• Resources Recycling
• /
• v.31 no.4
• /
• pp.12-18
• /
• 2022

Korea depends on the import of raw materials such as iron ore and coal for the steel industry. These raw materials have a major impact on the cost, productivity, and quality competitiveness in the global steel industry. To secure the competitiveness of steel companies, it is necessary to reduce the country's dependence on raw materials. This can be achieved using byproducts with a high Fe content, which are primarily generated by the steel industry. These byproducts are available in the form of a very fine powder, which can disperse as dust when used directly in plant processes. Dust dispersion has a negative impact on the environment and can lead to the loss of raw materials. To enable the use of a wide range of Fe-containing byproducts, it is necessary to pretreat them in the form of larger aggregates such as pellets and briquettes. There are several methods to achieve such aggregates. There are two ways to produce briquettes: using a hot briquette, which supplies additional heat to produce briquettes, or using a cold briquette, which does not use heat. A method for producing cold briquettes using Fe-containing byproducts was investigated in this study. The yield ratio and briquette strength were examined under various manufacturing conditions.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.1
• /
• pp.206-219
• /
• 2021

The warming of the climate is increasing the damage caused by termites to wooden buildings, cultural properties and houses. A group removal system can be installed around the building to detect and remove termite damage; however, if the site is not visited regularly, every one to two months, you cannot observe whether termites have spread within, and it is difficult to take prompt effective action. In addition, since the system is installed and operated in an exposed state for a long period of time, it may be ineffective or damaged, resulting in a loss of function. Furthermore if the system is installed near a cultural site, it may affect the aesthetic environment of the site. In this study, we created a detection system that uses wood, cellulose, magnets, and magnetic sensors to determine whether termites have entered the area. The data was then transferred to a low power LoRa Network which displayed the results without the necessity of visiting the site. The wood was made in the shape of a pile, and holes were made from the top to the bottom to make it easier for termites to enter and produce a cellulose sample. The cellulose sample was made in a cylindrical shape with a magnet wrapped in cellulose and inserted into the top of a hole in the wood. Then, the upper part of the wood pile was covered with a stopper to prevent foreign matter from entering. It also served to block external factors such as light and rainfall, and to create an environment where termites could add cellulose samples. When the cellulose was added by the termites, a space was created around the magnet, causing the magnet to either fall or tilt. The magnetic sensor inside the stopper was fixed on the top of the cellulose sample and measured the change in the distance between the magnet and the sensor according to the movement of the magnet. In outdoor experiments, 11 cellulose samples were inserted into the wood detection system and the termite inflow was confirmed through the movement of the magnet without visiting the site within 5 to 17 days. When making further improvements to the function and operation of the system it in the future, it is possible to confirm that termites have invaded without visiting the site. Then it is also possible to reduce damage and fruiting due to product exposure, and which would improve the condition and appearance of cultural properties.

• Korean Journal of Medicinal Crop Science
• /
• v.15 no.3
• /
• pp.199-202
• /
• 2007

This study was carried out to provide pest control information for the cultivation of Eleutherococcus senticosus Max. As a result of investigation of the diseases and insect pests, three pathogens and three insect pests were identified from the field sample, respectively. The identified insects pests were aphids, stinkbugs and Bothrogonia japonica. Occurrenre peaks of aphids were occurred on June and August, and generally young leaves and flower buds were injured mainly. The identified diseases were black ring spot caused by Phoma sp., gray mold caused by Botrytis cinerea and leaf blights caused by Rhizoctonia solani. The black ring spot was the most severe disease and was investigated from the beginning of June, and the incidence of the disease was 30% higher than that on September. As a result of growth test under different temperature conditions on PDA, these pathogens showed the best mycelial growth rate between 25 $^{\circ}$C and 30 $^{\circ}$C, and these results indicate that these diseases occur on hat summer season.

• Journal of the Korea Concrete Institute
• /
• v.14 no.6
• /
• pp.823-829
• /
• 2002

The composite frame system with reinforced concrete column and steel beam has some advantages in the structural efficiency by complementing the shortcomings between the two systems. The system, however has also a lot of problems in practical design and construction process due to the material dissimilarities. Considering these circumstances, this research is aimed at the development of the composite structural system which enables the steel beams to be connected to the R/C columns with higher structural safety and economy. Basically the proposed connection system is composed of four split tees, structural angles reinforced by stiffener, high strength steel rods, connecting plates and shear plates. The structural tests have been carried out to verify the moment transfer mechanism from beam flange to steel rods or connecting plates through the angle reinforced by siffener. The four prototype specimens have been tested until the flange of beam reached the plastic states. From the tests, no distinct material dissimilarities between concrete and steel have been detected and the stress transfer through wide flange beam - structural angle - high strength steel rod or connecting plate is very favorable.

• Journal of Korean Society of Forest Science
• /
• v.70 no.1
• /
• pp.55-62
• /
• 1985

This study was made on bamboo shoot's damage of Phyllostachys edulis by field mice in Jinju, Gyeongsangnam-do, and grasped the inhabitation environment by the analysis of around and lower vegetation in damaged bamboo stands, and made clear the species of field mice in damaged bamboo stand, the damaged degree and rate, therefore, were put in practice for contribution with damage prevention and extermination. The results were summarized as follows; The damaged degree were influenced by inhabitation environment and stand density around damaged bamboo stands. The damaged degree were shown 4,359.1 g with 7.1 shoots per. ha and the rate 0.23%. The damage season were from the middle of April to the middle and end of May, the most damaged season was about April 23. The length of damaged bamboo shoot was mean 28.12 cm, the inside diameter 7.49 cm, the weight 613.96 g. The damaged type of parts was shown to more numerous overland and surface damaged type of three types; overland, surface and underground damaged type. The field mice to be captured in damaged bamboo stand were three species; Apodemus agrarius coreae, Mus molossinus and Crocidura lasiura, the species of main damage was Apodemus agrarius coreae of captured Rodentia's 2 species. Crocidura lasiura in order Insectivora was found to inhabitate for the first time at southern region in Korea.

• Korean journal of applied entomology
• /
• v.34 no.4
• /
• pp.300-307
• /
• 1995

This study was carried out to investigate the life cycle of Cephonodes hylas (Linne), that is damaging to Gardenia jasminoides Ellis in the seedbed at Namhae during 1984 and 1985. Results are summarized as follows. The eggs were laid in mass on the leaf surface of the host plants. The oviposition period lasts for 26 days after late-May. The average number of eggs and average hatching rate were 20.36 and 97.61% , respectively. It takes 14-16 days until hatching. The egg shape was oval which its size was 1.01 mm in diameter and 1.48 mm in length. The body length of each larval instar from the 1st to the 5th were $3.52\pm$1.01, $6.46\pm$0.45, $13.19\pm$4.27, $24.08\pm$2.22 and $43.71\pm$5.62 mm, respectively. The average weight of each larval instar were $13.34\pm$2.41, $29.83\pm$6.88, $76.64\pm$31.31, $292.09\pm$107.70 and 2,$144.84\pm$760.70 mm, respectively. The larval period was observed from July to October, and total duration of larval stage was 116 days in which duration of each larval instar from the 1st to the 5th were 12, 36, 32, 16 and 20 days, respectively. During larval stage, a larvae feed on 17~18 seedlings. The 5th instar larvae built its place in soil for overwinter and became pupa. The body length of pupa was 33.6 mm and average weight was 2,032 mg Adult was emerged from overwintened pupa from mid through late-May in the followings year. The sex ratio of female was 42.82% and the color ratio of brown was 89.93%.

• Journal of Mushroom
• /
• v.16 no.1
• /
• pp.57-60
• /
• 2018

Agricultural sticky traps are used for forecasting flying insects, including fungus gnat adults. Forecasting using sticky trap is an important measure to determine pesticides or environmentally friendly control means. Sticky traps of various colors can be installed easily and quickly. The yellow sticky trap is most effective for forecasting fungus gnat adults. In addition, they are used for control purposes by mass trapping. We tested the optimum installation height of yellow sticky traps to forecast and control the fungus gnat adults effectively in the cultivation of mushroom and horticultural plants. The number of captured fungus gnat adults was highest on the second floor for button mushroom and oyster mushroom, 100 cm above the floor for sawdust shiitake mushroom, 20 cm under the floor for hydroponic strawberry, and 20 cm above the floor for hydroponic tomato. This suggests that sticky trap height should be installed differently depending on the cultivation type or environment for effective forecasting and control of fungus gnat adults.

• Journal of Korean Society of Forest Science
• /
• v.96 no.6
• /
• pp.750-755
• /
• 2007

This study was investigate to ecological characteristic of Trioza ukogi (shinji) on the Acanthopanax senticosus for. inermis Harms during 2004-2005 in Korea. The sizes of Trioza ukogi (shinji) were $0.40{\pm}0.03mm$ in eggs, $0.36{\pm}0.03mm$ in 1st instar nymphs, $2.50{\pm}0.25mm$ in mature nymphs and $5.17{\pm}0.28mm$ in adults (to tip of folded wings), respectively. T. ukogi has two generations per year. First generation appeared from mid-July to late August with peak in early August. Second generation appeared from mid-September to mid-October with peak in late September. Overwintering adults move to host tree and mate from the early April to late May with peak in late April. Overwintering female laid on the new leaves and first generation prefers to lay on the seeds. The number of ovarian eggs was 5$57.5{\pm}23$.

• Journal of Korean Society of Forest Science
• /
• v.88 no.4
• /
• pp.533-540
• /
• 1999

We observed that the thick outer bark layer of Quercus variabilis hindered oak longicorn beetle (Moechotypa diphysis) from laying its eggs in inner bark (secondary phloem tissues). The outer bark thickness of Q. variabilis was average of 7.4mm, while those of Q. mongolica. Q. serrata and Q. acutissima were average of 1.1mm, 1.3mm and 2.0mm, respectively. Inner bark thickness was 4.8mm in Q. acutissima and 3.6-3.9mm in the other oak species. The outer shape of ovipositional holes on the bark by the longicorn beetle was $8-12mm{\times}6-8mm$ wide oval in Q. variabilis, whereas $5-9mm{\times}1-5mm$ narrow fusiform in the other oak species. Oak longicorn beetle drilled average of three ovipositional holes per a 1.2m-long log in a few Q. variabilis logs and its ovipositional rate was 15%. Compared to this, the longicorn beetle preferred Q. mongolica. All the 32 investigated logs of this oak species were drilled to have 20 ovipositional holes per a log and ovipositional rate was 56%. One third of the eggs laid already hatched in early June to damage the inner bark. It seems that oak longicorn beetle prefers oak species with smooth, thin and stable outer bark surface.

• Korean journal of applied entomology
• /
• v.55 no.4
• /
• pp.465-469
• /
• 2016

An entomopathogenic fungus was isolated from the two-spotted spider mite (Tetranychus urticae) in a rearing house, and identified as Neozygites floridana (Entomophthorales: Neozygitaceae). A high infection rate induced by N. floridana could increase the price of the natural enemy. The body color of mites infected by this fungus changed to red or orange and swelling occurred. Fungal conidia were discharged into the webbing produced by the spider mites, making it relatively easy to infect the mites. Primary conidia were pear shaped and capilliconidia almond shaped. The fungus could not be cultured on solid media (PDA, SDAY, or EYSDA), but could possibly be cultured in liquid media (Grace's insect tissue culture medium + 5% fetal bovine serum). Kidney beans were supplied as food for T. urticae; the mite infection rate in a kidney bean canopy was about 36.1%. The density of infected mites was higher on the underside than on the upper side of leaves. Based on the results of this survey, we need to identify methods of fungal control for natural enemy production and biological control agents for T. urticae for effective crop management.