• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.5
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• pp.60-69
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• 2008

The principal reasons for applying a pigment coating to paper are to improve appearance and printability. The pigment coating provides a surface that is more uniform and more receptive to printing ink than are the uncoated fibers and, in turn, both facilitates the printing process and enhances the graphic reproduction. The improvement in print quality is readily apparent, especially in image areas or when multiple colors are involved. Although pigment coating of paper is to improve the printability, coated paper is not completely free from printing defects. Actually there are a number printing defects that are observed only with the coated papers. Among the printing defects that are commonly observed for coated papers, print mottle during multi-color offset printing is one of the most concerned defects, and it appears not only on solid tone area but also half dot print area. There are four main causes of print mottle ranging from printing inks, dampening solution, paper, and printing press or its operation. These indicates that almost every factors associated with lithographic printing can cause print mottle. Among these variation of paper quality influences most significantly on print mottle problems in multicolor offset printing, and this indicates that paper is most often to be blamed for its product deficiency as far as print mottle problems are concerned. Furthermore, most of the print mottle problems associated with paper is observed when coated papers are printed. Uncoated papers rarely show mottling problems. This indicates that print mottle is the most serious quality problems of coated paper products. Overcoming the print mottle is becoming more difficult because the operating speeds of coating and printing machines are increasing, coating weights are decreasing, and the demands on high-quality printing are increasing. Print mottle in offset printing is caused by (a) nonuniform back trap of ink caused by a nonuniform rate of ink drying, referred as "back trap mottle, and (b) nonuniform absorption of the dampening solution. Furthermore, both forms of print mottle have some relationship to the structure of the coated layer. The surest way of eliminating ink mottling is to eliminate unevenness in the base paper. Coating solutions, often easier to put into practice, should, however, be considered. In this paper the principal factors influencing print mottle of coated papers will be discussed. Especially the importance of base paper roughness, binder migration, even consolidation of coating layers, control of the drying rate, types of binders, etc. will be described.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2008.05a
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• pp.47-70
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• 2008

Cost efficiency is today the primary requirement in the paper and board industry. This has led therefore, to a greater preponderance of products with specifically designed functionality to take account of current industry needs. Continually increasing machine coating speeds together with these new coating colour components have put more emphasis on the importance of the correct rheology and water retention of the coating colours to achieve good runnability and end product quality. In the coating process, some penetration of the aqueous phase, to the base paper or board must occur to anchor the pre-coating to the base or the topcoat to the pre-coat. The aqueous phase acts as a vehicle not only for the binder, but also for the other components. If this water or material penetration is not controlled, there will be excessive material shift from the coating colour to the base, before immobilization of the coating colour will stop this migration. This can result in poor machine runnability, unstable system and uneven coating layer, impacting print quality. The performance of rheology modifiers or thickeners on the coating color have tended to be evaluated by the term, "water retention". This simple term is not sufficient to explain their performance changes during coating. In this paper we are introducing a new concept of "material retention", which takes note of the total composition of the coating colour material and therefore goes beyond the concept of only water retention. Controlled material retention leads to a more uniform z-directional distribution of coating colour components. The changes that can be made to z-directional uniformity will have positive effects on print quality as measured by surface strength, ink setting properties, print gloss, mottling tendency. Optical properties, such as light scattering, whiteness and light fastness delivery should also be improved. Additionally, controlled material retention minimizes changes to the coating colour with time in re-circulation giving less fluctuation in quality in the machine direction since it more closely resembles fresh coating for longer periods. Use of the material retention concept enables paper and board producers to have more stable runnability (i.e. lower process costs), improved end product quality (i.e. better performance of used chemicals) and/or optimized use of coating colour components (i.e. lower total formulation cost)

• Economic and Environmental Geology
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• v.29 no.4
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• pp.421-428
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• 1996

The occurrence, optical property, chemical composition, crystal structure and formation environments of the phillipsite within deep-sea manganese nodules were systematically investigated in this study. Phillipsite in manganese nodules occurs in nucleus of nodules along with consolidated bottom sediments, weathered volcanic debris, and interstitial grains in the each layer of manganese encrusts. Phillipsite is predominantly pseudomorphs of volcanic shards, and occurs as white to pale yellow in color lath-shaped and equant crystals. These show aggregations of prismatic, blocky, and bladed of 2 to $20{\mu}m$ long, and 2 to $5{\mu}m$ thick. The simplified average chemical formula of phillipsite is $({Ca_{0.1}Mg_{0.3}Na_{1.1}K_{1.5}})_3{(Fe_{0.3}Al_{4.2}Si_{11.8})O_{32}{\cdot}10H_2O}$ with a very siliceous and alkalic. The $Si/(Al+Fe^{+3})$ ratio is 2.37 to 2.78 and alkalis greatly exceed the divalent exchangeable cations, and Na/K ratio is 0.59 to 0.81. The phillipsite is monoclinic ($P2_l/m$) with the unit-cell parameters, $a=10.005{\AA}$, $b=14.129{\AA}$, $c=8.686{\AA}$, ${\beta}=124.35^{\circ}$, and $V=1013.6{\AA}^3$. Phillipsites in manganese nodules formed apparently authigenically at a temperature less than $10^{\circ}C$, and they crystallized at a pressure of less than 0.7 kb, and pH of about 8 in deep-sea environments.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.156-164
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• 2018

In order to investigate the upwelling and island effects following the wind storm events in the East Sea (i.e., Uljin-Ulleungdo-Dokdo line) during spring, we assessed the vertical and horizontal profiles of abiotic and biotic factors, including phytoplankton communities. The assessment was based on the Geostationary Ocean Color Imager (GOCI) and field survey data. A strong south wind occurred on May 3, when the lowest sea level pressure (987.3 hPa) in 2016 was observed. Interestingly, after this event, huge blooms of phytoplankton were observed on May 12 along the East Korean Warm Current (EKWC), including the in the offshore waters of Ulleungdo and Dokdo. Although the diatoms dominated the EKWC area between the Uljin coastal waters and Ulleungdo, the population density of raphidophytes Heterosigma akashiwo was high in the offshore waters of Ulleungdo-Dokdo. Based on the vertical profiles of Chlorophyll-a (Chl. a), the sub-surface Chl. a maximum appeared at 20 m depths between Uljin and Ulluengdo, whereas relatively high Chl. a was distributed equally across the entire water column around the waters of Ulleungdo and Dokdo islands. This implies that the water mixing (i.e., upwelling) at the two islands, that occurred after the strong wind event, may have brought the rapid proliferation of autotrophic algae, with nutrient input, to the euphotic layer. Therefore, we have demonstrated that a strong south wind caused the upwelling event around the south-eastern Korean peninsula, which is one of the most important role in occurring the spring phytoplankton blooms along the EKWC. In addition, the phytoplankton blooms may have potentially influenced the oligotrophic waters with discrete time lags in the vicinity of Ulleungdo and Dokdo. This indicates that the phytoplankton community structure in the offshore waters of Ulleungdo-Dokdo is dependent upon the complicated water masses moving related to meandering of the EKWC.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.344-351
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• 2005

Nitric oxide (NO) and calcium-binding proteins occur in various types of cells in the central nervous system. They are important signaling and calcium buffering molecules, respectively. In the present study, using immunocytochemistry we examined the distribution and the co-localization pattern of neurons containing neuronal nitric oxide synthase (nNOS) and parvalbumin in the visual cortex of hamster. The overall number of parvalbumin-immunoreactive (IR) neurons was 17 times higher than that of the nNOS-IR neurons in the hamster visual cortex. The highest differences were found in layer V, where parvalbumin-IR neurons were 54.7 times more abundant than nNOS-IR neurons. Many nNOS- and parvalbumin-IR neurons were similar in size, shape, and manner of distribution in the visual cortex. However, two-color immunofluorescence revealed that no neurons in the hamster visual cortex expressed both nNOS and parvalbumin. The present results indicate that there are subtle species differences in the co-localization pattern between nNOS and calcium-binding proteins. The present results also suggest not only the heterogeneity and functional diversity of nNOS-IRneurons in the visual cortex, but also the importance of understanding animal diversity

• Food Science of Animal Resources
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• v.32 no.1
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• pp.13-17
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• 2012

Two experiments were conducted to investigate the dietary effect of chlorella vulgaris on egg production and lutein incorporation into chicken eggs. In Exp. 1, a total of three hundred, 70 wk-old Hy-Line brown layers were divided into six groups with five replicates and fed each experimental diet (corn-SBM based control diet and diets with 0.1, 0.3 or 0.5% chlorella powder and with 0.8 or 2.4% chlorella cultured media) for 6 wk, respectively. The egg production in the groups fed diets containing the chlorella powder and chlorella cultured media were higher than that of the control group (p<0.001). As dietary chlorella levels increased, the yolk color linearly increased. However, there were no significant differences in egg-shell qualities. The layers fed diet with 2.4% chlorella cultured media showed the highest Haugh unit value. In Exp. 2, a total of one hundred-eight 80 wk-old Hy-Line brown layers were assigned into four groups with three replicates per group (9 birds per replicate). The birds were fed one of four experimental diets (0, 0.5, 1.0 or 2.0% chlorella powder) for 4 wk, followed by a 14 d feeding of a withdrawal diet devoid of chlorella powder. At 2 wk, the lutein greatly increased with increasing levels of chlorella powder in birds fed diets containing more than 1%. The maximum incorporation of lutein into eggs was reached after 2 or 3 wk of feeding diets with chlorella powder. After a 7 d withdrawal, the lutein contents of egg yolks in the groups fed diets with more than 1% chlorella powder were still higher than that of control group (p<0.05). No significant differences in the lutein levels were found among groups after a 14 d withdrawal period. These results indicated that the use of chlorella in layer diets was effective in improving egg production and egg quality and for the production of lutein fortified eggs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.3
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• pp.95-101
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• 1980

Optical properties were studied at the fishing ground of anchovy in the southern part of Korea based on seven oceanographic stations from May to August and November to December, 1977. Submarine daylight intensity was measured at intervals of 1m depth in the upper 30 m layer by the underwater luxmeter (Toshiba # 9). The absorption coefficient of the sea water ranged from 0.066 to 0.619 (mean 0.21) for six months. The transparency ranged from 2.6 to 16 meters (mean 8.4m). The relationship between absorption coefficient (n) and transparency (D) was k=1.70/D. The mean water color in this area was 4.8 $(3\~10)$ in Forel scales. The rates of light penetration for daylight at four different depths were computed with reference to the surface light intensity. The mean rates of light penetration were $69.38\%(25.43\~88.10\%),\;30.35\%\;(4.38\~59.46\%),\;12.53\%\;(0.75\~33.51\%),\;5.7\%(0.18\~20.27\%)$ at depths of 1, 5, 10 and 15 m respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.251-256
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• 2002

Fresh bamboo (Phyllostachys bambuoides sieb. et zucc.) was charred at the mechanical steel kiln and traditional earth kiln with subsequent condensation of its smoke to 10$0^{\circ}C$. It was settled down for 12 months to remove tar components and then the middle layer of the liquid was collected as a bamboo smoke distillates to analyze its chemical composition and physicochemical characteristics for use as food additives or processing aids. The gravity, transmittance, reflectivity, and viscosity were 1.008, 89.05%, 1.36%, and 12.48 cp in the bamboo smoke distillates processed by mechanical steel kiln (MBSD) and 1.012, 98.33%, 1.34% and 9.05 cp in the bamboo smoke distillates by traditional earth kiln (TBSD), respectively. The color of TSBD was brighter than that of MBSD. The pH and titratable acidity, tar and remains were 3.55 and 2.830%, 2.803% and 0.671%, respectively, in the MBSD and 2.93 and 3.470%, 0.051% and 0.004%, respectively, in the TBSD. The major phenolic compounds of bamboo smoke distillates (BSD) were phenol, Ο-cresol, p-cresol, and guaiacol and the major organic acids were acetic acid, propionic acid, iso-butyric acid, and n-butyric acid, and major alcohols were methanol, furfuryl alcohol, and maltol. The contents of phenolic compound and alcohol were more in MBSD than in TBSD whereas the content of organic acid was more in TBSD than in MBSD. Therefore, toxic compounds for the human body, such as methanol from BSD should be removed for use as a food ingredient in the future.

• Journal of Ginseng Research
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• v.28 no.3
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• pp.157-164
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• 2004

The study was conducted to investigate the tissue and chemical characteristics of rusty root epidermal cells. In histological study, the rusty symptoms were frequently observed in the epidermis of ginseng root and to be yellow under microscopic observation. Disks of the epidermal cell tissue of the rusty root were usually 2 and 3 times greater in the number of cell layer and thickness of cell wall than the healthy root, respectively. The color degree of methanol extracts from the rusty root epidermis was 5.5 times higher than that of the healthy root. And the extracts of rust matter in the root epidermis were easily dissolved in polar solvents compared to nonpolar solvents. UV-absorption spectra of methanol extracts in various fractions of phenolics showed a maximum peak between 275∼280 nm. The crude lipids and phenolic compounds such as acid insoluble bound phenolics, acid insoluble esterified phenolics, acid insoluble condensed phenolics, insoluble bound phenolics and free phenolics were also more in the rusty root epidermis than in the healthy one. Fe content in the rusty root epidermis was 2.7 times higher than that of healthy one. It was presumed that the phenolic compounds(precursor of the rusty) in association with lipid and iron in the root epidermis might defence the root when ginseng root was depressed by the unfavorable conditions in soil and/or portions of a root system were subjected to anoxic conditions.

• Composites Research
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• v.27 no.5
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• pp.183-189
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• 2014

Experimental considerations have been performed to obtain the clear optical microscopic images of graphene oxide which are useful to probe its quality and morphological information such as a shape, a size, and a thickness. In this study, we investigated the contrast enhancement of the optical images of graphene oxide after hydrazine vapor reduction on a Si substrate coated with a 300 nm-thick $SiO_2$ dielectric layer. Also, a green-filtered light source gave higher contrast images comparing to optical images under standard white light. Furthermore, it was found that a image channel separation technique can be an alternative to simply identify the morphological information of graphene oxide, where red, green, and blue color values are separated at each pixels of the optical image. The approaches performed in this study can be helpful to set up a simple and easy protocol for the morphological identification of graphene oxide using a conventional optical microscope instead of a scanning electron microscopy or an atomic force microscopy.