• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.444-451
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• 1999

The effect of individual density on the growth and survival of Laminaria japonica was experimentally evaluated. Four density treatments of young sporophytes (0.63 cm In maximum length) grown in the laboratory were transplanted to the southeastern coast of Korea and their survivorship and growth rate were measured twice a month from January to July, 1996. Plants showed higher survivorship at low density. Final densities at three lowest densities were similar, ranging from 34 to 38 inds${\cdot}100 cm^{-2}$. Planis at the highest density, however, suffered greater decline than at lower densities, and only 21 plants remained at the end of this study. Mean frond size (length and width) fluctuated throughout the study period at four densities. During the first two mouths after outplanting, mean frond size was negatively correlated with initial density, However, the size was density independent after three months. As stand density increased, size-frequency distribution through time tended to be more positively skewed. The 10 largest plants grew faster in frond size and attained larger size in the lower density. There was a positive relationship between plant size and relative growth rate (or survival). The slope of yield-density (Y-D) relationships at four densities ranged from -0.060 to -0.137. The study suggests that density can strongly affect the survival and growth of this alga. The density-dependent survival and growth patterns, however, were not strictly consistent with those of terrestrial plants.

• Journal of the Korean Wood Science and Technology
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• v.45 no.4
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• pp.432-443
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• 2017

Maltodextrin and citric acid are two types of natural materials with the potential as an eco-friendly binder. Maltodextrin is a natural substance rich in hydroxyl groups and can form hydrogen bonds with lignoselulosic material, while citric acid is a polycarboxylic acid which can form an ester bond with a hydroxyl group at lignoselulosic material. The combination of maltodextrin and citric acid as a natural binder materials supposed to be increase the ester bonds formed within the particleboard. This research determined to investigate the bonding properties of a new adhesive composed of maltodextrin/citric acid for nipa frond particleboard. Maltodextrin and citric acid were dissolved in distillated water at the ratios of 100/0, 87.5/12.5, 75/25 and 0/100, and the concentration of the solution was adjusted to 50% for maltodextrin and 60% citric acid (wt%). This adhesive solution was sprayed onto the particles at 20% resin content based on the weight of oven dried particles. Particleboards with a size of $25{\times}25{\times}1cm$, a target density $800kg/m^3$ were prepared by hot-pressing at press temperatures of $180^{\circ}C$ or $200^{\circ}C$, a press time of 10 minute and board pressure 3.6 MPa. Physical and mechanical properties of particleboard were tested by a standard method (JIS A 5908). The results showed that added citric acid level in maltodextrin/citric acid composition and hot-pressing temperature had affected to the properties of particleboard. The optimum properties of the board were achieved at a pressing temperature of $180^{\circ}C$ and the addition of only 20% citric acid. The results also indicated that the peak intensity of C=O group increased and OH group decreased with the addition of citric acid and an increase in the pressing temperature, suggesting an interreaction between the hydroxyl groups from the lignocellulosic materials and carboxyl groups from citric acid to form the ester groups.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.6 s.107
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• pp.109-116
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• 2005

This study was conducted to examine the growth and physiological characteristics of Asplenium scolopendrium native fern as affected by irrigation times and soil media as an environment modeled on habitate where was sunken-condition. 1. Light intensity was lower in sunken than in non-sunken, but air humidity was higher in sunken about $2040\%$. Soil moisture content was higher with the leaf mold in sunken irrigating 2 times/week. The results of chemical analysis of medium showed that EC, pH, organic matter content, total nitrogen, CEC, Exch-Ca, Exch-Mg and Exch-K were higher with leaf mold than sud: leafmold and field soil: sud: leaf mold. 2. In the case of irrigation 2 times/week Asplenium scolopendrium grew well sunken more than non-sunken. As non-sunken condition similar with, 7 times/week irrigation, plant height, frond width, frond length and stipe length increased. In case of soil media, growth of Asplenium scolopendrium was better with leaf mold than that of sand: leafmold or field soil: sand: leaf mold. 3. In the case of irrigation 2 times/week photosynthetic rate, $CO_2$ absorption rate and water efficiency were higher with non-sunken than that of sunken, expect of stomatal conduction, $CO_2$ use efficiency. The physiological characteristics of Asplenium scolopendrium were highest in non-sunken irrigating 7 times/week In case of soil media, physiological activity was higher with leaf mold than sand: leafmold or field soil: sand: leaf mold.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.157-162
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• 2009

High frequency plant proliferation system via direct frond regeneration of endemic duckweed plants Lemna paucicostata and Spirodela polyrhiza was established. Fronds of L. paucicostata and S. polyrhiza were able to multiply half-strength MS basal medium without plant growth regulators. However, addition of BA at a range of 1 to 3 mg/L was more effective than high concentration of BA treatments for fronds proliferation. Also half-strength MS salts was suitable for the fronds proliferation. Increase of salts concentration had inhibitory effect on fronds proliferation. Also the frequency of callus formation from fronds of L. paucicostata was 3.3%, when they cultured onto 1/2 MS medium supplemented with 1 mg/L of BA. Similarly the frequency of callus formation from S. polyrhiza was very low. After subculture of white globular structures derived from fronds of L. paucicostata, numerous globular somatic embryos and calluses were developed onto the surface of fronds. However these somatic embryos did not fully develop into normal plants when transferred to 1/2 MS basal medium. Therefore direct frond regeneration system was more efficient for mass proliferation of L. paucicostata and S. polyrhiza. The plant regeneration system of L. paucicostata and S. polyrhiza established in this study, might be applied to mass proliferation and genetic transformation for molecular breeding.

• ALGAE
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• v.31 no.4
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• pp.363-371
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• 2016

To examine the effects of two endophytic algae, Mikrosyphar zosterae (brown alga) and Ulvella ramosa (green alga), on the host Chondrus ocellatus (red alga), culture experiments were conducted. Four treatments were made: endophyte-free (Chondrus only), endophyte-M (Chondrus + Mikrosyphar), endophyte-U (Chondrus + Ulvella), and endophytes-M U (Chondrus + Mikrosyphar + Ulvella). After 3 weeks, the relative growth rates (RGRs) of frond lengths and the number of newly formed bladelets were examined. M. zosterae formed wart-like dots on C. ocellatus fronds, whereas U. ramosa made dark spots. The RGRs of frond lengths of C. ocellatus were significantly greater in the endophyte-free and endophyte-M treatment groups than in the endophyte-U and endophytes-M U treatment groups, indicating that the growth of host C. ocellatus was inhibited more by the green endophyte U. ramosa than the brown endophyte M. zosterae. The number of newly produced bladelets was greater in the endophyte-U and endophytes-M U groups than in the endophyte-free and endophyte-M treatment groups. These results indicate that the two endophytes inhibit growth of the host C. ocellatus. The negative effects of U. ramosa on C. ocellatus growth were more severe than those caused by M. zosterae. Furthermore, U. ramosa destroyed the apical meristems of C. ocellatus, whereas M. zosterae did not. On the other hand, C. ocellatus showed compensatory growth in the form of lateral branch production as U. ramosa attacked its apical meristems.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.10
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• pp.31-39
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• 2009

This paper presents the single supply power line communication(PLC) SoC ASIC with built-in analog frond-end circuit. To achieve the low power consumption along with low chip cost, this PLC SoC ASIC employs fully CMOS analog front-end(AFE) and several built-in Regulators(LDOs) powering for Core logic, ADC, DAC and IP Pad driver. The AFE includes RX of pre-amplifier, Programmable gain amplifier and 10 bit ADC and TX of 10bit Digital Analog Converter and Line driver. This PLC Soc was implemented with 0.18um 1 Poly 5 Metal CMOS process. The single power supply of 3.3V is required for the internal LDOs. The total power consumption is below 30mA at standby and 300mA at active which meets the eco-design requirement. The chips size is $3.686\;{\times}\;2.633\;mm^2$.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.8
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• pp.1113-1120
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• 2000

Productivity, nutrient contents, in vitro gas production and in sacco degradability of different fractions and whole OPF were determined to assess the feeding value of OPF as a ruminant feed. An in vivo digestibility trial was also carried out using goat. Freshly harvested OPF was randomly collected, partitioned and weighed. An OPF from 21 years older palm weighed 13.4 kg and the annual fresh matter yield of petiole, leaflet and midrib was 46.5, 11.8 and 3.4 ton/ha, respectively. Leaflet contained 439, 926, 698, 501, 168, 196, 748 and 52 (g/kg) of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose (CE), hemicellulose (HC), total carbohydrate (TC) and non fiber carbohydrate (NFC), respectively. Petiole contained lower (p<0.01) DM, CP and EE contents than leaflet. Organic matter, CE and TC contents were higher (p<0.01) in petiole compared to leaflet. Silica and lignin contents were highest (p<0.01) in midrib followed by leaflet, whole OPF and least in petiole. The Ca, P, Na, K and Mg contents (g/100 g DM) of leaflet were 0.529, 0.182, 0.039, 0.876, and 0.168, respectively. In vitro DM digestibility (g/100 g) at 48 h of leaflet, petiole and midrib was 32.7, 38.7 and 30.2, respectively. The in sacco DM degradation (g/100 g) at 48 h of leaflet was higher than that of whole OPF, petiole and midrib. The in vivo digestibility of DM, OM, CP and ADF of whole OPF was 52, 56, 43 and 26%, respectively. It can be concluded that leaflet is the most nutritious fraction of OPF and midrib is the least. The nutrient content and digestibility of the whole OPF showed that OPF could be an alternative roughage source for ruminant diets.

• Journal of Energy Engineering
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• v.27 no.1
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• pp.12-20
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• 2018

The FEED (Frond End Engineering Design) framework defines the activities and outputs to be performed at the FEED stage. In the meantime, many studies on FEED have been carried out, but most of them have slightly different opinions depending on experiences. It is important to define the FEED appropriately for the project and define the activities and outputs that are needed. It is also necessary to develop FEED processes on a solid basis, such as international system engineering process standards rather than experience. In this study, FEED is defined as suitable for the mineral carbonation system development project, and a method for developing the process and output to satisfy it is proposed based on the system engineering standard process.

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.336-341
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• 1982

The histochemical examination of Undaria pinnatifida Laver were conducted with light microscope and electron microscope. The results obtained were as follow: 1. Undaria pinnatifida frond were composed with epidermis, cortex and medulla. But the cutting section of Undaria pinnatifida Laver showed that only the epidermal cell were bound to each other. The cortex and medulla of the frond were destroyed during U.P. Laver process. 2. To identification of bind material of U.P. Laver, which were treated with sodium carbonate solution for extraction of alginic acid and reacted with Periodic Acid Schiff(PAS) reagent. And the PAS reaction result was negative by light microscope observation. On this result, we found out that the alginic acid has the binder role of U.P. Laver. 3. Also, the bind structure of U.P. Laver were observed by electron microscope and could well find out the epidermal cell wall and bind position of alginic acid, which were could not observed by light microscope.

• Applied Microscopy
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• v.34 no.2
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• pp.103-111
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• 2004

Fresh specimens of the aquatic macrophyte, Spirodela polyrhiza, have been examined employing scanning and transmission electron microscopy. Observations revealed the occurrence of microbial colonization during development. Submerged parts of the small, free-floating S. polyrhiza body exhibited a variety of microorganisms such as bacteria, cyanobacteria, and diatoms throughout their development. However, immature and/or young plants normally demonstrated much less microbial colonization compared to mature plants. During the study, heavy colonization by the microorganisms was routinely encountered at maturity, especially in the fully developed abaxial fronds and root caps. The mucilaginous layer was shown along the root caps, and the microorganisms appeared to be either clustered or attached to this layer. In contrast, only moderate degrees of colonization were observed in the root, and little to no colonization was observable in the adaxial frond surface. Transmission electron microscopy clearly demonstrated the microbial colonization to be external in the S. polyrhiza specimen examined in the current study. The association between the microorganisms and S. polyrhiza has been considered non-harmful, as no frond senescence and almost no mechanical penetration of the plant by the microorganisms were noticed during the study.