• Journal of Ecology and Environment
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• v.38 no.3
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• pp.375-381
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• 2015

We investigated the influence of summer rainfall on Pectinatella magnifica colonies in lotic ecosystems. Of the examined substrate materials, branches and aquatic macrophytes supported more colonies of P. magnifica than that by stones or artificial materials. The influence of rainfall on P. magnifica colonies differed in accordance with the type of substrate material at each study site. In the Geum River, little difference was noted in the number of P. magnifica colonies on branches before ($mean{\pm}SE$, $24{\pm}7.3$ individuals) and after rainfall ($20{\pm}8.4$ ind.); other substrate types supported fewer colonies of P. magnifica after rainfall. In contrast, in the Miryang River, rainfall had minimal effect on the number of P. magnifica colonies supported by macrophytes ($13{\pm}3.8$ and $12{\pm}4.3$ ind., respectively). Artificial material was more abundant in the Banbyeon Stream where it was able to support more colonies of P. magnifica. We found that the structure of different substrates sustains P. magnifica following rainfall. In the Miryang River, free-floating and submerged plants with a relatively heterogeneous substrate surface were the dominant macrophytes, whereas in the Geum River, simple macrophytes (i.e., emergent plants) were dominant. Therefore, we conclude that the substrate type on which P. magnifica grows plays an important role in resisting physical disturbances such as rainfall.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.356-359
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• 1999

To obtain a biomaterial that has both biological affinity and high mechanical strength, hydroxyapatite granules were implanted into the surface of pure titanium film coated titanium alloy. The film was coated by reactive DC sputtering method on the alloy substrate. Hydroxyapatite granules (32- $38\mu\textrm{m}$ in diameter)were spread over titanium alloy substrate and pressed to implant the granules in the substrate. They can be implanted into substrate under 17MPa at $800^{\circ}C$ for 10minutes. The only tops of the granules were exposed and they were firmly stuck in substrate. The hydroxyapatite implanted titanium alloy composites were expected to be useful for biomaterials as artificial bones and dental roots.

• Archives of Plastic Surgery
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• v.33 no.1
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• pp.21-30
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• 2006

Alginate, a polymer of guluronic and mannuronic acid, is used as a scaffolding material in biomedical applications. The research was to produce highly-purified alginate from seaweeds and to evaluate the efficacy of alginate as dermal substrate. Our alginate purification method showed a production rate as high as 25%. The purified alginate contained little polyphenol contents and endotoxin, proteins. For study of wound healing, full thickness skin defects were made on the dorsal area of the animal models. And then alginate, fibroblast-growth-factor mixed alginate, alginate-collagen complex, vaseline gauze as control were applied on the wound, respectively, and were evaluated grossly and histopathologically. For biocompatibility test, alginate and alginate-collagen complex discs were implanted on the back of Sprague-Dawly rats. Four weeks after implantation, the animals were examined immunologically against alginate and collagen. Alginate and FGF-mixed alginate, alginate-collagen complex group showed statistically higher percentage of wound contraction and wound healing than control group(p<0.05). Alginate-collagen complex group and FGF-mixed alginate group showed statistically higher percentage of wound healing than alginate group. The experiment of biocompatibility and immunologic reaction against impanted alginate or collagen needs more investigation. Highly-purified alginate from seaweeds by our purification method, showed the effect of wound healing, and addition of FGF or collagen increases the alginate's wound healing effect. It shows the possibility of alginate as a dermal substrate.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.11-14
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• 2017

In this paper, we introduce a method of light focusing effect using prism structure to solve optical discontinuity of conventional external signage LED panels. The prims structures were patterned on a transparent polycarbonate substrate with MEMS and femto-second laser process. We have confirmed that the patterned prism structures on the substrate made artificial LED lights on empty space between the panels by light guide effect of the structure. The artificial light's lateral positions were controlled by thickness of polycarbonate substrate. This cost effective prim patterned transparent film can be utilized on digital signage LED panels to achieve good optical communication.

• Ocean and Polar Research
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• v.45 no.1
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• pp.1-9
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• 2023

Marine microalgae have different collection methods depending on their habitat. In the case of adhesive microalgae, it is difficult to separate organisms from the substrate surface, and contamination is likely to occur during the sampling process. In this study, we analyzed the collection efficiency of adhesive microalgae using three artificial fiber materials (nylon, blend fabric, and viscose rayon). Each fiber showed different fiber diameter and pore characteristics (nylon 26.09 ㎛, blend fabric 56.6 ㎛, viscose rayon 101.3 ㎛). In addition, attached organisms were collected on the surface of artificial substrates at Bukseong Port in Incheon using each tested fiber material. After that, we investigated the population and species composition. The highest number of cells was found in nylon, which was 8 times higher than in the least collected viscose rayon material. In addition, we identified 24 microalgal species from the substrate, demonstrating that the species composition differed from that of surface water. The number of collected microalgae species varied depending on the fiber materials, with nylon containing all the adhesive microalgae. In contrast, only a few microalgae were observed in other fibers. These results suggest that, of the tested fibers, nylon material may be suitable for collecting adhesive microalgae. As a result, this study may be useful for future research on adhesive microalgae.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3139-3145
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• 2014

This paper describes the design of a size-reduced ring hybrid coupler for microwave band using an artificial dielectric substrate(ADS). ADS structure adopts the second substrate on which has lots of the metalized via-holes. The effective capacitance and effective dielectric constant per unit length of ADS increases compared to the normal substrate due to the via-holes. This enables the physical length of microstrip transmission line to be reduced by adopting ADS instead of the normal substrate. In order to present an example of size-reduction of microwave wireless circuit by ADS, a size-reduced 3GHz ring hybrid coupler is designed, fabricated and measured in this work. The designed coupler has the smaller size from the normal one by 65% due to the ADS, while no critical degradation from ideal performances is observed. The measured power division ratio at two output ports are -3.05dB and -3.135dB, respectively. In addition, the phase differences are 3o for in-phase division and 176o for out of phase split. The measured performances are so similar to ideal ones, and prove the design of size-reduced ring hybrid coupler using ADS is successful.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.4
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• pp.220-225
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• 2007

The succession of marine benthic algae and the restoration of an artificial seaweed forest on a porous type (shaped half saw teeth) artificial reef at Jeju island, Korea was studied. Young thalli of Sargassum horneri and Ecklonia cava were attached to different artificial substrates. In general, the succession on the artificial reefs led from filamentous algae to perennial algae and involved more than 25 species that are useful fishery resources, including E. cava. Coralline algae were dominant on the artificial reefs at the Kangjung site. The maximum algal biomass on the artificial reef in October 2005 was $1,990g/m^2$ at Biyang. In conclusion, a climax community and seaweed forest can be attained one year after the substrate is constructed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2319-2324
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• 2012

In this paper, the design of asymmetric branch line couplers using artificial dielectric substrate (ADS) is described. The effective permittivity and permeability increase in ADS because of the lots of the inserted via-holes. So the physical length and width of transmission lines realized on ADS are reduced compared to the standard lines. This enables one to design size-reduced microwave circuits. As an instance in this work, an asymmetric branch line coupler with the ratio of 3:1 is designed at 2GHz. The designed coupler has a small size of 53.4% compared to the normal circuit while the same performances are preserved. A good agreement between the simulated and measured asymmetric power dividing ratio is shown. The measured loss is only less than 0.2dB, which is a very small value.

• Journal of Mushroom
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• v.7 no.4
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• pp.156-162
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• 2009

These experiments were carried out to determine the optimal culture conditions for nine strains of collected Hatakeshimeji, Lyophyllum decastes (Fr.:Fr.) Sing. SPA 202 and SPA 205 strains were selected because mycelium grew fast and showed fine density. All strains showed fast mycelial growth and mycelial density on BC(Burke compost) media for 20 days of incubation. The optimal sawdust species for the mycelial growth were the fermented sawdusts of Quercus aliena and Populus deltoides. Spawn running period on the fermented sawdust substrate required 50 days at 20 to $25^{\circ}C$ and additional 7 days after soil casing. Cultivation period and temperature forprimordia formation and fruitbody development appeared from 10 to 11 days and from 7 to 8 days at 17 to $18^{\circ}C$ respectively. The length of pilei and stipes of SPA 202 harvested in optimal stage showed 60mm and 67mm, respectively. Yield of SPA 202 strain grown on fermented sawdust substrate was 130g per 1,100ml in bottle cultivation. The length of pilei and stipes of SPA 205harvested in optimal stage showed 51mm and 81mm, respectively. Yield of SPA 205 strain grown on fermented sawdust substrate was 129g per 1,100 ml in bottle cultivation. SPA 202 strain and SPA 205 strain in artificial bottle cultivation of Lyophyllum decastes used in fermented sawdust substrate were selected as themost appropriate strain in yield.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.6
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• pp.93-107
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• 2013

Construction of an artificial wetland for the growth of Sphagnum palustre with emergent macrophytes (Phragmites australis, Typha angustifolia, and Zizania latifolia) was firstly tried and the growth of those plant components according to various environmental combinations has been monitored for three years. Above-ground dry weight of Z. latifolia ($1,500g/m^2$) was higher than T. angustifolia ($900g/m^2$) and P. australis ($500g/m^2$) under most environmental conditions. In overall, planted emergent macrophytes seemed to prefer polishing sand without moss peat as a substrate and relatively deep water-depth condition (20cm) rather than shallow water-depth (5cm). Despite of high calcium content in inflow water (> 15ppm) into the constructed wetland, S. palustre populations have survived in most experimental plots during the monitoring period. Substrate layer including moss peat with high surface-area might play a role as an ion-filter. After three years, relatively thicker litter-layer in Z. latifolia plots due to vigorous growth appeared to heavily depress S. palustre by physical compressing and complete shading processes. Most of all, for the continuous growth of S. palustre, physio-chemical characteristics of water and substrate must be carefully managed. In addition, companion emergent species should be also cautiously selected not to depress S. palustre by much litter production. We suggest P. australis and T. angustifolia as companion species rather than Z. latifolia.