• Journal of the Korean Wood Science and Technology
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• v.10 no.2
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• pp.12-21
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• 1982

Red pine and Japanese larch (Larix leptolepis Gordon) grown in Korea have been the main species of coniferous resources in Korea. Especially, planting area of Japanese larch has been increased continueously in the recent years due to its superior plant type and rapid growth rate and its stocks reached approximately 4.32 million cubic meters at the present time. Although many research works have been done for the utilization of the larch wood in various ways, still many problems are existed in its chemical applications due to a large proportion of soluble extractives. In this study, chemical composition of larch extractives and chemical structure of its major component were analyzed. In order to identify the basic structure of major component, gas-liquid chromatography for separation of some completely methylated alditols as their acetates on a 3% - ECNSS-M on Gas Chrom Q. column was used. Proportion of extractives of Japanese larch wood was higher than that of other conifers and major component of the soluble extractives was arabinogalactan, a schematic structural formula which was presented in Figure 2. The molar ratio of arabinose and galactose was 1:4.5. The main chain of arabinogalactan was composed of 1,3 linked ${\beta}$-D-galactopyranose residues, each of which carried a side chain, attached to the C-6 positions. The exact nature of all of the side chains is not known, but the majority of these side chain was composed of 1, 6 linked ${\beta}$-D-galactopyranose residues, with 2~3 such units present per average chain. Some of the galactose units in the main chain had a residue of 3 - 0 - ${\beta}$-L-arabinopyranosyl-L-arabinofuranose. In addition, a few terminal residues of D-glucuronic acid also was confirmed, attached to C-6 position of the D-galactopyranose residue. It could concluded that the main structure of highly branched arabinogalactan from Japanese larch extractive was essentially the same as those of the other larch species.

• Journal of Biosystems Engineering
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• v.34 no.6
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• pp.404-410
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• 2009

This study was carried out to develop a self-propelled type explosive subsoiler for improving the root zone soil conditions in orchard and other forest fields. Prototype was designed to be able to inject air and other soil improving material such as lime into soil at the same time, and thus improve the air permeability and drainage of orchard soils to promote the root growth of tree for high quality fruit production. Soil penetration device of explosive subsoiler is composed of air hammer, penetration rob and air injection nozzle. To support the soil penetration device of explosive subsoiler to penetrate vertically, modified Scott-Russel mechanism was used. Timing control device for simultaneous injection of soil improving material with air was attached to the out side wall of air cylinder and as the cylinder move, the soil improving material was injected into soil at the same time. Turning radius of prototype was 2.2-2.3 m with good mobility in sloped land. It took approximately 1 minute for lime injection system to reach the optimum pressure of 9.9 kg/$cm^2$, average 10-20 seconds were required to rupture soil with the depth of 50 cm and 2-3 seconds were required for explosion, so all in all about 1 minute and 20 seconds were required for one cycle of explosion. Maximum soil rupture depth and diameter were 50 cm and 3-4 m respectively depending on the soil type and soil moisture content. For final design of explosive subsoiler inclination angle of lime hopper was increased from 60 degree to 70 degree and the shape of hopper was changed from rectangular cone to circular cone to solve the clogging problem of lime at out let. Agitating system operated by compressed air was attached to the metering device of the prototype, thus more than 90 cc of lime was discharged per cycle from metering device without clogging problems.

• Journal of Environmental Science International
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• v.21 no.12
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• pp.1495-1501
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• 2012

In this study, an experiment was conducted on influent water with low concentrations of organic matter, such as river water or secondary treatment water of a sewage treatment plant, according to HRT changes by using aerobic biofilm. In the biofilm process, as the biofilm increases in thickness, the inner membrane can be low in oxygen transfer rate and become anaerobic conditions, while the detachment of biomass from biofilm occurs. To overcome these limitations in the detachment of microorganisms in biofilm, the yarn, which was made from poly propylene(PP), was weaved and manufactured into a tube. Then, a test was carried out by injecting air so that the interior of the biofilm could create aerobic conditions. The results of the experiment showed that the removal efficiency of $TCOD_{cr}$ reached 66.1~81.2% by HRT 2hr, and 50.9 ~61.8% after HRT 1 hr. The removal efficiency of $SCOD_{cr}$ was 45.9 to 55.1% by HRT 1hr, and 26.1% in HRT 0.5hr, showing the highest removal efficiency in HRT 1hr. The SS removal efficiency was at 81.8 to 94.6%, and the effluent SS concentration was very low, indicating less than 2.2 mg/L in all HRT's. As a result, the $SCOD_{cr}$ and $NH_4{^+}$-N that were removed per specific surface area and attached to microbial biofilm showed the highest efficiency in HRT 1hr with 8.37 $gSCOD_{cr}/m^2{\cdot}d$, 2.93 $gNH_4{^+}-N/m^2{\cdot}d$. From the result of reviewing the characteristics of biofilm growth, microorganisms were found to be attached, and increased by 36 days. Later, they decreased in number through detachment, but showed a tendency to increase again 41 days later due to microbial reproduction.

• The Plant Pathology Journal
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• v.20 no.2
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• pp.97-102
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• 2004

Paenibacillus polymyxa E681, with its plant growth promotion and root colonization ability, has been proven to be a promising biocontrol agent of cucumber and barley. This study investigated the attributes related to the movement of bacteria from the seed to the radicle and to the whole root system. It also illustrated the existing form and population changes of the bacteria on seed and root using the scanning electron microscope and confocal laser scanning microscopy. The bacteria invaded and colonized the inside of the seed coat while the seeds were soaked in bacterial suspension. Almost the same number of bacteria on seed surface invaded the inside of the seed coat right after seed soaking. The population densities of E681 increased greatly inside as well as on the surface of the seed before the radicle emerged. The bacteria attached on the emerging radicle directly affected the initial population of newly emerg-ing root. The colonized cells on the root were arranged linearly toward the elongation of the root axis. In addition to colonizing the root surface, strain E681 was found inside the roots, where cells colonized the inter-cellular space between certain epidermal and cortical cells. When the cucumber seeds were soaked in bacterial suspension and sown in pot, the bacterial populations attached on both the surface and inside of the root were sustained up to harvesting time. This means that E681 successfully colonized the root of cucumber and sustained its population density up to harvesting time through seed treatment.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.4
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• pp.63-73
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• 2020

The area of paddy fields for upland crop cultivation is gradually increasing. In this context, we developed a chain type mole drainer that can be attached to a tractor to prevent the wet injury of crops. To conduct a field test, we formed underdrains at 2 m intervals in a paddy field wherein soybeans are cultivated, and we investigated the status of the soil moisture, groundwater level, and soybean growth during the cultivation period. The soil moisture content decreased by 22.3~26.8% in the test plot and by 5.9~6.9% in the control plot during a period of 57~88 hour after a rainfall of 41.5~157.0 mm. The effect of underdrainage was clear as the hourly groundwater level decreased approximately 2.8 times faster in the test plot compared with the control plot. Moreover, the soybean yield was greater by 78.6 kg/10a in the test plot than in the control plot. Therefore, for soybean cultivation in paddy fields, the use of the developed mole drainer is expected to help in improving the drainage and increasing the soybean yield.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.141-150
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• 1998

This study was conducted to find out the possibility of seeding of Zoysia japonica and woody plants for the revegetation of rock-exposed-cutslopes by Natural Topsoil Restoration Methods (NTRM). The 5cm thick layer of artificial soil was attached at rock-exposed cutslopes for the growth of Zoysia japonica and native woody plants by NTRM. The main results were summarized as follows. 1. Artificial soil attached at rock-exposed-slopes by NTRM was not eroded until recovered by Zoysia japonica and native woody plants. It shows extremely low soil erodibility. 2. One year later after seeding, woody plants show 100% ground coverage. But, in early stage, they grew more quickly at northwest slopes than at southeast slopes. 3. In seeding of Zoysia japonica, it grew more quickly at southeast slopes than at northwest slopes. Also, it grew better at lower part of the slopes than at middle part of the slopes. 4. After one year from seeding, the height of Lespedeza cyrtobotrya and Indigo/era pseudo-tinctoria were longer than any other plants. The next were Albizzia julibrissin, Lespedeza cuneata and wild flowers. The tree height of Rhus chinensis shows 28cm length, so it has enough possibility to be used for roadside revegetation works. 5. Lespedeza cyrtobotrya and Indigo/era pseudo-tinctoria show different importance values according to slope aspect. But, they show tendency to outweigh the other plants at all slope-aspects. 6. Most of the plants seeded by NTRM were germinated well and they covered rock-exposed-slopes so quickly and effectively. Thus it leads to conclusion that the revegetation methods used in this experiment was a very effective methods to recover rock-exposed-slopes by seeding of zoysia japonica and native woody plants.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.201-206
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• 2022

In this paper, a flushing system with automatic opening and closing function of the toilet cover was studied. It works by an infrared sensor attached to the cover is detected or not. When the infrared sensor of the open function detects it, the servomotor is driven on the toilet cover to raise the cover, and when the infrared sensor with the close function detects the infrared sensor, the cover is set to be lowered. A tilt sensor is attached to the inside of the cover to operate when the cover goes down, and when this is activated, the servomotor connected to the toilet lever opens the stopper of the supply port and sends water down. In addition, we minimized the inconveniences for the next user when they use the toilet by using the non-contact water level sensor and LED function to notice the water is clogged during the flushing process. Also, we implemented UV-LED function to prevent bacterial growth while the toilet is closed.

• Anatomy and Cell Biology
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• v.57 no.2
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• pp.288-293
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• 2024

The temporal fascia is a double lamina sandwiching a thick fat layer above the zygomatic bony arch. To characterize each lamina, their developmental processes were examined in fetuses. We observed histological sections from 22 half-heads of 10 mid-term fetuses at 14-18 weeks (crown-rump length, 95-150 mm) and 12 near-term fetuses at 26-40 weeks (crown-rump length, 215-334 mm). The superficial lamina of the temporal fascia was not evident at mid-term. Instead, a loose subcutaneous tissue was attached to the thin, deep lamina of the temporal fascia covering the temporalis muscle. At near-term, the deep lamina became thick, while the superficial lamina appeared and exhibited several variations: i) a mono-layered thick membrane (5 specimens); ii) a multi-layered membranous structure (6) and; iii) a cluster of independent thick fasciae each of which were separated by fatty tissues (1). In the second and third patterns, fatty tissue between the two laminae was likely to contain longitudinal fibrous bands in parallel with the deep lamina. Varying proportions of the multi-layered superficial lamina were not attached to the zygomatic arch, but extended below the bony arch. Whether or not lobulation or septation of fatty tissues was evident was not dependent on age. The deep lamina seemed to develop from the temporalis muscle depending on the muscle contraction. In contrast, the superficial lamina developed from subcutaneous collagenous bundles continuous to the cheek. Therein, a difference in development was clearly seen between two categories of the fasciae.

• Development and Reproduction
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• v.22 no.3
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• pp.263-273
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• 2018

Aquaporin (AQP) 3, a facilitated transporter of water and glycerol, expresses in placenta and fetal membranes, but the detailed localization and function of AQP3 in placenta remain unclear. To elucidate a role of AQP3 in placenta, we defined the expression and cellular localization of AQP3 in placenta and fetal membranes, and investigated the structural and functional differences between wild-type and AQP3 null mice. Gestational sacs were removed during mid-gestational period and amniotic fluid was aspirated for measurements of volume and composition. Fetuses with attached placenta and fetal membranes were weighed and processed for histological assessment. AQP3 strongly expressed in basolateral membrane of visceral yolk sac cells of fetal membrane, the syncytiotrophoblasts of the labyrinthine placenta and fetal nucleated red blood cell membrane. Mice lacking AQP3 did not exhibit a significant defect in differentiation of trophoblast stem cells and normal placentation. However, AQP3 null fetuses were smaller than their control litter mates in spite of a decrease in litter size. The total amniotic fluid volume per gestational sac was reduced, but the amniotic fluid-to-fetal weight ratio was increased in AQP3 null mice compared with wild-type mice. Glycerol, free fatty acid and triglyceride levels in amniotic fluid of AQP3 null mice were significantly reduced, whereas lactate level increased when compared to those of wild-type mice. These results suggest a role for AQP3 in supplying nutrients from yolk sac and maternal blood to developing fetus by facilitating transport of glycerol in addition to water, and its implication for the fetal growth in utero.

• Journal of the Korean Solar Energy Society
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• v.36 no.2
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• pp.1-7
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• 2016

This study was experimentally performed to analyze the growth characteristics of a plant(wax tree or privet) using the surface temperature measured from thermal images captured using a thermal camera with water and cider. To do that, this study measured every each 12 hours the surface temperature and the stem temperature of leaves attached to the plant sample until the plants wilt on summer season in the laboratory room. From the experimental results, this study revealed that the temperature of front and back of the leaves is a little different due to the pore. The mean surface temperature of a leaf in cider is $0.52^{\circ}C$ higher than that of a leaf in water. The phenomena that the leaves of plants fall could be also demonstrated using the surface temperature. Before a leaf is falling from the tree, the temperature of the stem is lowered about $2^{\circ}C$ than those of other parts in a leaf. This result can be validated from previous result performed in University of Wisconsin.