• Journal of Bio-Environment Control
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• v.1 no.2
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• pp.135-141
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• 1992

Effects of various artificial light sources on the growth of Chinese white cabbage, Chinese flat cabbage, lettuce, garland chrysanthemum, and green perilla were investigated. Plants were grown under different treatments for three weeks. Generally, the growth of artificial light treatment were better than natural daylight(ND). The greatest growth and external quality occurred in high-pressure sodium lamp(HPS). In incandescent lamp(IL), fresh weight was heavy, but marketable quality was poor because of succulent(or spindly) growth. Overall, vitamin C content were no difference among treatments. But relative chlorophyll content was somewhat high in HPS.

• Journal of Forest and Environmental Science
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• v.35 no.1
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• pp.25-30
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• 2019

The composition of artificial soil in a containerized seedling production plays an important role in seedling quality as well as environmental issues. We investigated the effects of different types of biomaterials and mixed ratio with artificial soil on the growth of Fraxinus rhynchophylla seedlings. Soil medium was supplemented with 3 levels (0%, 10%, 20%) of pine bark, mushroom sawdust and rice husk. Root collar diameter (RCD), height growth, and biomass have significantly increased when rice husk was applied. Compared with the control, RCD and height growth showed highest in 20% rice husk treatment with an increase of 5.7% and 17.6%, respectively. In contrast, the treatments of pine bark and mushroom sawdust showed lower results in growth parameters (RCD, height growth, and total biomass) than control. Seedling quality index was also highest at the 20% rice husk treatment, but there was not statistically different among treatments. Our results suggested rice husk can be substituted up to 20% of substrates for containerized F. rhynchophylla seedling production system.

• Korean Journal of Environmental Agriculture
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• v.41 no.4
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• pp.245-251
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• 2022

BACKGROUND: Selection an suitable light source is essential in the year-round production of horticultural crops in closed production systems such as plant factory with controlled environments. This study was investigated to confirm the effects of artificial light sources on growth of cherry tomato'CF Jelly'(Lycopersicon esculentum var.) under high-pressure sodium lamps (HPS), metal-halide lamps (MH), and LEDs. METHODS AND RESULTS: Light intensity of the light sources was controlled at 220±30 µmol/m²/s with 12 hrs of photoperiod for a day. Flower development was significantly faster in HPS and MH treatments compared to the LEDs. There was no significant difference between the leaf number and leaf shape under the HPS and MH treatments. Reproductive growth of cherry tomato was significantly promoted by the LEDs treatment of blue plus red lights. Fruit yield per plant also increased under the LEDs compared to the others. CONCLUSION(S): Growth, flowering, and fruit setting of the cherry tomato were accomplished by the artificial lights under plant factory conditions. The HPS treatment showed negative effect on fruit quality in terms of blossom-end rot incidence compared to the LEDs or MH treatment. Effect of the LEDs on promotion of fruit weight and yield was also proved. Additional research should be carried out for improving sugar metabolism or decreasing disease in the fruits under plant factory system using only artificial lights.

• Korean Journal of Medicinal Crop Science
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• v.28 no.3
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• pp.200-208
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• 2020

Background: Salvia miltiorrhiza Bunge has been used in traditional medicine. The type of light source has an effect on the growth properties and composition of functional compounds in plants. In this study, we analyzed the effects of different artificial light sources on the growth characteristics as well as antioxidant and antimicrobial activities of S. miltiorrhiza. Methods and Results: Seedlings of S. miltiorrhiza were grown under various artificial light sources, including fluorescent light (FL), light emitting diode (LED), and microwave electrodeless light (MEL), for 8 weeks. Growth characteristics were the best in plants treated with MEL. DPPH scavenging activity of the shoot was more pronounced with the FL treatments, while the roots were more active in plants grown under single wavelength lights (i.e., blue and red LEDs). Among the different light source treatments, the blue LED resulted in a higher total phenolic content in the plants. Furthermore, growing plants growth under the red LED enhanced their total flavonoid content. Notably, the antimicrobial properties of plants varied significantly between light source treatments in this study. Except for E. coli, all the tested microorganisms were susceptible to the plant extracts. Conclusions: The type of light source may be an important parameter for the enhancement of plant growth and functional compounds in S. miltiorrhiza.

• Korean Journal of Environment and Ecology
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• v.7 no.1
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• pp.10-21
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• 1993

Artificial acid rain (pH 3.0, 4.0 and 5.0) and ground was treated on the seeded pots of 4 species to examine its effects on germination and survival rate, seedling growth and contact angles on needle surface. Artificial acid rain was prepared by diluting sulfuric acid with ground water and ground water (pH 6.5) was used as control. Artificial acid rain was sprayed to seeded pots two or three times per week for growing season, one times per week for winter seasons. About 5mm of artificial acid rain was treated each time from early April, 1991 to early October, 1993. Germination and survival rate, soil acidity, seedling growth and contact angles on the needle surface were measured and compared among the treatments. The results were summarized as follows ; Artificial acid rain might have positive effects on growth-related characteristics of the seedlings in the first and second year of acid rain treatment, and the effects were differed among four species. All growth-related characteristics of the seedlings in third year, however, decreased with decrease of pH values of artificial acid rain. This was considered to the results of acidic accumulation over soil buffer capacity. Needle injury and biomass (defoliation) was correlated with the pH values of artificial acid rain, and this character might be a good criteria for early diagnosis of acid rain injury. The differences of soil acidity were significant among the treatments for all species. Contact angles between needle surface and water droplet decreased with decrease of pH values of artificial acid rain. Measuring and comparing contact angles might be very good criteria for early diagnosis of acid rain injury.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.2
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• pp.33-44
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• 2015

The generation of artificial gametes is a real challenge for the scientific community today. In vitro development of human eggs and sperm will pave the way for the understanding of the complex process of human gametogenesis and will provide with human gametes for the study of infertility and the onset of some inherited disorders. However, the great promise of artificial gametes resides in their future application on reproductive treatments for all these people wishing to have genetically related children and for which gamete donation is now their unique option of parenthood. This is the case of infertile patients devoid of suitable gametes, same sex couples, singles and those fertile couples in a high risk of transmitting serious diseases to their progeny. In the search of the best method to obtain artificial gametes, many researchers have successfully obtained human germ cell-like cells from stem cells at different stages of differentiation. In the near future, this field will evolve to new methods providing not only viable but also functional and safe artificial germ cells. These artificial sperm and eggs should be able to recapitulate all the genetic and epigenetic processes needed for the correct gametogenesis, fertilization and embryogenesis leading to the birth of a healthy and fertile newborn.

• Journal of Mechanical Science and Technology
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• v.16 no.3
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• pp.395-402
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• 2002

This paper shows how to formulate the transient analysis of 2-dimensional Hagen-Poiseuille flow using smoothed particle hydrodynamics (SPH). Treatments of viscosity, particle approximation and boundary conditions are explained. Numerical tests are calculated to examine effects caused by the number of particles, the number of particles per smoothing length, artificial viscosity and time increments for 2-dimensional Hagen-Poiseuille flow. Artificial viscosity for reducing the numerical instability directly affects the velocity of the flow, though effects of the other parameters do not produce as much effect as artificial viscosity. Numerical solutions using SPH show close agreement with the exact ones for the model flow, but SPH parameter must be chosen carefully Numerical solutions indicate that SPH is also an effective method for the analysis of 2-dimensional Hagen-Poiseuille flow.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.2
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• pp.28-38
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• 2000

The aim of this study is evaluate artificial soils which are used alone or in a blend with field soil for the greening of artificial ground. To achieve these, determination of physicochemical properties was made in four artificial media[Perlite small grain(PSG), perlite large grain(PLG), crushed porous glass+bark(AS), crushed porous glass(CPG)] used alone and/or in a blend with field soil, then evaluation of their effect on th plant growth of Ligustrum obtusifolium and Syringa vulgaris were conducted. In bulk density of root media at field capacity and the saturated hydraulic conductivity, LG and AS showed good performance. But, PLG was though to be unsuitable as artificial soil when used alone because of poor plant growth. PLG, AS, and CPG were thought to be good when it is used in a blend with field soil. But, PSG was thought to be unsuitable. In the result, PSG is recommended as artificial soil which is used alone for greening of artificial ground. PLG is recommended as artificial soil which is used in a blend with field soil. AS is recommended as artificial soil which is used alone and in a blend with field soil. Thought CPG+field soil(v/v, 1:1) might be undesirable in consideration of the chemical properties in six months after planting, it was thought to be superior to th other treatments in the plant growth. CPG can be used as artificial soil which is used in a blend with field soil. Follow-up studies are being conducted to investigate their effects on the plant growth of the other plants and the practical use of them in artificial grounds.

• Journal of Environmental Science International
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• v.33 no.5
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• pp.305-322
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• 2024

The aim of this study was to investigate the effects of artificial light sources on the germination and seedling vigor of lettuce, aiming to identify the optimal artificial light source for producing high-quality seedlings. Lettuce cultivar of 'Tomalin' and 'Seonpunggold' exhibited the highest seed emergence in the Metal halide(MH) lamp and High-pressure sodium(HPS) lamp treatment group, while the emergence rate parameter, T50, was the fastest in the HPS lamp treatment group. Both cultivars showed good growth characteristics such as number of leaves, root length, and stem diameter under RGB-LED, and their seedling vigor was excellent as well. The plant height was smallest in the Red + Green + Blue LED treatment, but the leaves were round and thick, resulting in higher biomass and dry weight. Single light sources of Red LED and Blue LED led to reduced growth compared with that under the mixed light treatments. Chlorophyll content in lettuce varied with the type of artificial light, with both cultivars exhibiting the highest chlorophyll content in the Red + Green + Blue LED treatment. The most suitable artificial light for lettuce seedling growth was the Red + Green + Blue LED treatment.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.9
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• pp.1267-1271
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• 2001

The objective of this study was to examine the significance of feeding induced hypovolemia (decrease in plasma volume) in controlling the feed intake of goats fed on dry feed. In order to alleviate hypovolemia with feeding, a 2 h intravenous infusion (16-18 ml/min) of artificial saliva or mannitol solution was begun 1 h prior to feeding and continued until 1h after the start of the 2 h feeding period. In comparison with no infusion (NI), cumulative feed intake was increased by 41% with artificial saliva infusion (ASI) and by 45% with mannitol infusion (MI) by the completion of the 2 h feeding period. Both infusion treatments (ASI and MI) were significantly different (p<0.05) from the NI treatment in terms of the cumulative feed intake. The cumulative feed intake between the ASI and MI treatments was not significantly different (p>0.05). No infusion treatment (NI) had the lowest cumulative feed intake (929 g DM), whereas MI had the highest (1345 g DM), after completion of the 2 h feeding period. Generally, infusion treatments also increased the rate of eating at all time points after feeding was commenced. Following the first 30 mins of feeding, the rate of eating decreased sharply, and subsequently declined gradually in all treatments. Compared to the NI, both ASI and MI significantly (p<0.05) decreased thirst level (water intake for 30 mins after the completion of the 2 h feeding period) by approximately 13%. However, the thirst level caused by ASI and MI was not significantly different (p>0.05). Both ASI and MI decreased the plasma concentrations of osmolality and total protein, and hematocrit at 1 h after infusion. The results suggested that the thirst sensation in the brain could be produced by feeding induced hypovolemia. Moreover, the results indicate that hypovolemia is one of the factors controlling the feed intake of goats fed on dry feed.