• Smart Structures and Systems
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• 제21권1호
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• pp.65-74
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• 2018

In this article, an analytic non-classical model for the free vibrations of nanobeams accounting for surface stress effects is developed. The classical continuum mechanics fails to capture the surface energy effects and hence is not directly applicable at nanoscale. A general beam model based on Gurtin-Murdoch continuum surface elasticity theory is developed for the analysis of thin and thick beams. Thus, surface energy has a significant effect on the response of nanoscale structures, and is associated with their size-dependent behavior. To check the validity of the present analytic solution, the numerical results are compared with those obtained in the scientific literature. The influences of beam thickness, surface density, surface residual stress and surface elastic constants on the natural frequencies of nanobeams are also investigated. It is indicated that the effect of surface stress on the vibrational response of a nanobeam is dependent on its aspect ratio and thickness.

• 한국문헌정보학회지
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• 제9권
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• pp.53-74
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• 1982

On admet Jusqu'ici que le XVe siecle est une $\acute{e}poque$ phare de l'histoire de l'imprimerie avec l'apparition de la typographie en Orient et en Occident, $c'est-\acute{a}-dire$ en $Cor\acute{e}e$ sur le Rhim. Cependant, $l'\acute{e}poque$ de l'invention typographique en $Cor\acute{e}e$ doit $\hat{e}tre$ $devanc\acute{e}e$ encore d'un ou deux siecle. Outre cette question, il est $\acute{a}$ noter ici que les caracteres mobiles $m\acute{e}talliques$ Kyemi, fondus en 1403, ont $jou\acute{e}$ un $r\hat{o}le$ $tr\acute{e}s$ important dans l'histoire de la typographie mondiale et que les $caract\acute{e}res$ kabin qui leur $succ\acute{e}derent$ en 1434 menerent la typographie $cor\acute{e}enne$ a son $apog\acute{e}e$. Or, les recherches $cor\acute{e}ennes$ se satifait de la primaute de l'invention en Coree des caracteres mobiles metalliques, mais n'adoptent pas une attitude suffisament critique. Aussi, l'auteur a-toil voulu s'interroger sur la veritable valeur de la typographie de la dynastie de Choson tant au point de vue de l'histoire de l'imprimerie mondiale. En premier lieu, on etudie, comme une chronique, les caracteres mobiles metalliques importants tout au long de la dynastie de Choson sans donner une interpretation nouvelle. C'est dans deux derniers, qu'on essaie de developper ses idees sur la typographie en Coree notamment la question technologique qui devrait etre le fond des recherches. Aussi, on y etudie, la technique de la typographie ancienne en Coree interpretee selon une methode scientifique et moderne et, enfin, le bilan synthetique en cherchant les raisons qui freinerent son developpement en Coree malgre la performance de ses debuts. A l'issue de ces recherches, on ne peut s'empecher d'eprouver une certaine insatisfaction a cause de l'ambiguite des explications que l'on trouve dans des documents fondamentaux. Avec ce difficulte on a voulu, au moins, exposer des points discutatables qui devraient etre les recherches a futur.

• Journal of Microbiology
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• 제42권3호
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• pp.169-173
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• 2004

Enterobacter cloacae (strain PR2/7), a genetically modified endophyte(GME) in citrus plants, carrying different plasmids (pEC3.0/18, pCelE, pEglA and pGFP), was inoculated into Citrus sinensis seedlings under greenhouse conditions. The impact of this on the indigenous bacterial endophytic community was studied by analyses of 2 different morphologic groups. The germination rates of inoculated seeds were evaluated in greenhouse, and plasmid stability under in vitro conditions. Results demonstrated a great and diverse endophytic community inside plants, and specialization in tissue colonization by some bacterial groups, in different treatments. Shifts in seed germination rate were observed among treatments: in general, the PR2/7 harboring pEglA bacterial- clone significantly reduced seed germination, compared to the PR2/7 harboring pEC3.0/18 clone. This suggests that the presence of the pEglA plasmid changes bacteria-seed interactions. The endophytic community of citrus seedlings changed according to treatment. In seedlings treated with the PR2/7 with pEglA clone, the population of group II decreased significantly, within the context of the total endophytic community. These results indicate that the application of GMEs induces shifts in the endophytic bacterial community of citrus seedlings.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.1005-1012
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• 2009

Lysozyme and the reduction of metabisulfite addition to red wine were evaluated during a winemaking process and after malolactic fermentation (MLF). Treatment, with lysozyme, of the must from Tempranillo grapes and at the end of alcoholic fermentation (AF) caused the 100% implantation of the inoculated bacterial strain and shortened the duration of MLF by 7 days. At the end of the MLF, wines treated with lysozyme showed lower volatile acidity, color intensity, and biogenic amine content. The differences in color intensity disappeared during wine stabilization. The lysozyme addition after MLF led to lower histamine concentrations in wines. These phenomena occurred irrespective of the lactic acid bacteria (LAB) proliferation control and of the Oenococcus oeni dominant strain identified at this period. The results of this study show the significance of preventive use of lysozyme in vinification of red wine to maintain low histamine levels and ensure a successful implantation of inoculated O. oeni starters.

• Journal of Microbiology and Biotechnology
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• 제11권5호
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• pp.812-818
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• 2001

Alginate and alginate-derived oligomannuronate enhanced penicillin production in shake flask and fermentor cultures of Penicillium chrysogenum Wis 54-1255 (containing a single copy of the penicillin gene cluster) and in the high producter strain P. chrysogenum AS-P-99 (containing multiple copies of the penicillin gene cluster). Alginate was not used as a single carbon source by P. chryogenum. The stimulatory effect on penicillin production was observed in a defined medium and, to a lower extent, in a complex production medium containing corn steep liquor. Alginate-supplemented cells showed higher transcript levels of the three penicillin biosynthetic genes, pcbAB, pcbC, and penDE, than cells grown in the absence of alginate. The promoters of the pcbAB, pcbC, and penDE genes were coupled to the reporter lacZ gene and introduced as monocopy constructions in P. chrysogenum Wis 54-1225 npe10 by targeted integration in the pyrG locus; the reporter ${\beta}$-galactosidase activity expressed from the three promoters was stimulated by alginate added to the culture medium of the transformants. These results indicate that the stimulation of penicillin production by alginate was derived from an increase in the transcriptional activity of the penicillin biosynthesis genes. The induction by alginate of the transcription of the three penicillin biosynthetic genes is good example of the coordinated induction of secondary metabolism genes by elicitors of plant (or microbial) origin.

• Parasites, Hosts and Diseases
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• 제45권4호
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• pp.255-266
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• 2007

The protective effect of the Synadenium carinatum latex lectin (ScLL), and the possibility of using it as an adjuvant in murine model of vaccination against American cutaneous leishmaniasis, were evaluated. BALB/c mice were immunized with the lectin ScLL (10, 50, 100$[\mu}g$/animal) separately or in association with the soluble Leishmania amazonensis antigen (SLA). After a challenge infection with $10^6$ promastigotes, the injury progression was monitored weekly by measuring the footpad swelling for 10 weeks. ScLL appeared to be capable of conferring partial protection to the animals, being most evident when ScLL was used in concentrations of 50 and 100${\mu}g$/animal. Also the parasite load in the interior of macrophages showed significant reduction (61.7%) when compared to the control group. With regard to the cellular response, ScLL 50 and 100 ${\mu}g$/animal stimulated the delayed-type hypersensitivity (DTH) reaction significantly (P < 0.05) higher than SLA or SLA plus ScLL 10 weeks after the challenge infection. The detection of high levels of IgG2a and the expression of mRNA cytokines, such as IFN-$\gamma$, IL-12, and TNF-$\alpha$ (Th1 profiles), corroborated the protective role of this lectin against cutaneous leishmaniasis. This is the first report of the ScLL effect on leishmaniasis and shows a promising role for ScLL to be explored in other experimental models for treatment of leishmaniasis.

• Korean Chemical Engineering Research
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• 제61권1호
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• pp.97-108
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• 2023

Two carbonaceous adsorbents CAT and CARBOPAL were tested for reducing the concentration of the three herbicides in water: 2,4-D (2,4-dichlorophenoxyacetic acid), TCP (2,4,6-trichlorophenol) and metolachlor. Textural and chemical characterization of the adsorbents include nitrogen isotherms, FTIR, titration and thermogravimetric analyses. Adsorption was studied in discontinuous adsorption experiments at different pH values. The experimental adsorption isotherms data were fitted to four theoretical models. Adsorbent characterization reveals that CAT has higher micropore area, lower pore diameter and lower acidity than CARBOPAL. The adsorption is a second-order process and the isotherms best fitted to Sips model. The efficiency of the process depends mainly on the charge of the adsorbate for TCP and 2,4-D, but it depends on the charge of the surface for metolachlor. Adsorption capacity is higher on CAT for 2,4-D and TCP (small molecules), and it is higher on CARBOPAL for metolachlor (large molecules). Theoretical calculations clearly support this assumption.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2349-2355
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• 2023

In the TRITIUM project, an on-site monitoring system is being developed to measure tritium (³H) levels in water near nuclear power plants. The quite low-energy betas emitted by ³H have a very short average path in water (5 ㎛ as shown by simulations for 18 keV electrons). This path would be further reduced by impurities present in the water, resulting in a significant reduction of the detection efficiency. Therefore, one of the essential requirements of the project is the elimination of these impurities through a filtration process and the removal of salts in solution. This paper describes a water treatment system developed for the project that meets the following requirements: the water produced should be of near-pure water quality according to ISO 3696 grade 3 standard (conductivity < 10 µS/cm); the system should operate autonomously and be remotely monitored.

• 이베로아메리카
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• 제12권1호
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• pp.55-86
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• 2010

Después de la década 1990, la soja ha sido un agro-producto más importante en Paraguay. Pero la soja ha convertido el campo rural en la zona de la producción, es decir, la zona de sojización, para la exportación. Por otro lado, el campo rural se ha deteriorado por el aumento de la extensión del cultivo sojal. Los cultivos se extienden a lo largo de cientos de kilómetrios y afectan zonas muy cercanas a comunidades, colonias y otros asentamientos campesionos e indígenas, incluyendo escuelas, hogares, charcas familiares y comunitarias. Los sojeros utilizaron los agrotóxicos que contaminaron la tierra, agua y alimentos. Aunque los campesinos no quieren vender sus tierras, no ven otras alternativas ante los graves problemas que conllevan las masivas fumigaciones. Ellos venden sus lotes y migraron a ciudades. Se pierde la soberanía territorial, pues las tierras pasan a manos extranjeras, y la soberanía alimentaria, porque se desplaza la diversificación y los cultivos de subsistencia, expulsando a los campesions hacia las ciudades. Ante el agravamiento de la situación causado por el incremento del cultivo de la soja, los campesinos empezaron a resistir, es decir, desarrollar 'la guerra de la soja' contra los sojeros y el gobierno paraguayo que no tenia refuerzos de resolver los problemas. Los campesinos formaron coordinadoras por la defensa de sus tierras y de su modo de vida contra los sojeros. Las luchas y movilizaciones reclaman no sólo un nuevo tipo de reforma agraria sino también la defensa de la soberanía económica, alimentaria y territorial, el derecho a producir con la propia semilla y a desarrollar técnicas agrícolas adecuadas de acuerdo con la economía campesina y el equilibrio del medio ambiente, el desarrollo de formas sociales de producción y la democratización en el medio rural.

• 한국지역지리학회지
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• 제19권4호
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• pp.627-640
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• 2013

본 연구는 전남 여수시 백도의 지형형성과정을 분석하는 데 목적이 있다. 백도는 다도해의 형성과정과 해안지형을 이해하는 데 중요한 단서가 되는 섬이다. 백도를 구성하고 있는 암석은 미문상 화강암으로서 약 6천만 년 전에 형성된 것이다. 현재의 백도 지형을 형성케 한 요인은 지구조운동에 의한 북동-남서 방향과 동북동-서남서 방향의 절리선과 지반의 융기 그리고 파랑에 의한 침식작용 때문이다. 또한 백도를 구성하는 미문상 화강암에 대한 지화학적 분석에 의하면 백도는 칼크알칼리 계열(Calc-Alkaline)의 마그마 분화 특징을 보이며, 화산호 화강암(VAG)에 속한다. 즉 대륙주변부의 섭입환경에서 생성된 마그마임을 의미한다. 또한 단층과 해안단구로 보이는 지형이 관찰되나 백도일원에 신생대 제4기 후빙기 때 해수면 상승보다 더 큰 융기운동이 있었는지에 대해 추후 논의가 필요하다.