated in the center with a 40-45 nm ZnO shell outside. The gas sensing operating temperature for Au@ZnO core-shell NPs was $300^{\circ}C$, whereas it was $350^{\circ}C$ for pure ZnO NPs and Au-loaded ZnO NPs. The maximum response of Au@ZnO core-shell NPs to 1000 ppm CO at $300^{\circ}C$ was 77.3, which was three-fold higher than that of 2 wt% Au-loaded ZnO NPs. Electronic and chemical effects were the primary reasons for the improved sensitivity of Au@ZnO core-shell NPs. It was confirmed that Au@ZnO core-shell NPs had better sensitivity and stability than Au-loaded ZnO NPs.

A Syntactic Account of the Properties of Bare Nominals in Discourse

  • Ahn, Hee-Don;Cho, Sung-Eun
    • Proceedings of the Korean Society for Language and Information Conference
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    • 2007.11a
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    • pp.57-66
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    • 2007
  • Case markers in Korean are omissible in colloquial speech. Previous discourse studies of Caseless bare NPs in Korean show that the information structure of zero Nominative not only differs from that of overt Nominative but it also differs from that of zero Accusative in many respects. This paper aims to provide a basis for these semantic/pragmatic properties of Caseless NPs through the syntactic difference between bare subjects and bare objects: namely, the former are left-dislocated NPs, whereas the latter form complex predicates with the subcategorizing verbs. Our analysis will account for the facts that (i) the distribution of bare subject NPs are more restricted than that of bare object NPs; (ii) bare subject NPs must be specific or topical; (iii) Acc-marked NPs in canonical position tend to be focalized.

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Geno- and Ecotoxicity Evaluation of Silver Nanoparticles in Freshwater Crustacean Daphnia magna

  • Park, Sun-Young;Choi, Jin-Hee
    • Environmental Engineering Research
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    • v.15 no.1
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    • pp.23-27
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    • 2010
  • Genotoxic- and ecotoxic assessments of silver nanoparticles (AgNPs) were conducted on the freshwater crustacean Daphnia magna. AgNPs may have genotoxic effects on D. magna, given that the DNA strand breaks increased when exposed to this nanoparticle. Increased mortality was concomitantly observed with DNA damage in the AgNPs-exposed D. magna, which suggests AgNPs-induced DNA damage might provoke higher-level consequences. The results of the comparative toxicities of AgNPs and Ag ions suggest that AgNPs are slightly more toxic than Ag ions. Overall, these results suggest that AgNPs may be genotoxic toward D. magna, which may contribute to the knowledge relating to the aquatic toxicity of AgNPs on aquatic ecosystems, for which little data are available.

Subject-Object Asymmetries of Morphological Case Realization

  • Ahn, Hee-Don;Cho, Sung-Eun
    • Language and Information
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    • v.11 no.1
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    • pp.53-76
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    • 2007
  • Case markers in Korean are omissible in colloquial speech. Previous discourse studies of Caseless bare NPs in Korean show that the information structure of zero Nominative not only differs from that of overt Nominative but it also differs from that of zero Accusative in many respects. This paper aims to provide a basis for these semantic/pragmatic properties of Caseless NPs through the syntactic difference between bare subjects and bare objects: namely, the former are left-dislocated NPs, whereas the latter form complex predicates with the subcategorizing verbs. Our analysis will account for the facts that (i) the distribution of bare subject NPs are more restricted than that of bare object NPs; (ii) bare subject NPs must be specific or topical; (iii) Acc-marked NPs in canonical position tend to be focalized.

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Curcumin-loaded PLGA Nanoparticles Conjugated with Anti-P-glycoprotein Antibody to Overcome Multidrug Resistance

  • Punfa, Wanisa;Suzuki, Shugo;Pitchakarn, Pornsiri;Yodkeeree, Supachai;Naiki, Taku;Takahashi, Satoru;Limtrakul, Pornngarm
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9249-9258
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    • 2014
  • Background: The encapsulation of curcumin (Cur) in polylactic-co-glycolic acid (PLGA) nanoparticles (Cur-NPs) was designed to improve its solubility and stability. Conjugation of the Cur-NPs with anti-P-glycoprotein (P-gp) antibody (Cur-NPs-APgp) may increase their targeting to P-gp, which is highly expressed in multidrugresistance (MDR) cancer cells. This study determined whether Cur-NPs-APgp could overcome MDR in a human cervical cancer model (KB-V1 cells) in vitro and in vivo. Materials and Methods: First, we determined the MDR-reversing property of Cur in P-gp-overexpressing KB-V1 cells in vitro and in vivo. Cur-NPs and Cur-NPs-APgp, in the range 150-180 nm, were constructed and subjected to an in vivo pharmacokinetic study compared with Cur. The in vitro and in vivo MDR-reversing properties of Cur-NPs and Cur-NPs-APgp were then investigated. Moreover, the stability of the NPs was determined in various solutions. Results: The combined treatment of paclitaxel (PTX) with Cur dramatically decreased cell viability and tumor growth compared to PTX treatment alone. After intravenous injection, Cur-NPs-APgp and Cur-NPs could be detected in the serum up to 60 and 120 min later, respectively, whereas Cur was not detected after 30 min. Pretreatment with Cur-NPs-APgp, but not with NPs or Cur-NPs, could enhance PTX sensitivity both in vitro and in vivo. The constructed NPs remained a consistent size, proving their stability in various solutions. Conclusions: Our functional Cur-NPs-APgp may be a suitable candidate for application in a drug delivery system for overcoming drug resistance. The further development of Cur-NPs-APgp may be beneficial to cancer patients by leading to its use as either as a MDR modulator or as an anticancer drug.

Skin Corrosion and Irritation Test of Nanoparticles Using Reconstructed Three-Dimensional Human Skin Model, EpiDermTM

  • Kim, Hyejin;Choi, Jonghye;Lee, Handule;Park, Juyoung;Yoon, Byung-Il;Jin, Seon Mi;Park, Kwangsik
    • Toxicological Research
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    • v.32 no.4
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    • pp.311-316
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    • 2016
  • Effects of nanoparticles (NPs) on skin corrosion and irritation using three-dimensional human skin models were investigated based on the test guidelines of Organization for Economic Co-operation and Development (OECD TG431 and TG439). EpiDerm$^{TM}$ skin was incubated with NPs including those harboring iron (FeNPs), aluminum oxide (AlNPs), titanium oxide (TNPs), and silver (AgNPs) for a defined time according to the test guidelines. Cell viabilities of EpiDerm$^{TM}$ skins were measured by the 3-(4, 5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide based method. FeNPs, AlNPs, TNPs, and AgNPs were non-corrosive because the viability was more than 50% after 3 min exposure and more than 15% after 60 min exposure, which are the non-corrosive criteria. All NPs were also non-irritants, based on viability exceeding 50% after 60 min exposure and 42 hr post-incubation. Release of interleukin 1-alpha and histopathological analysis supported the cell viability results. These findings suggest that FeNPs, AlNPs, TNPs, and AgNPs are 'non-corrosive' and 'non-irritant' to human skin by a globally harmonized classification system.

An Estimation of NPS Pollutant Loads using the Correlation between Storm Water Runoff and Pollutant Discharge in a Small Urban Drainage Basin (도시소유역에서의 유출과 비점원오염물 배출 간의 상관관계 수립에 의한 NPS 오염물 배출량의 산정)

  • 신현석;윤용남
    • Water for future
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    • v.26 no.4
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    • pp.85-95
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    • 1993
  • Three purposes of this study are as follows: The first was the development of the extention method for the limited data observed in an urban drainage basin. The second was the analysis of the correlation between storm water runoff and NPS(non-point source) pollutant discharge, The last was the calculation of the monthly and annual specific NPS loads using the established correlation. the selected model was the SWMM monthly and annual specific NPs loads using the established correlation. The selected model was the SWMM (Storm Water Management model) developed by the US EPA(environmental Protection Agency). As a result of this study, the best correlation between storm wate runoff and NPS pollutants discharge was produced by the non-linear correlation between runoff rate(mm/hr)and specific loads rate(g/ha/sec)for all pollutants studied ; SS, COD, BOD, and TN. The best correlation through the analysis based on evently total mass was made by the linear correlation between the specific accumulated runoff(mm) and the specific accumulated loads(kg/ha) for CASE 1., and by the non-linear correlation for CASE 2. The NPS annual specific loads for the urban basin studied were 4933 kg/ha/year for SS, 775kg/ha/year for BOD, 3094kg/ha /year for COD,257kg/ha/year for TN, respectively. And the proportion of the NPS annual specific loads to the total annual specific loads were 42 % for SS, 13 % for BOD, 29% for COD, and 21 % for TN.

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